| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- E X P _ P R A G -- |
| -- -- |
| -- B o d y -- |
| -- -- |
| -- Copyright (C) 1992-2015, 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 Casing; use Casing; |
| with Checks; use Checks; |
| with Debug; use Debug; |
| with Einfo; use Einfo; |
| with Errout; use Errout; |
| with Exp_Ch11; use Exp_Ch11; |
| with Exp_Util; use Exp_Util; |
| with Expander; use Expander; |
| with Inline; use Inline; |
| with Namet; use Namet; |
| with Nlists; use Nlists; |
| with Nmake; use Nmake; |
| with Opt; use Opt; |
| with Restrict; use Restrict; |
| with Rident; use Rident; |
| with Rtsfind; use Rtsfind; |
| with Sem; use Sem; |
| with Sem_Ch8; use Sem_Ch8; |
| with Sem_Util; use Sem_Util; |
| with Sinfo; use Sinfo; |
| with Sinput; use Sinput; |
| with Snames; use Snames; |
| with Stringt; use Stringt; |
| with Stand; use Stand; |
| with Tbuild; use Tbuild; |
| with Uintp; use Uintp; |
| with Validsw; use Validsw; |
| |
| package body Exp_Prag is |
| |
| ----------------------- |
| -- Local Subprograms -- |
| ----------------------- |
| |
| function Arg1 (N : Node_Id) return Node_Id; |
| function Arg2 (N : Node_Id) return Node_Id; |
| function Arg3 (N : Node_Id) return Node_Id; |
| -- Obtain specified pragma argument expression |
| |
| procedure Expand_Pragma_Abort_Defer (N : Node_Id); |
| procedure Expand_Pragma_Check (N : Node_Id); |
| procedure Expand_Pragma_Common_Object (N : Node_Id); |
| procedure Expand_Pragma_Import_Or_Interface (N : Node_Id); |
| procedure Expand_Pragma_Inspection_Point (N : Node_Id); |
| procedure Expand_Pragma_Interrupt_Priority (N : Node_Id); |
| procedure Expand_Pragma_Loop_Variant (N : Node_Id); |
| procedure Expand_Pragma_Psect_Object (N : Node_Id); |
| procedure Expand_Pragma_Relative_Deadline (N : Node_Id); |
| procedure Expand_Pragma_Suppress_Initialization (N : Node_Id); |
| |
| procedure Undo_Initialization (Def_Id : Entity_Id; N : Node_Id); |
| -- This procedure is used to undo initialization already done for Def_Id, |
| -- which is always an E_Variable, in response to the occurrence of the |
| -- pragma N, a pragma Interface, Import, or Suppress_Initialization. In all |
| -- these cases we want no initialization to occur, but we have already done |
| -- the initialization by the time we see the pragma, so we have to undo it. |
| |
| ---------- |
| -- Arg1 -- |
| ---------- |
| |
| function Arg1 (N : Node_Id) return Node_Id is |
| Arg : constant Node_Id := First (Pragma_Argument_Associations (N)); |
| begin |
| if Present (Arg) |
| and then Nkind (Arg) = N_Pragma_Argument_Association |
| then |
| return Expression (Arg); |
| else |
| return Arg; |
| end if; |
| end Arg1; |
| |
| ---------- |
| -- Arg2 -- |
| ---------- |
| |
| function Arg2 (N : Node_Id) return Node_Id is |
| Arg1 : constant Node_Id := First (Pragma_Argument_Associations (N)); |
| |
| begin |
| if No (Arg1) then |
| return Empty; |
| |
| else |
| declare |
| Arg : constant Node_Id := Next (Arg1); |
| begin |
| if Present (Arg) |
| and then Nkind (Arg) = N_Pragma_Argument_Association |
| then |
| return Expression (Arg); |
| else |
| return Arg; |
| end if; |
| end; |
| end if; |
| end Arg2; |
| |
| ---------- |
| -- Arg3 -- |
| ---------- |
| |
| function Arg3 (N : Node_Id) return Node_Id is |
| Arg1 : constant Node_Id := First (Pragma_Argument_Associations (N)); |
| |
| begin |
| if No (Arg1) then |
| return Empty; |
| |
| else |
| declare |
| Arg : Node_Id := Next (Arg1); |
| begin |
| if No (Arg) then |
| return Empty; |
| |
| else |
| Next (Arg); |
| |
| if Present (Arg) |
| and then Nkind (Arg) = N_Pragma_Argument_Association |
| then |
| return Expression (Arg); |
| else |
| return Arg; |
| end if; |
| end if; |
| end; |
| end if; |
| end Arg3; |
| |
| --------------------------- |
| -- Expand_Contract_Cases -- |
| --------------------------- |
| |
| -- Pragma Contract_Cases is expanded in the following manner: |
| |
| -- subprogram S is |
| -- Count : Natural := 0; |
| -- Flag_1 : Boolean := False; |
| -- . . . |
| -- Flag_N : Boolean := False; |
| -- Flag_N+1 : Boolean := False; -- when "others" present |
| -- Pref_1 : ...; |
| -- . . . |
| -- Pref_M : ...; |
| |
| -- <preconditions (if any)> |
| |
| -- -- Evaluate all case guards |
| |
| -- if Case_Guard_1 then |
| -- Flag_1 := True; |
| -- Count := Count + 1; |
| -- end if; |
| -- . . . |
| -- if Case_Guard_N then |
| -- Flag_N := True; |
| -- Count := Count + 1; |
| -- end if; |
| |
| -- -- Emit errors depending on the number of case guards that |
| -- -- evaluated to True. |
| |
| -- if Count = 0 then |
| -- raise Assertion_Error with "xxx contract cases incomplete"; |
| -- <or> |
| -- Flag_N+1 := True; -- when "others" present |
| |
| -- elsif Count > 1 then |
| -- declare |
| -- Str0 : constant String := |
| -- "contract cases overlap for subprogram ABC"; |
| -- Str1 : constant String := |
| -- (if Flag_1 then |
| -- Str0 & "case guard at xxx evaluates to True" |
| -- else Str0); |
| -- StrN : constant String := |
| -- (if Flag_N then |
| -- StrN-1 & "case guard at xxx evaluates to True" |
| -- else StrN-1); |
| -- begin |
| -- raise Assertion_Error with StrN; |
| -- end; |
| -- end if; |
| |
| -- -- Evaluate all attribute 'Old prefixes found in the selected |
| -- -- consequence. |
| |
| -- if Flag_1 then |
| -- Pref_1 := <prefix of 'Old found in Consequence_1> |
| -- . . . |
| -- elsif Flag_N then |
| -- Pref_M := <prefix of 'Old found in Consequence_N> |
| -- end if; |
| |
| -- procedure _Postconditions is |
| -- begin |
| -- <postconditions (if any)> |
| |
| -- if Flag_1 and then not Consequence_1 then |
| -- raise Assertion_Error with "failed contract case at xxx"; |
| -- end if; |
| -- . . . |
| -- if Flag_N[+1] and then not Consequence_N[+1] then |
| -- raise Assertion_Error with "failed contract case at xxx"; |
| -- end if; |
| -- end _Postconditions; |
| -- begin |
| -- . . . |
| -- end S; |
| |
| procedure Expand_Contract_Cases |
| (CCs : Node_Id; |
| Subp_Id : Entity_Id; |
| Decls : List_Id; |
| Stmts : in out List_Id) |
| is |
| Loc : constant Source_Ptr := Sloc (CCs); |
| |
| procedure Case_Guard_Error |
| (Decls : List_Id; |
| Flag : Entity_Id; |
| Error_Loc : Source_Ptr; |
| Msg : in out Entity_Id); |
| -- Given a declarative list Decls, status flag Flag, the location of the |
| -- error and a string Msg, construct the following check: |
| -- Msg : constant String := |
| -- (if Flag then |
| -- Msg & "case guard at Error_Loc evaluates to True" |
| -- else Msg); |
| -- The resulting code is added to Decls |
| |
| procedure Consequence_Error |
| (Checks : in out Node_Id; |
| Flag : Entity_Id; |
| Conseq : Node_Id); |
| -- Given an if statement Checks, status flag Flag and a consequence |
| -- Conseq, construct the following check: |
| -- [els]if Flag and then not Conseq then |
| -- raise Assertion_Error |
| -- with "failed contract case at Sloc (Conseq)"; |
| -- [end if;] |
| -- The resulting code is added to Checks |
| |
| function Declaration_Of (Id : Entity_Id) return Node_Id; |
