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Diffstat (limited to 'gcc-4.4.3/gcc/ada/exp_util.adb')
| -rw-r--r-- | gcc-4.4.3/gcc/ada/exp_util.adb | 5321 |
1 files changed, 0 insertions, 5321 deletions
diff --git a/gcc-4.4.3/gcc/ada/exp_util.adb b/gcc-4.4.3/gcc/ada/exp_util.adb deleted file mode 100644 index b36f80d46..000000000 --- a/gcc-4.4.3/gcc/ada/exp_util.adb +++ /dev/null @@ -1,5321 +0,0 @@ ------------------------------------------------------------------------------- --- -- --- GNAT COMPILER COMPONENTS -- --- -- --- E X P _ U T I L -- --- -- --- B o d y -- --- -- --- Copyright (C) 1992-2008, Free Software Foundation, Inc. -- --- -- --- GNAT is free software; you can redistribute it and/or modify it under -- --- terms of the GNU General Public License as published by the Free Soft- -- --- ware Foundation; either version 3, or (at your option) any later ver- -- --- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- --- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- --- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- --- for more details. You should have received a copy of the GNU General -- --- Public License distributed with GNAT; see file COPYING3. If not, go to -- --- http://www.gnu.org/licenses for a complete copy of the license. -- --- -- --- GNAT was originally developed by the GNAT team at New York University. -- --- Extensive contributions were provided by Ada Core Technologies Inc. -- --- -- ------------------------------------------------------------------------------- - -with Atree; use Atree; -with Checks; use Checks; -with Debug; use Debug; -with Einfo; use Einfo; -with Elists; use Elists; -with Errout; use Errout; -with Exp_Aggr; use Exp_Aggr; -with Exp_Ch6; use Exp_Ch6; -with Exp_Ch7; use Exp_Ch7; -with Inline; use Inline; -with Itypes; use Itypes; -with Lib; use Lib; -with Nlists; use Nlists; -with Nmake; use Nmake; -with Opt; use Opt; -with Restrict; use Restrict; -with Rident; use Rident; -with Sem; use Sem; -with Sem_Ch8; use Sem_Ch8; -with Sem_Eval; use Sem_Eval; -with Sem_Res; use Sem_Res; -with Sem_Type; use Sem_Type; -with Sem_Util; use Sem_Util; -with Snames; use Snames; -with Stand; use Stand; -with Stringt; use Stringt; -with Targparm; use Targparm; -with Tbuild; use Tbuild; -with Ttypes; use Ttypes; -with Uintp; use Uintp; -with Urealp; use Urealp; -with Validsw; use Validsw; - -package body Exp_Util is - - ----------------------- - -- Local Subprograms -- - ----------------------- - - function Build_Task_Array_Image - (Loc : Source_Ptr; - Id_Ref : Node_Id; - A_Type : Entity_Id; - Dyn : Boolean := False) return Node_Id; - -- Build function to generate the image string for a task that is an - -- array component, concatenating the images of each index. To avoid - -- storage leaks, the string is built with successive slice assignments. - -- The flag Dyn indicates whether this is called for the initialization - -- procedure of an array of tasks, or for the name of a dynamically - -- created task that is assigned to an indexed component. - - function Build_Task_Image_Function - (Loc : Source_Ptr; - Decls : List_Id; - Stats : List_Id; - Res : Entity_Id) return Node_Id; - -- Common processing for Task_Array_Image and Task_Record_Image. - -- Build function body that computes image. - - procedure Build_Task_Image_Prefix - (Loc : Source_Ptr; - Len : out Entity_Id; - Res : out Entity_Id; - Pos : out Entity_Id; - Prefix : Entity_Id; - Sum : Node_Id; - Decls : List_Id; - Stats : List_Id); - -- Common processing for Task_Array_Image and Task_Record_Image. - -- Create local variables and assign prefix of name to result string. - - function Build_Task_Record_Image - (Loc : Source_Ptr; - Id_Ref : Node_Id; - Dyn : Boolean := False) return Node_Id; - -- Build function to generate the image string for a task that is a - -- record component. Concatenate name of variable with that of selector. - -- The flag Dyn indicates whether this is called for the initialization - -- procedure of record with task components, or for a dynamically - -- created task that is assigned to a selected component. - - function Make_CW_Equivalent_Type - (T : Entity_Id; - E : Node_Id) return Entity_Id; - -- T is a class-wide type entity, E is the initial expression node that - -- constrains T in case such as: " X: T := E" or "new T'(E)" - -- This function returns the entity of the Equivalent type and inserts - -- on the fly the necessary declaration such as: - -- - -- type anon is record - -- _parent : Root_Type (T); constrained with E discriminants (if any) - -- Extension : String (1 .. expr to match size of E); - -- end record; - -- - -- This record is compatible with any object of the class of T thanks - -- to the first field and has the same size as E thanks to the second. - - function Make_Literal_Range - (Loc : Source_Ptr; - Literal_Typ : Entity_Id) return Node_Id; - -- Produce a Range node whose bounds are: - -- Low_Bound (Literal_Type) .. - -- Low_Bound (Literal_Type) + (Length (Literal_Typ) - 1) - -- this is used for expanding declarations like X : String := "sdfgdfg"; - -- - -- If the index type of the target array is not integer, we generate: - -- Low_Bound (Literal_Type) .. - -- Literal_Type'Val - -- (Literal_Type'Pos (Low_Bound (Literal_Type)) - -- + (Length (Literal_Typ) -1)) - - function New_Class_Wide_Subtype - (CW_Typ : Entity_Id; - N : Node_Id) return Entity_Id; - -- Create an implicit subtype of CW_Typ attached to node N - - ---------------------- - -- Adjust_Condition -- - ---------------------- - - procedure Adjust_Condition (N : Node_Id) is - begin - if No (N) then - return; - end if; - - declare - Loc : constant Source_Ptr := Sloc (N); - T : constant Entity_Id := Etype (N); - Ti : Entity_Id; - - begin - -- For now, we simply ignore a call where the argument has no - -- type (probably case of unanalyzed condition), or has a type - -- that is not Boolean. This is because this is a pretty marginal - -- piece of functionality, and violations of these rules are - -- likely to be truly marginal (how much code uses Fortran Logical - -- as the barrier to a protected entry?) and we do not want to - -- blow up existing programs. We can change this to an assertion - -- after 3.12a is released ??? - - if No (T) or else not Is_Boolean_Type (T) then - return; - end if; - - -- Apply validity checking if needed - - if Validity_Checks_On and Validity_Check_Tests then - Ensure_Valid (N); - end if; - - -- Immediate return if standard boolean, the most common case, - -- where nothing needs to be done. - - if Base_Type (T) = Standard_Boolean then - return; - end if; - - -- Case of zero/non-zero semantics or non-standard enumeration - -- representation. In each case, we rewrite the node as: - - -- ityp!(N) /= False'Enum_Rep - - -- where ityp is an integer type with large enough size to hold - -- any value of type T. - - if Nonzero_Is_True (T) or else Has_Non_Standard_Rep (T) then - if Esize (T) <= Esize (Standard_Integer) then - Ti := Standard_Integer; - else - Ti := Standard_Long_Long_Integer; - end if; - - Rewrite (N, - Make_Op_Ne (Loc, - Left_Opnd => Unchecked_Convert_To (Ti, N), - Right_Opnd => - Make_Attribute_Reference (Loc, - Attribute_Name => Name_Enum_Rep, - Prefix => - New_Occurrence_Of (First_Literal (T), Loc)))); - Analyze_And_Resolve (N, Standard_Boolean); - - else - Rewrite (N, Convert_To (Standard_Boolean, N)); - Analyze_And_Resolve (N, Standard_Boolean); - end if; - end; - end Adjust_Condition; - - ------------------------ - -- Adjust_Result_Type -- - ------------------------ - - procedure Adjust_Result_Type (N : Node_Id; T : Entity_Id) is - begin - -- Ignore call if current type is not Standard.Boolean - - if Etype (N) /= Standard_Boolean then - return; - end if; - - -- If result is already of correct type, nothing to do. Note that - -- this will get the most common case where everything has a type - -- of Standard.Boolean. - - if Base_Type (T) = Standard_Boolean then - return; - - else - declare - KP : constant Node_Kind := Nkind (Parent (N)); - - begin - -- If result is to be used as a Condition in the syntax, no need - -- to convert it back, since if it was changed to Standard.Boolean - -- using Adjust_Condition, that is just fine for this usage. - - if KP in N_Raise_xxx_Error or else KP in N_Has_Condition then - return; - - -- If result is an operand of another logical operation, no need - -- to reset its type, since Standard.Boolean is just fine, and - -- such operations always do Adjust_Condition on their operands. - - elsif KP in N_Op_Boolean - or else KP = N_And_Then - or else KP = N_Or_Else - or else KP = N_Op_Not - then - return; - - -- Otherwise we perform a conversion from the current type, - -- which must be Standard.Boolean, to the desired type. - - else - Set_Analyzed (N); - Rewrite (N, Convert_To (T, N)); - Analyze_And_Resolve (N, T); - end if; - end; - end if; - end Adjust_Result_Type; - - -------------------------- - -- Append_Freeze_Action -- - -------------------------- - - procedure Append_Freeze_Action (T : Entity_Id; N : Node_Id) is - Fnode : Node_Id; - - begin - Ensure_Freeze_Node (T); - Fnode := Freeze_Node (T); - - if No (Actions (Fnode)) then - Set_Actions (Fnode, New_List); - end if; - - Append (N, Actions (Fnode)); - end Append_Freeze_Action; - - --------------------------- - -- Append_Freeze_Actions -- - --------------------------- - - procedure Append_Freeze_Actions (T : Entity_Id; L : List_Id) is - Fnode : constant Node_Id := Freeze_Node (T); - - begin - if No (L) then - return; - - else - if No (Actions (Fnode)) then - Set_Actions (Fnode, L); - - else - Append_List (L, Actions (Fnode)); - end if; - - end if; - end Append_Freeze_Actions; - - ------------------------ - -- Build_Runtime_Call -- - ------------------------ - - function Build_Runtime_Call (Loc : Source_Ptr; RE : RE_Id) return Node_Id is - begin - -- If entity is not available, we can skip making the call (this avoids - -- junk duplicated error messages in a number of cases). - - if not RTE_Available (RE) then - return Make_Null_Statement (Loc); - else - return - Make_Procedure_Call_Statement (Loc, - Name => New_Reference_To (RTE (RE), Loc)); - end if; - end Build_Runtime_Call; - - ---------------------------- - -- Build_Task_Array_Image -- - ---------------------------- - - -- This function generates the body for a function that constructs the - -- image string for a task that is an array component. The function is - -- local to the init proc for the array type, and is called for each one - -- of the components. The constructed image has the form of an indexed - -- component, whose prefix is the outer variable of the array type. - -- The n-dimensional array type has known indices Index, Index2... - -- Id_Ref is an indexed component form created by the enclosing init proc. - -- Its successive indices are Val1, Val2, ... which are the loop variables - -- in the loops that call the individual task init proc on each component. - - -- The generated function has the following structure: - - -- function F return String is - -- Pref : string renames Task_Name; - -- T1 : String := Index1'Image (Val1); - -- ... - -- Tn : String := indexn'image (Valn); - -- Len : Integer := T1'Length + ... + Tn'Length + n + 1; - -- -- Len includes commas and the end parentheses. - -- Res : String (1..Len); - -- Pos : Integer := Pref'Length; - -- - -- begin - -- Res (1 .. Pos) := Pref; - -- Pos := Pos + 1; - -- Res (Pos) := '('; - -- Pos := Pos + 1; - -- Res (Pos .. Pos + T1'Length - 1) := T1; - -- Pos := Pos + T1'Length; - -- Res (Pos) := '.'; - -- Pos := Pos + 1; - -- ... - -- Res (Pos .. Pos + Tn'Length - 1) := Tn; - -- Res (Len) := ')'; - -- - -- return Res; - -- end F; - -- - -- Needless to say, multidimensional arrays of tasks are rare enough - -- that the bulkiness of this code is not really a concern. - - function Build_Task_Array_Image - (Loc : Source_Ptr; - Id_Ref : Node_Id; - A_Type : Entity_Id; - Dyn : Boolean := False) return Node_Id - is - Dims : constant Nat := Number_Dimensions (A_Type); - -- Number of dimensions for array of tasks - - Temps : array (1 .. Dims) of Entity_Id; - -- Array of temporaries to hold string for each index - - Indx : Node_Id; - -- Index expression - - Len : Entity_Id; - -- Total length of generated name - - Pos : Entity_Id; - -- Running index for substring assignments - - Pref : Entity_Id; - -- Name of enclosing variable, prefix of resulting name - - Res : Entity_Id; - -- String to hold result - - Val : Node_Id; - -- Value of successive indices - - Sum : Node_Id; - -- Expression to compute total size of string - - T : Entity_Id; - -- Entity for name at one index position - - Decls : constant List_Id := New_List; - Stats : constant List_Id := New_List; - - begin - Pref := Make_Defining_Identifier (Loc, New_Internal_Name ('P')); - - -- For a dynamic task, the name comes from the target variable. - -- For a static one it is a formal of the enclosing init proc. - - if Dyn then - Get_Name_String (Chars (Entity (Prefix (Id_Ref)))); - Append_To (Decls, - Make_Object_Declaration (Loc, - Defining_Identifier => Pref, - Object_Definition => New_Occurrence_Of (Standard_String, Loc), - Expression => - Make_String_Literal (Loc, - Strval => String_From_Name_Buffer))); - - else - Append_To (Decls, - Make_Object_Renaming_Declaration (Loc, - Defining_Identifier => Pref, - Subtype_Mark => New_Occurrence_Of (Standard_String, Loc), - Name => Make_Identifier (Loc, Name_uTask_Name))); - end if; - - Indx := First_Index (A_Type); - Val := First (Expressions (Id_Ref)); - - for J in 1 .. Dims loop - T := Make_Defining_Identifier (Loc, New_Internal_Name ('T')); - Temps (J) := T; - - Append_To (Decls, - Make_Object_Declaration (Loc, - Defining_Identifier => T, - Object_Definition => New_Occurrence_Of (Standard_String, Loc), - Expression => - Make_Attribute_Reference (Loc, - Attribute_Name => Name_Image, - Prefix => - New_Occurrence_Of (Etype (Indx), Loc), - Expressions => New_List ( - New_Copy_Tree (Val))))); - - Next_Index (Indx); - Next (Val); - end loop; - - Sum := Make_Integer_Literal (Loc, Dims + 1); - - Sum := - Make_Op_Add (Loc, - Left_Opnd => Sum, - Right_Opnd => - Make_Attribute_Reference (Loc, - Attribute_Name => Name_Length, - Prefix => - New_Occurrence_Of (Pref, Loc), - Expressions => New_List (Make_Integer_Literal (Loc, 1)))); - - for J in 1 .. Dims loop - Sum := - Make_Op_Add (Loc, - Left_Opnd => Sum, - Right_Opnd => - Make_Attribute_Reference (Loc, - Attribute_Name => Name_Length, - Prefix => - New_Occurrence_Of (Temps (J), Loc), - Expressions => New_List (Make_Integer_Literal (Loc, 1)))); - end loop; - - Build_Task_Image_Prefix (Loc, Len, Res, Pos, Pref, Sum, Decls, Stats); - - Set_Character_Literal_Name (Char_Code (Character'Pos ('('))); - - Append_To (Stats, - Make_Assignment_Statement (Loc, - Name => Make_Indexed_Component (Loc, - Prefix => New_Occurrence_Of (Res, Loc), - Expressions => New_List (New_Occurrence_Of (Pos, Loc))), - Expression => - Make_Character_Literal (Loc, - Chars => Name_Find, - Char_Literal_Value => - UI_From_Int (Character'Pos ('('))))); - - Append_To (Stats, - Make_Assignment_Statement (Loc, - Name => New_Occurrence_Of (Pos, Loc), - Expression => - Make_Op_Add (Loc, - Left_Opnd => New_Occurrence_Of (Pos, Loc), - Right_Opnd => Make_Integer_Literal (Loc, 1)))); - - for J in 1 .. Dims loop - - Append_To (Stats, - Make_Assignment_Statement (Loc, - Name => Make_Slice (Loc, - Prefix => New_Occurrence_Of (Res, Loc), - Discrete_Range => - Make_Range (Loc, - Low_Bound => New_Occurrence_Of (Pos, Loc), - High_Bound => Make_Op_Subtract (Loc, - Left_Opnd => - Make_Op_Add (Loc, - Left_Opnd => New_Occurrence_Of (Pos, Loc), - Right_Opnd => - Make_Attribute_Reference (Loc, - Attribute_Name => Name_Length, - Prefix => - New_Occurrence_Of (Temps (J), Loc), - Expressions => - New_List (Make_Integer_Literal (Loc, 1)))), - Right_Opnd => Make_Integer_Literal (Loc, 1)))), - - Expression => New_Occurrence_Of (Temps (J), Loc))); - - if J < Dims then - Append_To (Stats, - Make_Assignment_Statement (Loc, - Name => New_Occurrence_Of (Pos, Loc), - Expression => - Make_Op_Add (Loc, - Left_Opnd => New_Occurrence_Of (Pos, Loc), - Right_Opnd => - Make_Attribute_Reference (Loc, - Attribute_Name => Name_Length, - Prefix => New_Occurrence_Of (Temps (J), Loc), - Expressions => - New_List (Make_Integer_Literal (Loc, 1)))))); - - Set_Character_Literal_Name (Char_Code (Character'Pos (','))); - - Append_To (Stats, - Make_Assignment_Statement (Loc, - Name => Make_Indexed_Component (Loc, - Prefix => New_Occurrence_Of (Res, Loc), - Expressions => New_List (New_Occurrence_Of (Pos, Loc))), - Expression => - Make_Character_Literal (Loc, - Chars => Name_Find, - Char_Literal_Value => - UI_From_Int (Character'Pos (','))))); - - Append_To (Stats, - Make_Assignment_Statement (Loc, - Name => New_Occurrence_Of (Pos, Loc), - Expression => - Make_Op_Add (Loc, - Left_Opnd => New_Occurrence_Of (Pos, Loc), - Right_Opnd => Make_Integer_Literal (Loc, 1)))); - end if; - end loop; - - Set_Character_Literal_Name (Char_Code (Character'Pos (')'))); - - Append_To (Stats, - Make_Assignment_Statement (Loc, - Name => Make_Indexed_Component (Loc, - Prefix => New_Occurrence_Of (Res, Loc), - Expressions => New_List (New_Occurrence_Of (Len, Loc))), - Expression => - Make_Character_Literal (Loc, - Chars => Name_Find, - Char_Literal_Value => - UI_From_Int (Character'Pos (')'))))); - return Build_Task_Image_Function (Loc, Decls, Stats, Res); - end Build_Task_Array_Image; - - ---------------------------- - -- Build_Task_Image_Decls -- - ---------------------------- - - function Build_Task_Image_Decls - (Loc : Source_Ptr; - Id_Ref : Node_Id; - A_Type : Entity_Id; - In_Init_Proc : Boolean := False) return List_Id - is - Decls : constant List_Id := New_List; - T_Id : Entity_Id := Empty; - Decl : Node_Id; - Expr : Node_Id := Empty; - Fun : Node_Id := Empty; - Is_Dyn : constant Boolean := - Nkind (Parent (Id_Ref)) = N_Assignment_Statement - and then - Nkind (Expression (Parent (Id_Ref))) = N_Allocator; - - begin - -- If Discard_Names or No_Implicit_Heap_Allocations are in effect, - -- generate a dummy declaration only. - - if Restriction_Active (No_Implicit_Heap_Allocations) - or else Global_Discard_Names - then - T_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('J')); - Name_Len := 0; - - return - New_List ( - Make_Object_Declaration (Loc, - Defining_Identifier => T_Id, - Object_Definition => New_Occurrence_Of (Standard_String, Loc), - Expression => - Make_String_Literal (Loc, - Strval => String_From_Name_Buffer))); - - else - if Nkind (Id_Ref) = N_Identifier - or else Nkind (Id_Ref) = N_Defining_Identifier - then - -- For a simple variable, the image of the task is built from - -- the name of the variable. To avoid possible conflict with - -- the anonymous type created for a single protected object, - -- add a numeric suffix. - - T_Id := - Make_Defining_Identifier (Loc, - New_External_Name (Chars (Id_Ref), 'T', 1)); - - Get_Name_String (Chars (Id_Ref)); - - Expr := - Make_String_Literal (Loc, - Strval => String_From_Name_Buffer); - - elsif Nkind (Id_Ref) = N_Selected_Component then - T_Id := - Make_Defining_Identifier (Loc, - New_External_Name (Chars (Selector_Name (Id_Ref)), 'T')); - Fun := Build_Task_Record_Image (Loc, Id_Ref, Is_Dyn); - - elsif Nkind (Id_Ref) = N_Indexed_Component then - T_Id := - Make_Defining_Identifier (Loc, - New_External_Name (Chars (A_Type), 'N')); - - Fun := Build_Task_Array_Image (Loc, Id_Ref, A_Type, Is_Dyn); - end if; - end if; - - if Present (Fun) then - Append (Fun, Decls); - Expr := Make_Function_Call (Loc, - Name => New_Occurrence_Of (Defining_Entity (Fun), Loc)); - - if not In_Init_Proc and then VM_Target = No_VM then - Set_Uses_Sec_Stack (Defining_Entity (Fun)); - end if; - end if; - - Decl := Make_Object_Declaration (Loc, - Defining_Identifier => T_Id, - Object_Definition => New_Occurrence_Of (Standard_String, Loc), - Constant_Present => True, - Expression => Expr); - - Append (Decl, Decls); - return Decls; - end Build_Task_Image_Decls; - - ------------------------------- - -- Build_Task_Image_Function -- - ------------------------------- - - function Build_Task_Image_Function - (Loc : Source_Ptr; - Decls : List_Id; - Stats : List_Id; - Res : Entity_Id) return Node_Id - is - Spec : Node_Id; - - begin - Append_To (Stats, - Make_Simple_Return_Statement (Loc, - Expression => New_Occurrence_Of (Res, Loc))); - - Spec := Make_Function_Specification (Loc, - Defining_Unit_Name => - Make_Defining_Identifier (Loc, New_Internal_Name ('F')), - Result_Definition => New_Occurrence_Of (Standard_String, Loc)); - - -- Calls to 'Image use the secondary stack, which must be cleaned - -- up after the task name is built. - - return Make_Subprogram_Body (Loc, - Specification => Spec, - Declarations => Decls, - Handled_Statement_Sequence => - Make_Handled_Sequence_Of_Statements (Loc, Statements => Stats)); - end Build_Task_Image_Function; - - ----------------------------- - -- Build_Task_Image_Prefix -- - ----------------------------- - - procedure Build_Task_Image_Prefix - (Loc : Source_Ptr; - Len : out Entity_Id; - Res : out Entity_Id; - Pos : out Entity_Id; - Prefix : Entity_Id; - Sum : Node_Id; - Decls : List_Id; - Stats : List_Id) - is - begin - Len := Make_Defining_Identifier (Loc, New_Internal_Name ('L')); - - Append_To (Decls, - Make_Object_Declaration (Loc, - Defining_Identifier => Len, - Object_Definition => New_Occurrence_Of (Standard_Integer, Loc), - Expression => Sum)); - - Res := Make_Defining_Identifier (Loc, New_Internal_Name ('R')); - - Append_To (Decls, - Make_Object_Declaration (Loc, - Defining_Identifier => Res, - Object_Definition => - Make_Subtype_Indication (Loc, - Subtype_Mark => New_Occurrence_Of (Standard_String, Loc), - Constraint => - Make_Index_Or_Discriminant_Constraint (Loc, - Constraints => - New_List ( - Make_Range (Loc, - Low_Bound => Make_Integer_Literal (Loc, 1), - High_Bound => New_Occurrence_Of (Len, Loc))))))); - - Pos := Make_Defining_Identifier (Loc, New_Internal_Name ('P')); - - Append_To (Decls, - Make_Object_Declaration (Loc, - Defining_Identifier => Pos, - Object_Definition => New_Occurrence_Of (Standard_Integer, Loc))); - - -- Pos := Prefix'Length; - - Append_To (Stats, - Make_Assignment_Statement (Loc, - Name => New_Occurrence_Of (Pos, Loc), - Expression => - Make_Attribute_Reference (Loc, - Attribute_Name => Name_Length, - Prefix => New_Occurrence_Of (Prefix, Loc), - Expressions => - New_List (Make_Integer_Literal (Loc, 1))))); - - -- Res (1 .. Pos) := Prefix; - - Append_To (Stats, - Make_Assignment_Statement (Loc, - Name => Make_Slice (Loc, - Prefix => New_Occurrence_Of (Res, Loc), - Discrete_Range => - Make_Range (Loc, - Low_Bound => Make_Integer_Literal (Loc, 1), - High_Bound => New_Occurrence_Of (Pos, Loc))), - - Expression => New_Occurrence_Of (Prefix, Loc))); - - Append_To (Stats, - Make_Assignment_Statement (Loc, - Name => New_Occurrence_Of (Pos, Loc), - Expression => - Make_Op_Add (Loc, - Left_Opnd => New_Occurrence_Of (Pos, Loc), - Right_Opnd => Make_Integer_Literal (Loc, 1)))); - end Build_Task_Image_Prefix; - - ----------------------------- - -- Build_Task_Record_Image -- - ----------------------------- - - function Build_Task_Record_Image - (Loc : Source_Ptr; - Id_Ref : Node_Id; - Dyn : Boolean := False) return Node_Id - is - Len : Entity_Id; - -- Total length of generated name - - Pos : Entity_Id; - -- Index into result - - Res : Entity_Id; - -- String to hold result - - Pref : Entity_Id; - -- Name of enclosing variable, prefix of resulting name - - Sum : Node_Id; - -- Expression to compute total size of string - - Sel : Entity_Id; - -- Entity for selector name - - Decls : constant List_Id := New_List; - Stats : constant List_Id := New_List; - - begin - Pref := Make_Defining_Identifier (Loc, New_Internal_Name ('P')); - - -- For a dynamic task, the name comes from the target variable. - -- For a static one it is a formal of the enclosing init proc. - - if Dyn then - Get_Name_String (Chars (Entity (Prefix (Id_Ref)))); - Append_To (Decls, - Make_Object_Declaration (Loc, - Defining_Identifier => Pref, - Object_Definition => New_Occurrence_Of (Standard_String, Loc), - Expression => - Make_String_Literal (Loc, - Strval => String_From_Name_Buffer))); - - else - Append_To (Decls, - Make_Object_Renaming_Declaration (Loc, - Defining_Identifier => Pref, - Subtype_Mark => New_Occurrence_Of (Standard_String, Loc), - Name => Make_Identifier (Loc, Name_uTask_Name))); - end if; - - Sel := Make_Defining_Identifier (Loc, New_Internal_Name ('S')); - - Get_Name_String (Chars (Selector_Name (Id_Ref))); - - Append_To (Decls, - Make_Object_Declaration (Loc, - Defining_Identifier => Sel, - Object_Definition => New_Occurrence_Of (Standard_String, Loc), - Expression => - Make_String_Literal (Loc, - Strval => String_From_Name_Buffer))); - - Sum := Make_Integer_Literal (Loc, Nat (Name_Len + 1)); - - Sum := - Make_Op_Add (Loc, - Left_Opnd => Sum, - Right_Opnd => - Make_Attribute_Reference (Loc, - Attribute_Name => Name_Length, - Prefix => - New_Occurrence_Of (Pref, Loc), - Expressions => New_List (Make_Integer_Literal (Loc, 1)))); - - Build_Task_Image_Prefix (Loc, Len, Res, Pos, Pref, Sum, Decls, Stats); - - Set_Character_Literal_Name (Char_Code (Character'Pos ('.'))); - - -- Res (Pos) := '.'; - - Append_To (Stats, - Make_Assignment_Statement (Loc, - Name => Make_Indexed_Component (Loc, - Prefix => New_Occurrence_Of (Res, Loc), - Expressions => New_List (New_Occurrence_Of (Pos, Loc))), - Expression => - Make_Character_Literal (Loc, - Chars => Name_Find, - Char_Literal_Value => - UI_From_Int (Character'Pos ('.'))))); - - Append_To (Stats, - Make_Assignment_Statement (Loc, - Name => New_Occurrence_Of (Pos, Loc), - Expression => - Make_Op_Add (Loc, - Left_Opnd => New_Occurrence_Of (Pos, Loc), - Right_Opnd => Make_Integer_Literal (Loc, 1)))); - - -- Res (Pos .. Len) := Selector; - - Append_To (Stats, - Make_Assignment_Statement (Loc, - Name => Make_Slice (Loc, - Prefix => New_Occurrence_Of (Res, Loc), - Discrete_Range => - Make_Range (Loc, - Low_Bound => New_Occurrence_Of (Pos, Loc), - High_Bound => New_Occurrence_Of (Len, Loc))), - Expression => New_Occurrence_Of (Sel, Loc))); - - return Build_Task_Image_Function (Loc, Decls, Stats, Res); - end Build_Task_Record_Image; - - ---------------------------------- - -- Component_May_Be_Bit_Aligned -- - ---------------------------------- - - function Component_May_Be_Bit_Aligned (Comp : Entity_Id) return Boolean is - begin - -- If no component clause, then everything is fine, since the back end - -- never bit-misaligns by default, even if there is a pragma Packed for - -- the record. - - if No (Component_Clause (Comp)) then - return False; - end if; - - -- It is only array and record types that cause trouble - - if not Is_Record_Type (Etype (Comp)) - and then not Is_Array_Type (Etype (Comp)) - then - return False; - - -- If we know that we have a small (64 bits or less) record - -- or bit-packed array, then everything is fine, since the - -- back end can handle these cases correctly. - - elsif Esize (Comp) <= 64 - and then (Is_Record_Type (Etype (Comp)) - or else Is_Bit_Packed_Array (Etype (Comp))) - then - return False; - - -- Otherwise if the component is not byte aligned, we know we have the - -- nasty unaligned case. - - elsif Normalized_First_Bit (Comp) /= Uint_0 - or else Esize (Comp) mod System_Storage_Unit /= Uint_0 - then - return True; - - -- If we are large and byte aligned, then OK at this level - - else - return False; - end if; - end Component_May_Be_Bit_Aligned; - - ----------------------------------- - -- Corresponding_Runtime_Package -- - ----------------------------------- - - function Corresponding_Runtime_Package (Typ : Entity_Id) return RTU_Id is - Pkg_Id : RTU_Id := RTU_Null; - - begin - pragma Assert (Is_Concurrent_Type (Typ)); - - if Ekind (Typ) in Protected_Kind then - if Has_Entries (Typ) - or else Has_Interrupt_Handler (Typ) - or else (Has_Attach_Handler (Typ) - and then not Restricted_Profile) - - -- A protected type without entries that covers an interface and - -- overrides the abstract routines with protected procedures is - -- considered equivalent to a protected type with entries in the - -- context of dispatching select statements. It is sufficient to - -- check for the presence of an interface list in the declaration - -- node to recognize this case. - - or else Present (Interface_List (Parent (Typ))) - then - if Abort_Allowed - or else Restriction_Active (No_Entry_Queue) = False - or else Number_Entries (Typ) > 1 - or else (Has_Attach_Handler (Typ) - and then not Restricted_Profile) - then - Pkg_Id := System_Tasking_Protected_Objects_Entries; - else - Pkg_Id := System_Tasking_Protected_Objects_Single_Entry; - end if; - - else - Pkg_Id := System_Tasking_Protected_Objects; - end if; - end if; - - return Pkg_Id; - end Corresponding_Runtime_Package; - - ------------------------------- - -- Convert_To_Actual_Subtype -- - ------------------------------- - - procedure Convert_To_Actual_Subtype (Exp : Entity_Id) is - Act_ST : Entity_Id; - - begin - Act_ST := Get_Actual_Subtype (Exp); - - if Act_ST = Etype (Exp) then - return; - - else - Rewrite (Exp, - Convert_To (Act_ST, Relocate_Node (Exp))); - Analyze_And_Resolve (Exp, Act_ST); - end if; - end Convert_To_Actual_Subtype; - - ----------------------------------- - -- Current_Sem_Unit_Declarations -- - ----------------------------------- - - function Current_Sem_Unit_Declarations return List_Id is - U : Node_Id := Unit (Cunit (Current_Sem_Unit)); - Decls : List_Id; - - begin - -- If the current unit is a package body, locate the visible - -- declarations of the package spec. - - if Nkind (U) = N_Package_Body then - U := Unit (Library_Unit (Cunit (Current_Sem_Unit))); - end if; - - if Nkind (U) = N_Package_Declaration then - U := Specification (U); - Decls := Visible_Declarations (U); - - if No (Decls) then - Decls := New_List; - Set_Visible_Declarations (U, Decls); - end if; - - else - Decls := Declarations (U); - - if No (Decls) then - Decls := New_List; - Set_Declarations (U, Decls); - end if; - end if; - - return Decls; - end Current_Sem_Unit_Declarations; - - ----------------------- - -- Duplicate_Subexpr -- - ----------------------- - - function Duplicate_Subexpr - (Exp : Node_Id; - Name_Req : Boolean := False) return Node_Id - is - begin - Remove_Side_Effects (Exp, Name_Req); - return New_Copy_Tree (Exp); - end Duplicate_Subexpr; - - --------------------------------- - -- Duplicate_Subexpr_No_Checks -- - --------------------------------- - - function Duplicate_Subexpr_No_Checks - (Exp : Node_Id; - Name_Req : Boolean := False) return Node_Id - is - New_Exp : Node_Id; - - begin - Remove_Side_Effects (Exp, Name_Req); - New_Exp := New_Copy_Tree (Exp); - Remove_Checks (New_Exp); - return New_Exp; - end Duplicate_Subexpr_No_Checks; - - ----------------------------------- - -- Duplicate_Subexpr_Move_Checks -- - ----------------------------------- - - function Duplicate_Subexpr_Move_Checks - (Exp : Node_Id; - Name_Req : Boolean := False) return Node_Id - is - New_Exp : Node_Id; - - begin - Remove_Side_Effects (Exp, Name_Req); - New_Exp := New_Copy_Tree (Exp); - Remove_Checks (Exp); - return New_Exp; - end Duplicate_Subexpr_Move_Checks; - - -------------------- - -- Ensure_Defined -- - -------------------- - - procedure Ensure_Defined (Typ : Entity_Id; N : Node_Id) is - IR : Node_Id; - - begin - -- An itype reference must only be created if this is a local - -- itype, so that gigi can elaborate it on the proper objstack. - - if Is_Itype (Typ) - and then Scope (Typ) = Current_Scope - then - IR := Make_Itype_Reference (Sloc (N)); - Set_Itype (IR, Typ); - Insert_Action (N, IR); - end if; - end Ensure_Defined; - - -------------------- - -- Entry_Names_OK -- - -------------------- - - function Entry_Names_OK return Boolean is - begin - return - not Restricted_Profile - and then not Global_Discard_Names - and then not Restriction_Active (No_Implicit_Heap_Allocations) - and then not Restriction_Active (No_Local_Allocators); - end Entry_Names_OK; - - --------------------- - -- Evolve_And_Then -- - --------------------- - - procedure Evolve_And_Then (Cond : in out Node_Id; Cond1 : Node_Id) is - begin - if No (Cond) then - Cond := Cond1; - else - Cond := - Make_And_Then (Sloc (Cond1), - Left_Opnd => Cond, - Right_Opnd => Cond1); - end if; - end Evolve_And_Then; - - -------------------- - -- Evolve_Or_Else -- - -------------------- - - procedure Evolve_Or_Else (Cond : in out Node_Id; Cond1 : Node_Id) is - begin - if No (Cond) then - Cond := Cond1; - else - Cond := - Make_Or_Else (Sloc (Cond1), - Left_Opnd => Cond, - Right_Opnd => Cond1); - end if; - end Evolve_Or_Else; - - ------------------------------ - -- Expand_Subtype_From_Expr -- - ------------------------------ - - -- This function is applicable for both static and dynamic allocation of - -- objects which are constrained by an initial expression. Basically it - -- transforms an unconstrained subtype indication into a constrained one. - -- The expression may also be transformed in certain cases in order to - -- avoid multiple evaluation. In the static allocation case, the general - -- scheme is: - - -- Val : T := Expr; - - -- is transformed into - - -- Val : Constrained_Subtype_of_T := Maybe_Modified_Expr; - -- - -- Here are the main cases : - -- - -- <if Expr is a Slice> - -- Val : T ([Index_Subtype (Expr)]) := Expr; - -- - -- <elsif Expr is a String Literal> - -- Val : T (T'First .. T'First + Length (string literal) - 1) := Expr; - -- - -- <elsif Expr is Constrained> - -- subtype T is Type_Of_Expr - -- Val : T := Expr; - -- - -- <elsif Expr is an entity_name> - -- Val : T (constraints taken from Expr) := Expr; - -- - -- <else> - -- type Axxx is access all T; - -- Rval : Axxx := Expr'ref; - -- Val : T (constraints taken from Rval) := Rval.all; - - -- ??? note: when the Expression is allocated in the secondary stack - -- we could use it directly instead of copying it by declaring - -- Val : T (...) renames Rval.all - - procedure Expand_Subtype_From_Expr - (N : Node_Id; - Unc_Type : Entity_Id; - Subtype_Indic : Node_Id; - Exp : Node_Id) - is - Loc : constant Source_Ptr := Sloc (N); - Exp_Typ : constant Entity_Id := Etype (Exp); - T : Entity_Id; - - begin - -- In general we cannot build the subtype if expansion is disabled, - -- because internal entities may not have been defined. However, to - -- avoid some cascaded errors, we try to continue when the expression - -- is an array (or string), because it is safe to compute the bounds. - -- It is in fact required to do so even in a generic context, because - -- there may be constants that depend on bounds of string literal. - - if not Expander_Active - and then (No (Etype (Exp)) - or else Base_Type (Etype (Exp)) /= Standard_String) - then - return; - end if; - - if Nkind (Exp) = N_Slice then - declare - Slice_Type : constant Entity_Id := Etype (First_Index (Exp_Typ)); - - begin - Rewrite (Subtype_Indic, - Make_Subtype_Indication (Loc, - Subtype_Mark => New_Reference_To (Unc_Type, Loc), - Constraint => - Make_Index_Or_Discriminant_Constraint (Loc, - Constraints => New_List - (New_Reference_To (Slice_Type, Loc))))); - - -- This subtype indication may be used later for constraint checks - -- we better make sure that if a variable was used as a bound of - -- of the original slice, its value is frozen. - - Force_Evaluation (Low_Bound (Scalar_Range (Slice_Type))); - Force_Evaluation (High_Bound (Scalar_Range (Slice_Type))); - end; - - elsif Ekind (Exp_Typ) = E_String_Literal_Subtype then - Rewrite (Subtype_Indic, - Make_Subtype_Indication (Loc, - Subtype_Mark => New_Reference_To (Unc_Type, Loc), - Constraint => - Make_Index_Or_Discriminant_Constraint (Loc, - Constraints => New_List ( - Make_Literal_Range (Loc, - Literal_Typ => Exp_Typ))))); - - elsif Is_Constrained (Exp_Typ) - and then not Is_Class_Wide_Type (Unc_Type) - then - if Is_Itype (Exp_Typ) then - - -- Within an initialization procedure, a selected component - -- denotes a component of the enclosing record, and it appears - -- as an actual in a call to its own initialization procedure. - -- If this component depends on the outer discriminant, we must - -- generate the proper actual subtype for it. - - if Nkind (Exp) = N_Selected_Component - and then Within_Init_Proc - then - declare - Decl : constant Node_Id := - Build_Actual_Subtype_Of_Component (Exp_Typ, Exp); - begin - if Present (Decl) then - Insert_Action (N, Decl); - T := Defining_Identifier (Decl); - else - T := Exp_Typ; - end if; - end; - - -- No need to generate a new one (new what???) - - else - T := Exp_Typ; - end if; - - else - T := - Make_Defining_Identifier (Loc, - Chars => New_Internal_Name ('T')); - - Insert_Action (N, - Make_Subtype_Declaration (Loc, - Defining_Identifier => T, - Subtype_Indication => New_Reference_To (Exp_Typ, Loc))); - - -- This type is marked as an itype even though it has an - -- explicit declaration because otherwise it can be marked - -- with Is_Generic_Actual_Type and generate spurious errors. - -- (see sem_ch8.Analyze_Package_Renaming and sem_type.covers) - - Set_Is_Itype (T); - Set_Associated_Node_For_Itype (T, Exp); - end if; - - Rewrite (Subtype_Indic, New_Reference_To (T, Loc)); - - -- nothing needs to be done for private types with unknown discriminants - -- if the underlying type is not an unconstrained composite type. - - elsif Is_Private_Type (Unc_Type) - and then Has_Unknown_Discriminants (Unc_Type) - and then (not Is_Composite_Type (Underlying_Type (Unc_Type)) - or else Is_Constrained (Underlying_Type (Unc_Type))) - then - null; - - -- Nothing to be done for derived types with unknown discriminants if - -- the parent type also has unknown discriminants. - - elsif Is_Record_Type (Unc_Type) - and then not Is_Class_Wide_Type (Unc_Type) - and then Has_Unknown_Discriminants (Unc_Type) - and then Has_Unknown_Discriminants (Underlying_Type (Unc_Type)) - then - null; - - -- In Ada95, Nothing to be done if the type of the expression is - -- limited, because in this case the expression cannot be copied, - -- and its use can only be by reference. - - -- In Ada2005, the context can be an object declaration whose expression - -- is a function that returns in place. If the nominal subtype has - -- unknown discriminants, the call still provides constraints on the - -- object, and we have to create an actual subtype from it. - - -- If the type is class-wide, the expression is dynamically tagged and - -- we do not create an actual subtype either. Ditto for an interface. - - elsif Is_Limited_Type (Exp_Typ) - and then - (Is_Class_Wide_Type (Exp_Typ) - or else Is_Interface (Exp_Typ) - or else not Has_Unknown_Discriminants (Exp_Typ) - or else not Is_Composite_Type (Unc_Type)) - then - null; - - -- For limited interfaces, nothing to be done - - -- This branch may be redundant once the limited interface issue is - -- sorted out??? - - elsif Is_Interface (Exp_Typ) - and then Is_Limited_Interface (Exp_Typ) - then - null; - - -- For limited objects initialized with build in place function calls, - -- nothing to be done; otherwise we prematurely introduce an N_Reference - -- node in the expression initializing the object, which breaks the - -- circuitry that detects and adds the additional arguments to the - -- called function. - - elsif Is_Build_In_Place_Function_Call (Exp) then - null; - - else - Remove_Side_Effects (Exp); - Rewrite (Subtype_Indic, - Make_Subtype_From_Expr (Exp, Unc_Type)); - end if; - end Expand_Subtype_From_Expr; - - ------------------------ - -- Find_Interface_ADT -- - ------------------------ - - function Find_Interface_ADT - (T : Entity_Id; - Iface : Entity_Id) return Elmt_Id - is - ADT : Elmt_Id; - Typ : Entity_Id := T; - - begin - pragma Assert (Is_Interface (Iface)); - - -- Handle private types - - if Has_Private_Declaration (Typ) - and then Present (Full_View (Typ)) - then - Typ := Full_View (Typ); - end if; - - -- Handle access types - - if Is_Access_Type (Typ) then - Typ := Directly_Designated_Type (Typ); - end if; - - -- Handle task and protected types implementing interfaces - - if Is_Concurrent_Type (Typ) then - Typ := Corresponding_Record_Type (Typ); - end if; - - pragma Assert - (not Is_Class_Wide_Type (Typ) - and then Ekind (Typ) /= E_Incomplete_Type); - - if Is_Ancestor (Iface, Typ) then - return First_Elmt (Access_Disp_Table (Typ)); - - else - ADT := - Next_Elmt (Next_Elmt (First_Elmt (Access_Disp_Table (Typ)))); - while Present (ADT) - and then Present (Related_Type (Node (ADT))) - and then Related_Type (Node (ADT)) /= Iface - and then not Is_Ancestor (Iface, Related_Type (Node (ADT))) - loop - Next_Elmt (ADT); - end loop; - - pragma Assert (Present (Related_Type (Node (ADT)))); - return ADT; - end if; - end Find_Interface_ADT; - - ------------------------ - -- Find_Interface_Tag -- - ------------------------ - - function Find_Interface_Tag - (T : Entity_Id; - Iface : Entity_Id) return Entity_Id - is - AI_Tag : Entity_Id; - Found : Boolean := False; - Typ : Entity_Id := T; - - procedure Find_Tag (Typ : Entity_Id); - -- Internal subprogram used to recursively climb to the ancestors - - -------------- - -- Find_Tag -- - -------------- - - procedure Find_Tag (Typ : Entity_Id) is - AI_Elmt : Elmt_Id; - AI : Node_Id; - - begin - -- Check if the interface is an immediate ancestor of the type and - -- therefore shares the main tag. - - if Typ = Iface then - pragma Assert (Etype (First_Tag_Component (Typ)) = RTE (RE_Tag)); - AI_Tag := First_Tag_Component (Typ); - Found := True; - return; - end if; - - -- Climb to the root type handling private types - - if Present (Full_View (Etype (Typ))) then - if Full_View (Etype (Typ)) /= Typ then - Find_Tag (Full_View (Etype (Typ))); - end if; - - elsif Etype (Typ) /= Typ then - Find_Tag (Etype (Typ)); - end if; - - -- Traverse the list of interfaces implemented by the type - - if not Found - and then Present (Interfaces (Typ)) - and then not (Is_Empty_Elmt_List (Interfaces (Typ))) - then - -- Skip the tag associated with the primary table - - pragma Assert (Etype (First_Tag_Component (Typ)) = RTE (RE_Tag)); - AI_Tag := Next_Tag_Component (First_Tag_Component (Typ)); - pragma Assert (Present (AI_Tag)); - - AI_Elmt := First_Elmt (Interfaces (Typ)); - while Present (AI_Elmt) loop - AI := Node (AI_Elmt); - - if AI = Iface or else Is_Ancestor (Iface, AI) then - Found := True; - return; - end if; - - AI_Tag := Next_Tag_Component (AI_Tag); - Next_Elmt (AI_Elmt); - end loop; - end if; - end Find_Tag; - - -- Start of processing for Find_Interface_Tag - - begin - pragma Assert (Is_Interface (Iface)); - - -- Handle private types - - if Has_Private_Declaration (Typ) - and then Present (Full_View (Typ)) - then - Typ := Full_View (Typ); - end if; - - -- Handle access types - - if Is_Access_Type (Typ) then - Typ := Directly_Designated_Type (Typ); - end if; - - -- Handle task and protected types implementing interfaces - - if Is_Concurrent_Type (Typ) then - Typ := Corresponding_Record_Type (Typ); - end if; - - if Is_Class_Wide_Type (Typ) then - Typ := Etype (Typ); - end if; - - -- Handle entities from the limited view - - if Ekind (Typ) = E_Incomplete_Type then - pragma Assert (Present (Non_Limited_View (Typ))); - Typ := Non_Limited_View (Typ); - end if; - - Find_Tag (Typ); - pragma Assert (Found); - return AI_Tag; - end Find_Interface_Tag; - - ------------------ - -- Find_Prim_Op -- - ------------------ - - function Find_Prim_Op (T : Entity_Id; Name : Name_Id) return Entity_Id is - Prim : Elmt_Id; - Typ : Entity_Id := T; - Op : Entity_Id; - - begin - if Is_Class_Wide_Type (Typ) then - Typ := Root_Type (Typ); - end if; - - Typ := Underlying_Type (Typ); - - -- Loop through primitive operations - - Prim := First_Elmt (Primitive_Operations (Typ)); - while Present (Prim) loop - Op := Node (Prim); - - -- We can retrieve primitive operations by name if it is an internal - -- name. For equality we must check that both of its operands have - -- the same type, to avoid confusion with user-defined equalities - -- than may have a non-symmetric signature. - - exit when Chars (Op) = Name - and then - (Name /= Name_Op_Eq - or else Etype (First_Entity (Op)) = Etype (Last_Entity (Op))); - - Next_Elmt (Prim); - - -- Raise Program_Error if no primitive found - - if No (Prim) then - raise Program_Error; - end if; - end loop; - - return Node (Prim); - end Find_Prim_Op; - - ------------------ - -- Find_Prim_Op -- - ------------------ - - function Find_Prim_Op - (T : Entity_Id; - Name : TSS_Name_Type) return Entity_Id - is - Prim : Elmt_Id; - Typ : Entity_Id := T; - - begin - if Is_Class_Wide_Type (Typ) then - Typ := Root_Type (Typ); - end if; - - Typ := Underlying_Type (Typ); - - Prim := First_Elmt (Primitive_Operations (Typ)); - while not Is_TSS (Node (Prim), Name) loop - Next_Elmt (Prim); - - -- Raise program error if no primitive found - - if No (Prim) then - raise Program_Error; - end if; - end loop; - - return Node (Prim); - end Find_Prim_Op; - - ---------------------------- - -- Find_Protection_Object -- - ---------------------------- - - function Find_Protection_Object (Scop : Entity_Id) return Entity_Id is - S : Entity_Id; - - begin - S := Scop; - while Present (S) loop - if (Ekind (S) = E_Entry - or else Ekind (S) = E_Entry_Family - or else Ekind (S) = E_Function - or else Ekind (S) = E_Procedure) - and then Present (Protection_Object (S)) - then - return Protection_Object (S); - end if; - - S := Scope (S); - end loop; - - -- If we do not find a Protection object in the scope chain, then - -- something has gone wrong, most likely the object was never created. - - raise Program_Error; - end Find_Protection_Object; - - ---------------------- - -- Force_Evaluation -- - ---------------------- - - procedure Force_Evaluation (Exp : Node_Id; Name_Req : Boolean := False) is - begin - Remove_Side_Effects (Exp, Name_Req, Variable_Ref => True); - end Force_Evaluation; - - ------------------------ - -- Generate_Poll_Call -- - ------------------------ - - procedure Generate_Poll_Call (N : Node_Id) is - begin - -- No poll call if polling not active - - if not Polling_Required then - return; - - -- Otherwise generate require poll call - - else - Insert_Before_And_Analyze (N, - Make_Procedure_Call_Statement (Sloc (N), - Name => New_Occurrence_Of (RTE (RE_Poll), Sloc (N)))); - end if; - end Generate_Poll_Call; - - --------------------------------- - -- Get_Current_Value_Condition -- - --------------------------------- - - -- Note: the implementation of this procedure is very closely tied to the - -- implementation of Set_Current_Value_Condition. In the Get procedure, we - -- interpret Current_Value fields set by the Set procedure, so the two - -- procedures need to be closely coordinated. - - procedure Get_Current_Value_Condition - (Var : Node_Id; - Op : out Node_Kind; - Val : out Node_Id) - is - Loc : constant Source_Ptr := Sloc (Var); - Ent : constant Entity_Id := Entity (Var); - - procedure Process_Current_Value_Condition - (N : Node_Id; - S : Boolean); - -- N is an expression which holds either True (S = True) or False (S = - -- False) in the condition. This procedure digs out the expression and - -- if it refers to Ent, sets Op and Val appropriately. - - ------------------------------------- - -- Process_Current_Value_Condition -- - ------------------------------------- - - procedure Process_Current_Value_Condition - (N : Node_Id; - S : Boolean) - is - Cond : Node_Id; - Sens : Boolean; - - begin - Cond := N; - Sens := S; - - -- Deal with NOT operators, inverting sense - - while Nkind (Cond) = N_Op_Not loop - Cond := Right_Opnd (Cond); - Sens := not Sens; - end loop; - - -- Deal with AND THEN and AND cases - - if Nkind (Cond) = N_And_Then - or else Nkind (Cond) = N_Op_And - then - -- Don't ever try to invert a condition that is of the form - -- of an AND or AND THEN (since we are not doing sufficiently - -- general processing to allow this). - - if Sens = False then - Op := N_Empty; - Val := Empty; - return; - end if; - - -- Recursively process AND and AND THEN branches - - Process_Current_Value_Condition (Left_Opnd (Cond), True); - - if Op /= N_Empty then - return; - end if; - - Process_Current_Value_Condition (Right_Opnd (Cond), True); - return; - - -- Case of relational operator - - elsif Nkind (Cond) in N_Op_Compare then - Op := Nkind (Cond); - - -- Invert sense of test if inverted test - - if Sens = False then - case Op is - when N_Op_Eq => Op := N_Op_Ne; - when N_Op_Ne => Op := N_Op_Eq; - when N_Op_Lt => Op := N_Op_Ge; - when N_Op_Gt => Op := N_Op_Le; - when N_Op_Le => Op := N_Op_Gt; - when N_Op_Ge => Op := N_Op_Lt; - when others => raise Program_Error; - end case; - end if; - - -- Case of entity op value - - if Is_Entity_Name (Left_Opnd (Cond)) - and then Ent = Entity (Left_Opnd (Cond)) - and then Compile_Time_Known_Value (Right_Opnd (Cond)) - then - Val := Right_Opnd (Cond); - - -- Case of value op entity - - elsif Is_Entity_Name (Right_Opnd (Cond)) - and then Ent = Entity (Right_Opnd (Cond)) - and then Compile_Time_Known_Value (Left_Opnd (Cond)) - then - Val := Left_Opnd (Cond); - - -- We are effectively swapping operands - - case Op is - when N_Op_Eq => null; - when N_Op_Ne => null; - when N_Op_Lt => Op := N_Op_Gt; - when N_Op_Gt => Op := N_Op_Lt; - when N_Op_Le => Op := N_Op_Ge; - when N_Op_Ge => Op := N_Op_Le; - when others => raise Program_Error; - end case; - - else - Op := N_Empty; - end if; - - return; - - -- Case of Boolean variable reference, return as though the - -- reference had said var = True. - - else - if Is_Entity_Name (Cond) - and then Ent = Entity (Cond) - then - Val := New_Occurrence_Of (Standard_True, Sloc (Cond)); - - if Sens = False then - Op := N_Op_Ne; - else - Op := N_Op_Eq; - end if; - end if; - end if; - end Process_Current_Value_Condition; - - -- Start of processing for Get_Current_Value_Condition - - begin - Op := N_Empty; - Val := Empty; - - -- Immediate return, nothing doing, if this is not an object - - if Ekind (Ent) not in Object_Kind then - return; - end if; - - -- Otherwise examine current value - - declare - CV : constant Node_Id := Current_Value (Ent); - Sens : Boolean; - Stm : Node_Id; - - begin - -- If statement. Condition is known true in THEN section, known False - -- in any ELSIF or ELSE part, and unknown outside the IF statement. - - if Nkind (CV) = N_If_Statement then - - -- Before start of IF statement - - if Loc < Sloc (CV) then - return; - - -- After end of IF statement - - elsif Loc >= Sloc (CV) + Text_Ptr (UI_To_Int (End_Span (CV))) then - return; - end if; - - -- At this stage we know that we are within the IF statement, but - -- unfortunately, the tree does not record the SLOC of the ELSE so - -- we cannot use a simple SLOC comparison to distinguish between - -- the then/else statements, so we have to climb the tree. - - declare - N : Node_Id; - - begin - N := Parent (Var); - while Parent (N) /= CV loop - N := Parent (N); - - -- If we fall off the top of the tree, then that's odd, but - -- perhaps it could occur in some error situation, and the - -- safest response is simply to assume that the outcome of - -- the condition is unknown. No point in bombing during an - -- attempt to optimize things. - - if No (N) then - return; - end if; - end loop; - - -- Now we have N pointing to a node whose parent is the IF - -- statement in question, so now we can tell if we are within - -- the THEN statements. - - if Is_List_Member (N) - and then List_Containing (N) = Then_Statements (CV) - then - Sens := True; - - -- If the variable reference does not come from source, we - -- cannot reliably tell whether it appears in the else part. - -- In particular, if it appears in generated code for a node - -- that requires finalization, it may be attached to a list - -- that has not been yet inserted into the code. For now, - -- treat it as unknown. - - elsif not Comes_From_Source (N) then - return; - - -- Otherwise we must be in ELSIF or ELSE part - - else - Sens := False; - end if; - end; - - -- ELSIF part. Condition is known true within the referenced - -- ELSIF, known False in any subsequent ELSIF or ELSE part, and - -- unknown before the ELSE part or after the IF statement. - - elsif Nkind (CV) = N_Elsif_Part then - Stm := Parent (CV); - - -- Before start of ELSIF part - - if Loc < Sloc (CV) then - return; - - -- After end of IF statement - - elsif Loc >= Sloc (Stm) + - Text_Ptr (UI_To_Int (End_Span (Stm))) - then - return; - end if; - - -- Again we lack the SLOC of the ELSE, so we need to climb the - -- tree to see if we are within the ELSIF part in question. - - declare - N : Node_Id; - - begin - N := Parent (Var); - while Parent (N) /= Stm loop - N := Parent (N); - - -- If we fall off the top of the tree, then that's odd, but - -- perhaps it could occur in some error situation, and the - -- safest response is simply to assume that the outcome of - -- the condition is unknown. No point in bombing during an - -- attempt to optimize things. - - if No (N) then - return; - end if; - end loop; - - -- Now we have N pointing to a node whose parent is the IF - -- statement in question, so see if is the ELSIF part we want. - -- the THEN statements. - - if N = CV then - Sens := True; - - -- Otherwise we must be in subsequent ELSIF or ELSE part - - else - Sens := False; - end if; - end; - - -- Iteration scheme of while loop. The condition is known to be - -- true within the body of the loop. - - elsif Nkind (CV) = N_Iteration_Scheme then - declare - Loop_Stmt : constant Node_Id := Parent (CV); - - begin - -- Before start of body of loop - - if Loc < Sloc (Loop_Stmt) then - return; - - -- After end of LOOP statement - - elsif Loc >= Sloc (End_Label (Loop_Stmt)) then - return; - - -- We are within the body of the loop - - else - Sens := True; - end if; - end; - - -- All other cases of Current_Value settings - - else - return; - end if; - - -- If we fall through here, then we have a reportable condition, Sens - -- is True if the condition is true and False if it needs inverting. - - Process_Current_Value_Condition (Condition (CV), Sens); - end; - end Get_Current_Value_Condition; - - --------------------------------- - -- Has_Controlled_Coextensions -- - --------------------------------- - - function Has_Controlled_Coextensions (Typ : Entity_Id) return Boolean is - D_Typ : Entity_Id; - Discr : Entity_Id; - - begin - -- Only consider record types - - if Ekind (Typ) /= E_Record_Type - and then Ekind (Typ) /= E_Record_Subtype - then - return False; - end if; - - if Has_Discriminants (Typ) then - Discr := First_Discriminant (Typ); - while Present (Discr) loop - D_Typ := Etype (Discr); - - if Ekind (D_Typ) = E_Anonymous_Access_Type - and then - (Is_Controlled (Directly_Designated_Type (D_Typ)) - or else - Is_Concurrent_Type (Directly_Designated_Type (D_Typ))) - then - return True; - end if; - - Next_Discriminant (Discr); - end loop; - end if; - - return False; - end Has_Controlled_Coextensions; - - -------------------- - -- Homonym_Number -- - -------------------- - - function Homonym_Number (Subp : Entity_Id) return Nat is - Count : Nat; - Hom : Entity_Id; - - begin - Count := 1; - Hom := Homonym (Subp); - while Present (Hom) loop - if Scope (Hom) = Scope (Subp) then - Count := Count + 