https://gitlab.com/cmocka/cmocka/issues/20 As long as LTO options are used cmocka build fails: /usr/bin/gcc -O2 -g -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS -fexceptions -fstack-protector-strong -grecord-gcc-switches -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 -m64 -mtune=generic -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection -flto -Wl,-z,relro -Wl,--as-needed -Wl,-z,now -specs=/usr/lib/rpm/redhat/redhat-hardened-ld -flto -fuse-linker-plugin -Wl,--wrap=uptime CMakeFiles/test_uptime.dir/test_uptime.c.o -o test_uptime -Wl,-rpath,/home/tkloczko/rpmbuild/BUILD/cmocka-1.1.5/x86_64-redhat-linux-gnu/src ../../../src/libcmocka.so.0.7.0 /usr/lib64/librt.so /usr/bin/ld: /tmp/test_uptime.FbzbXG.ltrans0.ltrans.o: in function `calc_uptime': /home/tkloczko/rpmbuild/BUILD/cmocka-1.1.5/example/mock/uptime/uptime.c:35: undefined reference to `__wrap_uptime' collect2: error: ld returned 1 exit status
Note that this uses the --wrap option in order to overwrite a function symbol. It looks like --wrap doesn't support linking with LTO.
https://gitlab.com/cmocka/cmocka/tree/master/example/mock/uptime the README.md explains the usecase ...
Yes. And that documentation does not explains why it fails with LTO :P
Because of a linker bug?
See also https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88643
OK. Thank you :)
Hi Guys, Yeah, sorry, but at this time --wrap and LTO are not guaranteed to work. At least not when you are using --wrap to replace an existing symbol rather than providing a alternative implementation of an undefined symbol. :-( May I suggest omitting -flto from the build command line ? Cheers Nick
For now I've applied what disable build that faulting example binary using cmake option (suggested Andreas) so everything else can still be LTO optimised. SO is it some bug which can be fixed relatively easy or it is some LTO design issue which it is not so easy to solve? If solving that option could take longer IMO linker should report that -flto and --wrap cannot be used (for now) together. At least that should stop creating bug reports about that issue :)
(In reply to Tomasz Kłoczko from comment #8) > SO is it some bug which can be fixed relatively easy or it is some LTO > design issue which it is not so easy to solve? The latter. :-( > If solving that option could take longer IMO linker should report that -flto > and --wrap cannot be used (for now) together. At least that should stop > creating bug reports about that issue :) Except that --wrap will work with -flto if it is being used to provide a definition for a symbol that does not exist. So it would have to be a warning rather than an error message. Plus ... -flto is a compiler and compiler driver option but it is not actually a linker option. (It is never passed to the linker). Whereas --wrap is a linker option. So the only place that a warning message could be generated is in the compiler driver (ie the gcc program), or more likely, the spec file used by gcc to construct the command lines that it generates. All of which means that the generation of a warning message is a gcc issue and not a binutils issue. (Tah dah! I have ducked the responsibility :-). Cheers Nick
This bug appears to have been reported against 'rawhide' during the Fedora 31 development cycle. Changing version to '31'.
This bug appears to have been reported against 'rawhide' during the Fedora 31 development cycle. Changing version to 31.
This message is a reminder that Fedora 31 is nearing its end of life. Fedora will stop maintaining and issuing updates for Fedora 31 on 2020-11-24. It is Fedora's policy to close all bug reports from releases that are no longer maintained. At that time this bug will be closed as EOL if it remains open with a Fedora 'version' of '31'. Package Maintainer: If you wish for this bug to remain open because you plan to fix it in a currently maintained version, simply change the 'version' to a later Fedora version. Thank you for reporting this issue and we are sorry that we were not able to fix it before Fedora 31 is end of life. If you would still like to see this bug fixed and are able to reproduce it against a later version of Fedora, you are encouraged change the 'version' to a later Fedora version prior this bug is closed as described in the policy above. Although we aim to fix as many bugs as possible during every release's lifetime, sometimes those efforts are overtaken by events. Often a more recent Fedora release includes newer upstream software that fixes bugs or makes them obsolete.
Fedora 31 changed to end-of-life (EOL) status on 2020-11-24. Fedora 31 is no longer maintained, which means that it will not receive any further security or bug fix updates. As a result we are closing this bug. If you can reproduce this bug against a currently maintained version of Fedora please feel free to reopen this bug against that version. If you are unable to reopen this bug, please file a new report against the current release. If you experience problems, please add a comment to this bug. Thank you for reporting this bug and we are sorry it could not be fixed.