| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- C O N T R A C T S -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- 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. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| -- This package contains routines that perform analysis and expansion of |
| -- various contracts. |
| |
| with Types; use Types; |
| |
| package Contracts is |
| |
| procedure Add_Contract_Item (Prag : Node_Id; Id : Entity_Id); |
| -- Add pragma Prag to the contract of a constant, entry, entry family, |
| -- [generic] package, package body, protected unit, [generic] subprogram, |
| -- subprogram body, variable, task unit, or type denoted by Id. |
| -- The following are valid pragmas: |
| -- |
| -- Abstract_State |
| -- Async_Readers |
| -- Async_Writers |
| -- Attach_Handler |
| -- Constant_After_Elaboration |
| -- Contract_Cases |
| -- Depends |
| -- Effective_Reads |
| -- Effective_Writes |
| -- Extensions_Visible |
| -- Global |
| -- Initial_Condition |
| -- Initializes |
| -- Interrupt_Handler |
| -- No_Caching |
| -- Part_Of |
| -- Postcondition |
| -- Precondition |
| -- Refined_Depends |
| -- Refined_Global |
| -- Refined_Post |
| -- Refined_States |
| -- Test_Case |
| -- Volatile_Function |
| |
| procedure Analyze_Contracts (L : List_Id); |
| -- Analyze the contracts of all eligible constructs found in list L |
| |
| procedure Analyze_Pragmas_In_Declarations (Body_Id : Entity_Id); |
| -- Perform early analysis of pragmas at the top of a given subprogram's |
| -- declarations. |
| -- |
| -- The purpose of this is to analyze contract-related pragmas for later |
| -- processing, but also to handle other such pragmas before these |
| -- declarations get moved to an internal wrapper as part of contract |
| -- expansion. For example, pragmas Inline, Ghost, Volatile all need to |
| -- apply directly to the subprogram and not be moved to a wrapper. |
| |
| procedure Analyze_Entry_Or_Subprogram_Body_Contract (Body_Id : Entity_Id); |
| -- Analyze all delayed pragmas chained on the contract of entry or |
| -- subprogram body Body_Id as if they appeared at the end of a declarative |
| -- region. Pragmas in question are: |
| -- |
| -- Contract_Cases (stand alone subprogram body) |
| -- Depends (stand alone subprogram body) |
| -- Global (stand alone subprogram body) |
| -- Postcondition (stand alone subprogram body) |
| -- Precondition (stand alone subprogram body) |
| -- Refined_Depends |
| -- Refined_Global |
| -- Refined_Post |
| -- Subprogram_Variant (stand alone subprogram body) |
| -- Test_Case (stand alone subprogram body) |
| |
| procedure Analyze_Entry_Or_Subprogram_Contract |
| (Subp_Id : Entity_Id; |
| Freeze_Id : Entity_Id := Empty); |
| -- Analyze all delayed pragmas chained on the contract of entry or |
| -- subprogram Subp_Id as if they appeared at the end of a declarative |
| -- region. The pragmas in question are: |
| -- |
| -- Contract_Cases |
| -- Depends |
| -- Global |
| -- Postcondition |
| -- Precondition |
| -- Subprogram_Variant |
| -- Test_Case |
| -- |
| -- Freeze_Id is the entity of a [generic] package body or a [generic] |
| -- subprogram body which "freezes" the contract of Subp_Id. |
| |
| procedure Analyze_Object_Contract |
| (Obj_Id : Entity_Id; |
| Freeze_Id : Entity_Id := Empty); |
| -- Analyze all delayed pragmas chained on the contract of object Obj_Id as |
| -- if they appeared at the end of the declarative region. The pragmas to be |
| -- considered are: |
| -- |
| -- Async_Readers |
| -- Async_Writers |
| -- Depends (single concurrent object) |
| -- Effective_Reads |
| -- Effective_Writes |
| -- Global (single concurrent object) |
| -- Part_Of |
| -- |
| -- Freeze_Id is the entity of a [generic] package body or a [generic] |
| -- subprogram body which "freezes" the contract of Obj_Id. |
| |
| procedure Analyze_Type_Contract (Type_Id : Entity_Id); |
| -- Analyze all delayed pragmas chained on the contract of object Obj_Id as |
| -- if they appeared at the end of the declarative region. The pragmas to be |
| -- considered are: |
| -- |
| -- Async_Readers |
| -- Async_Writers |
| -- Effective_Reads |
| -- Effective_Writes |
| -- |
| -- In the case of a protected or task type, there will also be |
| -- a call to Analyze_Protected_Contract or Analyze_Task_Contract. |
| |
| procedure Analyze_Package_Body_Contract |
| (Body_Id : Entity_Id; |
| Freeze_Id : Entity_Id := Empty); |
| -- Analyze all delayed pragmas chained on the contract of package body |
| -- Body_Id as if they appeared at the end of a declarative region. The |
| -- pragmas that are considered are: |
| -- |
| -- Refined_State |
| -- |
| -- Freeze_Id is the entity of a [generic] package body or a [generic] |
| -- subprogram body which "freezes" the contract of Body_Id. |
| |
| procedure Analyze_Package_Contract (Pack_Id : Entity_Id); |
| -- Analyze all delayed pragmas chained on the contract of package Pack_Id |
| -- as if they appeared at the end of a declarative region. The pragmas |
| -- that are considered are: |
| -- |
| -- Initial_Condition |
| -- Initializes |
| |
| procedure Analyze_Protected_Contract (Prot_Id : Entity_Id); |
| -- Analyze all delayed pragmas chained on the contract of protected unit |
| -- Prot_Id if they appeared at the end of a declarative region. Currently |
| -- there are no such pragmas. |
| |
| procedure Analyze_Subprogram_Body_Stub_Contract (Stub_Id : Entity_Id); |
