[PATCH] Darwin, libgfortran : Do not use environ directly from the library.

[Iain Sandoe <iain@sandoe.co.uk>]

Hi,

not sure if this is covered directly by my Darwin maintainer’s hat so …

-----

On macOS / Darwin, the environ variable can be used directly in the
code of an executable, but cannot be used in the code of a shared
library (i.e. libgfortran.dylib)**

In such cases, the  function _NSGetEnviron should be called to get
the address of 'environ’.

tested on a number of Darwin platforms old and new, and on
x86_64/powerpc64-linux,

OK for master?
… and backports to open branches?
thanks
Iain

** we’ve been “getting away with it” because of the application of
dynamic_lookup in a rather broad manner, which I’m about to get rid
of.

—————

libgfortran/ChangeLog:

	* intrinsics/execute_command_line.c (environ): Use
	_NSGetEnviron to get the environment pointer on Darwin.



---
  libgfortran/intrinsics/execute_command_line.c | 5 +++++
  1 file changed, 5 insertions(+)

diff --git a/libgfortran/intrinsics/execute_command_line.c  
b/libgfortran/intrinsics/execute_command_line.c
index 71d61a766ad..6d7b8fc658e 100644
--- a/libgfortran/intrinsics/execute_command_line.c
+++ b/libgfortran/intrinsics/execute_command_line.c
@@ -34,7 +34,12 @@ see the files COPYING3 and COPYING.RUNTIME  
respectively.  If not, see
  #endif
  #ifdef HAVE_POSIX_SPAWN
  #include <spawn.h>
+# ifdef __APPLE__
+#  include <crt_externs.h>
+#  define environ (*_NSGetEnviron ())
+# else
  extern char **environ;
+# endif
  #endif
  #if defined(HAVE_POSIX_SPAWN) || defined(HAVE_FORK)
  #include <signal.h>
-- 
2.24.1