Introduce PID_ERROR as an invalid exec return value.

[pintos-anon] / src / lib / user / syscall.h

diff --git a/src/lib/user/syscall.h b/src/lib/user/syscall.h
index d0a22500dd8f36f7090ca57ee23173ff85ecfff4..188576d35edbe205507fa2d61e6dc4644014be87 100644 (file)
--- a/src/lib/user/syscall.h
+++ b/src/lib/user/syscall.h
@@ -5,6 +5,7 @@
 #include <debug.h>
 
 typedef int pid_t;
+#define PID_ERROR ((pid_t) -1)
 
 void halt (void) NO_RETURN;
 void exit (int status) NO_RETURN;