PR tree-optimization/86650 - -Warray-bounds missing inlining context

gcc/ChangeLog:

	PR tree-optimization/86650
	* tree-vrp.c (vrp_prop::check_array_ref): Print an inform message.
	(vrp_prop::check_mem_ref): Same.

gcc/testsuite/ChangeLog:

	PR tree-optimization/86650
	* gcc.dg/Warray-bounds-34.c: New test.

From-SVN: r263541

4 files changed, 124 insertions, 75 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 1e108ef..97ea6bc 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2018-08-14  Martin Sebor  <msebor@redhat.com>
+
+	PR tree-optimization/86650
+	* tree-vrp.c (vrp_prop::check_array_ref): Print an inform message.
+	(vrp_prop::check_mem_ref): Same.
+
 2018-08-13  Liu Hao <lh_mouse@126.com>
 
 	* pretty-print.c (eat_esc_sequence): Swap the foreground and
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 3bbc706..b456781 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2018-08-14  Martin Sebor  <msebor@redhat.com>
+
+	PR tree-optimization/86650
+	* gcc.dg/Warray-bounds-34.c: New test.
+
 2018-08-14  Janus Weil  <janus@gcc.gnu.org>
 
 	PR fortran/86116
diff --git a/gcc/testsuite/gcc.dg/Warray-bounds-34.c b/gcc/testsuite/gcc.dg/Warray-bounds-34.c
new file mode 100644
index 0000000..cea7c4b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/Warray-bounds-34.c
@@ -0,0 +1,18 @@
+/* PR tree-optimization/86650 - -Warray-bounds missing inlining context
+   { dg-do compile }
+   { dg-options "-O2 -Warray-bounds" } */
+
+int a[3];           /* { dg-message "while referencing .a." } */
+int x;
+
+inline void foo (int i)
+{
+  a[i + 1] = 123;   /* { dg-warning "\\\[-Warray-bounds]" } */
+}
+
+int bar (void)
+{
+  foo (3);
+
+  return x;
+}
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index e1875d8..d553a25 100644
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -4445,14 +4445,13 @@ vrp_prop::check_array_ref (location_t location, tree ref,
 
   tree artype = TREE_TYPE (TREE_OPERAND (ref, 0));
 
+  bool warned = false;
+
   /* Empty array.  */
   if (up_bound && tree_int_cst_equal (low_bound, up_bound_p1))
-    {
-      warning_at (location, OPT_Warray_bounds,
-		  "array subscript %E is above array bounds of %qT",
-		  low_bound, artype);
-      TREE_NO_WARNING (ref) = 1;
-    }
+    warned = warning_at (location, OPT_Warray_bounds,
+			 "array subscript %E is above array bounds of %qT",
+			 low_bound, artype);
 
   if (TREE_CODE (low_sub) == SSA_NAME)
     {
@@ -4473,12 +4472,10 @@ vrp_prop::check_array_ref (location_t location, tree ref,
 	      : tree_int_cst_le (up_bound, up_sub))
           && TREE_CODE (low_sub) == INTEGER_CST
           && tree_int_cst_le (low_sub, low_bound))
-        {
-          warning_at (location, OPT_Warray_bounds,
-		      "array subscript [%E, %E] is outside array bounds of %qT",
-		      low_sub, up_sub, artype);
-          TREE_NO_WARNING (ref) = 1;
-        }
+	warned = warning_at (location, OPT_Warray_bounds,
+			     "array subscript [%E, %E] is outside "
+			     "array bounds of %qT",
+			     low_sub, up_sub, artype);
     }
   else if (up_bound
 	   && TREE_CODE (up_sub) == INTEGER_CST
@@ -4492,10 +4489,9 @@ vrp_prop::check_array_ref (location_t location, tree ref,
 	  dump_generic_expr (MSG_NOTE, TDF_SLIM, ref);
 	  fprintf (dump_file, "\n");
 	}
-      warning_at (location, OPT_Warray_bounds,
-		  "array subscript %E is above array bounds of %qT",
-		  up_sub, artype);
-      TREE_NO_WARNING (ref) = 1;
+      warned = warning_at (location, OPT_Warray_bounds,
+			   "array subscript %E is above array bounds of %qT",
+			   up_sub, artype);
     }
   else if (TREE_CODE (low_sub) == INTEGER_CST
            && tree_int_cst_lt (low_sub, low_bound))
@@ -4506,9 +4502,18 @@ vrp_prop::check_array_ref (location_t location, tree ref,
 	  dump_generic_expr (MSG_NOTE, TDF_SLIM, ref);
 	  fprintf (dump_file, "\n");
 	}
-      warning_at (location, OPT_Warray_bounds,
-		  "array subscript %E is below array bounds of %qT",
-		  low_sub, artype);
+      warned = warning_at (location, OPT_Warray_bounds,
+			   "array subscript %E is below array bounds of %qT",
+			   low_sub, artype);
+    }
+
+  if (warned)
+    {
+      ref = TREE_OPERAND (ref, 0);
+
+      if (DECL_P (ref))
+	inform (DECL_SOURCE_LOCATION (ref), "while referencing %qD", ref);
+
       TREE_NO_WARNING (ref) = 1;
     }
 }
@@ -4523,7 +4528,8 @@ vrp_prop::check_array_ref (location_t location, tree ref,
    the address of the just-past-the-end element of an array).  */
 
