From ca20a05be41491f67bd5c40517bed08f5a7328ba Mon Sep 17 00:00:00 2001
From: Brian Norris <banorris@uci.edu>
Date: Tue, 13 Mar 2012 11:37:45 -0700
Subject: [PATCH] stricter typing of function pointers for makecontext()

We need to use functions with no arguments (i.e., 'void (*)()') in order to
retain strict type-checking with makecontext(). Of course, we still circumvent
this type checking with casting, but we should straighten this out sometime...
---
 libthreads.c | 2 +-
 libthreads.h | 4 ++--
 userprog.c   | 4 ++--
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/libthreads.c b/libthreads.c
index 1b7f3db..ca31067 100644
--- a/libthreads.c
+++ b/libthreads.c
@@ -100,7 +100,7 @@ static void thread_wait_finish(void)
 /*
  * User program API functions
  */
-int thread_create(struct thread *t, void (*start_routine), void *arg)
+int thread_create(struct thread *t, void (*start_routine)(), void *arg)
 {
 	int ret = 0;
 
diff --git a/libthreads.h b/libthreads.h
index 0848833..aa7faf4 100644
--- a/libthreads.h
+++ b/libthreads.h
@@ -11,7 +11,7 @@ typedef enum thread_state {
 } thread_state;
 
 struct thread {
-	void (*start_routine);
+	void (*start_routine)();
 	void *arg;
 	ucontext_t context;
 	void *stack;
@@ -19,7 +19,7 @@ struct thread {
 	thread_state state;
 };
 
-int thread_create(struct thread *t, void (*start_routine), void *arg);
+int thread_create(struct thread *t, void (*start_routine)(), void *arg);
 void thread_join(struct thread *t);
 int thread_yield(void);
 struct thread *thread_current(void);
diff --git a/userprog.c b/userprog.c
index c27c701..1837fc9 100644
--- a/userprog.c
+++ b/userprog.c
@@ -20,8 +20,8 @@ void user_main()
 	atomic_int obj;
 
 	printf("%s() creating 2 threads\n", __func__);
-	thread_create(&t1, &a, &obj);
-	thread_create(&t2, &a, &obj);
+	thread_create(&t1, (void (*)())&a, &obj);
+	thread_create(&t2, (void (*)())&a, &obj);
 
 	thread_join(&t1);
 	thread_join(&t2);
-- 
2.34.1