Created attachment 38209 [details] Minimal test case, compile with g++ -std=c++14 Referring to a function-static variable from within both of two nested lambda functions (the outer one being generic/polymorphic) causes an assembler error (symbol already defined). Minimal test case attached, tested on g++ 5.3.0.
Confirmed. GCC 4.9 complains: > g++-4.9 t.C -std=c++14 t.C: In instantiation of ‘main()::<lambda(auto:1)> [with auto:1 = int]’: t.C:2:8: required from ‘void foo(T) [with T = main()::<lambda(auto:1)>]’ t.C:12:3: required from here t.C:8:2: error: ‘x’ was not declared in this scope x; ^
I believe this bug manifested itself in Seastar (https://github.com/scylladb/seastar/commit/3d21ef5959bedb3ea15032d1632b0b2d7012044a). The original snippet from Nick causes the error on Fedora 23: Using built-in specs. COLLECT_GCC=g++ COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-redhat-linux/5.3.1/lto-wrapper Target: x86_64-redhat-linux Configured with: ../configure --enable-bootstrap --enable-languages=c,c++,objc,obj-c++,fortran,ada,go,lto --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-shared --enable-threads=posix --enable-checking=release --enable-multilib --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-linker-hash-style=gnu --enable-plugin --enable-initfini-array --disable-libgcj --with-isl --enable-libmpx --enable-gnu-indirect-function --with-tune=generic --with-arch_32=i686 --build=x86_64-redhat-linux Thread model: posix gcc version 5.3.1 20160406 (Red Hat 5.3.1-6) (GCC) and on Ubuntu 16.04: Using built-in specs. COLLECT_GCC=g++ COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/5/lto-wrapper Target: x86_64-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Ubuntu 5.4.0-6ubuntu1~16.04.4' --with-bugurl=file:///usr/share/doc/gcc-5/README.Bugs --enable-languages=c,ada,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-5 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-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 --with-system-zlib --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-5-amd64/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-5-amd64 --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-5-amd64 --with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --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=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu Thread model: posix gcc version 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.4) On both platforms, the error is the same: g++ -std=c++14 test.cc -o test /tmp/ccTNkOnu.s: Assembler messages: /tmp/ccTNkOnu.s:34: Error: symbol `_ZL1x' is already defined On gcc 7.1.1, the error is not present: Using built-in specs. COLLECT_GCC=/usr/bin/g++ COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-redhat-linux/7/lto-wrapper OFFLOAD_TARGET_NAMES=nvptx-none OFFLOAD_TARGET_DEFAULT=1 Target: x86_64-redhat-linux Configured with: ../configure --enable-bootstrap --enable-languages=c,c++,objc,obj-c++,fortran,ada,go,lto --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-shared --enable-threads=posix --enable-checking=release --enable-multilib --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-gcc-major-version-only --with-linker-hash-style=gnu --enable-plugin --enable-initfini-array --with-isl --enable-libmpx --enable-offload-targets=nvptx-none --without-cuda-driver --enable-gnu-indirect-function --with-tune=generic --with-arch_32=i686 --build=x86_64-redhat-linux Thread model: posix gcc version 7.1.1 20170622 (Red Hat 7.1.1-3) (GCC) To reproduce the exact compilation error with Seastar: docker pull fedora:23 docker run -it --rm fedora:23 bash dnf install -y git cd opt && git clone https://github.com/scylladb/seastar git checkout a2be7a4f312a62c67c79cf818970d0c954f5fc15 git submodule update --init ./install-dependencies.sh ./configure.py --mode=debug ninja-build build/debug/tests/lowres_clock_test.o The error: g++ -MD -MT build/debug/tests/lowres_clock_test.o -MF build/debug/tests/lowres_clock_test.o.d -fsanitize=address -fsanitize=leak -fsanitize=undefined -fno-sanitize=vptr -DASAN_ENABLED -O0 -DDEBUG -DDEBUG_SHARED_PTR -DDEFAULT_ALLOCATOR -DSEASTAR_THREAD_STACK_GUARDS -I/opt/seastar/build/debug/gen -I/opt/seastar/build/debug/c-ares -std=gnu++1y -g -Wall -Werror -Wno-error=deprecated-declarations -fvisibility=hidden -pthread -I/opt/seastar -U_FORTIFY_SOURCE -I/opt/seastar/fmt -DBOOST_TEST_DYN_LINK -Wno-overloaded-virtual -Wno-maybe-uninitialized -DFMT_HEADER_ONLY -DHAVE_HWLOC -DHAVE_NUMA -DHAVE_LZ4_COMPRESS_DEFAULT -c -o build/debug/tests/lowres_clock_test.o tests/lowres_clock_test.cc /tmp/cch6C9Km.s: Assembler messages: /tmp/cch6C9Km.s:19986: Error: symbol `_ZL14sleep_duration' is already defined I've attached the lowres_clock_test.ii file.
The .ii file is too large to attach. I hope the previous information I supplied is sufficient and helpful.
Author: paolo Date: Mon Oct 2 22:21:16 2017 New Revision: 253370 URL: https://gcc.gnu.org/viewcvs?rev=253370&root=gcc&view=rev Log: 2017-10-02 Paolo Carlini <paolo.carlini@oracle.com> PR c++/70570 * g++.dg/cpp1y/lambda-generic-70570.C: New. Added: trunk/gcc/testsuite/g++.dg/cpp1y/lambda-generic-70570.C Modified: trunk/gcc/testsuite/ChangeLog
Fixed a while ago, in 6.2.0. I added the testcase.