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-------------------------------------------------------------------------------
-- (C) Altran Praxis Limited
-------------------------------------------------------------------------------
--
-- The SPARK toolset is free software; you can redistribute it and/or modify it
-- under terms of the GNU General Public License as published by the Free
-- Software Foundation; either version 3, or (at your option) any later
-- version. The SPARK toolset is distributed in the hope that it will be
-- useful, but WITHOUT 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 the SPARK toolset; see file
-- COPYING3. If not, go to http://www.gnu.org/licenses for a complete copy of
-- the license.
--
--=============================================================================
separate (Sem.CompUnit)
procedure Wf_Proof_Function_Declaration
(Node : in STree.SyntaxNode;
Current_Scope : in Dictionary.Scopes;
The_Heap : in out Heap.HeapRecord;
Proof_Func_Sym : out Dictionary.Symbol)
is
Type_Sym : Dictionary.Symbol;
Constraint_Node : STree.SyntaxNode;
Ident_Node : STree.SyntaxNode;
Return_Type_Node : STree.SyntaxNode;
Spec_Node : STree.SyntaxNode;
Dummy_Component_Data : ComponentManager.ComponentData;
Ident_Str : LexTokenManager.Lex_String;
begin
ComponentManager.Initialise (Data => Dummy_Component_Data);
Spec_Node := Child_Node (Current_Node => Node);
-- ASSUME Spec_Node = function_specification
SystemErrors.RT_Assert
(C => Syntax_Node_Type (Node => Spec_Node) = SP_Symbols.function_specification,
Sys_Err => SystemErrors.Invalid_Syntax_Tree,
Msg => "Expect Spec_Node = function_specification in Wf_Proof_Function_Declaration");
Return_Type_Node := Last_Sibling_Of (Start_Node => Child_Node (Current_Node => Spec_Node));
-- ASSUME Return_Type_Node = type_mark
SystemErrors.RT_Assert
(C => Syntax_Node_Type (Node => Return_Type_Node) = SP_Symbols.type_mark,
Sys_Err => SystemErrors.Invalid_Syntax_Tree,
Msg => "Expect Node = Return_Type_Node = type_mark in Wf_Proof_Function_Declaration");
Constraint_Node := Next_Sibling (Current_Node => Spec_Node);
-- ASSUME Constraint_Node = function_constraint
SystemErrors.RT_Assert
(C => Syntax_Node_Type (Node => Constraint_Node) = SP_Symbols.function_constraint,
Sys_Err => SystemErrors.Invalid_Syntax_Tree,
Msg => "Expect Constraint_Node = function_constraint in Wf_Proof_Function_Declaration");
-- If we are in a package or protected body we may refine a proof function
-- definition
if In_Package_Body (Current_Scope => Current_Scope) or else In_Protected_Body (Current_Scope => Current_Scope) then
Ident_Node := Child_Node (Current_Node => Child_Node (Current_Node => Spec_Node));
-- ASSUME Ident_Node = identifier
SystemErrors.RT_Assert
(C => Syntax_Node_Type (Node => Ident_Node) = SP_Symbols.identifier,
Sys_Err => SystemErrors.Invalid_Syntax_Tree,
Msg => "Expect Ident_Node = identifier in Wf_Subprogram_Specification_From_Declaration");
Ident_Str := Node_Lex_String (Node => Ident_Node);
-- Lookup in the dictionary to see if the name already exists
Proof_Func_Sym :=
Dictionary.LookupItem
(Name => Ident_Str,
Scope => Current_Scope,
Context => Dictionary.ProofContext,
Full_Package_Name => False);
if not Dictionary.Is_Null_Symbol (Proof_Func_Sym) then
-- The name already exists in this scope.
-- Is it is declared in the visible part, or
Proof_Func_Sym :=
Dictionary.LookupImmediateScope
(Name => Ident_Str,
Scope => Dictionary.Set_Visibility
(The_Visibility => Dictionary.Visible,
The_Unit => Dictionary.GetRegion (Current_Scope)),
Context => Dictionary.ProofContext);
-- the private part of the unit?
if Dictionary.Is_Null_Symbol (Proof_Func_Sym) and then Dictionary.IsPackage (Dictionary.GetRegion (Current_Scope)) then
Proof_Func_Sym :=
Dictionary.LookupImmediateScope
(Name => Ident_Str,
Scope => Dictionary.Set_Visibility
(The_Visibility => Dictionary.Privat,
The_Unit => Dictionary.GetRegion (Current_Scope)),
Context => Dictionary.ProofContext);
end if;
if not Dictionary.Is_Null_Symbol (Proof_Func_Sym)
and then Dictionary.IsProofFunction (Proof_Func_Sym)
and then not Dictionary.IsImplicitProofFunction (Proof_Func_Sym) then
-- It is the refinement of an explicit proof function declared
-- in the visible or private part of the unit.
