* Debugger modules now have two methods: enter_debugger() and exit_debugger().

* The kernel now opens up to 8 debugger modules (and puts them into an array;
  maybe we'll want to switch to a doubly linked list when there is the need).
* Implemented an example debugger module that prints a stack trace of the
  current thread when the kernel debugger is entered (not included in the
  image).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23794 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/debug.h

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2007, Axel Dörfler, [email protected]
+ * Copyright 2002-2008, Axel Dörfler, [email protected]
  * Distributed under the terms of the Haiku License.
  *
  * Copyright 2001-2002, Travis Geiselbrecht. All rights reserved.
@@ -10,6 +10,8 @@
 
 
 #include <KernelExport.h>
+#include <module.h>
+
 
 #define KDEBUG 1
 
@@ -18,7 +20,7 @@
  * The kernel debug level. 
  * Level 1 is usual asserts, > 1 should be used for very expensive runtime checks
  */
-#define KDEBUG 1
+#	define KDEBUG 1
 #endif
 
 #define ASSERT_ALWAYS(x) \
@@ -42,6 +44,13 @@
 
 #define B_KDEBUG_DONT_PARSE_ARGUMENTS	(0x01)
 
+struct debugger_module_info {
+	module_info info;
+
+	void (*enter_debugger)(void);
+	void (*exit_debugger)(void);
+};
+
 extern int dbg_register_file[B_MAX_CPU_COUNT][14];
 
 #ifdef __cplusplus

src/add-ons/kernel/debugger/Jamfile

@@ -1,3 +1,4 @@
 SubDir HAIKU_TOP src add-ons kernel debugger ;
 
+SubInclude HAIKU_TOP src add-ons kernel debugger auto_stack_trace ;
 SubInclude HAIKU_TOP src add-ons kernel debugger hangman ;

src/add-ons/kernel/debugger/auto_stack_trace/Jamfile

@@ -0,0 +1,7 @@
+SubDir HAIKU_TOP src add-ons kernel debugger auto_stack_trace ;
+
+UsePrivateHeaders kernel ;
+
+KernelAddon <kdebug>auto_stack_trace :
+	auto_stack_trace.cpp
+	;

src/add-ons/kernel/debugger/auto_stack_trace/auto_stack_trace.cpp

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2008, Axel Dörfler, [email protected]
+ * Distributed under the terms of the MIT License.
+ */
+
+
+#include <debug.h>
+
+
+static void
+enter_debugger(void)
+{
+	evaluate_debug_command("sc");
+}
+
+
+static status_t
+std_ops(int32 op, ...)
+{
+	if (op == B_MODULE_INIT || op == B_MODULE_UNINIT)
+		return B_OK;
+
+	return B_BAD_VALUE;
+}
+
+
+static struct debugger_module_info sModuleInfo = {
+	{
+		"debugger/auto_stack_trace/v1",
+		0,
+		&std_ops
+	},
+	enter_debugger,
+	NULL
+};
+
+module_info *modules[] = { 
+	(module_info *)&sModuleInfo,
+	NULL
+};
+

src/add-ons/kernel/debugger/hangman/Jamfile

@@ -3,7 +3,7 @@ SubDir HAIKU_TOP src add-ons kernel debugger hangman ;
 SetSubDirSupportedPlatformsBeOSCompatible ;
 
 # UsePrivateHeaders drivers ;
-# UsePrivateHeaders kernel ;
+UsePrivateHeaders kernel ;
 
 
 KernelAddon <kdebug>hangman :

src/add-ons/kernel/debugger/hangman/hangman.c

@@ -1,8 +1,10 @@
 #ifdef _KERNEL_MODE
-#include <Drivers.h>
-#include <KernelExport.h>
-#include <module.h>
+#	include <Drivers.h>
+#	include <KernelExport.h>
+#	include <module.h>
+#	include <debug.h>
 #endif
+
 #include <OS.h>
 #include <image.h>
 #include <ctype.h>
@@ -440,37 +442,44 @@ find_device(const char *name)
 #  else /* as module */
 
