Re: [patch, fortran] Fix PR 44960, accepts invalid reference on function

[Thomas Koenig]

Hello world,

I found an ommission in primary.c which prevented issuing a
more specific error instead of "syntax error" for the case
when a function was declared in an EXTERNAL statement,
and I have now gone for the "Unexpected junk after foo"
variant.

Regression-tested. OK for trunk?

Regards

        Thomas

2020-01-18  Thomas König  <tkoe...@gcc.gnu.org>

        PR fortran/44960
        * primary.c (gfc_match_rvalue): Break after setting MATCH_ERROR.
        * resolve.c (resolve_function): Issue error when a
        function call contains a reference.

2020-01-18  Thomas König  <tkoe...@gcc.gnu.org>

        PR fortran/44960
        * gfortran.dg/function_reference_1.f90: New test.




diff --git a/gcc/fortran/primary.c b/gcc/fortran/primary.c
index 07b8ac08ba2..bd50827bb15 100644
--- a/gcc/fortran/primary.c
+++ b/gcc/fortran/primary.c
@@ -3661,6 +3661,7 @@ gfc_match_rvalue (gfc_expr **result)
 	  gfc_error ("The leftmost part-ref in a data-ref cannot be a "
 		     "function reference at %C");
 	  m = MATCH_ERROR;
+	  break;
 	}
 
       m = MATCH_YES;
diff --git a/gcc/fortran/resolve.c b/gcc/fortran/resolve.c
index 6f2a4c4d65a..697afadb378 100644
--- a/gcc/fortran/resolve.c
+++ b/gcc/fortran/resolve.c
@@ -3129,6 +3129,13 @@ resolve_function (gfc_expr *expr)
 	  || sym->intmod_sym_id == GFC_ISYM_CAF_SEND))
     return true;
 
+  if (expr->ref)
+    {
+      gfc_error ("Unexpected junk after %qs at %L", expr->symtree->n.sym->name,
+		 &expr->where);
+      return false;
+    }
+
   if (sym && sym->attr.intrinsic
       && !gfc_resolve_intrinsic (sym, &expr->where))
     return false;
diff --git a/gcc/testsuite/gfortran.dg/function_reference_1.f90 b/gcc/testsuite/gfortran.dg/function_reference_1.f90
new file mode 100644
index 00000000000..be634c9dd4b
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/function_reference_1.f90
@@ -0,0 +1,11 @@
+! { dg-do compile }
+! PR 44960 - this was erroneusly accepted.
+! Original test case by Daniel Franke.
+
+type t
+  integer :: a
+end type t
+type(t) :: foo
+print *, foo(1)%a ! { dg-error "Unexpected junk" }
+end
+
diff --git a/gcc/testsuite/gfortran.dg/function_reference_2.f90 b/gcc/testsuite/gfortran.dg/function_reference_2.f90
new file mode 100644
index 00000000000..375c58bb6d2
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/function_reference_2.f90
@@ -0,0 +1,10 @@
+! { dg-do compile }
+! PR 44960 - improve the error message
+program main
+  type t
+  integer :: a
+end type t
+type(t) :: foo
+external foo
+i = foo(1)%1 ! { dg-error "leftmost part-ref in a data-ref cannot be a function reference" }
+end

! { dg-do compile }
! PR 44960 - improve the error message
program main
  type t
  integer :: a
end type t
type(t) :: foo
external foo
i = foo(1)%1 ! { dg-error "leftmost part-ref in a data-ref cannot be a function reference" }
end

! { dg-do compile }
! PR 44960 - this was erroneusly accepted.
! Original test case by Daniel Franke.

type t
  integer :: a
end type t
type(t) :: foo
print *, foo(1)%a ! { dg-error "Unexpected junk" }
end