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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E M _ C H 4 --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2021, 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 Debug; use Debug;
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_Util; use Exp_Util;
with Itypes; use Itypes;
with Lib; use Lib;
with Lib.Xref; use Lib.Xref;
with Namet; use Namet;
with Namet.Sp; use Namet.Sp;
with Nlists; use Nlists;
with Nmake; use Nmake;
with Opt; use Opt;
with Output; use Output;
with Restrict; use Restrict;
with Rident; use Rident;
with Sem; use Sem;
with Sem_Aux; use Sem_Aux;
with Sem_Case; use Sem_Case;
with Sem_Cat; use Sem_Cat;
with Sem_Ch3; use Sem_Ch3;
with Sem_Ch6; use Sem_Ch6;
with Sem_Ch8; use Sem_Ch8;
with Sem_Dim; use Sem_Dim;
with Sem_Disp; use Sem_Disp;
with Sem_Dist; use Sem_Dist;
with Sem_Eval; use Sem_Eval;
with Sem_Res; use Sem_Res;
with Sem_Type; use Sem_Type;
with Sem_Util; use Sem_Util;
with Sem_Warn; use Sem_Warn;
with Stand; use Stand;
with Sinfo; use Sinfo;
with Sinfo.Nodes; use Sinfo.Nodes;
with Sinfo.Utils; use Sinfo.Utils;
with Snames; use Snames;
with Tbuild; use Tbuild;
with Uintp; use Uintp;
package body Sem_Ch4 is
-- Tables which speed up the identification of dangerous calls to Ada 2012
-- functions with writable actuals (AI05-0144).
-- The following table enumerates the Ada constructs which may evaluate in
-- arbitrary order. It does not cover all the language constructs which can
-- be evaluated in arbitrary order but the subset needed for AI05-0144.
Has_Arbitrary_Evaluation_Order : constant array (Node_Kind) of Boolean :=
(N_Aggregate => True,
N_Assignment_Statement => True,
N_Entry_Call_Statement => True,
N_Extension_Aggregate => True,
N_Full_Type_Declaration => True,
N_Indexed_Component => True,
N_Object_Declaration => True,
N_Pragma => True,
N_Range => True,
N_Slice => True,
N_Array_Type_Definition => True,
N_Membership_Test => True,
N_Binary_Op => True,
N_Subprogram_Call => True,
others => False);
-- The following table enumerates the nodes on which we stop climbing when
-- locating the outermost Ada construct that can be evaluated in arbitrary
-- order.
Stop_Subtree_Climbing : constant array (Node_Kind) of Boolean :=
(N_Aggregate => True,
N_Assignment_Statement => True,
N_Entry_Call_Statement => True,
N_Extended_Return_Statement => True,
N_Extension_Aggregate => True,
N_Full_Type_Declaration => True,
N_Object_Declaration => True,
N_Object_Renaming_Declaration => True,
N_Package_Specification => True,
N_Pragma => True,
N_Procedure_Call_Statement => True,
N_Simple_Return_Statement => True,
N_Has_Condition => True,
others => False);
-----------------------
-- Local Subprograms --
-----------------------
procedure Analyze_Concatenation_Rest (N : Node_Id);
-- Does the "rest" of the work of Analyze_Concatenation, after the left
-- operand has been analyzed. See Analyze_Concatenation for details.
procedure Analyze_Expression (N : Node_Id);
-- For expressions that are not names, this is just a call to analyze. If
-- the expression is a name, it may be a call to a parameterless function,
-- and if so must be converted into an explicit call node and analyzed as
-- such. This deproceduring must be done during the first pass of overload
-- resolution, because otherwise a procedure call with overloaded actuals
-- may fail to resolve.
procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id);
-- Analyze a call of the form "+"(x, y), etc. The prefix of the call is an
-- operator name or an expanded name whose selector is an operator name,
-- and one possible interpretation is as a predefined operator.
procedure Analyze_Overloaded_Selected_Component (N : Node_Id);
-- If the prefix of a selected_component is overloaded, the proper
-- interpretation that yields a record type with the proper selector
-- name must be selected.
procedure Analyze_User_Defined_Binary_Op (N : Node_Id; Op_Id : Entity_Id);
-- Procedure to analyze a user defined binary operator, which is resolved
-- like a function, but instead of a list of actuals it is presented
-- with the left and right operands of an operator node.
procedure Analyze_User_Defined_Unary_Op (N : Node_Id; Op_Id : Entity_Id);
-- Procedure to analyze a user defined unary operator, which is resolved
-- like a function, but instead of a list of actuals, it is presented with
-- the operand of the operator node.
procedure Ambiguous_Operands (N : Node_Id);
-- For equality, membership, and comparison operators with overloaded
-- arguments, list possible interpretations.
procedure Analyze_One_Call
(N : Node_Id;
Nam : Entity_Id;
Report : Boolean;
Success : out Boolean;
Skip_First : Boolean := False);
-- Check one interpretation of an overloaded subprogram name for
-- compatibility with the types of the actuals in a call. If there is a
-- single interpretation which does not match, post error if Report is
-- set to True.
--
-- Nam is the entity that provides the formals against which the actuals
-- are checked. Nam is either the name of a subprogram, or the internal
-- subprogram type constructed for an access_to_subprogram. If the actuals
-- are compatible with Nam, then Nam is added to the list of candidate
-- interpretations for N, and Success is set to True.
--
-- The flag Skip_First is used when analyzing a call that was rewritten
-- from object notation. In this case the first actual may have to receive
-- an explicit dereference, depending on the first formal of the operation
-- being called. The caller will have verified that the object is legal
-- for the call. If the remaining parameters match, the first parameter
-- will rewritten as a dereference if needed, prior to completing analysis.
procedure Check_Misspelled_Selector
(Prefix : Entity_Id;
Sel : Node_Id);
-- Give possible misspelling message if Sel seems likely to be a mis-
-- spelling of one of the selectors of the Prefix. This is called by
-- Analyze_Selected_Component after producing an invalid selector error
-- message.
function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean;
-- Verify that type T is declared in scope S. Used to find interpretations
-- for operators given by expanded names. This is abstracted as a separate
-- function to handle extensions to System, where S is System, but T is
-- declared in the extension.
procedure Find_Arithmetic_Types
(L, R : Node_Id;
Op_Id : Entity_Id;
N : Node_Id);
-- L and R are the operands of an arithmetic operator. Find consistent
-- pairs of interpretations for L and R that have a numeric type consistent
-- with the semantics of the operator.
procedure Find_Comparison_Types
(L, R : Node_Id;
Op_Id : Entity_Id;
N : Node_Id);
-- L and R are operands of a comparison operator. Find consistent pairs of
-- interpretations for L and R.
procedure Find_Concatenation_Types
(L, R : Node_Id;
Op_Id : Entity_Id;
N : Node_Id);
-- For the four varieties of concatenation
procedure Find_Equality_Types
(L, R : Node_Id;
Op_Id : Entity_Id;
N : Node_Id);
-- Ditto for equality operators
procedure Find_Boolean_Types
(L, R : Node_Id;
Op_Id : Entity_Id;
N : Node_Id);
-- Ditto for binary logical operations
procedure Find_Negation_Types
(R : Node_Id;
Op_Id : Entity_Id;
N : Node_Id);
-- Find consistent interpretation for operand of negation operator
procedure Find_Non_Universal_Interpretations
(N : Node_Id;
R : Node_Id;
Op_Id : Entity_Id;
T1 : Entity_Id);
-- For equality and comparison operators, the result is always boolean, and
-- the legality of the operation is determined from the visibility of the
-- operand types. If one of the operands has a universal interpretation,
-- the legality check uses some compatible non-universal interpretation of
-- the other operand. N can be an operator node, or a function call whose
-- name is an operator designator. Any_Access, which is the initial type of
-- the literal NULL, is a universal type for the purpose of this routine.
function Find_Primitive_Operation (N : Node_Id) return Boolean;
-- Find candidate interpretations for the name Obj.Proc when it appears in
-- a subprogram renaming declaration.
procedure Find_Unary_Types
(R : Node_Id;
Op_Id : Entity_Id;
N : Node_Id);
-- Unary arithmetic types: plus, minus, abs
procedure Check_Arithmetic_Pair
(T1, T2 : Entity_Id;
Op_Id : Entity_Id;
N : Node_Id);
-- Subsidiary procedure to Find_Arithmetic_Types. T1 and T2 are valid types
-- for left and right operand. Determine whether they constitute a valid
-- pair for the given operator, and record the corresponding interpretation
-- of the operator node. The node N may be an operator node (the usual
-- case) or a function call whose prefix is an operator designator. In
-- both cases Op_Id is the operator name itself.
procedure Diagnose_Call (N : Node_Id; Nam : Node_Id);
-- Give detailed information on overloaded call where none of the
-- interpretations match. N is the call node, Nam the designator for
-- the overloaded entity being called.
function Junk_Operand (N : Node_Id) return Boolean;
-- Test for an operand that is an inappropriate entity (e.g. a package
-- name or a label). If so, issue an error message and return True. If
-- the operand is not an inappropriate entity kind, return False.
procedure Operator_Check (N : Node_Id);
-- Verify that an operator has received some valid interpretation. If none
-- was found, determine whether a use clause would make the operation
-- legal. The variable Candidate_Type (defined in Sem_Type) is set for
-- every type compatible with the operator, even if the operator for the
-- type is not directly visible. The routine uses this type to emit a more
-- informative message.
function Has_Possible_Literal_Aspects (N : Node_Id) return Boolean;
-- Ada_2022: if an operand is a literal it may be subject to an
-- implicit conversion to a type for which a user-defined literal
-- function exists. During the first pass of type resolution we do
-- not know the context imposed on the literal, so we assume that
-- the literal type is a valid candidate and rely on the second pass
-- of resolution to find the type with the proper aspect. We only
-- add this interpretation if no other one was found, which may be
-- too restrictive but seems sufficient to handle most proper uses
-- of the new aspect. It is unclear whether a full implementation of
-- these aspects can be achieved without larger modifications to the
-- two-pass resolution algorithm.
procedure Remove_Abstract_Operations (N : Node_Id);
-- Ada 2005: implementation of AI-310. An abstract non-dispatching
-- operation is not a candidate interpretation.
function Try_Container_Indexing
(N : Node_Id;
Prefix : Node_Id;
Exprs : List_Id) return Boolean;
-- AI05-0139: Generalized indexing to support iterators over containers
-- ??? Need to provide a more detailed spec of what this function does
function Try_Indexed_Call
(N : Node_Id;
Nam : Entity_Id;
Typ : Entity_Id;
Skip_First : Boolean) return Boolean;
-- If a function has defaults for all its actuals, a call to it may in fact
-- be an indexing on the result of the call. Try_Indexed_Call attempts the
-- interpretation as an indexing, prior to analysis as a call. If both are
-- possible, the node is overloaded with both interpretations (same symbol
-- but two different types). If the call is written in prefix form, the
-- prefix becomes the first parameter in the call, and only the remaining
-- actuals must be checked for the presence of defaults.
function Try_Indirect_Call
(N : Node_Id;
Nam : Entity_Id;
Typ : Entity_Id) return Boolean;
-- Similarly, a function F that needs no actuals can return an access to a
-- subprogram, and the call F (X) interpreted as F.all (X). In this case
-- the call may be overloaded with both interpretations.
procedure wpo (T : Entity_Id);
pragma Warnings (Off, wpo);
-- Used for debugging: obtain list of primitive operations even if
-- type is not frozen and dispatch table is not built yet.
------------------------
-- Ambiguous_Operands --
------------------------
procedure Ambiguous_Operands (N : Node_Id) is
procedure List_Operand_Interps (Opnd : Node_Id);
--------------------------
-- List_Operand_Interps --
--------------------------
procedure List_Operand_Interps (Opnd : Node_Id) is
Nam : Node_Id := Empty;
Err : Node_Id := N;
begin
if Is_Overloaded (Opnd) then
if Nkind (Opnd) in N_Op then
Nam := Opnd;
elsif Nkind (Opnd) = N_Function_Call then
Nam := Name (Opnd);
elsif Ada_Version >= Ada_2012 then
declare
It : Interp;
I : Interp_Index;
begin
Get_First_Interp (Opnd, I, It);
while Present (It.Nam) loop
if Has_Implicit_Dereference (It.Typ) then
Error_Msg_N
("can be interpreted as implicit dereference", Opnd);
return;
end if;
Get_Next_Interp (I, It);
end loop;
end;
return;
end if;
else
return;
end if;
if Opnd = Left_Opnd (N) then
Error_Msg_N
("\left operand has the following interpretations", N);
else
Error_Msg_N
("\right operand has the following interpretations", N);
Err := Opnd;
end if;
List_Interps (Nam, Err);
end List_Operand_Interps;
-- Start of processing for Ambiguous_Operands
begin
if Nkind (N) in N_Membership_Test then
Error_Msg_N ("ambiguous operands for membership", N);
elsif Nkind (N) in N_Op_Eq | N_Op_Ne then
Error_Msg_N ("ambiguous operands for equality", N);
else
Error_Msg_N ("ambiguous operands for comparison", N);
end if;
if All_Errors_Mode then
List_Operand_Interps (Left_Opnd (N));
List_Operand_Interps (Right_Opnd (N));
else
Error_Msg_N ("\use -gnatf switch for details", N);
end if;
end Ambiguous_Operands;
-----------------------
-- Analyze_Aggregate --
-----------------------
-- Most of the analysis of Aggregates requires that the type be known, and
-- is therefore put off until resolution of the context. Delta aggregates
-- have a base component that determines the enclosing aggregate type so
-- its type can be ascertained earlier. This also allows delta aggregates
-- to appear in the context of a record type with a private extension, as
-- per the latest update of AI12-0127.
procedure Analyze_Aggregate (N : Node_Id) is
begin
if No (Etype (N)) then
if Nkind (N) = N_Delta_Aggregate then
declare
Base : constant Node_Id := Expression (N);
I : Interp_Index;
It : Interp;
begin
Analyze (Base);
-- If the base is overloaded, propagate interpretations to the
-- enclosing aggregate.
if Is_Overloaded (Base) then
Get_First_Interp (Base, I, It);
Set_Etype (N, Any_Type);
while Present (It.Nam) loop
Add_One_Interp (N, It.Typ, It.Typ);
Get_Next_Interp (I, It);
end loop;
else
Set_Etype (N, Etype (Base));
end if;
end;
else
Set_Etype (N, Any_Composite);
end if;
end if;
end Analyze_Aggregate;
-----------------------
-- Analyze_Allocator --
-----------------------
procedure Analyze_Allocator (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Sav_Errs : constant Nat := Serious_Errors_Detected;
E : Node_Id := Expression (N);
Acc_Type : Entity_Id;
Type_Id : Entity_Id;
P : Node_Id;
C : Node_Id;
Onode : Node_Id;
begin
-- Deal with allocator restrictions
-- In accordance with H.4(7), the No_Allocators restriction only applies
-- to user-written allocators. The same consideration applies to the
-- No_Standard_Allocators_Before_Elaboration restriction.
if Comes_From_Source (N) then
Check_Restriction (No_Allocators, N);
-- Processing for No_Standard_Allocators_After_Elaboration, loop to
-- look at enclosing context, checking task/main subprogram case.
C := N;
P := Parent (C);
while Present (P) loop
-- For the task case we need a handled sequence of statements,
-- where the occurrence of the allocator is within the statements
-- and the parent is a task body
if Nkind (P) = N_Handled_Sequence_Of_Statements
and then Is_List_Member (C)
and then List_Containing (C) = Statements (P)
then
Onode := Original_Node (Parent (P));
-- Check for allocator within task body, this is a definite
-- violation of No_Allocators_After_Elaboration we can detect
-- at compile time.
if Nkind (Onode) = N_Task_Body then
Check_Restriction
(No_Standard_Allocators_After_Elaboration, N);
exit;
end if;
end if;
-- The other case is appearance in a subprogram body. This is
-- a violation if this is a library level subprogram with no
-- parameters. Note that this is now a static error even if the
-- subprogram is not the main program (this is a change, in an
-- earlier version only the main program was affected, and the
-- check had to be done in the binder.
if Nkind (P) = N_Subprogram_Body
and then Nkind (Parent (P)) = N_Compilation_Unit
and then No (Parameter_Specifications (Specification (P)))
then
Check_Restriction
(No_Standard_Allocators_After_Elaboration, N);
end if;
C := P;
P := Parent (C);
end loop;
end if;
-- Ada 2012 (AI05-0111-3): Analyze the subpool_specification, if
-- any. The expected type for the name is any type. A non-overloading
-- rule then requires it to be of a type descended from
-- System.Storage_Pools.Subpools.Subpool_Handle.
-- This isn't exactly what the AI says, but it seems to be the right
-- rule. The AI should be fixed.???
declare
Subpool : constant Node_Id := Subpool_Handle_Name (N);
begin
if Present (Subpool) then
Analyze (Subpool);
if Is_Overloaded (Subpool) then
Error_Msg_N ("ambiguous subpool handle", Subpool);
end if;
-- Check that Etype (Subpool) is descended from Subpool_Handle
Resolve (Subpool);
end if;
end;
-- Analyze the qualified expression or subtype indication
if Nkind (E) = N_Qualified_Expression then
Acc_Type := Create_Itype (E_Allocator_Type, N);
Set_Etype (Acc_Type, Acc_Type);
Find_Type (Subtype_Mark (E));
-- Analyze the qualified expression, and apply the name resolution
-- rule given in 4.7(3).
Analyze (E);
Type_Id := Etype (E);
Set_Directly_Designated_Type (Acc_Type, Type_Id);
-- A qualified expression requires an exact match of the type,
-- class-wide matching is not allowed.
-- if Is_Class_Wide_Type (Type_Id)
-- and then Base_Type
-- (Etype (Expression (E))) /= Base_Type (Type_Id)
-- then
-- Wrong_Type (Expression (E), Type_Id);
-- end if;
-- We don't analyze the qualified expression itself because it's
-- part of the allocator. It is fully analyzed and resolved when
-- the allocator is resolved with the context type.
Set_Etype (E, Type_Id);
-- Case where allocator has a subtype indication
else
declare
Def_Id : Entity_Id;
Base_Typ : Entity_Id;
begin
-- If the allocator includes a N_Subtype_Indication then a
-- constraint is present, otherwise the node is a subtype mark.
-- Introduce an explicit subtype declaration into the tree
-- defining some anonymous subtype and rewrite the allocator to
-- use this subtype rather than the subtype indication.
-- It is important to introduce the explicit subtype declaration
-- so that the bounds of the subtype indication are attached to
-- the tree in case the allocator is inside a generic unit.
-- Finally, if there is no subtype indication and the type is
-- a tagged unconstrained type with discriminants, the designated
-- object is constrained by their default values, and it is
-- simplest to introduce an explicit constraint now. In some cases
-- this is done during expansion, but freeze actions are certain
-- to be emitted in the proper order if constraint is explicit.
if Is_Entity_Name (E) and then Expander_Active then
Find_Type (E);
Type_Id := Entity (E);
if Is_Tagged_Type (Type_Id)
and then Has_Defaulted_Discriminants (Type_Id)
and then not Is_Constrained (Type_Id)
then
declare
Constr : constant List_Id := New_List;
Loc : constant Source_Ptr := Sloc (E);
Discr : Entity_Id := First_Discriminant (Type_Id);
begin
while Present (Discr) loop
Append (Discriminant_Default_Value (Discr), Constr);
Next_Discriminant (Discr);
end loop;
Rewrite (E,
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (Type_Id, Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint (Loc,
Constraints => Constr)));
end;
end if;
end if;
if Nkind (E) = N_Subtype_Indication then
-- A constraint is only allowed for a composite type in Ada
-- 95. In Ada 83, a constraint is also allowed for an
-- access-to-composite type, but the constraint is ignored.
Find_Type (Subtype_Mark (E));
Base_Typ := Entity (Subtype_Mark (E));
if Is_Elementary_Type (Base_Typ) then
if not (Ada_Version = Ada_83
and then Is_Access_Type (Base_Typ))
then
Error_Msg_N ("constraint not allowed here", E);
if Nkind (Constraint (E)) =
N_Index_Or_Discriminant_Constraint
then
Error_Msg_N -- CODEFIX
("\if qualified expression was meant, " &
"use apostrophe", Constraint (E));
end if;
end if;
-- Get rid of the bogus constraint:
Rewrite (E, New_Copy_Tree (Subtype_Mark (E)));
Analyze_Allocator (N);
return;
end if;
-- In GNATprove mode we need to preserve the link between
-- the original subtype indication and the anonymous subtype,
-- to extend proofs to constrained access types. We only do
-- that outside of spec expressions, otherwise the declaration
-- cannot be inserted and analyzed. In such a case, GNATprove
-- later rejects the allocator as it is not used here in
-- a non-interfering context (SPARK 4.8(2) and 7.1.3(10)).
if Expander_Active
or else (GNATprove_Mode and then not In_Spec_Expression)
then
Def_Id := Make_Temporary (Loc, 'S');
Insert_Action (E,
Make_Subtype_Declaration (Loc,
Defining_Identifier => Def_Id,
Subtype_Indication => Relocate_Node (E)));
if Sav_Errs /= Serious_Errors_Detected
and then Nkind (Constraint (E)) =
N_Index_Or_Discriminant_Constraint
then
Error_Msg_N -- CODEFIX
("if qualified expression was meant, "
& "use apostrophe!", Constraint (E));
end if;
E := New_Occurrence_Of (Def_Id, Loc);
Rewrite (Expression (N), E);
end if;
end if;
Type_Id := Process_Subtype (E, N);
Acc_Type := Create_Itype (E_Allocator_Type, N);
Set_Etype (Acc_Type, Acc_Type);
Set_Directly_Designated_Type (Acc_Type, Type_Id);
Check_Fully_Declared (Type_Id, N);
-- Ada 2005 (AI-231): If the designated type is itself an access
-- type that excludes null, its default initialization will
-- be a null object, and we can insert an unconditional raise
-- before the allocator.
-- Ada 2012 (AI-104): A not null indication here is altogether
-- illegal.
if Can_Never_Be_Null (Type_Id) then
declare
Not_Null_Check : constant Node_Id :=
Make_Raise_Constraint_Error (Sloc (E),
Reason => CE_Null_Not_Allowed);
begin
if Expander_Active then
Insert_Action (N, Not_Null_Check);
Analyze (Not_Null_Check);
elsif Warn_On_Ada_2012_Compatibility then
Error_Msg_N
("null value not allowed here in Ada 2012?y?", E);
end if;
end;
end if;
-- Check for missing initialization. Skip this check if we already
-- had errors on analyzing the allocator, since in that case these
-- are probably cascaded errors.
if not Is_Definite_Subtype (Type_Id)
and then Serious_Errors_Detected = Sav_Errs
then
-- The build-in-place machinery may produce an allocator when
-- the designated type is indefinite but the underlying type is
-- not. In this case the unknown discriminants are meaningless
-- and should not trigger error messages. Check the parent node
-- because the allocator is marked as coming from source.
if Present (Underlying_Type (Type_Id))
and then Is_Definite_Subtype (Underlying_Type (Type_Id))
and then not Comes_From_Source (Parent (N))
then
null;
-- An unusual case arises when the parent of a derived type is
-- a limited record extension with unknown discriminants, and
-- its full view has no discriminants.
--
-- A more general fix might be to create the proper underlying
-- type for such a derived type, but it is a record type with
-- no private attributes, so this required extending the
-- meaning of this attribute. ???
elsif Ekind (Etype (Type_Id)) = E_Record_Type_With_Private
and then Present (Underlying_Type (Etype (Type_Id)))
and then
not Has_Discriminants (Underlying_Type (Etype (Type_Id)))
and then not Comes_From_Source (Parent (N))
then
null;
elsif Is_Class_Wide_Type (Type_Id) then
Error_Msg_N
("initialization required in class-wide allocation", N);
else
if Ada_Version < Ada_2005
and then Is_Limited_Type (Type_Id)
then
Error_Msg_N ("unconstrained allocation not allowed", N);
if Is_Array_Type (Type_Id) then
Error_Msg_N
("\constraint with array bounds required", N);
elsif Has_Unknown_Discriminants (Type_Id) then
null;
else pragma Assert (Has_Discriminants (Type_Id));
Error_Msg_N
("\constraint with discriminant values required", N);
end if;
-- Limited Ada 2005 and general nonlimited case.
-- This is an error, except in the case of an
-- uninitialized allocator that is generated
-- for a build-in-place function return of a
-- discriminated but compile-time-known-size
-- type.
else
if Original_Node (N) /= N
and then Nkind (Original_Node (N)) = N_Allocator
then
declare
Qual : constant Node_Id :=
Expression (Original_Node (N));
pragma Assert
(Nkind (Qual) = N_Qualified_Expression);
Call : constant Node_Id := Expression (Qual);
pragma Assert
(Is_Expanded_Build_In_Place_Call (Call));
begin
null;
end;
else
Error_Msg_N
("uninitialized unconstrained allocation not "
& "allowed", N);
if Is_Array_Type (Type_Id) then
Error_Msg_N
("\qualified expression or constraint with "
& "array bounds required", N);
elsif Has_Unknown_Discriminants (Type_Id) then
Error_Msg_N ("\qualified expression required", N);
else pragma Assert (Has_Discriminants (Type_Id));
Error_Msg_N
("\qualified expression or constraint with "
& "discriminant values required", N);
end if;
end if;
end if;
end if;
end if;
end;
end if;
if Is_Abstract_Type (Type_Id) then
Error_Msg_N ("cannot allocate abstract object", E);
end if;
if Has_Task (Designated_Type (Acc_Type)) then
Check_Restriction (No_Tasking, N);
Check_Restriction (Max_Tasks, N);
Check_Restriction (No_Task_Allocators, N);
end if;
-- Check restriction against dynamically allocated protected objects
if Has_Protected (Designated_Type (Acc_Type)) then
Check_Restriction (No_Protected_Type_Allocators, N);
end if;
-- AI05-0013-1: No_Nested_Finalization forbids allocators if the access
-- type is nested, and the designated type needs finalization. The rule
-- is conservative in that class-wide types need finalization.
if Needs_Finalization (Designated_Type (Acc_Type))
and then not Is_Library_Level_Entity (Acc_Type)
then
Check_Restriction (No_Nested_Finalization, N);
end if;
-- Check that an allocator of a nested access type doesn't create a
-- protected object when restriction No_Local_Protected_Objects applies.
if Has_Protected (Designated_Type (Acc_Type))
and then not Is_Library_Level_Entity (Acc_Type)
then
Check_Restriction (No_Local_Protected_Objects, N);
end if;
-- Likewise for No_Local_Timing_Events
if Has_Timing_Event (Designated_Type (Acc_Type))
and then not Is_Library_Level_Entity (Acc_Type)
then
Check_Restriction (No_Local_Timing_Events, N);
end if;
-- If the No_Streams restriction is set, check that the type of the
-- object is not, and does not contain, any subtype derived from
-- Ada.Streams.Root_Stream_Type. Note that we guard the call to
-- Has_Stream just for efficiency reasons. There is no point in
-- spending time on a Has_Stream check if the restriction is not set.
if Restriction_Check_Required (No_Streams) then
if Has_Stream (Designated_Type (Acc_Type)) then
Check_Restriction (No_Streams, N);
end if;
end if;
Set_Etype (N, Acc_Type);
if not Is_Library_Level_Entity (Acc_Type) then
Check_Restriction (No_Local_Allocators, N);
end if;
if Serious_Errors_Detected > Sav_Errs then
Set_Error_Posted (N);
Set_Etype (N, Any_Type);
end if;
end Analyze_Allocator;
---------------------------
-- Analyze_Arithmetic_Op --
---------------------------
procedure Analyze_Arithmetic_Op (N : Node_Id) is
L : constant Node_Id := Left_Opnd (N);
R : constant Node_Id := Right_Opnd (N);
Op_Id : Entity_Id;
begin
Candidate_Type := Empty;
Analyze_Expression (L);
Analyze_Expression (R);
-- If the entity is already set, the node is the instantiation of a
-- generic node with a non-local reference, or was manufactured by a
-- call to Make_Op_xxx. In either case the entity is known to be valid,
-- and we do not need to collect interpretations, instead we just get
-- the single possible interpretation.
Op_Id := Entity (N);
if Present (Op_Id) then
if Ekind (Op_Id) = E_Operator then
Set_Etype (N, Any_Type);
Find_Arithmetic_Types (L, R, Op_Id, N);
else
Set_Etype (N, Any_Type);
Add_One_Interp (N, Op_Id, Etype (Op_Id));
end if;
-- Entity is not already set, so we do need to collect interpretations
else
Set_Etype (N, Any_Type);
Op_Id := Get_Name_Entity_Id (Chars (N));
while Present (Op_Id) loop
if Ekind (Op_Id) = E_Operator
and then Present (Next_Entity (First_Entity (Op_Id)))
then
Find_Arithmetic_Types (L, R, Op_Id, N);
-- The following may seem superfluous, because an operator cannot
-- be generic, but this ignores the cleverness of the author of
-- ACVC bc1013a.
elsif Is_Overloadable (Op_Id) then
Analyze_User_Defined_Binary_Op (N, Op_Id);
end if;
Op_Id := Homonym (Op_Id);
end loop;
end if;
Operator_Check (N);
Check_Function_Writable_Actuals (N);
end Analyze_Arithmetic_Op;
------------------
-- Analyze_Call --
------------------
-- Function, procedure, and entry calls are checked here. The Name in
-- the call may be overloaded. The actuals have been analyzed and may
-- themselves be overloaded. On exit from this procedure, the node N
-- may have zero, one or more interpretations. In the first case an
-- error message is produced. In the last case, the node is flagged
-- as overloaded and the interpretations are collected in All_Interp.
-- If the name is an Access_To_Subprogram, it cannot be overloaded, but
-- the type-checking is similar to that of other calls.
procedure Analyze_Call (N : Node_Id) is
Actuals : constant List_Id := Parameter_Associations (N);
Loc : constant Source_Ptr := Sloc (N);
Nam : Node_Id;
X : Interp_Index;
It : Interp;
Nam_Ent : Entity_Id := Empty;
Success : Boolean := False;
Deref : Boolean := False;
-- Flag indicates whether an interpretation of the prefix is a
-- parameterless call that returns an access_to_subprogram.
procedure Check_Writable_Actuals (N : Node_Id);
-- If the call has out or in-out parameters then mark its outermost
-- enclosing construct as a node on which the writable actuals check
-- must be performed.
function Name_Denotes_Function return Boolean;
-- If the type of the name is an access to subprogram, this may be the
-- type of a name, or the return type of the function being called. If
-- the name is not an entity then it can denote a protected function.
-- Until we distinguish Etype from Return_Type, we must use this routine
-- to resolve the meaning of the name in the call.
procedure No_Interpretation;
-- Output error message when no valid interpretation exists
----------------------------
-- Check_Writable_Actuals --
----------------------------
-- The identification of conflicts in calls to functions with writable
-- actuals is performed in the analysis phase of the front end to ensure
-- that it reports exactly the same errors compiling with and without
-- expansion enabled. It is performed in two stages:
-- 1) When a call to a function with out-mode parameters is found,
-- we climb to the outermost enclosing construct that can be
-- evaluated in arbitrary order and we mark it with the flag
-- Check_Actuals.
-- 2) When the analysis of the marked node is complete, we traverse
-- its decorated subtree searching for conflicts (see function
-- Sem_Util.Check_Function_Writable_Actuals).
-- The unique exception to this general rule is for aggregates, since
-- their analysis is performed by the front end in the resolution
-- phase. For aggregates we do not climb to their enclosing construct:
-- we restrict the analysis to the subexpressions initializing the
-- aggregate components.
-- This implies that the analysis of expressions containing aggregates
-- is not complete, since there may be conflicts on writable actuals
-- involving subexpressions of the enclosing logical or arithmetic
-- expressions. However, we cannot wait and perform the analysis when
-- the whole subtree is resolved, since the subtrees may be transformed,
-- thus adding extra complexity and computation cost to identify and
-- report exactly the same errors compiling with and without expansion
-- enabled.
procedure Check_Writable_Actuals (N : Node_Id) is
begin
if Comes_From_Source (N)
and then Present (Get_Subprogram_Entity (N))
and then Has_Out_Or_In_Out_Parameter (Get_Subprogram_Entity (N))
then
-- For procedures and entries there is no need to climb since
-- we only need to check if the actuals of this call invoke
-- functions whose out-mode parameters overlap.
if Nkind (N) /= N_Function_Call then
Set_Check_Actuals (N);
-- For calls to functions we climb to the outermost enclosing
-- construct where the out-mode actuals of this function may
-- introduce conflicts.
else
declare
Outermost : Node_Id := Empty; -- init to avoid warning
P : Node_Id := N;
begin
while Present (P) loop
-- For object declarations we can climb to the node from
-- its object definition branch or from its initializing
-- expression. We prefer to mark the child node as the
-- outermost construct to avoid adding further complexity
-- to the routine that will later take care of
-- performing the writable actuals check.
if Has_Arbitrary_Evaluation_Order (Nkind (P))
and then Nkind (P) not in
N_Assignment_Statement | N_Object_Declaration
then
Outermost := P;
end if;
-- Avoid climbing more than needed
exit when Stop_Subtree_Climbing (Nkind (P))
or else (Nkind (P) = N_Range
and then
Nkind (Parent (P)) not in N_In | N_Not_In);
P := Parent (P);
end loop;
Set_Check_Actuals (Outermost);
end;
end if;
end if;
end Check_Writable_Actuals;
---------------------------
-- Name_Denotes_Function --
---------------------------
function Name_Denotes_Function return Boolean is
begin
if Is_Entity_Name (Nam) then
return Ekind (Entity (Nam)) = E_Function;
elsif Nkind (Nam) = N_Selected_Component then
return Ekind (Entity (Selector_Name (Nam))) = E_Function;
else
return False;
end if;
end Name_Denotes_Function;
-----------------------
-- No_Interpretation --
-----------------------
procedure No_Interpretation is
L : constant Boolean := Is_List_Member (N);
K : constant Node_Kind := Nkind (Parent (N));
begin
-- If the node is in a list whose parent is not an expression then it
-- must be an attempted procedure call.
if L and then K not in N_Subexpr then
if Ekind (Entity (Nam)) = E_Generic_Procedure then
Error_Msg_NE
("must instantiate generic procedure& before call",
Nam, Entity (Nam));
else
Error_Msg_N ("procedure or entry name expected", Nam);
end if;
-- Check for tasking cases where only an entry call will do
elsif not L
and then K in N_Entry_Call_Alternative | N_Triggering_Alternative
then
Error_Msg_N ("entry name expected", Nam);
-- Otherwise give general error message
else
Error_Msg_N ("invalid prefix in call", Nam);
end if;
end No_Interpretation;
-- Start of processing for Analyze_Call
begin
-- Initialize the type of the result of the call to the error type,
-- which will be reset if the type is successfully resolved.
Set_Etype (N, Any_Type);
Nam := Name (N);
if not Is_Overloaded (Nam) then
-- Only one interpretation to check
if Ekind (Etype (Nam)) = E_Subprogram_Type then
Nam_Ent := Etype (Nam);
-- If the prefix is an access_to_subprogram, this may be an indirect
-- call. This is the case if the name in the call is not an entity
-- name, or if it is a function name in the context of a procedure
-- call. In this latter case, we have a call to a parameterless
-- function that returns a pointer_to_procedure which is the entity
-- being called. Finally, F (X) may be a call to a parameterless
-- function that returns a pointer to a function with parameters.
