Reflections of variable length arrays are invalid and should be
rejected.
PR c++/127147
gcc/cp/ChangeLog:
* reflect.cc (get_reflection): Reject VLAs.
gcc/testsuite/ChangeLog:
* g++.dg/reflect/pr127147.C: New test.
---
gcc/cp/reflect.cc | 11 +++++++++++
gcc/testsuite/g++.dg/reflect/pr127147.C | 9 +++++++++
2 files changed, 20 insertions(+)
create mode 100644 gcc/testsuite/g++.dg/reflect/pr127147.C
diff --git a/gcc/cp/reflect.cc b/gcc/cp/reflect.cc
index 51f0885436e..cb9e901e5ae 100644
--- a/gcc/cp/reflect.cc
+++ b/gcc/cp/reflect.cc
@@ -202,6 +202,17 @@ get_reflection (location_t loc, tree t, reflect_kind
kind/*=REFLECT_UNDEF*/)
error_at (loc, "%<^^%> cannot be applied to a concept check");
return error_mark_node;
}
+ /* A variable length array cannot appear as an operand of the
+ reflection operator. */
+ else if (TREE_CODE (t) == ARRAY_TYPE)
+ {
+ tree nelts = array_type_nelts_top (t);
+ if (!tree_fits_shwi_p (nelts))
+ {
+ error_at (loc, "%<^^%> cannot be applied to a variable length array");
+ return error_mark_node;
+ }
+ }
/* Otherwise, if the template-name names a function template F,
then the template-name interpreted as an id-expression shall
diff --git a/gcc/testsuite/g++.dg/reflect/pr127147.C
b/gcc/testsuite/g++.dg/reflect/pr127147.C
new file mode 100644
index 00000000000..af1fb7e7f8d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/reflect/pr127147.C
@@ -0,0 +1,9 @@
+// PR c++/127147
+// { dg-do compile { target c++26 } }
+// { dg-additional-options "-freflection -Wno-vla" }
+
+consteval void
+foo (int a)
+{
+ auto b = ^^char[a]; // { dg-error "cannot be applied to a variable length
array" }
+}
--
2.55.0
