From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id 74D8F3858405 for ; Wed, 10 Nov 2021 05:53:15 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 74D8F3858405 Received: from mail-qk1-f197.google.com (mail-qk1-f197.google.com [209.85.222.197]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-534-wXqbuXnAOuyvN7-aSrW2eg-1; Wed, 10 Nov 2021 00:53:13 -0500 X-MC-Unique: wXqbuXnAOuyvN7-aSrW2eg-1 Received: by mail-qk1-f197.google.com with SMTP id br11-20020a05620a460b00b004630d0237f2so1165455qkb.17 for ; Tue, 09 Nov 2021 21:53:13 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=cPDUdKQmpiBN9NkbT5qQrtcH+Eb8aDvMfnHvYDxorS0=; b=LeqHaY+UB1K5/BS6XKl7bMk+JgO46eDfouSVdebKTnEiftMADEBV68iVN8KhEPUfjJ znQr8s6tFStPAvbzac4p9ni0VrDrR3VpFX4kqKQ6cy14/CRWhDPtLxhXRNJjI3ju0K/6 8KZUlYmv1k1ZANTXuARNBGFEWyhDaNj7UYHVW5RiwF6tqeKYyT2A5g4KE15H664t3yWT U1VDwGqx+3oRjn0GrhopiKF46ktLLeI5TzD/T0sLqGkEQtHlwDCAF4sCzs4qy+CLl5W+ eIL8qetctDJ2gKcANw41WHlfE+lQHjfYL+Kjo0cB0hd61XAOhSjNZ8hL7xcs/DhUC+Lc lpYg== X-Gm-Message-State: AOAM530rHzzpbTrryZA4XfvtSNHEUsgofhNII2crsNTGVNwElD30jDR3 WHpOed73QFR18MvIbqGzmp7FFRocW05Rw5NbXBSVQXhZMkBDRLkHGg/lVHQc1F5cVLEMqriPHAR aBTItVcPBS0b5IlNevA== X-Received: by 2002:ac8:5c54:: with SMTP id j20mr15005849qtj.190.1636523592654; Tue, 09 Nov 2021 21:53:12 -0800 (PST) X-Google-Smtp-Source: ABdhPJwq4kl4oHpMJU25DVCkufN/vWSKUJrL3qTKJqGFSCiw7vhM5e6f6mzof4s9J8cqHNnYYCxOAQ== X-Received: by 2002:ac8:5c54:: with SMTP id j20mr15005793qtj.190.1636523591989; Tue, 09 Nov 2021 21:53:11 -0800 (PST) Received: from [192.168.1.149] (130-44-159-43.s15913.c3-0.arl-cbr1.sbo-arl.ma.cable.rcncustomer.com. [130.44.159.43]) by smtp.gmail.com with ESMTPSA id g19sm14169391qtg.78.2021.11.09.21.53.11 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 09 Nov 2021 21:53:11 -0800 (PST) Message-ID: <700da883-5780-6d3d-aec3-ca842e1426ac@redhat.com> Date: Wed, 10 Nov 2021 00:53:10 -0500 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.3.0 Subject: Re: [PATCH v8] attribs: Implement -Wno-attributes=vendor::attr [PR101940] To: Marek Polacek Cc: Bernhard Reutner-Fischer , Marek Polacek via Gcc-patches , Jakub Jelinek References: <84D9B2CE-EA9B-46FB-9BF5-809D29B7018E@gmail.com> <516f3ddd-8634-9d73-ddd4-ae470f4284cf@redhat.com> <20211109080910.2eae4f69@nbbrfq> From: Jason Merrill In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-14.0 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, NICE_REPLY_A, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H2, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 10 Nov 2021 05:53:18 -0000 On 11/9/21 16:30, Marek Polacek wrote: > On Tue, Nov 09, 2021 at 02:17:14PM -0500, Marek Polacek wrote: >> On Tue, Nov 09, 2021 at 12:27:28PM -0500, Jason Merrill wrote: >>> On 11/9/21 10:55, Marek Polacek wrote: >>>> On Tue, Nov 09, 2021 at 08:09:10AM +0100, Bernhard Reutner-Fischer wrote: >>>>> On Tue, 9 Nov 2021 00:12:10 -0500 >>>>> Jason Merrill wrote: >>>>> >>>>>> On 11/8/21 20:41, Marek Polacek wrote: >>>>>>> On Sat, Nov 06, 2021 at 03:29:57PM -0400, Jason Merrill wrote: >>>>> >>>>>>> + for (auto opt : v) >>>>>>> + { >>>>>>> + char *cln = strstr (opt, "::"); >>>>>>> + /* We don't accept '::attr'. */ >>>>>>> + if (cln == nullptr || cln == opt) >>>>>>> + { >>>>>>> + error ("wrong argument to ignored attributes"); >>>>>>> + inform (input_location, "valid format is % or %"); >>>>>>> + continue; >>>>>>> + } >>>>>>> + char *vendor_start = opt; >>>>>>> + ptrdiff_t vendor_len = cln - opt; >>>>>>> + char *attr_start = cln + 2; >>>>>>> + /* This could really use rawmemchr :(. */ >>>>>>> + ptrdiff_t attr_len = strchr (attr_start, '\0') - attr_start; >>>>>>> + /* Verify that they look valid. */ >>>>>>> + auto valid_p = [](const char *const s, ptrdiff_t len) { >>>>>>> + for (int i = 0; i < len; ++i) >>>>>>> + if (!ISALNUM (*s) && *s != '_') >>>>>>> + return false; >>>>>>> + return true; >>>>>>> + }; >>>>>>> + if (!valid_p (vendor_start, vendor_len) >>>>>>> + || !valid_p (attr_start, attr_len)) >>>>>>> + { >>>>>>> + 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, ptrdiff_t &l) { >>>>>>> + if (l > 4 && s[0] == '_' && s[1] == '_' >>>>>>> + && s[l - 1] == '_' && s[l - 2] == '_') >>>>>>> + { >>>>>>> + s += 2; >>>>>>> + l -= 4; >>>>>>> + } >>>>>>> + }; >>>>>>> + strip (attr_start, attr_len); >>>>>>> + strip (vendor_start, vendor_len); >>>>>>> + /* We perform all this hijinks so that we don't have to copy OPT. */ >>>>>>> + tree vendor_id = get_identifier_with_length (vendor_start, vendor_len); >>>>>>> + tree attr_id = get_identifier_with_length (attr_start, attr_len); >>>>>>> + /* 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 (vendor_id, attr_id)) >>>>>>> + continue; >>>>>> >>>>>> Hmm, this looks like it isn't handling the case of previously ignoring >>>>>> vendor::; it seems we'll look for vendor:: instead, not >>>>>> find it, and register again. >>> >>>> Yes, for -Wno-attributes=vendor::,vendor:: we call register_scoped_attributes >>>> twice, but I think that's OK: register_scoped_attributes will see that >>>> find_attribute_namespace finds the namespace and returns without >>>> creating a new one. >>>> >>>> I think the current code handles -Wno-attributes=vendor::a,vendor:: well so >>>> I'm not sure if I should change it. >>> >>> Makes sense. But we should be able to avoid calling >>> lookup_scoped_attribute_spec, and even get_identifier_with_length (attr...), >>> if attr_len is 0. >> >> Duh, of course. Also no need to canonicalize an empty string. >> >>>>> I don't know if there are __attrib with 2 leading underscores but no >>>>> trailing that we accept and should normalize? >>>>> >>>>> And it is surprising that we do not have a simple normalize_attr_name(). >>>>> There must be existing spots where we would normalize attribute names? >>>>> extract_attribute_substring does about the same but with a struct substring(?). >>>>> Maybe that's just to avoid a normal string hash. >>>> >>>> We have canonicalize_attr_name which I based my code on. >>> >>> We could factor out of that function an overload equivalent to your strip >>> lambda? >> >> OK. Since it's taking a reference and I wanted it to work both with a size_t >> and ptrdiff_t, I made it a template. Is is too much? > > OK, this time for real. Here's another version, which doesn't crash on > -Wno-attributes=c::____. I apologize for the number of takes. :-( > > Bootstrap/regtest running on ppc64le-linux-gnu. OK if it passes? OK, thanks for your persistence. :) > -- >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:: > > 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) : 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. > --- > gcc/attribs.c | 127 +++++++++++++++++- > gcc/attribs.h | 28 +++- > gcc/c-family/c-pragma.c | 37 ++++- > gcc/common.opt | 9 +- > 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 | 55 ++++++++ > gcc/testsuite/c-c++-common/Wno-attributes-2.c | 56 ++++++++ > gcc/testsuite/c-c++-common/Wno-attributes-3.c | 9 ++ > gcc/toplev.c | 2 + > 12 files changed, 374 insertions(+), 12 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 > create mode 100644 gcc/testsuite/c-c++-common/Wno-attributes-3.c > > diff --git a/gcc/attribs.c b/gcc/attribs.c > index 83fafc98b7d..0284e5bf2fd 100644 > --- a/gcc/attribs.c > +++ b/gcc/attribs.c > @@ -87,6 +87,8 @@ struct scoped_attributes > const char *ns; > vec attributes; > hash_table *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 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 (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 +233,99 @@ 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 ignored_attributes_table; > + > +/* Parse arguments V of -Wno-attributes=. > + Currently we accept: > + vendor::attr > + vendor:: > + 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 *v) > +{ > + if (v == nullptr) > + return; > + > + for (auto opt : v) > + { > + char *cln = strstr (opt, "::"); > + /* We don't accept '::attr'. */ > + if (cln == nullptr || cln == opt) > + { > + error ("wrong argument to ignored attributes"); > + inform (input_location, "valid format is % or %"); > + continue; > + } > + const char *vendor_start = opt; > + ptrdiff_t vendor_len = cln - opt; > + const char *attr_start = cln + 2; > + /* This could really use rawmemchr :(. */ > + ptrdiff_t attr_len = strchr (attr_start, '\0') - attr_start; > + /* Verify that they look valid. */ > + auto valid_p = [](const char *const s, ptrdiff_t len) { > + bool ok = false; > + > + for (int i = 0; i < len; ++i) > + if (ISALNUM (s[i])) > + ok = true; > + else if (s[i] != '_') > + return false; > + > + return ok; > + }; > + if (!valid_p (vendor_start, vendor_len)) > + { > + error ("wrong argument to ignored attributes"); > + continue; > + } > + canonicalize_attr_name (vendor_start, vendor_len); > + /* We perform all this hijinks so that we don't have to copy OPT. */ > + tree vendor_id = get_identifier_with_length (vendor_start, vendor_len); > + const char *attr; > + /* In the "vendor::" case, we should ignore *any* attribute coming > + from this attribute namespace. */ > + if (attr_len > 0) > + { > + if (!valid_p (attr_start, attr_len)) > + { > + error ("wrong argument to ignored attributes"); > + continue; > + } > + canonicalize_attr_name (attr_start, attr_len); > + tree attr_id = get_identifier_with_length (attr_start, attr_len); > + attr = IDENTIFIER_POINTER (attr_id); > + /* 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 (vendor_id, attr_id)) > + continue; > + } > + else > + attr = nullptr; > + /* 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] = { attr, 0, 0, false, false, false, false, nullptr, nullptr }; > + table[1] = { nullptr, 0, 0, false, false, false, false, nullptr, > + nullptr }; > + register_scoped_attributes (table, IDENTIFIER_POINTER (vendor_id), !attr); > + } > +} > + > +/* Free data we might have allocated when adding extra attributes. */ > + > +void > +free_attr_data () > +{ > + for (auto x : ignored_attributes_table) > + delete[] x; > + ignored_attributes_table.release (); > +} > + > /* Initialize attribute tables, and make some sanity checks if checking is > enabled. */ > > @@ -252,6 +354,9 @@ init_attributes (void) > /* Put all the GNU attributes into the "gnu" namespace. */ > register_scoped_attributes (attribute_tables[i], "gnu"); > > + vec *ignored = (vec *) flag_ignored_attributes; > + handle_ignored_attributes_option (ignored); > + > invoke_plugin_callbacks (PLUGIN_ATTRIBUTES, NULL); > attributes_initialized = true; > } > @@ -456,6 +561,19 @@ 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 +674,8 @@ 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..ba657881940 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 *); > > /* Return a type like TTYPE except that its TYPE_ATTRIBUTES > is ATTRIBUTE. > @@ -114,17 +117,34 @@ extern unsigned decls_mismatched_attributes (tree, tree, tree, > > extern void maybe_diag_alias_attributes (tree, tree); > > +/* For a given string S of length L, strip leading and trailing '_' characters > + so that we have a canonical form of attribute names. NB: This function may > + change S and L. */ > + > +template > +inline bool > +canonicalize_attr_name (const char *&s, T &l) > +{ > + if (l > 4 && s[0] == '_' && s[1] == '_' && s[l - 1] == '_' && s[l - 2] == '_') > + { > + s += 2; > + l -= 4; > + return true; > + } > + return false; > +} > + > /* For a given IDENTIFIER_NODE, strip leading and trailing '_' characters > so that we have a canonical form of attribute names. */ > > static inline tree > canonicalize_attr_name (tree attr_name) > { > - const size_t l = IDENTIFIER_LENGTH (attr_name); > + size_t l = IDENTIFIER_LENGTH (attr_name); > const char *s = IDENTIFIER_POINTER (attr_name); > > - if (l > 4 && s[0] == '_' && s[1] == '_' && s[l - 1] == '_' && s[l - 2] == '_') > - return get_identifier_with_length (s + 2, l - 4); > + if (canonicalize_attr_name (s, l)) > + return get_identifier_with_length (s, l); > > return attr_name; > } > diff --git a/gcc/c-family/c-pragma.c b/gcc/c-family/c-pragma.c > index a9be8df0384..a299ceff6a2 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 v; > + for (char *p = strtok (args, ","); p; p = strtok (NULL, ",")) > + v.safe_push (p); > + handle_ignored_attributes_option (&v); > + free (args); > + 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/common.opt b/gcc/common.opt > index 1a5b9bfcca9..de9b848eda5 100644 > --- a/gcc/common.opt > +++ b/gcc/common.opt > @@ -83,7 +83,7 @@ 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 > @@ -91,6 +91,9 @@ 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. > @@ -549,6 +552,10 @@ 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/doc/extend.texi b/gcc/doc/extend.texi > index eee4c6737bb..6e6c580e329 100644 > --- a/gcc/doc/extend.texi > +++ b/gcc/doc/extend.texi > @@ -23767,6 +23767,25 @@ 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 2ea23d07c4c..297ca98deae 100644 > --- a/gcc/doc/invoke.texi > +++ b/gcc/doc/invoke.texi > @@ -8707,6 +8707,26 @@ 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 caed6255500..175b4635bb4 100644 > --- a/gcc/opts.c > +++ b/gcc/opts.c > @@ -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; > 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..aac1a69fd85 > --- /dev/null > +++ b/gcc/testsuite/c-c++-common/Wno-attributes-1.c > @@ -0,0 +1,55 @@ > +/* 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=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..4307c74b048 > --- /dev/null > +++ b/gcc/testsuite/c-c++-common/Wno-attributes-2.c > @@ -0,0 +1,56 @@ > +/* 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 "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" } */ > diff --git a/gcc/testsuite/c-c++-common/Wno-attributes-3.c b/gcc/testsuite/c-c++-common/Wno-attributes-3.c > new file mode 100644 > index 00000000000..64370f2ef6f > --- /dev/null > +++ b/gcc/testsuite/c-c++-common/Wno-attributes-3.c > @@ -0,0 +1,9 @@ > +/* PR c++/101940 */ > +/* { dg-do compile } */ > +/* { dg-additional-options "-Wno-attributes=___::" } */ > +/* { dg-additional-options "-Wno-attributes=c::____" } */ > +/* { dg-additional-options "-Wno-attributes=____::____" } */ > +/* { dg-additional-options "-Wno-attributes=c@::attr" } */ > +/* { dg-additional-options "-Wno-attributes=c2::@tr" } */ > + > +/* { dg-error "wrong argument to ignored attributes" "" { target *-*-* } 0 } */ > diff --git a/gcc/toplev.c b/gcc/toplev.c > index e91f083f8ff..99276bde87d 100644 > --- a/gcc/toplev.c > +++ b/gcc/toplev.c > @@ -457,6 +457,8 @@ compile_file (void) > if (flag_dump_locations) > dump_location_info (stderr); > > + free_attr_data (); > + > /* Compilation is now finished except for writing > what's left of the symbol table output. */ > > > base-commit: 8875a92d31329ae52b734683784c4b054839a661 >