https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85997
--- Comment #1 from joseph at codesourcery dot com <joseph at codesourcery dot com> --- Well, that's a VLA before the decay to pointer type, and thus violates the C90 constraint referenced in the diagnostic. So a diagnostic is obviously required with -std=c90 -pedantic or -Wc90-c99-compat, even if there are certain other uses of -Wvla for which you only want warnings about e.g. code that actually allocates memory for a VLA.
