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Diffstat (limited to 'gcc-4.4.0/gcc/ada/exp_ch4.adb')
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diff --git a/gcc-4.4.0/gcc/ada/exp_ch4.adb b/gcc-4.4.0/gcc/ada/exp_ch4.adb new file mode 100644 index 000000000..9309c4850 --- /dev/null +++ b/gcc-4.4.0/gcc/ada/exp_ch4.adb @@ -0,0 +1,9343 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- E X P _ C H 4 -- +-- -- +-- B o d y -- +-- -- +-- Copyright (C) 1992-2008, Free Software Foundation, Inc. -- +-- -- +-- GNAT is free software; you can redistribute it and/or modify it under -- +-- terms of the GNU General Public License as published by the Free Soft- -- +-- ware Foundation; either version 3, or (at your option) any later ver- -- +-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- +-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- +-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- +-- for more details. You should have received a copy of the GNU General -- +-- Public License distributed with GNAT; see file COPYING3. If not, go to -- +-- http://www.gnu.org/licenses for a complete copy of the license. -- +-- -- +-- GNAT was originally developed by the GNAT team at New York University. -- +-- Extensive contributions were provided by Ada Core Technologies Inc. -- +-- -- +------------------------------------------------------------------------------ + +with Atree; use Atree; +with Checks; use Checks; +with Einfo; use Einfo; +with Elists; use Elists; +with Errout; use Errout; +with Exp_Aggr; use Exp_Aggr; +with Exp_Atag; use Exp_Atag; +with Exp_Ch3; use Exp_Ch3; +with Exp_Ch6; use Exp_Ch6; +with Exp_Ch7; use Exp_Ch7; +with Exp_Ch9; use Exp_Ch9; +with Exp_Disp; use Exp_Disp; +with Exp_Fixd; use Exp_Fixd; +with Exp_Pakd; use Exp_Pakd; +with Exp_Tss; use Exp_Tss; +with Exp_Util; use Exp_Util; +with Exp_VFpt; use Exp_VFpt; +with Freeze; use Freeze; +with Inline; use Inline; +with Namet; use Namet; +with Nlists; use Nlists; +with Nmake; use Nmake; +with Opt; use Opt; +with Restrict; use Restrict; +with Rident; use Rident; +with Rtsfind; use Rtsfind; +with Sem; use Sem; +with Sem_Cat; use Sem_Cat; +with Sem_Ch3; use Sem_Ch3; +with Sem_Ch8; use Sem_Ch8; +with Sem_Ch13; use Sem_Ch13; +with Sem_Eval; use Sem_Eval; +with Sem_Res; use Sem_Res; +with Sem_Type; use Sem_Type; +with Sem_Util; use Sem_Util; +with Sem_Warn; use Sem_Warn; +with Sinfo; use Sinfo; +with Snames; use Snames; +with Stand; use Stand; +with Targparm; use Targparm; +with Tbuild; use Tbuild; +with Ttypes; use Ttypes; +with Uintp; use Uintp; +with Urealp; use Urealp; +with Validsw; use Validsw; + +package body Exp_Ch4 is + + ----------------------- + -- Local Subprograms -- + ----------------------- + + procedure Binary_Op_Validity_Checks (N : Node_Id); + pragma Inline (Binary_Op_Validity_Checks); + -- Performs validity checks for a binary operator + + procedure Build_Boolean_Array_Proc_Call + (N : Node_Id; + Op1 : Node_Id; + Op2 : Node_Id); + -- If a boolean array assignment can be done in place, build call to + -- corresponding library procedure. + + procedure Displace_Allocator_Pointer (N : Node_Id); + -- Ada 2005 (AI-251): Subsidiary procedure to Expand_N_Allocator and + -- Expand_Allocator_Expression. Allocating class-wide interface objects + -- this routine displaces the pointer to the allocated object to reference + -- the component referencing the corresponding secondary dispatch table. + + procedure Expand_Allocator_Expression (N : Node_Id); + -- Subsidiary to Expand_N_Allocator, for the case when the expression + -- is a qualified expression or an aggregate. + + procedure Expand_Array_Comparison (N : Node_Id); + -- This routine handles expansion of the comparison operators (N_Op_Lt, + -- N_Op_Le, N_Op_Gt, N_Op_Ge) when operating on an array type. The basic + -- code for these operators is similar, differing only in the details of + -- the actual comparison call that is made. Special processing (call a + -- run-time routine) + + function Expand_Array_Equality + (Nod : Node_Id; + Lhs : Node_Id; + Rhs : Node_Id; + Bodies : List_Id; + Typ : Entity_Id) return Node_Id; + -- Expand an array equality into a call to a function implementing this + -- equality, and a call to it. Loc is the location for the generated nodes. + -- Lhs and Rhs are the array expressions to be compared. Bodies is a list + -- on which to attach bodies of local functions that are created in the + -- process. It is the responsibility of the caller to insert those bodies + -- at the right place. Nod provides the Sloc value for the generated code. + -- Normally the types used for the generated equality routine are taken + -- from Lhs and Rhs. However, in some situations of generated code, the + -- Etype fields of Lhs and Rhs are not set yet. In such cases, Typ supplies + -- the type to be used for the formal parameters. + + procedure Expand_Boolean_Operator (N : Node_Id); + -- Common expansion processing for Boolean operators (And, Or, Xor) for the + -- case of array type arguments. + + function Expand_Composite_Equality + (Nod : Node_Id; + Typ : Entity_Id; + Lhs : Node_Id; + Rhs : Node_Id; + Bodies : List_Id) return Node_Id; + -- Local recursive function used to expand equality for nested composite + -- types. Used by Expand_Record/Array_Equality, Bodies is a list on which + -- to attach bodies of local functions that are created in the process. + -- This is the responsibility of the caller to insert those bodies at the + -- right place. Nod provides the Sloc value for generated code. Lhs and Rhs + -- are the left and right sides for the comparison, and Typ is the type of + -- the arrays to compare. + + procedure Expand_Concatenate_Other (Cnode : Node_Id; Opnds : List_Id); + -- This routine handles expansion of concatenation operations, where N is + -- the N_Op_Concat node being expanded and Operands is the list of operands + -- (at least two are present). The caller has dealt with converting any + -- singleton operands into singleton aggregates. + + procedure Expand_Concatenate_String (Cnode : Node_Id; Opnds : List_Id); + -- Routine to expand concatenation of 2-5 operands (in the list Operands) + -- and replace node Cnode with the result of the concatenation. If there + -- are two operands, they can be string or character. If there are more + -- than two operands, then are always of type string (i.e. the caller has + -- already converted character operands to strings in this case). + + procedure Fixup_Universal_Fixed_Operation (N : Node_Id); + -- N is a N_Op_Divide or N_Op_Multiply node whose result is universal + -- fixed. We do not have such a type at runtime, so the purpose of this + -- routine is to find the real type by looking up the tree. We also + -- determine if the operation must be rounded. + + function Get_Allocator_Final_List + (N : Node_Id; + T : Entity_Id; + PtrT : Entity_Id) return Entity_Id; + -- If the designated type is controlled, build final_list expression for + -- created object. If context is an access parameter, create a local access + -- type to have a usable finalization list. + + function Has_Inferable_Discriminants (N : Node_Id) return Boolean; + -- Ada 2005 (AI-216): A view of an Unchecked_Union object has inferable + -- discriminants if it has a constrained nominal type, unless the object + -- is a component of an enclosing Unchecked_Union object that is subject + -- to a per-object constraint and the enclosing object lacks inferable + -- discriminants. + -- + -- An expression of an Unchecked_Union type has inferable discriminants + -- if it is either a name of an object with inferable discriminants or a + -- qualified expression whose subtype mark denotes a constrained subtype. + + procedure Insert_Dereference_Action (N : Node_Id); + -- N is an expression whose type is an access. When the type of the + -- associated storage pool is derived from Checked_Pool, generate a + -- call to the 'Dereference' primitive operation. + + function Make_Array_Comparison_Op + (Typ : Entity_Id; + Nod : Node_Id) return Node_Id; + -- Comparisons between arrays are expanded in line. This function produces + -- the body of the implementation of (a > b), where a and b are one- + -- dimensional arrays of some discrete type. The original node is then + -- expanded into the appropriate call to this function. Nod provides the + -- Sloc value for the generated code. + + function Make_Boolean_Array_Op + (Typ : Entity_Id; + N : Node_Id) return Node_Id; + -- Boolean operations on boolean arrays are expanded in line. This function + -- produce the body for the node N, which is (a and b), (a or b), or (a xor + -- b). It is used only the normal case and not the packed case. The type + -- involved, Typ, is the Boolean array type, and the logical operations in + -- the body are simple boolean operations. Note that Typ is always a + -- constrained type (the caller has ensured this by using + -- Convert_To_Actual_Subtype if necessary). + + procedure Rewrite_Comparison (N : Node_Id); + -- If N is the node for a comparison whose outcome can be determined at + -- compile time, then the node N can be rewritten with True or False. If + -- the outcome cannot be determined at compile time, the call has no + -- effect. If N is a type conversion, then this processing is applied to + -- its expression. If N is neither comparison nor a type conversion, the + -- call has no effect. + + function Tagged_Membership (N : Node_Id) return Node_Id; + -- Construct the expression corresponding to the tagged membership test. + -- Deals with a second operand being (or not) a class-wide type. + + function Safe_In_Place_Array_Op + (Lhs : Node_Id; + Op1 : Node_Id; + Op2 : Node_Id) return Boolean; + -- In the context of an assignment, where the right-hand side is a boolean + -- operation on arrays, check whether operation can be performed in place. + + procedure Unary_Op_Validity_Checks (N : Node_Id); + pragma Inline (Unary_Op_Validity_Checks); + -- Performs validity checks for a unary operator + + ------------------------------- + -- Binary_Op_Validity_Checks -- + ------------------------------- + + procedure Binary_Op_Validity_Checks (N : Node_Id) is + begin + if Validity_Checks_On and Validity_Check_Operands then + Ensure_Valid (Left_Opnd (N)); + Ensure_Valid (Right_Opnd (N)); + end if; + end Binary_Op_Validity_Checks; + + ------------------------------------ + -- Build_Boolean_Array_Proc_Call -- + ------------------------------------ + + procedure Build_Boolean_Array_Proc_Call + (N : Node_Id; + Op1 : Node_Id; + Op2 : Node_Id) + is + Loc : constant Source_Ptr := Sloc (N); + Kind : constant Node_Kind := Nkind (Expression (N)); + Target : constant Node_Id := + Make_Attribute_Reference (Loc, + Prefix => Name (N), + Attribute_Name => Name_Address); + + Arg1 : constant Node_Id := Op1; + Arg2 : Node_Id := Op2; + Call_Node : Node_Id; + Proc_Name : Entity_Id; + + begin + if Kind = N_Op_Not then + if Nkind (Op1) in N_Binary_Op then + + -- Use negated version of the binary operators + + if Nkind (Op1) = N_Op_And then + Proc_Name := RTE (RE_Vector_Nand); + + elsif Nkind (Op1) = N_Op_Or then + Proc_Name := RTE (RE_Vector_Nor); + + else pragma Assert (Nkind (Op1) = N_Op_Xor); + Proc_Name := RTE (RE_Vector_Xor); + end if; + + Call_Node := + Make_Procedure_Call_Statement (Loc, + Name => New_Occurrence_Of (Proc_Name, Loc), + + Parameter_Associations => New_List ( + Target, + Make_Attribute_Reference (Loc, + Prefix => Left_Opnd (Op1), + Attribute_Name => Name_Address), + + Make_Attribute_Reference (Loc, + Prefix => Right_Opnd (Op1), + Attribute_Name => Name_Address), + + Make_Attribute_Reference (Loc, + Prefix => Left_Opnd (Op1), + Attribute_Name => Name_Length))); + + else + Proc_Name := RTE (RE_Vector_Not); + + Call_Node := + Make_Procedure_Call_Statement (Loc, + Name => New_Occurrence_Of (Proc_Name, Loc), + Parameter_Associations => New_List ( + Target, + + Make_Attribute_Reference (Loc, + Prefix => Op1, + Attribute_Name => Name_Address), + + Make_Attribute_Reference (Loc, + Prefix => Op1, + Attribute_Name => Name_Length))); + end if; + + else + -- We use the following equivalences: + + -- (not X) or (not Y) = not (X and Y) = Nand (X, Y) + -- (not X) and (not Y) = not (X or Y) = Nor (X, Y) + -- (not X) xor (not Y) = X xor Y + -- X xor (not Y) = not (X xor Y) = Nxor (X, Y) + + if Nkind (Op1) = N_Op_Not then + if Kind = N_Op_And then + Proc_Name := RTE (RE_Vector_Nor); + + elsif Kind = N_Op_Or then + Proc_Name := RTE (RE_Vector_Nand); + + else + Proc_Name := RTE (RE_Vector_Xor); + end if; + + else + if Kind = N_Op_And then + Proc_Name := RTE (RE_Vector_And); + + elsif Kind = N_Op_Or then + Proc_Name := RTE (RE_Vector_Or); + + elsif Nkind (Op2) = N_Op_Not then + Proc_Name := RTE (RE_Vector_Nxor); + Arg2 := Right_Opnd (Op2); + + else + Proc_Name := RTE (RE_Vector_Xor); + end if; + end if; + + Call_Node := + Make_Procedure_Call_Statement (Loc, + Name => New_Occurrence_Of (Proc_Name, Loc), + Parameter_Associations => New_List ( + Target, + Make_Attribute_Reference (Loc, + Prefix => Arg1, + Attribute_Name => Name_Address), + Make_Attribute_Reference (Loc, + Prefix => Arg2, + Attribute_Name => Name_Address), + Make_Attribute_Reference (Loc, + Prefix => Op1, + Attribute_Name => Name_Length))); + end if; + + Rewrite (N, Call_Node); + Analyze (N); + + exception + when RE_Not_Available => + return; + end Build_Boolean_Array_Proc_Call; + + -------------------------------- + -- Displace_Allocator_Pointer -- + -------------------------------- + + procedure Displace_Allocator_Pointer (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Orig_Node : constant Node_Id := Original_Node (N); + Dtyp : Entity_Id; + Etyp : Entity_Id; + PtrT : Entity_Id; + + begin + -- Do nothing in case of VM targets: the virtual machine will handle + -- interfaces directly. + + if VM_Target /= No_VM then + return; + end if; + + pragma Assert (Nkind (N) = N_Identifier + and then Nkind (Orig_Node) = N_Allocator); + + PtrT := Etype (Orig_Node); + Dtyp := Designated_Type (PtrT); + Etyp := Etype (Expression (Orig_Node)); + + if Is_Class_Wide_Type (Dtyp) + and then Is_Interface (Dtyp) + then + -- If the type of the allocator expression is not an interface type + -- we can generate code to reference the record component containing + -- the pointer to the secondary dispatch table. + + if not Is_Interface (Etyp) then + declare + Saved_Typ : constant Entity_Id := Etype (Orig_Node); + + begin + -- 1) Get access to the allocated object + + Rewrite (N, + Make_Explicit_Dereference (Loc, + Relocate_Node (N))); + Set_Etype (N, Etyp); + Set_Analyzed (N); + + -- 2) Add the conversion to displace the pointer to reference + -- the secondary dispatch table. + + Rewrite (N, Convert_To (Dtyp, Relocate_Node (N))); + Analyze_And_Resolve (N, Dtyp); + + -- 3) The 'access to the secondary dispatch table will be used + -- as the value returned by the allocator. + + Rewrite (N, + Make_Attribute_Reference (Loc, + Prefix => Relocate_Node (N), + Attribute_Name => Name_Access)); + Set_Etype (N, Saved_Typ); + Set_Analyzed (N); + end; + + -- If the type of the allocator expression is an interface type we + -- generate a run-time call to displace "this" to reference the + -- component containing the pointer to the secondary dispatch table + -- or else raise Constraint_Error if the actual object does not + -- implement the target interface. This case corresponds with the + -- following example: + + -- function Op (Obj : Iface_1'Class) return access Iface_2'Class is + -- begin + -- return new Iface_2'Class'(Obj); + -- end Op; + + else + Rewrite (N, + Unchecked_Convert_To (PtrT, + Make_Function_Call (Loc, + Name => New_Reference_To (RTE (RE_Displace), Loc), + Parameter_Associations => New_List ( + Unchecked_Convert_To (RTE (RE_Address), + Relocate_Node (N)), + + New_Occurrence_Of + (Elists.Node + (First_Elmt + (Access_Disp_Table (Etype (Base_Type (Dtyp))))), + Loc))))); + Analyze_And_Resolve (N, PtrT); + end if; + end if; + end Displace_Allocator_Pointer; + + --------------------------------- + -- Expand_Allocator_Expression -- + --------------------------------- + + procedure Expand_Allocator_Expression (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Exp : constant Node_Id := Expression (Expression (N)); + PtrT : constant Entity_Id := Etype (N); + DesigT : constant Entity_Id := Designated_Type (PtrT); + + procedure Apply_Accessibility_Check + (Ref : Node_Id; + Built_In_Place : Boolean := False); + -- Ada 2005 (AI-344): For an allocator with a class-wide designated + -- type, generate an accessibility check to verify that the level of the + -- type of the created object is not deeper than the level of the access + -- type. If the type of the qualified expression is class- wide, then + -- always generate the check (except in the case where it is known to be + -- unnecessary, see comment below). Otherwise, only generate the check + -- if the level of the qualified expression type is statically deeper + -- than the access type. + -- + -- Although the static accessibility will generally have been performed + -- as a legality check, it won't have been done in cases where the + -- allocator appears in generic body, so a run-time check is needed in + -- general. One special case is when the access type is declared in the + -- same scope as the class-wide allocator, in which case the check can + -- never fail, so it need not be generated. + -- + -- As an open issue, there seem to be cases where the static level + -- associated with the class-wide object's underlying type is not + -- sufficient to perform the proper accessibility check, such as for + -- allocators in nested subprograms or accept statements initialized by + -- class-wide formals when the actual originates outside at a deeper + -- static level. The nested subprogram case might require passing + -- accessibility levels along with class-wide parameters, and the task + -- case seems to be an actual gap in the language rules that needs to + -- be fixed by the ARG. ??? + + ------------------------------- + -- Apply_Accessibility_Check -- + ------------------------------- + + procedure Apply_Accessibility_Check + (Ref : Node_Id; + Built_In_Place : Boolean := False) + is + Ref_Node : Node_Id; + + begin + -- Note: we skip the accessibility check for the VM case, since + -- there does not seem to be any practical way of implementing it. + + if Ada_Version >= Ada_05 + and then VM_Target = No_VM + and then Is_Class_Wide_Type (DesigT) + and then not Scope_Suppress (Accessibility_Check) + and then + (Type_Access_Level (Etype (Exp)) > Type_Access_Level (PtrT) + or else + (Is_Class_Wide_Type (Etype (Exp)) + and then Scope (PtrT) /= Current_Scope)) + then + -- If the allocator was built in place Ref is already a reference + -- to the access object initialized to the result of the allocator + -- (see Exp_Ch6.Make_Build_In_Place_Call_In_Allocator). Otherwise + -- it is the entity associated with the object containing the + -- address of the allocated object. + + if Built_In_Place then + Ref_Node := New_Copy (Ref); + else + Ref_Node := New_Reference_To (Ref, Loc); + end if; + + Insert_Action (N, + Make_Raise_Program_Error (Loc, + Condition => + Make_Op_Gt (Loc, + Left_Opnd => + Build_Get_Access_Level (Loc, + Make_Attribute_Reference (Loc, + Prefix => Ref_Node, + Attribute_Name => Name_Tag)), + Right_Opnd => + Make_Integer_Literal (Loc, + Type_Access_Level (PtrT))), + Reason => PE_Accessibility_Check_Failed)); + end if; + end Apply_Accessibility_Check; + + -- Local variables + + Indic : constant Node_Id := Subtype_Mark (Expression (N)); + T : constant Entity_Id := Entity (Indic); + Flist : Node_Id; + Node : Node_Id; + Temp : Entity_Id; + + TagT : Entity_Id := Empty; + -- Type used as source for tag assignment + + TagR : Node_Id := Empty; + -- Target reference for tag assignment + + Aggr_In_Place : constant Boolean := Is_Delayed_Aggregate (Exp); + + Tag_Assign : Node_Id; + Tmp_Node : Node_Id; + + -- Start of processing for Expand_Allocator_Expression + + begin + if Is_Tagged_Type (T) or else Needs_Finalization (T) then + + -- Ada 2005 (AI-318-02): If the initialization expression is a call + -- to a build-in-place function, then access to the allocated object + -- must be passed to the function. Currently we limit such functions + -- to those with constrained limited result subtypes, but eventually + -- we plan to expand the allowed forms of functions that are treated + -- as build-in-place. + + if Ada_Version >= Ada_05 + and then Is_Build_In_Place_Function_Call (Exp) + then + Make_Build_In_Place_Call_In_Allocator (N, Exp); + Apply_Accessibility_Check (N, Built_In_Place => True); + return; + end if; + + -- Actions inserted before: + -- Temp : constant ptr_T := new T'(Expression); + -- <no CW> Temp._tag := T'tag; + -- <CTRL> Adjust (Finalizable (Temp.all)); + -- <CTRL> Attach_To_Final_List (Finalizable (Temp.all)); + + -- We analyze by hand the new internal allocator to avoid + -- any recursion and inappropriate call to Initialize + + -- We don't want to remove side effects when the expression must be + -- built in place. In the case of a build-in-place function call, + -- that could lead to a duplication of the call, which was already + -- substituted for the allocator. + + if not Aggr_In_Place then + Remove_Side_Effects (Exp); + end if; + + Temp := + Make_Defining_Identifier (Loc, New_Internal_Name ('P')); + + -- For a class wide allocation generate the following code: + + -- type Equiv_Record is record ... end record; + -- implicit subtype CW is <Class_Wide_Subytpe>; + -- temp : PtrT := new CW'(CW!(expr)); + + if Is_Class_Wide_Type (T) then + Expand_Subtype_From_Expr (Empty, T, Indic, Exp); + + -- Ada 2005 (AI-251): If the expression is a class-wide interface + -- object we generate code to move up "this" to reference the + -- base of the object before allocating the new object. + + -- Note that Exp'Address is recursively expanded into a call + -- to Base_Address (Exp.Tag) + + if Is_Class_Wide_Type (Etype (Exp)) + and then Is_Interface (Etype (Exp)) + and then VM_Target = No_VM + then + Set_Expression + (Expression (N), + Unchecked_Convert_To (Entity (Indic), + Make_Explicit_Dereference (Loc, + Unchecked_Convert_To (RTE (RE_Tag_Ptr), + Make_Attribute_Reference (Loc, + Prefix => Exp, + Attribute_Name => Name_Address))))); + + else + Set_Expression + (Expression (N), + Unchecked_Convert_To (Entity (Indic), Exp)); + end if; + + Analyze_And_Resolve (Expression (N), Entity (Indic)); + end if; + + -- Keep separate the management of allocators returning interfaces + + if not Is_Interface (Directly_Designated_Type (PtrT)) then + if Aggr_In_Place then + Tmp_Node := + Make_Object_Declaration (Loc, + Defining_Identifier => Temp, + Object_Definition => New_Reference_To (PtrT, Loc), + Expression => + Make_Allocator (Loc, + New_Reference_To (Etype (Exp), Loc))); + + Set_Comes_From_Source + (Expression (Tmp_Node), Comes_From_Source (N)); + + Set_No_Initialization (Expression (Tmp_Node)); + Insert_Action (N, Tmp_Node); + + if Needs_Finalization (T) + and then Ekind (PtrT) = E_Anonymous_Access_Type + then + -- Create local finalization list for access parameter + + Flist := Get_Allocator_Final_List (N, Base_Type (T), PtrT); + end if; + + Convert_Aggr_In_Allocator (N, Tmp_Node, Exp); + else + Node := Relocate_Node (N); + Set_Analyzed (Node); + Insert_Action (N, + Make_Object_Declaration (Loc, + Defining_Identifier => Temp, + Constant_Present => True, + Object_Definition => New_Reference_To (PtrT, Loc), + Expression => Node)); + end if; + + -- Ada 2005 (AI-251): Handle allocators whose designated type is an + -- interface type. In this case we use the type of the qualified + -- expression to allocate the object. + + else + declare + Def_Id : constant Entity_Id := + Make_Defining_Identifier (Loc, + New_Internal_Name ('T')); + New_Decl : Node_Id; + + begin + New_Decl := + Make_Full_Type_Declaration (Loc, + Defining_Identifier => Def_Id, + Type_Definition => + Make_Access_To_Object_Definition (Loc, + All_Present => True, + Null_Exclusion_Present => False, + Constant_Present => False, + Subtype_Indication => + New_Reference_To (Etype (Exp), Loc))); + + Insert_Action (N, New_Decl); + + -- Inherit the final chain to ensure that the expansion of the + -- aggregate is correct in case of controlled types + + if Needs_Finalization (Directly_Designated_Type (PtrT)) then + Set_Associated_Final_Chain (Def_Id, + Associated_Final_Chain (PtrT)); + end if; + + -- Declare the object using the previous type declaration + + if Aggr_In_Place then + Tmp_Node := + Make_Object_Declaration (Loc, + Defining_Identifier => Temp, + Object_Definition => New_Reference_To (Def_Id, Loc), + Expression => + Make_Allocator (Loc, + New_Reference_To (Etype (Exp), Loc))); + + Set_Comes_From_Source + (Expression (Tmp_Node), Comes_From_Source (N)); + + Set_No_Initialization (Expression (Tmp_Node)); + Insert_Action (N, Tmp_Node); + + if Needs_Finalization (T) + and then Ekind (PtrT) = E_Anonymous_Access_Type + then + -- Create local finalization list for access parameter + + Flist := + Get_Allocator_Final_List (N, Base_Type (T), PtrT); + end if; + + Convert_Aggr_In_Allocator (N, Tmp_Node, Exp); + else + Node := Relocate_Node (N); + Set_Analyzed (Node); + Insert_Action (N, + Make_Object_Declaration (Loc, + Defining_Identifier => Temp, + Constant_Present => True, + Object_Definition => New_Reference_To (Def_Id, Loc), + Expression => Node)); + end if; + + -- Generate an additional object containing the address of the + -- returned object. The type of this second object declaration + -- is the correct type required for the common processing that + -- is still performed by this subprogram. The displacement of + -- this pointer to reference the component associated with the + -- interface type will be done at the end of common processing. + + New_Decl := + Make_Object_Declaration (Loc, + Defining_Identifier => Make_Defining_Identifier (Loc, + New_Internal_Name ('P')), + Object_Definition => New_Reference_To (PtrT, Loc), + Expression => Unchecked_Convert_To (PtrT, + New_Reference_To (Temp, Loc))); + + Insert_Action (N, New_Decl); + + Tmp_Node := New_Decl; + Temp := Defining_Identifier (New_Decl); + end; + end if; + + Apply_Accessibility_Check (Temp); + + -- Generate the tag assignment + + -- Suppress the tag assignment when VM_Target because VM tags are + -- represented implicitly in objects. + + if VM_Target /= No_VM then + null; + + -- Ada 2005 (AI-251): Suppress the tag assignment with class-wide + -- interface objects because in this case the tag does not change. + + elsif Is_Interface (Directly_Designated_Type (Etype (N))) then + pragma Assert (Is_Class_Wide_Type + (Directly_Designated_Type (Etype (N)))); + null; + + elsif Is_Tagged_Type (T) and then not Is_Class_Wide_Type (T) then + TagT := T; + TagR := New_Reference_To (Temp, Loc); + + elsif Is_Private_Type (T) + and then Is_Tagged_Type (Underlying_Type (T)) + then + TagT := Underlying_Type (T); + TagR := + Unchecked_Convert_To (Underlying_Type (T), + Make_Explicit_Dereference (Loc, + Prefix => New_Reference_To (Temp, Loc))); + end if; + + if Present (TagT) then + Tag_Assign := + Make_Assignment_Statement (Loc, + Name => + Make_Selected_Component (Loc, + Prefix => TagR, + Selector_Name => + New_Reference_To (First_Tag_Component (TagT), Loc)), + + Expression => + Unchecked_Convert_To (RTE (RE_Tag), + New_Reference_To + (Elists.Node (First_Elmt (Access_Disp_Table (TagT))), + Loc))); + + -- The previous assignment has to be done in any case + + Set_Assignment_OK (Name (Tag_Assign)); + Insert_Action (N, Tag_Assign); + end if; + + if Needs_Finalization (DesigT) + and then Needs_Finalization (T) + then + declare + Attach : Node_Id; + Apool : constant Entity_Id := + Associated_Storage_Pool (PtrT); + + begin + -- If it is an allocation on the secondary stack (i.e. a value + -- returned from a function), the object is attached on the + -- caller side as soon as the call is completed (see + -- Expand_Ctrl_Function_Call) + + if Is_RTE (Apool, RE_SS_Pool) then + declare + F : constant Entity_Id := + Make_Defining_Identifier (Loc, + New_Internal_Name ('F')); + begin + Insert_Action (N, + Make_Object_Declaration (Loc, + Defining_Identifier => F, + Object_Definition => New_Reference_To (RTE + (RE_Finalizable_Ptr), Loc))); + + Flist := New_Reference_To (F, Loc); + Attach := Make_Integer_Literal (Loc, 1); + end; + + -- Normal case, not a secondary stack allocation + + else + if Needs_Finalization (T) + and then Ekind (PtrT) = E_Anonymous_Access_Type + then + -- Create local finalization list for access parameter + + Flist := + Get_Allocator_Final_List (N, Base_Type (T), PtrT); + else + Flist := Find_Final_List (PtrT); + end if; + + Attach := Make_Integer_Literal (Loc, 2); + end if; + + -- Generate an Adjust call if the object will be moved. In Ada + -- 2005, the object may be inherently limited, in which case + -- there is no Adjust procedure, and the object is built in + -- place. In Ada 95, the object can be limited but not + -- inherently limited if this allocator came from a return + -- statement (we're allocating the result on the secondary + -- stack). In that case, the object will be moved, so we _do_ + -- want to Adjust. + + if not Aggr_In_Place + and then not Is_Inherently_Limited_Type (T) + then + Insert_Actions (N, + Make_Adjust_Call ( + Ref => + + -- An unchecked conversion is needed in the classwide + -- case because the designated type can be an ancestor of + -- the subtype mark of the allocator. + + Unchecked_Convert_To (T, + Make_Explicit_Dereference (Loc, + Prefix => New_Reference_To (Temp, Loc))), + + Typ => T, + Flist_Ref => Flist, + With_Attach => Attach, + Allocator => True)); + end if; + end; + end if; + + Rewrite (N, New_Reference_To (Temp, Loc)); + Analyze_And_Resolve (N, PtrT); + + -- Ada 2005 (AI-251): Displace the pointer to reference the record + -- component containing the secondary dispatch table of the interface + -- type. + + if Is_Interface (Directly_Designated_Type (PtrT)) then + Displace_Allocator_Pointer (N); + end if; + + elsif Aggr_In_Place then + Temp := + Make_Defining_Identifier (Loc, New_Internal_Name ('P')); + Tmp_Node := + Make_Object_Declaration (Loc, + Defining_Identifier => Temp, + Object_Definition => New_Reference_To (PtrT, Loc), + Expression => Make_Allocator (Loc, + New_Reference_To (Etype (Exp), Loc))); + + Set_Comes_From_Source + (Expression (Tmp_Node), Comes_From_Source (N)); + + Set_No_Initialization (Expression (Tmp_Node)); + Insert_Action (N, Tmp_Node); + Convert_Aggr_In_Allocator (N, Tmp_Node, Exp); + Rewrite (N, New_Reference_To (Temp, Loc)); + Analyze_And_Resolve (N, PtrT); + + elsif Is_Access_Type (T) + and then Can_Never_Be_Null (T) + then + Install_Null_Excluding_Check (Exp); + + elsif Is_Access_Type (DesigT) + and then Nkind (Exp) = N_Allocator + and then Nkind (Expression (Exp)) /= N_Qualified_Expression + then + -- Apply constraint to designated subtype indication + + Apply_Constraint_Check (Expression (Exp), + Designated_Type (DesigT), + No_Sliding => True); + + if Nkind (Expression (Exp)) = N_Raise_Constraint_Error then + + -- Propagate constraint_error to enclosing allocator + + Rewrite (Exp, New_Copy (Expression (Exp))); + end if; + else + -- First check against the type of the qualified expression + -- + -- NOTE: The commented call should be correct, but for some reason + -- causes the compiler to bomb (sigsegv) on ACVC test c34007g, so for + -- now we just perform the old (incorrect) test against the + -- designated subtype with no sliding in the else part of the if + -- statement below. ??? + -- + -- Apply_Constraint_Check (Exp, T, No_Sliding => True); + + -- A check is also needed in cases where the designated subtype is + -- constrained and differs from the subtype given in the qualified + -- expression. Note that the check on the qualified expression does + -- not allow sliding, but this check does (a relaxation from Ada 83). + + if Is_Constrained (DesigT) + and then not Subtypes_Statically_Match (T, DesigT) + then + Apply_Constraint_Check + (Exp, DesigT, No_Sliding => False); + + -- The nonsliding check should really be performed (unconditionally) + -- against the subtype of the qualified expression, but that causes a + -- problem with c34007g (see above), so for now we retain this. + + else + Apply_Constraint_Check + (Exp, DesigT, No_Sliding => True); + end if; + + -- For an access to unconstrained packed array, GIGI needs to see an + -- expression with a constrained subtype in order to compute the + -- proper size for the allocator. + + if Is_Array_Type (T) + and then not Is_Constrained (T) + and then