On 08/16/2017 02:55 PM, David Malcolm wrote:
On Wed, 2017-08-16 at 10:12 -0600, Martin Sebor wrote:
PR c/81859 - [8 Regression] valgrind error from
warn_about_normalization
gcc/ChangeLog:
PR c/81859
* pretty-print.c (pp_format): Use strnlen in %.*s to avoid
reading
past the end of an array.
(test_pp_format): Add test cases.
Index: gcc/pretty-print.c
===================================================================
--- gcc/pretty-print.c (revision 251100)
+++ gcc/pretty-print.c (working copy)
@@ -668,15 +668,11 @@ pp_format (pretty_printer *pp, text_info *text)
s = va_arg (*text->args_ptr, const char *);
- /* Negative precision is treated as if it were
omitted. */
- if (n < 0)
- n = INT_MAX;
+ /* Append the lesser of precision and strlen (s)
characters
+ from the array (which need not be a nul-terminated
string).
+ Negative precision is treated as if it were
omitted. */
+ size_t len = n < 0 ? strlen (s) : strnlen (s, n);
- /* Append the lesser of precision and strlen (s)
characters. */
- size_t len = strlen (s);
- if ((unsigned) n < len)
- len = n;
-
pp_append_text (pp, s, s + len);
}
break;
@@ -1438,6 +1434,13 @@ test_pp_format ()
ASSERT_PP_FORMAT_2 ("A 12345678", "%c %x", 'A', 0x12345678);
ASSERT_PP_FORMAT_2 ("hello world 12345678", "%s %x", "hello
world",
0x12345678);
+
+ /* Not nul-terminated. */
+ char arr[5] = { '1', '2', '3', '4', '5' };
+ ASSERT_PP_FORMAT_2 ("123", "%.*s", 3, arr);
+ ASSERT_PP_FORMAT_2 ("1234", "%.*s", -1, "1234");
+ ASSERT_PP_FORMAT_2 ("12345", "%.*s", 7, "12345");
+
The other examples in this selftest append a trailing argument with a
known bit pattern (0x12345678), to ensure that we're consuming
arguments correctly.
Please can you do the same for these tests.
Sure. I committed the updated fix in r251157.
Martin
