Make backtraces slightly more reliable.

[pintos-anon] / src / lib / debug.c

diff --git a/src/lib/debug.c b/src/lib/debug.c
index 9fbf20656c66833b2dee6948c5ce167f6cb297aa..1dc1bf8fd69db3c5651654620dcf79200cbf6844 100644 (file)
--- a/src/lib/debug.c
+++ b/src/lib/debug.c
@@ -1,102 +1,32 @@
-#include "debug.h"
+#include <debug.h>
 #include <stdarg.h>
-#include "interrupt.h"
-#include "lib.h"
-
-#define MAX_CLASSES 16
-static bool all_enabled;
-static const char *enabled_classes[MAX_CLASSES];
-static size_t enabled_cnt;
-
-/* Enables the debug message classes specified in CLASSES.  The
-   string CLASSES is modified by and becomes owned by this
-   function. */
-void
-debug_enable (char *classes) 
-{
-  char *class, *save;
-
-  for (class = strtok_r (classes, ",", &save); class != NULL;
-       class = strtok_r (NULL, ",", &save))
-    {
-      if (strcmp (class, "all") && enabled_cnt < MAX_CLASSES)
-        enabled_classes[enabled_cnt++] = class;
-      else
-        all_enabled = true;
-    }
-}
-
-/* Checks whether CLASS is enabled. */
-static bool
-class_is_enabled (const char *class) 
-{
-  size_t i;
-  
-  if (all_enabled)
-    return true;
-
-  for (i = 0; i < enabled_cnt; i++)
-    if (!strcmp (enabled_classes[i], class))
-      return true;
-
-  return false;
-}
-
-/* Prints a debug message along with the source file name, line
-   number, and function name of where it was emitted.  CLASS is
-   used to filter out unwanted messages. */
-void
-debug_message (const char *file, int line, const char *function,
-               const char *class, const char *message, ...) 
-{
-  if (class_is_enabled (class)) 
-    {
-      va_list args;
-
-      enum intr_level old_level = intr_disable ();
-      printk ("%s:%d: %s(): ", file, line, function);
-      va_start (args, message);
-      vprintk (message, args);
-      printk ("\n");
-      va_end (args);
-      intr_set_level (old_level);
-    }
-}
-
-/* Halts the OS, printing the source file name, line number, and
-   function name, plus a user-specific message. */
-void
-debug_panic (const char *file, int line, const char *function,
-             const char *message, ...)
-{
-  va_list args;
-
-  intr_disable ();
-
-  printk ("PANIC at %s:%d in %s(): ", file, line, function);
-  va_start (args, message);
-  vprintk (message, args);
-  printk ("\n");
-  va_end (args);
-
-  debug_backtrace ();
-
-  for (;;);
-}
-
-/* Prints the call stack, that is, a list of addresses in each of
-   the functions we are nested within.  gdb or addr2line may be
-   applied to kernel.o to translate these into file names, line
-   numbers, and function names.  */
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+
+/* Prints the call stack, that is, a list of addresses, one in
+   each of the functions we are nested within.  gdb or addr2line
+   may be applied to kernel.o to translate these into file names,
+   line numbers, and function names.  */
 void
 debug_backtrace (void) 
 {
+  static bool explained;
   void **frame;
   
-  printk ("Call stack:");
+  printf ("Call stack:");
   for (frame = __builtin_frame_address (0);
-       frame != NULL && frame[0] != NULL;
+       (uintptr_t) frame >= 0x1000 && frame[0] != NULL;
        frame = frame[0]) 
-    printk (" %p", frame[1]);
-  printk (".\n");
+    printf (" %p", frame[1]);
+  printf (".\n");
+
+  if (!explained) 
+    {
+      explained = true;
+      printf ("The `backtrace' program can make call stacks useful.\n"
+              "Read \"Backtraces\" in the \"Debugging Tools\" chapter\n"
+              "of the Pintos documentation for more information.\n");
+    }
 }