From: Steven G. Kargl <kargl@gcc.gnu.org>
Date: Thu, 21 Aug 2025 21:31:16 +0000 (-0700)
Subject: Fortran: Fix NULL pointer issue.
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=refs%2Fheads%2Fmaster;p=thirdparty%2Fgcc.git

Fortran: Fix NULL pointer issue.

	PR fortran/121627

gcc/fortran/ChangeLog:

	* module.cc (create_int_parameter_array):  Avoid NULL
	pointer dereference and enhance error message.

gcc/testsuite/ChangeLog:

	* gfortran.dg/pr121627.f90: New test.
---

diff --git a/gcc/fortran/module.cc b/gcc/fortran/module.cc
index 070b3164ea3..e05b08bd14e 100644
--- a/gcc/fortran/module.cc
+++ b/gcc/fortran/module.cc
@@ -7277,10 +7277,13 @@ create_int_parameter_array (const char *name, int size, gfc_expr *value,
   tmp_symtree = gfc_find_symtree (gfc_current_ns->sym_root, name);
   if (tmp_symtree != NULL)
     {
-      if (strcmp (modname, tmp_symtree->n.sym->module) == 0)
+      if (tmp_symtree->n.sym->module &&
+	  strcmp (modname, tmp_symtree->n.sym->module) == 0)
 	return;
       else
-	gfc_error ("Symbol %qs already declared", name);
+	gfc_error ("Symbol %qs already declared at %L conflicts with "
+		   "symbol in %qs at %C", name,
+		   &tmp_symtree->n.sym->declared_at, modname);
     }
 
   gfc_get_sym_tree (name, gfc_current_ns, &tmp_symtree, false);
diff --git a/gcc/testsuite/gfortran.dg/pr121627.f90 b/gcc/testsuite/gfortran.dg/pr121627.f90
new file mode 100644
index 00000000000..c3ce218880c
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr121627.f90
@@ -0,0 +1,5 @@
+! { dg-do compile }
+program real_kinds         ! { dg-error "already declared at" }
+  use iso_fortran_env      ! { dg-error "already declared at" }
+  i = real64
+end program real_kinds