Is_Packed (T) + then + declare + ConstrT : constant Entity_Id := + Make_Defining_Identifier (Loc, + Chars => New_Internal_Name ('A')); + Internal_Exp : constant Node_Id := Relocate_Node (Exp); + begin + Insert_Action (Exp, + Make_Subtype_Declaration (Loc, + Defining_Identifier => ConstrT, + Subtype_Indication => + Make_Subtype_From_Expr (Exp, T))); + Freeze_Itype (ConstrT, Exp); + Rewrite (Exp, OK_Convert_To (ConstrT, Internal_Exp)); + end; + end if; + + -- Ada 2005 (AI-318-02): If the initialization expression is a call + -- to a build-in-place function, then access to the allocated object + -- must be passed to the function. Currently we limit such functions + -- to those with constrained limited result subtypes, but eventually + -- we plan to expand the allowed forms of functions that are treated + -- as build-in-place. + + if Ada_Version >= Ada_05 + and then Is_Build_In_Place_Function_Call (Exp) + then + Make_Build_In_Place_Call_In_Allocator (N, Exp); + end if; + end if; + + exception + when RE_Not_Available => + return; + end Expand_Allocator_Expression; + + ----------------------------- + -- Expand_Array_Comparison -- + ----------------------------- + + -- Expansion is only required in the case of array types. For the unpacked + -- case, an appropriate runtime routine is called. For packed cases, and + -- also in some other cases where a runtime routine cannot be called, the + -- form of the expansion is: + + -- [body for greater_nn; boolean_expression] + + -- The body is built by Make_Array_Comparison_Op, and the form of the + -- Boolean expression depends on the operator involved. + + procedure Expand_Array_Comparison (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Op1 : Node_Id := Left_Opnd (N); + Op2 : Node_Id := Right_Opnd (N); + Typ1 : constant Entity_Id := Base_Type (Etype (Op1)); + Ctyp : constant Entity_Id := Component_Type (Typ1); + + Expr : Node_Id; + Func_Body : Node_Id; + Func_Name : Entity_Id; + + Comp : RE_Id; + + Byte_Addressable : constant Boolean := System_Storage_Unit = Byte'Size; + -- True for byte addressable target + + function Length_Less_Than_4 (Opnd : Node_Id) return Boolean; + -- Returns True if the length of the given operand is known to be less + -- than 4. Returns False if this length is known to be four or greater + -- or is not known at compile time. + + ------------------------ + -- Length_Less_Than_4 -- + ------------------------ + + function Length_Less_Than_4 (Opnd : Node_Id) return Boolean is + Otyp : constant Entity_Id := Etype (Opnd); + + begin + if Ekind (Otyp) = E_String_Literal_Subtype then + return String_Literal_Length (Otyp) < 4; + + else + declare + Ityp : constant Entity_Id := Etype (First_Index (Otyp)); + Lo : constant Node_Id := Type_Low_Bound (Ityp); + Hi : constant Node_Id := Type_High_Bound (Ityp); + Lov : Uint; + Hiv : Uint; + + begin + if Compile_Time_Known_Value (Lo) then + Lov := Expr_Value (Lo); + else + return False; + end if; + + if Compile_Time_Known_Value (Hi) then + Hiv := Expr_Value (Hi); + else + return False; + end if; + + return Hiv < Lov + 3; + end; + end if; + end Length_Less_Than_4; + + -- Start of processing for Expand_Array_Comparison + + begin + -- Deal first with unpacked case, where we can call a runtime routine + -- except that we avoid this for targets for which are not addressable + -- by bytes, and for the JVM/CIL, since they do not support direct + -- addressing of array components. + + if not Is_Bit_Packed_Array (Typ1) + and then Byte_Addressable + and then VM_Target = No_VM + then + -- The call we generate is: + + -- Compare_Array_xn[_Unaligned] + -- (left'address, right'address, left'length, right'length) <op> 0 + + -- x = U for unsigned, S for signed + -- n = 8,16,32,64 for component size + -- Add _Unaligned if length < 4 and component size is 8. + -- <op> is the standard comparison operator + + if Component_Size (Typ1) = 8 then + if Length_Less_Than_4 (Op1) + or else + Length_Less_Than_4 (Op2) + then + if Is_Unsigned_Type (Ctyp) then + Comp := RE_Compare_Array_U8_Unaligned; + else + Comp := RE_Compare_Array_S8_Unaligned; + end if; + + else + if Is_Unsigned_Type (Ctyp) then + Comp := RE_Compare_Array_U8; + else + Comp := RE_Compare_Array_S8; + end if; + end if; + + elsif Component_Size (Typ1) = 16 then + if Is_Unsigned_Type (Ctyp) then + Comp := RE_Compare_Array_U16; + else + Comp := RE_Compare_Array_S16; + end if; + + elsif Component_Size (Typ1) = 32 then + if Is_Unsigned_Type (Ctyp) then + Comp := RE_Compare_Array_U32; + else + Comp := RE_Compare_Array_S32; + end if; + + else pragma Assert (Component_Size (Typ1) = 64); + if Is_Unsigned_Type (Ctyp) then + Comp := RE_Compare_Array_U64; + else + Comp := RE_Compare_Array_S64; + end if; + end if; + + Remove_Side_Effects (Op1, Name_Req => True); + Remove_Side_Effects (Op2, Name_Req => True); + + Rewrite (Op1, + Make_Function_Call (Sloc (Op1), + Name => New_Occurrence_Of (RTE (Comp), Loc), + + Parameter_Associations => New_List ( + Make_Attribute_Reference (Loc, + Prefix => Relocate_Node (Op1), + Attribute_Name => Name_Address), + + Make_Attribute_Reference (Loc, + Prefix => Relocate_Node (Op2), + Attribute_Name => Name_Address), + + Make_Attribute_Reference (Loc, + Prefix => Relocate_Node (Op1), + Attribute_Name => Name_Length), + + Make_Attribute_Reference (Loc, + Prefix => Relocate_Node (Op2), + Attribute_Name => Name_Length)))); + + Rewrite (Op2, + Make_Integer_Literal (Sloc (Op2), + Intval => Uint_0)); + + Analyze_And_Resolve (Op1, Standard_Integer); + Analyze_And_Resolve (Op2, Standard_Integer); + return; + end if; + + -- Cases where we cannot make runtime call + + -- For (a <= b) we convert to not (a > b) + + if Chars (N) = Name_Op_Le then + Rewrite (N, + Make_Op_Not (Loc, + Right_Opnd => + Make_Op_Gt (Loc, + Left_Opnd => Op1, + Right_Opnd => Op2))); + Analyze_And_Resolve (N, Standard_Boolean); + return; + + -- For < the Boolean expression is + -- greater__nn (op2, op1) + + elsif Chars (N) = Name_Op_Lt then + Func_Body := Make_Array_Comparison_Op (Typ1, N); + + -- Switch operands + + Op1 := Right_Opnd (N); + Op2 := Left_Opnd (N); + + -- For (a >= b) we convert to not (a < b) + + elsif Chars (N) = Name_Op_Ge then + Rewrite (N, + Make_Op_Not (Loc, + Right_Opnd => + Make_Op_Lt (Loc, + Left_Opnd => Op1, + Right_Opnd => Op2))); + Analyze_And_Resolve (N, Standard_Boolean); + return; + + -- For > the Boolean expression is + -- greater__nn (op1, op2) + + else + pragma Assert (Chars (N) = Name_Op_Gt); + Func_Body := Make_Array_Comparison_Op (Typ1, N); + end if; + + Func_Name := Defining_Unit_Name (Specification (Func_Body)); + Expr := + Make_Function_Call (Loc, + Name => New_Reference_To (Func_Name, Loc), + Parameter_Associations => New_List (Op1, Op2)); + + Insert_Action (N, Func_Body); + Rewrite (N, Expr); + Analyze_And_Resolve (N, Standard_Boolean); + + exception + when RE_Not_Available => + return; + end Expand_Array_Comparison; + + --------------------------- + -- Expand_Array_Equality -- + --------------------------- + + -- Expand an equality function for multi-dimensional arrays. Here is an + -- example of such a function for Nb_Dimension = 2 + + -- function Enn (A : atyp; B : btyp) return boolean is + -- begin + -- if (A'length (1) = 0 or else A'length (2) = 0) + -- and then + -- (B'length (1) = 0 or else B'length (2) = 0) + -- then + -- return True; -- RM 4.5.2(22) + -- end if; + + -- if A'length (1) /= B'length (1) + -- or else + -- A'length (2) /= B'length (2) + -- then + -- return False; -- RM 4.5.2(23) + -- end if; + + -- declare + -- A1 : Index_T1 := A'first (1); + -- B1 : Index_T1 := B'first (1); + -- begin + -- loop + -- declare + -- A2 : Index_T2 := A'first (2); + -- B2 : Index_T2 := B'first (2); + -- begin + -- loop + -- if A (A1, A2) /= B (B1, B2) then + -- return False; + -- end if; + + -- exit when A2 = A'last (2); + -- A2 := Index_T2'succ (A2); + -- B2 := Index_T2'succ (B2); + -- end loop; + -- end; + + -- exit when A1 = A'last (1); + -- A1 := Index_T1'succ (A1); + -- B1 := Index_T1'succ (B1); + -- end loop; + -- end; + + -- return true; + -- end Enn; + + -- Note on the formal types used (atyp and btyp). If either of the arrays + -- is of a private type, we use the underlying type, and do an unchecked + -- conversion of the actual. If either of the arrays has a bound depending + -- on a discriminant, then we use the base type since otherwise we have an + -- escaped discriminant in the function. + + -- If both arrays are constrained and have the same bounds, we can generate + -- a loop with an explicit iteration scheme using a 'Range attribute over + -- the first array. + + function Expand_Array_Equality + (Nod : Node_Id; + Lhs : Node_Id; + Rhs : Node_Id; + Bodies : List_Id; + Typ : Entity_Id) return Node_Id + is + Loc : constant Source_Ptr := Sloc (Nod); + Decls : constant List_Id := New_List; + Index_List1 : constant List_Id := New_List; + Index_List2 : constant List_Id := New_List; + + Actuals : List_Id; + Formals : List_Id; + Func_Name : Entity_Id; + Func_Body : Node_Id; + + A : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uA); + B : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uB); + + Ltyp : Entity_Id; + Rtyp : Entity_Id; + -- The parameter types to be used for the formals + + function Arr_Attr + (Arr : Entity_Id; + Nam : Name_Id; + Num : Int) return Node_Id; + -- This builds the attribute reference Arr'Nam (Expr) + + function Component_Equality (Typ : Entity_Id) return Node_Id; + -- Create one statement to compare corresponding components, designated + -- by a full set of indices. + + function Get_Arg_Type (N : Node_Id) return Entity_Id; + -- Given one of the arguments, computes the appropriate type to be used + -- for that argument in the corresponding function formal + + function Handle_One_Dimension + (N : Int; + Index : Node_Id) return Node_Id; + -- This procedure returns the following code + -- + -- declare + -- Bn : Index_T := B'First (N); + -- begin + -- loop + -- xxx + -- exit when An = A'Last (N); + -- An := Index_T'Succ (An) + -- Bn := Index_T'Succ (Bn) + -- end loop; + -- end; + -- + -- If both indices are constrained and identical, the procedure + -- returns a simpler loop: + -- + -- for An in A'Range (N) loop + -- xxx + -- end loop + -- + -- N is the dimension for which we are generating a loop. Index is the + -- N'th index node, whose Etype is Index_Type_n in the above code. The + -- xxx statement is either the loop or declare for the next dimension + -- or if this is the last dimension the comparison of corresponding + -- components of the arrays. + -- + -- The actual way the code works is to return the comparison of + -- corresponding components for the N+1 call. That's neater! + + function Test_Empty_Arrays return Node_Id; + -- This function constructs the test for both arrays being empty + -- (A'length (1) = 0 or else A'length (2) = 0 or else ...) + -- and then + -- (B'length (1) = 0 or else B'length (2) = 0 or else ...) + + function Test_Lengths_Correspond return Node_Id; + -- This function constructs the test for arrays having different lengths + -- in at least one index position, in which case the resulting code is: + + -- A'length (1) /= B'length (1) + -- or else + -- A'length (2) /= B'length (2) + -- or else + -- ... + + -------------- + -- Arr_Attr -- + -------------- + + function Arr_Attr + (Arr : Entity_Id; + Nam : Name_Id; + Num : Int) return Node_Id + is + begin + return + Make_Attribute_Reference (Loc, + Attribute_Name => Nam, + Prefix => New_Reference_To (Arr, Loc), + Expressions => New_List (Make_Integer_Literal (Loc, Num))); + end Arr_Attr; + + ------------------------ + -- Component_Equality -- + ------------------------ + + function Component_Equality (Typ : Entity_Id) return Node_Id is + Test : Node_Id; + L, R : Node_Id; + + begin + -- if a(i1...) /= b(j1...) then return false; end if; + + L := + Make_Indexed_Component (Loc, + Prefix => Make_Identifier (Loc, Chars (A)), + Expressions => Index_List1); + + R := + Make_Indexed_Component (Loc, + Prefix => Make_Identifier (Loc, Chars (B)), + Expressions => Index_List2); + + Test := Expand_Composite_Equality + (Nod, Component_Type (Typ), L, R, Decls); + + -- If some (sub)component is an unchecked_union, the whole operation + -- will raise program error. + + if Nkind (Test) = N_Raise_Program_Error then + + -- This node is going to be inserted at a location where a + -- statement is expected: clear its Etype so analysis will set + -- it to the expected Standard_Void_Type. + + Set_Etype (Test, Empty); + return Test; + + else + return + Make_Implicit_If_Statement (Nod, + Condition => Make_Op_Not (Loc, Right_Opnd => Test), + Then_Statements => New_List ( + Make_Simple_Return_Statement (Loc, + Expression => New_Occurrence_Of (Standard_False, Loc)))); + end if; + end Component_Equality; + + ------------------ + -- Get_Arg_Type -- + ------------------ + + function Get_Arg_Type (N : Node_Id) return Entity_Id is + T : Entity_Id; + X : Node_Id; + + begin + T := Etype (N); + + if No (T) then + return Typ; + + else + T := Underlying_Type (T); + + X := First_Index (T); + while Present (X) loop + if Denotes_Discriminant (Type_Low_Bound (Etype (X))) + or else + Denotes_Discriminant (Type_High_Bound (Etype (X))) + then + T := Base_Type (T); + exit; + end if; + + Next_Index (X); + end loop; + + return T; + end if; + end Get_Arg_Type; + + -------------------------- + -- Handle_One_Dimension -- + --------------------------- + + function Handle_One_Dimension + (N : Int; + Index : Node_Id) return Node_Id + is + Need_Separate_Indexes : constant Boolean := + Ltyp /= Rtyp + or else not Is_Constrained (Ltyp); + -- If the index types are identical, and we are working with + -- constrained types, then we can use the same index for both + -- of the arrays. + + An : constant Entity_Id := Make_Defining_Identifier (Loc, + Chars => New_Internal_Name ('A')); + + Bn : Entity_Id; + Index_T : Entity_Id; + Stm_List : List_Id; + Loop_Stm : Node_Id; + + begin + if N > Number_Dimensions (Ltyp) then + return Component_Equality (Ltyp); + end if; + + -- Case where we generate a loop + + Index_T := Base_Type (Etype (Index)); + + if Need_Separate_Indexes then + Bn := + Make_Defining_Identifier (Loc, + Chars => New_Internal_Name ('B')); + else + Bn := An; + end if; + + Append (New_Reference_To (An, Loc), Index_List1); + Append (New_Reference_To (Bn, Loc), Index_List2); + + Stm_List := New_List ( + Handle_One_Dimension (N + 1, Next_Index (Index))); + + if Need_Separate_Indexes then + + -- Generate guard for loop, followed by increments of indices + + Append_To (Stm_List, + Make_Exit_Statement (Loc, + Condition => + Make_Op_Eq (Loc, + Left_Opnd => New_Reference_To (An, Loc), + Right_Opnd => Arr_Attr (A, Name_Last, N)))); + + Append_To (Stm_List, + Make_Assignment_Statement (Loc, + Name => New_Reference_To (An, Loc), + Expression => + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Index_T, Loc), + Attribute_Name => Name_Succ, + Expressions => New_List (New_Reference_To (An, Loc))))); + + Append_To (Stm_List, + Make_Assignment_Statement (Loc, + Name => New_Reference_To (Bn, Loc), + Expression => + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Index_T, Loc), + Attribute_Name => Name_Succ, + Expressions => New_List (New_Reference_To (Bn, Loc))))); + end if; + + -- If separate indexes, we need a declare block for An and Bn, and a + -- loop without an iteration scheme. + + if Need_Separate_Indexes then + Loop_Stm := + Make_Implicit_Loop_Statement (Nod, Statements => Stm_List); + + return + Make_Block_Statement (Loc, + Declarations => New_List ( + Make_Object_Declaration (Loc, + Defining_Identifier => An, + Object_Definition => New_Reference_To (Index_T, Loc), + Expression => Arr_Attr (A, Name_First, N)), + + Make_Object_Declaration (Loc, + Defining_Identifier => Bn, + Object_Definition => New_Reference_To (Index_T, Loc), + Expression => Arr_Attr (B, Name_First, N))), + + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, + Statements => New_List (Loop_Stm))); + + -- If no separate indexes, return loop statement with explicit + -- iteration scheme on its own + + else + Loop_Stm := + Make_Implicit_Loop_Statement (Nod, + Statements => Stm_List, + Iteration_Scheme => + Make_Iteration_Scheme (Loc, + Loop_Parameter_Specification => + Make_Loop_Parameter_Specification (Loc, + Defining_Identifier => An, + Discrete_Subtype_Definition => + Arr_Attr (A, Name_Range, N)))); + return Loop_Stm; + end if; + end Handle_One_Dimension; + + ----------------------- + -- Test_Empty_Arrays -- + ----------------------- + + function Test_Empty_Arrays return Node_Id is + Alist : Node_Id; + Blist : Node_Id; + + Atest : Node_Id; + Btest : Node_Id; + + begin + Alist := Empty; + Blist := Empty; + for J in 1 .. Number_Dimensions (Ltyp) loop + Atest := + Make_Op_Eq (Loc, + Left_Opnd => Arr_Attr (A, Name_Length, J), + Right_Opnd => Make_Integer_Literal (Loc, 0)); + + Btest := + Make_Op_Eq (Loc, + Left_Opnd => Arr_Attr (B, Name_Length, J), + Right_Opnd => Make_Integer_Literal (Loc, 0)); + + if No (Alist) then + Alist := Atest; + Blist := Btest; + + else + Alist := + Make_Or_Else (Loc, + Left_Opnd => Relocate_Node (Alist), + Right_Opnd => Atest); + + Blist := + Make_Or_Else (Loc, + Left_Opnd => Relocate_Node (Blist), + Right_Opnd => Btest); + end if; + end loop; + + return + Make_And_Then (Loc, + Left_Opnd => Alist, + Right_Opnd => Blist); + end Test_Empty_Arrays; + + ----------------------------- + -- Test_Lengths_Correspond -- + ----------------------------- + + function Test_Lengths_Correspond return Node_Id is + Result : Node_Id; + Rtest : Node_Id; + + begin + Result := Empty; + for J in 1 .. Number_Dimensions (Ltyp) loop + Rtest := + Make_Op_Ne (Loc, + Left_Opnd => Arr_Attr (A, Name_Length, J), + Right_Opnd => Arr_Attr (B, Name_Length, J)); + + if No (Result) then + Result := Rtest; + else + Result := + Make_Or_Else (Loc, + Left_Opnd => Relocate_Node (Result), + Right_Opnd => Rtest); + end if; + end loop; + + return Result; + end Test_Lengths_Correspond; + + -- Start of processing for Expand_Array_Equality + + begin + Ltyp := Get_Arg_Type (Lhs); + Rtyp := Get_Arg_Type (Rhs); + + -- For now, if the argument types are not the same, go to the base type, + -- since the code assumes that the formals have the same type. This is + -- fixable in future ??? + + if Ltyp /= Rtyp then + Ltyp := Base_Type (Ltyp); + Rtyp := Base_Type (Rtyp); + pragma Assert (Ltyp = Rtyp); + end if; + + -- Build list of formals for function + + Formals := New_List ( + Make_Parameter_Specification (Loc, + Defining_Identifier => A, + Parameter_Type => New_Reference_To (Ltyp, Loc)), + + Make_Parameter_Specification (Loc, + Defining_Identifier => B, + Parameter_Type => New_Reference_To (Rtyp, Loc))); + + Func_Name := Make_Defining_Identifier (Loc, New_Internal_Name ('E')); + + -- Build statement sequence for function + + Func_Body := + Make_Subprogram_Body (Loc, + Specification => + Make_Function_Specification (Loc, + Defining_Unit_Name => Func_Name, + Parameter_Specifications => Formals, + Result_Definition => New_Reference_To (Standard_Boolean, Loc)), + + Declarations => Decls, + + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, + Statements => New_List ( + + Make_Implicit_If_Statement (Nod, + Condition => Test_Empty_Arrays, + Then_Statements => New_List ( + Make_Simple_Return_Statement (Loc, + Expression => + New_Occurrence_Of (Standard_True, Loc)))), + + Make_Implicit_If_Statement (Nod, + Condition => Test_Lengths_Correspond, + Then_Statements => New_List ( + Make_Simple_Return_Statement (Loc, + Expression => + New_Occurrence_Of (Standard_False, Loc)))), + + Handle_One_Dimension (1, First_Index (Ltyp)), + + Make_Simple_Return_Statement (Loc, + Expression => New_Occurrence_Of (Standard_True, Loc))))); + + Set_Has_Completion (Func_Name, True); + Set_Is_Inlined (Func_Name); + + -- If the array type is distinct from the type of the arguments, it + -- is the full view of a private type. Apply an unchecked conversion + -- to insure that analysis of the call succeeds. + + declare + L, R : Node_Id; + + begin + L := Lhs; + R := Rhs; + + if No (Etype (Lhs)) + or else Base_Type (Etype (Lhs)) /= Base_Type (Ltyp) + then + L := OK_Convert_To (Ltyp, Lhs); + end if; + + if No (Etype (Rhs)) + or else Base_Type (Etype (Rhs)) /= Base_Type (Rtyp) + then + R := OK_Convert_To (Rtyp, Rhs); + end if; + + Actuals := New_List (L, R); + end; + + Append_To (Bodies, Func_Body); + + return + Make_Function_Call (Loc, + Name => New_Reference_To (Func_Name, Loc), + Parameter_Associations => Actuals); + end Expand_Array_Equality; + + ----------------------------- + -- Expand_Boolean_Operator -- + ----------------------------- + + -- Note that we first get the actual subtypes of the operands, since we + -- always want to deal with types that have bounds. + + procedure Expand_Boolean_Operator (N : Node_Id) is + Typ : constant Entity_Id := Etype (N); + + begin + -- Special case of bit packed array where both operands are known to be + -- properly aligned. In this case we use an efficient run time routine + -- to carry out the operation (see System.Bit_Ops). + + if Is_Bit_Packed_Array (Typ) + and then not Is_Possibly_Unaligned_Object (Left_Opnd (N)) + and then not Is_Possibly_Unaligned_Object (Right_Opnd (N)) + then + Expand_Packed_Boolean_Operator (N); + return; + end if; + + -- For the normal non-packed case, the general expansion is to build + -- function for carrying out the comparison (use Make_Boolean_Array_Op) + -- and then inserting it into the tree. The original operator node is + -- then rewritten as a call to this function. We also use this in the + -- packed case if either operand is a possibly unaligned object. + + declare + Loc : constant Source_Ptr := Sloc (N); + L : constant Node_Id := Relocate_Node (Left_Opnd (N)); + R : constant Node_Id := Relocate_Node (Right_Opnd (N)); + Func_Body : Node_Id; + Func_Name : Entity_Id; + + begin + Convert_To_Actual_Subtype (L); + Convert_To_Actual_Subtype (R); + Ensure_Defined (Etype (L), N); + Ensure_Defined (Etype (R), N); + Apply_Length_Check (R, Etype (L)); + + if Nkind (N) = N_Op_Xor then + Silly_Boolean_Array_Xor_Test (N, Etype (L)); + end if; + + if Nkind (Parent (N)) = N_Assignment_Statement + and then Safe_In_Place_Array_Op (Name (Parent (N)), L, R) + then + Build_Boolean_Array_Proc_Call (Parent (N), L, R); + + elsif Nkind (Parent (N)) = N_Op_Not + and then Nkind (N) = N_Op_And + and then + Safe_In_Place_Array_Op (Name (Parent (Parent (N))), L, R) + then + return; + else + + Func_Body := Make_Boolean_Array_Op (Etype (L), N); + Func_Name := Defining_Unit_Name (Specification (Func_Body)); + Insert_Action (N, Func_Body); + + -- Now rewrite the expression with a call + + Rewrite (N, + Make_Function_Call (Loc, + Name => New_Reference_To (Func_Name, Loc), + Parameter_Associations => + New_List ( + L, + Make_Type_Conversion + (Loc, New_Reference_To (Etype (L), Loc), R)))); + + Analyze_And_Resolve (N, Typ); + end if; + end; + end Expand_Boolean_Operator; + + ------------------------------- + -- Expand_Composite_Equality -- + ------------------------------- + + -- This function is only called for comparing internal fields of composite + -- types when these fields are themselves composites. This is a special + -- case because it is not possible to respect normal Ada visibility rules. + + function Expand_Composite_Equality + (Nod : Node_Id; + Typ : Entity_Id; + Lhs : Node_Id; + Rhs : Node_Id; + Bodies : List_Id) return Node_Id + is + Loc : constant Source_Ptr := Sloc (Nod); + Full_Type : Entity_Id; + Prim : Elmt_Id; + Eq_Op : Entity_Id; + + begin + if Is_Private_Type (Typ) then + Full_Type := Underlying_Type (Typ); + else + Full_Type := Typ; + end if; + + -- Defense against malformed private types with no completion the error + -- will be diagnosed later by check_completion + + if No (Full_Type) then + return New_Reference_To (Standard_False, Loc); + end if; + + Full_Type := Base_Type (Full_Type); + + if Is_Array_Type (Full_Type) then + + -- If the operand is an elementary type other than a floating-point + -- type, then we can simply use the built-in block bitwise equality, + -- since the predefined equality operators always apply and bitwise + -- equality is fine for all these cases. + + if Is_Elementary_Type (Component_Type (Full_Type)) + and then not Is_Floating_Point_Type (Component_Type (Full_Type)) + then + return Make_Op_Eq (Loc, Left_Opnd => Lhs, Right_Opnd => Rhs); + + -- For composite component types, and floating-point types, use the + -- expansion. This deals with tagged component types (where we use + -- the applicable equality routine) and floating-point, (where we + -- need to worry about negative zeroes), and also the case of any + -- composite type recursively containing such fields. + + else + return Expand_Array_Equality (Nod, Lhs, Rhs, Bodies, Full_Type); + end if; + + elsif Is_Tagged_Type (Full_Type) then + + -- Call the primitive operation "=" of this type + + if Is_Class_Wide_Type (Full_Type) then + Full_Type := Root_Type (Full_Type); + end if; + + -- If this is derived from an untagged private type completed with a + -- tagged type, it does not have a full view, so we use the primitive + -- operations of the private type. This check should no longer be + -- necessary when these types receive their full views ??? + + if Is_Private_Type (Typ) + and then not Is_Tagged_Type (Typ) + and then not Is_Controlled (Typ) + and then Is_Derived_Type (Typ) + and then No (Full_View (Typ)) + then + Prim := First_Elmt (Collect_Primitive_Operations (Typ)); + else + Prim := First_Elmt (Primitive_Operations (Full_Type)); + end if; + + loop + Eq_Op := Node (Prim); + exit when Chars (Eq_Op) = Name_Op_Eq + and then Etype (First_Formal (Eq_Op)) = + Etype (Next_Formal (First_Formal (Eq_Op))) + and then Base_Type (Etype (Eq_Op)) = Standard_Boolean; + Next_Elmt (Prim); + pragma Assert (Present (Prim)); + end loop; + + Eq_Op := Node (Prim); + + return + Make_Function_Call (Loc, + Name => New_Reference_To (Eq_Op, Loc), + Parameter_Associations => + New_List + (Unchecked_Convert_To (Etype (First_Formal (Eq_Op)), Lhs), + Unchecked_Convert_To (Etype (First_Formal (Eq_Op)), Rhs))); + + elsif Is_Record_Type (Full_Type) then + Eq_Op := TSS (Full_Type, TSS_Composite_Equality); + + if Present (Eq_Op) then + if Etype (First_Formal (Eq_Op)) /= Full_Type then + + -- Inherited equality from parent type. Convert the actuals to + -- match signature of operation. + + declare + T : constant Entity_Id := Etype (First_Formal (Eq_Op)); + + begin + return + Make_Function_Call (Loc, + Name => New_Reference_To (Eq_Op, Loc), + Parameter_Associations => + New_List (OK_Convert_To (T, Lhs), + OK_Convert_To (T, Rhs))); + end; + + else + -- Comparison between Unchecked_Union components + + if Is_Unchecked_Union (Full_Type) then + declare + Lhs_Type : Node_Id := Full_Type; + Rhs_Type : Node_Id := Full_Type; + Lhs_Discr_Val : Node_Id; + Rhs_Discr_Val : Node_Id; + + begin + -- Lhs subtype + + if Nkind (Lhs) = N_Selected_Component then + Lhs_Type := Etype (Entity (Selector_Name (Lhs))); + end if; + + -- Rhs subtype + + if Nkind (Rhs) = N_Selected_Component then + Rhs_Type := Etype (Entity (Selector_Name (Rhs))); + end if; + + -- Lhs of the composite equality + + if Is_Constrained (Lhs_Type) then + + -- Since the enclosing record type can never be an + -- Unchecked_Union (this code is executed for records + -- that do not have variants), we may reference its + -- discriminant(s). + + if Nkind (Lhs) = N_Selected_Component + and then Has_Per_Object_Constraint ( + Entity (Selector_Name (Lhs))) + then + Lhs_Discr_Val := + Make_Selected_Component (Loc, + Prefix => Prefix (Lhs), + Selector_Name => + New_Copy ( + Get_Discriminant_Value ( + First_Discriminant (Lhs_Type), + Lhs_Type, + Stored_Constraint (Lhs_Type)))); + + else + Lhs_Discr_Val := New_Copy ( + Get_Discriminant_Value ( + First_Discriminant (Lhs_Type), + Lhs_Type, + Stored_Constraint (Lhs_Type))); + + end if; + else + -- It is not possible to infer the discriminant since + -- the subtype is not constrained. + + return + Make_Raise_Program_Error (Loc, + Reason => PE_Unchecked_Union_Restriction); + end if; + + -- Rhs of the composite equality + + if Is_Constrained (Rhs_Type) then + if Nkind (Rhs) = N_Selected_Component + and then Has_Per_Object_Constraint ( + Entity (Selector_Name (Rhs))) + then + Rhs_Discr_Val := + Make_Selected_Component (Loc, + Prefix => Prefix (Rhs), + Selector_Name => + New_Copy ( + Get_Discriminant_Value ( + First_Discriminant (Rhs_Type), + Rhs_Type, + Stored_Constraint (Rhs_Type)))); + + else + Rhs_Discr_Val := New_Copy ( + Get_Discriminant_Value ( + First_Discriminant (Rhs_Type), + Rhs_Type, + Stored_Constraint (Rhs_Type))); + + end if; + else + return + Make_Raise_Program_Error (Loc, + Reason => PE_Unchecked_Union_Restriction); + end if; + + -- Call the TSS equality function with the inferred + -- discriminant values. + + return + Make_Function_Call (Loc, + Name => New_Reference_To (Eq_Op, Loc), + Parameter_Associations => New_List ( + Lhs, + Rhs, + Lhs_Discr_Val, + Rhs_Discr_Val)); + end; + end if; + + -- Shouldn't this be an else, we can't fall through the above + -- IF, right??? + + return + Make_Function_Call (Loc, + Name => New_Reference_To (Eq_Op, Loc), + Parameter_Associations => New_List (Lhs, Rhs)); + end if; + + else + return Expand_Record_Equality (Nod, Full_Type, Lhs, Rhs, Bodies); + end if; + + else + -- It can be a simple record or the full view of a scalar private + + return Make_Op_Eq (Loc, Left_Opnd => Lhs, Right_Opnd => Rhs); + end if; + end Expand_Composite_Equality; + + ------------------------------ + -- Expand_Concatenate_Other -- + ------------------------------ + + -- Let n be the number of array operands to be concatenated, Base_Typ their + -- base type, Ind_Typ their index type, and Arr_Typ the original array type + -- to which the concatenation operator applies, then the following + -- subprogram is constructed: + + -- [function Cnn (S1 : Base_Typ; ...; Sn : Base_Typ) return Base_Typ is + -- L : Ind_Typ; + -- begin + -- if S1'Length /= 0 then + -- L := XXX; --> XXX = S1'First if Arr_Typ is unconstrained + -- XXX = Arr_Typ'First otherwise + -- elsif S2'Length /= 0 then + -- L := YYY; --> YYY = S2'First if Arr_Typ is unconstrained + -- YYY = Arr_Typ'First otherwise + -- ... + -- elsif Sn-1'Length /= 0 then + -- L := ZZZ; --> ZZZ = Sn-1'First if Arr_Typ is unconstrained + -- ZZZ = Arr_Typ'First otherwise + -- else + -- return Sn; + -- end if; + + -- declare + -- P : Ind_Typ; + -- H : Ind_Typ := + -- Ind_Typ'Val ((((S1'Length - 1) + S2'Length) + ... + Sn'Length) + -- + Ind_Typ'Pos (L)); + -- R : Base_Typ (L .. H); + -- begin + -- if S1'Length /= 0 then + -- P := S1'First; + -- loop + -- R (L) := S1 (P); + -- L := Ind_Typ'Succ (L); + -- exit when P = S1'Last; + -- P := Ind_Typ'Succ (P); + -- end loop; + -- end if; + -- + -- if S2'Length /= 0 then + -- L := Ind_Typ'Succ (L); + -- loop + -- R (L) := S2 (P); + -- L := Ind_Typ'Succ (L); + -- exit when P = S2'Last; + -- P := Ind_Typ'Succ (P); + -- end loop; + -- end if; + + -- ... + + -- if Sn'Length /= 0 then + -- P := Sn'First; + -- loop + -- R (L) := Sn (P); + -- L := Ind_Typ'Succ (L); + -- exit when P = Sn'Last; + -- P := Ind_Typ'Succ (P); + -- end loop; + -- end if; + + -- return R; + -- end; + -- end Cnn;] + + procedure Expand_Concatenate_Other (Cnode : Node_Id; Opnds : List_Id) is + Loc : constant Source_Ptr := Sloc (Cnode); + Nb_Opnds : constant Nat := List_Length (Opnds); + + Arr_Typ : constant Entity_Id := Etype (Entity (Cnode)); + Base_Typ : constant Entity_Id := Base_Type (Etype (Cnode)); + Ind_Typ : constant Entity_Id := Etype (First_Index (Base_Typ)); + + Func_Id : Node_Id; + Func_Spec : Node_Id; + Param_Specs : List_Id; + + Func_Body : Node_Id; + Func_Decls : List_Id; + Func_Stmts : List_Id; + + L_Decl : Node_Id; + + If_Stmt : Node_Id; + Elsif_List : List_Id; + + Declare_Block : Node_Id; + Declare_Decls : List_Id; + Declare_Stmts : List_Id; + + H_Decl : Node_Id; + I_Decl : Node_Id; + H_Init : Node_Id; + P_Decl : Node_Id; + R_Decl : Node_Id; + R_Constr : Node_Id; + R_Range : Node_Id; + + Params : List_Id; + Operand : Node_Id; + + function Copy_Into_R_S (I : Nat; Last : Boolean) return List_Id; + -- Builds the sequence of statement: + -- P := Si'First; + -- loop + -- R (L) := Si (P); + -- L := Ind_Typ'Succ (L); + -- exit when P = Si'Last; + -- P := Ind_Typ'Succ (P); + -- end loop; + -- + -- where i is the input parameter I given. + -- If the flag Last is true, the exit statement is emitted before + -- incrementing the lower bound, to prevent the creation out of + -- bound values. + + function Init_L (I : Nat) return Node_Id; + -- Builds the