On 9/20/21 18:59, Marek Polacek via Gcc-patches wrote:
On Mon, Sep 20, 2021 at 09:08:09PM +0200, Jakub Jelinek wrote:
On Mon, Sep 20, 2021 at 02:37:03PM -0400, Marek Polacek wrote:
So, wouldn't be this better specified as
Wno-attributes=
Common Joined RejectNegative
(not sure if RejectNegative is actually needed for an option
starting with Wno- )?
Looks like RejectNegative is not needed. I could do that, but I think
it regresses the diagnostic:
error: unrecognized command-line option '-Wattributes=attr::'
vs
error: arguments ignored for ‘-Wattributes=’; use ‘-Wno-attributes=’ instead
I prefer the latter. (I've changed the warning into error.)
Ok.
+/* { dg-additional-options "-std=c++11" { target c++ } } */
+/* { dg-additional-options "-Wno-attributes=company::,yoyodyne::attr" } */
+/* { dg-additional-options "-Wno-attributes=c1::attr,c1::attr,c1::__attr__" }
*/
+/* { dg-additional-options "-Wno-attributes=clang" } */
+/* { dg-additional-options "-Wno-attributes=c2::,c2::attr" } */
+/* { dg-additional-options "-Wno-attributes=c3::attr,c3::" } */
+/* { dg-additional-options "-Wno-attributes=x::," } */
Should the above be accepted (I mean trailing , ?) What does that mean?
I'm thinking it should: the arguments to -Wno-attributes= could be
generated by a tool so accepting the trailing , might help, like in
enums etc.
I don't think we allow that for any other options that accept a list of
something (except maybe -W{p,c,a,l}, those just pass the args through).
Generating a list that has comma separation only in between items and not
at the end is trivial.
Hmm, ok, here's a version with that checking added. Sadly it needs
to be handled before handle_ignored_attributes_option because of
strtok.
Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
-- >8 --
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::
clang
The last one is a special option to ignore clang-only attributes; in
this patch it is accepted but currently has no effect.
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.
* 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.
gcc/c-family/ChangeLog:
* c-pragma.c (handle_pragma_diagnostic): Handle #pragma GCC diagnostic
ignored_attributes.
gcc/c/ChangeLog:
* c-decl.c (c_parse_final_cleanups): Call free_attr_data.
gcc/cp/ChangeLog:
* decl2.c (c_parse_final_cleanups): Call free_attr_data.
gcc/testsuite/ChangeLog:
* c-c++-common/Wno-attributes-1.c: New test.
* c-c++-common/Wno-attributes-2.c: New test.
---
gcc/attribs.c | 126 +++++++++++++++++-
gcc/attribs.h | 5 +-
gcc/c-family/c-pragma.c | 37 ++++-
gcc/c/c-decl.c | 2 +
gcc/common.opt | 9 +-
gcc/cp/decl2.c | 2 +
gcc/doc/extend.texi | 19 +++
gcc/doc/invoke.texi | 20 +++
gcc/opts.c | 20 +++
gcc/plugin.h | 4 +-
gcc/testsuite/c-c++-common/Wno-attributes-1.c | 56 ++++++++
gcc/testsuite/c-c++-common/Wno-attributes-2.c | 57 ++++++++
12 files changed, 348 insertions(+), 9 deletions(-)
create mode 100644 gcc/testsuite/c-c++-common/Wno-attributes-1.c
create mode 100644 gcc/testsuite/c-c++-common/Wno-attributes-2.c
diff --git a/gcc/attribs.c b/gcc/attribs.c
index 83fafc98b7d..869006e3526 100644
--- a/gcc/attribs.c
+++ b/gcc/attribs.c
@@ -87,6 +87,8 @@ struct scoped_attributes
const char *ns;
vec<attribute_spec> attributes;
hash_table<attribute_hasher> *attribute_hash;
+ /* True if we should not warn about unknown attributes in this NS. */
+ bool ignored_p;
};
/* The table of scope attributes. */
@@ -95,6 +97,8 @@ static vec<scoped_attributes> attributes_table;
static scoped_attributes* find_attribute_namespace (const char*);
static void register_scoped_attribute (const struct attribute_spec *,
scoped_attributes *);
+static const struct attribute_spec *lookup_scoped_attribute_spec (const_tree,
+ const_tree);
