commit bc66878bdea0250991fc99b2d023146f67a6f4bb
Author: Sebastian Hahn <sebastian(a)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'. */