My dream, and something I would like to work towards is supporting something like this:
> [[clang::libcxx_diagnose_if(cond, "message", "warning", /* warning-id*/ "non-const-functor")]] > > -Wno-libcxx-warnings=non-const-functor This way libc++ warnings get treated differently from all other users of diagnose_if, and can be enabled and disabled separately. @George does this sound like a reasonable goal? If so I'm happy to start working on this. /Eric On Mon, Jan 23, 2017 at 11:46 AM, George Burgess <g...@google.com> wrote: > The only plan that we have at the moment is basically for a > -Wno-user-defined-warnings-in-system-headers type of flag. I agree that > it would be nice if we could be more granular than this, so I'll think > about what we can do. > > On Mon, Jan 23, 2017 at 8:36 AM, Nico Weber <tha...@chromium.org> wrote: > >> This happens to fire in practice in protobuf. It's probably a true >> positive and it's cool that this warning found it, but it means we have to >> disable Wuser-defined-warnings for a bit -- which then disables all of >> these user-defined warnings. Right now there aren't any others, but it >> feels like we'd want to have the ability to turn individual user-defined >> warnings on or off instead of just having a single toggle for all of them. >> Are there plans for something like that? >> >> On Fri, Jan 13, 2017 at 5:02 PM, Eric Fiselier via cfe-commits < >> cfe-commits@lists.llvm.org> wrote: >> >>> Author: ericwf >>> Date: Fri Jan 13 16:02:08 2017 >>> New Revision: 291961 >>> >>> URL: http://llvm.org/viewvc/llvm-project?rev=291961&view=rev >>> Log: >>> Add _LIBCPP_DIAGNOSE_WARNING and _LIBCPP_DIAGNOSE_ERROR macros. >>> >>> Clang recently added a `diagnose_if(cond, msg, type)` attribute >>> which can be used to generate diagnostics when `cond` is a constant >>> expression that evaluates to true. Otherwise no attribute has no >>> effect. >>> >>> This patch adds _LIBCPP_DIAGNOSE_ERROR/WARNING macros which >>> use this new attribute. Additionally this patch implements >>> a diagnostic message when a non-const-callable comparator is >>> given to a container. >>> >>> Note: For now the warning version of the diagnostic is useless >>> within libc++ since warning diagnostics are suppressed by the >>> system header pragma. I'm going to work on fixing this. >>> >>> Added: >>> libcxx/trunk/test/libcxx/containers/associative/non_const_co >>> mparator.fail.cpp >>> Modified: >>> libcxx/trunk/docs/UsingLibcxx.rst >>> libcxx/trunk/include/__config >>> libcxx/trunk/include/__tree >>> libcxx/trunk/include/map >>> libcxx/trunk/include/type_traits >>> libcxx/trunk/test/libcxx/compiler.py >>> libcxx/trunk/test/libcxx/test/config.py >>> libcxx/trunk/test/libcxx/test/format.py >>> libcxx/trunk/test/libcxx/utilities/tuple/tuple.tuple/diagnos >>> e_reference_binding.fail.cpp >>> >>> Modified: libcxx/trunk/docs/UsingLibcxx.rst >>> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/docs/UsingL >>> ibcxx.rst?rev=291961&r1=291960&r2=291961&view=diff >>> ============================================================ >>> ================== >>> --- libcxx/trunk/docs/UsingLibcxx.rst (original) >>> +++ libcxx/trunk/docs/UsingLibcxx.rst Fri Jan 13 16:02:08 2017 >>> @@ -173,3 +173,10 @@ thread safety annotations. >>> return Tup{"hello world", 42}; // explicit constructor called. OK. >>> } >>> >>> +**_LIBCPP_DISABLE_ADDITIONAL_DIAGNOSTICS**: >>> + This macro disables the additional diagnostics generated by libc++ >>> using the >>> + `diagnose_if` attribute. These additional diagnostics include checks >>> for: >>> + >>> + * Giving `set`, `map`, `multiset`, `multimap` a comparator which is >>> not >>> + const callable. >>> + >>> >>> Modified: libcxx/trunk/include/__config >>> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/__c >>> onfig?rev=291961&r1=291960&r2=291961&view=diff >>> ============================================================ >>> ================== >>> --- libcxx/trunk/include/__config (original) >>> +++ libcxx/trunk/include/__config Fri Jan 13 16:02:08 2017 >>> @@ -1006,6 +1006,16 @@ _LIBCPP_FUNC_VIS extern "C" void __sanit >>> #endif >>> #endif >>> >>> +#if __has_attribute(diagnose_if) && !defined(_LIBCPP_DISABLE_ADDIT >>> IONAL_DIAGNOSTICS) >>> +# define _LIBCPP_DIAGNOSE_WARNING(...) \ >>> + __attribute__((__diagnose_if__(__VA_ARGS__, "warning"))) >>> +# define _LIBCPP_DIAGNOSE_ERROR(...) \ >>> + __attribute__((__diagnose_if__(__VA_ARGS__, "error"))) >>> +#else >>> +# define _LIBCPP_DIAGNOSE_WARNING(...) >>> +# define _LIBCPP_DIAGNOSE_ERROR(...) >>> +#endif >>> + >>> #endif // __cplusplus >>> >>> #endif // _LIBCPP_CONFIG >>> >>> Modified: libcxx/trunk/include/__tree >>> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/__t >>> ree?rev=291961&r1=291960&r2=291961&view=diff >>> ============================================================ >>> ================== >>> --- libcxx/trunk/include/__tree (original) >>> +++ libcxx/trunk/include/__tree Fri Jan 13 16:02:08 2017 >>> @@ -41,6 +41,10 @@ template <class _Key, class _Value> >>> struct __value_type; >>> #endif >>> >>> +template <class _Key, class _CP, class _Compare, >>> + bool = is_empty<_Compare>::value && !__libcpp_is_final<_Compare>:: >>> value> >>> +class __map_value_compare; >>> + >>> template <class _Allocator> class __map_node_destructor; >>> template <class _TreeIterator> class _LIBCPP_TEMPLATE_VIS >>> __map_iterator; >>> template <class _TreeIterator> class _LIBCPP_TEMPLATE_VIS >>> __map_const_iterator; >>> @@ -955,6 +959,30 @@ private: >>> >>> }; >>> >>> +#ifndef _LIBCPP_CXX03_LANG >>> +template <class _Tp, class _Compare, class _Allocator> >>> +struct __diagnose_tree_helper { >>> + static constexpr bool __trigger_diagnostics() >>> + _LIBCPP_DIAGNOSE_WARNING(!__is_const_comparable<_Compare, >>> _Tp>::value, >>> + "the specified comparator type does not provide a const >>> call operator") >>> + { return true; } >>> +}; >>> + >>> +template <class _Key, class _Value, class _KeyComp, class _Alloc> >>> +struct __diagnose_tree_helper< >>> + __value_type<_Key, _Value>, >>> + __map_value_compare<_Key, __value_type<_Key, _Value>, _KeyComp>, >>> + _Alloc >>> +> >>> +{ >>> + static constexpr bool __trigger_diagnostics() >>> + _LIBCPP_DIAGNOSE_WARNING(!__is_const_comparable<_KeyComp, >>> _Key>::value, >>> + "the specified comparator type does not provide a const >>> call operator") >>> + { return true; } >>> +}; >>> + >>> +#endif >>> + >>> template <class _Tp, class _Compare, class _Allocator> >>> class __tree >>> { >>> @@ -1787,7 +1815,11 @@ __tree<_Tp, _Compare, _Allocator>::~__tr >>> { >>> static_assert((is_copy_constructible<value_compare>::value), >>> "Comparator must be copy-constructible."); >>> - destroy(__root()); >>> +#ifndef _LIBCPP_CXX03_LANG >>> + static_assert((__diagnose_tree_helper<_Tp, _Compare, _Allocator>:: >>> + __trigger_diagnostics()), ""); >>> +#endif >>> + destroy(__root()); >>> } >>> >>> template <class _Tp, class _Compare, class _Allocator> >>> >>> Modified: libcxx/trunk/include/map >>> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/map >>> ?rev=291961&r1=291960&r2=291961&view=diff >>> ============================================================ >>> ================== >>> --- libcxx/trunk/include/map (original) >>> +++ libcxx/trunk/include/map Fri Jan 13 16:02:08 2017 >>> @@ -453,9 +453,7 @@ swap(multimap<Key, T, Compare, Allocator >>> >>> _LIBCPP_BEGIN_NAMESPACE_STD >>> >>> -template <class _Key, class _CP, class _Compare, >>> - bool = is_empty<_Compare>::value && >>> !__libcpp_is_final<_Compare>::value >>> - > >>> +template <class _Key, class _CP, class _Compare, bool _IsSmall> >>> class __map_value_compare >>> : private _Compare >>> { >>> >>> Modified: libcxx/trunk/include/type_traits >>> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/typ >>> e_traits?rev=291961&r1=291960&r2=291961&view=diff >>> ============================================================ >>> ================== >>> --- libcxx/trunk/include/type_traits (original) >>> +++ libcxx/trunk/include/type_traits Fri Jan 13 16:02:08 2017 >>> @@ -4715,6 +4715,15 @@ struct __can_extract_map_key<_ValTy, _Ke >>> >>> #endif >>> >>> +template <class _Comp, class _ValueType, class = void> >>> +struct __is_const_comparable : false_type {}; >>> + >>> +template <class _Comp, class _ValueType> >>> +struct __is_const_comparable<_Comp, _ValueType, typename __void_t< >>> + decltype(_VSTD::declval<_Comp const&>()(_VSTD::declval<_ValueType >>> const&>(), >>> + _VSTD::declval<_ValueType >>> const&>())) >>> + >::type> : true_type {}; >>> + >>> _LIBCPP_END_NAMESPACE_STD >>> >>> #endif // _LIBCPP_TYPE_TRAITS >>> >>> Modified: libcxx/trunk/test/libcxx/compiler.py >>> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/libcxx >>> /compiler.py?rev=291961&r1=291960&r2=291961&view=diff >>> ============================================================ >>> ================== >>> --- libcxx/trunk/test/libcxx/compiler.py (original) >>> +++ libcxx/trunk/test/libcxx/compiler.py Fri Jan 13 16:02:08 2017 >>> @@ -296,7 +296,7 @@ class CXXCompiler(object): >>> >>> def addWarningFlagIfSupported(self, flag): >>> if self.hasWarningFlag(flag): >>> - assert flag not in self.warning_flags >>> - self.warning_flags += [flag] >>> + if flag not in self.warning_flags: >>> + self.warning_flags += [flag] >>> return True >>> return False >>> >>> Added: libcxx/trunk/test/libcxx/containers/associative/non_const_co >>> mparator.fail.cpp >>> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/libcxx >>> /containers/associative/non_const_comparator.fail.cpp?rev=29 >>> 1961&view=auto >>> ============================================================ >>> ================== >>> --- >>> libcxx/trunk/test/libcxx/containers/associative/non_const_comparator.fail.cpp >>> (added) >>> +++ >>> libcxx/trunk/test/libcxx/containers/associative/non_const_comparator.fail.cpp >>> Fri Jan 13 16:02:08 2017 >>> @@ -0,0 +1,45 @@ >>> +//===------------------------------------------------------ >>> ----------------===// >>> +// >>> +// The LLVM Compiler Infrastructure >>> +// >>> +// This file is dual licensed under the MIT and the University of >>> Illinois Open >>> +// Source Licenses. See LICENSE.TXT for details. >>> +// >>> +//===------------------------------------------------------ >>> ----------------===// >>> + >>> +// UNSUPPORTED: c++98, c++03 >>> +// REQUIRES: diagnose-if-support, verify-support >>> + >>> +// Test that libc++ generates a warning diagnostic when