static bool attributes_initialized = false;
@@ -121,12 +125,14 @@ extract_attribute_substring (struct substring *str)
/* Insert an array of attributes ATTRIBUTES into a namespace. This
array must be NULL terminated. NS is the name of attribute
- namespace. The function returns the namespace into which the
- attributes have been registered. */
+ namespace. IGNORED_P is true iff all unknown attributes in this
+ namespace should be ignored for the purposes of -Wattributes. The
+ function returns the namespace into which the attributes have been
+ registered. */
scoped_attributes *
register_scoped_attributes (const struct attribute_spec *attributes,
- const char *ns)
+ const char *ns, bool ignored_p /*=false*/)
{
scoped_attributes *result = NULL;
@@ -144,9 +150,12 @@ register_scoped_attributes (const struct attribute_spec *attributes,
memset (&sa, 0, sizeof (sa));
sa.ns = ns;
sa.attributes.create (64);
+ sa.ignored_p = ignored_p;
result = attributes_table.safe_push (sa);
result->attribute_hash = new hash_table<attribute_hasher> (200);
}
+ else
+ result->ignored_p |= ignored_p;
/* Really add the attributes to their namespace now. */
for (unsigned i = 0; attributes[i].name != NULL; ++i)
@@ -224,6 +233,98 @@ check_attribute_tables (void)
attribute_tables[j][l].name));
}
+/* Used to stash pointers to allocated memory so that we can free them at
+ the end of parsing of all TUs. */
+static vec<attribute_spec *> ignored_attributes_table;
+
+/* Parse arguments ARGS of -Wno-attributes=.
+ Currently we accept:
+ vendor::attr
+ vendor::
+ and as a special case:
+ clang
+ This functions also registers the parsed attributes so that we don't
+ warn that we don't recognize them. */
+
+void
+handle_ignored_attributes_option (vec<char *> *v)
+{
+ if (v == nullptr)
+ return;
+
+ for (auto opt : v)
+ {
+ if (strcmp (opt, "clang") == 0)
+ {
+ // TODO
+ continue;
+ }
If this doesn't work yet, let's not accept it at all for now.
+ char *q = strstr (opt, "::");
+ /* We don't accept '::attr'. */
+ if (q == nullptr || q == opt)
+ {
+ error ("wrong argument to ignored attributes");
+ inform (input_location, "valid format is %<ns::attr%>, %<ns::%>, "
+ "or %<clang%>");
...or even mention it. Users can ignore clang:: instead, it doesn't
matter to us if clang attributes are misspelled.
+ continue;
+ }
+ /* Cut off the vendor part. */
+ *q = '\0';
+ char *vendor = opt;
+ char *attr = q + 2;
+ /* Verify that they look valid. */
+ auto valid_p = [](const char *s) {
+ for (; *s != '\0'; ++s)
+ if (!ISALNUM (*s) && *s != '_')
+ return false;
+ return true;
+ };
+ if (!valid_p (vendor) || !valid_p (attr))
+ {
+ error ("wrong argument to ignored attributes");
+ continue;
+ }
+ /* Turn "__attr__" into "attr" so that we have a canonical form of
+ attribute names. Likewise for vendor. */
+ auto strip = [](char *&s) {
+ const size_t l = strlen (s);
+ if (l > 4 && s[0] == '_' && s[1] == '_'
+ && s[l - 1] == '_' && s[l - 2] == '_')
+ {
+ s[l - 2] = '\0';
+ s += 2;
+ }
+ };
+ strip (attr);
+ strip (vendor);
+ /* If we've already seen this vendor::attr, ignore it. Attempting to
+ register it twice would lead to a crash. */
+ if (lookup_scoped_attribute_spec (get_identifier (vendor),
+ get_identifier (attr)))
+ continue;
+ /* In the "vendor::" case, we should ignore *any* attribute coming
+ from this attribute namespace. */
+ const bool ignored_ns = attr[0] == '\0';
Maybe set attr to nullptr instead of declaring ignored_ns?
+ /* Create a table with extra attributes which we will register.
+ We can't free it here, so squirrel away the pointers. */
+ attribute_spec *table = new attribute_spec[2];
+ ignored_attributes_table.safe_push (table);
+ table[0] = { ignored_ns ? nullptr : attr, 0, 0, false, false,
...so this can just use attr.