statement: + -- L := Arr_Typ'First; If Arr_Typ is constrained + -- L := Si'First; otherwise (where I is the input param given) + + function H return Node_Id; + -- Builds reference to identifier H + + function Ind_Val (E : Node_Id) return Node_Id; + -- Builds expression Ind_Typ'Val (E); + + function L return Node_Id; + -- Builds reference to identifier L + + function L_Pos return Node_Id; + -- Builds expression Integer_Type'(Ind_Typ'Pos (L)). We qualify the + -- expression to avoid universal_integer computations whenever possible, + -- in the expression for the upper bound H. + + function L_Succ return Node_Id; + -- Builds expression Ind_Typ'Succ (L) + + function One return Node_Id; + -- Builds integer literal one + + function P return Node_Id; + -- Builds reference to identifier P + + function P_Succ return Node_Id; + -- Builds expression Ind_Typ'Succ (P) + + function R return Node_Id; + -- Builds reference to identifier R + + function S (I : Nat) return Node_Id; + -- Builds reference to identifier Si, where I is the value given + + function S_First (I : Nat) return Node_Id; + -- Builds expression Si'First, where I is the value given + + function S_Last (I : Nat) return Node_Id; + -- Builds expression Si'Last, where I is the value given + + function S_Length (I : Nat) return Node_Id; + -- Builds expression Si'Length, where I is the value given + + function S_Length_Test (I : Nat) return Node_Id; + -- Builds expression Si'Length /= 0, where I is the value given + + ------------------- + -- Copy_Into_R_S -- + ------------------- + + function Copy_Into_R_S (I : Nat; Last : Boolean) return List_Id is + Stmts : constant List_Id := New_List; + P_Start : Node_Id; + Loop_Stmt : Node_Id; + R_Copy : Node_Id; + Exit_Stmt : Node_Id; + L_Inc : Node_Id; + P_Inc : Node_Id; + + begin + -- First construct the initializations + + P_Start := Make_Assignment_Statement (Loc, + Name => P, + Expression => S_First (I)); + Append_To (Stmts, P_Start); + + -- Then build the loop + + R_Copy := Make_Assignment_Statement (Loc, + Name => Make_Indexed_Component (Loc, + Prefix => R, + Expressions => New_List (L)), + Expression => Make_Indexed_Component (Loc, + Prefix => S (I), + Expressions => New_List (P))); + + L_Inc := Make_Assignment_Statement (Loc, + Name => L, + Expression => L_Succ); + + Exit_Stmt := Make_Exit_Statement (Loc, + Condition => Make_Op_Eq (Loc, P, S_Last (I))); + + P_Inc := Make_Assignment_Statement (Loc, + Name => P, + Expression => P_Succ); + + if Last then + Loop_Stmt := + Make_Implicit_Loop_Statement (Cnode, + Statements => New_List (R_Copy, Exit_Stmt, L_Inc, P_Inc)); + else + Loop_Stmt := + Make_Implicit_Loop_Statement (Cnode, + Statements => New_List (R_Copy, L_Inc, Exit_Stmt, P_Inc)); + end if; + + Append_To (Stmts, Loop_Stmt); + + return Stmts; + end Copy_Into_R_S; + + ------- + -- H -- + ------- + + function H return Node_Id is + begin + return Make_Identifier (Loc, Name_uH); + end H; + + ------------- + -- Ind_Val -- + ------------- + + function Ind_Val (E : Node_Id) return Node_Id is + begin + return + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Ind_Typ, Loc), + Attribute_Name => Name_Val, + Expressions => New_List (E)); + end Ind_Val; + + ------------ + -- Init_L -- + ------------ + + function Init_L (I : Nat) return Node_Id is + E : Node_Id; + + begin + if Is_Constrained (Arr_Typ) then + E := Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Arr_Typ, Loc), + Attribute_Name => Name_First); + + else + E := S_First (I); + end if; + + return Make_Assignment_Statement (Loc, Name => L, Expression => E); + end Init_L; + + ------- + -- L -- + ------- + + function L return Node_Id is + begin + return Make_Identifier (Loc, Name_uL); + end L; + + ----------- + -- L_Pos -- + ----------- + + function L_Pos return Node_Id is + Target_Type : Entity_Id; + + begin + -- If the index type is an enumeration type, the computation can be + -- done in standard integer. Otherwise, choose a large enough integer + -- type to accommodate the index type computation. + + if Is_Enumeration_Type (Ind_Typ) + or else Root_Type (Ind_Typ) = Standard_Integer + or else Root_Type (Ind_Typ) = Standard_Short_Integer + or else Root_Type (Ind_Typ) = Standard_Short_Short_Integer + or else Is_Modular_Integer_Type (Ind_Typ) + then + Target_Type := Standard_Integer; + else + Target_Type := Root_Type (Ind_Typ); + end if; + + return + Make_Qualified_Expression (Loc, + Subtype_Mark => New_Reference_To (Target_Type, Loc), + Expression => + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Ind_Typ, Loc), + Attribute_Name => Name_Pos, + Expressions => New_List (L))); + end L_Pos; + + ------------ + -- L_Succ -- + ------------ + + function L_Succ return Node_Id is + begin + return + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Ind_Typ, Loc), + Attribute_Name => Name_Succ, + Expressions => New_List (L)); + end L_Succ; + + --------- + -- One -- + --------- + + function One return Node_Id is + begin + return Make_Integer_Literal (Loc, 1); + end One; + + ------- + -- P -- + ------- + + function P return Node_Id is + begin + return Make_Identifier (Loc, Name_uP); + end P; + + ------------ + -- P_Succ -- + ------------ + + function P_Succ return Node_Id is + begin + return + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Ind_Typ, Loc), + Attribute_Name => Name_Succ, + Expressions => New_List (P)); + end P_Succ; + + ------- + -- R -- + ------- + + function R return Node_Id is + begin + return Make_Identifier (Loc, Name_uR); + end R; + + ------- + -- S -- + ------- + + function S (I : Nat) return Node_Id is + begin + return Make_Identifier (Loc, New_External_Name ('S', I)); + end S; + + ------------- + -- S_First -- + ------------- + + function S_First (I : Nat) return Node_Id is + begin + return Make_Attribute_Reference (Loc, + Prefix => S (I), + Attribute_Name => Name_First); + end S_First; + + ------------ + -- S_Last -- + ------------ + + function S_Last (I : Nat) return Node_Id is + begin + return Make_Attribute_Reference (Loc, + Prefix => S (I), + Attribute_Name => Name_Last); + end S_Last; + + -------------- + -- S_Length -- + -------------- + + function S_Length (I : Nat) return Node_Id is + begin + return Make_Attribute_Reference (Loc, + Prefix => S (I), + Attribute_Name => Name_Length); + end S_Length; + + ------------------- + -- S_Length_Test -- + ------------------- + + function S_Length_Test (I : Nat) return Node_Id is + begin + return + Make_Op_Ne (Loc, + Left_Opnd => S_Length (I), + Right_Opnd => Make_Integer_Literal (Loc, 0)); + end S_Length_Test; + + -- Start of processing for Expand_Concatenate_Other + + begin + -- Construct the parameter specs and the overall function spec + + Param_Specs := New_List; + for I in 1 .. Nb_Opnds loop + Append_To + (Param_Specs, + Make_Parameter_Specification (Loc, + Defining_Identifier => + Make_Defining_Identifier (Loc, New_External_Name ('S', I)), + Parameter_Type => New_Reference_To (Base_Typ, Loc))); + end loop; + + Func_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('C')); + Func_Spec := + Make_Function_Specification (Loc, + Defining_Unit_Name => Func_Id, + Parameter_Specifications => Param_Specs, + Result_Definition => New_Reference_To (Base_Typ, Loc)); + + -- Construct L's object declaration + + L_Decl := + Make_Object_Declaration (Loc, + Defining_Identifier => Make_Defining_Identifier (Loc, Name_uL), + Object_Definition => New_Reference_To (Ind_Typ, Loc)); + + Func_Decls := New_List (L_Decl); + + -- Construct the if-then-elsif statements + + Elsif_List := New_List; + for I in 2 .. Nb_Opnds - 1 loop + Append_To (Elsif_List, Make_Elsif_Part (Loc, + Condition => S_Length_Test (I), + Then_Statements => New_List (Init_L (I)))); + end loop; + + If_Stmt := + Make_Implicit_If_Statement (Cnode, + Condition => S_Length_Test (1), + Then_Statements => New_List (Init_L (1)), + Elsif_Parts => Elsif_List, + Else_Statements => New_List (Make_Simple_Return_Statement (Loc, + Expression => S (Nb_Opnds)))); + + -- Construct the declaration for H + + P_Decl := + Make_Object_Declaration (Loc, + Defining_Identifier => Make_Defining_Identifier (Loc, Name_uP), + Object_Definition => New_Reference_To (Ind_Typ, Loc)); + + H_Init := Make_Op_Subtract (Loc, S_Length (1), One); + for I in 2 .. Nb_Opnds loop + H_Init := Make_Op_Add (Loc, H_Init, S_Length (I)); + end loop; + + -- If the index type is small modular type, we need to perform an + -- additional check that the upper bound fits in the index type. + -- Otherwise the computation of the upper bound can wrap around + -- and yield meaningless results. The constraint check has to be + -- explicit in the code, because the generated function is compiled + -- with checks disabled, for efficiency. + + if Is_Modular_Integer_Type (Ind_Typ) + and then Esize (Ind_Typ) < Esize (Standard_Integer) + then + I_Decl := + Make_Object_Declaration (Loc, + Defining_Identifier => Make_Defining_Identifier (Loc, Name_uI), + Object_Definition => New_Reference_To (Standard_Integer, Loc), + Expression => + Make_Type_Conversion (Loc, + New_Reference_To (Standard_Integer, Loc), + Make_Op_Add (Loc, H_Init, L_Pos))); + + H_Init := + Ind_Val ( + Make_Type_Conversion (Loc, + New_Reference_To (Ind_Typ, Loc), + New_Reference_To (Defining_Identifier (I_Decl), Loc))); + + -- For other index types, computation is safe + + else + H_Init := Ind_Val (Make_Op_Add (Loc, H_Init, L_Pos)); + end if; + + H_Decl := + Make_Object_Declaration (Loc, + Defining_Identifier => Make_Defining_Identifier (Loc, Name_uH), + Object_Definition => New_Reference_To (Ind_Typ, Loc), + Expression => H_Init); + + -- Construct the declaration for R + + R_Range := Make_Range (Loc, Low_Bound => L, High_Bound => H); + R_Constr := + Make_Index_Or_Discriminant_Constraint (Loc, + Constraints => New_List (R_Range)); + + R_Decl := + Make_Object_Declaration (Loc, + Defining_Identifier => Make_Defining_Identifier (Loc, Name_uR), + Object_Definition => + Make_Subtype_Indication (Loc, + Subtype_Mark => New_Reference_To (Base_Typ, Loc), + Constraint => R_Constr)); + + -- Construct the declarations for the declare block + + Declare_Decls := New_List (P_Decl, H_Decl, R_Decl); + + -- Add constraint check for the modular index case + + if Is_Modular_Integer_Type (Ind_Typ) + and then Esize (Ind_Typ) < Esize (Standard_Integer) + then + Insert_After (P_Decl, I_Decl); + + Insert_After (I_Decl, + Make_Raise_Constraint_Error (Loc, + Condition => + Make_Op_Gt (Loc, + Left_Opnd => + New_Reference_To (Defining_Identifier (I_Decl), Loc), + Right_Opnd => + Make_Type_Conversion (Loc, + New_Reference_To (Standard_Integer, Loc), + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Ind_Typ, Loc), + Attribute_Name => Name_Last))), + Reason => CE_Range_Check_Failed)); + end if; + + -- Construct list of statements for the declare block + + Declare_Stmts := New_List; + for I in 1 .. Nb_Opnds loop + Append_To (Declare_Stmts, + Make_Implicit_If_Statement (Cnode, + Condition => S_Length_Test (I), + Then_Statements => Copy_Into_R_S (I, I = Nb_Opnds))); + end loop; + + Append_To + (Declare_Stmts, Make_Simple_Return_Statement (Loc, Expression => R)); + + -- Construct the declare block + + Declare_Block := Make_Block_Statement (Loc, + Declarations => Declare_Decls, + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, Declare_Stmts)); + + -- Construct the list of function statements + + Func_Stmts := New_List (If_Stmt, Declare_Block); + + -- Construct the function body + + Func_Body := + Make_Subprogram_Body (Loc, + Specification => Func_Spec, + Declarations => Func_Decls, + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, Func_Stmts)); + + -- Insert the newly generated function in the code. This is analyzed + -- with all checks off, since we have completed all the checks. + + -- Note that this does *not* fix the array concatenation bug when the + -- low bound is Integer'first sibce that bug comes from the pointer + -- dereferencing an unconstrained array. And there we need a constraint + -- check to make sure the length of the concatenated array is ok. ??? + + Insert_Action (Cnode, Func_Body, Suppress => All_Checks); + + -- Construct list of arguments for the function call + + Params := New_List; + Operand := First (Opnds); + for I in 1 .. Nb_Opnds loop + Append_To (Params, Relocate_Node (Operand)); + Next (Operand); + end loop; + + -- Insert the function call + + Rewrite + (Cnode, + Make_Function_Call (Loc, New_Reference_To (Func_Id, Loc), Params)); + + Analyze_And_Resolve (Cnode, Base_Typ); + Set_Is_Inlined (Func_Id); + end Expand_Concatenate_Other; + + ------------------------------- + -- Expand_Concatenate_String -- + ------------------------------- + + procedure Expand_Concatenate_String (Cnode : Node_Id; Opnds : List_Id) is + Loc : constant Source_Ptr := Sloc (Cnode); + Opnd1 : constant Node_Id := First (Opnds); + Opnd2 : constant Node_Id := Next (Opnd1); + Typ1 : constant Entity_Id := Base_Type (Etype (Opnd1)); + Typ2 : constant Entity_Id := Base_Type (Etype (Opnd2)); + + R : RE_Id; + -- RE_Id value for function to be called + + begin + -- In all cases, we build a call to a routine giving the list of + -- arguments as the parameter list to the routine. + + case List_Length (Opnds) is + when 2 => + if Typ1 = Standard_Character then + if Typ2 = Standard_Character then + R := RE_Str_Concat_CC; + + else + pragma Assert (Typ2 = Standard_String); + R := RE_Str_Concat_CS; + end if; + + elsif Typ1 = Standard_String then + if Typ2 = Standard_Character then + R := RE_Str_Concat_SC; + + else + pragma Assert (Typ2 = Standard_String); + R := RE_Str_Concat; + end if; + + -- If we have anything other than Standard_Character or + -- Standard_String, then we must have had a serious error + -- earlier, so we just abandon the attempt at expansion. + + else + pragma Assert (Serious_Errors_Detected > 0); + return; + end if; + + when 3 => + R := RE_Str_Concat_3; + + when 4 => + R := RE_Str_Concat_4; + + when 5 => + R := RE_Str_Concat_5; + + when others => + R := RE_Null; + raise Program_Error; + end case; + + -- Now generate the appropriate call + + Rewrite (Cnode, + Make_Function_Call (Sloc (Cnode), + Name => New_Occurrence_Of (RTE (R), Loc), + Parameter_Associations => Opnds)); + + Analyze_And_Resolve (Cnode, Standard_String); + + exception + when RE_Not_Available => + return; + end Expand_Concatenate_String; + + ------------------------ + -- Expand_N_Allocator -- + ------------------------ + + procedure Expand_N_Allocator (N : Node_Id) is + PtrT : constant Entity_Id := Etype (N); + Dtyp : constant Entity_Id := Designated_Type (PtrT); + Etyp : constant Entity_Id := Etype (Expression (N)); + Loc : constant Source_Ptr := Sloc (N); + Desig : Entity_Id; + Temp : Entity_Id; + Nod : Node_Id; + + procedure Complete_Coextension_Finalization; + -- Generate finalization calls for all nested coextensions of N. This + -- routine may allocate list controllers if necessary. + + procedure Rewrite_Coextension (N : Node_Id); + -- Static coextensions have the same lifetime as the entity they + -- constrain. Such occurrences can be rewritten as aliased objects + -- and their unrestricted access used instead of the coextension. + + --------------------------------------- + -- Complete_Coextension_Finalization -- + --------------------------------------- + + procedure Complete_Coextension_Finalization is + Coext : Node_Id; + Coext_Elmt : Elmt_Id; + Flist : Node_Id; + Ref : Node_Id; + + function Inside_A_Return_Statement (N : Node_Id) return Boolean; + -- Determine whether node N is part of a return statement + + function Needs_Initialization_Call (N : Node_Id) return Boolean; + -- Determine whether node N is a subtype indicator allocator which + -- acts a coextension. Such coextensions need initialization. + + ------------------------------- + -- Inside_A_Return_Statement -- + ------------------------------- + + function Inside_A_Return_Statement (N : Node_Id) return Boolean is + P : Node_Id; + + begin + P := Parent (N); + while Present (P) loop + if Nkind_In + (P, N_Extended_Return_Statement, N_Simple_Return_Statement) + then + return True; + + -- Stop the traversal when we reach a subprogram body + + elsif Nkind (P) = N_Subprogram_Body then + return False; + end if; + + P := Parent (P); + end loop; + + return False; + end Inside_A_Return_Statement; + + ------------------------------- + -- Needs_Initialization_Call -- + ------------------------------- + + function Needs_Initialization_Call (N : Node_Id) return Boolean is + Obj_Decl : Node_Id; + + begin + if Nkind (N) = N_Explicit_Dereference + and then Nkind (Prefix (N)) = N_Identifier + and then Nkind (Parent (Entity (Prefix (N)))) = + N_Object_Declaration + then + Obj_Decl := Parent (Entity (Prefix (N))); + + return + Present (Expression (Obj_Decl)) + and then Nkind (Expression (Obj_Decl)) = N_Allocator + and then Nkind (Expression (Expression (Obj_Decl))) /= + N_Qualified_Expression; + end if; + + return False; + end Needs_Initialization_Call; + + -- Start of processing for Complete_Coextension_Finalization + + begin + -- When a coextension root is inside a return statement, we need to + -- use the finalization chain of the function's scope. This does not + -- apply for controlled named access types because in those cases we + -- can use the finalization chain of the type itself. + + if Inside_A_Return_Statement (N) + and then + (Ekind (PtrT) = E_Anonymous_Access_Type + or else + (Ekind (PtrT) = E_Access_Type + and then No (Associated_Final_Chain (PtrT)))) + then + declare + Decl : Node_Id; + Outer_S : Entity_Id; + S : Entity_Id := Current_Scope; + + begin + while Present (S) and then S /= Standard_Standard loop + if Ekind (S) = E_Function then + Outer_S := Scope (S); + + -- Retrieve the declaration of the body + + Decl := Parent (Parent ( + Corresponding_Body (Parent (Parent (S))))); + exit; + end if; + + S := Scope (S); + end loop; + + -- Push the scope of the function body since we are inserting + -- the list before the body, but we are currently in the body + -- itself. Override the finalization list of PtrT since the + -- finalization context is now different. + + Push_Scope (Outer_S); + Build_Final_List (Decl, PtrT); + Pop_Scope; + end; + + -- The root allocator may not be controlled, but it still needs a + -- finalization list for all nested coextensions. + + elsif No (Associated_Final_Chain (PtrT)) then + Build_Final_List (N, PtrT); + end if; + + Flist := + Make_Selected_Component (Loc, + Prefix => + New_Reference_To (Associated_Final_Chain (PtrT), Loc), + Selector_Name => + Make_Identifier (Loc, Name_F)); + + Coext_Elmt := First_Elmt (Coextensions (N)); + while Present (Coext_Elmt) loop + Coext := Node (Coext_Elmt); + + -- Generate: + -- typ! (coext.all) + + if Nkind (Coext) = N_Identifier then + Ref := + Make_Unchecked_Type_Conversion (Loc, + Subtype_Mark => New_Reference_To (Etype (Coext), Loc), + Expression => + Make_Explicit_Dereference (Loc, + Prefix => New_Copy_Tree (Coext))); + else + Ref := New_Copy_Tree (Coext); + end if; + + -- No initialization call if not allowed + + Check_Restriction (No_Default_Initialization, N); + + if not Restriction_Active (No_Default_Initialization) then + + -- Generate: + -- initialize (Ref) + -- attach_to_final_list (Ref, Flist, 2) + + if Needs_Initialization_Call (Coext) then + Insert_Actions (N, + Make_Init_Call ( + Ref => Ref, + Typ => Etype (Coext), + Flist_Ref => Flist, + With_Attach => Make_Integer_Literal (Loc, Uint_2))); + + -- Generate: + -- attach_to_final_list (Ref, Flist, 2) + + else + Insert_Action (N, + Make_Attach_Call ( + Obj_Ref => Ref, + Flist_Ref => New_Copy_Tree (Flist), + With_Attach => Make_Integer_Literal (Loc, Uint_2))); + end if; + end if; + + Next_Elmt (Coext_Elmt); + end loop; + end Complete_Coextension_Finalization; + + ------------------------- + -- Rewrite_Coextension -- + ------------------------- + + procedure Rewrite_Coextension (N : Node_Id) is + Temp : constant Node_Id := + Make_Defining_Identifier (Loc, + New_Internal_Name ('C')); + + -- Generate: + -- Cnn : aliased Etyp; + + Decl : constant Node_Id := + Make_Object_Declaration (Loc, + Defining_Identifier => Temp, + Aliased_Present => True, + Object_Definition => + New_Occurrence_Of (Etyp, Loc)); + Nod : Node_Id; + + begin + if Nkind (Expression (N)) = N_Qualified_Expression then + Set_Expression (Decl, Expression (Expression (N))); + end if; + + -- Find the proper insertion node for the declaration + + Nod := Parent (N); + while Present (Nod) loop + exit when Nkind (Nod) in N_Statement_Other_Than_Procedure_Call + or else Nkind (Nod) = N_Procedure_Call_Statement + or else Nkind (Nod) in N_Declaration; + Nod := Parent (Nod); + end loop; + + Insert_Before (Nod, Decl); + Analyze (Decl); + + Rewrite (N, + Make_Attribute_Reference (Loc, + Prefix => New_Occurrence_Of (Temp, Loc), + Attribute_Name => Name_Unrestricted_Access)); + + Analyze_And_Resolve (N, PtrT); + end Rewrite_Coextension; + + -- Start of processing for Expand_N_Allocator + + begin + -- RM E.2.3(22). We enforce that the expected type of an allocator + -- shall not be a remote access-to-class-wide-limited-private type + + -- Why is this being done at expansion time, seems clearly wrong ??? + + Validate_Remote_Access_To_Class_Wide_Type (N); + + -- Set the Storage Pool + + Set_Storage_Pool (N, Associated_Storage_Pool (Root_Type (PtrT))); + + if Present (Storage_Pool (N)) then + if Is_RTE (Storage_Pool (N), RE_SS_Pool) then + if VM_Target = No_VM then + Set_Procedure_To_Call (N, RTE (RE_SS_Allocate)); + end if; + + elsif Is_Class_Wide_Type (Etype (Storage_Pool (N))) then + Set_Procedure_To_Call (N, RTE (RE_Allocate_Any)); + + else + Set_Procedure_To_Call (N, + Find_Prim_Op (Etype (Storage_Pool (N)), Name_Allocate)); + end if; + end if; + + -- Under certain circumstances we can replace an allocator by an access + -- to statically allocated storage. The conditions, as noted in AARM + -- 3.10 (10c) are as follows: + + -- Size and initial value is known at compile time + -- Access type is access-to-constant + + -- The allocator is not part of a constraint on a record component, + -- because in that case the inserted actions are delayed until the + -- record declaration is fully analyzed, which is too late for the + -- analysis of the rewritten allocator. + + if Is_Access_Constant (PtrT) + and then Nkind (Expression (N)) = N_Qualified_Expression + and then Compile_Time_Known_Value (Expression (Expression (N))) + and then Size_Known_At_Compile_Time (Etype (Expression + (Expression (N)))) + and then not Is_Record_Type (Current_Scope) + then + -- Here we can do the optimization. For the allocator + + -- new x'(y) + + -- We insert an object declaration + + -- Tnn : aliased x := y; + + -- and replace the allocator by Tnn'Unrestricted_Access. Tnn is + -- marked as requiring static allocation. + + Temp := + Make_Defining_Identifier (Loc, New_Internal_Name ('T')); + + Desig := Subtype_Mark (Expression (N)); + + -- If context is constrained, use constrained subtype directly, + -- so that the constant is not labelled as having a nominally + -- unconstrained subtype. + + if Entity (Desig) = Base_Type (Dtyp) then + Desig := New_Occurrence_Of (Dtyp, Loc); + end if; + + Insert_Action (N, + Make_Object_Declaration (Loc, + Defining_Identifier => Temp, + Aliased_Present => True, + Constant_Present => Is_Access_Constant (PtrT), + Object_Definition => Desig, + Expression => Expression (Expression (N)))); + + Rewrite (N, + Make_Attribute_Reference (Loc, + Prefix => New_Occurrence_Of (Temp, Loc), + Attribute_Name => Name_Unrestricted_Access)); + + Analyze_And_Resolve (N, PtrT); + + -- We set the variable as statically allocated, since we don't want + -- it going on the stack of the current procedure! + + Set_Is_Statically_Allocated (Temp); + return; + end if; + + -- Same if the allocator is an access discriminant for a local object: + -- instead of an allocator we create a local value and constrain the + -- the enclosing object with the corresponding access attribute. + + if Is_Static_Coextension (N) then + Rewrite_Coextension (N); + return; + end if; + + -- The current allocator creates an object which may contain nested + -- coextensions. Use the current allocator's finalization list to + -- generate finalization call for all nested coextensions. + + if Is_Coextension_Root (N) then + Complete_Coextension_Finalization; + end if; + + -- Handle case of qualified expression (other than optimization above) + + if Nkind (Expression (N)) = N_Qualified_Expression then + Expand_Allocator_Expression (N); + return; + end if; + + -- If the allocator is for a type which requires initialization, and + -- there is no initial value (i.e. operand is a subtype indication + -- rather than a qualified expression), then we must generate a call to + -- the initialization routine using an expressions action node: + + -- [Pnnn : constant ptr_T := new (T); Init (Pnnn.all,...); Pnnn] + + -- Here ptr_T is the pointer type for the allocator, and T is the + -- subtype of the allocator. A special case arises if the designated + -- type of the access type is a task or contains tasks. In this case + -- the call to Init (Temp.all ...) is replaced by code that ensures + -- that tasks get activated (see Exp_Ch9.Build_Task_Allocate_Block + -- for details). In addition, if the type T is a task T, then the + -- first argument to Init must be converted to the task record type. + + declare + T : constant Entity_Id := Entity (Expression (N)); + Init : Entity_Id; + Arg1 : Node_Id; + Args : List_Id; + Decls : List_Id; + Decl : Node_Id; + Discr : Elmt_Id; + Flist : Node_Id; + Temp_Decl : Node_Id; + Temp_Type : Entity_Id; + Attach_Level : Uint; + + begin + if No_Initialization (N) then + null; + + -- Case of no initialization procedure present + + elsif not Has_Non_Null_Base_Init_Proc (T) then + + -- Case of simple initialization required + + if Needs_Simple_Initialization (T) then + Check_Restriction (No_Default_Initialization, N); + Rewrite (Expression (N), + Make_Qualified_Expression (Loc, + Subtype_Mark => New_Occurrence_Of (T, Loc), + Expression => Get_Simple_Init_Val (T, N))); + + Analyze_And_Resolve (Expression (Expression (N)), T); + Analyze_And_Resolve (Expression (N), T); + Set_Paren_Count (Expression (Expression (N)), 1); + Expand_N_Allocator (N); + + -- No initialization required + + else + null; + end if; + + -- Case of initialization procedure present, must be called + + else + Check_Restriction (No_Default_Initialization, N); + + if not Restriction_Active (No_Default_Initialization) then + Init := Base_Init_Proc (T); + Nod := N; + Temp := Make_Defining_Identifier (Loc, New_Internal_Name ('P')); + + -- Construct argument list for the initialization routine call + + Arg1 := + Make_Explicit_Dereference (Loc, + Prefix => New_Reference_To (Temp, Loc)); + Set_Assignment_OK (Arg1); + Temp_Type := PtrT; + + -- The initialization procedure expects a specific type. if the + -- context is access to class wide, indicate that the object + -- being allocated has the right specific type. + + if Is_Class_Wide_Type (Dtyp) then + Arg1 := Unchecked_Convert_To (T, Arg1); + end if; + + -- If designated type is a concurrent type or if it is private + -- type whose definition is a concurrent type, the first + -- argument in the Init routine has to be unchecked conversion + -- to the corresponding record type. If the designated type is + -- a derived type, we also convert the argument to its root + -- type. + + if Is_Concurrent_Type (T) then + Arg1 := + Unchecked_Convert_To (Corresponding_Record_Type (T), Arg1); + + elsif Is_Private_Type (T) + and then Present (Full_View (T)) + and then Is_Concurrent_Type (Full_View (T)) + then + Arg1 := + Unchecked_Convert_To + (Corresponding_Record_Type (Full_View (T)), Arg1); + + elsif Etype (First_Formal (Init)) /= Base_Type (T) then + declare + Ftyp : constant Entity_Id := Etype (First_Formal (Init)); + begin + Arg1 := OK_Convert_To (Etype (Ftyp), Arg1); + Set_Etype (Arg1, Ftyp); + end; + end if; + + Args := New_List (Arg1); + + -- For the task case, pass the Master_Id of the access type as + -- the value of the _Master parameter, and _Chain as the value + -- of the _Chain parameter (_Chain will be defined as part of + -- the generated code for the allocator). + + -- In Ada 2005, the context may be a function that returns an + -- anonymous access type. In that case the Master_Id has been + -- created when expanding the function declaration. + + if Has_Task (T) then + if No (Master_Id (Base_Type (PtrT))) then + + -- If we have a non-library level task with restriction + -- No_Task_Hierarchy set, then no point in expanding. + + if not Is_Library_Level_Entity (T) + and then Restriction_Active (No_Task_Hierarchy) + then + return; + end if; + + -- The designated type was an incomplete type, and the + -- access type did not get expanded. Salvage it now. + + pragma Assert (Present (Parent (Base_Type (PtrT)))); + Expand_N_Full_Type_Declaration + (Parent (Base_Type (PtrT))); + end if; + + -- If the context of the allocator is a declaration or an + -- assignment, we can generate a meaningful image for it, + -- even though subsequent assignments might remove the + -- connection between task and entity. We build this image + -- when the left-hand side is a simple variable, a simple + -- indexed assignment or a simple selected component. + + if Nkind (Parent (N)) = N_Assignment_Statement then + declare + Nam : constant Node_Id := Name (Parent (N)); + + begin + if Is_Entity_Name (Nam) then + Decls := + Build_Task_Image_Decls + (Loc, + New_Occurrence_Of + (Entity (Nam), Sloc (Nam)), T); + + elsif Nkind_In + (Nam, N_Indexed_Component, N_Selected_Component) + and then Is_Entity_Name (Prefix (Nam)) + then + Decls := + Build_Task_Image_Decls + (Loc, Nam, Etype (Prefix (Nam))); + else + Decls := Build_Task_Image_Decls (Loc, T, T); + end if; + end; + + elsif Nkind (Parent (N)) = N_Object_Declaration then + Decls := + Build_Task_Image_Decls + (Loc, Defining_Identifier (Parent (N)), T); + + else + Decls := Build_Task_Image_Decls (Loc, T, T); + end if; + + Append_To (Args, + New_Reference_To + (Master_Id (Base_Type (Root_Type (PtrT))), Loc)); + Append_To (Args, Make_Identifier (Loc, Name_uChain)); + + Decl := Last (Decls); + Append_To (Args, + New_Occurrence_Of (Defining_Identifier (Decl), Loc)); + + -- Has_Task is false, Decls not used + + else + Decls := No_List; + end if; + + -- Add discriminants if discriminated type + + declare + Dis : Boolean := False; + Typ : Entity_Id; + + begin + if Has_Discriminants (T) then + Dis := True; + Typ := T; + + elsif Is_Private_Type (T) + and then Present (Full_View (T)) + and then Has_Discriminants (Full_View (T)) + then + Dis := True; + Typ := Full_View (T); + end if; + + if Dis then + + -- If the allocated object will be constrained by the + -- default values for discriminants, then build a subtype + -- with those defaults, and change the allocated subtype + -- to that. Note that this happens in fewer cases in Ada + -- 2005 (AI-363). + + if not Is_Constrained (Typ) + and then Present (Discriminant_Default_Value + (First_Discriminant (Typ))) + and then (Ada_Version < Ada_05 + or else + not Has_Constrained_Partial_View (Typ)) + then + Typ := Build_Default_Subtype (Typ, N); + Set_Expression (N, New_Reference_To (Typ, Loc)); + end if; + + Discr := First_Elmt (Discriminant_Constraint (Typ)); + while Present (Discr) loop + Nod := Node (Discr); + Append (New_Copy_Tree (Node (Discr)), Args); + + -- AI-416: when the discriminant constraint is an + -- anonymous access type make sure an accessibility + -- check is inserted if necessary (3.10.2(22.q/2)) + + if Ada_Version >= Ada_05 + and then + Ekind (Etype (Nod)) = E_Anonymous_Access_Type + then + Apply_Accessibility_Check + (Nod, Typ, Insert_Node => Nod); + end if; + + Next_Elmt (Discr); + end loop; + end if; + end; + + -- We set the allocator as analyzed so that when we analyze the + -- expression actions node, we do not get an unwanted recursive + -- expansion of the allocator expression. + + Set_Analyzed (N, True); + Nod := Relocate_Node (N); + + -- Here is the transformation: + -- input: new T + -- output: Temp : constant ptr_T := new T; + -- Init (Temp.all, ...); + -- <CTRL> Attach_To_Final_List (Finalizable (Temp.all)); + -- <CTRL> Initialize (Finalizable (Temp.all)); + + -- Here ptr_T is the pointer type for the allocator, and is the + -- subtype of the allocator. + + Temp_Decl := + Make_Object_Declaration (Loc, + Defining_Identifier => Temp, + Constant_Present => True, + Object_Definition => New_Reference_To (Temp_Type, Loc), + Expression => Nod); + + Set_Assignment_OK (Temp_Decl); + Insert_Action (N, Temp_Decl, Suppress => All_Checks); + + -- If