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Diffstat (limited to 'gcc-4.2.1/gcc/ada/exp_attr.adb')
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diff --git a/gcc-4.2.1/gcc/ada/exp_attr.adb b/gcc-4.2.1/gcc/ada/exp_attr.adb new file mode 100644 index 000000000..3f23d7cb6 --- /dev/null +++ b/gcc-4.2.1/gcc/ada/exp_attr.adb @@ -0,0 +1,4804 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- E X P _ A T T R -- +-- -- +-- B o d y -- +-- -- +-- Copyright (C) 1992-2006, 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 2, 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 COPYING. If not, write -- +-- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, -- +-- Boston, MA 02110-1301, USA. -- +-- -- +-- 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 Exp_Ch2; use Exp_Ch2; +with Exp_Ch9; use Exp_Ch9; +with Exp_Imgv; use Exp_Imgv; +with Exp_Pakd; use Exp_Pakd; +with Exp_Strm; use Exp_Strm; +with Exp_Tss; use Exp_Tss; +with Exp_Util; use Exp_Util; +with Exp_VFpt; use Exp_VFpt; +with Gnatvsn; use Gnatvsn; +with Hostparm; use Hostparm; +with Lib; use Lib; +with Namet; use Namet; +with Nmake; use Nmake; +with Nlists; use Nlists; +with Opt; use Opt; +with Restrict; use Restrict; +with Rident; use Rident; +with Rtsfind; use Rtsfind; +with Sem; use Sem; +with Sem_Ch7; use Sem_Ch7; +with Sem_Ch8; use Sem_Ch8; +with Sem_Eval; use Sem_Eval; +with Sem_Res; use Sem_Res; +with Sem_Util; use Sem_Util; +with Sinfo; use Sinfo; +with Snames; use Snames; +with Stand; use Stand; +with Stringt; use Stringt; +with Tbuild; use Tbuild; +with Ttypes; use Ttypes; +with Uintp; use Uintp; +with Uname; use Uname; +with Validsw; use Validsw; + +package body Exp_Attr is + + ----------------------- + -- Local Subprograms -- + ----------------------- + + procedure Compile_Stream_Body_In_Scope + (N : Node_Id; + Decl : Node_Id; + Arr : Entity_Id; + Check : Boolean); + -- The body for a stream subprogram may be generated outside of the scope + -- of the type. If the type is fully private, it may depend on the full + -- view of other types (e.g. indices) that are currently private as well. + -- We install the declarations of the package in which the type is declared + -- before compiling the body in what is its proper environment. The Check + -- parameter indicates if checks are to be suppressed for the stream body. + -- We suppress checks for array/record reads, since the rule is that these + -- are like assignments, out of range values due to uninitialized storage, + -- or other invalid values do NOT cause a Constraint_Error to be raised. + + procedure Expand_Fpt_Attribute + (N : Node_Id; + Pkg : RE_Id; + Nam : Name_Id; + Args : List_Id); + -- This procedure expands a call to a floating-point attribute function. + -- N is the attribute reference node, and Args is a list of arguments to + -- be passed to the function call. Pkg identifies the package containing + -- the appropriate instantiation of System.Fat_Gen. Float arguments in Args + -- have already been converted to the floating-point type for which Pkg was + -- instantiated. The Nam argument is the relevant attribute processing + -- routine to be called. This is the same as the attribute name, except in + -- the Unaligned_Valid case. + + procedure Expand_Fpt_Attribute_R (N : Node_Id); + -- This procedure expands a call to a floating-point attribute function + -- that takes a single floating-point argument. The function to be called + -- is always the same as the attribute name. + + procedure Expand_Fpt_Attribute_RI (N : Node_Id); + -- This procedure expands a call to a floating-point attribute function + -- that takes one floating-point argument and one integer argument. The + -- function to be called is always the same as the attribute name. + + procedure Expand_Fpt_Attribute_RR (N : Node_Id); + -- This procedure expands a call to a floating-point attribute function + -- that takes two floating-point arguments. The function to be called + -- is always the same as the attribute name. + + procedure Expand_Pred_Succ (N : Node_Id); + -- Handles expansion of Pred or Succ attributes for case of non-real + -- operand with overflow checking required. + + function Get_Index_Subtype (N : Node_Id) return Entity_Id; + -- Used for Last, Last, and Length, when the prefix is an array type, + -- Obtains the corresponding index subtype. + + procedure Expand_Access_To_Type (N : Node_Id); + -- A reference to a type within its own scope is resolved to a reference + -- to the current instance of the type in its initialization procedure. + + procedure Find_Fat_Info + (T : Entity_Id; + Fat_Type : out Entity_Id; + Fat_Pkg : out RE_Id); + -- Given a floating-point type T, identifies the package containing the + -- attributes for this type (returned in Fat_Pkg), and the corresponding + -- type for which this package was instantiated from Fat_Gen. Error if T + -- is not a floating-point type. + + function Find_Stream_Subprogram + (Typ : Entity_Id; + Nam : TSS_Name_Type) return Entity_Id; + -- Returns the stream-oriented subprogram attribute for Typ. For tagged + -- types, the corresponding primitive operation is looked up, else the + -- appropriate TSS from the type itself, or from its closest ancestor + -- defining it, is returned. In both cases, inheritance of representation + -- aspects is thus taken into account. + + function Get_Stream_Convert_Pragma (T : Entity_Id) return Node_Id; + -- Given a type, find a corresponding stream convert pragma that applies to + -- the implementation base type of this type (Typ). If found, return the + -- pragma node, otherwise return Empty if no pragma is found. + + function Is_Constrained_Packed_Array (Typ : Entity_Id) return Boolean; + -- Utility for array attributes, returns true on packed constrained + -- arrays, and on access to same. + + ---------------------------------- + -- Compile_Stream_Body_In_Scope -- + ---------------------------------- + + procedure Compile_Stream_Body_In_Scope + (N : Node_Id; + Decl : Node_Id; + Arr : Entity_Id; + Check : Boolean) + is + Installed : Boolean := False; + Scop : constant Entity_Id := Scope (Arr); + Curr : constant Entity_Id := Current_Scope; + + begin + if Is_Hidden (Arr) + and then not In_Open_Scopes (Scop) + and then Ekind (Scop) = E_Package + then + New_Scope (Scop); + Install_Visible_Declarations (Scop); + Install_Private_Declarations (Scop); + Installed := True; + + -- The entities in the package are now visible, but the generated + -- stream entity must appear in the current scope (usually an + -- enclosing stream function) so that itypes all have their proper + -- scopes. + + New_Scope (Curr); + end if; + + if Check then + Insert_Action (N, Decl); + else + Insert_Action (N, Decl, Suppress => All_Checks); + end if; + + if Installed then + + -- Remove extra copy of current scope, and package itself + + Pop_Scope; + End_Package_Scope (Scop); + end if; + end Compile_Stream_Body_In_Scope; + + --------------------------- + -- Expand_Access_To_Type -- + --------------------------- + + procedure Expand_Access_To_Type (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Typ : constant Entity_Id := Etype (N); + Pref : constant Node_Id := Prefix (N); + Par : Node_Id; + Formal : Entity_Id; + + begin + if Is_Entity_Name (Pref) + and then Is_Type (Entity (Pref)) + then + -- If the current instance name denotes a task type, + -- then the access attribute is rewritten to be the + -- name of the "_task" parameter associated with the + -- task type's task body procedure. An unchecked + -- conversion is applied to ensure a type match in + -- cases of expander-generated calls (e.g., init procs). + + if Is_Task_Type (Entity (Pref)) then + Formal := + First_Entity (Get_Task_Body_Procedure (Entity (Pref))); + + while Present (Formal) loop + exit when Chars (Formal) = Name_uTask; + Next_Entity (Formal); + end loop; + + pragma Assert (Present (Formal)); + + Rewrite (N, + Unchecked_Convert_To (Typ, New_Occurrence_Of (Formal, Loc))); + Set_Etype (N, Typ); + + -- The expression must appear in a default expression, + -- (which in the initialization procedure is the rhs of + -- an assignment), and not in a discriminant constraint. + + else + Par := Parent (N); + + while Present (Par) loop + exit when Nkind (Par) = N_Assignment_Statement; + + if Nkind (Par) = N_Component_Declaration then + return; + end if; + + Par := Parent (Par); + end loop; + + if Present (Par) then + Rewrite (N, + Make_Attribute_Reference (Loc, + Prefix => Make_Identifier (Loc, Name_uInit), + Attribute_Name => Attribute_Name (N))); + + Analyze_And_Resolve (N, Typ); + end if; + end if; + end if; + end Expand_Access_To_Type; + + -------------------------- + -- Expand_Fpt_Attribute -- + -------------------------- + + procedure Expand_Fpt_Attribute + (N : Node_Id; + Pkg : RE_Id; + Nam : Name_Id; + Args : List_Id) + is + Loc : constant Source_Ptr := Sloc (N); + Typ : constant Entity_Id := Etype (N); + Fnm : Node_Id; + + begin + -- The function name is the selected component Attr_xxx.yyy where + -- Attr_xxx is the package name, and yyy is the argument Nam. + + -- Note: it would be more usual to have separate RE entries for each + -- of the entities in the Fat packages, but first they have identical + -- names (so we would have to have lots of renaming declarations to + -- meet the normal RE rule of separate names for all runtime entities), + -- and second there would be an awful lot of them! + + Fnm := + Make_Selected_Component (Loc, + Prefix => New_Reference_To (RTE (Pkg), Loc), + Selector_Name => Make_Identifier (Loc, Nam)); + + -- The generated call is given the provided set of parameters, and then + -- wrapped in a conversion which converts the result to the target type + -- We use the base type as the target because a range check may be + -- required. + + Rewrite (N, + Unchecked_Convert_To (Base_Type (Etype (N)), + Make_Function_Call (Loc, + Name => Fnm, + Parameter_Associations => Args))); + + Analyze_And_Resolve (N, Typ); + end Expand_Fpt_Attribute; + + ---------------------------- + -- Expand_Fpt_Attribute_R -- + ---------------------------- + + -- The single argument is converted to its root type to call the + -- appropriate runtime function, with the actual call being built + -- by Expand_Fpt_Attribute + + procedure Expand_Fpt_Attribute_R (N : Node_Id) is + E1 : constant Node_Id := First (Expressions (N)); + Ftp : Entity_Id; + Pkg : RE_Id; + begin + Find_Fat_Info (Etype (E1), Ftp, Pkg); + Expand_Fpt_Attribute + (N, Pkg, Attribute_Name (N), + New_List (Unchecked_Convert_To (Ftp, Relocate_Node (E1)))); + end Expand_Fpt_Attribute_R; + + ----------------------------- + -- Expand_Fpt_Attribute_RI -- + ----------------------------- + + -- The first argument is converted to its root type and the second + -- argument is converted to standard long long integer to call the + -- appropriate runtime function, with the actual call being built + -- by Expand_Fpt_Attribute + + procedure Expand_Fpt_Attribute_RI (N : Node_Id) is + E1 : constant Node_Id := First (Expressions (N)); + Ftp : Entity_Id; + Pkg : RE_Id; + E2 : constant Node_Id := Next (E1); + begin + Find_Fat_Info (Etype (E1), Ftp, Pkg); + Expand_Fpt_Attribute + (N, Pkg, Attribute_Name (N), + New_List ( + Unchecked_Convert_To (Ftp, Relocate_Node (E1)), + Unchecked_Convert_To (Standard_Integer, Relocate_Node (E2)))); + end Expand_Fpt_Attribute_RI; + + ----------------------------- + -- Expand_Fpt_Attribute_RR -- + ----------------------------- + + -- The two arguments is converted to their root types to call the + -- appropriate runtime function, with the actual call being built + -- by Expand_Fpt_Attribute + + procedure Expand_Fpt_Attribute_RR (N : Node_Id) is + E1 : constant Node_Id := First (Expressions (N)); + Ftp : Entity_Id; + Pkg : RE_Id; + E2 : constant Node_Id := Next (E1); + begin + Find_Fat_Info (Etype (E1), Ftp, Pkg); + Expand_Fpt_Attribute + (N, Pkg, Attribute_Name (N), + New_List ( + Unchecked_Convert_To (Ftp, Relocate_Node (E1)), + Unchecked_Convert_To (Ftp, Relocate_Node (E2)))); + end Expand_Fpt_Attribute_RR; + + ---------------------------------- + -- Expand_N_Attribute_Reference -- + ---------------------------------- + + procedure Expand_N_Attribute_Reference (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Typ : constant Entity_Id := Etype (N); + Btyp : constant Entity_Id := Base_Type (Typ); + Pref : constant Node_Id := Prefix (N); + Exprs : constant List_Id := Expressions (N); + Id : constant Attribute_Id := Get_Attribute_Id (Attribute_Name (N)); + + procedure Rewrite_Stream_Proc_Call (Pname : Entity_Id); + -- Rewrites a stream attribute for Read, Write or Output with the + -- procedure call. Pname is the entity for the procedure to call. + + ------------------------------ + -- Rewrite_Stream_Proc_Call -- + ------------------------------ + + procedure Rewrite_Stream_Proc_Call (Pname : Entity_Id) is + Item : constant Node_Id := Next (First (Exprs)); + Formal : constant Entity_Id := Next_Formal (First_Formal (Pname)); + Formal_Typ : constant Entity_Id := Etype (Formal); + Is_Written : constant Boolean := (Ekind (Formal) /= E_In_Parameter); + + begin + -- The expansion depends on Item, the second actual, which is + -- the object being streamed in or out. + + -- If the item is a component of a packed array type, and + -- a conversion is needed on exit, we introduce a temporary to + -- hold the value, because otherwise the packed reference will + -- not be properly expanded. + + if Nkind (Item) = N_Indexed_Component + and then Is_Packed (Base_Type (Etype (Prefix (Item)))) + and then Base_Type (Etype (Item)) /= Base_Type (Formal_Typ) + and then Is_Written + then + declare + Temp : constant Entity_Id := + Make_Defining_Identifier + (Loc, New_Internal_Name ('V')); + Decl : Node_Id; + Assn : Node_Id; + + begin + Decl := + Make_Object_Declaration (Loc, + Defining_Identifier => Temp, + Object_Definition => + New_Occurrence_Of (Formal_Typ, Loc)); + Set_Etype (Temp, Formal_Typ); + + Assn := + Make_Assignment_Statement (Loc, + Name => New_Copy_Tree (Item), + Expression => + Unchecked_Convert_To + (Etype (Item), New_Occurrence_Of (Temp, Loc))); + + Rewrite (Item, New_Occurrence_Of (Temp, Loc)); + Insert_Actions (N, + New_List ( + Decl, + Make_Procedure_Call_Statement (Loc, + Name => New_Occurrence_Of (Pname, Loc), + Parameter_Associations => Exprs), + Assn)); + + Rewrite (N, Make_Null_Statement (Loc)); + return; + end; + end if; + + -- For the class-wide dispatching cases, and for cases in which + -- the base type of the second argument matches the base type of + -- the corresponding formal parameter (that is to say the stream + -- operation is not inherited), we are all set, and can use the + -- argument unchanged. + + -- For all other cases we do an unchecked conversion of the second + -- parameter to the type of the formal of the procedure we are + -- calling. This deals with the private type cases, and with going + -- to the root type as required in elementary type case. + + if not Is_Class_Wide_Type (Entity (Pref)) + and then not Is_Class_Wide_Type (Etype (Item)) + and then Base_Type (Etype (Item)) /= Base_Type (Formal_Typ) + then + Rewrite (Item, + Unchecked_Convert_To (Formal_Typ, Relocate_Node (Item))); + + -- For untagged derived types set Assignment_OK, to prevent + -- copies from being created when the unchecked conversion + -- is expanded (which would happen in Remove_Side_Effects + -- if Expand_N_Unchecked_Conversion were allowed to call + -- Force_Evaluation). The copy could violate Ada semantics + -- in cases such as an actual that is an out parameter. + -- Note that this approach is also used in exp_ch7 for calls + -- to controlled type operations to prevent problems with + -- actuals wrapped in unchecked conversions. + + if Is_Untagged_Derivation (Etype (Expression (Item))) then + Set_Assignment_OK (Item); + end if; + end if; + + -- And now rewrite the call + + Rewrite (N, + Make_Procedure_Call_Statement (Loc, + Name => New_Occurrence_Of (Pname, Loc), + Parameter_Associations => Exprs)); + + Analyze (N); + end Rewrite_Stream_Proc_Call; + + -- Start of processing for Expand_N_Attribute_Reference + + begin + -- Do required validity checking, if enabled. Do not apply check to + -- output parameters of an Asm instruction, since the value of this + -- is not set till after the attribute has been elaborated. + + if Validity_Checks_On and then Validity_Check_Operands + and then Id /= Attribute_Asm_Output + then + declare + Expr : Node_Id; + begin + Expr := First (Expressions (N)); + while Present (Expr) loop + Ensure_Valid (Expr); + Next (Expr); + end loop; + end; + end if; + + -- Remaining processing depends on specific attribute + + case Id is + + ------------ + -- Access -- + ------------ + + when Attribute_Access => + + if Ekind (Btyp) = E_Access_Protected_Subprogram_Type then + + -- The value of the attribute_reference is a record containing + -- two fields: an access to the protected object, and an access + -- to the subprogram itself. The prefix is a selected component. + + declare + Agg : Node_Id; + Sub : Entity_Id; + E_T : constant Entity_Id := Equivalent_Type (Btyp); + Acc : constant Entity_Id := + Etype (Next_Component (First_Component (E_T))); + Obj_Ref : Node_Id; + Curr : Entity_Id; + + begin + -- Within the body of the protected type, the prefix + -- designates a local operation, and the object is the first + -- parameter of the corresponding protected body of the + -- current enclosing operation. + + if Is_Entity_Name (Pref) then + pragma Assert (In_Open_Scopes (Scope (Entity (Pref)))); + Sub := + New_Occurrence_Of + (Protected_Body_Subprogram (Entity (Pref)), Loc); + Curr := Current_Scope; + + while Scope (Curr) /= Scope (Entity (Pref)) loop + Curr := Scope (Curr); + end loop; + + Obj_Ref := + Make_Attribute_Reference (Loc, + Prefix => + New_Occurrence_Of + (First_Formal + (Protected_Body_Subprogram (Curr)), Loc), + Attribute_Name => Name_Address); + + -- Case where the prefix is not an entity name. Find the + -- version of the protected operation to be called from + -- outside the protected object. + + else + Sub := + New_Occurrence_Of + (External_Subprogram + (Entity (Selector_Name (Pref))), Loc); + + Obj_Ref := + Make_Attribute_Reference (Loc, + Prefix => Relocate_Node (Prefix (Pref)), + Attribute_Name => Name_Address); + end if; + + Agg := + Make_Aggregate (Loc, + Expressions => + New_List ( + Obj_Ref, + Unchecked_Convert_To (Acc, + Make_Attribute_Reference (Loc, + Prefix => Sub, + Attribute_Name => Name_Address)))); + + Rewrite (N, Agg); + + Analyze_And_Resolve (N, E_T); + + -- For subsequent analysis, the node must retain its type. + -- The backend will replace it with the equivalent type where + -- needed. + + Set_Etype (N, Typ); + end; + + elsif Ekind (Btyp) = E_General_Access_Type then + declare + Ref_Object : constant Node_Id := Get_Referenced_Object (Pref); + Parm_Ent : Entity_Id; + Conversion : Node_Id; + + begin + -- If the prefix of an Access attribute is a dereference of an + -- access parameter (or a renaming of such a dereference) and + -- the context is a general access type (but not an anonymous + -- access type), then rewrite the attribute as a conversion of + -- the access parameter to the context access type. This will + -- result in an accessibility check being performed, if needed. + + -- (X.all'Access => Acc_Type (X)) + + if Nkind (Ref_Object) = N_Explicit_Dereference + and then Is_Entity_Name (Prefix (Ref_Object)) + then + Parm_Ent := Entity (Prefix (Ref_Object)); + + if Ekind (Parm_Ent) in Formal_Kind + and then Ekind (Etype (Parm_Ent)) = E_Anonymous_Access_Type + and then Present (Extra_Accessibility (Parm_Ent)) + then + Conversion := + Convert_To (Typ, New_Copy_Tree (Prefix (Ref_Object))); + + Rewrite (N, Conversion); + Analyze_And_Resolve (N, Typ); + end if; + + -- Ada 2005 (AI-251): If the designated type is an interface, + -- then rewrite the referenced object as a conversion to force + -- the displacement of the pointer to the secondary dispatch + -- table. + + elsif Is_Interface (Directly_Designated_Type (Btyp)) then + Conversion := Convert_To (Typ, New_Copy_Tree (Ref_Object)); + Rewrite (N, Conversion); + Analyze_And_Resolve (N, Typ); + end if; + end; + + -- If the prefix is a type name, this is a reference to the current + -- instance of the type, within its initialization procedure. + + else + Expand_Access_To_Type (N); + end if; + + -------------- + -- Adjacent -- + -------------- + + -- Transforms 'Adjacent into a call to the floating-point attribute + -- function Adjacent in Fat_xxx (where xxx is the root type) + + when Attribute_Adjacent => + Expand_Fpt_Attribute_RR (N); + + ------------- + -- Address -- + ------------- + + when Attribute_Address => Address : declare + Task_Proc : Entity_Id; + + begin + -- If the prefix is a task or a task type, the useful address + -- is that of the procedure for the task body, i.e. the actual + -- program unit. We replace the original entity with that of + -- the procedure. + + if Is_Entity_Name (Pref) + and then Is_Task_Type (Entity (Pref)) + then + Task_Proc := Next_Entity (Root_Type (Etype (Pref))); + + while Present (Task_Proc) loop + exit when Ekind (Task_Proc) = E_Procedure + and then Etype (First_Formal (Task_Proc)) = + Corresponding_Record_Type (Etype (Pref)); + Next_Entity (Task_Proc); + end loop; + + if Present (Task_Proc) then + Set_Entity (Pref, Task_Proc); + Set_Etype (Pref, Etype (Task_Proc)); + end if; + + -- Similarly, the address of a protected operation is the address + -- of the corresponding protected body, regardless of the protected + -- object from which it is selected. + + elsif Nkind (Pref) = N_Selected_Component + and then Is_Subprogram (Entity (Selector_Name (Pref))) + and then Is_Protected_Type (Scope (Entity (Selector_Name (Pref)))) + then + Rewrite (Pref, + New_Occurrence_Of ( + External_Subprogram (Entity (Selector_Name (Pref))), Loc)); + + elsif Nkind (Pref) = N_Explicit_Dereference + and then Ekind (Etype (Pref)) = E_Subprogram_Type + and then Convention (Etype (Pref)) = Convention_Protected + then + -- The prefix is be a dereference of an access_to_protected_ + -- subprogram. The desired address is the second component of + -- the record that represents the access. + + declare + Addr : constant Entity_Id := Etype (N); + Ptr : constant Node_Id := Prefix (Pref); + T : constant Entity_Id := + Equivalent_Type (Base_Type (Etype (Ptr))); + + begin + Rewrite (N, + Unchecked_Convert_To (Addr, + Make_Selected_Component (Loc, + Prefix => Unchecked_Convert_To (T, Ptr), + Selector_Name => New_Occurrence_Of ( + Next_Entity (First_Entity (T)), Loc)))); + + Analyze_And_Resolve (N, Addr); + end; + end if; + + -- Deal with packed array reference, other cases are handled by gigi + + if Involves_Packed_Array_Reference (Pref) then + Expand_Packed_Address_Reference (N); + end if; + end Address; + + --------------- + -- Alignment -- + --------------- + + when Attribute_Alignment => Alignment : declare + Ptyp : constant Entity_Id := Etype (Pref); + New_Node : Node_Id; + + begin + -- For class-wide types, X'Class'Alignment is transformed into a + -- direct reference to the Alignment of the class type, so that the + -- back end does not have to deal with the X'Class'Alignment + -- reference. + + if Is_Entity_Name (Pref) + and then Is_Class_Wide_Type (Entity (Pref)) + then + Rewrite (Prefix (N), New_Occurrence_Of (Entity (Pref), Loc)); + return; + + -- For x'Alignment applied to an object of a class wide type, + -- transform X'Alignment into a call to the predefined primitive + -- operation _Alignment applied to X. + + elsif Is_Class_Wide_Type (Ptyp) then + New_Node := + Make_Function_Call (Loc, + Name => New_Reference_To + (Find_Prim_Op (Ptyp, Name_uAlignment), Loc), + Parameter_Associations => New_List (Pref)); + + if Typ /= Standard_Integer then + + -- The context is a specific integer type with which the + -- original attribute was compatible. The function has a + -- specific type as well, so to preserve the compatibility + -- we must convert explicitly. + + New_Node := Convert_To (Typ, New_Node); + end if; + + Rewrite (N, New_Node); + Analyze_And_Resolve (N, Typ); + return; + + -- For all other cases, we just have to deal with the case of + -- the fact that the result can be universal. + + else + Apply_Universal_Integer_Attribute_Checks (N); + end if; + end Alignment; + + --------------- + -- AST_Entry -- + --------------- + + when Attribute_AST_Entry => AST_Entry : declare + Ttyp : Entity_Id; + T_Id : Node_Id; + Eent : Entity_Id; + + Entry_Ref : Node_Id; + -- The reference to the entry or entry family + + Index : Node_Id; + -- The index expression for an entry family reference, or + -- the Empty if Entry_Ref references a simple entry. + + begin + if Nkind (Pref) = N_Indexed_Component then + Entry_Ref := Prefix (Pref); + Index := First (Expressions (Pref)); + else + Entry_Ref := Pref; + Index := Empty; + end if; + + -- Get expression for Task_Id and the entry entity + + if Nkind (Entry_Ref) = N_Selected_Component then + T_Id := + Make_Attribute_Reference (Loc, + Attribute_Name => Name_Identity, + Prefix => Prefix (Entry_Ref)); + + Ttyp := Etype (Prefix (Entry_Ref)); + Eent := Entity (Selector_Name (Entry_Ref)); + + else + T_Id := + Make_Function_Call (Loc, + Name => New_Occurrence_Of (RTE (RE_Current_Task), Loc)); + + Eent := Entity (Entry_Ref); + + -- We have to find the enclosing task to get the task type + -- There must be one, since we already validated this earlier + + Ttyp := Current_Scope; + while not Is_Task_Type (Ttyp) loop + Ttyp := Scope (Ttyp); + end loop; + end if; + + -- Now rewrite the attribute with a call to Create_AST_Handler + + Rewrite (N, + Make_Function_Call (Loc, + Name => New_Occurrence_Of (RTE (RE_Create_AST_Handler), Loc), + Parameter_Associations => New_List ( + T_Id, + Entry_Index_Expression (Loc, Eent, Index, Ttyp)))); + + Analyze_And_Resolve (N, RTE (RE_AST_Handler)); + end AST_Entry; + + ------------------ + -- Bit_Position -- + ------------------ + + -- We compute this if a component clause was present, otherwise + -- we leave the computation up to Gigi, since we don't know what + -- layout will be chosen. + + -- Note that the attribute can apply to a naked record component + -- in generated code (i.e. the prefix is an identifier that + -- references the component or discriminant entity). + + when Attribute_Bit_Position => Bit_Position : + declare + CE : Entity_Id; + + begin + if Nkind (Pref) = N_Identifier then + CE := Entity (Pref); + else + CE := Entity (Selector_Name (Pref)); + end if; + + if Known_Static_Component_Bit_Offset (CE) then + Rewrite (N, + Make_Integer_Literal (Loc, + Intval => Component_Bit_Offset (CE))); + Analyze_And_Resolve (N, Typ); + + else + Apply_Universal_Integer_Attribute_Checks (N); + end if; + end Bit_Position; + + ------------------ + -- Body_Version -- + ------------------ + + -- A reference to P'Body_Version or P'Version is expanded to + + -- Vnn : Unsigned; + -- pragma Import (C, Vnn, "uuuuT"; + -- ... + -- Get_Version_String (Vnn) + + -- where uuuu is the unit name (dots replaced by double underscore) + -- and T is B for the cases of Body_Version, or Version applied to a + -- subprogram acting as its own spec, and S for Version applied to a + -- subprogram spec or package. This sequence of code references the + -- the unsigned constant created in the main program by the binder. + + -- A special exception occurs for Standard, where the string + -- returned is a copy of the library string in gnatvsn.ads. + + when Attribute_Body_Version | Attribute_Version => Version : declare + E : constant Entity_Id := + Make_Defining_Identifier (Loc, New_Internal_Name ('V')); + Pent : Entity_Id := Entity (Pref); + S : String_Id; + + begin + -- If not library unit, get to containing library unit + + while Pent /= Standard_Standard + and then Scope (Pent) /= Standard_Standard + loop + Pent := Scope (Pent); + end loop; + + -- Special case Standard + + if Pent = Standard_Standard + or else Pent = Standard_ASCII + then + Rewrite (N, + Make_String_Literal (Loc, + Strval => Verbose_Library_Version)); + + -- All other cases + + else + -- Build required string constant + + Get_Name_String (Get_Unit_Name (Pent)); + + Start_String; + for J in 1 .. Name_Len - 2 loop + if Name_Buffer (J) = '.' then + Store_String_Chars ("__"); + else + Store_String_Char (Get_Char_Code (Name_Buffer (J))); + end if; + end loop; + + -- Case of subprogram acting as its own spec, always use body + + if Nkind (Declaration_Node (Pent)) in N_Subprogram_Specification + and then Nkind (Parent (Declaration_Node (Pent))) = + N_Subprogram_Body + and then Acts_As_Spec (Parent (Declaration_Node (Pent))) + then + Store_String_Chars ("B"); + + -- Case of no body present, always use spec + + elsif not Unit_Requires_Body (Pent) then + Store_String_Chars ("S"); + + -- Otherwise use B for Body_Version, S for spec + + elsif Id = Attribute_Body_Version then + Store_String_Chars ("B"); + else + Store_String_Chars ("S"); + end if; + + S := End_String; + Lib.Version_Referenced (S); + + -- Insert the object declaration + + Insert_Actions (N, New_List ( + Make_Object_Declaration (Loc, + Defining_Identifier => E, + Object_Definition => + New_Occurrence_Of (RTE (RE_Unsigned), Loc)))); + + -- Set entity as imported with correct external name + + Set_Is_Imported (E); + Set_Interface_Name (E, Make_String_Literal (Loc, S)); + + -- And now rewrite original reference + + Rewrite (N, + Make_Function_Call (Loc, + Name => New_Reference_To (RTE (RE_Get_Version_String), Loc), + Parameter_Associations => New_List ( + New_Occurrence_Of (E, Loc)))); + end if; + + Analyze_And_Resolve (N, RTE (RE_Version_String)); + end Version; + + ------------- + -- Ceiling -- + ------------- + + -- Transforms 'Ceiling into a call to the floating-point attribute + -- function Ceiling in Fat_xxx (where xxx is the root type) + + when Attribute_Ceiling => + Expand_Fpt_Attribute_R (N); + + -------------- + -- Callable -- + -------------- + + -- Transforms 'Callable attribute into a call to the Callable function + + when Attribute_Callable => Callable : + begin + -- We have an object of a task interface class-wide type as a prefix + -- to Callable. Generate: + + -- callable (Pref._disp_get_task_id); + + if Ada_Version >= Ada_05 + and then Ekind (Etype (Pref)) = E_Class_Wide_Type + and then Is_Interface (Etype (Pref)) + and then Is_Task_Interface (Etype (Pref)) + then + Rewrite (N, + Make_Function_Call (Loc, + Name => + New_Reference_To (RTE (RE_Callable), Loc), + Parameter_Associations => New_List ( + Make_Selected_Component (Loc, + Prefix => + New_Copy_Tree (Pref), + Selector_Name => + Make_Identifier (Loc, Name_uDisp_Get_Task_Id))))); + else + Rewrite (N, + Build_Call_With_Task (Pref, RTE (RE_Callable))); + end if; + + Analyze_And_Resolve (N, Standard_Boolean); + end Callable; + + ------------ + -- Caller -- + ------------ + + -- Transforms 'Caller attribute into a call to either the + -- Task_Entry_Caller or the Protected_Entry_Caller function. + + when Attribute_Caller => Caller : declare + Id_Kind : constant Entity_Id := RTE (RO_AT_Task_Id); + Ent : constant Entity_Id := Entity (Pref); + Conctype : constant Entity_Id := Scope (Ent); + Nest_Depth : Integer := 0; + Name : Node_Id; + S : Entity_Id; + + begin + -- Protected case + + if Is_Protected_Type (Conctype) then + if Abort_Allowed + or else Restriction_Active (No_Entry_Queue) = False + or else Number_Entries (Conctype) > 1 + then + Name := + New_Reference_To + (RTE (RE_Protected_Entry_Caller), Loc); + else + Name := + New_Reference_To + (RTE (RE_Protected_Single_Entry_Caller), Loc); + end if; + + Rewrite (N, + Unchecked_Convert_To (Id_Kind, + Make_Function_Call (Loc, + Name => Name, + Parameter_Associations => New_List + (New_Reference_To ( + Object_Ref + (Corresponding_Body (Parent (Conctype))), Loc))))); + + -- Task case + + else + -- Determine the nesting depth of the E'Caller attribute, that + -- is, how many accept statements are nested within the accept + -- statement for E at the point of E'Caller. The runtime uses + -- this depth to find the specified entry call. + + for J in reverse 0 .. Scope_Stack.Last loop + S := Scope_Stack.Table (J).Entity; + + -- We should not reach the scope of the entry, as it should + -- already have been checked in Sem_Attr that this attribute + -- reference is within a matching accept statement. + + pragma Assert (S /= Conctype); + + if S = Ent then + exit; + + elsif Is_Entry (S) then + Nest_Depth := Nest_Depth + 1; + end if; + end loop; + + Rewrite (N, + Unchecked_Convert_To (Id_Kind, + Make_Function_Call (Loc, + Name => New_Reference_To ( + RTE (RE_Task_Entry_Caller), Loc), + Parameter_Associations => New_List ( + Make_Integer_Literal (Loc, + Intval => Int (Nest_Depth)))))); + end if; + + Analyze_And_Resolve (N, Id_Kind); + end Caller; + + ------------- + -- Compose -- + ------------- + + -- Transforms 'Compose into a call to the floating-point attribute + -- function Compose in Fat_xxx (where xxx is the root type) + + -- Note: we strictly should have special code here to deal with the + -- case of absurdly negative arguments (less than Integer'First) + -- which will return a (signed) zero value, but it hardly seems + -- worth the effort. Absurdly large positive arguments will raise + -- constraint error which is fine. + + when Attribute_Compose => + Expand_Fpt_Attribute_RI (N); + + ----------------- + -- Constrained -- + ----------------- + + when Attribute_Constrained => Constrained : declare + Formal_Ent : constant Entity_Id := Param_Entity (Pref); + Typ : constant Entity_Id := Etype (Pref); + + begin + -- Reference to a parameter where the value is passed as an extra + -- actual, corresponding to the extra formal referenced by the + -- Extra_Constrained field of the corresponding formal. If this + -- is an entry in-parameter, it is replaced by a constant renaming + -- for which Extra_Constrained is never created. + + if Present (Formal_Ent) + and then Ekind (Formal_Ent) /= E_Constant + and then Present (Extra_Constrained (Formal_Ent)) + then + Rewrite (N, + New_Occurrence_Of + (Extra_Constrained (Formal_Ent), Sloc (N))); + + -- For variables with a Extra_Constrained field, we use the + -- corresponding entity. + + elsif Nkind (Pref) = N_Identifier + and then Ekind (Entity (Pref)) = E_Variable + and then Present (Extra_Constrained (Entity (Pref))) + then + Rewrite (N, + New_Occurrence_Of + (Extra_Constrained (Entity (Pref)), Sloc (N))); + + -- For all other entity names, we can tell at compile time + + elsif Is_Entity_Name (Pref) then + declare + Ent : constant Entity_Id := Entity (Pref); + Res : Boolean; + + begin + -- (RM J.4) obsolescent cases + + if Is_Type (Ent) then + + -- Private type + + if Is_Private_Type (Ent) then + Res := not Has_Discriminants (Ent) + or else Is_Constrained (Ent); + + -- It not a private type, must be a generic actual type + -- that corresponded to a private type. We know that this + -- correspondence holds, since otherwise the reference + -- within the generic template would have been illegal. + + else + if Is_Composite_Type (Underlying_Type (Ent)) then + Res := Is_Constrained (Ent); + else + Res := True; + end if; + end if; + + -- If the prefix is not a variable or is aliased, then + -- definitely true; if it's a formal parameter without + -- an associated extra formal, then treat it as constrained. + + elsif not Is_Variable (Pref) + or else Present (Formal_Ent) + or else Is_Aliased_View (Pref) + then + Res := True; + + -- Variable case, just look at type to see if it is + -- constrained. Note that the one case where this is + -- not accurate (the procedure formal case), has been + -- handled above. + + else + Res := Is_Constrained (Etype (Ent)); + end if; + + Rewrite (N, + New_Reference_To (Boolean_Literals (Res), Loc)); + end; + + -- Prefix is not an entity name. These are also cases where + -- we can always tell at compile time by looking at the form + -- and type of the prefix. If an explicit dereference of an + -- object with constrained partial view, this is unconstrained + -- (Ada 2005 AI-363). + + else + Rewrite (N, + New_Reference_To ( + Boolean_Literals ( + not Is_Variable (Pref) + or else + (Nkind (Pref) = N_Explicit_Dereference + and then + not Has_Constrained_Partial_View (Base_Type (Typ))) + or else Is_Constrained (Typ)), + Loc)); + end if; + + Analyze_And_Resolve (N, Standard_Boolean); + end Constrained; + + --------------- + -- Copy_Sign -- + --------------- + + -- Transforms 'Copy_Sign into a call to the floating-point attribute + -- function Copy_Sign in Fat_xxx (where xxx is the root type) + + when Attribute_Copy_Sign => + Expand_Fpt_Attribute_RR (N); + + ----------- + -- Count -- + ----------- + + -- Transforms 'Count attribute into a call to the Count function + + when Attribute_Count => Count : + declare + Entnam : Node_Id; + Index : Node_Id; + Name : Node_Id; + Call : Node_Id; + Conctyp : Entity_Id; + + begin + -- If the prefix is a member of an entry family, retrieve both + -- entry name and index. For a simple entry there is no index. + + if Nkind (Pref) = N_Indexed_Component then + Entnam := Prefix (Pref); + Index := First (Expressions (Pref)); + else + Entnam := Pref; + Index := Empty; + end if; + + -- Find the concurrent type in which this attribute is referenced + -- (there had better be one). + + Conctyp := Current_Scope; + while not Is_Concurrent_Type (Conctyp) loop + Conctyp := Scope (Conctyp); + end loop; + + -- Protected case + + if Is_Protected_Type (Conctyp) then + + if Abort_Allowed + or else Restriction_Active (No_Entry_Queue) = False + or else Number_Entries (Conctyp) > 1 + then + Name := New_Reference_To (RTE (RE_Protected_Count), Loc); + + Call := + Make_Function_Call (Loc, + Name => Name, + Parameter_Associations => New_List ( + New_Reference_To ( + Object_Ref ( + Corresponding_Body (Parent (Conctyp))), Loc), + Entry_Index_Expression ( + Loc, Entity (Entnam), Index, Scope (Entity (Entnam))))); + else + Name := New_Reference_To (RTE (RE_Protected_Count_Entry), Loc); + + Call := Make_Function_Call (Loc, + Name => Name, + Parameter_Associations => New_List ( + New_Reference_To ( + Object_Ref ( + Corresponding_Body (Parent (Conctyp))), Loc))); + end if; + + -- Task case + + else + Call := + Make_Function_Call (Loc, + Name => New_Reference_To (RTE (RE_Task_Count), Loc), + Parameter_Associations => New_List ( + Entry_Index_Expression + (Loc, Entity (Entnam), Index, Scope (Entity (Entnam))))); + end if; + + -- The call returns type Natural but the context is universal integer + -- so any integer type is allowed. The attribute was already resolved + -- so its Etype is the required result type. If the base type of the + -- context type is other than Standard.Integer we put in a conversion + -- to the required type. This can be a normal typed conversion since + -- both input and output types of the conversion are integer types + + if Base_Type (Typ) /= Base_Type (Standard_Integer) then + Rewrite (N, Convert_To (Typ, Call)); + else + Rewrite (N, Call); + end if; + + Analyze_And_Resolve (N, Typ); + end Count; + + --------------- + -- Elab_Body -- + --------------- + + -- This processing is shared by Elab_Spec + + -- What we do is to insert the following declarations + + -- procedure tnn; + -- pragma Import (C, enn, "name___elabb/s"); + + -- and then the Elab_Body/Spec attribute is replaced by a reference + -- to this defining identifier. + + when Attribute_Elab_Body | + Attribute_Elab_Spec => + + Elab_Body : declare + Ent : constant Entity_Id := + Make_Defining_Identifier (Loc, + New_Internal_Name ('E')); + Str : String_Id; + Lang : Node_Id; + + procedure Make_Elab_String (Nod : Node_Id); + -- Given Nod, an identifier, or a selected component, put the + -- image into the current string literal, with double underline + -- between components. + + procedure Make_Elab_String (Nod : Node_Id) is + begin + if Nkind (Nod) = N_Selected_Component then + Make_Elab_String (Prefix (Nod)); + if Java_VM then + Store_String_Char ('$'); + else + Store_String_Char ('_'); + Store_String_Char ('_'); + end if; + + Get_Name_String (Chars (Selector_Name (Nod))); + + else + pragma Assert (Nkind (Nod) = N_Identifier); + Get_Name_String (Chars (Nod)); + end if; + + Store_String_Chars (Name_Buffer (1 .. Name_Len)); + end Make_Elab_String; + + -- Start of processing for Elab_Body/Elab_Spec + + begin + -- First we need to prepare the string literal for the name of + -- the elaboration routine to be referenced. + + Start_String; + Make_Elab_String (Pref); + + if Java_VM then + Store_String_Chars ("._elab"); + Lang := Make_Identifier (Loc, Name_Ada); + else + Store_String_Chars ("___elab"); + Lang := Make_Identifier (Loc, Name_C); + end if; + + if Id = Attribute_Elab_Body then + Store_String_Char ('b'); + else + Store_String_Char ('s'); + end if; + + Str := End_String; + + Insert_Actions (N, New_List ( + Make_Subprogram_Declaration (Loc, + Specification => + Make_Procedure_Specification (Loc, + Defining_Unit_Name => Ent)), + + Make_Pragma (Loc, + Chars => Name_Import, + Pragma_Argument_Associations => New_List ( + Make_Pragma_Argument_Association (Loc, + Expression => Lang), + + Make_Pragma_Argument_Association (Loc, + Expression => + Make_Identifier (Loc, Chars (Ent))), + + Make_Pragma_Argument_Association (Loc, + Expression => + Make_String_Literal (Loc, Str)))))); + + Set_Entity (N, Ent); + Rewrite (N, New_Occurrence_Of (Ent, Loc)); + end Elab_Body; + + ---------------- + -- Elaborated -- + ---------------- + + -- Elaborated is always True for preelaborated units, predefined + -- units, pure units and units which have Elaborate_Body pragmas. + -- These units have no elaboration entity. + + -- Note: The Elaborated attribute is never passed through to Gigi + + when Attribute_Elaborated => Elaborated : declare + Ent : constant Entity_Id := Entity (Pref); + + begin + if Present (Elaboration_Entity (Ent)) then + Rewrite (N, + New_Occurrence_Of (Elaboration_Entity (Ent), Loc)); + else + Rewrite (N, New_Occurrence_Of (Standard_True, Loc)); + end if; + end Elaborated; + + -------------- + -- Enum_Rep -- + -------------- + + when Attribute_Enum_Rep => Enum_Rep : + begin + -- X'Enum_Rep (Y) expands to + + -- target-type (Y) + + -- This is simply a direct conversion from the enumeration type + -- to the target integer type, which is treated by Gigi as a normal + -- integer conversion, treating the enumeration type as an integer, + -- which is exactly what we want! We set Conversion_OK to make sure + -- that the analyzer does not complain about what otherwise might + -- be an illegal conversion. + + if Is_Non_Empty_List (Exprs) then + Rewrite (N, + OK_Convert_To (Typ, Relocate_Node (First (Exprs)))); + + -- X'Enum_Rep where X is an enumeration literal is replaced by + -- the literal value. + + elsif Ekind (Entity (Pref)) = E_Enumeration_Literal then + Rewrite (N, + Make_Integer_Literal (Loc, Enumeration_Rep (Entity (Pref)))); + + -- If this is a renaming of a literal, recover the representation + -- of the original. + + elsif Ekind (Entity (Pref)) = E_Constant + and then Present (Renamed_Object (Entity (Pref))) + and then + Ekind (Entity (Renamed_Object (Entity (Pref)))) + = E_Enumeration_Literal + then + Rewrite (N, + Make_Integer_Literal (Loc, + Enumeration_Rep (Entity (Renamed_Object (Entity (Pref)))))); + + -- X'Enum_Rep where X is an object does a direct unchecked conversion + -- of the object value, as described for the type case above. + + else + Rewrite (N, + OK_Convert_To (Typ, Relocate_Node (Pref))); + end if; + + Set_Etype (N, Typ); + Analyze_And_Resolve (N, Typ); + + end Enum_Rep; + + -------------- + -- Exponent -- + -------------- + + -- Transforms 'Exponent into a call to the floating-point attribute + -- function Exponent in Fat_xxx (where xxx is the root type) + + when Attribute_Exponent => + Expand_Fpt_Attribute_R (N); + + ------------------ + -- External_Tag -- + ------------------ + + -- transforme X'External_Tag into Ada.Tags.External_Tag (X'tag) + + when Attribute_External_Tag => External_Tag : + begin + Rewrite (N, + Make_Function_Call (Loc, + Name => New_Reference_To (RTE (RE_External_Tag), Loc), + Parameter_Associations => New_List ( + Make_Attribute_Reference (Loc, + Attribute_Name => Name_Tag, + Prefix => Prefix (N))))); + + Analyze_And_Resolve (N, Standard_String); + end External_Tag; + + ----------- + -- First -- + ----------- + + when Attribute_First => declare + Ptyp : constant Entity_Id := Etype (Pref); + + begin + -- If the prefix type is a constrained packed array type which + -- already has a Packed_Array_Type representation defined, then + -- replace this attribute with a direct reference to 'First of the + -- appropriate index subtype (since otherwise Gigi will try to give + -- us the value of 'First for this implementation type). + + if Is_Constrained_Packed_Array (Ptyp) then + Rewrite (N, + Make_Attribute_Reference (Loc, + Attribute_Name => Name_First, + Prefix => New_Reference_To (Get_Index_Subtype (N), Loc))); + Analyze_And_Resolve (N, Typ); + + elsif Is_Access_Type (Ptyp) then + Apply_Access_Check (N); + end if; + end; + + --------------- + -- First_Bit -- + --------------- + + -- We compute this if a component clause was present, otherwise + -- we leave the computation up to Gigi, since we don't know what + -- layout will be chosen. + + when Attribute_First_Bit => First_Bit : + declare + CE : constant Entity_Id := Entity (Selector_Name (Pref)); + + begin + if Known_Static_Component_Bit_Offset (CE) then + Rewrite (N, + Make_Integer_Literal (Loc, + Component_Bit_Offset (CE) mod System_Storage_Unit)); + + Analyze_And_Resolve (N, Typ); + + else + Apply_Universal_Integer_Attribute_Checks (N); + end if; + end First_Bit; + + ----------------- + -- Fixed_Value -- + ----------------- + + -- We transform: + + -- fixtype'Fixed_Value (integer-value) + + -- into + + -- fixtype(integer-value) + + -- we do all the required analysis of the conversion here, because + -- we do not want this to go through the fixed-point conversion + -- circuits. Note that gigi always treats fixed-point as equivalent + -- to the corresponding integer type anyway. + + when Attribute_Fixed_Value => Fixed_Value : + begin + Rewrite (N, + Make_Type_Conversion (Loc, + Subtype_Mark => New_Occurrence_Of (Entity (Pref), Loc), + Expression => Relocate_Node (First (Exprs)))); + Set_Etype (N, Entity (Pref)); + Set_Analyzed (N); + + -- Note: it might appear that a properly analyzed unchecked conversion + -- would be just fine here, but that's not the case, since the full + -- range checks performed by the following call are critical! + + Apply_Type_Conversion_Checks (N); + end Fixed_Value; + + ----------- + -- Floor -- + ----------- + + -- Transforms 'Floor into a call to the floating-point attribute + -- function Floor in Fat_xxx (where xxx is the root type) + + when Attribute_Floor => + Expand_Fpt_Attribute_R (N); + + ---------- + -- Fore -- + ---------- + + -- For the fixed-point type Typ: + + -- Typ'Fore + + -- expands into + + -- Result_Type (System.Fore (Universal_Real (Type'First)), + -- Universal_Real (Type'Last)) + + -- Note that we know that the type is a non-static subtype, or Fore + -- would have itself been computed dynamically in Eval_Attribute. + + when Attribute_Fore => Fore : + declare + Ptyp : constant Entity_Id := Etype (Pref); + + begin + Rewrite (N, + Convert_To (Typ, + Make_Function_Call (Loc, + Name => New_Reference_To (RTE (RE_Fore), Loc), + + Parameter_Associations => New_List ( + Convert_To (Universal_Real, + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Ptyp, Loc), + Attribute_Name => Name_First)), + + Convert_To (Universal_Real, + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Ptyp, Loc), + Attribute_Name => Name_Last)))))); + + Analyze_And_Resolve (N, Typ); + end Fore; + + -------------- + -- Fraction -- + -------------- + + -- Transforms 'Fraction into a call to the floating-point attribute + -- function Fraction in Fat_xxx (where xxx is the root type) + + when Attribute_Fraction => + Expand_Fpt_Attribute_R (N); + + -------------- + -- Identity -- + -------------- + + -- For an exception returns a reference to the exception data: + -- Exception_Id!(Prefix'Reference) + + -- For a task it returns a reference to the _task_id component of + -- corresponding record: + + -- taskV!