This patch fixes an error in the compiler whereby an allocator for a
limited type may cause spurious accessibility errors due to a
miscalculation of access levels on internally generated temporaries
within the instance.
Tested on x86_64-pc-linux-gnu, committed on trunk
gcc/ada/
* exp_ch4.adb (Expand_N_Type_Conversion): Remove flawed test for
whether "statically deeper" accessibility rules apply to a given
target type and instead use the new routine
Statically_Deeper_Relation_Applies.
(Statically_Deeper_Relation_Applies): Created to centralize the
calculation of whether a target type within a conversion must
have static accessibility checks.
* sem_ch13.adb (Check_One_Function): Minor comment revision.diff --git a/gcc/ada/exp_ch4.adb b/gcc/ada/exp_ch4.adb
--- a/gcc/ada/exp_ch4.adb
+++ b/gcc/ada/exp_ch4.adb
@@ -11305,6 +11305,11 @@ package body Exp_Ch4 is
-- True iff Present (Effective_Extra_Accessibility (Id)) successfully
-- evaluates to True.
+ function Statically_Deeper_Relation_Applies (Targ_Typ : Entity_Id)
+ return Boolean;
+ -- Given a target type for a conversion, determine whether the
+ -- statically deeper accessibility rules apply to it.
+
--------------------------
-- Discrete_Range_Check --
--------------------------
@@ -11887,6 +11892,25 @@ package body Exp_Ch4 is
end if;
end Has_Extra_Accessibility;
+ ----------------------------------------
+ -- Statically_Deeper_Relation_Applies --
+ ----------------------------------------
+
+ function Statically_Deeper_Relation_Applies (Targ_Typ : Entity_Id)
+ return Boolean
+ is
+ begin
+ -- The case where the target type is an anonymous access type is
+ -- ignored since they have different semantics and get covered by
+ -- various runtime checks depending on context.
+
+ -- Note, the current implementation of this predicate is incomplete
+ -- and doesn't fully reflect the rules given in RM 3.10.2 (19) and
+ -- (19.1) ???
+
+ return Ekind (Targ_Typ) /= E_Anonymous_Access_Type;
+ end Statically_Deeper_Relation_Applies;
+
-- Start of processing for Expand_N_Type_Conversion
begin
@@ -12133,21 +12157,7 @@ package body Exp_Ch4 is
-- Note: warnings are issued by the analyzer for the instance cases
elsif In_Instance_Body
-
- -- The case where the target type is an anonymous access type of
- -- a discriminant is excluded, because the level of such a type
- -- depends on the context and currently the level returned for such
- -- types is zero, resulting in warnings about check failures
- -- in certain legal cases involving class-wide interfaces as the
- -- designated type (some cases, such as return statements, are
- -- checked at run time, but not clear if these are handled right
- -- in general, see 3.10.2(12/2-12.5/3) ???).
-
- and then
- not (Ekind (Target_Type) = E_Anonymous_Access_Type
- and then Present (Associated_Node_For_Itype (Target_Type))
- and then Nkind (Associated_Node_For_Itype (Target_Type)) =
- N_Discriminant_Specification)
+ and then Statically_Deeper_Relation_Applies (Target_Type)
and then
Type_Access_Level (Operand_Type) > Type_Access_Level (Target_Type)
then
diff --git a/gcc/ada/sem_ch13.adb b/gcc/ada/sem_ch13.adb
--- a/gcc/ada/sem_ch13.adb
+++ b/gcc/ada/sem_ch13.adb
@@ -5488,7 +5488,7 @@ package body Sem_Ch13 is
end if;
end if;
- -- All checks succeeded.
+ -- All checks succeeded
Indexing_Found := True;
end Check_One_Function;
