3 files changed, 23 insertions, 7 deletions
diff --git a/compiler.h b/compiler.h
index de7c0e4f..e9022f86 100644
--- a/compiler.h
+++ b/compiler.h
@@ -188,4 +188,13 @@ char *strsep(char **, const char *);
 # define no_return void
 #endif
 
+/*
+ * How to tell the compiler that a function takes a printf-like string
+ */
+#ifdef __GNUC__
+# define printf_func(fmt, list) __attribute__((format(printf, fmt, list)))
+#else
+# define printf_func(fmt, list)
+#endif
+
 #endif	/* NASM_COMPILER_H */
diff --git a/nasmlib.c b/nasmlib.c
index ecd6d8df..3c26546a 100644
--- a/nasmlib.c
+++ b/nasmlib.c
@@ -1,6 +1,6 @@
 /* ----------------------------------------------------------------------- *
  *   
- *   Copyright 1996-2014 The NASM Authors - All Rights Reserved
+ *   Copyright 1996-2016 The NASM Authors - All Rights Reserved
  *   See the file AUTHORS included with the NASM distribution for
  *   the specific copyright holders.
  *
@@ -83,6 +83,15 @@ void nasm_error(int severity, const char *fmt, ...)
     va_end(ap);
 }
 
+no_return nasm_panic(int flags, const char *fmt, ...)
+{
+    va_list ap;
+
+    va_start(ap, fmt);
+    nasm_verror(flags | ERR_PANIC, fmt, ap);
+    abort();			/* We should never get here */
+}
+
 void *nasm_malloc(size_t size)
 {
     void *p = malloc(size);
diff --git a/nasmlib.h b/nasmlib.h
index 9cd417f1..52eadd87 100644
--- a/nasmlib.h
+++ b/nasmlib.h
@@ -1,6 +1,6 @@
 /* ----------------------------------------------------------------------- *
  *
- *   Copyright 1996-2009 The NASM Authors - All Rights Reserved
+ *   Copyright 1996-2016 The NASM Authors - All Rights Reserved
  *   See the file AUTHORS included with the NASM distribution for
  *   the specific copyright holders.
  *
@@ -75,12 +75,10 @@ extern unsigned char nasm_tolower_tab[256];
  */
 typedef void (*efunc) (int severity, const char *fmt, ...);
 typedef void (*vefunc) (int severity, const char *fmt, va_list ap);
-#ifdef __GNUC__
-void nasm_error(int severity, const char *fmt, ...) __attribute__((format(printf, 2, 3)));
-#else
-void nasm_error(int severity, const char *fmt, ...);
-#endif
+void printf_func(2, 3) nasm_error(int severity, const char *fmt, ...);
 void nasm_set_verror(vefunc);
+no_return printf_func(2, 3) nasm_panic(int flags, const char *fmt, ...);
+#define panic() nasm_panic(ERR_NOFILE, "Internal error at %s:%d\n", __FILE__, __LINE__);
 
 /*
  * These are the error severity codes which get passed as the first