| -- Given the entity Id of a boolean flag, generate: |
| -- Id : Boolean := False; |
| |
| procedure Expand_Attributes_In_Consequence |
| (Decls : List_Id; |
| Evals : in out Node_Id; |
| Flag : Entity_Id; |
| Conseq : Node_Id); |
| -- Perform specialized expansion of all attribute 'Old references found |
| -- in consequence Conseq such that at runtime only prefixes coming from |
| -- the selected consequence are evaluated. Similarly expand attribute |
| -- 'Result references by replacing them with identifier _result which |
| -- resolves to the sole formal parameter of procedure _Postconditions. |
| -- Any temporaries generated in the process are added to declarations |
| -- Decls. Evals is a complex if statement tasked with the evaluation of |
| -- all prefixes coming from a single selected consequence. Flag is the |
| -- corresponding case guard flag. Conseq is the consequence expression. |
| |
| function Increment (Id : Entity_Id) return Node_Id; |
| -- Given the entity Id of a numerical variable, generate: |
| -- Id := Id + 1; |
| |
| function Set (Id : Entity_Id) return Node_Id; |
| -- Given the entity Id of a boolean variable, generate: |
| -- Id := True; |
| |
| ---------------------- |
| -- Case_Guard_Error -- |
| ---------------------- |
| |
| procedure Case_Guard_Error |
| (Decls : List_Id; |
| Flag : Entity_Id; |
| Error_Loc : Source_Ptr; |
| Msg : in out Entity_Id) |
| is |
| New_Line : constant Character := Character'Val (10); |
| New_Msg : constant Entity_Id := Make_Temporary (Loc, 'S'); |
| |
| begin |
| Start_String; |
| Store_String_Char (New_Line); |
| Store_String_Chars (" case guard at "); |
| Store_String_Chars (Build_Location_String (Error_Loc)); |
| Store_String_Chars (" evaluates to True"); |
| |
| -- Generate: |
| -- New_Msg : constant String := |
| -- (if Flag then |
| -- Msg & "case guard at Error_Loc evaluates to True" |
| -- else Msg); |
| |
| Append_To (Decls, |
| Make_Object_Declaration (Loc, |
| Defining_Identifier => New_Msg, |
| Constant_Present => True, |
| Object_Definition => New_Occurrence_Of (Standard_String, Loc), |
| Expression => |
| Make_If_Expression (Loc, |
| Expressions => New_List ( |
| New_Occurrence_Of (Flag, Loc), |
| |
| Make_Op_Concat (Loc, |
| Left_Opnd => New_Occurrence_Of (Msg, Loc), |
| Right_Opnd => Make_String_Literal (Loc, End_String)), |
| |
| New_Occurrence_Of (Msg, Loc))))); |
| |
| Msg := New_Msg; |
| end Case_Guard_Error; |
| |
| ----------------------- |
| -- Consequence_Error -- |
| ----------------------- |
| |
| procedure Consequence_Error |
| (Checks : in out Node_Id; |
| Flag : Entity_Id; |
| Conseq : Node_Id) |
| is |
| Cond : Node_Id; |
| Error : Node_Id; |
| |
| begin |
| -- Generate: |
| -- Flag and then not Conseq |
| |
| Cond := |
| Make_And_Then (Loc, |
| Left_Opnd => New_Occurrence_Of (Flag, Loc), |
| Right_Opnd => |
| Make_Op_Not (Loc, |
| Right_Opnd => Relocate_Node (Conseq))); |
| |
| -- Generate: |
| -- raise Assertion_Error |
| -- with "failed contract case at Sloc (Conseq)"; |
| |
| Start_String; |
| Store_String_Chars ("failed contract case at "); |
| Store_String_Chars (Build_Location_String (Sloc (Conseq))); |
| |
| Error := |
| Make_Procedure_Call_Statement (Loc, |
| Name => |
| New_Occurrence_Of (RTE (RE_Raise_Assert_Failure), Loc), |
| Parameter_Associations => New_List ( |
| Make_String_Literal (Loc, End_String))); |
| |
| if No (Checks) then |
| Checks := |
| Make_Implicit_If_Statement (CCs, |
| Condition => Cond, |
| Then_Statements => New_List (Error)); |
| |
| else |
| if No (Elsif_Parts (Checks)) then |
| Set_Elsif_Parts (Checks, New_List); |
| end if; |
| |
| Append_To (Elsif_Parts (Checks), |
| Make_Elsif_Part (Loc, |
| Condition => Cond, |
| Then_Statements => New_List (Error))); |
| end if; |
| end Consequence_Error; |
| |
| -------------------- |
| -- Declaration_Of -- |
| -------------------- |
| |
| function Declaration_Of (Id : Entity_Id) return Node_Id is |
| begin |
| return |
| Make_Object_Declaration (Loc, |
| Defining_Identifier => Id, |
| Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc), |
| Expression => New_Occurrence_Of (Standard_False, Loc)); |
| end Declaration_Of; |
| |
| -------------------------------------- |
| -- Expand_Attributes_In_Consequence -- |
| -------------------------------------- |
| |
| procedure Expand_Attributes_In_Consequence |
| (Decls : List_Id; |
| Evals : in out Node_Id; |
| Flag : Entity_Id; |
| Conseq : Node_Id) |
| is |
| Eval_Stmts : List_Id := No_List; |
| -- The evaluation sequence expressed as assignment statements of all |
| -- prefixes of attribute 'Old found in the current consequence. |
| |
| function Expand_Attributes (N : Node_Id) return Traverse_Result; |
| -- Determine whether an arbitrary node denotes attribute 'Old or |
| -- 'Result and if it does, perform all expansion-related actions. |
| |
| ----------------------- |
| -- Expand_Attributes -- |
| ----------------------- |
| |
| function Expand_Attributes (N : Node_Id) return Traverse_Result is |
| Decl : Node_Id; |
| Pref : Node_Id; |
| Temp : Entity_Id; |
| |
| begin |
| -- Attribute 'Old |
| |
| if Nkind (N) = N_Attribute_Reference |
| and then Attribute_Name (N) = Name_Old |
| then |
| Pref := Prefix (N); |
| Temp := Make_Temporary (Loc, 'T', Pref); |
| Set_Etype (Temp, Etype (Pref)); |
| |
| -- Generate a temporary to capture the value of the prefix: |
| -- Temp : <Pref type>; |
| -- Place that temporary at the beginning of declarations, to |
| -- prevent anomalies in the GNATprove flow-analysis pass in |
| -- the precondition procedure that follows. |
| |
| Decl := |
| Make_Object_Declaration (Loc, |
| Defining_Identifier => Temp, |
| Object_Definition => |
| New_Occurrence_Of (Etype (Pref), Loc)); |
| Set_No_Initialization (Decl); |
| |
| Prepend_To (Decls, Decl); |
| Analyze (Decl); |
| |
| -- Evaluate the prefix, generate: |
| -- Temp := <Pref>; |
| |
| if No (Eval_Stmts) then |
| Eval_Stmts := New_List; |
| end if; |
| |
| Append_To (Eval_Stmts, |
| Make_Assignment_Statement (Loc, |
| Name => New_Occurrence_Of (Temp, Loc), |
| Expression => Pref)); |
| |
| -- Ensure that the prefix is valid |
| |
| if Validity_Checks_On and then Validity_Check_Operands then |
| Ensure_Valid (Pref); |
| end if; |
| |
| -- Replace the original attribute 'Old by a reference to the |
| -- generated temporary. |
| |
| Rewrite (N, New_Occurrence_Of (Temp, Loc)); |
| |
| -- Attribute 'Result |
| |
| elsif Is_Attribute_Result (N) then |
| Rewrite (N, Make_Identifier (Loc, Name_uResult)); |
| end if; |
| |
| return OK; |
| end Expand_Attributes; |
| |
| procedure Expand_Attributes_In is |
| new Traverse_Proc (Expand_Attributes); |
| |
| -- Start of processing for Expand_Attributes_In_Consequence |
| |
| begin |
| -- Inspect the consequence and expand any attribute 'Old and 'Result |
| -- references found within. |
| |
| Expand_Attributes_In (Conseq); |
| |
| -- The consequence does not contain any attribute 'Old references |
| |
| if No (Eval_Stmts) then |
| return; |
| end if; |
| |
