[gcc r13-6067] Fortran: error recovery on checking procedure argument intent [PR103608]

[gcc r13-6067] Fortran: error recovery on checking procedure argument intent [PR103608]

[Harald Anlauf]

https://gcc.gnu.org/g:c75cbeba81e5b4737a9ab7dd28cce650965535a9

commit r13-6067-gc75cbeba81e5b4737a9ab7dd28cce650965535a9
Author: Steve Kargl <kargl@gcc.gnu.org>
Date:   Wed Feb 15 22:40:37 2023 +0100

    Fortran: error recovery on checking procedure argument intent [PR103608]
    
    gcc/fortran/ChangeLog:
    
            PR fortran/103608
            * frontend-passes.cc (do_intent): Catch NULL pointer dereference on
            reference to invalid formal argument.
    
    gcc/testsuite/ChangeLog:
    
            PR fortran/103608
            * gfortran.dg/pr103608.f90: New test.

Diff:
---
 gcc/fortran/frontend-passes.cc         |  3 ++-
 gcc/testsuite/gfortran.dg/pr103608.f90 | 14 ++++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/gcc/fortran/frontend-passes.cc b/gcc/fortran/frontend-passes.cc
index 1cbc63016da..02fcb41dbc4 100644
--- a/gcc/fortran/frontend-passes.cc
+++ b/gcc/fortran/frontend-passes.cc
@@ -3049,7 +3049,8 @@ do_intent (gfc_expr **e)
 	  do_sym = dl->ext.iterator->var->symtree->n.sym;
 
 	  if (a->expr && a->expr->symtree
-	      && a->expr->symtree->n.sym == do_sym)
+	      && a->expr->symtree->n.sym == do_sym
+	      && f->sym)
 	    {
 	      if (f->sym->attr.intent == INTENT_OUT)
 		gfc_error_now ("Variable %qs at %L set to undefined value "
diff --git a/gcc/testsuite/gfortran.dg/pr103608.f90 b/gcc/testsuite/gfortran.dg/pr103608.f90
new file mode 100644
index 00000000000..5c37cb78dc6
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr103608.f90
@@ -0,0 +1,14 @@
+! { dg-do compile }
+! { dg-options "-w" }
+! PR fortran/103608 - ICE in do_intent
+! Contributed by G.Steinmetz
+
+program p
+  implicit none
+  integer :: i
+  integer :: x     ! { dg-error "Alternate return specifier" }
+  x(*) = 0
+  do i = 1, 2
+     print *, x(i) ! { dg-error "Missing alternate return specifier" }
+  end do
+end