1; - end if; - - Hom := Homonym (Hom); - end loop; - - return Count; - end Homonym_Number; - - ------------------------------ - -- In_Unconditional_Context -- - ------------------------------ - - function In_Unconditional_Context (Node : Node_Id) return Boolean is - P : Node_Id; - - begin - P := Node; - while Present (P) loop - case Nkind (P) is - when N_Subprogram_Body => - return True; - - when N_If_Statement => - return False; - - when N_Loop_Statement => - return False; - - when N_Case_Statement => - return False; - - when others => - P := Parent (P); - end case; - end loop; - - return False; - end In_Unconditional_Context; - - ------------------- - -- Insert_Action -- - ------------------- - - procedure Insert_Action (Assoc_Node : Node_Id; Ins_Action : Node_Id) is - begin - if Present (Ins_Action) then - Insert_Actions (Assoc_Node, New_List (Ins_Action)); - end if; - end Insert_Action; - - -- Version with check(s) suppressed - - procedure Insert_Action - (Assoc_Node : Node_Id; Ins_Action : Node_Id; Suppress : Check_Id) - is - begin - Insert_Actions (Assoc_Node, New_List (Ins_Action), Suppress); - end Insert_Action; - - -------------------- - -- Insert_Actions -- - -------------------- - - procedure Insert_Actions (Assoc_Node : Node_Id; Ins_Actions : List_Id) is - N : Node_Id; - P : Node_Id; - - Wrapped_Node : Node_Id := Empty; - - begin - if No (Ins_Actions) or else Is_Empty_List (Ins_Actions) then - return; - end if; - - -- Ignore insert of actions from inside default expression (or other - -- similar "spec expression") in the special spec-expression analyze - -- mode. Any insertions at this point have no relevance, since we are - -- only doing the analyze to freeze the types of any static expressions. - -- See section "Handling of Default Expressions" in the spec of package - -- Sem for further details. - - if In_Spec_Expression then - return; - end if; - - -- If the action derives from stuff inside a record, then the actions - -- are attached to the current scope, to be inserted and analyzed on - -- exit from the scope. The reason for this is that we may also - -- be generating freeze actions at the same time, and they must - -- eventually be elaborated in the correct order. - - if Is_Record_Type (Current_Scope) - and then not Is_Frozen (Current_Scope) - then - if No (Scope_Stack.Table - (Scope_Stack.Last).Pending_Freeze_Actions) - then - Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions := - Ins_Actions; - else - Append_List - (Ins_Actions, - Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions); - end if; - - return; - end if; - - -- We now intend to climb up the tree to find the right point to - -- insert the actions. We start at Assoc_Node, unless this node is - -- a subexpression in which case we start with its parent. We do this - -- for two reasons. First it speeds things up. Second, if Assoc_Node - -- is itself one of the special nodes like N_And_Then, then we assume - -- that an initial request to insert actions for such a node does not - -- expect the actions to get deposited in the node for later handling - -- when the node is expanded, since clearly the node is being dealt - -- with by the caller. Note that in the subexpression case, N is - -- always the child we came from. - - -- N_Raise_xxx_Error is an annoying special case, it is a statement - -- if it has type Standard_Void_Type, and a subexpression otherwise. - -- otherwise. Procedure attribute references are also statements. - - if Nkind (Assoc_Node) in N_Subexpr - and then (Nkind (Assoc_Node) in N_Raise_xxx_Error - or else Etype (Assoc_Node) /= Standard_Void_Type) - and then (Nkind (Assoc_Node) /= N_Attribute_Reference - or else - not Is_Procedure_Attribute_Name - (Attribute_Name (Assoc_Node))) - then - P := Assoc_Node; -- ??? does not agree with above! - N := Parent (Assoc_Node); - - -- Non-subexpression case. Note that N is initially Empty in this - -- case (N is only guaranteed Non-Empty in the subexpr case). - - else - P := Assoc_Node; - N := Empty; - end if; - - -- Capture root of the transient scope - - if Scope_Is_Transient then - Wrapped_Node := Node_To_Be_Wrapped; - end if; - - loop - pragma Assert (Present (P)); - - case Nkind (P) is - - -- Case of right operand of AND THEN or OR ELSE. Put the actions - -- in the Actions field of the right operand. They will be moved - -- out further when the AND THEN or OR ELSE operator is expanded. - -- Nothing special needs to be done for the left operand since - -- in that case the actions are executed unconditionally. - - when N_And_Then | N_Or_Else => - if N = Right_Opnd (P) then - - -- We are now going to either append the actions to the - -- actions field of the short-circuit operation. We will - -- also analyze the actions now. - - -- This analysis is really too early, the proper thing would - -- be to just park them there now, and only analyze them if - -- we find we really need them, and to it at the proper - -- final insertion point. However attempting to this proved - -- tricky, so for now we just kill current values before and - -- after the analyze call to make sure we avoid peculiar - -- optimizations from this out of order insertion. - - Kill_Current_Values; - - if Present (Actions (P)) then - Insert_List_After_And_Analyze - (Last (Actions (P)), Ins_Actions); - else - Set_Actions (P, Ins_Actions); - Analyze_List (Actions (P)); - end if; - - Kill_Current_Values; - - return; - end if; - - -- Then or Else operand of conditional expression. Add actions to - -- Then_Actions or Else_Actions field as appropriate. The actions - -- will be moved further out when the conditional is expanded. - - when N_Conditional_Expression => - declare - ThenX : constant Node_Id := Next (First (Expressions (P))); - ElseX : constant Node_Id := Next (ThenX); - - begin - -- Actions belong to the then expression, temporarily - -- place them as Then_Actions of the conditional expr. - -- They will be moved to the proper place later when - -- the conditional expression is expanded. - - if N = ThenX then - if Present (Then_Actions (P)) then - Insert_List_After_And_Analyze - (Last (Then_Actions (P)), Ins_Actions); - else - Set_Then_Actions (P, Ins_Actions); - Analyze_List (Then_Actions (P)); - end if; - - return; - - -- Actions belong to the else expression, temporarily - -- place them as Else_Actions of the conditional expr. - -- They will be moved to the proper place later when - -- the conditional expression is expanded. - - elsif N = ElseX then - if Present (Else_Actions (P)) then - Insert_List_After_And_Analyze - (Last (Else_Actions (P)), Ins_Actions); - else - Set_Else_Actions (P, Ins_Actions); - Analyze_List (Else_Actions (P)); - end if; - - return; - - -- Actions belong to the condition. In this case they are - -- unconditionally executed, and so we can continue the - -- search for the proper insert point. - - else - null; - end if; - end; - - -- Case of appearing in the condition of a while expression or - -- elsif. We insert the actions into the Condition_Actions field. - -- They will be moved further out when the while loop or elsif - -- is analyzed. - - when N_Iteration_Scheme | - N_Elsif_Part - => - if N = Condition (P) then - if Present (Condition_Actions (P)) then - Insert_List_After_And_Analyze - (Last (Condition_Actions (P)), Ins_Actions); - else - Set_Condition_Actions (P, Ins_Actions); - - -- Set the parent of the insert actions explicitly. - -- This is not a syntactic field, but we need the - -- parent field set, in particular so that freeze - -- can understand that it is dealing with condition - -- actions, and properly insert the freezing actions. - - Set_Parent (Ins_Actions, P); - Analyze_List (Condition_Actions (P)); - end if; - - return; - end if; - - -- Statements, declarations, pragmas, representation clauses - - when - -- Statements - - N_Procedure_Call_Statement | - N_Statement_Other_Than_Procedure_Call | - - -- Pragmas - - N_Pragma | - - -- Representation_Clause - - N_At_Clause | - N_Attribute_Definition_Clause | - N_Enumeration_Representation_Clause | - N_Record_Representation_Clause | - - -- Declarations - - N_Abstract_Subprogram_Declaration | - N_Entry_Body | - N_Exception_Declaration | - N_Exception_Renaming_Declaration | - N_Formal_Abstract_Subprogram_Declaration | - N_Formal_Concrete_Subprogram_Declaration | - N_Formal_Object_Declaration | - N_Formal_Type_Declaration | - N_Full_Type_Declaration | - N_Function_Instantiation | - N_Generic_Function_Renaming_Declaration | - N_Generic_Package_Declaration | - N_Generic_Package_Renaming_Declaration | - N_Generic_Procedure_Renaming_Declaration | - N_Generic_Subprogram_Declaration | - N_Implicit_Label_Declaration | - N_Incomplete_Type_Declaration | - N_Number_Declaration | - N_Object_Declaration | - N_Object_Renaming_Declaration | - N_Package_Body | - N_Package_Body_Stub | - N_Package_Declaration | - N_Package_Instantiation | - N_Package_Renaming_Declaration | - N_Private_Extension_Declaration | - N_Private_Type_Declaration | - N_Procedure_Instantiation | - N_Protected_Body | - N_Protected_Body_Stub | - N_Protected_Type_Declaration | - N_Single_Task_Declaration | - N_Subprogram_Body | - N_Subprogram_Body_Stub | - N_Subprogram_Declaration | - N_Subprogram_Renaming_Declaration | - N_Subtype_Declaration | - N_Task_Body | - N_Task_Body_Stub | - N_Task_Type_Declaration | - - -- Freeze entity behaves like a declaration or statement - - N_Freeze_Entity - => - -- Do not insert here if the item is not a list member (this - -- happens for example with a triggering statement, and the - -- proper approach is to insert before the entire select). - - if not Is_List_Member (P) then - null; - - -- Do not insert if parent of P is an N_Component_Association - -- node (i.e. we are in the context of an N_Aggregate or - -- N_Extension_Aggregate node. In this case we want to insert - -- before the entire aggregate. - - elsif Nkind (Parent (P)) = N_Component_Association then - null; - - -- Do not insert if the parent of P is either an N_Variant - -- node or an N_Record_Definition node, meaning in either - -- case that P is a member of a component list, and that - -- therefore the actions should be inserted outside the - -- complete record declaration. - - elsif Nkind (Parent (P)) = N_Variant - or else Nkind (Parent (P)) = N_Record_Definition - then - null; - - -- Do not insert freeze nodes within the loop generated for - -- an aggregate, because they may be elaborated too late for - -- subsequent use in the back end: within a package spec the - -- loop is part of the elaboration procedure and is only - -- elaborated during the second pass. - -- If the loop comes from source, or the entity is local to - -- the loop itself it must remain within. - - elsif Nkind (Parent (P)) = N_Loop_Statement - and then not Comes_From_Source (Parent (P)) - and then Nkind (First (Ins_Actions)) = N_Freeze_Entity - and then - Scope (Entity (First (Ins_Actions))) /= Current_Scope - then - null; - - -- Otherwise we can go ahead and do the insertion - - elsif P = Wrapped_Node then - Store_Before_Actions_In_Scope (Ins_Actions); - return; - - else - Insert_List_Before_And_Analyze (P, Ins_Actions); - return; - end if; - - -- A special case, N_Raise_xxx_Error can act either as a - -- statement or a subexpression. We tell the difference - -- by looking at the Etype. It is set to Standard_Void_Type - -- in the statement case. - - when - N_Raise_xxx_Error => - if Etype (P) = Standard_Void_Type then - if P = Wrapped_Node then - Store_Before_Actions_In_Scope (Ins_Actions); - else - Insert_List_Before_And_Analyze (P, Ins_Actions); - end if; - - return; - - -- In the subexpression case, keep climbing - - else - null; - end if; - - -- If a component association appears within a loop created for - -- an array aggregate, attach the actions to the association so - -- they can be subsequently inserted within the loop. For other - -- component associations insert outside of the aggregate. For - -- an association that will generate a loop, its Loop_Actions - -- attribute is already initialized (see exp_aggr.adb). - - -- The list of loop_actions can in turn generate additional ones, - -- that are inserted before the associated node. If the associated - -- node is outside the aggregate, the new actions are collected - -- at the end of the loop actions, to respect the order in which - -- they are to be elaborated. - - when - N_Component_Association => - if Nkind (Parent (P)) = N_Aggregate - and then Present (Loop_Actions (P)) - then - if Is_Empty_List (Loop_Actions (P)) then - Set_Loop_Actions (P, Ins_Actions); - Analyze_List (Ins_Actions); - - else - declare - Decl : Node_Id; - - begin - -- Check whether these actions were generated - -- by a declaration that is part of the loop_ - -- actions for the component_association. - - Decl := Assoc_Node; - while Present (Decl) loop - exit when Parent (Decl) = P - and then Is_List_Member (Decl) - and then - List_Containing (Decl) = Loop_Actions (P); - Decl := Parent (Decl); - end loop; - - if Present (Decl) then - Insert_List_Before_And_Analyze - (Decl, Ins_Actions); - else - Insert_List_After_And_Analyze - (Last (Loop_Actions (P)), Ins_Actions); - end if; - end; - end if; - - return; - - else - null; - end if; - - -- Another special case, an attribute denoting a procedure call - - when - N_Attribute_Reference => - if Is_Procedure_Attribute_Name (Attribute_Name (P)) then - if P = Wrapped_Node then - Store_Before_Actions_In_Scope (Ins_Actions); - else - Insert_List_Before_And_Analyze (P, Ins_Actions); - end if; - - return; - - -- In the subexpression case, keep climbing - - else - null; - end if; - - -- For all other node types, keep climbing tree - - when - N_Abortable_Part | - N_Accept_Alternative | - N_Access_Definition | - N_Access_Function_Definition | - N_Access_Procedure_Definition | - N_Access_To_Object_Definition | - N_Aggregate | - N_Allocator | - N_Case_Statement_Alternative | - N_Character_Literal | - N_Compilation_Unit | - N_Compilation_Unit_Aux | - N_Component_Clause | - N_Component_Declaration | - N_Component_Definition | - N_Component_List | - N_Constrained_Array_Definition | - N_Decimal_Fixed_Point_Definition | - N_Defining_Character_Literal | - N_Defining_Identifier | - N_Defining_Operator_Symbol | - N_Defining_Program_Unit_Name | - N_Delay_Alternative | - N_Delta_Constraint | - N_Derived_Type_Definition | - N_Designator | - N_Digits_Constraint | - N_Discriminant_Association | - N_Discriminant_Specification | - N_Empty | - N_Entry_Body_Formal_Part | - N_Entry_Call_Alternative | - N_Entry_Declaration | - N_Entry_Index_Specification | - N_Enumeration_Type_Definition | - N_Error | - N_Exception_Handler | - N_Expanded_Name | - N_Explicit_Dereference | - N_Extension_Aggregate | - N_Floating_Point_Definition | - N_Formal_Decimal_Fixed_Point_Definition | - N_Formal_Derived_Type_Definition | - N_Formal_Discrete_Type_Definition | - N_Formal_Floating_Point_Definition | - N_Formal_Modular_Type_Definition | - N_Formal_Ordinary_Fixed_Point_Definition | - N_Formal_Package_Declaration | - N_Formal_Private_Type_Definition | - N_Formal_Signed_Integer_Type_Definition | - N_Function_Call | - N_Function_Specification | - N_Generic_Association | - N_Handled_Sequence_Of_Statements | - N_Identifier | - N_In | - N_Index_Or_Discriminant_Constraint | - N_Indexed_Component | - N_Integer_Literal | - N_Itype_Reference | - N_Label | - N_Loop_Parameter_Specification | - N_Mod_Clause | - N_Modular_Type_Definition | - N_Not_In | - N_Null | - N_Op_Abs | - N_Op_Add | - N_Op_And | - N_Op_Concat | - N_Op_Divide | - N_Op_Eq | - N_Op_Expon | - N_Op_Ge | - N_Op_Gt | - N_Op_Le | - N_Op_Lt | - N_Op_Minus | - N_Op_Mod | - N_Op_Multiply | - N_Op_Ne | - N_Op_Not | - N_Op_Or | - N_Op_Plus | - N_Op_Rem | - N_Op_Rotate_Left | - N_Op_Rotate_Right | - N_Op_Shift_Left | - N_Op_Shift_Right | - N_Op_Shift_Right_Arithmetic | - N_Op_Subtract | - N_Op_Xor | - N_Operator_Symbol | - N_Ordinary_Fixed_Point_Definition | - N_Others_Choice | - N_Package_Specification | - N_Parameter_Association | - N_Parameter_Specification | - N_Pop_Constraint_Error_Label | - N_Pop_Program_Error_Label | - N_Pop_Storage_Error_Label | - N_Pragma_Argument_Association | - N_Procedure_Specification | - N_Protected_Definition | - N_Push_Constraint_Error_Label | - N_Push_Program_Error_Label | - N_Push_Storage_Error_Label | - N_Qualified_Expression | - N_Range | - N_Range_Constraint | - N_Real_Literal | - N_Real_Range_Specification | - N_Record_Definition | - N_Reference | - N_Selected_Component | - N_Signed_Integer_Type_Definition | - N_Single_Protected_Declaration | - N_Slice | - N_String_Literal | - N_Subprogram_Info | - N_Subtype_Indication | - N_Subunit | - N_Task_Definition | - N_Terminate_Alternative | - N_Triggering_Alternative | - N_Type_Conversion | - N_Unchecked_Expression | - N_Unchecked_Type_Conversion | - N_Unconstrained_Array_Definition | - N_Unused_At_End | - N_Unused_At_Start | - N_Use_Package_Clause | - N_Use_Type_Clause | - N_Variant | - N_Variant_Part | - N_Validate_Unchecked_Conversion | - N_With_Clause - => - null; - - end case; - - -- Make sure that inserted actions stay in the transient scope - - if P = Wrapped_Node then - Store_Before_Actions_In_Scope (Ins_Actions); - return; - end if; - - -- If we fall through above tests, keep climbing tree - - N := P; - - if Nkind (Parent (N)) = N_Subunit then - - -- This is the proper body corresponding to a stub. Insertion - -- must be done at the point of the stub, which is in the decla- - -- rative part of the parent unit. - - P := Corresponding_Stub (Parent (N)); - - else - P := Parent (N); - end if; - end loop; - end Insert_Actions; - - -- Version with check(s) suppressed - - procedure Insert_Actions - (Assoc_Node : Node_Id; - Ins_Actions : List_Id; - Suppress : Check_Id) - is - begin - if Suppress = All_Checks then - declare - Svg : constant Suppress_Array := Scope_Suppress; - begin - Scope_Suppress := (others => True); - Insert_Actions (Assoc_Node, Ins_Actions); - Scope_Suppress := Svg; - end; - - else - declare - Svg : constant Boolean := Scope_Suppress (Suppress); - begin - Scope_Suppress (Suppress) := True; - Insert_Actions (Assoc_Node, Ins_Actions); - Scope_Suppress (Suppress) := Svg; - end; - end if; - end Insert_Actions; - - -------------------------- - -- Insert_Actions_After -- - -------------------------- - - procedure Insert_Actions_After - (Assoc_Node : Node_Id; - Ins_Actions : List_Id) - is - begin - if Scope_Is_Transient - and then Assoc_Node = Node_To_Be_Wrapped - then - Store_After_Actions_In_Scope (Ins_Actions); - else - Insert_List_After_And_Analyze (Assoc_Node, Ins_Actions); - end if; - end Insert_Actions_After; - - --------------------------------- - -- Insert_Library_Level_Action -- - --------------------------------- - - procedure Insert_Library_Level_Action (N : Node_Id) is - Aux : constant Node_Id := Aux_Decls_Node (Cunit (Main_Unit)); - - begin - Push_Scope (Cunit_Entity (Main_Unit)); - -- ??? should this be Current_Sem_Unit instead of Main_Unit? - - if No (Actions (Aux)) then - Set_Actions (Aux, New_List (N)); - else - Append (N, Actions (Aux)); - end if; - - Analyze (N); - Pop_Scope; - end Insert_Library_Level_Action; - - ---------------------------------- - -- Insert_Library_Level_Actions -- - ---------------------------------- - - procedure Insert_Library_Level_Actions (L : List_Id) is - Aux : constant Node_Id := Aux_Decls_Node (Cunit (Main_Unit)); - - begin - if Is_Non_Empty_List (L) then - Push_Scope (Cunit_Entity (Main_Unit)); - -- ??? should this be Current_Sem_Unit instead of Main_Unit? - - if No (Actions (Aux)) then - Set_Actions (Aux, L); - Analyze_List (L); - else - Insert_List_After_And_Analyze (Last (Actions (Aux)), L); - end if; - - Pop_Scope; - end if; - end Insert_Library_Level_Actions; - - ---------------------- - -- Inside_Init_Proc -- - ---------------------- - - function Inside_Init_Proc return Boolean is - S : Entity_Id; - - begin - S := Current_Scope; - while Present (S) - and then S /= Standard_Standard - loop - if Is_Init_Proc (S) then - return True; - else - S := Scope (S); - end if; - end loop; - - return False; - end Inside_Init_Proc; - - ---------------------------- - -- Is_All_Null_Statements -- - ---------------------------- - - function Is_All_Null_Statements (L : List_Id) return Boolean is - Stm : Node_Id; - - begin - Stm := First (L); - while Present (Stm) loop - if Nkind (Stm) /= N_Null_Statement then - return False; - end if; - - Next (Stm); - end loop; - - return True; - end Is_All_Null_Statements; - - ---------------------------------- - -- Is_Library_Level_Tagged_Type -- - ---------------------------------- - - function Is_Library_Level_Tagged_Type (Typ : Entity_Id) return Boolean is - begin - return Is_Tagged_Type (Typ) - and then Is_Library_Level_Entity (Typ); - end Is_Library_Level_Tagged_Type; - - ---------------------------------- - -- Is_Possibly_Unaligned_Object -- - ---------------------------------- - - function Is_Possibly_Unaligned_Object (N : Node_Id) return Boolean is - T : constant Entity_Id := Etype (N); - - begin - -- If renamed object, apply test to underlying object - - if Is_Entity_Name (N) - and then Is_Object (Entity (N)) - and then Present (Renamed_Object (Entity (N))) - then - return Is_Possibly_Unaligned_Object (Renamed_Object (Entity (N))); - end if; - - -- Tagged and controlled types and aliased types are always aligned, - -- as are concurrent types. - - if Is_Aliased (T) - or else Has_Controlled_Component (T) - or else Is_Concurrent_Type (T) - or else Is_Tagged_Type (T) - or else Is_Controlled (T) - then - return False; - end if; - - -- If this is an element of a packed array, may be unaligned - - if Is_Ref_To_Bit_Packed_Array (N) then - return True; - end if; - - -- Case of component reference - - if Nkind (N) = N_Selected_Component then - declare - P : constant Node_Id := Prefix (N); - C : constant Entity_Id := Entity (Selector_Name (N)); - M : Nat; - S : Nat; - - begin - -- If component reference is for an array with non-static bounds, - -- then it is always aligned: we can only process unaligned - -- arrays with static bounds (more accurately bounds known at - -- compile time). - - if Is_Array_Type (T) - and then not Compile_Time_Known_Bounds (T) - then - return False; - end if; - - -- If component is aliased, it is definitely properly aligned - - if Is_Aliased (C) then - return False; - end if; - - -- If component is for a type implemented as a scalar, and the - -- record is packed, and the component is other than the first - -- component of the record, then the component may be unaligned. - - if Is_Packed (Etype (P)) - and then Represented_As_Scalar (Etype (C)) - and then First_Entity (Scope (C)) /= C - then - return True; - end if; - - -- Compute maximum possible alignment for T - - -- If alignment is known, then that settles things - - if Known_Alignment (T) then - M := UI_To_Int (Alignment (T)); - - -- If alignment is not known, tentatively set max alignment - - else - M := Ttypes.Maximum_Alignment; - - -- We can reduce this if the Esize is known since the default - -- alignment will never be more than the smallest power of 2 - -- that does not exceed this Esize value. - - if Known_Esize (T) then - S := UI_To_Int (Esize (T)); - - while (M / 2) >= S loop - M := M / 2; - end loop; - end if; - end if; - - -- If the component reference is for a record that has a specified - -- alignment, and we either know it is too small, or cannot tell, - -- then the component may be unaligned - - if Known_Alignment (Etype (P)) - and then Alignment (Etype (P)) < Ttypes.Maximum_Alignment - and then M > Alignment (Etype (P)) - then - return True; - end if; - - -- Case of component clause present which may specify an - -- unaligned position. - - if Present (Component_Clause (C)) then - - -- Otherwise we can do a test to make sure that the actual - -- start position in the record, and the length, are both - -- consistent with the required alignment. If not, we know - -- that we are unaligned. - - declare - Align_In_Bits : constant Nat := M * System_Storage_Unit; - begin - if Component_Bit_Offset (C) mod Align_In_Bits /= 0 - or else Esize (C) mod Align_In_Bits /= 0 - then - return True; - end if; - end; - end if; - - -- Otherwise, for a component reference, test prefix - - return Is_Possibly_Unaligned_Object (P); - end; - - -- If not a component reference, must be aligned - - else - return False; - end if; - end Is_Possibly_Unaligned_Object; - - --------------------------------- - -- Is_Possibly_Unaligned_Slice -- - --------------------------------- - - function Is_Possibly_Unaligned_Slice (N : Node_Id) return Boolean is - begin - -- Go to renamed object - - if Is_Entity_Name (N) - and then Is_Object (Entity (N)) - and then Present (Renamed_Object (Entity (N))) - then - return Is_Possibly_Unaligned_Slice (Renamed_Object (Entity (N))); - end if; - - -- The reference must be a slice - - if Nkind (N) /= N_Slice then - return False; - end if; - - -- Always assume the worst for a nested record component with a - -- component clause, which gigi/gcc does not appear to handle well. - -- It is not clear why this special test is needed at all ??? - - if Nkind (Prefix (N)) = N_Selected_Component - and then Nkind (Prefix (Prefix (N))) = N_Selected_Component - and then - Present (Component_Clause (Entity (Selector_Name (Prefix (N))))) - then - return True; - end if; - - -- We only need to worry if the target has strict alignment - - if not Target_Strict_Alignment then - return False; - end if; - - -- If it is a slice, then look at the array type being sliced - - declare - Sarr : constant Node_Id := Prefix (N); - -- Prefix of the slice, i.e. the array being sliced - - Styp : constant Entity_Id := Etype (Prefix (N)); - -- Type of the array being sliced - - Pref : Node_Id; - Ptyp : Entity_Id; - - begin - -- The problems arise if the array object that is being sliced - -- is a component of a record or array, and we cannot guarantee - -- the alignment of the array within its containing object. - - -- To investigate this, we look at successive prefixes to see - -- if we have a worrisome indexed or selected component. - - Pref := Sarr; - loop - -- Case of array is part of an indexed component reference - - if Nkind (Pref) = N_Indexed_Component then - Ptyp := Etype (Prefix (Pref)); - - -- The only problematic case is when the array is packed, - -- in which case we really know nothing about the alignment - -- of individual components. - - if Is_Bit_Packed_Array (Ptyp) then - return True; - end if; - - -- Case of array is part of a selected component reference - - elsif Nkind (Pref) = N_Selected_Component then - Ptyp := Etype (Prefix (Pref)); - - -- We are definitely in trouble if the record in question - -- has an alignment, and either we know this alignment is - -- inconsistent with the alignment of the slice, or we - -- don't know what the alignment of the slice should be. - - if Known_Alignment (Ptyp) - and then (Unknown_Alignment (Styp) - or else Alignment (Styp) > Alignment (Ptyp)) - then - return True; - end if; - - -- We are in potential trouble if the record type is packed. - -- We could special case when we know that the array is the - -- first component, but that's not such a simple case ??? - - if Is_Packed (Ptyp) then - return True; - end if; - - -- We are in trouble if there is a component clause, and - -- either we do not know the alignment of the slice, or - -- the alignment of the slice is inconsistent with the - -- bit position specified by the component clause. - - declare - Field : constant Entity_Id := Entity (Selector_Name (Pref)); - begin - if Present (Component_Clause (Field)) - and then - (Unknown_Alignment (Styp) - or else - (Component_Bit_Offset (Field) mod - (System_Storage_Unit * Alignment (Styp))) /= 0) - then - return True; - end if; - end; - - -- For cases other than selected or indexed components we - -- know we are OK, since no issues arise over alignment. - - else - return False; - end if; - - -- We processed an indexed component or selected component - -- reference that looked safe, so keep checking prefixes. - - Pref := Prefix (Pref); - end loop; - end; - end Is_Possibly_Unaligned_Slice; - - -------------------------------- - -- Is_Ref_To_Bit_Packed_Array -- - -------------------------------- - - function Is_Ref_To_Bit_Packed_Array (N : Node_Id) return Boolean is - Result : Boolean; - Expr : Node_Id; - - begin - if Is_Entity_Name (N) - and then Is_Object (Entity (N)) - and then Present (Renamed_Object (Entity (N))) - then - return Is_Ref_To_Bit_Packed_Array (Renamed_Object (Entity (N))); - end if; - - if Nkind (N) = N_Indexed_Component - or else - Nkind (N) = N_Selected_Component - then - if Is_Bit_Packed_Array (Etype (Prefix (N))) then - Result := True; - else - Result := Is_Ref_To_Bit_Packed_Array (Prefix (N)); - end if; - - if Result and then Nkind (N) = N_Indexed_Component then - Expr := First (Expressions (N)); - while Present (Expr) loop - Force_Evaluation (Expr); - Next (Expr); - end loop; - end if; - - return Result; - - else - return False; - end if; - end Is_Ref_To_Bit_Packed_Array; - - -------------------------------- - -- Is_Ref_To_Bit_Packed_Slice -- - -------------------------------- - - function Is_Ref_To_Bit_Packed_Slice (N : Node_Id) return Boolean is - begin - if Nkind (N) = N_Type_Conversion then - return Is_Ref_To_Bit_Packed_Slice (Expression (N)); - - elsif Is_Entity_Name (N) - and then Is_Object (Entity (N)) - and then Present (Renamed_Object (Entity (N))) - then - return Is_Ref_To_Bit_Packed_Slice (Renamed_Object (Entity (N))); - - elsif Nkind (N) = N_Slice - and then Is_Bit_Packed_Array (Etype (Prefix (N))) - then - return True; - - elsif Nkind (N) = N_Indexed_Component - or else - Nkind (N) = N_Selected_Component - then - return Is_Ref_To_Bit_Packed_Slice (Prefix (N)); - - else - return False; - end if; - end Is_Ref_To_Bit_Packed_Slice; - - ----------------------- - -- Is_Renamed_Object -- - ----------------------- - - function Is_Renamed_Object (N : Node_Id) return Boolean is - Pnod : constant Node_Id := Parent (N); - Kind : constant Node_Kind := Nkind (Pnod); - - begin - if Kind = N_Object_Renaming_Declaration then - return True; - - elsif Kind = N_Indexed_Component - or else Kind = N_Selected_Component - then - return Is_Renamed_Object (Pnod); - - else - return False; - end if; - end Is_Renamed_Object; - - ---------------------------- - -- Is_Untagged_Derivation -- - ---------------------------- - - function Is_Untagged_Derivation (T : Entity_Id) return Boolean is - begin - return (not Is_Tagged_Type (T) and then Is_Derived_Type (T)) - or else - (Is_Private_Type (T) and then Present (Full_View (T)) - and then not Is_Tagged_Type (Full_View (T)) - and then Is_Derived_Type (Full_View (T)) - and then Etype (Full_View (T)) /= T); - end Is_Untagged_Derivation; - - --------------------------- - -- Is_Volatile_Reference -- - --------------------------- - - function Is_Volatile_Reference (N : Node_Id) return Boolean is - begin - if Nkind (N) in N_Has_Etype - and then Present (Etype (N)) - and then Treat_As_Volatile (Etype (N)) - then - return True; - - elsif Is_Entity_Name (N) then - return Treat_As_Volatile (Entity (N)); - - elsif Nkind (N) = N_Slice then - return Is_Volatile_Reference (Prefix (N)); - - elsif Nkind_In (N, N_Indexed_Component, N_Selected_Component) then - if (Is_Entity_Name (Prefix (N)) - and then Has_Volatile_Components (Entity (Prefix (N)))) - or else (Present (Etype (Prefix (N))) - and then Has_Volatile_Components (Etype (Prefix (N)))) - then - return True; - else - return Is_Volatile_Reference (Prefix (N)); - end if; - - else - return False; - end if; - end Is_Volatile_Reference; - - -------------------- - -- Kill_Dead_Code -- - -------------------- - - procedure Kill_Dead_Code (N : Node_Id; Warn : Boolean := False) is - begin - if Present (N) then - Remove_Warning_Messages (N); - - if Warn then - Error_Msg_F - ("?this code can never be executed and has been deleted!", N); - end if; - - -- Recurse into block statements and bodies to process declarations - -- and statements - - if Nkind (N) = N_Block_Statement - or else Nkind (N) = N_Subprogram_Body - or else Nkind (N) = N_Package_Body - then - Kill_Dead_Code (Declarations (N), False); - Kill_Dead_Code (Statements (Handled_Statement_Sequence (N))); - - if Nkind (N) = N_Subprogram_Body then - Set_Is_Eliminated (Defining_Entity (N)); - end if; - - elsif Nkind (N) = N_Package_Declaration then - Kill_Dead_Code (Visible_Declarations (Specification (N))); - Kill_Dead_Code (Private_Declarations (Specification (N))); - - -- ??? After this point, Delete_Tree has been called on all - -- declarations in Specification (N), so references to - -- entities therein look suspicious. - - declare - E : Entity_Id := First_Entity (Defining_Entity (N)); - begin - while Present (E) loop - if Ekind (E) = E_Operator then - Set_Is_Eliminated (E); - end if; - - Next_Entity (E); - end loop; - end; - - -- Recurse into composite statement to kill individual statements, - -- in particular instantiations. - - elsif Nkind (N) = N_If_Statement then - Kill_Dead_Code (Then_Statements (N)); - Kill_Dead_Code (Elsif_Parts (N)); - Kill_Dead_Code (Else_Statements (N)); - - elsif Nkind (N) = N_Loop_Statement then - Kill_Dead_Code (Statements (N)); - - elsif Nkind (N) = N_Case_Statement then - declare - Alt : Node_Id; - begin - Alt := First (Alternatives (N)); - while Present (Alt) loop - Kill_Dead_Code (Statements (Alt)); - Next (Alt); - end loop; - end; - - elsif Nkind (N) = N_Case_Statement_Alternative then - Kill_Dead_Code (Statements (N)); - - -- Deal with dead instances caused by deleting instantiations - - elsif Nkind (N) in N_Generic_Instantiation then - Remove_Dead_Instance (N); - end if; - end if; - end Kill_Dead_Code; - - -- Case where argument is a list of nodes to be killed - - procedure Kill_Dead_Code (L : List_Id; Warn : Boolean := False) is - N : Node_Id; - W : Boolean; - begin - W := Warn; - if Is_Non_Empty_List (L) then - N := First (L); - while Present (N) loop - Kill_Dead_Code (N, W); - W := False; - Next (N); - end loop; - end if; - end Kill_Dead_Code; - - ------------------------ - -- Known_Non_Negative -- - ------------------------ - - function Known_Non_Negative (Opnd : Node_Id) return Boolean is - begin - if Is_OK_Static_Expression (Opnd) - and then Expr_Value (Opnd) >= 0 - then - return True; - - else - declare - Lo : constant Node_Id := Type_Low_Bound (Etype (Opnd)); - - begin - return - Is_OK_Static_Expression (Lo) and then Expr_Value (Lo) >= 0; - end; - end if; - end Known_Non_Negative; - - -------------------- - -- Known_Non_Null -- - -------------------- - - function Known_Non_Null (N : Node_Id) return Boolean is - begin - -- Checks for case where N is an entity reference - - if Is_Entity_Name (N) and then Present (Entity (N)) then - declare - E : constant Entity_Id := Entity (N); - Op : Node_Kind; - Val : Node_Id; - - begin - -- First check if we are in decisive conditional - - Get_Current_Value_Condition (N, Op, Val); - - if Known_Null (Val) then - if Op = N_Op_Eq then - return False; - elsif Op = N_Op_Ne then - return True; - end if; - end if; - - -- If OK to do replacement, test Is_Known_Non_Null flag - - if OK_To_Do_Constant_Replacement (E) then - return Is_Known_Non_Null (E); - - -- Otherwise if not safe to do replacement, then say so - - else - return False; - end if; - end; - - -- True if access attribute - - elsif Nkind (N) = N_Attribute_Reference - and then (Attribute_Name (N) = Name_Access - or else - Attribute_Name (N) = Name_Unchecked_Access - or else - Attribute_Name (N) = Name_Unrestricted_Access) - then - return True; - - -- True if allocator - - elsif Nkind (N) = N_Allocator then - return True; - - -- For a conversion, true if expression is known non-null - - elsif Nkind (N) = N_Type_Conversion then - return Known_Non_Null (Expression (N)); - - -- Above are all cases where the value could be determined to be - -- non-null. In all other cases, we don't know, so return False. - - else - return False; - end if; - end Known_Non_Null; - - ---------------- - -- Known_Null -- - ---------------- - - function Known_Null (N : Node_Id) return Boolean is - begin - -- Checks for case where N is an entity reference - - if Is_Entity_Name (N) and then Present (Entity (N)) then - declare - E : constant Entity_Id := Entity (N); - Op : Node_Kind; - Val : Node_Id; - - begin - -- Constant null value is for sure null - - if Ekind (E) = E_Constant - and then Known_Null (Constant_Value (E)) - then - return True; - end if; - - -- First check if we are in decisive conditional - - Get_Current_Value_Condition (N, Op, Val); - - if Known_Null (Val) then - if Op = N_Op_Eq then - return True; - elsif Op = N_Op_Ne then - return False; - end if; - end if; - - -- If OK to do replacement, test Is_Known_Null flag - - if