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author | Marek Polacek <polacek@redhat.com> | 2021-09-09 09:17:27 -0400 |
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committer | Marek Polacek <polacek@redhat.com> | 2021-11-10 09:17:13 -0500 |
commit | a1ad0d84d7fcbcaa7a697290387b911eb7e1bd46 (patch) | |
tree | c949ed2541754ece382176b093be439453662d04 /gcc/opts.c | |
parent | 9701f153f6dfcc365ac0d96cdcf7df69a2de81dc (diff) | |
download | gcc-a1ad0d84d7fcbcaa7a697290387b911eb7e1bd46.zip gcc-a1ad0d84d7fcbcaa7a697290387b911eb7e1bd46.tar.gz gcc-a1ad0d84d7fcbcaa7a697290387b911eb7e1bd46.tar.bz2 |
attribs: Implement -Wno-attributes=vendor::attr [PR101940]
It is desirable for -Wattributes to warn about e.g.
[[deprecate]] void g(); // typo, should warn
However, -Wattributes also warns about vendor-specific attributes
(that's because lookup_scoped_attribute_spec -> find_attribute_namespace
finds nothing), which, with -Werror, causes grief. We don't want the
-Wattributes warning for
[[company::attr]] void f();
GCC warns because it doesn't know the "company" namespace; it only knows
the "gnu" and "omp" namespaces. We could entirely disable warning about
attributes in unknown scopes but then the compiler would also miss typos
like
[[company::attrx]] void f();
or
[[gmu::warn_used_result]] int write();
so that is not a viable solution. A workaround is to use a #pragma:
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wattributes"
[[company::attr]] void f() {}
#pragma GCC diagnostic pop
but that's a mouthful and awkward to use and could also hide typos. In
fact, any macro-based solution doesn't seem like a way forward.
This patch implements -Wno-attributes=, which takes these arguments:
company::attr
company::
This option should go well with using @file: the user could have a file
containing
-Wno-attributes=vendor::attr1,vendor::attr2
and then invoke gcc with '@attrs' or similar.
I've also added a new pragma which has the same effect:
The pragma along with the new option should help with various static
analysis tools.
PR c++/101940
gcc/ChangeLog:
* attribs.c (struct scoped_attributes): Add a bool member.
(lookup_scoped_attribute_spec): Forward declare.
(register_scoped_attributes): New bool parameter, defaulted to
false. Use it.
(handle_ignored_attributes_option): New function.
(free_attr_data): New function.
(init_attributes): Call handle_ignored_attributes_option.
(attr_namespace_ignored_p): New function.
(decl_attributes): Check attr_namespace_ignored_p before
warning.
* attribs.h (free_attr_data): Declare.
(register_scoped_attributes): Adjust declaration.
(handle_ignored_attributes_option): Declare.
(canonicalize_attr_name): New function template.
(canonicalize_attr_name): Use it.
* common.opt (Wattributes=): New option with a variable.
* doc/extend.texi: Document #pragma GCC diagnostic ignored_attributes.
* doc/invoke.texi: Document -Wno-attributes=.
* opts.c (common_handle_option) <case OPT_Wattributes_>: Handle.
* plugin.h (register_scoped_attributes): Adjust declaration.
* toplev.c (compile_file): Call free_attr_data.
gcc/c-family/ChangeLog:
* c-pragma.c (handle_pragma_diagnostic): Handle #pragma GCC diagnostic
ignored_attributes.
gcc/testsuite/ChangeLog:
* c-c++-common/Wno-attributes-1.c: New test.
* c-c++-common/Wno-attributes-2.c: New test.
* c-c++-common/Wno-attributes-3.c: New test.
Diffstat (limited to 'gcc/opts.c')
-rw-r--r-- | gcc/opts.c | 20 |
1 files changed, 20 insertions, 0 deletions
@@ -2611,6 +2611,26 @@ common_handle_option (struct gcc_options *opts, /* Currently handled in a prescan. */ break; + case OPT_Wattributes_: + if (lang_mask == CL_DRIVER) + break; + + if (value) + { + error_at (loc, "arguments ignored for %<-Wattributes=%>; use " + "%<-Wno-attributes=%> instead"); + break; + } + else if (arg[strlen (arg) - 1] == ',') + { + error_at (loc, "trailing %<,%> in arguments for " + "%<-Wno-attributes=%>"); + break; + } + + add_comma_separated_to_vector (&opts->x_flag_ignored_attributes, arg); + break; + case OPT_Werror: dc->warning_as_error_requested = value; break; |