-- Note that if F returns an access-to-subprogram whose designated
-- type is an array, F (X) cannot be interpreted as an indirect call
-- through the result of the call to F.
elsif Is_Access_Subprogram_Type (Base_Type (Etype (Nam)))
and then
(not Name_Denotes_Function
or else Nkind (N) = N_Procedure_Call_Statement
or else
(Nkind (Parent (N)) /= N_Explicit_Dereference
and then Is_Entity_Name (Nam)
and then No (First_Formal (Entity (Nam)))
and then not
Is_Array_Type (Etype (Designated_Type (Etype (Nam))))
and then Present (Actuals)))
then
Nam_Ent := Designated_Type (Etype (Nam));
Insert_Explicit_Dereference (Nam);
-- Selected component case. Simple entry or protected operation,
-- where the entry name is given by the selector name.
elsif Nkind (Nam) = N_Selected_Component then
Nam_Ent := Entity (Selector_Name (Nam));
if Ekind (Nam_Ent) not in E_Entry
| E_Entry_Family
| E_Function
| E_Procedure
then
Error_Msg_N ("name in call is not a callable entity", Nam);
Set_Etype (N, Any_Type);
return;
end if;
-- If the name is an Indexed component, it can be a call to a member
-- of an entry family. The prefix must be a selected component whose
-- selector is the entry. Analyze_Procedure_Call normalizes several
-- kinds of call into this form.
elsif Nkind (Nam) = N_Indexed_Component then
if Nkind (Prefix (Nam)) = N_Selected_Component then
Nam_Ent := Entity (Selector_Name (Prefix (Nam)));
else
Error_Msg_N ("name in call is not a callable entity", Nam);
Set_Etype (N, Any_Type);
return;
end if;
elsif not Is_Entity_Name (Nam) then
Error_Msg_N ("name in call is not a callable entity", Nam);
Set_Etype (N, Any_Type);
return;
else
Nam_Ent := Entity (Nam);
-- If not overloadable, this may be a generalized indexing
-- operation with named associations. Rewrite again as an
-- indexed component and analyze as container indexing.
if not Is_Overloadable (Nam_Ent) then
if Present
(Find_Value_Of_Aspect
(Etype (Nam_Ent), Aspect_Constant_Indexing))
then
Replace (N,
Make_Indexed_Component (Sloc (N),
Prefix => Nam,
Expressions => Parameter_Associations (N)));
if Try_Container_Indexing (N, Nam, Expressions (N)) then
return;
else
No_Interpretation;
end if;
else
No_Interpretation;
end if;
return;
end if;
end if;
-- Operations generated for RACW stub types are called only through
-- dispatching, and can never be the static interpretation of a call.
if Is_RACW_Stub_Type_Operation (Nam_Ent) then
No_Interpretation;
return;
end if;
Analyze_One_Call (N, Nam_Ent, True, Success);
-- If the nonoverloaded interpretation is a call to an abstract
-- nondispatching operation, then flag an error and return.
-- Should this be incorporated in Remove_Abstract_Operations (which
-- currently only deals with cases where the name is overloaded)? ???
if Is_Overloadable (Nam_Ent)
and then Is_Abstract_Subprogram (Nam_Ent)
and then not Is_Dispatching_Operation (Nam_Ent)
then
Set_Etype (N, Any_Type);
Error_Msg_Sloc := Sloc (Nam_Ent);
Error_Msg_NE
("cannot call abstract operation& declared#", N, Nam_Ent);
return;
end if;
-- If this is an indirect call, the return type of the access_to
-- subprogram may be an incomplete type. At the point of the call,
-- use the full type if available, and at the same time update the
-- return type of the access_to_subprogram.
if Success
and then Nkind (Nam) = N_Explicit_Dereference
and then Ekind (Etype (N)) = E_Incomplete_Type
and then Present (Full_View (Etype (N)))
then
Set_Etype (N, Full_View (Etype (N)));
Set_Etype (Nam_Ent, Etype (N));
end if;
-- Overloaded call
else
-- An overloaded selected component must denote overloaded operations
-- of a concurrent type. The interpretations are attached to the
-- simple name of those operations.
if Nkind (Nam) = N_Selected_Component then
Nam := Selector_Name (Nam);
end if;
Get_First_Interp (Nam, X, It);
while Present (It.Nam) loop
Nam_Ent := It.Nam;
Deref := False;
-- Name may be call that returns an access to subprogram, or more
-- generally an overloaded expression one of whose interpretations
-- yields an access to subprogram. If the name is an entity, we do
-- not dereference, because the node is a call that returns the
-- access type: note difference between f(x), where the call may
-- return an access subprogram type, and f(x)(y), where the type
-- returned by the call to f is implicitly dereferenced to analyze
-- the outer call.
if Is_Access_Type (Nam_Ent) then
Nam_Ent := Designated_Type (Nam_Ent);
elsif Is_Access_Type (Etype (Nam_Ent))
and then
(not Is_Entity_Name (Nam)
or else Nkind (N) = N_Procedure_Call_Statement)
and then Ekind (Designated_Type (Etype (Nam_Ent)))
= E_Subprogram_Type
then
Nam_Ent := Designated_Type (Etype (Nam_Ent));
if Is_Entity_Name (Nam) then
Deref := True;
end if;
end if;
-- If the call has been rewritten from a prefixed call, the first
-- parameter has been analyzed, but may need a subsequent
-- dereference, so skip its analysis now.
if Is_Rewrite_Substitution (N)
and then Nkind (Original_Node (N)) = Nkind (N)
and then Nkind (Name (N)) /= Nkind (Name (Original_Node (N)))
and then Present (Parameter_Associations (N))
and then Present (Etype (First (Parameter_Associations (N))))
then
Analyze_One_Call
(N, Nam_Ent, False, Success, Skip_First => True);
else
Analyze_One_Call (N, Nam_Ent, False, Success);
end if;
-- If the interpretation succeeds, mark the proper type of the
-- prefix (any valid candidate will do). If not, remove the
-- candidate interpretation. If this is a parameterless call
-- on an anonymous access to subprogram, X is a variable with
-- an access discriminant D, the entity in the interpretation is
-- D, so rewrite X as X.D.all.
if Success then
if Deref
and then Nkind (Parent (N)) /= N_Explicit_Dereference
then
if Ekind (It.Nam) = E_Discriminant
and then Has_Implicit_Dereference (It.Nam)
then
Rewrite (Name (N),
Make_Explicit_Dereference (Loc,
Prefix =>
Make_Selected_Component (Loc,
Prefix =>
New_Occurrence_Of (Entity (Nam), Loc),
Selector_Name =>
New_Occurrence_Of (It.Nam, Loc))));
Analyze (N);
return;
else
Set_Entity (Nam, It.Nam);
Insert_Explicit_Dereference (Nam);
Set_Etype (Nam, Nam_Ent);
end if;
else
Set_Etype (Nam, It.Typ);
end if;
elsif Nkind (Name (N)) in N_Function_Call | N_Selected_Component
then
Remove_Interp (X);
end if;
Get_Next_Interp (X, It);
end loop;
-- If the name is the result of a function call, it can only be a
-- call to a function returning an access to subprogram. Insert
-- explicit dereference.
if Nkind (Nam) = N_Function_Call then
Insert_Explicit_Dereference (Nam);
end if;
if Etype (N) = Any_Type then
-- None of the interpretations is compatible with the actuals
Diagnose_Call (N, Nam);
-- Special checks for uninstantiated put routines
if Nkind (N) = N_Procedure_Call_Statement
and then Is_Entity_Name (Nam)
and then Chars (Nam) = Name_Put
and then List_Length (Actuals) = 1
then
declare
Arg : constant Node_Id := First (Actuals);
Typ : Entity_Id;
begin
if Nkind (Arg) = N_Parameter_Association then
Typ := Etype (Explicit_Actual_Parameter (Arg));
else
Typ := Etype (Arg);
end if;
if Is_Signed_Integer_Type (Typ) then
Error_Msg_N
("possible missing instantiation of "
& "'Text_'I'O.'Integer_'I'O!", Nam);
elsif Is_Modular_Integer_Type (Typ) then
Error_Msg_N
("possible missing instantiation of "
& "'Text_'I'O.'Modular_'I'O!", Nam);
elsif Is_Floating_Point_Type (Typ) then
Error_Msg_N
("possible missing instantiation of "
& "'Text_'I'O.'Float_'I'O!", Nam);
elsif Is_Ordinary_Fixed_Point_Type (Typ) then
Error_Msg_N
("possible missing instantiation of "
& "'Text_'I'O.'Fixed_'I'O!", Nam);
elsif Is_Decimal_Fixed_Point_Type (Typ) then
Error_Msg_N
("possible missing instantiation of "
& "'Text_'I'O.'Decimal_'I'O!", Nam);
elsif Is_Enumeration_Type (Typ) then
Error_Msg_N
("possible missing instantiation of "
& "'Text_'I'O.'Enumeration_'I'O!", Nam);
end if;
end;
end if;
elsif not Is_Overloaded (N)
and then Is_Entity_Name (Nam)
then
-- Resolution yields a single interpretation. Verify that the
-- reference has capitalization consistent with the declaration.
Set_Entity_With_Checks (Nam, Entity (Nam));
Generate_Reference (Entity (Nam), Nam);
Set_Etype (Nam, Etype (Entity (Nam)));
else
Remove_Abstract_Operations (N);
end if;
end if;
-- Check the accessibility level for actuals for explicitly aliased
-- formals.
if Nkind (N) = N_Function_Call
and then Comes_From_Source (N)
and then Present (Nam_Ent)
and then In_Return_Value (N)
then
declare
Form : Node_Id;
Act : Node_Id;
begin
Act := First_Actual (N);
Form := First_Formal (Nam_Ent);
while Present (Form) and then Present (Act) loop
-- Check whether the formal is aliased and if the accessibility
-- level of the actual is deeper than the accessibility level
-- of the enclosing subprogam to which the current return
-- statement applies.
-- Should we be checking Is_Entity_Name on Act? Won't this miss
-- other cases ???
if Is_Explicitly_Aliased (Form)
and then Is_Entity_Name (Act)
and then Static_Accessibility_Level
(Act, Zero_On_Dynamic_Level)
> Subprogram_Access_Level (Current_Subprogram)
then
Error_Msg_N ("actual for explicitly aliased formal is too"
& " short lived", Act);
end if;
Next_Formal (Form);
Next_Actual (Act);
end loop;
end;
end if;
if Ada_Version >= Ada_2012 then
-- Check if the call contains a function with writable actuals
Check_Writable_Actuals (N);
-- If found and the outermost construct that can be evaluated in
-- an arbitrary order is precisely this call, then check all its
-- actuals.
Check_Function_Writable_Actuals (N);
-- The return type of the function may be incomplete. This can be
-- the case if the type is a generic formal, or a limited view. It
-- can also happen when the function declaration appears before the
-- full view of the type (which is legal in Ada 2012) and the call
-- appears in a different unit, in which case the incomplete view
-- must be replaced with the full view (or the nonlimited view)
-- to prevent subsequent type errors. Note that the usual install/
-- removal of limited_with clauses is not sufficient to handle this
-- case, because the limited view may have been captured in another
-- compilation unit that defines the current function.
if Is_Incomplete_Type (Etype (N)) then
if Present (Full_View (Etype (N))) then
if Is_Entity_Name (Nam) then
Set_Etype (Nam, Full_View (Etype (N)));
Set_Etype (Entity (Nam), Full_View (Etype (N)));
end if;
Set_Etype (N, Full_View (Etype (N)));
elsif From_Limited_With (Etype (N))
and then Present (Non_Limited_View (Etype (N)))
then
Set_Etype (N, Non_Limited_View (Etype (N)));
-- If there is no completion for the type, this may be because
-- there is only a limited view of it and there is nothing in
-- the context of the current unit that has required a regular
-- compilation of the unit containing the type. We recognize
-- this unusual case by the fact that unit is not analyzed.
-- Note that the call being analyzed is in a different unit from
-- the function declaration, and nothing indicates that the type
-- is a limited view.
elsif Ekind (Scope (Etype (N))) = E_Package
and then Present (Limited_View (Scope (Etype (N))))
and then not Analyzed (Unit_Declaration_Node (Scope (Etype (N))))
then
Error_Msg_NE
("cannot call function that returns limited view of}",
N, Etype (N));
Error_Msg_NE
("\there must be a regular with_clause for package & in the "
& "current unit, or in some unit in its context",
N, Scope (Etype (N)));
Set_Etype (N, Any_Type);
end if;
end if;
end if;
end Analyze_Call;
-----------------------------
-- Analyze_Case_Expression --
-----------------------------
procedure Analyze_Case_Expression (N : Node_Id) is
procedure Non_Static_Choice_Error (Choice : Node_Id);
-- Error routine invoked by the generic instantiation below when
-- the case expression has a non static choice.
package Case_Choices_Analysis is new
Generic_Analyze_Choices
(Process_Associated_Node => No_OP);
use Case_Choices_Analysis;
package Case_Choices_Checking is new
Generic_Check_Choices
(Process_Empty_Choice => No_OP,
Process_Non_Static_Choice => Non_Static_Choice_Error,
Process_Associated_Node => No_OP);
use Case_Choices_Checking;
-----------------------------
-- Non_Static_Choice_Error --
-----------------------------
procedure Non_Static_Choice_Error (Choice : Node_Id) is
begin
Flag_Non_Static_Expr
("choice given in case expression is not static!", Choice);
end Non_Static_Choice_Error;
-- Local variables
Expr : constant Node_Id := Expression (N);
Alt : Node_Id;
Exp_Type : Entity_Id;
Exp_Btype : Entity_Id;
FirstX : Node_Id := Empty;
-- First expression in the case for which there is some type information
-- available, i.e. it is not Any_Type, which can happen because of some
-- error, or from the use of e.g. raise Constraint_Error.
Others_Present : Boolean;
-- Indicates if Others was present
Wrong_Alt : Node_Id := Empty;
-- For error reporting
-- Start of processing for Analyze_Case_Expression
begin
if Comes_From_Source (N) then
Check_Compiler_Unit ("case expression", N);
end if;
Analyze_And_Resolve (Expr, Any_Discrete);
Check_Unset_Reference (Expr);
Exp_Type := Etype (Expr);
Exp_Btype := Base_Type (Exp_Type);
Alt := First (Alternatives (N));
while Present (Alt) loop
if Error_Posted (Expression (Alt)) then
return;
end if;
Analyze (Expression (Alt));
if No (FirstX) and then Etype (Expression (Alt)) /= Any_Type then
FirstX := Expression (Alt);
end if;
Next (Alt);
end loop;
-- Get our initial type from the first expression for which we got some
-- useful type information from the expression.
if No (FirstX) then
return;
end if;
if not Is_Overloaded (FirstX) then
Set_Etype (N, Etype (FirstX));
else
declare
I : Interp_Index;
It : Interp;
begin
Set_Etype (N, Any_Type);
Get_First_Interp (FirstX, I, It);
while Present (It.Nam) loop
-- For each interpretation of the first expression, we only
-- add the interpretation if every other expression in the
-- case expression alternatives has a compatible type.
Alt := Next (First (Alternatives (N)));
while Present (Alt) loop
exit when not Has_Compatible_Type (Expression (Alt), It.Typ);
Next (Alt);
end loop;
if No (Alt) then
Add_One_Interp (N, It.Typ, It.Typ);
else
Wrong_Alt := Alt;
end if;
Get_Next_Interp (I, It);
end loop;
end;
end if;
Exp_Btype := Base_Type (Exp_Type);
-- The expression must be of a discrete type which must be determinable
-- independently of the context in which the expression occurs, but
-- using the fact that the expression must be of a discrete type.
-- Moreover, the type this expression must not be a character literal
-- (which is always ambiguous).
-- If error already reported by Resolve, nothing more to do
if Exp_Btype = Any_Discrete or else Exp_Btype = Any_Type then
return;
-- Special casee message for character literal
elsif Exp_Btype = Any_Character then
Error_Msg_N
("character literal as case expression is ambiguous", Expr);
return;
end if;
if Etype (N) = Any_Type and then Present (Wrong_Alt) then
Error_Msg_N
("type incompatible with that of previous alternatives",
Expression (Wrong_Alt));
return;
end if;
-- If the case expression is a formal object of mode in out, then
-- treat it as having a nonstatic subtype by forcing use of the base
-- type (which has to get passed to Check_Case_Choices below). Also
-- use base type when the case expression is parenthesized.
if Paren_Count (Expr) > 0
or else (Is_Entity_Name (Expr)
and then Ekind (Entity (Expr)) = E_Generic_In_Out_Parameter)
then
Exp_Type := Exp_Btype;
end if;
-- The case expression alternatives cover the range of a static subtype
-- subject to aspect Static_Predicate. Do not check the choices when the
-- case expression has not been fully analyzed yet because this may lead
-- to bogus errors.
if Is_OK_Static_Subtype (Exp_Type)
and then Has_Static_Predicate_Aspect (Exp_Type)
and then In_Spec_Expression
then
null;
-- Call Analyze_Choices and Check_Choices to do the rest of the work
else
Analyze_Choices (Alternatives (N), Exp_Type);
Check_Choices (N, Alternatives (N), Exp_Type, Others_Present);
if Exp_Type = Universal_Integer and then not Others_Present then
Error_Msg_N
("case on universal integer requires OTHERS choice", Expr);
end if;
end if;
end Analyze_Case_Expression;
---------------------------
-- Analyze_Comparison_Op --
---------------------------
procedure Analyze_Comparison_Op (N : Node_Id) is
L : constant Node_Id := Left_Opnd (N);
R : constant Node_Id := Right_Opnd (N);
Op_Id : Entity_Id := Entity (N);
begin
Set_Etype (N, Any_Type);
Candidate_Type := Empty;
Analyze_Expression (L);
Analyze_Expression (R);
if Present (Op_Id) then
if Ekind (Op_Id) = E_Operator then
Find_Comparison_Types (L, R, Op_Id, N);
else
Add_One_Interp (N, Op_Id, Etype (Op_Id));
end if;
if Is_Overloaded (L) then
Set_Etype (L, Intersect_Types (L, R));
end if;
else
Op_Id := Get_Name_Entity_Id (Chars (N));
while Present (Op_Id) loop
if Ekind (Op_Id) = E_Operator then
Find_Comparison_Types (L, R, Op_Id, N);
else
Analyze_User_Defined_Binary_Op (N, Op_Id);
end if;
Op_Id := Homonym (Op_Id);
end loop;
end if;
Operator_Check (N);
Check_Function_Writable_Actuals (N);
end Analyze_Comparison_Op;
---------------------------
-- Analyze_Concatenation --
---------------------------
procedure Analyze_Concatenation (N : Node_Id) is
-- We wish to avoid deep recursion, because concatenations are often
-- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
-- operands nonrecursively until we find something that is not a
-- concatenation (A in this case), or has already been analyzed. We
-- analyze that, and then walk back up the tree following Parent
-- pointers, calling Analyze_Concatenation_Rest to do the rest of the
-- work at each level. The Parent pointers allow us to avoid recursion,
-- and thus avoid running out of memory.
NN : Node_Id := N;
L : Node_Id;
begin
Candidate_Type := Empty;
-- The following code is equivalent to:
-- Set_Etype (N, Any_Type);
-- Analyze_Expression (Left_Opnd (N));
-- Analyze_Concatenation_Rest (N);
-- where the Analyze_Expression call recurses back here if the left
-- operand is a concatenation.
-- Walk down left operands
loop
Set_Etype (NN, Any_Type);
L := Left_Opnd (NN);
exit when Nkind (L) /= N_Op_Concat or else Analyzed (L);
NN := L;
end loop;
-- Now (given the above example) NN is A&B and L is A
-- First analyze L ...
Analyze_Expression (L);
-- ... then walk NN back up until we reach N (where we started), calling
-- Analyze_Concatenation_Rest along the way.
loop
Analyze_Concatenation_Rest (NN);
exit when NN = N;
NN := Parent (NN);
end loop;
end Analyze_Concatenation;
--------------------------------
-- Analyze_Concatenation_Rest --
--------------------------------
-- If the only one-dimensional array type in scope is String,
-- this is the resulting type of the operation. Otherwise there
-- will be a concatenation operation defined for each user-defined
-- one-dimensional array.
procedure Analyze_Concatenation_Rest (N : Node_Id) is
L : constant Node_Id := Left_Opnd (N);
R : constant Node_Id := Right_Opnd (N);
Op_Id : Entity_Id := Entity (N);
LT : Entity_Id;
RT : Entity_Id;
begin
Analyze_Expression (R);
-- If the entity is present, the node appears in an instance, and
-- denotes a predefined concatenation operation. The resulting type is
-- obtained from the arguments when possible. If the arguments are
-- aggregates, the array type and the concatenation type must be
-- visible.
if Present (Op_Id) then
if Ekind (Op_Id) = E_Operator then
LT := Base_Type (Etype (L));
RT := Base_Type (Etype (R));
if Is_Array_Type (LT)
and then (RT = LT or else RT = Base_Type (Component_Type (LT)))
then
Add_One_Interp (N, Op_Id, LT);
elsif Is_Array_Type (RT)
and then LT = Base_Type (Component_Type (RT))
then
Add_One_Interp (N, Op_Id, RT);
-- If one operand is a string type or a user-defined array type,
-- and the other is a literal, result is of the specific type.
elsif
(Root_Type (LT) = Standard_String
or else Scope (LT) /= Standard_Standard)
and then Etype (R) = Any_String
then
Add_One_Interp (N, Op_Id, LT);
elsif
(Root_Type (RT) = Standard_String
or else Scope (RT) /= Standard_Standard)
and then Etype (L) = Any_String
then
Add_One_Interp (N, Op_Id, RT);
elsif not Is_Generic_Type (Etype (Op_Id)) then
Add_One_Interp (N, Op_Id, Etype (Op_Id));
else
-- Type and its operations must be visible
Set_Entity (N, Empty);
Analyze_Concatenation (N);
end if;
else
Add_One_Interp (N, Op_Id, Etype (Op_Id));
end if;
else
Op_Id := Get_Name_Entity_Id (Name_Op_Concat);
while Present (Op_Id) loop
if Ekind (Op_Id) = E_Operator then
-- Do not consider operators declared in dead code, they
-- cannot be part of the resolution.
if Is_Eliminated (Op_Id) then
null;
else
Find_Concatenation_Types (L, R, Op_Id, N);
end if;
else
Analyze_User_Defined_Binary_Op (N, Op_Id);
end if;
Op_Id := Homonym (Op_Id);
end loop;
end if;
Operator_Check (N);
end Analyze_Concatenation_Rest;
-------------------------
-- Analyze_Equality_Op --
-------------------------
procedure Analyze_Equality_Op (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
L : constant Node_Id := Left_Opnd (N);
R : constant Node_Id := Right_Opnd (N);
Op_Id : Entity_Id;
begin
Set_Etype (N, Any_Type);
Candidate_Type := Empty;
Analyze_Expression (L);
Analyze_Expression (R);
-- If the entity is set, the node is a generic instance with a non-local
-- reference to the predefined operator or to a user-defined function.
-- It can also be an inequality that is expanded into the negation of a
-- call to a user-defined equality operator.
-- For the predefined case, the result is Boolean, regardless of the
-- type of the operands. The operands may even be limited, if they are
-- generic actuals. If they are overloaded, label the left argument with
-- the common type that must be present, or with the type of the formal
-- of the user-defined function.
if Present (Entity (N)) then
Op_Id := Entity (N);
if Ekind (Op_Id) = E_Operator then
Add_One_Interp (N, Op_Id, Standard_Boolean);
else
Add_One_Interp (N, Op_Id, Etype (Op_Id));
end if;
if Is_Overloaded (L) then
if Ekind (Op_Id) = E_Operator then
Set_Etype (L, Intersect_Types (L, R));
else
Set_Etype (L, Etype (First_Formal (Op_Id)));
end if;
end if;
else
Op_Id := Get_Name_Entity_Id (Chars (N));
while Present (Op_Id) loop
if Ekind (Op_Id) = E_Operator then
Find_Equality_Types (L, R, Op_Id, N);
else
Analyze_User_Defined_Binary_Op (N, Op_Id);
end if;
Op_Id := Homonym (Op_Id);
end loop;
end if;
-- If there was no match, and the operator is inequality, this may be
-- a case where inequality has not been made explicit, as for tagged
-- types. Analyze the node as the negation of an equality operation.
-- This cannot be done earlier, because before analysis we cannot rule
-- out the presence of an explicit inequality.
if Etype (N) = Any_Type
and then Nkind (N) = N_Op_Ne
then
Op_Id := Get_Name_Entity_Id (Name_Op_Eq);
while Present (Op_Id) loop
if Ekind (Op_Id) = E_Operator then
Find_Equality_Types (L, R, Op_Id, N);
else
Analyze_User_Defined_Binary_Op (N, Op_Id);
end if;
Op_Id := Homonym (Op_Id);
end loop;
if Etype (N) /= Any_Type then
Op_Id := Entity (N);
Rewrite (N,
Make_Op_Not (Loc,
Right_Opnd =>
Make_Op_Eq (Loc,
Left_Opnd => Left_Opnd (N),
Right_Opnd => Right_Opnd (N))));
Set_Entity (Right_Opnd (N), Op_Id);
Analyze (N);
end if;
end if;
Operator_Check (N);
Check_Function_Writable_Actuals (N);
end Analyze_Equality_Op;
----------------------------------
-- Analyze_Explicit_Dereference --
----------------------------------
procedure Analyze_Explicit_Dereference (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
P : constant Node_Id := Prefix (N);
T : Entity_Id;
I : Interp_Index;
It : Interp;
New_N : Node_Id;
function Is_Function_Type return Boolean;
-- Check whether node may be interpreted as an implicit function call
----------------------
-- Is_Function_Type --
----------------------
function Is_Function_Type return Boolean is
I : Interp_Index;
It : Interp;
begin
if not Is_Overloaded (N) then
return Ekind (Base_Type (Etype (N))) = E_Subprogram_Type
and then Etype (Base_Type (Etype (N))) /= Standard_Void_Type;
else
Get_First_Interp (N, I, It);
while Present (It.Nam) loop
if Ekind (Base_Type (It.Typ)) /= E_Subprogram_Type
or else Etype (Base_Type (It.Typ)) = Standard_Void_Type
then
return False;
end if;
Get_Next_Interp (I, It);
end loop;
return True;
end if;
end Is_Function_Type;
-- Start of processing for Analyze_Explicit_Dereference
begin
-- In formal verification mode, keep track of all reads and writes
-- through explicit dereferences.
if GNATprove_Mode then
SPARK_Specific.Generate_Dereference (N);
end if;
Analyze (P);
Set_Etype (N, Any_Type);
-- Test for remote access to subprogram type, and if so return
-- after rewriting the original tree.
if Remote_AST_E_Dereference (P) then
return;
end if;
-- Normal processing for other than remote access to subprogram type
if not Is_Overloaded (P) then
if Is_Access_Type (Etype (P)) then
-- Set the Etype
declare
DT : constant Entity_Id := Designated_Type (Etype (P));
begin
-- An explicit dereference is a legal occurrence of an
-- incomplete type imported through a limited_with clause, if
-- the full view is visible, or if we are within an instance
-- body, where the enclosing body has a regular with_clause
-- on the unit.
if From_Limited_With (DT)
and then not From_Limited_With (Scope (DT))
and then
(Is_Immediately_Visible (Scope (DT))
or else
(Is_Child_Unit (Scope (DT))
and then Is_Visible_Lib_Unit (Scope (DT)))
or else In_Instance_Body)
then
Set_Etype (N, Available_View (DT));
else
Set_Etype (N, DT);
end if;
end;
elsif Etype (P) /= Any_Type then
Error_Msg_N ("prefix of dereference must be an access type", N);
return;
end if;
else
Get_First_Interp (P, I, It);
while Present (It.Nam) loop
T := It.Typ;
if Is_Access_Type (T) then
Add_One_Interp (N, Designated_Type (T), Designated_Type (T));
end if;
Get_Next_Interp (I, It);
end loop;
-- Error if no interpretation of the prefix has an access type
if Etype (N) = Any_Type then
Error_Msg_N
("access type required in prefix of explicit dereference", P);
Set_Etype (N, Any_Type);
return;
end if;
end if;
if Is_Function_Type
and then Nkind (Parent (N)) /= N_Indexed_Component
and then (Nkind (Parent (N)) /= N_Function_Call
or else N /= Name (Parent (N)))
and then (Nkind (Parent (N)) /= N_Procedure_Call_Statement
or else N /= Name (Parent (N)))
and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
and then (Nkind (Parent (N)) /= N_Attribute_Reference
or else
(Attribute_Name (Parent (N)) /= Name_Address
and then
Attribute_Name (Parent (N)) /= Name_Access))
then
-- Name is a function call with no actuals, in a context that
-- requires deproceduring (including as an actual in an enclosing
-- function or procedure call). There are some pathological cases
-- where the prefix might include functions that return access to
-- subprograms and others that return a regular type. Disambiguation
-- of those has to take place in Resolve.
New_N :=
Make_Function_Call (Loc,
Name => Make_Explicit_Dereference (Loc, P),
Parameter_Associations => New_List);
-- If the prefix is overloaded, remove operations that have formals,
-- we know that this is a parameterless call.
if Is_Overloaded (P) then
Get_First_Interp (P, I, It);
while Present (It.Nam) loop
T := It.Typ;
if No (First_Formal (Base_Type (Designated_Type (T)))) then
Set_Etype (P, T);
else
Remove_Interp (I);
end if;
Get_Next_Interp (I, It);
end loop;
end if;
Rewrite (N, New_N);
Analyze (N);
elsif not Is_Function_Type
and then Is_Overloaded (N)
then
-- The prefix may include access to subprograms and other access
-- types. If the context selects the interpretation that is a
-- function call (not a procedure call) we cannot rewrite the node
-- yet, but we include the result of the call interpretation.
Get_First_Interp (N, I, It);
while Present (It.Nam) loop
if Ekind (Base_Type (It.Typ)) = E_Subprogram_Type
and then Etype (Base_Type (It.Typ)) /= Standard_Void_Type
and then Nkind (Parent (N)) /= N_Procedure_Call_Statement
then
Add_One_Interp (N, Etype (It.Typ), Etype (It.Typ));
end if;
Get_Next_Interp (I, It);
end loop;
end if;
-- A value of remote access-to-class-wide must not be dereferenced
-- (RM E.2.2(16)).
Validate_Remote_Access_To_Class_Wide_Type (N);
end Analyze_Explicit_Dereference;
------------------------
-- Analyze_Expression --
------------------------
procedure Analyze_Expression (N : Node_Id) is
begin
-- If the expression is an indexed component that will be rewritten
-- as a container indexing, it has already been analyzed.
if Nkind (N) = N_Indexed_Component
and then Present (Generalized_Indexing (N))
then
null;
else
Analyze (N);
Check_Parameterless_Call (N);
end if;
end Analyze_Expression;
-------------------------------------
-- Analyze_Expression_With_Actions --
-------------------------------------
procedure Analyze_Expression_With_Actions (N : Node_Id) is
procedure Check_Action_OK (A : Node_Id);
-- Check that the action A is allowed as a declare_item of a declare
-- expression if N and A come from source.
---------------------
-- Check_Action_OK --
---------------------
procedure Check_Action_OK (A : Node_Id) is
begin
if not Comes_From_Source (N) or else not Comes_From_Source (A) then
return; -- Allow anything in generated code
end if;
case Nkind (A) is
when N_Object_Declaration =>
if Nkind (Object_Definition (A)) = N_Access_Definition then
Error_Msg_N
("anonymous access type not allowed in declare_expression",
Object_Definition (A));
end if;
if Aliased_Present (A) then
Error_Msg_N ("ALIASED not allowed in declare_expression", A);
end if;
if Constant_Present (A)
and then not Is_Limited_Type (Etype (Defining_Identifier (A)))
then
return; -- nonlimited constants are OK
end if;
when N_Object_Renaming_Declaration =>
if Present (Access_Definition (A)) then
Error_Msg_N
("anonymous access type not allowed in declare_expression",
Access_Definition (A));
end if;
if not Is_Limited_Type (Etype (Defining_Identifier (A))) then
return; -- ???For now; the RM rule is a bit more complicated
end if;
when others =>
null; -- Nothing else allowed, not even pragmas
end case;
Error_Msg_N ("object renaming or constant declaration expected", A);
end Check_Action_OK;
A : Node_Id;
EWA_Scop : Entity_Id;
-- Start of processing for Analyze_Expression_With_Actions
begin
-- Create a scope, which is needed to provide proper visibility of the
-- declare_items.
EWA_Scop := New_Internal_Entity (E_Block, Current_Scope, Sloc (N), 'B');
Set_Etype (EWA_Scop, Standard_Void_Type);
Set_Scope (EWA_Scop, Current_Scope);
Set_Parent (EWA_Scop, N);
Push_Scope (EWA_Scop);
-- If this Expression_With_Actions node comes from source, then it
-- represents a declare_expression; increment the counter to take note
-- of that.
if Comes_From_Source (N) then
In_Declare_Expr := In_Declare_Expr + 1;
end if;
A := First (Actions (N));
while Present (A) loop
Analyze (A);
Check_Action_OK (A);
Next (A);
end loop;
Analyze_Expression (Expression (N));
Set_Etype (N, Etype (Expression (N)));
End_Scope;
if Comes_From_Source (N) then
In_Declare_Expr := In_Declare_Expr - 1;
end if;
end Analyze_Expression_With_Actions;
---------------------------
-- Analyze_If_Expression --
---------------------------
procedure Analyze_If_Expression (N : Node_Id) is
Condition : constant Node_Id := First (Expressions (N));
Then_Expr : Node_Id;
Else_Expr : Node_Id;
begin
-- Defend against error of missing expressions from previous error
if No (Condition) then
Check_Error_Detected;
return;
end if;
Then_Expr := Next (Condition);
if No (Then_Expr) then
Check_Error_Detected;
return;
end if;
Else_Expr := Next (Then_Expr);
if Comes_From_Source (N) then
Check_Compiler_Unit ("if expression", N);
end if;
-- Analyze and resolve the condition. We need to resolve this now so
-- that it gets folded to True/False if possible, before we analyze
-- the THEN/ELSE branches, because when analyzing these branches, we
-- may call Is_Statically_Unevaluated, which expects the condition of
-- an enclosing IF to have been analyze/resolved/evaluated.
Analyze_Expression (Condition);
Resolve (Condition, Any_Boolean);
-- Analyze THEN expression and (if present) ELSE expression. For those
-- we delay resolution in the normal manner, because of overloading etc.
Analyze_Expression (Then_Expr);
if Present (Else_Expr) then
Analyze_Expression (Else_Expr);
end if;
-- If then expression not overloaded, then that decides the type
if not Is_Overloaded (Then_Expr) then
Set_Etype (N, Etype (Then_Expr));
-- Case where then expression is overloaded
else
declare
I : Interp_Index;
It : Interp;
begin
Set_Etype (N, Any_Type);
-- Loop through interpretations of Then_Expr
Get_First_Interp (Then_Expr, I, It);
while Present (It.Nam) loop
-- Add possible interpretation of Then_Expr if no Else_Expr, or
-- Else_Expr is present and has a compatible type.
if No (Else_Expr)
or else Has_Compatible_Type (Else_Expr, It.Typ)
then
Add_One_Interp (N, It.Typ, It.Typ);
end if;
Get_Next_Interp (I, It);
end loop;
-- If no valid interpretation has been found, then the type of the
-- ELSE expression does not match any interpretation of the THEN
-- expression.
if Etype (N) = Any_Type then
Error_Msg_N
("type incompatible with that of THEN expression",
Else_Expr);
return;
end if;
end;
end if;
end Analyze_If_Expression;
------------------------------------
-- Analyze_Indexed_Component_Form --
------------------------------------
procedure Analyze_Indexed_Component_Form (N : Node_Id) is
P : constant Node_Id := Prefix (N);
Exprs : constant List_Id := Expressions (N);
Exp : Node_Id;
P_T : Entity_Id;
E : Node_Id;
U_N : Entity_Id;
procedure Process_Function_Call;
-- Prefix in indexed component form is an overloadable entity, so the
-- node is very likely a function call; reformat it as such. The only
-- exception is a call to a parameterless function that returns an
-- array type, or an access type thereof, in which case this will be
-- undone later by Resolve_Call or Resolve_Entry_Call.
procedure Process_Indexed_Component;
-- Prefix in indexed component form is actually an indexed component.
-- This routine processes it, knowing that the prefix is already
-- resolved.
procedure Process_Indexed_Component_Or_Slice;
-- An indexed component with a single index may designate a slice if
-- the index is a subtype mark. This routine disambiguates these two
-- cases by resolving the prefix to see if it is a subtype mark.
procedure Process_Overloaded_Indexed_Component;
-- If the prefix of an indexed component is overloaded, the proper
-- interpretation is selected by the index types and the context.
---------------------------
-- Process_Function_Call --
---------------------------
procedure Process_Function_Call is
Loc : constant Source_Ptr := Sloc (N);
Actual : Node_Id;
begin
Change_Node (N, N_Function_Call);
Set_Name (N, P);
Set_Parameter_Associations (N, Exprs);
-- Analyze actuals prior to analyzing the call itself
Actual := First (Parameter_Associations (N));
while Present (Actual) loop
Analyze (Actual);
Check_Parameterless_Call (Actual);
-- Move to next actual. Note that we use Next, not Next_Actual
-- here. The reason for this is a bit subtle. If a function call
-- includes named associations, the parser recognizes the node
-- as a call, and it is analyzed as such. If all associations are
-- positional, the parser builds an indexed_component node, and
-- it is only after analysis of the prefix that the construct
-- is recognized as a call, in which case Process_Function_Call
-- rewrites the node and analyzes the actuals. If the list of
-- actuals is malformed, the parser may leave the node as an
-- indexed component (despite the presence of named associations).