+ false, false, nullptr, nullptr };
+ table[1] = { nullptr, 0, 0, false, false, false, false, nullptr, nullptr
};
+ register_scoped_attributes (table, vendor, ignored_ns);
+ }
+}
+
+/* Free data we might have allocated when adding extra attributes. */
+
+void
+free_attr_data ()
+{
+ for (auto x : ignored_attributes_table)
+ delete[] x;
+}
You probably also want to zero out ignored_attributes_table at this point.
/* Initialize attribute tables, and make some sanity checks if checking is
enabled. */
@@ -252,6 +353,9 @@ init_attributes (void)
/* Put all the GNU attributes into the "gnu" namespace. */
register_scoped_attributes (attribute_tables[i], "gnu");
+ vec<char *> *ignored = (vec<char *> *) flag_ignored_attributes;
+ handle_ignored_attributes_option (ignored);
+
invoke_plugin_callbacks (PLUGIN_ATTRIBUTES, NULL);
attributes_initialized = true;
}
@@ -456,6 +560,19 @@ diag_attr_exclusions (tree last_decl, tree node, tree
attrname,
return found;
}
+/* Return true iff we should not complain about unknown attributes
+ coming from the attribute namespace NS. This is the case for
+ the -Wno-attributes=ns:: command-line option. */
+
+static bool
+attr_namespace_ignored_p (tree ns)
+{
+ if (ns == NULL_TREE)
+ return false;
+ scoped_attributes *r = find_attribute_namespace (IDENTIFIER_POINTER (ns));
+ return r && r->ignored_p;
+}
+
/* Process the attributes listed in ATTRIBUTES and install them in *NODE,
which is either a DECL (including a TYPE_DECL) or a TYPE. If a DECL,
it should be modified in place; if a TYPE, a copy should be created
@@ -556,7 +673,8 @@ decl_attributes (tree *node, tree attributes, int flags,
if (spec == NULL)
{
- if (!(flags & (int) ATTR_FLAG_BUILT_IN))
+ if (!(flags & (int) ATTR_FLAG_BUILT_IN)
+ && !attr_namespace_ignored_p (ns))
{
if (ns == NULL_TREE || !cxx11_attr_p)
warning (OPT_Wattributes, "%qE attribute directive ignored",
diff --git a/gcc/attribs.h b/gcc/attribs.h
index 138c509bce1..96a527f67a9 100644
--- a/gcc/attribs.h
+++ b/gcc/attribs.h
@@ -21,6 +21,7 @@ along with GCC; see the file COPYING3. If not see
#define GCC_ATTRIBS_H
extern const struct attribute_spec *lookup_attribute_spec (const_tree);
+extern void free_attr_data ();
extern void init_attributes (void);
/* Process the attributes listed in ATTRIBUTES and install them in *NODE,
@@ -40,12 +41,14 @@ extern void apply_tm_attr (tree, tree);
extern tree make_attribute (const char *, const char *, tree);
extern struct scoped_attributes* register_scoped_attributes (const struct attribute_spec *,
- const char *);
+ const char *,
+ bool = false);
extern char *sorted_attr_string (tree);
extern bool common_function_versions (tree, tree);
extern tree make_dispatcher_decl (const tree);
extern bool is_function_default_version (const tree);
+extern void handle_ignored_attributes_option (vec<char *> *);
/* Return a type like TTYPE except that its TYPE_ATTRIBUTES
is ATTRIBUTE.