the container is >>> +// provided a non-const callable comparator. >>> + >>> +#include <set> >>> +#include <map> >>> + >>> +struct BadCompare { >>> + template <class T, class U> >>> + bool operator()(T const& t, U const& u) { >>> + return t < u; >>> + } >>> +}; >>> + >>> +int main() { >>> + static_assert(!std::__is_const_comparable<BadCompare, int>::value, >>> ""); >>> + // expected-warning@__tree:* 4 {{the specified comparator type does >>> not provide a const call operator}} >>> + { >>> + using C = std::set<int, BadCompare>; >>> + C s; >>> + } >>> + { >>> + using C = std::multiset<long, BadCompare>; >>> + C s; >>> + } >>> + { >>> + using C = std::map<int, int, BadCompare>; >>> + C s; >>> + } >>> + { >>> + using C = std::multimap<long, int, BadCompare>; >>> + C s; >>> + } >>> +} >>> >>> Modified: libcxx/trunk/test/libcxx/test/config.py >>> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/libcxx >>> /test/config.py?rev=291961&r1=291960&r2=291961&view=diff >>> ============================================================ >>> ================== >>> --- libcxx/trunk/test/libcxx/test/config.py (original) >>> +++ libcxx/trunk/test/libcxx/test/config.py Fri Jan 13 16:02:08 2017 >>> @@ -712,33 +712,35 @@ class Configuration(object): >>> ['c++11', 'c++14', 'c++1z'])) != 0 >>> enable_warnings = self.get_lit_bool('enable_warnings', >>> default_enable_warnings) >>> - if enable_warnings: >>> - self.cxx.useWarnings(True) >>> - self.cxx.warning_flags += [ >>> - '-D_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER', >>> - '-Wall', '-Wextra', '-Werror' >>> - ] >>> - self.cxx.addWarningFlagIfSupported('-Wshadow') >>> - self.cxx.addWarningFlagIfSuppo >>> rted('-Wno-unused-command-line-argument') >>> - self.cxx.addWarningFlagIfSupported('-Wno-attributes') >>> - self.cxx.addWarningFlagIfSupported('-Wno-pessimizing-move') >>> - self.cxx.addWarningFlagIfSupported('-Wno-c++11-extensions') >>> - self.cxx.addWarningFlagIfSuppo >>> rted('-Wno-user-defined-literals') >>> - # These warnings should be enabled in order to support the >>> MSVC >>> - # team using the test suite; They enable the warnings below >>> and >>> - # expect the test suite to be clean. >>> - self.cxx.addWarningFlagIfSupported('-Wsign-compare') >>> - self.cxx.addWarningFlagIfSupported('-Wunused-variable') >>> - self.cxx.addWarningFlagIfSupported('-Wunused-parameter') >>> - self.cxx.addWarningFlagIfSupported('-Wunreachable-code') >>> - # FIXME: Enable the two warnings below. >>> - self.cxx.addWarningFlagIfSupported('-Wno-conversion') >>> + self.cxx.useWarnings(enable_warnings) >>> + self.cxx.warning_flags += [ >>> + '-D_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER', >>> + '-Wall', '-Wextra', '-Werror' >>> + ] >>> + if self.cxx.hasWarningFlag('-Wuser-defined-warnings'): >>> + self.cxx.warning_flags += ['-Wuser-defined-warnings'] >>> + self.config.available_features.add('diagnose-if-support') >>> + self.cxx.addWarningFlagIfSupported('-Wshadow') >>> + self.cxx.addWarningFlagIfSupported('-Wno-unused-command-line >>> -argument') >>> + self.cxx.addWarningFlagIfSupported('-Wno-attributes') >>> + self.cxx.addWarningFlagIfSupported('-Wno-pessimizing-move') >>> + self.cxx.addWarningFlagIfSupported('-Wno-c++11-extensions') >>> + self.cxx.addWarningFlagIfSupported('-Wno-user-defined-litera >>> ls') >>> + # These warnings should be enabled in order to support the MSVC >>> + # team using the test suite; They enable the warnings below and >>> + # expect the test suite to be