Fix luajit compatibility for new code

The more recent version of lite-xl use the bit32 library and
the lua_Buffer functions. These function were not implemented
by the minimal compatiblity layer and are now added with this commit.

The code is adapted from:

https://github.com/keplerproject/lua-compat-5.2

data/core/compat.lua

@@ -1,2 +1,5 @@
 table.unpack = unpack
 
+table.pack = function(...)
+   return { n = select('#', ...), ... }
+end

licenses/licenses.md

@@ -22,6 +22,29 @@ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 
+## lua-compat-5.2
+
+The MIT License (MIT)
+
+Copyright (c) 2013 Hisham Muhammad
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
 ## Fira Sans
 
 Digitized data copyright (c) 2012-2015, The Mozilla Foundation and Telefonica S.A.

meson.build

@@ -45,7 +45,7 @@ endif
 if not get_option('source-only')
     libm = cc.find_library('m', required : false)
     libdl = cc.find_library('dl', required : false)
-    lua_dep = dependency('luajit', fallback: ['luajit', 'lua_dep'],
+    lua_dep = dependency('luajit', fallback: ['luajit', 'luajit_dep'],
         default_options: ['default_library=static']
     )
     pcre2_dep = dependency('libpcre2-8')

src/api/compat.c

@@ -1,3 +1,5 @@
+#include <string.h>
+
 #include <lauxlib.h>
 
 #include "compat.h"
@@ -62,3 +64,80 @@ void luaL_setmetatable (lua_State *L, const char *tname) {
   lua_setmetatable(L, -2);
 }
 
+void luaL_buffinit (lua_State *L, luaL_Buffer_52 *B) {
+  /* make it crash if used via pointer to a 5.1-style luaL_Buffer */
+  B->b.p = NULL;
+  B->b.L = NULL;
+  B->b.lvl = 0;
+  /* reuse the buffer from the 5.1-style luaL_Buffer though! */
+  B->ptr = B->b.buffer;
+  B->capacity = LUAL_BUFFERSIZE;
+  B->nelems = 0;
+  B->L2 = L;
+}
+
+
+char *luaL_prepbuffsize (luaL_Buffer_52 *B, size_t s) {
+  if (B->capacity - B->nelems < s) { /* needs to grow */
+    char* newptr = NULL;
+    size_t newcap = B->capacity * 2;
+    if (newcap - B->nelems < s)
+      newcap = B->nelems + s;
+    if (newcap < B->capacity) /* overflow */
+      luaL_error(B->L2, "buffer too large");
+    newptr = lua_newuserdata(B->L2, newcap);
+    memcpy(newptr, B->ptr, B->nelems);
+    if (B->ptr != B->b.buffer)
+      lua_replace(B->L2, -2); /* remove old buffer */
+    B->ptr = newptr;
+    B->capacity = newcap;
+  }
+  return B->ptr+B->nelems;
+}
+
+
+void luaL_addlstring (luaL_Buffer_52 *B, const char *s, size_t l) {
+  memcpy(luaL_prepbuffsize(B, l), s, l);
+  luaL_addsize(B, l);
+}
+
+
+void luaL_addvalue (luaL_Buffer_52 *B) {
+  size_t len = 0;
+  const char *s = lua_tolstring(B->L2, -1, &len);
+  if (!s)
+    luaL_error(B->L2, "cannot convert value to string");
+  if (B->ptr != B->b.buffer)
+    lua_insert(B->L2, -2); /* userdata buffer must be at stack top */
+  luaL_addlstring(B, s, len);
+  lua_remove(B->L2, B->ptr != B->b.buffer ? -2 : -1);
+}
+
+
+void luaL_pushresult (luaL_Buffer_52 *B) {
+  lua_pushlstring(B->L2, B->ptr, B->nelems);
+  if (B->ptr != B->b.buffer)
+    lua_replace(B->L2, -2); /* remove userdata buffer */
+}
+
+#define lua_number2unsigned(i,n)	((i)=(lua_Unsigned)(n))
+#define lua_unsigned2number(u)  \
+    (((u) <= (lua_Unsigned)INT_MAX) ? (lua_Number)(int)(u) : (lua_Number)(u))
+
+lua_Unsigned luaL_checkunsigned (lua_State *L, int i) {
+  lua_Unsigned result;
+  lua_Number n = lua_tonumber(L, i);
+  if (n == 0 && !lua_isnumber(L, i))
+    luaL_checktype(L, i, LUA_TNUMBER);
+  lua_number2unsigned(result, n);
+  return result;
+}
+
+lua_Unsigned luaL_optunsigned (lua_State *L, int i, lua_Unsigned def) {
+  return luaL_opt(L, luaL_checkunsigned, i, def);
+}
+
+void lua_pushunsigned (lua_State *L, lua_Unsigned n) {
+  lua_pushnumber(L, lua_unsigned2number(n));
+}
+

