PR c++/87996 - size of array is negative error when SIZE_MAX/2 < sizeof(array) <= SIZE_MAX

gcc/ChangeLog:

	PR c++/87996
	* builtins.c (max_object_size): Move from here...
	* builtins.h (max_object_size): ...and here...
	* tree.c (max_object_size): ...to here...
	* tree.h (max_object_size): ...and here.

gcc/c-family/ChangeLog:

	PR c++/87996
	* c-common.c (invalid_array_size_error): New function.
	(valid_array_size_p): Call it.  Handle size as well as type.
	* c-common.h (valid_constant_size_p): New function.
	(enum cst_size_error): New type.

gcc/cp/ChangeLog:

	PR c++/87996
	* decl.c (compute_array_index_type_loc): Preserve signed sizes
	for diagnostics.  Call valid_array_size_p instead of error.
	* init.c (build_new_1): Compute size for diagnostic.  Call
	invalid_array_size_error
	(build_new): Call valid_array_size_p instead of error.

gcc/testsuite/ChangeLog:

	PR c++/87996
	* c-c++-common/array-5.c: New test.
	* c-c++-common/pr68107.c: Adjust text of diagnostics.
	* g++.dg/init/new38.C: Same.
	* g++.dg/init/new43.C: Same.
	* g++.dg/init/new44.C: Same.
	* g++.dg/init/new46.C: Same.
	* g++.dg/other/large-size-array.C: Same.
	* g++.dg/other/new-size-type.C: Same.
	* g++.dg/template/array30.C: Same.
	* g++.dg/template/array32.C: New test.
	* g++.dg/template/dependent-name3.C: Adjust.
	* gcc.dg/large-size-array-3.c: Same.
	* gcc.dg/large-size-array-5.c: Same.
	* gcc.dg/large-size-array.c: Same.
	* g++.old-deja/g++.brendan/array1.C: Same.
	* g++.old-deja/g++.mike/p6149.C: Same.

From-SVN: r268774

3 files changed, 80 insertions, 17 deletions

diff --git a/gcc/c-family/ChangeLog b/gcc/c-family/ChangeLog
index dd1173f..7dae7bf 100644
--- a/gcc/c-family/ChangeLog
+++ b/gcc/c-family/ChangeLog
@@ -1,3 +1,11 @@
+2019-02-11  Martin Sebor  <msebor@redhat.com>
+
+	PR c++/87996
+	* c-common.c (invalid_array_size_error): New function.
+	(valid_array_size_p): Call it.  Handle size as well as type.
+	* c-common.h (valid_constant_size_p): New function.
+	(enum cst_size_error): New type.
+
 2019-01-31  David Malcolm  <dmalcolm@redhat.com>
 
 	PR c/89122
diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index d3b5879..ae23e59 100644
--- a/gcc/c-family/c-common.c
+++ b/gcc/c-family/c-common.c
@@ -8231,29 +8231,82 @@ reject_gcc_builtin (const_tree expr, location_t loc /* = UNKNOWN_LOCATION */)
   return false;
 }
 
+/* Issue an ERROR for an invalid SIZE of array NAME which is null
+   for unnamed arrays.  */
+
+void
+invalid_array_size_error (location_t loc, cst_size_error error,
+			  const_tree size, const_tree name)
+{
+  tree maxsize = max_object_size ();
+  switch (error)
+    {
+    case cst_size_negative:
+      if (name)
+	error_at (loc, "size %qE of array %qE is negative",
+		  size, name);
+      else
+	error_at (loc, "size %qE of array is negative",
+		  size);
+      break;
+    case cst_size_too_big:
+      if (name)
+	error_at (loc, "size %qE of array %qE exceeds maximum "
+		  "object size %qE", size, name, maxsize);
+      else
+	error_at (loc, "size %qE of array exceeds maximum "
+		  "object size %qE", size, maxsize);
+      break;
+    case cst_size_overflow:
+      if (name)
+	error_at (loc, "size of array %qE exceeds maximum "
+		  "object size %qE", name, maxsize);
+      else
+	error_at (loc, "size of array exceeds maximum "
+		  "object size %qE", maxsize);
+      break;
+    default:
+      gcc_unreachable ();
+    }
+}
+
 /* Check if array size calculations overflow or if the array covers more
    than half of the address space.  Return true if the size of the array
-   is valid, false otherwise.  TYPE is the type of the array and NAME is
-   the name of the array, or NULL_TREE for unnamed arrays.  */
+   is valid, false otherwise.  T is either the type of the array or its
+   size, and NAME is the name of the array, or null for unnamed arrays.  */
 
 bool
-valid_array_size_p (location_t loc, tree type, tree name, bool complain)
+valid_array_size_p (location_t loc, const_tree t, tree name, bool complain)
 {
-  if (type != error_mark_node
-      && COMPLETE_TYPE_P (type)
-      && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST
-      && !valid_constant_size_p (TYPE_SIZE_UNIT (type)))
+  if (t == error_mark_node)
+    return true;
+
+  const_tree size;
+  if (TYPE_P (t))
     {
-      if (complain)
-	{
-	  if (name)
-	    error_at (loc, "size of array %qE is too large", name);
-	  else
-	    error_at (loc, "size of unnamed array is too large");
-	}
-      return false;
+      if (!COMPLETE_TYPE_P (t))
+	return true;
+      size = TYPE_SIZE_UNIT (t);
     }
-  return true;
+  else
+    size = t;
+
+  if (TREE_CODE (size) != INTEGER_CST)
+    return true;
+
+  cst_size_error error;
+  if (valid_constant_size_p (size, &error))
+    return true;
+
+  if (!complain)
+    return false;
+
+  if (TREE_CODE (TREE_TYPE (size)) == ENUMERAL_TYPE)
+    /* Show the value of the enumerator rather than its name.  */
+    size = convert (ssizetype, const_cast<tree> (size));
+
+  invalid_array_size_error (loc, error, size, name);
+  return false;
 }
 
 /* Read SOURCE_DATE_EPOCH from environment to have a deterministic
diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
index 69cb76c..394a0ea 100644
--- a/gcc/c-family/c-common.h
+++ b/gcc/c-family/c-common.h
@@ -1270,7 +1270,9 @@ extern tree find_inv_trees (tree *, int *, void *);
 extern tree replace_inv_trees (tree *, int *, void *);
 
 extern bool reject_gcc_builtin (const_tree, location_t = UNKNOWN_LOCATION);
-extern bool valid_array_size_p (location_t, tree, tree, bool = true);
+extern bool valid_array_size_p (location_t, const_tree, tree, bool = true);
+extern void invalid_array_size_error (location_t, cst_size_error,
+				      const_tree, const_tree);
 
 /* In c-warn.c.  */
 extern void constant_expression_warning (tree);