the designated type is a task type or contains tasks, + -- create block to activate created tasks, and insert + -- declaration for Task_Image variable ahead of call. + + if Has_Task (T) then + declare + L : constant List_Id := New_List; + Blk : Node_Id; + begin + Build_Task_Allocate_Block (L, Nod, Args); + Blk := Last (L); + Insert_List_Before (First (Declarations (Blk)), Decls); + Insert_Actions (N, L); + end; + + else + Insert_Action (N, + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To (Init, Loc), + Parameter_Associations => Args)); + end if; + + if Needs_Finalization (T) then + + -- Postpone the generation of a finalization call for the + -- current allocator if it acts as a coextension. + + if Is_Dynamic_Coextension (N) then + if No (Coextensions (N)) then + Set_Coextensions (N, New_Elmt_List); + end if; + + Append_Elmt (New_Copy_Tree (Arg1), Coextensions (N)); + + else + Flist := + Get_Allocator_Final_List (N, Base_Type (T), PtrT); + + -- Anonymous access types created for access parameters + -- are attached to an explicitly constructed controller, + -- which ensures that they can be finalized properly, + -- even if their deallocation might not happen. The list + -- associated with the controller is doubly-linked. For + -- other anonymous access types, the object may end up + -- on the global final list which is singly-linked. + -- Work needed for access discriminants in Ada 2005 ??? + + if Ekind (PtrT) = E_Anonymous_Access_Type + and then + Nkind (Associated_Node_For_Itype (PtrT)) + not in N_Subprogram_Specification + then + Attach_Level := Uint_1; + else + Attach_Level := Uint_2; + end if; + + Insert_Actions (N, + Make_Init_Call ( + Ref => New_Copy_Tree (Arg1), + Typ => T, + Flist_Ref => Flist, + With_Attach => Make_Integer_Literal (Loc, + Intval => Attach_Level))); + end if; + end if; + + Rewrite (N, New_Reference_To (Temp, Loc)); + Analyze_And_Resolve (N, PtrT); + end if; + end if; + end; + + -- Ada 2005 (AI-251): If the allocator is for a class-wide interface + -- object that has been rewritten as a reference, we displace "this" + -- to reference properly its secondary dispatch table. + + if Nkind (N) = N_Identifier + and then Is_Interface (Dtyp) + then + Displace_Allocator_Pointer (N); + end if; + + exception + when RE_Not_Available => + return; + end Expand_N_Allocator; + + ----------------------- + -- Expand_N_And_Then -- + ----------------------- + + -- Expand into conditional expression if Actions present, and also deal + -- with optimizing case of arguments being True or False. + + procedure Expand_N_And_Then (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Typ : constant Entity_Id := Etype (N); + Left : constant Node_Id := Left_Opnd (N); + Right : constant Node_Id := Right_Opnd (N); + Actlist : List_Id; + + begin + -- Deal with non-standard booleans + + if Is_Boolean_Type (Typ) then + Adjust_Condition (Left); + Adjust_Condition (Right); + Set_Etype (N, Standard_Boolean); + end if; + + -- Check for cases where left argument is known to be True or False + + if Compile_Time_Known_Value (Left) then + + -- If left argument is True, change (True and then Right) to Right. + -- Any actions associated with Right will be executed unconditionally + -- and can thus be inserted into the tree unconditionally. + + if Expr_Value_E (Left) = Standard_True then + if Present (Actions (N)) then + Insert_Actions (N, Actions (N)); + end if; + + Rewrite (N, Right); + + -- If left argument is False, change (False and then Right) to False. + -- In this case we can forget the actions associated with Right, + -- since they will never be executed. + + else pragma Assert (Expr_Value_E (Left) = Standard_False); + Kill_Dead_Code (Right); + Kill_Dead_Code (Actions (N)); + Rewrite (N, New_Occurrence_Of (Standard_False, Loc)); + end if; + + Adjust_Result_Type (N, Typ); + return; + end if; + + -- If Actions are present, we expand + + -- left and then right + + -- into + + -- if left then right else false end + + -- with the actions becoming the Then_Actions of the conditional + -- expression. This conditional expression is then further expanded + -- (and will eventually disappear) + + if Present (Actions (N)) then + Actlist := Actions (N); + Rewrite (N, + Make_Conditional_Expression (Loc, + Expressions => New_List ( + Left, + Right, + New_Occurrence_Of (Standard_False, Loc)))); + + Set_Then_Actions (N, Actlist); + Analyze_And_Resolve (N, Standard_Boolean); + Adjust_Result_Type (N, Typ); + return; + end if; + + -- No actions present, check for cases of right argument True/False + + if Compile_Time_Known_Value (Right) then + + -- Change (Left and then True) to Left. Note that we know there are + -- no actions associated with the True operand, since we just checked + -- for this case above. + + if Expr_Value_E (Right) = Standard_True then + Rewrite (N, Left); + + -- Change (Left and then False) to False, making sure to preserve any + -- side effects associated with the Left operand. + + else pragma Assert (Expr_Value_E (Right) = Standard_False); + Remove_Side_Effects (Left); + Rewrite + (N, New_Occurrence_Of (Standard_False, Loc)); + end if; + end if; + + Adjust_Result_Type (N, Typ); + end Expand_N_And_Then; + + ------------------------------------- + -- Expand_N_Conditional_Expression -- + ------------------------------------- + + -- Expand into expression actions if then/else actions present + + procedure Expand_N_Conditional_Expression (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Cond : constant Node_Id := First (Expressions (N)); + Thenx : constant Node_Id := Next (Cond); + Elsex : constant Node_Id := Next (Thenx); + Typ : constant Entity_Id := Etype (N); + Cnn : Entity_Id; + New_If : Node_Id; + + begin + -- If either then or else actions are present, then given: + + -- if cond then then-expr else else-expr end + + -- we insert the following sequence of actions (using Insert_Actions): + + -- Cnn : typ; + -- if cond then + -- <<then actions>> + -- Cnn := then-expr; + -- else + -- <<else actions>> + -- Cnn := else-expr + -- end if; + + -- and replace the conditional expression by a reference to Cnn + + if Present (Then_Actions (N)) or else Present (Else_Actions (N)) then + Cnn := Make_Defining_Identifier (Loc, New_Internal_Name ('C')); + + New_If := + Make_Implicit_If_Statement (N, + Condition => Relocate_Node (Cond), + + Then_Statements => New_List ( + Make_Assignment_Statement (Sloc (Thenx), + Name => New_Occurrence_Of (Cnn, Sloc (Thenx)), + Expression => Relocate_Node (Thenx))), + + Else_Statements => New_List ( + Make_Assignment_Statement (Sloc (Elsex), + Name => New_Occurrence_Of (Cnn, Sloc (Elsex)), + Expression => Relocate_Node (Elsex)))); + + Set_Assignment_OK (Name (First (Then_Statements (New_If)))); + Set_Assignment_OK (Name (First (Else_Statements (New_If)))); + + if Present (Then_Actions (N)) then + Insert_List_Before + (First (Then_Statements (New_If)), Then_Actions (N)); + end if; + + if Present (Else_Actions (N)) then + Insert_List_Before + (First (Else_Statements (New_If)), Else_Actions (N)); + end if; + + Rewrite (N, New_Occurrence_Of (Cnn, Loc)); + + Insert_Action (N, + Make_Object_Declaration (Loc, + Defining_Identifier => Cnn, + Object_Definition => New_Occurrence_Of (Typ, Loc))); + + Insert_Action (N, New_If); + Analyze_And_Resolve (N, Typ); + end if; + end Expand_N_Conditional_Expression; + + ----------------------------------- + -- Expand_N_Explicit_Dereference -- + ----------------------------------- + + procedure Expand_N_Explicit_Dereference (N : Node_Id) is + begin + -- Insert explicit dereference call for the checked storage pool case + + Insert_Dereference_Action (Prefix (N)); + end Expand_N_Explicit_Dereference; + + ----------------- + -- Expand_N_In -- + ----------------- + + procedure Expand_N_In (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Rtyp : constant Entity_Id := Etype (N); + Lop : constant Node_Id := Left_Opnd (N); + Rop : constant Node_Id := Right_Opnd (N); + Static : constant Boolean := Is_OK_Static_Expression (N); + + procedure Substitute_Valid_Check; + -- Replaces node N by Lop'Valid. This is done when we have an explicit + -- test for the left operand being in range of its subtype. + + ---------------------------- + -- Substitute_Valid_Check -- + ---------------------------- + + procedure Substitute_Valid_Check is + begin + Rewrite (N, + Make_Attribute_Reference (Loc, + Prefix => Relocate_Node (Lop), + Attribute_Name => Name_Valid)); + + Analyze_And_Resolve (N, Rtyp); + + Error_Msg_N ("?explicit membership test may be optimized away", N); + Error_Msg_N ("\?use ''Valid attribute instead", N); + return; + end Substitute_Valid_Check; + + -- Start of processing for Expand_N_In + + begin + -- Check case of explicit test for an expression in range of its + -- subtype. This is suspicious usage and we replace it with a 'Valid + -- test and give a warning. + + if Is_Scalar_Type (Etype (Lop)) + and then Nkind (Rop) in N_Has_Entity + and then Etype (Lop) = Entity (Rop) + and then Comes_From_Source (N) + and then VM_Target = No_VM + then + Substitute_Valid_Check; + return; + end if; + + -- Do validity check on operands + + if Validity_Checks_On and Validity_Check_Operands then + Ensure_Valid (Left_Opnd (N)); + Validity_Check_Range (Right_Opnd (N)); + end if; + + -- Case of explicit range + + if Nkind (Rop) = N_Range then + declare + Lo : constant Node_Id := Low_Bound (Rop); + Hi : constant Node_Id := High_Bound (Rop); + + Ltyp : constant Entity_Id := Etype (Lop); + + Lo_Orig : constant Node_Id := Original_Node (Lo); + Hi_Orig : constant Node_Id := Original_Node (Hi); + + Lcheck : constant Compare_Result := + Compile_Time_Compare (Lop, Lo, Assume_Valid => True); + Ucheck : constant Compare_Result := + Compile_Time_Compare (Lop, Hi, Assume_Valid => True); + + Warn1 : constant Boolean := + Constant_Condition_Warnings + and then Comes_From_Source (N); + -- This must be true for any of the optimization warnings, we + -- clearly want to give them only for source with the flag on. + + Warn2 : constant Boolean := + Warn1 + and then Nkind (Original_Node (Rop)) = N_Range + and then Is_Integer_Type (Etype (Lo)); + -- For the case where only one bound warning is elided, we also + -- insist on an explicit range and an integer type. The reason is + -- that the use of enumeration ranges including an end point is + -- common, as is the use of a subtype name, one of whose bounds + -- is the same as the type of the expression. + + begin + -- If test is explicit x'first .. x'last, replace by valid check + + if Is_Scalar_Type (Ltyp) + and then Nkind (Lo_Orig) = N_Attribute_Reference + and then Attribute_Name (Lo_Orig) = Name_First + and then Nkind (Prefix (Lo_Orig)) in N_Has_Entity + and then Entity (Prefix (Lo_Orig)) = Ltyp + and then Nkind (Hi_Orig) = N_Attribute_Reference + and then Attribute_Name (Hi_Orig) = Name_Last + and then Nkind (Prefix (Hi_Orig)) in N_Has_Entity + and then Entity (Prefix (Hi_Orig)) = Ltyp + and then Comes_From_Source (N) + and then VM_Target = No_VM + then + Substitute_Valid_Check; + return; + end if; + + -- If bounds of type are known at compile time, and the end points + -- are known at compile time and identical, this is another case + -- for substituting a valid test. We only do this for discrete + -- types, since it won't arise in practice for float types. + + if Comes_From_Source (N) + and then Is_Discrete_Type (Ltyp) + and then Compile_Time_Known_Value (Type_High_Bound (Ltyp)) + and then Compile_Time_Known_Value (Type_Low_Bound (Ltyp)) + and then Compile_Time_Known_Value (Lo) + and then Compile_Time_Known_Value (Hi) + and then Expr_Value (Type_High_Bound (Ltyp)) = Expr_Value (Hi) + and then Expr_Value (Type_Low_Bound (Ltyp)) = Expr_Value (Lo) + + -- Kill warnings in instances, since they may be cases where we + -- have a test in the generic that makes sense with some types + -- and not with other types. + + and then not In_Instance + then + Substitute_Valid_Check; + return; + end if; + + -- If we have an explicit range, do a bit of optimization based + -- on range analysis (we may be able to kill one or both checks). + + -- If either check is known to fail, replace result by False since + -- the other check does not matter. Preserve the static flag for + -- legality checks, because we are constant-folding beyond RM 4.9. + + if Lcheck = LT or else Ucheck = GT then + if Warn1 and then not In_Instance then + Error_Msg_N ("?range test optimized away", N); + Error_Msg_N ("\?value is known to be out of range", N); + end if; + + Rewrite (N, + New_Reference_To (Standard_False, Loc)); + Analyze_And_Resolve (N, Rtyp); + Set_Is_Static_Expression (N, Static); + + return; + + -- If both checks are known to succeed, replace result by True, + -- since we know we are in range. + + elsif Lcheck in Compare_GE and then Ucheck in Compare_LE then + if Warn1 and then not In_Instance then + Error_Msg_N ("?range test optimized away", N); + Error_Msg_N ("\?value is known to be in range", N); + end if; + + Rewrite (N, + New_Reference_To (Standard_True, Loc)); + Analyze_And_Resolve (N, Rtyp); + Set_Is_Static_Expression (N, Static); + + return; + + -- If lower bound check succeeds and upper bound check is not + -- known to succeed or fail, then replace the range check with + -- a comparison against the upper bound. + + elsif Lcheck in Compare_GE then + if Warn2 and then not In_Instance then + Error_Msg_N ("?lower bound test optimized away", Lo); + Error_Msg_N ("\?value is known to be in range", Lo); + end if; + + Rewrite (N, + Make_Op_Le (Loc, + Left_Opnd => Lop, + Right_Opnd => High_Bound (Rop))); + Analyze_And_Resolve (N, Rtyp); + + return; + + -- If upper bound check succeeds and lower bound check is not + -- known to succeed or fail, then replace the range check with + -- a comparison against the lower bound. + + elsif Ucheck in Compare_LE then + if Warn2 and then not In_Instance then + Error_Msg_N ("?upper bound test optimized away", Hi); + Error_Msg_N ("\?value is known to be in range", Hi); + end if; + + Rewrite (N, + Make_Op_Ge (Loc, + Left_Opnd => Lop, + Right_Opnd => Low_Bound (Rop))); + Analyze_And_Resolve (N, Rtyp); + + return; + end if; + end; + + -- For all other cases of an explicit range, nothing to be done + + return; + + -- Here right operand is a subtype mark + + else + declare + Typ : Entity_Id := Etype (Rop); + Is_Acc : constant Boolean := Is_Access_Type (Typ); + Obj : Node_Id := Lop; + Cond : Node_Id := Empty; + + begin + Remove_Side_Effects (Obj); + + -- For tagged type, do tagged membership operation + + if Is_Tagged_Type (Typ) then + + -- No expansion will be performed when VM_Target, as the VM + -- back-ends will handle the membership tests directly (tags + -- are not explicitly represented in Java objects, so the + -- normal tagged membership expansion is not what we want). + + if VM_Target = No_VM then + Rewrite (N, Tagged_Membership (N)); + Analyze_And_Resolve (N, Rtyp); + end if; + + return; + + -- If type is scalar type, rewrite as x in t'first .. t'last. + -- This reason we do this is that the bounds may have the wrong + -- type if they come from the original type definition. + + elsif Is_Scalar_Type (Typ) then + Rewrite (Rop, + Make_Range (Loc, + Low_Bound => + Make_Attribute_Reference (Loc, + Attribute_Name => Name_First, + Prefix => New_Reference_To (Typ, Loc)), + + High_Bound => + Make_Attribute_Reference (Loc, + Attribute_Name => Name_Last, + Prefix => New_Reference_To (Typ, Loc)))); + Analyze_And_Resolve (N, Rtyp); + return; + + -- Ada 2005 (AI-216): Program_Error is raised when evaluating + -- a membership test if the subtype mark denotes a constrained + -- Unchecked_Union subtype and the expression lacks inferable + -- discriminants. + + elsif Is_Unchecked_Union (Base_Type (Typ)) + and then Is_Constrained (Typ) + and then not Has_Inferable_Discriminants (Lop) + then + Insert_Action (N, + Make_Raise_Program_Error (Loc, + Reason => PE_Unchecked_Union_Restriction)); + + -- Prevent Gigi from generating incorrect code by rewriting + -- the test as a standard False. + + Rewrite (N, + New_Occurrence_Of (Standard_False, Loc)); + + return; + end if; + + -- Here we have a non-scalar type + + if Is_Acc then + Typ := Designated_Type (Typ); + end if; + + if not Is_Constrained (Typ) then + Rewrite (N, + New_Reference_To (Standard_True, Loc)); + Analyze_And_Resolve (N, Rtyp); + + -- For the constrained array case, we have to check the subscripts + -- for an exact match if the lengths are non-zero (the lengths + -- must match in any case). + + elsif Is_Array_Type (Typ) then + + Check_Subscripts : declare + function Construct_Attribute_Reference + (E : Node_Id; + Nam : Name_Id; + Dim : Nat) return Node_Id; + -- Build attribute reference E'Nam(Dim) + + ----------------------------------- + -- Construct_Attribute_Reference -- + ----------------------------------- + + function Construct_Attribute_Reference + (E : Node_Id; + Nam : Name_Id; + Dim : Nat) return Node_Id + is + begin + return + Make_Attribute_Reference (Loc, + Prefix => E, + Attribute_Name => Nam, + Expressions => New_List ( + Make_Integer_Literal (Loc, Dim))); + end Construct_Attribute_Reference; + + -- Start processing for Check_Subscripts + + begin + for J in 1 .. Number_Dimensions (Typ) loop + Evolve_And_Then (Cond, + Make_Op_Eq (Loc, + Left_Opnd => + Construct_Attribute_Reference + (Duplicate_Subexpr_No_Checks (Obj), + Name_First, J), + Right_Opnd => + Construct_Attribute_Reference + (New_Occurrence_Of (Typ, Loc), Name_First, J))); + + Evolve_And_Then (Cond, + Make_Op_Eq (Loc, + Left_Opnd => + Construct_Attribute_Reference + (Duplicate_Subexpr_No_Checks (Obj), + Name_Last, J), + Right_Opnd => + Construct_Attribute_Reference + (New_Occurrence_Of (Typ, Loc), Name_Last, J))); + end loop; + + if Is_Acc then + Cond := + Make_Or_Else (Loc, + Left_Opnd => + Make_Op_Eq (Loc, + Left_Opnd => Obj, + Right_Opnd => Make_Null (Loc)), + Right_Opnd => Cond); + end if; + + Rewrite (N, Cond); + Analyze_And_Resolve (N, Rtyp); + end Check_Subscripts; + + -- These are the cases where constraint checks may be required, + -- e.g. records with possible discriminants + + else + -- Expand the test into a series of discriminant comparisons. + -- The expression that is built is the negation of the one that + -- is used for checking discriminant constraints. + + Obj := Relocate_Node (Left_Opnd (N)); + + if Has_Discriminants (Typ) then + Cond := Make_Op_Not (Loc, + Right_Opnd => Build_Discriminant_Checks (Obj, Typ)); + + if Is_Acc then + Cond := Make_Or_Else (Loc, + Left_Opnd => + Make_Op_Eq (Loc, + Left_Opnd => Obj, + Right_Opnd => Make_Null (Loc)), + Right_Opnd => Cond); + end if; + + else + Cond := New_Occurrence_Of (Standard_True, Loc); + end if; + + Rewrite (N, Cond); + Analyze_And_Resolve (N, Rtyp); + end if; + end; + end if; + end Expand_N_In; + + -------------------------------- + -- Expand_N_Indexed_Component -- + -------------------------------- + + procedure Expand_N_Indexed_Component (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Typ : constant Entity_Id := Etype (N); + P : constant Node_Id := Prefix (N); + T : constant Entity_Id := Etype (P); + + begin + -- A special optimization, if we have an indexed component that is + -- selecting from a slice, then we can eliminate the slice, since, for + -- example, x (i .. j)(k) is identical to x(k). The only difference is + -- the range check required by the slice. The range check for the slice + -- itself has already been generated. The range check for the + -- subscripting operation is ensured by converting the subject to + -- the subtype of the slice. + + -- This optimization not only generates better code, avoiding slice + -- messing especially in the packed case, but more importantly bypasses + -- some problems in handling this peculiar case, for example, the issue + -- of dealing specially with object renamings. + + if Nkind (P) = N_Slice then + Rewrite (N, + Make_Indexed_Component (Loc, + Prefix => Prefix (P), + Expressions => New_List ( + Convert_To + (Etype (First_Index (Etype (P))), + First (Expressions (N)))))); + Analyze_And_Resolve (N, Typ); + return; + end if; + + -- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place + -- function, then additional actuals must be passed. + + if Ada_Version >= Ada_05 + and then Is_Build_In_Place_Function_Call (P) + then + Make_Build_In_Place_Call_In_Anonymous_Context (P); + end if; + + -- If the prefix is an access type, then we unconditionally rewrite if + -- as an explicit deference. This simplifies processing for several + -- cases, including packed array cases and certain cases in which checks + -- must be generated. We used to try to do this only when it was + -- necessary, but it cleans up the code to do it all the time. + + if Is_Access_Type (T) then + Insert_Explicit_Dereference (P); + Analyze_And_Resolve (P, Designated_Type (T)); + end if; + + -- Generate index and validity checks + + Generate_Index_Checks (N); + + if Validity_Checks_On and then Validity_Check_Subscripts then + Apply_Subscript_Validity_Checks (N); + end if; + + -- All done for the non-packed case + + if not Is_Packed (Etype (Prefix (N))) then + return; + end if; + + -- For packed arrays that are not bit-packed (i.e. the case of an array + -- with one or more index types with a non-contiguous enumeration type), + -- we can always use the normal packed element get circuit. + + if not Is_Bit_Packed_Array (Etype (Prefix (N))) then + Expand_Packed_Element_Reference (N); + return; + end if; + + -- For a reference to a component of a bit packed array, we have to + -- convert it to a reference to the corresponding Packed_Array_Type. + -- We only want to do this for simple references, and not for: + + -- Left side of assignment, or prefix of left side of assignment, or + -- prefix of the prefix, to handle packed arrays of packed arrays, + -- This case is handled in Exp_Ch5.Expand_N_Assignment_Statement + + -- Renaming objects in renaming associations + -- This case is handled when a use of the renamed variable occurs + + -- Actual parameters for a procedure call + -- This case is handled in Exp_Ch6.Expand_Actuals + + -- The second expression in a 'Read attribute reference + + -- The prefix of an address or size attribute reference + + -- The following circuit detects these exceptions + + declare + Child : Node_Id := N; + Parnt : Node_Id := Parent (N); + + begin + loop + if Nkind (Parnt) = N_Unchecked_Expression then + null; + + elsif Nkind_In (Parnt, N_Object_Renaming_Declaration, + N_Procedure_Call_Statement) + or else (Nkind (Parnt) = N_Parameter_Association + and then + Nkind (Parent (Parnt)) = N_Procedure_Call_Statement) + then + return; + + elsif Nkind (Parnt) = N_Attribute_Reference + and then (Attribute_Name (Parnt) = Name_Address + or else + Attribute_Name (Parnt) = Name_Size) + and then Prefix (Parnt) = Child + then + return; + + elsif Nkind (Parnt) = N_Assignment_Statement + and then Name (Parnt) = Child + then + return; + + -- If the expression is an index of an indexed component, it must + -- be expanded regardless of context. + + elsif Nkind (Parnt) = N_Indexed_Component + and then Child /= Prefix (Parnt) + then + Expand_Packed_Element_Reference (N); + return; + + elsif Nkind (Parent (Parnt)) = N_Assignment_Statement + and then Name (Parent (Parnt)) = Parnt + then + return; + + elsif Nkind (Parnt) = N_Attribute_Reference + and then Attribute_Name (Parnt) = Name_Read + and then Next (First (Expressions (Parnt))) = Child + then + return; + + elsif Nkind_In (Parnt, N_Indexed_Component, N_Selected_Component) + and then Prefix (Parnt) = Child + then + null; + + else + Expand_Packed_Element_Reference (N); + return; + end if; + + -- Keep looking up tree for unchecked expression, or if we are the + -- prefix of a possible assignment left side. + + Child := Parnt; + Parnt := Parent (Child); + end loop; + end; + end Expand_N_Indexed_Component; + + --------------------- + -- Expand_N_Not_In -- + --------------------- + + -- Replace a not in b by not (a in b) so that the expansions for (a in b) + -- can be done. This avoids needing to duplicate this expansion code. + + procedure Expand_N_Not_In (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Typ : constant Entity_Id := Etype (N); + Cfs : constant Boolean := Comes_From_Source (N); + + begin + Rewrite (N, + Make_Op_Not (Loc, + Right_Opnd => + Make_In (Loc, + Left_Opnd => Left_Opnd (N), + Right_Opnd => Right_Opnd (N)))); + + -- We want this to appear as coming from source if original does (see + -- transformations in Expand_N_In). + + Set_Comes_From_Source (N, Cfs); + Set_Comes_From_Source (Right_Opnd (N), Cfs); + + -- Now analyze transformed node + + Analyze_And_Resolve (N, Typ); + end Expand_N_Not_In; + + ------------------- + -- Expand_N_Null -- + ------------------- + + -- The only replacement required is for the case of a null of type that is + -- an access to protected subprogram. We represent such access values as a + -- record, and so we must replace the occurrence of null by the equivalent + -- record (with a null address and a null pointer in it), so that the + -- backend creates the proper value. + + procedure Expand_N_Null (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Typ : constant Entity_Id := Etype (N); + Agg : Node_Id; + + begin + if Is_Access_Protected_Subprogram_Type (Typ) then + Agg := + Make_Aggregate (Loc, + Expressions => New_List ( + New_Occurrence_Of (RTE (RE_Null_Address), Loc), + Make_Null (Loc))); + + Rewrite (N, Agg); + Analyze_And_Resolve (N, Equivalent_Type (Typ)); + + -- For subsequent semantic analysis, the node must retain its type. + -- Gigi in any case replaces this type by the corresponding record + -- type before processing the node. + + Set_Etype (N, Typ); + end if; + + exception + when RE_Not_Available => + return; + end Expand_N_Null; + + --------------------- + -- Expand_N_Op_Abs -- + --------------------- + + procedure Expand_N_Op_Abs (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Expr : constant Node_Id := Right_Opnd (N); + + begin + Unary_Op_Validity_Checks (N); + + -- Deal with software overflow checking + + if not Backend_Overflow_Checks_On_Target + and then Is_Signed_Integer_Type (Etype (N)) + and then Do_Overflow_Check (N) + then + -- The only case to worry about is when the argument is equal to the + -- largest negative number, so what we do is to insert the check: + + -- [constraint_error when Expr = typ'Base'First] + + -- with the usual Duplicate_Subexpr use coding for expr + + Insert_Action (N, + Make_Raise_Constraint_Error (Loc, + Condition => + Make_Op_Eq (Loc, + Left_Opnd => Duplicate_Subexpr (Expr), + Right_Opnd => + Make_Attribute_Reference (Loc, + Prefix => + New_Occurrence_Of (Base_Type (Etype (Expr)), Loc), + Attribute_Name => Name_First)), + Reason => CE_Overflow_Check_Failed)); + end if; + + -- Vax floating-point types case + + if Vax_Float (Etype (N)) then + Expand_Vax_Arith (N); + end if; + end Expand_N_Op_Abs; + + --------------------- + -- Expand_N_Op_Add -- + --------------------- + + procedure Expand_N_Op_Add (N : Node_Id) is + Typ : constant Entity_Id := Etype (N); + + begin + Binary_Op_Validity_Checks (N); + + -- N + 0 = 0 + N = N for integer types + + if Is_Integer_Type (Typ) then + if Compile_Time_Known_Value (Right_Opnd (N)) + and then Expr_Value (Right_Opnd (N)) = Uint_0 + then + Rewrite (N, Left_Opnd (N)); + return; + + elsif Compile_Time_Known_Value (Left_Opnd (N)) + and then Expr_Value (Left_Opnd (N)) = Uint_0 + then + Rewrite (N, Right_Opnd (N)); + return; + end if; + end if; + + -- Arithmetic overflow checks for signed integer/fixed point types + + if Is_Signed_Integer_Type (Typ) + or else Is_Fixed_Point_Type (Typ) + then + Apply_Arithmetic_Overflow_Check (N); + return; + + -- Vax floating-point types case + + elsif Vax_Float (Typ) then + Expand_Vax_Arith (N); + end if; + end Expand_N_Op_Add; + + --------------------- + -- Expand_N_Op_And -- + --------------------- + + procedure Expand_N_Op_And (N : Node_Id) is + Typ : constant Entity_Id := Etype (N); + + begin + Binary_Op_Validity_Checks (N); + + if Is_Array_Type (Etype (N)) then + Expand_Boolean_Operator (N); + + elsif Is_Boolean_Type (Etype (N)) then + Adjust_Condition (Left_Opnd (N)); + Adjust_Condition (Right_Opnd (N)); + Set_Etype (N, Standard_Boolean); + Adjust_Result_Type (N, Typ); + end if; + end Expand_N_Op_And; + + ------------------------ + -- Expand_N_Op_Concat -- + ------------------------ + + Max_Available_String_Operands : Int := -1; + -- This is initialized the first time this routine is called. It records + -- a value of 0,2,3,4,5 depending on what Str_Concat_n procedures are + -- available in the run-time: + -- + -- 0 None available + -- 2 RE_Str_Concat available, RE_Str_Concat_3 not available + -- 3 RE_Str_Concat/Concat_2 available, RE_Str_Concat_4 not available + -- 4 RE_Str_Concat/Concat_2/3 available, RE_Str_Concat_5 not available + -- 5 All routines including RE_Str_Concat_5 available + + Char_Concat_Available : Boolean; + -- Records if the routines RE_Str_Concat_CC/CS/SC are available. True if + -- all three are available, False if any one of these is unavailable. + + procedure Expand_N_Op_Concat (N : Node_Id) is + Opnds : List_Id; + -- List of operands to be concatenated + + Opnd : Node_Id; + -- Single operand for concatenation + + Cnode : Node_Id; + -- Node which is to be replaced by the result of concatenating the nodes + -- in the list Opnds. + + Atyp : Entity_Id; + -- Array type of concatenation result type + + Ctyp : Entity_Id; + -- Component type of concatenation represented by Cnode + + begin + -- Initialize global variables showing run-time status + + if Max_Available_String_Operands < 1 then + + -- See what routines are available and set max operand count + -- according to the highest count available in the run-time. + + if not RTE_Available (RE_Str_Concat) then + Max_Available_String_Operands := 0; + + elsif not RTE_Available (RE_Str_Concat_3) then + Max_Available_String_Operands := 2; + + elsif not RTE_Available (RE_Str_Concat_4) then + Max_Available_String_Operands := 3; + + elsif not RTE_Available (RE_Str_Concat_5) then + Max_Available_String_Operands := 4; + + else + Max_Available_String_Operands := 5; + end if; + + Char_Concat_Available := + RTE_Available (RE_Str_Concat_CC) + and then + RTE_Available (RE_Str_Concat_CS) + and then + RTE_Available (RE_Str_Concat_SC); + end if; + + -- Ensure validity of both operands + + Binary_Op_Validity_Checks (N); + + -- If we are the left operand of a concatenation higher up the tree, + -- then do nothing for now, since we want to deal with a series of + -- concatenations as a unit. + + if Nkind (Parent (N)) = N_Op_Concat + and then N = Left_Opnd (Parent (N)) + then + return; + end if; + + -- We get here with a concatenation whose left operand may be a + -- concatenation itself with a consistent type. We need to process + -- these concatenation operands from left to right, which means + -- from the deepest node in the tree to the highest node. + + Cnode := N; + while Nkind (Left_Opnd (Cnode)) = N_Op_Concat loop + Cnode := Left_Opnd (Cnode); + end loop; + + -- Now Opnd is the deepest Opnd, and its parents are the concatenation + -- nodes above, so now we process bottom up, doing the operations. We + -- gather a string that is as long as possible up to five operands + + -- The outer loop runs more than once if there are more than five + -- concatenations of type Standard.String, the most we handle for + -- this case, or if more than one concatenation type is involved. + + Outer : loop + Opnds := New_List (Left_Opnd (Cnode), Right_Opnd (Cnode)); + Set_Parent (Opnds, N); + + -- The inner loop gathers concatenation operands. We gather any + -- number of these in the non-string case, or if no concatenation + -- routines are available for string (since in that case we will + -- treat string like any other non-string case). Otherwise we only + -- gather as many operands as can be handled by the available + -- procedures in the run-time library (normally 5, but may be + -- less for the configurable run-time case). + + Inner : while Cnode /= N + and then (Base_Type (Etype (Cnode)) /= Standard_String + or else + Max_Available_String_Operands = 0 + or else + List_Length (Opnds) < + Max_Available_String_Operands) + and then Base_Type (Etype (Cnode)) = + Base_Type (Etype (Parent (Cnode))) + loop + Cnode := Parent (Cnode); + Append (Right_Opnd (Cnode), Opnds); + end loop Inner; + + -- Here we process the collected operands. First we convert singleton + -- operands to singleton aggregates. This is skipped however for the + -- case of two operands of type String since we have special routines + -- for