src/api/compat.h

@@ -1,9 +1,25 @@
+/* Adapted from:
+** https://github.com/keplerproject/lua-compat-5.2
+*/
 #ifndef COMPAT_H
 #define COMPAT_H
 
+#include <stdint.h>
+
 #include <lua.h>
 #include <lauxlib.h>
 
+typedef uint32_t lua_Unsigned;
+
+typedef struct luaL_Buffer_52 {
+  luaL_Buffer b; /* make incorrect code crash! */
+  char *ptr;
+  size_t nelems;
+  size_t capacity;
+  lua_State *L2;
+} luaL_Buffer_52;
+#define luaL_Buffer luaL_Buffer_52
+
 #define luaL_newlibtable(L, l) \
   (lua_createtable(L, 0, sizeof(l)/sizeof(*(l))-1))
 #define luaL_newlib(L, l) \
@@ -13,5 +29,45 @@ extern void luaL_requiref (lua_State *L, const char *modname, lua_CFunction open
 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);
+extern void lua_pushunsigned (lua_State *L, lua_Unsigned n);
+extern lua_Unsigned luaL_checkunsigned (lua_State *L, int i);
+extern lua_Unsigned luaL_optunsigned (lua_State *L, int i, lua_Unsigned def);
+
+#define lua_rawlen(L, i) lua_objlen(L, i)
+
+#define luaL_buffinit luaL_buffinit_52
+void luaL_buffinit (lua_State *L, luaL_Buffer_52 *B);
+
+#define luaL_prepbuffsize luaL_prepbuffsize_52
+char *luaL_prepbuffsize (luaL_Buffer_52 *B, size_t s);
+
+#define luaL_addlstring luaL_addlstring_52
+void luaL_addlstring (luaL_Buffer_52 *B, const char *s, size_t l);
+
+#define luaL_addvalue luaL_addvalue_52
+void luaL_addvalue (luaL_Buffer_52 *B);
+
+#define luaL_pushresult luaL_pushresult_52
+void luaL_pushresult (luaL_Buffer_52 *B);
+
+#undef luaL_buffinitsize
+#define luaL_buffinitsize(L, B, s) \
+  (luaL_buffinit(L, B), luaL_prepbuffsize(B, s))
+
+#undef luaL_prepbuffer
+#define luaL_prepbuffer(B) \
+  luaL_prepbuffsize(B, LUAL_BUFFERSIZE)
+
+#undef luaL_addsize
+#define luaL_addsize(B, s) \
+  ((B)->nelems += (s))
+
+#undef luaL_addstring
+#define luaL_addstring(B, s) \
+  luaL_addlstring(B, s, strlen(s))
+
+#undef luaL_pushresultsize
+#define luaL_pushresultsize(B, s) \
+  (luaL_addsize(B, s), luaL_pushresult(B))
 
 #endif

src/main.c

@@ -83,6 +83,8 @@ void set_macos_bundle_resources(lua_State *L);
 #endif
 #endif
 
+int luaopen_bit32 (lua_State *L);
+
 int main(int argc, char **argv) {
 #ifdef _WIN32
   HINSTANCE lib = LoadLibrary("user32.dll");
@@ -117,6 +119,8 @@ int main(int argc, char **argv) {
 init_lua:
   L = luaL_newstate();
   luaL_openlibs(L);
+  luaopen_bit32(L);
+  lua_setglobal(L, "bit32");
   api_load_libs(L);
 
 

src/meson.build

@@ -7,6 +7,7 @@ lite_sources = [
     'api/regex.c',
     'api/system.c',
     'api/process.c',
+    'lbitlib.c',
     'renderer.c',
     'renwindow.c',
     'fontdesc.c',