From 5380b6a41b6a8a54fb2f2d0e33281868ce7cc8a7 Mon Sep 17 00:00:00 2001
From: Lynix <lynix680@gmail.com>
Date: Sat, 20 Jan 2018 14:20:46 +0100
Subject: [PATCH] Lua/LuaInstance: Move library initializations to
 LoadLibraries

---
 ChangeLog.md                       |  1 +
 SDK/src/NDK/Application.cpp        |  1 +
 include/Nazara/Lua/Enums.hpp       | 27 ++++++++++++++++++
 include/Nazara/Lua/LuaInstance.hpp |  3 ++
 src/Nazara/Lua/LuaInstance.cpp     | 44 +++++++++++++++++++++++++++++-
 5 files changed, 75 insertions(+), 1 deletion(-)

diff --git a/ChangeLog.md b/ChangeLog.md
index 18a8b61c2..da2a0c98e 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -58,6 +58,7 @@ Nazara Engine:
 - Update Constraint2Ds classes (Add : Ref, Library, ConstRef, New function and Update : ctors)
 - Fix LuaClass not working correctly when Lua stack wasn't empty
 - Add RigidBody2D simulation control (via EnableSimulation and IsSimulationEnabled), which allows to disable physics and collisions at will.
+- ⚠️ LuaInstance no longer load all lua libraries on construction, this is done in the new LoadLibraries method which allows you to excludes some libraries
 
 Nazara Development Kit:
 - Added ImageWidget (#139)
diff --git a/SDK/src/NDK/Application.cpp b/SDK/src/NDK/Application.cpp
index efe80531c..5e0f07d00 100644
--- a/SDK/src/NDK/Application.cpp
+++ b/SDK/src/NDK/Application.cpp
@@ -165,6 +165,7 @@ namespace Ndk
 			consoleRef.AddLine(str);
 		});
 
+		overlay->lua.LoadLibraries();
 		LuaAPI::RegisterClasses(overlay->lua);
 
 		// Override "print" function to add a line in the console
diff --git a/include/Nazara/Lua/Enums.hpp b/include/Nazara/Lua/Enums.hpp
index f62357e6f..e92f058d5 100644
--- a/include/Nazara/Lua/Enums.hpp
+++ b/include/Nazara/Lua/Enums.hpp
@@ -7,6 +7,8 @@
 #ifndef NAZARA_ENUMS_LUA_HPP
 #define NAZARA_ENUMS_LUA_HPP
 
+#include <Nazara/Core/Flags.hpp>
+
 namespace Nz
 {
 	enum LuaBindMode
@@ -26,6 +28,21 @@ namespace Nz
 		LuaComparison_Max = LuaComparison_LessOrEqual
 	};
 
+	enum LuaLib
+	{
+		LuaLib_Coroutine,
+		LuaLib_Debug,
+		LuaLib_Math,
+		LuaLib_Io,
+		LuaLib_Package,
+		LuaLib_Os,
+		LuaLib_String,
+		LuaLib_Table,
+		LuaLib_Utf8,
+
+		LuaLib_Max = LuaLib_Utf8
+	};
+
 	enum LuaOperation
 	{
 		LuaOperation_Addition,
@@ -61,6 +78,16 @@ namespace Nz
 
 		LuaType_Max = LuaType_Userdata
 	};
+
+	template<>
+	struct EnumAsFlags<LuaLib>
+	{
+		static constexpr LuaLib max = LuaLib_Max;
+	};
+
+	using LuaLibFlags = Flags<LuaLib>;
+
+	constexpr LuaLibFlags LuaLib_All = LuaLibFlags(LuaLibFlags::ValueMask);
 }
 
 #endif // NAZARA_ENUMS_LUA_HPP
diff --git a/include/Nazara/Lua/LuaInstance.hpp b/include/Nazara/Lua/LuaInstance.hpp
index ac93a059a..c45a77a94 100644
--- a/include/Nazara/Lua/LuaInstance.hpp
+++ b/include/Nazara/Lua/LuaInstance.hpp
@@ -9,6 +9,7 @@
 
 #include <Nazara/Prerequisites.hpp>
 #include <Nazara/Core/Clock.hpp>
+#include <Nazara/Lua/Enums.hpp>
 #include <Nazara/Lua/LuaState.hpp>
 #include <cstddef>
 
@@ -29,6 +30,8 @@ namespace Nz
 			inline std::size_t GetMemoryUsage() const;
 			inline UInt32 GetTimeLimit() const;
 
+			void LoadLibraries(LuaLibFlags libFlags = LuaLib_All);
+
 			inline void SetMemoryLimit(std::size_t memoryLimit);
 			inline void SetTimeLimit(UInt32 limit);
 
diff --git a/src/Nazara/Lua/LuaInstance.cpp b/src/Nazara/Lua/LuaInstance.cpp
index 64eedf502..85567df81 100644
--- a/src/Nazara/Lua/LuaInstance.cpp
+++ b/src/Nazara/Lua/LuaInstance.cpp
@@ -8,6 +8,7 @@
 #include <Lua/lualib.h>
 #include <Nazara/Core/Clock.hpp>
 #include <Nazara/Core/Error.hpp>
+#include <array>
 #include <cassert>
 #include <cstdlib>
 #include <stdexcept>
@@ -35,7 +36,6 @@ namespace Nz
 		m_state = lua_newstate(MemoryAllocator, this);
 		lua_atpanic(m_state, AtPanic);
 		lua_sethook(m_state, TimeLimiter, LUA_MASKCOUNT, 1000);
-		luaL_openlibs(m_state);
 	}
 
 	LuaInstance::LuaInstance(LuaInstance&& instance) :
@@ -60,6 +60,48 @@ namespace Nz
 			lua_close(m_state);
 	}
 
+	void LuaInstance::LoadLibraries(LuaLibFlags libFlags)
+	{
+		// From luaL_openlibs
+		std::array<luaL_Reg, LuaLib_Max + 1> libs;
+		std::size_t libCount = 0;
+
+		libs[libCount++] = { "_G", luaopen_base };
+
+		if (libFlags & LuaLib_Coroutine)
+			libs[libCount++] = { LUA_COLIBNAME, luaopen_coroutine };
+
+		if (libFlags & LuaLib_Debug)
+			libs[libCount++] = { LUA_DBLIBNAME, luaopen_debug };
+
+		if (libFlags & LuaLib_Io)
+			libs[libCount++] = { LUA_IOLIBNAME, luaopen_io };
+
+		if (libFlags & LuaLib_Math)
+			libs[libCount++] = { LUA_MATHLIBNAME, luaopen_math };
+
+		if (libFlags & LuaLib_Os)
+			libs[libCount++] = { LUA_OSLIBNAME, luaopen_os };
+
+		if (libFlags & LuaLib_Package)
+			libs[libCount++] = { LUA_LOADLIBNAME, luaopen_package };
+
+		if (libFlags & LuaLib_String)
+			libs[libCount++] = { LUA_STRLIBNAME, luaopen_string };
+
+		if (libFlags & LuaLib_Table)
+			libs[libCount++] = { LUA_TABLIBNAME, luaopen_table };
+
+		if (libFlags & LuaLib_Utf8)
+			libs[libCount++] = { LUA_UTF8LIBNAME, luaopen_utf8 };
+
+		for (std::size_t i = 0; i < libCount; ++i)
+		{
+			luaL_requiref(m_state, libs[i].name, libs[i].func, 1);
+			lua_pop(m_state, 1);  /* remove lib */
+		}
+	}
+
 	LuaInstance& LuaInstance::operator=(LuaInstance&& instance)
 	{
 		LuaState::operator=(std::move(instance));