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| author | Marek Polacek <polacek@redhat.com> | 2020-11-06 12:33:53 -0500 |
|---|---|---|
| committer | Marek Polacek <polacek@redhat.com> | 2020-11-09 18:22:58 -0500 |
| commit | 04126e46eb2d829d7b4149d394b667e878912cc8 (patch) | |
| tree | d335d40d1f5e99dad16532ef1f34e6099465ff31 /gcc/c-family/c-common.c | |
| parent | d3fd75d869480044213553000d2c9dc236a4f7af (diff) | |
| download | gcc-04126e46eb2d829d7b4149d394b667e878912cc8.tar.gz | |
c++: DR 1914 - Allow duplicate standard attributes.
Following Joseph's change for C to allow duplicate C2x standard attributes
<https://gcc.gnu.org/pipermail/gcc-patches/2020-October/557272.html>,
this patch does a similar thing for C++. This is DR 1914, to be resolved by
<wg21.link/p2156>, which is not part of the standard yet, but has wide
support so looks like a shoo-in. The duplications now produce warnings
instead, but only if the attribute wasn't specified via a macro.
gcc/c-family/ChangeLog:
DR 1914
* c-common.c (attribute_fallthrough_p): Tweak the warning
message.
gcc/cp/ChangeLog:
DR 1914
* parser.c (cp_parser_check_std_attribute): Return bool. Add a
location_t parameter. Return true if the attribute wasn't duplicated.
Give a warning instead of an error. Check more attributes.
(cp_parser_std_attribute_list): Don't add duplicated attributes to
the list. Pass location to cp_parser_check_std_attribute.
gcc/testsuite/ChangeLog:
DR 1914
* c-c++-common/attr-fallthrough-2.c: Adjust dg-warning.
* g++.dg/cpp0x/fallthrough2.C: Likewise.
* g++.dg/cpp0x/gen-attrs-60.C: Turn dg-error into dg-warning.
* g++.dg/cpp1y/attr-deprecated-2.C: Likewise.
* g++.dg/cpp2a/attr-likely2.C: Adjust dg-warning.
* g++.dg/cpp2a/nodiscard-once.C: Turn dg-error into dg-warning.
* g++.dg/cpp0x/gen-attrs-72.C: New test.
Diffstat (limited to 'gcc/c-family/c-common.c')
| -rw-r--r-- | gcc/c-family/c-common.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c index d4d3228b8f6..29508bca97b 100644 --- a/gcc/c-family/c-common.c +++ b/gcc/c-family/c-common.c @@ -5752,9 +5752,10 @@ attribute_fallthrough_p (tree attr) tree t = lookup_attribute ("fallthrough", attr); if (t == NULL_TREE) return false; - /* This attribute shall appear at most once in each attribute-list. */ + /* It is no longer true that "this attribute shall appear at most once in + each attribute-list", but we still give a warning. */ if (lookup_attribute ("fallthrough", TREE_CHAIN (t))) - warning (OPT_Wattributes, "%<fallthrough%> attribute specified multiple " + warning (OPT_Wattributes, "attribute %<fallthrough%> specified multiple " "times"); /* No attribute-argument-clause shall be present. */ else if (TREE_VALUE (t) != NULL_TREE) |