Christopher Faylor wrote:
On Wed, Oct 05, 2011 at 11:17:58PM +0200, Christian Franke wrote:
Christopher Faylor wrote:
On Wed, Oct 05, 2011 at 12:57:44PM +0200, Christian Franke wrote:
...
diff --git a/winsup/cygwin/include/cygwin/wait.h
b/winsup/cygwin/include/cygwin/wait.h
index bed81b7..e4edba2 100644
--- a/winsup/cygwin/include/cygwin/wait.h
+++ b/winsup/cygwin/include/cygwin/wait.h
@@ -1,6 +1,6 @@
/* cygwin/wait.h
- Copyright 2006, 2009 Red Hat, Inc.
+ Copyright 2006, 2009, 2011 Red Hat, Inc.
This file is part of Cygwin.
@@ -16,6 +16,9 @@ details. */
#define WCONTINUED 8
#define __W_CONTINUED 0xffff
+/* Will be redefined in sys/wait.h. */
+#define __wait_status_to_int(w) (w)
+
Why is this necessary? It doesn't look like it is ever expanded in
cygwin/wait.h.
This would be needed if cygwin/wait.h is included separately without
sys/wait.h
(e.g. stdlib.h -> cygwin/stdlib.h -> cygwin/wait.h)
and some W*() macro is actually used.
If a redefinition is necessary why not put it all in one place?
The W*() macros and union wait are closely related. So a probably better
approach would be to move union wait to cygwin/wait.h and define
__wait_status_to_int() only there.
But then C++ compile may fail because cygwin/wait.h is sometimes
included indirectly inside an extern "C" block:
w32api/shlobj.h -> extern "C" { w32api/ole2.h ...-> stdlib.h ...->
cygwin/wait.h }
Ok. I see that Linux's use of similar macros is convoluted too.
I really would rather keep this all together but I guess it isn't
possible without redesigning stdlib.h and */wait.h.
Linux uses the following approach for the C++ case:
typedef void *__wait_status_ptr_t;
#define __wait_status_to_int(w) (*(int*)&(w))
This prevents the C++ inline function problem but is not typesafe at all.
Meantime I found out that the inline functions can be used even if a
file is included in an extern "C" block. It is possible to nest another
extern "C++" block:
// w32api/shlobj.h:
extern "C" {
#include ...
...
// cygwin/wait.h:
...
#ifdef __cplusplus
extern "C++" {
inline int __wait_status_to_int(int __status) { .... }
inline int __wait_status_to_int(const union wait &__status) { .... }
}
#endif
}
So it would be possible to move union wait and related functions to
cygwin/wait.h. Possible new problem: This pollutes the stdlib.h
namespace with 'union wait' and '#define w_termsig' etc..
Also since Cygwin is C++ why do you need the __INSIDE_CYGWIN__ here?
There are still ten *.c files in winsup/cygwin :-)
% cd winsup/cygwin
% grep wait.h **/*.c
%
OK, __INSIDE_CYGWIN__ is not needed here in practice (but possibly in
theory :-)
Would the patch with __INSIDE_CYGWIN__ removed be GTG?
Christian
