Slight improvement to tracing output.

- If a trace entry has a stack trace, attempt to demangle the associated symbols.
  Could be enhanced further to also demangle the arguments but doesn't yet.
  Interestingly there are some mangled symbols that our demangler appears to
  not handle correctly (gcc4).

src/system/kernel/debug/tracing.cpp

@@ -1,6 +1,7 @@
 /*
  * Copyright 2008-2011, Ingo Weinhold, [email protected].
  * Copyright 2008-2009, Axel Dörfler, [email protected].
+ * Copyright 2012, Rene Gollent, [email protected].
  * Distributed under the terms of the MIT License.
  */
 
@@ -13,6 +14,7 @@
 
 #include <arch/debug.h>
 #include <debug.h>
+#include <debug_heap.h>
 #include <elf.h>
 #include <int.h>
 #include <kernel.h>
@@ -141,22 +143,37 @@ print_stack_trace(struct tracing_stack_trace* stackTrace,
 	if (stackTrace == NULL || stackTrace->depth <= 0)
 		return;
 
+	static const size_t kBufferSize = 256;
+	char* buffer = (char*)debug_malloc(kBufferSize);
+
 	for (int32 i = 0; i < stackTrace->depth; i++) {
 		addr_t address = stackTrace->return_addresses[i];
 
 		const char* symbol;
+		const char* demangledName = NULL;
 		const char* imageName;
 		bool exactMatch;
 		addr_t baseAddress;
 
 		if (elf_debug_lookup_symbol_address(address, &baseAddress, &symbol,
 				&imageName, &exactMatch) == B_OK) {
-			print("  %p  %s + 0x%lx (%s)%s\n", (void*)address, symbol,
+
+			if (buffer != NULL) {
+				bool isObjectMethod;
+				demangledName = debug_demangle_symbol(symbol, buffer,
+					kBufferSize, &isObjectMethod);
+			}
+
+			print("  %p  %s + 0x%lx (%s)%s\n", (void*)address,
+				demangledName != NULL ? demangledName : symbol,
 				address - baseAddress, imageName,
 				exactMatch ? "" : " (nearest)");
 		} else
 			print("  %p\n", (void*)address);
 	}
+
+	if (buffer != NULL)
+		debug_free(buffer);
 }