| -- Augment the machinery to trigger the evaluation of all prefixes |
| -- found in the step above. If Eval is empty, then this is the first |
| -- consequence to yield expansion of 'Old. Generate: |
| |
| -- if Flag then |
| -- <evaluation statements> |
| -- end if; |
| |
| if No (Evals) then |
| Evals := |
| Make_Implicit_If_Statement (CCs, |
| Condition => New_Occurrence_Of (Flag, Loc), |
| Then_Statements => Eval_Stmts); |
| |
| -- Otherwise generate: |
| -- elsif Flag then |
| -- <evaluation statements> |
| -- end if; |
| |
| else |
| if No (Elsif_Parts (Evals)) then |
| Set_Elsif_Parts (Evals, New_List); |
| end if; |
| |
| Append_To (Elsif_Parts (Evals), |
| Make_Elsif_Part (Loc, |
| Condition => New_Occurrence_Of (Flag, Loc), |
| Then_Statements => Eval_Stmts)); |
| end if; |
| end Expand_Attributes_In_Consequence; |
| |
| --------------- |
| -- Increment -- |
| --------------- |
| |
| function Increment (Id : Entity_Id) return Node_Id is |
| begin |
| return |
| Make_Assignment_Statement (Loc, |
| Name => New_Occurrence_Of (Id, Loc), |
| Expression => |
| Make_Op_Add (Loc, |
| Left_Opnd => New_Occurrence_Of (Id, Loc), |
| Right_Opnd => Make_Integer_Literal (Loc, 1))); |
| end Increment; |
| |
| --------- |
| -- Set -- |
| --------- |
| |
| function Set (Id : Entity_Id) return Node_Id is |
| begin |
| return |
| Make_Assignment_Statement (Loc, |
| Name => New_Occurrence_Of (Id, Loc), |
| Expression => New_Occurrence_Of (Standard_True, Loc)); |
| end Set; |
| |
| -- Local variables |
| |
| Aggr : constant Node_Id := |
| Expression (First |
| (Pragma_Argument_Associations (CCs))); |
| Case_Guard : Node_Id; |
| CG_Checks : Node_Id; |
| CG_Stmts : List_Id; |
| Conseq : Node_Id; |
| Conseq_Checks : Node_Id := Empty; |
| Count : Entity_Id; |
| Count_Decl : Node_Id; |
| Error_Decls : List_Id; |
| Flag : Entity_Id; |
| Flag_Decl : Node_Id; |
| If_Stmt : Node_Id; |
| Msg_Str : Entity_Id; |
| Multiple_PCs : Boolean; |
| Old_Evals : Node_Id := Empty; |
| Others_Decl : Node_Id; |
| Others_Flag : Entity_Id := Empty; |
| Post_Case : Node_Id; |
| |
| -- Start of processing for Expand_Contract_Cases |
| |
| begin |
| -- Do nothing if pragma is not enabled. If pragma is disabled, it has |
| -- already been rewritten as a Null statement. |
| |
| if Is_Ignored (CCs) then |
| return; |
| |
| -- Guard against malformed contract cases |
| |
| elsif Nkind (Aggr) /= N_Aggregate then |
| return; |
| end if; |
| |
| Multiple_PCs := List_Length (Component_Associations (Aggr)) > 1; |
| |
| -- Create the counter which tracks the number of case guards that |
| -- evaluate to True. |
| |
| -- Count : Natural := 0; |
| |
| Count := Make_Temporary (Loc, 'C'); |
| Count_Decl := |
| Make_Object_Declaration (Loc, |
| Defining_Identifier => Count, |
| Object_Definition => New_Occurrence_Of (Standard_Natural, Loc), |
| Expression => Make_Integer_Literal (Loc, 0)); |
| |
| Prepend_To (Decls, Count_Decl); |
| Analyze (Count_Decl); |
| |
| -- Create the base error message for multiple overlapping case guards |
| |
| -- Msg_Str : constant String := |
| -- "contract cases overlap for subprogram Subp_Id"; |
| |
| if Multiple_PCs then |
| Msg_Str := Make_Temporary (Loc, 'S'); |
| |
| Start_String; |
| Store_String_Chars ("contract cases overlap for subprogram "); |
| Store_String_Chars (Get_Name_String (Chars (Subp_Id))); |
| |
| Error_Decls := New_List ( |
| Make_Object_Declaration (Loc, |
| Defining_Identifier => Msg_Str, |
| Constant_Present => True, |
| Object_Definition => New_Occurrence_Of (Standard_String, Loc), |
| Expression => Make_String_Literal (Loc, End_String))); |
| end if; |
| |
| -- Process individual post cases |
| |
| Post_Case := First (Component_Associations (Aggr)); |
| while Present (Post_Case) loop |
| Case_Guard := First (Choices (Post_Case)); |
| Conseq := Expression (Post_Case); |
| |
| -- The "others" choice requires special processing |
| |
| if Nkind (Case_Guard) = N_Others_Choice then |
| Others_Flag := Make_Temporary (Loc, 'F'); |
| Others_Decl := Declaration_Of (Others_Flag); |
| |
| Prepend_To (Decls, Others_Decl); |
| Analyze (Others_Decl); |
| |
| -- Check possible overlap between a case guard and "others" |
| |
| if Multiple_PCs and Exception_Extra_Info then |
| Case_Guard_Error |
| (Decls => Error_Decls, |
| Flag => Others_Flag, |
| Error_Loc => Sloc (Case_Guard), |
| Msg => Msg_Str); |
| end if; |
| |
| -- Inspect the consequence and perform special expansion of any |
| -- attribute 'Old and 'Result references found within. |
| |
| Expand_Attributes_In_Consequence |
| (Decls => Decls, |
| Evals => Old_Evals, |
| Flag => Others_Flag, |
| Conseq => Conseq); |
| |
| -- Check the corresponding consequence of "others" |
| |
| Consequence_Error |
| (Checks => Conseq_Checks, |
| Flag => Others_Flag, |
| Conseq => Conseq); |
| |
| -- Regular post case |
| |
| else |
| -- Create the flag which tracks the state of its associated case |
| -- guard. |
| |
| Flag := Make_Temporary (Loc, 'F'); |
| Flag_Decl := Declaration_Of (Flag); |
| |
| Prepend_To (Decls, Flag_Decl); |
| Analyze (Flag_Decl); |
| |
| -- The flag is set when the case guard is evaluated to True |
| -- if Case_Guard then |
| -- Flag := True; |
| -- Count := Count + 1; |
| -- end if; |
| |
| If_Stmt := |
| Make_Implicit_If_Statement (CCs, |
| Condition => Relocate_Node (Case_Guard), |
| Then_Statements => New_List ( |
| Set (Flag), |
| Increment (Count))); |
| |
| Append_To (Decls, If_Stmt); |
| Analyze (If_Stmt); |
| |
| -- Check whether this case guard overlaps with another one |
| |
| if Multiple_PCs and Exception_Extra_Info then |
| Case_Guard_Error |
| (Decls => Error_Decls, |
| Flag => Flag, |
| Error_Loc => Sloc (Case_Guard), |
| Msg => Msg_Str); |
| end if; |
| |
| -- Inspect the consequence and perform special expansion of any |
| -- attribute 'Old and 'Result references found within. |
| |
| Expand_Attributes_In_Consequence |
| (Decls => Decls, |
| Evals => Old_Evals, |
| Flag => Flag, |
| Conseq => Conseq); |
| |
| -- The corresponding consequence of the case guard which evaluated |
| -- to True must hold on exit from the subprogram. |
| |
| Consequence_Error |
| (Checks => Conseq_Checks, |
| Flag => Flag, |
| Conseq => Conseq); |
| end if; |
| |
| Next (Post_Case); |
| end loop; |
| |
| -- Raise Assertion_Error when none of the case guards evaluate to True. |
| -- The only exception is when we have "others", in which case there is |
| -- no error because "others" acts as a default True. |
| |
| -- Generate: |
| -- Flag := True; |
| |
| if Present (Others_Flag) then |
| CG_Stmts := New_List (Set (Others_Flag)); |
| |
| -- Generate: |
| -- raise Assertion_Error with "xxx contract cases incomplete"; |
| |
| else |
| Start_String; |
| Store_String_Chars (Build_Location_String (Loc)); |
| Store_String_Chars (" contract cases incomplete"); |
| |
| CG_Stmts := New_List ( |
| Make_Procedure_Call_Statement (Loc, |
| Name => |
| New_Occurrence_Of (RTE (RE_Raise_Assert_Failure), Loc), |
| Parameter_Associations => New_List ( |