diff --git a/gcc/c-family/c-pragma.c b/gcc/c-family/c-pragma.c
index a9be8df0384..6beba5503f0 100644
--- a/gcc/c-family/c-pragma.c
+++ b/gcc/c-family/c-pragma.c
@@ -764,7 +764,7 @@ handle_pragma_diagnostic(cpp_reader *ARG_UNUSED(dummy))
if (token != CPP_NAME)
{
warning_at (loc, OPT_Wpragmas,
- "missing [error|warning|ignored|push|pop]"
+ "missing [error|warning|ignored|push|pop|ignored_attributes]"
" after %<#pragma GCC diagnostic%>");
return;
}
@@ -787,10 +787,43 @@ handle_pragma_diagnostic(cpp_reader *ARG_UNUSED(dummy))
diagnostic_pop_diagnostics (global_dc, input_location);
return;
}
+ else if (strcmp (kind_string, "ignored_attributes") == 0)
+ {
+ token = pragma_lex (&x, &loc);
+ if (token != CPP_STRING)
+ {
+ warning_at (loc, OPT_Wpragmas,
+ "missing attribute name after %<#pragma GCC diagnostic "
+ "ignored_attributes%>");
+ return;
+ }
+ char *args = xstrdup (TREE_STRING_POINTER (x));
+ const size_t l = strlen (args);
+ if (l == 0)
+ {
+ warning_at (loc, OPT_Wpragmas, "missing argument to %<#pragma GCC "
+ "diagnostic ignored_attributes%>");
+ free (args);
+ return;
+ }
+ else if (args[l - 1] == ',')
+ {
+ warning_at (loc, OPT_Wpragmas, "trailing %<,%> in arguments for "
+ "%<#pragma GCC diagnostic ignored_attributes%>");
+ free (args);
+ return;
+ }
+ auto_vec<char *> v;
+ for (char *p = strtok (args, ","); p; p = strtok (NULL, ","))
+ v.safe_push (p);
+ handle_ignored_attributes_option (&v);
+ /* ??? We can't free (args); here. */
Perhaps we want to copy strings in handle_ignored_attributes_option
rather than here?
+ return;
+ }
else
{
warning_at (loc, OPT_Wpragmas,
- "expected [error|warning|ignored|push|pop]"
+ "expected [error|warning|ignored|push|pop|ignored_attributes]"
" after %<#pragma GCC diagnostic%>");
return;
}
diff --git a/gcc/c/c-decl.c b/gcc/c/c-decl.c
index 771efa3eadf..345c8f9d620 100644
--- a/gcc/c/c-decl.c
+++ b/gcc/c/c-decl.c
@@ -12295,6 +12295,8 @@ c_parse_final_cleanups (void)
c_write_global_declarations_1 (BLOCK_VARS (DECL_INITIAL (t)));
c_write_global_declarations_1 (BLOCK_VARS (ext_block));
+ free_attr_data ();
Since handle_ignored_attributes_option is in language-independent code,
shouldn't this call be as well?
if (!in_lto_p)
free_attr_access_data ();
diff --git a/gcc/common.opt b/gcc/common.opt
index b921f5e3b25..0da1d714819 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -80,7 +80,7 @@ int flag_gen_aux_info = 0
Variable
int flag_shlib
-; These two are really VEC(char_p,heap) *.
+; These three are really VEC(char_p,heap) *.
Variable
void *flag_instrument_functions_exclude_functions
@@ -88,6 +88,9 @@ void *flag_instrument_functions_exclude_functions
Variable
void *flag_instrument_functions_exclude_files
+Variable
+void *flag_ignored_attributes
+
; Generic structs (e.g. templates not explicitly specialized)
; may not have a compilation unit associated with them, and so
; may need to be treated differently from ordinary structs.
@@ -546,6 +549,10 @@ Wattributes
Common Var(warn_attributes) Init(1) Warning
Warn about inappropriate attribute usage.
+Wattributes=
+Common Joined
+Do not warn about specified attributes.
+
Wattribute-alias
Common Alias(Wattribute_alias=, 1, 0) Warning
Warn about type safety and similar errors and mismatches in declarations with
alias attributes.
diff --git a/gcc/cp/decl2.c b/gcc/cp/decl2.c
index a79a70ba9c2..58388c51dab 100644
--- a/gcc/cp/decl2.c
+++ b/gcc/cp/decl2.c
@@ -5305,6 +5305,8 @@ c_parse_final_cleanups (void)
cp_tree_c_finish_parsing ();
clear_consteval_vfns (consteval_vtables);
+ free_attr_data ();
+
/* The entire file is now complete. If requested, dump everything
to a file. */
dump_tu ();
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 9501a60f20e..48eaf16d209 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -23745,6 +23745,25 @@ restored.
foo(d); /* depends on command-line options */
@end smallexample
+@item #pragma GCC diagnostic ignored_attributes
+
+Similarly to @option{-Wno-attributes=}, this pragma allows users to suppress
+warnings about unknown scoped attributes (in C++11 and C2X). For example,
+@code{#pragma GCC diagnostic ignored_attributes "vendor::attr"} disables
+warning about the following declaration:
+
+@smallexample
+[[vendor::attr]] void f();
+@end smallexample
+
+whereas @code{#pragma GCC diagnostic ignored_attributes "vendor::"} prevents
+warning about both of these declarations:
+
+@smallexample
+[[vendor::safe]] void f();
+[[vendor::unsafe]] void f2();
+@end smallexample
+
@end table
GCC also offers a simple mechanism for printing messages during
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 4acb94181d2..2b0ec511984 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -8621,6 +8621,26 @@ unrecognized attributes, function attributes applied to
variables,
etc. This does not stop errors for incorrect use of supported
attributes.
