Added errno.h and ptrdiff_t

photon/libc/errno/errno.c

@@ -0,0 +1,9 @@
+
+
+/* XXX This isn't thread safe */
+static int __errno = 0;
+
+int *__errno_location(void)
+{
+    return &__errno;
+}

photon/libc/include/errno.h

@@ -0,0 +1,18 @@
+#ifndef ERRNO_H_
+#define ERRNO_H_
+
+#include <sys/_errno.h>
+
+#define errno (*__errno_location())
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+extern int *__errno_location(void);
+
+#if defined(__cplusplus)
+}
+#endif
+
+#endif

photon/libc/include/stddef.h

@@ -10,13 +10,21 @@
 extern "C" {
 #endif /* defined(__cplusplus) */
 
+#ifndef __ptrdiff_t_defined
+#define __ptrdiff_t_defined
 typedef __intptr_t ptrdiff_t;
+#endif
 
-#ifndef __SIZE_T_DEFINED
-#define __SIZE_T_DEFINED
+#ifndef __size_t_defined
+#define __size_t_defined
 typedef __uintptr_t size_t;
 #endif
 
+#ifndef __ssize_t_defined
+#define __ssize_t_defined
+typedef __intptr_t ssize_t;
+#endif
+
 #if defined(__cplusplus)
 }
 #endif /* defined(__cplusplus) */