 void
-vrp_prop::check_mem_ref (location_t location, tree ref, bool ignore_off_by_one)
+vrp_prop::check_mem_ref (location_t location, tree ref,
+			 bool ignore_off_by_one)
 {
   if (TREE_NO_WARNING (ref))
     return;
@@ -4744,16 +4750,21 @@ vrp_prop::check_mem_ref (location_t location, tree ref, bool ignore_off_by_one)
 	  offrange[1] = offrange[1] / eltsize;
 	}
 
+      bool warned;
       if (offrange[0] == offrange[1])
-	warning_at (location, OPT_Warray_bounds,
-		    "array subscript %wi is outside array bounds "
-		    "of %qT",
-		    offrange[0].to_shwi (), reftype);
+	warned = warning_at (location, OPT_Warray_bounds,
+			     "array subscript %wi is outside array bounds "
+			     "of %qT",
+			     offrange[0].to_shwi (), reftype);
       else
-	warning_at (location, OPT_Warray_bounds,
-		    "array subscript [%wi, %wi] is outside array bounds "
-		    "of %qT",
-		    offrange[0].to_shwi (), offrange[1].to_shwi (), reftype);
+	warned = warning_at (location, OPT_Warray_bounds,
+			     "array subscript [%wi, %wi] is outside "
+			     "array bounds of %qT",
+			     offrange[0].to_shwi (),
+			     offrange[1].to_shwi (), reftype);
+      if (warned && DECL_P (arg))
+	inform (DECL_SOURCE_LOCATION (arg), "while referencing %qD", arg);
+
       TREE_NO_WARNING (ref) = 1;
       return;
     }
@@ -4793,60 +4804,69 @@ vrp_prop::search_for_addr_array (tree t, location_t location)
     }
   while (handled_component_p (t) || TREE_CODE (t) == MEM_REF);
 
-  if (TREE_CODE (t) == MEM_REF
-      && TREE_CODE (TREE_OPERAND (t, 0)) == ADDR_EXPR
-      && !TREE_NO_WARNING (t))
-    {
-      tree tem = TREE_OPERAND (TREE_OPERAND (t, 0), 0);
-      tree low_bound, up_bound, el_sz;
-      offset_int idx;
-      if (TREE_CODE (TREE_TYPE (tem)) != ARRAY_TYPE
-	  || TREE_CODE (TREE_TYPE (TREE_TYPE (tem))) == ARRAY_TYPE
-	  || !TYPE_DOMAIN (TREE_TYPE (tem)))
-	return;
+  if (TREE_CODE (t) != MEM_REF
+      || TREE_CODE (TREE_OPERAND (t, 0)) != ADDR_EXPR
+      || TREE_NO_WARNING (t))
+    return;
 
