When generating constraint checks for types whose size depend on a
discriminant, the frontend would generate a reference to the
discriminant. This would result in a crash as the backend actually needs
a reference to the object itself.
Tested on x86_64-pc-linux-gnu, committed on trunk
gcc/ada/
* exp_attr.adb (Expand_N_Attribute_Reference): Check if type
depends on discriminant.diff --git a/gcc/ada/exp_attr.adb b/gcc/ada/exp_attr.adb
--- a/gcc/ada/exp_attr.adb
+++ b/gcc/ada/exp_attr.adb
@@ -3456,8 +3456,12 @@ package body Exp_Attr is
-- replace this attribute with a direct reference to the attribute of
-- the appropriate index subtype (since otherwise the back end will
-- try to give us the value of 'First for this implementation type).
+ -- Do not do this if Ptyp depends on a discriminant as its bounds
+ -- are only available through N.
- if Is_Constrained_Packed_Array (Ptyp) then
+ if Is_Constrained_Packed_Array (Ptyp)
+ and then not Size_Depends_On_Discriminant (Ptyp)
+ then
Rewrite (N,
Make_Attribute_Reference (Loc,
Attribute_Name => Attribute_Name (N),