these cases. + + Atyp := Base_Type (Etype (Cnode)); + Ctyp := Base_Type (Component_Type (Etype (Cnode))); + + if (List_Length (Opnds) > 2 or else Atyp /= Standard_String) + or else not Char_Concat_Available + then + Opnd := First (Opnds); + loop + if Base_Type (Etype (Opnd)) = Ctyp then + Rewrite (Opnd, + Make_Aggregate (Sloc (Cnode), + Expressions => New_List (Relocate_Node (Opnd)))); + Analyze_And_Resolve (Opnd, Atyp); + end if; + + Next (Opnd); + exit when No (Opnd); + end loop; + end if; + + -- Now call appropriate continuation routine + + if Atyp = Standard_String + and then Max_Available_String_Operands > 0 + then + Expand_Concatenate_String (Cnode, Opnds); + else + Expand_Concatenate_Other (Cnode, Opnds); + end if; + + exit Outer when Cnode = N; + Cnode := Parent (Cnode); + end loop Outer; + end Expand_N_Op_Concat; + + ------------------------ + -- Expand_N_Op_Divide -- + ------------------------ + + procedure Expand_N_Op_Divide (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Lopnd : constant Node_Id := Left_Opnd (N); + Ropnd : constant Node_Id := Right_Opnd (N); + Ltyp : constant Entity_Id := Etype (Lopnd); + Rtyp : constant Entity_Id := Etype (Ropnd); + Typ : Entity_Id := Etype (N); + Rknow : constant Boolean := Is_Integer_Type (Typ) + and then + Compile_Time_Known_Value (Ropnd); + Rval : Uint; + + begin + Binary_Op_Validity_Checks (N); + + if Rknow then + Rval := Expr_Value (Ropnd); + end if; + + -- N / 1 = N for integer types + + if Rknow and then Rval = Uint_1 then + Rewrite (N, Lopnd); + return; + end if; + + -- Convert x / 2 ** y to Shift_Right (x, y). Note that the fact that + -- Is_Power_Of_2_For_Shift is set means that we know that our left + -- operand is an unsigned integer, as required for this to work. + + if Nkind (Ropnd) = N_Op_Expon + and then Is_Power_Of_2_For_Shift (Ropnd) + + -- We cannot do this transformation in configurable run time mode if we + -- have 64-bit -- integers and long shifts are not available. + + and then + (Esize (Ltyp) <= 32 + or else Support_Long_Shifts_On_Target) + then + Rewrite (N, + Make_Op_Shift_Right (Loc, + Left_Opnd => Lopnd, + Right_Opnd => + Convert_To (Standard_Natural, Right_Opnd (Ropnd)))); + Analyze_And_Resolve (N, Typ); + return; + end if; + + -- Do required fixup of universal fixed operation + + if Typ = Universal_Fixed then + Fixup_Universal_Fixed_Operation (N); + Typ := Etype (N); + end if; + + -- Divisions with fixed-point results + + if Is_Fixed_Point_Type (Typ) then + + -- No special processing if Treat_Fixed_As_Integer is set, since + -- from a semantic point of view such operations are simply integer + -- operations and will be treated that way. + + if not Treat_Fixed_As_Integer (N) then + if Is_Integer_Type (Rtyp) then + Expand_Divide_Fixed_By_Integer_Giving_Fixed (N); + else + Expand_Divide_Fixed_By_Fixed_Giving_Fixed (N); + end if; + end if; + + -- Other cases of division of fixed-point operands. Again we exclude the + -- case where Treat_Fixed_As_Integer is set. + + elsif (Is_Fixed_Point_Type (Ltyp) or else + Is_Fixed_Point_Type (Rtyp)) + and then not Treat_Fixed_As_Integer (N) + then + if Is_Integer_Type (Typ) then + Expand_Divide_Fixed_By_Fixed_Giving_Integer (N); + else + pragma Assert (Is_Floating_Point_Type (Typ)); + Expand_Divide_Fixed_By_Fixed_Giving_Float (N); + end if; + + -- Mixed-mode operations can appear in a non-static universal context, + -- in which case the integer argument must be converted explicitly. + + elsif Typ = Universal_Real + and then Is_Integer_Type (Rtyp) + then + Rewrite (Ropnd, + Convert_To (Universal_Real, Relocate_Node (Ropnd))); + + Analyze_And_Resolve (Ropnd, Universal_Real); + + elsif Typ = Universal_Real + and then Is_Integer_Type (Ltyp) + then + Rewrite (Lopnd, + Convert_To (Universal_Real, Relocate_Node (Lopnd))); + + Analyze_And_Resolve (Lopnd, Universal_Real); + + -- Non-fixed point cases, do integer zero divide and overflow checks + + elsif Is_Integer_Type (Typ) then + Apply_Divide_Check (N); + + -- Check for 64-bit division available, or long shifts if the divisor + -- is a small power of 2 (since such divides will be converted into + -- long shifts. + + if Esize (Ltyp) > 32 + and then not Support_64_Bit_Divides_On_Target + and then + (not Rknow + or else not Support_Long_Shifts_On_Target + or else (Rval /= Uint_2 and then + Rval /= Uint_4 and then + Rval /= Uint_8 and then + Rval /= Uint_16 and then + Rval /= Uint_32 and then + Rval /= Uint_64)) + then + Error_Msg_CRT ("64-bit division", N); + end if; + + -- Deal with Vax_Float + + elsif Vax_Float (Typ) then + Expand_Vax_Arith (N); + return; + end if; + end Expand_N_Op_Divide; + + -------------------- + -- Expand_N_Op_Eq -- + -------------------- + + procedure Expand_N_Op_Eq (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Typ : constant Entity_Id := Etype (N); + Lhs : constant Node_Id := Left_Opnd (N); + Rhs : constant Node_Id := Right_Opnd (N); + Bodies : constant List_Id := New_List; + A_Typ : constant Entity_Id := Etype (Lhs); + + Typl : Entity_Id := A_Typ; + Op_Name : Entity_Id; + Prim : Elmt_Id; + + procedure Build_Equality_Call (Eq : Entity_Id); + -- If a constructed equality exists for the type or for its parent, + -- build and analyze call, adding conversions if the operation is + -- inherited. + + function Has_Unconstrained_UU_Component (Typ : Node_Id) return Boolean; + -- Determines whether a type has a subcomponent of an unconstrained + -- Unchecked_Union subtype. Typ is a record type. + + ------------------------- + -- Build_Equality_Call -- + ------------------------- + + procedure Build_Equality_Call (Eq : Entity_Id) is + Op_Type : constant Entity_Id := Etype (First_Formal (Eq)); + L_Exp : Node_Id := Relocate_Node (Lhs); + R_Exp : Node_Id := Relocate_Node (Rhs); + + begin + if Base_Type (Op_Type) /= Base_Type (A_Typ) + and then not Is_Class_Wide_Type (A_Typ) + then + L_Exp := OK_Convert_To (Op_Type, L_Exp); + R_Exp := OK_Convert_To (Op_Type, R_Exp); + end if; + + -- If we have an Unchecked_Union, we need to add the inferred + -- discriminant values as actuals in the function call. At this + -- point, the expansion has determined that both operands have + -- inferable discriminants. + + if Is_Unchecked_Union (Op_Type) then + declare + Lhs_Type : constant Node_Id := Etype (L_Exp); + Rhs_Type : constant Node_Id := Etype (R_Exp); + Lhs_Discr_Val : Node_Id; + Rhs_Discr_Val : Node_Id; + + begin + -- Per-object constrained selected components require special + -- attention. If the enclosing scope of the component is an + -- Unchecked_Union, we cannot reference its discriminants + -- directly. This is why we use the two extra parameters of + -- the equality function of the enclosing Unchecked_Union. + + -- type UU_Type (Discr : Integer := 0) is + -- . . . + -- end record; + -- pragma Unchecked_Union (UU_Type); + + -- 1. Unchecked_Union enclosing record: + + -- type Enclosing_UU_Type (Discr : Integer := 0) is record + -- . . . + -- Comp : UU_Type (Discr); + -- . . . + -- end Enclosing_UU_Type; + -- pragma Unchecked_Union (Enclosing_UU_Type); + + -- Obj1 : Enclosing_UU_Type; + -- Obj2 : Enclosing_UU_Type (1); + + -- [. . .] Obj1 = Obj2 [. . .] + + -- Generated code: + + -- if not (uu_typeEQ (obj1.comp, obj2.comp, a, b)) then + + -- A and B are the formal parameters of the equality function + -- of Enclosing_UU_Type. The function always has two extra + -- formals to capture the inferred discriminant values. + + -- 2. Non-Unchecked_Union enclosing record: + + -- type + -- Enclosing_Non_UU_Type (Discr : Integer := 0) + -- is record + -- . . . + -- Comp : UU_Type (Discr); + -- . . . + -- end Enclosing_Non_UU_Type; + + -- Obj1 : Enclosing_Non_UU_Type; + -- Obj2 : Enclosing_Non_UU_Type (1); + + -- ... Obj1 = Obj2 ... + + -- Generated code: + + -- if not (uu_typeEQ (obj1.comp, obj2.comp, + -- obj1.discr, obj2.discr)) then + + -- In this case we can directly reference the discriminants of + -- the enclosing record. + + -- Lhs of equality + + if Nkind (Lhs) = N_Selected_Component + and then Has_Per_Object_Constraint + (Entity (Selector_Name (Lhs))) + then + -- Enclosing record is an Unchecked_Union, use formal A + + if Is_Unchecked_Union (Scope + (Entity (Selector_Name (Lhs)))) + then + Lhs_Discr_Val := + Make_Identifier (Loc, + Chars => Name_A); + + -- Enclosing record is of a non-Unchecked_Union type, it is + -- possible to reference the discriminant. + + else + Lhs_Discr_Val := + Make_Selected_Component (Loc, + Prefix => Prefix (Lhs), + Selector_Name => + New_Copy + (Get_Discriminant_Value + (First_Discriminant (Lhs_Type), + Lhs_Type, + Stored_Constraint (Lhs_Type)))); + end if; + + -- Comment needed here ??? + + else + -- Infer the discriminant value + + Lhs_Discr_Val := + New_Copy + (Get_Discriminant_Value + (First_Discriminant (Lhs_Type), + Lhs_Type, + Stored_Constraint (Lhs_Type))); + end if; + + -- Rhs of equality + + if Nkind (Rhs) = N_Selected_Component + and then Has_Per_Object_Constraint + (Entity (Selector_Name (Rhs))) + then + if Is_Unchecked_Union + (Scope (Entity (Selector_Name (Rhs)))) + then + Rhs_Discr_Val := + Make_Identifier (Loc, + Chars => Name_B); + + else + Rhs_Discr_Val := + Make_Selected_Component (Loc, + Prefix => Prefix (Rhs), + Selector_Name => + New_Copy (Get_Discriminant_Value ( + First_Discriminant (Rhs_Type), + Rhs_Type, + Stored_Constraint (Rhs_Type)))); + + end if; + else + Rhs_Discr_Val := + New_Copy (Get_Discriminant_Value ( + First_Discriminant (Rhs_Type), + Rhs_Type, + Stored_Constraint (Rhs_Type))); + + end if; + + Rewrite (N, + Make_Function_Call (Loc, + Name => New_Reference_To (Eq, Loc), + Parameter_Associations => New_List ( + L_Exp, + R_Exp, + Lhs_Discr_Val, + Rhs_Discr_Val))); + end; + + -- Normal case, not an unchecked union + + else + Rewrite (N, + Make_Function_Call (Loc, + Name => New_Reference_To (Eq, Loc), + Parameter_Associations => New_List (L_Exp, R_Exp))); + end if; + + Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks); + end Build_Equality_Call; + + ------------------------------------ + -- Has_Unconstrained_UU_Component -- + ------------------------------------ + + function Has_Unconstrained_UU_Component + (Typ : Node_Id) return Boolean + is + Tdef : constant Node_Id := + Type_Definition (Declaration_Node (Base_Type (Typ))); + Clist : Node_Id; + Vpart : Node_Id; + + function Component_Is_Unconstrained_UU + (Comp : Node_Id) return Boolean; + -- Determines whether the subtype of the component is an + -- unconstrained Unchecked_Union. + + function Variant_Is_Unconstrained_UU + (Variant : Node_Id) return Boolean; + -- Determines whether a component of the variant has an unconstrained + -- Unchecked_Union subtype. + + ----------------------------------- + -- Component_Is_Unconstrained_UU -- + ----------------------------------- + + function Component_Is_Unconstrained_UU + (Comp : Node_Id) return Boolean + is + begin + if Nkind (Comp) /= N_Component_Declaration then + return False; + end if; + + declare + Sindic : constant Node_Id := + Subtype_Indication (Component_Definition (Comp)); + + begin + -- Unconstrained nominal type. In the case of a constraint + -- present, the node kind would have been N_Subtype_Indication. + + if Nkind (Sindic) = N_Identifier then + return Is_Unchecked_Union (Base_Type (Etype (Sindic))); + end if; + + return False; + end; + end Component_Is_Unconstrained_UU; + + --------------------------------- + -- Variant_Is_Unconstrained_UU -- + --------------------------------- + + function Variant_Is_Unconstrained_UU + (Variant : Node_Id) return Boolean + is + Clist : constant Node_Id := Component_List (Variant); + + begin + if Is_Empty_List (Component_Items (Clist)) then + return False; + end if; + + -- We only need to test one component + + declare + Comp : Node_Id := First (Component_Items (Clist)); + + begin + while Present (Comp) loop + if Component_Is_Unconstrained_UU (Comp) then + return True; + end if; + + Next (Comp); + end loop; + end; + + -- None of the components withing the variant were of + -- unconstrained Unchecked_Union type. + + return False; + end Variant_Is_Unconstrained_UU; + + -- Start of processing for Has_Unconstrained_UU_Component + + begin + if Null_Present (Tdef) then + return False; + end if; + + Clist := Component_List (Tdef); + Vpart := Variant_Part (Clist); + + -- Inspect available components + + if Present (Component_Items (Clist)) then + declare + Comp : Node_Id := First (Component_Items (Clist)); + + begin + while Present (Comp) loop + + -- One component is sufficient + + if Component_Is_Unconstrained_UU (Comp) then + return True; + end if; + + Next (Comp); + end loop; + end; + end if; + + -- Inspect available components withing variants + + if Present (Vpart) then + declare + Variant : Node_Id := First (Variants (Vpart)); + + begin + while Present (Variant) loop + + -- One component within a variant is sufficient + + if Variant_Is_Unconstrained_UU (Variant) then + return True; + end if; + + Next (Variant); + end loop; + end; + end if; + + -- Neither the available components, nor the components inside the + -- variant parts were of an unconstrained Unchecked_Union subtype. + + return False; + end Has_Unconstrained_UU_Component; + + -- Start of processing for Expand_N_Op_Eq + + begin + Binary_Op_Validity_Checks (N); + + if Ekind (Typl) = E_Private_Type then + Typl := Underlying_Type (Typl); + elsif Ekind (Typl) = E_Private_Subtype then + Typl := Underlying_Type (Base_Type (Typl)); + else + null; + end if; + + -- It may happen in error situations that the underlying type is not + -- set. The error will be detected later, here we just defend the + -- expander code. + + if No (Typl) then + return; + end if; + + Typl := Base_Type (Typl); + + -- Boolean types (requiring handling of non-standard case) + + if Is_Boolean_Type (Typl) then + Adjust_Condition (Left_Opnd (N)); + Adjust_Condition (Right_Opnd (N)); + Set_Etype (N, Standard_Boolean); + Adjust_Result_Type (N, Typ); + + -- Array types + + elsif Is_Array_Type (Typl) then + + -- If we are doing full validity checking, and it is possible for the + -- array elements to be invalid then expand out array comparisons to + -- make sure that we check the array elements. + + if Validity_Check_Operands + and then not Is_Known_Valid (Component_Type (Typl)) + then + declare + Save_Force_Validity_Checks : constant Boolean := + Force_Validity_Checks; + begin + Force_Validity_Checks := True; + Rewrite (N, + Expand_Array_Equality + (N, + Relocate_Node (Lhs), + Relocate_Node (Rhs), + Bodies, + Typl)); + Insert_Actions (N, Bodies); + Analyze_And_Resolve (N, Standard_Boolean); + Force_Validity_Checks := Save_Force_Validity_Checks; + end; + + -- Packed case where both operands are known aligned + + elsif Is_Bit_Packed_Array (Typl) + and then not Is_Possibly_Unaligned_Object (Lhs) + and then not Is_Possibly_Unaligned_Object (Rhs) + then + Expand_Packed_Eq (N); + + -- Where the component type is elementary we can use a block bit + -- comparison (if supported on the target) exception in the case + -- of floating-point (negative zero issues require element by + -- element comparison), and atomic types (where we must be sure + -- to load elements independently) and possibly unaligned arrays. + + elsif Is_Elementary_Type (Component_Type (Typl)) + and then not Is_Floating_Point_Type (Component_Type (Typl)) + and then not Is_Atomic (Component_Type (Typl)) + and then not Is_Possibly_Unaligned_Object (Lhs) + and then not Is_Possibly_Unaligned_Object (Rhs) + and then Support_Composite_Compare_On_Target + then + null; + + -- For composite and floating-point cases, expand equality loop to + -- make sure of using proper comparisons for tagged types, and + -- correctly handling the floating-point case. + + else + Rewrite (N, + Expand_Array_Equality + (N, + Relocate_Node (Lhs), + Relocate_Node (Rhs), + Bodies, + Typl)); + Insert_Actions (N, Bodies, Suppress => All_Checks); + Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks); + end if; + + -- Record Types + + elsif Is_Record_Type (Typl) then + + -- For tagged types, use the primitive "=" + + if Is_Tagged_Type (Typl) then + + -- No need to do anything else compiling under restriction + -- No_Dispatching_Calls. During the semantic analysis we + -- already notified such violation. + + if Restriction_Active (No_Dispatching_Calls) then + return; + end if; + + -- If this is derived from an untagged private type completed with + -- a tagged type, it does not have a full view, so we use the + -- primitive operations of the private type. This check should no + -- longer be necessary when these types get their full views??? + + if Is_Private_Type (A_Typ) + and then not Is_Tagged_Type (A_Typ) + and then Is_Derived_Type (A_Typ) + and then No (Full_View (A_Typ)) + then + -- Search for equality operation, checking that the operands + -- have the same type. Note that we must find a matching entry, + -- or something is very wrong! + + Prim := First_Elmt (Collect_Primitive_Operations (A_Typ)); + + while Present (Prim) loop + exit when Chars (Node (Prim)) = Name_Op_Eq + and then Etype (First_Formal (Node (Prim))) = + Etype (Next_Formal (First_Formal (Node (Prim)))) + and then + Base_Type (Etype (Node (Prim))) = Standard_Boolean; + + Next_Elmt (Prim); + end loop; + + pragma Assert (Present (Prim)); + Op_Name := Node (Prim); + + -- Find the type's predefined equality or an overriding + -- user- defined equality. The reason for not simply calling + -- Find_Prim_Op here is that there may be a user-defined + -- overloaded equality op that precedes the equality that we want, + -- so we have to explicitly search (e.g., there could be an + -- equality with two different parameter types). + + else + if Is_Class_Wide_Type (Typl) then + Typl := Root_Type (Typl); + end if; + + Prim := First_Elmt (Primitive_Operations (Typl)); + while Present (Prim) loop + exit when Chars (Node (Prim)) = Name_Op_Eq + and then Etype (First_Formal (Node (Prim))) = + Etype (Next_Formal (First_Formal (Node (Prim)))) + and then + Base_Type (Etype (Node (Prim))) = Standard_Boolean; + + Next_Elmt (Prim); + end loop; + + pragma Assert (Present (Prim)); + Op_Name := Node (Prim); + end if; + + Build_Equality_Call (Op_Name); + + -- Ada 2005 (AI-216): Program_Error is raised when evaluating the + -- predefined equality operator for a type which has a subcomponent + -- of an Unchecked_Union type whose nominal subtype is unconstrained. + + elsif Has_Unconstrained_UU_Component (Typl) then + Insert_Action (N, + Make_Raise_Program_Error (Loc, + Reason => PE_Unchecked_Union_Restriction)); + + -- Prevent Gigi from generating incorrect code by rewriting the + -- equality as a standard False. + + Rewrite (N, + New_Occurrence_Of (Standard_False, Loc)); + + elsif Is_Unchecked_Union (Typl) then + + -- If we can infer the discriminants of the operands, we make a + -- call to the TSS equality function. + + if Has_Inferable_Discriminants (Lhs) + and then + Has_Inferable_Discriminants (Rhs) + then + Build_Equality_Call + (TSS (Root_Type (Typl), TSS_Composite_Equality)); + + else + -- Ada 2005 (AI-216): Program_Error is raised when evaluating + -- the predefined equality operator for an Unchecked_Union type + -- if either of the operands lack inferable discriminants. + + Insert_Action (N, + Make_Raise_Program_Error (Loc, + Reason => PE_Unchecked_Union_Restriction)); + + -- Prevent Gigi from generating incorrect code by rewriting + -- the equality as a standard False. + + Rewrite (N, + New_Occurrence_Of (Standard_False, Loc)); + + end if; + + -- If a type support function is present (for complex cases), use it + + elsif Present (TSS (Root_Type (Typl), TSS_Composite_Equality)) then + Build_Equality_Call + (TSS (Root_Type (Typl), TSS_Composite_Equality)); + + -- Otherwise expand the component by component equality. Note that + -- we never use block-bit comparisons for records, because of the + -- problems with gaps. The backend will often be able to recombine + -- the separate comparisons that we generate here. + + else + Remove_Side_Effects (Lhs); + Remove_Side_Effects (Rhs); + Rewrite (N, + Expand_Record_Equality (N, Typl, Lhs, Rhs, Bodies)); + + Insert_Actions (N, Bodies, Suppress => All_Checks); + Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks); + end if; + end if; + + -- Test if result is known at compile time + + Rewrite_Comparison (N); + + -- If we still have comparison for Vax_Float, process it + + if Vax_Float (Typl) and then Nkind (N) in N_Op_Compare then + Expand_Vax_Comparison (N); + return; + end if; + end Expand_N_Op_Eq; + + ----------------------- + -- Expand_N_Op_Expon -- + ----------------------- + + procedure Expand_N_Op_Expon (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Typ : constant Entity_Id := Etype (N); + Rtyp : constant Entity_Id := Root_Type (Typ); + Base : constant Node_Id := Relocate_Node (Left_Opnd (N)); + Bastyp : constant Node_Id := Etype (Base); + Exp : constant Node_Id := Relocate_Node (Right_Opnd (N)); + Exptyp : constant Entity_Id := Etype (Exp); + Ovflo : constant Boolean := Do_Overflow_Check (N); + Expv : Uint; + Xnode : Node_Id; + Temp : Node_Id; + Rent : RE_Id; + Ent : Entity_Id; + Etyp : Entity_Id; + + begin + Binary_Op_Validity_Checks (N); + + -- If either operand is of a private type, then we have the use of an + -- intrinsic operator, and we get rid of the privateness, by using root + -- types of underlying types for the actual operation. Otherwise the + -- private types will cause trouble if we expand multiplications or + -- shifts etc. We also do this transformation if the result type is + -- different from the base type. + + if Is_Private_Type (Etype (Base)) + or else + Is_Private_Type (Typ) + or else + Is_Private_Type (Exptyp) + or else + Rtyp /= Root_Type (Bastyp) + then + declare + Bt : constant Entity_Id := Root_Type (Underlying_Type (Bastyp)); + Et : constant Entity_Id := Root_Type (Underlying_Type (Exptyp)); + + begin + Rewrite (N, + Unchecked_Convert_To (Typ, + Make_Op_Expon (Loc, + Left_Opnd => Unchecked_Convert_To (Bt, Base), + Right_Opnd => Unchecked_Convert_To (Et, Exp)))); + Analyze_And_Resolve (N, Typ); + return; + end; + end if; + + -- Test for case of known right argument + + if Compile_Time_Known_Value (Exp) then + Expv := Expr_Value (Exp); + + -- We only fold small non-negative exponents. You might think we + -- could fold small negative exponents for the real case, but we + -- can't because we are required to raise Constraint_Error for + -- the case of 0.0 ** (negative) even if Machine_Overflows = False. + -- See ACVC test C4A012B. + + if Expv >= 0 and then Expv <= 4 then + + -- X ** 0 = 1 (or 1.0) + + if Expv = 0 then + + -- Call Remove_Side_Effects to ensure that any side effects + -- in the ignored left operand (in particular function calls + -- to user defined functions) are properly executed. + + Remove_Side_Effects (Base); + + if Ekind (Typ) in Integer_Kind then + Xnode := Make_Integer_Literal (Loc, Intval => 1); + else + Xnode := Make_Real_Literal (Loc, Ureal_1); + end if; + + -- X ** 1 = X + + elsif Expv = 1 then + Xnode := Base; + + -- X ** 2 = X * X + + elsif Expv = 2 then + Xnode := + Make_Op_Multiply (Loc, + Left_Opnd => Duplicate_Subexpr (Base), + Right_Opnd => Duplicate_Subexpr_No_Checks (Base)); + + -- X ** 3 = X * X * X + + elsif Expv = 3 then + Xnode := + Make_Op_Multiply (Loc, + Left_Opnd => + Make_Op_Multiply (Loc, + Left_Opnd => Duplicate_Subexpr (Base), + Right_Opnd => Duplicate_Subexpr_No_Checks (Base)), + Right_Opnd => Duplicate_Subexpr_No_Checks (Base)); + + -- X ** 4 -> + -- En : constant base'type := base * base; + -- ... + -- En * En + + else -- Expv = 4 + Temp := + Make_Defining_Identifier (Loc, New_Internal_Name ('E')); + + Insert_Actions (N, New_List ( + Make_Object_Declaration (Loc, + Defining_Identifier => Temp, + Constant_Present => True, + Object_Definition => New_Reference_To (Typ, Loc), + Expression => + Make_Op_Multiply (Loc, + Left_Opnd => Duplicate_Subexpr (Base), + Right_Opnd => Duplicate_Subexpr_No_Checks (Base))))); + + Xnode := + Make_Op_Multiply (Loc, + Left_Opnd => New_Reference_To (Temp, Loc), + Right_Opnd => New_Reference_To (Temp, Loc)); + end if; + + Rewrite (N, Xnode); + Analyze_And_Resolve (N, Typ); + return; + end if; + end if; + + -- Case of (2 ** expression) appearing as an argument of an integer + -- multiplication, or as the right argument of a division of a non- + -- negative integer. In such cases we leave the node untouched, setting + -- the flag Is_Natural_Power_Of_2_for_Shift set, then the expansion + -- of the higher level node converts it into a shift. + + -- Note: this transformation is not applicable for a modular type with + -- a non-binary modulus in the multiplication case, since we get a wrong + -- result if the shift causes an overflow before the modular reduction. + + if Nkind (Base) = N_Integer_Literal + and then Intval (Base) = 2 + and then Is_Integer_Type (Root_Type (Exptyp)) + and then Esize (Root_Type (Exptyp)) <= Esize (Standard_Integer) + and then Is_Unsigned_Type (Exptyp) + and then not Ovflo + and then Nkind (Parent (N)) in N_Binary_Op + then + declare + P : constant Node_Id := Parent (N); + L : constant Node_Id := Left_Opnd (P); + R : constant Node_Id := Right_Opnd (P); + + begin + if (Nkind (P) = N_Op_Multiply + and then not Non_Binary_Modulus (Typ) + and then + ((Is_Integer_Type (Etype (L)) and then R = N) + or else + (Is_Integer_Type (Etype (R)) and then L = N)) + and then not Do_Overflow_Check (P)) + + or else + (Nkind (P) = N_Op_Divide + and then Is_Integer_Type (Etype (L)) + and then Is_Unsigned_Type (Etype (L)) + and then R = N + and then not Do_Overflow_Check (P)) + then + Set_Is_Power_Of_2_For_Shift (N); + return; + end if; + end; + end if; + + -- Fall through if exponentiation must be done using a runtime routine + + -- First deal with modular case + + if Is_Modular_Integer_Type (Rtyp) then + + -- Non-binary case, we call the special exponentiation routine for + -- the non-binary case, converting the argument to Long_Long_Integer + -- and passing the modulus value. Then the result is converted back + -- to the base type. + + if Non_Binary_Modulus (Rtyp) then + Rewrite (N, + Convert_To (Typ, + Make_Function_Call (Loc, + Name => New_Reference_To (RTE (RE_Exp_Modular), Loc), + Parameter_Associations => New_List ( + Convert_To (Standard_Integer, Base), + Make_Integer_Literal (Loc, Modulus (Rtyp)), + Exp)))); + + -- Binary case, in this case, we call one of two routines, either the + -- unsigned integer case, or the unsigned long long integer case, + -- with a final "and" operation to do the required mod. + + else + if UI_To_Int (Esize (Rtyp)) <= Standard_Integer_Size then + Ent := RTE (RE_Exp_Unsigned); + else + Ent := RTE (RE_Exp_Long_Long_Unsigned); + end if; + + Rewrite (N, + Convert_To (Typ, + Make_Op_And (Loc, + Left_Opnd => + Make_Function_Call (Loc, + Name => New_Reference_To (Ent, Loc), + Parameter_Associations => New_List ( + Convert_To (Etype (First_Formal (Ent)), Base), + Exp)), + Right_Opnd => + Make_Integer_Literal (Loc, Modulus (Rtyp) - 1)))); + + end if; + + -- Common exit point for modular type case + + Analyze_And_Resolve (N, Typ); + return; + + -- Signed integer cases, done using either Integer or Long_Long_Integer. + -- It is not worth having routines for Short_[Short_]Integer, since for + -- most machines it would not help, and it would generate more code that + -- might need certification when a certified run time is required. + + -- In the integer cases, we have two routines, one for when overflow + -- checks are required, and one when they are not required, since there + -- is a real gain in omitting checks on many machines. + + elsif Rtyp = Base_Type (Standard_Long_Long_Integer) + or else (Rtyp = Base_Type (Standard_Long_Integer) + and then + Esize (Standard_Long_Integer) > Esize (Standard_Integer)) + or else (Rtyp = Universal_Integer) + then + Etyp := Standard_Long_Long_Integer; + + if Ovflo then + Rent := RE_Exp_Long_Long_Integer; + else + Rent := RE_Exn_Long_Long_Integer; + end if; + + elsif Is_Signed_Integer_Type (Rtyp) then + Etyp := Standard_Integer; + + if Ovflo then + Rent := RE_Exp_Integer; + else + Rent := RE_Exn_Integer; + end if; + + -- Floating-point cases, always done using Long_Long_Float. We do not + -- need separate routines for the overflow case here, since in the case + -- of floating-point, we generate infinities anyway as a rule (either + -- that or we automatically trap overflow), and if there is an infinity + -- generated and a range check is required, the check will fail anyway. + + else + pragma Assert (Is_Floating_Point_Type (Rtyp)); + Etyp := Standard_Long_Long_Float; + Rent := RE_Exn_Long_Long_Float; + end if; + + -- Common processing for integer cases and floating-point cases. + -- If we are in the right type, we can call runtime routine directly + + if Typ = Etyp + and then Rtyp /= Universal_Integer + and then Rtyp /= Universal_Real + then + Rewrite (N, + Make_Function_Call (Loc, + Name => New_Reference_To (RTE (Rent), Loc), + Parameter_Associations => New_List (Base, Exp))); + + -- Otherwise we have to introduce conversions (conversions are also + -- required in the universal cases, since the runtime routine is + -- typed using one of the standard types. + + else + Rewrite (N, + Convert_To (Typ, + Make_Function_Call (Loc, + Name => New_Reference_To (RTE (Rent), Loc), + Parameter_Associations => New_List ( + Convert_To (Etyp, Base), + Exp)))); + end if; + + Analyze_And_Resolve (N, Typ); + return; + + exception + when RE_Not_Available => + return; + end Expand_N_Op_Expon; + + -------------------- + -- Expand_N_Op_Ge -- + -------------------- + + procedure Expand_N_Op_Ge (N : Node_Id) is + Typ : constant Entity_Id := Etype (N); + Op1 : constant Node_Id := Left_Opnd (N); + Op2 : constant Node_Id := Right_Opnd (N); + Typ1 : constant Entity_Id := Base_Type (Etype (Op1)); + + begin + Binary_Op_Validity_Checks (N); + + if Is_Array_Type (Typ1) then + Expand_Array_Comparison (N); + return; + end if; + + if Is_Boolean_Type (Typ1) then + Adjust_Condition (Op1); + Adjust_Condition (Op2); + Set_Etype (N, Standard_Boolean); + Adjust_Result_Type (N, Typ); + end if; + + Rewrite_Comparison (N); + + -- If we still have comparison, and Vax_Float type, process it + + if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then + Expand_Vax_Comparison (N); + return; + end if; + end Expand_N_Op_Ge; + + -------------------- + -- Expand_N_Op_Gt -- + -------------------- + + procedure Expand_N_Op_Gt (N : Node_Id) is + Typ : constant Entity_Id := Etype (N); + Op1 : constant Node_Id := Left_Opnd (N); + Op2 : constant Node_Id := Right_Opnd (N); + Typ1 : constant Entity_Id := Base_Type (Etype (Op1)); + + begin + Binary_Op_Validity_Checks (N); + + if Is_Array_Type (Typ1) then + Expand_Array_Comparison (N); + return; + end if; + + if Is_Boolean_Type (Typ1) then + Adjust_Condition (Op1); + Adjust_Condition (Op2); + Set_Etype (N, Standard_Boolean); + Adjust_Result_Type (N, Typ); + end if; + + Rewrite_Comparison (N); + + -- If we still have comparison, and Vax_Float type, process it + + if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then + Expand_Vax_Comparison (N); + return; + end if; + end Expand_N_Op_Gt; + + -------------------- + -- Expand_N_Op_Le -- + -------------------- + + procedure Expand_N_Op_Le (N : Node_Id) is + Typ : constant Entity_Id := Etype (N); + Op1 : constant Node_Id := Left_Opnd (N); + Op2 : constant Node_Id := Right_Opnd (N); + Typ1 : constant Entity_Id := Base_Type (Etype (Op1)); + + begin + Binary_Op_Validity_Checks (N); + + if Is_Array_Type (Typ1) then + Expand_Array_Comparison (N); + return; + end if; + + if Is_Boolean_Type (Typ1) then + Adjust_Condition (Op1); + Adjust_Condition (Op2); + Set_Etype (N, Standard_Boolean); + Adjust_Result_Type (N, Typ); + end if; + + Rewrite_Comparison (N); + + -- If we still have comparison, and Vax_Float type, process it + + if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then + Expand_Vax_Comparison (N); + return; + end if; + end Expand_N_Op_Le; + + -------------------- + -- Expand_N_Op_Lt -- + -------------------- + + procedure Expand_N_Op_Lt (N : Node_Id) is + Typ : constant Entity_Id := Etype (N); + Op1 : constant Node_Id := Left_Opnd (N); + Op2 : constant Node_Id := Right_Opnd (N); + Typ1 : constant Entity_Id := Base_Type (Etype (Op1)); + + begin + Binary_Op_Validity_Checks (N); + + if Is_Array_Type (Typ1) then + Expand_Array_Comparison (N); + return; + end if; + + if Is_Boolean_Type (Typ1) then + Adjust_Condition (Op1); + Adjust_Condition (Op2); + Set_Etype (N, Standard_Boolean); + Adjust_Result_Type (N, Typ); + end if; + + Rewrite_Comparison (N); + + -- If we still have comparison, and Vax_Float