PR middle-end/92622 - FAIL: gcc.dg/Warray-bounds-22.c on ILP32: missing warnings…

PR middle-end/92622 - FAIL: gcc.dg/Warray-bounds-22.c on ILP32: missing warnings for VLA on lines 67 and 69

gcc/ChangeLog:

	PR middle-end/92622
	* tree-vrp.c (vrp_prop::check_array_ref): Avoid using a variable
	left uninitialized by get_addr_base_and_unit_offset ofn failure.

From-SVN: r279029

gcc/ChangeLog

+2019-12-05  Martin Sebor  <msebor@redhat.com>
+
+	PR middle-end/92622
+	* tree-vrp.c (vrp_prop::check_array_ref): Avoid using a variable
+	left uninitialized by get_addr_base_and_unit_offset on failure.
+
 2019-12-05  Jan Hubicka  <hubicka@ucw.cz>
 
 	* ipa-prop.c (ipa_set_jf_unknown): Do not clear bits and m_vr.

gcc/tree-vrp.c

@@ -3516,7 +3516,6 @@ vrp_prop::check_array_ref (location_t location, tree ref,
 	  tree ptrdiff_max = TYPE_MAX_VALUE (ptrdiff_type_node);
 	  tree maxbound = ptrdiff_max;
 	  tree arg = TREE_OPERAND (ref, 0);
-	  poly_int64 off;
 
 	  const bool compref = TREE_CODE (arg) == COMPONENT_REF;
 	  if (compref)
@@ -3535,8 +3534,10 @@ vrp_prop::check_array_ref (location_t location, tree ref,
 		 size wouldn't necessarily be correct if the reference is
 		 to its flexible array member initialized in a different
 		 translation unit.  */
-	      tree base = get_addr_base_and_unit_offset (arg, &off);
-	      if (!compref && base && DECL_P (base))
+	      poly_int64 off;
+	      if (tree base = get_addr_base_and_unit_offset (arg, &off))
+		{
+		  if (!compref && DECL_P (base))
 		    if (tree basesize = DECL_SIZE_UNIT (base))
 		      if (TREE_CODE (basesize) == INTEGER_CST)
 			{
@@ -3549,6 +3550,7 @@ vrp_prop::check_array_ref (location_t location, tree ref,
 						 wi::sub (wi::to_wide (maxbound),
 							  off));
 		}
+	    }
 	  else
 	    maxbound = fold_convert (sizetype, maxbound);