| Make_String_Literal (Loc, End_String)))); |
| end if; |
| |
| CG_Checks := |
| Make_Implicit_If_Statement (CCs, |
| Condition => |
| Make_Op_Eq (Loc, |
| Left_Opnd => New_Occurrence_Of (Count, Loc), |
| Right_Opnd => Make_Integer_Literal (Loc, 0)), |
| Then_Statements => CG_Stmts); |
| |
| -- Detect a possible failure due to several case guards evaluating to |
| -- True. |
| |
| -- Generate: |
| -- elsif Count > 0 then |
| -- declare |
| -- <Error_Decls> |
| -- begin |
| -- raise Assertion_Error with <Msg_Str>; |
| -- end if; |
| |
| if Multiple_PCs then |
| Set_Elsif_Parts (CG_Checks, New_List ( |
| Make_Elsif_Part (Loc, |
| Condition => |
| Make_Op_Gt (Loc, |
| Left_Opnd => New_Occurrence_Of (Count, Loc), |
| Right_Opnd => Make_Integer_Literal (Loc, 1)), |
| |
| Then_Statements => New_List ( |
| Make_Block_Statement (Loc, |
| Declarations => Error_Decls, |
| Handled_Statement_Sequence => |
| Make_Handled_Sequence_Of_Statements (Loc, |
| Statements => New_List ( |
| Make_Procedure_Call_Statement (Loc, |
| Name => |
| New_Occurrence_Of |
| (RTE (RE_Raise_Assert_Failure), Loc), |
| Parameter_Associations => New_List ( |
| New_Occurrence_Of (Msg_Str, Loc)))))))))); |
| end if; |
| |
| Append_To (Decls, CG_Checks); |
| Analyze (CG_Checks); |
| |
| -- Once all case guards are evaluated and checked, evaluate any prefixes |
| -- of attribute 'Old founds in the selected consequence. |
| |
| if Present (Old_Evals) then |
| Append_To (Decls, Old_Evals); |
| Analyze (Old_Evals); |
| end if; |
| |
| -- Raise Assertion_Error when the corresponding consequence of a case |
| -- guard that evaluated to True fails. |
| |
| if No (Stmts) then |
| Stmts := New_List; |
| end if; |
| |
| Append_To (Stmts, Conseq_Checks); |
| end Expand_Contract_Cases; |
| |
| --------------------- |
| -- Expand_N_Pragma -- |
| --------------------- |
| |
| procedure Expand_N_Pragma (N : Node_Id) is |
| Pname : constant Name_Id := Pragma_Name (N); |
| |
| begin |
| -- Note: we may have a pragma whose Pragma_Identifier field is not a |
| -- recognized pragma, and we must ignore it at this stage. |
| |
| if Is_Pragma_Name (Pname) then |
| case Get_Pragma_Id (Pname) is |
| |
| -- Pragmas requiring special expander action |
| |
| when Pragma_Abort_Defer => |
| Expand_Pragma_Abort_Defer (N); |
| |
| when Pragma_Check => |
| Expand_Pragma_Check (N); |
| |
| when Pragma_Common_Object => |
| Expand_Pragma_Common_Object (N); |
| |
| when Pragma_Import => |
| Expand_Pragma_Import_Or_Interface (N); |
| |
| when Pragma_Inspection_Point => |
| Expand_Pragma_Inspection_Point (N); |
| |
| when Pragma_Interface => |
| Expand_Pragma_Import_Or_Interface (N); |
| |
| when Pragma_Interrupt_Priority => |
| Expand_Pragma_Interrupt_Priority (N); |
| |
| when Pragma_Loop_Variant => |
| Expand_Pragma_Loop_Variant (N); |
| |
| when Pragma_Psect_Object => |
| Expand_Pragma_Psect_Object (N); |
| |
| when Pragma_Relative_Deadline => |
| Expand_Pragma_Relative_Deadline (N); |
| |
| when Pragma_Suppress_Initialization => |
| Expand_Pragma_Suppress_Initialization (N); |
| |
| -- All other pragmas need no expander action |
| |
| when others => null; |
| end case; |
| end if; |
| |
| end Expand_N_Pragma; |
| |
| ------------------------------- |
| -- Expand_Pragma_Abort_Defer -- |
| ------------------------------- |
| |
| -- An Abort_Defer pragma appears as the first statement in a handled |
| -- statement sequence (right after the begin). It defers aborts for |
| -- the entire statement sequence, but not for any declarations or |
| -- handlers (if any) associated with this statement sequence. |
| |
| -- The transformation is to transform |
| |
| -- pragma Abort_Defer; |
| -- statements; |
| |
| -- into |
| |
| -- begin |
| -- Abort_Defer.all; |
| -- statements |
| -- exception |
| -- when all others => |
| -- Abort_Undefer.all; |
| -- raise; |
| -- at end |
| -- Abort_Undefer_Direct; |
| -- end; |
| |
| procedure Expand_Pragma_Abort_Defer (N : Node_Id) is |
| Loc : constant Source_Ptr := Sloc (N); |
| Stm : Node_Id; |
| Stms : List_Id; |
| HSS : Node_Id; |
| Blk : constant Entity_Id := |
| New_Internal_Entity (E_Block, Current_Scope, Sloc (N), 'B'); |
| AUD : constant Entity_Id := RTE (RE_Abort_Undefer_Direct); |
| |
| begin |
| Stms := New_List (Build_Runtime_Call (Loc, RE_Abort_Defer)); |
| loop |
| Stm := Remove_Next (N); |
| exit when No (Stm); |
| Append (Stm, Stms); |
| end loop; |
| |
| HSS := |
| Make_Handled_Sequence_Of_Statements (Loc, |
| Statements => Stms, |
| At_End_Proc => New_Occurrence_Of (AUD, Loc)); |
| |
| -- Present the Abort_Undefer_Direct function to the backend so that it |
| -- can inline the call to the function. |
| |
| Add_Inlined_Body (AUD, N); |
| |
| Rewrite (N, |
| Make_Block_Statement (Loc, |
| Handled_Statement_Sequence => HSS)); |
| |
| Set_Scope (Blk, Current_Scope); |
| Set_Etype (Blk, Standard_Void_Type); |
| Set_Identifier (N, New_Occurrence_Of (Blk, Sloc (N))); |
| Expand_At_End_Handler (HSS, Blk); |
| Analyze (N); |
| end Expand_Pragma_Abort_Defer; |
| |
| -------------------------- |
| -- Expand_Pragma_Check -- |
| -------------------------- |
| |
| procedure Expand_Pragma_Check (N : Node_Id) is |
| Cond : constant Node_Id := Arg2 (N); |
| Nam : constant Name_Id := Chars (Arg1 (N)); |
| Msg : Node_Id; |
| |
| Loc : constant Source_Ptr := Sloc (First_Node (Cond)); |
| -- Source location used in the case of a failed assertion: point to the |
| -- failing condition, not Loc. Note that the source location of the |
| -- expression is not usually the best choice here, because it points to |
| -- the location of the topmost tree node, which may be an operator in |
| -- the middle of the source text of the expression. For example, it gets |
| -- located on the last AND keyword in a chain of boolean expressiond |
| -- AND'ed together. It is best to put the message on the first character |
| -- of the condition, which is the effect of the First_Node call here. |
| -- This source location is used to build the default exception message, |
| -- and also as the sloc of the call to the runtime subprogram raising |
| -- Assert_Failure, so that coverage analysis tools can relate the |
| -- call to the failed check. |
| |
| begin |
| -- Nothing to do if pragma is ignored |
| |
| if Is_Ignored (N) then |
| return; |
| end if; |
| |
| -- Since this check is active, we rewrite the pragma into a |
| -- corresponding if statement, and then analyze the statement |
| |
| -- The normal case expansion transforms: |
| |
| -- pragma Check (name, condition [,message]); |
| |
| -- into |
| |
| -- if not condition then |
| -- System.Assertions.Raise_Assert_Failure (Str); |
| -- end if; |
| |
| -- where Str is the message if one is present, or the default of |
| -- name failed at file:line if no message is given (the "name failed |
| -- at" is omitted for name = Assertion, since it is redundant, given |
| -- that the name of the exception is Assert_Failure.) |
| |
| -- Also, instead of "XXX failed at", we generate slightly |
| -- different messages for some of the contract assertions (see |
