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| author | Marek Polacek <polacek@redhat.com> | 2021-12-16 16:29:41 -0500 |
|---|---|---|
| committer | Marek Polacek <polacek@redhat.com> | 2021-12-17 17:56:26 -0500 |
| commit | 6afb8a68a9113897ccf39e40983e042ed90d7aed (patch) | |
| tree | dd26347d03e98714dcb291f7a409dde9c04d02e9 /gcc/cp/parser.c | |
| parent | 00ea158fa0d44d6d81f5e8a8d875c917bd086b99 (diff) | |
| download | gcc-6afb8a68a9113897ccf39e40983e042ed90d7aed.zip gcc-6afb8a68a9113897ccf39e40983e042ed90d7aed.tar.gz gcc-6afb8a68a9113897ccf39e40983e042ed90d7aed.tar.bz2 | |
attribs: Fix wrong error with -Wno-attribute=A::b [PR103649]
My patch to implement -Wno-attribute=A::b caused a bogus error when
parsing
[[foo::bar(1, 2)]];
when -Wno-attributes=foo::bar was specified on the command line, because
when we create a fake foo::bar attribute and insert it into our attribute
table, it is created with max_length == 0 which doesn't allow any args.
That is wrong -- we know nothing about the attribute, so we shouldn't
require any specific number of arguments. And since unknown attributes
can be rather complex (see for example omp::{directive,sequence}), we
must skip parsing their arguments. To that end, I'm using max_length
with value -2.
Also let's not warn about things like
[[vendor::assume(true)]];
because they may have some meaning (this is reminiscent of C++ Portable
Assumptions).
PR c/103649
gcc/ChangeLog:
* attribs.c (handle_ignored_attributes_option): Create the fake
attribute with max_length == -2.
(attribute_ignored_p): New overloads.
* attribs.h (attribute_ignored_p): Declare them.
* tree-core.h (struct attribute_spec): Document that max_length
can be -2.
gcc/c/ChangeLog:
* c-decl.c (c_warn_unused_attributes): Don't warn for
attribute_ignored_p.
* c-parser.c (c_parser_std_attribute): Skip parsing of the attribute
arguments when the attribute is ignored.
gcc/cp/ChangeLog:
* parser.c (cp_parser_declaration): Don't warn for attribute_ignored_p.
(cp_parser_std_attribute): Skip parsing of the attribute
arguments when the attribute is ignored.
gcc/testsuite/ChangeLog:
* c-c++-common/Wno-attributes-6.c: New test.
Diffstat (limited to 'gcc/cp/parser.c')
| -rw-r--r-- | gcc/cp/parser.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c index 44eed7e..33fb40a 100644 --- a/gcc/cp/parser.c +++ b/gcc/cp/parser.c @@ -14776,7 +14776,7 @@ cp_parser_declaration (cp_parser* parser, tree prefix_attrs) } } - if (std_attrs != NULL_TREE) + if (std_attrs != NULL_TREE && !attribute_ignored_p (std_attrs)) warning_at (make_location (attrs_loc, attrs_loc, parser->lexer), OPT_Wattributes, "attribute ignored"); if (cp_lexer_next_token_is (parser->lexer, CPP_SEMICOLON)) @@ -28979,7 +28979,9 @@ cp_parser_std_attribute (cp_parser *parser, tree attr_ns) /* A GNU attribute that takes an identifier in parameter. */ attr_flag = id_attr; - if (as == NULL) + /* If this is a fake attribute created to handle -Wno-attributes, + we must skip parsing the arguments. */ + if (as == NULL || attribute_ignored_p (as)) { if ((flag_openmp || flag_openmp_simd) && attr_ns == omp_identifier) { |