Tighten scope of non-POSIX visibility macros

The __BSD_VISIBLE and _DARWIN_C_SOURCE macros expose non-POSIX prototypes in
system header files.  We should scope these to just the ".c" modules that
actually need them, and avoid defining them in header files used in other C
modules.

2 files changed, 34 insertions, 4 deletions

diff --git a/rts/posix/Itimer.c b/rts/posix/Itimer.c
index 80925df703..98b23f623e 100644
--- a/rts/posix/Itimer.c
+++ b/rts/posix/Itimer.c
@@ -18,6 +18,27 @@
  */
 
 #include "PosixSource.h"
+
+/* We've defined _POSIX_SOURCE via "PosixSource.h", and yet still use
+   some non-POSIX features.  With _POSIX_SOURCE defined, visibility of
+   non-POSIX extension prototypes requires _DARWIN_C_SOURCE on Mac OS X and
+   __BSD_VISIBLE on FreeBSD and DragonflyBSD.  Otherwise, for example, code
+   using pthread_setname_np(3) and variants will not compile.  We must
+   therefore define the additional macros that expose non-POSIX APIs early,
+   before any of the relevant system headers are included via "Rts.h".
+
+   An alternative approach could be to write portable wrappers or stubs for all
+   the non-posix functions in a C-module that does not include "PosixSource.h",
+   and then use only POSIX features and the portable wrapper functions in all
+   other C-modules. */
+#include "ghcconfig.h"
+#if defined(freebsd_HOST_OS) || defined(dragonfly_HOST_OS)
+#define __BSD_VISIBLE   1
+#endif
+#if defined(darwin_HOST_OS)
+#define _DARWIN_C_SOURCE 1
+#endif
+
 #include "Rts.h"
 
 /*
diff --git a/rts/posix/OSThreads.c b/rts/posix/OSThreads.c
index b815894a9f..e039b43573 100644
--- a/rts/posix/OSThreads.c
+++ b/rts/posix/OSThreads.c
@@ -9,14 +9,23 @@
 
 #include "PosixSource.h"
 
+/* We've defined _POSIX_SOURCE via "PosixSource.h", and yet still use
+   some non-POSIX features.  With _POSIX_SOURCE defined, visibility of
+   non-POSIX extension prototypes requires _DARWIN_C_SOURCE on Mac OS X and
+   __BSD_VISIBLE on FreeBSD and DragonflyBSD.  Otherwise, for example, code
+   using pthread_setname_np(3) and variants will not compile.  We must
+   therefore define the additional macros that expose non-POSIX APIs early,
+   before any of the relevant system headers are included via "Rts.h".
+
+   An alternative approach could be to write portable wrappers or stubs for all
+   the non-posix functions in a C-module that does not include "PosixSource.h",
+   and then use only POSIX features and the portable wrapper functions in all
+   other C-modules. */
+#include "ghcconfig.h"
 #if defined(freebsd_HOST_OS) || defined(dragonfly_HOST_OS)
-/* Inclusion of system headers usually requires __BSD_VISIBLE on FreeBSD and
- * DragonflyBSD, because of some specific types, like u_char, u_int, etc. */
 #define __BSD_VISIBLE   1
 #endif
 #if defined(darwin_HOST_OS)
-/* Inclusion of system headers usually requires _DARWIN_C_SOURCE on Mac OS X
- * because of some specific types like u_char, u_int, etc. */
 #define _DARWIN_C_SOURCE 1
 #endif