https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82288
Bug ID: 82288 Summary: Defining a type in a parameter type of a lambda calling an undefined function results in a Segfault Product: gcc Version: 7.2.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: jasper at mezzo dot de Target Milestone: --- This very simple (though incorrect) piece of code produces a segfault: ----------------------------- int main() { [](struct {} *arg) { a();}; } ----------------------------- $ c++ mnwe.cpp mnwe.cpp: In function ‘int main()’: mnwe.cpp:2:13: error: types may not be defined in parameter types [](struct {} *arg) { a();}; ^ c++: internal compiler error: Segmentation fault (program cc1plus) Please submit a full bug report, with preprocessed source if appropriate. See <https://bugs.archlinux.org/> for instructions. The segfault goes away if any one of these are done: - define a() somewhere - replace the `struct {}` in the parameter list with `int` - define a function instead of the lambda System Information: System Type: Arch Linux GCC version: 7.2.0 (package version 7.2.0-3) Output of c++ -v: $ c++ -v Using built-in specs. COLLECT_GCC=c++ COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/7.2.0/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++ --enable-shared --enable-threads=posix --enable-libmpx --with-system-zlib --with-isl --enable-__cxa_atexit --disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch --disable-libssp --enable-gnu-unique-object --enable-linker-build-id --enable-lto --enable-plugin --enable-install-libiberty --with-linker-hash-style=gnu --enable-gnu-indirect-function --disable-multilib --disable-werror --enable-checking=release --enable-default-pie --enable-default-ssp Thread model: posix gcc version 7.2.0 (GCC)