OK_To_Do_Constant_Replacement (E) then - return Is_Known_Null (E); - - -- Otherwise if not safe to do replacement, then say so - - else - return False; - end if; - end; - - -- True if explicit reference to null - - elsif Nkind (N) = N_Null then - return True; - - -- For a conversion, true if expression is known null - - elsif Nkind (N) = N_Type_Conversion then - return Known_Null (Expression (N)); - - -- Above are all cases where the value could be determined to be null. - -- In all other cases, we don't know, so return False. - - else - return False; - end if; - end Known_Null; - - ----------------------------- - -- Make_CW_Equivalent_Type -- - ----------------------------- - - -- Create a record type used as an equivalent of any member - -- of the class which takes its size from exp. - - -- Generate the following code: - - -- type Equiv_T is record - -- _parent : T (List of discriminant constraints taken from Exp); - -- Ext__50 : Storage_Array (1 .. (Exp'size - Typ'object_size)/8); - -- end Equiv_T; - -- - -- ??? Note that this type does not guarantee same alignment as all - -- derived types - - function Make_CW_Equivalent_Type - (T : Entity_Id; - E : Node_Id) return Entity_Id - is - Loc : constant Source_Ptr := Sloc (E); - Root_Typ : constant Entity_Id := Root_Type (T); - List_Def : constant List_Id := Empty_List; - Comp_List : constant List_Id := New_List; - Equiv_Type : Entity_Id; - Range_Type : Entity_Id; - Str_Type : Entity_Id; - Constr_Root : Entity_Id; - Sizexpr : Node_Id; - - begin - if not Has_Discriminants (Root_Typ) then - Constr_Root := Root_Typ; - else - Constr_Root := - Make_Defining_Identifier (Loc, New_Internal_Name ('R')); - - -- subtype cstr__n is T (List of discr constraints taken from Exp) - - Append_To (List_Def, - Make_Subtype_Declaration (Loc, - Defining_Identifier => Constr_Root, - Subtype_Indication => - Make_Subtype_From_Expr (E, Root_Typ))); - end if; - - -- Generate the range subtype declaration - - Range_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('G')); - - if not Is_Interface (Root_Typ) then - -- subtype rg__xx is - -- Storage_Offset range 1 .. (Expr'size - typ'size) / Storage_Unit - - Sizexpr := - Make_Op_Subtract (Loc, - Left_Opnd => - Make_Attribute_Reference (Loc, - Prefix => - OK_Convert_To (T, Duplicate_Subexpr_No_Checks (E)), - Attribute_Name => Name_Size), - Right_Opnd => - Make_Attribute_Reference (Loc, - Prefix => New_Reference_To (Constr_Root, Loc), - Attribute_Name => Name_Object_Size)); - else - -- subtype rg__xx is - -- Storage_Offset range 1 .. Expr'size / Storage_Unit - - Sizexpr := - Make_Attribute_Reference (Loc, - Prefix => - OK_Convert_To (T, Duplicate_Subexpr_No_Checks (E)), - Attribute_Name => Name_Size); - end if; - - Set_Paren_Count (Sizexpr, 1); - - Append_To (List_Def, - Make_Subtype_Declaration (Loc, - Defining_Identifier => Range_Type, - Subtype_Indication => - Make_Subtype_Indication (Loc, - Subtype_Mark => New_Reference_To (RTE (RE_Storage_Offset), Loc), - Constraint => Make_Range_Constraint (Loc, - Range_Expression => - Make_Range (Loc, - Low_Bound => Make_Integer_Literal (Loc, 1), - High_Bound => - Make_Op_Divide (Loc, - Left_Opnd => Sizexpr, - Right_Opnd => Make_Integer_Literal (Loc, - Intval => System_Storage_Unit))))))); - - -- subtype str__nn is Storage_Array (rg__x); - - Str_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('S')); - Append_To (List_Def, - Make_Subtype_Declaration (Loc, - Defining_Identifier => Str_Type, - Subtype_Indication => - Make_Subtype_Indication (Loc, - Subtype_Mark => New_Reference_To (RTE (RE_Storage_Array), Loc), - Constraint => - Make_Index_Or_Discriminant_Constraint (Loc, - Constraints => - New_List (New_Reference_To (Range_Type, Loc)))))); - - -- type Equiv_T is record - -- [ _parent : Tnn; ] - -- E : Str_Type; - -- end Equiv_T; - - Equiv_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('T')); - - -- When the target requires front-end layout, it's necessary to allow - -- the equivalent type to be frozen so that layout can occur (when the - -- associated class-wide subtype is frozen, the equivalent type will - -- be frozen, see freeze.adb). For other targets, Gigi wants to have - -- the equivalent type marked as frozen and deals with this type itself. - -- In the Gigi case this will also avoid the generation of an init - -- procedure for the type. - - if not Frontend_Layout_On_Target then - Set_Is_Frozen (Equiv_Type); - end if; - - Set_Ekind (Equiv_Type, E_Record_Type); - Set_Parent_Subtype (Equiv_Type, Constr_Root); - - if not Is_Interface (Root_Typ) then - Append_To (Comp_List, - Make_Component_Declaration (Loc, - Defining_Identifier => - Make_Defining_Identifier (Loc, Name_uParent), - Component_Definition => - Make_Component_Definition (Loc, - Aliased_Present => False, - Subtype_Indication => New_Reference_To (Constr_Root, Loc)))); - end if; - - Append_To (Comp_List, - Make_Component_Declaration (Loc, - Defining_Identifier => - Make_Defining_Identifier (Loc, - Chars => New_Internal_Name ('C')), - Component_Definition => - Make_Component_Definition (Loc, - Aliased_Present => False, - Subtype_Indication => New_Reference_To (Str_Type, Loc)))); - - Append_To (List_Def, - Make_Full_Type_Declaration (Loc, - Defining_Identifier => Equiv_Type, - Type_Definition => - Make_Record_Definition (Loc, - Component_List => - Make_Component_List (Loc, - Component_Items => Comp_List, - Variant_Part => Empty)))); - - -- Suppress all checks during the analysis of the expanded code - -- to avoid the generation of spurious warnings under ZFP run-time. - - Insert_Actions (E, List_Def, Suppress => All_Checks); - return Equiv_Type; - end Make_CW_Equivalent_Type; - - ------------------------ - -- Make_Literal_Range -- - ------------------------ - - function Make_Literal_Range - (Loc : Source_Ptr; - Literal_Typ : Entity_Id) return Node_Id - is - Lo : constant Node_Id := - New_Copy_Tree (String_Literal_Low_Bound (Literal_Typ)); - Index : constant Entity_Id := Etype (Lo); - - Hi : Node_Id; - Length_Expr : constant Node_Id := - Make_Op_Subtract (Loc, - Left_Opnd => - Make_Integer_Literal (Loc, - Intval => String_Literal_Length (Literal_Typ)), - Right_Opnd => - Make_Integer_Literal (Loc, 1)); - - begin - Set_Analyzed (Lo, False); - - if Is_Integer_Type (Index) then - Hi := - Make_Op_Add (Loc, - Left_Opnd => New_Copy_Tree (Lo), - Right_Opnd => Length_Expr); - else - Hi := - Make_Attribute_Reference (Loc, - Attribute_Name => Name_Val, - Prefix => New_Occurrence_Of (Index, Loc), - Expressions => New_List ( - Make_Op_Add (Loc, - Left_Opnd => - Make_Attribute_Reference (Loc, - Attribute_Name => Name_Pos, - Prefix => New_Occurrence_Of (Index, Loc), - Expressions => New_List (New_Copy_Tree (Lo))), - Right_Opnd => Length_Expr))); - end if; - - return - Make_Range (Loc, - Low_Bound => Lo, - High_Bound => Hi); - end Make_Literal_Range; - - ---------------------------- - -- Make_Subtype_From_Expr -- - ---------------------------- - - -- 1. If Expr is an unconstrained array expression, creates - -- Unc_Type(Expr'first(1)..Expr'last(1),..., Expr'first(n)..Expr'last(n)) - - -- 2. If Expr is a unconstrained discriminated type expression, creates - -- Unc_Type(Expr.Discr1, ... , Expr.Discr_n) - - -- 3. If Expr is class-wide, creates an implicit class wide subtype - - function Make_Subtype_From_Expr - (E : Node_Id; - Unc_Typ : Entity_Id) return Node_Id - is - Loc : constant Source_Ptr := Sloc (E); - List_Constr : constant List_Id := New_List; - D : Entity_Id; - - Full_Subtyp : Entity_Id; - Priv_Subtyp : Entity_Id; - Utyp : Entity_Id; - Full_Exp : Node_Id; - - begin - if Is_Private_Type (Unc_Typ) - and then Has_Unknown_Discriminants (Unc_Typ) - then - -- Prepare the subtype completion, Go to base type to - -- find underlying type, because the type may be a generic - -- actual or an explicit subtype. - - Utyp := Underlying_Type (Base_Type (Unc_Typ)); - Full_Subtyp := Make_Defining_Identifier (Loc, - New_Internal_Name ('C')); - Full_Exp := - Unchecked_Convert_To - (Utyp, Duplicate_Subexpr_No_Checks (E)); - Set_Parent (Full_Exp, Parent (E)); - - Priv_Subtyp := - Make_Defining_Identifier (Loc, New_Internal_Name ('P')); - - Insert_Action (E, - Make_Subtype_Declaration (Loc, - Defining_Identifier => Full_Subtyp, - Subtype_Indication => Make_Subtype_From_Expr (Full_Exp, Utyp))); - - -- Define the dummy private subtype - - Set_Ekind (Priv_Subtyp, Subtype_Kind (Ekind (Unc_Typ))); - Set_Etype (Priv_Subtyp, Base_Type (Unc_Typ)); - Set_Scope (Priv_Subtyp, Full_Subtyp); - Set_Is_Constrained (Priv_Subtyp); - Set_Is_Tagged_Type (Priv_Subtyp, Is_Tagged_Type (Unc_Typ)); - Set_Is_Itype (Priv_Subtyp); - Set_Associated_Node_For_Itype (Priv_Subtyp, E); - - if Is_Tagged_Type (Priv_Subtyp) then - Set_Class_Wide_Type - (Base_Type (Priv_Subtyp), Class_Wide_Type (Unc_Typ)); - Set_Primitive_Operations (Priv_Subtyp, - Primitive_Operations (Unc_Typ)); - end if; - - Set_Full_View (Priv_Subtyp, Full_Subtyp); - - return New_Reference_To (Priv_Subtyp, Loc); - - elsif Is_Array_Type (Unc_Typ) then - for J in 1 .. Number_Dimensions (Unc_Typ) loop - Append_To (List_Constr, - Make_Range (Loc, - Low_Bound => - Make_Attribute_Reference (Loc, - Prefix => Duplicate_Subexpr_No_Checks (E), - Attribute_Name => Name_First, - Expressions => New_List ( - Make_Integer_Literal (Loc, J))), - - High_Bound => - Make_Attribute_Reference (Loc, - Prefix => Duplicate_Subexpr_No_Checks (E), - Attribute_Name => Name_Last, - Expressions => New_List ( - Make_Integer_Literal (Loc, J))))); - end loop; - - elsif Is_Class_Wide_Type (Unc_Typ) then - declare - CW_Subtype : Entity_Id; - EQ_Typ : Entity_Id := Empty; - - begin - -- A class-wide equivalent type is not needed when VM_Target - -- because the VM back-ends handle the class-wide object - -- initialization itself (and doesn't need or want the - -- additional intermediate type to handle the assignment). - - if Expander_Active and then VM_Target = No_VM then - EQ_Typ := Make_CW_Equivalent_Type (Unc_Typ, E); - end if; - - CW_Subtype := New_Class_Wide_Subtype (Unc_Typ, E); - Set_Equivalent_Type (CW_Subtype, EQ_Typ); - - if Present (EQ_Typ) then - Set_Is_Class_Wide_Equivalent_Type (EQ_Typ); - end if; - - Set_Cloned_Subtype (CW_Subtype, Base_Type (Unc_Typ)); - - return New_Occurrence_Of (CW_Subtype, Loc); - end; - - -- Indefinite record type with discriminants - - else - D := First_Discriminant (Unc_Typ); - while Present (D) loop - Append_To (List_Constr, - Make_Selected_Component (Loc, - Prefix => Duplicate_Subexpr_No_Checks (E), - Selector_Name => New_Reference_To (D, Loc))); - - Next_Discriminant (D); - end loop; - end if; - - return - Make_Subtype_Indication (Loc, - Subtype_Mark => New_Reference_To (Unc_Typ, Loc), - Constraint => - Make_Index_Or_Discriminant_Constraint (Loc, - Constraints => List_Constr)); - end Make_Subtype_From_Expr; - - ----------------------------- - -- May_Generate_Large_Temp -- - ----------------------------- - - -- At the current time, the only types that we return False for (i.e. - -- where we decide we know they cannot generate large temps) are ones - -- where we know the size is 256 bits or less at compile time, and we - -- are still not doing a thorough job on arrays and records ??? - - function May_Generate_Large_Temp (Typ : Entity_Id) return Boolean is - begin - if not Size_Known_At_Compile_Time (Typ) then - return False; - - elsif Esize (Typ) /= 0 and then Esize (Typ) <= 256 then - return False; - - elsif Is_Array_Type (Typ) - and then Present (Packed_Array_Type (Typ)) - then - return May_Generate_Large_Temp (Packed_Array_Type (Typ)); - - -- We could do more here to find other small types ??? - - else - return True; - end if; - end May_Generate_Large_Temp; - - ---------------------------- - -- New_Class_Wide_Subtype -- - ---------------------------- - - function New_Class_Wide_Subtype - (CW_Typ : Entity_Id; - N : Node_Id) return Entity_Id - is - Res : constant Entity_Id := Create_Itype (E_Void, N); - Res_Name : constant Name_Id := Chars (Res); - Res_Scope : constant Entity_Id := Scope (Res); - - begin - Copy_Node (CW_Typ, Res); - Set_Comes_From_Source (Res, False); - Set_Sloc (Res, Sloc (N)); - Set_Is_Itype (Res); - Set_Associated_Node_For_Itype (Res, N); - Set_Is_Public (Res, False); -- By default, may be changed below. - Set_Public_Status (Res); - Set_Chars (Res, Res_Name); - Set_Scope (Res, Res_Scope); - Set_Ekind (Res, E_Class_Wide_Subtype); - Set_Next_Entity (Res, Empty); - Set_Etype (Res, Base_Type (CW_Typ)); - - -- For targets where front-end layout is required, reset the Is_Frozen - -- status of the subtype to False (it can be implicitly set to true - -- from the copy of the class-wide type). For other targets, Gigi - -- doesn't want the class-wide subtype to go through the freezing - -- process (though it's unclear why that causes problems and it would - -- be nice to allow freezing to occur normally for all targets ???). - - if Frontend_Layout_On_Target then - Set_Is_Frozen (Res, False); - end if; - - Set_Freeze_Node (Res, Empty); - return (Res); - end New_Class_Wide_Subtype; - - -------------------------------- - -- Non_Limited_Designated_Type -- - --------------------------------- - - function Non_Limited_Designated_Type (T : Entity_Id) return Entity_Id is - Desig : constant Entity_Id := Designated_Type (T); - begin - if Ekind (Desig) = E_Incomplete_Type - and then Present (Non_Limited_View (Desig)) - then - return Non_Limited_View (Desig); - else - return Desig; - end if; - end Non_Limited_Designated_Type; - - ----------------------------------- - -- OK_To_Do_Constant_Replacement -- - ----------------------------------- - - function OK_To_Do_Constant_Replacement (E : Entity_Id) return Boolean is - ES : constant Entity_Id := Scope (E); - CS : Entity_Id; - - begin - -- Do not replace statically allocated objects, because they may be - -- modified outside the current scope. - - if Is_Statically_Allocated (E) then - return False; - - -- Do not replace aliased or volatile objects, since we don't know what - -- else might change the value. - - elsif Is_Aliased (E) or else Treat_As_Volatile (E) then - return False; - - -- Debug flag -gnatdM disconnects this optimization - - elsif Debug_Flag_MM then - return False; - - -- Otherwise check scopes - - else - CS := Current_Scope; - - loop - -- If we are in right scope, replacement is safe - - if CS = ES then - return True; - - -- Packages do not affect the determination of safety - - elsif Ekind (CS) = E_Package then - exit when CS = Standard_Standard; - CS := Scope (CS); - - -- Blocks do not affect the determination of safety - - elsif Ekind (CS) = E_Block then - CS := Scope (CS); - - -- Loops do not affect the determination of safety. Note that we - -- kill all current values on entry to a loop, so we are just - -- talking about processing within a loop here. - - elsif Ekind (CS) = E_Loop then - CS := Scope (CS); - - -- Otherwise, the reference is dubious, and we cannot be sure that - -- it is safe to do the replacement. - - else - exit; - end if; - end loop; - - return False; - end if; - end OK_To_Do_Constant_Replacement; - - ------------------------------------ - -- Possible_Bit_Aligned_Component -- - ------------------------------------ - - function Possible_Bit_Aligned_Component (N : Node_Id) return Boolean is - begin - case Nkind (N) is - - -- Case of indexed component - - when N_Indexed_Component => - declare - P : constant Node_Id := Prefix (N); - Ptyp : constant Entity_Id := Etype (P); - - begin - -- If we know the component size and it is less than 64, then - -- we are definitely OK. The back end always does assignment of - -- misaligned small objects correctly. - - if Known_Static_Component_Size (Ptyp) - and then Component_Size (Ptyp) <= 64 - then - return False; - - -- Otherwise, we need to test the prefix, to see if we are - -- indexing from a possibly unaligned component. - - else - return Possible_Bit_Aligned_Component (P); - end if; - end; - - -- Case of selected component - - when N_Selected_Component => - declare - P : constant Node_Id := Prefix (N); - Comp : constant Entity_Id := Entity (Selector_Name (N)); - - begin - -- If there is no component clause, then we are in the clear - -- since the back end will never misalign a large component - -- unless it is forced to do so. In the clear means we need - -- only the recursive test on the prefix. - - if Component_May_Be_Bit_Aligned (Comp) then - return True; - else - return Possible_Bit_Aligned_Component (P); - end if; - end; - - -- For a slice, test the prefix, if that is possibly misaligned, - -- then for sure the slice is! - - when N_Slice => - return Possible_Bit_Aligned_Component (Prefix (N)); - - -- If we have none of the above, it means that we have fallen off the - -- top testing prefixes recursively, and we now have a stand alone - -- object, where we don't have a problem. - - when others => - return False; - - end case; - end Possible_Bit_Aligned_Component; - - ------------------------- - -- Remove_Side_Effects -- - ------------------------- - - procedure Remove_Side_Effects - (Exp : Node_Id; - Name_Req : Boolean := False; - Variable_Ref : Boolean := False) - is - Loc : constant Source_Ptr := Sloc (Exp); - Exp_Type : constant Entity_Id := Etype (Exp); - Svg_Suppress : constant Suppress_Array := Scope_Suppress; - Def_Id : Entity_Id; - Ref_Type : Entity_Id; - Res : Node_Id; - Ptr_Typ_Decl : Node_Id; - New_Exp : Node_Id; - E : Node_Id; - - function Side_Effect_Free (N : Node_Id) return Boolean; - -- Determines if the tree N represents an expression that is known not - -- to have side effects, and for which no processing is required. - - function Side_Effect_Free (L : List_Id) return Boolean; - -- Determines if all elements of the list L are side effect free - - function Safe_Prefixed_Reference (N : Node_Id) return Boolean; - -- The argument N is a construct where the Prefix is dereferenced if it - -- is an access type and the result is a variable. The call returns True - -- if the construct is side effect free (not considering side effects in - -- other than the prefix which are to be tested by the caller). - - function Within_In_Parameter (N : Node_Id) return Boolean; - -- Determines if N is a subcomponent of a composite in-parameter. If so, - -- N is not side-effect free when the actual is global and modifiable - -- indirectly from within a subprogram, because it may be passed by - -- reference. The front-end must be conservative here and assume