PR middle-end/88226 - missing warning on fprintf, fputs, and puts with an unterminated array

gcc/ChangeLog:

	PR middle-end/88226
	* builtins.c (check_nul_terminated_array): New function.
	(fold_builtin_0): Remove declaration.
	(fold_builtin_1): Same.
	(fold_builtin_2): Same.
	(fold_builtin_3): Same.
	(fold_builtin_strpbrk): Add argument.
	(fold_builtin_strspn): Same.
	(fold_builtin_strcspn): Same.
	(expand_builtin_strcat): Call it.  Remove unused argument.
	(expand_builtin_stpncpy): Same.
	(expand_builtin_strncat): Same.
	(expand_builtin_strncpy): Same.  Adjust indentation.
	(expand_builtin_strcmp): Same.
	(expand_builtin_strncmp): Same.
	(expand_builtin_fork_or_exec): Same.
	(expand_builtin): Handle more built-ins.
	(fold_builtin_2): Add argument.
	(fold_builtin_n): Make static.  Add argument.
	(fold_call_expr): Pass new argument to fold_builtin_n and fold_builtin_2.
	(fold_builtin_call_array): Pass new argument to fold_builtin_n.
	(fold_builtin_strpbrk): Add argument.  Call check_nul_terminated_array.
	(fold_call_stmt): Pass new argument to fold_builtin_n.
	* builtins.h: Correct a comment.
	* gimple-fold.c (gimple_fold_builtin_strchr): Call
	check_nul_terminated_array.
	* tree-ssa-strlen.c (handle_builtin_strlen): Call
	check_nul_terminated_array.
	(handle_builtin_strchr): Same.
	(handle_builtin_string_cmp): Same.

gcc/testsuite/ChangeLog:

	PR middle-end/88226
	* gcc.dg/Wstringop-overflow-22.c: New test.
	* gcc.dg/tree-ssa/builtin-fprintf-warn-1.c: Remove xfails.

From-SVN: r278623

1 files changed, 16 insertions, 6 deletions

diff --git a/gcc/tree-ssa-strlen.c b/gcc/tree-ssa-strlen.c
index be0f37c..06fa99e 100644
--- a/gcc/tree-ssa-strlen.c
+++ b/gcc/tree-ssa-strlen.c
@@ -1946,8 +1946,6 @@ handle_builtin_strlen (gimple_stmt_iterator *gsi)
 static void
 handle_builtin_strchr (gimple_stmt_iterator *gsi)
 {
-  int idx;
-  tree src;
   gimple *stmt = gsi_stmt (*gsi);
   tree lhs = gimple_call_lhs (stmt);
 
@@ -1957,8 +1955,14 @@ handle_builtin_strchr (gimple_stmt_iterator *gsi)
   if (!integer_zerop (gimple_call_arg (stmt, 1)))
     return;
 
-  src = gimple_call_arg (stmt, 0);
-  idx = get_stridx (src);
+  tree src = gimple_call_arg (stmt, 0);
+
+  /* Avoid folding if the first argument is not a nul-terminated array.
+     Defer warning until later.  */
+  if (!check_nul_terminated_array (NULL_TREE, src))
+    return;
+
+  int idx = get_stridx (src);
   if (idx)
     {
       strinfo *si = NULL;
@@ -3794,11 +3798,11 @@ handle_builtin_string_cmp (gimple_stmt_iterator *gsi)
 
   /* For strncmp set to the the value of the third argument if known.  */
   HOST_WIDE_INT bound = -1;
-
+  tree len = NULL_TREE;
   /* Extract the strncmp bound.  */
   if (gimple_call_num_args (stmt) == 3)
     {
-      tree len = gimple_call_arg (stmt, 2);
+      len = gimple_call_arg (stmt, 2);
       if (tree_fits_shwi_p (len))
         bound = tree_to_shwi (len);
 
@@ -3807,6 +3811,12 @@ handle_builtin_string_cmp (gimple_stmt_iterator *gsi)
 	return false;
     }
 
+  /* Avoid folding if either argument is not a nul-terminated array.
+     Defer warning until later.  */
+  if (!check_nul_terminated_array (NULL_TREE, arg1, len)
+      || !check_nul_terminated_array (NULL_TREE, arg2, len))
+    return false;
+
   {
     /* Set to the length of one argument (or its complement if it's
        the lower bound of a range) and the size of the array storing