commit bc66878bdea0250991fc99b2d023146f67a6f4bb Author: Sebastian Hahn <sebastian@torproject.org> Date: Sun Feb 19 16:09:08 2012 +0100 Don't redeclare environ if std headers already did This would cause a redundant redeclaration warning on some versions of Linux otherwise. --- configure.in | 16 ++++++++++++++++ src/common/compat.c | 10 ++++++++-- 2 files changed, 24 insertions(+), 2 deletions(-) diff --git a/configure.in b/configure.in index 7b6d8fb..7415ce8 100644 --- a/configure.in +++ b/configure.in @@ -1086,6 +1086,17 @@ int main(int c, char **v) { puts(__FUNCTION__); }])], tor_cv_have_FUNCTION_macro=yes, tor_cv_have_FUNCTION_macro=no)) +AC_CACHE_CHECK([whether we have extern char **environ already declared], + tor_cv_have_environ_declared, + AC_COMPILE_IFELSE([AC_LANG_SOURCE([ +/* We define _GNU_SOURCE here because it is also defined in compat.c. + * Without it environ doesn't get declared. */ +#define _GNU_SOURCE +#include <unistd.h> +int main(int c, char **v) { char **t = environ; }])], + tor_cv_have_environ_declared=yes, + tor_cv_have_environ_declared=no)) + if test "$tor_cv_have_func_macro" = 'yes'; then AC_DEFINE(HAVE_MACRO__func__, 1, [Defined if the compiler supports __func__]) fi @@ -1099,6 +1110,11 @@ if test "$tor_cv_have_FUNCTION_macro" = 'yes'; then [Defined if the compiler supports __FUNCTION__]) fi +if test "$tor_cv_have_environ_declared" = 'yes'; then + AC_DEFINE(HAVE_EXTERN_ENVIRON_DECLARED__, 1, + [Defined if we have extern char **environ already declared]) +fi + # $prefix stores the value of the --prefix command line option, or # NONE if the option wasn't set. In the case that it wasn't set, make # it be the default, so that we can use it to expand directories now. diff --git a/src/common/compat.c b/src/common/compat.c index f25a8ac..30bde3d 100644 --- a/src/common/compat.c +++ b/src/common/compat.c @@ -16,7 +16,11 @@ * We also need it to make memmem get defined (where available) */ /* XXXX023 We should just use AC_USE_SYSTEM_EXTENSIONS in our autoconf, - * and get this (and other important stuff!) automatically */ + * and get this (and other important stuff!) automatically. Once we do that, + * make sure to also change the extern char **environ detection in + * configure.in, because whether that is declared or not depends on whether + * we have _GNU_SOURCE defined! Maybe that means that once we take this out, + * we can also take out the configure check. */ #define _GNU_SOURCE #include "compat.h" @@ -1663,9 +1667,11 @@ make_path_absolute(char *fname) } #ifndef HAVE__NSGETENVIRON -/* FreeBSD needs this; it doesn't seem to hurt other platforms. */ +#ifndef HAVE_EXTERN_ENVIRON_DECLARED__ +/* Some platforms declare environ under some circumstances, others don't. */ extern char **environ; #endif +#endif /** Return the current environment. This is a portable replacement for * 'environ'. */