From 7163ace3318d666d40771f5c8e7c4a148827070f Mon Sep 17 00:00:00 2001 From: Siddhesh Poyarekar Date: Thu, 12 Nov 2020 12:09:56 +0530 Subject: Use __builtin___stpncpy_chk when available The builtin has been available in gcc since 4.7.0 and in clang since 2.6. This fixes stpncpy fortification with clang since it does a better job of plugging in __stpncpy_chk in the right place than the header hackery. This has been tested by building and running all tests with gcc 10.2.1 and also with clang tip as of a few days ago (just the tests in debug/ since running all tests don't work with clang at the moment) to make sure that both compilers pass the stpncpy tests. --- string/bits/string_fortified.h | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/string/bits/string_fortified.h b/string/bits/string_fortified.h index c8d3051af8..4c1aeb45f1 100644 --- a/string/bits/string_fortified.h +++ b/string/bits/string_fortified.h @@ -91,7 +91,13 @@ __NTH (strncpy (char *__restrict __dest, const char *__restrict __src, return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest)); } -/* XXX We have no corresponding builtin yet. */ +#if __GNUC_PREREQ (4, 7) || __glibc_clang_prereq (2, 6) +__fortify_function char * +__NTH (stpncpy (char *__dest, const char *__src, size_t __n)) +{ + return __builtin___stpncpy_chk (__dest, __src, __n, __bos (__dest)); +} +#else extern char *__stpncpy_chk (char *__dest, const char *__src, size_t __n, size_t __destlen) __THROW __attr_access ((__write_only__, 1, 3)) __attr_access ((__read_only__, 2)); @@ -106,6 +112,7 @@ __NTH (stpncpy (char *__dest, const char *__src, size_t __n)) return __stpncpy_chk (__dest, __src, __n, __bos (__dest)); return __stpncpy_alias (__dest, __src, __n); } +#endif __fortify_function char * -- cgit v1.2.1