| -- code below for details). |
| |
| -- An alternative expansion is used when the No_Exception_Propagation |
| -- restriction is active and there is a local Assert_Failure handler. |
| -- This is not a common combination of circumstances, but it occurs in |
| -- the context of Aunit and the zero footprint profile. In this case we |
| -- generate: |
| |
| -- if not condition then |
| -- raise Assert_Failure; |
| -- end if; |
| |
| -- This will then be transformed into a goto, and the local handler will |
| -- be able to handle the assert error (which would not be the case if a |
| -- call is made to the Raise_Assert_Failure procedure). |
| |
| -- We also generate the direct raise if the Suppress_Exception_Locations |
| -- is active, since we don't want to generate messages in this case. |
| |
| -- Note that the reason we do not always generate a direct raise is that |
| -- the form in which the procedure is called allows for more efficient |
| -- breakpointing of assertion errors. |
| |
| -- Generate the appropriate if statement. Note that we consider this to |
| -- be an explicit conditional in the source, not an implicit if, so we |
| -- do not call Make_Implicit_If_Statement. |
| |
| -- Case where we generate a direct raise |
| |
| if ((Debug_Flag_Dot_G |
| or else Restriction_Active (No_Exception_Propagation)) |
| and then Present (Find_Local_Handler (RTE (RE_Assert_Failure), N))) |
| or else (Opt.Exception_Locations_Suppressed and then No (Arg3 (N))) |
| then |
| Rewrite (N, |
| Make_If_Statement (Loc, |
| Condition => Make_Op_Not (Loc, Right_Opnd => Cond), |
| Then_Statements => New_List ( |
| Make_Raise_Statement (Loc, |
| Name => New_Occurrence_Of (RTE (RE_Assert_Failure), Loc))))); |
| |
| -- Case where we call the procedure |
| |
| else |
| -- If we have a message given, use it |
| |
| if Present (Arg3 (N)) then |
| Msg := Get_Pragma_Arg (Arg3 (N)); |
| |
| -- Here we have no string, so prepare one |
| |
| else |
| declare |
| Loc_Str : constant String := Build_Location_String (Loc); |
| |
| begin |
| Name_Len := 0; |
| |
| -- For Assert, we just use the location |
| |
| if Nam = Name_Assert then |
| null; |
| |
| -- For predicate, we generate the string "predicate failed |
| -- at yyy". We prefer all lower case for predicate. |
| |
| elsif Nam = Name_Predicate then |
| Add_Str_To_Name_Buffer ("predicate failed at "); |
| |
| -- For special case of Precondition/Postcondition the string is |
| -- "failed xx from yy" where xx is precondition/postcondition |
| -- in all lower case. The reason for this different wording is |
| -- that the failure is not at the point of occurrence of the |
| -- pragma, unlike the other Check cases. |
| |
| elsif Nam_In (Nam, Name_Precondition, Name_Postcondition) then |
| Get_Name_String (Nam); |
| Insert_Str_In_Name_Buffer ("failed ", 1); |
| Add_Str_To_Name_Buffer (" from "); |
| |
| -- For special case of Invariant, the string is "failed |
| -- invariant from yy", to be consistent with the string that is |
| -- generated for the aspect case (the code later on checks for |
| -- this specific string to modify it in some cases, so this is |
| -- functionally important). |
| |
| elsif Nam = Name_Invariant then |
| Add_Str_To_Name_Buffer ("failed invariant from "); |
| |
| -- For all other checks, the string is "xxx failed at yyy" |
| -- where xxx is the check name with current source file casing. |
| |
| else |
| Get_Name_String (Nam); |
| Set_Casing (Identifier_Casing (Current_Source_File)); |
| Add_Str_To_Name_Buffer (" failed at "); |
| end if; |
| |
| -- In all cases, add location string |
| |
| Add_Str_To_Name_Buffer (Loc_Str); |
| |
| -- Build the message |
| |
| Msg := Make_String_Literal (Loc, Name_Buffer (1 .. Name_Len)); |
| end; |
| end if; |
| |
| -- Now rewrite as an if statement |
| |
| Rewrite (N, |
| Make_If_Statement (Loc, |
| Condition => Make_Op_Not (Loc, Right_Opnd => Cond), |
| Then_Statements => New_List ( |
| Make_Procedure_Call_Statement (Loc, |
| Name => |
| New_Occurrence_Of (RTE (RE_Raise_Assert_Failure), Loc), |
| Parameter_Associations => New_List (Relocate_Node (Msg)))))); |
| end if; |
| |
| Analyze (N); |
| |
| -- If new condition is always false, give a warning |
| |
| if Warn_On_Assertion_Failure |
| and then Nkind (N) = N_Procedure_Call_Statement |
| and then Is_RTE (Entity (Name (N)), RE_Raise_Assert_Failure) |
| then |
| -- If original condition was a Standard.False, we assume that this is |
| -- indeed intended to raise assert error and no warning is required. |
| |
| if Is_Entity_Name (Original_Node (Cond)) |
| and then Entity (Original_Node (Cond)) = Standard_False |
| then |
| return; |
| |
| elsif Nam = Name_Assert then |
| Error_Msg_N ("?A?assertion will fail at run time", N); |
| else |
| |
| Error_Msg_N ("?A?check will fail at run time", N); |
| end if; |
| end if; |
| end Expand_Pragma_Check; |
| |
| --------------------------------- |
| -- Expand_Pragma_Common_Object -- |
| --------------------------------- |
| |
| -- Use a machine attribute to replicate semantic effect in DEC Ada |
| |
| -- pragma Machine_Attribute (intern_name, "common_object", extern_name); |
| |
| -- For now we do nothing with the size attribute ??? |
| |
| -- Note: Psect_Object shares this processing |
| |
| procedure Expand_Pragma_Common_Object (N : Node_Id) is |
| Loc : constant Source_Ptr := Sloc (N); |
| |
| Internal : constant Node_Id := Arg1 (N); |
| External : constant Node_Id := Arg2 (N); |
| |
| Psect : Node_Id; |
| -- Psect value upper cased as string literal |
| |
| Iloc : constant Source_Ptr := Sloc (Internal); |
| Eloc : constant Source_Ptr := Sloc (External); |
| Ploc : Source_Ptr; |
| |
| begin |
| -- Acquire Psect value and fold to upper case |
| |
| if Present (External) then |
| if Nkind (External) = N_String_Literal then |
| String_To_Name_Buffer (Strval (External)); |
| else |
| Get_Name_String (Chars (External)); |
| end if; |
| |
| Set_All_Upper_Case; |
| |
| Psect := |
| Make_String_Literal (Eloc, Strval => String_From_Name_Buffer); |
| |
| else |
| Get_Name_String (Chars (Internal)); |
| Set_All_Upper_Case; |
| Psect := |
| Make_String_Literal (Iloc, Strval => String_From_Name_Buffer); |
| end if; |
| |
| Ploc := Sloc (Psect); |
| |
| -- Insert the pragma |
| |
| Insert_After_And_Analyze (N, |
| Make_Pragma (Loc, |
| Chars => Name_Machine_Attribute, |
| Pragma_Argument_Associations => New_List ( |
| Make_Pragma_Argument_Association (Iloc, |
| Expression => New_Copy_Tree (Internal)), |
| Make_Pragma_Argument_Association (Eloc, |
| Expression => |
| Make_String_Literal (Sloc => Ploc, Strval => "common_object")), |
| Make_Pragma_Argument_Association (Ploc, |
| Expression => New_Copy_Tree (Psect))))); |
| end Expand_Pragma_Common_Object; |
| |
| --------------------------------------- |
| -- Expand_Pragma_Import_Or_Interface -- |
| --------------------------------------- |
| |
| procedure Expand_Pragma_Import_Or_Interface (N : Node_Id) is |
| Def_Id : Entity_Id; |
| |
| begin |
