https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68788
Bug ID: 68788 Summary: -Wa doesn't work with -flto Product: gcc Version: 5.1.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: driver Assignee: unassigned at gcc dot gnu.org Reporter: jon at beniston dot com Target Milestone: --- It seems it isn't possible to use the -Wa option to pass options to the assembler when -flto is used. E.g. gcc -Wa,--my-option works OK, but when using: gcc -flto -Wa,--my-option -v I can see that --my-option isn't passed to the assembler. It seems this was mentioned on the mailing list a while ago: https://gcc.gnu.org/ml/gcc-help/2013-04/msg00081.html There's nothing in the docs to suggest this shouldn't work: https://gcc.gnu.org/onlinedocs/gcc-5.3.0/gcc/Assembler-Options.html#Assembler-Options