defines for building on Hurd and BSD kernels

src/OpenThreads/pthreads/PThread.cpp

@@ -43,8 +43,10 @@
 #endif
 #if defined (__FreeBSD__) || defined (__APPLE__) || defined (__MACH__)
     #include <sys/types.h>
+#if !defined (__GNU__)
     #include <sys/sysctl.h>
 #endif
+#endif
 
 #if defined(__ANDROID__)
     #ifndef PAGE_SIZE
@@ -1012,7 +1014,7 @@ int Thread::microSleep(unsigned int microsec)
 //
 int OpenThreads::GetNumberOfProcessors()
 {
-#if defined(__linux__)
+#if defined(__linux__) || defined(__GNU__)
    long ret = sysconf(_SC_NPROCESSORS_ONLN);
    if (ret == -1)
       return 0;

src/osgDB/FileNameUtils.cpp

@@ -30,6 +30,10 @@
     using std::tolower;
 #endif
 
+#if defined(__GNU__) && !defined(PATH_MAX)
+#define PATH_MAX 4096
+#endif
+
 using namespace std;
 
 static const char * const PATH_SEPARATORS = "/\\";