(Prefix)._Task_Id, converted to the type Task_Id defined + + -- in Ada.Task_Identification + + when Attribute_Identity => Identity : declare + Id_Kind : Entity_Id; + + begin + if Etype (Pref) = Standard_Exception_Type then + Id_Kind := RTE (RE_Exception_Id); + + if Present (Renamed_Object (Entity (Pref))) then + Set_Entity (Pref, Renamed_Object (Entity (Pref))); + end if; + + Rewrite (N, + Unchecked_Convert_To (Id_Kind, Make_Reference (Loc, Pref))); + else + Id_Kind := RTE (RO_AT_Task_Id); + + Rewrite (N, + Unchecked_Convert_To (Id_Kind, Concurrent_Ref (Pref))); + end if; + + Analyze_And_Resolve (N, Id_Kind); + end Identity; + + ----------- + -- Image -- + ----------- + + -- Image attribute is handled in separate unit Exp_Imgv + + when Attribute_Image => + Exp_Imgv.Expand_Image_Attribute (N); + + --------- + -- Img -- + --------- + + -- X'Img is expanded to typ'Image (X), where typ is the type of X + + when Attribute_Img => Img : + begin + Rewrite (N, + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Etype (Pref), Loc), + Attribute_Name => Name_Image, + Expressions => New_List (Relocate_Node (Pref)))); + + Analyze_And_Resolve (N, Standard_String); + end Img; + + ----------- + -- Input -- + ----------- + + when Attribute_Input => Input : declare + P_Type : constant Entity_Id := Entity (Pref); + B_Type : constant Entity_Id := Base_Type (P_Type); + U_Type : constant Entity_Id := Underlying_Type (P_Type); + Strm : constant Node_Id := First (Exprs); + Fname : Entity_Id; + Decl : Node_Id; + Call : Node_Id; + Prag : Node_Id; + Arg2 : Node_Id; + Rfunc : Node_Id; + + Cntrl : Node_Id := Empty; + -- Value for controlling argument in call. Always Empty except in + -- the dispatching (class-wide type) case, where it is a reference + -- to the dummy object initialized to the right internal tag. + + procedure Freeze_Stream_Subprogram (F : Entity_Id); + -- The expansion of the attribute reference may generate a call to + -- a user-defined stream subprogram that is frozen by the call. This + -- can lead to access-before-elaboration problem if the reference + -- appears in an object declaration and the subprogram body has not + -- been seen. The freezing of the subprogram requires special code + -- because it appears in an expanded context where expressions do + -- not freeze their constituents. + + ------------------------------ + -- Freeze_Stream_Subprogram -- + ------------------------------ + + procedure Freeze_Stream_Subprogram (F : Entity_Id) is + Decl : constant Node_Id := Unit_Declaration_Node (F); + Bod : Node_Id; + + begin + -- If this is user-defined subprogram, the corresponding + -- stream function appears as a renaming-as-body, and the + -- user subprogram must be retrieved by tree traversal. + + if Present (Decl) + and then Nkind (Decl) = N_Subprogram_Declaration + and then Present (Corresponding_Body (Decl)) + then + Bod := Corresponding_Body (Decl); + + if Nkind (Unit_Declaration_Node (Bod)) = + N_Subprogram_Renaming_Declaration + then + Set_Is_Frozen (Entity (Name (Unit_Declaration_Node (Bod)))); + end if; + end if; + end Freeze_Stream_Subprogram; + + -- Start of processing for Input + + begin + -- If no underlying type, we have an error that will be diagnosed + -- elsewhere, so here we just completely ignore the expansion. + + if No (U_Type) then + return; + end if; + + -- If there is a TSS for Input, just call it + + Fname := Find_Stream_Subprogram (P_Type, TSS_Stream_Input); + + if Present (Fname) then + null; + + else + -- If there is a Stream_Convert pragma, use it, we rewrite + + -- sourcetyp'Input (stream) + + -- as + + -- sourcetyp (streamread (strmtyp'Input (stream))); + + -- where stmrearead is the given Read function that converts + -- an argument of type strmtyp to type sourcetyp or a type + -- from which it is derived. The extra conversion is required + -- for the derived case. + + Prag := Get_Stream_Convert_Pragma (P_Type); + + if Present (Prag) then + Arg2 := Next (First (Pragma_Argument_Associations (Prag))); + Rfunc := Entity (Expression (Arg2)); + + Rewrite (N, + Convert_To (B_Type, + Make_Function_Call (Loc, + Name => New_Occurrence_Of (Rfunc, Loc), + Parameter_Associations => New_List ( + Make_Attribute_Reference (Loc, + Prefix => + New_Occurrence_Of + (Etype (First_Formal (Rfunc)), Loc), + Attribute_Name => Name_Input, + Expressions => Exprs))))); + + Analyze_And_Resolve (N, B_Type); + return; + + -- Elementary types + + elsif Is_Elementary_Type (U_Type) then + + -- A special case arises if we have a defined _Read routine, + -- since in this case we are required to call this routine. + + if Present (TSS (Base_Type (U_Type), TSS_Stream_Read)) then + Build_Record_Or_Elementary_Input_Function + (Loc, U_Type, Decl, Fname); + Insert_Action (N, Decl); + + -- For normal cases, we call the I_xxx routine directly + + else + Rewrite (N, Build_Elementary_Input_Call (N)); + Analyze_And_Resolve (N, P_Type); + return; + end if; + + -- Array type case + + elsif Is_Array_Type (U_Type) then + Build_Array_Input_Function (Loc, U_Type, Decl, Fname); + Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False); + + -- Dispatching case with class-wide type + + elsif Is_Class_Wide_Type (P_Type) then + + declare + Rtyp : constant Entity_Id := Root_Type (P_Type); + Dnn : Entity_Id; + Decl : Node_Id; + + begin + -- Read the internal tag (RM 13.13.2(34)) and use it to + -- initialize a dummy tag object: + + -- Dnn : Ada.Tags.Tag + -- := Descendant_Tag (String'Input (Strm), P_Type); + + -- This dummy object is used only to provide a controlling + -- argument for the eventual _Input call. Descendant_Tag is + -- called rather than Internal_Tag to ensure that we have a + -- tag for a type that is descended from the prefix type and + -- declared at the same accessibility level (the exception + -- Tag_Error will be raised otherwise). The level check is + -- required for Ada 2005 because tagged types can be + -- extended in nested scopes (AI-344). + + Dnn := + Make_Defining_Identifier (Loc, + Chars => New_Internal_Name ('D')); + + Decl := + Make_Object_Declaration (Loc, + Defining_Identifier => Dnn, + Object_Definition => + New_Occurrence_Of (RTE (RE_Tag), Loc), + Expression => + Make_Function_Call (Loc, + Name => + New_Occurrence_Of (RTE (RE_Descendant_Tag), Loc), + Parameter_Associations => New_List ( + Make_Attribute_Reference (Loc, + Prefix => + New_Occurrence_Of (Standard_String, Loc), + Attribute_Name => Name_Input, + Expressions => New_List ( + Relocate_Node + (Duplicate_Subexpr (Strm)))), + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (P_Type, Loc), + Attribute_Name => Name_Tag)))); + + Insert_Action (N, Decl); + + -- Now we need to get the entity for the call, and construct + -- a function call node, where we preset a reference to Dnn + -- as the controlling argument (doing an unchecked convert + -- to the class-wide tagged type to make it look like a real + -- tagged object). + + Fname := Find_Prim_Op (Rtyp, TSS_Stream_Input); + Cntrl := Unchecked_Convert_To (P_Type, + New_Occurrence_Of (Dnn, Loc)); + Set_Etype (Cntrl, P_Type); + Set_Parent (Cntrl, N); + end; + + -- For tagged types, use the primitive Input function + + elsif Is_Tagged_Type (U_Type) then + Fname := Find_Prim_Op (U_Type, TSS_Stream_Input); + + -- All other record type cases, including protected records. The + -- latter only arise for expander generated code for handling + -- shared passive partition access. + + else + pragma Assert + (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type)); + + -- Ada 2005 (AI-216): Program_Error is raised when executing + -- the default implementation of the Input attribute of an + -- unchecked union type if the type lacks default discriminant + -- values. + + if Is_Unchecked_Union (Base_Type (U_Type)) + and then No (Discriminant_Constraint (U_Type)) + then + Insert_Action (N, + Make_Raise_Program_Error (Loc, + Reason => PE_Unchecked_Union_Restriction)); + + return; + end if; + + Build_Record_Or_Elementary_Input_Function + (Loc, Base_Type (U_Type), Decl, Fname); + Insert_Action (N, Decl); + + if Nkind (Parent (N)) = N_Object_Declaration + and then Is_Record_Type (U_Type) + then + -- The stream function may contain calls to user-defined + -- Read procedures for individual components. + + declare + Comp : Entity_Id; + Func : Entity_Id; + + begin + Comp := First_Component (U_Type); + while Present (Comp) loop + Func := + Find_Stream_Subprogram + (Etype (Comp), TSS_Stream_Read); + + if Present (Func) then + Freeze_Stream_Subprogram (Func); + end if; + + Next_Component (Comp); + end loop; + end; + end if; + end if; + end if; + + -- If we fall through, Fname is the function to be called. The result + -- is obtained by calling the appropriate function, then converting + -- the result. The conversion does a subtype check. + + Call := + Make_Function_Call (Loc, + Name => New_Occurrence_Of (Fname, Loc), + Parameter_Associations => New_List ( + Relocate_Node (Strm))); + + Set_Controlling_Argument (Call, Cntrl); + Rewrite (N, Unchecked_Convert_To (P_Type, Call)); + Analyze_And_Resolve (N, P_Type); + + if Nkind (Parent (N)) = N_Object_Declaration then + Freeze_Stream_Subprogram (Fname); + end if; + end Input; + + ------------------- + -- Integer_Value -- + ------------------- + + -- We transform + + -- inttype'Fixed_Value (fixed-value) + + -- into + + -- inttype(integer-value)) + + -- we do all the required analysis of the conversion here, because + -- we do not want this to go through the fixed-point conversion + -- circuits. Note that gigi always treats fixed-point as equivalent + -- to the corresponding integer type anyway. + + when Attribute_Integer_Value => Integer_Value : + begin + Rewrite (N, + Make_Type_Conversion (Loc, + Subtype_Mark => New_Occurrence_Of (Entity (Pref), Loc), + Expression => Relocate_Node (First (Exprs)))); + Set_Etype (N, Entity (Pref)); + Set_Analyzed (N); + + -- Note: it might appear that a properly analyzed unchecked conversion + -- would be just fine here, but that's not the case, since the full + -- range checks performed by the following call are critical! + + Apply_Type_Conversion_Checks (N); + end Integer_Value; + + ---------- + -- Last -- + ---------- + + when Attribute_Last => declare + Ptyp : constant Entity_Id := Etype (Pref); + + begin + -- If the prefix type is a constrained packed array type which + -- already has a Packed_Array_Type representation defined, then + -- replace this attribute with a direct reference to 'Last of the + -- appropriate index subtype (since otherwise Gigi will try to give + -- us the value of 'Last for this implementation type). + + if Is_Constrained_Packed_Array (Ptyp) then + Rewrite (N, + Make_Attribute_Reference (Loc, + Attribute_Name => Name_Last, + Prefix => New_Reference_To (Get_Index_Subtype (N), Loc))); + Analyze_And_Resolve (N, Typ); + + elsif Is_Access_Type (Ptyp) then + Apply_Access_Check (N); + end if; + end; + + -------------- + -- Last_Bit -- + -------------- + + -- We compute this if a component clause was present, otherwise + -- we leave the computation up to Gigi, since we don't know what + -- layout will be chosen. + + when Attribute_Last_Bit => Last_Bit : + declare + CE : constant Entity_Id := Entity (Selector_Name (Pref)); + + begin + if Known_Static_Component_Bit_Offset (CE) + and then Known_Static_Esize (CE) + then + Rewrite (N, + Make_Integer_Literal (Loc, + Intval => (Component_Bit_Offset (CE) mod System_Storage_Unit) + + Esize (CE) - 1)); + + Analyze_And_Resolve (N, Typ); + + else + Apply_Universal_Integer_Attribute_Checks (N); + end if; + end Last_Bit; + + ------------------ + -- Leading_Part -- + ------------------ + + -- Transforms 'Leading_Part into a call to the floating-point attribute + -- function Leading_Part in Fat_xxx (where xxx is the root type) + + -- Note: strictly, we should have special case code to deal with + -- absurdly large positive arguments (greater than Integer'Last), which + -- result in returning the first argument unchanged, but it hardly seems + -- worth the effort. We raise constraint error for absurdly negative + -- arguments which is fine. + + when Attribute_Leading_Part => + Expand_Fpt_Attribute_RI (N); + + ------------ + -- Length -- + ------------ + + when Attribute_Length => declare + Ptyp : constant Entity_Id := Etype (Pref); + Ityp : Entity_Id; + Xnum : Uint; + + begin + -- Processing for packed array types + + if Is_Array_Type (Ptyp) and then Is_Packed (Ptyp) then + Ityp := Get_Index_Subtype (N); + + -- If the index type, Ityp, is an enumeration type with + -- holes, then we calculate X'Length explicitly using + + -- Typ'Max + -- (0, Ityp'Pos (X'Last (N)) - + -- Ityp'Pos (X'First (N)) + 1); + + -- Since the bounds in the template are the representation + -- values and gigi would get the wrong value. + + if Is_Enumeration_Type (Ityp) + and then Present (Enum_Pos_To_Rep (Base_Type (Ityp))) + then + if No (Exprs) then + Xnum := Uint_1; + else + Xnum := Expr_Value (First (Expressions (N))); + end if; + + Rewrite (N, + Make_Attribute_Reference (Loc, + Prefix => New_Occurrence_Of (Typ, Loc), + Attribute_Name => Name_Max, + Expressions => New_List + (Make_Integer_Literal (Loc, 0), + + Make_Op_Add (Loc, + Left_Opnd => + Make_Op_Subtract (Loc, + Left_Opnd => + Make_Attribute_Reference (Loc, + Prefix => New_Occurrence_Of (Ityp, Loc), + Attribute_Name => Name_Pos, + + Expressions => New_List ( + Make_Attribute_Reference (Loc, + Prefix => Duplicate_Subexpr (Pref), + Attribute_Name => Name_Last, + Expressions => New_List ( + Make_Integer_Literal (Loc, Xnum))))), + + Right_Opnd => + Make_Attribute_Reference (Loc, + Prefix => New_Occurrence_Of (Ityp, Loc), + Attribute_Name => Name_Pos, + + Expressions => New_List ( + Make_Attribute_Reference (Loc, + Prefix => + Duplicate_Subexpr_No_Checks (Pref), + Attribute_Name => Name_First, + Expressions => New_List ( + Make_Integer_Literal (Loc, Xnum)))))), + + Right_Opnd => Make_Integer_Literal (Loc, 1))))); + + Analyze_And_Resolve (N, Typ, Suppress => All_Checks); + return; + + -- If the prefix type is a constrained packed array type which + -- already has a Packed_Array_Type representation defined, then + -- replace this attribute with a direct reference to 'Range_Length + -- of the appropriate index subtype (since otherwise Gigi will try + -- to give us the value of 'Length for this implementation type). + + elsif Is_Constrained (Ptyp) then + Rewrite (N, + Make_Attribute_Reference (Loc, + Attribute_Name => Name_Range_Length, + Prefix => New_Reference_To (Ityp, Loc))); + Analyze_And_Resolve (N, Typ); + end if; + + -- If we have a packed array that is not bit packed, which was + + -- Access type case + + elsif Is_Access_Type (Ptyp) then + Apply_Access_Check (N); + + -- If the designated type is a packed array type, then we + -- convert the reference to: + + -- typ'Max (0, 1 + + -- xtyp'Pos (Pref'Last (Expr)) - + -- xtyp'Pos (Pref'First (Expr))); + + -- This is a bit complex, but it is the easiest thing to do + -- that works in all cases including enum types with holes + -- xtyp here is the appropriate index type. + + declare + Dtyp : constant Entity_Id := Designated_Type (Ptyp); + Xtyp : Entity_Id; + + begin + if Is_Array_Type (Dtyp) and then Is_Packed (Dtyp) then + Xtyp := Get_Index_Subtype (N); + + Rewrite (N, + Make_Attribute_Reference (Loc, + Prefix => New_Occurrence_Of (Typ, Loc), + Attribute_Name => Name_Max, + Expressions => New_List ( + Make_Integer_Literal (Loc, 0), + + Make_Op_Add (Loc, + Make_Integer_Literal (Loc, 1), + Make_Op_Subtract (Loc, + Left_Opnd => + Make_Attribute_Reference (Loc, + Prefix => New_Occurrence_Of (Xtyp, Loc), + Attribute_Name => Name_Pos, + Expressions => New_List ( + Make_Attribute_Reference (Loc, + Prefix => Duplicate_Subexpr (Pref), + Attribute_Name => Name_Last, + Expressions => + New_Copy_List (Exprs)))), + + Right_Opnd => + Make_Attribute_Reference (Loc, + Prefix => New_Occurrence_Of (Xtyp, Loc), + Attribute_Name => Name_Pos, + Expressions => New_List ( + Make_Attribute_Reference (Loc, + Prefix => + Duplicate_Subexpr_No_Checks (Pref), + Attribute_Name => Name_First, + Expressions => + New_Copy_List (Exprs))))))))); + + Analyze_And_Resolve (N, Typ); + end if; + end; + + -- Otherwise leave it to gigi + + else + Apply_Universal_Integer_Attribute_Checks (N); + end if; + end; + + ------------- + -- Machine -- + ------------- + + -- Transforms 'Machine into a call to the floating-point attribute + -- function Machine in Fat_xxx (where xxx is the root type) + + when Attribute_Machine => + Expand_Fpt_Attribute_R (N); + + ---------------------- + -- Machine_Rounding -- + ---------------------- + + -- Transforms 'Machine_Rounding into a call to the floating-point + -- attribute function Machine_Rounding in Fat_xxx (where xxx is the root + -- type). + + when Attribute_Machine_Rounding => + Expand_Fpt_Attribute_R (N); + + ------------------ + -- Machine_Size -- + ------------------ + + -- Machine_Size is equivalent to Object_Size, so transform it into + -- Object_Size and that way Gigi never sees Machine_Size. + + when Attribute_Machine_Size => + Rewrite (N, + Make_Attribute_Reference (Loc, + Prefix => Prefix (N), + Attribute_Name => Name_Object_Size)); + + Analyze_And_Resolve (N, Typ); + + -------------- + -- Mantissa -- + -------------- + + -- The only case that can get this far is the dynamic case of the old + -- Ada 83 Mantissa attribute for the fixed-point case. For this case, we + -- expand: + + -- typ'Mantissa + + -- into + + -- ityp (System.Mantissa.Mantissa_Value + -- (Integer'Integer_Value (typ'First), + -- Integer'Integer_Value (typ'Last))); + + when Attribute_Mantissa => Mantissa : declare + Ptyp : constant Entity_Id := Etype (Pref); + + begin + Rewrite (N, + Convert_To (Typ, + Make_Function_Call (Loc, + Name => New_Occurrence_Of (RTE (RE_Mantissa_Value), Loc), + + Parameter_Associations => New_List ( + + Make_Attribute_Reference (Loc, + Prefix => New_Occurrence_Of (Standard_Integer, Loc), + Attribute_Name => Name_Integer_Value, + Expressions => New_List ( + + Make_Attribute_Reference (Loc, + Prefix => New_Occurrence_Of (Ptyp, Loc), + Attribute_Name => Name_First))), + + Make_Attribute_Reference (Loc, + Prefix => New_Occurrence_Of (Standard_Integer, Loc), + Attribute_Name => Name_Integer_Value, + Expressions => New_List ( + + Make_Attribute_Reference (Loc, + Prefix => New_Occurrence_Of (Ptyp, Loc), + Attribute_Name => Name_Last))))))); + + Analyze_And_Resolve (N, Typ); + end Mantissa; + + -------------------- + -- Mechanism_Code -- + -------------------- + + when