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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- C O N T R A C T S --
-- --
-- B o d y --
-- --
-- Copyright (C) 2015-2022, 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 Aspects; use Aspects;
with Atree; use Atree;
with Einfo; use Einfo;
with Einfo.Entities; use Einfo.Entities;
with Einfo.Utils; use Einfo.Utils;
with Elists; use Elists;
with Errout; use Errout;
with Exp_Prag; use Exp_Prag;
with Exp_Tss; use Exp_Tss;
with Exp_Util; use Exp_Util;
with Freeze; use Freeze;
with Lib; use Lib;
with Namet; use Namet;
with Nlists; use Nlists;
with Nmake; use Nmake;
with Opt; use Opt;
with Sem; use Sem;
with Sem_Aux; use Sem_Aux;
with Sem_Ch6; use Sem_Ch6;
with Sem_Ch8; use Sem_Ch8;
with Sem_Ch12; use Sem_Ch12;
with Sem_Ch13; use Sem_Ch13;
with Sem_Disp; use Sem_Disp;
with Sem_Prag; use Sem_Prag;
with Sem_Res; use Sem_Res;
with Sem_Type; use Sem_Type;
with Sem_Util; use Sem_Util;
with Sinfo; use Sinfo;
with Sinfo.Nodes; use Sinfo.Nodes;
with Sinfo.Utils; use Sinfo.Utils;
with Sinput; use Sinput;
with Snames; use Snames;
with Stand; use Stand;
with Stringt; use Stringt;
with Tbuild; use Tbuild;
package body Contracts is
procedure Analyze_Package_Instantiation_Contract (Inst_Id : Entity_Id);
-- Analyze all delayed pragmas chained on the contract of package
-- instantiation Inst_Id as if they appear at the end of a declarative
-- region. The pragmas in question are:
--
-- Part_Of
procedure Check_Class_Condition
(Cond : Node_Id;
Subp : Entity_Id;
Par_Subp : Entity_Id;
Is_Precondition : Boolean);
-- Perform checking of class-wide pre/postcondition Cond inherited by Subp
-- from Par_Subp. Is_Precondition enables check specific for preconditions.
-- In SPARK_Mode, an inherited operation that is not overridden but has
-- inherited modified conditions pre/postconditions is illegal.
procedure Check_Type_Or_Object_External_Properties
(Type_Or_Obj_Id : Entity_Id);
-- Perform checking of external properties pragmas that is common to both
-- type declarations and object declarations.
procedure Expand_Subprogram_Contract (Body_Id : Entity_Id);
-- Expand the contracts of a subprogram body and its correspoding spec (if
-- any). This routine processes all [refined] pre- and postconditions as
-- well as Contract_Cases, Subprogram_Variant, invariants and predicates.
-- Body_Id denotes the entity of the subprogram body.
procedure Set_Class_Condition
(Kind : Condition_Kind;
Subp : Entity_Id;
Cond : Node_Id);
-- Set the class-wide Kind condition of Subp
-----------------------
-- Add_Contract_Item --
-----------------------
procedure Add_Contract_Item (Prag : Node_Id; Id : Entity_Id) is
Items : Node_Id := Contract (Id);
procedure Add_Classification;
-- Prepend Prag to the list of classifications
procedure Add_Contract_Test_Case;
-- Prepend Prag to the list of contract and test cases
procedure Add_Pre_Post_Condition;
-- Prepend Prag to the list of pre- and postconditions
------------------------
-- Add_Classification --
------------------------
procedure Add_Classification is
begin
Set_Next_Pragma (Prag, Classifications (Items));
Set_Classifications (Items, Prag);
end Add_Classification;
----------------------------
-- Add_Contract_Test_Case --
----------------------------
procedure Add_Contract_Test_Case is
begin
Set_Next_Pragma (Prag, Contract_Test_Cases (Items));
Set_Contract_Test_Cases (Items, Prag);
end Add_Contract_Test_Case;
----------------------------
-- Add_Pre_Post_Condition --
----------------------------
procedure Add_Pre_Post_Condition is
begin
Set_Next_Pragma (Prag, Pre_Post_Conditions (Items));
Set_Pre_Post_Conditions (Items, Prag);
end Add_Pre_Post_Condition;
-- Local variables
-- A contract must contain only pragmas
pragma Assert (Nkind (Prag) = N_Pragma);
Prag_Nam : constant Name_Id := Pragma_Name (Prag);
-- Start of processing for Add_Contract_Item
begin
-- Create a new contract when adding the first item
if No (Items) then
Items := Make_Contract (Sloc (Id));
Set_Contract (Id, Items);
end if;
-- Constants, the applicable pragmas are:
-- Part_Of
if Ekind (Id) = E_Constant then
if Prag_Nam in Name_Async_Readers
| Name_Async_Writers
| Name_Effective_Reads
| Name_Effective_Writes
| Name_No_Caching
| Name_Part_Of
then
Add_Classification;
-- The pragma is not a proper contract item
else
raise Program_Error;
end if;
-- Entry bodies, the applicable pragmas are:
-- Refined_Depends
-- Refined_Global
-- Refined_Post
elsif Is_Entry_Body (Id) then
if Prag_Nam in Name_Refined_Depends | Name_Refined_Global then
Add_Classification;
elsif Prag_Nam = Name_Refined_Post then
Add_Pre_Post_Condition;
-- The pragma is not a proper contract item
else
raise Program_Error;
end if;
-- Entry or subprogram declarations, the applicable pragmas are:
-- Attach_Handler
-- Contract_Cases
-- Depends
-- Extensions_Visible
-- Global
-- Interrupt_Handler
-- Postcondition
-- Precondition
-- Test_Case
-- Volatile_Function
elsif Is_Entry_Declaration (Id)
or else Ekind (Id) in E_Function
| E_Generic_Function
| E_Generic_Procedure
| E_Procedure
then
if Prag_Nam in Name_Attach_Handler | Name_Interrupt_Handler
and then Ekind (Id) in E_Generic_Procedure | E_Procedure
then
Add_Classification;
elsif Prag_Nam in Name_Depends
| Name_Extensions_Visible
| Name_Global
then
Add_Classification;
elsif Prag_Nam = Name_Volatile_Function
and then Ekind (Id) in E_Function | E_Generic_Function
then
Add_Classification;
elsif Prag_Nam in Name_Contract_Cases
| Name_Subprogram_Variant
| Name_Test_Case
then
Add_Contract_Test_Case;
elsif Prag_Nam in Name_Postcondition | Name_Precondition then
Add_Pre_Post_Condition;
-- The pragma is not a proper contract item
else
raise Program_Error;
end if;
-- Packages or instantiations, the applicable pragmas are:
-- Abstract_States
-- Initial_Condition
-- Initializes
-- Part_Of (instantiation only)
elsif Is_Package_Or_Generic_Package (Id) then
if Prag_Nam in Name_Abstract_State
| Name_Initial_Condition
| Name_Initializes
then
Add_Classification;
-- Indicator Part_Of must be associated with a package instantiation
elsif Prag_Nam = Name_Part_Of and then Is_Generic_Instance (Id) then
Add_Classification;
-- The pragma is not a proper contract item
else
raise Program_Error;
end if;
-- Package bodies, the applicable pragmas are:
-- Refined_States
elsif Ekind (Id) = E_Package_Body then
if Prag_Nam = Name_Refined_State then
Add_Classification;
-- The pragma is not a proper contract item
else
raise Program_Error;
end if;
-- The four volatility refinement pragmas are ok for all types.
-- Part_Of is ok for task types and protected types.
-- Depends and Global are ok for task types.
elsif Is_Type (Id) then
declare
Is_OK : constant Boolean :=
Prag_Nam in Name_Async_Readers
| Name_Async_Writers
| Name_Effective_Reads
| Name_Effective_Writes
or else (Ekind (Id) = E_Task_Type
and Prag_Nam in Name_Part_Of
| Name_Depends
| Name_Global)
or else (Ekind (Id) = E_Protected_Type
and Prag_Nam = Name_Part_Of);
begin
if Is_OK then
Add_Classification;
else
-- The pragma is not a proper contract item
raise Program_Error;
end if;
end;
-- Subprogram bodies, the applicable pragmas are:
-- Postcondition
-- Precondition
-- Refined_Depends
-- Refined_Global
-- Refined_Post
elsif Ekind (Id) = E_Subprogram_Body then
if Prag_Nam in Name_Refined_Depends | Name_Refined_Global then
Add_Classification;
elsif Prag_Nam in Name_Postcondition
| Name_Precondition
| Name_Refined_Post
then
Add_Pre_Post_Condition;
-- The pragma is not a proper contract item
else
raise Program_Error;
end if;
-- Task bodies, the applicable pragmas are:
-- Refined_Depends
-- Refined_Global
elsif Ekind (Id) = E_Task_Body then
if Prag_Nam in Name_Refined_Depends | Name_Refined_Global then
Add_Classification;
-- The pragma is not a proper contract item
else
raise Program_Error;
end if;
-- Task units, the applicable pragmas are:
-- Depends
-- Global
-- Part_Of
-- Variables, the applicable pragmas are:
-- Async_Readers
-- Async_Writers
-- Constant_After_Elaboration
-- Depends
-- Effective_Reads
-- Effective_Writes
-- Global
-- No_Caching
-- Part_Of
elsif Ekind (Id) = E_Variable then
if Prag_Nam in Name_Async_Readers
| Name_Async_Writers
| Name_Constant_After_Elaboration
| Name_Depends
| Name_Effective_Reads
| Name_Effective_Writes
| Name_Global
| Name_No_Caching
| Name_Part_Of
then
Add_Classification;
-- The pragma is not a proper contract item
else
raise Program_Error;
end if;
else
raise Program_Error;
end if;
end Add_Contract_Item;
-----------------------
-- Analyze_Contracts --
-----------------------
procedure Analyze_Contracts (L : List_Id) is
Decl : Node_Id;
begin
Decl := First (L);
while Present (Decl) loop
-- Entry or subprogram declarations
if Nkind (Decl) in N_Abstract_Subprogram_Declaration
| N_Entry_Declaration
| N_Generic_Subprogram_Declaration
| N_Subprogram_Declaration
then
Analyze_Entry_Or_Subprogram_Contract (Defining_Entity (Decl));
-- Entry or subprogram bodies
elsif Nkind (Decl) in N_Entry_Body | N_Subprogram_Body then
Analyze_Entry_Or_Subprogram_Body_Contract (Defining_Entity (Decl));
-- Objects
elsif Nkind (Decl) = N_Object_Declaration then
Analyze_Object_Contract (Defining_Entity (Decl));
-- Package instantiation
elsif Nkind (Decl) = N_Package_Instantiation then
Analyze_Package_Instantiation_Contract (Defining_Entity (Decl));
-- Protected units
elsif Nkind (Decl) in N_Protected_Type_Declaration
| N_Single_Protected_Declaration
then
Analyze_Protected_Contract (Defining_Entity (Decl));
-- Subprogram body stubs
elsif Nkind (Decl) = N_Subprogram_Body_Stub then
Analyze_Subprogram_Body_Stub_Contract (Defining_Entity (Decl));
-- Task units
elsif Nkind (Decl) in N_Single_Task_Declaration
| N_Task_Type_Declaration
then
Analyze_Task_Contract (Defining_Entity (Decl));
-- For type declarations, we need to do the preanalysis of Iterable
-- and the 3 Xxx_Literal aspect specifications.
-- Other type aspects need to be resolved here???
elsif Nkind (Decl) = N_Private_Type_Declaration
and then Present (Aspect_Specifications (Decl))
then
declare
E : constant Entity_Id := Defining_Identifier (Decl);
It : constant Node_Id := Find_Aspect (E, Aspect_Iterable);
I_Lit : constant Node_Id :=
Find_Aspect (E, Aspect_Integer_Literal);
R_Lit : constant Node_Id :=
Find_Aspect (E, Aspect_Real_Literal);
S_Lit : constant Node_Id :=
Find_Aspect (E, Aspect_String_Literal);
begin
if Present (It) then
Validate_Iterable_Aspect (E, It);
end if;
if Present (I_Lit) then
Validate_Literal_Aspect (E, I_Lit);
end if;
if Present (R_Lit) then
Validate_Literal_Aspect (E, R_Lit);
end if;
if Present (S_Lit) then
Validate_Literal_Aspect (E, S_Lit);
end if;
end;
end if;
if Nkind (Decl) in N_Full_Type_Declaration
| N_Private_Type_Declaration
| N_Task_Type_Declaration
| N_Protected_Type_Declaration
| N_Formal_Type_Declaration
then
Analyze_Type_Contract (Defining_Identifier (Decl));
end if;
Next (Decl);
end loop;
end Analyze_Contracts;
-----------------------------------------------
-- Analyze_Entry_Or_Subprogram_Body_Contract --
-----------------------------------------------
-- WARNING: This routine manages SPARK regions. Return statements must be
-- replaced by gotos which jump to the end of the routine and restore the
-- SPARK mode.
procedure Analyze_Entry_Or_Subprogram_Body_Contract (Body_Id : Entity_Id) is
Body_Decl : constant Node_Id := Unit_Declaration_Node (Body_Id);
Items : constant Node_Id := Contract (Body_Id);
Spec_Id : constant Entity_Id := Unique_Defining_Entity (Body_Decl);
Saved_SM : constant SPARK_Mode_Type := SPARK_Mode;
Saved_SMP : constant Node_Id := SPARK_Mode_Pragma;
-- Save the SPARK_Mode-related data to restore on exit
begin
-- When a subprogram body declaration is illegal, its defining entity is
-- left unanalyzed. There is nothing left to do in this case because the
-- body lacks a contract, or even a proper Ekind.
if Ekind (Body_Id) = E_Void then
return;
-- Do not analyze a contract multiple times
elsif Present (Items) then
if Analyzed (Items) then
return;
else
Set_Analyzed (Items);
end if;
end if;
-- Due to the timing of contract analysis, delayed pragmas may be
-- subject to the wrong SPARK_Mode, usually that of the enclosing
-- context. To remedy this, restore the original SPARK_Mode of the
-- related subprogram body.
Set_SPARK_Mode (Body_Id);
-- Ensure that the contract cases or postconditions mention 'Result or
-- define a post-state.
Check_Result_And_Post_State (Body_Id);
-- A stand-alone nonvolatile function body cannot have an effectively
-- volatile formal parameter or return type (SPARK RM 7.1.3(9)). This
-- check is relevant only when SPARK_Mode is on, as it is not a standard
-- legality rule. The check is performed here because Volatile_Function
-- is processed after the analysis of the related subprogram body. The
-- check only applies to source subprograms and not to generated TSS
-- subprograms.
if SPARK_Mode = On
and then Ekind (Body_Id) in E_Function | E_Generic_Function
and then Comes_From_Source (Spec_Id)
and then not Is_Volatile_Function (Body_Id)
then
Check_Nonvolatile_Function_Profile (Body_Id);
end if;
-- Restore the SPARK_Mode of the enclosing context after all delayed
-- pragmas have been analyzed.
