It would be nice to have an option for gfortran that emits a warning when an undeclared function or subroutine is called. This would be similar to -Wimplicit-interface, except that this new warning would also accept non-explicit interfaces. For example, the fragment external a call a leads to a warning with -Wimplicit-interface, but I would like to get no warning for this construct.
Confirmed.
I'm not sure about the wording, but the following patch does what you want: Index: interface.c =================================================================== --- interface.c (revision 129869) +++ interface.c (working copy) @@ -2216,12 +2216,16 @@ check_intents (gfc_formal_arglist *f, gf void gfc_procedure_use (gfc_symbol *sym, gfc_actual_arglist **ap, locus *where) { - - /* Warn about calls with an implicit interface. */ + /* Warn about calls with an implicit interface, or to procedures not + explicitly declared. */ if (gfc_option.warn_implicit_interface && sym->attr.if_source == IFSRC_UNKNOWN) gfc_warning ("Procedure '%s' called with an implicit interface at %L", sym->name, where); + else if (gfc_option.warn_implicit_procedure && sym->attr.proc == PROC_UNKNOWN + && sym->attr.if_source == IFSRC_UNKNOWN) + gfc_warning ("Procedure '%s' called at %L is not explicitly declared", + sym->name, where); if (sym->attr.if_source == IFSRC_UNKNOWN || !compare_actual_formal (ap, sym->formal, 0, You also need to add the option in lang.opt and gfortran.h, and handle it in options.c, of course ;-)
Working on updating and working out FX's patch.
Extended patch based on the one from comment #2 posted: http://gcc.gnu.org/ml/fortran/2009-04/msg00148.html
Created attachment 17865 [details] Latest patch
Created attachment 17866 [details] ChangeLog for patch posted
Daniel, is there anything going to happen with those patches you attached? :)
Well, on 10th of August I posted this to the mailing list to get comments about what to do with this PR and some other. I did so far never get any replies :) So actually I'd like to work things out here and either fix or close the PR. But I've no real plan at the moment because I'd like to get other's opinions. The patch itself seems fine to me, the point is whether we want that warning or not.
Subject: Bug 22552 Author: domob Date: Sun Dec 27 09:30:57 2009 New Revision: 155479 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=155479 Log: 2009-12-27 Francois-Xavier Coudert <fxcoudert@gcc.gnu.org> Daniel Kraft <d@domob.eu> PR fortran/22552 * lang.opt (Wimplicit-procedure): New option. * gfortran.h (struct gfc_option_t): New member `warn_implicit_procedure' * options.c (gfc_handle_option): Handle -Wimplicit-procedure. * interface.c (gfc_procedure_use): Warn about procedure never explicitly declared if requested by the new flag. * invoke.texi: Document new flag -Wimplicit-procedure. 2009-12-27 Francois-Xavier Coudert <fxcoudert@gcc.gnu.org> Daniel Kraft <d@domob.eu> PR fortran/22552 * gfortran.dg/warn_implicit_procedure_1.f90: New test. Added: trunk/gcc/testsuite/gfortran.dg/warn_implicit_procedure_1.f90 Modified: trunk/gcc/fortran/ChangeLog trunk/gcc/fortran/gfortran.h trunk/gcc/fortran/interface.c trunk/gcc/fortran/invoke.texi trunk/gcc/fortran/lang.opt trunk/gcc/fortran/options.c trunk/gcc/testsuite/ChangeLog
Implemented on trunk with (basically) the patch attached.