From 3e0814cd9862b89c7a39672672937477bd87ddfb Mon Sep 17 00:00:00 2001 From: Andreas Rottmann Date: Thu, 27 May 2010 18:23:15 +0200 Subject: Imported Upstream version 0.9.3 --- gnulib-m4/strncat.m4 | 106 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 106 insertions(+) create mode 100644 gnulib-m4/strncat.m4 (limited to 'gnulib-m4/strncat.m4') diff --git a/gnulib-m4/strncat.m4 b/gnulib-m4/strncat.m4 new file mode 100644 index 0000000..e4ff70e --- /dev/null +++ b/gnulib-m4/strncat.m4 @@ -0,0 +1,106 @@ +# strncat.m4 serial 1 +dnl Copyright (C) 2002-2004, 2009-2010 Free Software Foundation, Inc. +dnl This file is free software; the Free Software Foundation +dnl gives unlimited permission to copy and/or distribute it, +dnl with or without modifications, as long as this notice is preserved. + +AC_DEFUN_ONCE([gl_FUNC_STRNCAT], +[ + AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS]) + AC_REQUIRE([AC_PROG_CC]) + AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles + + dnl Check for prerequisites for memory fence checks. + gl_FUNC_MMAP_ANON + AC_CHECK_HEADERS_ONCE([sys/mman.h]) + AC_CHECK_FUNCS_ONCE([mprotect]) + + dnl Detect bug in Solaris 8..10 on SPARC: + dnl strncat should not dereference more than n bytes, but always dereferences + dnl n+1 bytes if the first n bytes don't contain a NUL byte. + dnl Assume that strncat works on platforms that lack mprotect. + AC_CACHE_CHECK([whether strncat works], [gl_cv_func_strncat_works], + [AC_RUN_IFELSE([AC_LANG_PROGRAM([[ +#include +#if HAVE_SYS_MMAN_H +# include +# include +# include +# include +# ifndef MAP_FILE +# define MAP_FILE 0 +# endif +#endif +]], [[ + char *fence = NULL; +#if HAVE_SYS_MMAN_H && HAVE_MPROTECT +# if HAVE_MAP_ANONYMOUS + const int flags = MAP_ANONYMOUS | MAP_PRIVATE; + const int fd = -1; +# else /* !HAVE_MAP_ANONYMOUS */ + const int flags = MAP_FILE | MAP_PRIVATE; + int fd = open ("/dev/zero", O_RDONLY, 0666); + if (fd >= 0) +# endif + { + int pagesize = getpagesize (); + char *two_pages = + (char *) mmap (NULL, 2 * pagesize, PROT_READ | PROT_WRITE, + flags, fd, 0); + if (two_pages != (char *)(-1) + && mprotect (two_pages + pagesize, pagesize, PROT_NONE) == 0) + fence = two_pages + pagesize; + } +#endif + if (fence) + { + char dest[8]; + + dest[0] = '*'; + dest[1] = 'a'; + dest[2] = '\0'; + dest[3] = 'w'; + dest[4] = 'x'; + dest[5] = 'y'; + dest[6] = 'z'; + + *(fence - 3) = '7'; + *(fence - 2) = '2'; + *(fence - 1) = '9'; + + if (strncat (dest + 1, fence - 3, 3) != dest + 1) + return 1; + if (dest[0] != '*') + return 2; + if (dest[1] != 'a' + || dest[2] != '7' || dest[3] != '2' || dest[4] != '9' + || dest[5] != '\0') + return 3; + if (dest[6] != 'z') + return 4; + } + return 0; +]])], [gl_cv_func_strncat_works=yes], [gl_cv_func_strncat_works=no], + [ + case "$host_os" in + # Guess no on Solaris. + solaris*) gl_cv_func_strncat_works="guessing no";; + # Guess yes otherwise. + *) gl_cv_func_strncat_works="guessing yes";; + esac + ]) + ]) + case "$gl_cv_func_strncat_works" in + *yes) ;; + *) + REPLACE_STRNCAT=1 + AC_LIBOBJ([strncat]) + gl_PREREQ_STRNCAT + ;; + esac +]) + +# Prerequisites of lib/strncat.c. +AC_DEFUN([gl_PREREQ_STRNCAT], [ + : +]) -- cgit v1.2.3