Restore_SPARK_Mode (Saved_SM, Saved_SMP);
-- Capture all global references in a generic subprogram body now that
-- the contract has been analyzed.
if Is_Generic_Declaration_Or_Body (Body_Decl) then
Save_Global_References_In_Contract
(Templ => Original_Node (Body_Decl),
Gen_Id => Spec_Id);
end if;
-- Deal with preconditions, [refined] postconditions, Contract_Cases,
-- Subprogram_Variant, invariants and predicates associated with body
-- and its spec. Do not expand the contract of subprogram body stubs.
if Nkind (Body_Decl) = N_Subprogram_Body then
Expand_Subprogram_Contract (Body_Id);
end if;
end Analyze_Entry_Or_Subprogram_Body_Contract;
------------------------------------------
-- Analyze_Entry_Or_Subprogram_Contract --
------------------------------------------
-- WARNING: This routine manages SPARK regions. Return statements must be
-- replaced by gotos which jump to the end of the routine and restore the
-- SPARK mode.
procedure Analyze_Entry_Or_Subprogram_Contract
(Subp_Id : Entity_Id;
Freeze_Id : Entity_Id := Empty)
is
Items : constant Node_Id := Contract (Subp_Id);
Subp_Decl : constant Node_Id := Unit_Declaration_Node (Subp_Id);
Saved_SM : constant SPARK_Mode_Type := SPARK_Mode;
Saved_SMP : constant Node_Id := SPARK_Mode_Pragma;
-- Save the SPARK_Mode-related data to restore on exit
Skip_Assert_Exprs : constant Boolean :=
Is_Entry (Subp_Id) and then not GNATprove_Mode;
Depends : Node_Id := Empty;
Global : Node_Id := Empty;
Prag : Node_Id;
Prag_Nam : Name_Id;
begin
-- Do not analyze a contract multiple times
if Present (Items) then
if Analyzed (Items) then
return;
else
Set_Analyzed (Items);
end if;
end if;
-- Due to the timing of contract analysis, delayed pragmas may be
-- subject to the wrong SPARK_Mode, usually that of the enclosing
-- context. To remedy this, restore the original SPARK_Mode of the
-- related subprogram body.
Set_SPARK_Mode (Subp_Id);
-- All subprograms carry a contract, but for some it is not significant
-- and should not be processed.
if not Has_Significant_Contract (Subp_Id) then
null;
elsif Present (Items) then
-- Do not analyze the pre/postconditions of an entry declaration
-- unless annotating the original tree for GNATprove. The
-- real analysis occurs when the pre/postconditons are relocated to
-- the contract wrapper procedure (see Build_Contract_Wrapper).
if Skip_Assert_Exprs then
null;
-- Otherwise analyze the pre/postconditions.
-- If these come from an aspect specification, their expressions
-- might include references to types that are not frozen yet, in the
-- case where the body is a rewritten expression function that is a
-- completion, so freeze all types within before constructing the
-- contract code.
else
declare
Bod : Node_Id;
Freeze_Types : Boolean := False;
begin
if Present (Freeze_Id) then
Bod := Unit_Declaration_Node (Freeze_Id);
if Nkind (Bod) = N_Subprogram_Body
and then Was_Expression_Function (Bod)
and then Ekind (Subp_Id) = E_Function
and then Chars (Subp_Id) = Chars (Freeze_Id)
and then Subp_Id /= Freeze_Id
then
Freeze_Types := True;
end if;
end if;
Prag := Pre_Post_Conditions (Items);
while Present (Prag) loop
if Freeze_Types
and then Present (Corresponding_Aspect (Prag))
then
Freeze_Expr_Types
(Def_Id => Subp_Id,
Typ => Standard_Boolean,
Expr =>
Expression
(First (Pragma_Argument_Associations (Prag))),
N => Bod);
end if;
Analyze_Pre_Post_Condition_In_Decl_Part (Prag, Freeze_Id);
Prag := Next_Pragma (Prag);
end loop;
end;
end if;
-- Analyze contract-cases, subprogram-variant and test-cases
Prag := Contract_Test_Cases (Items);
while Present (Prag) loop
Prag_Nam := Pragma_Name (Prag);
if Prag_Nam = Name_Contract_Cases then
-- Do not analyze the contract cases of an entry declaration
-- unless annotating the original tree for GNATprove.
-- The real analysis occurs when the contract cases are moved
-- to the contract wrapper procedure (Build_Contract_Wrapper).
if Skip_Assert_Exprs then
null;
-- Otherwise analyze the contract cases
else
Analyze_Contract_Cases_In_Decl_Part (Prag, Freeze_Id);
end if;
elsif Prag_Nam = Name_Subprogram_Variant then
Analyze_Subprogram_Variant_In_Decl_Part (Prag);
else
pragma Assert (Prag_Nam = Name_Test_Case);
Analyze_Test_Case_In_Decl_Part (Prag);
end if;
Prag := Next_Pragma (Prag);
end loop;
-- Analyze classification pragmas
Prag := Classifications (Items);
while Present (Prag) loop
Prag_Nam := Pragma_Name (Prag);
if Prag_Nam = Name_Depends then
Depends := Prag;
elsif Prag_Nam = Name_Global then
Global := Prag;
end if;
Prag := Next_Pragma (Prag);
end loop;
-- Analyze Global first, as Depends may mention items classified in
-- the global categorization.
if Present (Global) then
Analyze_Global_In_Decl_Part (Global);
end if;
-- Depends must be analyzed after Global in order to see the modes of
-- all global items.
if Present (Depends) then
Analyze_Depends_In_Decl_Part (Depends);
end if;
-- Ensure that the contract cases or postconditions mention 'Result
-- or define a post-state.
Check_Result_And_Post_State (Subp_Id);
end if;
-- A nonvolatile function cannot have an effectively volatile formal
-- parameter or return type (SPARK RM 7.1.3(9)). This check is relevant
-- only when SPARK_Mode is on, as it is not a standard legality rule.
-- The check is performed here because pragma Volatile_Function is
-- processed after the analysis of the related subprogram declaration.
if SPARK_Mode = On
and then Ekind (Subp_Id) in E_Function | E_Generic_Function
and then Comes_From_Source (Subp_Id)
and then not Is_Volatile_Function (Subp_Id)
then
Check_Nonvolatile_Function_Profile (Subp_Id);
end if;
-- Restore the SPARK_Mode of the enclosing context after all delayed
-- pragmas have been analyzed.
Restore_SPARK_Mode (Saved_SM, Saved_SMP);
-- Capture all global references in a generic subprogram now that the
-- contract has been analyzed.
if Is_Generic_Declaration_Or_Body (Subp_Decl) then
Save_Global_References_In_Contract
(Templ => Original_Node (Subp_Decl),
Gen_Id => Subp_Id);
end if;
end Analyze_Entry_Or_Subprogram_Contract;
----------------------------------------------
-- Check_Type_Or_Object_External_Properties --
----------------------------------------------
procedure Check_Type_Or_Object_External_Properties
(Type_Or_Obj_Id : Entity_Id)
is
Is_Type_Id : constant Boolean := Is_Type (Type_Or_Obj_Id);
Decl_Kind : constant String :=
(if Is_Type_Id then "type" else "object");
-- Local variables
AR_Val : Boolean := False;
AW_Val : Boolean := False;
ER_Val : Boolean := False;
EW_Val : Boolean := False;
Seen : Boolean := False;
Prag : Node_Id;
Obj_Typ : Entity_Id;
-- Start of processing for Check_Type_Or_Object_External_Properties
begin
-- Analyze all external properties
if Is_Type_Id then
Obj_Typ := Type_Or_Obj_Id;
-- If the parent type of a derived type is volatile
-- then the derived type inherits volatility-related flags.
if Is_Derived_Type (Type_Or_Obj_Id) then
declare
Parent_Type : constant Entity_Id :=
Etype (Base_Type (Type_Or_Obj_Id));
begin
if Is_Effectively_Volatile (Parent_Type) then
AR_Val := Async_Readers_Enabled (Parent_Type);
AW_Val := Async_Writers_Enabled (Parent_Type);
ER_Val := Effective_Reads_Enabled (Parent_Type);
EW_Val := Effective_Writes_Enabled (Parent_Type);
end if;
end;
end if;
else
Obj_Typ := Etype (Type_Or_Obj_Id);
end if;
Prag := Get_Pragma (Type_Or_Obj_Id, Pragma_Async_Readers);
if Present (Prag) then
declare
Saved_AR_Val : constant Boolean := AR_Val;
begin
Analyze_External_Property_In_Decl_Part (Prag, AR_Val);
Seen := True;
if Saved_AR_Val and not AR_Val then
Error_Msg_N
("illegal non-confirming Async_Readers specification",
Prag);
end if;
end;
end if;
Prag := Get_Pragma (Type_Or_Obj_Id, Pragma_Async_Writers);
if Present (Prag) then
declare
Saved_AW_Val : constant Boolean := AW_Val;
begin
Analyze_External_Property_In_Decl_Part (Prag, AW_Val);
Seen := True;
if Saved_AW_Val and not AW_Val then
Error_Msg_N
("illegal non-confirming Async_Writers specification",
Prag);
end if;
end;
end if;
Prag := Get_Pragma (Type_Or_Obj_Id, Pragma_Effective_Reads);
if Present (Prag) then
declare
Saved_ER_Val : constant Boolean := ER_Val;
begin
Analyze_External_Property_In_Decl_Part (Prag, ER_Val);
Seen := True;
if Saved_ER_Val and not ER_Val then
Error_Msg_N
("illegal non-confirming Effective_Reads specification",
Prag);
end if;
end;
end if;
Prag := Get_Pragma (Type_Or_Obj_Id, Pragma_Effective_Writes);
if Present (Prag) then
declare
Saved_EW_Val : constant Boolean := EW_Val;
begin
Analyze_External_Property_In_Decl_Part (Prag, EW_Val);
Seen := True;
if Saved_EW_Val and not EW_Val then
Error_Msg_N
("illegal non-confirming Effective_Writes specification",
Prag);
end if;
end;
end if;
-- Verify the mutual interaction of the various external properties
if Seen then
Check_External_Properties
(Type_Or_Obj_Id, AR_Val, AW_Val, ER_Val, EW_Val);
end if;
-- The following checks are relevant only when SPARK_Mode is on, as
-- they are not standard Ada legality rules. Internally generated
-- temporaries are ignored, as well as return objects.
if SPARK_Mode = On
and then Comes_From_Source (Type_Or_Obj_Id)
and then not Is_Return_Object (Type_Or_Obj_Id)
then
if Is_Effectively_Volatile (Type_Or_Obj_Id) then
-- The declaration of an effectively volatile object or type must
-- appear at the library level (SPARK RM 7.1.3(3), C.6(6)).
if not Is_Library_Level_Entity (Type_Or_Obj_Id) then
Error_Msg_N
("effectively volatile "
& Decl_Kind
& " & must be declared at library level "
& "(SPARK RM 7.1.3(3))", Type_Or_Obj_Id);
-- An object of a discriminated type cannot be effectively
-- volatile except for protected objects (SPARK RM 7.1.3(5)).
elsif Has_Discriminants (Obj_Typ)
and then not Is_Protected_Type (Obj_Typ)
then
Error_Msg_N
("discriminated " & Decl_Kind & " & cannot be volatile",
Type_Or_Obj_Id);
end if;
-- An object decl shall be compatible with respect to volatility
-- with its type (SPARK RM 7.1.3(2)).
if not Is_Type_Id then
if Is_Effectively_Volatile (Obj_Typ) then
Check_Volatility_Compatibility
(Type_Or_Obj_Id, Obj_Typ,
"volatile object", "its type",
Srcpos_Bearer => Type_Or_Obj_Id);
end if;
-- A component of a composite type (in this case, the composite
-- type is an array type) shall be compatible with respect to
-- volatility with the composite type (SPARK RM 7.1.3(6)).
elsif Is_Array_Type (Obj_Typ) then
Check_Volatility_Compatibility
(Component_Type (Obj_Typ), Obj_Typ,
"component type", "its enclosing array type",
Srcpos_Bearer => Obj_Typ);
-- A component of a composite type (in this case, the composite
-- type is a record type) shall be compatible with respect to
-- volatility with the composite type (SPARK RM 7.1.3(6)).
elsif Is_Record_Type (Obj_Typ) then
declare
Comp : Entity_Id := First_Component (Obj_Typ);
begin
while Present (Comp) loop
Check_Volatility_Compatibility
(Etype (Comp), Obj_Typ,
"record component " & Get_Name_String (Chars (Comp)),
"its enclosing record type",
Srcpos_Bearer => Comp);
Next_Component (Comp);
end loop;
end;
end if;
-- The type or object is not effectively volatile
else
-- A non-effectively volatile type cannot have effectively
-- volatile components (SPARK RM 7.1.3(6)).
if Is_Type_Id
and then not Is_Effectively_Volatile (Type_Or_Obj_Id)
and then Has_Volatile_Component (Type_Or_Obj_Id)
then
Error_Msg_N
("non-volatile type & cannot have volatile"
& " components",
Type_Or_Obj_Id);
end if;
end if;
end if;
end Check_Type_Or_Object_External_Properties;
-----------------------------
-- Analyze_Object_Contract --
-----------------------------
-- WARNING: This routine manages SPARK regions. Return statements must be
-- replaced by gotos which jump to the end of the routine and restore the
-- SPARK mode.
procedure Analyze_Object_Contract
(Obj_Id : Entity_Id;
Freeze_Id : Entity_Id := Empty)
is
Obj_Typ : constant Entity_Id := Etype (Obj_Id);
Saved_SM : constant SPARK_Mode_Type := SPARK_Mode;
Saved_SMP : constant Node_Id := SPARK_Mode_Pragma;
-- Save the SPARK_Mode-related data to restore on exit
NC_Val : Boolean;
Items : Node_Id;
Prag : Node_Id;
Ref_Elmt : Elmt_Id;
begin
-- The loop parameter in an element iterator over a formal container
-- is declared with an object declaration, but no contracts apply.
if Ekind (Obj_Id) = E_Loop_Parameter then
return;
end if;
-- Do not analyze a contract multiple times
Items := Contract (Obj_Id);
if Present (Items) then
if Analyzed (Items) then
return;
else
Set_Analyzed (Items);
end if;
end if;
-- The anonymous object created for a single concurrent type inherits
-- the SPARK_Mode from the type. Due to the timing of contract analysis,
-- delayed pragmas may be subject to the wrong SPARK_Mode, usually that
-- of the enclosing context. To remedy this, restore the original mode
-- of the related anonymous object.
if Is_Single_Concurrent_Object (Obj_Id)
and then Present (SPARK_Pragma (Obj_Id))
then
Set_SPARK_Mode (Obj_Id);
end if;
-- Checks related to external properties, same for constants and
-- variables.
Check_Type_Or_Object_External_Properties (Type_Or_Obj_Id => Obj_Id);
-- Analyze the non-external volatility property No_Caching
Prag := Get_Pragma (Obj_Id, Pragma_No_Caching);
if Present (Prag) then
Analyze_External_Property_In_Decl_Part (Prag, NC_Val);
end if;
-- Constant-related checks
if Ekind (Obj_Id) = E_Constant then
-- Analyze indicator Part_Of
Prag := Get_Pragma (Obj_Id, Pragma_Part_Of);
-- Check whether the lack of indicator Part_Of agrees with the
-- placement of the constant with respect to the state space.
if No (Prag) then
Check_Missing_Part_Of (Obj_Id);
end if;
-- Variable-related checks
else pragma Assert (Ekind (Obj_Id) = E_Variable);
-- The anonymous object created for a single task type carries
-- pragmas Depends and Global of the type.
if Is_Single_Task_Object (Obj_Id) then
-- Analyze Global first, as Depends may mention items classified
-- in the global categorization.
Prag := Get_Pragma (Obj_Id, Pragma_Global);
if Present (Prag) then
Analyze_Global_In_Decl_Part (Prag);
end if;
-- Depends must be analyzed after Global in order to see the modes
-- of all global items.