+Additionally, using @option{-Wno-attributes=}, it is possible to suppress
+warnings about unknown scoped attributes (in C++11 and C2X). For example,
+@option{-Wno-attributes=vendor::attr} disables warning about the following
+declaration:
+
+@smallexample
+[[vendor::attr]] void f();
+@end smallexample
+
+It is also possible to disable warning about all attributes in a namespace
+using @option{-Wno-attributes=vendor::} which prevents warning about both
+of these declarations:
+
+@smallexample
+[[vendor::safe]] void f();
+[[vendor::unsafe]] void f2();
+@end smallexample
+
+Note that @option{-Wno-attributes=} does not imply @option{-Wno-attributes}.
+
@item -Wno-builtin-declaration-mismatch
@opindex Wno-builtin-declaration-mismatch
@opindex Wbuiltin-declaration-mismatch
diff --git a/gcc/opts.c b/gcc/opts.c
index 1d2d22d7a3f..ba664a515a2 100644
--- a/gcc/opts.c
+++ b/gcc/opts.c
@@ -2546,6 +2546,26 @@ 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;
diff --git a/gcc/plugin.h b/gcc/plugin.h
index 1640e253ca5..5556763d1bf 100644
--- a/gcc/plugin.h
+++ b/gcc/plugin.h
@@ -197,7 +197,9 @@ invoke_plugin_callbacks (int event ATTRIBUTE_UNUSED,
/* In attribs.c. */
extern void register_attribute (const struct attribute_spec *attr);
+/* The default argument for the third parameter is given in attribs.h. */
extern struct scoped_attributes* register_scoped_attributes (const struct
attribute_spec *,
- const char *);
+ const char *,
+ bool);
#endif /* PLUGIN_H */
diff --git a/gcc/testsuite/c-c++-common/Wno-attributes-1.c
b/gcc/testsuite/c-c++-common/Wno-attributes-1.c
new file mode 100644
index 00000000000..c174eef5fba
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/Wno-attributes-1.c
@@ -0,0 +1,56 @@
+/* PR c++/101940 */
+/* { dg-do compile } */
+/* { dg-additional-options "-std=c++11" { target c++ } } */
+/* { dg-additional-options "-Wno-attributes=company::,yoyodyne::attr" } */
+/* { dg-additional-options "-Wno-attributes=c1::attr,c1::attr,c1::__attr__" }
*/
+/* { dg-additional-options "-Wno-attributes=clang" } */
+/* { dg-additional-options "-Wno-attributes=c2::,c2::attr" } */
+/* { dg-additional-options "-Wno-attributes=c3::attr,c3::" } */
+/* { dg-additional-options "-Wno-attributes=x::" } */
+/* { dg-additional-options "-Wno-attributes=yoyodyne::attr_new" } */
+/* { dg-additional-options "-Wno-attributes=c4::__attr__" } */
+/* { dg-additional-options "-Wno-attributes=c5::attr" } */
+/* { dg-additional-options "-Wno-attributes=__c6__::attr" } */
+
+[[company::attr]] void f1();
+[[company::attr2]] void f2();
+
+[[yoyodyne::attr]] void f3();
+[[yoyodyne::__attr__]] void f3__();
+[[yoyodyne::attrx]] void f4(); /* { dg-warning "ignored" } */
+[[yoyodyne::__attrx__]] void f4__(); /* { dg-warning "ignored" } */
+
+[[c1::attr]] void f5();
+
+[[c2::attr]] void f6();
+[[c2::attrx]] void f7();
+[[c2::__attr__]] void f6__();
+[[c2::__attrx__]] void f7__();
+
+[[c3::attr]] void f8();
+[[c3::attrx]] void f9();
+
+[[x::x]] void f10();
+
+[[yoyodyne::attr_new]] void f11();
+[[yoyodyne::__attr_new__]] void f11__();
