efriedma added inline comments.
================
Comment at: clang/test/Sema/vla.c:134
+ // expected-warning@+1{{variable length array folded to constant array as an
extension}}
+ char (*a9)[] = (char[2][ksize]) {{1,2,3,4},{4,3,2,1}};
+
----------------
aaron.ballman wrote:
> efriedma wrote:
> > aaron.ballman wrote:
> > > Doesn't this violate the constraints in C17 6.5.2.5p1, "The type name
> > > shall specify a complete object type or an array of unknown size, but not
> > > a variable-length array type"?
> > Yes, this is a constraint violation. This patch downgrades the error to a
> > warning, for compatibility with older versions of clang.
> It was an error in older versions of Clang, so downgrading it to a warning
> can't make code *more* compatible with older versions. This also makes it
> harder to port C code to other compilers because Clang happily accepts code
> that the C standard says should be rejected.
>
> I'm not strongly opposed to the change, but I also don't like ignoring
> constraint violations in the standard as that comes awfully close to what
> `-fpermissive` does (and at least with that awful flag you have to opt *into*
> the less strictly conforming behavior instead of getting it by default as
> with extensions).
>
> I'm curious if @rsmith has thoughts here?
> It was an error in older versions of Clang
https://godbolt.org/z/rvbffY
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D98363/new/
https://reviews.llvm.org/D98363
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
