Fortran: diagnostics of MODULE PROCEDURE declaration conflicts [PR104649]

gcc/fortran/ChangeLog:

	PR fortran/104649
	* decl.cc (gfc_match_formal_arglist): Handle conflicting declarations
	of a MODULE PROCEDURE when one of the declarations is an alternate
	return.

gcc/testsuite/ChangeLog:

	PR fortran/104649
	* gfortran.dg/pr104649.f90: New test.

Co-authored-by: Steven G. Kargl <kargl@gcc.gnu.org>

diff --git a/gcc/fortran/decl.cc b/gcc/fortran/decl.cc
index bdd3be32a4685b1edee0301bd5e2fb831acdf14c..4893c5820650bdb49787144a5f1ae9785fa627db 100644 (file)
--- a/gcc/fortran/decl.cc
+++ b/gcc/fortran/decl.cc
@@ -6796,12 +6796,25 @@ ok:
              || (p->next == NULL && q->next != NULL))
            arg_count_mismatch = true;
          else if ((p->sym == NULL && q->sym == NULL)
-                   || strcmp (p->sym->name, q->sym->name) == 0)
+                   || (p->sym && q->sym
+                       && strcmp (p->sym->name, q->sym->name) == 0))
            continue;
          else
-           gfc_error_now ("Mismatch in MODULE PROCEDURE formal "
-                          "argument names (%s/%s) at %C",
-                          p->sym->name, q->sym->name);
+           {
+             if (q->sym == NULL)
+               gfc_error_now ("MODULE PROCEDURE formal argument %qs "
+                              "conflicts with alternate return at %C",
+                              p->sym->name);
+             else if (p->sym == NULL)
+               gfc_error_now ("MODULE PROCEDURE formal argument is "
+                              "alternate return and conflicts with "
+                              "%qs in the separate declaration at %C",
+                              q->sym->name);
+             else
+               gfc_error_now ("Mismatch in MODULE PROCEDURE formal "
+                              "argument names (%s/%s) at %C",
+                              p->sym->name, q->sym->name);
+           }
        }
 
       if (arg_count_mismatch)

diff --git a/gcc/testsuite/gfortran.dg/pr104649.f90 b/gcc/testsuite/gfortran.dg/pr104649.f90
new file mode 100644 (file)
index 0000000..f301ffc
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr104649.f90
@@ -0,0 +1,44 @@
+! { dg-do compile }
+! { dg-options "-w" }
+! PR fortran/104649
+! Contributed by G.Steinmetz
+
+module m
+  interface
+    module subroutine s(x)
+      real :: x
+    end
+  end interface
+end
+submodule(m) m2
+contains
+  module subroutine s(*) ! { dg-error "conflicts with alternate return" }
+  end
+end
+
+module n
+  interface
+     module subroutine s(*)
+     end
+  end interface
+end
+submodule(n) n2
+contains
+  module subroutine s(x) ! { dg-error "formal argument is alternate return" }
+    real :: x
+  end
+end
+
+module p
+  interface
+     module subroutine s(x)
+       real :: x
+     end
+  end interface
+end
+submodule(p) p2
+contains
+  module subroutine s(y) ! { dg-error "Mismatch in MODULE PROCEDURE formal argument names" }
+    real :: y
+  end
+end