https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82467
Bug ID: 82467 Summary: name mangling error when using constrained an specialized template functions Product: gcc Version: 6.3.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: saphirahemp at yahoo dot de Target Milestone: --- Created attachment 42321 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=42321&action=edit the *i* file It seems that the compiler produces some collisions in case of this special constellation - template specialization for type T and constrained function that accepts T. example for integer: template<> void f(int t) {} template<class T> requires requires(T t){ t + t;} void f(T t) {} int main(){ f(1); } will result in an error when compiling: g++-6 -fconcepts int.cpp /tmp/ccooj1kv.s: Assembler messages: /tmp/ccooj1kv.s:65: Error: symbol `_Z1fIiEvT_' is already defined /tmp/ccooj1kv.s: Error: .size expression for _Z1fIiEvT_ does not evaluate to a constant The same code with float instead of int will produce the same error message, with a slightly different symbol: _Z1fIfEvT_ instead of _Z1fIiEvT_. further informations: the exact version of GCC and the system type; gcc version 6.3.0 20170519 (Ubuntu/Linaro 6.3.0-18ubuntu2~16.04) Target: x86_64-linux-gnu the options given when GCC was configured/built; Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 6.3.0-18ubuntu2~16.04' --with-bugurl=file:///usr/share/doc/gcc-6/README.Bugs --enable-languages=c,ada,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-6 --program-prefix=x86_64-linux-gnu- --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-6-amd64/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-6-amd64 --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-6-amd64 --with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --with-target-system-zlib --enable-objc-gc=auto --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 the complete command line that triggers the bug; g++-6 -fconcepts int.cpp the compiler output (error messages, warnings, etc.); /tmp/ccooj1kv.s: Assembler messages: /tmp/ccooj1kv.s:65: Error: symbol `_Z1fIiEvT_' is already defined /tmp/ccooj1kv.s: Error: .size expression for _Z1fIiEvT_ does not evaluate to a constant