[libcxx] r309474 - [libc++] Hoist extern template above first use
Hans Wennborg via cfe-commits
cfe-commits at lists.llvm.org
Fri Aug 18 13:32:51 PDT 2017
Eric, sounds like there are no known issues with this, then. What do
you think about merging it?
On Thu, Aug 17, 2017 at 5:30 PM, Petr Hosek <phosek at chromium.org> wrote:
> Confirmed, this changes is harmless. The failure we're seeing seems to have
> been introduced by Clang in r310983, sorry about the confusion.
>
> On Thu, Aug 17, 2017 at 4:35 PM Shoaib Meenai <smeenai at fb.com> wrote:
>>
>> See Petr's follow-up. It doesn't look like this was the responsible
>> change.
>>
>>
>>
>> From: Eric Fiselier <eric at efcs.ca>
>> Date: Thursday, August 17, 2017 at 4:02 PM
>> To: Petr Hosek <phosek at chromium.org>
>> Cc: cfe-commits <cfe-commits at lists.llvm.org>, Marshall Clow
>> <mclow.lists at gmail.com>, Hans Wennborg <hans at chromium.org>, Shoaib Meenai
>> <smeenai at fb.com>
>> Subject: Re: [libcxx] r309474 - [libc++] Hoist extern template above first
>> use
>>
>>
>>
>> probably shouldn't merge this then.
>>
>>
>>
>> On Aug 17, 2017 4:54 PM, "Petr Hosek via cfe-commits"
>> <cfe-commits at lists.llvm.org> wrote:
>>
>> This broke our build of WebKit with the following build failure:
>>
>>
>>
>> ../../buildtools/linux-x64/clang/bin/clang++ -MD -MF
>> obj/apps/web_view/web_view_test.test_webview.o.d
>> -DTOOLCHAIN_VERSION=4e89c701396412a50a901115ab4a2a09145f3777
>> -D_LIBCPP_ENABLE_THREAD_SAFETY_ANNOTATIONS -DCAIRO_HAS_FC_FONT=0
>> -DU_USING_ICU_NAMESPACE=0 -DU_ENABLE_DYLOAD=0 -DU_STATIC_IMPLEMENTATION
>> -DICU_UTIL_DATA_IMPL=ICU_UTIL_DATA_FILE -I../.. -Igen
>> -I../../third_party/webkit/Source/WebKit/fuchsia
>> -I../../third_party/boringssl/include -Igen/third_party/cairo
>> -I../../third_party/curl/include -Iobj/third_party/curl
>> -Iobj/third_party/curl/curl -I../../third_party/freetype2/include
>> -I../../third_party/harfbuzz/src -I../../third_party/icu/source/common
>> -I../../third_party/icu/source/i18n -I../../third_party/libjpeg-turbo
>> -I../../third_party/libpng -I../../third_party/zlib
>> -I../../third_party/libxml2/include -I../../third_party/sqlite -g
>> --sysroot=/usr/local/google/home/phosek/fuchsia/out/build-magenta/build-magenta-pc-x86-64/sysroot
>> --target=x86_64-fuchsia -no-canonical-prefixes
>> -fdebug-prefix-map=/usr/local/google/home/phosek/fuchsia=. -Wall -Wextra
>> -Wno-unused-parameter -Wno-enum-compare-switch -Wno-unused-lambda-capture
>> -Wno-user-defined-warnings -fvisibility=hidden -g -Og -fsanitize=safe-stack
>> -fstack-protector-strong -Werror -Wno-error=deprecated-declarations
>> -fvisibility-inlines-hidden -std=c++14 -fno-exceptions -fno-rtti
>> -Wthread-safety -c ../../apps/web_view/test_webview.cpp -o
>> obj/apps/web_view/web_view_test.test_webview.o
>>
>> In file included from ../../apps/web_view/test_webview.cpp:1:
>>
>> In file included from
>> ../../third_party/webkit/Source/WebKit/fuchsia/WebView.h:28:
>>
>> In file included from
>> ../../buildtools/linux-x64/clang/lib/x86_64-fuchsia/include/c++/v1/functional:484:
>>
>>
>> ../../buildtools/linux-x64/clang/lib/x86_64-fuchsia/include/c++/v1/type_traits:4323:23:
>> error: implicit instantiation of undefined template
>> 'std::__2::basic_string<char, std::__2::char_traits<char>,
>> std::__2::allocator<char> >'
>>
>>
>> _LIBCPP_INVOKE_RETURN(_VSTD::forward<_Fp>(__f)(_VSTD::forward<_Args>(__args)...))
