Initial draft of transition to use LuaJIT2 instead of Lua 5.2

There is problem with utf8 expression matching on common.utf8_chars

data/core/compat.lua

@@ -0,0 +1,2 @@
+table.unpack = unpack
+

data/core/init.lua

@@ -1,4 +1,5 @@
 require "core.strict"
+require "core.compat"
 local common = require "core.common"
 local config = require "core.config"
 local style = require "core.style"

meson.build

@@ -3,13 +3,17 @@ project('lite', 'c', 'cpp', default_options : ['c_std=gnu11', 'cpp_std=c++03'])
 cc = meson.get_compiler('c')
 libm = cc.find_library('m', required : false)
 libdl = cc.find_library('dl', required : false)
-lua_dep = dependency('lua5.2', required : false)
 
-if not lua_dep.found()
-    lua_subproject = subproject('lua', default_options: [
-        'shared=false', 'use_readline=false', 'app=false'
-    ])
-    lua_dep = lua_subproject.get_variable('lua_dep')
+if get_option('luajit')
+    lua_dep = dependency('luajit')
+else
+    lua_dep = dependency('lua5.2', required : false)
+    if not lua_dep.found()
+        lua_subproject = subproject('lua', default_options: [
+            'shared=false', 'use_readline=false', 'app=false'
+        ])
+        lua_dep = lua_subproject.get_variable('lua_dep')
+    endif
 endif
 
 sdl_dep = dependency('sdl2', method: 'config-tool')

src/api/api.h

@@ -5,6 +5,8 @@
 #include "lauxlib.h"
 #include "lualib.h"
 
+#include "compat.h"
+
 #define API_TYPE_FONT "Font"
 
 void api_load_libs(lua_State *L);

src/api/compat.c

@@ -0,0 +1,64 @@
+#include <lauxlib.h>
+
+#include "compat.h"
+
+static int lua_absindex (lua_State *L, int i) {
+  if (i < 0 && i > LUA_REGISTRYINDEX)
+    i += lua_gettop(L) + 1;
+  return i;
+}
+
+int luaL_getsubtable (lua_State *L, int i, const char *name) {
+  int abs_i = lua_absindex(L, i);
+  luaL_checkstack(L, 3, "not enough stack slots");
+  lua_pushstring(L, name);
+  lua_gettable(L, abs_i);
+  if (lua_istable(L, -1))
+    return 1;
+  lua_pop(L, 1);
+  lua_newtable(L);
+  lua_pushstring(L, name);
+  lua_pushvalue(L, -2);
+  lua_settable(L, abs_i);
+  return 0;
+}
+
+void luaL_requiref (lua_State *L, const char *modname, lua_CFunction openf, int glb) {
+  luaL_checkstack(L, 3, "not enough stack slots available");
+  luaL_getsubtable(L, LUA_REGISTRYINDEX, "_LOADED");
+  lua_getfield(L, -1, modname);
+  if (lua_isnil(L, -1)) {
+    lua_pop(L, 1);
+    lua_pushcfunction(L, openf);
+    lua_pushstring(L, modname);
+    lua_call(L, 1, 1);
+    lua_pushvalue(L, -1);
+    lua_setfield(L, -3, modname);
+  }
+  if (glb) {
+    lua_pushvalue(L, -1);
+    lua_setglobal(L, modname);
+  }
+  lua_replace(L, -2);
+}
+
+void luaL_setfuncs (lua_State *L, const luaL_Reg *l, int nup) {
+  luaL_checkstack(L, nup+1, "too many upvalues");
+  for (; l->name != NULL; l++) {  /* fill the table with given functions */
+    int i;
+    lua_pushstring(L, l->name);
+    for (i = 0; i < nup; i++)  /* copy upvalues to the top */
+      lua_pushvalue(L, -(nup + 1));
+    lua_pushcclosure(L, l->func, nup);  /* closure with those upvalues */
+    lua_settable(L, -(nup + 3)); /* table must be below the upvalues, the name and the closure */
+  }
+  lua_pop(L, nup);  /* remove upvalues */
+}
+
+
+void luaL_setmetatable (lua_State *L, const char *tname) {
+  luaL_checkstack(L, 1, "not enough stack slots");
+  luaL_getmetatable(L, tname);
+  lua_setmetatable(L, -2);
+}
+

src/api/compat.h

@@ -0,0 +1,17 @@
+#ifndef COMPAT_H
+#define COMPAT_H
+
+#include <lua.h>
+#include <lauxlib.h>
+
+#define luaL_newlibtable(L, l) \
+  (lua_createtable(L, 0, sizeof(l)/sizeof(*(l))-1))
+#define luaL_newlib(L, l) \
+  (luaL_newlibtable(L, l), luaL_register(L, NULL, l))
+
+extern void luaL_requiref (lua_State *L, const char *modname, lua_CFunction openf, int glb);
+extern void luaL_setfuncs (lua_State *L, const luaL_Reg *l, int nup);
+extern void luaL_setmetatable (lua_State *L, const char *tname);
+extern int luaL_getsubtable (lua_State *L, int i, const char *name);
+
+#endif

src/meson.build

@@ -1,4 +1,5 @@
 lite_sources = [
+    'api/compat.c',
     'api/api.c',
     'api/renderer.c',
     'api/renderer_font.c',

subprojects/luajit.wrap

@@ -0,0 +1,5 @@
+[wrap-git]
+directory = luajit
+url = https://github.com/franko/luajit
+revision = v2.0.5-lhelper2
+