-- Check that the return type of the refinement is consistent
Wf_Type_Mark
(Node => Return_Type_Node,
Current_Scope => Current_Scope,
Context => Dictionary.ProofContext,
Type_Sym => Type_Sym);
if not Dictionary.Types_Are_Equal
(Left_Symbol => Type_Sym,
Right_Symbol => Dictionary.GetType (Proof_Func_Sym),
Full_Range_Subtype => False) then
if Dictionary.IsUnknownTypeMark (Dictionary.GetType (Proof_Func_Sym)) then
-- remind user that return type on spec was illegal
ErrorHandler.Semantic_Error
(Err_Num => 841,
Reference => ErrorHandler.No_Reference,
Position => Node_Position (Node => Return_Type_Node),
Id_Str => Dictionary.GetSimpleName (Proof_Func_Sym));
else
-- report inconsistency
ErrorHandler.Semantic_Error
(Err_Num => 22,
Reference => ErrorHandler.No_Reference,
Position => Node_Position (Node => Return_Type_Node),
Id_Str => Dictionary.GetSimpleName (Proof_Func_Sym));
end if;
end if;
else
-- Name in use for something other than an explicit proof function.
ErrorHandler.Semantic_Error
(Err_Num => 10,
Reference => ErrorHandler.No_Reference,
Position => Node_Position (Node => Ident_Node),
Id_Str => Ident_Str);
-- Add the proof function declaration anyway to avoid the
-- propagation of errors.
Dictionary.AddSubprogram
(Name => Ident_Str,
Comp_Unit => ContextManager.Ops.Current_Unit,
Specification => Dictionary.Location'(Start_Position => Node_Position (Node => Ident_Node),
End_Position => Node_Position (Node => Ident_Node)),
Scope => Current_Scope,
Context => Dictionary.ProofContext,
Subprogram => Proof_Func_Sym);
STree.Add_Node_Symbol (Node => Ident_Node,
Sym => Proof_Func_Sym);
end if;
-- Now enter the refined proof function constraints in to the dictionary.
-- ASSUME Constraint_Node = function_constraint
--# accept F, 10, Dummy_Component_Data, "As can be seen from the name, this is not needed here.";
Wf_Subprogram_Constraint
(Node => Constraint_Node,
Subprogram_Sym => Proof_Func_Sym,
First_Seen => False,
Component_Data => Dummy_Component_Data,
The_Heap => The_Heap);
--# end accept;
-- If the refinement contains an implicit return - warn. See
-- Sem.Subprogram_Specification.Wf_Subprogram_Specification
-- for more information.
if not Dictionary.HasImplicitReturnVariable (Dictionary.IsAbstract, Proof_Func_Sym) and then
Dictionary.HasImplicitReturnVariable (Dictionary.IsRefined, Proof_Func_Sym) then
ErrorHandler.Semantic_Warning_Sym
(Err_Num => 321,
Position => Node_Position (Node),
Sym => Proof_Func_Sym,
Scope => Current_Scope);
end if;
-- Refinements cannot be checked.
if Dictionary.HasPostcondition (Dictionary.IsAbstract, Proof_Func_Sym) and
Dictionary.HasPostcondition (Dictionary.IsRefined, Proof_Func_Sym) then
ErrorHandler.Semantic_Warning_Sym
(Err_Num => 322,
Position => Node_Position (Node),
Sym => Proof_Func_Sym,
Scope => Current_Scope);
end if;
if Dictionary.HasPrecondition (Dictionary.IsAbstract, Proof_Func_Sym) and
Dictionary.HasPrecondition (Dictionary.IsRefined, Proof_Func_Sym) then
ErrorHandler.Semantic_Warning_Sym
(Err_Num => 323,
Position => Node_Position (Node),
Sym => Proof_Func_Sym,
Scope => Current_Scope);
end if;
else
-- It is a new identifier in this scope it cannot be a refinement.
-- Assume it is a new proof function declaration
--# accept Flow, 10, Dummy_Component_Data, "Expected ineffective assignment";
Subprogram_Specification.Wf_Subprogram_Specification
(Spec_Node => Spec_Node,
Anno_Node => STree.NullNode,
Constraint_Node => Constraint_Node,
Inherit_Node => STree.NullNode,
Context_Node => STree.NullNode,
Generic_Formal_Part_Node => STree.NullNode,
Current_Scope => Current_Scope,
Generic_Unit => Dictionary.NullSymbol,
Current_Context => Dictionary.ProofContext,
Component_Data => Dummy_Component_Data,
The_Heap => The_Heap,
Subprog_Sym => Proof_Func_Sym);
--# end accept;
end if;
else
-- The declaration is not in a package or protected body it cannot be
-- a refinement. Assume a new proof function declaration.
--# accept Flow, 10, Dummy_Component_Data, "Expected ineffective assignment";
Subprogram_Specification.Wf_Subprogram_Specification
(Spec_Node => Spec_Node,
Anno_Node => STree.NullNode,
Constraint_Node => Constraint_Node,
Inherit_Node => STree.NullNode,
Context_Node => STree.NullNode,
Generic_Formal_Part_Node => STree.NullNode,
Current_Scope => Current_Scope,
Generic_Unit => Dictionary.NullSymbol,
Current_Context => Dictionary.ProofContext,
Component_Data => Dummy_Component_Data,
The_Heap => The_Heap,
Subprog_Sym => Proof_Func_Sym);
--# end accept;
end if;
end Wf_Proof_Function_Declaration;
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