Add a lua stack dumper debugging function.

Unless enabled by a define DEBUG_LUA, nothing should happen. (Unsure about
the best way to guard this.)

src/scripting/debug_lua.cpp

@@ -0,0 +1,110 @@
+/*
+   Copyright (C) 2009 - 2011 by Guillaume Melquiond <guillaume.melquiond@gmail.com>
+   Part of the Battle for Wesnoth Project http://www.wesnoth.org/
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY.
+
+   See the COPYING file for more details.
+*/
+
+#ifdef DEBUG_LUA
+
+#include <cassert>
+
+#include "debug_lua.hpp"
+
+#include "log.hpp"
+
+static lg::log_domain log_scripting_lua("scripting/lua");
+#define LOG_LUA LOG_STREAM(info, log_scripting_lua)
+
+
+static void value_to_stringstream(
+	std::stringstream& output,
+	int i, lua_State* L,
+	std::string indent,
+	const bool verbose_table = true)
+{
+	const int t = lua_type(L, i);
+	switch (t) {
+		case LUA_TSTRING:
+			output << "STRING; VALUE: " << lua_tostring(L, i);
+		break;
+		case LUA_TBOOLEAN:
+			output << "BOOLEAN; VALUE: " << (lua_toboolean(L, i) ? "true" : "false");
+		break;
+		case LUA_TNUMBER:
+			output << "NUMBER; VALUE: " << lua_tonumber(L, i);
+		break;
+		case LUA_TNIL:
+			output << "NIL; VALUE: nil";
+		break;
+		case LUA_TTABLE:
+		{
+			output << "TABLE; VALUE: " << lua_topointer(L, i);
+			if(verbose_table)
+			{
+				indent += "\t";
+				unsigned keyindex = lua_gettop(L) + 1;
+				lua_pushnil(L);
+				while(lua_next(L, i) != 0)
+				{
+					output << "\n" << indent << "KEY: ";
+					const int keytype = lua_type(L, keyindex);
+					switch(keytype) {
+						case LUA_TSTRING:
+							output << lua_tostring(L, keyindex);
+						break;
+						case LUA_TBOOLEAN:
+							output << (lua_toboolean(L, keyindex) ? "true" : "false");
+						break;
+						case LUA_TNUMBER:
+							output << lua_tonumber(L, keyindex);
+						break;
+						default:
+							output << lua_topointer(L, keyindex);
+						break;
+					}
+					output << "; TYPE: ";
+					value_to_stringstream(output, keyindex + 1, L, indent);
+					lua_pop(L, 1);
+				}
+			}
+		}
+		break;
+		case LUA_TUSERDATA:
+			output << "USERDATA; VALUE: " << lua_topointer(L, i);
+		break;
+		case LUA_TFUNCTION:
+			output << "FUNCTION; VALUE: " << lua_topointer(L, i);
+		break;
+		case LUA_TTHREAD:
+			output << "THREAD; VALUE: " << lua_topointer(L, i);
+		break;
+		default:
+			//There are no other types!
+			assert(false);
+		break;
+	}
+}
+
+void ds(lua_State *L, const bool verbose_table) {
+	std::stringstream output;
+	output << "\n";
+	int top = lua_gettop(L);
+	for (int i = 1; i <= top; i++) {
+		output << "INDEX: " << i << "; TYPE: ";
+		value_to_stringstream(output, i, L, "", verbose_table);
+		output << "\n";
+	}
+	output << "\n";
+	LOG_LUA << output.str();
+}
+
+#endif
+

src/scripting/debug_lua.hpp

@@ -0,0 +1,27 @@
+/*
+   Copyright (C) 2009 - 2011 by Guillaume Melquiond <guillaume.melquiond@gmail.com>
+   Part of the Battle for Wesnoth Project http://www.wesnoth.org/
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY.
+
+   See the COPYING file for more details.
+*/
+
+#ifdef DEBUG_LUA
+
+#ifndef DEBUG_LUA_HPP_INCLUDED
+#define DEBUG_LUA_HPP_INCLUDED
+
+#include "lua/lualib.h"
+
+
+void ds(lua_State *L, const bool verbose_table = true);
+
+#endif
+
+#endif

src/scripting/lua.cpp

@@ -72,6 +72,10 @@
 #include "gui/widgets/progress_bar.hpp"
 #include "gui/widgets/window.hpp"
 
+#ifdef DEBUG_LUA
+#include "scripting/debug_lua.hpp"
+#endif
+
 static lg::log_domain log_scripting_lua("scripting/lua");
 #define LOG_LUA LOG_STREAM(info, log_scripting_lua)
 #define ERR_LUA LOG_STREAM(err, log_scripting_lua)