that - -- this may happen with any array or record type. On the other hand, we - -- cannot create temporaries for all expressions for which this - -- condition is true, for various reasons that might require clearing up - -- ??? For example, discriminant references that appear out of place, or - -- spurious type errors with class-wide expressions. As a result, we - -- limit the transformation to loop bounds, which is so far the only - -- case that requires it. - - ----------------------------- - -- Safe_Prefixed_Reference -- - ----------------------------- - - function Safe_Prefixed_Reference (N : Node_Id) return Boolean is - begin - -- If prefix is not side effect free, definitely not safe - - if not Side_Effect_Free (Prefix (N)) then - return False; - - -- If the prefix is of an access type that is not access-to-constant, - -- then this construct is a variable reference, which means it is to - -- be considered to have side effects if Variable_Ref is set True - -- Exception is an access to an entity that is a constant or an - -- in-parameter which does not come from source, and is the result - -- of a previous removal of side-effects. - - elsif Is_Access_Type (Etype (Prefix (N))) - and then not Is_Access_Constant (Etype (Prefix (N))) - and then Variable_Ref - then - if not Is_Entity_Name (Prefix (N)) then - return False; - else - return Ekind (Entity (Prefix (N))) = E_Constant - or else Ekind (Entity (Prefix (N))) = E_In_Parameter; - end if; - - -- The following test is the simplest way of solving a complex - -- problem uncovered by BB08-010: Side effect on loop bound that - -- is a subcomponent of a global variable: - -- If a loop bound is a subcomponent of a global variable, a - -- modification of that variable within the loop may incorrectly - -- affect the execution of the loop. - - elsif not - (Nkind (Parent (Parent (N))) /= N_Loop_Parameter_Specification - or else not Within_In_Parameter (Prefix (N))) - then - return False; - - -- All other cases are side effect free - - else - return True; - end if; - end Safe_Prefixed_Reference; - - ---------------------- - -- Side_Effect_Free -- - ---------------------- - - function Side_Effect_Free (N : Node_Id) return Boolean is - begin - -- Note on checks that could raise Constraint_Error. Strictly, if - -- we take advantage of 11.6, these checks do not count as side - -- effects. However, we would just as soon consider that they are - -- side effects, since the backend CSE does not work very well on - -- expressions which can raise Constraint_Error. On the other - -- hand, if we do not consider them to be side effect free, then - -- we get some awkward expansions in -gnato mode, resulting in - -- code insertions at a point where we do not have a clear model - -- for performing the insertions. - - -- Special handling for entity names - - if Is_Entity_Name (N) then - - -- If the entity is a constant, it is definitely side effect - -- free. Note that the test of Is_Variable (N) below might - -- be expected to catch this case, but it does not, because - -- this test goes to the original tree, and we may have - -- already rewritten a variable node with a constant as - -- a result of an earlier Force_Evaluation call. - - if Ekind (Entity (N)) = E_Constant - or else Ekind (Entity (N)) = E_In_Parameter - then - return True; - - -- Functions are not side effect free - - elsif Ekind (Entity (N)) = E_Function then - return False; - - -- Variables are considered to be a side effect if Variable_Ref - -- is set or if we have a volatile reference and Name_Req is off. - -- If Name_Req is True then we can't help returning a name which - -- effectively allows multiple references in any case. - - elsif Is_Variable (N) then - return not Variable_Ref - and then (not Is_Volatile_Reference (N) or else Name_Req); - - -- Any other entity (e.g. a subtype name) is definitely side - -- effect free. - - else - return True; - end if; - - -- A value known at compile time is always side effect free - - elsif Compile_Time_Known_Value (N) then - return True; - - -- A variable renaming is not side-effect free, because the - -- renaming will function like a macro in the front-end in - -- some cases, and an assignment can modify the component - -- designated by N, so we need to create a temporary for it. - - elsif Is_Entity_Name (Original_Node (N)) - and then Is_Renaming_Of_Object (Entity (Original_Node (N))) - and then Ekind (Entity (Original_Node (N))) /= E_Constant - then - return False; - end if; - - -- For other than entity names and compile time known values, - -- check the node kind for special processing. - - case Nkind (N) is - - -- An attribute reference is side effect free if its expressions - -- are side effect free and its prefix is side effect free or - -- is an entity reference. - - -- Is this right? what about x'first where x is a variable??? - - when N_Attribute_Reference => - return Side_Effect_Free (Expressions (N)) - and then Attribute_Name (N) /= Name_Input - and then (Is_Entity_Name (Prefix (N)) - or else Side_Effect_Free (Prefix (N))); - - -- A binary operator is side effect free if and both operands - -- are side effect free. For this purpose binary operators - -- include membership tests and short circuit forms - - when N_Binary_Op | - N_Membership_Test | - N_And_Then | - N_Or_Else => - return Side_Effect_Free (Left_Opnd (N)) - and then Side_Effect_Free (Right_Opnd (N)); - - -- An explicit dereference is side effect free only if it is - -- a side effect free prefixed reference. - - when N_Explicit_Dereference => - return Safe_Prefixed_Reference (N); - - -- A call to _rep_to_pos is side effect free, since we generate - -- this pure function call ourselves. Moreover it is critically - -- important to make this exception, since otherwise we can - -- have discriminants in array components which don't look - -- side effect free in the case of an array whose index type - -- is an enumeration type with an enumeration rep clause. - - -- All other function calls are not side effect free - - when N_Function_Call => - return Nkind (Name (N)) = N_Identifier - and then Is_TSS (Name (N), TSS_Rep_To_Pos) - and then - Side_Effect_Free (First (Parameter_Associations (N))); - - -- An indexed component is side effect free if it is a side - -- effect free prefixed reference and all the indexing - -- expressions are side effect free. - - when N_Indexed_Component => - return Side_Effect_Free (Expressions (N)) - and then Safe_Prefixed_Reference (N); - - -- A type qualification is side effect free if the expression - -- is side effect free. - - when N_Qualified_Expression => - return Side_Effect_Free (Expression (N)); - - -- A selected component is side effect free only if it is a - -- side effect free prefixed reference. If it designates a - -- component with a rep. clause it must be treated has having - -- a potential side effect, because it may be modified through - -- a renaming, and a subsequent use of the renaming as a macro - -- will yield the wrong value. This complex interaction between - -- renaming and removing side effects is a reminder that the - -- latter has become a headache to maintain, and that it should - -- be removed in favor of the gcc mechanism to capture values ??? - - when N_Selected_Component => - if Nkind (Parent (N)) = N_Explicit_Dereference - and then Has_Non_Standard_Rep (Designated_Type (Etype (N))) - then - return False; - else - return Safe_Prefixed_Reference (N); - end if; - - -- A range is side effect free if the bounds are side effect free - - when N_Range => - return Side_Effect_Free (Low_Bound (N)) - and then Side_Effect_Free (High_Bound (N)); - - -- A slice is side effect free if it is a side effect free - -- prefixed reference and the bounds are side effect free. - - when N_Slice => - return Side_Effect_Free (Discrete_Range (N)) - and then Safe_Prefixed_Reference (N); - - -- A type conversion is side effect free if the expression to be - -- converted is side effect free. - - when N_Type_Conversion => - return Side_Effect_Free (Expression (N)); - - -- A unary operator is side effect free if the operand - -- is side effect free. - - when N_Unary_Op => - return Side_Effect_Free (Right_Opnd (N)); - - -- An unchecked type conversion is side effect free only if it - -- is safe and its argument is side effect free. - - when N_Unchecked_Type_Conversion => - return Safe_Unchecked_Type_Conversion (N) - and then Side_Effect_Free (Expression (N)); - - -- An unchecked expression is side effect free if its expression - -- is side effect free. - - when N_Unchecked_Expression => - return Side_Effect_Free (Expression (N)); - - -- A literal is side effect free - - when N_Character_Literal | - N_Integer_Literal | - N_Real_Literal | - N_String_Literal => - return True; - - -- We consider that anything else has side effects. This is a bit - -- crude, but we are pretty close for most common cases, and we - -- are certainly correct (i.e. we never return True when the - -- answer should be False). - - when others => - return False; - end case; - end Side_Effect_Free; - - -- A list is side effect free if all elements of the list are - -- side effect free. - - function Side_Effect_Free (L : List_Id) return Boolean is - N : Node_Id; - - begin - if L = No_List or else L = Error_List then - return True; - - else - N := First (L); - while Present (N) loop - if not Side_Effect_Free (N) then - return False; - else - Next (N); - end if; - end loop; - - return True; - end if; - end Side_Effect_Free; - - ------------------------- - -- Within_In_Parameter -- - ------------------------- - - function Within_In_Parameter (N : Node_Id) return Boolean is - begin - if not Comes_From_Source (N) then - return False; - - elsif Is_Entity_Name (N) then - return Ekind (Entity (N)) = E_In_Parameter; - - elsif Nkind (N) = N_Indexed_Component - or else Nkind (N) = N_Selected_Component - then - return Within_In_Parameter (Prefix (N)); - else - - return False; - end if; - end Within_In_Parameter; - - -- Start of processing for Remove_Side_Effects - - begin - -- If we are side effect free already or expansion is disabled, - -- there is nothing to do. - - if Side_Effect_Free (Exp) or else not Expander_Active then - return; - end if; - - -- All this must not have any checks - - Scope_Suppress := (others => True); - - -- If it is a scalar type and we need to capture the value, just make - -- a copy. Likewise for a function call, an attribute reference or an - -- operator. And if we have a volatile reference and Name_Req is not - -- set (see comments above for Side_Effect_Free). - - if Is_Elementary_Type (Exp_Type) - and then (Variable_Ref - or else Nkind (Exp) = N_Function_Call - or else Nkind (Exp) = N_Attribute_Reference - or else Nkind (Exp) in N_Op - or else (not Name_Req and then Is_Volatile_Reference (Exp))) - then - Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R')); - Set_Etype (Def_Id, Exp_Type); - Res := New_Reference_To (Def_Id, Loc); - - E := - Make_Object_Declaration (Loc, - Defining_Identifier => Def_Id, - Object_Definition => New_Reference_To (Exp_Type, Loc), - Constant_Present => True, - Expression => Relocate_Node (Exp)); - - Set_Assignment_OK (E); - Insert_Action (Exp, E); - - -- If the expression has the form v.all then we can just capture - -- the pointer, and then do an explicit dereference on the result. - - elsif Nkind (Exp) = N_Explicit_Dereference then - Def_Id := - Make_Defining_Identifier (Loc, New_Internal_Name ('R')); - Res := - Make_Explicit_Dereference (Loc, New_Reference_To (Def_Id, Loc)); - - Insert_Action (Exp, - Make_Object_Declaration (Loc, - Defining_Identifier => Def_Id, - Object_Definition => - New_Reference_To (Etype (Prefix (Exp)), Loc), - Constant_Present => True, - Expression => Relocate_Node (Prefix (Exp)))); - - -- Similar processing for an unchecked conversion of an expression - -- of the form v.all, where we want the same kind of treatment. - - elsif Nkind (Exp) = N_Unchecked_Type_Conversion - and then Nkind (Expression (Exp)) = N_Explicit_Dereference - then - Remove_Side_Effects (Expression (Exp), Name_Req, Variable_Ref); - Scope_Suppress := Svg_Suppress; - return; - - -- If this is a type conversion, leave the type conversion and remove - -- the side effects in the expression. This is important in several - -- circumstances: for change of representations, and also when this is - -- a view conversion to a smaller object, where gigi can end up creating - -- its own temporary of the wrong size. - - elsif Nkind (Exp) = N_Type_Conversion then - Remove_Side_Effects (Expression (Exp), Name_Req, Variable_Ref); - Scope_Suppress := Svg_Suppress; - return; - - -- If this is an unchecked conversion that Gigi can't handle, make - -- a copy or a use a renaming to capture the value. - - elsif Nkind (Exp) = N_Unchecked_Type_Conversion - and then not Safe_Unchecked_Type_Conversion (Exp) - then - if CW_Or_Has_Controlled_Part (Exp_Type) then - - -- Use a renaming to capture the expression, rather than create - -- a controlled temporary. - - Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R')); - Res := New_Reference_To (Def_Id, Loc); - - Insert_Action (Exp, - Make_Object_Renaming_Declaration (Loc, - Defining_Identifier => Def_Id, - Subtype_Mark => New_Reference_To (Exp_Type, Loc), - Name => Relocate_Node (Exp))); - - else - Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R')); - Set_Etype (Def_Id, Exp_Type); - Res := New_Reference_To (Def_Id, Loc); - - E := - Make_Object_Declaration (Loc, - Defining_Identifier => Def_Id, - Object_Definition => New_Reference_To (Exp_Type, Loc), - Constant_Present => not Is_Variable (Exp), - Expression => Relocate_Node (Exp)); - - Set_Assignment_OK (E); - Insert_Action (Exp, E); - end if; - - -- For expressions that denote objects, we can use a renaming scheme. - -- We skip using this if we have a volatile reference and we do not - -- have Name_Req set true (see comments above for Side_Effect_Free). - - elsif Is_Object_Reference (Exp) - and then Nkind (Exp) /= N_Function_Call - and then (Name_Req or else not Is_Volatile_Reference (Exp)) - then - Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R')); - - if Nkind (Exp) = N_Selected_Component - and then Nkind (Prefix (Exp)) = N_Function_Call - and then Is_Array_Type (Exp_Type) - then - -- Avoid generating a variable-sized temporary, by generating - -- the renaming declaration just for the function call. The - -- transformation could be refined to apply only when the array - -- component is constrained by a discriminant??? - - Res := - Make_Selected_Component (Loc, - Prefix => New_Occurrence_Of (Def_Id, Loc), - Selector_Name => Selector_Name (Exp)); - - Insert_Action (Exp, - Make_Object_Renaming_Declaration (Loc, - Defining_Identifier => Def_Id, - Subtype_Mark => - New_Reference_To (Base_Type (Etype (Prefix (Exp))), Loc), - Name => Relocate_Node (Prefix (Exp)))); - - else - Res := New_Reference_To (Def_Id, Loc); - - Insert_Action (Exp, - Make_Object_Renaming_Declaration (Loc, - Defining_Identifier => Def_Id, - Subtype_Mark => New_Reference_To (Exp_Type, Loc), - Name => Relocate_Node (Exp))); - - end if; - - -- If this is a packed reference, or a selected component with a - -- non-standard representation, a reference to the temporary will - -- be replaced by a copy of the original expression (see - -- Exp_Ch2.Expand_Renaming). Otherwise the temporary must be - -- elaborated by gigi, and is of course not to be replaced in-line - -- by the expression it renames, which would defeat the purpose of - -- removing the side-effect. - - if (Nkind (Exp) = N_Selected_Component - or else Nkind (Exp) = N_Indexed_Component) - and then Has_Non_Standard_Rep (Etype (Prefix (Exp))) - then - null; - else - Set_Is_Renaming_Of_Object (Def_Id, False); - end if; - - -- Otherwise we generate a reference to the value - - else - -- Special processing for function calls that return a task. We need - -- to build a declaration that will enable build-in-place expansion - -- of the call. - - -- This is relevant only in Ada 2005 mode. In Ada 95 programs we have - -- to accommodate functions returning limited objects by reference. - - if Nkind (Exp) = N_Function_Call - and then Is_Task_Type (Etype (Exp)) - and then Ada_Version >= Ada_05 - then - declare - Obj : constant Entity_Id := - Make_Defining_Identifier (Loc, - Chars => New_Internal_Name ('F')); - Decl : Node_Id; - - begin - Decl := - Make_Object_Declaration (Loc, - Defining_Identifier => Obj, - Object_Definition => New_Occurrence_Of (Exp_Type, Loc), - Expression => Relocate_Node (Exp)); - Insert_Action (Exp, Decl); - Set_Etype (Obj, Exp_Type); - Rewrite (Exp, New_Occurrence_Of (Obj, Loc)); - return; - end; - end if; - - Ref_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('A')); - - Ptr_Typ_Decl := - Make_Full_Type_Declaration (Loc, - Defining_Identifier => Ref_Type, - Type_Definition => - Make_Access_To_Object_Definition (Loc, - All_Present => True, - Subtype_Indication => - New_Reference_To (Exp_Type, Loc))); - - E := Exp; - Insert_Action (Exp, Ptr_Typ_Decl); - - Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R')); - Set_Etype (Def_Id, Exp_Type); - - Res := - Make_Explicit_Dereference (Loc, - Prefix => New_Reference_To (Def_Id, Loc)); - - if Nkind (E) = N_Explicit_Dereference then - New_Exp := Relocate_Node (Prefix (E)); - else - E := Relocate_Node (E); - New_Exp := Make_Reference (Loc, E); - end if; - - if Is_Delayed_Aggregate (E) then - - -- The expansion of nested aggregates is delayed until the - -- enclosing aggregate is expanded. As aggregates are often - -- qualified, the predicate applies to qualified expressions - -- as well, indicating that the enclosing aggregate has not - -- been expanded yet. At this point the aggregate is part of - -- a stand-alone declaration, and must be fully expanded. - - if Nkind (E) = N_Qualified_Expression then - Set_Expansion_Delayed (Expression (E), False); - Set_Analyzed (Expression (E), False); - else - Set_Expansion_Delayed (E, False); - end if; - - Set_Analyzed (E, False); - end if; - - Insert_Action (Exp, - Make_Object_Declaration (Loc, - Defining_Identifier => Def_Id, - Object_Definition => New_Reference_To (Ref_Type, Loc), - Expression => New_Exp)); - end if; - - -- Preserve the Assignment_OK flag in all copies, since at least - -- one copy may be used in a context where this flag must be set - -- (otherwise why would the flag be set in the first place). - - Set_Assignment_OK (Res, Assignment_OK (Exp)); - - -- Finally rewrite the original expression and we are done - - Rewrite (Exp, Res); - Analyze_And_Resolve (Exp, Exp_Type); - Scope_Suppress := Svg_Suppress; - end Remove_Side_Effects; - - --------------------------- - -- Represented_As_Scalar -- - --------------------------- - - function Represented_As_Scalar (T : Entity_Id) return Boolean is - UT : constant Entity_Id := Underlying_Type (T); - begin - return Is_Scalar_Type (UT) - or else (Is_Bit_Packed_Array (UT) - and then Is_Scalar_Type (Packed_Array_Type (UT))); - end Represented_As_Scalar; - - ------------------------------------ - -- Safe_Unchecked_Type_Conversion -- - ------------------------------------ - - -- Note: this function knows quite a bit about the exact requirements - -- of Gigi with respect to unchecked type conversions, and its code - -- must be coordinated with any changes in Gigi in this area. - - -- The above requirements should be documented in Sinfo ??? - - function Safe_Unchecked_Type_Conversion (Exp : Node_Id) return Boolean is - Otyp : Entity_Id; - Ityp : Entity_Id; - Oalign : Uint; - Ialign : Uint; - Pexp : constant Node_Id := Parent (Exp); - - begin - -- If the expression is the RHS of an assignment or object declaration - -- we are always OK because there will always be a target. - - -- Object renaming declarations, (generated for view conversions of - -- actuals in inlined calls), like object declarations, provide an - -- explicit type, and are safe as well. - - if (Nkind (Pexp) = N_Assignment_Statement - and then Expression (Pexp) = Exp) - or else Nkind (Pexp) = N_Object_Declaration - or else Nkind (Pexp) = N_Object_Renaming_Declaration - then - return True; - - -- If the expression is the prefix of an N_Selected_Component - -- we should also be OK because GCC knows to look inside the - -- conversion except if the type is discriminated. We assume - -- that we are OK anyway if the type is not set yet or if it is - -- controlled since we can't afford to introduce a temporary in - -- this case. - - elsif Nkind (Pexp) = N_Selected_Component - and then Prefix (Pexp) = Exp - then - if No (Etype (Pexp)) then - return True; - else - return - not Has_Discriminants (Etype (Pexp)) - or else Is_Constrained (Etype (Pexp)); - end if; - end if; - - -- Set the output type, this comes from Etype if it is set, otherwise - -- we take it from the subtype mark, which we assume was already - -- fully analyzed. - - if Present (Etype (Exp)) then - Otyp := Etype (Exp); - else - Otyp := Entity (Subtype_Mark (Exp)); - end if; - - -- The input type always comes from the expression, and we assume - -- this is indeed always analyzed, so we can simply get the Etype. - - Ityp := Etype (Expression (Exp)); - - -- Initialize alignments to unknown so far - - Oalign := No_Uint; - Ialign := No_Uint; - - -- Replace a concurrent type by its corresponding record type - -- and each type by its underlying type and do the tests on those. - -- The original type may be a private type whose completion is a - -- concurrent type, so find the underlying type first. - - if Present (Underlying_Type (Otyp)) then - Otyp := Underlying_Type (Otyp); - end if; - - if Present (Underlying_Type (Ityp)) then - Ityp := Underlying_Type (Ityp); - end if; - - if Is_Concurrent_Type (Otyp) then - Otyp := Corresponding_Record_Type (Otyp); - end if; - - if Is_Concurrent_Type (Ityp) then - Ityp := Corresponding_Record_Type (Ityp); - end if; - - -- If the base types are the same, we know there is no problem since - -- this conversion will be a noop. - - if Implementation_Base_Type (Otyp) = Implementation_Base_Type (Ityp) then - return True; - - -- Same if this is an upwards conversion of an untagged type, and there - -- are no constraints involved (could be more general???) - - elsif Etype (Ityp) = Otyp - and then not Is_Tagged_Type (Ityp) - and then not Has_Discriminants (Ityp) - and then No (First_Rep_Item (Base_Type (Ityp))) - then - return True; - - -- If the size of output type is known at compile time, there is - -- never a problem. Note that unconstrained records are considered - -- to be of known size, but we can't consider them that way here, - -- because we are talking about the actual size of the object. - - -- We also make sure that in addition to the size being known, we do - -- not have a case which might generate an embarrassingly large temp - -- in stack checking mode. - - elsif Size_Known_At_Compile_Time (Otyp) - and then - (not Stack_Checking_Enabled - or else not May_Generate_Large_Temp (Otyp)) - and then not (Is_Record_Type (Otyp) and then not Is_Constrained (Otyp)) - then - return True; - - -- If either type is tagged, then we know the alignment is OK so - -- Gigi will be able to use pointer punning. - - elsif Is_Tagged_Type (Otyp) or else Is_Tagged_Type (Ityp) then - return True; - - -- If either type is a limited record type, we cannot do a copy, so - -- say safe since there's nothing else we can do. - - elsif Is_Limited_Record (Otyp) or else Is_Limited_Record (Ityp) then - return True; - - -- Conversions to and from packed array types are always ignored and - -- hence are safe. - - elsif Is_Packed_Array_Type (Otyp) - or else Is_Packed_Array_Type (Ityp) - then - return True; - end if; - - -- The only other cases known to be safe is if the input type's - -- alignment is known to be at least the maximum alignment for the - -- target or if both alignments are known and the output type's - -- alignment is no stricter than the input's. We can use the alignment - -- of the component type of an array if a type is an unpacked - -- array type. - - if Present (Alignment_Clause (Otyp)) then - Oalign := Expr_Value (Expression (Alignment_Clause (Otyp))); - - elsif Is_Array_Type (Otyp) - and then Present (Alignment_Clause (Component_Type (Otyp))) - then - Oalign := Expr_Value (Expression (Alignment_Clause - (Component_Type (Otyp)))); - end if; - - if Present (Alignment_Clause (Ityp)) then - Ialign := Expr_Value (Expression (Alignment_Clause (Ityp))); - - elsif Is_Array_Type (Ityp) - and then Present (Alignment_Clause (Component_Type (Ityp))) - then - Ialign := Expr_Value (Expression (Alignment_Clause - (Component_Type (Ityp)))); - end if; - - if Ialign /= No_Uint and then Ialign > Maximum_Alignment then - return True; - - elsif Ialign /= No_Uint and then Oalign /= No_Uint - and then Ialign <= Oalign - then - return True; - - -- Otherwise, Gigi cannot handle this and we must make a temporary - - else - return False; - end if; - end Safe_Unchecked_Type_Conversion; - - --------------------------------- - -- Set_Current_Value_Condition -- - --------------------------------- - - -- Note: the implementation of this procedure is very closely tied to the - -- implementation of Get_Current_Value_Condition. Here we set required - -- Current_Value fields, and in Get_Current_Value_Condition, we interpret - -- them, so they must have a consistent view. - - procedure Set_Current_Value_Condition (Cnode : Node_Id) is - - procedure Set_Entity_Current_Value (N : Node_Id); - -- If N is an entity reference, where the entity is of an appropriate - -- kind, then set the current value of this entity to Cnode, unless - -- there is already a definite value set there. - - procedure Set_Expression_Current_Value (N : Node_Id); - -- If N is of an appropriate form, sets an appropriate entry in current - -- value fields of relevant entities. Multiple entities can be affected - -- in the case of an AND or AND THEN. - - ------------------------------ - -- Set_Entity_Current_Value -- - ------------------------------ - - procedure Set_Entity_Current_Value (N : Node_Id) is - begin - if Is_Entity_Name (N) then - declare - Ent : constant Entity_Id := Entity (N); - - begin - -- Don't capture if not safe to do so - - if not Safe_To_Capture_Value (N, Ent, Cond => True) then - return; - end if; - - -- Here we have a case where the Current_Value field may - -- need to be set. We set it if it is not already set to a - -- compile time expression value. - - -- Note that this represents a decision that one condition - -- blots out another previous one. That's certainly right - -- if they occur at the same level. If the second one is - -- nested, then the decision is neither right nor wrong (it - -- would be equally OK to leave the outer one in place, or - -- take the new inner one. Really we should record both, but - -- our data structures are not that elaborate. - - if Nkind (Current_Value (Ent)) not in N_Subexpr then - Set_Current_Value (Ent, Cnode); - end if; - end; - end if; - end Set_Entity_Current_Value; - - ---------------------------------- - -- Set_Expression_Current_Value -- - ---------------------------------- - - procedure Set_Expression_Current_Value (N : Node_Id) is - Cond : Node_Id; - - begin - Cond := N; - - -- Loop to deal with (ignore for now) any NOT operators present. The - -- presence of NOT operators will be handled properly when we call - -- Get_Current_Value_Condition. - - while Nkind (Cond) = N_Op_Not loop - Cond := Right_Opnd (Cond); - end loop; - - -- For an AND or AND THEN, recursively process operands - - if Nkind (Cond) = N_Op_And or else Nkind (Cond) = N_And_Then then - Set_Expression_Current_Value (Left_Opnd (Cond)); - Set_Expression_Current_Value (Right_Opnd (Cond)); - return; - end if; - - -- Check possible relational operator - - if Nkind (Cond) in N_Op_Compare then - if Compile_Time_Known_Value (Right_Opnd (Cond)) then - Set_Entity_Current_Value (Left_Opnd (Cond)); - elsif Compile_Time_Known_Value (Left_Opnd (Cond)) then - Set_Entity_Current_Value (Right_Opnd (Cond)); - end if; - - -- Check possible boolean variable reference - - else - Set_Entity_Current_Value (Cond); - end if; - end Set_Expression_Current_Value; - - -- Start of processing for Set_Current_Value_Condition - - begin - Set_Expression_Current_Value (Condition (Cnode)); - end Set_Current_Value_Condition; - - -------------------------- - -- Set_Elaboration_Flag -- - -------------------------- - - procedure Set_Elaboration_Flag (N : Node_Id; Spec_Id : Entity_Id) is - Loc : constant Source_Ptr := Sloc (N); - Ent : constant Entity_Id := Elaboration_Entity (Spec_Id); - Asn : Node_Id; - - begin - if Present (Ent) then - - -- Nothing to do if at the compilation unit level, because in this - -- case the flag is set by the binder generated elaboration routine. - - if Nkind (Parent (N)) = N_Compilation_Unit then - null; - - -- Here we do need to generate an assignment statement - - else - Check_Restriction (No_Elaboration_Code, N); - Asn := - Make_Assignment_Statement (Loc, - Name => New_Occurrence_Of (Ent, Loc), - Expression => New_Occurrence_Of (Standard_True, Loc)); - - if Nkind (Parent (N)) = N_Subunit then - Insert_After (Corresponding_Stub (Parent (N)), Asn); - else - Insert_After (N, Asn); - end if; - - Analyze (Asn); - - -- Kill current value indication. This is necessary because the - -- tests of this flag are inserted out of sequence and must not - -- pick up bogus indications of the wrong constant value. - - Set_Current_Value (Ent, Empty); - end if; - end if; - end Set_Elaboration_Flag; - - ---------------------------- - -- Set_Renamed_Subprogram -- - ---------------------------- - - procedure Set_Renamed_Subprogram (N : Node_Id; E : Entity_Id) is - begin - -- If input node is an identifier, we can just reset it - - if Nkind (N) = N_Identifier then - Set_Chars (N, Chars (E)); - Set_Entity (N, E); - - -- Otherwise we have to do a rewrite, preserving Comes_From_Source - - else - declare - CS : constant Boolean := Comes_From_Source (N); - begin - Rewrite (N, Make_Identifier (Sloc (N), Chars => Chars (E))); - Set_Entity (N, E); - Set_Comes_From_Source (N, CS); - Set_Analyzed (N, True); - end; - end if; - end Set_Renamed_Subprogram; - - ---------------------------------- - -- Silly_Boolean_Array_Not_Test -- - ---------------------------------- - - -- This procedure implements an odd and silly test. We explicitly check - -- for the case where the 'First of the component type is equal to the - -- 'Last of this component type, and if this is the case, we make sure - -- that constraint error is raised. The reason is that the NOT is bound - -- to cause CE in this case, and we will not otherwise catch it. - - -- Believe it or not, this was reported as a bug. Note that nearly - -- always, the test will evaluate statically to False, so the code will - -- be statically removed, and no extra overhead caused. - - procedure Silly_Boolean_Array_Not_Test (N : Node_Id; T : Entity_Id) is - Loc : constant Source_Ptr := Sloc (N); - CT : constant Entity_Id := Component_Type (T); - - begin - Insert_Action (N, - Make_Raise_Constraint_Error (Loc, - Condition => - Make_Op_Eq (Loc, - Left_Opnd => - Make_Attribute_Reference (Loc, - Prefix => New_Occurrence_Of (CT, Loc), - Attribute_Name => Name_First), - - Right_Opnd => - Make_Attribute_Reference (Loc, - Prefix => New_Occurrence_Of (CT, Loc), - Attribute_Name => Name_Last)), - Reason => CE_Range_Check_Failed)); - end Silly_Boolean_Array_Not_Test; - - ---------------------------------- - -- Silly_Boolean_Array_Xor_Test -- - ---------------------------------- - - -- This procedure implements an odd and silly test. We explicitly check - -- for the XOR case where the component type is True .. True, since this - -- will raise constraint error. A special check is required since CE - -- will not be required otherwise (cf Expand_Packed_Not). - - -- No such check is required for AND and OR, since for both these cases - -- False op False = False, and True op True = True. - - procedure Silly_Boolean_Array_Xor_Test (N : Node_Id; T : Entity_Id) is - Loc : constant Source_Ptr := Sloc (N); - CT : constant Entity_Id := Component_Type (T); - BT : constant Entity_Id := Base_Type (CT); - - begin - Insert_Action (N, - Make_Raise_Constraint_Error (Loc, - Condition => - Make_Op_And (Loc, - Left_Opnd => - Make_Op_Eq (Loc, - Left_Opnd => - Make_Attribute_Reference (Loc, - Prefix => New_Occurrence_Of (CT, Loc), - Attribute_Name => Name_First), - - Right_Opnd => - Convert_To (BT, - New_Occurrence_Of (Standard_True, Loc))), - - Right_Opnd => - Make_Op_Eq (Loc, - Left_Opnd => - Make_Attribute_Reference (Loc, - Prefix => New_Occurrence_Of (CT, Loc), - Attribute_Name => Name_Last), - - Right_Opnd => - Convert_To (BT, - New_Occurrence_Of (Standard_True, Loc)))), - Reason => CE_Range_Check_Failed)); - end Silly_Boolean_Array_Xor_Test; - - -------------------------- - -- Target_Has_Fixed_Ops -- - -------------------------- - - Integer_Sized_Small : Ureal; - -- Set to 2.0 ** -(Integer'Size - 1) the first time that this - -- function is called (we don't want to compute it more than once!) - - Long_Integer_Sized_Small : Ureal; - -- Set to 2.0 ** -(Long_Integer'Size - 1) the first time that this - -- function is called (we don't want to compute it more than once) - - First_Time_For_THFO : Boolean := True; - -- Set to False after first call (if Fractional_Fixed_Ops_On_Target) - - function Target_Has_Fixed_Ops - (Left_Typ : Entity_Id; - Right_Typ : Entity_Id; - Result_Typ : Entity_Id) return Boolean - is - function Is_Fractional_Type (Typ : Entity_Id) return Boolean; - -- Return True if the given type is a fixed-point type with a small - -- value equal to 2 ** (-(T'Object_Size - 1)) and whose values have - -- an absolute value less than 1.0. This is currently limited - -- to fixed-point types that map to Integer or Long_Integer. - - ------------------------ - -- Is_Fractional_Type -- - ------------------------ - - function Is_Fractional_Type (Typ : Entity_Id) return Boolean is - begin - if Esize (Typ) = Standard_Integer_Size then - return Small_Value (Typ) = Integer_Sized_Small; - - elsif Esize (Typ) = Standard_Long_Integer_Size then - return Small_Value (Typ) = Long_Integer_Sized_Small; - - else - return False; - end if; - end Is_Fractional_Type; - - -- Start of processing for Target_Has_Fixed_Ops - - begin - -- Return False if Fractional_Fixed_Ops_On_Target is false - - if not Fractional_Fixed_Ops_On_Target then - return False; - end if; - - -- Here the target has Fractional_Fixed_Ops, if first time, compute - -- standard constants used by Is_Fractional_Type. - - if First_Time_For_THFO then - First_Time_For_THFO := False; - - Integer_Sized_Small := - UR_From_Components - (Num => Uint_1, - Den => UI_From_Int (Standard_Integer_Size - 1), - Rbase => 2); - - Long_Integer_Sized_Small := - UR_From_Components - (Num => Uint_1, - Den => UI_From_Int (Standard_Long_Integer_Size - 1), - Rbase => 2); - end if; - - -- Return True if target supports fixed-by-fixed multiply/divide - -- for fractional fixed-point types (see Is_Fractional_Type) and - -- the operand and result types are equivalent fractional types. - - return Is_Fractional_Type (Base_Type (Left_Typ)) - and then Is_Fractional_Type (Base_Type (Right_Typ)) - and then Is_Fractional_Type (Base_Type (Result_Typ)) - and then Esize (Left_Typ) = Esize (Right_Typ) - and then Esize (Left_Typ) = Esize (Result_Typ); - end Target_Has_Fixed_Ops; - - ------------------------------------------ - -- Type_May_Have_Bit_Aligned_Components -- - ------------------------------------------ - - function Type_May_Have_Bit_Aligned_Components - (Typ : Entity_Id) return Boolean - is - begin - -- Array type, check component type - - if Is_Array_Type (Typ) then - return - Type_May_Have_Bit_Aligned_Components (Component_Type (Typ)); - - -- Record type, check components - - elsif Is_Record_Type (Typ) then - declare - E : Entity_Id; - - begin - E := First_Component_Or_Discriminant (Typ); - while Present (E) loop - if Component_May_Be_Bit_Aligned (E) - or else Type_May_Have_Bit_Aligned_Components (Etype (E)) - then - return True; - end if; - - Next_Component_Or_Discriminant (E); - end loop; - - return False; - end; - - -- Type other than array or record is always OK - - else - return False; - end if; - end Type_May_Have_Bit_Aligned_Components; - - ---------------------------- - -- Wrap_Cleanup_Procedure -- - ---------------------------- - - procedure Wrap_Cleanup_Procedure (N : Node_Id) is - Loc : constant Source_Ptr := Sloc (N); - Stseq : constant Node_Id := Handled_Statement_Sequence (N); - Stmts : constant List_Id := Statements (Stseq); - - begin - if Abort_Allowed then - Prepend_To (Stmts, Build_Runtime_Call (Loc, RE_Abort_Defer)); - Append_To (Stmts, Build_Runtime_Call (Loc, RE_Abort_Undefer)); - end if; - end Wrap_Cleanup_Procedure; - -end Exp_Util; |