-- The iterator Next_Actual is equivalent to Next if the list is
-- positional, but follows the normalized chain of actuals when
-- named associations are present. In this case normalization has
-- not taken place, and actuals remain unanalyzed, which leads to
-- subsequent crashes or loops if there is an attempt to continue
-- analysis of the program.
-- IF there is a single actual and it is a type name, the node
-- can only be interpreted as a slice of a parameterless call.
-- Rebuild the node as such and analyze.
if No (Next (Actual))
and then Is_Entity_Name (Actual)
and then Is_Type (Entity (Actual))
and then Is_Discrete_Type (Entity (Actual))
and then not Is_Current_Instance (Actual)
then
Replace (N,
Make_Slice (Loc,
Prefix => P,
Discrete_Range =>
New_Occurrence_Of (Entity (Actual), Loc)));
Analyze (N);
return;
else
Next (Actual);
end if;
end loop;
Analyze_Call (N);
end Process_Function_Call;
-------------------------------
-- Process_Indexed_Component --
-------------------------------
procedure Process_Indexed_Component is
Exp : Node_Id;
Array_Type : Entity_Id;
Index : Node_Id;
Pent : Entity_Id := Empty;
begin
Exp := First (Exprs);
if Is_Overloaded (P) then
Process_Overloaded_Indexed_Component;
else
Array_Type := Etype (P);
if Is_Entity_Name (P) then
Pent := Entity (P);
elsif Nkind (P) = N_Selected_Component
and then Is_Entity_Name (Selector_Name (P))
then
Pent := Entity (Selector_Name (P));
end if;
-- Prefix must be appropriate for an array type, taking into
-- account a possible implicit dereference.
if Is_Access_Type (Array_Type) then
Error_Msg_NW
(Warn_On_Dereference, "?d?implicit dereference", N);
Array_Type := Implicitly_Designated_Type (Array_Type);
end if;
if Is_Array_Type (Array_Type) then
-- In order to correctly access First_Index component later,
-- replace string literal subtype by its parent type.
if Ekind (Array_Type) = E_String_Literal_Subtype then
Array_Type := Etype (Array_Type);
end if;
elsif Present (Pent) and then Ekind (Pent) = E_Entry_Family then
Analyze (Exp);
Set_Etype (N, Any_Type);
if not Has_Compatible_Type (Exp, Entry_Index_Type (Pent)) then
Error_Msg_N ("invalid index type in entry name", N);
elsif Present (Next (Exp)) then
Error_Msg_N ("too many subscripts in entry reference", N);
else
Set_Etype (N, Etype (P));
end if;
return;
elsif Is_Record_Type (Array_Type)
and then Remote_AST_I_Dereference (P)
then
return;
elsif Try_Container_Indexing (N, P, Exprs) then
return;
elsif Array_Type = Any_Type then
Set_Etype (N, Any_Type);
-- In most cases the analysis of the prefix will have emitted
-- an error already, but if the prefix may be interpreted as a
-- call in prefixed notation, the report is left to the caller.
-- To prevent cascaded errors, report only if no previous ones.
if Serious_Errors_Detected = 0 then
Error_Msg_N ("invalid prefix in indexed component", P);
if Nkind (P) = N_Expanded_Name then
Error_Msg_NE ("\& is not visible", P, Selector_Name (P));
end if;
end if;
return;
-- Here we definitely have a bad indexing
else
if Nkind (Parent (N)) = N_Requeue_Statement
and then Present (Pent) and then Ekind (Pent) = E_Entry
then
Error_Msg_N
("REQUEUE does not permit parameters", First (Exprs));
elsif Is_Entity_Name (P)
and then Etype (P) = Standard_Void_Type
then
Error_Msg_NE ("incorrect use of &", P, Entity (P));
else
Error_Msg_N ("array type required in indexed component", P);
end if;
Set_Etype (N, Any_Type);
return;
end if;
Index := First_Index (Array_Type);
while Present (Index) and then Present (Exp) loop
if not Has_Compatible_Type (Exp, Etype (Index)) then
Wrong_Type (Exp, Etype (Index));
Set_Etype (N, Any_Type);
return;
end if;
Next_Index (Index);
Next (Exp);
end loop;
Set_Etype (N, Component_Type (Array_Type));
Check_Implicit_Dereference (N, Etype (N));
if Present (Index) then
Error_Msg_N
("too few subscripts in array reference", First (Exprs));
elsif Present (Exp) then
Error_Msg_N ("too many subscripts in array reference", Exp);
end if;
end if;
end Process_Indexed_Component;
----------------------------------------
-- Process_Indexed_Component_Or_Slice --
----------------------------------------
procedure Process_Indexed_Component_Or_Slice is
begin
Exp := First (Exprs);
while Present (Exp) loop
Analyze_Expression (Exp);
Next (Exp);
end loop;
Exp := First (Exprs);
-- If one index is present, and it is a subtype name, then the node
-- denotes a slice (note that the case of an explicit range for a
-- slice was already built as an N_Slice node in the first place,
-- so that case is not handled here).
-- We use a replace rather than a rewrite here because this is one
-- of the cases in which the tree built by the parser is plain wrong.
if No (Next (Exp))
and then Is_Entity_Name (Exp)
and then Is_Type (Entity (Exp))
then
Replace (N,
Make_Slice (Sloc (N),
Prefix => P,
Discrete_Range => New_Copy (Exp)));
Analyze (N);
-- Otherwise (more than one index present, or single index is not
-- a subtype name), then we have the indexed component case.
else
Process_Indexed_Component;
end if;
end Process_Indexed_Component_Or_Slice;
------------------------------------------
-- Process_Overloaded_Indexed_Component --
------------------------------------------
procedure Process_Overloaded_Indexed_Component is
Exp : Node_Id;
I : Interp_Index;
It : Interp;
Typ : Entity_Id;
Index : Node_Id;
Found : Boolean;
begin
Set_Etype (N, Any_Type);
Get_First_Interp (P, I, It);
while Present (It.Nam) loop
Typ := It.Typ;
if Is_Access_Type (Typ) then
Typ := Designated_Type (Typ);
Error_Msg_NW
(Warn_On_Dereference, "?d?implicit dereference", N);
end if;
if Is_Array_Type (Typ) then
-- Got a candidate: verify that index types are compatible
Index := First_Index (Typ);
Found := True;
Exp := First (Exprs);
while Present (Index) and then Present (Exp) loop
if Has_Compatible_Type (Exp, Etype (Index)) then
null;
else
Found := False;
Remove_Interp (I);
exit;
end if;
Next_Index (Index);
Next (Exp);
end loop;
if Found and then No (Index) and then No (Exp) then
declare
CT : constant Entity_Id :=
Base_Type (Component_Type (Typ));
begin
Add_One_Interp (N, CT, CT);
Check_Implicit_Dereference (N, CT);
end;
end if;
elsif Try_Container_Indexing (N, P, Exprs) then
return;
end if;
Get_Next_Interp (I, It);
end loop;
if Etype (N) = Any_Type then
Error_Msg_N ("no legal interpretation for indexed component", N);
Set_Is_Overloaded (N, False);
end if;
end Process_Overloaded_Indexed_Component;
-- Start of processing for Analyze_Indexed_Component_Form
begin
-- Get name of array, function or type
Analyze (P);
-- If P is an explicit dereference whose prefix is of a remote access-
-- to-subprogram type, then N has already been rewritten as a subprogram
-- call and analyzed.
if Nkind (N) in N_Subprogram_Call then
return;
-- When the prefix is attribute 'Loop_Entry and the sole expression of
-- the indexed component denotes a loop name, the indexed form is turned
-- into an attribute reference.
elsif Nkind (N) = N_Attribute_Reference
and then Attribute_Name (N) = Name_Loop_Entry
then
return;
end if;
pragma Assert (Nkind (N) = N_Indexed_Component);
P_T := Base_Type (Etype (P));
if Is_Entity_Name (P) and then Present (Entity (P)) then
U_N := Entity (P);
if Is_Type (U_N) then
-- Reformat node as a type conversion
E := Remove_Head (Exprs);
if Present (First (Exprs)) then
Error_Msg_N
("argument of type conversion must be single expression", N);
end if;
Change_Node (N, N_Type_Conversion);
Set_Subtype_Mark (N, P);
Set_Etype (N, U_N);
Set_Expression (N, E);
-- After changing the node, call for the specific Analysis
-- routine directly, to avoid a double call to the expander.
Analyze_Type_Conversion (N);
return;
end if;
if Is_Overloadable (U_N) then
Process_Function_Call;
elsif Ekind (Etype (P)) = E_Subprogram_Type
or else (Is_Access_Type (Etype (P))
and then
Ekind (Designated_Type (Etype (P))) =
E_Subprogram_Type)
then
-- Call to access_to-subprogram with possible implicit dereference
Process_Function_Call;
elsif Is_Generic_Subprogram (U_N) then
-- A common beginner's (or C++ templates fan) error
Error_Msg_N ("generic subprogram cannot be called", N);
Set_Etype (N, Any_Type);
return;
else
Process_Indexed_Component_Or_Slice;
end if;
-- If not an entity name, prefix is an expression that may denote
-- an array or an access-to-subprogram.
else
if Ekind (P_T) = E_Subprogram_Type
or else (Is_Access_Type (P_T)
and then
Ekind (Designated_Type (P_T)) = E_Subprogram_Type)
then
Process_Function_Call;
elsif Nkind (P) = N_Selected_Component
and then Present (Entity (Selector_Name (P)))
and then Is_Overloadable (Entity (Selector_Name (P)))
then
Process_Function_Call;
else
-- Indexed component, slice, or a call to a member of a family
-- entry, which will be converted to an entry call later.
Process_Indexed_Component_Or_Slice;
end if;
end if;
Analyze_Dimension (N);
end Analyze_Indexed_Component_Form;
------------------------
-- Analyze_Logical_Op --
------------------------
procedure Analyze_Logical_Op (N : Node_Id) is
L : constant Node_Id := Left_Opnd (N);
R : constant Node_Id := Right_Opnd (N);
Op_Id : Entity_Id := Entity (N);
begin
Set_Etype (N, Any_Type);
Candidate_Type := Empty;
Analyze_Expression (L);
Analyze_Expression (R);
if Present (Op_Id) then
if Ekind (Op_Id) = E_Operator then
Find_Boolean_Types (L, R, Op_Id, N);
else
Add_One_Interp (N, Op_Id, Etype (Op_Id));
end if;
else
Op_Id := Get_Name_Entity_Id (Chars (N));
while Present (Op_Id) loop
if Ekind (Op_Id) = E_Operator then
Find_Boolean_Types (L, R, Op_Id, N);
else
Analyze_User_Defined_Binary_Op (N, Op_Id);
end if;
Op_Id := Homonym (Op_Id);
end loop;
end if;
Operator_Check (N);
Check_Function_Writable_Actuals (N);
end Analyze_Logical_Op;
---------------------------
-- Analyze_Membership_Op --
---------------------------
procedure Analyze_Membership_Op (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
L : constant Node_Id := Left_Opnd (N);
R : constant Node_Id := Right_Opnd (N);
Index : Interp_Index;
It : Interp;
Found : Boolean := False;
I_F : Interp_Index;
T_F : Entity_Id;
procedure Analyze_Set_Membership;
-- If a set of alternatives is present, analyze each and find the
-- common type to which they must all resolve.
procedure Find_Interpretation;
function Find_Interpretation return Boolean;
-- Routine and wrapper to find a matching interpretation in case
-- of overloading. The wrapper returns True iff a matching
-- interpretation is found. Beware, in absence of overloading,
-- using this function will break gnat's bootstrapping.
procedure Try_One_Interp (T1 : Entity_Id);
-- Routine to try one proposed interpretation. Note that the context
-- of the operation plays no role in resolving the arguments, so that
-- if there is more than one interpretation of the operands that is
-- compatible with a membership test, the operation is ambiguous.
----------------------------
-- Analyze_Set_Membership --
----------------------------
procedure Analyze_Set_Membership is
Alt : Node_Id;
Index : Interp_Index;
It : Interp;
Candidate_Interps : Node_Id;
Common_Type : Entity_Id := Empty;
begin
if Comes_From_Source (N) then
Check_Compiler_Unit ("set membership", N);
end if;
Analyze (L);
Candidate_Interps := L;
if not Is_Overloaded (L) then
Common_Type := Etype (L);
Alt := First (Alternatives (N));
while Present (Alt) loop
Analyze (Alt);
if not Has_Compatible_Type (Alt, Common_Type) then
Wrong_Type (Alt, Common_Type);
end if;
Next (Alt);
end loop;
else
Alt := First (Alternatives (N));
while Present (Alt) loop
Analyze (Alt);
if not Is_Overloaded (Alt) then
Common_Type := Etype (Alt);
else
Get_First_Interp (Alt, Index, It);
while Present (It.Typ) loop
if not
Has_Compatible_Type (Candidate_Interps, It.Typ)
then
Remove_Interp (Index);
end if;
Get_Next_Interp (Index, It);
end loop;
Get_First_Interp (Alt, Index, It);
if No (It.Typ) then
Error_Msg_N ("alternative has no legal type", Alt);
return;
end if;
-- If alternative is not overloaded, we have a unique type
-- for all of them.
Set_Etype (Alt, It.Typ);
-- If the alternative is an enumeration literal, use the one
-- for this interpretation.
if Is_Entity_Name (Alt) then
Set_Entity (Alt, It.Nam);
end if;
Get_Next_Interp (Index, It);
if No (It.Typ) then
Set_Is_Overloaded (Alt, False);
Common_Type := Etype (Alt);
end if;
Candidate_Interps := Alt;
end if;
Next (Alt);
end loop;
end if;
Set_Etype (N, Standard_Boolean);
if Present (Common_Type) then
Set_Etype (L, Common_Type);
-- The left operand may still be overloaded, to be resolved using
-- the Common_Type.
else
Error_Msg_N ("cannot resolve membership operation", N);
end if;
end Analyze_Set_Membership;
-------------------------
-- Find_Interpretation --
-------------------------
procedure Find_Interpretation is
begin
Get_First_Interp (L, Index, It);
while Present (It.Typ) loop
Try_One_Interp (It.Typ);
Get_Next_Interp (Index, It);
end loop;
end Find_Interpretation;
function Find_Interpretation return Boolean is
begin
Find_Interpretation;
return Found;
end Find_Interpretation;
--------------------
-- Try_One_Interp --
--------------------
procedure Try_One_Interp (T1 : Entity_Id) is
begin
if Has_Compatible_Type (R, T1) then
if Found
and then Base_Type (T1) /= Base_Type (T_F)
then
It := Disambiguate (L, I_F, Index, Any_Type);
if It = No_Interp then
Ambiguous_Operands (N);
Set_Etype (L, Any_Type);
return;
else
T_F := It.Typ;
end if;
else
Found := True;
T_F := T1;
I_F := Index;
end if;
Set_Etype (L, T_F);
end if;
end Try_One_Interp;
Op : Node_Id;
-- Start of processing for Analyze_Membership_Op
begin
Analyze_Expression (L);
if No (R) then
pragma Assert (Ada_Version >= Ada_2012);
Analyze_Set_Membership;
Check_Function_Writable_Actuals (N);
return;
end if;
if Nkind (R) = N_Range
or else (Nkind (R) = N_Attribute_Reference
and then Attribute_Name (R) = Name_Range)
then
Analyze (R);
if not Is_Overloaded (L) then
Try_One_Interp (Etype (L));
else
Find_Interpretation;
end if;
-- If not a range, it can be a subtype mark, or else it is a degenerate
-- membership test with a singleton value, i.e. a test for equality,
-- if the types are compatible.
else
Analyze (R);
if Is_Entity_Name (R)
and then Is_Type (Entity (R))
then
Find_Type (R);
Check_Fully_Declared (Entity (R), R);
elsif Ada_Version >= Ada_2012 and then
((Is_Overloaded (L) and then Find_Interpretation) or else
(not Is_Overloaded (L) and then Has_Compatible_Type (R, Etype (L))))
then
if Nkind (N) = N_In then
Op := Make_Op_Eq (Loc, Left_Opnd => L, Right_Opnd => R);
else
Op := Make_Op_Ne (Loc, Left_Opnd => L, Right_Opnd => R);
end if;
if Is_Record_Or_Limited_Type (Etype (L)) then
-- We reset the Entity in order to use the primitive equality
-- of the type, as per RM 4.5.2 (28.1/4).
Set_Entity (Op, Empty);
end if;
Rewrite (N, Op);
Analyze (N);
return;
else
-- In all versions of the language, if we reach this point there
-- is a previous error that will be diagnosed below.
Find_Type (R);
end if;
end if;
-- Compatibility between expression and subtype mark or range is
-- checked during resolution. The result of the operation is Boolean
-- in any case.
Set_Etype (N, Standard_Boolean);
if Comes_From_Source (N)
and then Present (Right_Opnd (N))
and then Is_CPP_Class (Etype (Etype (Right_Opnd (N))))
then
Error_Msg_N ("membership test not applicable to cpp-class types", N);
end if;
Check_Function_Writable_Actuals (N);
end Analyze_Membership_Op;
-----------------
-- Analyze_Mod --
-----------------
procedure Analyze_Mod (N : Node_Id) is
begin
-- A special warning check, if we have an expression of the form:
-- expr mod 2 * literal
-- where literal is 128 or less, then probably what was meant was
-- expr mod 2 ** literal
-- so issue an appropriate warning.
if Warn_On_Suspicious_Modulus_Value
and then Nkind (Right_Opnd (N)) = N_Integer_Literal
and then Intval (Right_Opnd (N)) = Uint_2
and then Nkind (Parent (N)) = N_Op_Multiply
and then Nkind (Right_Opnd (Parent (N))) = N_Integer_Literal
and then Intval (Right_Opnd (Parent (N))) <= Uint_128
then
Error_Msg_N
("suspicious MOD value, was '*'* intended'??.m?", Parent (N));
end if;
-- Remaining processing is same as for other arithmetic operators
Analyze_Arithmetic_Op (N);
end Analyze_Mod;
----------------------
-- Analyze_Negation --
----------------------
procedure Analyze_Negation (N : Node_Id) is
R : constant Node_Id := Right_Opnd (N);
Op_Id : Entity_Id := Entity (N);
begin
Set_Etype (N, Any_Type);
Candidate_Type := Empty;
Analyze_Expression (R);
if Present (Op_Id) then
if Ekind (Op_Id) = E_Operator then
Find_Negation_Types (R, Op_Id, N);
else
Add_One_Interp (N, Op_Id, Etype (Op_Id));
end if;
else
Op_Id := Get_Name_Entity_Id (Chars (N));
while Present (Op_Id) loop
if Ekind (Op_Id) = E_Operator then
Find_Negation_Types (R, Op_Id, N);
else
Analyze_User_Defined_Unary_Op (N, Op_Id);
end if;
Op_Id := Homonym (Op_Id);
end loop;
end if;
Operator_Check (N);
end Analyze_Negation;
------------------
-- Analyze_Null --
------------------
procedure Analyze_Null (N : Node_Id) is
begin
Set_Etype (N, Any_Access);
end Analyze_Null;
----------------------
-- Analyze_One_Call --
----------------------
procedure Analyze_One_Call
(N : Node_Id;
Nam : Entity_Id;
Report : Boolean;
Success : out Boolean;
Skip_First : Boolean := False)
is
Actuals : constant List_Id := Parameter_Associations (N);
Prev_T : constant Entity_Id := Etype (N);
-- Recognize cases of prefixed calls that have been rewritten in
-- various ways. The simplest case is a rewritten selected component,
-- but it can also be an already-examined indexed component, or a
-- prefix that is itself a rewritten prefixed call that is in turn
-- an indexed call (the syntactic ambiguity involving the indexing of
-- a function with defaulted parameters that returns an array).
-- A flag Maybe_Indexed_Call might be useful here ???
Must_Skip : constant Boolean := Skip_First
or else Nkind (Original_Node (N)) = N_Selected_Component
or else
(Nkind (Original_Node (N)) = N_Indexed_Component
and then Nkind (Prefix (Original_Node (N))) =
N_Selected_Component)
or else
(Nkind (Parent (N)) = N_Function_Call
and then Is_Array_Type (Etype (Name (N)))
and then Etype (Original_Node (N)) =
Component_Type (Etype (Name (N)))
and then Nkind (Original_Node (Parent (N))) =
N_Selected_Component);
-- The first formal must be omitted from the match when trying to find
-- a primitive operation that is a possible interpretation, and also
-- after the call has been rewritten, because the corresponding actual
-- is already known to be compatible, and because this may be an
-- indexing of a call with default parameters.
First_Form : Entity_Id;
Formal : Entity_Id;
Actual : Node_Id;
Is_Indexed : Boolean := False;
Is_Indirect : Boolean := False;
Subp_Type : constant Entity_Id := Etype (Nam);
Norm_OK : Boolean;
function Compatible_Types_In_Predicate
(T1 : Entity_Id;
T2 : Entity_Id) return Boolean;
-- For an Ada 2012 predicate or invariant, a call may mention an
-- incomplete type, while resolution of the corresponding predicate
-- function may see the full view, as a consequence of the delayed
-- resolution of the corresponding expressions. This may occur in
-- the body of a predicate function, or in a call to such. Anomalies
-- involving private and full views can also happen. In each case,
-- rewrite node or add conversions to remove spurious type errors.
procedure Indicate_Name_And_Type;
-- If candidate interpretation matches, indicate name and type of result
-- on call node.
function Operator_Hidden_By (Fun : Entity_Id) return Boolean;
-- There may be a user-defined operator that hides the current
-- interpretation. We must check for this independently of the
-- analysis of the call with the user-defined operation, because
-- the parameter names may be wrong and yet the hiding takes place.
-- This fixes a problem with ACATS test B34014O.
--
-- When the type Address is a visible integer type, and the DEC
-- system extension is visible, the predefined operator may be
-- hidden as well, by one of the address operations in auxdec.
-- Finally, the abstract operations on address do not hide the
-- predefined operator (this is the purpose of making them abstract).
-----------------------------------
-- Compatible_Types_In_Predicate --
-----------------------------------
function Compatible_Types_In_Predicate
(T1 : Entity_Id;
T2 : Entity_Id) return Boolean
is
function Common_Type (T : Entity_Id) return Entity_Id;
-- Find non-private underlying full view if any, without going to
-- ancestor type (as opposed to Underlying_Type).
-----------------
-- Common_Type --
-----------------
function Common_Type (T : Entity_Id) return Entity_Id is
CT : Entity_Id;
begin
CT := T;
if Is_Private_Type (CT) and then Present (Full_View (CT)) then
CT := Full_View (CT);
end if;
if Is_Private_Type (CT)
and then Present (Underlying_Full_View (CT))
then
CT := Underlying_Full_View (CT);
end if;
return Base_Type (CT);
end Common_Type;
-- Start of processing for Compatible_Types_In_Predicate
begin
if (Ekind (Current_Scope) = E_Function
and then Is_Predicate_Function (Current_Scope))
or else
(Ekind (Nam) = E_Function
and then Is_Predicate_Function (Nam))
then
if Is_Incomplete_Type (T1)
and then Present (Full_View (T1))
and then Full_View (T1) = T2
then
Set_Etype (Formal, Etype (Actual));
return True;
elsif Common_Type (T1) = Common_Type (T2) then
Rewrite (Actual, Unchecked_Convert_To (Etype (Formal), Actual));
return True;
else
return False;
end if;
else
return False;
end if;
end Compatible_Types_In_Predicate;
----------------------------
-- Indicate_Name_And_Type --
----------------------------
procedure Indicate_Name_And_Type is
begin
Add_One_Interp (N, Nam, Etype (Nam));
Check_Implicit_Dereference (N, Etype (Nam));
Success := True;
-- If the prefix of the call is a name, indicate the entity
-- being called. If it is not a name, it is an expression that
-- denotes an access to subprogram or else an entry or family. In
-- the latter case, the name is a selected component, and the entity
-- being called is noted on the selector.
if not Is_Type (Nam) then
if Is_Entity_Name (Name (N)) then
Set_Entity (Name (N), Nam);
Set_Etype (Name (N), Etype (Nam));
elsif Nkind (Name (N)) = N_Selected_Component then
Set_Entity (Selector_Name (Name (N)), Nam);
end if;
end if;
if Debug_Flag_E and not Report then
Write_Str (" Overloaded call ");
Write_Int (Int (N));
Write_Str (" compatible with ");
Write_Int (Int (Nam));
Write_Eol;
end if;
end Indicate_Name_And_Type;
------------------------
-- Operator_Hidden_By --
------------------------
function Operator_Hidden_By (Fun : Entity_Id) return Boolean is
Act1 : constant Node_Id := First_Actual (N);
Act2 : constant Node_Id := Next_Actual (Act1);
Form1 : constant Entity_Id := First_Formal (Fun);
Form2 : constant Entity_Id := Next_Formal (Form1);
begin
if Ekind (Fun) /= E_Function or else Is_Abstract_Subprogram (Fun) then
return False;
elsif not Has_Compatible_Type (Act1, Etype (Form1)) then
return False;
elsif Present (Form2) then
if No (Act2)
or else not Has_Compatible_Type (Act2, Etype (Form2))
then
return False;
end if;
elsif Present (Act2) then
return False;
end if;
-- Now we know that the arity of the operator matches the function,
-- and the function call is a valid interpretation. The function
-- hides the operator if it has the right signature, or if one of
-- its operands is a non-abstract operation on Address when this is
-- a visible integer type.
return Hides_Op (Fun, Nam)
or else Is_Descendant_Of_Address (Etype (Form1))
or else
(Present (Form2)
and then Is_Descendant_Of_Address (Etype (Form2)));
end Operator_Hidden_By;
-- Start of processing for Analyze_One_Call
begin
Success := False;
-- If the subprogram has no formals or if all the formals have defaults,
-- and the return type is an array type, the node may denote an indexing
-- of the result of a parameterless call. In Ada 2005, the subprogram
-- may have one non-defaulted formal, and the call may have been written
-- in prefix notation, so that the rebuilt parameter list has more than
-- one actual.
if not Is_Overloadable (Nam)
and then Ekind (Nam) /= E_Subprogram_Type
and then Ekind (Nam) /= E_Entry_Family
then
return;
end if;
-- An indexing requires at least one actual. The name of the call cannot
-- be an implicit indirect call, so it cannot be a generated explicit
-- dereference.
if not Is_Empty_List (Actuals)
and then
(Needs_No_Actuals (Nam)
or else
(Needs_One_Actual (Nam)
and then Present (Next_Actual (First (Actuals)))))
then
if Is_Array_Type (Subp_Type)
and then
(Nkind (Name (N)) /= N_Explicit_Dereference
or else Comes_From_Source (Name (N)))
then
Is_Indexed := Try_Indexed_Call (N, Nam, Subp_Type, Must_Skip);
elsif Is_Access_Type (Subp_Type)
and then Is_Array_Type (Designated_Type (Subp_Type))
then
Is_Indexed :=
Try_Indexed_Call
(N, Nam, Designated_Type (Subp_Type), Must_Skip);
-- The prefix can also be a parameterless function that returns an
-- access to subprogram, in which case this is an indirect call.
-- If this succeeds, an explicit dereference is added later on,
-- in Analyze_Call or Resolve_Call.
elsif Is_Access_Type (Subp_Type)
and then Ekind (Designated_Type (Subp_Type)) = E_Subprogram_Type
then
Is_Indirect := Try_Indirect_Call (N, Nam, Subp_Type);
end if;
end if;
-- If the call has been transformed into a slice, it is of the form
-- F (Subtype) where F is parameterless. The node has been rewritten in
-- Try_Indexed_Call and there is nothing else to do.
if Is_Indexed
and then Nkind (N) = N_Slice
then
return;
end if;
Normalize_Actuals
(N, Nam, (Report and not Is_Indexed and not Is_Indirect), Norm_OK);
if not Norm_OK then
-- If an indirect call is a possible interpretation, indicate
-- success to the caller. This may be an indexing of an explicit
-- dereference of a call that returns an access type (see above).
if Is_Indirect
or else (Is_Indexed
and then Nkind (Name (N)) = N_Explicit_Dereference
and then Comes_From_Source (Name (N)))
then
Success := True;
return;
-- Mismatch in number or names of parameters
elsif Debug_Flag_E then
Write_Str (" normalization fails in call ");
Write_Int (Int (N));
Write_Str (" with subprogram ");
Write_Int (Int (Nam));
Write_Eol;
end if;
-- If the context expects a function call, discard any interpretation
-- that is a procedure. If the node is not overloaded, leave as is for
-- better error reporting when type mismatch is found.
elsif Nkind (N) = N_Function_Call
and then Is_Overloaded (Name (N))
and then Ekind (Nam) = E_Procedure
then
return;
-- Ditto for function calls in a procedure context
elsif Nkind (N) = N_Procedure_Call_Statement
and then Is_Overloaded (Name (N))
and then Etype (Nam) /= Standard_Void_Type
then
return;
elsif No (Actuals) then
-- If Normalize succeeds, then there are default parameters for
-- all formals.
Indicate_Name_And_Type;
elsif Ekind (Nam) = E_Operator then
if Nkind (N) = N_Procedure_Call_Statement then
return;
end if;
-- This can occur when the prefix of the call is an operator
-- name or an expanded name whose selector is an operator name.
Analyze_Operator_Call (N, Nam);
if Etype (N) /= Prev_T then
-- Check that operator is not hidden by a function interpretation
if Is_Overloaded (Name (N)) then
declare
I : Interp_Index;
It : Interp;
begin
Get_First_Interp (Name (N), I, It);
while Present (It.Nam) loop
if Operator_Hidden_By (It.Nam) then
Set_Etype (N, Prev_T);
return;
end if;
Get_Next_Interp (I, It);
end loop;
end;
end if;
-- If operator matches formals, record its name on the call.
-- If the operator is overloaded, Resolve will select the
-- correct one from the list of interpretations. The call
-- node itself carries the first candidate.
Set_Entity (Name (N), Nam);
Success := True;
elsif Report and then Etype (N) = Any_Type then
Error_Msg_N ("incompatible arguments for operator", N);
end if;
else
-- Normalize_Actuals has chained the named associations in the
-- correct order of the formals.
Actual := First_Actual (N);
Formal := First_Formal (Nam);
First_Form := Formal;
-- If we are analyzing a call rewritten from object notation, skip
-- first actual, which may be rewritten later as an explicit
-- dereference.
if Must_Skip then
Next_Actual (Actual);
Next_Formal (Formal);
end if;
while Present (Actual) and then Present (Formal) loop
if Nkind (Parent (Actual)) /= N_Parameter_Association
or else Chars (Selector_Name (Parent (Actual))) = Chars (Formal)
then
-- The actual can be compatible with the formal, but we must
-- also check that the context is not an address type that is
-- visibly an integer type. In this case the use of literals is
-- illegal, except in the body of descendants of system, where
-- arithmetic operations on address are of course used.
if Has_Compatible_Type (Actual, Etype (Formal))
and then
(Etype (Actual) /= Universal_Integer
or else not Is_Descendant_Of_Address (Etype (Formal))
or else In_Predefined_Unit (N))
then
Next_Actual (Actual);
Next_Formal (Formal);
-- In Allow_Integer_Address mode, we allow an actual integer to
-- match a formal address type and vice versa. We only do this
-- if we are certain that an error will otherwise be issued
elsif Address_Integer_Convert_OK
(Etype (Actual), Etype (Formal))
and then (Report and not Is_Indexed and not Is_Indirect)
then
-- Handle this case by introducing an unchecked conversion
Rewrite (Actual,
Unchecked_Convert_To (Etype (Formal),
Relocate_Node (Actual)));
Analyze_And_Resolve (Actual, Etype (Formal));
Next_Actual (Actual);
Next_Formal (Formal);
-- Under relaxed RM semantics silently replace occurrences of
-- null by System.Address_Null. We only do this if we know that
-- an error will otherwise be issued.
elsif Null_To_Null_Address_Convert_OK (Actual, Etype (Formal))
and then (Report and not Is_Indexed and not Is_Indirect)
then
Replace_Null_By_Null_Address (Actual);
Analyze_And_Resolve (Actual, Etype (Formal));
Next_Actual (Actual);
Next_Formal (Formal);
elsif Compatible_Types_In_Predicate
(Etype (Formal), Etype (Actual))
then
Next_Actual (Actual);
Next_Formal (Formal);
-- Handle failed type check
else
if Debug_Flag_E then
Write_Str (" type checking fails in call ");
Write_Int (Int (N));
Write_Str (" with formal ");
Write_Int (Int (Formal));
Write_Str (" in subprogram ");
Write_Int (Int (Nam));
Write_Eol;
end if;
-- Comment needed on the following test???
if Report and not Is_Indexed and not Is_Indirect then
-- Ada 2005 (AI-251): Complete the error notification
-- to help new Ada 2005 users.
if Is_Class_Wide_Type (Etype (Formal))
and then Is_Interface (Etype (Etype (Formal)))
and then not Interface_Present_In_Ancestor
(Typ => Etype (Actual),
Iface => Etype (Etype (Formal)))
then
Error_Msg_NE
("(Ada 2005) does not implement interface }",
Actual, Etype (Etype (Formal)));
end if;
Wrong_Type (Actual, Etype (Formal));
if Nkind (Actual) = N_Op_Eq
and then Nkind (Left_Opnd (Actual)) = N_Identifier
then
Formal := First_Formal (Nam);
while Present (Formal) loop
if Chars (Left_Opnd (Actual)) = Chars (Formal) then
Error_Msg_N -- CODEFIX
("possible misspelling of `='>`!", Actual);
exit;
end if;
Next_Formal (Formal);
end loop;
end if;
if All_Errors_Mode then
Error_Msg_Sloc := Sloc (Nam);
if Etype (Formal) = Any_Type then
Error_Msg_N
("there is no legal actual parameter", Actual);
end if;
if Is_Overloadable (Nam)
and then Present (Alias (Nam))
and then not Comes_From_Source (Nam)
then
Error_Msg_NE
("\\ =='> in call to inherited operation & #!",
Actual, Nam);
elsif Ekind (Nam) = E_Subprogram_Type then
declare
Access_To_Subprogram_Typ :
constant Entity_Id :=
Defining_Identifier
(Associated_Node_For_Itype (Nam));
begin
Error_Msg_NE
("\\ =='> in call to dereference of &#!",
Actual, Access_To_Subprogram_Typ);
end;
else
Error_Msg_NE
("\\ =='> in call to &#!", Actual, Nam);
end if;
end if;
end if;
return;
end if;
else
-- Normalize_Actuals has verified that a default value exists
-- for this formal. Current actual names a subsequent formal.
Next_Formal (Formal);
end if;
end loop;
-- Due to our current model of controlled type expansion we may
-- have resolved a user call to a non-visible controlled primitive
-- since these inherited subprograms may be generated in the current
-- scope. This is a side effect of the need for the expander to be
-- able to resolve internally generated calls.
-- Specifically, the issue appears when predefined controlled
-- operations get called on a type extension whose parent is a
-- private extension completed with a controlled extension - see
-- below:
-- package X is
-- type Par_Typ is tagged private;
-- private
-- type Par_Typ is new Controlled with null record;
-- end;
-- ...
