On 24/05/17 14:50 -0400, Jason Merrill wrote:
On Wed, May 24, 2017 at 10:20 AM, Jonathan Wakely <jwak...@redhat.com> wrote:
On 23/05/17 16:26 -0400, Jason Merrill wrote:
On Tue, May 23, 2017 at 2:00 PM, Jonathan Wakely <jwak...@redhat.com>
wrote:
On 19/05/17 15:14 -0400, Jason Merrill wrote:
On Thu, Apr 27, 2017 at 12:59 PM, Jonathan Wakely <jwak...@redhat.com>
wrote:
I also tried to add a warning like EDG's (see the PR) but it gave a
false positive for direct-list-init of scoped enums (P0138R2, r240449)
because that code goes through build_c_cast to perform the conversion,
so looks like a cast to my new warning.
The enum init code could strip the cv-quals when calling build_c_cast
to avoid the warning.
Thanks, that works. I don't think this warning fits under any existing
option, so I'll add a new one. -Wuseless-cast-qual maybe? Or is that
too close to -Wuseless-cast and -Wcast-qual and would cause confusion?
-Wcast-rvalue-qual ?
I realised that -Wignored-qualifiers is a good fit. That warns about
ignored cv-qualifiers on return types, which is a very similar case.
This patch adds a new function to conditionally warn and calls that
from the build_*_cast functions after they produce a valid result. I
originally put the warnings next to the cv_unqualified calls that
strip the quals, but was getting duplicate warnings when build_cp_cast
calls more than one of the build_*_cast_1 functions.
This also removes the unnecessary check for reference types that
Nathan pointed out.
Tested x86_64-linux and powerpc64-linux. OK for trunk?
+/*
+ Warns if the cast ignores cv-qualifiers on TYPE.
+ */
The GCC sources don't put /* and */ on their own line. OK with that
change, thanks!
OK, I'll also fix it on the maybe_warn_about_useless_cast function
just above, which I copied :-)
diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index ecc7190..b81d6c8 100644
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -6655,9 +6655,7 @@ check_for_casting_away_constness (tree src_type, tree dest_type,
}
}
-/*
- Warns if the cast from expression EXPR to type TYPE is useless.
- */
+/* Warns if the cast from expression EXPR to type TYPE is useless. */
void
maybe_warn_about_useless_cast (tree type, tree expr, tsubst_flags_t complain)
{
@@ -6673,9 +6671,7 @@ maybe_warn_about_useless_cast (tree type, tree expr, tsubst_flags_t complain)
}
}
-/*
- Warns if the cast ignores cv-qualifiers on TYPE.
- */
+/* Warns if the cast ignores cv-qualifiers on TYPE. */
void
maybe_warn_about_cast_ignoring_quals (tree type, tsubst_flags_t complain)
{