| -- Analyze all delayed pragmas chained on the contract of subprogram body |
| -- stub Stub_Id as if they appeared at the end of a declarative region. The |
| -- pragmas in question are: |
| -- |
| -- Contract_Cases |
| -- Depends |
| -- Global |
| -- Postcondition |
| -- Precondition |
| -- Refined_Depends |
| -- Refined_Global |
| -- Refined_Post |
| -- Test_Case |
| |
| procedure Analyze_Task_Contract (Task_Id : Entity_Id); |
| -- Analyze all delayed pragmas chained on the contract of task unit Task_Id |
| -- as if they appeared at the end of a declarative region. The pragmas in |
| -- question are: |
| -- |
| -- Depends |
| -- Global |
| |
| procedure Build_Entry_Contract_Wrapper (E : Entity_Id; Decl : Node_Id); |
| -- Build the body of a wrapper procedure for an entry or entry family that |
| -- has contract cases, preconditions, or postconditions, and add it to the |
| -- freeze actions of the related synchronized type. |
| -- |
| -- The body first verifies the preconditions and case guards of the |
| -- contract cases, then invokes the entry [family], and finally verifies |
| -- the postconditions and the consequences of the contract cases. E denotes |
| -- the entry family. Decl denotes the declaration of the enclosing |
| -- synchronized type. |
| |
| procedure Create_Generic_Contract (Unit : Node_Id); |
| -- Create a contract node for a generic package, generic subprogram, or a |
| -- generic body denoted by Unit by collecting all source contract-related |
| -- pragmas in the contract of the unit. |
| |
| procedure Freeze_Previous_Contracts (Body_Decl : Node_Id); |
| -- Freeze the contracts of all source constructs found in the declarative |
| -- list which contains entry, package, protected, subprogram, or task body |
| -- denoted by Body_Decl. In addition, freeze the contract of the nearest |
| -- enclosing package body. |
| |
| procedure Inherit_Subprogram_Contract |
| (Subp : Entity_Id; |
| From_Subp : Entity_Id); |
| -- Inherit relevant contract items from source subprogram From_Subp. Subp |
| -- denotes the destination subprogram. The inherited items are: |
| -- Extensions_Visible |
| -- ??? it would be nice if this routine handles Pre'Class and Post'Class |
| |
| procedure Instantiate_Subprogram_Contract (Templ : Node_Id; L : List_Id); |
| -- Instantiate all source pragmas found in the contract of the generic |
| -- subprogram declaration template denoted by Templ. The instantiated |
| -- pragmas are added to list L. |
| |
| procedure Make_Class_Precondition_Subps |
| (Subp_Id : Entity_Id; |
| Late_Overriding : Boolean := False); |
| -- Build helpers that at run time evaluate statically and dynamically the |
| -- class-wide preconditions of Subp_Id; build also the indirect-call |
| -- wrapper (ICW) required to check class-wide preconditions when the |
| -- subprogram is invoked through an access-to-subprogram, or when it |
| -- overrides an inherited class-wide precondition (see AI12-0195-1). |
| -- Late_Overriding enables special handling required for late-overriding |
| -- subprograms. |
| -- |
| -- For example, if we have a subprogram with the following profile: |
| -- |
| -- procedure Prim (Obj : TagTyp; <additional formals>) |
| -- with Pre'Class => F1 (Obj) and F2(Obj) |
| -- |
| -- We build the following helper that evaluates statically the class-wide |
| -- precondition: |
| -- |
| -- function PrimSP (Obj : TagTyp) return Boolean is |
| -- begin |
| -- return F1 (Obj) and F2(Obj); |
| -- end PrimSP; |
| -- |
| -- ... and the following helper that evaluates dynamically the class-wide |
| -- precondition: |
| -- |
| -- function PrimDP (Obj : TagTyp'Class; ...) return Boolean is |
| -- begin |
| -- return F1 (Obj) and F2(Obj); |
| -- end PrimSP; |
| -- |
| -- ... and the following indirect-call wrapper (ICW) that is used by the |
| -- code generated by the compiler for indirect calls: |
| -- |
| -- procedure PrimICW (Obj : TagTyp; <additional formals> is |
| -- begin |
| -- if not PrimSP (Obj) then |
| -- $raise_assert_failure ("failed precondition in call at ..."); |
| -- end if; |
| -- |
| -- Prim (Obj, ...); |
| -- end Prim; |
| |
| procedure Merge_Class_Conditions (Spec_Id : Entity_Id); |
| -- Merge and preanalyze all class-wide conditions of Spec_Id (class-wide |
| -- preconditions merged with operator or-else; class-wide postconditions |
| -- merged with operator and-then). Ignored pre/postconditions are also |
| -- merged since, although they are not required to generate code, their |
| -- preanalysis is required to perform semantic checks. Resulting merged |
| -- expressions are later installed by the expander in helper subprograms |
| -- which are invoked from the caller side; they are also used to build |
| -- the dispatch-table wrapper (DTW), if required. |
| |
| procedure Preanalyze_Class_Conditions (Spec_Id : Entity_Id); |
| -- Preanalyze class-wide pre-/postconditions of the given subprogram |
| -- specification. |
| |
| procedure Process_Class_Conditions_At_Freeze_Point (Typ : Entity_Id); |
| -- Merge, preanalyze, and check class-wide pre/postconditions of Typ |
| -- primitives. |
| |
| procedure Save_Global_References_In_Contract |
| (Templ : Node_Id; |
| Gen_Id : Entity_Id); |
| -- Save all global references found within the aspect specifications and |
| -- the contract-related source pragmas assocated with generic template |
| -- Templ. Gen_Id denotes the entity of the analyzed generic copy. |
| |
| end Contracts; |