-- procedure Main is
-- type Ext_Typ is new Par_Typ with null record;
-- Obj : Ext_Typ;
-- begin
-- Finalize (Obj); -- Will improperly resolve
-- end;
-- To avoid breaking privacy, Is_Hidden gets set elsewhere on such
-- primitives, but we still need to verify that Nam is indeed a
-- non-visible controlled subprogram. So, we do that here and issue
-- the appropriate error.
if Is_Hidden (Nam)
and then not In_Instance
and then not Comes_From_Source (Nam)
and then Comes_From_Source (N)
-- Verify Nam is a non-visible controlled primitive
and then Chars (Nam) in Name_Adjust
| Name_Finalize
| Name_Initialize
and then Ekind (Nam) = E_Procedure
and then Is_Controlled (Etype (First_Form))
and then No (Next_Formal (First_Form))
and then not Is_Visibly_Controlled (Etype (First_Form))
then
Error_Msg_Node_2 := Etype (First_Form);
Error_Msg_NE ("call to non-visible controlled primitive & on type"
& " &", N, Nam);
end if;
-- On exit, all actuals match
Indicate_Name_And_Type;
end if;
end Analyze_One_Call;
---------------------------
-- Analyze_Operator_Call --
---------------------------
procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id) is
Op_Name : constant Name_Id := Chars (Op_Id);
Act1 : constant Node_Id := First_Actual (N);
Act2 : constant Node_Id := Next_Actual (Act1);
begin
-- Binary operator case
if Present (Act2) then
-- If more than two operands, then not binary operator after all
if Present (Next_Actual (Act2)) then
return;
end if;
-- Otherwise action depends on operator
case Op_Name is
when Name_Op_Add
| Name_Op_Divide
| Name_Op_Expon
| Name_Op_Mod
| Name_Op_Multiply
| Name_Op_Rem
| Name_Op_Subtract
=>
Find_Arithmetic_Types (Act1, Act2, Op_Id, N);
when Name_Op_And
| Name_Op_Or
| Name_Op_Xor
=>
Find_Boolean_Types (Act1, Act2, Op_Id, N);
when Name_Op_Ge
| Name_Op_Gt
| Name_Op_Le
| Name_Op_Lt
=>
Find_Comparison_Types (Act1, Act2, Op_Id, N);
when Name_Op_Eq
| Name_Op_Ne
=>
Find_Equality_Types (Act1, Act2, Op_Id, N);
when Name_Op_Concat =>
Find_Concatenation_Types (Act1, Act2, Op_Id, N);
-- Is this when others, or should it be an abort???
when others =>
null;
end case;
-- Unary operator case
else
case Op_Name is
when Name_Op_Abs
| Name_Op_Add
| Name_Op_Subtract
=>
Find_Unary_Types (Act1, Op_Id, N);
when Name_Op_Not =>
Find_Negation_Types (Act1, Op_Id, N);
-- Is this when others correct, or should it be an abort???
when others =>
null;
end case;
end if;
end Analyze_Operator_Call;
-------------------------------------------
-- Analyze_Overloaded_Selected_Component --
-------------------------------------------
procedure Analyze_Overloaded_Selected_Component (N : Node_Id) is
Nam : constant Node_Id := Prefix (N);
Sel : constant Node_Id := Selector_Name (N);
Comp : Entity_Id;
I : Interp_Index;
It : Interp;
T : Entity_Id;
begin
Set_Etype (Sel, Any_Type);
Get_First_Interp (Nam, I, It);
while Present (It.Typ) loop
if Is_Access_Type (It.Typ) then
T := Designated_Type (It.Typ);
Error_Msg_NW (Warn_On_Dereference, "?d?implicit dereference", N);
else
T := It.Typ;
end if;
-- Locate the component. For a private prefix the selector can denote
-- a discriminant.
if Is_Record_Type (T) or else Is_Private_Type (T) then
-- If the prefix is a class-wide type, the visible components are
-- those of the base type.
if Is_Class_Wide_Type (T) then
T := Etype (T);
end if;
Comp := First_Entity (T);
while Present (Comp) loop
if Chars (Comp) = Chars (Sel)
and then Is_Visible_Component (Comp, Sel)
then
-- AI05-105: if the context is an object renaming with
-- an anonymous access type, the expected type of the
-- object must be anonymous. This is a name resolution rule.
if Nkind (Parent (N)) /= N_Object_Renaming_Declaration
or else No (Access_Definition (Parent (N)))
or else Is_Anonymous_Access_Type (Etype (Comp))
then
Set_Entity (Sel, Comp);
Set_Etype (Sel, Etype (Comp));
Add_One_Interp (N, Etype (Comp), Etype (Comp));
Check_Implicit_Dereference (N, Etype (Comp));
-- This also specifies a candidate to resolve the name.
-- Further overloading will be resolved from context.
-- The selector name itself does not carry overloading
-- information.
Set_Etype (Nam, It.Typ);
else
-- Named access type in the context of a renaming
-- declaration with an access definition. Remove
-- inapplicable candidate.
Remove_Interp (I);
end if;
end if;
Next_Entity (Comp);
end loop;
elsif Is_Concurrent_Type (T) then
Comp := First_Entity (T);
while Present (Comp)
and then Comp /= First_Private_Entity (T)
loop
if Chars (Comp) = Chars (Sel) then
if Is_Overloadable (Comp) then
Add_One_Interp (Sel, Comp, Etype (Comp));
else
Set_Entity_With_Checks (Sel, Comp);
Generate_Reference (Comp, Sel);
end if;
Set_Etype (Sel, Etype (Comp));
Set_Etype (N, Etype (Comp));
Set_Etype (Nam, It.Typ);
end if;
Next_Entity (Comp);
end loop;
Set_Is_Overloaded (N, Is_Overloaded (Sel));
end if;
Get_Next_Interp (I, It);
end loop;
if Etype (N) = Any_Type
and then not Try_Object_Operation (N)
then
Error_Msg_NE ("undefined selector& for overloaded prefix", N, Sel);
Set_Entity (Sel, Any_Id);
Set_Etype (Sel, Any_Type);
end if;
end Analyze_Overloaded_Selected_Component;
----------------------------------
-- Analyze_Qualified_Expression --
----------------------------------
procedure Analyze_Qualified_Expression (N : Node_Id) is
Mark : constant Entity_Id := Subtype_Mark (N);
Expr : constant Node_Id := Expression (N);
I : Interp_Index;
It : Interp;
T : Entity_Id;
begin
Analyze_Expression (Expr);
Set_Etype (N, Any_Type);
Find_Type (Mark);
T := Entity (Mark);
if Nkind (Enclosing_Declaration (N)) in
N_Formal_Type_Declaration |
N_Full_Type_Declaration |
N_Incomplete_Type_Declaration |
N_Protected_Type_Declaration |
N_Private_Extension_Declaration |
N_Private_Type_Declaration |
N_Subtype_Declaration |
N_Task_Type_Declaration
and then T = Defining_Identifier (Enclosing_Declaration (N))
then
Error_Msg_N ("current instance not allowed", Mark);
T := Any_Type;
end if;
Set_Etype (N, T);
if T = Any_Type then
return;
end if;
Check_Fully_Declared (T, N);
-- If expected type is class-wide, check for exact match before
-- expansion, because if the expression is a dispatching call it
-- may be rewritten as explicit dereference with class-wide result.
-- If expression is overloaded, retain only interpretations that
-- will yield exact matches.
if Is_Class_Wide_Type (T) then
if not Is_Overloaded (Expr) then
if Base_Type (Etype (Expr)) /= Base_Type (T)
and then Etype (Expr) /= Raise_Type
then
if Nkind (Expr) = N_Aggregate then
Error_Msg_N ("type of aggregate cannot be class-wide", Expr);
else
Wrong_Type (Expr, T);
end if;
end if;
else
Get_First_Interp (Expr, I, It);
while Present (It.Nam) loop
if Base_Type (It.Typ) /= Base_Type (T) then
Remove_Interp (I);
end if;
Get_Next_Interp (I, It);
end loop;
end if;
end if;
Set_Etype (N, T);
end Analyze_Qualified_Expression;
-----------------------------------
-- Analyze_Quantified_Expression --
-----------------------------------
procedure Analyze_Quantified_Expression (N : Node_Id) is
function Is_Empty_Range (Typ : Entity_Id) return Boolean;
-- If the iterator is part of a quantified expression, and the range is
-- known to be statically empty, emit a warning and replace expression
-- with its static value. Returns True if the replacement occurs.
function No_Else_Or_Trivial_True (If_Expr : Node_Id) return Boolean;
-- Determine whether if expression If_Expr lacks an else part or if it
-- has one, it evaluates to True.
--------------------
-- Is_Empty_Range --
--------------------
function Is_Empty_Range (Typ : Entity_Id) return Boolean is
Loc : constant Source_Ptr := Sloc (N);
begin
if Is_Array_Type (Typ)
and then Compile_Time_Known_Bounds (Typ)
and then
(Expr_Value (Type_Low_Bound (Etype (First_Index (Typ)))) >
Expr_Value (Type_High_Bound (Etype (First_Index (Typ)))))
then
Preanalyze_And_Resolve (Condition (N), Standard_Boolean);
if All_Present (N) then
Error_Msg_N
("??quantified expression with ALL "
& "over a null range has value True", N);
Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
else
Error_Msg_N
("??quantified expression with SOME "
& "over a null range has value False", N);
Rewrite (N, New_Occurrence_Of (Standard_False, Loc));
end if;
Analyze (N);
return True;
else
return False;
end if;
end Is_Empty_Range;
-----------------------------
-- No_Else_Or_Trivial_True --
-----------------------------
function No_Else_Or_Trivial_True (If_Expr : Node_Id) return Boolean is
Else_Expr : constant Node_Id :=
Next (Next (First (Expressions (If_Expr))));
begin
return
No (Else_Expr)
or else (Compile_Time_Known_Value (Else_Expr)
and then Is_True (Expr_Value (Else_Expr)));
end No_Else_Or_Trivial_True;
-- Local variables
Cond : constant Node_Id := Condition (N);
Loop_Id : Entity_Id;
QE_Scop : Entity_Id;
-- Start of processing for Analyze_Quantified_Expression
begin
-- Create a scope to emulate the loop-like behavior of the quantified
-- expression. The scope is needed to provide proper visibility of the
-- loop variable.
QE_Scop := New_Internal_Entity (E_Loop, Current_Scope, Sloc (N), 'L');
Set_Etype (QE_Scop, Standard_Void_Type);
Set_Scope (QE_Scop, Current_Scope);
Set_Parent (QE_Scop, N);
Push_Scope (QE_Scop);
-- All constituents are preanalyzed and resolved to avoid untimely
-- generation of various temporaries and types. Full analysis and
-- expansion is carried out when the quantified expression is
-- transformed into an expression with actions.
if Present (Iterator_Specification (N)) then
Preanalyze (Iterator_Specification (N));
-- Do not proceed with the analysis when the range of iteration is
-- empty. The appropriate error is issued by Is_Empty_Range.
if Is_Entity_Name (Name (Iterator_Specification (N)))
and then Is_Empty_Range (Etype (Name (Iterator_Specification (N))))
then
return;
end if;
else pragma Assert (Present (Loop_Parameter_Specification (N)));
declare
Loop_Par : constant Node_Id := Loop_Parameter_Specification (N);
begin
Preanalyze (Loop_Par);
if Nkind (Discrete_Subtype_Definition (Loop_Par)) = N_Function_Call
and then Parent (Loop_Par) /= N
then
-- The parser cannot distinguish between a loop specification
-- and an iterator specification. If after preanalysis the
-- proper form has been recognized, rewrite the expression to
-- reflect the right kind. This is needed for proper ASIS
-- navigation. If expansion is enabled, the transformation is
-- performed when the expression is rewritten as a loop.
-- Is this still needed???
Set_Iterator_Specification (N,
New_Copy_Tree (Iterator_Specification (Parent (Loop_Par))));
Set_Defining_Identifier (Iterator_Specification (N),
Relocate_Node (Defining_Identifier (Loop_Par)));
Set_Name (Iterator_Specification (N),
Relocate_Node (Discrete_Subtype_Definition (Loop_Par)));
Set_Comes_From_Source (Iterator_Specification (N),
Comes_From_Source (Loop_Parameter_Specification (N)));
Set_Loop_Parameter_Specification (N, Empty);
end if;
end;
end if;
Preanalyze_And_Resolve (Cond, Standard_Boolean);
End_Scope;
Set_Etype (N, Standard_Boolean);
-- Verify that the loop variable is used within the condition of the
-- quantified expression.
if Present (Iterator_Specification (N)) then
Loop_Id := Defining_Identifier (Iterator_Specification (N));
else
Loop_Id := Defining_Identifier (Loop_Parameter_Specification (N));
end if;
declare
type Subexpr_Kind is (Full, Conjunct, Disjunct);
procedure Check_Subexpr (Expr : Node_Id; Kind : Subexpr_Kind);
-- Check that the quantified variable appears in every sub-expression
-- of the quantified expression. If Kind is Full, Expr is the full
-- expression. If Kind is Conjunct (resp. Disjunct), Expr is a
-- conjunct (resp. disjunct) of the full expression.
-------------------
-- Check_Subexpr --
-------------------
procedure Check_Subexpr (Expr : Node_Id; Kind : Subexpr_Kind) is
begin
if Nkind (Expr) in N_Op_And | N_And_Then
and then Kind /= Disjunct
then
Check_Subexpr (Left_Opnd (Expr), Conjunct);
Check_Subexpr (Right_Opnd (Expr), Conjunct);
elsif Nkind (Expr) in N_Op_Or | N_Or_Else
and then Kind /= Conjunct
then
Check_Subexpr (Left_Opnd (Expr), Disjunct);
Check_Subexpr (Right_Opnd (Expr), Disjunct);
elsif Kind /= Full
and then not Referenced (Loop_Id, Expr)
then
declare
Sub : constant String :=
(if Kind = Conjunct then "conjunct" else "disjunct");
begin
Error_Msg_NE
("?.t?unused variable & in " & Sub, Expr, Loop_Id);
Error_Msg_NE
("\consider extracting " & Sub & " from quantified "
& "expression", Expr, Loop_Id);
end;
end if;
end Check_Subexpr;
begin
if Warn_On_Suspicious_Contract
and then not Is_Internal_Name (Chars (Loop_Id))
-- Generating C, this check causes spurious warnings on inlined
-- postconditions; we can safely disable it because this check
-- was previously performed when analyzing the internally built
-- postconditions procedure.
and then not (Modify_Tree_For_C and In_Inlined_Body)
then
if not Referenced (Loop_Id, Cond) then
Error_Msg_N ("?.t?unused variable &", Loop_Id);
else
Check_Subexpr (Cond, Kind => Full);
end if;
end if;
end;
-- Diagnose a possible misuse of the SOME existential quantifier. When
-- we have a quantified expression of the form:
-- for some X => (if P then Q [else True])
-- any value for X that makes P False results in the if expression being
-- trivially True, and so also results in the quantified expression
-- being trivially True.
if Warn_On_Suspicious_Contract
and then not All_Present (N)
and then Nkind (Cond) = N_If_Expression
and then No_Else_Or_Trivial_True (Cond)
then
Error_Msg_N ("?.t?suspicious expression", N);
Error_Msg_N ("\\did you mean (for all X ='> (if P then Q))", N);
Error_Msg_N ("\\or (for some X ='> P and then Q) instead'?", N);
end if;
end Analyze_Quantified_Expression;
-------------------
-- Analyze_Range --
-------------------
procedure Analyze_Range (N : Node_Id) is
L : constant Node_Id := Low_Bound (N);
H : constant Node_Id := High_Bound (N);
I1, I2 : Interp_Index;
It1, It2 : Interp;
procedure Check_Common_Type (T1, T2 : Entity_Id);
-- Verify the compatibility of two types, and choose the
-- non universal one if the other is universal.
procedure Check_High_Bound (T : Entity_Id);
-- Test one interpretation of the low bound against all those
-- of the high bound.
procedure Check_Universal_Expression (N : Node_Id);
-- In Ada 83, reject bounds of a universal range that are not literals
-- or entity names.
-----------------------
-- Check_Common_Type --
-----------------------
procedure Check_Common_Type (T1, T2 : Entity_Id) is
begin
if Covers (T1 => T1, T2 => T2)
or else
Covers (T1 => T2, T2 => T1)
then
if Is_Universal_Numeric_Type (T1)
or else T1 = Any_Character
then
Add_One_Interp (N, Base_Type (T2), Base_Type (T2));
elsif T1 = T2 then
Add_One_Interp (N, T1, T1);
else
Add_One_Interp (N, Base_Type (T1), Base_Type (T1));
end if;
end if;
end Check_Common_Type;
----------------------
-- Check_High_Bound --
----------------------
procedure Check_High_Bound (T : Entity_Id) is
begin
if not Is_Overloaded (H) then
Check_Common_Type (T, Etype (H));
else
Get_First_Interp (H, I2, It2);
while Present (It2.Typ) loop
Check_Common_Type (T, It2.Typ);
Get_Next_Interp (I2, It2);
end loop;
end if;
end Check_High_Bound;
--------------------------------
-- Check_Universal_Expression --
--------------------------------
procedure Check_Universal_Expression (N : Node_Id) is
begin
if Etype (N) = Universal_Integer
and then Nkind (N) /= N_Integer_Literal
and then not Is_Entity_Name (N)
and then Nkind (N) /= N_Attribute_Reference
then
Error_Msg_N ("illegal bound in discrete range", N);
end if;
end Check_Universal_Expression;
-- Start of processing for Analyze_Range
begin
Set_Etype (N, Any_Type);
Analyze_Expression (L);
Analyze_Expression (H);
if Etype (L) = Any_Type or else Etype (H) = Any_Type then
return;
else
if not Is_Overloaded (L) then
Check_High_Bound (Etype (L));
else
Get_First_Interp (L, I1, It1);
while Present (It1.Typ) loop
Check_High_Bound (It1.Typ);
Get_Next_Interp (I1, It1);
end loop;
end if;
-- If result is Any_Type, then we did not find a compatible pair
if Etype (N) = Any_Type then
Error_Msg_N ("incompatible types in range", N);
end if;
end if;
if Ada_Version = Ada_83
and then
(Nkind (Parent (N)) = N_Loop_Parameter_Specification
or else Nkind (Parent (N)) = N_Constrained_Array_Definition)
then
Check_Universal_Expression (L);
Check_Universal_Expression (H);
end if;
Check_Function_Writable_Actuals (N);
end Analyze_Range;
-----------------------
-- Analyze_Reference --
-----------------------
procedure Analyze_Reference (N : Node_Id) is
P : constant Node_Id := Prefix (N);
E : Entity_Id;
T : Entity_Id;
Acc_Type : Entity_Id;
begin
Analyze (P);
-- An interesting error check, if we take the 'Ref of an object for
-- which a pragma Atomic or Volatile has been given, and the type of the
-- object is not Atomic or Volatile, then we are in trouble. The problem
-- is that no trace of the atomic/volatile status will remain for the
-- backend to respect when it deals with the resulting pointer, since
-- the pointer type will not be marked atomic (it is a pointer to the
-- base type of the object).
-- It is not clear if that can ever occur, but in case it does, we will
-- generate an error message. Not clear if this message can ever be
-- generated, and pretty clear that it represents a bug if it is, still
-- seems worth checking, except in CodePeer mode where we do not really
-- care and don't want to bother the user.
T := Etype (P);
if Is_Entity_Name (P)
and then Is_Object_Reference (P)
and then not CodePeer_Mode
then
E := Entity (P);
T := Etype (P);
if (Has_Atomic_Components (E)
and then not Has_Atomic_Components (T))
or else
(Has_Volatile_Components (E)
and then not Has_Volatile_Components (T))
or else (Is_Atomic (E) and then not Is_Atomic (T))
or else (Is_Volatile (E) and then not Is_Volatile (T))
then
Error_Msg_N ("cannot take reference to Atomic/Volatile object", N);
end if;
end if;
-- Carry on with normal processing
Acc_Type := Create_Itype (E_Allocator_Type, N);
Set_Etype (Acc_Type, Acc_Type);
Set_Directly_Designated_Type (Acc_Type, Etype (P));
Set_Etype (N, Acc_Type);
end Analyze_Reference;
--------------------------------
-- Analyze_Selected_Component --
--------------------------------
-- Prefix is a record type or a task or protected type. In the latter case,
-- the selector must denote a visible entry.
procedure Analyze_Selected_Component (N : Node_Id) is
Name : constant Node_Id := Prefix (N);
Sel : constant Node_Id := Selector_Name (N);
Act_Decl : Node_Id;
Comp : Entity_Id;
Has_Candidate : Boolean := False;
Hidden_Comp : Entity_Id;
In_Scope : Boolean;
Is_Private_Op : Boolean;
Parent_N : Node_Id;
Prefix_Type : Entity_Id;
Type_To_Use : Entity_Id;
-- In most cases this is the Prefix_Type, but if the Prefix_Type is
-- a class-wide type, we use its root type, whose components are
-- present in the class-wide type.
Is_Single_Concurrent_Object : Boolean;
-- Set True if the prefix is a single task or a single protected object
procedure Find_Component_In_Instance (Rec : Entity_Id);
-- In an instance, a component of a private extension may not be visible
-- while it was visible in the generic. Search candidate scope for a
-- component with the proper identifier. This is only done if all other
-- searches have failed. If a match is found, the Etype of both N and
-- Sel are set from this component, and the entity of Sel is set to
-- reference this component. If no match is found, Entity (Sel) remains
-- unset. For a derived type that is an actual of the instance, the
-- desired component may be found in any ancestor.
function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean;
-- It is known that the parent of N denotes a subprogram call. Comp
-- is an overloadable component of the concurrent type of the prefix.
-- Determine whether all formals of the parent of N and Comp are mode
-- conformant. If the parent node is not analyzed yet it may be an
-- indexed component rather than a function call.
function Has_Dereference (Nod : Node_Id) return Boolean;
-- Check whether prefix includes a dereference, explicit or implicit,
-- at any recursive level.
function Try_By_Protected_Procedure_Prefixed_View return Boolean;
-- Return True if N is an access attribute whose prefix is a prefixed
-- class-wide (synchronized or protected) interface view for which some
-- interpretation is a procedure with synchronization kind By_Protected
-- _Procedure, and collect all its interpretations (since it may be an
-- overloaded interface primitive); otherwise return False.
--------------------------------
-- Find_Component_In_Instance --
--------------------------------
procedure Find_Component_In_Instance (Rec : Entity_Id) is
Comp : Entity_Id;
Typ : Entity_Id;
begin
Typ := Rec;
while Present (Typ) loop
Comp := First_Component (Typ);
while Present (Comp) loop
if Chars (Comp) = Chars (Sel) then
Set_Entity_With_Checks (Sel, Comp);
Set_Etype (Sel, Etype (Comp));
Set_Etype (N, Etype (Comp));
return;
end if;
Next_Component (Comp);
end loop;
-- If not found, the component may be declared in the parent
-- type or its full view, if any.
if Is_Derived_Type (Typ) then
Typ := Etype (Typ);
if Is_Private_Type (Typ) then
Typ := Full_View (Typ);
end if;
else
return;
end if;
end loop;
-- If we fall through, no match, so no changes made
return;
end Find_Component_In_Instance;
------------------------------
-- Has_Mode_Conformant_Spec --
------------------------------
function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean is
Comp_Param : Entity_Id;
Param : Node_Id;
Param_Typ : Entity_Id;
begin
Comp_Param := First_Formal (Comp);
if Nkind (Parent (N)) = N_Indexed_Component then
Param := First (Expressions (Parent (N)));
else
Param := First (Parameter_Associations (Parent (N)));
end if;
while Present (Comp_Param)
and then Present (Param)
loop
Param_Typ := Find_Parameter_Type (Param);
if Present (Param_Typ)
and then
not Conforming_Types
(Etype (Comp_Param), Param_Typ, Mode_Conformant)
then
return False;
end if;
Next_Formal (Comp_Param);
Next (Param);
end loop;
-- One of the specs has additional formals; there is no match, unless
-- this may be an indexing of a parameterless call.
-- Note that when expansion is disabled, the corresponding record
-- type of synchronized types is not constructed, so that there is
-- no point is attempting an interpretation as a prefixed call, as
-- this is bound to fail because the primitive operations will not
-- be properly located.
if Present (Comp_Param) or else Present (Param) then
if Needs_No_Actuals (Comp)
and then Is_Array_Type (Etype (Comp))
and then not Expander_Active
then
return True;
else
return False;
end if;
end if;
return True;
end Has_Mode_Conformant_Spec;
---------------------
-- Has_Dereference --
---------------------
function Has_Dereference (Nod : Node_Id) return Boolean is
begin
if Nkind (Nod) = N_Explicit_Dereference then
return True;
elsif Is_Access_Type (Etype (Nod)) then
return True;
elsif Nkind (Nod) in N_Indexed_Component | N_Selected_Component then
return Has_Dereference (Prefix (Nod));
else
return False;
end if;
end Has_Dereference;
----------------------------------------------
-- Try_By_Protected_Procedure_Prefixed_View --
----------------------------------------------
function Try_By_Protected_Procedure_Prefixed_View return Boolean is
Candidate : Node_Id := Empty;
Elmt : Elmt_Id;
Prim : Node_Id;
begin
if Nkind (Parent (N)) = N_Attribute_Reference
and then Attribute_Name (Parent (N)) in
Name_Access
| Name_Unchecked_Access
| Name_Unrestricted_Access
and then Is_Class_Wide_Type (Prefix_Type)
and then (Is_Synchronized_Interface (Prefix_Type)
or else Is_Protected_Interface (Prefix_Type))
then
-- If we have not found yet any interpretation then mark this
-- one as the first interpretation (cf. Add_One_Interp).
if No (Etype (Sel)) then
Set_Etype (Sel, Any_Type);
end if;
Elmt := First_Elmt (Primitive_Operations (Etype (Prefix_Type)));
while Present (Elmt) loop
Prim := Node (Elmt);
if Chars (Prim) = Chars (Sel)
and then Is_By_Protected_Procedure (Prim)
then
Candidate := New_Copy (Prim);
-- Skip the controlling formal; required to check type
-- conformance of the target access to protected type
-- (see Conforming_Types).
Set_First_Entity (Candidate,
Next_Entity (First_Entity (Prim)));
Add_One_Interp (Sel, Candidate, Etype (Prim));
Set_Etype (N, Etype (Prim));
end if;
Next_Elmt (Elmt);
end loop;
end if;
-- Propagate overloaded attribute
if Present (Candidate) and then Is_Overloaded (Sel) then
Set_Is_Overloaded (N);
end if;
return Present (Candidate);
end Try_By_Protected_Procedure_Prefixed_View;
-- Start of processing for Analyze_Selected_Component
begin
Set_Etype (N, Any_Type);
if Is_Overloaded (Name) then
Analyze_Overloaded_Selected_Component (N);
return;
elsif Etype (Name) = Any_Type then
Set_Entity (Sel, Any_Id);
Set_Etype (Sel, Any_Type);
return;
else
Prefix_Type := Etype (Name);
end if;
if Is_Access_Type (Prefix_Type) then
-- A RACW object can never be used as prefix of a selected component
-- since that means it is dereferenced without being a controlling
-- operand of a dispatching operation (RM E.2.2(16/1)). Before
-- reporting an error, we must check whether this is actually a
-- dispatching call in prefix form.
if Is_Remote_Access_To_Class_Wide_Type (Prefix_Type)
and then Comes_From_Source (N)
then
if Try_Object_Operation (N) then
return;
else
Error_Msg_N
("invalid dereference of a remote access-to-class-wide value",
N);
end if;
-- Normal case of selected component applied to access type
else
Error_Msg_NW (Warn_On_Dereference, "?d?implicit dereference", N);
Prefix_Type := Implicitly_Designated_Type (Prefix_Type);
end if;
-- If we have an explicit dereference of a remote access-to-class-wide
-- value, then issue an error (see RM-E.2.2(16/1)). However we first
-- have to check for the case of a prefix that is a controlling operand
-- of a prefixed dispatching call, as the dereference is legal in that
-- case. Normally this condition is checked in Validate_Remote_Access_
-- To_Class_Wide_Type, but we have to defer the checking for selected
-- component prefixes because of the prefixed dispatching call case.
-- Note that implicit dereferences are checked for this just above.
elsif Nkind (Name) = N_Explicit_Dereference
and then Is_Remote_Access_To_Class_Wide_Type (Etype (Prefix (Name)))
and then Comes_From_Source (N)
then
if Try_Object_Operation (N) then
return;
else
Error_Msg_N
("invalid dereference of a remote access-to-class-wide value",
N);
end if;
end if;
-- (Ada 2005): if the prefix is the limited view of a type, and
-- the context already includes the full view, use the full view
-- in what follows, either to retrieve a component of to find
-- a primitive operation. If the prefix is an explicit dereference,
-- set the type of the prefix to reflect this transformation.
-- If the nonlimited view is itself an incomplete type, get the
-- full view if available.
if From_Limited_With (Prefix_Type)
and then Has_Non_Limited_View (Prefix_Type)
then
Prefix_Type := Get_Full_View (Non_Limited_View (Prefix_Type));
if Nkind (N) = N_Explicit_Dereference then
Set_Etype (Prefix (N), Prefix_Type);
end if;
end if;
if Ekind (Prefix_Type) = E_Private_Subtype then
Prefix_Type := Base_Type (Prefix_Type);
end if;
Type_To_Use := Prefix_Type;
-- For class-wide types, use the entity list of the root type. This
-- indirection is specially important for private extensions because
-- only the root type get switched (not the class-wide type).
if Is_Class_Wide_Type (Prefix_Type) then
Type_To_Use := Root_Type (Prefix_Type);
end if;
-- If the prefix is a single concurrent object, use its name in error
-- messages, rather than that of its anonymous type.
Is_Single_Concurrent_Object :=
Is_Concurrent_Type (Prefix_Type)
and then Is_Internal_Name (Chars (Prefix_Type))
and then not Is_Derived_Type (Prefix_Type)
and then Is_Entity_Name (Name);
Comp := First_Entity (Type_To_Use);
-- If the selector has an original discriminant, the node appears in
-- an instance. Replace the discriminant with the corresponding one
-- in the current discriminated type. For nested generics, this must
-- be done transitively, so note the new original discriminant.
if Nkind (Sel) = N_Identifier
and then In_Instance
and then Present (Original_Discriminant (Sel))
then
Comp := Find_Corresponding_Discriminant (Sel, Prefix_Type);
-- Mark entity before rewriting, for completeness and because
-- subsequent semantic checks might examine the original node.
Set_Entity (Sel, Comp);
Rewrite (Selector_Name (N), New_Occurrence_Of (Comp, Sloc (N)));
Set_Original_Discriminant (Selector_Name (N), Comp);
Set_Etype (N, Etype (Comp));
Check_Implicit_Dereference (N, Etype (Comp));
elsif Is_Record_Type (Prefix_Type) then
-- Find component with given name. In an instance, if the node is
-- known as a prefixed call, do not examine components whose
-- visibility may be accidental.
while Present (Comp) and then not Is_Prefixed_Call (N) loop
if Chars (Comp) = Chars (Sel)
and then Is_Visible_Component (Comp, N)
then
Set_Entity_With_Checks (Sel, Comp);
Set_Etype (Sel, Etype (Comp));
if Ekind (Comp) = E_Discriminant then
if Is_Unchecked_Union (Base_Type (Prefix_Type)) then
Error_Msg_N
("cannot reference discriminant of unchecked union",
Sel);
end if;
if Is_Generic_Type (Prefix_Type)
or else
Is_Generic_Type (Root_Type (Prefix_Type))
then
Set_Original_Discriminant (Sel, Comp);
end if;
end if;
-- Resolve the prefix early otherwise it is not possible to
-- build the actual subtype of the component: it may need
-- to duplicate this prefix and duplication is only allowed
-- on fully resolved expressions.
Resolve (Name);
-- Ada 2005 (AI-50217): Check wrong use of incomplete types or
-- subtypes in a package specification.
-- Example:
-- limited with Pkg;
-- package Pkg is
-- type Acc_Inc is access Pkg.T;
-- X : Acc_Inc;
-- N : Natural := X.all.Comp; -- ERROR, limited view
-- end Pkg; -- Comp is not visible
if Nkind (Name) = N_Explicit_Dereference
and then From_Limited_With (Etype (Prefix (Name)))
and then not Is_Potentially_Use_Visible (Etype (Name))
and then Nkind (Parent (Cunit_Entity (Current_Sem_Unit))) =
N_Package_Specification
then
Error_Msg_NE
("premature usage of incomplete}", Prefix (Name),
Etype (Prefix (Name)));
end if;
-- We never need an actual subtype for the case of a selection
-- for a indexed component of a non-packed array, since in
-- this case gigi generates all the checks and can find the
-- necessary bounds information.
-- We also do not need an actual subtype for the case of a
-- first, last, length, or range attribute applied to a
-- non-packed array, since gigi can again get the bounds in
-- these cases (gigi cannot handle the packed case, since it
-- has the bounds of the packed array type, not the original
-- bounds of the type). However, if the prefix is itself a
-- selected component, as in a.b.c (i), gigi may regard a.b.c
-- as a dynamic-sized temporary, so we do generate an actual
-- subtype for this case.
Parent_N := Parent (N);
if not Is_Packed (Etype (Comp))
and then
((Nkind (Parent_N) = N_Indexed_Component
and then Nkind (Name) /= N_Selected_Component)
or else
(Nkind (Parent_N) = N_Attribute_Reference
and then
Attribute_Name (Parent_N) in Name_First
| Name_Last
| Name_Length
| Name_Range))
then
Set_Etype (N, Etype (Comp));
-- If full analysis is not enabled, we do not generate an
-- actual subtype, because in the absence of expansion
-- reference to a formal of a protected type, for example,
-- will not be properly transformed, and will lead to
-- out-of-scope references in gigi.
-- In all other cases, we currently build an actual subtype.
-- It seems likely that many of these cases can be avoided,
-- but right now, the front end makes direct references to the
-- bounds (e.g. in generating a length check), and if we do
-- not make an actual subtype, we end up getting a direct
-- reference to a discriminant, which will not do.
elsif Full_Analysis then
Act_Decl :=
Build_Actual_Subtype_Of_Component (Etype (Comp), N);
Insert_Action (N, Act_Decl);
if No (Act_Decl) then
Set_Etype (N, Etype (Comp));
else
-- If discriminants were present in the component
-- declaration, they have been replaced by the
-- actual values in the prefix object.
declare
Subt : constant Entity_Id :=
Defining_Identifier (Act_Decl);
begin
Set_Etype (Subt, Base_Type (Etype (Comp)));
Set_Etype (N, Subt);
end;
end if;
-- If Full_Analysis not enabled, just set the Etype
else
Set_Etype (N, Etype (Comp));
end if;
Check_Implicit_Dereference (N, Etype (N));
return;
end if;
-- If the prefix is a private extension, check only the visible
-- components of the partial view. This must include the tag,
-- which can appear in expanded code in a tag check.
if Ekind (Type_To_Use) = E_Record_Type_With_Private
and then Chars (Selector_Name (N)) /= Name_uTag
then
exit when Comp = Last_Entity (Type_To_Use);
end if;
Next_Entity (Comp);
end loop;
-- Ada 2005 (AI-252): The selected component can be interpreted as
-- a prefixed view of a subprogram. Depending on the context, this is
-- either a name that can appear in a renaming declaration, or part
-- of an enclosing call given in prefix form.
-- Ada 2005 (AI05-0030): In the case of dispatching requeue, the
-- selected component should resolve to a name.
-- Extension feature: Also support calls with prefixed views for
-- untagged record types.
if Ada_Version >= Ada_2005
and then (Is_Tagged_Type (Prefix_Type) or else Extensions_Allowed)
and then not Is_Concurrent_Type (Prefix_Type)
then
if Nkind (Parent (N)) = N_Generic_Association
or else Nkind (Parent (N)) = N_Requeue_Statement
or else Nkind (Parent (N)) = N_Subprogram_Renaming_Declaration
then
if Find_Primitive_Operation (N) then
return;
end if;
elsif Try_By_Protected_Procedure_Prefixed_View then
return;
elsif Try_Object_Operation (N) then
return;
end if;
-- If the transformation fails, it will be necessary to redo the
-- analysis with all errors enabled, to indicate candidate
-- interpretations and reasons for each failure ???
end if;
elsif Is_Private_Type (Prefix_Type) then
-- Allow access only to discriminants of the type. If the type has
-- no full view, gigi uses the parent type for the components, so we
-- do the same here.
if No (Full_View (Prefix_Type)) then
Type_To_Use := Root_Type (Base_Type (Prefix_Type));
Comp := First_Entity (Type_To_Use);
end if;
while Present (Comp) loop
if Chars (Comp) = Chars (Sel) then
if Ekind (Comp) = E_Discriminant then
Set_Entity_With_Checks (Sel, Comp);
Generate_Reference (Comp, Sel);
Set_Etype (Sel, Etype (Comp));
Set_Etype (N, Etype (Comp));
Check_Implicit_Dereference (N, Etype (N));
if Is_Generic_Type (Prefix_Type)
or else Is_Generic_Type (Root_Type (Prefix_Type))
then
Set_Original_Discriminant (Sel, Comp);
end if;
-- Before declaring an error, check whether this is tagged
-- private type and a call to a primitive operation.
elsif Ada_Version >= Ada_2005
and then Is_Tagged_Type (Prefix_Type)
and then Try_Object_Operation (N)
then
return;
else
Error_Msg_Node_2 := First_Subtype (Prefix_Type);
Error_Msg_NE ("invisible selector& for }", N, Sel);
Set_Entity (Sel, Any_Id);
Set_Etype (N, Any_Type);
end if;
return;
end if;
Next_Entity (Comp);
end loop;
-- Extension feature: Also support calls with prefixed views for
-- untagged private types.
if Extensions_Allowed then
if Try_Object_Operation (N) then
return;
end if;
end if;
elsif Is_Concurrent_Type (Prefix_Type) then
-- Find visible operation with given name. For a protected type,
-- the possible candidates are discriminants, entries or protected
-- subprograms. For a task type, the set can only include entries or
-- discriminants if the task type is not an enclosing scope. If it
-- is an enclosing scope (e.g. in an inner task) then all entities
-- are visible, but the prefix must denote the enclosing scope, i.e.
