X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Flib%2Fuser%2Fsyscall.h;h=188576d35edbe205507fa2d61e6dc4644014be87;hb=15bd5676b2d0ae5f2e96c33b3b7007dd24105141;hp=d0a22500dd8f36f7090ca57ee23173ff85ecfff4;hpb=75663d9273af881a832699bfab6575ec1507761e;p=pintos-anon

diff --git a/src/lib/user/syscall.h b/src/lib/user/syscall.h
index d0a2250..188576d 100644
--- 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;