https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97372
Bug ID: 97372 Summary: Segmentation fault using Tracy 0.7.3 in template class Product: gcc Version: 10.2.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: public at enkore dot de Target Milestone: --- Full reproducer attached: $ g++ gcc_segfault_repro.ii gcc_segfault_repro.cpp: In instantiation of ‘ThreadTask2<T>::ThreadTask2() [with T = int]’: gcc_segfault_repro.cpp:15:22: required from here gcc_segfault_repro.cpp:7:135: internal compiler error: Segmentation fault 7 | TracyLockable(std::mutex, _state_mutex); | ^ $ gcc -v Using built-in specs. COLLECT_GCC=/usr/bin/gcc COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/10.2.0/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: /build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=https://bugs.archlinux.org/ --enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++,d --with-isl --with-linker-hash-style=gnu --with-system-zlib --enable-__cxa_atexit --enable-cet=auto --enable-checking=release --enable-clocale=gnu --enable-default-pie --enable-default-ssp --enable-gnu-indirect-function --enable-gnu-unique-object --enable-install-libiberty --enable-linker-build-id --enable-lto --enable-multilib --enable-plugin --enable-shared --enable-threads=posix --disable-libssp --disable-libstdcxx-pch --disable-libunwind-exceptions --disable-werror gdc_include_dir=/usr/include/dlang/gdc Thread model: posix Supported LTO compression algorithms: zlib zstd gcc version 10.2.0 (GCC) Offending code looks like this (using Tracy from https://github.com/wolfpld/tracy): #include <mutex> #include <Tracy.hpp> template<typename T> class ThreadTask2 { TracyLockable(std::mutex, _state_mutex); public: ThreadTask2() { } }; void x() { ThreadTask2<int> foo; } When the template is removed from ThreadTask2, GCC stops segfaulting. In the actual codebase GCC points out a slightly more specific source location, but this may be an artifact and unrelated to the bug itself: Tracy.hpp:141:159: internal compiler error: Segmentation fault 141 | #define TracyLockable( type, varname ) tracy::Lockable<type> varname { [] () -> const tracy::SourceLocationData* { static constexpr tracy::SourceLocationData srcloc { nullptr, #type " " #varname, __FILE__, __LINE__, 0 }; return &srcloc; }() }; | ^~~~~~ common.h:76:13: note: in expansion of macro ‘TracyLockable’ 76 | mutable TracyLockable(std::mutex, _state_mutex); |