On Sun, 17 Jan 2021, Uecker, Martin wrote:
> I did not add tests for c11 for warnings because we already
> had warnings before and the tests for these exist. (I removed
> -Wdiscarded-array-qualifiers from the old tests as this flag
> is not needed.) Or should there be additional warnings
> with -Wc11-c2x-compat for c11? But warning twice about
> the same issue does not seem ideal...
If something is already warned about by default in C11 mode,
-Wc11-c2x-compat doesn't need to produce extra warnings.
> + int (*x)[3];
> + const int (*p)[3] = x; /* { dg-warning "pointers to arrays with
> different qualifiers are
> incompatible in ISO C before C2X" } */
"incompatible" doesn't seem the right wording for the diagnostic. The
types are incompatible (i.e. not compatible types) regardless of standard
version; the issue in this case is the rules for assignment.
> diff --git a/gcc/testsuite/gcc.dg/c2x-qual-6.c
> b/gcc/testsuite/gcc.dg/c2x-qual-6.c
> new file mode 100644
> index 00000000000..dca50ac014f
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/c2x-qual-6.c
> @@ -0,0 +1,9 @@
> +/* Test related to qualifiers and pointers to arrays in C2X, PR98397 */
> +/* { dg-do compile } */
> +/* { dg-options "-std=c2x -pedantic-errors -Wc11-c2x-compat" } */
> +
> +void f(void)
> +{
> + const void* x;
> + const int (*p)[3] = x; /* { dg-error "array with qualifier on the
> element is not qualified
> before C2X" } */
This is showing a bug in the compiler implementation. In C2X mode, this
message should be a warning not a pedwarn because the code is not a
constraint violation. -Wc11-c2x-compat should produce a warning
(independent of -pedantic), but -pedantic-errors should not turn it into
an error.
--
Joseph S. Myers
jos...@codesourcery.com
