no GetSignalBacktraceContext or CrashSignalHandler on DARWIN

stepmania/src/archutils/Unix/Backtrace.h

@@ -34,8 +34,10 @@ void GetCurrentBacktraceContext( BacktraceContext *ctx );
 
 /* Set up a BacktraceContext to get a backtrace after receiving a signal, given
  * a ucontext_t (see sigaction(2)).  (This interface is UNIX-specific.) */
+#if !defined(DARWIN)
 #include <ucontext.h>
 void GetSignalBacktraceContext( BacktraceContext *ctx, const ucontext_t *uc );
+#endif
 
 #if defined(DARWIN)
 #include <MachineExceptions.h>

stepmania/src/archutils/Unix/CrashHandler.cpp

@@ -337,6 +337,7 @@ void ForceCrashHandler( const char *reason )
 	RunCrashHandler( &crash );
 }
 
+#if !defined(DARWIN)
 void CrashSignalHandler( int signal, siginfo_t *si, const ucontext_t *uc )
 {
 	CrashData crash;
@@ -347,6 +348,7 @@ void CrashSignalHandler( int signal, siginfo_t *si, const ucontext_t *uc )
 	GetSignalBacktraceContext( &crash.ctx, uc );
 	RunCrashHandler( &crash );
 }
+#endif
 
 #if defined(DARWIN)
 OSStatus CrashExceptionHandler( ExceptionInformation *e )

stepmania/src/archutils/Unix/CrashHandler.h

@@ -1,14 +1,16 @@
 #ifndef CRASH_HANDLER_H
 #define CRASH_HANDLER_H
 
-#include <signal.h>
-#include <ucontext.h>
-
 void ForceCrashHandler( const char *reason );
-void CrashSignalHandler( int signal, siginfo_t *si, const ucontext_t *uc );
 void CrashHandlerHandleArgs( int argc, char* argv[] );
 void InitializeCrashHandler();
 	
+#if !defined(DARWIN)
+#include <signal.h>
+#include <ucontext.h>
+void CrashSignalHandler( int signal, siginfo_t *si, const ucontext_t *uc );
+#endif
+
 #if defined(DARWIN)
 #include <MachineExceptions.h>
 OSStatus CrashExceptionHandler( ExceptionInformation *e );