On Tue, Oct 05, 2004 at 06:23:46PM +0200, Markus Sch?pflin wrote:
Jonathan Wakely wrote:
On Tue, Oct 05, 2004 at 04:28:46PM +0100, John Maddock wrote:
Markus, I believe what you're seeing is the problem that prompted the GCC developers to unconditionally define _REENTRANT even when -pthread is not given (and which breaks Boost for GCC 3.4), see http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11953
That's what I thought, but http://tinyurl.com/3lyr8 suggests that _REENTRANT *is* defined, even without -pthread (unless this is an artifact of including <iostream>).
<iostream> includes <ostream> which includes <ios> which includes <iosfwd> which includes $platform/bits/c++io.h which includes gthr.h which includes gthr-default.h which defines _REENTRANT to 1.
That's what I also discovered.
Solution: define _REENTRANT before including anything, or include a libstdc++ header (which will define _REENTRANT and include pthread.h)
The native compiler (toolset tru64cxx65) doesn't define _REENTRANT and things seem to work out correctly.
If you use the tru64cxx65 equivalent of -pthread then I bet it _does_ define _REENTRANT. The problem is that GCC was changed so that _REENTRANT is defined whether or not -pthread is used.
GCC's include files OTOH unconditionally define _REENTRANT before including "pthread.h" which forces boost to also include "pthread.h", if I understand things correctly.
Near enough, yeah.
But reentrant is not defined at the point where "pthread.h" is included which leads to the problem described.
Why not though, that's the question. Since <boost/config.h> is included first by shared_ptr.hpp, that should include <string> (or any other libstdc++ header) which should define _REENTRANT and therefore it should be set when we come to pthread.h If you want to, run the test with the GCC flag -save-temps and send me the preprocessed .ii file, and I'll get medieval on it. jon -- "Hell is other people's code." - Me, after a day spent refactoring particularly smelly garbage.