Prag := Get_Pragma (Obj_Id, Pragma_Depends);
if Present (Prag) then
Analyze_Depends_In_Decl_Part (Prag);
end if;
end if;
Prag := Get_Pragma (Obj_Id, Pragma_Part_Of);
-- Analyze indicator Part_Of
if Present (Prag) then
Analyze_Part_Of_In_Decl_Part (Prag, Freeze_Id);
-- The variable is a constituent of a single protected/task type
-- and behaves as a component of the type. Verify that references
-- to the variable occur within the definition or body of the type
-- (SPARK RM 9.3).
if Present (Encapsulating_State (Obj_Id))
and then Is_Single_Concurrent_Object
(Encapsulating_State (Obj_Id))
and then Present (Part_Of_References (Obj_Id))
then
Ref_Elmt := First_Elmt (Part_Of_References (Obj_Id));
while Present (Ref_Elmt) loop
Check_Part_Of_Reference (Obj_Id, Node (Ref_Elmt));
Next_Elmt (Ref_Elmt);
end loop;
end if;
-- Otherwise check whether the lack of indicator Part_Of agrees with
-- the placement of the variable with respect to the state space.
else
Check_Missing_Part_Of (Obj_Id);
end if;
end if;
-- Common checks
if Comes_From_Source (Obj_Id) and then Is_Ghost_Entity (Obj_Id) then
-- A Ghost object cannot be of a type that yields a synchronized
-- object (SPARK RM 6.9(19)).
if Yields_Synchronized_Object (Obj_Typ) then
Error_Msg_N ("ghost object & cannot be synchronized", Obj_Id);
-- A Ghost object cannot be effectively volatile (SPARK RM 6.9(7) and
-- SPARK RM 6.9(19)).
elsif Is_Effectively_Volatile (Obj_Id) then
Error_Msg_N ("ghost object & cannot be volatile", Obj_Id);
-- A Ghost object cannot be imported or exported (SPARK RM 6.9(7)).
-- One exception to this is the object that represents the dispatch
-- table of a Ghost tagged type, as the symbol needs to be exported.
elsif Is_Exported (Obj_Id) then
Error_Msg_N ("ghost object & cannot be exported", Obj_Id);
elsif Is_Imported (Obj_Id) then
Error_Msg_N ("ghost object & cannot be imported", Obj_Id);
end if;
end if;
-- Restore the SPARK_Mode of the enclosing context after all delayed
-- pragmas have been analyzed.
Restore_SPARK_Mode (Saved_SM, Saved_SMP);
end Analyze_Object_Contract;
-----------------------------------
-- Analyze_Package_Body_Contract --
-----------------------------------
-- WARNING: This routine manages SPARK regions. Return statements must be
-- replaced by gotos which jump to the end of the routine and restore the
-- SPARK mode.
procedure Analyze_Package_Body_Contract
(Body_Id : Entity_Id;
Freeze_Id : Entity_Id := Empty)
is
Body_Decl : constant Node_Id := Unit_Declaration_Node (Body_Id);
Items : constant Node_Id := Contract (Body_Id);
Spec_Id : constant Entity_Id := Spec_Entity (Body_Id);
Saved_SM : constant SPARK_Mode_Type := SPARK_Mode;
Saved_SMP : constant Node_Id := SPARK_Mode_Pragma;
-- Save the SPARK_Mode-related data to restore on exit
Ref_State : Node_Id;
begin
-- Do not analyze a contract multiple times
if Present (Items) then
if Analyzed (Items) then
return;
else
Set_Analyzed (Items);
end if;
end if;
-- Due to the timing of contract analysis, delayed pragmas may be
-- subject to the wrong SPARK_Mode, usually that of the enclosing
-- context. To remedy this, restore the original SPARK_Mode of the
-- related package body.
Set_SPARK_Mode (Body_Id);
Ref_State := Get_Pragma (Body_Id, Pragma_Refined_State);
-- The analysis of pragma Refined_State detects whether the spec has
-- abstract states available for refinement.
if Present (Ref_State) then
Analyze_Refined_State_In_Decl_Part (Ref_State, Freeze_Id);
end if;
-- Restore the SPARK_Mode of the enclosing context after all delayed
-- pragmas have been analyzed.
Restore_SPARK_Mode (Saved_SM, Saved_SMP);
-- Capture all global references in a generic package body now that the
-- contract has been analyzed.
if Is_Generic_Declaration_Or_Body (Body_Decl) then
Save_Global_References_In_Contract
(Templ => Original_Node (Body_Decl),
Gen_Id => Spec_Id);
end if;
end Analyze_Package_Body_Contract;
------------------------------
-- Analyze_Package_Contract --
------------------------------
-- WARNING: This routine manages SPARK regions. Return statements must be
-- replaced by gotos which jump to the end of the routine and restore the
-- SPARK mode.
procedure Analyze_Package_Contract (Pack_Id : Entity_Id) is
Items : constant Node_Id := Contract (Pack_Id);
Pack_Decl : constant Node_Id := Unit_Declaration_Node (Pack_Id);
Saved_SM : constant SPARK_Mode_Type := SPARK_Mode;
Saved_SMP : constant Node_Id := SPARK_Mode_Pragma;
-- Save the SPARK_Mode-related data to restore on exit
Init : Node_Id := Empty;
Init_Cond : Node_Id := Empty;
Prag : Node_Id;
Prag_Nam : Name_Id;
begin
-- Do not analyze a contract multiple times
if Present (Items) then
if Analyzed (Items) then
return;
else
Set_Analyzed (Items);
end if;
end if;
-- Due to the timing of contract analysis, delayed pragmas may be
-- subject to the wrong SPARK_Mode, usually that of the enclosing
-- context. To remedy this, restore the original SPARK_Mode of the
-- related package.
Set_SPARK_Mode (Pack_Id);
if Present (Items) then
-- Locate and store pragmas Initial_Condition and Initializes, since
-- their order of analysis matters.
Prag := Classifications (Items);
while Present (Prag) loop
Prag_Nam := Pragma_Name (Prag);
if Prag_Nam = Name_Initial_Condition then
Init_Cond := Prag;
elsif Prag_Nam = Name_Initializes then
Init := Prag;
end if;
Prag := Next_Pragma (Prag);
end loop;
-- Analyze the initialization-related pragmas. Initializes must come
-- before Initial_Condition due to item dependencies.
if Present (Init) then
Analyze_Initializes_In_Decl_Part (Init);
end if;
if Present (Init_Cond) then
Analyze_Initial_Condition_In_Decl_Part (Init_Cond);
end if;
end if;
-- Restore the SPARK_Mode of the enclosing context after all delayed
-- pragmas have been analyzed.
Restore_SPARK_Mode (Saved_SM, Saved_SMP);
-- Capture all global references in a generic package now that the
-- contract has been analyzed.
if Is_Generic_Declaration_Or_Body (Pack_Decl) then
Save_Global_References_In_Contract
(Templ => Original_Node (Pack_Decl),
Gen_Id => Pack_Id);
end if;
end Analyze_Package_Contract;
--------------------------------------------
-- Analyze_Package_Instantiation_Contract --
--------------------------------------------
-- WARNING: This routine manages SPARK regions. Return statements must be
-- replaced by gotos which jump to the end of the routine and restore the
-- SPARK mode.
procedure Analyze_Package_Instantiation_Contract (Inst_Id : Entity_Id) is
Inst_Spec : constant Node_Id :=
Instance_Spec (Unit_Declaration_Node (Inst_Id));
Saved_SM : constant SPARK_Mode_Type := SPARK_Mode;
Saved_SMP : constant Node_Id := SPARK_Mode_Pragma;
-- Save the SPARK_Mode-related data to restore on exit
Pack_Id : Entity_Id;
Prag : Node_Id;
begin
-- Nothing to do when the package instantiation is erroneous or left
-- partially decorated.
if No (Inst_Spec) then
return;
end if;
Pack_Id := Defining_Entity (Inst_Spec);
Prag := Get_Pragma (Pack_Id, Pragma_Part_Of);
-- Due to the timing of contract analysis, delayed pragmas may be
-- subject to the wrong SPARK_Mode, usually that of the enclosing
-- context. To remedy this, restore the original SPARK_Mode of the
-- related package.
Set_SPARK_Mode (Pack_Id);
-- Check whether the lack of indicator Part_Of agrees with the placement
-- of the package instantiation with respect to the state space. Nested
-- package instantiations do not need to be checked because they inherit
-- Part_Of indicator of the outermost package instantiation (see routine
-- Propagate_Part_Of in Sem_Prag).
if In_Instance then
null;
elsif No (Prag) then
Check_Missing_Part_Of (Pack_Id);
end if;
-- Restore the SPARK_Mode of the enclosing context after all delayed
-- pragmas have been analyzed.
Restore_SPARK_Mode (Saved_SM, Saved_SMP);
end Analyze_Package_Instantiation_Contract;
--------------------------------
-- Analyze_Protected_Contract --
--------------------------------
procedure Analyze_Protected_Contract (Prot_Id : Entity_Id) is
Items : constant Node_Id := Contract (Prot_Id);
begin
-- Do not analyze a contract multiple times
if Present (Items) then
if Analyzed (Items) then
return;
else
Set_Analyzed (Items);
end if;
end if;
end Analyze_Protected_Contract;
-------------------------------------------
-- Analyze_Subprogram_Body_Stub_Contract --
-------------------------------------------
procedure Analyze_Subprogram_Body_Stub_Contract (Stub_Id : Entity_Id) is
Stub_Decl : constant Node_Id := Parent (Parent (Stub_Id));
Spec_Id : constant Entity_Id := Corresponding_Spec_Of_Stub (Stub_Decl);
begin
-- A subprogram body stub may act as its own spec or as the completion
-- of a previous declaration. Depending on the context, the contract of
-- the stub may contain two sets of pragmas.
-- The stub is a completion, the applicable pragmas are:
-- Refined_Depends
-- Refined_Global
if Present (Spec_Id) then
Analyze_Entry_Or_Subprogram_Body_Contract (Stub_Id);
-- The stub acts as its own spec, the applicable pragmas are:
-- Contract_Cases
-- Depends
-- Global
-- Postcondition
-- Precondition
-- Subprogram_Variant
-- Test_Case
else
Analyze_Entry_Or_Subprogram_Contract (Stub_Id);
end if;
end Analyze_Subprogram_Body_Stub_Contract;
---------------------------
-- Analyze_Task_Contract --
---------------------------
-- WARNING: This routine manages SPARK regions. Return statements must be
-- replaced by gotos which jump to the end of the routine and restore the
-- SPARK mode.
procedure Analyze_Task_Contract (Task_Id : Entity_Id) is
Items : constant Node_Id := Contract (Task_Id);
Saved_SM : constant SPARK_Mode_Type := SPARK_Mode;
Saved_SMP : constant Node_Id := SPARK_Mode_Pragma;
-- Save the SPARK_Mode-related data to restore on exit
Prag : Node_Id;
begin
-- Do not analyze a contract multiple times
if Present (Items) then
if Analyzed (Items) then
return;
else
Set_Analyzed (Items);
end if;
end if;
-- Due to the timing of contract analysis, delayed pragmas may be
-- subject to the wrong SPARK_Mode, usually that of the enclosing
-- context. To remedy this, restore the original SPARK_Mode of the
-- related task unit.
Set_SPARK_Mode (Task_Id);
-- Analyze Global first, as Depends may mention items classified in the
-- global categorization.
Prag := Get_Pragma (Task_Id, Pragma_Global);
if Present (Prag) then
Analyze_Global_In_Decl_Part (Prag);
end if;
-- Depends must be analyzed after Global in order to see the modes of
-- all global items.
Prag := Get_Pragma (Task_Id, Pragma_Depends);
if Present (Prag) then
Analyze_Depends_In_Decl_Part (Prag);
end if;
-- Restore the SPARK_Mode of the enclosing context after all delayed
-- pragmas have been analyzed.
Restore_SPARK_Mode (Saved_SM, Saved_SMP);
end Analyze_Task_Contract;
---------------------------
-- Analyze_Type_Contract --
---------------------------
procedure Analyze_Type_Contract (Type_Id : Entity_Id) is
begin
Check_Type_Or_Object_External_Properties
(Type_Or_Obj_Id => Type_Id);
end Analyze_Type_Contract;
---------------------------
-- Check_Class_Condition --
---------------------------
procedure Check_Class_Condition
(Cond : Node_Id;
Subp : Entity_Id;
Par_Subp : Entity_Id;
Is_Precondition : Boolean)
is
function Check_Entity (N : Node_Id) return Traverse_Result;
-- Check reference to formal of inherited operation or to primitive
-- operation of root type.
------------------
-- Check_Entity --
------------------
function Check_Entity (N : Node_Id) return Traverse_Result is
New_E : Entity_Id;
Orig_E : Entity_Id;
begin
if Nkind (N) = N_Identifier
and then Present (Entity (N))
and then
(Is_Formal (Entity (N)) or else Is_Subprogram (Entity (N)))
and then
(Nkind (Parent (N)) /= N_Attribute_Reference
or else Attribute_Name (Parent (N)) /= Name_Class)
then
-- These checks do not apply to dispatching calls within the
-- condition, but only to calls whose static tag is that of
-- the parent type.
if Is_Subprogram (Entity (N))
and then Nkind (Parent (N)) = N_Function_Call
and then Present (Controlling_Argument (Parent (N)))
then
return OK;
end if;
-- Determine whether entity has a renaming
Orig_E := Entity (N);
New_E := Get_Mapped_Entity (Orig_E);
if Present (New_E) then
-- AI12-0166: A precondition for a protected operation
-- cannot include an internal call to a protected function
-- of the type. In the case of an inherited condition for an
-- overriding operation, both the operation and the function
-- are given by primitive wrappers.
if Is_Precondition
and then Ekind (New_E) = E_Function
and then Is_Primitive_Wrapper (New_E)
and then Is_Primitive_Wrapper (Subp)
and then Scope (Subp) = Scope (New_E)
then
Error_Msg_Node_2 := Wrapped_Entity (Subp);
Error_Msg_NE
("internal call to& cannot appear in inherited "
& "precondition of protected operation&",
Subp, Wrapped_Entity (New_E));
end if;
end if;
-- Check that there are no calls left to abstract operations if
-- the current subprogram is not abstract.
if Present (New_E)
and then Nkind (Parent (N)) = N_Function_Call
and then N = Name (Parent (N))
then
if not Is_Abstract_Subprogram (Subp)
and then Is_Abstract_Subprogram (New_E)
then
Error_Msg_Sloc := Sloc (Current_Scope);
Error_Msg_Node_2 := Subp;
if Comes_From_Source (Subp) then
Error_Msg_NE
("cannot call abstract subprogram & in inherited "
& "condition for&#", Subp, New_E);
else
Error_Msg_NE
("cannot call abstract subprogram & in inherited "
& "condition for inherited&#", Subp, New_E);
end if;
-- In SPARK mode, report error on inherited condition for an
-- inherited operation if it contains a call to an overriding
-- operation, because this implies that the pre/postconditions
-- of the inherited operation have changed silently.
elsif SPARK_Mode = On
and then Warn_On_Suspicious_Contract
and then Present (Alias (Subp))
and then Present (New_E)
and then Comes_From_Source (New_E)
then
Error_Msg_N
("cannot modify inherited condition (SPARK RM 6.1.1(1))",
Parent (Subp));
Error_Msg_Sloc := Sloc (New_E);
Error_Msg_Node_2 := Subp;
Error_Msg_NE
("\overriding of&# forces overriding of&",
Parent (Subp), New_E);
end if;
end if;
end if;
return OK;
end Check_Entity;
procedure Check_Condition_Entities is
new Traverse_Proc (Check_Entity);
-- Start of processing for Check_Class_Condition
begin
-- No check required if the subprograms match
if Par_Subp = Subp then
return;
end if;
Update_Primitives_Mapping (Par_Subp, Subp);
Map_Formals (Par_Subp, Subp);
Check_Condition_Entities (Cond);
end Check_Class_Condition;
-----------------------------
-- Create_Generic_Contract --
-----------------------------
procedure Create_Generic_Contract (Unit : Node_Id) is
Templ : constant Node_Id := Original_Node (Unit);
Templ_Id : constant Entity_Id := Defining_Entity (Templ);
procedure Add_Generic_Contract_Pragma (Prag : Node_Id);
-- Add a single contract-related source pragma Prag to the contract of
-- generic template Templ_Id.