Attribute_Mechanism_Code => + + -- We must replace the prefix in the renamed case + + if Is_Entity_Name (Pref) + and then Present (Alias (Entity (Pref))) + then + Set_Renamed_Subprogram (Pref, Alias (Entity (Pref))); + end if; + + --------- + -- Mod -- + --------- + + when Attribute_Mod => Mod_Case : declare + Arg : constant Node_Id := Relocate_Node (First (Exprs)); + Hi : constant Node_Id := Type_High_Bound (Etype (Arg)); + Modv : constant Uint := Modulus (Btyp); + + begin + + -- This is not so simple. The issue is what type to use for the + -- computation of the modular value. + + -- The easy case is when the modulus value is within the bounds + -- of the signed integer type of the argument. In this case we can + -- just do the computation in that signed integer type, and then + -- do an ordinary conversion to the target type. + + if Modv <= Expr_Value (Hi) then + Rewrite (N, + Convert_To (Btyp, + Make_Op_Mod (Loc, + Left_Opnd => Arg, + Right_Opnd => Make_Integer_Literal (Loc, Modv)))); + + -- Here we know that the modulus is larger than type'Last of the + -- integer type. There are two cases to consider: + + -- a) The integer value is non-negative. In this case, it is + -- returned as the result (since it is less than the modulus). + + -- b) The integer value is negative. In this case, we know that the + -- result is modulus + value, where the value might be as small as + -- -modulus. The trouble is what type do we use to do the subtract. + -- No type will do, since modulus can be as big as 2**64, and no + -- integer type accomodates this value. Let's do bit of algebra + + -- modulus + value + -- = modulus - (-value) + -- = (modulus - 1) - (-value - 1) + + -- Now modulus - 1 is certainly in range of the modular type. + -- -value is in the range 1 .. modulus, so -value -1 is in the + -- range 0 .. modulus-1 which is in range of the modular type. + -- Furthermore, (-value - 1) can be expressed as -(value + 1) + -- which we can compute using the integer base type. + + -- Once this is done we analyze the conditional expression without + -- range checks, because we know everything is in range, and we + -- want to prevent spurious warnings on either branch. + + else + Rewrite (N, + Make_Conditional_Expression (Loc, + Expressions => New_List ( + Make_Op_Ge (Loc, + Left_Opnd => Duplicate_Subexpr (Arg), + Right_Opnd => Make_Integer_Literal (Loc, 0)), + + Convert_To (Btyp, + Duplicate_Subexpr_No_Checks (Arg)), + + Make_Op_Subtract (Loc, + Left_Opnd => + Make_Integer_Literal (Loc, + Intval => Modv - 1), + Right_Opnd => + Convert_To (Btyp, + Make_Op_Minus (Loc, + Right_Opnd => + Make_Op_Add (Loc, + Left_Opnd => Duplicate_Subexpr_No_Checks (Arg), + Right_Opnd => + Make_Integer_Literal (Loc, + Intval => 1)))))))); + + end if; + + Analyze_And_Resolve (N, Btyp, Suppress => All_Checks); + end Mod_Case; + + ----------- + -- Model -- + ----------- + + -- Transforms 'Model into a call to the floating-point attribute + -- function Model in Fat_xxx (where xxx is the root type) + + when Attribute_Model => + Expand_Fpt_Attribute_R (N); + + ----------------- + -- Object_Size -- + ----------------- + + -- The processing for Object_Size shares the processing for Size + + ------------ + -- Output -- + ------------ + + when Attribute_Output => Output : declare + P_Type : constant Entity_Id := Entity (Pref); + U_Type : constant Entity_Id := Underlying_Type (P_Type); + Pname : Entity_Id; + Decl : Node_Id; + Prag : Node_Id; + Arg3 : Node_Id; + Wfunc : Node_Id; + + begin + -- If no underlying type, we have an error that will be diagnosed + -- elsewhere, so here we just completely ignore the expansion. + + if No (U_Type) then + return; + end if; + + -- If TSS for Output is present, just call it + + Pname := Find_Stream_Subprogram (P_Type, TSS_Stream_Output); + + if Present (Pname) then + null; + + else + -- If there is a Stream_Convert pragma, use it, we rewrite + + -- sourcetyp'Output (stream, Item) + + -- as + + -- strmtyp'Output (Stream, strmwrite (acttyp (Item))); + + -- where strmwrite is the given Write function that converts an + -- argument of type sourcetyp or a type acctyp, from which it is + -- derived to type strmtyp. The conversion to acttyp is required + -- for the derived case. + + Prag := Get_Stream_Convert_Pragma (P_Type); + + if Present (Prag) then + Arg3 := + Next (Next (First (Pragma_Argument_Associations (Prag)))); + Wfunc := Entity (Expression (Arg3)); + + Rewrite (N, + Make_Attribute_Reference (Loc, + Prefix => New_Occurrence_Of (Etype (Wfunc), Loc), + Attribute_Name => Name_Output, + Expressions => New_List ( + Relocate_Node (First (Exprs)), + Make_Function_Call (Loc, + Name => New_Occurrence_Of (Wfunc, Loc), + Parameter_Associations => New_List ( + Convert_To (Etype (First_Formal (Wfunc)), + Relocate_Node (Next (First (Exprs))))))))); + + Analyze (N); + return; + + -- For elementary types, we call the W_xxx routine directly. + -- Note that the effect of Write and Output is identical for + -- the case of an elementary type, since there are no + -- discriminants or bounds. + + elsif Is_Elementary_Type (U_Type) then + + -- A special case arises if we have a defined _Write routine, + -- since in this case we are required to call this routine. + + if Present (TSS (Base_Type (U_Type), TSS_Stream_Write)) then + Build_Record_Or_Elementary_Output_Procedure + (Loc, U_Type, Decl, Pname); + Insert_Action (N, Decl); + + -- For normal cases, we call the W_xxx routine directly + + else + Rewrite (N, Build_Elementary_Write_Call (N)); + Analyze (N); + return; + end if; + + -- Array type case + + elsif Is_Array_Type (U_Type) then + Build_Array_Output_Procedure (Loc, U_Type, Decl, Pname); + Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False); + + -- Class-wide case, first output external tag, then dispatch + -- to the appropriate primitive Output function (RM 13.13.2(31)). + + elsif Is_Class_Wide_Type (P_Type) then + Tag_Write : declare + Strm : constant Node_Id := First (Exprs); + Item : constant Node_Id := Next (Strm); + + begin + -- The code is: + -- if Get_Access_Level (Item'Tag) + -- /= Get_Access_Level (P_Type'Tag) + -- then + -- raise Tag_Error; + -- end if; + -- String'Output (Strm, External_Tag (Item'Tag)); + + -- Ada 2005 (AI-344): Check that the accessibility level + -- of the type of the output object is not deeper than + -- that of the attribute's prefix type. + + if Ada_Version >= Ada_05 then + Insert_Action (N, + Make_Implicit_If_Statement (N, + Condition => + Make_Op_Ne (Loc, + Left_Opnd => + Make_Function_Call (Loc, + Name => + New_Reference_To + (RTE (RE_Get_Access_Level), Loc), + Parameter_Associations => + New_List (Make_Attribute_Reference (Loc, + Prefix => + Relocate_Node ( + Duplicate_Subexpr (Item, + Name_Req => True)), + Attribute_Name => + Name_Tag))), + Right_Opnd => + Make_Integer_Literal + (Loc, Type_Access_Level (P_Type))), + Then_Statements => + New_List (Make_Raise_Statement (Loc, + New_Occurrence_Of ( + RTE (RE_Tag_Error), Loc))))); + end if; + + Insert_Action (N, + Make_Attribute_Reference (Loc, + Prefix => New_Occurrence_Of (Standard_String, Loc), + Attribute_Name => Name_Output, + Expressions => New_List ( + Relocate_Node (Duplicate_Subexpr (Strm)), + Make_Function_Call (Loc, + Name => + New_Occurrence_Of (RTE (RE_External_Tag), Loc), + Parameter_Associations => New_List ( + Make_Attribute_Reference (Loc, + Prefix => + Relocate_Node + (Duplicate_Subexpr (Item, Name_Req => True)), + Attribute_Name => Name_Tag)))))); + end Tag_Write; + + Pname := Find_Prim_Op (U_Type, TSS_Stream_Output); + + -- Tagged type case, use the primitive Output function + + elsif Is_Tagged_Type (U_Type) then + Pname := Find_Prim_Op (U_Type, TSS_Stream_Output); + +-- -- All other record type cases, including protected records. +-- -- The latter only arise for expander generated code for +-- -- handling shared passive partition access. + + else + pragma Assert + (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type)); + + -- Ada 2005 (AI-216): Program_Error is raised when executing + -- the default implementation of the Output attribute of an + -- unchecked union type if the type lacks default discriminant + -- values. + + if Is_Unchecked_Union (Base_Type (U_Type)) + and then No (Discriminant_Constraint (U_Type)) + then + Insert_Action (N, + Make_Raise_Program_Error (Loc, + Reason => PE_Unchecked_Union_Restriction)); + + return; + end if; + + Build_Record_Or_Elementary_Output_Procedure + (Loc, Base_Type (U_Type), Decl, Pname); + Insert_Action (N, Decl); + end if; + end if; + + -- If we fall through, Pname is the name of the procedure to call + + Rewrite_Stream_Proc_Call (Pname); + end Output; + + --------- + -- Pos -- + --------- + + -- For enumeration types with a standard representation, Pos is + -- handled by Gigi. + + -- For enumeration types, with a non-standard representation we + -- generate a call to the _Rep_To_Pos function created when the + -- type was frozen. The call has the form + + -- _rep_to_pos (expr, flag) + + -- The parameter flag is True if range checks are enabled, causing + -- Program_Error to be raised if the expression has an invalid + -- representation, and False if range checks are suppressed. + + -- For integer types, Pos is equivalent to a simple integer + -- conversion and we rewrite it as such + + when Attribute_Pos => Pos : + declare + Etyp : Entity_Id := Base_Type (Entity (Pref)); + + begin + -- Deal with zero/non-zero boolean values + + if Is_Boolean_Type (Etyp) then + Adjust_Condition (First (Exprs)); + Etyp := Standard_Boolean; + Set_Prefix (N, New_Occurrence_Of (Standard_Boolean, Loc)); + end if; + + -- Case of enumeration type + + if Is_Enumeration_Type (Etyp) then + + -- Non-standard enumeration type (generate call) + + if Present (Enum_Pos_To_Rep (Etyp)) then + Append_To (Exprs, Rep_To_Pos_Flag (Etyp, Loc)); + Rewrite (N, + Convert_To (Typ, + Make_Function_Call (Loc, + Name => + New_Reference_To (TSS (Etyp, TSS_Rep_To_Pos), Loc), + Parameter_Associations => Exprs))); + + Analyze_And_Resolve (N, Typ); + + -- Standard enumeration type (do universal integer check) + + else + Apply_Universal_Integer_Attribute_Checks (N); + end if; + + -- Deal with integer types (replace by conversion) + + elsif Is_Integer_Type (Etyp) then + Rewrite (N, Convert_To (Typ, First (Exprs))); + Analyze_And_Resolve (N, Typ); + end if; + + end Pos; + + -------------- + -- Position -- + -------------- + + -- We compute this if a component clause was present, otherwise + -- we leave the computation up to Gigi, since we don't know what + -- layout will be chosen. + + when Attribute_Position => Position : + declare + CE : constant Entity_Id := Entity (Selector_Name (Pref)); + + begin + if Present (Component_Clause (CE)) then + Rewrite (N, + Make_Integer_Literal (Loc, + Intval => Component_Bit_Offset (CE) / System_Storage_Unit)); + Analyze_And_Resolve (N, Typ); + + else + Apply_Universal_Integer_Attribute_Checks (N); + end if; + end Position; + + ---------- + -- Pred -- + ---------- + + -- 1. Deal with enumeration types with holes + -- 2. For floating-point, generate call to attribute function + -- 3. For other cases, deal with constraint checking + + when Attribute_Pred => Pred : + declare + Ptyp : constant Entity_Id := Base_Type (Etype (Pref)); + + begin + -- For enumeration types with non-standard representations, we + -- expand typ'Pred (x) into + + -- Pos_To_Rep (Rep_To_Pos (x) - 1) + + -- If the representation is contiguous, we compute instead + -- Lit1 + Rep_to_Pos (x -1), to catch invalid representations. + + if Is_Enumeration_Type (Ptyp) + and then Present (Enum_Pos_To_Rep (Ptyp)) + then + if Has_Contiguous_Rep (Ptyp) then + Rewrite (N, + Unchecked_Convert_To (Ptyp, + Make_Op_Add (Loc, + Left_Opnd => + Make_Integer_Literal (Loc, + Enumeration_Rep (First_Literal (Ptyp))), + Right_Opnd => + Make_Function_Call (Loc, + Name => + New_Reference_To + (TSS (Ptyp, TSS_Rep_To_Pos), Loc), + + Parameter_Associations => + New_List ( + Unchecked_Convert_To (Ptyp, + Make_Op_Subtract (Loc, + Left_Opnd => + Unchecked_Convert_To (Standard_Integer, + Relocate_Node (First (Exprs))), + Right_Opnd => + Make_Integer_Literal (Loc, 1))), + Rep_To_Pos_Flag (Ptyp, Loc)))))); + + else + -- Add Boolean parameter True, to request program errror if + -- we have a bad representation on our hands. If checks are + -- suppressed, then add False instead + + Append_To (Exprs, Rep_To_Pos_Flag (Ptyp, Loc)); + Rewrite (N, + Make_Indexed_Component (Loc, + Prefix => New_Reference_To (Enum_Pos_To_Rep (Ptyp), Loc), + Expressions => New_List ( + Make_Op_Subtract (Loc, + Left_Opnd => + Make_Function_Call (Loc, + Name => + New_Reference_To (TSS (Ptyp, TSS_Rep_To_Pos), Loc), + Parameter_Associations => Exprs), + Right_Opnd => Make_Integer_Literal (Loc, 1))))); + end if; + + Analyze_And_Resolve (N, Typ); + + -- For floating-point, we transform 'Pred into a call to the Pred + -- floating-point attribute function in Fat_xxx (xxx is root type) + + elsif Is_Floating_Point_Type (Ptyp) then + Expand_Fpt_Attribute_R (N); + Analyze_And_Resolve (N, Typ); + + -- For modular types, nothing to do (no overflow, since wraps) + + elsif Is_Modular_Integer_Type (Ptyp) then + null; + + -- For other types, if range checking is enabled, we must generate + -- a check if overflow checking is enabled. + + elsif not Overflow_Checks_Suppressed (Ptyp) then + Expand_Pred_Succ (N); + end if; + end Pred; + + ------------------ + -- Range_Length -- + ------------------ + + when Attribute_Range_Length => Range_Length : declare + P_Type : constant Entity_Id := Etype (Pref); + + begin + -- The only special processing required is for the case where + -- Range_Length is applied to an enumeration type with holes. + -- In this case we transform + + -- X'Range_Length + + -- to + + -- X'Pos (X'Last) - X'Pos (X'First) + 1 + + -- So that the result reflects the proper Pos values instead + -- of the underlying representations. + + if Is_Enumeration_Type (P_Type) + and then Has_Non_Standard_Rep (P_Type) + then + Rewrite (N, + Make_Op_Add (Loc, + Left_Opnd => + Make_Op_Subtract (Loc, + Left_Opnd => + Make_Attribute_Reference (Loc, + Attribute_Name => Name_Pos, + Prefix => New_Occurrence_Of (P_Type, Loc), + Expressions => New_List ( + Make_Attribute_Reference (Loc, + Attribute_Name => Name_Last, + Prefix => New_Occurrence_Of (P_Type, Loc)))), + + Right_Opnd => + Make_Attribute_Reference (Loc, + Attribute_Name => Name_Pos, + Prefix => New_Occurrence_Of (P_Type, Loc), + Expressions => New_List ( + Make_Attribute_Reference (Loc, + Attribute_Name => Name_First, + Prefix => New_Occurrence_Of (P_Type, Loc))))), + + Right_Opnd => + Make_Integer_Literal (Loc, 1))); + + Analyze_And_Resolve (N, Typ); + + -- For all other cases, attribute is handled by Gigi, but we need + -- to deal with the case of the range check on a universal integer. + + else + Apply_Universal_Integer_Attribute_Checks (N); + end if; + end Range_Length; + + ---------- + -- Read -- + ---------- + + when Attribute_Read => Read : declare + P_Type : constant Entity_Id := Entity (Pref); + B_Type : constant Entity_Id := Base_Type (P_Type); + U_Type : constant Entity_Id := Underlying_Type (P_Type); + Pname : Entity_Id; + Decl : Node_Id; + Prag : Node_Id; + Arg2 : Node_Id; + Rfunc : Node_Id; + Lhs : Node_Id; + Rhs : Node_Id; + + begin + -- If no underlying type, we have an error that will be diagnosed + -- elsewhere, so here we just completely ignore the expansion. + + if No (U_Type) then + return; + end if; + + -- The simple case, if there is a TSS for Read, just call it + + Pname := Find_Stream_Subprogram (P_Type, TSS_Stream_Read); + + if Present (Pname) then + null; + + else + -- If there is a Stream_Convert pragma, use it, we rewrite + + -- sourcetyp'Read (stream, Item) + + -- as + + -- Item := sourcetyp (strmread (strmtyp'Input (Stream))); + + -- where strmread is the given Read function that converts an + -- argument of type strmtyp to type sourcetyp or a type from which + -- it is derived. The conversion to sourcetyp is required in the + -- latter case. + + -- A special case arises if Item is a type conversion in which + -- case, we have to expand to: + + -- Itemx := typex (strmread (strmtyp'Input (Stream))); + + -- where Itemx is the expression of the type conversion (i.e. + -- the actual object), and typex is the type of Itemx. + + Prag := Get_Stream_Convert_Pragma (P_Type); + + if Present (Prag) then + Arg2 := Next (First (Pragma_Argument_Associations (Prag))); + Rfunc := Entity (Expression (Arg2)); + Lhs := Relocate_Node (Next (First (Exprs))); + Rhs := + Convert_To (B_Type, + Make_Function_Call (Loc, + Name => New_Occurrence_Of (Rfunc, Loc), + Parameter_Associations => New_List ( + Make_Attribute_Reference (Loc, + Prefix => + New_Occurrence_Of + (Etype (First_Formal (Rfunc)), Loc), + Attribute_Name => Name_Input, + Expressions => New_List ( + Relocate_Node (First (Exprs))))))); + + if Nkind (Lhs) = N_Type_Conversion then + Lhs := Expression (Lhs); + Rhs := Convert_To (Etype (Lhs), Rhs); + end if; + + Rewrite (N, + Make_Assignment_Statement (Loc, + Name => Lhs, + Expression => Rhs)); + Set_Assignment_OK (Lhs); + Analyze (N); + return; + + -- For elementary types, we call the I_xxx routine using the first + -- parameter and then assign the result into the second parameter. + -- We set Assignment_OK to deal with the conversion case. + + elsif Is_Elementary_Type (U_Type) then + declare + Lhs : Node_Id; + Rhs : Node_Id; + + begin + Lhs := Relocate_Node (Next (First (Exprs))); + Rhs := Build_Elementary_Input_Call (N); + + if Nkind (Lhs) = N_Type_Conversion then + Lhs := Expression (Lhs); + Rhs := Convert_To (Etype (Lhs), Rhs); + end if; + + Set_Assignment_OK (Lhs); + + Rewrite (N, + Make_Assignment_Statement (Loc, + Name => Lhs, + Expression => Rhs)); + + Analyze (N); + return; + end; + + -- Array type case + + elsif Is_Array_Type (U_Type) then + Build_Array_Read_Procedure (N, U_Type, Decl, Pname); + Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False); + + -- Tagged type case, use the primitive Read function. Note that + -- this will dispatch in the class-wide case which is what we want + + elsif Is_Tagged_Type (U_Type) then + Pname := Find_Prim_Op (U_Type, TSS_Stream_Read); + + -- All other record type cases, including protected records. The + -- latter only arise for expander generated code for handling + -- shared passive partition access. + + else + pragma Assert + (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type)); + + -- Ada 2005 (AI-216): Program_Error is raised when executing + -- the default implementation of the Read attribute of an + -- Unchecked_Union type. + + if Is_Unchecked_Union (Base_Type (U_Type)) then + Insert_Action (N, + Make_Raise_Program_Error (Loc, + Reason => PE_Unchecked_Union_Restriction)); + end if; + + if Has_Discriminants (U_Type) + and then Present + (Discriminant_Default_Value (First_Discriminant (U_Type))) + then + Build_Mutable_Record_Read_Procedure + (Loc, Base_Type (U_Type), Decl, Pname); + else + Build_Record_Read_Procedure + (Loc, Base_Type (U_Type), Decl, Pname); + end if; + + -- Suppress checks, uninitialized or otherwise invalid + -- data does not cause constraint errors to be raised for + -- a complete record read. + + Insert_Action (N, Decl, All_Checks); + end if; + end if; + + Rewrite_Stream_Proc_Call (Pname); + end Read; + + --------------- + -- Remainder -- + --------------- + + -- Transforms 'Remainder into a call to the floating-point attribute + -- function Remainder in Fat_xxx (where xxx is the root type) + + when Attribute_Remainder => + Expand_Fpt_Attribute_RR (N); + + ----------- + -- Round -- + ----------- + + -- The handling of the Round attribute is quite delicate. The processing + -- in Sem_Attr introduced a conversion to universal real, reflecting the + -- semantics of Round, but we do not want anything to do with universal + -- real at runtime, since this corresponds to using floating-point + -- arithmetic. + + -- What we have now is that the Etype of the Round attribute correctly + -- indicates the final result type. The operand of the Round is the + -- conversion to universal real, described above, and the operand of + -- this conversion is the actual operand of Round, which may be the + -- special case of a fixed point multiplication or division (Etype = + -- universal fixed) + + -- The exapander will expand first the operand of the conversion, then + -- the conversion, and finally the round attribute itself, since we + -- always work inside out. But we cannot simply process naively in this + -- order. In the semantic world where universal fixed and real really + -- exist and have infinite precision, there is no problem, but in the + -- implementation world, where universal real is a floating-point type, + -- we would get the wrong result. + + -- So the approach is as follows. First, when expanding a multiply or + -- divide whose type is universal fixed, we do nothing at all, instead + -- deferring the operation till later. + + -- The actual processing is done in Expand_N_Type_Conversion which + -- handles the special case of Round by looking at its parent to see if + -- it is a Round attribute, and if it is, handling the conversion (or + -- its fixed multiply/divide child) in an appropriate manner. + + -- This means that by the time we get to expanding the Round attribute + -- itself, the Round is nothing more than a type conversion (and will + -- often be a null type conversion), so we just replace it with the + -- appropriate conversion operation. + + when Attribute_Round => + Rewrite (N, + Convert_To (Etype (N), Relocate_Node (First (Exprs)))); + Analyze_And_Resolve (N); + + -------------- + -- Rounding -- + -------------- + + -- Transforms 'Rounding into a call to the floating-point attribute + -- function Rounding in Fat_xxx (where xxx is the root type) + + when Attribute_Rounding => + Expand_Fpt_Attribute_R (N); + + ------------- + -- Scaling -- + ------------- + + -- Transforms 'Scaling into a call to the floating-point attribute + -- function Scaling in Fat_xxx (where xxx is the root type) + + when Attribute_Scaling => + Expand_Fpt_Attribute_RI (N); + + ---------- + -- Size -- + ---------- + + when Attribute_Size | + Attribute_Object_Size | + Attribute_Value_Size | + Attribute_VADS_Size => Size : + + declare + Ptyp : constant Entity_Id := Etype (Pref); + Siz : Uint; + New_Node : Node_Id; + + begin + -- Processing for VADS_Size case. Note that this processing removes + -- all traces of VADS_Size from the tree, and completes all required + -- processing for VADS_Size by translating the attribute reference + -- to an appropriate Size or Object_Size reference. + + if Id = Attribute_VADS_Size + or else (Use_VADS_Size and then Id = Attribute_Size) + then + -- If the size is specified, then we simply use the specified + -- size. This applies to both types and objects. The size of an + -- object can be specified in the following ways: + + -- An explicit size object is given for an object + -- A component size is specified for an indexed component + -- A component clause is specified for a selected component + -- The object is a component of a packed composite object + + -- If the size is specified, then VADS_Size of an object + + if (Is_Entity_Name (Pref) + and then Present (Size_Clause (Entity (Pref)))) + or else + (Nkind (Pref) = N_Component_Clause + and then (Present (Component_Clause + (Entity (Selector_Name (Pref)))) + or else Is_Packed (Etype (Prefix (Pref))))) + or else + (Nkind (Pref) = N_Indexed_Component + and then (Component_Size (Etype (Prefix (Pref))) /= 0 + or else Is_Packed (Etype (Prefix (Pref))))) + then + Set_Attribute_Name (N, Name_Size); + + -- Otherwise if we have an object rather than a type, then the + -- VADS_Size attribute applies to the type of the object, rather + -- than the object itself. This is one of the respects in which + -- VADS_Size differs from Size. + + else + if (not Is_Entity_Name (Pref) + or else not Is_Type (Entity (Pref))) + and then (Is_Scalar_Type (Etype (Pref)) + or else Is_Constrained (Etype (Pref))) + then + Rewrite (Pref, New_Occurrence_Of (Etype (Pref), Loc)); + end if; + + -- For a scalar type for which no size was explicitly given, + -- VADS_Size means Object_Size. This is the other respect in + -- which VADS_Size differs from Size. + + if Is_Scalar_Type (Etype (Pref)) + and then No (Size_Clause (Etype (Pref))) + then + Set_Attribute_Name (N, Name_Object_Size); + + -- In all other cases, Size and VADS_Size are the sane + + else + Set_Attribute_Name (N, Name_Size); + end if; + end if; + end if; + + -- For class-wide types, X'Class'Size is transformed into a + -- direct reference to the Size of the class type, so that gigi + -- does not have to deal with the X'Class'Size reference. + + if Is_Entity_Name (Pref) + and then Is_Class_Wide_Type (Entity (Pref)) + then + Rewrite (Prefix (N), New_Occurrence_Of (Entity (Pref), Loc)); + return; + + -- For X'Size applied to an object of a class-wide type, transform + -- X'Size into a call to the primitive operation _Size applied to X. + + elsif Is_Class_Wide_Type (Ptyp) then + New_Node := + Make_Function_Call (Loc, + Name => New_Reference_To + (Find_Prim_Op (Ptyp, Name_uSize), Loc), + Parameter_Associations => New_List (Pref)); + + if Typ /= Standard_Long_Long_Integer then + + -- The context is a specific integer type with which the + -- original attribute was compatible. The function has a + -- specific type as well, so to preserve the compatibility + -- we must convert explicitly. + + New_Node := Convert_To (Typ, New_Node); + end if; + + Rewrite (N, New_Node); + Analyze_And_Resolve (N, Typ); + return; + + -- For an array component, we can do Size in the front end + -- if the component_size of the array is set. + + elsif Nkind (Pref) = N_Indexed_Component then + Siz := Component_Size (Etype (Prefix (Pref))); + + -- For a record component, we can do Size in the front end if there + -- is a component clause, or if the record is packed and the + -- component's size is known at compile time. + + elsif Nkind (Pref) = N_Selected_Component then + declare + Rec : constant Entity_Id := Etype (Prefix (Pref)); + Comp : constant Entity_Id := Entity (Selector_Name (Pref)); + + begin + if Present (Component_Clause (Comp)) then + Siz := Esize (Comp); + + elsif Is_Packed (Rec) then + Siz := RM_Size (Ptyp); + + else + Apply_Universal_Integer_Attribute_Checks (N); + return; + end if; + end; + + -- All other cases are handled by Gigi + + else + Apply_Universal_Integer_Attribute_Checks (N); + + -- If Size is applied to a formal parameter that is of a packed + -- array subtype, then apply Size to the actual subtype. + + if Is_Entity_Name (Pref) + and then Is_Formal (Entity (Pref)) + and then Is_Array_Type (Etype (Pref)) + and then Is_Packed (Etype (Pref)) + then + Rewrite (N, + Make_Attribute_Reference (Loc, + Prefix => + New_Occurrence_Of (Get_Actual_Subtype (Pref), Loc), + Attribute_Name => Name_Size)); + Analyze_And_Resolve (N, Typ); + end if; + + -- If Size is applied to a dereference of an access to + -- unconstrained packed array, GIGI needs to see its + -- unconstrained nominal type, but also a hint to the actual + -- constrained type. + + if Nkind (Pref) = N_Explicit_Dereference + and then Is_Array_Type (Etype (Pref)) + and then not Is_Constrained (Etype (Pref)) + and then Is_Packed (Etype (Pref)) + then + Set_Actual_Designated_Subtype (Pref, + Get_Actual_Subtype (Pref)); + end if; + + return; + end if; + + -- Common processing for record and array component case + + if Siz /= 0 then + Rewrite (N, Make_Integer_Literal (Loc, Siz)); + + Analyze_And_Resolve (N, Typ); + + -- The result is not a static expression + + Set_Is_Static_Expression (N, False); + end if; + end Size; + + ------------------ + -- Storage_Pool -- + ------------------ + + when Attribute_Storage_Pool => + Rewrite (N, + Make_Type_Conversion (Loc, + Subtype_Mark => New_Reference_To (Etype (N), Loc), + Expression => New_Reference_To (Entity (N), Loc))); + Analyze_And_Resolve (N, Typ); + + ------------------ + -- Storage_Size -- + ------------------ + + when Attribute_Storage_Size => Storage_Size : + declare + Ptyp : constant Entity_Id := Etype (Pref); + + begin + -- Access type case, always go to the root type + + -- The case of access types results in a value of zero for the case + -- where no storage size attribute clause has been given. If a + -- storage size has been given, then the attribute is converted + -- to a reference to the variable used to hold this value. + + if Is_Access_Type (Ptyp) then + if Present (Storage_Size_Variable (Root_Type (Ptyp))) then + Rewrite (N, + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Typ, Loc), + Attribute_Name => Name_Max, + Expressions => New_List ( + Make_Integer_Literal (Loc, 0), + Convert_To (Typ, + New_Reference_To + (Storage_Size_Variable (Root_Type (Ptyp)), Loc))))); + + elsif Present (Associated_Storage_Pool (Root_Type (Ptyp))) then + Rewrite (N, + OK_Convert_To (Typ, + Make_Function_Call (Loc, + Name => + New_Reference_To + (Find_Prim_Op + (Etype (Associated_Storage_Pool (Root_Type (Ptyp))), + Attribute_Name (N)), + Loc), + + Parameter_Associations => New_List (New_Reference_To ( + Associated_Storage_Pool (Root_Type (Ptyp)), Loc))))); + else + Rewrite (N, Make_Integer_Literal (Loc, 0)); + end if; + + Analyze_And_Resolve (N, Typ); + + -- The case of a task type (an obsolescent feature) is handled the + -- same way, seems as reasonable as anything, and it is what the + -- ACVC tests (e.g. CD1009K) seem to expect. + + -- If there is no Storage_Size variable, then we return the default + -- task stack size, otherwise, expand a Storage_Size attribute as + -- follows: + + -- Typ (Adjust_Storage_Size (taskZ)) + + -- except for the case of a task object which has a Storage_Size + -- pragma: + + -- Typ (Adjust_Storage_Size (taskV!(name)._Size)) + + else + if No (Storage_Size_Variable (Ptyp)) then + Rewrite (N, + Convert_To (Typ, + Make_Function_Call (Loc, + Name => + New_Occurrence_Of (RTE (RE_Default_Stack_Size), Loc)))); + + else + if not (Is_Entity_Name (Pref) and then + Is_Task_Type (Entity (Pref))) and then + Chars (Last_Entity (Corresponding_Record_Type (Ptyp))) = + Name_uSize + then + Rewrite (N, + Convert_To (Typ, + Make_Function_Call (Loc, + Name => New_Occurrence_Of ( + RTE (RE_Adjust_Storage_Size), Loc), + Parameter_Associations => + New_List ( + Make_Selected_Component (Loc, + Prefix => + Unchecked_Convert_To ( + Corresponding_Record_Type (Ptyp), + New_Copy_Tree (Pref)), + Selector_Name => + Make_Identifier (Loc, Name_uSize)))))); + + -- Task not having Storage_Size pragma + + else + Rewrite (N, + Convert_To (Typ, + Make_Function_Call (Loc, + Name => New_Occurrence_Of ( + RTE (RE_Adjust_Storage_Size), Loc), + Parameter_Associations => + New_List ( + New_Reference_To ( + Storage_Size_Variable (Ptyp), Loc))))); + end if; + + Analyze_And_Resolve (N, Typ); + end if; + end if; + end Storage_Size; + + ----------------- + -- Stream_Size -- + ----------------- + + when Attribute_Stream_Size => Stream_Size : declare + Ptyp : constant Entity_Id := Etype (Pref); + Size : Int; + + begin + -- If we have a Stream_Size clause for this type use it, otherwise + -- the Stream_Size if the size of the type. + + if Has_Stream_Size_Clause (Ptyp) then + Size := UI_To_Int + (Static_Integer (Expression (Stream_Size_Clause (Ptyp)))); + else + Size := UI_To_Int (Esize (Ptyp)); + end if; + + Rewrite (N, Make_Integer_Literal (Loc, Intval => Size)); + Analyze_And_Resolve (N, Typ); + end Stream_Size; + + ---------- + -- Succ -- + ---------- + + -- 1. Deal with enumeration types with holes + -- 2. For floating-point, generate call to attribute function + -- 3. For other cases, deal with constraint checking + + when Attribute_Succ => Succ : + declare + Ptyp : constant Entity_Id := Base_Type (Etype (Pref)); + + begin + -- For enumeration types with non-standard representations, we + -- expand typ'Succ (x) into + + -- Pos_To_Rep (Rep_To_Pos (x) + 1) + + -- If the representation is contiguous, we compute instead + -- Lit1 + Rep_to_Pos (x+1), to catch invalid representations. + + if Is_Enumeration_Type (Ptyp) + and then Present (Enum_Pos_To_Rep (Ptyp)) + then + if Has_Contiguous_Rep (Ptyp) then + Rewrite (N, + Unchecked_Convert_To (Ptyp, + Make_Op_Add (Loc, + Left_Opnd => + Make_Integer_Literal (Loc, + Enumeration_Rep (First_Literal (Ptyp))), + Right_Opnd => + Make_Function_Call (Loc, + Name => + New_Reference_To + (TSS (Ptyp, TSS_Rep_To_Pos), Loc), + + Parameter_Associations => + New_List ( + Unchecked_Convert_To (Ptyp, + Make_Op_Add (Loc, + Left_Opnd => + Unchecked_Convert_To (Standard_Integer, + Relocate_Node (First (Exprs))), + Right_Opnd => + Make_Integer_Literal (Loc, 1))), + Rep_To_Pos_Flag (Ptyp, Loc)))))); + else + -- Add Boolean parameter True, to request program errror if + -- we have a bad representation on our hands. Add False if + -- checks are suppressed. + + Append_To (Exprs, Rep_To_Pos_Flag (Ptyp, Loc)); + Rewrite (N, + Make_Indexed_Component (Loc, + Prefix => New_Reference_To (Enum_Pos_To_Rep (Ptyp), Loc), + Expressions => New_List ( + Make_Op_Add (Loc, + Left_Opnd => + Make_Function_Call (Loc, + Name => + New_Reference_To + (TSS (Ptyp, TSS_Rep_To_Pos), Loc), + Parameter_Associations => Exprs), + Right_Opnd => Make_Integer_Literal (Loc, 1))))); + end if; + + Analyze_And_Resolve (N, Typ); + + -- For floating-point, we transform 'Succ into a call to the Succ + -- floating-point attribute function in Fat_xxx (xxx is root type) + + elsif Is_Floating_Point_Type (Ptyp) then + Expand_Fpt_Attribute_R (N); + Analyze_And_Resolve (N, Typ); + + -- For modular types, nothing to do (no overflow, since wraps) + + elsif Is_Modular_Integer_Type (Ptyp) then + null; + + -- For other types, if range checking is enabled, we must generate + -- a check if overflow checking is enabled. + + elsif not Overflow_Checks_Suppressed (Ptyp) then + Expand_Pred_Succ (N); + end if; + end Succ; + + --------- + -- Tag -- + --------- + + -- Transforms X'Tag into a direct reference to the tag of X + + when Attribute_Tag => Tag : + declare + Ttyp : Entity_Id; + Prefix_Is_Type : Boolean; + + begin + if Is_Entity_Name (Pref) and then Is_Type (Entity (Pref)) then + Ttyp := Entity (Pref); + Prefix_Is_Type := True; + else + Ttyp := Etype (Pref); + Prefix_Is_Type := False; + end if; + + if Is_Class_Wide_Type (Ttyp) then + Ttyp := Root_Type (Ttyp); + end if; + + Ttyp := Underlying_Type (Ttyp); + + if Prefix_Is_Type then + + -- For JGNAT we leave the type attribute unexpanded because + -- there's not a dispatching table to reference. + + if not Java_VM then + Rewrite (N, + Unchecked_Convert_To (RTE (RE_Tag), + New_Reference_To + (Node (First_Elmt (Access_Disp_Table (Ttyp))), Loc))); + Analyze_And_Resolve (N, RTE (RE_Tag)); + end if; + + else + Rewrite (N, + Make_Selected_Component (Loc, + Prefix => Relocate_Node (Pref), + Selector_Name => + New_Reference_To (First_Tag_Component (Ttyp), Loc))); + Analyze_And_Resolve (N, RTE (RE_Tag)); + end if; + end Tag; + + ---------------- + -- Terminated -- + ---------------- + + -- Transforms 'Terminated attribute into a call to Terminated function + + when Attribute_Terminated => Terminated : + begin + -- The prefix of Terminated is of a task interface class-wide type. + -- Generate: + + -- terminated (Pref._disp_get_task_id); + + if Ada_Version >= Ada_05 + and then Ekind (Etype (Pref)) = E_Class_Wide_Type + and then Is_Interface (Etype (Pref)) + and then Is_Task_Interface (Etype (Pref)) + then + Rewrite (N, + Make_Function_Call (Loc, + Name => + New_Reference_To (RTE (RE_Terminated), Loc), + Parameter_Associations => New_List ( + Make_Selected_Component (Loc, + Prefix => + New_Copy_Tree (Pref), + Selector_Name => + Make_Identifier (Loc, Name_uDisp_Get_Task_Id))))); + + elsif Restricted_Profile then + Rewrite (N, + Build_Call_With_Task (Pref, RTE (RE_Restricted_Terminated))); + + else + Rewrite (N, + Build_Call_With_Task (Pref, RTE (RE_Terminated))); + end if; + + Analyze_And_Resolve (N, Standard_Boolean); + end Terminated; + + ---------------- + -- To_Address -- + ---------------- + + -- Transforms System'To_Address (X) into unchecked conversion + -- from (integral) type of X to type address. + + when Attribute_To_Address => + Rewrite (N, + Unchecked_Convert_To (RTE (RE_Address), + Relocate_Node (First (Exprs)))); + Analyze_And_Resolve (N, RTE (RE_Address)); + + ---------------- + -- Truncation -- + ---------------- + + -- Transforms 'Truncation into a call to the floating-point attribute + -- function Truncation in Fat_xxx (where xxx is the root type) + + when Attribute_Truncation => + Expand_Fpt_Attribute_R (N); + + ----------------------- + -- Unbiased_Rounding -- + ----------------------- + + -- Transforms 'Unbiased_Rounding into a call to the floating-point + -- attribute function Unbiased_Rounding in Fat_xxx (where xxx is the + -- root type) + + when Attribute_Unbiased_Rounding => + Expand_Fpt_Attribute_R (N); + + ---------------------- + -- Unchecked_Access -- + ---------------------- + + when Attribute_Unchecked_Access => + + -- Ada 2005 (AI-251): If the designated type is an interface, then + -- rewrite the referenced object as a conversion to force the + -- displacement of the pointer to the secondary dispatch table. + + if Is_Interface (Directly_Designated_Type (Btyp)) then + declare + Ref_Object : constant Node_Id := Get_Referenced_Object (Pref); + Conversion : Node_Id; + begin + Conversion := Convert_To (Typ, New_Copy_Tree (Ref_Object)); + Rewrite (N, Conversion); + Analyze_And_Resolve (N, Typ); + end; + + -- Otherwise this is like normal Access without a check + + else + Expand_Access_To_Type (N); + end if; + + ----------------- + -- UET_Address -- + ----------------- + + when Attribute_UET_Address => UET_Address : declare + Ent : constant Entity_Id := + Make_Defining_Identifier (Loc, New_Internal_Name ('T')); + + begin + Insert_Action (N, + Make_Object_Declaration (Loc, + Defining_Identifier => Ent, + Aliased_Present => True, + Object_Definition => + New_Occurrence_Of (RTE (RE_Address), Loc))); + + -- Construct name __gnat_xxx__SDP, where xxx is the unit name + -- in normal external form. + + Get_External_Unit_Name_String (Get_Unit_Name (Pref)); + Name_Buffer (1 + 7 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len); + Name_Len := Name_Len + 7; + Name_Buffer (1 .. 7) := "__gnat_"; + Name_Buffer (Name_Len + 1 .. Name_Len + 5) := "__SDP"; + Name_Len := Name_Len + 5; + + Set_Is_Imported (Ent); + Set_Interface_Name (Ent, + Make_String_Literal (Loc, + Strval => String_From_Name_Buffer)); + + Rewrite (N, + Make_Attribute_Reference (Loc, + Prefix => New_Occurrence_Of (Ent, Loc), + Attribute_Name => Name_Address)); + + Analyze_And_Resolve (N, Typ); + end UET_Address; + + ------------------------- + -- Unrestricted_Access -- + ------------------------- + + when Attribute_Unrestricted_Access => + + -- Ada 2005 (AI-251): If the designated type is an interface, then + -- rewrite the referenced object as a conversion to force the + -- displacement of the pointer to the secondary dispatch table. + + if Is_Interface (Directly_Designated_Type (Btyp)) then + declare + Ref_Object : constant Node_Id := Get_Referenced_Object (Pref); + Conversion : Node_Id; + begin + Conversion := Convert_To (Typ, New_Copy_Tree (Ref_Object)); + Rewrite (N, Conversion); + Analyze_And_Resolve (N, Typ); + end; + + -- Otherwise this is like Access without a check + + else + Expand_Access_To_Type (N); + end if; + + --------------- + -- VADS_Size -- + --------------- + + -- The processing for VADS_Size is shared with Size + + --------- + -- Val -- + --------- + + -- For enumeration types with a standard representation, and for all + -- other types, Val is handled by Gigi. For enumeration types with + -- a non-standard representation we use the _Pos_To_Rep array that + -- was created when the type was frozen. + + when Attribute_Val => Val : + declare + Etyp : constant Entity_Id := Base_Type (Entity (Pref)); + + begin + if Is_Enumeration_Type (Etyp) + and then Present (Enum_Pos_To_Rep (Etyp)) + then + if Has_Contiguous_Rep (Etyp) then + declare + Rep_Node : constant Node_Id := + Unchecked_Convert_To (Etyp, + Make_Op_Add (Loc, + Left_Opnd => + Make_Integer_Literal (Loc, + Enumeration_Rep (First_Literal (Etyp))), + Right_Opnd => + (Convert_To (Standard_Integer, + Relocate_Node (First (Exprs)))))); + + begin + Rewrite (N, + Unchecked_Convert_To (Etyp, + Make_Op_Add (Loc, + Left_Opnd => + Make_Integer_Literal (Loc, + Enumeration_Rep (First_Literal (Etyp))), + Right_Opnd => + Make_Function_Call (Loc, + Name => + New_Reference_To + (TSS (Etyp, TSS_Rep_To_Pos), Loc), + Parameter_Associations => New_List ( + Rep_Node, + Rep_To_Pos_Flag (Etyp, Loc)))))); + end; + + else + Rewrite (N, + Make_Indexed_Component (Loc, + Prefix => New_Reference_To (Enum_Pos_To_Rep (Etyp), Loc), + Expressions => New_List ( + Convert_To (Standard_Integer, + Relocate_Node (First (Exprs)))))); + end if; + + Analyze_And_Resolve (N, Typ); + end if; + end Val; + + ----------- + -- Valid -- + ----------- + + -- The code for valid is dependent on the particular types involved. + -- See separate sections below for the generated code in each case. + + when Attribute_Valid => Valid : + declare + Ptyp : constant Entity_Id := Etype (Pref); + Btyp : Entity_Id := Base_Type (Ptyp); + Tst : Node_Id; + + Save_Validity_Checks_On : constant Boolean := Validity_Checks_On; + -- Save the validity checking mode. We always turn off validity + -- checking during process of 'Valid since this is one place + -- where we do not want the implicit validity checks to intefere + -- with the explicit validity check that the programmer is doing. + + function Make_Range_Test return Node_Id; + -- Build the code for a range test of the form + -- Btyp!(Pref) >= Btyp!(Ptyp'First) + -- and then + -- Btyp!(Pref) <= Btyp!(Ptyp'Last) + + --------------------- + -- Make_Range_Test -- + --------------------- + + function Make_Range_Test return Node_Id is + begin + return + Make_And_Then (Loc, + Left_Opnd => + Make_Op_Ge (Loc, + Left_Opnd => + Unchecked_Convert_To (Btyp, Duplicate_Subexpr (Pref)), + + Right_Opnd => + Unchecked_Convert_To (Btyp, + Make_Attribute_Reference (Loc, + Prefix => New_Occurrence_Of (Ptyp, Loc), + Attribute_Name => Name_First))), + + Right_Opnd => + Make_Op_Le (Loc, + Left_Opnd => + Unchecked_Convert_To (Btyp, + Duplicate_Subexpr_No_Checks (Pref)), + + Right_Opnd => + Unchecked_Convert_To (Btyp, + Make_Attribute_Reference (Loc, + Prefix => New_Occurrence_Of (Ptyp, Loc), + Attribute_Name => Name_Last)))); + end Make_Range_Test; + + -- Start of processing for Attribute_Valid + + begin + -- Turn off validity checks. We do not want any implicit validity + -- checks to intefere with the explicit check from the attribute + + Validity_Checks_On := False; + + -- Floating-point case. This case is handled by the Valid attribute + -- code in the floating-point attribute run-time library. + + if Is_Floating_Point_Type (Ptyp) then + declare + Pkg : RE_Id; + Ftp : Entity_Id; + + begin + -- For vax fpt types, call appropriate routine in special vax + -- floating point unit. We do not have to worry about loads in + -- this case, since these types have no signalling NaN's. + + if Vax_Float (Btyp) then + Expand_Vax_Valid (N); + + -- Non VAX float case + + else + Find_Fat_Info (Etype (Pref), Ftp, Pkg); + + -- If the floating-point object might be unaligned, we need + -- to call the special routine Unaligned_Valid, which makes + -- the needed copy, being careful not to load the value into + -- any floating-point register. The argument in this case is + -- obj'Address (see Unchecked_Valid routine in Fat_Gen). + + if Is_Possibly_Unaligned_Object (Pref) then + Set_Attribute_Name (N, Name_Unaligned_Valid); + Expand_Fpt_Attribute + (N, Pkg, Name_Unaligned_Valid, + New_List ( + Make_Attribute_Reference (Loc, + Prefix => Relocate_Node (Pref), + Attribute_Name => Name_Address))); + + -- In the normal case where we are sure the object is + -- aligned, we generate a call to Valid, and the argument in + -- this case is obj'Unrestricted_Access (after converting + -- obj to the right floating-point type). + + else + Expand_Fpt_Attribute + (N, Pkg, Name_Valid, + New_List ( + Make_Attribute_Reference (Loc, + Prefix => Unchecked_Convert_To (Ftp, Pref), + Attribute_Name => Name_Unrestricted_Access))); + end if; + end if; + + -- One more task, we still need a range check. Required + -- only if we have a constraint, since the Valid routine + -- catches infinities properly (infinities are never valid). + + -- The way we do the range check is simply to create the + -- expression: Valid (N) and then Base_Type(Pref) in Typ. + + if not Subtypes_Statically_Match (Ptyp, Btyp) then + Rewrite (N, + Make_And_Then (Loc, + Left_Opnd => Relocate_Node (N), + Right_Opnd => + Make_In (Loc, + Left_Opnd => Convert_To (Btyp, Pref), + Right_Opnd => New_Occurrence_Of (Ptyp, Loc)))); + end if; + end; + + -- Enumeration type with holes + + -- For enumeration types with holes, the Pos value constructed by + -- the Enum_Rep_To_Pos function built in Exp_Ch3 called with a + -- second argument of False returns minus one for an invalid value, + -- and the non-negative pos value for a valid value, so the + -- expansion of X'Valid is simply: + + -- type(X)'Pos (X) >= 0 + + -- We can't quite generate it that way because of the requirement + -- for the non-standard second argument of False in the resulting + -- rep_to_pos call, so we have to explicitly create: + + -- _rep_to_pos (X, False) >= 0 + + -- If we have an enumeration subtype, we also check that the + -- value is in range: + + -- _rep_to_pos (X, False) >= 0 + -- and then + -- (X >= type(X)'First and then type(X)'Last <= X) + + elsif Is_Enumeration_Type (Ptyp) + and then Present (Enum_Pos_To_Rep (Base_Type (Ptyp))) + then + Tst := + Make_Op_Ge (Loc, + Left_Opnd => + Make_Function_Call (Loc, + Name => + New_Reference_To + (TSS (Base_Type (Ptyp), TSS_Rep_To_Pos), Loc), + Parameter_Associations => New_List ( + Pref, + New_Occurrence_Of (Standard_False, Loc))), + Right_Opnd => Make_Integer_Literal (Loc, 0)); + + if Ptyp /= Btyp + and then + (Type_Low_Bound (Ptyp) /= Type_Low_Bound (Btyp) + or else + Type_High_Bound (Ptyp) /= Type_High_Bound (Btyp)) + then + -- The call to Make_Range_Test will create declarations + -- that need a proper insertion point, but Pref is now + -- attached to a node with no ancestor. Attach to tree + -- even if it is to be rewritten below. + + Set_Parent (Tst, Parent (N)); + + Tst := + Make_And_Then (Loc, + Left_Opnd => Make_Range_Test, + Right_Opnd => Tst); + end if; + + Rewrite (N, Tst); + + -- Fortran convention booleans + + -- For the very special case of Fortran convention booleans, the + -- value is always valid, since it is an integer with the semantics + -- that non-zero is true, and any value is permissible. + + elsif Is_Boolean_Type (Ptyp) + and then Convention (Ptyp) = Convention_Fortran + then + Rewrite (N, New_Occurrence_Of (Standard_True, Loc)); + + -- For biased representations, we will be doing an unchecked + -- conversion without unbiasing the result. That means that the range + -- test has to take this into account, and the proper form of the + -- test is: + + -- Btyp!(Pref) < Btyp!(Ptyp'Range_Length) + + elsif Has_Biased_Representation (Ptyp) then + Btyp := RTE (RE_Unsigned_32); + Rewrite (N, + Make_Op_Lt (Loc, + Left_Opnd => + Unchecked_Convert_To (Btyp, Duplicate_Subexpr (Pref)), + Right_Opnd => + Unchecked_Convert_To (Btyp, + Make_Attribute_Reference (Loc, + Prefix => New_Occurrence_Of (Ptyp, Loc), + Attribute_Name => Name_Range_Length)))); + + -- For all other scalar types, what we want logically is a + -- range test: + + -- X in type(X)'First .. type(X)'Last + + -- But that's precisely what won't work because of possible + -- unwanted optimization (and indeed the basic motivation for + -- the Valid attribute is exactly that this test does not work!) + -- What will work is: + + -- Btyp!(X) >= Btyp!(type(X)'First) + -- and then + -- Btyp!(X) <= Btyp!(type(X)'Last) + + -- where Btyp is an integer type large enough to cover the full + -- range of possible stored values (i.e. it is chosen on the basis + -- of the size of the type, not the range of the values). We write + -- this as two tests, rather than a range check, so that static + -- evaluation will easily remove either or both of the checks if + -- they can be -statically determined to be true (this happens + -- when the type of X is static and the range extends to the full + -- range of stored values). + + -- Unsigned types. Note: it is safe to consider only whether the + -- subtype is unsigned, since we will in that case be doing all + -- unsigned comparisons based on the subtype range. Since we use the + -- actual subtype object size, this is appropriate. + + -- For example, if we have + + -- subtype x is integer range 1 .. 