[PATCH fortran/95342] - [9/10/11 Regression] ICE in gfc_match_subroutine, at fortran/decl.c:7913

[Harald Anlauf]

Dear all,

two almost obvious, trivial issues issues with NULL pointer dereferences.
Steve found the locations, but his solution changes the error messages
as compared to 7/8.  I've chosen the conservative way which keeps the
documented intent of the source code.

Regtested on x86_64-pc-linux-gnu.

OK for master?  Backport to affected 10- and 9-branches?
(8.4.1 was/is fine).

Thanks,
Harald


PR fortran/95342 - ICE in gfc_match_subroutine, at fortran/decl.c:7913

Add checks for NULL pointers before dereferencing them.

gcc/fortran/ChangeLog:

        PR fortran/95342
        * decl.c (gfc_match_function_decl): Avoid NULL pointer dereference.
        (gfc_match_subroutine): Likewise.

gcc/testsuite/ChangeLog:

        PR fortran/95342
        * gfortran.dg/pr95342.f90: New test.


diff --git a/gcc/fortran/decl.c b/gcc/fortran/decl.c
index 93a155c5f75..c85ae0de952 100644
--- a/gcc/fortran/decl.c
+++ b/gcc/fortran/decl.c
@@ -7408,6 +7408,7 @@ gfc_match_function_decl (void)
      procedure interface body.  */
     if (sym->attr.is_bind_c && sym->attr.module_procedure && sym->old_symbol
   	&& strcmp (sym->name, sym->old_symbol->name) == 0
+	&& sym->binding_label && sym->old_symbol->binding_label
 	&& strcmp (sym->binding_label, sym->old_symbol->binding_label) != 0)
       {
 	  const char *null = "NULL", *s1, *s2;
@@ -7923,6 +7924,7 @@ gfc_match_subroutine (void)
 	 procedure interface body.  */
       if (sym->attr.module_procedure && sym->old_symbol
   	  && strcmp (sym->name, sym->old_symbol->name) == 0
+	  && sym->binding_label && sym->old_symbol->binding_label
 	  && strcmp (sym->binding_label, sym->old_symbol->binding_label) != 0)
 	{
 	  const char *null = "NULL", *s1, *s2;
diff --git a/gcc/testsuite/gfortran.dg/pr95342.f90 b/gcc/testsuite/gfortran.dg/pr95342.f90
new file mode 100644
index 00000000000..41c987d3bbb
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr95342.f90
@@ -0,0 +1,20 @@
+! { dg-do compile }
+! PR fortran/95342 - ICE in gfc_match_subroutine, at fortran/decl.c:7913
+
+module m1
+  interface
+     module subroutine s()
+     end
+     subroutine s() bind(c) ! { dg-error "EXTERNAL attribute conflicts" }
+     end                    ! { dg-error "END INTERFACE" }
+  end interface
+end
+
+module m2
+  interface
+     module function f()
+     end
+     function f() bind(c)
+     end                    ! { dg-error "Duplicate EXTERNAL attribute" }
+  end interface
+end