[Bug c++/104712] -fkeep-inline-functions causing link errors (debian but not godbolt?)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104712 ajrh at ajrh dot net changed: What|Removed |Added CC||ajrh at ajrh dot net --- Comment #6 from ajrh at ajrh dot net --- Created attachment 52525 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52525=edit mention -ffunction-sections -Wl,-gc-sections in gcov manual On deeper investigation the original code had lots of unused inlined explicit template specializations, and a few of these had constants missing the 'inline' keyword. So gcc is behaving perfectly.Apologies for the misleading testcase. I understand better now:--keep-inline-functions is correctly generating lots of otherwise dead code, and of course some of it might not link. Though I only wanted to link it in order to run gcov to find and remove all the dead code, an amusing catch-22. Am I correct that a good way to fix this sometimes will be to use -ffunction-sections -Wl,-gc-sections ?E.g. in the example below: extern int i; inline int f(const char *x) { return i; } int main(int argc, char *argv[]) { return !!argc; } gcc -o x --coverage x.cpp && {x; gcov x} File 'x.cpp' Lines executed:100.00% of 2 gcc -o x --coverage -fkeep-inline-functions x.cpp && {x; gcov x} x.cpp:(.text._Z1fPKc[_Z1fPKc]+0x1c): undefined reference to `i' g++ -o x --coverage -fkeep-inline-functions -ffunction-sections -Wl,-gc-sections x.cpp && {x; gcov x} File 'x.cpp' Lines executed:50.00% of 4 If that's right it might be useful to mention as a hint in the manual. Attached a texi patch if so. Thank you all for the help.
[Bug c++/104712] -fkeep-inline-functions causing link errors (debian but not godbolt?)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104712 --- Comment #2 from ajrh at ajrh dot net --- Oh drat, reduced test cases are maddening... it's an inline static const in my original. I'll try to reduce something again.
[Bug c++/104712] New: -fkeep-inline-functions causing link errors (debian but not godbolt?)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104712 Bug ID: 104712 Summary: -fkeep-inline-functions causing link errors (debian but not godbolt?) Product: gcc Version: 11.2.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: ajrh at ajrh dot net Target Milestone: --- For use with gcov, I'm trying to use the --keep-inline-functions flag, as suggested in the GCC manual, but it's causing a lot of link errors on various types of objects. The undefined references were my initial problem, I'm not sure about the relocation errors also. Possibly it's config-specific, as I made one example via creduce, which gives the error below, but it appears to compile fine in godbolt.Debian config attached below also. template void g(T, T) { } class C { static int XYZZY; int x; void f() { g(x, XYZZY); } }; int main() { return 0; } This compiles and runs cleanly with 'g++ -Wall foo.cpp && a.out' But with the flag added: g++ -Wall -fkeep-inline-functions foo.cpp /usr/bin/ld: /tmp/ccewh7OH.o: warning: relocation against `_ZN1C5XYZZYE' in read-only section `.text._ZN1C1fEv[_ZN1C1fEv]' /usr/bin/ld: /tmp/ccewh7OH.o: in function `C::f()': foo.cpp:(.text._ZN1C1fEv[_ZN1C1fEv]+0xe): undefined reference to `C::XYZZY' /usr/bin/ld: warning: creating DT_TEXTREL in a PIE collect2: error: ld returned 1 exit status gcc -v Using built-in specs. COLLECT_GCC=gcc COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/11/lto-wrapper OFFLOAD_TARGET_NAMES=nvptx-none:amdgcn-amdhsa OFFLOAD_TARGET_DEFAULT=1 Target: x86_64-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Debian 11.2.0-14' --with-bugurl=file:///usr/share/doc/gcc-11/README.Bugs --enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++,m2 --prefix=/usr --with-gcc-major-version-only --program-suffix=-11 --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 --enable-bootstrap --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-plugin --enable-default-pie --with-system-zlib --enable-libphobos-checking=release --with-target-system-zlib=auto --enable-objc-gc=auto --enable-multiarch --disable-werror --enable-cet --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none=/build/gcc-11-y1lmfE/gcc-11-11.2.0/debian/tmp-nvptx/usr,amdgcn-amdhsa=/build/gcc-11-y1lmfE/gcc-11-11.2.0/debian/tmp-gcn/usr --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu --with-build-config=bootstrap-lto-lean --enable-link-serialization=2 Thread model: posix Supported LTO compression algorithms: zlib zstd gcc version 11.2.0 (Debian 11.2.0-14)
[Bug c++/48969] New: ICE with -std=c++0x
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48969 Summary: ICE with -std=c++0x Product: gcc Version: 4.6.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ AssignedTo: unassig...@gcc.gnu.org ReportedBy: a...@ajrh.net The file below compiles OK if the -std=c++0x flag is not passed g++ -c -std=c++0x x.cpp g++: internal compiler error: Segmentation fault (program cc1plus) Please submit a full bug report, [...] === templateunsigned int N struct Pair { }; struct Foo { enum { Mask = 1 }; } foo; templatetypename A, typename B class PairA::Mask | B::Mask operator|(const A , const B ) { foo | foo; };
[Bug inline-asm/38680] New: -masm= option might usefully define a preprocessor macro?
to allow compatibility error checking, and also maybe to enable conditional .intel_syntax ... .att_syntax bracketing, it might be helpful if the -masm= switch defined a preprocessor variable to indicate the top level syntax? -- Summary: -masm= option might usefully define a preprocessor macro? Product: gcc Version: unknown Status: UNCONFIRMED Severity: enhancement Priority: P3 Component: inline-asm AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: ajrh at ajrh dot net GCC build triplet: i486-linux-gnu GCC host triplet: i486-linux-gnu GCC target triplet: i486-linux-gnu http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38680