type, process it + + if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then + Expand_Vax_Comparison (N); + return; + end if; + end Expand_N_Op_Lt; + + ----------------------- + -- Expand_N_Op_Minus -- + ----------------------- + + procedure Expand_N_Op_Minus (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Typ : constant Entity_Id := Etype (N); + + begin + Unary_Op_Validity_Checks (N); + + if not Backend_Overflow_Checks_On_Target + and then Is_Signed_Integer_Type (Etype (N)) + and then Do_Overflow_Check (N) + then + -- Software overflow checking expands -expr into (0 - expr) + + Rewrite (N, + Make_Op_Subtract (Loc, + Left_Opnd => Make_Integer_Literal (Loc, 0), + Right_Opnd => Right_Opnd (N))); + + Analyze_And_Resolve (N, Typ); + + -- Vax floating-point types case + + elsif Vax_Float (Etype (N)) then + Expand_Vax_Arith (N); + end if; + end Expand_N_Op_Minus; + + --------------------- + -- Expand_N_Op_Mod -- + --------------------- + + procedure Expand_N_Op_Mod (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Typ : constant Entity_Id := Etype (N); + Left : constant Node_Id := Left_Opnd (N); + Right : constant Node_Id := Right_Opnd (N); + DOC : constant Boolean := Do_Overflow_Check (N); + DDC : constant Boolean := Do_Division_Check (N); + + LLB : Uint; + Llo : Uint; + Lhi : Uint; + LOK : Boolean; + Rlo : Uint; + Rhi : Uint; + ROK : Boolean; + + pragma Warnings (Off, Lhi); + + begin + Binary_Op_Validity_Checks (N); + + Determine_Range (Right, ROK, Rlo, Rhi); + Determine_Range (Left, LOK, Llo, Lhi); + + -- Convert mod to rem if operands are known non-negative. We do this + -- since it is quite likely that this will improve the quality of code, + -- (the operation now corresponds to the hardware remainder), and it + -- does not seem likely that it could be harmful. + + if LOK and then Llo >= 0 + and then + ROK and then Rlo >= 0 + then + Rewrite (N, + Make_Op_Rem (Sloc (N), + Left_Opnd => Left_Opnd (N), + Right_Opnd => Right_Opnd (N))); + + -- Instead of reanalyzing the node we do the analysis manually. This + -- avoids anomalies when the replacement is done in an instance and + -- is epsilon more efficient. + + Set_Entity (N, Standard_Entity (S_Op_Rem)); + Set_Etype (N, Typ); + Set_Do_Overflow_Check (N, DOC); + Set_Do_Division_Check (N, DDC); + Expand_N_Op_Rem (N); + Set_Analyzed (N); + + -- Otherwise, normal mod processing + + else + if Is_Integer_Type (Etype (N)) then + Apply_Divide_Check (N); + end if; + + -- Apply optimization x mod 1 = 0. We don't really need that with + -- gcc, but it is useful with other back ends (e.g. AAMP), and is + -- certainly harmless. + + if Is_Integer_Type (Etype (N)) + and then Compile_Time_Known_Value (Right) + and then Expr_Value (Right) = Uint_1 + then + -- Call Remove_Side_Effects to ensure that any side effects in + -- the ignored left operand (in particular function calls to + -- user defined functions) are properly executed. + + Remove_Side_Effects (Left); + + Rewrite (N, Make_Integer_Literal (Loc, 0)); + Analyze_And_Resolve (N, Typ); + return; + end if; + + -- Deal with annoying case of largest negative number remainder + -- minus one. Gigi does not handle this case correctly, because + -- it generates a divide instruction which may trap in this case. + + -- In fact the check is quite easy, if the right operand is -1, then + -- the mod value is always 0, and we can just ignore the left operand + -- completely in this case. + + -- The operand type may be private (e.g. in the expansion of an + -- intrinsic operation) so we must use the underlying type to get the + -- bounds, and convert the literals explicitly. + + LLB := + Expr_Value + (Type_Low_Bound (Base_Type (Underlying_Type (Etype (Left))))); + + if ((not ROK) or else (Rlo <= (-1) and then (-1) <= Rhi)) + and then + ((not LOK) or else (Llo = LLB)) + then + Rewrite (N, + Make_Conditional_Expression (Loc, + Expressions => New_List ( + Make_Op_Eq (Loc, + Left_Opnd => Duplicate_Subexpr (Right), + Right_Opnd => + Unchecked_Convert_To (Typ, + Make_Integer_Literal (Loc, -1))), + Unchecked_Convert_To (Typ, + Make_Integer_Literal (Loc, Uint_0)), + Relocate_Node (N)))); + + Set_Analyzed (Next (Next (First (Expressions (N))))); + Analyze_And_Resolve (N, Typ); + end if; + end if; + end Expand_N_Op_Mod; + + -------------------------- + -- Expand_N_Op_Multiply -- + -------------------------- + + procedure Expand_N_Op_Multiply (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Lop : constant Node_Id := Left_Opnd (N); + Rop : constant Node_Id := Right_Opnd (N); + + Lp2 : constant Boolean := + Nkind (Lop) = N_Op_Expon + and then Is_Power_Of_2_For_Shift (Lop); + + Rp2 : constant Boolean := + Nkind (Rop) = N_Op_Expon + and then Is_Power_Of_2_For_Shift (Rop); + + Ltyp : constant Entity_Id := Etype (Lop); + Rtyp : constant Entity_Id := Etype (Rop); + Typ : Entity_Id := Etype (N); + + begin + Binary_Op_Validity_Checks (N); + + -- Special optimizations for integer types + + if Is_Integer_Type (Typ) then + + -- N * 0 = 0 for integer types + + if Compile_Time_Known_Value (Rop) + and then Expr_Value (Rop) = Uint_0 + then + -- Call Remove_Side_Effects to ensure that any side effects in + -- the ignored left operand (in particular function calls to + -- user defined functions) are properly executed. + + Remove_Side_Effects (Lop); + + Rewrite (N, Make_Integer_Literal (Loc, Uint_0)); + Analyze_And_Resolve (N, Typ); + return; + end if; + + -- Similar handling for 0 * N = 0 + + if Compile_Time_Known_Value (Lop) + and then Expr_Value (Lop) = Uint_0 + then + Remove_Side_Effects (Rop); + Rewrite (N, Make_Integer_Literal (Loc, Uint_0)); + Analyze_And_Resolve (N, Typ); + return; + end if; + + -- N * 1 = 1 * N = N for integer types + + -- This optimisation is not done if we are going to + -- rewrite the product 1 * 2 ** N to a shift. + + if Compile_Time_Known_Value (Rop) + and then Expr_Value (Rop) = Uint_1 + and then not Lp2 + then + Rewrite (N, Lop); + return; + + elsif Compile_Time_Known_Value (Lop) + and then Expr_Value (Lop) = Uint_1 + and then not Rp2 + then + Rewrite (N, Rop); + return; + end if; + end if; + + -- Convert x * 2 ** y to Shift_Left (x, y). Note that the fact that + -- Is_Power_Of_2_For_Shift is set means that we know that our left + -- operand is an integer, as required for this to work. + + if Rp2 then + if Lp2 then + + -- Convert 2 ** A * 2 ** B into 2 ** (A + B) + + Rewrite (N, + Make_Op_Expon (Loc, + Left_Opnd => Make_Integer_Literal (Loc, 2), + Right_Opnd => + Make_Op_Add (Loc, + Left_Opnd => Right_Opnd (Lop), + Right_Opnd => Right_Opnd (Rop)))); + Analyze_And_Resolve (N, Typ); + return; + + else + Rewrite (N, + Make_Op_Shift_Left (Loc, + Left_Opnd => Lop, + Right_Opnd => + Convert_To (Standard_Natural, Right_Opnd (Rop)))); + Analyze_And_Resolve (N, Typ); + return; + end if; + + -- Same processing for the operands the other way round + + elsif Lp2 then + Rewrite (N, + Make_Op_Shift_Left (Loc, + Left_Opnd => Rop, + Right_Opnd => + Convert_To (Standard_Natural, Right_Opnd (Lop)))); + Analyze_And_Resolve (N, Typ); + return; + end if; + + -- Do required fixup of universal fixed operation + + if Typ = Universal_Fixed then + Fixup_Universal_Fixed_Operation (N); + Typ := Etype (N); + end if; + + -- Multiplications with fixed-point results + + if Is_Fixed_Point_Type (Typ) then + + -- No special processing if Treat_Fixed_As_Integer is set, since from + -- a semantic point of view such operations are simply integer + -- operations and will be treated that way. + + if not Treat_Fixed_As_Integer (N) then + + -- Case of fixed * integer => fixed + + if Is_Integer_Type (Rtyp) then + Expand_Multiply_Fixed_By_Integer_Giving_Fixed (N); + + -- Case of integer * fixed => fixed + + elsif Is_Integer_Type (Ltyp) then + Expand_Multiply_Integer_By_Fixed_Giving_Fixed (N); + + -- Case of fixed * fixed => fixed + + else + Expand_Multiply_Fixed_By_Fixed_Giving_Fixed (N); + end if; + end if; + + -- Other cases of multiplication of fixed-point operands. Again we + -- exclude the cases where Treat_Fixed_As_Integer flag is set. + + elsif (Is_Fixed_Point_Type (Ltyp) or else Is_Fixed_Point_Type (Rtyp)) + and then not Treat_Fixed_As_Integer (N) + then + if Is_Integer_Type (Typ) then + Expand_Multiply_Fixed_By_Fixed_Giving_Integer (N); + else + pragma Assert (Is_Floating_Point_Type (Typ)); + Expand_Multiply_Fixed_By_Fixed_Giving_Float (N); + end if; + + -- Mixed-mode operations can appear in a non-static universal context, + -- in which case the integer argument must be converted explicitly. + + elsif Typ = Universal_Real + and then Is_Integer_Type (Rtyp) + then + Rewrite (Rop, Convert_To (Universal_Real, Relocate_Node (Rop))); + + Analyze_And_Resolve (Rop, Universal_Real); + + elsif Typ = Universal_Real + and then Is_Integer_Type (Ltyp) + then + Rewrite (Lop, Convert_To (Universal_Real, Relocate_Node (Lop))); + + Analyze_And_Resolve (Lop, Universal_Real); + + -- Non-fixed point cases, check software overflow checking required + + elsif Is_Signed_Integer_Type (Etype (N)) then + Apply_Arithmetic_Overflow_Check (N); + + -- Deal with VAX float case + + elsif Vax_Float (Typ) then + Expand_Vax_Arith (N); + return; + end if; + end Expand_N_Op_Multiply; + + -------------------- + -- Expand_N_Op_Ne -- + -------------------- + + procedure Expand_N_Op_Ne (N : Node_Id) is + Typ : constant Entity_Id := Etype (Left_Opnd (N)); + + begin + -- Case of elementary type with standard operator + + if Is_Elementary_Type (Typ) + and then Sloc (Entity (N)) = Standard_Location + then + Binary_Op_Validity_Checks (N); + + -- Boolean types (requiring handling of non-standard case) + + if Is_Boolean_Type (Typ) then + Adjust_Condition (Left_Opnd (N)); + Adjust_Condition (Right_Opnd (N)); + Set_Etype (N, Standard_Boolean); + Adjust_Result_Type (N, Typ); + end if; + + Rewrite_Comparison (N); + + -- If we still have comparison for Vax_Float, process it + + if Vax_Float (Typ) and then Nkind (N) in N_Op_Compare then + Expand_Vax_Comparison (N); + return; + end if; + + -- For all cases other than elementary types, we rewrite node as the + -- negation of an equality operation, and reanalyze. The equality to be + -- used is defined in the same scope and has the same signature. This + -- signature must be set explicitly since in an instance it may not have + -- the same visibility as in the generic unit. This avoids duplicating + -- or factoring the complex code for record/array equality tests etc. + + else + declare + Loc : constant Source_Ptr := Sloc (N); + Neg : Node_Id; + Ne : constant Entity_Id := Entity (N); + + begin + Binary_Op_Validity_Checks (N); + + Neg := + Make_Op_Not (Loc, + Right_Opnd => + Make_Op_Eq (Loc, + Left_Opnd => Left_Opnd (N), + Right_Opnd => Right_Opnd (N))); + Set_Paren_Count (Right_Opnd (Neg), 1); + + if Scope (Ne) /= Standard_Standard then + Set_Entity (Right_Opnd (Neg), Corresponding_Equality (Ne)); + end if; + + -- For navigation purposes, the inequality is treated as an + -- implicit reference to the corresponding equality. Preserve the + -- Comes_From_ source flag so that the proper Xref entry is + -- generated. + + Preserve_Comes_From_Source (Neg, N); + Preserve_Comes_From_Source (Right_Opnd (Neg), N); + Rewrite (N, Neg); + Analyze_And_Resolve (N, Standard_Boolean); + end; + end if; + end Expand_N_Op_Ne; + + --------------------- + -- Expand_N_Op_Not -- + --------------------- + + -- If the argument is other than a Boolean array type, there is no special + -- expansion required. + + -- For the packed case, we call the special routine in Exp_Pakd, except + -- that if the component size is greater than one, we use the standard + -- routine generating a gruesome loop (it is so peculiar to have packed + -- arrays with non-standard Boolean representations anyway, so it does not + -- matter that we do not handle this case efficiently). + + -- For the unpacked case (and for the special packed case where we have non + -- standard Booleans, as discussed above), we generate and insert into the + -- tree the following function definition: + + -- function Nnnn (A : arr) is + -- B : arr; + -- begin + -- for J in a'range loop + -- B (J) := not A (J); + -- end loop; + -- return B; + -- end Nnnn; + + -- Here arr is the actual subtype of the parameter (and hence always + -- constrained). Then we replace the not with a call to this function. + + procedure Expand_N_Op_Not (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Typ : constant Entity_Id := Etype (N); + Opnd : Node_Id; + Arr : Entity_Id; + A : Entity_Id; + B : Entity_Id; + J : Entity_Id; + A_J : Node_Id; + B_J : Node_Id; + + Func_Name : Entity_Id; + Loop_Statement : Node_Id; + + begin + Unary_Op_Validity_Checks (N); + + -- For boolean operand, deal with non-standard booleans + + if Is_Boolean_Type (Typ) then + Adjust_Condition (Right_Opnd (N)); + Set_Etype (N, Standard_Boolean); + Adjust_Result_Type (N, Typ); + return; + end if; + + -- Only array types need any other processing + + if not Is_Array_Type (Typ) then + return; + end if; + + -- Case of array operand. If bit packed with a component size of 1, + -- handle it in Exp_Pakd if the operand is known to be aligned. + + if Is_Bit_Packed_Array (Typ) + and then Component_Size (Typ) = 1 + and then not Is_Possibly_Unaligned_Object (Right_Opnd (N)) + then + Expand_Packed_Not (N); + return; + end if; + + -- Case of array operand which is not bit-packed. If the context is + -- a safe assignment, call in-place operation, If context is a larger + -- boolean expression in the context of a safe assignment, expansion is + -- done by enclosing operation. + + Opnd := Relocate_Node (Right_Opnd (N)); + Convert_To_Actual_Subtype (Opnd); + Arr := Etype (Opnd); + Ensure_Defined (Arr, N); + Silly_Boolean_Array_Not_Test (N, Arr); + + if Nkind (Parent (N)) = N_Assignment_Statement then + if Safe_In_Place_Array_Op (Name (Parent (N)), N, Empty) then + Build_Boolean_Array_Proc_Call (Parent (N), Opnd, Empty); + return; + + -- Special case the negation of a binary operation + + elsif Nkind_In (Opnd, N_Op_And, N_Op_Or, N_Op_Xor) + and then Safe_In_Place_Array_Op + (Name (Parent (N)), Left_Opnd (Opnd), Right_Opnd (Opnd)) + then + Build_Boolean_Array_Proc_Call (Parent (N), Opnd, Empty); + return; + end if; + + elsif Nkind (Parent (N)) in N_Binary_Op + and then Nkind (Parent (Parent (N))) = N_Assignment_Statement + then + declare + Op1 : constant Node_Id := Left_Opnd (Parent (N)); + Op2 : constant Node_Id := Right_Opnd (Parent (N)); + Lhs : constant Node_Id := Name (Parent (Parent (N))); + + begin + if Safe_In_Place_Array_Op (Lhs, Op1, Op2) then + if N = Op1 + and then Nkind (Op2) = N_Op_Not + then + -- (not A) op (not B) can be reduced to a single call + + return; + + elsif N = Op2 + and then Nkind (Parent (N)) = N_Op_Xor + then + -- A xor (not B) can also be special-cased + + return; + end if; + end if; + end; + end if; + + A := Make_Defining_Identifier (Loc, Name_uA); + B := Make_Defining_Identifier (Loc, Name_uB); + J := Make_Defining_Identifier (Loc, Name_uJ); + + A_J := + Make_Indexed_Component (Loc, + Prefix => New_Reference_To (A, Loc), + Expressions => New_List (New_Reference_To (J, Loc))); + + B_J := + Make_Indexed_Component (Loc, + Prefix => New_Reference_To (B, Loc), + Expressions => New_List (New_Reference_To (J, Loc))); + + Loop_Statement := + Make_Implicit_Loop_Statement (N, + Identifier => Empty, + + Iteration_Scheme => + Make_Iteration_Scheme (Loc, + Loop_Parameter_Specification => + Make_Loop_Parameter_Specification (Loc, + Defining_Identifier => J, + Discrete_Subtype_Definition => + Make_Attribute_Reference (Loc, + Prefix => Make_Identifier (Loc, Chars (A)), + Attribute_Name => Name_Range))), + + Statements => New_List ( + Make_Assignment_Statement (Loc, + Name => B_J, + Expression => Make_Op_Not (Loc, A_J)))); + + Func_Name := Make_Defining_Identifier (Loc, New_Internal_Name ('N')); + Set_Is_Inlined (Func_Name); + + Insert_Action (N, + Make_Subprogram_Body (Loc, + Specification => + Make_Function_Specification (Loc, + Defining_Unit_Name => Func_Name, + Parameter_Specifications => New_List ( + Make_Parameter_Specification (Loc, + Defining_Identifier => A, + Parameter_Type => New_Reference_To (Typ, Loc))), + Result_Definition => New_Reference_To (Typ, Loc)), + + Declarations => New_List ( + Make_Object_Declaration (Loc, + Defining_Identifier => B, + Object_Definition => New_Reference_To (Arr, Loc))), + + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, + Statements => New_List ( + Loop_Statement, + Make_Simple_Return_Statement (Loc, + Expression => + Make_Identifier (Loc, Chars (B))))))); + + Rewrite (N, + Make_Function_Call (Loc, + Name => New_Reference_To (Func_Name, Loc), + Parameter_Associations => New_List (Opnd))); + + Analyze_And_Resolve (N, Typ); + end Expand_N_Op_Not; + + -------------------- + -- Expand_N_Op_Or -- + -------------------- + + procedure Expand_N_Op_Or (N : Node_Id) is + Typ : constant Entity_Id := Etype (N); + + begin + Binary_Op_Validity_Checks (N); + + if Is_Array_Type (Etype (N)) then + Expand_Boolean_Operator (N); + + elsif Is_Boolean_Type (Etype (N)) then + Adjust_Condition (Left_Opnd (N)); + Adjust_Condition (Right_Opnd (N)); + Set_Etype (N, Standard_Boolean); + Adjust_Result_Type (N, Typ); + end if; + end Expand_N_Op_Or; + + ---------------------- + -- Expand_N_Op_Plus -- + ---------------------- + + procedure Expand_N_Op_Plus (N : Node_Id) is + begin + Unary_Op_Validity_Checks (N); + end Expand_N_Op_Plus; + + --------------------- + -- Expand_N_Op_Rem -- + --------------------- + + procedure Expand_N_Op_Rem (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Typ : constant Entity_Id := Etype (N); + + Left : constant Node_Id := Left_Opnd (N); + Right : constant Node_Id := Right_Opnd (N); + + LLB : Uint; + Llo : Uint; + Lhi : Uint; + LOK : Boolean; + Rlo : Uint; + Rhi : Uint; + ROK : Boolean; + + pragma Warnings (Off, Lhi); + + begin + Binary_Op_Validity_Checks (N); + + if Is_Integer_Type (Etype (N)) then + Apply_Divide_Check (N); + end if; + + -- Apply optimization x rem 1 = 0. We don't really need that with gcc, + -- but it is useful with other back ends (e.g. AAMP), and is certainly + -- harmless. + + if Is_Integer_Type (Etype (N)) + and then Compile_Time_Known_Value (Right) + and then Expr_Value (Right) = Uint_1 + then + -- Call Remove_Side_Effects to ensure that any side effects in the + -- ignored left operand (in particular function calls to user defined + -- functions) are properly executed. + + Remove_Side_Effects (Left); + + Rewrite (N, Make_Integer_Literal (Loc, 0)); + Analyze_And_Resolve (N, Typ); + return; + end if; + + -- Deal with annoying case of largest negative number remainder minus + -- one. Gigi does not handle this case correctly, because it generates + -- a divide instruction which may trap in this case. + + -- In fact the check is quite easy, if the right operand is -1, then + -- the remainder is always 0, and we can just ignore the left operand + -- completely in this case. + + Determine_Range (Right, ROK, Rlo, Rhi); + Determine_Range (Left, LOK, Llo, Lhi); + + -- The operand type may be private (e.g. in the expansion of an + -- intrinsic operation) so we must use the underlying type to get the + -- bounds, and convert the literals explicitly. + + LLB := + Expr_Value + (Type_Low_Bound (Base_Type (Underlying_Type (Etype (Left))))); + + -- Now perform the test, generating code only if needed + + if ((not ROK) or else (Rlo <= (-1) and then (-1) <= Rhi)) + and then + ((not LOK) or else (Llo = LLB)) + then + Rewrite (N, + Make_Conditional_Expression (Loc, + Expressions => New_List ( + Make_Op_Eq (Loc, + Left_Opnd => Duplicate_Subexpr (Right), + Right_Opnd => + Unchecked_Convert_To (Typ, + Make_Integer_Literal (Loc, -1))), + + Unchecked_Convert_To (Typ, + Make_Integer_Literal (Loc, Uint_0)), + + Relocate_Node (N)))); + + Set_Analyzed (Next (Next (First (Expressions (N))))); + Analyze_And_Resolve (N, Typ); + end if; + end Expand_N_Op_Rem; + + ----------------------------- + -- Expand_N_Op_Rotate_Left -- + ----------------------------- + + procedure Expand_N_Op_Rotate_Left (N : Node_Id) is + begin + Binary_Op_Validity_Checks (N); + end Expand_N_Op_Rotate_Left; + + ------------------------------ + -- Expand_N_Op_Rotate_Right -- + ------------------------------ + + procedure Expand_N_Op_Rotate_Right (N : Node_Id) is + begin + Binary_Op_Validity_Checks (N); + end Expand_N_Op_Rotate_Right; + + ---------------------------- + -- Expand_N_Op_Shift_Left -- + ---------------------------- + + procedure Expand_N_Op_Shift_Left (N : Node_Id) is + begin + Binary_Op_Validity_Checks (N); + end Expand_N_Op_Shift_Left; + + ----------------------------- + -- Expand_N_Op_Shift_Right -- + ----------------------------- + + procedure Expand_N_Op_Shift_Right (N : Node_Id) is + begin + Binary_Op_Validity_Checks (N); + end Expand_N_Op_Shift_Right; + + ---------------------------------------- + -- Expand_N_Op_Shift_Right_Arithmetic -- + ---------------------------------------- + + procedure Expand_N_Op_Shift_Right_Arithmetic (N : Node_Id) is + begin + Binary_Op_Validity_Checks (N); + end Expand_N_Op_Shift_Right_Arithmetic; + + -------------------------- + -- Expand_N_Op_Subtract -- + -------------------------- + + procedure Expand_N_Op_Subtract (N : Node_Id) is + Typ : constant Entity_Id := Etype (N); + + begin + Binary_Op_Validity_Checks (N); + + -- N - 0 = N for integer types + + if Is_Integer_Type (Typ) + and then Compile_Time_Known_Value (Right_Opnd (N)) + and then Expr_Value (Right_Opnd (N)) = 0 + then + Rewrite (N, Left_Opnd (N)); + return; + end if; + + -- Arithmetic overflow checks for signed integer/fixed point types + + if Is_Signed_Integer_Type (Typ) + or else Is_Fixed_Point_Type (Typ) + then + Apply_Arithmetic_Overflow_Check (N); + + -- Vax floating-point types case + + elsif Vax_Float (Typ) then + Expand_Vax_Arith (N); + end if; + end Expand_N_Op_Subtract; + + --------------------- + -- Expand_N_Op_Xor -- + --------------------- + + procedure Expand_N_Op_Xor (N : Node_Id) is + Typ : constant Entity_Id := Etype (N); + + begin + Binary_Op_Validity_Checks (N); + + if Is_Array_Type (Etype (N)) then + Expand_Boolean_Operator (N); + + elsif Is_Boolean_Type (Etype (N)) then + Adjust_Condition (Left_Opnd (N)); + Adjust_Condition (Right_Opnd (N)); + Set_Etype (N, Standard_Boolean); + Adjust_Result_Type (N, Typ); + end if; + end Expand_N_Op_Xor; + + ---------------------- + -- Expand_N_Or_Else -- + ---------------------- + + -- Expand into conditional expression if Actions present, and also + -- deal with optimizing case of arguments being True or False. + + procedure Expand_N_Or_Else (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Typ : constant Entity_Id := Etype (N); + Left : constant Node_Id := Left_Opnd (N); + Right : constant Node_Id := Right_Opnd (N); + Actlist : List_Id; + + begin + -- Deal with non-standard booleans + + if Is_Boolean_Type (Typ) then + Adjust_Condition (Left); + Adjust_Condition (Right); + Set_Etype (N, Standard_Boolean); + end if; + + -- Check for cases where left argument is known to be True or False + + if Compile_Time_Known_Value (Left) then + + -- If left argument is False, change (False or else Right) to Right. + -- Any actions associated with Right will be executed unconditionally + -- and can thus be inserted into the tree unconditionally. + + if Expr_Value_E (Left) = Standard_False then + if Present (Actions (N)) then + Insert_Actions (N, Actions (N)); + end if; + + Rewrite (N, Right); + + -- If left argument is True, change (True and then Right) to True. In + -- this case we can forget the actions associated with Right, since + -- they will never be executed. + + else pragma Assert (Expr_Value_E (Left) = Standard_True); + Kill_Dead_Code (Right); + Kill_Dead_Code (Actions (N)); + Rewrite (N, New_Occurrence_Of (Standard_True, Loc)); + end if; + + Adjust_Result_Type (N, Typ); + return; + end if; + + -- If Actions are present, we expand + + -- left or else right + + -- into + + -- if left then True else right end + + -- with the actions becoming the Else_Actions of the conditional + -- expression. This conditional expression is then further expanded + -- (and will eventually disappear) + + if Present (Actions (N)) then + Actlist := Actions (N); + Rewrite (N, + Make_Conditional_Expression (Loc, + Expressions => New_List ( + Left, + New_Occurrence_Of (Standard_True, Loc), + Right))); + + Set_Else_Actions (N, Actlist); + Analyze_And_Resolve (N, Standard_Boolean); + Adjust_Result_Type (N, Typ); + return; + end if; + + -- No actions present, check for cases of right argument True/False + + if Compile_Time_Known_Value (Right) then + + -- Change (Left or else False) to Left. Note that we know there are + -- no actions associated with the True operand, since we just checked + -- for this case above. + + if Expr_Value_E (Right) = Standard_False then + Rewrite (N, Left); + + -- Change (Left or else True) to True, making sure to preserve any + -- side effects associated with the Left operand. + + else pragma Assert (Expr_Value_E (Right) = Standard_True); + Remove_Side_Effects (Left); + Rewrite + (N, New_Occurrence_Of (Standard_True, Loc)); + end if; + end if; + + Adjust_Result_Type (N, Typ); + end Expand_N_Or_Else; + + ----------------------------------- + -- Expand_N_Qualified_Expression -- + ----------------------------------- + + procedure Expand_N_Qualified_Expression (N : Node_Id) is + Operand : constant Node_Id := Expression (N); + Target_Type : constant Entity_Id := Entity (Subtype_Mark (N)); + + begin + -- Do validity check if validity checking operands + + if Validity_Checks_On + and then Validity_Check_Operands + then + Ensure_Valid (Operand); + end if; + + -- Apply possible constraint check + + Apply_Constraint_Check (Operand, Target_Type, No_Sliding => True); + end Expand_N_Qualified_Expression; + + --------------------------------- + -- Expand_N_Selected_Component -- + --------------------------------- + + -- If the selector is a discriminant of a concurrent object, rewrite the + -- prefix to denote the corresponding record type. + + procedure Expand_N_Selected_Component (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Par : constant Node_Id := Parent (N); + P : constant Node_Id := Prefix (N); + Ptyp : Entity_Id := Underlying_Type (Etype (P)); + Disc : Entity_Id; + New_N : Node_Id; + Dcon : Elmt_Id; + + function In_Left_Hand_Side (Comp : Node_Id) return Boolean; + -- Gigi needs a temporary for prefixes that depend on a discriminant, + -- unless the context of an assignment can provide size information. + -- Don't we have a general routine that does this??? + + ----------------------- + -- In_Left_Hand_Side -- + ----------------------- + + function In_Left_Hand_Side (Comp : Node_Id) return Boolean is + begin + return (Nkind (Parent (Comp)) = N_Assignment_Statement + and then Comp = Name (Parent (Comp))) + or else (Present (Parent (Comp)) + and then Nkind (Parent (Comp)) in N_Subexpr + and then In_Left_Hand_Side (Parent (Comp))); + end In_Left_Hand_Side; + + -- Start of processing for Expand_N_Selected_Component + + begin + -- Insert explicit dereference if required + + if Is_Access_Type (Ptyp) then + Insert_Explicit_Dereference (P); + Analyze_And_Resolve (P, Designated_Type (Ptyp)); + + if Ekind (Etype (P)) = E_Private_Subtype + and then Is_For_Access_Subtype (Etype (P)) + then + Set_Etype (P, Base_Type (Etype (P))); + end if; + + Ptyp := Etype (P); + end if; + + -- Deal with discriminant check required + + if Do_Discriminant_Check (N) then + + -- Present the discriminant checking function to the backend, so that + -- it can inline the call to the function. + + Add_Inlined_Body + (Discriminant_Checking_Func + (Original_Record_Component (Entity (Selector_Name (N))))); + + -- Now reset the flag and generate the call + + Set_Do_Discriminant_Check (N, False); + Generate_Discriminant_Check (N); + end if; + + -- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place + -- function, then additional actuals must be passed. + + if Ada_Version >= Ada_05 + and then Is_Build_In_Place_Function_Call (P) + then + Make_Build_In_Place_Call_In_Anonymous_Context (P); + end if; + + -- Gigi cannot handle unchecked conversions that are the prefix of a + -- selected component with discriminants. This must be checked during + -- expansion, because during analysis the type of the selector is not + -- known at the point the prefix is analyzed. If the conversion is the + -- target of an assignment, then we cannot force the evaluation. + + if Nkind (Prefix (N)) = N_Unchecked_Type_Conversion + and then Has_Discriminants (Etype (N)) + and then not In_Left_Hand_Side (N) + then + Force_Evaluation (Prefix (N)); + end if; + + -- Remaining processing applies only if selector is a discriminant + + if Ekind (Entity (Selector_Name (N))) = E_Discriminant then + + -- If the selector is a discriminant of a constrained record type, + -- we may be able to rewrite the expression with the actual value + -- of the discriminant, a useful optimization in some cases. + + if Is_Record_Type (Ptyp) + and then Has_Discriminants (Ptyp) + and then Is_Constrained (Ptyp) + then + -- Do this optimization for discrete types only, and not for + -- access types (access discriminants get us into trouble!) + + if not Is_Discrete_Type (Etype (N)) then + null; + + -- Don't do this on the left hand of an assignment statement. + -- Normally one would think that references like this would + -- not occur, but they do in generated code, and mean that + -- we really do want to assign the discriminant! + + elsif Nkind (Par) = N_Assignment_Statement + and then Name (Par) = N + then + null; + + -- Don't do this optimization for the prefix of an attribute or + -- the operand of an object renaming declaration since these are + -- contexts where we do not want the value anyway. + + elsif (Nkind (Par) = N_Attribute_Reference + and then Prefix (Par) = N) + or else Is_Renamed_Object (N) + then + null; + + -- Don't do this optimization if we are within the code for a + -- discriminant check, since the whole point of such a check may + -- be to verify the condition on which the code below depends! + + elsif Is_In_Discriminant_Check (N) then + null; + + -- Green light to see if we can do the optimization. There is + -- still one condition that inhibits the optimization below but + -- now is the time to check the particular discriminant. + + else + -- Loop through discriminants to find the matching discriminant + -- constraint to see if we can copy it. + + Disc := First_Discriminant (Ptyp); + Dcon := First_Elmt (Discriminant_Constraint (Ptyp)); + Discr_Loop : while Present (Dcon) loop + + -- Check if this is the matching discriminant + + if Disc = Entity (Selector_Name (N)) then + + -- Here we have the matching discriminant. Check for + -- the case of a discriminant of a component that is + -- constrained by an outer discriminant, which cannot + -- be optimized away. + + if + Denotes_Discriminant + (Node (Dcon), Check_Concurrent => True) + then + exit Discr_Loop; + + -- In the context of a case statement, the expression may + -- have the base type of the discriminant, and we need to + -- preserve the constraint to avoid spurious errors on + -- missing cases. + + elsif Nkind (Parent (N)) = N_Case_Statement + and then Etype (Node (Dcon)) /= Etype (Disc) + then + Rewrite (N, + Make_Qualified_Expression (Loc, + Subtype_Mark => + New_Occurrence_Of (Etype (Disc), Loc), + Expression => + New_Copy_Tree (Node (Dcon)))); + Analyze_And_Resolve (N, Etype (Disc)); + + -- In case that comes out as a static expression, + -- reset it (a selected component is never static). + + Set_Is_Static_Expression (N, False); + return; + + -- Otherwise we can just copy the constraint, but the + -- result is certainly not static! In some cases the + -- discriminant constraint has been analyzed in the + -- context of the original subtype indication, but for + -- itypes the constraint might not have been analyzed + -- yet, and this must be done now. + + else + Rewrite (N, New_Copy_Tree (Node (Dcon))); + Analyze_And_Resolve (N); + Set_Is_Static_Expression (N, False); + return; + end if; + end if; + + Next_Elmt (Dcon); + Next_Discriminant (Disc); + end loop Discr_Loop; + + -- Note: the above loop should always find a matching + -- discriminant, but if it does not, we just missed an + -- optimization due to some glitch (perhaps a previous error), + -- so ignore. + + end if; + end if; + + -- The only remaining processing is in the case of a discriminant of + -- a concurrent object, where we rewrite the prefix to denote the + -- corresponding record type. If the type is derived and has renamed + -- discriminants, use corresponding