From 86ef85d3f7e790e2bbace497fe55ca93d99dad32 Mon Sep 17 00:00:00 2001 From: Martin Sebor Date: Thu, 17 Aug 2017 16:50:06 +0000 Subject: [PATCH] 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. From-SVN: r251157 --- gcc/ChangeLog | 7 +++++++ gcc/pretty-print.c | 19 +++++++++++-------- 2 files changed, 18 insertions(+), 8 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index a51c2599a77..0b4b336d614 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2017-08-17 Martin Sebor + + 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. + 2017-08-17 Richard Sandiford * internal-fn.def (CLRSB, CLZ, CTZ, FFS, PARITY, POPCOUNT): Add diff --git a/gcc/pretty-print.c b/gcc/pretty-print.c index 556462fafe7..7340cd4a565 100644 --- a/gcc/pretty-print.c +++ b/gcc/pretty-print.c @@ -668,14 +668,10 @@ 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. */ - size_t len = strlen (s); - if ((unsigned) n < len) - len = n; + /* 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); pp_append_text (pp, s, s + len); } @@ -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_3 ("123 12345678", "%.*s %x", 3, arr, 0x12345678); + ASSERT_PP_FORMAT_3 ("1234 12345678", "%.*s %x", -1, "1234", 0x12345678); + ASSERT_PP_FORMAT_3 ("12345 12345678", "%.*s %x", 7, "12345", 0x12345678); + /* We can't test for %p; the pointer is printed in an implementation-defined manner. */ ASSERT_PP_FORMAT_2 ("normal colored normal 12345678", -- 2.30.2