| -- In Relaxed_RM_Semantics, support old Ada 83 style: |
| -- pragma Import (Entity, "external name"); |
| |
| if Relaxed_RM_Semantics |
| and then List_Length (Pragma_Argument_Associations (N)) = 2 |
| and then Chars (Pragma_Identifier (N)) = Name_Import |
| and then Nkind (Arg2 (N)) = N_String_Literal |
| then |
| Def_Id := Entity (Arg1 (N)); |
| else |
| Def_Id := Entity (Arg2 (N)); |
| end if; |
| |
| -- Variable case (we have to undo any initialization already done) |
| |
| if Ekind (Def_Id) = E_Variable then |
| Undo_Initialization (Def_Id, N); |
| |
| -- Case of exception with convention C++ |
| |
| elsif Ekind (Def_Id) = E_Exception |
| and then Convention (Def_Id) = Convention_CPP |
| then |
| -- Import a C++ convention |
| |
| declare |
| Loc : constant Source_Ptr := Sloc (N); |
| Rtti_Name : constant Node_Id := Arg3 (N); |
| Dum : constant Entity_Id := Make_Temporary (Loc, 'D'); |
| Exdata : List_Id; |
| Lang_Char : Node_Id; |
| Foreign_Data : Node_Id; |
| |
| begin |
| Exdata := Component_Associations (Expression (Parent (Def_Id))); |
| |
| Lang_Char := Next (First (Exdata)); |
| |
| -- Change the one-character language designator to 'C' |
| |
| Rewrite (Expression (Lang_Char), |
| Make_Character_Literal (Loc, |
| Chars => Name_uC, |
| Char_Literal_Value => UI_From_Int (Character'Pos ('C')))); |
| Analyze (Expression (Lang_Char)); |
| |
| -- Change the value of Foreign_Data |
| |
| Foreign_Data := Next (Next (Next (Next (Lang_Char)))); |
| |
| Insert_Actions (Def_Id, New_List ( |
| Make_Object_Declaration (Loc, |
| Defining_Identifier => Dum, |
| Object_Definition => |
| New_Occurrence_Of (Standard_Character, Loc)), |
| |
| Make_Pragma (Loc, |
| Chars => Name_Import, |
| Pragma_Argument_Associations => New_List ( |
| Make_Pragma_Argument_Association (Loc, |
| Expression => Make_Identifier (Loc, Name_Ada)), |
| |
| Make_Pragma_Argument_Association (Loc, |
| Expression => Make_Identifier (Loc, Chars (Dum))), |
| |
| Make_Pragma_Argument_Association (Loc, |
| Chars => Name_External_Name, |
| Expression => Relocate_Node (Rtti_Name)))))); |
| |
| Rewrite (Expression (Foreign_Data), |
| Unchecked_Convert_To (Standard_A_Char, |
| Make_Attribute_Reference (Loc, |
| Prefix => Make_Identifier (Loc, Chars (Dum)), |
| Attribute_Name => Name_Address))); |
| Analyze (Expression (Foreign_Data)); |
| end; |
| |
| -- No special expansion required for any other case |
| |
| else |
| null; |
| end if; |
| end Expand_Pragma_Import_Or_Interface; |
| |
| ------------------------------------- |
| -- Expand_Pragma_Initial_Condition -- |
| ------------------------------------- |
| |
| procedure Expand_Pragma_Initial_Condition (Spec_Or_Body : Node_Id) is |
| Loc : constant Source_Ptr := Sloc (Spec_Or_Body); |
| Check : Node_Id; |
| Expr : Node_Id; |
| Init_Cond : Node_Id; |
| List : List_Id; |
| Pack_Id : Entity_Id; |
| |
| begin |
| if Nkind (Spec_Or_Body) = N_Package_Body then |
| Pack_Id := Corresponding_Spec (Spec_Or_Body); |
| |
| if Present (Handled_Statement_Sequence (Spec_Or_Body)) then |
| List := Statements (Handled_Statement_Sequence (Spec_Or_Body)); |
| |
| -- The package body lacks statements, create an empty list |
| |
| else |
| List := New_List; |
| |
| Set_Handled_Statement_Sequence (Spec_Or_Body, |
| Make_Handled_Sequence_Of_Statements (Loc, Statements => List)); |
| end if; |
| |
| elsif Nkind (Spec_Or_Body) = N_Package_Declaration then |
| Pack_Id := Defining_Entity (Spec_Or_Body); |
| |
| if Present (Visible_Declarations (Specification (Spec_Or_Body))) then |
| List := Visible_Declarations (Specification (Spec_Or_Body)); |
| |
| -- The package lacks visible declarations, create an empty list |
| |
| else |
| List := New_List; |
| |
| Set_Visible_Declarations (Specification (Spec_Or_Body), List); |
| end if; |
| |
| -- This routine should not be used on anything other than packages |
| |
| else |
| raise Program_Error; |
| end if; |
| |
| Init_Cond := Get_Pragma (Pack_Id, Pragma_Initial_Condition); |
| |
| -- The caller should check whether the package is subject to pragma |
| -- Initial_Condition. |
| |
| pragma Assert (Present (Init_Cond)); |
| |
| Expr := |
| Get_Pragma_Arg (First (Pragma_Argument_Associations (Init_Cond))); |
| |
| -- The assertion expression was found to be illegal, do not generate the |
| -- runtime check as it will repeat the illegality. |
| |
| if Error_Posted (Init_Cond) or else Error_Posted (Expr) then |
| return; |
| end if; |
| |
| -- Generate: |
| -- pragma Check (Initial_Condition, <Expr>); |
| |
| Check := |
| Make_Pragma (Loc, |
| Chars => Name_Check, |
| Pragma_Argument_Associations => New_List ( |
| Make_Pragma_Argument_Association (Loc, |
| Expression => Make_Identifier (Loc, Name_Initial_Condition)), |
| |
| Make_Pragma_Argument_Association (Loc, |
| Expression => New_Copy_Tree (Expr)))); |
| |
| Append_To (List, Check); |
| Analyze (Check); |
| end Expand_Pragma_Initial_Condition; |
| |
| ------------------------------------ |
| -- Expand_Pragma_Inspection_Point -- |
| ------------------------------------ |
| |
| -- If no argument is given, then we supply a default argument list that |
| -- includes all objects declared at the source level in all subprograms |
| -- that enclose the inspection point pragma. |
| |
| procedure Expand_Pragma_Inspection_Point (N : Node_Id) is |
| Loc : constant Source_Ptr := Sloc (N); |
| A : List_Id; |
| Assoc : Node_Id; |
| S : Entity_Id; |
| E : Entity_Id; |
| |
| begin |
| if No (Pragma_Argument_Associations (N)) then |
| A := New_List; |
| S := Current_Scope; |
| |
| while S /= Standard_Standard loop |
| E := First_Entity (S); |
| while Present (E) loop |
| if Comes_From_Source (E) |
| and then Is_Object (E) |
| and then not Is_Entry_Formal (E) |
| and then Ekind (E) /= E_Component |
| and then Ekind (E) /= E_Discriminant |
| and then Ekind (E) /= E_Generic_In_Parameter |
| and then Ekind (E) /= E_Generic_In_Out_Parameter |
| then |
| Append_To (A, |
| Make_Pragma_Argument_Association (Loc, |
| Expression => New_Occurrence_Of (E, Loc))); |
| end if; |
| |
| Next_Entity (E); |
| end loop; |
| |
| S := Scope (S); |
| end loop; |
| |
| Set_Pragma_Argument_Associations (N, A); |
| end if; |
| |
| -- Expand the arguments of the pragma. Expanding an entity reference |
| -- is a noop, except in a protected operation, where a reference may |
| -- have to be transformed into a reference to the corresponding prival. |
| -- Are there other pragmas that may require this ??? |
| |
| Assoc := First (Pragma_Argument_Associations (N)); |
| |
| while Present (Assoc) loop |
| Expand (Expression (Assoc)); |
| Next (Assoc); |
| end loop; |
| end Expand_Pragma_Inspection_Point; |
| |
| -------------------------------------- |
| -- Expand_Pragma_Interrupt_Priority -- |
| -------------------------------------- |
| |
| -- Supply default argument if none exists (System.Interrupt_Priority'Last) |
| |
| procedure Expand_Pragma_Interrupt_Priority (N : Node_Id) is |
| Loc : constant Source_Ptr := Sloc (N); |
| |
| begin |
| if No (Pragma_Argument_Associations (N)) then |