---------------------------------
-- Add_Generic_Contract_Pragma --
---------------------------------
procedure Add_Generic_Contract_Pragma (Prag : Node_Id) is
Prag_Templ : Node_Id;
begin
-- Mark the pragma to prevent the premature capture of global
-- references when capturing global references of the context
-- (see Save_References_In_Pragma).
Set_Is_Generic_Contract_Pragma (Prag);
-- Pragmas that apply to a generic subprogram declaration are not
-- part of the semantic structure of the generic template:
-- generic
-- procedure Example (Formal : Integer);
-- pragma Precondition (Formal > 0);
-- Create a generic template for such pragmas and link the template
-- of the pragma with the generic template.
if Nkind (Templ) = N_Generic_Subprogram_Declaration then
Rewrite
(Prag, Copy_Generic_Node (Prag, Empty, Instantiating => False));
Prag_Templ := Original_Node (Prag);
Set_Is_Generic_Contract_Pragma (Prag_Templ);
Add_Contract_Item (Prag_Templ, Templ_Id);
-- Otherwise link the pragma with the generic template
else
Add_Contract_Item (Prag, Templ_Id);
end if;
end Add_Generic_Contract_Pragma;
-- Local variables
Context : constant Node_Id := Parent (Unit);
Decl : Node_Id := Empty;
-- Start of processing for Create_Generic_Contract
begin
-- A generic package declaration carries contract-related source pragmas
-- in its visible declarations.
if Nkind (Templ) = N_Generic_Package_Declaration then
Mutate_Ekind (Templ_Id, E_Generic_Package);
if Present (Visible_Declarations (Specification (Templ))) then
Decl := First (Visible_Declarations (Specification (Templ)));
end if;
-- A generic package body carries contract-related source pragmas in its
-- declarations.
elsif Nkind (Templ) = N_Package_Body then
Mutate_Ekind (Templ_Id, E_Package_Body);
if Present (Declarations (Templ)) then
Decl := First (Declarations (Templ));
end if;
-- Generic subprogram declaration
elsif Nkind (Templ) = N_Generic_Subprogram_Declaration then
if Nkind (Specification (Templ)) = N_Function_Specification then
Mutate_Ekind (Templ_Id, E_Generic_Function);
else
Mutate_Ekind (Templ_Id, E_Generic_Procedure);
end if;
-- When the generic subprogram acts as a compilation unit, inspect
-- the Pragmas_After list for contract-related source pragmas.
if Nkind (Context) = N_Compilation_Unit then
if Present (Aux_Decls_Node (Context))
and then Present (Pragmas_After (Aux_Decls_Node (Context)))
then
Decl := First (Pragmas_After (Aux_Decls_Node (Context)));
end if;
-- Otherwise inspect the successive declarations for contract-related
-- source pragmas.
else
Decl := Next (Unit);
end if;
-- A generic subprogram body carries contract-related source pragmas in
-- its declarations.
elsif Nkind (Templ) = N_Subprogram_Body then
Mutate_Ekind (Templ_Id, E_Subprogram_Body);
if Present (Declarations (Templ)) then
Decl := First (Declarations (Templ));
end if;
end if;
-- Inspect the relevant declarations looking for contract-related source
-- pragmas and add them to the contract of the generic unit.
while Present (Decl) loop
if Comes_From_Source (Decl) then
if Nkind (Decl) = N_Pragma then
-- The source pragma is a contract annotation
if Is_Contract_Annotation (Decl) then
Add_Generic_Contract_Pragma (Decl);
end if;
-- The region where a contract-related source pragma may appear
-- ends with the first source non-pragma declaration or statement.
else
exit;
end if;
end if;
Next (Decl);
end loop;
end Create_Generic_Contract;
--------------------------------
-- Expand_Subprogram_Contract --
--------------------------------
procedure Expand_Subprogram_Contract (Body_Id : Entity_Id) is
Body_Decl : constant Node_Id := Unit_Declaration_Node (Body_Id);
Spec_Id : constant Entity_Id := Corresponding_Spec (Body_Decl);
procedure Add_Invariant_And_Predicate_Checks
(Subp_Id : Entity_Id;
Stmts : in out List_Id;
Result : out Node_Id);
-- Process the result of function Subp_Id (if applicable) and all its
-- formals. Add invariant and predicate checks where applicable. The
-- routine appends all the checks to list Stmts. If Subp_Id denotes a
-- function, Result contains the entity of parameter _Result, to be
-- used in the creation of procedure _Postconditions.
procedure Add_Stable_Property_Contracts
(Subp_Id : Entity_Id; Class_Present : Boolean);
-- Augment postcondition contracts to reflect Stable_Property aspect
-- (if Class_Present = False) or Stable_Property'Class aspect (if
-- Class_Present = True).
procedure Append_Enabled_Item (Item : Node_Id; List : in out List_Id);
-- Append a node to a list. If there is no list, create a new one. When
-- the item denotes a pragma, it is added to the list only when it is
-- enabled.
procedure Build_Postconditions_Procedure
(Subp_Id : Entity_Id;
Stmts : List_Id;
Result : Entity_Id);
-- Create the body of procedure _Postconditions which handles various
-- assertion actions on exit from subprogram Subp_Id. Stmts is the list
-- of statements to be checked on exit. Parameter Result is the entity
-- of parameter _Result when Subp_Id denotes a function.
procedure Process_Contract_Cases (Stmts : in out List_Id);
-- Process pragma Contract_Cases. This routine prepends items to the
-- body declarations and appends items to list Stmts.
procedure Process_Postconditions (Stmts : in out List_Id);
-- Collect all [inherited] spec and body postconditions and accumulate
-- their pragma Check equivalents in list Stmts.
procedure Process_Preconditions;
-- Collect all [inherited] spec and body preconditions and prepend their
-- pragma Check equivalents to the declarations of the body.
----------------------------------------
-- Add_Invariant_And_Predicate_Checks --
----------------------------------------
procedure Add_Invariant_And_Predicate_Checks
(Subp_Id : Entity_Id;
Stmts : in out List_Id;
Result : out Node_Id)
is
procedure Add_Invariant_Access_Checks (Id : Entity_Id);
-- Id denotes the return value of a function or a formal parameter.
-- Add an invariant check if the type of Id is access to a type with
-- invariants. The routine appends the generated code to Stmts.
function Invariant_Checks_OK (Typ : Entity_Id) return Boolean;
-- Determine whether type Typ can benefit from invariant checks. To
-- qualify, the type must have a non-null invariant procedure and
-- subprogram Subp_Id must appear visible from the point of view of
-- the type.
---------------------------------
-- Add_Invariant_Access_Checks --
---------------------------------
procedure Add_Invariant_Access_Checks (Id : Entity_Id) is
Loc : constant Source_Ptr := Sloc (Body_Decl);
Ref : Node_Id;
Typ : Entity_Id;
begin
Typ := Etype (Id);
if Is_Access_Type (Typ) and then not Is_Access_Constant (Typ) then
Typ := Designated_Type (Typ);
if Invariant_Checks_OK (Typ) then
Ref :=
Make_Explicit_Dereference (Loc,
Prefix => New_Occurrence_Of (Id, Loc));
Set_Etype (Ref, Typ);
-- Generate:
-- if <Id> /= null then
-- <invariant_call (<Ref>)>
-- end if;
Append_Enabled_Item
(Item =>
Make_If_Statement (Loc,
Condition =>
Make_Op_Ne (Loc,
Left_Opnd => New_Occurrence_Of (Id, Loc),
Right_Opnd => Make_Null (Loc)),
Then_Statements => New_List (
Make_Invariant_Call (Ref))),
List => Stmts);
end if;
end if;
end Add_Invariant_Access_Checks;
-------------------------
-- Invariant_Checks_OK --
-------------------------
function Invariant_Checks_OK (Typ : Entity_Id) return Boolean is
function Has_Public_Visibility_Of_Subprogram return Boolean;
-- Determine whether type Typ has public visibility of subprogram
-- Subp_Id.
-----------------------------------------
-- Has_Public_Visibility_Of_Subprogram --
-----------------------------------------
function Has_Public_Visibility_Of_Subprogram return Boolean is
Subp_Decl : constant Node_Id := Unit_Declaration_Node (Subp_Id);
begin
-- An Initialization procedure must be considered visible even
-- though it is internally generated.
if Is_Init_Proc (Defining_Entity (Subp_Decl)) then
return True;
elsif Ekind (Scope (Typ)) /= E_Package then
return False;
-- Internally generated code is never publicly visible except
-- for a subprogram that is the implementation of an expression
-- function. In that case the visibility is determined by the
-- last check.
elsif not Comes_From_Source (Subp_Decl)
and then
(Nkind (Original_Node (Subp_Decl)) /= N_Expression_Function
or else not
Comes_From_Source (Defining_Entity (Subp_Decl)))
then
return False;
-- Determine whether the subprogram is declared in the visible
-- declarations of the package containing the type, or in the
-- visible declaration of a child unit of that package.
else
declare
Decls : constant List_Id :=
List_Containing (Subp_Decl);
Subp_Scope : constant Entity_Id :=
Scope (Defining_Entity (Subp_Decl));
Typ_Scope : constant Entity_Id := Scope (Typ);
begin
return
Decls = Visible_Declarations
(Specification (Unit_Declaration_Node (Typ_Scope)))
or else
(Ekind (Subp_Scope) = E_Package
and then Typ_Scope /= Subp_Scope
and then Is_Child_Unit (Subp_Scope)
and then
Is_Ancestor_Package (Typ_Scope, Subp_Scope)
and then
Decls = Visible_Declarations
(Specification
(Unit_Declaration_Node (Subp_Scope))));
end;
end if;
end Has_Public_Visibility_Of_Subprogram;
-- Start of processing for Invariant_Checks_OK
begin
return
Has_Invariants (Typ)
and then Present (Invariant_Procedure (Typ))
and then not Has_Null_Body (Invariant_Procedure (Typ))
and then Has_Public_Visibility_Of_Subprogram;
end Invariant_Checks_OK;
-- Local variables
Loc : constant Source_Ptr := Sloc (Body_Decl);
-- Source location of subprogram body contract
Formal : Entity_Id;
Typ : Entity_Id;
-- Start of processing for Add_Invariant_And_Predicate_Checks
begin
Result := Empty;
-- Process the result of a function
if Ekind (Subp_Id) = E_Function then
Typ := Etype (Subp_Id);
-- Generate _Result which is used in procedure _Postconditions to
-- verify the return value.
Result := Make_Defining_Identifier (Loc, Name_uResult);
Set_Etype (Result, Typ);
-- Add an invariant check when the return type has invariants and
-- the related function is visible to the outside.
if Invariant_Checks_OK (Typ) then
Append_Enabled_Item
(Item =>
Make_Invariant_Call (New_Occurrence_Of (Result, Loc)),
List => Stmts);
end if;
-- Add an invariant check when the return type is an access to a
-- type with invariants.
Add_Invariant_Access_Checks (Result);
end if;
-- Add invariant checks for all formals that qualify (see AI05-0289
-- and AI12-0044).
Formal := First_Formal (Subp_Id);
while Present (Formal) loop
Typ := Etype (Formal);
if Ekind (Formal) /= E_In_Parameter
or else Ekind (Subp_Id) = E_Procedure
or else Is_Access_Type (Typ)
then
if Invariant_Checks_OK (Typ) then
Append_Enabled_Item
(Item =>
Make_Invariant_Call (New_Occurrence_Of (Formal, Loc)),
List => Stmts);
end if;
Add_Invariant_Access_Checks (Formal);
-- Note: we used to add predicate checks for OUT and IN OUT
-- formals here, but that was misguided, since such checks are
-- performed on the caller side, based on the predicate of the
-- actual, rather than the predicate of the formal.
end if;
Next_Formal (Formal);
end loop;
end Add_Invariant_And_Predicate_Checks;
-----------------------------------
-- Add_Stable_Property_Contracts --
-----------------------------------
procedure Add_Stable_Property_Contracts
(Subp_Id : Entity_Id; Class_Present : Boolean)
is
Loc : constant Source_Ptr := Sloc (Subp_Id);
procedure Insert_Stable_Property_Check
(Formal : Entity_Id; Property_Function : Entity_Id);
-- Build the pragma for one check and insert it in the tree.
function Make_Stable_Property_Condition
(Formal : Entity_Id; Property_Function : Entity_Id) return Node_Id;
-- Builds tree for "Func (Formal) = Func (Formal)'Old" expression.
function Stable_Properties
(Aspect_Bearer : Entity_Id; Negated : out Boolean)
return Subprogram_List;
-- If no aspect specified, then returns length-zero result.
-- Negated indicates that reserved word NOT was specified.
----------------------------------
-- Insert_Stable_Property_Check --
----------------------------------
procedure Insert_Stable_Property_Check
(Formal : Entity_Id; Property_Function : Entity_Id) is
Args : constant List_Id :=
New_List
(Make_Pragma_Argument_Association
(Sloc => Loc,
Expression =>
Make_Stable_Property_Condition
(Formal => Formal,
Property_Function => Property_Function)),
Make_Pragma_Argument_Association
(Sloc => Loc,
Expression =>
Make_String_Literal
(Sloc => Loc,
Strval =>
"failed stable property check at "
& Build_Location_String (Loc)
& " for parameter "
& To_String (Fully_Qualified_Name_String
(Formal, Append_NUL => False))
& " and property function "
& To_String (Fully_Qualified_Name_String
(Property_Function, Append_NUL => False))
)));
Prag : constant Node_Id :=
Make_Pragma (Loc,
Pragma_Identifier =>
Make_Identifier (Loc, Name_Postcondition),
Pragma_Argument_Associations => Args,
Class_Present => Class_Present);
Subp_Decl : Node_Id := Subp_Id;
begin
-- Enclosing_Declaration may return, for example,
-- a N_Procedure_Specification node. Cope with this.
loop
Subp_Decl := Enclosing_Declaration (Subp_Decl);
exit when Is_Declaration (Subp_Decl);
Subp_Decl := Parent (Subp_Decl);
pragma Assert (Present (Subp_Decl));
end loop;
Insert_After_And_Analyze (Subp_Decl, Prag);
end Insert_Stable_Property_Check;
------------------------------------
-- Make_Stable_Property_Condition --
------------------------------------
function Make_Stable_Property_Condition
(Formal : Entity_Id; Property_Function : Entity_Id) return Node_Id
is
function Call_Property_Function return Node_Id is
(Make_Function_Call
(Loc,
Name =>
New_Occurrence_Of (Property_Function, Loc),
Parameter_Associations =>
New_List (New_Occurrence_Of (Formal, Loc))));
begin
return Make_Op_Eq
(Loc,
Call_Property_Function,
Make_Attribute_Reference
(Loc,
Prefix => Call_Property_Function,
Attribute_Name => Name_Old));
end Make_Stable_Property_Condition;
-----------------------
-- Stable_Properties --
-----------------------
function Stable_Properties
(Aspect_Bearer : Entity_Id; Negated : out Boolean)
return Subprogram_List
is
Aspect_Spec : Node_Id :=
Find_Value_Of_Aspect
(Aspect_Bearer, Aspect_Stable_Properties,
Class_Present => Class_Present);
begin
-- ??? For a derived type, we wish Find_Value_Of_Aspect
-- somehow knew that this aspect is not inherited.
-- But it doesn't, so we cope with that here.
--
-- There are probably issues here with inheritance from
-- interface types, where just looking for the one parent type
-- isn't enough. But this is far from the only work needed for
-- Stable_Properties'Class for interface types.
if Is_Derived_Type (Aspect_Bearer) then
declare
Parent_Type : constant Entity_Id :=
Etype (Base_Type (Aspect_Bearer));
begin
if Aspect_Spec =
Find_Value_Of_Aspect
(Parent_Type, Aspect_Stable_Properties,
Class_Present => Class_Present)
then
-- prevent inheritance
Aspect_Spec := Empty;
end if;
end;
end if;
if No (Aspect_Spec) then
Negated := Aspect_Bearer = Subp_Id;
-- This is a little bit subtle.
-- We need to assign True in the Subp_Id case in order to
-- distinguish between no aspect spec at all vs. an
-- explicitly specified "with S_P => []" empty list.
-- In both cases Stable_Properties will return a length-0
-- array, but the two cases are not equivalent.
-- Very roughly speaking the lack of an S_P aspect spec for
-- a subprogram would be equivalent to something like
-- "with S_P => [not]", where we apply the "not" modifier to
-- an empty set of subprograms, if such a construct existed.
-- We could just assign True here, but it seems untidy to
-- return True in the case of an aspect spec for a type
-- (since negation is only allowed for subp S_P aspects).
return (1 .. 0 => <>);
else
return Parse_Aspect_Stable_Properties
(Aspect_Spec, Negated => Negated);
end if;
end Stable_Properties;
Formal : Entity_Id := First_Formal (Subp_Id);
Type_Of_Formal : Entity_Id;
Subp_Properties_Negated : Boolean;
Subp_Properties : constant Subprogram_List :=
Stable_Properties (Subp_Id, Subp_Properties_Negated);
-- start of processing for Add_Stable_Property_Contracts
begin
if not (Is_Primitive (Subp_Id) and then Comes_From_Source (Subp_Id))
then
return;
end if;
while Present (Formal) loop
Type_Of_Formal := Base_Type (Etype (Formal));
if not Subp_Properties_Negated then
for SPF_Id of Subp_Properties loop
if Type_Of_Formal = Base_Type (Etype (First_Formal (SPF_Id)))
and then Scope (Type_Of_Formal) = Scope (Subp_Id)
then
-- ??? Need to filter out checks for SPFs that are
-- mentioned explicitly in the postcondition of
-- Subp_Id.
Insert_Stable_Property_Check
(Formal => Formal, Property_Function => SPF_Id);
end if;
end loop;
elsif Scope (Type_Of_Formal) = Scope (Subp_Id) then
declare
Ignored : Boolean range False .. False;
Typ_Property_Funcs : constant Subprogram_List :=
Stable_Properties (Type_Of_Formal, Negated => Ignored);
function Excluded_By_Aspect_Spec_Of_Subp
(SPF_Id : Entity_Id) return Boolean;
-- Examine Subp_Properties to determine whether SPF should
-- be excluded.
-------------------------------------
-- Excluded_By_Aspect_Spec_Of_Subp --
-------------------------------------
function Excluded_By_Aspect_Spec_Of_Subp
(SPF_Id : Entity_Id) return Boolean is
begin
pragma Assert (Subp_Properties_Negated);
-- Look through renames for equality test here ???
return (for some F of Subp_Properties => F = SPF_Id);
end Excluded_By_Aspect_Spec_Of_Subp;
-- Look through renames for equality test here ???
Subp_Is_Stable_Property_Function : constant Boolean :=
(for some F of Typ_Property_Funcs => F = Subp_Id);
begin
if not Subp_Is_Stable_Property_Function then
for SPF_Id of Typ_Property_Funcs loop
if not Excluded_By_Aspect_Spec_Of_Subp (SPF_Id) then
-- ??? Need to filter out checks for SPFs that are
-- mentioned explicitly in the postcondition of
-- Subp_Id.
Insert_Stable_Property_Check
(Formal => Formal, Property_Function => SPF_Id);
end if;
end loop;
end if;
end;
end if;
Next_Formal (Formal);
end loop;
end Add_Stable_Property_Contracts;
-------------------------
-- Append_Enabled_Item --
-------------------------
procedure Append_Enabled_Item (Item : Node_Id; List : in out List_Id) is
begin
-- Do not chain ignored or disabled pragmas
if Nkind (Item) = N_Pragma
and then (Is_Ignored (Item) or else Is_Disabled (Item))
then
null;
-- Otherwise, add the item
else
if No (List) then
List := New_List;
end if;
-- If the pragma is a conjunct in a composite postcondition, it
-- has been processed in reverse order. In the postcondition body
-- it must appear before the others.
if Nkind (Item) = N_Pragma
and then From_Aspect_Specification (Item)
and then Split_PPC (Item)
then
Prepend (Item, List);
else
Append (Item, List);
end if;
end if;
end Append_Enabled_Item;
------------------------------------
-- Build_Postconditions_Procedure --
------------------------------------
procedure Build_Postconditions_Procedure
(Subp_Id : Entity_Id;
Stmts : List_Id;
Result : Entity_Id)
is
Loc : constant Source_Ptr := Sloc (Body_Decl);
Last_Decl : Node_Id;
Params : List_Id := No_List;
Proc_Bod : Node_Id;
Proc_Decl : Node_Id;
Proc_Id : Entity_Id;
Proc_Spec : Node_Id;
-- Extra declarations needed to handle interactions between
-- postconditions and finalization.
Postcond_Enabled_Decl : Node_Id;
Return_Success_Decl : Node_Id;
Result_Obj_Decl : Node_Id;
Result_Obj_Type_Decl : Node_Id;
Result_Obj_Type : Entity_Id;
-- Start of processing for Build_Postconditions_Procedure
begin
-- Nothing to do if there are no actions to check on exit
if No (Stmts) then
return;
end if;
-- Otherwise, we generate the postcondition procedure and add
-- associated objects and conditions used to coordinate postcondition
-- evaluation with finalization.
-- Generate:
--
-- procedure _postconditions (Return_Exp : Result_Typ);
--
-- -- Result_Obj_Type created when Result_Type is non-elementary
-- [type Result_Obj_Type is access all Result_Typ;]
--
-- Result_Obj : Result_Obj_Type;
--
-- Postcond_Enabled : Boolean := True;
-- Return_Success_For_Postcond : Boolean := False;
--
-- procedure _postconditions (Return_Exp : Result_Typ) is
-- begin
-- if Postcond_Enabled and then Return_Success_For_Postcond then
-- [stmts];
-- end if;
-- end;
Proc_Id := Make_Defining_Identifier (Loc, Name_uPostconditions);
Set_Debug_Info_Needed (Proc_Id);
Set_Postconditions_Proc (Subp_Id, Proc_Id);
-- Force the front-end inlining of _Postconditions when generating C
-- code, since its body may have references to itypes defined in the
-- enclosing subprogram, which would cause problems for unnesting
-- routines in the absence of inlining.
if Modify_Tree_For_C then
Set_Has_Pragma_Inline (Proc_Id);
Set_Has_Pragma_Inline_Always (Proc_Id);
Set_Is_Inlined (Proc_Id);
end if;
-- The related subprogram is a function: create the specification of
-- parameter _Result.
if Present (Result) then
Params := New_List (
Make_Parameter_Specification (Loc,
Defining_Identifier => Result,
Parameter_Type =>
New_Occurrence_Of (Etype (Result), Loc)));
end if;
Proc_Spec :=
Make_Procedure_Specification (Loc,
Defining_Unit_Name => Proc_Id,
Parameter_Specifications => Params);
Proc_Decl := Make_Subprogram_Declaration (Loc, Proc_Spec);
-- Insert _Postconditions before the first source declaration of the
-- body. This ensures that the body will not cause any premature
-- freezing, as it may mention types:
-- Generate:
--
-- procedure Proc (Obj : Array_Typ) is
-- procedure _postconditions is
-- begin
-- ... Obj ...
-- end _postconditions;
--
-- subtype T is Array_Typ (Obj'First (1) .. Obj'Last (1));
-- begin
-- In the example above, Obj is of type T but the incorrect placement
-- of _Postconditions will cause a crash in gigi due to an out-of-
-- order reference. The body of _Postconditions must be placed after
-- the declaration of Temp to preserve correct visibility.
Insert_Before_First_Source_Declaration
(Proc_Decl, Declarations (Body_Decl));
Analyze (Proc_Decl);
Last_Decl := Proc_Decl;
-- When Result is present (e.g. the postcondition checks apply to a
-- function) we make a local object to capture the result, so, if
-- needed, we can call the generated postconditions procedure during
-- finalization instead of at the point of return.
-- Note: The placement of the following declarations before the
-- declaration of the body of the postconditions, but after the
-- declaration of the postconditions spec is deliberate and required
-- since other code within the expander expects them to be located
-- here. Perhaps when more space is available in the tree this will
-- no longer be necessary ???
if Present (Result) then
-- Elementary result types mean a copy is cheap and preferred over
-- using pointers.
if Is_Elementary_Type (Etype (Result)) then
Result_Obj_Type := Etype (Result);
-- Otherwise, we create a named access type to capture the result
-- Generate:
--
-- type Result_Obj_Type is access all [Result_Type];
else
Result_Obj_Type := Make_Temporary (Loc, 'R');
Result_Obj_Type_Decl :=
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Result_Obj_Type,
Type_Definition =>
Make_Access_To_Object_Definition (Loc,
All_Present => True,
Subtype_Indication => New_Occurrence_Of
(Etype (Result), Loc)));
Insert_After_And_Analyze (Proc_Decl, Result_Obj_Type_Decl);
Last_Decl := Result_Obj_Type_Decl;
end if;
-- Create the result obj declaration
-- Generate:
--
-- Result_Object_For_Postcond : Result_Obj_Type;
Result_Obj_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier =>
Make_Defining_Identifier
(Loc, Name_uResult_Object_For_Postcond),
Object_Definition =>
New_Occurrence_Of
(Result_Obj_Type, Loc));
Set_No_Initialization (Result_Obj_Decl);
Insert_After_And_Analyze (Last_Decl, Result_Obj_Decl);
Last_Decl := Result_Obj_Decl;
end if;
-- Build the Postcond_Enabled flag used to delay evaluation of
-- postconditions until finalization has been performed when cleanup
-- actions are present.
-- NOTE: This flag could be made into a predicate since we should be
-- able at compile time to recognize when finalization and cleanup
-- actions occur, but in practice this is not possible ???
-- Generate:
--
-- Postcond_Enabled : Boolean := True;
Postcond_Enabled_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier =>
Make_Defining_Identifier
(Loc, Name_uPostcond_Enabled),
Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc),
Expression => New_Occurrence_Of (Standard_True, Loc));
Insert_After_And_Analyze (Last_Decl, Postcond_Enabled_Decl);
Last_Decl := Postcond_Enabled_Decl;
-- Create a flag to indicate that return has been reached
-- This is necessary for deciding whether to execute _postconditions
-- during finalization.
-- Generate:
--
-- Return_Success_For_Postcond : Boolean := False;
Return_Success_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier =>
Make_Defining_Identifier
(Loc, Name_uReturn_Success_For_Postcond),
Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc),
Expression => New_Occurrence_Of (Standard_False, Loc));
Insert_After_And_Analyze (Last_Decl, Return_Success_Decl);
Last_Decl := Return_Success_Decl;
-- Set an explicit End_Label to override the sloc of the implicit
-- RETURN statement, and prevent it from inheriting the sloc of one
-- the postconditions: this would cause confusing debug info to be
-- produced, interfering with coverage-analysis tools.
-- NOTE: Coverage-analysis and static-analysis tools rely on the
-- postconditions procedure being free of internally generated code
-- since some of these tools, like CodePeer, treat _postconditions
-- as original source.
-- Generate:
--
-- procedure _postconditions is
-- begin
-- [Stmts];
-- end;
Proc_Bod :=
Make_Subprogram_Body (Loc,
Specification =>
Copy_Subprogram_Spec (Proc_Spec),
Declarations => Empty_List,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
End_Label => Make_Identifier (Loc, Chars (Proc_Id)),
Statements => Stmts));
Insert_After_And_Analyze (Last_Decl, Proc_Bod);
end Build_Postconditions_Procedure;
----------------------------
-- Process_Contract_Cases --
----------------------------
procedure Process_Contract_Cases (Stmts : in out List_Id) is
procedure Process_Contract_Cases_For (Subp_Id : Entity_Id);
-- Process pragma Contract_Cases for subprogram Subp_Id
--------------------------------
-- Process_Contract_Cases_For --
--------------------------------
procedure Process_Contract_Cases_For (Subp_Id : Entity_Id) is
Items : constant Node_Id := Contract (Subp_Id);
Prag : Node_Id;
begin
if Present (Items) then
Prag := Contract_Test_Cases (Items);
while Present (Prag) loop
if Is_Checked (Prag) then
if Pragma_Name (Prag) = Name_Contract_Cases then
Expand_Pragma_Contract_Cases
(CCs => Prag,
Subp_Id => Subp_Id,
Decls => Declarations (Body_Decl),
Stmts => Stmts);
elsif Pragma_Name (Prag) = Name_Subprogram_Variant then
Expand_Pragma_Subprogram_Variant
(Prag => Prag,
Subp_Id => Subp_Id,
Body_Decls => Declarations (Body_Decl));
end if;
end if;
Prag := Next_Pragma (Prag);
end loop;
end if;
end Process_Contract_Cases_For;
pragma Unmodified (Stmts);
-- Stmts is passed as IN OUT to signal that the list can be updated,
-- even if the corresponding integer value representing the list does
-- not change.
-- Start of processing for Process_Contract_Cases
begin
Process_Contract_Cases_For (Body_Id);
if Present (Spec_Id) then
Process_Contract_Cases_For (Spec_Id);
end if;
end Process_Contract_Cases;
----------------------------
-- Process_Postconditions --
----------------------------
procedure Process_Postconditions (Stmts : in out List_Id) is
procedure Process_Body_Postconditions (Post_Nam : Name_Id);
-- Collect all [refined] postconditions of a specific kind denoted
-- by Post_Nam that belong to the body, and generate pragma Check
-- equivalents in list Stmts.
procedure Process_Spec_Postconditions;
-- Collect all [inherited] postconditions of the spec, and generate
-- pragma Check equivalents in list Stmts.
