On Fri, May 04, 2018 at 02:05:11PM -0600, Jeff Law wrote: > On 05/04/2018 01:55 PM, Steve Kargl wrote: > > On Fri, May 04, 2018 at 01:32:00PM -0600, Jeff Law wrote: > >> > >> The Fortran front end has its own code to parse # <line> <file> > >> directives. We've run into a case where it does not function correctly. > >> In particular when the directive changes the current file, subsequent > >> diagnostics still refer to the original filename. > >> > >> Concretely take this code and compile it with -Wall: > >> > >> # 12345 "foo-f" > >> SUBROUTINE s(dummy) > >> INTEGER, INTENT(in) :: dummy > >> END SUBROUTINE > > > > Can you tell us where the above comes from? > Use of # <line> <file> is a standard CPP directive one can use to change > the compiler's notion of file/line. It's defined by ISO for C/C++ and > appears to be relatively common in other Fortran compilers. GNU Fortran > tries to handle it and just gets it slightly wrong. > > It's most typically used when source code is generated by another program. > > > If I have the three lines of code in a file > > name 'a.inc', and use either the Fortran > > INCLUDE statement or a cpp #include statement > > I get what I expect. > Right. That uses a slightly different form internally. It'll get > turned into > > # <line> <file> <flags> > > Where the flags will indicate entry/exit from included files. That form > is handled correctly by the GNU Fortran front end. But this form is not > for external use.
Thanks for the explanation. The patch looks good to me. -- Steve