>>
>> ^
>>
>>
>> ../../buildtools/linux-x64/clang/lib/x86_64-fuchsia/include/c++/v1/__config:468:15:
>> note: expanded from macro '_VSTD'
>>
>> #define _VSTD std::_LIBCPP_NAMESPACE
>>
>> ^
>>
>>
>> ../../buildtools/linux-x64/clang/lib/x86_64-fuchsia/include/c++/v1/type_traits:4340:9:
>> note: in instantiation of exception specification for
>> '__invoke<std::__2::function<std::__2::basic_string<char,
>> std::__2::char_traits<char>, std::__2::allocator<char> > (const
>> std::__2::basic_string<char, std::__2::char_traits<char>,
>> std::__2::allocator<char> > &)> &, const std::__2::basic_string<char,
>> std::__2::char_traits<char>, std::__2::allocator<char> > &>' requested here
>>
>> _VSTD::__invoke(_VSTD::declval<_Fp>(),
>> _VSTD::declval<_Args>()...));
>>
>> ^
>>
>>
>> ../../buildtools/linux-x64/clang/lib/x86_64-fuchsia/include/c++/v1/__config:468:15:
>> note: expanded from macro '_VSTD'
>>
>> #define _VSTD std::_LIBCPP_NAMESPACE
>>
>> ^
>>
>>
>> ../../buildtools/linux-x64/clang/lib/x86_64-fuchsia/include/c++/v1/functional:1601:33:
>> note: in instantiation of template class 'std::__2::__invokable_r<void,
>> std::__2::function<std::__2::basic_string<char, std::__2::char_traits<char>,
>> std::__2::allocator<char> > (const std::__2::basic_string<char,
>> std::__2::char_traits<char>, std::__2::allocator<char> > &)> &, const
>> std::__2::basic_string<char, std::__2::char_traits<char>,
>> std::__2::allocator<char> > &>' requested here
>>
>> __invokable<_Fp&, _ArgTypes...>::value>
>>
>> ^
>>
>>
>> ../../buildtools/linux-x64/clang/lib/x86_64-fuchsia/include/c++/v1/functional:1626:9:
>> note: in instantiation of default argument for
>> '__callable<std::__2::function<std::__2::basic_string<char,
>> std::__2::char_traits<char>, std::__2::allocator<char> > (const
>> std::__2::basic_string<char, std::__2::char_traits<char>,
>> std::__2::allocator<char> > &)> >' required here
>>
>> __callable<_Fp>::value && !is_same<_Fp, function>::value
>>
>> ^~~~~~~~~~~~~~~
>>
>>
>> ../../buildtools/linux-x64/clang/lib/x86_64-fuchsia/include/c++/v1/functional:1628:5:
>> note: in instantiation of default argument for
>> 'function<std::__2::function<std::__2::basic_string<char,
>> std::__2::char_traits<char>, std::__2::allocator<char> > (const
>> std::__2::basic_string<char, std::__2::char_traits<char>,
>> std::__2::allocator<char> > &)> >' required here
>>
>> function(_Fp);
>>
>> ^~~~~~~~~~~~~
>>
>>
>> ../../buildtools/linux-x64/clang/lib/x86_64-fuchsia/include/c++/v1/functional:1588:28:
>> note: while substituting deduced template arguments into function template
>> 'function' [with _Fp = std::__2::function<std::__2::basic_string<char,
>> std::__2::char_traits<char>, std::__2::allocator<char> > (const
>> std::__2::basic_string<char, std::__2::char_traits<char>,
>> std::__2::allocator<char> > &)>, $1 = (no value)]
>>
>> class _LIBCPP_TEMPLATE_VIS function<_Rp(_ArgTypes...)>
>>
>> ^
>>
>> ../../third_party/webkit/Source/WebKit/fuchsia/WebView.h:48:7: note: while
>> declaring the implicit copy constructor for 'WebView'
>>
>> class WebView {
>>
>> ^
>>
>>
>> ../../buildtools/linux-x64/clang/lib/x86_64-fuchsia/include/c++/v1/iosfwd:193:32:
>> note: template is declared here
>>
>> class _LIBCPP_TEMPLATE_VIS basic_string;
>>
>> ^
>>
>> 1 error generated.