---------------------------------
-- Process_Body_Postconditions --
---------------------------------
procedure Process_Body_Postconditions (Post_Nam : Name_Id) is
Items : constant Node_Id := Contract (Body_Id);
Unit_Decl : constant Node_Id := Parent (Body_Decl);
Decl : Node_Id;
Prag : Node_Id;
begin
-- Process the contract
if Present (Items) then
Prag := Pre_Post_Conditions (Items);
while Present (Prag) loop
if Pragma_Name (Prag) = Post_Nam
and then Is_Checked (Prag)
then
Append_Enabled_Item
(Item => Build_Pragma_Check_Equivalent (Prag),
List => Stmts);
end if;
Prag := Next_Pragma (Prag);
end loop;
end if;
-- The subprogram body being processed is actually the proper body
-- of a stub with a corresponding spec. The subprogram stub may
-- carry a postcondition pragma, in which case it must be taken
-- into account. The pragma appears after the stub.
if Present (Spec_Id) and then Nkind (Unit_Decl) = N_Subunit then
Decl := Next (Corresponding_Stub (Unit_Decl));
while Present (Decl) loop
-- Note that non-matching pragmas are skipped
if Nkind (Decl) = N_Pragma then
if Pragma_Name (Decl) = Post_Nam
and then Is_Checked (Decl)
then
Append_Enabled_Item
(Item => Build_Pragma_Check_Equivalent (Decl),
List => Stmts);
end if;
-- Skip internally generated code
elsif not Comes_From_Source (Decl) then
null;
-- Postcondition pragmas are usually grouped together. There
-- is no need to inspect the whole declarative list.
else
exit;
end if;
Next (Decl);
end loop;
end if;
end Process_Body_Postconditions;
---------------------------------
-- Process_Spec_Postconditions --
---------------------------------
procedure Process_Spec_Postconditions is
Subps : constant Subprogram_List :=
Inherited_Subprograms (Spec_Id);
Seen : Subprogram_List (Subps'Range) := (others => Empty);
function Seen_Subp (Subp_Id : Entity_Id) return Boolean;
-- Return True if the contract of subprogram Subp_Id has been
-- processed.
---------------
-- Seen_Subp --
---------------
function Seen_Subp (Subp_Id : Entity_Id) return Boolean is
begin
for Index in Seen'Range loop
if Seen (Index) = Subp_Id then
return True;
end if;
end loop;
return False;
end Seen_Subp;
-- Local variables
Item : Node_Id;
Items : Node_Id;
Prag : Node_Id;
Subp_Id : Entity_Id;
-- Start of processing for Process_Spec_Postconditions
begin
-- Process the contract
Items := Contract (Spec_Id);
if Present (Items) then
Prag := Pre_Post_Conditions (Items);
while Present (Prag) loop
if Pragma_Name (Prag) = Name_Postcondition
and then Is_Checked (Prag)
then
Append_Enabled_Item
(Item => Build_Pragma_Check_Equivalent (Prag),
List => Stmts);
end if;
Prag := Next_Pragma (Prag);
end loop;
end if;
-- Process the contracts of all inherited subprograms, looking for
-- class-wide postconditions.
for Index in Subps'Range loop
Subp_Id := Subps (Index);
if Present (Alias (Subp_Id)) then
Subp_Id := Ultimate_Alias (Subp_Id);
end if;
-- Wrappers of class-wide pre/postconditions reference the
-- parent primitive that has the inherited contract.
if Is_Wrapper (Subp_Id)
and then Present (LSP_Subprogram (Subp_Id))
then
Subp_Id := LSP_Subprogram (Subp_Id);
end if;
Items := Contract (Subp_Id);
if not Seen_Subp (Subp_Id) and then Present (Items) then
Seen (Index) := Subp_Id;
Prag := Pre_Post_Conditions (Items);
while Present (Prag) loop
if Pragma_Name (Prag) = Name_Postcondition
and then Class_Present (Prag)
then
Item :=
Build_Pragma_Check_Equivalent
(Prag => Prag,
Subp_Id => Spec_Id,
Inher_Id => Subp_Id);
-- The pragma Check equivalent of the class-wide
-- postcondition is still created even though the
-- pragma may be ignored because the equivalent
-- performs semantic checks.
if Is_Checked (Prag) then
Append_Enabled_Item (Item, Stmts);
end if;
end if;
Prag := Next_Pragma (Prag);
end loop;
end if;
end loop;
end Process_Spec_Postconditions;
pragma Unmodified (Stmts);
-- Stmts is passed as IN OUT to signal that the list can be updated,
-- even if the corresponding integer value representing the list does
-- not change.
-- Start of processing for Process_Postconditions
begin
-- The processing of postconditions is done in reverse order (body
-- first) to ensure the following arrangement:
-- <refined postconditions from body>
-- <postconditions from body>
-- <postconditions from spec>
-- <inherited postconditions>
Process_Body_Postconditions (Name_Refined_Post);
Process_Body_Postconditions (Name_Postcondition);
if Present (Spec_Id) then
Process_Spec_Postconditions;
end if;
end Process_Postconditions;
---------------------------
-- Process_Preconditions --
---------------------------
procedure Process_Preconditions is
Insert_Node : Node_Id := Empty;
-- The insertion node after which all pragma Check equivalents are
-- inserted.
function Is_Prologue_Renaming (Decl : Node_Id) return Boolean;
-- Determine whether arbitrary declaration Decl denotes a renaming of
-- a discriminant or protection field _object.
procedure Prepend_To_Decls (Item : Node_Id);
-- Prepend a single item to the declarations of the subprogram body
procedure Prepend_Pragma_To_Decls (Prag : Node_Id);
-- Prepend a normal precondition to the declarations of the body and
-- analyze it.
procedure Process_Preconditions_For (Subp_Id : Entity_Id);
-- Collect all preconditions of subprogram Subp_Id and prepend their
-- pragma Check equivalents to the declarations of the body.
--------------------------
-- Is_Prologue_Renaming --
--------------------------
function Is_Prologue_Renaming (Decl : Node_Id) return Boolean is
Nam : Node_Id;
Obj : Entity_Id;
Pref : Node_Id;
Sel : Node_Id;
begin
if Nkind (Decl) = N_Object_Renaming_Declaration then
Obj := Defining_Entity (Decl);
Nam := Name (Decl);
if Nkind (Nam) = N_Selected_Component then
Pref := Prefix (Nam);
Sel := Selector_Name (Nam);
-- A discriminant renaming appears as
-- Discr : constant ... := Prefix.Discr;
if Ekind (Obj) = E_Constant
and then Is_Entity_Name (Sel)
and then Present (Entity (Sel))
and then Ekind (Entity (Sel)) = E_Discriminant
then
return True;
-- A protection field renaming appears as
-- Prot : ... := _object._object;
-- A renamed private component is just a component of
-- _object, with an arbitrary name.
elsif Ekind (Obj) in E_Variable | E_Constant
and then Nkind (Pref) = N_Identifier
and then Chars (Pref) = Name_uObject
and then Nkind (Sel) = N_Identifier
then
return True;
end if;
end if;
end if;
return False;
end Is_Prologue_Renaming;
----------------------
-- Prepend_To_Decls --
----------------------
procedure Prepend_To_Decls (Item : Node_Id) is
Decls : List_Id;
begin
Decls := Declarations (Body_Decl);
-- Ensure that the body has a declarative list
if No (Decls) then
Decls := New_List;
Set_Declarations (Body_Decl, Decls);
end if;
Prepend_To (Decls, Item);
end Prepend_To_Decls;
-----------------------------
-- Prepend_Pragma_To_Decls --
-----------------------------
procedure Prepend_Pragma_To_Decls (Prag : Node_Id) is
Check_Prag : Node_Id;
begin
-- Skip the sole class-wide precondition (if any) since it is
-- processed by Merge_Class_Conditions.
if Class_Present (Prag) then
null;
-- Accumulate the corresponding Check pragmas at the top of the
-- declarations. Prepending the items ensures that they will be
-- evaluated in their original order.
else
Check_Prag := Build_Pragma_Check_Equivalent (Prag);
if Present (Insert_Node) then
Insert_After (Insert_Node, Check_Prag);
else
Prepend_To_Decls (Check_Prag);
end if;
Analyze (Check_Prag);
end if;
end Prepend_Pragma_To_Decls;
-------------------------------
-- Process_Preconditions_For --
-------------------------------
procedure Process_Preconditions_For (Subp_Id : Entity_Id) is
Items : constant Node_Id := Contract (Subp_Id);
Subp_Decl : constant Node_Id := Unit_Declaration_Node (Subp_Id);
Decl : Node_Id;
Freeze_T : Boolean;
Prag : Node_Id;
begin
-- Process the contract. If the body is an expression function
-- that is a completion, freeze types within, because this may
-- not have been done yet, when the subprogram declaration and
-- its completion by an expression function appear in distinct
-- declarative lists of the same unit (visible and private).
Freeze_T :=
Was_Expression_Function (Body_Decl)
and then Sloc (Body_Id) /= Sloc (Subp_Id)
and then In_Same_Source_Unit (Body_Id, Subp_Id)
and then not In_Same_List (Body_Decl, Subp_Decl);
if Present (Items) then
Prag := Pre_Post_Conditions (Items);
while Present (Prag) loop
if Pragma_Name (Prag) = Name_Precondition
and then Is_Checked (Prag)
then
if Freeze_T
and then Present (Corresponding_Aspect (Prag))
then
Freeze_Expr_Types
(Def_Id => Subp_Id,
Typ => Standard_Boolean,
Expr =>
Expression
(First (Pragma_Argument_Associations (Prag))),
N => Body_Decl);
end if;
Prepend_Pragma_To_Decls (Prag);
end if;
Prag := Next_Pragma (Prag);
end loop;
end if;
-- The subprogram declaration being processed is actually a body
-- stub. The stub may carry a precondition pragma, in which case
-- it must be taken into account. The pragma appears after the
-- stub.
if Nkind (Subp_Decl) = N_Subprogram_Body_Stub then
-- Inspect the declarations following the body stub
Decl := Next (Subp_Decl);
while Present (Decl) loop
-- Note that non-matching pragmas are skipped
if Nkind (Decl) = N_Pragma then
if Pragma_Name (Decl) = Name_Precondition
and then Is_Checked (Decl)
then
Prepend_Pragma_To_Decls (Decl);
end if;
-- Skip internally generated code
elsif not Comes_From_Source (Decl) then
null;
-- Preconditions are usually grouped together. There is no
-- need to inspect the whole declarative list.
else
exit;
end if;
Next (Decl);
end loop;
end if;
end Process_Preconditions_For;
-- Local variables
Decls : constant List_Id := Declarations (Body_Decl);
Decl : Node_Id;
-- Start of processing for Process_Preconditions
begin
-- Find the proper insertion point for all pragma Check equivalents
if Present (Decls) then
Decl := First (Decls);
while Present (Decl) loop
-- First source declaration terminates the search, because all
-- preconditions must be evaluated prior to it, by definition.
if Comes_From_Source (Decl) then
exit;
-- Certain internally generated object renamings such as those
-- for discriminants and protection fields must be elaborated
-- before the preconditions are evaluated, as their expressions
-- may mention the discriminants. The renamings include those
-- for private components so we need to find the last such.
elsif Is_Prologue_Renaming (Decl) then
while Present (Next (Decl))
and then Is_Prologue_Renaming (Next (Decl))
loop
Next (Decl);
end loop;
Insert_Node := Decl;
-- Otherwise the declaration does not come from source. This
-- also terminates the search, because internal code may raise
-- exceptions which should not preempt the preconditions.
else
exit;
end if;
Next (Decl);
end loop;
-- The processing of preconditions is done in reverse order (body
-- first), because each pragma Check equivalent is inserted at the
-- top of the declarations. This ensures that the final order is
-- consistent with following diagram:
-- <inherited preconditions>
-- <preconditions from spec>
-- <preconditions from body>
Process_Preconditions_For (Body_Id);
end if;
if Present (Spec_Id) then
Process_Preconditions_For (Spec_Id);
end if;
end Process_Preconditions;
-- Local variables
Restore_Scope : Boolean := False;
Result : Entity_Id;
Stmts : List_Id := No_List;
Subp_Id : Entity_Id;
-- Start of processing for Expand_Subprogram_Contract
begin
-- Obtain the entity of the initial declaration
if Present (Spec_Id) then
Subp_Id := Spec_Id;
else
Subp_Id := Body_Id;
end if;
-- Do not perform expansion activity when it is not needed
if not Expander_Active then
return;
-- GNATprove does not need the executable semantics of a contract
elsif GNATprove_Mode then
return;
-- The contract of a generic subprogram or one declared in a generic
-- context is not expanded, as the corresponding instance will provide
-- the executable semantics of the contract.
elsif Is_Generic_Subprogram (Subp_Id) or else Inside_A_Generic then
return;
-- All subprograms carry a contract, but for some it is not significant
-- and should not be processed. This is a small optimization.
elsif not Has_Significant_Contract (Subp_Id) then
return;
-- The contract of an ignored Ghost subprogram does not need expansion,
-- because the subprogram and all calls to it will be removed.
elsif Is_Ignored_Ghost_Entity (Subp_Id) then
return;
-- No action needed for helpers and indirect-call wrapper built to
-- support class-wide preconditions.
elsif Present (Class_Preconditions_Subprogram (Subp_Id)) then
return;
-- Do not re-expand the same contract. This scenario occurs when a
-- construct is rewritten into something else during its analysis
-- (expression functions for instance).
elsif Has_Expanded_Contract (Subp_Id) then
return;
end if;
-- Prevent multiple expansion attempts of the same contract
Set_Has_Expanded_Contract (Subp_Id);
-- Ensure that the formal parameters are visible when expanding all
-- contract items.
if not In_Open_Scopes (Subp_Id) then
Restore_Scope := True;
Push_Scope (Subp_Id);
if Is_Generic_Subprogram (Subp_Id) then
Install_Generic_Formals (Subp_Id);
else
Install_Formals (Subp_Id);
end if;
end if;
-- The expansion of a subprogram contract involves the creation of Check
-- pragmas to verify the contract assertions of the spec and body in a
-- particular order. The order is as follows:
-- function Example (...) return ... is
-- procedure _Postconditions (...) is
-- begin
-- <refined postconditions from body>
-- <postconditions from body>
-- <postconditions from spec>
-- <inherited postconditions>
-- <contract case consequences>
-- <invariant check of function result>
-- <invariant and predicate checks of parameters>
-- end _Postconditions;
-- <inherited preconditions>
-- <preconditions from spec>
-- <preconditions from body>
-- <contract case conditions>
-- <source declarations>
-- begin
-- <source statements>
-- _Preconditions (Result);
-- return Result;
-- end Example;
-- Routine _Postconditions holds all contract assertions that must be
-- verified on exit from the related subprogram.
-- Step 1: augment contracts list with postconditions associated with
-- Stable_Properties and Stable_Properties'Class aspects. This must
-- precede Process_Postconditions.
for Class_Present in Boolean loop
Add_Stable_Property_Contracts
(Subp_Id, Class_Present => Class_Present);
end loop;
-- Step 2: Handle all preconditions. This action must come before the
-- processing of pragma Contract_Cases because the pragma prepends items
-- to the body declarations.
Process_Preconditions;
-- Step 3: Handle all postconditions. This action must come before the
-- processing of pragma Contract_Cases because the pragma appends items
-- to list Stmts.
Process_Postconditions (Stmts);
-- Step 4: Handle pragma Contract_Cases. This action must come before
-- the processing of invariants and predicates because those append
-- items to list Stmts.
Process_Contract_Cases (Stmts);
-- Step 5: Apply invariant and predicate checks on a function result and
-- all formals. The resulting checks are accumulated in list Stmts.
