[COMMITTED,08/13] ada: Allow mutably tagged types to work with qualified expressions
Commit Message
From: Justin Squirek <squirek@adacore.com>
This patch modifies the experimental 'Size'Class feature such that objects of
mutably tagged types can be assigned qualified expressions featuring a
definite type (e.g. Mutable_Obj := Root_Child_T'(Root_T with others => <>)).
gcc/ada/
* sem_ch5.adb:
(Analyze_Assignment): Add special expansion for qualified expressions
in certain cases dealing with mutably tagged types.
Tested on x86_64-pc-linux-gnu, committed on master.
---
gcc/ada/sem_ch5.adb | 14 ++++++++++++++
1 file changed, 14 insertions(+)
@@ -697,6 +697,19 @@ package body Sem_Ch5 is
then
Resolve (Rhs, Base_Type (T1));
+ -- When the right hand side is a qualified expression and the left hand
+ -- side is mutably tagged we force the right hand side to be class-wide
+ -- so that they are compatible both for the purposes of checking
+ -- legality rules as well as assignment expansion.
+
+ elsif Is_Mutably_Tagged_Type (T1)
+ and then Nkind (Rhs) = N_Qualified_Expression
+ then
+ Make_Mutably_Tagged_Conversion (Rhs, T1);
+ Resolve (Rhs, T1);
+
+ -- Otherwise, resolve the right hand side normally
+
else
Resolve (Rhs, T1);
end if;
@@ -765,6 +778,7 @@ package body Sem_Ch5 is
and then not Is_Class_Wide_Type (T2)
and then not Is_Tag_Indeterminate (Rhs)
and then not Is_Dynamically_Tagged (Rhs)
+ and then not Is_Mutably_Tagged_Type (T1)
then
Error_Msg_N ("dynamically tagged expression required!", Rhs);
end if;