200; + -- for x'Object_Size use 8; + + -- Now the base type is signed, but objects of this type are bits + -- unsigned, and doing an unsigned test of the range 1 to 200 is + -- correct, even though a value greater than 127 looks signed to a + -- signed comparison. + + elsif Is_Unsigned_Type (Ptyp) then + if Esize (Ptyp) <= 32 then + Btyp := RTE (RE_Unsigned_32); + else + Btyp := RTE (RE_Unsigned_64); + end if; + + Rewrite (N, Make_Range_Test); + + -- Signed types + + else + if Esize (Ptyp) <= Esize (Standard_Integer) then + Btyp := Standard_Integer; + else + Btyp := Universal_Integer; + end if; + + Rewrite (N, Make_Range_Test); + end if; + + Analyze_And_Resolve (N, Standard_Boolean); + Validity_Checks_On := Save_Validity_Checks_On; + end Valid; + + ----------- + -- Value -- + ----------- + + -- Value attribute is handled in separate unti Exp_Imgv + + when Attribute_Value => + Exp_Imgv.Expand_Value_Attribute (N); + + ----------------- + -- Value_Size -- + ----------------- + + -- The processing for Value_Size shares the processing for Size + + ------------- + -- Version -- + ------------- + + -- The processing for Version shares the processing for Body_Version + + ---------------- + -- Wide_Image -- + ---------------- + + -- We expand typ'Wide_Image (X) into + + -- String_To_Wide_String + -- (typ'Image (X), Wide_Character_Encoding_Method) + + -- This works in all cases because String_To_Wide_String converts any + -- wide character escape sequences resulting from the Image call to the + -- proper Wide_Character equivalent + + -- not quite right for typ = Wide_Character ??? + + when Attribute_Wide_Image => Wide_Image : + begin + Rewrite (N, + Make_Function_Call (Loc, + Name => New_Reference_To (RTE (RE_String_To_Wide_String), Loc), + Parameter_Associations => New_List ( + Make_Attribute_Reference (Loc, + Prefix => Pref, + Attribute_Name => Name_Image, + Expressions => Exprs), + + Make_Integer_Literal (Loc, + Intval => Int (Wide_Character_Encoding_Method))))); + + Analyze_And_Resolve (N, Standard_Wide_String); + end Wide_Image; + + --------------------- + -- Wide_Wide_Image -- + --------------------- + + -- We expand typ'Wide_Wide_Image (X) into + + -- String_To_Wide_Wide_String + -- (typ'Image (X), Wide_Character_Encoding_Method) + + -- This works in all cases because String_To_Wide_Wide_String converts + -- any wide character escape sequences resulting from the Image call to + -- the proper Wide_Character equivalent + + -- not quite right for typ = Wide_Wide_Character ??? + + when Attribute_Wide_Wide_Image => Wide_Wide_Image : + begin + Rewrite (N, + Make_Function_Call (Loc, + Name => New_Reference_To + (RTE (RE_String_To_Wide_Wide_String), Loc), + Parameter_Associations => New_List ( + Make_Attribute_Reference (Loc, + Prefix => Pref, + Attribute_Name => Name_Image, + Expressions => Exprs), + + Make_Integer_Literal (Loc, + Intval => Int (Wide_Character_Encoding_Method))))); + + Analyze_And_Resolve (N, Standard_Wide_Wide_String); + end Wide_Wide_Image; + + ---------------- + -- Wide_Value -- + ---------------- + + -- We expand typ'Wide_Value (X) into + + -- typ'Value + -- (Wide_String_To_String (X, Wide_Character_Encoding_Method)) + + -- Wide_String_To_String is a runtime function that converts its wide + -- string argument to String, converting any non-translatable characters + -- into appropriate escape sequences. This preserves the required + -- semantics of Wide_Value in all cases, and results in a very simple + -- implementation approach. + + -- It's not quite right where typ = Wide_Character, because the encoding + -- method may not cover the whole character type ??? + + when Attribute_Wide_Value => Wide_Value : + begin + Rewrite (N, + Make_Attribute_Reference (Loc, + Prefix => Pref, + Attribute_Name => Name_Value, + + Expressions => New_List ( + Make_Function_Call (Loc, + Name => + New_Reference_To (RTE (RE_Wide_String_To_String), Loc), + + Parameter_Associations => New_List ( + Relocate_Node (First (Exprs)), + Make_Integer_Literal (Loc, + Intval => Int (Wide_Character_Encoding_Method))))))); + + Analyze_And_Resolve (N, Typ); + end Wide_Value; + + --------------------- + -- Wide_Wide_Value -- + --------------------- + + -- We expand typ'Wide_Value_Value (X) into + + -- typ'Value + -- (Wide_Wide_String_To_String (X, Wide_Character_Encoding_Method)) + + -- Wide_Wide_String_To_String is a runtime function that converts its + -- wide string argument to String, converting any non-translatable + -- characters into appropriate escape sequences. This preserves the + -- required semantics of Wide_Wide_Value in all cases, and results in a + -- very simple implementation approach. + + -- It's not quite right where typ = Wide_Wide_Character, because the + -- encoding method may not cover the whole character type ??? + + when Attribute_Wide_Wide_Value => Wide_Wide_Value : + begin + Rewrite (N, + Make_Attribute_Reference (Loc, + Prefix => Pref, + Attribute_Name => Name_Value, + + Expressions => New_List ( + Make_Function_Call (Loc, + Name => + New_Reference_To (RTE (RE_Wide_Wide_String_To_String), Loc), + + Parameter_Associations => New_List ( + Relocate_Node (First (Exprs)), + Make_Integer_Literal (Loc, + Intval => Int (Wide_Character_Encoding_Method))))))); + + Analyze_And_Resolve (N, Typ); + end Wide_Wide_Value; + + --------------------- + -- Wide_Wide_Width -- + --------------------- + + -- Wide_Wide_Width attribute is handled in separate unit Exp_Imgv + + when Attribute_Wide_Wide_Width => + Exp_Imgv.Expand_Width_Attribute (N, Wide_Wide); + + ---------------- + -- Wide_Width -- + ---------------- + + -- Wide_Width attribute is handled in separate unit Exp_Imgv + + when Attribute_Wide_Width => + Exp_Imgv.Expand_Width_Attribute (N, Wide); + + ----------- + -- Width -- + ----------- + + -- Width attribute is handled in separate unit Exp_Imgv + + when Attribute_Width => + Exp_Imgv.Expand_Width_Attribute (N, Normal); + + ----------- + -- Write -- + ----------- + + when Attribute_Write => Write : declare + P_Type : constant Entity_Id := Entity (Pref); + U_Type : constant Entity_Id := Underlying_Type (P_Type); + Pname : Entity_Id; + Decl : Node_Id; + Prag : Node_Id; + Arg3 : Node_Id; + Wfunc : Node_Id; + + begin + -- If no underlying type, we have an error that will be diagnosed + -- elsewhere, so here we just completely ignore the expansion. + + if No (U_Type) then + return; + end if; + + -- The simple case, if there is a TSS for Write, just call it + + Pname := Find_Stream_Subprogram (P_Type, TSS_Stream_Write); + + if Present (Pname) then + null; + + else + -- If there is a Stream_Convert pragma, use it, we rewrite + + -- sourcetyp'Output (stream, Item) + + -- as + + -- strmtyp'Output (Stream, strmwrite (acttyp (Item))); + + -- where strmwrite is the given Write function that converts an + -- argument of type sourcetyp or a type acctyp, from which it is + -- derived to type strmtyp. The conversion to acttyp is required + -- for the derived case. + + Prag := Get_Stream_Convert_Pragma (P_Type); + + if Present (Prag) then + Arg3 := + Next (Next (First (Pragma_Argument_Associations (Prag)))); + Wfunc := Entity (Expression (Arg3)); + + Rewrite (N, + Make_Attribute_Reference (Loc, + Prefix => New_Occurrence_Of (Etype (Wfunc), Loc), + Attribute_Name => Name_Output, + Expressions => New_List ( + Relocate_Node (First (Exprs)), + Make_Function_Call (Loc, + Name => New_Occurrence_Of (Wfunc, Loc), + Parameter_Associations => New_List ( + Convert_To (Etype (First_Formal (Wfunc)), + Relocate_Node (Next (First (Exprs))))))))); + + Analyze (N); + return; + + -- For elementary types, we call the W_xxx routine directly + + elsif Is_Elementary_Type (U_Type) then + Rewrite (N, Build_Elementary_Write_Call (N)); + Analyze (N); + return; + + -- Array type case + + elsif Is_Array_Type (U_Type) then + Build_Array_Write_Procedure (N, U_Type, Decl, Pname); + Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False); + + -- Tagged type case, use the primitive Write function. Note that + -- this will dispatch in the class-wide case which is what we want + + elsif Is_Tagged_Type (U_Type) then + Pname := Find_Prim_Op (U_Type, TSS_Stream_Write); + + -- All other record type cases, including protected records. + -- The latter only arise for expander generated code for + -- handling shared passive partition access. + + else + pragma Assert + (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type)); + + -- Ada 2005 (AI-216): Program_Error is raised when executing + -- the default implementation of the Write attribute of an + -- Unchecked_Union type. + + if Is_Unchecked_Union (Base_Type (U_Type)) then + Insert_Action (N, + Make_Raise_Program_Error (Loc, + Reason => PE_Unchecked_Union_Restriction)); + end if; + + if Has_Discriminants (U_Type) + and then Present + (Discriminant_Default_Value (First_Discriminant (U_Type))) + then + Build_Mutable_Record_Write_Procedure + (Loc, Base_Type (U_Type), Decl, Pname); + else + Build_Record_Write_Procedure + (Loc, Base_Type (U_Type), Decl, Pname); + end if; + + Insert_Action (N, Decl); + end if; + end if; + + -- If we fall through, Pname is the procedure to be called + + Rewrite_Stream_Proc_Call (Pname); + end Write; + + -- Component_Size is handled by Gigi, unless the component size is known + -- at compile time, which is always true in the packed array case. It is + -- important that the packed array case is handled in the front end (see + -- Eval_Attribute) since Gigi would otherwise get confused by the + -- equivalent packed array type. + + when Attribute_Component_Size => + null; + + -- The following attributes are handled by the back end (except that + -- static cases have already been evaluated during semantic processing, + -- but in any case the back end should not count on this). The one bit + -- of special processing required is that these attributes typically + -- generate conditionals in the code, so we need to check the relevant + -- restriction. + + when Attribute_Max | + Attribute_Min => + Check_Restriction (No_Implicit_Conditionals, N); + + -- The following attributes are handled by the back end (except that + -- static cases have already been evaluated during semantic processing, + -- but in any case the back end should not count on this). + + -- Gigi also handles the non-class-wide cases of Size + + when Attribute_Bit_Order | + Attribute_Code_Address | + Attribute_Definite | + Attribute_Null_Parameter | + Attribute_Passed_By_Reference | + Attribute_Pool_Address => + null; + + -- The following attributes are also handled by Gigi, but return a + -- universal integer result, so may need a conversion for checking + -- that the result is in range. + + when Attribute_Aft | + Attribute_Bit | + Attribute_Max_Size_In_Storage_Elements + => + Apply_Universal_Integer_Attribute_Checks (N); + + -- The following attributes should not appear at this stage, since they + -- have already been handled by the analyzer (and properly rewritten + -- with corresponding values or entities to represent the right values) + + when Attribute_Abort_Signal | + Attribute_Address_Size | + Attribute_Base | + Attribute_Class | + Attribute_Default_Bit_Order | + Attribute_Delta | + Attribute_Denorm | + Attribute_Digits | + Attribute_Emax | + Attribute_Epsilon | + Attribute_Has_Access_Values | + Attribute_Has_Discriminants | + Attribute_Large | + Attribute_Machine_Emax | + Attribute_Machine_Emin | + Attribute_Machine_Mantissa | + Attribute_Machine_Overflows | + Attribute_Machine_Radix | + Attribute_Machine_Rounds | + Attribute_Maximum_Alignment | + Attribute_Model_Emin | + Attribute_Model_Epsilon | + Attribute_Model_Mantissa | + Attribute_Model_Small | + Attribute_Modulus | + Attribute_Partition_ID | + Attribute_Range | + Attribute_Safe_Emax | + Attribute_Safe_First | + Attribute_Safe_Large | + Attribute_Safe_Last | + Attribute_Safe_Small | + Attribute_Scale | + Attribute_Signed_Zeros | + Attribute_Small | + Attribute_Storage_Unit | + Attribute_Target_Name | + Attribute_Type_Class | + Attribute_Unconstrained_Array | + Attribute_Universal_Literal_String | + Attribute_Wchar_T_Size | + Attribute_Word_Size => + + raise Program_Error; + + -- The Asm_Input and Asm_Output attributes are not expanded at this + -- stage, but will be eliminated in the expansion of the Asm call, + -- see Exp_Intr for details. So Gigi will never see these either. + + when Attribute_Asm_Input | + Attribute_Asm_Output => + + null; + + end case; + + exception + when RE_Not_Available => + return; + end Expand_N_Attribute_Reference; + + ---------------------- + -- Expand_Pred_Succ -- + ---------------------- + + -- For typ'Pred (exp), we generate the check + + -- [constraint_error when exp = typ'Base'First] + + -- Similarly, for typ'Succ (exp), we generate the check + + -- [constraint_error when exp = typ'Base'Last] + + -- These checks are not generated for modular types, since the proper + -- semantics for Succ and Pred on modular types is to wrap, not raise CE. + + procedure Expand_Pred_Succ (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Cnam : Name_Id; + + begin + if Attribute_Name (N) = Name_Pred then + Cnam := Name_First; + else + Cnam := Name_Last; + end if; + + Insert_Action (N, + Make_Raise_Constraint_Error (Loc, + Condition => + Make_Op_Eq (Loc, + Left_Opnd => + Duplicate_Subexpr_Move_Checks (First (Expressions (N))), + Right_Opnd => + Make_Attribute_Reference (Loc, + Prefix => + New_Reference_To (Base_Type (Etype (Prefix (N))), Loc), + Attribute_Name => Cnam)), + Reason => CE_Overflow_Check_Failed)); + end Expand_Pred_Succ; + + ------------------- + -- Find_Fat_Info -- + ------------------- + + procedure Find_Fat_Info + (T : Entity_Id; + Fat_Type : out Entity_Id; + Fat_Pkg : out RE_Id) + is + Btyp : constant Entity_Id := Base_Type (T); + Rtyp : constant Entity_Id := Root_Type (T); + Digs : constant Nat := UI_To_Int (Digits_Value (Btyp)); + + begin + -- If the base type is VAX float, then get appropriate VAX float type + + if Vax_Float (Btyp) then + case Digs is + when 6 => + Fat_Type := RTE (RE_Fat_VAX_F); + Fat_Pkg := RE_Attr_VAX_F_Float; + + when 9 => + Fat_Type := RTE (RE_Fat_VAX_D); + Fat_Pkg := RE_Attr_VAX_D_Float; + + when 15 => + Fat_Type := RTE (RE_Fat_VAX_G); + Fat_Pkg := RE_Attr_VAX_G_Float; + + when others => + raise Program_Error; + end case; + + -- If root type is VAX float, this is the case where the library has + -- been recompiled in VAX float mode, and we have an IEEE float type. + -- This is when we use the special IEEE Fat packages. + + elsif Vax_Float (Rtyp) then + case Digs is + when 6 => + Fat_Type := RTE (RE_Fat_IEEE_Short); + Fat_Pkg := RE_Attr_IEEE_Short; + + when 15 => + Fat_Type := RTE (RE_Fat_IEEE_Long); + Fat_Pkg := RE_Attr_IEEE_Long; + + when others => + raise Program_Error; + end case; + + -- If neither the base type nor the root type is VAX_Float then VAX + -- float is out of the picture, and we can just use the root type. + + else + Fat_Type := Rtyp; + + if Fat_Type = Standard_Short_Float then + Fat_Pkg := RE_Attr_Short_Float; + elsif Fat_Type = Standard_Float then + Fat_Pkg := RE_Attr_Float; + elsif Fat_Type = Standard_Long_Float then + Fat_Pkg := RE_Attr_Long_Float; + elsif Fat_Type = Standard_Long_Long_Float then + Fat_Pkg := RE_Attr_Long_Long_Float; + else + raise Program_Error; + end if; + end if; + end Find_Fat_Info; + + ---------------------------- + -- Find_Stream_Subprogram -- + ---------------------------- + + function Find_Stream_Subprogram + (Typ : Entity_Id; + Nam : TSS_Name_Type) return Entity_Id + is + Ent : constant Entity_Id := TSS (Typ, Nam); + begin + if Present (Ent) then + return Ent; + end if; + + if Is_Tagged_Type (Typ) + and then Is_Derived_Type (Typ) + then + return Find_Prim_Op (Typ, Nam); + else + return Find_Inherited_TSS (Typ, Nam); + end if; + end Find_Stream_Subprogram; + + ----------------------- + -- Get_Index_Subtype -- + ----------------------- + + function Get_Index_Subtype (N : Node_Id) return Node_Id is + P_Type : Entity_Id := Etype (Prefix (N)); + Indx : Node_Id; + J : Int; + + begin + if Is_Access_Type (P_Type) then + P_Type := Designated_Type (P_Type); + end if; + + if No (Expressions (N)) then + J := 1; + else + J := UI_To_Int (Expr_Value (First (Expressions (N)))); + end if; + + Indx := First_Index (P_Type); + while J > 1 loop + Next_Index (Indx); + J := J - 1; + end loop; + + return Etype (Indx); + end Get_Index_Subtype; + + ------------------------------- + -- Get_Stream_Convert_Pragma -- + ------------------------------- + + function Get_Stream_Convert_Pragma (T : Entity_Id) return Node_Id is + Typ : Entity_Id; + N : Node_Id; + + begin + -- Note: we cannot use Get_Rep_Pragma here because of the peculiarity + -- that a stream convert pragma for a tagged type is not inherited from + -- its parent. Probably what is wrong here is that it is basically + -- incorrect to consider a stream convert pragma to be a representation + -- pragma at all ??? + + N := First_Rep_Item (Implementation_Base_Type (T)); + while Present (N) loop + if Nkind (N) = N_Pragma and then Chars (N) = Name_Stream_Convert then + + -- For tagged types this pragma is not inherited, so we + -- must verify that it is defined for the given type and + -- not an ancestor. + + Typ := + Entity (Expression (First (Pragma_Argument_Associations (N)))); + + if not Is_Tagged_Type (T) + or else T = Typ + or else (Is_Private_Type (Typ) and then T = Full_View (Typ)) + then + return N; + end if; + end if; + + Next_Rep_Item (N); + end loop; + + return Empty; + end Get_Stream_Convert_Pragma; + + --------------------------------- + -- Is_Constrained_Packed_Array -- + --------------------------------- + + function Is_Constrained_Packed_Array (Typ : Entity_Id) return Boolean is + Arr : Entity_Id := Typ; + + begin + if Is_Access_Type (Arr) then + Arr := Designated_Type (Arr); + end if; + + return Is_Array_Type (Arr) + and then Is_Constrained (Arr) + and then Present (Packed_Array_Type (Arr)); + end Is_Constrained_Packed_Array; + +end Exp_Attr; |