Add_Invariant_And_Predicate_Checks (Subp_Id, Stmts, Result);
-- Step 6: Construct procedure _Postconditions
Build_Postconditions_Procedure (Subp_Id, Stmts, Result);
if Restore_Scope then
End_Scope;
end if;
end Expand_Subprogram_Contract;
-------------------------------
-- Freeze_Previous_Contracts --
-------------------------------
procedure Freeze_Previous_Contracts (Body_Decl : Node_Id) is
function Causes_Contract_Freezing (N : Node_Id) return Boolean;
pragma Inline (Causes_Contract_Freezing);
-- Determine whether arbitrary node N causes contract freezing. This is
-- used as an assertion for the current body declaration that caused
-- contract freezing, and as a condition to detect body declaration that
-- already caused contract freezing before.
procedure Freeze_Contracts;
pragma Inline (Freeze_Contracts);
-- Freeze the contracts of all eligible constructs which precede body
-- Body_Decl.
procedure Freeze_Enclosing_Package_Body;
pragma Inline (Freeze_Enclosing_Package_Body);
-- Freeze the contract of the nearest package body (if any) which
-- encloses body Body_Decl.
------------------------------
-- Causes_Contract_Freezing --
------------------------------
function Causes_Contract_Freezing (N : Node_Id) return Boolean is
begin
-- The following condition matches guards for calls to
-- Freeze_Previous_Contracts from routines that analyze various body
-- declarations. In particular, it detects expression functions, as
-- described in the call from Analyze_Subprogram_Body_Helper.
return
Comes_From_Source (Original_Node (N))
and then
Nkind (N) in
N_Entry_Body | N_Package_Body | N_Protected_Body |
N_Subprogram_Body | N_Subprogram_Body_Stub | N_Task_Body;
end Causes_Contract_Freezing;
----------------------
-- Freeze_Contracts --
----------------------
procedure Freeze_Contracts is
Body_Id : constant Entity_Id := Defining_Entity (Body_Decl);
Decl : Node_Id;
begin
-- Nothing to do when the body which causes freezing does not appear
-- in a declarative list because there cannot possibly be constructs
-- with contracts.
if not Is_List_Member (Body_Decl) then
return;
end if;
-- Inspect the declarations preceding the body, and freeze individual
-- contracts of eligible constructs.
Decl := Prev (Body_Decl);
while Present (Decl) loop
-- Stop the traversal when a preceding construct that causes
-- freezing is encountered as there is no point in refreezing
-- the already frozen constructs.
if Causes_Contract_Freezing (Decl) then
exit;
-- Entry or subprogram declarations
elsif Nkind (Decl) in N_Abstract_Subprogram_Declaration
| N_Entry_Declaration
| N_Generic_Subprogram_Declaration
| N_Subprogram_Declaration
then
Analyze_Entry_Or_Subprogram_Contract
(Subp_Id => Defining_Entity (Decl),
Freeze_Id => Body_Id);
-- Objects
elsif Nkind (Decl) = N_Object_Declaration then
Analyze_Object_Contract
(Obj_Id => Defining_Entity (Decl),
Freeze_Id => Body_Id);
-- Protected units
elsif Nkind (Decl) in N_Protected_Type_Declaration
| N_Single_Protected_Declaration
then
Analyze_Protected_Contract (Defining_Entity (Decl));
-- Subprogram body stubs
elsif Nkind (Decl) = N_Subprogram_Body_Stub then
Analyze_Subprogram_Body_Stub_Contract (Defining_Entity (Decl));
-- Task units
elsif Nkind (Decl) in N_Single_Task_Declaration
| N_Task_Type_Declaration
then
Analyze_Task_Contract (Defining_Entity (Decl));
end if;
if Nkind (Decl) in N_Full_Type_Declaration
| N_Private_Type_Declaration
| N_Task_Type_Declaration
| N_Protected_Type_Declaration
| N_Formal_Type_Declaration
then
Analyze_Type_Contract (Defining_Identifier (Decl));
end if;
Prev (Decl);
end loop;
end Freeze_Contracts;
-----------------------------------
-- Freeze_Enclosing_Package_Body --
-----------------------------------
procedure Freeze_Enclosing_Package_Body is
Orig_Decl : constant Node_Id := Original_Node (Body_Decl);
Par : Node_Id;
begin
-- Climb the parent chain looking for an enclosing package body. Do
-- not use the scope stack, because a body utilizes the entity of its
-- corresponding spec.
Par := Parent (Body_Decl);
while Present (Par) loop
if Nkind (Par) = N_Package_Body then
Analyze_Package_Body_Contract
(Body_Id => Defining_Entity (Par),
Freeze_Id => Defining_Entity (Body_Decl));
exit;
-- Do not look for an enclosing package body when the construct
-- which causes freezing is a body generated for an expression
-- function and it appears within a package spec. This ensures
-- that the traversal will not reach too far up the parent chain
-- and attempt to freeze a package body which must not be frozen.
-- package body Enclosing_Body
-- with Refined_State => (State => Var)
-- is
-- package Nested is
-- type Some_Type is ...;
-- function Cause_Freezing return ...;
-- private
-- function Cause_Freezing is (...);
-- end Nested;
--
-- Var : Nested.Some_Type;
elsif Nkind (Par) = N_Package_Declaration
and then Nkind (Orig_Decl) = N_Expression_Function
then
exit;
-- Prevent the search from going too far
elsif Is_Body_Or_Package_Declaration (Par) then
exit;
end if;
Par := Parent (Par);
end loop;
end Freeze_Enclosing_Package_Body;
-- Local variables
Body_Id : constant Entity_Id := Defining_Entity (Body_Decl);
-- Start of processing for Freeze_Previous_Contracts
begin
pragma Assert (Causes_Contract_Freezing (Body_Decl));
-- A body that is in the process of being inlined appears from source,
-- but carries name _parent. Such a body does not cause freezing of
-- contracts.
if Chars (Body_Id) = Name_uParent then
return;
end if;
Freeze_Enclosing_Package_Body;
Freeze_Contracts;
end Freeze_Previous_Contracts;
--------------------------
-- Get_Postcond_Enabled --
--------------------------
function Get_Postcond_Enabled (Subp : Entity_Id) return Entity_Id is
Decl : Node_Id;
begin
Decl :=
Next (Unit_Declaration_Node (Postconditions_Proc (Subp)));
while Present (Decl) loop
if Nkind (Decl) = N_Object_Declaration
and then Chars (Defining_Identifier (Decl))
= Name_uPostcond_Enabled
then
return Defining_Identifier (Decl);
end if;
Next (Decl);
end loop;
return Empty;
end Get_Postcond_Enabled;
------------------------------------
-- Get_Result_Object_For_Postcond --
------------------------------------
function Get_Result_Object_For_Postcond
(Subp : Entity_Id) return Entity_Id
is
Decl : Node_Id;
begin
Decl :=
Next (Unit_Declaration_Node (Postconditions_Proc (Subp)));
while Present (Decl) loop
if Nkind (Decl) = N_Object_Declaration
and then Chars (Defining_Identifier (Decl))
= Name_uResult_Object_For_Postcond
then
return Defining_Identifier (Decl);
end if;
Next (Decl);
end loop;
return Empty;
end Get_Result_Object_For_Postcond;
-------------------------------------
-- Get_Return_Success_For_Postcond --
-------------------------------------
function Get_Return_Success_For_Postcond (Subp : Entity_Id) return Entity_Id
is
Decl : Node_Id;
begin
Decl :=
Next (Unit_Declaration_Node (Postconditions_Proc (Subp)));
while Present (Decl) loop
if Nkind (Decl) = N_Object_Declaration
and then Chars (Defining_Identifier (Decl))
= Name_uReturn_Success_For_Postcond
then
return Defining_Identifier (Decl);
end if;
Next (Decl);
end loop;
return Empty;
end Get_Return_Success_For_Postcond;
---------------------------------
-- Inherit_Subprogram_Contract --
---------------------------------
procedure Inherit_Subprogram_Contract
(Subp : Entity_Id;
From_Subp : Entity_Id)
is
procedure Inherit_Pragma (Prag_Id : Pragma_Id);
-- Propagate a pragma denoted by Prag_Id from From_Subp's contract to
-- Subp's contract.
--------------------
-- Inherit_Pragma --
--------------------
procedure Inherit_Pragma (Prag_Id : Pragma_Id) is
Prag : constant Node_Id := Get_Pragma (From_Subp, Prag_Id);
New_Prag : Node_Id;
begin
-- A pragma cannot be part of more than one First_Pragma/Next_Pragma
-- chains, therefore the node must be replicated. The new pragma is
-- flagged as inherited for distinction purposes.
if Present (Prag) then
New_Prag := New_Copy_Tree (Prag);
Set_Is_Inherited_Pragma (New_Prag);
Add_Contract_Item (New_Prag, Subp);
end if;
end Inherit_Pragma;
-- Start of processing for Inherit_Subprogram_Contract
begin
-- Inheritance is carried out only when both entities are subprograms
-- with contracts.
if Is_Subprogram_Or_Generic_Subprogram (Subp)
and then Is_Subprogram_Or_Generic_Subprogram (From_Subp)
and then Present (Contract (From_Subp))
then
Inherit_Pragma (Pragma_Extensions_Visible);
end if;
end Inherit_Subprogram_Contract;
-------------------------------------
-- Instantiate_Subprogram_Contract --
-------------------------------------
procedure Instantiate_Subprogram_Contract (Templ : Node_Id; L : List_Id) is
procedure Instantiate_Pragmas (First_Prag : Node_Id);
-- Instantiate all contract-related source pragmas found in the list,
-- starting with pragma First_Prag. Each instantiated pragma is added
-- to list L.
-------------------------
-- Instantiate_Pragmas --
-------------------------
procedure Instantiate_Pragmas (First_Prag : Node_Id) is
Inst_Prag : Node_Id;
Prag : Node_Id;
begin
Prag := First_Prag;
while Present (Prag) loop
if Is_Generic_Contract_Pragma (Prag) then
Inst_Prag :=
Copy_Generic_Node (Prag, Empty, Instantiating => True);
Set_Analyzed (Inst_Prag, False);
Append_To (L, Inst_Prag);
end if;
Prag := Next_Pragma (Prag);
end loop;
end Instantiate_Pragmas;
-- Local variables
Items : constant Node_Id := Contract (Defining_Entity (Templ));
-- Start of processing for Instantiate_Subprogram_Contract
begin
if Present (Items) then
Instantiate_Pragmas (Pre_Post_Conditions (Items));
Instantiate_Pragmas (Contract_Test_Cases (Items));
Instantiate_Pragmas (Classifications (Items));
end if;
end Instantiate_Subprogram_Contract;
-----------------------------------
-- Make_Class_Precondition_Subps --
-----------------------------------
procedure Make_Class_Precondition_Subps
(Subp_Id : Entity_Id;
Late_Overriding : Boolean := False)
is
Loc : constant Source_Ptr := Sloc (Subp_Id);
Tagged_Type : constant Entity_Id := Find_Dispatching_Type (Subp_Id);
procedure Add_Indirect_Call_Wrapper;
-- Build the indirect-call wrapper and append it to the freezing actions
-- of Tagged_Type.
procedure Add_Call_Helper
(Helper_Id : Entity_Id;
Is_Dynamic : Boolean);
-- Factorizes code for building a call helper with the given identifier
-- and append it to the freezing actions of Tagged_Type. Is_Dynamic
-- controls building the static or dynamic version of the helper.
-------------------------------
-- Add_Indirect_Call_Wrapper --
-------------------------------
procedure Add_Indirect_Call_Wrapper is
function Build_ICW_Body return Node_Id;
-- Build the body of the indirect call wrapper
function Build_ICW_Decl return Node_Id;
-- Build the declaration of the indirect call wrapper
--------------------
-- Build_ICW_Body --
--------------------
function Build_ICW_Body return Node_Id is
ICW_Id : constant Entity_Id := Indirect_Call_Wrapper (Subp_Id);
Spec : constant Node_Id := Parent (ICW_Id);
Body_Spec : Node_Id;
Call : Node_Id;
ICW_Body : Node_Id;
begin
Body_Spec := Copy_Subprogram_Spec (Spec);
-- Build call to wrapped subprogram
declare
Actuals : constant List_Id := Empty_List;
Formal_Spec : Entity_Id :=
First (Parameter_Specifications (Spec));
begin
-- Build parameter association & call
while Present (Formal_Spec) loop
Append_To (Actuals,
New_Occurrence_Of
(Defining_Identifier (Formal_Spec), Loc));
Next (Formal_Spec);
end loop;
if Ekind (ICW_Id) = E_Procedure then
Call :=
Make_Procedure_Call_Statement (Loc,
Name => New_Occurrence_Of (Subp_Id, Loc),
Parameter_Associations => Actuals);
else
Call :=
Make_Simple_Return_Statement (Loc,
Expression =>
Make_Function_Call (Loc,
Name => New_Occurrence_Of (Subp_Id, Loc),
Parameter_Associations => Actuals));
end if;
end;
ICW_Body :=
Make_Subprogram_Body (Loc,
Specification => Body_Spec,
Declarations => New_List,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (Call)));
-- The new operation is internal and overriding indicators do not
-- apply.
Set_Must_Override (Body_Spec, False);
return ICW_Body;
end Build_ICW_Body;
--------------------
-- Build_ICW_Decl --
--------------------
function Build_ICW_Decl return Node_Id is
ICW_Id : constant Entity_Id :=
Make_Defining_Identifier (Loc,
New_External_Name (Chars (Subp_Id),
Suffix => "ICW",
Suffix_Index => Source_Offset (Loc)));
Decl : Node_Id;
Spec : Node_Id;
begin
Spec := Copy_Subprogram_Spec (Parent (Subp_Id));
Set_Must_Override (Spec, False);
Set_Must_Not_Override (Spec, False);
Set_Defining_Unit_Name (Spec, ICW_Id);
Mutate_Ekind (ICW_Id, Ekind (Subp_Id));
Set_Is_Public (ICW_Id);
-- The indirect call wrapper is commonly used for indirect calls
-- but inlined for direct calls performed from the DTW.
Set_Is_Inlined (ICW_Id);
if Nkind (Spec) = N_Procedure_Specification then
Set_Null_Present (Spec, False);
end if;
Decl := Make_Subprogram_Declaration (Loc, Spec);
-- Link original subprogram to indirect wrapper and vice versa
Set_Indirect_Call_Wrapper (Subp_Id, ICW_Id);
Set_Class_Preconditions_Subprogram (ICW_Id, Subp_Id);
-- Inherit debug info flag to allow debugging the wrapper
if Needs_Debug_Info (Subp_Id) then
Set_Debug_Info_Needed (ICW_Id);
end if;
return Decl;
end Build_ICW_Decl;
-- Local Variables
ICW_Body : Node_Id;
ICW_Decl : Node_Id;
-- Start of processing for Add_Indirect_Call_Wrapper
begin
pragma Assert (No (Indirect_Call_Wrapper (Subp_Id)));
ICW_Decl := Build_ICW_Decl;
Append_Freeze_Action (Tagged_Type, ICW_Decl);
Analyze (ICW_Decl);
ICW_Body := Build_ICW_Body;
Append_Freeze_Action (Tagged_Type, ICW_Body);
-- We cannot defer the analysis of this ICW wrapper when it is
-- built as a consequence of building its partner DTW wrapper
-- at the freezing point of the tagged type.
if Is_Dispatch_Table_Wrapper (Subp_Id) then
Analyze (ICW_Body);
end if;
end Add_Indirect_Call_Wrapper;
---------------------
-- Add_Call_Helper --
---------------------
procedure Add_Call_Helper
(Helper_Id : Entity_Id;
Is_Dynamic : Boolean)
is
function Build_Call_Helper_Body return Node_Id;
-- Build the body of a call helper
function Build_Call_Helper_Decl return Node_Id;
-- Build the declaration of a call helper
function Build_Call_Helper_Spec (Spec_Id : Entity_Id) return Node_Id;
-- Build the specification of the helper
----------------------------
-- Build_Call_Helper_Body --
----------------------------
function Build_Call_Helper_Body return Node_Id is
function Copy_And_Update_References
(Expr : Node_Id) return Node_Id;
-- Copy Expr updating references to formals of Helper_Id; update
-- also references to loop identifiers of quantified expressions.
