On Wed, Jan 22, 2020 at 12:12 PM Kevin Kofler <kevin.kofler@xxxxxxxxx> wrote: > > Miro Hrončok wrote: > > https://gcc.gnu.org/gcc-10/porting_to.html#common > > > > "Default to -fno-common > > > > A common mistake in C is omitting extern when declaring a global variable > > in a header file. If the header is included by several files it results in > > multiple definitions of the same variable. In previous GCC versions this > > error is ignored. GCC 10 defaults to -fno-common, which means a linker > > error will now be reported. To fix this, use extern in header files when > > declaring global variables, and ensure each global is defined in exactly > > one C file. As a workaround, legacy C code can be compiled with -fcommon. > > > > > > int x; // tentative definition - avoid in header files > > > > extern int y; // correct declaration in a header file" > > I fail to see how this kind of incompatible change that breaks hundreds of > packages (and certainly a lot more software out there) is an improvement. > > Kevin Kofler Honestly, it would have been good to mention that GCC 10 contains such a breaking change, either on the GCC10 Change proposal wiki page, or in the FESCo ticket. Neither was the case. :( Now we still don't have a publicly available list of broken packages (which, apparently, was known?) - can we please get the list? I don't care where, but adding a link to it to either the Change wiki page or the FESCo ticket would be great, so we can better deal with it. Fabio > _______________________________________________ > devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx > To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: https://lists.fedoraproject.org/archives/list/devel@xxxxxxxxxxxxxxxxxxxxxxx _______________________________________________ devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@xxxxxxxxxxxxxxxxxxxxxxx