 
-status_t std_ops(int32 op, ...);
-
-status_t
+static status_t
 std_ops(int32 op, ...)
 {
 	status_t err;
 
 	switch (op) {
-	case B_MODULE_INIT:
-		err = init_words(FORTUNE_FILE);
-		if (err < B_OK) {
-			dprintf("hangman: error reading fortune file: %s\n", strerror(err));
-			return B_ERROR;
-		}
-		add_debugger_command("kdlhangman", kdlhangman, KCMD_HELP);
-		return B_OK;
-	case B_MODULE_UNINIT:
-		remove_debugger_command("kdlhangman", kdlhangman);
-		return B_ERROR;
+		case B_MODULE_INIT:
+			err = init_words(FORTUNE_FILE);
+			if (err < B_OK) {
+				dprintf("hangman: error reading fortune file: %s\n",
+					strerror(err));
+				return B_ERROR;
+			}
+			add_debugger_command("kdlhangman", kdlhangman, KCMD_HELP);
+			return B_OK;
+		case B_MODULE_UNINIT:
+			remove_debugger_command("kdlhangman", kdlhangman);
+			return B_OK;
 	}
+
 	return B_ERROR;
 }
 
 
-static module_info minfo = {
-	"debugger/hangman/v1",
-	B_KEEP_LOADED,
-	&std_ops
+static struct debugger_module_info sModuleInfo = {
+	{
+		"debugger/hangman/v1",
+		B_KEEP_LOADED,
+		&std_ops
+	},
+	NULL,
+	NULL
 };
 
-module_info *modules[] = { &minfo, NULL };
+module_info *modules[] = { 
+	(module_info *)&sModuleInfo,
+	NULL
+};
 
 #  endif /* AS_DRIVER */
 

src/system/kernel/debug/debug.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2007, Axel Dörfler, [email protected]
+ * Copyright 2002-2008, Axel Dörfler, [email protected]
  * Distributed under the terms of the MIT License.
  *
  * Copyright 2001, Travis Geiselbrecht. All rights reserved.
@@ -74,6 +74,10 @@ static int64 sMessageRepeatFirstTime = 0;
 static int64 sMessageRepeatLastTime = 0;
 static int32 sMessageRepeatCount = 0;
 
+static debugger_module_info *sDebuggerModules[8];
+static const uint32 kMaxDebuggerModules = sizeof(sDebuggerModules)
+	/ sizeof(sDebuggerModules[0]);
+
 #define LINE_BUFFER_SIZE 1024
 #define HISTORY_SIZE 16
 
@@ -850,6 +854,23 @@ err1:
 }
 
 
+void
+call_modules_hook(bool enter)
+{
+	uint32 index = 0;
+	while (index < kMaxDebuggerModules && sDebuggerModules[index] != NULL) {
+		debugger_module_info *module = sDebuggerModules[index];
+
+		if (enter && module->enter_debugger != NULL)
+			module->enter_debugger();
+		else if (!enter && module->exit_debugger != NULL)
+			module->exit_debugger();
+
+		index++;
+	}
+}
+
+
 //	#pragma mark - private kernel API
 
 
@@ -995,17 +1016,19 @@ debug_init_post_modules(struct kernel_args *args)
 
 	// load kernel debugger addons
 	cookie = open_module_list("debugger");
-	while (true) {
+	uint32 count = 0;
+	while (count < kMaxDebuggerModules) {
 		char name[B_FILE_NAME_LENGTH];
 		size_t nameLength = sizeof(name);
-		module_info *module;
 
 		if (read_next_module_name(cookie, name, &nameLength) != B_OK)
 			break;
-		if (get_module(name, &module) == B_OK)
-			dprintf("kernel debugger extention \"%s\": loaded\n", name);
-		else
-			dprintf("kernel debugger extention \"%s\": failed to load\n", name);
+
+		if (get_module(name, (module_info **)&sDebuggerModules[count]) == B_OK) {
+			dprintf("kernel debugger extension \"%s\": loaded\n", name);
+			count++;
+		} else
+			dprintf("kernel debugger extension \"%s\": failed to load\n", name);
 	}
 	close_module_list(cookie);
 
@@ -1093,8 +1116,11 @@ kernel_debugger(const char *message)
 	// sort the commands
 	sort_debugger_commands();
 
+	call_modules_hook(true);
+
 	kernel_debugger_loop();
 
+	call_modules_hook(false);
 	set_dprintf_enabled(dprintfState);
 
 	sBlueScreenEnabled = false;