[PATCH] Fix compilation on OS X.

On OS X libc headers don't define `environ', and since ec535cc2 removed
the redundant declaration this code no longer builds on OS X.
---
 compat/unsetenv.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/compat/unsetenv.c b/compat/unsetenv.c
index 4ea1856..addf3dc 100644
--- a/compat/unsetenv.c
+++ b/compat/unsetenv.c

@@ -1,5 +1,10 @@
 #include "../git-compat-util.h"
 
+#ifdef __APPLE__
+// On OS X libc headers don't define this symbol.
+extern char **environ;
+#endif
+
 void gitunsetenv (const char *name)
 {
      int src, dst;

-- 
1.8.2.1.539.g4196a96

Benoit Sigoure wrote:

Shouldn't this go into git-compat-util.h, since there may be other
files depending on this variable?

On Sat, Jul 20, 2013 at 12:55 AM, Ramkumar Ramachandra
[off-list ref] wrote:

Benoit Sigoure wrote:

quoted

diff --git a/compat/unsetenv.c b/compat/unsetenv.c
index 4ea1856..addf3dc 100644
--- a/compat/unsetenv.c
+++ b/compat/unsetenv.c

@@ -1,5 +1,10 @@
 #include "../git-compat-util.h"

+#ifdef __APPLE__
+// On OS X libc headers don't define this symbol.
+extern char **environ;
+#endif
+

Shouldn't this go into git-compat-util.h, since there may be other
files depending on this variable?

I thought about that but there are no other files that use `environ'
so I opted for putting it here instead.

-- 
Benoit "tsuna" Sigoure

On 2013-07-20 09.49, Benoit Sigoure wrote:

+#ifdef __APPLE__
+// On OS X libc headers don't define this symbol.
+extern char **environ;
+#endif
+

A more generic approach could be:

In the file "config.mak.uname": Define a variable in the Darwin section like this
NO_EXT_ENVIRON = UnfortunatelyYes

In "Makefile", pick it up, and convert it into a compiler option:
ifdef NO_EXT_ENVIRON
	BASIC_CFLAGS += -DNO_EXT_ENVIRON
endif

And in "git-compat-util.h", add these lines "at a good place":
#ifdef NO_EXT_ENVIRON
extern char **environ;
#endif

This will allow other OS to use the NO_EXT_ENVIRON when needed,.

Thanks for working on this.
/Torsten

On OS X libc headers don't define `environ', and since ec535cc2 removed
the redundant declaration this code no longer builds on OS X.
---
 Makefile          | 5 +++++
 config.mak.uname  | 1 +
 git-compat-util.h | 4 ++++
 3 files changed, 10 insertions(+)

diff --git a/Makefile b/Makefile
index 0600eb4..774db18 100644
--- a/Makefile
+++ b/Makefile

@@ -98,6 +98,8 @@ all::
 #
 # Define NO_UNSETENV if you don't have unsetenv in the C library.
 #
+# Define NO_EXT_ENVIRON if your C library doesn't define `environ'.
+#
 # Define NO_MKDTEMP if you don't have mkdtemp in the C library.
 #
 # Define MKDIR_WO_TRAILING_SLASH if your mkdir() can't deal with trailing slash.

@@ -1307,6 +1309,9 @@ ifdef NO_UNSETENV
 	COMPAT_CFLAGS += -DNO_UNSETENV
 	COMPAT_OBJS += compat/unsetenv.o
 endif
+ifdef NO_EXT_ENVIRON
+	COMPAT_CFLAGS += -DNO_EXT_ENVIRON
+endif
 ifdef NO_SYS_SELECT_H
 	BASIC_CFLAGS += -DNO_SYS_SELECT_H
 endif

diff --git a/config.mak.uname b/config.mak.uname
index 7ac541e..ebcfbfd 100644
--- a/config.mak.uname
+++ b/config.mak.uname

@@ -93,6 +93,7 @@ ifeq ($(uname_S),Darwin)
 		NO_STRLCPY = YesPlease
 	endif
 	NO_MEMMEM = YesPlease
+        NO_EXT_ENVIRON = UnfortunatelyYes
 	USE_ST_TIMESPEC = YesPlease
 	HAVE_DEV_TTY = YesPlease
 	NEEDS_CLIPPED_WRITE = YesPlease

diff --git a/git-compat-util.h b/git-compat-util.h
index ff193f4..3bac4e9 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h

@@ -408,6 +408,10 @@ extern ssize_t git_pread(int fd, void *buf, size_t count, off_t offset);
  */
 extern ssize_t read_in_full(int fd, void *buf, size_t count);
 
+#ifdef NO_EXT_ENVIRON
+extern char **environ;
+#endif
+
 #ifdef NO_SETENV
 #define setenv gitsetenv
 extern int gitsetenv(const char *, const char *, int);

-- 
1.8.2.1.539.g4196a96