https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91496
Bug ID: 91496 Summary: !GCC$ directives error if mistyped or unknown Product: gcc Version: 4.7.2 Status: UNCONFIRMED Severity: normal Priority: P3 Component: fortran Assignee: unassigned at gcc dot gnu.org Reporter: nickpapior at gmail dot com Target Milestone: --- In fortran codes I would like to use directives such as: !GCC$ unroll <> When trying to compile a fortran source code with the above directive it fails with: Error: Unclassifiable GCC directive at (1) A small test code: program test integer :: i real :: a(3) !GCC$ unroll 3 do i = 1, 3 a(i) = 2. end do print *, sum(a) end program Tested versions: Failed: 4.7.2 Failed: 4.8.3 Failed: 4.8.4 Failed: 4.8.5 Failed: 4.9.1 Failed: 4.9.2 Failed: 5.1.0 Failed: 5.2.0 Failed: 5.3.0 Failed: 5.4.0 Failed: 6.1.0 Failed: 6.2.0 Failed: 6.3.0 Failed: 6.4.0 Failed: 6.5.0 Failed: 7.1.0 Failed: 7.2.0 Failed: 7.3.0 Failed: 7.4.0 Success: 8.1.0 Success: 8.2.0 Success: 8.3.0 I would recommend that using non-existing or mis-typed directives should *never* issues errors, but rather warnings. The reasoning is that if new directives are added the source would need pre-processor statements to determine the used gfortran version in order to decide on the acceptance of each directive. This becomes cumbersome and unnecessary.