From 0ed6dd46fbebdeed9f99ef250b6e2279e6fe17b8 Mon Sep 17 00:00:00 2001
From: Thomas Goyne <plorkyeran@aegisub.org>
Date: Sat, 27 Feb 2016 18:59:03 -0800
Subject: [PATCH] Add support for using system LuaJIT rather than the bundled
 copy

Closes #1904.
---
 Makefile.inc.in   |  4 ++--
 configure.ac      | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 src/Makefile      |  8 ++++----
 src/auto4_lua.cpp |  2 +-
 4 files changed, 53 insertions(+), 7 deletions(-)

diff --git a/Makefile.inc.in b/Makefile.inc.in
index 5a52d25cb..8d5566af3 100644
--- a/Makefile.inc.in
+++ b/Makefile.inc.in
@@ -79,7 +79,7 @@ CFLAGS_ICONV       = @ICONV_CFLAGS@
 CFLAGS_ICU         = @ICU_I18N_CFLAGS@
 CFLAGS_LIBASS      = @LIBASS_CFLAGS@
 CFLAGS_LIBPULSE    = @LIBPULSE_CFLAGS@
-CFLAGS_LUA         = -I$(TOP)vendor/luajit/include
+CFLAGS_LUA         = @LUAJIT_CFLAGS@
 CFLAGS_OPENAL      = @OPENAL_CFLAGS@
 CFLAGS_OSS         = @OSS_CFLAGS@
 CFLAGS_PORTAUDIO   = @PORTAUDIO_CFLAGS@
@@ -97,7 +97,7 @@ LIBS_ICONV         = @ICONV_LIBS@
 LIBS_ICU           = @ICU_UC_LIBS@ @ICU_I18N_LIBS@
 LIBS_LIBASS        = @LIBASS_LIBS@
 LIBS_LIBPULSE      = @LIBPULSE_LIBS@
-LIBS_LUA           = $(TOP)vendor/luajit/src/libluajit.a
+LIBS_LUA           = @LUAJIT_LIBS@
 LIBS_OPENAL        = @OPENAL_LIBS@
 LIBS_PORTAUDIO     = @PORTAUDIO_LIBS@
 LIBS_PTHREAD       = @PTHREAD_LIBS@
diff --git a/configure.ac b/configure.ac
index 7492568bb..91902cf39 100644
--- a/configure.ac
+++ b/configure.ac
@@ -383,6 +383,51 @@ AGI_OPT_PKG(fftw3, [build without fftw support [auto]], [Enable fftw support])
 AGI_OPT_PKG(hunspell, [build without hunspell spell-checking [auto]], [Enable Hunspell support])
 AGI_OPT_PKG(uchardet, [build without automatic character set detection [auto]], [Enable uchardet support])
 
+########
+# LuaJIT
+########
+system_luajit="bundled"
+AC_ARG_WITH(system-luajit, AS_HELP_STRING([--without-system-luajit], [Use built-in LuaJIT [auto]]))
+# Check if it's available at all
+AS_IF([test x$with_system_luajit = xno], [],
+      [PKG_CHECK_MODULES(LUAJIT, luajit >= 2.0.0, [], [
+       AS_IF([test x$with_system_luajit = xyes],
+             [AC_MSG_FAILURE([--with-sytem-luajit was specified, but luajit could not be found])])
+       with_system_luajit="no"])])
+
+# Check if it's compiled in Lua 5.2 mode
+AS_IF([test x$with_system_luajit != xno], [
+  aegisub_save_LIBS="$LIBS"
+  aegisub_save_CPPFLAGS="$CPPFLAGS"
+  CPPFLAGS="$CPPFLAGS $LUAJIT_CFLAGS"
+  LIBS="$LIBS $LUAJIT_LIBS"
+  AC_CACHE_CHECK(
+    [whether LuaJIT is compiled in 5.2 mode], [agi_cv_luajit_is_52],
+    [AC_RUN_IFELSE([AC_LANG_PROGRAM(
+     [[#include <lauxlib.h>]],
+     [[lua_State *L = luaL_newstate();
+       if (!L) return 1;
+       // This is valid in lua 5.2, but a syntax error in 5.1
+       const char testprogram[] = "function foo() while true do break return end end";
+       return luaL_loadstring(L, testprogram) == LUA_ERRSYNTAX;
+     ]])], [agi_cv_luajit_is_52="yes"], [agi_cv_luajit_is_52="no"])])
+  CPPFLAGS="$aegisub_save_CPPFLAGS"
+  LIBS="$aegisub_save_LIBS"
+
+  if test $agi_cv_luajit_is_52 != yes; then
+    AS_IF([test x$with_system_luajit = xyes],
+          [AC_MSG_FAILURE([LuaJIT must be compiled in Lua 5.2 mode])])
+    with_system_luajit="no"
+  else
+    with_system_luajit="yes"
+    system_luajit="system"
+  fi
+])
+
+AS_IF([test $with_system_luajit = no],
+      [AC_SUBST([LUAJIT_CFLAGS], ['-I$(TOP)vendor/luajit/include'])
+       AC_SUBST([LUAJIT_LIBS], ['$(TOP)vendor/luajit/src/libluajit.a'])])
+
 ######################################################
 # Debugging support
 ######################################################
@@ -572,4 +617,5 @@ Misc Packages
   uchardet:              $with_uchardet $uchardet_disabled
   Hunspell:              $with_hunspell $hunspell_disabled
   FFTW3:                 $with_fftw3 $fftw3_disabled
+  LuaJIT:                $system_luajit
 ])
diff --git a/src/Makefile b/src/Makefile
index 1fb983ce2..0ee6c84c8 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -198,10 +198,10 @@ $(d)subtitles_provider.o_FLAGS          := $(CFLAGS_LIBASS)
 $(d)subtitles_provider_libass.o_FLAGS   := $(CFLAGS_LIBASS) -Wno-c++11-narrowing
 $(d)text_file_reader.o_FLAGS            := -D_X86_
 $(d)video_provider_manager.o_FLAGS      := $(CFLAGS_FFMS2)
-$(d)auto4_lua.o_FLAGS                   := -I$(TOP)vendor/luajit/include
-$(d)auto4_lua_assfile.o_FLAGS           := -I$(TOP)vendor/luajit/include
-$(d)auto4_lua_dialog.o_FLAGS            := -I$(TOP)vendor/luajit/include
-$(d)auto4_lua_progresssink.o_FLAGS      := -I$(TOP)vendor/luajit/include
+$(d)auto4_lua.o_FLAGS                   := $(CFLAGS_LUA)
+$(d)auto4_lua_assfile.o_FLAGS           := $(CFLAGS_LUA)
+$(d)auto4_lua_dialog.o_FLAGS            := $(CFLAGS_LUA)
+$(d)auto4_lua_progresssink.o_FLAGS      := $(CFLAGS_LUA)
 
 $(src_OBJ): $(d)libresrc/bitmap.h $(d)libresrc/default_config.h
 
diff --git a/src/auto4_lua.cpp b/src/auto4_lua.cpp
index 3ce9f2adb..245689679 100644
--- a/src/auto4_lua.cpp
+++ b/src/auto4_lua.cpp
@@ -396,7 +396,7 @@ namespace {
 		name = GetPrettyFilename().string();
 
 		// create lua environment
-		L = lua_open();
+		L = luaL_newstate();
 		if (!L) {
 			description = "Could not initialize Lua state";
 			return;