===================================================================
@@ -1721,13 +1721,8 @@
Scan; -- past ALIASED
Set_Aliased_Present (Decl_Node);
- if Ada_Version < Ada_2012 then
- Error_Msg_SC -- CODEFIX
- ("ALIASED not allowed in extended return in Ada 2012?");
- else
- Error_Msg_SC -- CODEFIX
- ("ALIASED not allowed in extended return");
- end if;
+ -- The restrictions on the use of aliased in an extended return
+ -- are semantic, not syntactic.
if Token = Tok_Constant then
Scan; -- past CONSTANT
===================================================================
@@ -787,6 +787,7 @@
Analyze_And_Resolve (Expr, R_Type);
Check_Limited_Return (Expr);
+
end if;
-- RETURN only allowed in SPARK as the last statement in function
@@ -806,8 +807,9 @@
-- Analyze parts specific to extended_return_statement:
declare
- Obj_Decl : constant Node_Id :=
+ Obj_Decl : constant Node_Id :=
Last (Return_Object_Declarations (N));
+ Has_Aliased : constant Boolean := Aliased_Present (Obj_Decl);
HSS : constant Node_Id := Handled_Statement_Sequence (N);
@@ -842,6 +844,19 @@
Set_Referenced (Defining_Identifier (Obj_Decl));
Check_References (Stm_Entity);
+
+ -- Check RM 6.5 (5.9/3)
+
+ if Has_Aliased then
+ if Ada_Version < Ada_2012 then
+ Error_Msg_N ("aliased only allowed for limited"
+ & " return objects in Ada 2012?", N);
+
+ elsif not Is_Immutably_Limited_Type (R_Type) then
+ Error_Msg_N ("aliased only allowed for limited"
+ & " return objects", N);
+ end if;
+ end if;
end;
end if;
An early version of the Ada 2012 RM made it illegal to declare the return object aliased in an extended return statement. A later decision (AI05-0277) made it legal in the confirming case where the return type is immutably limited, This patch accordingly moves the application of this rule from the syntax to the semantics. compiling test_aliased.adb below in Ada 2005 mode must yield: test_aliased.adb:8:08: warning: aliased only allowed for limited return objects in Ada 2012 test_aliased.adb:15:06: warning: aliased only allowed for limited return objects in Ada 2012 while compiling it in Ada 2012 mode must yield: test_aliased.adb:8:08: aliased only allowed for limited return objects -- procedure Test_Aliased is type Lim is limited record Value : Integer; end record; function Wrong return Natural is begin return Result : Aliased Natural do Result := 15; End return; end Wrong; function OK return Lim is begin return Result : aliased Lim do Result.Value := 123; end return; end OK; begin null; end Test_Aliased; Tested on x86_64-pc-linux-gnu, committed on trunk 2012-12-05 Ed Schonberg <schonberg@adacore.com> * par-ch6.adb (P_Return_Object_Declaration): Do not check for legality of Aliased keyword. * sem_ch6.adb (Analyze_Function_Return): The keyword aliased is legal in an extended return statement only if the return type is immutably limited.