discriminant, which is the one + -- that appears in the corresponding record. + + if not Is_Concurrent_Type (Ptyp) then + return; + end if; + + Disc := Entity (Selector_Name (N)); + + if Is_Derived_Type (Ptyp) + and then Present (Corresponding_Discriminant (Disc)) + then + Disc := Corresponding_Discriminant (Disc); + end if; + + New_N := + Make_Selected_Component (Loc, + Prefix => + Unchecked_Convert_To (Corresponding_Record_Type (Ptyp), + New_Copy_Tree (P)), + Selector_Name => Make_Identifier (Loc, Chars (Disc))); + + Rewrite (N, New_N); + Analyze (N); + end if; + end Expand_N_Selected_Component; + + -------------------- + -- Expand_N_Slice -- + -------------------- + + procedure Expand_N_Slice (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Typ : constant Entity_Id := Etype (N); + Pfx : constant Node_Id := Prefix (N); + Ptp : Entity_Id := Etype (Pfx); + + function Is_Procedure_Actual (N : Node_Id) return Boolean; + -- Check whether the argument is an actual for a procedure call, in + -- which case the expansion of a bit-packed slice is deferred until the + -- call itself is expanded. The reason this is required is that we might + -- have an IN OUT or OUT parameter, and the copy out is essential, and + -- that copy out would be missed if we created a temporary here in + -- Expand_N_Slice. Note that we don't bother to test specifically for an + -- IN OUT or OUT mode parameter, since it is a bit tricky to do, and it + -- is harmless to defer expansion in the IN case, since the call + -- processing will still generate the appropriate copy in operation, + -- which will take care of the slice. + + procedure Make_Temporary; + -- Create a named variable for the value of the slice, in cases where + -- the back-end cannot handle it properly, e.g. when packed types or + -- unaligned slices are involved. + + ------------------------- + -- Is_Procedure_Actual -- + ------------------------- + + function Is_Procedure_Actual (N : Node_Id) return Boolean is + Par : Node_Id := Parent (N); + + begin + loop + -- If our parent is a procedure call we can return + + if Nkind (Par) = N_Procedure_Call_Statement then + return True; + + -- If our parent is a type conversion, keep climbing the tree, + -- since a type conversion can be a procedure actual. Also keep + -- climbing if parameter association or a qualified expression, + -- since these are additional cases that do can appear on + -- procedure actuals. + + elsif Nkind_In (Par, N_Type_Conversion, + N_Parameter_Association, + N_Qualified_Expression) + then + Par := Parent (Par); + + -- Any other case is not what we are looking for + + else + return False; + end if; + end loop; + end Is_Procedure_Actual; + + -------------------- + -- Make_Temporary -- + -------------------- + + procedure Make_Temporary is + Decl : Node_Id; + Ent : constant Entity_Id := + Make_Defining_Identifier (Loc, New_Internal_Name ('T')); + begin + Decl := + Make_Object_Declaration (Loc, + Defining_Identifier => Ent, + Object_Definition => New_Occurrence_Of (Typ, Loc)); + + Set_No_Initialization (Decl); + + Insert_Actions (N, New_List ( + Decl, + Make_Assignment_Statement (Loc, + Name => New_Occurrence_Of (Ent, Loc), + Expression => Relocate_Node (N)))); + + Rewrite (N, New_Occurrence_Of (Ent, Loc)); + Analyze_And_Resolve (N, Typ); + end Make_Temporary; + + -- Start of processing for Expand_N_Slice + + begin + -- Special handling for access types + + if Is_Access_Type (Ptp) then + + Ptp := Designated_Type (Ptp); + + Rewrite (Pfx, + Make_Explicit_Dereference (Sloc (N), + Prefix => Relocate_Node (Pfx))); + + Analyze_And_Resolve (Pfx, Ptp); + end if; + + -- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place + -- function, then additional actuals must be passed. + + if Ada_Version >= Ada_05 + and then Is_Build_In_Place_Function_Call (Pfx) + then + Make_Build_In_Place_Call_In_Anonymous_Context (Pfx); + end if; + + -- Range checks are potentially also needed for cases involving a slice + -- indexed by a subtype indication, but Do_Range_Check can currently + -- only be set for expressions ??? + + if not Index_Checks_Suppressed (Ptp) + and then (not Is_Entity_Name (Pfx) + or else not Index_Checks_Suppressed (Entity (Pfx))) + and then Nkind (Discrete_Range (N)) /= N_Subtype_Indication + + -- Do not enable range check to nodes associated with the frontend + -- expansion of the dispatch table. We first check if Ada.Tags is + -- already loaded to avoid the addition of an undesired dependence + -- on such run-time unit. + + and then + (VM_Target /= No_VM + or else not + (RTU_Loaded (Ada_Tags) + and then Nkind (Prefix (N)) = N_Selected_Component + and then Present (Entity (Selector_Name (Prefix (N)))) + and then Entity (Selector_Name (Prefix (N))) = + RTE_Record_Component (RE_Prims_Ptr))) + then + Enable_Range_Check (Discrete_Range (N)); + end if; + + -- The remaining case to be handled is packed slices. We can leave + -- packed slices as they are in the following situations: + + -- 1. Right or left side of an assignment (we can handle this + -- situation correctly in the assignment statement expansion). + + -- 2. Prefix of indexed component (the slide is optimized away in this + -- case, see the start of Expand_N_Slice.) + + -- 3. Object renaming declaration, since we want the name of the + -- slice, not the value. + + -- 4. Argument to procedure call, since copy-in/copy-out handling may + -- be required, and this is handled in the expansion of call + -- itself. + + -- 5. Prefix of an address attribute (this is an error which is caught + -- elsewhere, and the expansion would interfere with generating the + -- error message). + + if not Is_Packed (Typ) then + + -- Apply transformation for actuals of a function call, where + -- Expand_Actuals is not used. + + if Nkind (Parent (N)) = N_Function_Call + and then Is_Possibly_Unaligned_Slice (N) + then + Make_Temporary; + end if; + + elsif Nkind (Parent (N)) = N_Assignment_Statement + or else (Nkind (Parent (Parent (N))) = N_Assignment_Statement + and then Parent (N) = Name (Parent (Parent (N)))) + then + return; + + elsif Nkind (Parent (N)) = N_Indexed_Component + or else Is_Renamed_Object (N) + or else Is_Procedure_Actual (N) + then + return; + + elsif Nkind (Parent (N)) = N_Attribute_Reference + and then Attribute_Name (Parent (N)) = Name_Address + then + return; + + else + Make_Temporary; + end if; + end Expand_N_Slice; + + ------------------------------ + -- Expand_N_Type_Conversion -- + ------------------------------ + + procedure Expand_N_Type_Conversion (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Operand : constant Node_Id := Expression (N); + Target_Type : constant Entity_Id := Etype (N); + Operand_Type : Entity_Id := Etype (Operand); + + procedure Handle_Changed_Representation; + -- This is called in the case of record and array type conversions to + -- see if there is a change of representation to be handled. Change of + -- representation is actually handled at the assignment statement level, + -- and what this procedure does is rewrite node N conversion as an + -- assignment to temporary. If there is no change of representation, + -- then the conversion node is unchanged. + + procedure Real_Range_Check; + -- Handles generation of range check for real target value + + ----------------------------------- + -- Handle_Changed_Representation -- + ----------------------------------- + + procedure Handle_Changed_Representation is + Temp : Entity_Id; + Decl : Node_Id; + Odef : Node_Id; + Disc : Node_Id; + N_Ix : Node_Id; + Cons : List_Id; + + begin + -- Nothing else to do if no change of representation + + if Same_Representation (Operand_Type, Target_Type) then + return; + + -- The real change of representation work is done by the assignment + -- statement processing. So if this type conversion is appearing as + -- the expression of an assignment statement, nothing needs to be + -- done to the conversion. + + elsif Nkind (Parent (N)) = N_Assignment_Statement then + return; + + -- Otherwise we need to generate a temporary variable, and do the + -- change of representation assignment into that temporary variable. + -- The conversion is then replaced by a reference to this variable. + + else + Cons := No_List; + + -- If type is unconstrained we have to add a constraint, copied + -- from the actual value of the left hand side. + + if not Is_Constrained (Target_Type) then + if Has_Discriminants (Operand_Type) then + Disc := First_Discriminant (Operand_Type); + + if Disc /= First_Stored_Discriminant (Operand_Type) then + Disc := First_Stored_Discriminant (Operand_Type); + end if; + + Cons := New_List; + while Present (Disc) loop + Append_To (Cons, + Make_Selected_Component (Loc, + Prefix => Duplicate_Subexpr_Move_Checks (Operand), + Selector_Name => + Make_Identifier (Loc, Chars (Disc)))); + Next_Discriminant (Disc); + end loop; + + elsif Is_Array_Type (Operand_Type) then + N_Ix := First_Index (Target_Type); + Cons := New_List; + + for J in 1 .. Number_Dimensions (Operand_Type) loop + + -- We convert the bounds explicitly. We use an unchecked + -- conversion because bounds checks are done elsewhere. + + Append_To (Cons, + Make_Range (Loc, + Low_Bound => + Unchecked_Convert_To (Etype (N_Ix), + Make_Attribute_Reference (Loc, + Prefix => + Duplicate_Subexpr_No_Checks + (Operand, Name_Req => True), + Attribute_Name => Name_First, + Expressions => New_List ( + Make_Integer_Literal (Loc, J)))), + + High_Bound => + Unchecked_Convert_To (Etype (N_Ix), + Make_Attribute_Reference (Loc, + Prefix => + Duplicate_Subexpr_No_Checks + (Operand, Name_Req => True), + Attribute_Name => Name_Last, + Expressions => New_List ( + Make_Integer_Literal (Loc, J)))))); + + Next_Index (N_Ix); + end loop; + end if; + end if; + + Odef := New_Occurrence_Of (Target_Type, Loc); + + if Present (Cons) then + Odef := + Make_Subtype_Indication (Loc, + Subtype_Mark => Odef, + Constraint => + Make_Index_Or_Discriminant_Constraint (Loc, + Constraints => Cons)); + end if; + + Temp := Make_Defining_Identifier (Loc, New_Internal_Name ('C')); + Decl := + Make_Object_Declaration (Loc, + Defining_Identifier => Temp, + Object_Definition => Odef); + + Set_No_Initialization (Decl, True); + + -- Insert required actions. It is essential to suppress checks + -- since we have suppressed default initialization, which means + -- that the variable we create may have no discriminants. + + Insert_Actions (N, + New_List ( + Decl, + Make_Assignment_Statement (Loc, + Name => New_Occurrence_Of (Temp, Loc), + Expression => Relocate_Node (N))), + Suppress => All_Checks); + + Rewrite (N, New_Occurrence_Of (Temp, Loc)); + return; + end if; + end Handle_Changed_Representation; + + ---------------------- + -- Real_Range_Check -- + ---------------------- + + -- Case of conversions to floating-point or fixed-point. If range checks + -- are enabled and the target type has a range constraint, we convert: + + -- typ (x) + + -- to + + -- Tnn : typ'Base := typ'Base (x); + -- [constraint_error when Tnn < typ'First or else Tnn > typ'Last] + -- Tnn + + -- This is necessary when there is a conversion of integer to float or + -- to fixed-point to ensure that the correct checks are made. It is not + -- necessary for float to float where it is enough to simply set the + -- Do_Range_Check flag. + + procedure Real_Range_Check is + Btyp : constant Entity_Id := Base_Type (Target_Type); + Lo : constant Node_Id := Type_Low_Bound (Target_Type); + Hi : constant Node_Id := Type_High_Bound (Target_Type); + Xtyp : constant Entity_Id := Etype (Operand); + Conv : Node_Id; + Tnn : Entity_Id; + + begin + -- Nothing to do if conversion was rewritten + + if Nkind (N) /= N_Type_Conversion then + return; + end if; + + -- Nothing to do if range checks suppressed, or target has the same + -- range as the base type (or is the base type). + + if Range_Checks_Suppressed (Target_Type) + or else (Lo = Type_Low_Bound (Btyp) + and then + Hi = Type_High_Bound (Btyp)) + then + return; + end if; + + -- Nothing to do if expression is an entity on which checks have been + -- suppressed. + + if Is_Entity_Name (Operand) + and then Range_Checks_Suppressed (Entity (Operand)) + then + return; + end if; + + -- Nothing to do if bounds are all static and we can tell that the + -- expression is within the bounds of the target. Note that if the + -- operand is of an unconstrained floating-point type, then we do + -- not trust it to be in range (might be infinite) + + declare + S_Lo : constant Node_Id := Type_Low_Bound (Xtyp); + S_Hi : constant Node_Id := Type_High_Bound (Xtyp); + + begin + if (not Is_Floating_Point_Type (Xtyp) + or else Is_Constrained (Xtyp)) + and then Compile_Time_Known_Value (S_Lo) + and then Compile_Time_Known_Value (S_Hi) + and then Compile_Time_Known_Value (Hi) + and then Compile_Time_Known_Value (Lo) + then + declare + D_Lov : constant Ureal := Expr_Value_R (Lo); + D_Hiv : constant Ureal := Expr_Value_R (Hi); + S_Lov : Ureal; + S_Hiv : Ureal; + + begin + if Is_Real_Type (Xtyp) then + S_Lov := Expr_Value_R (S_Lo); + S_Hiv := Expr_Value_R (S_Hi); + else + S_Lov := UR_From_Uint (Expr_Value (S_Lo)); + S_Hiv := UR_From_Uint (Expr_Value (S_Hi)); + end if; + + if D_Hiv > D_Lov + and then S_Lov >= D_Lov + and then S_Hiv <= D_Hiv + then + Set_Do_Range_Check (Operand, False); + return; + end if; + end; + end if; + end; + + -- For float to float conversions, we are done + + if Is_Floating_Point_Type (Xtyp) + and then + Is_Floating_Point_Type (Btyp) + then + return; + end if; + + -- Otherwise rewrite the conversion as described above + + Conv := Relocate_Node (N); + Rewrite + (Subtype_Mark (Conv), New_Occurrence_Of (Btyp, Loc)); + Set_Etype (Conv, Btyp); + + -- Enable overflow except for case of integer to float conversions, + -- where it is never required, since we can never have overflow in + -- this case. + + if not Is_Integer_Type (Etype (Operand)) then + Enable_Overflow_Check (Conv); + end if; + + Tnn := + Make_Defining_Identifier (Loc, + Chars => New_Internal_Name ('T')); + + Insert_Actions (N, New_List ( + Make_Object_Declaration (Loc, + Defining_Identifier => Tnn, + Object_Definition => New_Occurrence_Of (Btyp, Loc), + Expression => Conv), + + Make_Raise_Constraint_Error (Loc, + Condition => + Make_Or_Else (Loc, + Left_Opnd => + Make_Op_Lt (Loc, + Left_Opnd => New_Occurrence_Of (Tnn, Loc), + Right_Opnd => + Make_Attribute_Reference (Loc, + Attribute_Name => Name_First, + Prefix => + New_Occurrence_Of (Target_Type, Loc))), + + Right_Opnd => + Make_Op_Gt (Loc, + Left_Opnd => New_Occurrence_Of (Tnn, Loc), + Right_Opnd => + Make_Attribute_Reference (Loc, + Attribute_Name => Name_Last, + Prefix => + New_Occurrence_Of (Target_Type, Loc)))), + Reason => CE_Range_Check_Failed))); + + Rewrite (N, New_Occurrence_Of (Tnn, Loc)); + Analyze_And_Resolve (N, Btyp); + end Real_Range_Check; + + -- Start of processing for Expand_N_Type_Conversion + + begin + -- Nothing at all to do if conversion is to the identical type so remove + -- the conversion completely, it is useless. + + if Operand_Type = Target_Type then + Rewrite (N, Relocate_Node (Operand)); + return; + end if; + + -- Nothing to do if this is the second argument of read. This is a + -- "backwards" conversion that will be handled by the specialized code + -- in attribute processing. + + if Nkind (Parent (N)) = N_Attribute_Reference + and then Attribute_Name (Parent (N)) = Name_Read + and then Next (First (Expressions (Parent (N)))) = N + then + return; + end if; + + -- Here if we may need to expand conversion + + -- Do validity check if validity checking operands + + if Validity_Checks_On + and then Validity_Check_Operands + then + Ensure_Valid (Operand); + end if; + + -- Special case of converting from non-standard boolean type + + if Is_Boolean_Type (Operand_Type) + and then (Nonzero_Is_True (Operand_Type)) + then + Adjust_Condition (Operand); + Set_Etype (Operand, Standard_Boolean); + Operand_Type := Standard_Boolean; + end if; + + -- Case of converting to an access type + + if Is_Access_Type (Target_Type) then + + -- Apply an accessibility check when the conversion operand is an + -- access parameter (or a renaming thereof), unless conversion was + -- expanded from an Unchecked_ or Unrestricted_Access attribute. + -- Note that other checks may still need to be applied below (such + -- as tagged type checks). + + if Is_Entity_Name (Operand) + and then + (Is_Formal (Entity (Operand)) + or else + (Present (Renamed_Object (Entity (Operand))) + and then Is_Entity_Name (Renamed_Object (Entity (Operand))) + and then Is_Formal + (Entity (Renamed_Object (Entity (Operand)))))) + and then Ekind (Etype (Operand)) = E_Anonymous_Access_Type + and then (Nkind (Original_Node (N)) /= N_Attribute_Reference + or else Attribute_Name (Original_Node (N)) = Name_Access) + then + Apply_Accessibility_Check + (Operand, Target_Type, Insert_Node => Operand); + + -- If the level of the operand type is statically deeper than the + -- level of the target type, then force Program_Error. Note that this + -- can only occur for cases where the attribute is within the body of + -- an instantiation (otherwise the conversion will already have been + -- rejected as illegal). Note: warnings are issued by the analyzer + -- for the instance cases. + + elsif In_Instance_Body + and then Type_Access_Level (Operand_Type) > + Type_Access_Level (Target_Type) + then + Rewrite (N, + Make_Raise_Program_Error (Sloc (N), + Reason => PE_Accessibility_Check_Failed)); + Set_Etype (N, Target_Type); + + -- When the operand is a selected access discriminant the check needs + -- to be made against the level of the object denoted by the prefix + -- of the selected name. Force Program_Error for this case as well + -- (this accessibility violation can only happen if within the body + -- of an instantiation). + + elsif In_Instance_Body + and then Ekind (Operand_Type) = E_Anonymous_Access_Type + and then Nkind (Operand) = N_Selected_Component + and then Object_Access_Level (Operand) > + Type_Access_Level (Target_Type) + then + Rewrite (N, + Make_Raise_Program_Error (Sloc (N), + Reason => PE_Accessibility_Check_Failed)); + Set_Etype (N, Target_Type); + end if; + end if; + + -- Case of conversions of tagged types and access to tagged types + + -- When needed, that is to say when the expression is class-wide, Add + -- runtime a tag check for (strict) downward conversion by using the + -- membership test, generating: + + -- [constraint_error when Operand not in Target_Type'Class] + + -- or in the access type case + + -- [constraint_error + -- when Operand /= null + -- and then Operand.all not in + -- Designated_Type (Target_Type)'Class] + + if (Is_Access_Type (Target_Type) + and then Is_Tagged_Type (Designated_Type (Target_Type))) + or else Is_Tagged_Type (Target_Type) + then + -- Do not do any expansion in the access type case if the parent is a + -- renaming, since this is an error situation which will be caught by + -- Sem_Ch8, and the expansion can interfere with this error check. + + if Is_Access_Type (Target_Type) + and then Is_Renamed_Object (N) + then + return; + end if; + + -- Otherwise, proceed with processing tagged conversion + + declare + Actual_Op_Typ : Entity_Id; + Actual_Targ_Typ : Entity_Id; + Make_Conversion : Boolean := False; + Root_Op_Typ : Entity_Id; + + procedure Make_Tag_Check (Targ_Typ : Entity_Id); + -- Create a membership check to test whether Operand is a member + -- of Targ_Typ. If the original Target_Type is an access, include + -- a test for null value. The check is inserted at N. + + -------------------- + -- Make_Tag_Check -- + -------------------- + + procedure Make_Tag_Check (Targ_Typ : Entity_Id) is + Cond : Node_Id; + + begin + -- Generate: + -- [Constraint_Error + -- when Operand /= null + -- and then Operand.all not in Targ_Typ] + + if Is_Access_Type (Target_Type) then + Cond := + Make_And_Then (Loc, + Left_Opnd => + Make_Op_Ne (Loc, + Left_Opnd => Duplicate_Subexpr_No_Checks (Operand), + Right_Opnd => Make_Null (Loc)), + + Right_Opnd => + Make_Not_In (Loc, + Left_Opnd => + Make_Explicit_Dereference (Loc, + Prefix => Duplicate_Subexpr_No_Checks (Operand)), + Right_Opnd => New_Reference_To (Targ_Typ, Loc))); + + -- Generate: + -- [Constraint_Error when Operand not in Targ_Typ] + + else + Cond := + Make_Not_In (Loc, + Left_Opnd => Duplicate_Subexpr_No_Checks (Operand), + Right_Opnd => New_Reference_To (Targ_Typ, Loc)); + end if; + + Insert_Action (N, + Make_Raise_Constraint_Error (Loc, + Condition => Cond, + Reason => CE_Tag_Check_Failed)); + end Make_Tag_Check; + + -- Start of processing + + begin + if Is_Access_Type (Target_Type) then + Actual_Op_Typ := Designated_Type (Operand_Type); + Actual_Targ_Typ := Designated_Type (Target_Type); + + else + Actual_Op_Typ := Operand_Type; + Actual_Targ_Typ := Target_Type; + end if; + + Root_Op_Typ := Root_Type (Actual_Op_Typ); + + -- Ada 2005 (AI-251): Handle interface type conversion + + if Is_Interface (Actual_Op_Typ) then + Expand_Interface_Conversion (N, Is_Static => False); + return; + end if; + + if not Tag_Checks_Suppressed (Actual_Targ_Typ) then + + -- Create a runtime tag check for a downward class-wide type + -- conversion. + + if Is_Class_Wide_Type (Actual_Op_Typ) + and then Root_Op_Typ /= Actual_Targ_Typ + and then Is_Ancestor (Root_Op_Typ, Actual_Targ_Typ) + then + Make_Tag_Check (Class_Wide_Type (Actual_Targ_Typ)); + Make_Conversion := True; + end if; + + -- AI05-0073: If the result subtype of the function is defined + -- by an access_definition designating a specific tagged type + -- T, a check is made that the result value is null or the tag + -- of the object designated by the result value identifies T. + -- Constraint_Error is raised if this check fails. + + if Nkind (Parent (N)) = Sinfo.N_Return_Statement then + declare + Func : Entity_Id; + Func_Typ : Entity_Id; + + begin + -- Climb scope stack looking for the enclosing function + + Func := Current_Scope; + while Present (Func) + and then Ekind (Func) /= E_Function + loop + Func := Scope (Func); + end loop; + + -- The function's return subtype must be defined using + -- an access definition. + + if Nkind (Result_Definition (Parent (Func))) = + N_Access_Definition + then + Func_Typ := Directly_Designated_Type (Etype (Func)); + + -- The return subtype denotes a specific tagged type, + -- in other words, a non class-wide type. + + if Is_Tagged_Type (Func_Typ) + and then not Is_Class_Wide_Type (Func_Typ) + then + Make_Tag_Check (Actual_Targ_Typ); + Make_Conversion := True; + end if; + end if; + end; + end if; + + -- We have generated a tag check for either a class-wide type + -- conversion or for AI05-0073. + + if Make_Conversion then + declare + Conv : Node_Id; + begin + Conv := + Make_Unchecked_Type_Conversion (Loc, + Subtype_Mark => New_Occurrence_Of (Target_Type, Loc), + Expression => Relocate_Node (Expression (N))); + Rewrite (N, Conv); + Analyze_And_Resolve (N, Target_Type); + end; + end if; + end if; + end; + + -- Case of other access type conversions + + elsif Is_Access_Type (Target_Type) then + Apply_Constraint_Check (Operand, Target_Type); + + -- Case of conversions from a fixed-point type + + -- These conversions require special expansion and processing, found in + -- the Exp_Fixd package. We ignore cases where Conversion_OK is set, + -- since from a semantic point of view, these are simple integer + -- conversions, which do not need further processing. + + elsif Is_Fixed_Point_Type (Operand_Type) + and then not Conversion_OK (N) + then + -- We should never see universal fixed at this case, since the + -- expansion of the constituent divide or multiply should have + -- eliminated the explicit mention of universal fixed. + + pragma Assert (Operand_Type /= Universal_Fixed); + + -- Check for special case of the conversion to universal real that + -- occurs as a result of the use of a round attribute. In this case, + -- the real type for the conversion is taken from the target type of + -- the Round attribute and the result must be marked as rounded. + + if Target_Type = Universal_Real + and then Nkind (Parent (N)) = N_Attribute_Reference + and then Attribute_Name (Parent (N)) = Name_Round + then + Set_Rounded_Result (N); + Set_Etype (N, Etype (Parent (N))); + end if; + + -- Otherwise do correct fixed-conversion, but skip these if the + -- Conversion_OK flag is set, because from a semantic point of + -- view these are simple integer conversions needing no further + -- processing (the backend will simply treat them as integers) + + if not Conversion_OK (N) then + if Is_Fixed_Point_Type (Etype (N)) then + Expand_Convert_Fixed_To_Fixed (N); + Real_Range_Check; + + elsif Is_Integer_Type (Etype (N)) then + Expand_Convert_Fixed_To_Integer (N); + + else + pragma Assert (Is_Floating_Point_Type (Etype (N))); + Expand_Convert_Fixed_To_Float (N); + Real_Range_Check; + end if; + end if; + + -- Case of conversions to a fixed-point type + + -- These conversions require special expansion and processing, found in + -- the Exp_Fixd package. Again, ignore cases where Conversion_OK is set, + -- since from a semantic point of view, these are simple integer + -- conversions, which do not need further processing. + + elsif Is_Fixed_Point_Type (Target_Type) + and then not Conversion_OK (N) + then + if Is_Integer_Type (Operand_Type) then + Expand_Convert_Integer_To_Fixed (N); + Real_Range_Check; + else + pragma Assert (Is_Floating_Point_Type (Operand_Type)); + Expand_Convert_Float_To_Fixed (N); + Real_Range_Check; + end if; + + -- Case of float-to-integer conversions + + -- We also handle float-to-fixed conversions with Conversion_OK set + -- since semantically the fixed-point target is treated as though it + -- were an integer in such cases. + + elsif Is_Floating_Point_Type (Operand_Type) + and then + (Is_Integer_Type (Target_Type) + or else + (Is_Fixed_Point_Type (Target_Type) and then Conversion_OK (N))) + then + -- One more check here, gcc is still not able to do conversions of + -- this type with proper overflow checking, and so gigi is doing an + -- approximation of what is required by doing floating-point compares + -- with the end-point. But that can lose precision in some cases, and + -- give a wrong result. Converting the operand to Universal_Real is + -- helpful, but still does not catch all cases with 64-bit integers + -- on targets with only 64-bit floats + + -- The above comment seems obsoleted by Apply_Float_Conversion_Check + -- Can this code be removed ??? + + if Do_Range_Check (Operand) then + Rewrite (Operand, + Make_Type_Conversion (Loc, + Subtype_Mark => + New_Occurrence_Of (Universal_Real, Loc), + Expression => + Relocate_Node (Operand))); + + Set_Etype (Operand, Universal_Real); + Enable_Range_Check (Operand); + Set_Do_Range_Check (Expression (Operand), False); + end if; + + -- Case of array conversions + + -- Expansion of array conversions, add required length/range checks but + -- only do this if there is no change of representation. For handling of + -- this case, see Handle_Changed_Representation. + + elsif Is_Array_Type (Target_Type) then + + if Is_Constrained (Target_Type) then + Apply_Length_Check (Operand, Target_Type); + else + Apply_Range_Check (Operand, Target_Type); + end if; + + Handle_Changed_Representation; + + -- Case of conversions of discriminated types + + -- Add required discriminant checks if target is constrained. Again this + -- change is skipped if we have a change of representation. + + elsif Has_Discriminants (Target_Type) + and then Is_Constrained (Target_Type) + then + Apply_Discriminant_Check (Operand, Target_Type); + Handle_Changed_Representation; + + -- Case of all other record conversions. The only processing required + -- is to check for a change of representation requiring the special + -- assignment processing. + + elsif Is_Record_Type (Target_Type) then + + -- Ada 2005 (AI-216): Program_Error is raised when converting from + -- a derived Unchecked_Union type to an unconstrained type that is + -- not Unchecked_Union if the operand lacks inferable discriminants. + + if Is_Derived_Type (Operand_Type) + and then Is_Unchecked_Union (Base_Type (Operand_Type)) + and then not Is_Constrained (Target_Type) + and then not Is_Unchecked_Union (Base_Type (Target_Type)) + and then not Has_Inferable_Discriminants (Operand) + then + -- To prevent Gigi from generating illegal code, we generate a + -- Program_Error node, but we give it the target type of the + -- conversion. + + declare + PE : constant Node_Id := Make_Raise_Program_Error (Loc, + Reason => PE_Unchecked_Union_Restriction); + + begin + Set_Etype (PE, Target_Type); + Rewrite (N, PE); + + end; + else + Handle_Changed_Representation; + end if; + + -- Case of conversions of enumeration types + + elsif Is_Enumeration_Type (Target_Type) then + + -- Special processing is required if there is a change of + -- representation (from enumeration representation clauses) + + if not Same_Representation (Target_Type, Operand_Type) then + + -- Convert: x(y) to x'val (ytyp'val (y)) + + Rewrite (N, + Make_Attribute_Reference (Loc, + Prefix => New_Occurrence_Of (Target_Type, Loc), + Attribute_Name => Name_Val, + Expressions => New_List ( + Make_Attribute_Reference (Loc, + Prefix => New_Occurrence_Of (Operand_Type, Loc), + Attribute_Name => Name_Pos, + Expressions => New_List (Operand))))); + + Analyze_And_Resolve (N, Target_Type); + end if; + + -- Case of conversions to floating-point + + elsif Is_Floating_Point_Type (Target_Type) then + Real_Range_Check; + end if; + + -- At this stage, either the conversion node has been transformed into + -- some other equivalent expression, or left as a conversion that can + -- be handled by Gigi. The conversions that Gigi can handle are the + -- following: + + -- Conversions with no change of representation or type + + -- Numeric conversions involving integer, floating- and fixed-point + -- values. Fixed-point values are allowed only if Conversion_OK is + -- set, i.e. if the fixed-point values are to be treated as integers. + + -- No other conversions should be passed to Gigi + + -- Check: are these rules stated in sinfo??? if so, why restate here??? + + -- The only remaining step is to generate a range check if we still have + -- a type conversion at this stage and Do_Range_Check is set. For now we + -- do this only for conversions of discrete types. + + if Nkind (N) = N_Type_Conversion + and then Is_Discrete_Type (Etype (N)) + then + declare + Expr : constant Node_Id := Expression (N); + Ftyp : Entity_Id; + Ityp : Entity_Id; + + begin + if Do_Range_Check (Expr) + and then Is_Discrete_Type (Etype (Expr)) + then + Set_Do_Range_Check (Expr, False); + + -- Before we do a range check, we have to deal with treating a + -- fixed-point operand as an integer. The way we do this is + -- simply to do an unchecked conversion to an appropriate + -- integer type large enough to hold the result. + + -- This code is not active yet, because we are only dealing + -- with discrete types so far ??? + + if Nkind (Expr) in N_Has_Treat_Fixed_As_Integer + and then Treat_Fixed_As_Integer (Expr) + then + Ftyp := Base_Type (Etype (Expr)); + + if Esize (Ftyp) >= Esize (Standard_Integer) then + Ityp := Standard_Long_Long_Integer; + else + Ityp := Standard_Integer; + end if; + + Rewrite (Expr, Unchecked_Convert_To (Ityp, Expr)); + end if; + + -- Reset overflow flag, since the range check will include + -- dealing with possible overflow, and generate the check If + -- Address is either a source type or target type, suppress + -- range check to avoid typing anomalies when it is a visible + -- integer type. + + Set_Do_Overflow_Check (N, False); + if not Is_Descendent_Of_Address (Etype (Expr)) + and then not Is_Descendent_Of_Address (Target_Type) + then + Generate_Range_Check + (Expr, Target_Type, CE_Range_Check_Failed); + end if; + end if; + end; + end if; + + -- Final step, if the result is a type conversion involving Vax_Float + -- types, then it is subject for further special processing. + + if Nkind (N) = N_Type_Conversion + and then (Vax_Float (Operand_Type) or else Vax_Float (Target_Type)) + then + Expand_Vax_Conversion (N); + return; + end if; + end Expand_N_Type_Conversion; + + ----------------------------------- + -- Expand_N_Unchecked_Expression -- + ----------------------------------- + + -- Remove the unchecked expression node from the tree. It's job was simply + -- to make sure that its constituent expression was handled with checks + -- off, and now that that is done, we can remove it from the tree, and + -- indeed must, since gigi does not expect to see these nodes. + + procedure Expand_N_Unchecked_Expression (N : Node_Id) is + Exp : constant Node_Id := Expression (N); + + begin + Set_Assignment_OK (Exp, Assignment_OK (N) or Assignment_OK (Exp)); + Rewrite (N, Exp); + end Expand_N_Unchecked_Expression; + + ---------------------------------------- + -- Expand_N_Unchecked_Type_Conversion -- + ---------------------------------------- + + -- If this cannot be handled by Gigi and we haven't already made a + -- temporary for it, do it now. + + procedure Expand_N_Unchecked_Type_Conversion (N : Node_Id) is + Target_Type : constant Entity_Id := Etype (N); + Operand : constant Node_Id := Expression (N); + Operand_Type : constant Entity_Id := Etype (Operand); + + begin + -- If we have a conversion of a compile time known value to a target + -- type and the value is in range of the target type, then we can simply + -- replace the construct by an integer literal of the correct type. We + -- only apply this to integer types being converted. Possibly it may + -- apply in other cases, but it is too much trouble to worry about. + + -- Note that we do not do this transformation if the Kill_Range_Check + -- flag is set, since then the value may be outside the expected range. + -- This happens in the Normalize_Scalars case. + + -- We also skip this if either the target or operand type is biased + -- because in this case, the unchecked conversion is supposed to + -- preserve the bit pattern, not the integer value. + + if Is_Integer_Type (Target_Type) + and then not Has_Biased_Representation (Target_Type) + and then Is_Integer_Type (Operand_Type) + and then not Has_Biased_Representation (Operand_Type) + and then Compile_Time_Known_Value (Operand) + and then not Kill_Range_Check (N) + then + declare + Val : constant Uint := Expr_Value (Operand); + + begin + if Compile_Time_Known_Value (Type_Low_Bound (Target_Type)) + and then + Compile_Time_Known_Value (Type_High_Bound (Target_Type)) + and then + Val >= Expr_Value (Type_Low_Bound (Target_Type)) + and then + Val <= Expr_Value (Type_High_Bound (Target_Type)) + then + Rewrite (N, Make_Integer_Literal (Sloc (N), Val)); + + -- If Address is the target type, just set the type to avoid a + -- spurious type error on the literal when Address is a visible + -- integer type. + + if Is_Descendent_Of_Address (Target_Type) then + Set_Etype (N, Target_Type); + else + Analyze_And_Resolve (N, Target_Type); + end if; + + return; + end if; + end; + end if; + + -- Nothing to do if conversion is safe + + if Safe_Unchecked_Type_Conversion (N) then + return; + end if; + + -- Otherwise force evaluation unless Assignment_OK flag is set (this + -- flag indicates ??? -- more comments needed here) + + if Assignment_OK (N) then + null; + else + Force_Evaluation (N); + end if; + end Expand_N_Unchecked_Type_Conversion; + + ---------------------------- + -- Expand_Record_Equality -- + ---------------------------- + + -- For non-variant records, Equality is expanded when needed into: + + -- and then Lhs.Discr1 = Rhs.Discr1 + -- and then ... + -- and then Lhs.Discrn = Rhs.Discrn + -- and then Lhs.Cmp1 = Rhs.Cmp1 + -- and then ... + -- and then Lhs.Cmpn = Rhs.Cmpn + + -- The expression is folded by the back-end for adjacent fields. This + -- function is called for tagged record in only one occasion: for imple- + -- menting predefined primitive equality (see Predefined_Primitives_Bodies) + -- otherwise the primitive "=" is used directly. + + function Expand_Record_Equality + (Nod : Node_Id; + Typ : Entity_Id; + Lhs : Node_Id; + Rhs : Node_Id; + Bodies : List_Id) return Node_Id + is + Loc : constant Source_Ptr := Sloc (Nod); + + Result : Node_Id; + C : Entity_Id; + + First_Time : Boolean := True; + + function Suitable_Element (C : Entity_Id) return Entity_Id; + -- Return the first field to compare beginning with C, skipping the + -- inherited components. + + ---------------------- + -- Suitable_Element -- + ---------------------- + + function Suitable_Element (C : Entity_Id) return Entity_Id is + begin + if No (C) then + return Empty; + + elsif Ekind (C) /= E_Discriminant + and then Ekind (C) /= E_Component + then + return Suitable_Element (Next_Entity (C)); + + elsif Is_Tagged_Type (Typ) + and then C /= Original_Record_Component (C) + then + return Suitable_Element (Next_Entity (C)); + + elsif Chars (C) = Name_uController + or else Chars (C) = Name_uTag + then + return Suitable_Element (Next_Entity (C)); + + elsif Is_Interface (Etype (C)) then + return Suitable_Element (Next_Entity (C)); + + else + return C; + end if; + end Suitable_Element; + + -- Start of processing for Expand_Record_Equality + + begin + -- Generates the following code: (assuming that Typ has one Discr and + -- component C2 is also a record) + + -- True + -- and then Lhs.Discr1 = Rhs.Discr1 + -- and then Lhs.C1 = Rhs.C1 + -- and then Lhs.C2.C1=Rhs.C2.C1 and then ... Lhs.C2.Cn=Rhs.C2.Cn + -- and then ... + -- and then Lhs.Cmpn = Rhs.Cmpn + + Result := New_Reference_To (Standard_True, Loc); + C := Suitable_Element (First_Entity (Typ)); + + while Present (C) loop + declare + New_Lhs : Node_Id; + New_Rhs : Node_Id; + Check : Node_Id; + + begin + if First_Time then + First_Time := False; + New_Lhs := Lhs; + New_Rhs := Rhs; + else + New_Lhs := New_Copy_Tree (Lhs); + New_Rhs := New_Copy_Tree (Rhs); + end if; + + Check := + Expand_Composite_Equality (Nod, Etype (C), + Lhs => + Make_Selected_Component (Loc, + Prefix => New_Lhs, + Selector_Name => New_Reference_To (C, Loc)), + Rhs => + Make_Selected_Component (Loc, + Prefix => New_Rhs, + Selector_Name => New_Reference_To (C, Loc)), + Bodies => Bodies); + + -- If some (sub)component is an unchecked_union, the whole + -- operation will raise program error. + + if Nkind (Check) = N_Raise_Program_Error then + Result := Check; + Set_Etype (Result, Standard_Boolean); + exit; + else + Result := + Make_And_Then (Loc, + Left_Opnd => Result, + Right_Opnd => Check); + end if; + end; + + C := Suitable_Element (Next_Entity (C)); + end loop; + + return Result; + end Expand_Record_Equality; + + ------------------------------------- + -- Fixup_Universal_Fixed_Operation -- + ------------------------------------- + + procedure Fixup_Universal_Fixed_Operation (N : Node_Id) is + Conv : constant Node_Id := Parent (N); + + begin + -- We must have a type conversion immediately above us + + pragma Assert (Nkind (Conv) = N_Type_Conversion); + + -- Normally the type conversion gives our target type. The exception + -- occurs in the case of the Round attribute, where the conversion + -- will be to universal real, and our real type comes from the Round + -- attribute (as well as an indication that we must round the result) + + if Nkind (Parent (Conv)) = N_Attribute_Reference + and then Attribute_Name (Parent (Conv)) = Name_Round + then + Set_Etype (N, Etype (Parent (Conv))); + Set_Rounded_Result (N); + + -- Normal case where type comes from conversion above us + + else + Set_Etype (N, Etype (Conv)); + end if; + end Fixup_Universal_Fixed_Operation; + + ------------------------------ + -- Get_Allocator_Final_List -- + ------------------------------ + + function Get_Allocator_Final_List + (N : Node_Id; + T : Entity_Id; + PtrT : Entity_Id) return Entity_Id + is + Loc : constant Source_Ptr := Sloc (N); + + Owner : Entity_Id := PtrT; + -- The entity whose finalization list must be used to attach the + -- allocated object. + + begin + if Ekind (PtrT) = E_Anonymous_Access_Type then + + -- If the context is an access parameter, we need to create a + -- non-anonymous access type in order to have a usable final list, + -- because there is otherwise no pool to which the allocated object + -- can belong. We create both the type and the finalization chain + -- here, because freezing an internal type does not create such a + -- chain. The Final_Chain that is thus created is shared by the + -- access parameter. The access type is tested against the result + -- type of the function to exclude allocators whose type is an + -- anonymous access result type. We freeze the type at once to + -- ensure that it is properly decorated for the back-end, even + -- if the context and current scope is a loop. + + if Nkind (Associated_Node_For_Itype (PtrT)) + in N_Subprogram_Specification + and then + PtrT /= + Etype (Defining_Unit_Name (Associated_Node_For_Itype (PtrT))) + then + Owner := Make_Defining_Identifier (Loc, New_Internal_Name ('J')); + Insert_Action (N, + Make_Full_Type_Declaration (Loc, + Defining_Identifier => Owner, + Type_Definition => + Make_Access_To_Object_Definition (Loc, + Subtype_Indication => + New_Occurrence_Of (T, Loc)))); + + Freeze_Before (N, Owner); + Build_Final_List (N, Owner); + Set_Associated_Final_Chain (PtrT, Associated_Final_Chain (Owner)); + + -- Ada 2005 (AI-318-02): If the context is a return object + -- declaration, then the anonymous return subtype is defined to have + -- the same accessibility level as that of the function's result + -- subtype, which means that we want the scope where the function is + -- declared. + + elsif Nkind (Associated_Node_For_Itype (PtrT)) = N_Object_Declaration + and then Ekind (Scope (PtrT)) = E_Return_Statement + then + Owner := Scope (Return_Applies_To (Scope (PtrT))); + + -- Case of an access discriminant, or (Ada 2005), of an anonymous + -- access component or anonymous access function result: find the + -- final list associated with the scope of the type. (In the + -- anonymous access component kind, a list controller will have + -- been allocated when freezing the record type, and PtrT has an + -- Associated_Final_Chain attribute designating it.) + + elsif No (Associated_Final_Chain (PtrT)) then + Owner := Scope (PtrT); + end if; + end if; + + return Find_Final_List (Owner); + end Get_Allocator_Final_List; + + --------------------------------- + -- Has_Inferable_Discriminants -- + --------------------------------- + + function Has_Inferable_Discriminants (N : Node_Id) return Boolean is + + function Prefix_Is_Formal_Parameter (N : Node_Id) return Boolean; + -- Determines whether the left-most prefix of a selected component is a + -- formal parameter in a subprogram. Assumes N is a selected component. + + -------------------------------- + -- Prefix_Is_Formal_Parameter -- + -------------------------------- + + function Prefix_Is_Formal_Parameter (N : Node_Id) return Boolean is + Sel_Comp : Node_Id := N; + + begin + -- Move to the left-most prefix by climbing up the tree + + while Present (Parent (Sel_Comp)) + and then Nkind (Parent (Sel_Comp)) = N_Selected_Component + loop + Sel_Comp := Parent (Sel_Comp); + end loop; + + return Ekind (Entity (Prefix (Sel_Comp))) in Formal_Kind; + end Prefix_Is_Formal_Parameter; + + -- Start of processing for Has_Inferable_Discriminants + + begin + -- For identifiers and indexed components, it is sufficient to have a + -- constrained Unchecked_Union nominal subtype. + + if Nkind_In (N, N_Identifier, N_Indexed_Component) then + return Is_Unchecked_Union (Base_Type (Etype (N))) + and then + Is_Constrained (Etype (N)); + + -- For selected components, the subtype of the selector must be a + -- constrained Unchecked_Union. If the component is subject to a + -- per-object constraint, then the enclosing object must have inferable + -- discriminants. + + elsif Nkind (N) = N_Selected_Component then + if Has_Per_Object_Constraint (Entity (Selector_Name (N))) then + + -- A small hack. If we have a per-object constrained selected + -- component of a formal parameter, return True since we do not + -- know the actual parameter association yet. + + if Prefix_Is_Formal_Parameter (N) then + return True; + end if; + + -- Otherwise, check the enclosing object and the selector + + return Has_Inferable_Discriminants (Prefix (N)) + and then + Has_Inferable_Discriminants (Selector_Name (N)); + end if; + + -- The call to Has_Inferable_Discriminants will determine whether + -- the selector has a constrained Unchecked_Union nominal type. + + return Has_Inferable_Discriminants (Selector_Name (N)); + + -- A qualified expression has inferable discriminants if its subtype + -- mark is a constrained Unchecked_Union subtype. + + elsif Nkind (N) = N_Qualified_Expression then + return Is_Unchecked_Union (Subtype_Mark (N)) + and then + Is_Constrained (Subtype_Mark (N)); + + end if; + + return False; + end Has_Inferable_Discriminants; + + ------------------------------- + -- Insert_Dereference_Action -- + ------------------------------- + + procedure Insert_Dereference_Action (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Typ : constant Entity_Id := Etype (N); + Pool : constant Entity_Id := Associated_Storage_Pool (Typ); + Pnod : constant Node_Id := Parent (N); + + function Is_Checked_Storage_Pool (P : Entity_Id) return Boolean; + -- Return true if type of P is derived from Checked_Pool; + + ----------------------------- + -- Is_Checked_Storage_Pool -- + ----------------------------- + + function Is_Checked_Storage_Pool (P : Entity_Id) return Boolean is + T : Entity_Id; + + begin + if No (P) then + return False; + end if; + + T := Etype (P); + while T /= Etype (T) loop + if Is_RTE (T, RE_Checked_Pool) then + return True; + else + T := Etype (T); + end if; + end loop; + + return False; + end Is_Checked_Storage_Pool; + + -- Start of processing for Insert_Dereference_Action + + begin + pragma Assert (Nkind (Pnod) = N_Explicit_Dereference); + + if not (Is_Checked_Storage_Pool (Pool) + and then Comes_From_Source (Original_Node (Pnod))) + then + return; + end if; + + Insert_Action (N, + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To ( + Find_Prim_Op (Etype (Pool), Name_Dereference), Loc), + + Parameter_Associations => New_List ( + + -- Pool + + New_Reference_To (Pool, Loc), + + -- Storage_Address. We use the attribute Pool_Address, which uses + -- the pointer itself to find the address of the object, and which + -- handles unconstrained arrays properly by computing the address + -- of the template. i.e. the correct address of the corresponding + -- allocation. + + Make_Attribute_Reference (Loc, + Prefix => Duplicate_Subexpr_Move_Checks (N), + Attribute_Name => Name_Pool_Address), + + -- Size_In_Storage_Elements + + Make_Op_Divide (Loc, + Left_Opnd => + Make_Attribute_Reference (Loc, + Prefix => + Make_Explicit_Dereference (Loc, + Duplicate_Subexpr_Move_Checks (N)), + Attribute_Name => Name_Size), + Right_Opnd => + Make_Integer_Literal (Loc, System_Storage_Unit)), + + -- Alignment + + Make_Attribute_Reference (Loc, + Prefix => + Make_Explicit_Dereference (Loc, + Duplicate_Subexpr_Move_Checks (N)), + Attribute_Name => Name_Alignment)))); + + exception + when RE_Not_Available => + return; + end Insert_Dereference_Action; + + ------------------------------ + -- Make_Array_Comparison_Op -- + ------------------------------ + + -- This is a hand-coded expansion of the following generic function: + + -- generic + -- type elem is (<>); + -- type index is (<>); + -- type a is array (index range <>) of elem; + + -- function Gnnn (X : a; Y: a) return boolean is + -- J : index := Y'first; + + -- begin + -- if X'length = 0 then + -- return false; + + -- elsif Y'length = 0 then + -- return true; + + -- else + -- for I in X'range loop + -- if X (I) = Y (J) then + -- if J = Y'last then + -- exit; + -- else + -- J := index'succ (J); + -- end if; + + -- else + -- return X (I) > Y (J); + -- end if; + -- end loop; + + -- return X'length > Y'length; + -- end if; + -- end Gnnn; + + -- Note that since we are essentially doing this expansion by hand, we + -- do not need to generate an actual or formal generic part, just the + -- instantiated function itself. + + function Make_Array_Comparison_Op + (Typ : Entity_Id; + Nod : Node_Id) return Node_Id + is + Loc : constant Source_Ptr := Sloc (Nod); + + X : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uX); + Y : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uY); + I : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uI); + J : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uJ); + + Index : constant Entity_Id := Base_Type (Etype (First_Index (Typ))); + + Loop_Statement : Node_Id; + Loop_Body : Node_Id; + If_Stat : Node_Id; + Inner_If : Node_Id; + Final_Expr : Node_Id; + Func_Body : Node_Id; + Func_Name : Entity_Id; + Formals : List_Id; + Length1 : Node_Id; + Length2 : Node_Id; + + begin + -- if J = Y'last then + -- exit; + -- else + -- J := index'succ (J); + -- end if; + + Inner_If := + Make_Implicit_If_Statement (Nod, + Condition => + Make_Op_Eq (Loc, + Left_Opnd => New_Reference_To (J, Loc), + Right_Opnd => + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Y, Loc), + Attribute_Name => Name_Last)), + + Then_Statements => New_List ( + Make_Exit_Statement (Loc)), + + Else_Statements => + New_List ( + Make_Assignment_Statement (Loc, + Name => New_Reference_To (J, Loc), + Expression => + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Index, Loc), + Attribute_Name => Name_Succ, + Expressions => New_List (New_Reference_To (J, Loc)))))); + + -- if X (I) = Y (J) then + -- if ... end if; + -- else + -- return X (I) > Y (J); + -- end if; + + Loop_Body := + Make_Implicit_If_Statement (Nod, + Condition => + Make_Op_Eq (Loc, + Left_Opnd => + Make_Indexed_Component (Loc, + Prefix => New_Reference_To (X, Loc), + Expressions => New_List (New_Reference_To (I, Loc))), + + Right_Opnd => + Make_Indexed_Component (Loc, + Prefix => New_Reference_To (Y, Loc), + Expressions => New_List (New_Reference_To (J, Loc)))), + + Then_Statements => New_List (Inner_If), + + Else_Statements => New_List ( + Make_Simple_Return_Statement (Loc, + Expression => + Make_Op_Gt (Loc, + Left_Opnd => + Make_Indexed_Component (Loc, + Prefix => New_Reference_To (X, Loc), + Expressions => New_List (New_Reference_To (I, Loc))), + + Right_Opnd => + Make_Indexed_Component (Loc, + Prefix => New_Reference_To (Y, Loc), + Expressions => New_List ( + New_Reference_To (J, Loc))))))); + + -- for I in X'range loop + -- if ... end if; + -- end loop; + + Loop_Statement := + Make_Implicit_Loop_Statement (Nod, + Identifier => Empty, + + Iteration_Scheme => + Make_Iteration_Scheme (Loc, + Loop_Parameter_Specification => + Make_Loop_Parameter_Specification (Loc, + Defining_Identifier => I, + Discrete_Subtype_Definition => + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (X, Loc), + Attribute_Name => Name_Range))), + + Statements => New_List (Loop_Body)); + + -- if X'length = 0 then + -- return false; + -- elsif Y'length = 0 then + -- return true; + -- else + -- for ... loop ... end loop; + -- return X'length > Y'length; + -- end if; + + Length1 := + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (X, Loc), + Attribute_Name => Name_Length); + + Length2 := + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Y, Loc), + Attribute_Name => Name_Length); + + Final_Expr := + Make_Op_Gt (Loc, + Left_Opnd => Length1, + Right_Opnd => Length2); + + If_Stat := + Make_Implicit_If_Statement (Nod, + Condition => + Make_Op_Eq (Loc, + Left_Opnd => + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (X, Loc), + Attribute_Name => Name_Length), + Right_Opnd => + Make_Integer_Literal (Loc, 0)), + + Then_Statements => + New_List ( + Make_Simple_Return_Statement (Loc, + Expression => New_Reference_To (Standard_False, Loc))), + + Elsif_Parts => New_List ( + Make_Elsif_Part (Loc, + Condition => + Make_Op_Eq (Loc, + Left_Opnd => + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Y, Loc), + Attribute_Name => Name_Length), + Right_Opnd => + Make_Integer_Literal (Loc, 0)), + + Then_Statements => + New_List ( + Make_Simple_Return_Statement (Loc, + Expression => New_Reference_To (Standard_True, Loc))))), + + Else_Statements => New_List ( + Loop_Statement, + Make_Simple_Return_Statement (Loc, + Expression => Final_Expr))); + + -- (X : a; Y: a) + + Formals := New_List ( + Make_Parameter_Specification (Loc, + Defining_Identifier => X, + Parameter_Type => New_Reference_To (Typ, Loc)), + + Make_Parameter_Specification (Loc, + Defining_Identifier => Y, + Parameter_Type => New_Reference_To (Typ, Loc))); + + -- function Gnnn (...) return boolean is + -- J : index := Y'first; + -- begin + -- if ... end if; + -- end Gnnn; + + Func_Name := Make_Defining_Identifier (Loc, New_Internal_Name ('G')); + + Func_Body := + Make_Subprogram_Body (Loc, + Specification => + Make_Function_Specification (Loc, + Defining_Unit_Name => Func_Name, + Parameter_Specifications => Formals, + Result_Definition => New_Reference_To (Standard_Boolean, Loc)), + + Declarations => New_List ( + Make_Object_Declaration (Loc, + Defining_Identifier => J, + Object_Definition => New_Reference_To (Index, Loc), + Expression => + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Y, Loc), + Attribute_Name => Name_First))), + + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, + Statements => New_List (If_Stat))); + + return Func_Body; + end Make_Array_Comparison_Op; + + --------------------------- + -- Make_Boolean_Array_Op -- + --------------------------- + + -- For logical operations on boolean arrays, expand in line the following, + -- replacing 'and' with 'or' or 'xor' where needed: + + -- function Annn (A : typ; B: typ) return typ is + -- C : typ; + -- begin + -- for J in A'range loop + -- C (J) := A (J) op B (J); + -- end loop; + -- return C; + -- end Annn; + + -- Here typ is the boolean array type + + function Make_Boolean_Array_Op + (Typ : Entity_Id; + N : Node_Id) return Node_Id + is + Loc : constant Source_Ptr := Sloc (N); + + A : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uA); + B : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uB); + C : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uC); + J : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uJ); + + A_J : Node_Id; + B_J : Node_Id; + C_J : Node_Id; + Op : Node_Id; + + Formals : List_Id; + Func_Name : Entity_Id; + Func_Body : Node_Id; + Loop_Statement : Node_Id; + + begin + A_J := + Make_Indexed_Component (Loc, + Prefix => New_Reference_To (A, Loc), + Expressions => New_List (New_Reference_To (J, Loc))); + + B_J := + Make_Indexed_Component (Loc, + Prefix => New_Reference_To (B, Loc), + Expressions => New_List (New_Reference_To (J, Loc))); + + C_J := + Make_Indexed_Component (Loc, + Prefix => New_Reference_To (C, Loc), + Expressions => New_List (New_Reference_To (J, Loc))); + + if Nkind (N) = N_Op_And then + Op := + Make_Op_And (Loc, + Left_Opnd => A_J, + Right_Opnd => B_J); + + elsif Nkind (N) = N_Op_Or then + Op := + Make_Op_Or (Loc, + Left_Opnd => A_J, + Right_Opnd => B_J); + + else + Op := + Make_Op_Xor (Loc, + Left_Opnd => A_J, + Right_Opnd => B_J); + end if; + + Loop_Statement := + Make_Implicit_Loop_Statement (N, + Identifier => Empty, + + Iteration_Scheme => + Make_Iteration_Scheme (Loc, + Loop_Parameter_Specification => + Make_Loop_Parameter_Specification (Loc, + Defining_Identifier => J, + Discrete_Subtype_Definition => + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (A, Loc), + Attribute_Name => Name_Range))), + + Statements => New_List ( + Make_Assignment_Statement (Loc, + Name => C_J, + Expression => Op))); + + Formals := New_List ( + Make_Parameter_Specification (Loc, + Defining_Identifier => A, + Parameter_Type => New_Reference_To (Typ, Loc)), + + Make_Parameter_Specification (Loc, + Defining_Identifier => B, + Parameter_Type => New_Reference_To (Typ, Loc))); + + Func_Name := + Make_Defining_Identifier (Loc, New_Internal_Name ('A')); + Set_Is_Inlined (Func_Name); + + Func_Body := + Make_Subprogram_Body (Loc, + Specification => + Make_Function_Specification (Loc, + Defining_Unit_Name => Func_Name, + Parameter_Specifications => Formals, + Result_Definition => New_Reference_To (Typ, Loc)), + + Declarations => New_List ( + Make_Object_Declaration (Loc, + Defining_Identifier => C, + Object_Definition => New_Reference_To (Typ, Loc))), + + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, + Statements => New_List ( + Loop_Statement, + Make_Simple_Return_Statement (Loc, + Expression => New_Reference_To (C, Loc))))); + + return Func_Body; + end Make_Boolean_Array_Op; + + ------------------------ + -- Rewrite_Comparison -- + ------------------------ + + procedure Rewrite_Comparison (N : Node_Id) is + begin + if Nkind (N) = N_Type_Conversion then + Rewrite_Comparison (Expression (N)); + return; + + elsif Nkind (N) not in N_Op_Compare then + return; + end if; + + declare + Typ : constant Entity_Id := Etype (N); + Op1 : constant Node_Id := Left_Opnd (N); + Op2 : constant Node_Id := Right_Opnd (N); + + Res : constant Compare_Result := + Compile_Time_Compare (Op1, Op2, Assume_Valid => True); + -- Res indicates if compare outcome can be compile time determined + + True_Result : Boolean; + False_Result : Boolean; + + begin + case N_Op_Compare (Nkind (N)) is + when N_Op_Eq => + True_Result := Res = EQ; + False_Result := Res = LT or else Res = GT or else Res = NE; + + when N_Op_Ge => + True_Result := Res in Compare_GE; + False_Result := Res = LT; + + if Res = LE + and then Constant_Condition_Warnings + and then Comes_From_Source (Original_Node (N)) + and then Nkind (Original_Node (N)) = N_Op_Ge + and then not In_Instance + and then Is_Integer_Type (Etype (Left_Opnd (N))) + and then not Has_Warnings_Off (Etype (Left_Opnd (N))) + then + Error_Msg_N + ("can never be greater than, could replace by ""'=""?", N); + end if; + + when N_Op_Gt => + True_Result := Res = GT; + False_Result := Res in Compare_LE; + + when N_Op_Lt => + True_Result := Res = LT; + False_Result := Res in Compare_GE; + + when N_Op_Le => + True_Result := Res in Compare_LE; + False_Result := Res = GT; + + if Res = GE + and then Constant_Condition_Warnings + and then Comes_From_Source (Original_Node (N)) + and then Nkind (Original_Node (N)) = N_Op_Le + and then not In_Instance + and then Is_Integer_Type (Etype (Left_Opnd (N))) + and then not Has_Warnings_Off (Etype (Left_Opnd (N))) + then + Error_Msg_N + ("can never be less than, could replace by ""'=""?", N); + end if; + + when N_Op_Ne => + True_Result := Res = NE or else Res = GT or else Res = LT; + False_Result := Res = EQ; + end case; + + if True_Result then + Rewrite (N, + Convert_To (Typ, + New_Occurrence_Of (Standard_True, Sloc (N)))); + Analyze_And_Resolve (N, Typ); + Warn_On_Known_Condition (N); + + elsif False_Result then + Rewrite (N, + Convert_To (Typ, + New_Occurrence_Of (Standard_False, Sloc (N)))); + Analyze_And_Resolve (N, Typ); + Warn_On_Known_Condition (N); + end if; + end; + end Rewrite_Comparison; + + ---------------------------- + -- Safe_In_Place_Array_Op -- + ---------------------------- + + function Safe_In_Place_Array_Op + (Lhs : Node_Id; + Op1 : Node_Id; + Op2 : Node_Id) return Boolean + is + Target : Entity_Id; + + function Is_Safe_Operand (Op : Node_Id) return Boolean; + -- Operand is safe if it cannot overlap part of the target of the + -- operation. If the operand and the target are identical, the operand + -- is safe. The operand can be empty in the case of negation. + + function Is_Unaliased (N : Node_Id) return Boolean; + -- Check that N is a stand-alone entity + + ------------------ + -- Is_Unaliased -- + ------------------ + + function Is_Unaliased (N : Node_Id) return Boolean is + begin + return + Is_Entity_Name (N) + and then No (Address_Clause (Entity (N))) + and then No (Renamed_Object (Entity (N))); + end Is_Unaliased; + + --------------------- + -- Is_Safe_Operand -- + --------------------- + + function Is_Safe_Operand (Op : Node_Id) return Boolean is + begin + if No (Op) then + return True; + + elsif Is_Entity_Name (Op) then + return Is_Unaliased (Op); + + elsif Nkind_In (Op, N_Indexed_Component, N_Selected_Component) then + return Is_Unaliased (Prefix (Op)); + + elsif Nkind (Op) = N_Slice then + return + Is_Unaliased (Prefix (Op)) + and then Entity (Prefix (Op)) /= Target; + + elsif Nkind (Op) = N_Op_Not then + return Is_Safe_Operand (Right_Opnd (Op)); + + else + return False; + end if; + end Is_Safe_Operand; + + -- Start of processing for Is_Safe_In_Place_Array_Op + + begin + -- Skip this processing if the component size is different from system + -- storage unit (since at least for NOT this would cause problems). + + if Component_Size (Etype (Lhs)) /= System_Storage_Unit then + return False; + + -- Cannot do in place stuff on VM_Target since cannot pass addresses + + elsif VM_Target /= No_VM then + return False; + + -- Cannot do in place stuff if non-standard Boolean representation + + elsif Has_Non_Standard_Rep (Component_Type (Etype (Lhs))) then + return False; + + elsif not Is_Unaliased (Lhs) then + return False; + else + Target := Entity (Lhs); + + return + Is_Safe_Operand (Op1) + and then Is_Safe_Operand (Op2); + end if; + end Safe_In_Place_Array_Op; + + ----------------------- + -- Tagged_Membership -- + ----------------------- + + -- There are two different cases to consider depending on whether the right + -- operand is a class-wide type or not. If not we just compare the actual + -- tag of the left expr to the target type tag: + -- + -- Left_Expr.Tag = Right_Type'Tag; + -- + -- If it is a class-wide type we use the RT function CW_Membership which is + -- usually implemented by looking in the ancestor tables contained in the + -- dispatch table pointed by Left_Expr.Tag for Typ'Tag + + -- Ada 2005 (AI-251): If it is a class-wide interface type we use the RT + -- function IW_Membership which is usually implemented by looking in the + -- table of abstract interface types plus the ancestor table contained in + -- the dispatch table pointed by Left_Expr.Tag for Typ'Tag + + function Tagged_Membership (N : Node_Id) return Node_Id is + Left : constant Node_Id := Left_Opnd (N); + Right : constant Node_Id := Right_Opnd (N); + Loc : constant Source_Ptr := Sloc (N); + + Left_Type : Entity_Id; + Right_Type : Entity_Id; + Obj_Tag : Node_Id; + + begin + Left_Type := Etype (Left); + Right_Type := Etype (Right); + + if Is_Class_Wide_Type (Left_Type) then + Left_Type := Root_Type (Left_Type); + end if; + + Obj_Tag := + Make_Selected_Component (Loc, + Prefix => Relocate_Node (Left), + Selector_Name => + New_Reference_To (First_Tag_Component (Left_Type), Loc)); + + if Is_Class_Wide_Type (Right_Type) then + + -- No need to issue a run-time check if we statically know that the + -- result of this membership test is always true. For example, + -- considering the following declarations: + + -- type Iface is interface; + -- type T is tagged null record; + -- type DT is new T and Iface with null record; + + -- Obj1 : T; + -- Obj2 : DT; + + -- These membership tests are always true: + + -- Obj1 in T'Class + -- Obj2 in T'Class; + -- Obj2 in Iface'Class; + + -- We do not need to handle cases where the membership is illegal. + -- For example: + + -- Obj1 in DT'Class; -- Compile time error + -- Obj1 in Iface'Class; -- Compile time error + + if not Is_Class_Wide_Type (Left_Type) + and then (Is_Ancestor (Etype (Right_Type), Left_Type) + or else (Is_Interface (Etype (Right_Type)) + and then Interface_Present_In_Ancestor + (Typ => Left_Type, + Iface => Etype (Right_Type)))) + then + return New_Reference_To (Standard_True, Loc); + end if; + + -- Ada 2005 (AI-251): Class-wide applied to interfaces + + if Is_Interface (Etype (Class_Wide_Type (Right_Type))) + + -- Support to: "Iface_CW_Typ in Typ'Class" + + or else Is_Interface (Left_Type) + then + -- Issue error if IW_Membership operation not available in a + -- configurable run time setting. + + if not RTE_Available (RE_IW_Membership) then + Error_Msg_CRT + ("dynamic membership test on interface types", N); + return Empty; + end if; + + return + Make_Function_Call (Loc, + Name => New_Occurrence_Of (RTE (RE_IW_Membership), Loc), + Parameter_Associations => New_List ( + Make_Attribute_Reference (Loc, + Prefix => Obj_Tag, + Attribute_Name => Name_Address), + New_Reference_To ( + Node (First_Elmt + (Access_Disp_Table (Root_Type (Right_Type)))), + Loc))); + + -- Ada 95: Normal case + + else + return + Build_CW_Membership (Loc, + Obj_Tag_Node => Obj_Tag, + Typ_Tag_Node => + New_Reference_To ( + Node (First_Elmt + (Access_Disp_Table (Root_Type (Right_Type)))), + Loc)); + end if; + + -- Right_Type is not a class-wide type + + else + -- No need to check the tag of the object if Right_Typ is abstract + + if Is_Abstract_Type (Right_Type) then + return New_Reference_To (Standard_False, Loc); + + else + return + Make_Op_Eq (Loc, + Left_Opnd => Obj_Tag, + Right_Opnd => + New_Reference_To + (Node (First_Elmt (Access_Disp_Table (Right_Type))), Loc)); + end if; + end if; + end Tagged_Membership; + + ------------------------------ + -- Unary_Op_Validity_Checks -- + ------------------------------ + + procedure Unary_Op_Validity_Checks (N : Node_Id) is + begin + if Validity_Checks_On and Validity_Check_Operands then + Ensure_Valid (Right_Opnd (N)); + end if; + end Unary_Op_Validity_Checks; + +end Exp_Ch4; |