>>
>>
>>
>> On Wed, Aug 9, 2017 at 4:50 PM Hans Wennborg via cfe-commits
>> <cfe-commits at lists.llvm.org> wrote:
>>
>> Marshall: ping?
>>
>> On Thu, Aug 3, 2017 at 10:20 AM, Hans Wennborg <hans at chromium.org> wrote:
>> > Sounds good to me, but Eric or Marshall need to sign off.
>> >
>> > On Thu, Aug 3, 2017 at 10:15 AM, Shoaib Meenai <smeenai at fb.com> wrote:
>> >> Ping.
>> >>
>> >> On 7/28/17, 7:57 PM, "Shoaib Meenai" <smeenai at fb.com> wrote:
>> >>
>> >> Marshall, Eric, Hans,
>> >>
>> >> Any objections to backporting this to 5.0? It fixes a potential
>> >> visibility
>> >> issue for clients of the header.
>> >>
>> >> On 7/28/17, 7:54 PM, "cfe-commits on behalf of Shoaib Meenai via
>> >> cfe-commits" <cfe-commits-bounces at lists.llvm.org on behalf of
>> >> cfe-commits at lists.llvm.org> wrote:
>> >>
>> >> Author: smeenai
>> >> Date: Fri Jul 28 19:54:41 2017
>> >> New Revision: 309474
>> >>
>> >> URL:
>> >> https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_viewvc_llvm-2Dproject-3Frev-3D309474-26view-3Drev&d=DwIGaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=o3kDXzdBUE3ljQXKeTWOMw&m=EcGbIxegCOTbSLMJelp_vOaeGiS_iQ1eciM_oeX41-E&s=5q7TS5mhaUsf-1jQBqX62RvjcqAiy2whh8RO7yFhPyA&e=
>> >> Log:
>> >> [libc++] Hoist extern template above first use
>> >>
>> >> This function template is referenced inside class basic_string
>> >> as a
>> >> friend function. The extern template declaration needs to be
>> >> above that
>> >> friend declaration to actually take effect.
>> >>
>> >> This is important because this function was marked as exported
>> >> in
>> >> r307966, so without the extern template taking effect, it can
>> >> leak into
>> >> other DSOs as a visible symbol.
>> >>
>> >> Modified:
>> >> libcxx/trunk/include/string
>> >>
>> >> Modified: libcxx/trunk/include/string
>> >> URL:
>> >> https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_viewvc_llvm-2Dproject_libcxx_trunk_include_string-3Frev-3D309474-26r1-3D309473-26r2-3D309474-26view-3Ddiff&d=DwIGaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=o3kDXzdBUE3ljQXKeTWOMw&m=EcGbIxegCOTbSLMJelp_vOaeGiS_iQ1eciM_oeX41-E&s=zFJXc9CA6Sgyh25kGeAh4Qo36gpNQX_zo2qRlRFJoL8&e=
>> >>
>> >> ==============================================================================
>> >> --- libcxx/trunk/include/string (original)
>> >> +++ libcxx/trunk/include/string Fri Jul 28 19:54:41 2017
>> >> @@ -556,6 +556,8 @@ template<class _CharT, class _Traits, cl
>> >> basic_string<_CharT, _Traits, _Allocator>
>> >> operator+(const basic_string<_CharT, _Traits, _Allocator>&
>> >> __x, _CharT __y);
>> >>
>> >> +_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS string
>> >> operator+<char, char_traits<char>, allocator<char> >(char const*, string
>> >> const&))
>> >> +
>> >> template <bool>
>> >> class _LIBCPP_TEMPLATE_VIS __basic_string_common
>> >> {
>> >> @@ -3999,7 +4001,6 @@ basic_string<_CharT, _Traits, _Allocator
>> >>
>> >> _LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS
>> >> basic_string<char>)
>> >> _LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS
>> >> basic_string<wchar_t>)
>> >> -_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS string
>> >> operator+<char, char_traits<char>, allocator<char> >(char const*, string
>> >> const&))
>> >>
>> >> #if _LIBCPP_STD_VER > 11
>> >> // Literal suffixes for basic_string [basic.string.literals]
>> >>
>> >>
>> >> _______________________________________________
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>> >>
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>> >>
>> >>
>> >>
>> >>
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