+[[yoyodyne::attr_mew]] void f12(); /* { dg-warning "ignored" } */
+[[yoyodyne::__attr_mew__]] void f12__(); /* { dg-warning "ignored" } */
+
+[[c4::attr]] void f13();
+[[c4::__attr__]] void f13__();
+[[c4::attrx]] void f14(); /* { dg-warning "ignored" } */
+
+[[c5::attr]] void f15();
+[[c5::__attr__]] void f15__();
+[[__c5__::attr]] void __f15();
+[[__c5__::__attr__]] void __f15__();
+[[c5::attrx]] void f15x(); /* { dg-warning "ignored" } */
+[[__c5__::attrx]] void f15x(); /* { dg-warning "ignored" } */
+
+[[c6::attr]] void f16();
+[[c6::__attr__]] void f16__();
+[[__c6__::attr]] void __f16();
+[[__c6__::__attr__]] void __f16__();
+[[c6::attrx]] void f16x(); /* { dg-warning "ignored" } */
+[[__c6__::attrx]] void f16x(); /* { dg-warning "ignored" } */
diff --git a/gcc/testsuite/c-c++-common/Wno-attributes-2.c
b/gcc/testsuite/c-c++-common/Wno-attributes-2.c
new file mode 100644
index 00000000000..8e9f55ea2da
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/Wno-attributes-2.c
@@ -0,0 +1,57 @@
+/* PR c++/101940 */
+/* { dg-do compile } */
+/* { dg-additional-options "-std=c++11" { target c++ } } */
+
+#pragma GCC diagnostic ignored_attributes "company::,yoyodyne::attr"
+#pragma GCC diagnostic ignored_attributes "c1::attr,c1::attr,c1::__attr__"
+#pragma GCC diagnostic ignored_attributes "clang"
+#pragma GCC diagnostic ignored_attributes "c2::,c2::attr"
+#pragma GCC diagnostic ignored_attributes "c3::attr,c3::"
+#pragma GCC diagnostic ignored_attributes "x::"
+#pragma GCC diagnostic ignored_attributes "yoyodyne::attr_new"
+#pragma GCC diagnostic ignored_attributes "c4::__attr__"
+#pragma GCC diagnostic ignored_attributes "c5::attr"
+#pragma GCC diagnostic ignored_attributes "__c6__::attr"
+
+[[company::attr]] void f1();
+[[company::attr2]] void f2();
+
+[[yoyodyne::attr]] void f3();
+[[yoyodyne::__attr__]] void f3__();
+[[yoyodyne::attrx]] void f4(); /* { dg-warning "ignored" } */
+[[yoyodyne::__attrx__]] void f4__(); /* { dg-warning "ignored" } */
+
+[[c1::attr]] void f5();
+
+[[c2::attr]] void f6();
+[[c2::attrx]] void f7();
+[[c2::__attr__]] void f6__();
+[[c2::__attrx__]] void f7__();
+
+[[c3::attr]] void f8();
+[[c3::attrx]] void f9();
+
+[[x::x]] void f10();
+
+[[yoyodyne::attr_new]] void f11();
+[[yoyodyne::__attr_new__]] void f11__();
+[[yoyodyne::attr_mew]] void f12(); /* { dg-warning "ignored" } */
+[[yoyodyne::__attr_mew__]] void f12__(); /* { dg-warning "ignored" } */
+
+[[c4::attr]] void f13();
+[[c4::__attr__]] void f13__();
+[[c4::attrx]] void f14(); /* { dg-warning "ignored" } */
+
+[[c5::attr]] void f15();
+[[c5::__attr__]] void f15__();
+[[__c5__::attr]] void __f15();
+[[__c5__::__attr__]] void __f15__();
+[[c5::attrx]] void f15x(); /* { dg-warning "ignored" } */
+[[__c5__::attrx]] void f15x(); /* { dg-warning "ignored" } */
+
+[[c6::attr]] void f16();
+[[c6::__attr__]] void f16__();
+[[__c6__::attr]] void __f16();
+[[__c6__::__attr__]] void __f16__();
+[[c6::attrx]] void f16x(); /* { dg-warning "ignored" } */
+[[__c6__::attrx]] void f16x(); /* { dg-warning "ignored" } */
base-commit: b333c3acb8d436b256ba8922c6426c93860bb616