-      low_bound = TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (tem)));
-      up_bound = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (tem)));
-      el_sz = TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (tem)));
-      if (!low_bound
-	  || TREE_CODE (low_bound) != INTEGER_CST
-	  || !up_bound
-	  || TREE_CODE (up_bound) != INTEGER_CST
-	  || !el_sz
-	  || TREE_CODE (el_sz) != INTEGER_CST)
-	return;
+  tree tem = TREE_OPERAND (TREE_OPERAND (t, 0), 0);
+  tree low_bound, up_bound, el_sz;
+  if (TREE_CODE (TREE_TYPE (tem)) != ARRAY_TYPE
+      || TREE_CODE (TREE_TYPE (TREE_TYPE (tem))) == ARRAY_TYPE
+      || !TYPE_DOMAIN (TREE_TYPE (tem)))
+    return;
 
-      if (!mem_ref_offset (t).is_constant (&idx))
-	return;
+  low_bound = TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (tem)));
+  up_bound = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (tem)));
+  el_sz = TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (tem)));
+  if (!low_bound
+      || TREE_CODE (low_bound) != INTEGER_CST
+      || !up_bound
+      || TREE_CODE (up_bound) != INTEGER_CST
+      || !el_sz
+      || TREE_CODE (el_sz) != INTEGER_CST)
+    return;
 
-      idx = wi::sdiv_trunc (idx, wi::to_offset (el_sz));
-      if (idx < 0)
+  offset_int idx;
+  if (!mem_ref_offset (t).is_constant (&idx))
+    return;
+
+  bool warned = false;
+  idx = wi::sdiv_trunc (idx, wi::to_offset (el_sz));
+  if (idx < 0)
+    {
+      if (dump_file && (dump_flags & TDF_DETAILS))
 	{
-	  if (dump_file && (dump_flags & TDF_DETAILS))
-	    {
-	      fprintf (dump_file, "Array bound warning for ");
-	      dump_generic_expr (MSG_NOTE, TDF_SLIM, t);
-	      fprintf (dump_file, "\n");
-	    }
-	  warning_at (location, OPT_Warray_bounds,
-		      "array subscript %wi is below array bounds of %qT",
-		      idx.to_shwi (), TREE_TYPE (tem));
-	  TREE_NO_WARNING (t) = 1;
+	  fprintf (dump_file, "Array bound warning for ");
+	  dump_generic_expr (MSG_NOTE, TDF_SLIM, t);
+	  fprintf (dump_file, "\n");
 	}
-      else if (idx > (wi::to_offset (up_bound)
-		      - wi::to_offset (low_bound) + 1))
+      warned = warning_at (location, OPT_Warray_bounds,
+			   "array subscript %wi is below "
+			   "array bounds of %qT",
+			   idx.to_shwi (), TREE_TYPE (tem));
+    }
+  else if (idx > (wi::to_offset (up_bound)
+		  - wi::to_offset (low_bound) + 1))
+    {
+      if (dump_file && (dump_flags & TDF_DETAILS))
 	{
-	  if (dump_file && (dump_flags & TDF_DETAILS))
-	    {
-	      fprintf (dump_file, "Array bound warning for ");
-	      dump_generic_expr (MSG_NOTE, TDF_SLIM, t);
-	      fprintf (dump_file, "\n");
-	    }
-	  warning_at (location, OPT_Warray_bounds,
-		      "array subscript %wu is above array bounds of %qT",
-		      idx.to_uhwi (), TREE_TYPE (tem));
-	  TREE_NO_WARNING (t) = 1;
+	  fprintf (dump_file, "Array bound warning for ");
+	  dump_generic_expr (MSG_NOTE, TDF_SLIM, t);
+	  fprintf (dump_file, "\n");
 	}
+      warned = warning_at (location, OPT_Warray_bounds,
+			   "array subscript %wu is above "
+			   "array bounds of %qT",
+			   idx.to_uhwi (), TREE_TYPE (tem));
+    }
+
+  if (warned)
+    {
+      if (DECL_P (t))
+	inform (DECL_SOURCE_LOCATION (t), "while referencing %qD", t);
+
+      TREE_NO_WARNING (t) = 1;
     }
 }