clean. >>> + self.cxx.addWarningFlagIfSupported('-Wsign-compare') >>> + self.cxx.addWarningFlagIfSupported('-Wunused-variable') >>> + self.cxx.addWarningFlagIfSupported('-Wunused-parameter') >>> + self.cxx.addWarningFlagIfSupported('-Wunreachable-code') >>> + # FIXME: Enable the two warnings below. >>> + self.cxx.addWarningFlagIfSupported('-Wno-conversion') >>> + self.cxx.addWarningFlagIfSupported('-Wno-unused-local-typedef') >>> + std = self.get_lit_conf('std', None) >>> + if std in ['c++98', 'c++03']: >>> + # The '#define static_assert' provided by libc++ in C++03 >>> mode >>> + # causes an unused local typedef whenever it is used. >>> self.cxx.addWarningFlagIfSupported('-Wno-unused-local-typed >>> ef') >>> - std = self.get_lit_conf('std', None) >>> - if std in ['c++98', 'c++03']: >>> - # The '#define static_assert' provided by libc++ in >>> C++03 mode >>> - # causes an unused local typedef whenever it is used. >>> - self.cxx.addWarningFlagIfSuppo >>> rted('-Wno-unused-local-typedef') >>> >>> def configure_sanitizer(self): >>> san = self.get_lit_conf('use_sanitizer', '').strip() >>> >>> Modified: libcxx/trunk/test/libcxx/test/format.py >>> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/libcxx >>> /test/format.py?rev=291961&r1=291960&r2=291961&view=diff >>> ============================================================ >>> ================== >>> --- libcxx/trunk/test/libcxx/test/format.py (original) >>> +++ libcxx/trunk/test/libcxx/test/format.py Fri Jan 13 16:02:08 2017 >>> @@ -223,6 +223,10 @@ class LibcxxTestFormat(object): >>> test_cxx.flags += ['-fsyntax-only'] >>> if use_verify: >>> test_cxx.useVerify() >>> + test_cxx.useWarnings() >>> + if '-Wuser-defined-warnings' in test_cxx.warning_flags: >>> + test_cxx.warning_flags += ['-Wno-error=user-defined-warn >>> ings'] >>> + >>> cmd, out, err, rc = test_cxx.compile(source_path, >>> out=os.devnull) >>> expected_rc = 0 if use_verify else 1 >>> if rc == expected_rc: >>> >>> Modified: libcxx/trunk/test/libcxx/utilities/tuple/tuple.tuple/diagnos >>> e_reference_binding.fail.cpp >>> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/libcxx >>> /utilities/tuple/tuple.tuple/diagnose_reference_binding.fail >>> .cpp?rev=291961&r1=291960&r2=291961&view=diff >>> ============================================================ >>> ================== >>> --- >>> libcxx/trunk/test/libcxx/utilities/tuple/tuple.tuple/diagnose_reference_binding.fail.cpp >>> (original) >>> +++ >>> libcxx/trunk/test/libcxx/utilities/tuple/tuple.tuple/diagnose_reference_binding.fail.cpp >>> Fri Jan 13 16:02:08 2017 >>> @@ -30,4 +30,11 @@ int main() { >>> // bind rvalue to constructed non-rvalue >>> std::tuple<std::string &&> t2("hello"); // expected-note >>> {{requested here}} >>> std::tuple<std::string &&> t3(std::allocator_arg, alloc, "hello"); >>> // expected-note {{requested here}} >>> + >>> + // FIXME: The below warnings may get emitted as an error, a >>> warning, or not emitted at all >>> + // depending on the flags used to compile this test. >>> + { >>> + // expected-warning@tuple:* 0+ {{binding reference member 'value' >>> to a temporary value}} >>> + // expected-error@tuple:* 0+ {{binding reference member 'value' to >>> a temporary value}} >>> + } >>> } >>> >>> >>> _______________________________________________ >>> cfe-commits mailing list >>> cfe-commits@lists.llvm.org >>> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits >>> >> >> >
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