-- can only be a direct name or an expanded name.
Set_Etype (Sel, Any_Type);
Hidden_Comp := Empty;
In_Scope := In_Open_Scopes (Prefix_Type);
Is_Private_Op := False;
while Present (Comp) loop
-- Do not examine private operations of the type if not within
-- its scope.
if Chars (Comp) = Chars (Sel) then
if Is_Overloadable (Comp)
and then (In_Scope
or else Comp /= First_Private_Entity (Type_To_Use))
then
Add_One_Interp (Sel, Comp, Etype (Comp));
if Comp = First_Private_Entity (Type_To_Use) then
Is_Private_Op := True;
end if;
-- If the prefix is tagged, the correct interpretation may
-- lie in the primitive or class-wide operations of the
-- type. Perform a simple conformance check to determine
-- whether Try_Object_Operation should be invoked even if
-- a visible entity is found.
if Is_Tagged_Type (Prefix_Type)
and then Nkind (Parent (N)) in N_Function_Call
| N_Indexed_Component
| N_Procedure_Call_Statement
and then Has_Mode_Conformant_Spec (Comp)
then
Has_Candidate := True;
end if;
-- Note: a selected component may not denote a component of a
-- protected type (4.1.3(7)).
elsif Ekind (Comp) in E_Discriminant | E_Entry_Family
or else (In_Scope
and then not Is_Protected_Type (Prefix_Type)
and then Is_Entity_Name (Name))
then
Set_Entity_With_Checks (Sel, Comp);
Generate_Reference (Comp, Sel);
-- The selector is not overloadable, so we have a candidate
-- interpretation.
Has_Candidate := True;
else
if Ekind (Comp) = E_Component then
Hidden_Comp := Comp;
end if;
goto Next_Comp;
end if;
Set_Etype (Sel, Etype (Comp));
Set_Etype (N, Etype (Comp));
if Ekind (Comp) = E_Discriminant then
Set_Original_Discriminant (Sel, Comp);
end if;
end if;
<<Next_Comp>>
if Comp = First_Private_Entity (Type_To_Use) then
if Etype (Sel) /= Any_Type then
-- If the first private entity's name matches, then treat
-- it as a private op: needed for the error check for
-- illegal selection of private entities further below.
if Chars (Comp) = Chars (Sel) then
Is_Private_Op := True;
end if;
-- We have a candidate, so exit the loop
exit;
else
-- Indicate that subsequent operations are private,
-- for better error reporting.
Is_Private_Op := True;
end if;
end if;
-- Do not examine private operations if not within scope of
-- the synchronized type.
exit when not In_Scope
and then
Comp = First_Private_Entity (Base_Type (Prefix_Type));
Next_Entity (Comp);
end loop;
-- If the scope is a current instance, the prefix cannot be an
-- expression of the same type, unless the selector designates a
-- public operation (otherwise that would represent an attempt to
-- reach an internal entity of another synchronized object).
-- This is legal if prefix is an access to such type and there is
-- a dereference, or is a component with a dereferenced prefix.
-- It is also legal if the prefix is a component of a task type,
-- and the selector is one of the task operations.
if In_Scope
and then not Is_Entity_Name (Name)
and then not Has_Dereference (Name)
then
if Is_Task_Type (Prefix_Type)
and then Present (Entity (Sel))
and then Is_Entry (Entity (Sel))
then
null;
elsif Is_Protected_Type (Prefix_Type)
and then Is_Overloadable (Entity (Sel))
and then not Is_Private_Op
then
null;
else
Error_Msg_NE
("invalid reference to internal operation of some object of "
& "type &", N, Type_To_Use);
Set_Entity (Sel, Any_Id);
Set_Etype (Sel, Any_Type);
return;
end if;
-- Another special case: the prefix may denote an object of the type
-- (but not a type) in which case this is an external call and the
-- operation must be public.
elsif In_Scope
and then Is_Object_Reference (Original_Node (Prefix (N)))
and then Comes_From_Source (N)
and then Is_Private_Op
then
if Present (Hidden_Comp) then
Error_Msg_NE
("invalid reference to private component of object of type "
& "&", N, Type_To_Use);
else
Error_Msg_NE
("invalid reference to private operation of some object of "
& "type &", N, Type_To_Use);
end if;
Set_Entity (Sel, Any_Id);
Set_Etype (Sel, Any_Type);
return;
end if;
-- If there is no visible entity with the given name or none of the
-- visible entities are plausible interpretations, check whether
-- there is some other primitive operation with that name.
if Ada_Version >= Ada_2005 and then Is_Tagged_Type (Prefix_Type) then
if (Etype (N) = Any_Type
or else not Has_Candidate)
and then Try_Object_Operation (N)
then
return;
-- If the context is not syntactically a procedure call, it
-- may be a call to a primitive function declared outside of
-- the synchronized type.
-- If the context is a procedure call, there might still be
-- an overloading between an entry and a primitive procedure
-- declared outside of the synchronized type, called in prefix
-- notation. This is harder to disambiguate because in one case
-- the controlling formal is implicit ???
elsif Nkind (Parent (N)) /= N_Procedure_Call_Statement
and then Nkind (Parent (N)) /= N_Indexed_Component
and then Try_Object_Operation (N)
then
return;
end if;
-- Ada 2012 (AI05-0090-1): If we found a candidate of a call to an
-- entry or procedure of a tagged concurrent type we must check
-- if there are class-wide subprograms covering the primitive. If
-- true then Try_Object_Operation reports the error.
if Has_Candidate
and then Is_Concurrent_Type (Prefix_Type)
and then Nkind (Parent (N)) = N_Procedure_Call_Statement
then
-- Duplicate the call. This is required to avoid problems with
-- the tree transformations performed by Try_Object_Operation.
-- Set properly the parent of the copied call, because it is
-- about to be reanalyzed.
declare
Par : constant Node_Id := New_Copy_Tree (Parent (N));
begin
Set_Parent (Par, Parent (Parent (N)));
if Try_Object_Operation
(Sinfo.Nodes.Name (Par), CW_Test_Only => True)
then
return;
end if;
end;
end if;
end if;
if Etype (N) = Any_Type and then Is_Protected_Type (Prefix_Type) then
-- Case of a prefix of a protected type: selector might denote
-- an invisible private component.
Comp := First_Private_Entity (Base_Type (Prefix_Type));
while Present (Comp) and then Chars (Comp) /= Chars (Sel) loop
Next_Entity (Comp);
end loop;
if Present (Comp) then
if Is_Single_Concurrent_Object then
Error_Msg_Node_2 := Entity (Name);
Error_Msg_NE ("invisible selector& for &", N, Sel);
else
Error_Msg_Node_2 := First_Subtype (Prefix_Type);
Error_Msg_NE ("invisible selector& for }", N, Sel);
end if;
return;
end if;
end if;
Set_Is_Overloaded (N, Is_Overloaded (Sel));
-- Extension feature: Also support calls with prefixed views for
-- untagged types.
elsif Extensions_Allowed
and then Try_Object_Operation (N)
then
return;
else
-- Invalid prefix
Error_Msg_NE ("invalid prefix in selected component&", N, Sel);
end if;
-- If N still has no type, the component is not defined in the prefix
if Etype (N) = Any_Type then
if Is_Single_Concurrent_Object then
Error_Msg_Node_2 := Entity (Name);
Error_Msg_NE ("no selector& for&", N, Sel);
Check_Misspelled_Selector (Type_To_Use, Sel);
-- If this is a derived formal type, the parent may have different
-- visibility at this point. Try for an inherited component before
-- reporting an error.
elsif Is_Generic_Type (Prefix_Type)
and then Ekind (Prefix_Type) = E_Record_Type_With_Private
and then Prefix_Type /= Etype (Prefix_Type)
and then Is_Record_Type (Etype (Prefix_Type))
then
Set_Etype (Prefix (N), Etype (Prefix_Type));
Analyze_Selected_Component (N);
return;
-- Similarly, if this is the actual for a formal derived type, or
-- a derived type thereof, the component inherited from the generic
-- parent may not be visible in the actual, but the selected
-- component is legal. Climb up the derivation chain of the generic
-- parent type until we find the proper ancestor type.
elsif In_Instance and then Is_Tagged_Type (Prefix_Type) then
declare
Par : Entity_Id := Prefix_Type;
begin
-- Climb up derivation chain to generic actual subtype
while not Is_Generic_Actual_Type (Par) loop
if Ekind (Par) = E_Record_Type then
Par := Parent_Subtype (Par);
exit when No (Par);
else
exit when Par = Etype (Par);
Par := Etype (Par);
end if;
end loop;
if Present (Par) and then Is_Generic_Actual_Type (Par) then
-- Now look for component in ancestor types
Par := Generic_Parent_Type (Declaration_Node (Par));
loop
Find_Component_In_Instance (Par);
exit when Present (Entity (Sel))
or else Par = Etype (Par);
Par := Etype (Par);
end loop;
-- Another special case: the type is an extension of a private
-- type T, either is an actual in an instance or is immediately
-- visible, and we are in the body of the instance, which means
-- the generic body had a full view of the type declaration for
-- T or some ancestor that defines the component in question.
-- This happens because Is_Visible_Component returned False on
-- this component, as T or the ancestor is still private since
-- the Has_Private_View mechanism is bypassed because T or the
-- ancestor is not directly referenced in the generic body.
elsif Is_Derived_Type (Type_To_Use)
and then (Used_As_Generic_Actual (Type_To_Use)
or else Is_Immediately_Visible (Type_To_Use))
and then In_Instance_Body
then
Find_Component_In_Instance (Parent_Subtype (Type_To_Use));
end if;
end;
-- The search above must have eventually succeeded, since the
-- selected component was legal in the generic.
if No (Entity (Sel)) then
raise Program_Error;
end if;
return;
-- Component not found, specialize error message when appropriate
else
if Ekind (Prefix_Type) = E_Record_Subtype then
-- Check whether this is a component of the base type which
-- is absent from a statically constrained subtype. This will
-- raise constraint error at run time, but is not a compile-
-- time error. When the selector is illegal for base type as
-- well fall through and generate a compilation error anyway.
Comp := First_Component (Base_Type (Prefix_Type));
while Present (Comp) loop
if Chars (Comp) = Chars (Sel)
and then Is_Visible_Component (Comp, Sel)
then
Set_Entity_With_Checks (Sel, Comp);
Generate_Reference (Comp, Sel);
Set_Etype (Sel, Etype (Comp));
Set_Etype (N, Etype (Comp));
-- Emit appropriate message. The node will be replaced
-- by an appropriate raise statement.
-- Note that in SPARK mode, as with all calls to apply a
-- compile time constraint error, this will be made into
-- an error to simplify the processing of the formal
-- verification backend.
Apply_Compile_Time_Constraint_Error
(N, "component not present in }??",
CE_Discriminant_Check_Failed,
Ent => Prefix_Type,
Emit_Message =>
SPARK_Mode = On or not In_Instance_Not_Visible);
return;
end if;
Next_Component (Comp);
end loop;
end if;
Error_Msg_Node_2 := First_Subtype (Prefix_Type);
Error_Msg_NE ("no selector& for}", N, Sel);
-- Add information in the case of an incomplete prefix
if Is_Incomplete_Type (Type_To_Use) then
declare
Inc : constant Entity_Id := First_Subtype (Type_To_Use);
begin
if From_Limited_With (Scope (Type_To_Use)) then
Error_Msg_NE
("\limited view of& has no components", N, Inc);
else
Error_Msg_NE
("\premature usage of incomplete type&", N, Inc);
if Nkind (Parent (Inc)) =
N_Incomplete_Type_Declaration
then
-- Record location of premature use in entity so that
-- a continuation message is generated when the
-- completion is seen.
Set_Premature_Use (Parent (Inc), N);
end if;
end if;
end;
end if;
Check_Misspelled_Selector (Type_To_Use, Sel);
end if;
Set_Entity (Sel, Any_Id);
Set_Etype (Sel, Any_Type);
end if;
end Analyze_Selected_Component;
---------------------------
-- Analyze_Short_Circuit --
---------------------------
procedure Analyze_Short_Circuit (N : Node_Id) is
L : constant Node_Id := Left_Opnd (N);
R : constant Node_Id := Right_Opnd (N);
Ind : Interp_Index;
It : Interp;
begin
Analyze_Expression (L);
Analyze_Expression (R);
Set_Etype (N, Any_Type);
if not Is_Overloaded (L) then
if Root_Type (Etype (L)) = Standard_Boolean
and then Has_Compatible_Type (R, Etype (L))
then
Add_One_Interp (N, Etype (L), Etype (L));
end if;
else
Get_First_Interp (L, Ind, It);
while Present (It.Typ) loop
if Root_Type (It.Typ) = Standard_Boolean
and then Has_Compatible_Type (R, It.Typ)
then
Add_One_Interp (N, It.Typ, It.Typ);
end if;
Get_Next_Interp (Ind, It);
end loop;
end if;
-- Here we have failed to find an interpretation. Clearly we know that
-- it is not the case that both operands can have an interpretation of
-- Boolean, but this is by far the most likely intended interpretation.
-- So we simply resolve both operands as Booleans, and at least one of
-- these resolutions will generate an error message, and we do not need
-- to give another error message on the short circuit operation itself.
if Etype (N) = Any_Type then
Resolve (L, Standard_Boolean);
Resolve (R, Standard_Boolean);
Set_Etype (N, Standard_Boolean);
end if;
end Analyze_Short_Circuit;
-------------------
-- Analyze_Slice --
-------------------
procedure Analyze_Slice (N : Node_Id) is
D : constant Node_Id := Discrete_Range (N);
P : constant Node_Id := Prefix (N);
Array_Type : Entity_Id;
Index_Type : Entity_Id;
procedure Analyze_Overloaded_Slice;
-- If the prefix is overloaded, select those interpretations that
-- yield a one-dimensional array type.
------------------------------
-- Analyze_Overloaded_Slice --
------------------------------
procedure Analyze_Overloaded_Slice is
I : Interp_Index;
It : Interp;
Typ : Entity_Id;
begin
Set_Etype (N, Any_Type);
Get_First_Interp (P, I, It);
while Present (It.Nam) loop
Typ := It.Typ;
if Is_Access_Type (Typ) then
Typ := Designated_Type (Typ);
Error_Msg_NW
(Warn_On_Dereference, "?d?implicit dereference", N);
end if;
if Is_Array_Type (Typ)
and then Number_Dimensions (Typ) = 1
and then Has_Compatible_Type (D, Etype (First_Index (Typ)))
then
Add_One_Interp (N, Typ, Typ);
end if;
Get_Next_Interp (I, It);
end loop;
if Etype (N) = Any_Type then
Error_Msg_N ("expect array type in prefix of slice", N);
end if;
end Analyze_Overloaded_Slice;
-- Start of processing for Analyze_Slice
begin
Analyze (P);
Analyze (D);
if Is_Overloaded (P) then
Analyze_Overloaded_Slice;
else
Array_Type := Etype (P);
Set_Etype (N, Any_Type);
if Is_Access_Type (Array_Type) then
Error_Msg_NW (Warn_On_Dereference, "?d?implicit dereference", N);
Array_Type := Implicitly_Designated_Type (Array_Type);
end if;
if not Is_Array_Type (Array_Type) then
Wrong_Type (P, Any_Array);
elsif Number_Dimensions (Array_Type) > 1 then
Error_Msg_N
("type is not one-dimensional array in slice prefix", N);
else
if Ekind (Array_Type) = E_String_Literal_Subtype then
Index_Type := Etype (String_Literal_Low_Bound (Array_Type));
else
Index_Type := Etype (First_Index (Array_Type));
end if;
if not Has_Compatible_Type (D, Index_Type) then
Wrong_Type (D, Index_Type);
else
Set_Etype (N, Array_Type);
end if;
end if;
end if;
end Analyze_Slice;
-----------------------------
-- Analyze_Type_Conversion --
-----------------------------
procedure Analyze_Type_Conversion (N : Node_Id) is
Expr : constant Node_Id := Expression (N);
Typ : Entity_Id;
begin
-- If Conversion_OK is set, then the Etype is already set, and the only
-- processing required is to analyze the expression. This is used to
-- construct certain "illegal" conversions which are not allowed by Ada
-- semantics, but can be handled by Gigi, see Sinfo for further details.
if Conversion_OK (N) then
Analyze (Expr);
return;
end if;
-- Otherwise full type analysis is required, as well as some semantic
-- checks to make sure the argument of the conversion is appropriate.
Find_Type (Subtype_Mark (N));
Typ := Entity (Subtype_Mark (N));
Set_Etype (N, Typ);
Check_Fully_Declared (Typ, N);
Analyze_Expression (Expr);
Validate_Remote_Type_Type_Conversion (N);
-- Only remaining step is validity checks on the argument. These
-- are skipped if the conversion does not come from the source.
if not Comes_From_Source (N) then
return;
-- If there was an error in a generic unit, no need to replicate the
-- error message. Conversely, constant-folding in the generic may
-- transform the argument of a conversion into a string literal, which
-- is legal. Therefore the following tests are not performed in an
-- instance. The same applies to an inlined body.
elsif In_Instance or In_Inlined_Body then
return;
elsif Nkind (Expr) = N_Null then
Error_Msg_N ("argument of conversion cannot be null", N);
Error_Msg_N ("\use qualified expression instead", N);
Set_Etype (N, Any_Type);
elsif Nkind (Expr) = N_Aggregate then
Error_Msg_N ("argument of conversion cannot be aggregate", N);
Error_Msg_N ("\use qualified expression instead", N);
elsif Nkind (Expr) = N_Allocator then
Error_Msg_N ("argument of conversion cannot be allocator", N);
Error_Msg_N ("\use qualified expression instead", N);
elsif Nkind (Expr) = N_String_Literal then
Error_Msg_N ("argument of conversion cannot be string literal", N);
Error_Msg_N ("\use qualified expression instead", N);
elsif Nkind (Expr) = N_Character_Literal then
if Ada_Version = Ada_83 then
Resolve (Expr, Typ);
else
Error_Msg_N
("argument of conversion cannot be character literal", N);
Error_Msg_N ("\use qualified expression instead", N);
end if;
elsif Nkind (Expr) = N_Attribute_Reference
and then Attribute_Name (Expr) in Name_Access
| Name_Unchecked_Access
| Name_Unrestricted_Access
then
Error_Msg_N
("argument of conversion cannot be access attribute", N);
Error_Msg_N ("\use qualified expression instead", N);
end if;
-- A formal parameter of a specific tagged type whose related subprogram
-- is subject to pragma Extensions_Visible with value "False" cannot
-- appear in a class-wide conversion (SPARK RM 6.1.7(3)). Do not check
-- internally generated expressions.
if Is_Class_Wide_Type (Typ)
and then Comes_From_Source (Expr)
and then Is_EVF_Expression (Expr)
then
Error_Msg_N
("formal parameter cannot be converted to class-wide type when "
& "Extensions_Visible is False", Expr);
end if;
end Analyze_Type_Conversion;
----------------------
-- Analyze_Unary_Op --
----------------------
procedure Analyze_Unary_Op (N : Node_Id) is
R : constant Node_Id := Right_Opnd (N);
Op_Id : Entity_Id := Entity (N);
begin
Set_Etype (N, Any_Type);
Candidate_Type := Empty;
Analyze_Expression (R);
if Present (Op_Id) then
if Ekind (Op_Id) = E_Operator then
Find_Unary_Types (R, Op_Id, N);
else
Add_One_Interp (N, Op_Id, Etype (Op_Id));
end if;
else
Op_Id := Get_Name_Entity_Id (Chars (N));
while Present (Op_Id) loop
if Ekind (Op_Id) = E_Operator then
if No (Next_Entity (First_Entity (Op_Id))) then
Find_Unary_Types (R, Op_Id, N);
end if;
elsif Is_Overloadable (Op_Id) then
Analyze_User_Defined_Unary_Op (N, Op_Id);
end if;
Op_Id := Homonym (Op_Id);
end loop;
end if;
Operator_Check (N);
end Analyze_Unary_Op;
----------------------------------
-- Analyze_Unchecked_Expression --
----------------------------------
procedure Analyze_Unchecked_Expression (N : Node_Id) is
begin
Analyze (Expression (N), Suppress => All_Checks);
Set_Etype (N, Etype (Expression (N)));
Save_Interps (Expression (N), N);
end Analyze_Unchecked_Expression;
---------------------------------------
-- Analyze_Unchecked_Type_Conversion --
---------------------------------------
procedure Analyze_Unchecked_Type_Conversion (N : Node_Id) is
begin
Find_Type (Subtype_Mark (N));
Analyze_Expression (Expression (N));
Set_Etype (N, Entity (Subtype_Mark (N)));
end Analyze_Unchecked_Type_Conversion;
------------------------------------
-- Analyze_User_Defined_Binary_Op --
------------------------------------
procedure Analyze_User_Defined_Binary_Op
(N : Node_Id;
Op_Id : Entity_Id) is
begin
declare
F1 : constant Entity_Id := First_Formal (Op_Id);
F2 : constant Entity_Id := Next_Formal (F1);
begin
-- Verify that Op_Id is a visible binary function. Note that since
-- we know Op_Id is overloaded, potentially use visible means use
-- visible for sure (RM 9.4(11)).
if Ekind (Op_Id) = E_Function
and then Present (F2)
and then (Is_Immediately_Visible (Op_Id)
or else Is_Potentially_Use_Visible (Op_Id))
and then Has_Compatible_Type (Left_Opnd (N), Etype (F1))
and then Has_Compatible_Type (Right_Opnd (N), Etype (F2))
then
Add_One_Interp (N, Op_Id, Etype (Op_Id));
-- If the left operand is overloaded, indicate that the current
-- type is a viable candidate. This is redundant in most cases,
-- but for equality and comparison operators where the context
-- does not impose a type on the operands, setting the proper
-- type is necessary to avoid subsequent ambiguities during
-- resolution, when both user-defined and predefined operators
-- may be candidates.
if Is_Overloaded (Left_Opnd (N)) then
Set_Etype (Left_Opnd (N), Etype (F1));
end if;
if Debug_Flag_E then
Write_Str ("user defined operator ");
Write_Name (Chars (Op_Id));
Write_Str (" on node ");
Write_Int (Int (N));
Write_Eol;
end if;
end if;
end;
end Analyze_User_Defined_Binary_Op;
-----------------------------------
-- Analyze_User_Defined_Unary_Op --
-----------------------------------
procedure Analyze_User_Defined_Unary_Op
(N : Node_Id;
Op_Id : Entity_Id)
is
begin
-- Only do analysis if the operator Comes_From_Source, since otherwise
-- the operator was generated by the expander, and all such operators
-- always refer to the operators in package Standard.
if Comes_From_Source (N) then
declare
F : constant Entity_Id := First_Formal (Op_Id);
begin
-- Verify that Op_Id is a visible unary function. Note that since
-- we know Op_Id is overloaded, potentially use visible means use
-- visible for sure (RM 9.4(11)).
if Ekind (Op_Id) = E_Function
and then No (Next_Formal (F))
and then (Is_Immediately_Visible (Op_Id)
or else Is_Potentially_Use_Visible (Op_Id))
and then Has_Compatible_Type (Right_Opnd (N), Etype (F))
then
Add_One_Interp (N, Op_Id, Etype (Op_Id));
end if;
end;
end if;
end Analyze_User_Defined_Unary_Op;
---------------------------
-- Check_Arithmetic_Pair --
---------------------------
procedure Check_Arithmetic_Pair
(T1, T2 : Entity_Id;
Op_Id : Entity_Id;
N : Node_Id)
is
Op_Name : constant Name_Id := Chars (Op_Id);
function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean;
-- Check whether the fixed-point type Typ has a user-defined operator
-- (multiplication or division) that should hide the corresponding
-- predefined operator. Used to implement Ada 2005 AI-264, to make
-- such operators more visible and therefore useful.
--
-- If the name of the operation is an expanded name with prefix
-- Standard, the predefined universal fixed operator is available,
-- as specified by AI-420 (RM 4.5.5 (19.1/2)).
function Specific_Type (T1, T2 : Entity_Id) return Entity_Id;
-- Get specific type (i.e. non-universal type if there is one)
------------------
-- Has_Fixed_Op --
------------------
function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean is
Bas : constant Entity_Id := Base_Type (Typ);
Ent : Entity_Id;
F1 : Entity_Id;
F2 : Entity_Id;
begin
-- If the universal_fixed operation is given explicitly the rule
-- concerning primitive operations of the type do not apply.
if Nkind (N) = N_Function_Call
and then Nkind (Name (N)) = N_Expanded_Name
and then Entity (Prefix (Name (N))) = Standard_Standard
then
return False;
end if;
-- The operation is treated as primitive if it is declared in the
-- same scope as the type, and therefore on the same entity chain.
Ent := Next_Entity (Typ);
while Present (Ent) loop
if Chars (Ent) = Chars (Op) then
F1 := First_Formal (Ent);
F2 := Next_Formal (F1);
-- The operation counts as primitive if either operand or
-- result are of the given base type, and both operands are
-- fixed point types.
if (Base_Type (Etype (F1)) = Bas
and then Is_Fixed_Point_Type (Etype (F2)))
or else
(Base_Type (Etype (F2)) = Bas
and then Is_Fixed_Point_Type (Etype (F1)))
or else
(Base_Type (Etype (Ent)) = Bas
and then Is_Fixed_Point_Type (Etype (F1))
and then Is_Fixed_Point_Type (Etype (F2)))
then
return True;
end if;
end if;
Next_Entity (Ent);
end loop;
return False;
end Has_Fixed_Op;
-------------------
-- Specific_Type --
-------------------
function Specific_Type (T1, T2 : Entity_Id) return Entity_Id is
begin
if Is_Universal_Numeric_Type (T1) then
return Base_Type (T2);
else
return Base_Type (T1);
end if;
end Specific_Type;
-- Start of processing for Check_Arithmetic_Pair
begin
if Op_Name in Name_Op_Add | Name_Op_Subtract then
if Is_Numeric_Type (T1)
and then Is_Numeric_Type (T2)
and then (Covers (T1 => T1, T2 => T2)
or else
Covers (T1 => T2, T2 => T1))
then
Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
end if;
elsif Op_Name in Name_Op_Multiply | Name_Op_Divide then
if Is_Fixed_Point_Type (T1)
and then (Is_Fixed_Point_Type (T2) or else T2 = Universal_Real)
then
-- Add one interpretation with universal fixed result
if not Has_Fixed_Op (T1, Op_Id)
or else Nkind (Parent (N)) = N_Type_Conversion
then
Add_One_Interp (N, Op_Id, Universal_Fixed);
end if;
elsif Is_Fixed_Point_Type (T2)
and then T1 = Universal_Real
and then
(not Has_Fixed_Op (T1, Op_Id)
or else Nkind (Parent (N)) = N_Type_Conversion)
then
Add_One_Interp (N, Op_Id, Universal_Fixed);
elsif Is_Numeric_Type (T1)
and then Is_Numeric_Type (T2)
and then (Covers (T1 => T1, T2 => T2)
or else
Covers (T1 => T2, T2 => T1))
then
Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
elsif Is_Fixed_Point_Type (T1)
and then (Base_Type (T2) = Base_Type (Standard_Integer)
or else T2 = Universal_Integer)
then
Add_One_Interp (N, Op_Id, T1);
elsif T2 = Universal_Real
and then Base_Type (T1) = Base_Type (Standard_Integer)
and then Op_Name = Name_Op_Multiply
then
Add_One_Interp (N, Op_Id, Any_Fixed);
elsif T1 = Universal_Real
and then Base_Type (T2) = Base_Type (Standard_Integer)
then
Add_One_Interp (N, Op_Id, Any_Fixed);
elsif Is_Fixed_Point_Type (T2)
and then (Base_Type (T1) = Base_Type (Standard_Integer)
or else T1 = Universal_Integer)
and then Op_Name = Name_Op_Multiply
then
Add_One_Interp (N, Op_Id, T2);
elsif T1 = Universal_Real and then T2 = Universal_Integer then
Add_One_Interp (N, Op_Id, T1);
elsif T2 = Universal_Real
and then T1 = Universal_Integer
and then Op_Name = Name_Op_Multiply
then
Add_One_Interp (N, Op_Id, T2);
end if;
elsif Op_Name = Name_Op_Mod or else Op_Name = Name_Op_Rem then
if Is_Integer_Type (T1)
and then (Covers (T1 => T1, T2 => T2)
or else
Covers (T1 => T2, T2 => T1))
then
Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
end if;
elsif Op_Name = Name_Op_Expon then
if Is_Numeric_Type (T1)
and then not Is_Fixed_Point_Type (T1)
and then (Base_Type (T2) = Base_Type (Standard_Integer)
or else T2 = Universal_Integer)
then
Add_One_Interp (N, Op_Id, Base_Type (T1));
end if;
else pragma Assert (Nkind (N) in N_Op_Shift);
-- If not one of the predefined operators, the node may be one
-- of the intrinsic functions. Its kind is always specific, and
-- we can use it directly, rather than the name of the operation.
if Is_Integer_Type (T1)
and then (Base_Type (T2) = Base_Type (Standard_Integer)
or else T2 = Universal_Integer)
then
Add_One_Interp (N, Op_Id, Base_Type (T1));
end if;
end if;
end Check_Arithmetic_Pair;
-------------------------------
-- Check_Misspelled_Selector --
-------------------------------
procedure Check_Misspelled_Selector
(Prefix : Entity_Id;
Sel : Node_Id)
is
Max_Suggestions : constant := 2;
Nr_Of_Suggestions : Natural := 0;
Suggestion_1 : Entity_Id := Empty;
Suggestion_2 : Entity_Id := Empty;
Comp : Entity_Id;
begin
-- All the components of the prefix of selector Sel are matched against
-- Sel and a count is maintained of possible misspellings. When at
-- the end of the analysis there are one or two (not more) possible
-- misspellings, these misspellings will be suggested as possible
-- correction.
if not (Is_Private_Type (Prefix) or else Is_Record_Type (Prefix)) then
-- Concurrent types should be handled as well ???
return;
end if;
Comp := First_Entity (Prefix);
while Nr_Of_Suggestions <= Max_Suggestions and then Present (Comp) loop
if Is_Visible_Component (Comp, Sel) then
if Is_Bad_Spelling_Of (Chars (Comp), Chars (Sel)) then
Nr_Of_Suggestions := Nr_Of_Suggestions + 1;
case Nr_Of_Suggestions is
when 1 => Suggestion_1 := Comp;
when 2 => Suggestion_2 := Comp;
when others => null;
end case;
end if;
end if;
Next_Entity (Comp);
end loop;
-- Report at most two suggestions
if Nr_Of_Suggestions = 1 then
Error_Msg_NE -- CODEFIX
("\possible misspelling of&", Sel, Suggestion_1);
elsif Nr_Of_Suggestions = 2 then
Error_Msg_Node_2 := Suggestion_2;
Error_Msg_NE -- CODEFIX
("\possible misspelling of& or&", Sel, Suggestion_1);
end if;
end Check_Misspelled_Selector;
----------------------
-- Defined_In_Scope --
----------------------
function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean
is
S1 : constant Entity_Id := Scope (Base_Type (T));
begin
return S1 = S
or else (S1 = System_Aux_Id and then S = Scope (S1));
end Defined_In_Scope;
-------------------
-- Diagnose_Call --
-------------------
procedure Diagnose_Call (N : Node_Id; Nam : Node_Id) is
Actual : Node_Id;
X : Interp_Index;
It : Interp;
Err_Mode : Boolean;
New_Nam : Node_Id;
Void_Interp_Seen : Boolean := False;
Success : Boolean;
pragma Warnings (Off, Boolean);
begin
if Ada_Version >= Ada_2005 then
Actual := First_Actual (N);
while Present (Actual) loop
-- Ada 2005 (AI-50217): Post an error in case of premature
-- usage of an entity from the limited view.
if not Analyzed (Etype (Actual))
and then From_Limited_With (Etype (Actual))
then
Error_Msg_Qual_Level := 1;
Error_Msg_NE
("missing with_clause for scope of imported type&",
Actual, Etype (Actual));
Error_Msg_Qual_Level := 0;
end if;
Next_Actual (Actual);
end loop;
end if;
-- Before listing the possible candidates, check whether this is
-- a prefix of a selected component that has been rewritten as a
-- parameterless function call because there is a callable candidate
-- interpretation. If there is a hidden package in the list of homonyms
-- of the function name (bad programming style in any case) suggest that
-- this is the intended entity.
if No (Parameter_Associations (N))
and then Nkind (Parent (N)) = N_Selected_Component
and then Nkind (Parent (Parent (N))) in N_Declaration
and then Is_Overloaded (Nam)
then
declare
Ent : Entity_Id;
begin
Ent := Current_Entity (Nam);
while Present (Ent) loop
if Ekind (Ent) = E_Package then
Error_Msg_N
("no legal interpretations as function call,!", Nam);
Error_Msg_NE ("\package& is not visible", N, Ent);
Rewrite (Parent (N),
New_Occurrence_Of (Any_Type, Sloc (N)));
return;
end if;
Ent := Homonym (Ent);
end loop;
end;
end if;
-- Analyze each candidate call again, with full error reporting for
-- each.
Error_Msg_N
("no candidate interpretations match the actuals:!", Nam);
Err_Mode := All_Errors_Mode;
All_Errors_Mode := True;
-- If this is a call to an operation of a concurrent type,
-- the failed interpretations have been removed from the
-- name. Recover them to provide full diagnostics.
if Nkind (Parent (Nam)) = N_Selected_Component then
Set_Entity (Nam, Empty);
New_Nam := New_Copy_Tree (Parent (Nam));
Set_Is_Overloaded (New_Nam, False);
Set_Is_Overloaded (Selector_Name (New_Nam), False);
Set_Parent (New_Nam, Parent (Parent (Nam)));
Analyze_Selected_Component (New_Nam);
Get_First_Interp (Selector_Name (New_Nam), X, It);
else
Get_First_Interp (Nam, X, It);
end if;
while Present (It.Nam) loop
if Etype (It.Nam) = Standard_Void_Type then
Void_Interp_Seen := True;
end if;
Analyze_One_Call (N, It.Nam, True, Success);
Get_Next_Interp (X, It);
end loop;
if Nkind (N) = N_Function_Call then
Get_First_Interp (Nam, X, It);
if No (It.Typ)
and then Ekind (Entity (Name (N))) = E_Function
and then Present (Homonym (Entity (Name (N))))
then
-- A name may appear overloaded if it has a homonym, even if that
-- homonym is non-overloadable, in which case the overload list is
-- in fact empty. This specialized case deserves a special message
-- if the homonym is a child package.
declare
Nam : constant Node_Id := Name (N);
H : constant Entity_Id := Homonym (Entity (Nam));
begin
if Ekind (H) = E_Package and then Is_Child_Unit (H) then
Error_Msg_Qual_Level := 2;
Error_Msg_NE ("if an entity in package& is meant, ", Nam, H);
Error_Msg_NE ("\use a fully qualified name", Nam, H);
Error_Msg_Qual_Level := 0;
end if;
end;
else
while Present (It.Nam) loop
if Ekind (It.Nam) in E_Function | E_Operator then
return;
else
Get_Next_Interp (X, It);
end if;
end loop;
-- If all interpretations are procedures, this deserves a more
-- precise message. Ditto if this appears as the prefix of a
-- selected component, which may be a lexical error.
Error_Msg_N
("\context requires function call, found procedure name", Nam);
if Nkind (Parent (N)) = N_Selected_Component
and then N = Prefix (Parent (N))
then
Error_Msg_N -- CODEFIX
("\period should probably be semicolon", Parent (N));
end if;
end if;
elsif Nkind (N) = N_Procedure_Call_Statement
and then not Void_Interp_Seen
then
Error_Msg_N ("\function name found in procedure call", Nam);
end if;
All_Errors_Mode := Err_Mode;
end Diagnose_Call;
---------------------------
-- Find_Arithmetic_Types --
---------------------------
procedure Find_Arithmetic_Types
(L, R : Node_Id;
Op_Id : Entity_Id;
N : Node_Id)
is
Index1 : Interp_Index;
Index2 : Interp_Index;
It1 : Interp;
It2 : Interp;
procedure Check_Right_Argument (T : Entity_Id);
-- Check right operand of operator
--------------------------
-- Check_Right_Argument --
--------------------------
procedure Check_Right_Argument (T : Entity_Id) is
begin
if not Is_Overloaded (R) then
Check_Arithmetic_Pair (T, Etype (R), Op_Id, N);
else
Get_First_Interp (R, Index2, It2);
while Present (It2.Typ) loop
Check_Arithmetic_Pair (T, It2.Typ, Op_Id, N);
Get_Next_Interp (Index2, It2);
end loop;
end if;
end Check_Right_Argument;
-- Start of processing for Find_Arithmetic_Types
begin
if not Is_Overloaded (L) then
Check_Right_Argument (Etype (L));
else
Get_First_Interp (L, Index1, It1);
while Present (It1.Typ) loop
Check_Right_Argument (It1.Typ);
Get_Next_Interp (Index1, It1);
end loop;
end if;
end Find_Arithmetic_Types;
------------------------
-- Find_Boolean_Types --
------------------------
procedure Find_Boolean_Types
(L, R : Node_Id;
Op_Id : Entity_Id;
N : Node_Id)
is
Index : Interp_Index;
It : Interp;
procedure Check_Numeric_Argument (T : Entity_Id);
-- Special case for logical operations one of whose operands is an
-- integer literal. If both are literal the result is any modular type.
