The MSVC 9 compiler does not define __STDC__. And we cannot define __STDC__, because then many declarations will be hidden in the system header files. So the workaround is either to test for _MSC_VER explicitly (this is what the GNU standards recommend [1]), or to assume an ANSI C compiler outright.
[1] http://www.gnu.org/prep/standards/html_node/Standard-C.html 2011-09-10 Bruno Haible <br...@clisp.org> iconv, unsetenv: Add support for MSVC compiler. * m4/iconv.m4 (AM_ICONV): Use ISO C declaration syntax on MSVC. * m4/setenv.m4 (gl_FUNC_UNSETENV): Drop support for K&R C compilers. --- m4/iconv.m4.orig Sat Sep 10 22:15:51 2011 +++ m4/iconv.m4 Sat Sep 10 16:07:21 2011 @@ -1,4 +1,4 @@ -# iconv.m4 serial 17 (gettext-0.18.2) +# iconv.m4 serial 18 (gettext-0.18.2) dnl Copyright (C) 2000-2002, 2007-2011 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -242,7 +242,7 @@ #ifdef __cplusplus "C" #endif -#if defined(__STDC__) || defined(__cplusplus) +#if defined(__STDC__) || defined(_MSC_VER) || defined(__cplusplus) size_t iconv (iconv_t cd, char * *inbuf, size_t *inbytesleft, char * *outbuf, size_t *outbytesleft); #else size_t iconv(); --- m4/setenv.m4.orig Sat Sep 10 22:15:51 2011 +++ m4/setenv.m4 Sat Sep 10 16:06:45 2011 @@ -1,4 +1,4 @@ -# setenv.m4 serial 24 +# setenv.m4 serial 25 dnl Copyright (C) 2001-2004, 2006-2011 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -77,11 +77,7 @@ #ifdef __cplusplus "C" #endif -#if defined(__STDC__) || defined(__cplusplus) int unsetenv (const char *name); -#else -int unsetenv(); -#endif ]], [[]])], [gt_cv_func_unsetenv_ret='int'], -- In memoriam Sergei Tretyakov <http://en.wikipedia.org/wiki/Sergei_Tretyakov>
