Added the beginnings of a small private API for debug support.

Entirely implemented on top of the public <debugger.h> API, but more
convenient to use. Lives in a separate library libdebug.so.



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@11925 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/debug/debug_support.h

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2005, Ingo Weinhold, [email protected].
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef _DEBUG_SUPPORT_H
+#define _DEBUG_SUPPORT_H
+
+#include <debugger.h>
+#include <OS.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct debug_context {
+	port_id	nub_port;
+	port_id	reply_port;
+} debug_context;
+
+
+status_t init_debug_context(debug_context *context, port_id nubPort);
+void destroy_debug_context(debug_context *context);
+
+status_t send_debug_message(debug_context *context, int32 messageCode,
+			const void *message, int32 messageSize, void *reply,
+			int32 replySize);
+
+ssize_t debug_read_memory_partial(debug_context *context, const void *address,
+			void *buffer, size_t size);
+ssize_t debug_read_memory(debug_context *context, const void *address,
+			void *buffer, size_t size);
+ssize_t debug_read_string(debug_context *context, const void *_address,
+			char *buffer, size_t size);
+
+
+#ifdef __cplusplus
+}	// extern "C"
+#endif
+
+
+#endif	// _DEBUG_SUPPORT_H

src/kits/Jamfile

@@ -102,6 +102,7 @@ SEARCH on [ FGristFiles KMessage.cpp ]
 	= [ FDirName $(OBOS_TOP) src kernel core messaging ] ;
 
 SubInclude OBOS_TOP src kits app ;
+SubInclude OBOS_TOP src kits debug ;
 SubInclude OBOS_TOP src kits interface ;
 SubInclude OBOS_TOP src kits mail ;
 SubInclude OBOS_TOP src kits media ;

src/kits/debug/Jamfile

@@ -0,0 +1,12 @@
+SubDir OBOS_TOP src kits debug ;
+
+UsePrivateHeaders debug ;
+UsePrivateHeaders shared ;
+
+SharedLibrary debug :
+	debug_support.cpp
+;
+
+LinkSharedOSLibs libdebug.so :
+	libroot.so
+;

src/kits/debug/debug_support.cpp

@@ -0,0 +1,181 @@
+/*
+ * Copyright 2005, Ingo Weinhold, [email protected].
+ * Distributed under the terms of the MIT License.
+ */
+
+#include <string.h>
+
+#include <debug_support.h>
+
+// init_debug_context
+status_t
+init_debug_context(debug_context *context, port_id nubPort)
+{
+	if (!context || nubPort < 0)
+		return B_BAD_VALUE;
+
+	context->nub_port = nubPort;
+
+	// create the reply port
+	context->reply_port = create_port(1, "debug reply port");
+	if (context->reply_port < 0)
+		return context->reply_port;
+
+	return B_OK;
+}
+
+// destroy_debug_context
+void
+destroy_debug_context(debug_context *context)
+{
+	if (context) {
+		if (context->reply_port >= 0)
+			delete_port(context->reply_port);
+	}
+}
+
+// send_debug_message
+status_t
+send_debug_message(debug_context *context, int32 messageCode,
+	const void *message, int32 messageSize, void *reply, int32 replySize)
+{
+	if (!context)
+		return B_BAD_VALUE;
+
+	// send message
+	while (true) {
+		status_t result = write_port(context->nub_port, messageCode, message,
+			messageSize);
+		if (result == B_OK)
+			break;
+		if (result != B_INTERRUPTED)
+			return result;
+	}
+
+	if (!reply)
+		return B_OK;
+
+	// read reply
+	while (true) {
+		int32 code;
+		ssize_t bytesRead = read_port(context->reply_port, &code, reply,
+			replySize);
+		if (bytesRead > 0)
+			return B_OK;
+		if (bytesRead != B_INTERRUPTED)
+			return bytesRead;
+	}
+}
+
+// debug_read_memory_partial
+ssize_t
+debug_read_memory_partial(debug_context *context, const void *address,
+	void *buffer, size_t size)
+{
+	if (!context)
+		return B_BAD_VALUE;
+
+	if (size == 0)
+		return 0;
+	if (size > B_MAX_READ_WRITE_MEMORY_SIZE)
+		size = B_MAX_READ_WRITE_MEMORY_SIZE;
+
+	// prepare the message
+	debug_nub_read_memory message;
+	message.reply_port = context->reply_port;
+	message.address = (void*)address;
+	message.size = size;
+
+	// send the message
+	debug_nub_read_memory_reply reply;
+	status_t error = send_debug_message(context, B_DEBUG_MESSAGE_READ_MEMORY,
+		&message, sizeof(message), &reply, sizeof(reply));
+
+	if (error != B_OK)
+		return error;
+	if (reply.error != B_OK)
+		return reply.error;
+
+	// copy the read data
+	memcpy(buffer, reply.data, reply.size);
+	return reply.size;
+}
+
+// debug_read_memory
+ssize_t
+debug_read_memory(debug_context *context, const void *_address, void *_buffer,
+	size_t size)
+{
+	const char *address = (const char *)_address;
+	char *buffer = (char*)_buffer;
+
+	// check parameters
+	if (!context || !address || !buffer)
+		return B_BAD_VALUE;
+	if (size == 0)
+		return 0;
+
+	// read as long as we can read data
+	ssize_t sumRead = 0;
+	while (size > 0) {
+		ssize_t bytesRead = debug_read_memory_partial(context, address, buffer,
+			size);
+		if (bytesRead < 0) {
+			if (sumRead > 0)
+				return sumRead;
+			return bytesRead;
+		}
+
+		address += bytesRead;
+		buffer += bytesRead;
+		sumRead += bytesRead;
+		size -= bytesRead;
+	}
+
+	return sumRead;
+}
+
+// debug_read_string
+ssize_t
+debug_read_string(debug_context *context, const void *_address, char *buffer,
+	size_t size)
+{
+	const char *address = (const char *)_address;
+
+	// check parameters
+	if (!context || !address || !buffer || size == 0)
+		return B_BAD_VALUE;
+
+	// read as long as we can read data
+	ssize_t sumRead = 0;
+	while (size > 0) {
+		ssize_t bytesRead = debug_read_memory_partial(context, address, buffer,
+			size);
+		if (bytesRead < 0) {
+			// always null-terminate what we have (even, if it is an empty
+			// string) and be done
+			*buffer = '\0';
+			return (sumRead > 0 ? sumRead : bytesRead);
+		}
+
+		int chunkSize = strnlen(buffer, bytesRead);
+		if (chunkSize < bytesRead) {
+			// we found a terminating null
+			sumRead += chunkSize;
+			return sumRead;
+		}
+
+		address += bytesRead;
+		buffer += bytesRead;
+		sumRead += bytesRead;
+		size -= bytesRead;
+	}
+
+	// We filled the complete buffer without encountering a terminating null
+	// replace the last char. But nevertheless return the full size to indicate
+	// that the buffer was too small.
+	buffer[-1] = '\0';
+
+	return sumRead;
+}
+