[Bug c++/67888] New: Compiling clang 3.7.0 results in is used but never defined

[rodrigc at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67888

            Bug ID: 67888
           Summary: Compiling clang 3.7.0 results in is used but never
                    defined
           Product: gcc
           Version: 4.9.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: rodrigc at gcc dot gnu.org
  Target Milestone: ---

Created attachment 36460
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36460&action=edit
Module.ii.bz2

Version of GCC:

Using built-in specs.
COLLECT_GCC=/usr/local/bin/x86_64-portbld-freebsd11.0-g++
COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/x86_64-portbld-freebsd11.0/4.9.2/lto-wrapper
Target: x86_64-portbld-freebsd11.0
Configured with: ./../gcc-4.9.2/configure --target=x86_64-portbld-freebsd11.0
--disable-nls --enable-languages=c,c++ --without-headers --with-gmp=/usr/local
--with-pkgversion='FreeBSD Ports Collection for amd64' --with-system-zlib
--with-as=/usr/local/bin/x86_64-freebsd-as
--with-ld=/usr/local/bin/x86_64-freebsd-ld --prefix=/usr/local
--localstatedir=/var --mandir=/usr/local/man --infodir=/usr/local/info/
--build=x86_64-portbld-freebsd11.0
Thread model: posix
gcc version 4.9.2 (FreeBSD Ports Collection for amd64) 


System:
FreeBSD 11.0-CURRENT #6 r286639

Problem Description:

When clang 3.7.0 is compiled with gcc 4.9.2, using this command:

/usr/local/bin/x86_64-portbld-freebsd11.0-g++ -save-temps -isystem
/usr/obj/opt2/branches/head/tmp/usr/include
-L/usr/obj/opt2/branches/head/tmp/usr/lib
--sysroot=/usr/obj/opt2/branches/head/tmp -B/usr/local/x86_64-freebsd/bin/
-I/usr/obj/opt2/branches/head/tmp/usr/include/c++/v1 -std=gnu++11
-L/usr/obj/opt2/branches/head/tmp/../lib/libc++
--sysroot=/usr/obj/opt2/branches/head/tmp -B/usr/local/x86_64-freebsd/bin/  -O2
-pipe
-I/opt2/branches/head/lib/clang/libclangbasic/../../../contrib/llvm/include
-I/opt2/branches/head/lib/clang/libclangbasic/../../../contrib/llvm/tools/clang/include
-I/opt2/branches/head/lib/clang/libclangbasic/../../../contrib/llvm/tools/clang/lib/Basic
-I.
-I/opt2/branches/head/lib/clang/libclangbasic/../../../contrib/llvm/../../lib/clang/include
-DLLVM_ON_UNIX -DLLVM_ON_FREEBSD -D__STDC_LIMIT_MACROS -D__STDC_CONSTANT_MACROS
-DCLANG_ENABLE_ARCMT -DCLANG_ENABLE_STATIC_ANALYZER -fno-strict-aliasing
-DLLVM_DEFAULT_TARGET_TRIPLE=\"x86_64-unknown-freebsd11.0\"
-DLLVM_HOST_TRIPLE=\"x86_64-unknown-freebsd11.0\" -DDEFAULT_SYSROOT=\"\"
-fstack-protector-strong  -std=c++11 -fno-exceptions -fno-rtti  -c
/opt2/branches/head/lib/clang/libclangbasic/../../../contrib/llvm/tools/clang/lib/Basic/Module.cpp
-o Module.o


the following error is observed:

In file included from
/opt2/branches/head/lib/clang/libclangbasic/../../../contrib/llvm/tools/clang/include/clang/Basic/SourceLocation.h:22:0,
                 from
/opt2/branches/head/lib/clang/libclangbasic/../../../contrib/llvm/tools/clang/include/clang/Basic/Module.h:18,
                 from
/opt2/branches/head/lib/clang/libclangbasic/../../../contrib/llvm/tools/clang/lib/Basic/Module.cpp:15:
/usr/obj/opt2/branches/head/tmp/usr/include/c++/v1/functional:1322:17: error:
'_Rp std::__1::__function::__base<_Rp(_ArgTypes ...)>::operator()(_ArgTypes&&
...) [with _Rp = void; _ArgTypes =
{clang::VisibleModuleSet::setVisible(clang::Module*, clang::SourceLocation,
clang::VisibleModuleSet::VisibleCallback,
clang::VisibleModuleSet::ConflictCallback)::Visiting}]', declared using local
type 'clang::VisibleModuleSet::setVisible(clang::Module*,
clang::SourceLocation, clang::VisibleModuleSet::VisibleCallback,
clang::VisibleModuleSet::ConflictCallback)::Visiting', is used but never
defined [-fpermissive]
     virtual _Rp operator()(_ArgTypes&& ...) = 0;