--------------------------------
-- Copy_And_Update_References --
--------------------------------
function Copy_And_Update_References
(Expr : Node_Id) return Node_Id
is
Assoc_List : constant Elist_Id := New_Elmt_List;
procedure Map_Quantified_Expression_Loop_Identifiers;
-- Traverse Expr and append to Assoc_List the mapping of loop
-- identifers of quantified expressions with its new copy.
------------------------------------------------
-- Map_Quantified_Expression_Loop_Identifiers --
------------------------------------------------
procedure Map_Quantified_Expression_Loop_Identifiers is
function Map_Loop_Param (N : Node_Id) return Traverse_Result;
-- Append to Assoc_List the mapping of loop identifers of
-- quantified expressions with its new copy.
--------------------
-- Map_Loop_Param --
--------------------
function Map_Loop_Param (N : Node_Id) return Traverse_Result
is
begin
if Nkind (N) = N_Loop_Parameter_Specification
and then Nkind (Parent (N)) = N_Quantified_Expression
then
declare
Def_Id : constant Entity_Id :=
Defining_Identifier (N);
begin
Append_Elmt (Def_Id, Assoc_List);
Append_Elmt (New_Copy (Def_Id), Assoc_List);
end;
end if;
return OK;
end Map_Loop_Param;
procedure Map_Quantified_Expressions is
new Traverse_Proc (Map_Loop_Param);
begin
Map_Quantified_Expressions (Expr);
end Map_Quantified_Expression_Loop_Identifiers;
-- Local variables
Subp_Formal_Id : Entity_Id := First_Formal (Subp_Id);
Helper_Formal_Id : Entity_Id := First_Formal (Helper_Id);
-- Start of processing for Copy_And_Update_References
begin
while Present (Subp_Formal_Id) loop
Append_Elmt (Subp_Formal_Id, Assoc_List);
Append_Elmt (Helper_Formal_Id, Assoc_List);
Next_Formal (Subp_Formal_Id);
Next_Formal (Helper_Formal_Id);
end loop;
Map_Quantified_Expression_Loop_Identifiers;
return New_Copy_Tree (Expr, Map => Assoc_List);
end Copy_And_Update_References;
-- Local variables
Helper_Decl : constant Node_Id := Parent (Parent (Helper_Id));
Body_Id : Entity_Id;
Body_Spec : Node_Id;
Body_Stmts : Node_Id;
Helper_Body : Node_Id;
Return_Expr : Node_Id;
-- Start of processing for Build_Call_Helper_Body
begin
pragma Assert (Analyzed (Unit_Declaration_Node (Helper_Id)));
pragma Assert (No (Corresponding_Body (Helper_Decl)));
Body_Id := Make_Defining_Identifier (Loc, Chars (Helper_Id));
Body_Spec := Build_Call_Helper_Spec (Body_Id);
Set_Corresponding_Body (Helper_Decl, Body_Id);
Set_Must_Override (Body_Spec, False);
if Present (Class_Preconditions (Subp_Id)) then
Return_Expr :=
Copy_And_Update_References (Class_Preconditions (Subp_Id));
-- When the subprogram is compiled with assertions disabled the
-- helper just returns True; done to avoid reporting errors at
-- link time since a unit may be compiled with assertions disabled
-- and another (which depends on it) compiled with assertions
-- enabled.
else
pragma Assert (Present (Ignored_Class_Preconditions (Subp_Id)));
Return_Expr := New_Occurrence_Of (Standard_True, Loc);
end if;
Body_Stmts :=
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (
Make_Simple_Return_Statement (Loc, Return_Expr)));
Helper_Body :=
Make_Subprogram_Body (Loc,
Specification => Body_Spec,
Declarations => New_List,
Handled_Statement_Sequence => Body_Stmts);
return Helper_Body;
end Build_Call_Helper_Body;
----------------------------
-- Build_Call_Helper_Decl --
----------------------------
function Build_Call_Helper_Decl return Node_Id is
Decl : Node_Id;
Spec : Node_Id;
begin
Spec := Build_Call_Helper_Spec (Helper_Id);
Set_Must_Override (Spec, False);
Set_Must_Not_Override (Spec, False);
Set_Is_Inlined (Helper_Id);
Set_Is_Public (Helper_Id);
Decl := Make_Subprogram_Declaration (Loc, Spec);
-- Inherit debug info flag from Subp_Id to Helper_Id to allow
-- debugging of the helper subprogram.
if Needs_Debug_Info (Subp_Id) then
Set_Debug_Info_Needed (Helper_Id);
end if;
return Decl;
end Build_Call_Helper_Decl;
----------------------------
-- Build_Call_Helper_Spec --
----------------------------
function Build_Call_Helper_Spec (Spec_Id : Entity_Id) return Node_Id
is
Spec : constant Node_Id := Parent (Subp_Id);
Def_Id : constant Node_Id := Defining_Unit_Name (Spec);
Formal : Entity_Id;
Func_Formals : constant List_Id := New_List;
P_Spec : constant List_Id := Parameter_Specifications (Spec);
Par_Formal : Node_Id;
Param : Node_Id;
Param_Type : Node_Id;
begin
-- Create a list of formal parameters with the same types as the
-- original subprogram but changing the controlling formal.
Param := First (P_Spec);
Formal := First_Formal (Def_Id);
while Present (Formal) loop
Par_Formal := Parent (Formal);
if Is_Dynamic and then Is_Controlling_Formal (Formal) then
if Nkind (Parameter_Type (Par_Formal))
= N_Access_Definition
then
Param_Type :=
Copy_Separate_Tree (Parameter_Type (Par_Formal));
Rewrite (Subtype_Mark (Param_Type),
Make_Attribute_Reference (Loc,
Prefix => Relocate_Node (Subtype_Mark (Param_Type)),
Attribute_Name => Name_Class));
else
Param_Type :=
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Etype (Formal), Loc),
Attribute_Name => Name_Class);
end if;
else
Param_Type := New_Occurrence_Of (Etype (Formal), Loc);
end if;
Append_To (Func_Formals,
Make_Parameter_Specification (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc, Chars (Formal)),
In_Present => In_Present (Par_Formal),
Out_Present => Out_Present (Par_Formal),
Null_Exclusion_Present => Null_Exclusion_Present
(Par_Formal),
Parameter_Type => Param_Type));
Next (Param);
Next_Formal (Formal);
end loop;
return
Make_Function_Specification (Loc,
Defining_Unit_Name => Spec_Id,
Parameter_Specifications => Func_Formals,
Result_Definition =>
New_Occurrence_Of (Standard_Boolean, Loc));
end Build_Call_Helper_Spec;
-- Local variables
Helper_Body : Node_Id;
Helper_Decl : Node_Id;
-- Start of processing for Add_Call_Helper
begin
Helper_Decl := Build_Call_Helper_Decl;
Mutate_Ekind (Helper_Id, Ekind (Subp_Id));
-- Add the helper to the freezing actions of the tagged type
Append_Freeze_Action (Tagged_Type, Helper_Decl);
Analyze (Helper_Decl);
Helper_Body := Build_Call_Helper_Body;
Append_Freeze_Action (Tagged_Type, Helper_Body);
-- If this helper is built as part of building the DTW at the
-- freezing point of its tagged type then we cannot defer
-- its analysis.
if Late_Overriding then
pragma Assert (Is_Dispatch_Table_Wrapper (Subp_Id));
Analyze (Helper_Body);
end if;
end Add_Call_Helper;
-- Local variables
Helper_Id : Entity_Id;
-- Start of processing for Make_Class_Precondition_Subps
begin
if Present (Class_Preconditions (Subp_Id))
or Present (Ignored_Class_Preconditions (Subp_Id))
then
pragma Assert
(Comes_From_Source (Subp_Id)
or else Is_Dispatch_Table_Wrapper (Subp_Id));
if No (Dynamic_Call_Helper (Subp_Id)) then
-- Build and add to the freezing actions of Tagged_Type its
-- dynamic-call helper.
Helper_Id :=
Make_Defining_Identifier (Loc,
New_External_Name (Chars (Subp_Id),
Suffix => "DP",
Suffix_Index => Source_Offset (Loc)));
Add_Call_Helper (Helper_Id, Is_Dynamic => True);
-- Link original subprogram to helper and vice versa
Set_Dynamic_Call_Helper (Subp_Id, Helper_Id);
Set_Class_Preconditions_Subprogram (Helper_Id, Subp_Id);
end if;
if not Is_Abstract_Subprogram (Subp_Id)
and then No (Static_Call_Helper (Subp_Id))
then
-- Build and add to the freezing actions of Tagged_Type its
-- static-call helper.
Helper_Id :=
Make_Defining_Identifier (Loc,
New_External_Name (Chars (Subp_Id),
Suffix => "SP",
Suffix_Index => Source_Offset (Loc)));
Add_Call_Helper (Helper_Id, Is_Dynamic => False);
-- Link original subprogram to helper and vice versa
Set_Static_Call_Helper (Subp_Id, Helper_Id);
Set_Class_Preconditions_Subprogram (Helper_Id, Subp_Id);
-- Build and add to the freezing actions of Tagged_Type the
-- indirect-call wrapper.
Add_Indirect_Call_Wrapper;
end if;
end if;
end Make_Class_Precondition_Subps;
----------------------------------------------
-- Process_Class_Conditions_At_Freeze_Point --
----------------------------------------------
procedure Process_Class_Conditions_At_Freeze_Point (Typ : Entity_Id) is
procedure Check_Class_Conditions (Spec_Id : Entity_Id);
-- Check class-wide pre/postconditions of Spec_Id
function Has_Class_Postconditions_Subprogram
(Spec_Id : Entity_Id) return Boolean;
-- Return True if Spec_Id has (or inherits) a postconditions subprogram.
function Has_Class_Preconditions_Subprogram
(Spec_Id : Entity_Id) return Boolean;
-- Return True if Spec_Id has (or inherits) a preconditions subprogram.
----------------------------
-- Check_Class_Conditions --
----------------------------
procedure Check_Class_Conditions (Spec_Id : Entity_Id) is
Par_Subp : Entity_Id;
begin
for Kind in Condition_Kind loop
Par_Subp := Nearest_Class_Condition_Subprogram (Kind, Spec_Id);
if Present (Par_Subp) then
Check_Class_Condition
(Cond => Class_Condition (Kind, Par_Subp),
Subp => Spec_Id,
Par_Subp => Par_Subp,
Is_Precondition => Kind in Ignored_Class_Precondition
| Class_Precondition);
end if;
end loop;
end Check_Class_Conditions;
-----------------------------------------
-- Has_Class_Postconditions_Subprogram --
-----------------------------------------
function Has_Class_Postconditions_Subprogram
(Spec_Id : Entity_Id) return Boolean is
begin
return
Present (Nearest_Class_Condition_Subprogram
(Spec_Id => Spec_Id,
Kind => Class_Postcondition))
or else
Present (Nearest_Class_Condition_Subprogram
(Spec_Id => Spec_Id,
Kind => Ignored_Class_Postcondition));
end Has_Class_Postconditions_Subprogram;
----------------------------------------
-- Has_Class_Preconditions_Subprogram --
----------------------------------------
function Has_Class_Preconditions_Subprogram
(Spec_Id : Entity_Id) return Boolean is
begin
return
Present (Nearest_Class_Condition_Subprogram
(Spec_Id => Spec_Id,
Kind => Class_Precondition))
or else
Present (Nearest_Class_Condition_Subprogram
(Spec_Id => Spec_Id,
Kind => Ignored_Class_Precondition));
end Has_Class_Preconditions_Subprogram;
-- Local variables
Prim_Elmt : Elmt_Id := First_Elmt (Primitive_Operations (Typ));
Prim : Entity_Id;
-- Start of processing for Process_Class_Conditions_At_Freeze_Point
begin
while Present (Prim_Elmt) loop
Prim := Node (Prim_Elmt);
if Has_Class_Preconditions_Subprogram (Prim)
or else Has_Class_Postconditions_Subprogram (Prim)
then
if Comes_From_Source (Prim) then
if Has_Significant_Contract (Prim) then
Merge_Class_Conditions (Prim);
end if;
-- Handle wrapper of protected operation
elsif Is_Primitive_Wrapper (Prim) then
Merge_Class_Conditions (Prim);
-- Check inherited class-wide conditions, excluding internal
-- entities built for mapping of interface primitives.
elsif Is_Derived_Type (Typ)
and then Present (Alias (Prim))
and then No (Interface_Alias (Prim))
then
Check_Class_Conditions (Prim);
end if;
end if;
Next_Elmt (Prim_Elmt);
end loop;
end Process_Class_Conditions_At_Freeze_Point;
----------------------------
-- Merge_Class_Conditions --
----------------------------
procedure Merge_Class_Conditions (Spec_Id : Entity_Id) is
procedure Preanalyze_Condition
(Subp : Entity_Id;
Expr : Node_Id);
-- Preanalyze the class-wide condition Expr of Subp
procedure Process_Inherited_Conditions (Kind : Condition_Kind);
-- Collect all inherited class-wide conditions of Spec_Id and merge
-- them into one big condition.
--------------------------
-- Preanalyze_Condition --
--------------------------
procedure Preanalyze_Condition
(Subp : Entity_Id;
Expr : Node_Id)
is
procedure Clear_Unset_References;
-- Clear unset references on formals of Subp since preanalysis
-- occurs in a place unrelated to the actual code.
procedure Remove_Controlling_Arguments;
-- Traverse Expr and clear the Controlling_Argument of calls to
-- nonabstract functions.
procedure Remove_Formals (Id : Entity_Id);
-- Remove formals from homonym chains and make them not visible
procedure Restore_Original_Selected_Component;
-- Traverse Expr searching for dispatching calls to functions whose
-- original node was a selected component, and replace them with
-- their original node.
----------------------------
-- Clear_Unset_References --
----------------------------
procedure Clear_Unset_References is
F : Entity_Id := First_Formal (Subp);
begin
while Present (F) loop
Set_Unset_Reference (F, Empty);
Next_Formal (F);
end loop;
end Clear_Unset_References;
----------------------------------
-- Remove_Controlling_Arguments --
----------------------------------
procedure Remove_Controlling_Arguments is
function Remove_Ctrl_Arg (N : Node_Id) return Traverse_Result;
-- Reset the Controlling_Argument of calls to nonabstract
-- function calls.
---------------------
-- Remove_Ctrl_Arg --
---------------------
function Remove_Ctrl_Arg (N : Node_Id) return Traverse_Result is
begin
if Nkind (N) = N_Function_Call
and then Present (Controlling_Argument (N))
and then not Is_Abstract_Subprogram (Entity (Name (N)))
then
Set_Controlling_Argument (N, Empty);
end if;
return OK;
end Remove_Ctrl_Arg;
procedure Remove_Ctrl_Args is new Traverse_Proc (Remove_Ctrl_Arg);
begin
Remove_Ctrl_Args (Expr);
end Remove_Controlling_Arguments;