https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108369
--- Comment #12 from Steve Kargl <sgk at troutmask dot apl.washington.edu> --- On Fri, Jan 13, 2023 at 11:49:44AM +0000, ben.brewer at codethink dot co.uk wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108369 > > --- Comment #11 from Ben Brewer <ben.brewer at codethink dot co.uk> --- > So I was using "-x f77" which I would expect to instruct the compiler to run > in > a mode compatible with Fortran 77, it seems non-intuitive to have to enable > -std=legacy to compile the very tests which define f77. > gfortran started life as a Fortran 95 compiler with a bunch of extensions. The -x f77 option might be a relic from g77 and only effects whether one has fixed source form code or free source form code. "f77" appears twice in gcc.info under the description of the -x option. The meaning of "-x f77" isn't actually documented. To set the Fortran standard conformance, use the -std option (e.g., -std=legacy, -std=f95, -std=f2003, -std=f2008, -std=f2018). There isn't an -std=f77, If one is compiling old code, it is recommended to use -std=legacy to turn off a bunch of warning/errors.