| Set_Pragma_Argument_Associations (N, New_List ( |
| Make_Pragma_Argument_Association (Loc, |
| Expression => |
| Make_Attribute_Reference (Loc, |
| Prefix => |
| New_Occurrence_Of (RTE (RE_Interrupt_Priority), Loc), |
| Attribute_Name => Name_Last)))); |
| end if; |
| end Expand_Pragma_Interrupt_Priority; |
| |
| -------------------------------- |
| -- Expand_Pragma_Loop_Variant -- |
| -------------------------------- |
| |
| -- Pragma Loop_Variant is expanded in the following manner: |
| |
| -- Original code |
| |
| -- for | while ... loop |
| -- <preceding source statements> |
| -- pragma Loop_Variant |
| -- (Increases => Incr_Expr, |
| -- Decreases => Decr_Expr); |
| -- <succeeding source statements> |
| -- end loop; |
| |
| -- Expanded code |
| |
| -- Curr_1 : <type of Incr_Expr>; |
| -- Curr_2 : <type of Decr_Expr>; |
| -- Old_1 : <type of Incr_Expr>; |
| -- Old_2 : <type of Decr_Expr>; |
| -- Flag : Boolean := False; |
| |
| -- for | while ... loop |
| -- <preceding source statements> |
| |
| -- if Flag then |
| -- Old_1 := Curr_1; |
| -- Old_2 := Curr_2; |
| -- end if; |
| |
| -- Curr_1 := <Incr_Expr>; |
| -- Curr_2 := <Decr_Expr>; |
| |
| -- if Flag then |
| -- if Curr_1 /= Old_1 then |
| -- pragma Check (Loop_Variant, Curr_1 > Old_1); |
| -- else |
| -- pragma Check (Loop_Variant, Curr_2 < Old_2); |
| -- end if; |
| -- else |
| -- Flag := True; |
| -- end if; |
| |
| -- <succeeding source statements> |
| -- end loop; |
| |
| procedure Expand_Pragma_Loop_Variant (N : Node_Id) is |
| Loc : constant Source_Ptr := Sloc (N); |
| |
| Last_Var : constant Node_Id := Last (Pragma_Argument_Associations (N)); |
| |
| Curr_Assign : List_Id := No_List; |
| Flag_Id : Entity_Id := Empty; |
| If_Stmt : Node_Id := Empty; |
| Old_Assign : List_Id := No_List; |
| Loop_Scop : Entity_Id; |
| Loop_Stmt : Node_Id; |
| Variant : Node_Id; |
| |
| procedure Process_Variant (Variant : Node_Id; Is_Last : Boolean); |
| -- Process a single increasing / decreasing termination variant. Flag |
| -- Is_Last should be set when processing the last variant. |
| |
| --------------------- |
| -- Process_Variant -- |
| --------------------- |
| |
| procedure Process_Variant (Variant : Node_Id; Is_Last : Boolean) is |
| function Make_Op |
| (Loc : Source_Ptr; |
| Curr_Val : Node_Id; |
| Old_Val : Node_Id) return Node_Id; |
| -- Generate a comparison between Curr_Val and Old_Val depending on |
| -- the change mode (Increases / Decreases) of the variant. |
| |
| ------------- |
| -- Make_Op -- |
| ------------- |
| |
| function Make_Op |
| (Loc : Source_Ptr; |
| Curr_Val : Node_Id; |
| Old_Val : Node_Id) return Node_Id |
| is |
| begin |
| if Chars (Variant) = Name_Increases then |
| return Make_Op_Gt (Loc, Curr_Val, Old_Val); |
| else pragma Assert (Chars (Variant) = Name_Decreases); |
| return Make_Op_Lt (Loc, Curr_Val, Old_Val); |
| end if; |
| end Make_Op; |
| |
| -- Local variables |
| |
| Expr : constant Node_Id := Expression (Variant); |
| Expr_Typ : constant Entity_Id := Etype (Expr); |
| Loc : constant Source_Ptr := Sloc (Expr); |
| Loop_Loc : constant Source_Ptr := Sloc (Loop_Stmt); |
| Curr_Id : Entity_Id; |
| Old_Id : Entity_Id; |
| Prag : Node_Id; |
| |
| -- Start of processing for Process_Variant |
| |
| begin |
| -- All temporaries generated in this routine must be inserted before |
| -- the related loop statement. Ensure that the proper scope is on the |
| -- stack when analyzing the temporaries. Note that we also use the |
| -- Sloc of the related loop. |
| |
| Push_Scope (Scope (Loop_Scop)); |
| |
| -- Step 1: Create the declaration of the flag which controls the |
| -- behavior of the assertion on the first iteration of the loop. |
| |
| if No (Flag_Id) then |
| |
| -- Generate: |
| -- Flag : Boolean := False; |
| |
| Flag_Id := Make_Temporary (Loop_Loc, 'F'); |
| |
| Insert_Action (Loop_Stmt, |
| Make_Object_Declaration (Loop_Loc, |
| Defining_Identifier => Flag_Id, |
| Object_Definition => |
| New_Occurrence_Of (Standard_Boolean, Loop_Loc), |
| Expression => |
| New_Occurrence_Of (Standard_False, Loop_Loc))); |
| |
| -- Prevent an unwanted optimization where the Current_Value of |
| -- the flag eliminates the if statement which stores the variant |
| -- values coming from the previous iteration. |
| |
| -- Flag : Boolean := False; |
| -- loop |
| -- if Flag then -- condition rewritten to False |
| -- Old_N := Curr_N; -- and if statement eliminated |
| -- end if; |
| -- . . . |
| -- Flag := True; |
| -- end loop; |
| |
| Set_Current_Value (Flag_Id, Empty); |
| end if; |
| |
| -- Step 2: Create the temporaries which store the old and current |
| -- values of the associated expression. |
| |
| -- Generate: |
| -- Curr : <type of Expr>; |
| |
| Curr_Id := Make_Temporary (Loc, 'C'); |
| |
| Insert_Action (Loop_Stmt, |
| Make_Object_Declaration (Loop_Loc, |
| Defining_Identifier => Curr_Id, |
| Object_Definition => New_Occurrence_Of (Expr_Typ, Loop_Loc))); |
| |
| -- Generate: |
| -- Old : <type of Expr>; |
| |
| Old_Id := Make_Temporary (Loc, 'P'); |
| |
| Insert_Action (Loop_Stmt, |
| Make_Object_Declaration (Loop_Loc, |
| Defining_Identifier => Old_Id, |
| Object_Definition => New_Occurrence_Of (Expr_Typ, Loop_Loc))); |
| |
| -- Restore original scope after all temporaries have been analyzed |
| |
| Pop_Scope; |
| |
| -- Step 3: Store value of the expression from the previous iteration |
| |
| if No (Old_Assign) then |
| Old_Assign := New_List; |
| end if; |
| |
| -- Generate: |
| -- Old := Curr; |
| |
| Append_To (Old_Assign, |
| Make_Assignment_Statement (Loc, |
| Name => New_Occurrence_Of (Old_Id, Loc), |
| Expression => New_Occurrence_Of (Curr_Id, Loc))); |
| |
| -- Step 4: Store the current value of the expression |
| |
| if No (Curr_Assign) then |
| Curr_Assign := New_List; |
| end if; |
| |
| -- Generate: |
| -- Curr := <Expr>; |
| |
| Append_To (Curr_Assign, |
| Make_Assignment_Statement (Loc, |
| Name => New_Occurrence_Of (Curr_Id, Loc), |
| Expression => Relocate_Node (Expr))); |
| |
| -- Step 5: Create corresponding assertion to verify change of value |
| |
| -- Generate: |
| -- pragma Check (Loop_Variant, Curr <|> Old); |
| |
| Prag := |
| Make_Pragma (Loc, |
| Chars => Name_Check, |
| Pragma_Argument_Associations => New_List ( |
| Make_Pragma_Argument_Association (Loc, |
| Expression => Make_Identifier (Loc, Name_Loop_Variant)), |
| Make_Pragma_Argument_Association (Loc, |
| Expression => |
| Make_Op (Loc, |
| Curr_Val => New_Occurrence_Of (Curr_Id, Loc), |
| Old_Val => New_Occurrence_Of (Old_Id, Loc))))); |
| |
| -- Generate: |
| -- if Curr /= Old then |
| -- <Prag>; |
| |
| if No (If_Stmt) then |
| |
| -- When there is just one termination variant, do not compare the |
| -- old and current value for equality, just check the pragma. |
| |
| if Is_Last then |
| If_Stmt := Prag; |
| else |
| If_Stmt := |
| Make_If_Statement (Loc, |
| Condition => |
| Make_Op_Ne (Loc, |
| Left_Opnd => New_Occurrence_Of (Curr_Id, Loc), |
| Right_Opnd => New_Occurrence_Of (Old_Id, Loc)), |
