From: Eric Botcazou <[email protected]>
The bottom line is that we need to suspend the B.3.3(23/2) rule during the
expansion of the equality function of an unchecked union itself containing
a component of an unchecked union type subject to a per-object constraint,
but this was done too broadly instead of specifically for this case.
gcc/ada/ChangeLog:
* sem_util.adb (Prefix_Is_Formal_Parameter): Rename into...
(Prefix_Is_Formal_Parameter_Of_EQ): ...this. Return True only if
the formal parameter is that of an equality function built for an
unchecked union type.
(Has_Inferable_Discriminants): Adjust to above renaming.
Tested on x86_64-pc-linux-gnu, committed on master.
---
gcc/ada/sem_util.adb | 29 ++++++++++++++++-------------
1 file changed, 16 insertions(+), 13 deletions(-)
diff --git a/gcc/ada/sem_util.adb b/gcc/ada/sem_util.adb
index 65fa66745a2..77a3dbec80f 100644
--- a/gcc/ada/sem_util.adb
+++ b/gcc/ada/sem_util.adb
@@ -12492,15 +12492,16 @@ package body Sem_Util is
function Has_Inferable_Discriminants (N : Node_Id) return Boolean is
- function Prefix_Is_Formal_Parameter (N : Node_Id) return Boolean;
- -- Determines whether the left-most prefix of a selected component is a
- -- formal parameter in a subprogram. Assumes N is a selected component.
+ function Prefix_Is_Formal_Parameter_Of_EQ (N : Node_Id) return Boolean;
+ -- Determines whether the left-most prefix of selected component N
+ -- is a formal parameter of the predefined equality function of an
+ -- Unchecked_Union type.
- --------------------------------
- -- Prefix_Is_Formal_Parameter --
- --------------------------------
+ --------------------------------------
+ -- Prefix_Is_Formal_Parameter_Of_EQ --
+ --------------------------------------
- function Prefix_Is_Formal_Parameter (N : Node_Id) return Boolean is
+ function Prefix_Is_Formal_Parameter_Of_EQ (N : Node_Id) return Boolean is
Sel_Comp : Node_Id;
begin
@@ -12513,8 +12514,10 @@ package body Sem_Util is
Sel_Comp := Parent (Sel_Comp);
end loop;
- return Is_Formal (Entity (Prefix (Sel_Comp)));
- end Prefix_Is_Formal_Parameter;
+ return Is_Formal (Entity (Prefix (Sel_Comp)))
+ and then
+ Is_Unchecked_Union_Equality (Scope (Entity (Prefix (Sel_Comp))));
+ end Prefix_Is_Formal_Parameter_Of_EQ;
-- Start of processing for Has_Inferable_Discriminants
@@ -12532,14 +12535,14 @@ package body Sem_Util is
return False;
end if;
- -- A small hack. If we have a per-object constrained selected
- -- component of a formal parameter, return True since we do not
- -- know the actual parameter association yet.
+ -- We need to return True for the component of a formal parameter
+ -- of the predefined equality function of an Unchecked_Union type
+ -- when expanding it (see Expand_Unchecked_Union_Equality).
return not Has_Per_Object_Constraint (Entity (Selector_Name (N)))
or else not Is_Unchecked_Union (Etype (Prefix (N)))
or else Has_Inferable_Discriminants (Prefix (N))
- or else Prefix_Is_Formal_Parameter (N);
+ or else Prefix_Is_Formal_Parameter_Of_EQ (N);
-- A qualified expression has inferable discriminants if its subtype
-- mark is a constrained Unchecked_Union subtype.
--
2.53.0
