https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79457
Bug ID: 79457 Summary: Segmentation fault in templated decltype evaluation Product: gcc Version: 7.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: teemu at hecknology dot net Target Milestone: --- Created attachment 40715 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=40715&action=edit Minimal example GCC crashes compiling the attached source file. Clang builds the code in question properly. [ teemu@apotheosis ~/crash ]$ /usr/lib/gcc-snapshot/bin/g++ bug.cpp -std=c++11 -save-temps bug.cpp: In substitution of 'template<class T> template<class R> using S = decltype (((Foo*)(void)0)->Foo<T>::goo[R()]) [with R = R; T = T]': bug.cpp:13:5: required from here bug.cpp:7:21: internal compiler error: in lookup_member, at cp/search.c:1256 using S = decltype(goo[R()]); ^~~ Version information (of gcc-snapshot; the example also crashes just the same in default distribution-provided g++ 6.2.0): [ teemu@apotheosis ~/crash ]$ /usr/lib/gcc-snapshot/bin/g++ -v Using built-in specs. COLLECT_GCC=/usr/lib/gcc-snapshot/bin/g++ COLLECT_LTO_WRAPPER=/usr/lib/gcc-snapshot/libexec/gcc/x86_64-linux-gnu/7.0.0/lto-wrapper Target: x86_64-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Ubuntu 20161006-1ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-snapshot/README.Bugs --enable-languages=c,ada,c++,go,fortran,objc,obj-c++ --prefix=/usr/lib/gcc-snapshot --program-prefix= --enable-shared --enable-linker-build-id --disable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-libmpx --enable-plugin --enable-default-pie --with-system-zlib --enable-objc-gc --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-checking=yes --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu Thread model: posix gcc version 7.0.0 20161006 (experimental) [trunk revision 240826] (Ubuntu 20161006-1ubuntu1) [ teemu@apotheosis ~/crash ]$ uname -a Linux apotheosis 4.8.0-37-generic #39-Ubuntu SMP Thu Jan 26 02:27:07 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux [ teemu@apotheosis ~/crash ]$ cat /etc/issue Ubuntu 16.10 \n \l