----------------------------
-- Check_Numeric_Argument --
----------------------------
procedure Check_Numeric_Argument (T : Entity_Id) is
begin
if T = Universal_Integer then
Add_One_Interp (N, Op_Id, Any_Modular);
elsif Is_Modular_Integer_Type (T) then
Add_One_Interp (N, Op_Id, T);
end if;
end Check_Numeric_Argument;
-- Start of processing for Find_Boolean_Types
begin
if not Is_Overloaded (L) then
if Etype (L) = Universal_Integer
or else Etype (L) = Any_Modular
then
if not Is_Overloaded (R) then
Check_Numeric_Argument (Etype (R));
else
Get_First_Interp (R, Index, It);
while Present (It.Typ) loop
Check_Numeric_Argument (It.Typ);
Get_Next_Interp (Index, It);
end loop;
end if;
-- If operands are aggregates, we must assume that they may be
-- boolean arrays, and leave disambiguation for the second pass.
-- If only one is an aggregate, verify that the other one has an
-- interpretation as a boolean array
elsif Nkind (L) = N_Aggregate then
if Nkind (R) = N_Aggregate then
Add_One_Interp (N, Op_Id, Etype (L));
elsif not Is_Overloaded (R) then
if Valid_Boolean_Arg (Etype (R)) then
Add_One_Interp (N, Op_Id, Etype (R));
end if;
else
Get_First_Interp (R, Index, It);
while Present (It.Typ) loop
if Valid_Boolean_Arg (It.Typ) then
Add_One_Interp (N, Op_Id, It.Typ);
end if;
Get_Next_Interp (Index, It);
end loop;
end if;
elsif Valid_Boolean_Arg (Etype (L))
and then Has_Compatible_Type (R, Etype (L))
then
Add_One_Interp (N, Op_Id, Etype (L));
end if;
else
Get_First_Interp (L, Index, It);
while Present (It.Typ) loop
if Valid_Boolean_Arg (It.Typ)
and then Has_Compatible_Type (R, It.Typ)
then
Add_One_Interp (N, Op_Id, It.Typ);
end if;
Get_Next_Interp (Index, It);
end loop;
end if;
end Find_Boolean_Types;
---------------------------
-- Find_Comparison_Types --
---------------------------
procedure Find_Comparison_Types
(L, R : Node_Id;
Op_Id : Entity_Id;
N : Node_Id)
is
Index : Interp_Index;
It : Interp;
Found : Boolean := False;
I_F : Interp_Index;
T_F : Entity_Id;
Scop : Entity_Id := Empty;
procedure Try_One_Interp (T1 : Entity_Id);
-- Routine to try one proposed interpretation. Note that the context
-- of the operator plays no role in resolving the arguments, so that
-- if there is more than one interpretation of the operands that is
-- compatible with comparison, the operation is ambiguous.
--------------------
-- Try_One_Interp --
--------------------
procedure Try_One_Interp (T1 : Entity_Id) is
begin
-- If the operator is an expanded name, then the type of the operand
-- must be defined in the corresponding scope. If the type is
-- universal, the context will impose the correct type. Note that we
-- also avoid returning if we are currently within a generic instance
-- due to the fact that the generic package declaration has already
-- been successfully analyzed and Defined_In_Scope expects the base
-- type to be defined within the instance which will never be the
-- case.
if Present (Scop)
and then not Defined_In_Scope (T1, Scop)
and then not In_Instance
and then T1 /= Universal_Integer
and then T1 /= Universal_Real
and then T1 /= Any_String
and then T1 /= Any_Composite
then
return;
end if;
if Valid_Comparison_Arg (T1) and then Has_Compatible_Type (R, T1) then
if Found and then Base_Type (T1) /= Base_Type (T_F) then
It := Disambiguate (L, I_F, Index, Any_Type);
if It = No_Interp then
Ambiguous_Operands (N);
Set_Etype (L, Any_Type);
return;
else
T_F := It.Typ;
end if;
else
Found := True;
T_F := T1;
I_F := Index;
end if;
Set_Etype (L, T_F);
Find_Non_Universal_Interpretations (N, R, Op_Id, T1);
end if;
end Try_One_Interp;
-- Start of processing for Find_Comparison_Types
begin
-- If left operand is aggregate, the right operand has to
-- provide a usable type for it.
if Nkind (L) = N_Aggregate and then Nkind (R) /= N_Aggregate then
Find_Comparison_Types (L => R, R => L, Op_Id => Op_Id, N => N);
return;
end if;
if Nkind (N) = N_Function_Call
and then Nkind (Name (N)) = N_Expanded_Name
then
Scop := Entity (Prefix (Name (N)));
-- The prefix may be a package renaming, and the subsequent test
-- requires the original package.
if Ekind (Scop) = E_Package
and then Present (Renamed_Entity (Scop))
then
Scop := Renamed_Entity (Scop);
Set_Entity (Prefix (Name (N)), Scop);
end if;
end if;
if not Is_Overloaded (L) then
Try_One_Interp (Etype (L));
else
Get_First_Interp (L, Index, It);
while Present (It.Typ) loop
Try_One_Interp (It.Typ);
Get_Next_Interp (Index, It);
end loop;
end if;
end Find_Comparison_Types;
----------------------------------------
-- Find_Non_Universal_Interpretations --
----------------------------------------
procedure Find_Non_Universal_Interpretations
(N : Node_Id;
R : Node_Id;
Op_Id : Entity_Id;
T1 : Entity_Id)
is
Index : Interp_Index;
It : Interp;
begin
if T1 = Universal_Integer or else T1 = Universal_Real
-- If the left operand of an equality operator is null, the visibility
-- of the operator must be determined from the interpretation of the
-- right operand. This processing must be done for Any_Access, which
-- is the internal representation of the type of the literal null.
or else T1 = Any_Access
then
if not Is_Overloaded (R) then
Add_One_Interp (N, Op_Id, Standard_Boolean, Base_Type (Etype (R)));
else
Get_First_Interp (R, Index, It);
while Present (It.Typ) loop
if Covers (It.Typ, T1) then
Add_One_Interp
(N, Op_Id, Standard_Boolean, Base_Type (It.Typ));
end if;
Get_Next_Interp (Index, It);
end loop;
end if;
elsif Has_Compatible_Type (R, T1) or else Covers (Etype (R), T1) then
Add_One_Interp (N, Op_Id, Standard_Boolean, Base_Type (T1));
end if;
end Find_Non_Universal_Interpretations;
------------------------------
-- Find_Concatenation_Types --
------------------------------
procedure Find_Concatenation_Types
(L, R : Node_Id;
Op_Id : Entity_Id;
N : Node_Id)
is
Is_String : constant Boolean := Nkind (L) = N_String_Literal
or else
Nkind (R) = N_String_Literal;
Op_Type : constant Entity_Id := Etype (Op_Id);
begin
if Is_Array_Type (Op_Type)
-- Small but very effective optimization: if at least one operand is a
-- string literal, then the type of the operator must be either array
-- of characters or array of strings.
and then (not Is_String
or else
Is_Character_Type (Component_Type (Op_Type))
or else
Is_String_Type (Component_Type (Op_Type)))
and then not Is_Limited_Type (Op_Type)
and then (Has_Compatible_Type (L, Op_Type)
or else
Has_Compatible_Type (L, Component_Type (Op_Type)))
and then (Has_Compatible_Type (R, Op_Type)
or else
Has_Compatible_Type (R, Component_Type (Op_Type)))
then
Add_One_Interp (N, Op_Id, Op_Type);
end if;
end Find_Concatenation_Types;
-------------------------
-- Find_Equality_Types --
-------------------------
procedure Find_Equality_Types
(L, R : Node_Id;
Op_Id : Entity_Id;
N : Node_Id)
is
Index : Interp_Index := 0;
It : Interp;
Found : Boolean := False;
Is_Universal_Access : Boolean := False;
I_F : Interp_Index;
T_F : Entity_Id;
Scop : Entity_Id := Empty;
procedure Check_Access_Attribute (N : Node_Id);
-- For any object, '[Unchecked_]Access of such object can never be
-- passed as a parameter of a call to the Universal_Access equality
-- operator.
-- This is because the expected type for Obj'Access in a call to
-- the Standard."=" operator whose formals are of type
-- Universal_Access is Universal_Integer, and Universal_Access
-- doesn't have a designated type. For more detail see RM 6.4.1(3)
-- and 3.10.2.
-- This procedure assumes that the context is a universal_access.
function Check_Access_Object_Types
(N : Node_Id; Typ : Entity_Id) return Boolean;
-- Check for RM 4.5.2 (9.6/2): When both are of access-to-object types,
-- the designated types shall be the same or one shall cover the other,
-- and if the designated types are elementary or array types, then the
-- designated subtypes shall statically match.
-- If N is not overloaded, then its unique type must be compatible as
-- per above. Otherwise iterate through the interpretations of N looking
-- for a compatible one.
procedure Check_Compatible_Profiles (N : Node_Id; Typ : Entity_Id);
-- Check for RM 4.5.2(9.7/2): When both are of access-to-subprogram
-- types, the designated profiles shall be subtype conformant.
function References_Anonymous_Access_Type
(N : Node_Id; Typ : Entity_Id) return Boolean;
-- Return True either if N is not overloaded and its Etype is an
-- anonymous access type or if one of the interpretations of N refers
-- to an anonymous access type compatible with Typ.
procedure Try_One_Interp (T1 : Entity_Id);
-- The context of the equality operator plays no role in resolving the
-- arguments, so that if there is more than one interpretation of the
-- operands that is compatible with equality, the construct is ambiguous
-- and an error can be emitted now, after trying to disambiguate, i.e.
-- applying preference rules.
----------------------------
-- Check_Access_Attribute --
----------------------------
procedure Check_Access_Attribute (N : Node_Id) is
begin
if Nkind (N) = N_Attribute_Reference
and then Attribute_Name (N) in Name_Access | Name_Unchecked_Access
then
Error_Msg_N
("access attribute cannot be used as actual for "
& "universal_access equality", N);
end if;
end Check_Access_Attribute;
-------------------------------
-- Check_Access_Object_Types --
-------------------------------
function Check_Access_Object_Types
(N : Node_Id; Typ : Entity_Id) return Boolean
is
function Check_Designated_Types (DT1, DT2 : Entity_Id) return Boolean;
-- Check RM 4.5.2 (9.6/2) on the given designated types.
----------------------------
-- Check_Designated_Types --
----------------------------
function Check_Designated_Types
(DT1, DT2 : Entity_Id) return Boolean is
begin
-- If the designated types are elementary or array types, then
-- the designated subtypes shall statically match.
if Is_Elementary_Type (DT1) or else Is_Array_Type (DT1) then
if Base_Type (DT1) /= Base_Type (DT2) then
return False;
else
return Subtypes_Statically_Match (DT1, DT2);
end if;
-- Otherwise, the designated types shall be the same or one
-- shall cover the other.
else
return DT1 = DT2
or else Covers (DT1, DT2)
or else Covers (DT2, DT1);
end if;
end Check_Designated_Types;
-- Start of processing for Check_Access_Object_Types
begin
-- Return immediately with no checks if Typ is not an
-- access-to-object type.
if not Is_Access_Object_Type (Typ) then
return True;
-- Any_Type is compatible with all types in this context, and is used
-- in particular for the designated type of a 'null' value.
elsif Directly_Designated_Type (Typ) = Any_Type
or else Nkind (N) = N_Null
then
return True;
end if;
if not Is_Overloaded (N) then
if Is_Access_Object_Type (Etype (N)) then
return Check_Designated_Types
(Designated_Type (Typ), Designated_Type (Etype (N)));
end if;
else
declare
Typ_Is_Anonymous : constant Boolean :=
Is_Anonymous_Access_Type (Typ);
I : Interp_Index;
It : Interp;
begin
Get_First_Interp (N, I, It);
while Present (It.Typ) loop
-- The check on designated types if only relevant when one
-- of the types is anonymous, ignore other (non relevant)
-- types.
if (Typ_Is_Anonymous
or else Is_Anonymous_Access_Type (It.Typ))
and then Is_Access_Object_Type (It.Typ)
then
if Check_Designated_Types
(Designated_Type (Typ), Designated_Type (It.Typ))
then
return True;
end if;
end if;
Get_Next_Interp (I, It);
end loop;
end;
end if;
return False;
end Check_Access_Object_Types;
-------------------------------
-- Check_Compatible_Profiles --
-------------------------------
procedure Check_Compatible_Profiles (N : Node_Id; Typ : Entity_Id) is
I : Interp_Index;
It : Interp;
I1 : Interp_Index := 0;
Found : Boolean := False;
Tmp : Entity_Id := Empty;
begin
if not Is_Overloaded (N) then
Check_Subtype_Conformant
(Designated_Type (Etype (N)), Designated_Type (Typ), N);
else
Get_First_Interp (N, I, It);
while Present (It.Typ) loop
if Is_Access_Subprogram_Type (It.Typ) then
if not Found then
Found := True;
Tmp := It.Typ;
I1 := I;
else
It := Disambiguate (N, I1, I, Any_Type);
if It /= No_Interp then
Tmp := It.Typ;
I1 := I;
else
Found := False;
exit;
end if;
end if;
end if;
Get_Next_Interp (I, It);
end loop;
if Found then
Check_Subtype_Conformant
(Designated_Type (Tmp), Designated_Type (Typ), N);
end if;
end if;
end Check_Compatible_Profiles;
--------------------------------------
-- References_Anonymous_Access_Type --
--------------------------------------
function References_Anonymous_Access_Type
(N : Node_Id; Typ : Entity_Id) return Boolean
is
I : Interp_Index;
It : Interp;
begin
if not Is_Overloaded (N) then
return Is_Anonymous_Access_Type (Etype (N));
else
Get_First_Interp (N, I, It);
while Present (It.Typ) loop
if Is_Anonymous_Access_Type (It.Typ)
and then (Covers (It.Typ, Typ) or else Covers (Typ, It.Typ))
then
return True;
end if;
Get_Next_Interp (I, It);
end loop;
return False;
end if;
end References_Anonymous_Access_Type;
--------------------
-- Try_One_Interp --
--------------------
procedure Try_One_Interp (T1 : Entity_Id) is
Universal_Access : Boolean;
Bas : Entity_Id;
begin
-- Perform a sanity check in case of previous errors
if No (T1) then
return;
end if;
Bas := Base_Type (T1);
-- If the operator is an expanded name, then the type of the operand
-- must be defined in the corresponding scope. If the type is
-- universal, the context will impose the correct type. An anonymous
-- type for a 'Access reference is also universal in this sense, as
-- the actual type is obtained from context.
-- In Ada 2005, the equality operator for anonymous access types
-- is declared in Standard, and preference rules apply to it.
Universal_Access := Is_Anonymous_Access_Type (T1)
or else References_Anonymous_Access_Type (R, T1);
if Present (Scop) then
-- Note that we avoid returning if we are currently within a
-- generic instance due to the fact that the generic package
-- declaration has already been successfully analyzed and
-- Defined_In_Scope expects the base type to be defined within
-- the instance which will never be the case.
if Defined_In_Scope (T1, Scop)
or else In_Instance
or else T1 = Universal_Integer
or else T1 = Universal_Real
or else T1 = Any_Access
or else T1 = Any_String
or else T1 = Any_Composite
or else (Ekind (T1) = E_Access_Subprogram_Type
and then not Comes_From_Source (T1))
then
null;
elsif Scop /= Standard_Standard or else not Universal_Access then
-- The scope does not contain an operator for the type
return;
end if;
-- If we have infix notation, the operator must be usable. Within
-- an instance, the type may have been immediately visible if the
-- types are compatible.
elsif In_Open_Scopes (Scope (Bas))
or else Is_Potentially_Use_Visible (Bas)
or else In_Use (Bas)
or else (In_Use (Scope (Bas)) and then not Is_Hidden (Bas))
or else
((In_Instance or else In_Inlined_Body)
and then Has_Compatible_Type (R, T1))
then
null;
elsif not Universal_Access then
-- Save candidate type for subsequent error message, if any
if not Is_Limited_Type (T1) then
Candidate_Type := T1;
end if;
return;
end if;
-- Ada 2005 (AI-230): Keep restriction imposed by Ada 83 and 95:
-- Do not allow anonymous access types in equality operators.
if Ada_Version < Ada_2005 and then Universal_Access then
return;
end if;
-- If the right operand has a type compatible with T1, check for an
-- acceptable interpretation, unless T1 is limited (no predefined
-- equality available), or this is use of a "/=" for a tagged type.
-- In the latter case, possible interpretations of equality need
-- to be considered, we don't want the default inequality declared
-- in Standard to be chosen, and the "/=" will be rewritten as a
-- negation of "=" (see the end of Analyze_Equality_Op). This ensures
-- that rewriting happens during analysis rather than being
-- delayed until expansion (is this still needed now that ASIS mode
-- is gone???). Note that if the node is N_Op_Ne, but Op_Id
-- is Name_Op_Eq then we still proceed with the interpretation,
-- because that indicates the potential rewriting case where the
-- interpretation to consider is actually "=" and the node may be
-- about to be rewritten by Analyze_Equality_Op.
-- Finally, also check for RM 4.5.2 (9.6/2).
if T1 /= Standard_Void_Type
and then (Universal_Access or else Has_Compatible_Type (R, T1))
and then
((not Is_Limited_Type (T1)
and then not Is_Limited_Composite (T1))
or else
(Is_Array_Type (T1)
and then not Is_Limited_Type (Component_Type (T1))
and then Available_Full_View_Of_Component (T1)))
and then
(Nkind (N) /= N_Op_Ne
or else not Is_Tagged_Type (T1)
or else Chars (Op_Id) = Name_Op_Eq)
and then (not Universal_Access
or else Check_Access_Object_Types (R, T1))
then
if Found
and then Base_Type (T1) /= Base_Type (T_F)
then
It := Disambiguate (L, I_F, Index, Any_Type);
if It = No_Interp then
Ambiguous_Operands (N);
Set_Etype (L, Any_Type);
return;
else
T_F := It.Typ;
Is_Universal_Access := Universal_Access;
end if;
else
Found := True;
T_F := T1;
I_F := Index;
Is_Universal_Access := Universal_Access;
end if;
if not Analyzed (L) then
Set_Etype (L, T_F);
end if;
Find_Non_Universal_Interpretations (N, R, Op_Id, T1);
-- Case of operator was not visible, Etype still set to Any_Type
if Etype (N) = Any_Type then
Found := False;
end if;
end if;
end Try_One_Interp;
-- Start of processing for Find_Equality_Types
begin
-- If left operand is aggregate, the right operand has to
-- provide a usable type for it.
if Nkind (L) = N_Aggregate
and then Nkind (R) /= N_Aggregate
then
Find_Equality_Types (L => R, R => L, Op_Id => Op_Id, N => N);
return;
end if;
if Nkind (N) = N_Function_Call
and then Nkind (Name (N)) = N_Expanded_Name
then
Scop := Entity (Prefix (Name (N)));
-- The prefix may be a package renaming, and the subsequent test
-- requires the original package.
if Ekind (Scop) = E_Package
and then Present (Renamed_Entity (Scop))
then
Scop := Renamed_Entity (Scop);
Set_Entity (Prefix (Name (N)), Scop);
end if;
end if;
if not Is_Overloaded (L) then
Try_One_Interp (Etype (L));
else
Get_First_Interp (L, Index, It);
while Present (It.Typ) loop
Try_One_Interp (It.Typ);
Get_Next_Interp (Index, It);
end loop;
end if;
if Is_Universal_Access then
if Is_Access_Subprogram_Type (Etype (L))
and then Nkind (L) /= N_Null
and then Nkind (R) /= N_Null
then
Check_Compatible_Profiles (R, Etype (L));
end if;
Check_Access_Attribute (R);
Check_Access_Attribute (L);
end if;
end Find_Equality_Types;
-------------------------
-- Find_Negation_Types --
-------------------------
procedure Find_Negation_Types
(R : Node_Id;
Op_Id : Entity_Id;
N : Node_Id)
is
Index : Interp_Index;
It : Interp;
begin
if not Is_Overloaded (R) then
if Etype (R) = Universal_Integer then
Add_One_Interp (N, Op_Id, Any_Modular);
elsif Valid_Boolean_Arg (Etype (R)) then
Add_One_Interp (N, Op_Id, Etype (R));
end if;
else
Get_First_Interp (R, Index, It);
while Present (It.Typ) loop
if Valid_Boolean_Arg (It.Typ) then
Add_One_Interp (N, Op_Id, It.Typ);
end if;
Get_Next_Interp (Index, It);
end loop;
end if;
end Find_Negation_Types;
------------------------------
-- Find_Primitive_Operation --
------------------------------
function Find_Primitive_Operation (N : Node_Id) return Boolean is
Obj : constant Node_Id := Prefix (N);
Op : constant Node_Id := Selector_Name (N);
Prim : Elmt_Id;
Prims : Elist_Id;
Typ : Entity_Id;
begin
Set_Etype (Op, Any_Type);
if Is_Access_Type (Etype (Obj)) then
Typ := Designated_Type (Etype (Obj));
else
Typ := Etype (Obj);
end if;
if Is_Class_Wide_Type (Typ) then
Typ := Root_Type (Typ);
end if;
Prims := Primitive_Operations (Typ);
Prim := First_Elmt (Prims);
while Present (Prim) loop
if Chars (Node (Prim)) = Chars (Op) then
Add_One_Interp (Op, Node (Prim), Etype (Node (Prim)));
Set_Etype (N, Etype (Node (Prim)));
end if;
Next_Elmt (Prim);
end loop;
-- Now look for class-wide operations of the type or any of its
-- ancestors by iterating over the homonyms of the selector.
declare
Cls_Type : constant Entity_Id := Class_Wide_Type (Typ);
Hom : Entity_Id;
begin
Hom := Current_Entity (Op);
while Present (Hom) loop
if (Ekind (Hom) = E_Procedure
or else
Ekind (Hom) = E_Function)
and then Scope (Hom) = Scope (Typ)
and then Present (First_Formal (Hom))
and then
(Base_Type (Etype (First_Formal (Hom))) = Cls_Type
or else
(Is_Access_Type (Etype (First_Formal (Hom)))
and then
Ekind (Etype (First_Formal (Hom))) =
E_Anonymous_Access_Type
and then
Base_Type
(Designated_Type (Etype (First_Formal (Hom)))) =
Cls_Type))
then
Add_One_Interp (Op, Hom, Etype (Hom));
Set_Etype (N, Etype (Hom));
end if;
Hom := Homonym (Hom);
end loop;
end;
return Etype (Op) /= Any_Type;
end Find_Primitive_Operation;
----------------------
-- Find_Unary_Types --
----------------------
procedure Find_Unary_Types
(R : Node_Id;
Op_Id : Entity_Id;
N : Node_Id)
is
Index : Interp_Index;
It : Interp;
begin
if not Is_Overloaded (R) then
if Is_Numeric_Type (Etype (R)) then
-- In an instance a generic actual may be a numeric type even if
-- the formal in the generic unit was not. In that case, the
-- predefined operator was not a possible interpretation in the
-- generic, and cannot be one in the instance, unless the operator
-- is an actual of an instance.
if In_Instance
and then
not Is_Numeric_Type (Corresponding_Generic_Type (Etype (R)))
then
null;
else
Add_One_Interp (N, Op_Id, Base_Type (Etype (R)));
end if;
end if;
else
Get_First_Interp (R, Index, It);
while Present (It.Typ) loop
if Is_Numeric_Type (It.Typ) then
if In_Instance
and then
not Is_Numeric_Type
(Corresponding_Generic_Type (Etype (It.Typ)))
then
null;
else
Add_One_Interp (N, Op_Id, Base_Type (It.Typ));
end if;
end if;
Get_Next_Interp (Index, It);
end loop;
end if;
end Find_Unary_Types;
------------------
-- Junk_Operand --
------------------
function Junk_Operand (N : Node_Id) return Boolean is
Enode : Node_Id;
begin
if Error_Posted (N) then
return False;
end if;
-- Get entity to be tested
if Is_Entity_Name (N)
and then Present (Entity (N))
then
Enode := N;
-- An odd case, a procedure name gets converted to a very peculiar
-- function call, and here is where we detect this happening.
elsif Nkind (N) = N_Function_Call
and then Is_Entity_Name (Name (N))
and then Present (Entity (Name (N)))
then
Enode := Name (N);
-- Another odd case, there are at least some cases of selected
-- components where the selected component is not marked as having
-- an entity, even though the selector does have an entity
elsif Nkind (N) = N_Selected_Component
and then Present (Entity (Selector_Name (N)))
then
Enode := Selector_Name (N);
else
return False;
end if;
-- Now test the entity we got to see if it is a bad case
case Ekind (Entity (Enode)) is
when E_Package =>
Error_Msg_N
("package name cannot be used as operand", Enode);
when Generic_Unit_Kind =>
Error_Msg_N
("generic unit name cannot be used as operand", Enode);
when Type_Kind =>
Error_Msg_N
("subtype name cannot be used as operand", Enode);
when Entry_Kind =>
Error_Msg_N
("entry name cannot be used as operand", Enode);
when E_Procedure =>
Error_Msg_N
("procedure name cannot be used as operand", Enode);
when E_Exception =>
Error_Msg_N
("exception name cannot be used as operand", Enode);
when E_Block
| E_Label
| E_Loop
=>
Error_Msg_N
("label name cannot be used as operand", Enode);
when others =>
return False;
end case;
return True;
end Junk_Operand;
--------------------
-- Operator_Check --
--------------------
procedure Operator_Check (N : Node_Id) is
begin
Remove_Abstract_Operations (N);
-- Test for case of no interpretation found for operator
if Etype (N) = Any_Type then
declare
L : Node_Id;
R : Node_Id;
Op_Id : Entity_Id := Empty;
begin
R := Right_Opnd (N);
if Nkind (N) in N_Binary_Op then
L := Left_Opnd (N);
else
L := Empty;
end if;
-- If either operand has no type, then don't complain further,
-- since this simply means that we have a propagated error.
if R = Error
or else Etype (R) = Any_Type
or else (Nkind (N) in N_Binary_Op and then Etype (L) = Any_Type)
then
-- For the rather unusual case where one of the operands is
-- a Raise_Expression, whose initial type is Any_Type, use
-- the type of the other operand.
if Nkind (L) = N_Raise_Expression then
Set_Etype (L, Etype (R));
Set_Etype (N, Etype (R));
elsif Nkind (R) = N_Raise_Expression then
Set_Etype (R, Etype (L));
Set_Etype (N, Etype (L));
end if;
return;
-- We explicitly check for the case of concatenation of component
-- with component to avoid reporting spurious matching array types
-- that might happen to be lurking in distant packages (such as
-- run-time packages). This also prevents inconsistencies in the
-- messages for certain ACVC B tests, which can vary depending on
-- types declared in run-time interfaces. Another improvement when
-- aggregates are present is to look for a well-typed operand.
elsif Present (Candidate_Type)
and then (Nkind (N) /= N_Op_Concat
or else Is_Array_Type (Etype (L))
or else Is_Array_Type (Etype (R)))
then
if Nkind (N) = N_Op_Concat then
if Etype (L) /= Any_Composite
and then Is_Array_Type (Etype (L))
then
Candidate_Type := Etype (L);
elsif Etype (R) /= Any_Composite
and then Is_Array_Type (Etype (R))
then
Candidate_Type := Etype (R);
end if;
end if;
Error_Msg_NE -- CODEFIX
("operator for} is not directly visible!",
N, First_Subtype (Candidate_Type));
declare
U : constant Node_Id :=
Cunit (Get_Source_Unit (Candidate_Type));
begin
if Unit_Is_Visible (U) then
Error_Msg_N -- CODEFIX
("use clause would make operation legal!", N);
else
Error_Msg_NE -- CODEFIX
("add with_clause and use_clause for&!",
N, Defining_Entity (Unit (U)));
end if;
end;
return;
-- If either operand is a junk operand (e.g. package name), then
-- post appropriate error messages, but do not complain further.
-- Note that the use of OR in this test instead of OR ELSE is
-- quite deliberate, we may as well check both operands in the
-- binary operator case.
elsif Junk_Operand (R)
or -- really mean OR here and not OR ELSE, see above
(Nkind (N) in N_Binary_Op and then Junk_Operand (L))
then
return;
elsif Has_Possible_Literal_Aspects (N) then
return;
-- If we have a logical operator, one of whose operands is
-- Boolean, then we know that the other operand cannot resolve to
-- Boolean (since we got no interpretations), but in that case we
-- pretty much know that the other operand should be Boolean, so
-- resolve it that way (generating an error).
elsif Nkind (N) in N_Op_And | N_Op_Or | N_Op_Xor then
if Etype (L) = Standard_Boolean then
Resolve (R, Standard_Boolean);
return;
elsif Etype (R) = Standard_Boolean then
Resolve (L, Standard_Boolean);
return;
end if;
-- For an arithmetic operator or comparison operator, if one
-- of the operands is numeric, then we know the other operand
-- is not the same numeric type. If it is a non-numeric type,
-- then probably it is intended to match the other operand.
elsif Nkind (N) in N_Op_Add
| N_Op_Divide
| N_Op_Ge
| N_Op_Gt
| N_Op_Le
| N_Op_Lt
| N_Op_Mod
| N_Op_Multiply
| N_Op_Rem
| N_Op_Subtract
then
-- If Allow_Integer_Address is active, check whether the
-- operation becomes legal after converting an operand.
if Is_Numeric_Type (Etype (L))
and then not Is_Numeric_Type (Etype (R))
then
if Address_Integer_Convert_OK (Etype (R), Etype (L)) then
Rewrite (L,
Unchecked_Convert_To (
Standard_Address, Relocate_Node (L)));
Rewrite (R,
Unchecked_Convert_To (
Standard_Address, Relocate_Node (R)));
if Nkind (N) in N_Op_Ge | N_Op_Gt | N_Op_Le | N_Op_Lt then
Analyze_Comparison_Op (N);
else
Analyze_Arithmetic_Op (N);
end if;
else
Resolve (R, Etype (L));
end if;
return;
elsif Is_Numeric_Type (Etype (R))
and then not Is_Numeric_Type (Etype (L))
then
if Address_Integer_Convert_OK (Etype (L), Etype (R)) then
Rewrite (L,
Unchecked_Convert_To (
Standard_Address, Relocate_Node (L)));
Rewrite (R,
Unchecked_Convert_To (
Standard_Address, Relocate_Node (R)));
if Nkind (N) in N_Op_Ge | N_Op_Gt | N_Op_Le | N_Op_Lt then
Analyze_Comparison_Op (N);
else
Analyze_Arithmetic_Op (N);
end if;
return;
else
Resolve (L, Etype (R));
end if;
return;
elsif Allow_Integer_Address
and then Is_Descendant_Of_Address (Etype (L))
and then Is_Descendant_Of_Address (Etype (R))
and then not Error_Posted (N)
then
declare
Addr_Type : constant Entity_Id := Etype (L);
begin
Rewrite (L,
Unchecked_Convert_To (
Standard_Address, Relocate_Node (L)));
Rewrite (R,
Unchecked_Convert_To (
Standard_Address, Relocate_Node (R)));
if Nkind (N) in N_Op_Ge | N_Op_Gt | N_Op_Le | N_Op_Lt then
Analyze_Comparison_Op (N);
else
Analyze_Arithmetic_Op (N);
end if;
-- If this is an operand in an enclosing arithmetic
-- operation, Convert the result as an address so that
-- arithmetic folding of address can continue.
if Nkind (Parent (N)) in N_Op then
Rewrite (N,
Unchecked_Convert_To (Addr_Type, Relocate_Node (N)));
end if;
return;
end;
-- Under relaxed RM semantics silently replace occurrences of
-- null by System.Address_Null.
elsif Null_To_Null_Address_Convert_OK (N) then
Replace_Null_By_Null_Address (N);
if Nkind (N) in N_Op_Ge | N_Op_Gt | N_Op_Le | N_Op_Lt then
Analyze_Comparison_Op (N);
else
Analyze_Arithmetic_Op (N);
end if;
return;
end if;
-- Comparisons on A'Access are common enough to deserve a
-- special message.
elsif Nkind (N) in N_Op_Eq | N_Op_Ne
and then Ekind (Etype (L)) = E_Access_Attribute_Type
and then Ekind (Etype (R)) = E_Access_Attribute_Type
then
Error_Msg_N
("two access attributes cannot be compared directly", N);
Error_Msg_N
("\use qualified expression for one of the operands",
N);
return;
-- Another one for C programmers
elsif Nkind (N) = N_Op_Concat
and then Valid_Boolean_Arg (Etype (L))
and then Valid_Boolean_Arg (Etype (R))
then
Error_Msg_N ("invalid operands for concatenation", N);
Error_Msg_N -- CODEFIX
("\maybe AND was meant", N);
return;
-- A special case for comparison of access parameter with null
elsif Nkind (N) = N_Op_Eq
and then Is_Entity_Name (L)
and then Nkind (Parent (Entity (L))) = N_Parameter_Specification
and then Nkind (Parameter_Type (Parent (Entity (L)))) =
N_Access_Definition
and then Nkind (R) = N_Null
then
Error_Msg_N ("access parameter is not allowed to be null", L);
Error_Msg_N ("\(call would raise Constraint_Error)", L);
return;
-- Another special case for exponentiation, where the right
-- operand must be Natural, independently of the base.
elsif Nkind (N) = N_Op_Expon
and then Is_Numeric_Type (Etype (L))
and then not Is_Overloaded (R)
and then
First_Subtype (Base_Type (Etype (R))) /= Standard_Integer
and then Base_Type (Etype (R)) /= Universal_Integer
then
if Ada_Version >= Ada_2012
and then Has_Dimension_System (Etype (L))
then
Error_Msg_NE
("exponent for dimensioned type must be a rational" &
", found}", R, Etype (R));
else
Error_Msg_NE
("exponent must be of type Natural, found}", R, Etype (R));
end if;
return;
elsif Nkind (N) in N_Op_Eq | N_Op_Ne then
if Address_Integer_Convert_OK (Etype (R), Etype (L)) then
Rewrite (L,
Unchecked_Convert_To (
Standard_Address, Relocate_Node (L)));
Rewrite (R,
Unchecked_Convert_To (
Standard_Address, Relocate_Node (R)));
Analyze_Equality_Op (N);
return;
-- Under relaxed RM semantics silently replace occurrences of
-- null by System.Address_Null.
elsif Null_To_Null_Address_Convert_OK (N) then
Replace_Null_By_Null_Address (N);
Analyze_Equality_Op (N);
return;
end if;
end if;
-- If we fall through then just give general message. Note that in
-- the following messages, if the operand is overloaded we choose
-- an arbitrary type to complain about, but that is probably more
-- useful than not giving a type at all.
if Nkind (N) in N_Unary_Op then
Error_Msg_Node_2 := Etype (R);
Error_Msg_N ("operator& not defined for}", N);
return;
else
if Nkind (N) in N_Binary_Op then
if not Is_Overloaded (L)
and then not Is_Overloaded (R)
and then Base_Type (Etype (L)) = Base_Type (Etype (R))
then
Error_Msg_Node_2 := First_Subtype (Etype (R));
Error_Msg_N ("there is no applicable operator& for}", N);
else
-- Another attempt to find a fix: one of the candidate
-- interpretations may not be use-visible. This has
-- already been checked for predefined operators, so
-- we examine only user-defined functions.
