c: pedwarn on flexible array member initialization with {} for C23+ [PR119350]

Even in C23/C2Y any initialization of flexible array member is still
invalid, so we should emit a pedwarn on it.  But we no longer do for
initialization with {}.  The reason is that for C17 and earlier,
we already emitted a pedwarn on the {} initializer and so emitting
another pedwarn on the flexible array member initialization would
be diagnosing the same thing multiple times.

In C23 we no longer pedwarn on {}, it is standard.
The following patch arranges a pedwarning for that for C23+, so that
at least one pedwarning is emitted.

So that we don't "regress" from C17 to C23 on nested flexible array
member initialization with no -pedantic/-pedantic-errors/-Wpedantic,
the patch emits even the
initialization of flexible array member in a nested context
diagnostic as pedwarn in the {} case, after all, it doesn't cause
much trouble, we just ignore it like before, it wouldn't initialize
anything.

2025-03-19  Jakub Jelinek  <jakub@redhat.com>

	PR c/119350
	* c-typeck.cc (pop_init_level): Don't ignore empty brackets for
	flag_isoc23, still set constructor_type to NULL in that case but
	emit a pedwarn_init in that case.

	* gcc.dg/pr119350-1.c: New test.
	* gcc.dg/pr119350-2.c: New test.
	* gcc.dg/pr119350-3.c: New test.

0 files changed, 0 insertions, 0 deletions