diff options
Diffstat (limited to 'm4/ax_func_snprintf.m4')
-rw-r--r-- | m4/ax_func_snprintf.m4 | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/m4/ax_func_snprintf.m4 b/m4/ax_func_snprintf.m4 new file mode 100644 index 0000000..c060d6e --- /dev/null +++ b/m4/ax_func_snprintf.m4 @@ -0,0 +1,84 @@ +# =========================================================================== +# http://www.gnu.org/software/autoconf-archive/ax_func_snprintf.html +# =========================================================================== +# +# SYNOPSIS +# +# AX_FUNC_SNPRINTF +# +# DESCRIPTION +# +# Checks for a fully C99 compliant snprintf, in particular checks whether +# it does bounds checking and returns the correct string length; does the +# same check for vsnprintf. If no working snprintf or vsnprintf is found, +# request a replacement and warn the user about it. Note: the mentioned +# replacement is freely available and may be used in any project +# regardless of it's license. +# +# LICENSE +# +# Copyright (c) 2008 Ruediger Kuhlmann <info@ruediger-kuhlmann.de> +# +# Copying and distribution of this file, with or without modification, are +# permitted in any medium without royalty provided the copyright notice +# and this notice are preserved. This file is offered as-is, without any +# warranty. + +#serial 5 + +AC_DEFUN([AX_FUNC_SNPRINTF], +[AC_CHECK_FUNCS(snprintf vsnprintf) +AC_MSG_CHECKING(for working snprintf) +AC_CACHE_VAL(ac_cv_have_working_snprintf, +[AC_RUN_IFELSE([AC_LANG_SOURCE([[#include <stdio.h> +#include <string.h> + +int main(void) +{ + char bufs[5] = { 'x', 'x', 'x', '\0', '\0' }; + char bufd[5] = { 'x', 'x', 'x', '\0', '\0' }; + int i; + i = snprintf (bufs, 2, "%s", "111"); + if (strcmp (bufs, "1")) return (1); + if (i != 3) return (1); + i = snprintf (bufd, 2, "%d", 111); + if (strcmp (bufd, "1")) return (1); + if (i != 3) return (1); + return(0); +}]])],[ac_cv_have_working_snprintf=yes],[ac_cv_have_working_snprintf=no],[ac_cv_have_working_snprintf=cross])]) +AC_MSG_RESULT([$ac_cv_have_working_snprintf]) +AC_MSG_CHECKING(for working vsnprintf) +AC_CACHE_VAL(ac_cv_have_working_vsnprintf, +[AC_RUN_IFELSE([AC_LANG_SOURCE([[#include <stdio.h> +#include <stdarg.h> +#include <string.h> + +int my_vsnprintf (char *buf, const char *tmpl, ...) +{ + int i; + va_list args; + va_start (args, tmpl); + i = vsnprintf (buf, 2, tmpl, args); + va_end (args); + return i; +} + +int main(void) +{ + char bufs[5] = { 'x', 'x', 'x', '\0', '\0' }; + char bufd[5] = { 'x', 'x', 'x', '\0', '\0' }; + int i; + i = my_vsnprintf (bufs, "%s", "111"); + if (strcmp (bufs, "1")) return (1); + if (i != 3) return (1); + i = my_vsnprintf (bufd, "%d", 111); + if (strcmp (bufd, "1")) return (1); + if (i != 3) return (1); + return(0); +}]])],[ac_cv_have_working_vsnprintf=yes],[ac_cv_have_working_vsnprintf=no],[ac_cv_have_working_vsnprintf=cross])]) +AC_MSG_RESULT([$ac_cv_have_working_vsnprintf]) +if test x$ac_cv_have_working_snprintf$ac_cv_have_working_vsnprintf != "xyesyes"; then + AC_LIBOBJ(snprintf) + AC_MSG_WARN([Replacing missing/broken (v)snprintf() with sudo's version.]) + AC_DEFINE(PREFER_PORTABLE_SNPRINTF, 1, [Enable replacement (v)snprintf if system (v)snprintf is broken.]) +fi]) |