Op_Id := Get_Name_Entity_Id (Chars (N));
while Present (Op_Id) loop
if Ekind (Op_Id) /= E_Operator
and then Is_Overloadable (Op_Id)
then
if not Is_Immediately_Visible (Op_Id)
and then not In_Use (Scope (Op_Id))
and then not Is_Abstract_Subprogram (Op_Id)
and then not Is_Hidden (Op_Id)
and then Ekind (Scope (Op_Id)) = E_Package
and then
Has_Compatible_Type
(L, Etype (First_Formal (Op_Id)))
and then Present
(Next_Formal (First_Formal (Op_Id)))
and then
Has_Compatible_Type
(R,
Etype (Next_Formal (First_Formal (Op_Id))))
then
Error_Msg_N
("no legal interpretation for operator&", N);
Error_Msg_NE
("\use clause on& would make operation legal",
N, Scope (Op_Id));
exit;
end if;
end if;
Op_Id := Homonym (Op_Id);
end loop;
if No (Op_Id) then
Error_Msg_N ("invalid operand types for operator&", N);
if Nkind (N) /= N_Op_Concat then
Error_Msg_NE ("\left operand has}!", N, Etype (L));
Error_Msg_NE ("\right operand has}!", N, Etype (R));
-- For multiplication and division operators with
-- a fixed-point operand and an integer operand,
-- indicate that the integer operand should be of
-- type Integer.
if Nkind (N) in N_Op_Multiply | N_Op_Divide
and then Is_Fixed_Point_Type (Etype (L))
and then Is_Integer_Type (Etype (R))
then
Error_Msg_N
("\convert right operand to `Integer`", N);
elsif Nkind (N) = N_Op_Multiply
and then Is_Fixed_Point_Type (Etype (R))
and then Is_Integer_Type (Etype (L))
then
Error_Msg_N
("\convert left operand to `Integer`", N);
end if;
-- For concatenation operators it is more difficult to
-- determine which is the wrong operand. It is worth
-- flagging explicitly an access type, for those who
-- might think that a dereference happens here.
elsif Is_Access_Type (Etype (L)) then
Error_Msg_N ("\left operand is access type", N);
elsif Is_Access_Type (Etype (R)) then
Error_Msg_N ("\right operand is access type", N);
end if;
end if;
end if;
end if;
end if;
end;
end if;
end Operator_Check;
----------------------------------
-- Has_Possible_Literal_Aspects --
----------------------------------
function Has_Possible_Literal_Aspects (N : Node_Id) return Boolean is
R : constant Node_Id := Right_Opnd (N);
L : Node_Id := Empty;
procedure Check_Literal_Opnd (Opnd : Node_Id);
-- If an operand is a literal to which an aspect may apply,
-- add the corresponding type to operator node.
------------------------
-- Check_Literal_Opnd --
------------------------
procedure Check_Literal_Opnd (Opnd : Node_Id) is
begin
if Nkind (Opnd) in N_Numeric_Or_String_Literal
or else (Is_Entity_Name (Opnd)
and then Present (Entity (Opnd))
and then Is_Named_Number (Entity (Opnd)))
then
Add_One_Interp (N, Etype (Opnd), Etype (Opnd));
end if;
end Check_Literal_Opnd;
-- Start of processing for Has_Possible_Literal_Aspects
begin
if Ada_Version < Ada_2022 then
return False;
end if;
if Nkind (N) in N_Binary_Op then
L := Left_Opnd (N);
else
L := Empty;
end if;
Check_Literal_Opnd (R);
-- Check left operand only if right one did not provide a
-- possible interpretation. Note that literal types are not
-- overloadable, in the sense that there is no overloadable
-- entity name whose several interpretations can be used to
-- indicate possible resulting types, so there is no way to
-- provide more than one interpretation to the operator node.
-- The choice of one operand over the other is arbitrary at
-- this point, and may lead to spurious resolution when both
-- operands are literals of different kinds, but the second
-- pass of resolution will examine anew both operands to
-- determine whether a user-defined literal may apply to
-- either or both.
if Present (L)
and then Etype (N) = Any_Type
then
Check_Literal_Opnd (L);
end if;
return Etype (N) /= Any_Type;
end Has_Possible_Literal_Aspects;
--------------------------------
-- Remove_Abstract_Operations --
--------------------------------
procedure Remove_Abstract_Operations (N : Node_Id) is
Abstract_Op : Entity_Id := Empty;
Address_Descendant : Boolean := False;
I : Interp_Index;
It : Interp;
-- AI-310: If overloaded, remove abstract non-dispatching operations. We
-- activate this if either extensions are enabled, or if the abstract
-- operation in question comes from a predefined file. This latter test
-- allows us to use abstract to make operations invisible to users. In
-- particular, if type Address is non-private and abstract subprograms
-- are used to hide its operators, they will be truly hidden.
type Operand_Position is (First_Op, Second_Op);
Univ_Type : constant Entity_Id := Universal_Interpretation (N);
procedure Remove_Address_Interpretations (Op : Operand_Position);
-- Ambiguities may arise when the operands are literal and the address
-- operations in s-auxdec are visible. In that case, remove the
-- interpretation of a literal as Address, to retain the semantics
-- of Address as a private type.
------------------------------------
-- Remove_Address_Interpretations --
------------------------------------
procedure Remove_Address_Interpretations (Op : Operand_Position) is
Formal : Entity_Id;
begin
if Is_Overloaded (N) then
Get_First_Interp (N, I, It);
while Present (It.Nam) loop
Formal := First_Entity (It.Nam);
if Op = Second_Op then
Next_Entity (Formal);
end if;
if Is_Descendant_Of_Address (Etype (Formal)) then
Address_Descendant := True;
Remove_Interp (I);
end if;
Get_Next_Interp (I, It);
end loop;
end if;
end Remove_Address_Interpretations;
-- Start of processing for Remove_Abstract_Operations
begin
if Is_Overloaded (N) then
if Debug_Flag_V then
Write_Line ("Remove_Abstract_Operations: ");
Write_Overloads (N);
end if;
Get_First_Interp (N, I, It);
while Present (It.Nam) loop
if Is_Overloadable (It.Nam)
and then Is_Abstract_Subprogram (It.Nam)
and then not Is_Dispatching_Operation (It.Nam)
then
Abstract_Op := It.Nam;
if Is_Descendant_Of_Address (It.Typ) then
Address_Descendant := True;
Remove_Interp (I);
exit;
-- In Ada 2005, this operation does not participate in overload
-- resolution. If the operation is defined in a predefined
-- unit, it is one of the operations declared abstract in some
-- variants of System, and it must be removed as well.
elsif Ada_Version >= Ada_2005
or else In_Predefined_Unit (It.Nam)
then
Remove_Interp (I);
exit;
end if;
end if;
Get_Next_Interp (I, It);
end loop;
if No (Abstract_Op) then
-- If some interpretation yields an integer type, it is still
-- possible that there are address interpretations. Remove them
-- if one operand is a literal, to avoid spurious ambiguities
-- on systems where Address is a visible integer type.
if Is_Overloaded (N)
and then Nkind (N) in N_Op
and then Is_Integer_Type (Etype (N))
then
if Nkind (N) in N_Binary_Op then
if Nkind (Right_Opnd (N)) = N_Integer_Literal then
Remove_Address_Interpretations (Second_Op);
elsif Nkind (Left_Opnd (N)) = N_Integer_Literal then
Remove_Address_Interpretations (First_Op);
end if;
end if;
end if;
elsif Nkind (N) in N_Op then
-- Remove interpretations that treat literals as addresses. This
-- is never appropriate, even when Address is defined as a visible
-- Integer type. The reason is that we would really prefer Address
-- to behave as a private type, even in this case. If Address is a
-- visible integer type, we get lots of overload ambiguities.
if Nkind (N) in N_Binary_Op then
declare
U1 : constant Boolean :=
Present (Universal_Interpretation (Right_Opnd (N)));
U2 : constant Boolean :=
Present (Universal_Interpretation (Left_Opnd (N)));
begin
if U1 then
Remove_Address_Interpretations (Second_Op);
end if;
if U2 then
Remove_Address_Interpretations (First_Op);
end if;
if not (U1 and U2) then
-- Remove corresponding predefined operator, which is
-- always added to the overload set.
Get_First_Interp (N, I, It);
while Present (It.Nam) loop
if Scope (It.Nam) = Standard_Standard
and then Base_Type (It.Typ) =
Base_Type (Etype (Abstract_Op))
then
Remove_Interp (I);
end if;
Get_Next_Interp (I, It);
end loop;
elsif Is_Overloaded (N)
and then Present (Univ_Type)
then
-- If both operands have a universal interpretation,
-- it is still necessary to remove interpretations that
-- yield Address. Any remaining ambiguities will be
-- removed in Disambiguate.
Get_First_Interp (N, I, It);
while Present (It.Nam) loop
if Is_Descendant_Of_Address (It.Typ) then
Remove_Interp (I);
elsif not Is_Type (It.Nam) then
Set_Entity (N, It.Nam);
end if;
Get_Next_Interp (I, It);
end loop;
end if;
end;
end if;
elsif Nkind (N) = N_Function_Call
and then
(Nkind (Name (N)) = N_Operator_Symbol
or else
(Nkind (Name (N)) = N_Expanded_Name
and then
Nkind (Selector_Name (Name (N))) = N_Operator_Symbol))
then
declare
Arg1 : constant Node_Id := First (Parameter_Associations (N));
U1 : constant Boolean :=
Present (Universal_Interpretation (Arg1));
U2 : constant Boolean :=
Present (Next (Arg1)) and then
Present (Universal_Interpretation (Next (Arg1)));
begin
if U1 then
Remove_Address_Interpretations (First_Op);
end if;
if U2 then
Remove_Address_Interpretations (Second_Op);
end if;
if not (U1 and U2) then
Get_First_Interp (N, I, It);
while Present (It.Nam) loop
if Scope (It.Nam) = Standard_Standard
and then It.Typ = Base_Type (Etype (Abstract_Op))
then
Remove_Interp (I);
end if;
Get_Next_Interp (I, It);
end loop;
end if;
end;
end if;
-- If the removal has left no valid interpretations, emit an error
-- message now and label node as illegal.
if Present (Abstract_Op) then
Get_First_Interp (N, I, It);
if No (It.Nam) then
-- Removal of abstract operation left no viable candidate
Set_Etype (N, Any_Type);
Error_Msg_Sloc := Sloc (Abstract_Op);
Error_Msg_NE
("cannot call abstract operation& declared#", N, Abstract_Op);
-- In Ada 2005, an abstract operation may disable predefined
-- operators. Since the context is not yet known, we mark the
-- predefined operators as potentially hidden. Do not include
-- predefined operators when addresses are involved since this
-- case is handled separately.
elsif Ada_Version >= Ada_2005 and then not Address_Descendant then
while Present (It.Nam) loop
if Is_Numeric_Type (It.Typ)
and then Scope (It.Typ) = Standard_Standard
and then Ekind (It.Nam) = E_Operator
then
Set_Abstract_Op (I, Abstract_Op);
end if;
Get_Next_Interp (I, It);
end loop;
end if;
end if;
if Debug_Flag_V then
Write_Line ("Remove_Abstract_Operations done: ");
Write_Overloads (N);
end if;
end if;
end Remove_Abstract_Operations;
----------------------------
-- Try_Container_Indexing --
----------------------------
function Try_Container_Indexing
(N : Node_Id;
Prefix : Node_Id;
Exprs : List_Id) return Boolean
is
Pref_Typ : Entity_Id := Etype (Prefix);
function Constant_Indexing_OK return Boolean;
-- Constant_Indexing is legal if there is no Variable_Indexing defined
-- for the type, or else node not a target of assignment, or an actual
-- for an IN OUT or OUT formal (RM 4.1.6 (11)).
function Expr_Matches_In_Formal
(Subp : Entity_Id;
Par : Node_Id) return Boolean;
-- Find formal corresponding to given indexed component that is an
-- actual in a call. Note that the enclosing subprogram call has not
-- been analyzed yet, and the parameter list is not normalized, so
-- that if the argument is a parameter association we must match it
-- by name and not by position.
function Find_Indexing_Operations
(T : Entity_Id;
Nam : Name_Id;
Is_Constant : Boolean) return Node_Id;
-- Return a reference to the primitive operation of type T denoted by
-- name Nam. If the operation is overloaded, the reference carries all
-- interpretations. Flag Is_Constant should be set when the context is
-- constant indexing.
--------------------------
-- Constant_Indexing_OK --
--------------------------
function Constant_Indexing_OK return Boolean is
Par : Node_Id;
begin
if No (Find_Value_Of_Aspect (Pref_Typ, Aspect_Variable_Indexing)) then
return True;
elsif not Is_Variable (Prefix) then
return True;
end if;
Par := N;
while Present (Par) loop
if Nkind (Parent (Par)) = N_Assignment_Statement
and then Par = Name (Parent (Par))
then
return False;
-- The call may be overloaded, in which case we assume that its
-- resolution does not depend on the type of the parameter that
-- includes the indexing operation.
elsif Nkind (Parent (Par)) in N_Subprogram_Call
and then Is_Entity_Name (Name (Parent (Par)))
then
declare
Proc : Entity_Id;
begin
-- We should look for an interpretation with the proper
-- number of formals, and determine whether it is an
-- In_Parameter, but for now we examine the formal that
-- corresponds to the indexing, and assume that variable
-- indexing is required if some interpretation has an
-- assignable formal at that position. Still does not
-- cover the most complex cases ???
if Is_Overloaded (Name (Parent (Par))) then
declare
Proc : constant Node_Id := Name (Parent (Par));
I : Interp_Index;
It : Interp;
begin
Get_First_Interp (Proc, I, It);
while Present (It.Nam) loop
if not Expr_Matches_In_Formal (It.Nam, Par) then
return False;
end if;
Get_Next_Interp (I, It);
end loop;
end;
-- All interpretations have a matching in-mode formal
return True;
else
Proc := Entity (Name (Parent (Par)));
-- If this is an indirect call, get formals from
-- designated type.
if Is_Access_Subprogram_Type (Etype (Proc)) then
Proc := Designated_Type (Etype (Proc));
end if;
end if;
return Expr_Matches_In_Formal (Proc, Par);
end;
elsif Nkind (Parent (Par)) = N_Object_Renaming_Declaration then
return False;
-- If the indexed component is a prefix it may be the first actual
-- of a prefixed call. Retrieve the called entity, if any, and
-- check its first formal. Determine if the context is a procedure
-- or function call.
elsif Nkind (Parent (Par)) = N_Selected_Component then
declare
Sel : constant Node_Id := Selector_Name (Parent (Par));
Nam : constant Entity_Id := Current_Entity (Sel);
begin
if Present (Nam) and then Is_Overloadable (Nam) then
if Nkind (Parent (Parent (Par))) =
N_Procedure_Call_Statement
then
return False;
elsif Ekind (Nam) = E_Function
and then Present (First_Formal (Nam))
then
return Ekind (First_Formal (Nam)) = E_In_Parameter;
end if;
end if;
end;
elsif Nkind (Par) in N_Op then
return True;
end if;
Par := Parent (Par);
end loop;
-- In all other cases, constant indexing is legal
return True;
end Constant_Indexing_OK;
----------------------------
-- Expr_Matches_In_Formal --
----------------------------
function Expr_Matches_In_Formal
(Subp : Entity_Id;
Par : Node_Id) return Boolean
is
Actual : Node_Id;
Formal : Node_Id;
begin
Formal := First_Formal (Subp);
Actual := First (Parameter_Associations ((Parent (Par))));
if Nkind (Par) /= N_Parameter_Association then
-- Match by position
while Present (Actual) and then Present (Formal) loop
exit when Actual = Par;
Next (Actual);
if Present (Formal) then
Next_Formal (Formal);
-- Otherwise this is a parameter mismatch, the error is
-- reported elsewhere, or else variable indexing is implied.
else
return False;
end if;
end loop;
else
-- Match by name
while Present (Formal) loop
exit when Chars (Formal) = Chars (Selector_Name (Par));
Next_Formal (Formal);
if No (Formal) then
return False;
end if;
end loop;
end if;
return Present (Formal) and then Ekind (Formal) = E_In_Parameter;
end Expr_Matches_In_Formal;
------------------------------
-- Find_Indexing_Operations --
------------------------------
function Find_Indexing_Operations
(T : Entity_Id;
Nam : Name_Id;
Is_Constant : Boolean) return Node_Id
is
procedure Inspect_Declarations
(Typ : Entity_Id;
Ref : in out Node_Id);
-- Traverse the declarative list where type Typ resides and collect
-- all suitable interpretations in node Ref.
procedure Inspect_Primitives
(Typ : Entity_Id;
Ref : in out Node_Id);
-- Traverse the list of primitive operations of type Typ and collect
-- all suitable interpretations in node Ref.
function Is_OK_Candidate
(Subp_Id : Entity_Id;
Typ : Entity_Id) return Boolean;
-- Determine whether subprogram Subp_Id is a suitable indexing
-- operation for type Typ. To qualify as such, the subprogram must
-- be a function, have at least two parameters, and the type of the
-- first parameter must be either Typ, or Typ'Class, or access [to
-- constant] with designated type Typ or Typ'Class.
procedure Record_Interp (Subp_Id : Entity_Id; Ref : in out Node_Id);
-- Store subprogram Subp_Id as an interpretation in node Ref
--------------------------
-- Inspect_Declarations --
--------------------------
procedure Inspect_Declarations
(Typ : Entity_Id;
Ref : in out Node_Id)
is
Typ_Decl : constant Node_Id := Declaration_Node (Typ);
Decl : Node_Id;
Subp_Id : Entity_Id;
begin
-- Ensure that the routine is not called with itypes, which lack a
-- declarative node.
pragma Assert (Present (Typ_Decl));
pragma Assert (Is_List_Member (Typ_Decl));
Decl := First (List_Containing (Typ_Decl));
while Present (Decl) loop
if Nkind (Decl) = N_Subprogram_Declaration then
Subp_Id := Defining_Entity (Decl);
if Is_OK_Candidate (Subp_Id, Typ) then
Record_Interp (Subp_Id, Ref);
end if;
end if;
Next (Decl);
end loop;
end Inspect_Declarations;
------------------------
-- Inspect_Primitives --
------------------------
procedure Inspect_Primitives
(Typ : Entity_Id;
Ref : in out Node_Id)
is
Prim_Elmt : Elmt_Id;
Prim_Id : Entity_Id;
begin
Prim_Elmt := First_Elmt (Primitive_Operations (Typ));
while Present (Prim_Elmt) loop
Prim_Id := Node (Prim_Elmt);
if Is_OK_Candidate (Prim_Id, Typ) then
Record_Interp (Prim_Id, Ref);
end if;
Next_Elmt (Prim_Elmt);
end loop;
end Inspect_Primitives;
---------------------
-- Is_OK_Candidate --
---------------------
function Is_OK_Candidate
(Subp_Id : Entity_Id;
Typ : Entity_Id) return Boolean
is
Formal : Entity_Id;
Formal_Typ : Entity_Id;
Param_Typ : Node_Id;
begin
-- To classify as a suitable candidate, the subprogram must be a
-- function whose name matches the argument of aspect Constant or
-- Variable_Indexing.
if Ekind (Subp_Id) = E_Function and then Chars (Subp_Id) = Nam then
Formal := First_Formal (Subp_Id);
-- The candidate requires at least two parameters
if Present (Formal) and then Present (Next_Formal (Formal)) then
Formal_Typ := Empty;
Param_Typ := Parameter_Type (Parent (Formal));
-- Use the designated type when the first parameter is of an
-- access type.
if Nkind (Param_Typ) = N_Access_Definition
and then Present (Subtype_Mark (Param_Typ))
then
-- When the context is a constant indexing, the access
-- definition must be access-to-constant. This does not
-- apply to variable indexing.
if not Is_Constant
or else Constant_Present (Param_Typ)
then
Formal_Typ := Etype (Subtype_Mark (Param_Typ));
end if;
-- Otherwise use the parameter type
else
Formal_Typ := Etype (Param_Typ);
end if;
if Present (Formal_Typ) then
-- Use the specific type when the parameter type is
-- class-wide.
if Is_Class_Wide_Type (Formal_Typ) then
Formal_Typ := Etype (Base_Type (Formal_Typ));
end if;
-- Use the full view when the parameter type is private
-- or incomplete.
if Is_Incomplete_Or_Private_Type (Formal_Typ)
and then Present (Full_View (Formal_Typ))
then
Formal_Typ := Full_View (Formal_Typ);
end if;
-- The type of the first parameter must denote the type
-- of the container or acts as its ancestor type.
return
Formal_Typ = Typ
or else Is_Ancestor (Formal_Typ, Typ);
end if;
end if;
end if;
return False;
end Is_OK_Candidate;
-------------------
-- Record_Interp --
-------------------
procedure Record_Interp (Subp_Id : Entity_Id; Ref : in out Node_Id) is
begin
if Present (Ref) then
Add_One_Interp (Ref, Subp_Id, Etype (Subp_Id));
-- Otherwise this is the first interpretation. Create a reference
-- where all remaining interpretations will be collected.
else
Ref := New_Occurrence_Of (Subp_Id, Sloc (T));
end if;
end Record_Interp;
-- Local variables
Ref : Node_Id;
Typ : Entity_Id;
-- Start of processing for Find_Indexing_Operations
begin
Typ := T;
-- Use the specific type when the parameter type is class-wide
if Is_Class_Wide_Type (Typ) then
Typ := Root_Type (Typ);
end if;
Ref := Empty;
Typ := Underlying_Type (Base_Type (Typ));
Inspect_Primitives (Typ, Ref);
-- Now look for explicit declarations of an indexing operation.
-- If the type is private the operation may be declared in the
-- visible part that contains the partial view.
if Is_Private_Type (T) then
Inspect_Declarations (T, Ref);
end if;
Inspect_Declarations (Typ, Ref);
return Ref;
end Find_Indexing_Operations;
-- Local variables
Loc : constant Source_Ptr := Sloc (N);
Assoc : List_Id;
C_Type : Entity_Id;
Func : Entity_Id;
Func_Name : Node_Id;
Indexing : Node_Id;
Is_Constant_Indexing : Boolean := False;
-- This flag reflects the nature of the container indexing. Note that
-- the context may be suited for constant indexing, but the type may
-- lack a Constant_Indexing annotation.
-- Start of processing for Try_Container_Indexing
begin
-- Node may have been analyzed already when testing for a prefixed
-- call, in which case do not redo analysis.
if Present (Generalized_Indexing (N)) then
return True;
end if;
-- An explicit dereference needs to be created in the case of a prefix
-- that's an access.
-- It seems that this should be done elsewhere, but not clear where that
-- should happen. Normally Insert_Explicit_Dereference is called via
-- Resolve_Implicit_Dereference, called from Resolve_Indexed_Component,
-- but that won't be called in this case because we transform the
-- indexing to a call. Resolve_Call.Check_Prefixed_Call takes care of
-- implicit dereferencing and referencing on prefixed calls, but that
-- would be too late, even if we expanded to a prefix call, because
-- Process_Indexed_Component will flag an error before the resolution
-- happens. ???
if Is_Access_Type (Pref_Typ) then
Pref_Typ := Implicitly_Designated_Type (Pref_Typ);
Insert_Explicit_Dereference (Prefix);
Error_Msg_NW (Warn_On_Dereference, "?d?implicit dereference", N);
end if;
C_Type := Pref_Typ;
-- If indexing a class-wide container, obtain indexing primitive from
-- specific type.
if Is_Class_Wide_Type (C_Type) then
C_Type := Etype (Base_Type (C_Type));
end if;
-- Check whether the type has a specified indexing aspect
Func_Name := Empty;
-- The context is suitable for constant indexing, so obtain the name of
-- the indexing function from aspect Constant_Indexing.
if Constant_Indexing_OK then
Func_Name :=
Find_Value_Of_Aspect (Pref_Typ, Aspect_Constant_Indexing);
end if;
if Present (Func_Name) then
Is_Constant_Indexing := True;
-- Otherwise attempt variable indexing
else
Func_Name :=
Find_Value_Of_Aspect (Pref_Typ, Aspect_Variable_Indexing);
end if;
-- The type is not subject to either form of indexing, therefore the
-- indexed component does not denote container indexing. If this is a
-- true error, it is diagnosed by the caller.
if No (Func_Name) then
-- The prefix itself may be an indexing of a container. Rewrite it
-- as such and retry.
if Has_Implicit_Dereference (Pref_Typ) then
Build_Explicit_Dereference
(Prefix, Get_Reference_Discriminant (Pref_Typ));
return Try_Container_Indexing (N, Prefix, Exprs);
-- Otherwise this is definitely not container indexing
else
return False;
end if;
-- If the container type is derived from another container type, the
-- value of the inherited aspect is the Reference operation declared
-- for the parent type.
-- However, Reference is also a primitive operation of the type, and the
-- inherited operation has a different signature. We retrieve the right
-- ones (the function may be overloaded) from the list of primitive
-- operations of the derived type.
-- Note that predefined containers are typically all derived from one of
-- the Controlled types. The code below is motivated by containers that
-- are derived from other types with a Reference aspect.
-- Note as well that we need to examine the base type, given that
-- the container object may be a constrained subtype or itype that
-- does not have an explicit declaration.
elsif Is_Derived_Type (C_Type)
and then Etype (First_Formal (Entity (Func_Name))) /= Pref_Typ
then
Func_Name :=
Find_Indexing_Operations
(T => Base_Type (C_Type),
Nam => Chars (Func_Name),
Is_Constant => Is_Constant_Indexing);
end if;
Assoc := New_List (Relocate_Node (Prefix));
-- A generalized indexing may have nore than one index expression, so
-- transfer all of them to the argument list to be used in the call.
-- Note that there may be named associations, in which case the node
-- was rewritten earlier as a call, and has been transformed back into
-- an indexed expression to share the following processing.
-- The generalized indexing node is the one on which analysis and
-- resolution take place. Before expansion the original node is replaced
-- with the generalized indexing node, which is a call, possibly with a
-- dereference operation.
if Comes_From_Source (N) then
Check_Compiler_Unit ("generalized indexing", N);
end if;
-- Create argument list for function call that represents generalized
-- indexing. Note that indices (i.e. actuals) may themselves be
-- overloaded.
declare
Arg : Node_Id;
New_Arg : Node_Id;
begin
Arg := First (Exprs);
while Present (Arg) loop
New_Arg := Relocate_Node (Arg);
-- The arguments can be parameter associations, in which case the
-- explicit actual parameter carries the overloadings.
if Nkind (New_Arg) /= N_Parameter_Association then
Save_Interps (Arg, New_Arg);
end if;
Append (New_Arg, Assoc);
Next (Arg);
end loop;
end;
if not Is_Overloaded (Func_Name) then
Func := Entity (Func_Name);
-- Can happen in case of e.g. cascaded errors
if No (Func) then
return False;
end if;
Indexing :=
Make_Function_Call (Loc,
Name => New_Occurrence_Of (Func, Loc),
Parameter_Associations => Assoc);
Set_Parent (Indexing, Parent (N));
Set_Generalized_Indexing (N, Indexing);
Analyze (Indexing);
Set_Etype (N, Etype (Indexing));
-- If the return type of the indexing function is a reference type,
-- add the dereference as a possible interpretation. Note that the
-- indexing aspect may be a function that returns the element type
-- with no intervening implicit dereference, and that the reference
-- discriminant is not the first discriminant.
if Has_Discriminants (Etype (Func)) then
Check_Implicit_Dereference (N, Etype (Func));
end if;
else
-- If there are multiple indexing functions, build a function call
-- and analyze it for each of the possible interpretations.
Indexing :=
Make_Function_Call (Loc,
Name =>
Make_Identifier (Loc, Chars (Func_Name)),
Parameter_Associations => Assoc);
Set_Parent (Indexing, Parent (N));
Set_Generalized_Indexing (N, Indexing);
Set_Etype (N, Any_Type);
Set_Etype (Name (Indexing), Any_Type);
declare
I : Interp_Index;
It : Interp;
Success : Boolean;
begin
Get_First_Interp (Func_Name, I, It);
Set_Etype (Indexing, Any_Type);
-- Analyze each candidate function with the given actuals
while Present (It.Nam) loop
Analyze_One_Call (Indexing, It.Nam, False, Success);
Get_Next_Interp (I, It);
end loop;
-- If there are several successful candidates, resolution will
-- be by result. Mark the interpretations of the function name
-- itself.
if Is_Overloaded (Indexing) then
Get_First_Interp (Indexing, I, It);
while Present (It.Nam) loop
Add_One_Interp (Name (Indexing), It.Nam, It.Typ);
Get_Next_Interp (I, It);
end loop;
else
Set_Etype (Name (Indexing), Etype (Indexing));
end if;
-- Now add the candidate interpretations to the indexing node
-- itself, to be replaced later by the function call.
if Is_Overloaded (Name (Indexing)) then
Get_First_Interp (Name (Indexing), I, It);
while Present (It.Nam) loop
Add_One_Interp (N, It.Nam, It.Typ);
-- Add dereference interpretation if the result type has
-- implicit reference discriminants.
if Has_Discriminants (Etype (It.Nam)) then
Check_Implicit_Dereference (N, Etype (It.Nam));
end if;
Get_Next_Interp (I, It);
end loop;
else
Set_Etype (N, Etype (Name (Indexing)));
if Has_Discriminants (Etype (N)) then
Check_Implicit_Dereference (N, Etype (N));
end if;
end if;
end;
end if;
if Etype (Indexing) = Any_Type then
Error_Msg_NE
("container cannot be indexed with&", N, Etype (First (Exprs)));
Rewrite (N, New_Occurrence_Of (Any_Id, Loc));
end if;
return True;
end Try_Container_Indexing;
-----------------------
-- Try_Indirect_Call --
-----------------------
function Try_Indirect_Call
(N : Node_Id;
Nam : Entity_Id;
Typ : Entity_Id) return Boolean
is
Actual : Node_Id;
Formal : Entity_Id;
Call_OK : Boolean;
pragma Warnings (Off, Call_OK);
begin
Normalize_Actuals (N, Designated_Type (Typ), False, Call_OK);
Actual := First_Actual (N);
Formal := First_Formal (Designated_Type (Typ));
while Present (Actual) and then Present (Formal) loop
if not Has_Compatible_Type (Actual, Etype (Formal)) then
return False;
end if;
Next (Actual);
Next_Formal (Formal);
end loop;
if No (Actual) and then No (Formal) then
Add_One_Interp (N, Nam, Etype (Designated_Type (Typ)));
-- Nam is a candidate interpretation for the name in the call,
-- if it is not an indirect call.
if not Is_Type (Nam)
and then Is_Entity_Name (Name (N))
then
Set_Entity (Name (N), Nam);
end if;
return True;
else
return False;
end if;
end Try_Indirect_Call;
----------------------
-- Try_Indexed_Call --
----------------------
function Try_Indexed_Call
(N : Node_Id;
Nam : Entity_Id;
Typ : Entity_Id;
Skip_First : Boolean) return Boolean
is
Loc : constant Source_Ptr := Sloc (N);
Actuals : constant List_Id := Parameter_Associations (N);
Actual : Node_Id;
Index : Entity_Id;
begin
Actual := First (Actuals);
-- If the call was originally written in prefix form, skip the first
-- actual, which is obviously not defaulted.
if Skip_First then
Next (Actual);
end if;
Index := First_Index (Typ);
while Present (Actual) and then Present (Index) loop
-- If the parameter list has a named association, the expression
-- is definitely a call and not an indexed component.
if Nkind (Actual) = N_Parameter_Association then
return False;
end if;
if Is_Entity_Name (Actual)
and then Is_Type (Entity (Actual))
and then No (Next (Actual))
then
-- A single actual that is a type name indicates a slice if the
-- type is discrete, and an error otherwise.
if Is_Discrete_Type (Entity (Actual)) then
Rewrite (N,
Make_Slice (Loc,
Prefix =>
Make_Function_Call (Loc,
Name => Relocate_Node (Name (N))),
Discrete_Range =>
New_Occurrence_Of (Entity (Actual), Sloc (Actual))));
Analyze (N);
else
Error_Msg_N ("invalid use of type in expression", Actual);
Set_Etype (N, Any_Type);
end if;
return True;
elsif not Has_Compatible_Type (Actual, Etype (Index)) then
return False;
end if;
Next (Actual);
Next_Index (Index);
end loop;
if No (Actual) and then No (Index) then
Add_One_Interp (N, Nam, Component_Type (Typ));
-- Nam is a candidate interpretation for the name in the call,
-- if it is not an indirect call.
if not Is_Type (Nam)
and then Is_Entity_Name (Name (N))
then
Set_Entity (Name (N), Nam);
end if;
return True;
else
return False;
end if;
end Try_Indexed_Call;
--------------------------
-- Try_Object_Operation --
--------------------------
function Try_Object_Operation
(N : Node_Id; CW_Test_Only : Boolean := False) return Boolean
is
K : constant Node_Kind := Nkind (Parent (N));
Is_Subprg_Call : constant Boolean := K in N_Subprogram_Call;
Loc : constant Source_Ptr := Sloc (N);
Obj : constant Node_Id := Prefix (N);
Subprog : constant Node_Id :=
Make_Identifier (Sloc (Selector_Name (N)),
Chars => Chars (Selector_Name (N)));
-- Identifier on which possible interpretations will be collected
Report_Error : Boolean := False;
-- If no candidate interpretation matches the context, redo analysis
-- with Report_Error True to provide additional information.
Actual : Node_Id;
Candidate : Entity_Id := Empty;
New_Call_Node : Node_Id := Empty;
Node_To_Replace : Node_Id;
Obj_Type : Entity_Id := Etype (Obj);
Success : Boolean := False;
procedure Complete_Object_Operation
(Call_Node : Node_Id;
Node_To_Replace : Node_Id);
-- Make Subprog the name of Call_Node, replace Node_To_Replace with
-- Call_Node, insert the object (or its dereference) as the first actual
-- in the call, and complete the analysis of the call.
procedure Report_Ambiguity (Op : Entity_Id);
-- If a prefixed procedure call is ambiguous, indicate whether the call
-- includes an implicit dereference or an implicit 'Access.
procedure Transform_Object_Operation
(Call_Node : out Node_Id;
Node_To_Replace : out Node_Id);
-- Transform Obj.Operation (X, Y, ...) into Operation (Obj, X, Y ...).
-- Call_Node is the resulting subprogram call, Node_To_Replace is
-- either N or the parent of N, and Subprog is a reference to the
-- subprogram we are trying to match. Note that the transformation
-- may be partially destructive for the parent of N, so it needs to
-- be undone in the case where Try_Object_Operation returns false.
function Try_Class_Wide_Operation
(Call_Node : Node_Id;
Node_To_Replace : Node_Id) return Boolean;
-- Traverse all ancestor types looking for a class-wide subprogram for
-- which the current operation is a valid non-dispatching call.
procedure Try_One_Prefix_Interpretation (T : Entity_Id);
-- If prefix is overloaded, its interpretation may include different
-- tagged types, and we must examine the primitive operations and the
-- class-wide operations of each in order to find candidate
-- interpretations for the call as a whole.
function Try_Primitive_Operation
(Call_Node : Node_Id;
Node_To_Replace : Node_Id) return Boolean;
-- Traverse the list of primitive subprograms looking for a dispatching
-- operation for which the current node is a valid call.
function Valid_Candidate
(Success : Boolean;
Call : Node_Id;
Subp : Entity_Id) return Entity_Id;
-- If the subprogram is a valid interpretation, record it, and add to
-- the list of interpretations of Subprog. Otherwise return Empty.
-------------------------------
-- Complete_Object_Operation --
-------------------------------
procedure Complete_Object_Operation
(Call_Node : Node_Id;
Node_To_Replace : Node_Id)
is
Control : constant Entity_Id := First_Formal (Entity (Subprog));
Formal_Type : constant Entity_Id := Etype (Control);
First_Actual : Node_Id;
begin
-- Place the name of the operation, with its interpretations,
-- on the rewritten call.
Set_Name (Call_Node, Subprog);
First_Actual := First (Parameter_Associations (Call_Node));
-- For cross-reference purposes, treat the new node as being in the
-- source if the original one is. Set entity and type, even though
-- they may be overwritten during resolution if overloaded.
