This AI restricts renaming of a qualified expression to cases where the
operand is a constant, or the target subtype statically matches the
nominal subtype of the operand, or is unconstrained with no predicates.
Tested on x86_64-pc-linux-gnu, committed on trunk
gcc/ada/
* sem_ch8.adb (Analyze_Object_Renaming): Check for AI12-0401.
diff --git a/gcc/ada/sem_ch8.adb b/gcc/ada/sem_ch8.adb
--- a/gcc/ada/sem_ch8.adb
+++ b/gcc/ada/sem_ch8.adb
@@ -1038,6 +1038,22 @@ package body Sem_Ch8 is
Mark_Ghost_Renaming (N, Entity (Nam));
end if;
+ -- Check against AI12-0401 here before Resolve may rewrite Nam and
+ -- potentially generate spurious warnings.
+
+ if Nkind (Nam) = N_Qualified_Expression
+ and then Is_Variable (Expression (Nam))
+ and then not
+ (Subtypes_Statically_Match (T, Etype (Expression (Nam)))
+ or else
+ Subtypes_Statically_Match (Base_Type (T), Etype (Nam)))
+ then
+ Error_Msg_N
+ ("subtype of renamed qualified expression does not " &
+ "statically match", N);
+ return;
+ end if;
+
Resolve (Nam, T);
-- If the renamed object is a function call of a limited type,