A user die function.

aab8fae3 · Silas Boyd-Wickizer · ca52df2f · aab8fae3 · aab8fae3
--- a/printf.c
+++ b/printf.c
@@ -35,7 +35,7 @@ printint(void (*putch) (void*, char), void *putarg,
 // Only understands %d, %x, %p, %s.
 void
 vprintfmt(void (*putch) (void*, char), void *putarg,
-          char *fmt, va_list ap)
+          const char *fmt, va_list ap)
 {
  char *s;
  int c, i, state;
@@ -143,3 +143,15 @@ snprintf(char *buf, u32 n, char *fmt, ...)
  vsnprintf(buf, n, fmt, ap);
  va_end(ap);
 }
+
+void __attribute__((noreturn))
+die(const char* errstr, ...)
+{
+  va_list ap;
+
+  va_start(ap, errstr);
+  vprintfmt(writec, (void*) (u64)1, errstr, ap);
+  va_end(ap);
+  printf(1, "\n");
+  exit();
+}
--- a/user.h
+++ b/user.h
@@ -32,8 +32,6 @@ char* strcpy(char*, char*);
 void *memmove(void*, void*, int);
 char* strchr(const char*, char c);
 int strcmp(const char*, const char*);
-void printf(int, char*, ...);
-void snprintf(char *buf, unsigned int n, char *fmt, ...);
 char* gets(char*, int max);
 unsigned int strlen(char*);
 void* memset(void*, int, unsigned int);
@@ -43,3 +41,8 @@ int atoi(const char*);

 // uthread.S
 int forkt(void *sp, void *pc, void *arg);
+
+// printf.c
+void printf(int, char*, ...);
+void snprintf(char *buf, unsigned int n, char *fmt, ...);
+void die(const char* errstr, ...) __attribute__((noreturn));