Set_Comes_From_Source (Subprog, Comes_From_Source (N));
Set_Comes_From_Source (Call_Node, Comes_From_Source (N));
if Nkind (N) = N_Selected_Component
and then not Inside_A_Generic
then
Set_Entity (Selector_Name (N), Entity (Subprog));
Set_Etype (Selector_Name (N), Etype (Entity (Subprog)));
end if;
-- If need be, rewrite first actual as an explicit dereference. If
-- the call is overloaded, the rewriting can only be done once the
-- primitive operation is identified.
if Is_Overloaded (Subprog) then
-- The prefix itself may be overloaded, and its interpretations
-- must be propagated to the new actual in the call.
if Is_Overloaded (Obj) then
Save_Interps (Obj, First_Actual);
end if;
Rewrite (First_Actual, Obj);
elsif not Is_Access_Type (Formal_Type)
and then Is_Access_Type (Etype (Obj))
then
Rewrite (First_Actual,
Make_Explicit_Dereference (Sloc (Obj), Obj));
Analyze (First_Actual);
-- If we need to introduce an explicit dereference, verify that
-- the resulting actual is compatible with the mode of the formal.
if Ekind (First_Formal (Entity (Subprog))) /= E_In_Parameter
and then Is_Access_Constant (Etype (Obj))
then
Error_Msg_NE
("expect variable in call to&", Prefix (N), Entity (Subprog));
end if;
-- Conversely, if the formal is an access parameter and the object is
-- not an access type or a reference type (i.e. a type with the
-- Implicit_Dereference aspect specified), replace the actual with a
-- 'Access reference. Its analysis will check that the object is
-- aliased.
elsif Is_Access_Type (Formal_Type)
and then not Is_Access_Type (Etype (Obj))
and then
(not Has_Implicit_Dereference (Etype (Obj))
or else
not Is_Access_Type (Designated_Type (Etype
(Get_Reference_Discriminant (Etype (Obj))))))
then
-- A special case: A.all'Access is illegal if A is an access to a
-- constant and the context requires an access to a variable.
if not Is_Access_Constant (Formal_Type) then
if (Nkind (Obj) = N_Explicit_Dereference
and then Is_Access_Constant (Etype (Prefix (Obj))))
or else not Is_Variable (Obj)
then
Error_Msg_NE
("actual for & must be a variable", Obj, Control);
end if;
end if;
Rewrite (First_Actual,
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Access,
Prefix => Relocate_Node (Obj)));
-- If the object is not overloaded verify that taking access of
-- it is legal. Otherwise check is made during resolution.
if not Is_Overloaded (Obj)
and then not Is_Aliased_View (Obj)
then
Error_Msg_NE
("object in prefixed call to & must be aliased "
& "(RM 4.1.3 (13 1/2))", Prefix (First_Actual), Subprog);
end if;
Analyze (First_Actual);
else
if Is_Overloaded (Obj) then
Save_Interps (Obj, First_Actual);
end if;
Rewrite (First_Actual, Obj);
end if;
if In_Extended_Main_Source_Unit (Current_Scope) then
-- The operation is obtained from the dispatch table and not by
-- visibility, and may be declared in a unit that is not
-- explicitly referenced in the source, but is nevertheless
-- required in the context of the current unit. Indicate that
-- operation and its scope are referenced, to prevent spurious and
-- misleading warnings. If the operation is overloaded, all
-- primitives are in the same scope and we can use any of them.
-- Don't do that outside the main unit since otherwise this will
-- e.g. prevent the detection of some unused with clauses.
Set_Referenced (Entity (Subprog), True);
Set_Referenced (Scope (Entity (Subprog)), True);
end if;
Rewrite (Node_To_Replace, Call_Node);
-- Propagate the interpretations collected in subprog to the new
-- function call node, to be resolved from context.
if Is_Overloaded (Subprog) then
Save_Interps (Subprog, Node_To_Replace);
else
-- The type of the subprogram may be a limited view obtained
-- transitively from another unit. If full view is available,
-- use it to analyze call. If there is no nonlimited view, then
-- this is diagnosed when analyzing the rewritten call.
declare
T : constant Entity_Id := Etype (Subprog);
begin
if From_Limited_With (T) then
Set_Etype (Entity (Subprog), Available_View (T));
end if;
end;
Analyze (Node_To_Replace);
-- If the operation has been rewritten into a call, which may get
-- subsequently an explicit dereference, preserve the type on the
-- original node (selected component or indexed component) for
-- subsequent legality tests, e.g. Is_Variable. which examines
-- the original node.
if Nkind (Node_To_Replace) = N_Function_Call then
Set_Etype
(Original_Node (Node_To_Replace), Etype (Node_To_Replace));
end if;
end if;
end Complete_Object_Operation;
----------------------
-- Report_Ambiguity --
----------------------
procedure Report_Ambiguity (Op : Entity_Id) is
Access_Actual : constant Boolean :=
Is_Access_Type (Etype (Prefix (N)));
Access_Formal : Boolean := False;
begin
Error_Msg_Sloc := Sloc (Op);
if Present (First_Formal (Op)) then
Access_Formal := Is_Access_Type (Etype (First_Formal (Op)));
end if;
if Access_Formal and then not Access_Actual then
if Nkind (Parent (Op)) = N_Full_Type_Declaration then
Error_Msg_N
("\possible interpretation "
& "(inherited, with implicit 'Access) #", N);
else
Error_Msg_N
("\possible interpretation (with implicit 'Access) #", N);
end if;
elsif not Access_Formal and then Access_Actual then
if Nkind (Parent (Op)) = N_Full_Type_Declaration then
Error_Msg_N
("\possible interpretation "
& "(inherited, with implicit dereference) #", N);
else
Error_Msg_N
("\possible interpretation (with implicit dereference) #", N);
end if;
else
if Nkind (Parent (Op)) = N_Full_Type_Declaration then
Error_Msg_N ("\possible interpretation (inherited)#", N);
else
Error_Msg_N -- CODEFIX
("\possible interpretation#", N);
end if;
end if;
end Report_Ambiguity;
--------------------------------
-- Transform_Object_Operation --
--------------------------------
procedure Transform_Object_Operation
(Call_Node : out Node_Id;
Node_To_Replace : out Node_Id)
is
Dummy : constant Node_Id := New_Copy (Obj);
-- Placeholder used as a first parameter in the call, replaced
-- eventually by the proper object.
Parent_Node : constant Node_Id := Parent (N);
Actual : Node_Id;
Actuals : List_Id;
begin
-- Common case covering 1) Call to a procedure and 2) Call to a
-- function that has some additional actuals.
if Nkind (Parent_Node) in N_Subprogram_Call
-- N is a selected component node containing the name of the
-- subprogram. If N is not the name of the parent node we must
-- not replace the parent node by the new construct. This case
-- occurs when N is a parameterless call to a subprogram that
-- is an actual parameter of a call to another subprogram. For
-- example:
-- Some_Subprogram (..., Obj.Operation, ...)
and then N = Name (Parent_Node)
then
Node_To_Replace := Parent_Node;
Actuals := Parameter_Associations (Parent_Node);
if Present (Actuals) then
Prepend (Dummy, Actuals);
else
Actuals := New_List (Dummy);
end if;
if Nkind (Parent_Node) = N_Procedure_Call_Statement then
Call_Node :=
Make_Procedure_Call_Statement (Loc,
Name => New_Copy (Subprog),
Parameter_Associations => Actuals);
else
Call_Node :=
Make_Function_Call (Loc,
Name => New_Copy (Subprog),
Parameter_Associations => Actuals);
end if;
-- Before analysis, a function call appears as an indexed component
-- if there are no named associations.
elsif Nkind (Parent_Node) = N_Indexed_Component
and then N = Prefix (Parent_Node)
then
Node_To_Replace := Parent_Node;
Actuals := Expressions (Parent_Node);
Actual := First (Actuals);
while Present (Actual) loop
Analyze (Actual);
Next (Actual);
end loop;
Prepend (Dummy, Actuals);
Call_Node :=
Make_Function_Call (Loc,
Name => New_Copy (Subprog),
Parameter_Associations => Actuals);
-- Parameterless call: Obj.F is rewritten as F (Obj)
else
Node_To_Replace := N;
Call_Node :=
Make_Function_Call (Loc,
Name => New_Copy (Subprog),
Parameter_Associations => New_List (Dummy));
end if;
end Transform_Object_Operation;
------------------------------
-- Try_Class_Wide_Operation --
------------------------------
function Try_Class_Wide_Operation
(Call_Node : Node_Id;
Node_To_Replace : Node_Id) return Boolean
is
Anc_Type : Entity_Id;
Matching_Op : Entity_Id := Empty;
Error : Boolean;
procedure Traverse_Homonyms
(Anc_Type : Entity_Id;
Error : out Boolean);
-- Traverse the homonym chain of the subprogram searching for those
-- homonyms whose first formal has the Anc_Type's class-wide type,
-- or an anonymous access type designating the class-wide type. If
-- an ambiguity is detected, then Error is set to True.
procedure Traverse_Interfaces
(Anc_Type : Entity_Id;
Error : out Boolean);
-- Traverse the list of interfaces, if any, associated with Anc_Type
-- and search for acceptable class-wide homonyms associated with each
-- interface. If an ambiguity is detected, then Error is set to True.
-----------------------
-- Traverse_Homonyms --
-----------------------
procedure Traverse_Homonyms
(Anc_Type : Entity_Id;
Error : out Boolean)
is
function First_Formal_Match
(Subp_Id : Entity_Id;
Typ : Entity_Id) return Boolean;
-- Predicate to verify that the first foramal of class-wide
-- subprogram Subp_Id matches type Typ of the prefix.
------------------------
-- First_Formal_Match --
------------------------
function First_Formal_Match
(Subp_Id : Entity_Id;
Typ : Entity_Id) return Boolean
is
Ctrl : constant Entity_Id := First_Formal (Subp_Id);
begin
return
Present (Ctrl)
and then
(Base_Type (Etype (Ctrl)) = Typ
or else
(Ekind (Etype (Ctrl)) = E_Anonymous_Access_Type
and then
Base_Type (Designated_Type (Etype (Ctrl))) =
Typ));
end First_Formal_Match;
-- Local variables
CW_Typ : constant Entity_Id := Class_Wide_Type (Anc_Type);
Candidate : Entity_Id;
-- If homonym is a renaming, examine the renamed program
Hom : Entity_Id;
Hom_Ref : Node_Id;
Success : Boolean;
-- Start of processing for Traverse_Homonyms
begin
Error := False;
-- Find a non-hidden operation whose first parameter is of the
-- class-wide type, a subtype thereof, or an anonymous access
-- to same. If in an instance, the operation can be considered
-- even if hidden (it may be hidden because the instantiation
-- is expanded after the containing package has been analyzed).
-- If the subprogram is a generic actual in an enclosing instance,
-- it appears as a renaming that is a candidate interpretation as
-- well.
Hom := Current_Entity (Subprog);
while Present (Hom) loop
if Ekind (Hom) in E_Procedure | E_Function
and then Present (Renamed_Entity (Hom))
and then Is_Generic_Actual_Subprogram (Hom)
and then In_Open_Scopes (Scope (Hom))
then
Candidate := Renamed_Entity (Hom);
else
Candidate := Hom;
end if;
if Ekind (Candidate) in E_Function | E_Procedure
and then (not Is_Hidden (Candidate) or else In_Instance)
and then Scope (Candidate) = Scope (Base_Type (Anc_Type))
and then First_Formal_Match (Candidate, CW_Typ)
then
-- If the context is a procedure call, ignore functions
-- in the name of the call.
if Ekind (Candidate) = E_Function
and then Nkind (Parent (N)) = N_Procedure_Call_Statement
and then N = Name (Parent (N))
then
goto Next_Hom;
-- If the context is a function call, ignore procedures
-- in the name of the call.
elsif Ekind (Candidate) = E_Procedure
and then Nkind (Parent (N)) /= N_Procedure_Call_Statement
then
goto Next_Hom;
end if;
Set_Etype (Call_Node, Any_Type);
Set_Is_Overloaded (Call_Node, False);
Success := False;
if No (Matching_Op) then
Hom_Ref := New_Occurrence_Of (Candidate, Sloc (Subprog));
Set_Etype (Call_Node, Any_Type);
Set_Name (Call_Node, Hom_Ref);
Set_Parent (Call_Node, Parent (Node_To_Replace));
Analyze_One_Call
(N => Call_Node,
Nam => Candidate,
Report => Report_Error,
Success => Success,
Skip_First => True);
Matching_Op :=
Valid_Candidate (Success, Call_Node, Candidate);
else
Analyze_One_Call
(N => Call_Node,
Nam => Candidate,
Report => Report_Error,
Success => Success,
Skip_First => True);
-- The same operation may be encountered on two homonym
-- traversals, before and after looking at interfaces.
-- Check for this case before reporting a real ambiguity.
if Present
(Valid_Candidate (Success, Call_Node, Candidate))
and then Nkind (Call_Node) /= N_Function_Call
and then Candidate /= Matching_Op
then
Error_Msg_NE ("ambiguous call to&", N, Hom);
Report_Ambiguity (Matching_Op);
Report_Ambiguity (Hom);
Check_Ambiguous_Aggregate (New_Call_Node);
Error := True;
return;
end if;
end if;
end if;
<<Next_Hom>>
Hom := Homonym (Hom);
end loop;
end Traverse_Homonyms;
-------------------------
-- Traverse_Interfaces --
-------------------------
procedure Traverse_Interfaces
(Anc_Type : Entity_Id;
Error : out Boolean)
is
Intface_List : constant List_Id :=
Abstract_Interface_List (Anc_Type);
Intface : Node_Id;
begin
Error := False;
if Is_Non_Empty_List (Intface_List) then
Intface := First (Intface_List);
while Present (Intface) loop
-- Look for acceptable class-wide homonyms associated with
-- the interface.
Traverse_Homonyms (Etype (Intface), Error);
if Error then
return;
end if;
-- Continue the search by looking at each of the interface's
-- associated interface ancestors.
Traverse_Interfaces (Etype (Intface), Error);
if Error then
return;
end if;
Next (Intface);
end loop;
end if;
end Traverse_Interfaces;
-- Start of processing for Try_Class_Wide_Operation
begin
-- If we are searching only for conflicting class-wide subprograms
-- then initialize directly Matching_Op with the target entity.
if CW_Test_Only then
Matching_Op := Entity (Selector_Name (N));
end if;
-- Loop through ancestor types (including interfaces), traversing
-- the homonym chain of the subprogram, trying out those homonyms
-- whose first formal has the class-wide type of the ancestor, or
-- an anonymous access type designating the class-wide type.
Anc_Type := Obj_Type;
loop
-- Look for a match among homonyms associated with the ancestor
Traverse_Homonyms (Anc_Type, Error);
if Error then
return True;
end if;
-- Continue the search for matches among homonyms associated with
-- any interfaces implemented by the ancestor.
Traverse_Interfaces (Anc_Type, Error);
if Error then
return True;
end if;
exit when Etype (Anc_Type) = Anc_Type;
Anc_Type := Etype (Anc_Type);
end loop;
if Present (Matching_Op) then
Set_Etype (Call_Node, Etype (Matching_Op));
end if;
return Present (Matching_Op);
end Try_Class_Wide_Operation;
-----------------------------------
-- Try_One_Prefix_Interpretation --
-----------------------------------
procedure Try_One_Prefix_Interpretation (T : Entity_Id) is
Prev_Obj_Type : constant Entity_Id := Obj_Type;
-- If the interpretation does not have a valid candidate type,
-- preserve current value of Obj_Type for subsequent errors.
begin
Obj_Type := T;
if Is_Access_Type (Obj_Type) then
Obj_Type := Designated_Type (Obj_Type);
end if;
if Ekind (Obj_Type)
in E_Private_Subtype | E_Record_Subtype_With_Private
then
Obj_Type := Base_Type (Obj_Type);
end if;
if Is_Class_Wide_Type (Obj_Type) then
Obj_Type := Etype (Class_Wide_Type (Obj_Type));
end if;
-- The type may have be obtained through a limited_with clause,
-- in which case the primitive operations are available on its
-- nonlimited view. If still incomplete, retrieve full view.
if Ekind (Obj_Type) = E_Incomplete_Type
and then From_Limited_With (Obj_Type)
and then Has_Non_Limited_View (Obj_Type)
then
Obj_Type := Get_Full_View (Non_Limited_View (Obj_Type));
end if;
-- If the object is not tagged, or the type is still an incomplete
-- type, this is not a prefixed call. Restore the previous type as
-- the current one is not a legal candidate.
-- Extension feature: Calls with prefixed views are also supported
-- for untagged types, so skip the early return when extensions are
-- enabled, unless the type doesn't have a primitive operations list
-- (such as in the case of predefined types).
if (not Is_Tagged_Type (Obj_Type)
and then
(not Extensions_Allowed
or else not Present (Primitive_Operations (Obj_Type))))
or else Is_Incomplete_Type (Obj_Type)
then
Obj_Type := Prev_Obj_Type;
return;
end if;
declare
Dup_Call_Node : constant Node_Id := New_Copy (New_Call_Node);
Ignore : Boolean;
Prim_Result : Boolean := False;
begin
if not CW_Test_Only then
Prim_Result :=
Try_Primitive_Operation
(Call_Node => New_Call_Node,
Node_To_Replace => Node_To_Replace);
-- Extension feature: In the case where the prefix is of an
-- access type, and a primitive wasn't found for the designated
-- type, then if the access type has primitives we attempt a
-- prefixed call using one of its primitives. (It seems that
-- this isn't quite right to give preference to the designated
-- type in the case where both the access and designated types
-- have homographic prefixed-view operations that could result
-- in an ambiguity, but handling properly may be tricky. ???)
if Extensions_Allowed
and then not Prim_Result
and then Is_Named_Access_Type (Prev_Obj_Type)
and then Present (Direct_Primitive_Operations (Prev_Obj_Type))
then
-- Temporarily reset Obj_Type to the original access type
Obj_Type := Prev_Obj_Type;
Prim_Result :=
Try_Primitive_Operation
(Call_Node => New_Call_Node,
Node_To_Replace => Node_To_Replace);
-- Restore Obj_Type to the designated type (is this really
-- necessary, or should it only be done when Prim_Result is
-- still False?).
Obj_Type := Designated_Type (Obj_Type);
end if;
end if;
-- Check if there is a class-wide subprogram covering the
-- primitive. This check must be done even if a candidate
-- was found in order to report ambiguous calls.
if not Prim_Result then
Ignore :=
Try_Class_Wide_Operation
(Call_Node => New_Call_Node,
Node_To_Replace => Node_To_Replace);
-- If we found a primitive we search for class-wide subprograms
-- using a duplicate of the call node (done to avoid missing its
-- decoration if there is no ambiguity).
else
Ignore :=
Try_Class_Wide_Operation
(Call_Node => Dup_Call_Node,
Node_To_Replace => Node_To_Replace);
end if;
end;
end Try_One_Prefix_Interpretation;
-----------------------------
-- Try_Primitive_Operation --
-----------------------------
function Try_Primitive_Operation
(Call_Node : Node_Id;
Node_To_Replace : Node_Id) return Boolean
is
Elmt : Elmt_Id;
Prim_Op : Entity_Id;
Matching_Op : Entity_Id := Empty;
Prim_Op_Ref : Node_Id := Empty;
Corr_Type : Entity_Id := Empty;
-- If the prefix is a synchronized type, the controlling type of
-- the primitive operation is the corresponding record type, else
-- this is the object type itself.
Success : Boolean := False;
function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id;
-- For tagged types the candidate interpretations are found in
-- the list of primitive operations of the type and its ancestors.
-- For formal tagged types we have to find the operations declared
-- in the same scope as the type (including in the generic formal
-- part) because the type itself carries no primitive operations,
-- except for formal derived types that inherit the operations of
-- the parent and progenitors.
--
-- If the context is a generic subprogram body, the generic formals
-- are visible by name, but are not in the entity list of the
-- subprogram because that list starts with the subprogram formals.
-- We retrieve the candidate operations from the generic declaration.
function Extended_Primitive_Ops (T : Entity_Id) return Elist_Id;
-- Prefix notation can also be used on operations that are not
-- primitives of the type, but are declared in the same immediate
-- declarative part, which can only mean the corresponding package
-- body (see RM 4.1.3 (9.2/3)). If we are in that body we extend the
-- list of primitives with body operations with the same name that
-- may be candidates, so that Try_Primitive_Operations can examine
-- them if no real primitive is found.
function Is_Private_Overriding (Op : Entity_Id) return Boolean;
-- An operation that overrides an inherited operation in the private
-- part of its package may be hidden, but if the inherited operation
-- is visible a direct call to it will dispatch to the private one,
-- which is therefore a valid candidate.
function Names_Match
(Obj_Type : Entity_Id;
Prim_Op : Entity_Id;
Subprog : Entity_Id) return Boolean;
-- Return True if the names of Prim_Op and Subprog match. If Obj_Type
-- is a protected type then compare also the original name of Prim_Op
-- with the name of Subprog (since the expander may have added a
-- prefix to its original name --see Exp_Ch9.Build_Selected_Name).
function Valid_First_Argument_Of (Op : Entity_Id) return Boolean;
-- Verify that the prefix, dereferenced if need be, is a valid
-- controlling argument in a call to Op. The remaining actuals
-- are checked in the subsequent call to Analyze_One_Call.
------------------------------
-- Collect_Generic_Type_Ops --
------------------------------
function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id is
Bas : constant Entity_Id := Base_Type (T);
Candidates : constant Elist_Id := New_Elmt_List;
Subp : Entity_Id;
Formal : Entity_Id;
procedure Check_Candidate;
-- The operation is a candidate if its first parameter is a
-- controlling operand of the desired type.
-----------------------
-- Check_Candidate; --
-----------------------
procedure Check_Candidate is
begin
Formal := First_Formal (Subp);
if Present (Formal)
and then Is_Controlling_Formal (Formal)
and then
(Base_Type (Etype (Formal)) = Bas
or else
(Is_Access_Type (Etype (Formal))
and then Designated_Type (Etype (Formal)) = Bas))
then
Append_Elmt (Subp, Candidates);
end if;
end Check_Candidate;
-- Start of processing for Collect_Generic_Type_Ops
begin
if Is_Derived_Type (T) then
return Primitive_Operations (T);
elsif Ekind (Scope (T)) in E_Procedure | E_Function then
-- Scan the list of generic formals to find subprograms
-- that may have a first controlling formal of the type.
if Nkind (Unit_Declaration_Node (Scope (T))) =
N_Generic_Subprogram_Declaration
then
declare
Decl : Node_Id;
begin
Decl :=
First (Generic_Formal_Declarations
(Unit_Declaration_Node (Scope (T))));
while Present (Decl) loop
if Nkind (Decl) in N_Formal_Subprogram_Declaration then
Subp := Defining_Entity (Decl);
Check_Candidate;
end if;
Next (Decl);
end loop;
end;
end if;
return Candidates;
else
-- Scan the list of entities declared in the same scope as
-- the type. In general this will be an open scope, given that
-- the call we are analyzing can only appear within a generic
-- declaration or body (either the one that declares T, or a
-- child unit).
-- For a subtype representing a generic actual type, go to the
-- base type.
if Is_Generic_Actual_Type (T) then
Subp := First_Entity (Scope (Base_Type (T)));
else
Subp := First_Entity (Scope (T));
end if;
while Present (Subp) loop
if Is_Overloadable (Subp) then
Check_Candidate;
end if;
Next_Entity (Subp);
end loop;
return Candidates;
end if;
end Collect_Generic_Type_Ops;
----------------------------
-- Extended_Primitive_Ops --
----------------------------
function Extended_Primitive_Ops (T : Entity_Id) return Elist_Id is
Type_Scope : constant Entity_Id := Scope (T);
Op_List : Elist_Id := Primitive_Operations (T);
begin
if Is_Package_Or_Generic_Package (Type_Scope)
and then ((In_Package_Body (Type_Scope)
and then In_Open_Scopes (Type_Scope)) or else In_Instance_Body)
then
-- Retrieve list of declarations of package body if possible
declare
The_Body : constant Node_Id :=
Corresponding_Body (Unit_Declaration_Node (Type_Scope));
begin
if Present (The_Body) then
declare
Body_Decls : constant List_Id :=
Declarations (Unit_Declaration_Node (The_Body));
Op_Found : Boolean := False;
Op : Entity_Id := Current_Entity (Subprog);
begin
while Present (Op) loop
if Comes_From_Source (Op)
and then Is_Overloadable (Op)
-- Exclude overriding primitive operations of a
-- type extension declared in the package body,
-- to prevent duplicates in extended list.
and then not Is_Primitive (Op)
and then Is_List_Member
(Unit_Declaration_Node (Op))
and then List_Containing
(Unit_Declaration_Node (Op)) = Body_Decls
then
if not Op_Found then
-- Copy list of primitives so it is not
-- affected for other uses.
Op_List := New_Copy_Elist (Op_List);
Op_Found := True;
end if;
Append_Elmt (Op, Op_List);
end if;
Op := Homonym (Op);
end loop;
end;
end if;
end;
end if;
return Op_List;
end Extended_Primitive_Ops;
---------------------------
-- Is_Private_Overriding --
---------------------------
function Is_Private_Overriding (Op : Entity_Id) return Boolean is
Visible_Op : Entity_Id;
begin
-- The subprogram may be overloaded with both visible and private
-- entities with the same name. We have to scan the chain of
-- homonyms to determine whether there is a previous implicit
-- declaration in the same scope that is overridden by the
-- private candidate.
Visible_Op := Homonym (Op);
while Present (Visible_Op) loop
if Scope (Op) /= Scope (Visible_Op) then
return False;
elsif not Comes_From_Source (Visible_Op)
and then Alias (Visible_Op) = Op
and then not Is_Hidden (Visible_Op)
then
return True;
end if;
Visible_Op := Homonym (Visible_Op);
end loop;
return False;
end Is_Private_Overriding;
-----------------
-- Names_Match --
-----------------
function Names_Match
(Obj_Type : Entity_Id;
Prim_Op : Entity_Id;
Subprog : Entity_Id) return Boolean is
begin
-- Common case: exact match
if Chars (Prim_Op) = Chars (Subprog) then
return True;
-- For protected type primitives the expander may have built the
-- name of the dispatching primitive prepending the type name to
-- avoid conflicts with the name of the protected subprogram (see
-- Exp_Ch9.Build_Selected_Name).
elsif Is_Protected_Type (Obj_Type) then
return
Present (Original_Protected_Subprogram (Prim_Op))
and then Chars (Original_Protected_Subprogram (Prim_Op)) =
Chars (Subprog);
-- In an instance, the selector name may be a generic actual that
-- renames a primitive operation of the type of the prefix.
elsif In_Instance and then Present (Current_Entity (Subprog)) then
declare
Subp : constant Entity_Id := Current_Entity (Subprog);
begin
if Present (Subp)
and then Is_Subprogram (Subp)
and then Present (Renamed_Entity (Subp))
and then Is_Generic_Actual_Subprogram (Subp)
and then Chars (Renamed_Entity (Subp)) = Chars (Prim_Op)
then
return True;
end if;
end;
end if;
return False;
end Names_Match;
-----------------------------
-- Valid_First_Argument_Of --
-----------------------------
function Valid_First_Argument_Of (Op : Entity_Id) return Boolean is
Typ : Entity_Id := Etype (First_Formal (Op));
begin
if Is_Concurrent_Type (Typ)
and then Present (Corresponding_Record_Type (Typ))
then
Typ := Corresponding_Record_Type (Typ);
end if;
-- Simple case. Object may be a subtype of the tagged type or may
-- be the corresponding record of a synchronized type.
return Obj_Type = Typ
or else Base_Type (Obj_Type) = Base_Type (Typ)
or else Corr_Type = Typ
-- Object may be of a derived type whose parent has unknown
-- discriminants, in which case the type matches the underlying
-- record view of its base.
or else
(Has_Unknown_Discriminants (Typ)
and then Typ = Underlying_Record_View (Base_Type (Obj_Type)))
-- Prefix can be dereferenced
or else
(Is_Access_Type (Corr_Type)
and then Designated_Type (Corr_Type) = Typ)
-- Formal is an access parameter, for which the object can
-- provide an access.
or else
(Ekind (Typ) = E_Anonymous_Access_Type
and then
Base_Type (Designated_Type (Typ)) = Base_Type (Corr_Type));
end Valid_First_Argument_Of;
-- Start of processing for Try_Primitive_Operation
begin
-- Look for subprograms in the list of primitive operations. The name
-- must be identical, and the kind of call indicates the expected
-- kind of operation (function or procedure). If the type is a
-- (tagged) synchronized type, the primitive ops are attached to the
-- corresponding record (base) type.
if Is_Concurrent_Type (Obj_Type) then
if Present (Corresponding_Record_Type (Obj_Type)) then
Corr_Type := Base_Type (Corresponding_Record_Type (Obj_Type));
Elmt := First_Elmt (Primitive_Operations (Corr_Type));
else
Corr_Type := Obj_Type;
Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
end if;
elsif not Is_Generic_Type (Obj_Type) then
Corr_Type := Obj_Type;
Elmt := First_Elmt (Extended_Primitive_Ops (Obj_Type));
else
Corr_Type := Obj_Type;
Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
end if;
while Present (Elmt) loop
Prim_Op := Node (Elmt);
if Names_Match (Obj_Type, Prim_Op, Subprog)
and then Present (First_Formal (Prim_Op))
and then Valid_First_Argument_Of (Prim_Op)
and then
(Nkind (Call_Node) = N_Function_Call)
=
(Ekind (Prim_Op) = E_Function)
then
-- Ada 2005 (AI-251): If this primitive operation corresponds
-- to an immediate ancestor interface there is no need to add
-- it to the list of interpretations; the corresponding aliased
-- primitive is also in this list of primitive operations and
-- will be used instead.
if (Present (Interface_Alias (Prim_Op))
and then Is_Ancestor (Find_Dispatching_Type
(Alias (Prim_Op)), Corr_Type))
-- Do not consider hidden primitives unless the type is in an
-- open scope or we are within an instance, where visibility
-- is known to be correct, or else if this is an overriding
-- operation in the private part for an inherited operation.
or else (Is_Hidden (Prim_Op)
and then not Is_Immediately_Visible (Obj_Type)
and then not In_Instance
and then not Is_Private_Overriding (Prim_Op))
then
goto Continue;
end if;
Set_Etype (Call_Node, Any_Type);
Set_Is_Overloaded (Call_Node, False);
if No (Matching_Op) then
Prim_Op_Ref := New_Occurrence_Of (Prim_Op, Sloc (Subprog));
Candidate := Prim_Op;
Set_Parent (Call_Node, Parent (Node_To_Replace));
Set_Name (Call_Node, Prim_Op_Ref);
Success := False;
Analyze_One_Call
(N => Call_Node,
Nam => Prim_Op,
Report => Report_Error,
Success => Success,
Skip_First => True);
Matching_Op := Valid_Candidate (Success, Call_Node, Prim_Op);
-- More than one interpretation, collect for subsequent
-- disambiguation. If this is a procedure call and there
-- is another match, report ambiguity now.
else
Analyze_One_Call
(N => Call_Node,
Nam => Prim_Op,
Report => Report_Error,
Success => Success,
Skip_First => True);
if Present (Valid_Candidate (Success, Call_Node, Prim_Op))
and then Nkind (Call_Node) /= N_Function_Call
then
Error_Msg_NE ("ambiguous call to&", N, Prim_Op);
Report_Ambiguity (Matching_Op);
Report_Ambiguity (Prim_Op);
Check_Ambiguous_Aggregate (Call_Node);
return True;
end if;
end if;
end if;
<<Continue>>
Next_Elmt (Elmt);
end loop;
if Present (Matching_Op) then
Set_Etype (Call_Node, Etype (Matching_Op));
end if;
return Present (Matching_Op);
end Try_Primitive_Operation;
---------------------
-- Valid_Candidate --
---------------------
function Valid_Candidate
(Success : Boolean;
Call : Node_Id;
Subp : Entity_Id) return Entity_Id
is
Arr_Type : Entity_Id;
Comp_Type : Entity_Id;
begin
-- If the subprogram is a valid interpretation, record it in global
-- variable Subprog, to collect all possible overloadings.
if Success then
if Subp /= Entity (Subprog) then
Add_One_Interp (Subprog, Subp, Etype (Subp));
end if;
end if;
-- If the call may be an indexed call, retrieve component type of
-- resulting expression, and add possible interpretation.
Arr_Type := Empty;
Comp_Type := Empty;
if Nkind (Call) = N_Function_Call
and then Nkind (Parent (N)) = N_Indexed_Component
and then Needs_One_Actual (Subp)
then
if Is_Array_Type (Etype (Subp)) then
Arr_Type := Etype (Subp);
elsif Is_Access_Type (Etype (Subp))
and then Is_Array_Type (Designated_Type (Etype (Subp)))
then
Arr_Type := Designated_Type (Etype (Subp));
end if;
end if;
if Present (Arr_Type) then
-- Verify that the actuals (excluding the object) match the types
-- of the indexes.
declare
Actual : Node_Id;
Index : Node_Id;
begin
Actual := Next (First_Actual (Call));
Index := First_Index (Arr_Type);
while Present (Actual) and then Present (Index) loop
if not Has_Compatible_Type (Actual, Etype (Index)) then
Arr_Type := Empty;
exit;
end if;
Next_Actual (Actual);
Next_Index (Index);
end loop;
if No (Actual)
and then No (Index)
and then Present (Arr_Type)
then
Comp_Type := Component_Type (Arr_Type);
end if;
end;
if Present (Comp_Type)
and then Etype (Subprog) /= Comp_Type
then
Add_One_Interp (Subprog, Subp, Comp_Type);
end if;
end if;
if Etype (Call) /= Any_Type then
return Subp;
else
return Empty;
end if;
end Valid_Candidate;
-- Start of processing for Try_Object_Operation
begin
Analyze_Expression (Obj);
-- Analyze the actuals if node is known to be a subprogram call
if Is_Subprg_Call and then N = Name (Parent (N)) then
Actual := First (Parameter_Associations (Parent (N)));
while Present (Actual) loop
Analyze_Expression (Actual);
Next (Actual);
end loop;
end if;
-- Build a subprogram call node, using a copy of Obj as its first
-- actual. This is a placeholder, to be replaced by an explicit
-- dereference when needed.
Transform_Object_Operation
(Call_Node => New_Call_Node,
Node_To_Replace => Node_To_Replace);
Set_Etype (New_Call_Node, Any_Type);
Set_Etype (Subprog, Any_Type);
Set_Parent (New_Call_Node, Parent (Node_To_Replace));
if not Is_Overloaded (Obj) then
Try_One_Prefix_Interpretation (Obj_Type);
else
declare
I : Interp_Index;
It : Interp;
begin
Get_First_Interp (Obj, I, It);
while Present (It.Nam) loop
Try_One_Prefix_Interpretation (It.Typ);
Get_Next_Interp (I, It);
end loop;
end;
end if;
if Etype (New_Call_Node) /= Any_Type then
-- No need to complete the tree transformations if we are only
-- searching for conflicting class-wide subprograms
if CW_Test_Only then
return False;
else
Complete_Object_Operation
(Call_Node => New_Call_Node,
Node_To_Replace => Node_To_Replace);
return True;
end if;
elsif Present (Candidate) then
-- The argument list is not type correct. Re-analyze with error
-- reporting enabled, and use one of the possible candidates.
-- In All_Errors_Mode, re-analyze all failed interpretations.
if All_Errors_Mode then
Report_Error := True;
if Try_Primitive_Operation
(Call_Node => New_Call_Node,
Node_To_Replace => Node_To_Replace)
or else
Try_Class_Wide_Operation
(Call_Node => New_Call_Node,
Node_To_Replace => Node_To_Replace)
then
null;
end if;
else
Analyze_One_Call
(N => New_Call_Node,
Nam => Candidate,
Report => True,
Success => Success,
Skip_First => True);
-- The error may hot have been reported yet for overloaded
-- prefixed calls, depending on the non-matching candidate,
-- in which case provide a concise error now.
if Serious_Errors_Detected = 0 then
Error_Msg_NE
("cannot resolve prefixed call to primitive operation of&",
N, Entity (Obj));
end if;
end if;
-- No need for further errors
return True;
else
-- There was no candidate operation, but Analyze_Selected_Component
-- may continue the analysis so we need to undo the change possibly
-- made to the Parent of N earlier by Transform_Object_Operation.
declare
Parent_Node : constant Node_Id := Parent (N);
begin
if Node_To_Replace = Parent_Node then
Remove (First (Parameter_Associations (New_Call_Node)));
Set_Parent
(Parameter_Associations (New_Call_Node), Parent_Node);
end if;
end;
return False;
end if;
end Try_Object_Operation;
---------
-- wpo --
---------
procedure wpo (T : Entity_Id) is
Op : Entity_Id;
E : Elmt_Id;
begin
if not Is_Tagged_Type (T) then
return;
end if;
E := First_Elmt (Primitive_Operations (Base_Type (T)));
while Present (E) loop
Op := Node (E);
Write_Int (Int (Op));
Write_Str (" === ");
Write_Name (Chars (Op));
Write_Str (" in ");
Write_Name (Chars (Scope (Op)));
Next_Elmt (E);
Write_Eol;
end loop;
end wpo;
end Sem_Ch4;