| Then_Statements => New_List (Prag)); |
| end if; |
| |
| -- Generate: |
| -- else |
| -- <Prag>; |
| -- end if; |
| |
| elsif Is_Last then |
| Set_Else_Statements (If_Stmt, New_List (Prag)); |
| |
| -- Generate: |
| -- elsif Curr /= Old then |
| -- <Prag>; |
| |
| else |
| if Elsif_Parts (If_Stmt) = No_List then |
| Set_Elsif_Parts (If_Stmt, New_List); |
| end if; |
| |
| Append_To (Elsif_Parts (If_Stmt), |
| Make_Elsif_Part (Loc, |
| Condition => |
| Make_Op_Ne (Loc, |
| Left_Opnd => New_Occurrence_Of (Curr_Id, Loc), |
| Right_Opnd => New_Occurrence_Of (Old_Id, Loc)), |
| Then_Statements => New_List (Prag))); |
| end if; |
| end Process_Variant; |
| |
| -- Start of processing for Expand_Pragma_Loop_Variant |
| |
| begin |
| -- If pragma is not enabled, rewrite as Null statement. If pragma is |
| -- disabled, it has already been rewritten as a Null statement. |
| |
| if Is_Ignored (N) then |
| Rewrite (N, Make_Null_Statement (Loc)); |
| Analyze (N); |
| return; |
| end if; |
| |
| -- Locate the enclosing loop for which this assertion applies. In the |
| -- case of Ada 2012 array iteration, we might be dealing with nested |
| -- loops. Only the outermost loop has an identifier. |
| |
| Loop_Stmt := N; |
| while Present (Loop_Stmt) loop |
| if Nkind (Loop_Stmt) = N_Loop_Statement |
| and then Present (Identifier (Loop_Stmt)) |
| then |
| exit; |
| end if; |
| |
| Loop_Stmt := Parent (Loop_Stmt); |
| end loop; |
| |
| Loop_Scop := Entity (Identifier (Loop_Stmt)); |
| |
| -- Create the circuitry which verifies individual variants |
| |
| Variant := First (Pragma_Argument_Associations (N)); |
| while Present (Variant) loop |
| Process_Variant (Variant, Is_Last => Variant = Last_Var); |
| |
| Next (Variant); |
| end loop; |
| |
| -- Construct the segment which stores the old values of all expressions. |
| -- Generate: |
| -- if Flag then |
| -- <Old_Assign> |
| -- end if; |
| |
| Insert_Action (N, |
| Make_If_Statement (Loc, |
| Condition => New_Occurrence_Of (Flag_Id, Loc), |
| Then_Statements => Old_Assign)); |
| |
| -- Update the values of all expressions |
| |
| Insert_Actions (N, Curr_Assign); |
| |
| -- Add the assertion circuitry to test all changes in expressions. |
| -- Generate: |
| -- if Flag then |
| -- <If_Stmt> |
| -- else |
| -- Flag := True; |
| -- end if; |
| |
| Insert_Action (N, |
| Make_If_Statement (Loc, |
| Condition => New_Occurrence_Of (Flag_Id, Loc), |
| Then_Statements => New_List (If_Stmt), |
| Else_Statements => New_List ( |
| Make_Assignment_Statement (Loc, |
| Name => New_Occurrence_Of (Flag_Id, Loc), |
| Expression => New_Occurrence_Of (Standard_True, Loc))))); |
| |
| -- Note: the pragma has been completely transformed into a sequence of |
| -- corresponding declarations and statements. We leave it in the tree |
| -- for documentation purposes. It will be ignored by the backend. |
| |
| end Expand_Pragma_Loop_Variant; |
| |
| -------------------------------- |
| -- Expand_Pragma_Psect_Object -- |
| -------------------------------- |
| |
| -- Convert to Common_Object, and expand the resulting pragma |
| |
| procedure Expand_Pragma_Psect_Object (N : Node_Id) |
| renames Expand_Pragma_Common_Object; |
| |
| ------------------------------------- |
| -- Expand_Pragma_Relative_Deadline -- |
| ------------------------------------- |
| |
| procedure Expand_Pragma_Relative_Deadline (N : Node_Id) is |
| P : constant Node_Id := Parent (N); |
| Loc : constant Source_Ptr := Sloc (N); |
| |
| begin |
| -- Expand the pragma only in the case of the main subprogram. For tasks |
| -- the expansion is done in exp_ch9. Generate a call to Set_Deadline |
| -- at Clock plus the relative deadline specified in the pragma. Time |
| -- values are translated into Duration to allow for non-private |
| -- addition operation. |
| |
| if Nkind (P) = N_Subprogram_Body then |
| Rewrite |
| (N, |
| Make_Procedure_Call_Statement (Loc, |
| Name => New_Occurrence_Of (RTE (RE_Set_Deadline), Loc), |
| Parameter_Associations => New_List ( |
| Unchecked_Convert_To (RTE (RO_RT_Time), |
| Make_Op_Add (Loc, |
| Left_Opnd => |
| Make_Function_Call (Loc, |
| New_Occurrence_Of (RTE (RO_RT_To_Duration), Loc), |
| New_List (Make_Function_Call (Loc, |
| New_Occurrence_Of (RTE (RE_Clock), Loc)))), |
| Right_Opnd => |
| Unchecked_Convert_To (Standard_Duration, Arg1 (N))))))); |
| |
| Analyze (N); |
| end if; |
| end Expand_Pragma_Relative_Deadline; |
| |
| ------------------------------------------- |
| -- Expand_Pragma_Suppress_Initialization -- |
| ------------------------------------------- |
| |
| procedure Expand_Pragma_Suppress_Initialization (N : Node_Id) is |
| Def_Id : constant Entity_Id := Entity (Arg1 (N)); |
| |
| begin |
| -- Variable case (we have to undo any initialization already done) |
| |
| if Ekind (Def_Id) = E_Variable then |
| Undo_Initialization (Def_Id, N); |
| end if; |
| end Expand_Pragma_Suppress_Initialization; |
| |
| ------------------------- |
| -- Undo_Initialization -- |
| ------------------------- |
| |
| procedure Undo_Initialization (Def_Id : Entity_Id; N : Node_Id) is |
| Init_Call : Node_Id; |
| |
| begin |
| -- When applied to a variable, the default initialization must not be |
| -- done. As it is already done when the pragma is found, we just get rid |
| -- of the call the initialization procedure which followed the object |
| -- declaration. The call is inserted after the declaration, but validity |
| -- checks may also have been inserted and thus the initialization call |
| -- does not necessarily appear immediately after the object declaration. |
| |
| -- We can't use the freezing mechanism for this purpose, since we have |
| -- to elaborate the initialization expression when it is first seen (so |
| -- this elaboration cannot be deferred to the freeze point). |
| |
| -- Find and remove generated initialization call for object, if any |
| |
| Init_Call := Remove_Init_Call (Def_Id, Rep_Clause => N); |
| |
| -- Any default initialization expression should be removed (e.g. |
| -- null defaults for access objects, zero initialization of packed |
| -- bit arrays). Imported objects aren't allowed to have explicit |
| -- initialization, so the expression must have been generated by |
| -- the compiler. |
| |
| if No (Init_Call) and then Present (Expression (Parent (Def_Id))) then |
| Set_Expression (Parent (Def_Id), Empty); |
| end if; |
| |
| -- The object may not have any initialization, but in the presence of |
| -- Initialize_Scalars code is inserted after then declaration, which |
| -- must now be removed as well. The code carries the same source |
| -- location as the declaration itself. |
| |
| if Initialize_Scalars and then Is_Array_Type (Etype (Def_Id)) then |
| declare |
| Init : Node_Id; |
| Nxt : Node_Id; |
| begin |
| Init := Next (Parent (Def_Id)); |
| while not Comes_From_Source (Init) |
| and then Sloc (Init) = Sloc (Def_Id) |
| loop |
| Nxt := Next (Init); |
| Remove (Init); |
| Init := Nxt; |
| end loop; |
| end; |
| end if; |
| end Undo_Initialization; |
| |
| end Exp_Prag; |
