lbase.c

// This code is part of lua2exe
// Base executable VM
#include<lua/lua.h>
#include<lua/lualib.h>
#include<lua/lauxlib.h>
#include<stdlib.h>
#include<stdio.h>
#include<stdint.h>
#ifndef NO_COMPRESSION
#include<lz4.h>
#endif

#pragma pack(1)
#define ENTRIES_KEY "$L2E"

typedef struct {
int32_t fileTableOffset;
char magic[8];
} trailer;

typedef struct {
uint32_t compressedLen;
uint32_t uncompressedLen;
char compressed;
} entry;

static const char* const ENTRY_PATHS[] = {
LUA_PATH_MARK ".lua",
LUA_PATH_MARK ".lc",
LUA_PATH_MARK LUA_DIRSEP "init.lua",
LUA_PATH_MARK LUA_DIRSEP "init.lc",
NULL
};

#if defined __WIN32 || defined __WIN64
#include<windows.h>
static const char* getSelfName (const char* argv0) {
char buf[512];
if (!GetModuleFileNameA(NULL, buf, 511)) return NULL;
return strdup(buf);
}
#else
#error Platform currently unsupported
#endif

static int loadentry (lua_State* L, FILE* fpSelf, const char* entryName) {
static char* buf1 = NULL, *buf2 = NULL;
static uint32_t buflen1=0, buflen2=0;
if (LUA_TTABLE != lua_getfield(L, LUA_REGISTRYINDEX, ENTRIES_KEY)) {
lua_pop(L, 1);
return LUA_ERRERR;
}
if (LUA_TNUMBER != lua_getfield(L, -1, entryName)) {
lua_pop(L, 2);
return LUA_ERRFILE;
}
int32_t offset = lua_tointeger(L, -1);
lua_pop(L, 2);
if (fseek(fpSelf, offset, SEEK_SET)) return LUA_ERRERR;
entry e = { 0, 0, 0 };
if (1!=fread(&e, sizeof(e), 1, fpSelf)) return LUA_ERRERR;
if (!buf1 || buflen1<e.compressedLen)  buf1 = realloc(buf1, buflen1=e.compressedLen);
if (! buf2 || buflen2<e.uncompressedLen)  buf2 = realloc(buf2, buflen2=e.uncompressedLen);
if (!buf1 || !buf2) return LUA_ERRMEM;
if (1!=fread(buf1, e.compressedLen, 1, fpSelf)) return LUA_ERRERR;
char namebuf[512]={0};
snprintf(namebuf, 511, "@%s", entryName);
char* buf=buf1; int len=buflen1;
#ifndef NO_COMPRESSION
if (e.compressed) {
buf=buf2; 
len = LZ4_decompress_safe(buf1, buf2, e.compressedLen, e.uncompressedLen);
if (len<0) return luaL_error(L, "decompression error %d", len);
}
#endif
buf[len]=0;
return luaL_loadbufferx(L, buf, len, namebuf, "bt");
}

static int lua_loadentry (lua_State* L) {
FILE* fpSelf = (FILE*) lua_topointer(L, lua_upvalueindex(1));
const char* name = luaL_gsub(L, luaL_checkstring(L, 1), ".", LUA_DIRSEP);
int ntop = lua_gettop(L);
for (const char* const* path = ENTRY_PATHS; *path; path++) {
const char* entryName = luaL_gsub(L, *path, LUA_PATH_MARK, name);
if (LUA_OK == loadentry(L, fpSelf, entryName)) {
lua_pushfstring(L, "Resource %s", entryName);
return 2;
}}
int etop = lua_gettop(L);
luaL_Buffer b;
luaL_buffinit(L, &b);
for (int i=ntop+1; i<=etop; i++) {
luaL_addstring(&b, "No resource ");
lua_pushvalue(L, i);
luaL_addvalue(&b);
if (i<etop) luaL_addstring(&b, "\n");
}
luaL_pushresult(&b);
return 1;
}

int lua_getbacktrace (lua_State* l) {
lua_getglobal(l, "debug");
lua_getfield(l, -1, "traceback");
lua_pushvalue(l,1);
lua_pushinteger(l,2);
if (lua_pcall(l, 2, 1, 0)) {
printf("Error in error handling !\r\n");
}
return 1;
}

int main (int argc, char** argv) {
lua_State* L = NULL;
FILE* fpSelf = NULL;
const char* fnSelf = NULL;
trailer trail = {0};

#define fail(E) { fprintf(stderr, E "\n", fnSelf); goto end; }

L = luaL_newstate();
if (!L) fail("Couldn't allocate lua state")
luaL_openlibs(L);

fnSelf = getSelfName(argv[0]);
if (!fnSelf || !*fnSelf) fail("Unable to determine self executable path")

fpSelf = fopen(fnSelf, "rb");
if (!fpSelf) fail("Couldn't open self executable %s")

if (fseek(fpSelf, (size_t)-sizeof(trailer), SEEK_END)) fail("Couldn't seek to trailer")
if (!fread(&trail, sizeof(trailer), 1, fpSelf)) fail("Couldn't read trailer")
if (strncmp(trail.magic, "lua2exe1", 8)) fail("magic value error")
if (fseek(fpSelf, trail.fileTableOffset, SEEK_SET)) fail("Couldn't seek to file table")

int32_t nameLen, entryPos, entryCount=0;
char entryName[512] = {0};

lua_settop(L, 0);
lua_newtable(L);

while (
fread(&nameLen, 4, 1, fpSelf) 
&& nameLen!=-1 
&& fread(entryName, nameLen, 1, fpSelf)
&& fread(&entryPos, 4, 1, fpSelf)
&& entryPos!=-1 && entryPos>0
) {
entryName[nameLen] = 0;
lua_pushinteger(L, entryPos);
lua_setfield(L, -2, entryName);
lua_pushstring(L, entryName);
lua_rawseti(L, -2, ++entryCount);
}
lua_pushvalue(L, -1);
lua_setfield(L, LUA_REGISTRYINDEX, ENTRIES_KEY);

lua_newtable(L);
for (int i=0; i<argc; i++) {
lua_pushstring(L, argv[i]);
lua_rawseti(L, -2, i);
}
lua_setglobal(L, "arg");

// Put loader into package.searchers
lua_getglobal(L, "package");
lua_getglobal(L, "table");
lua_getfield(L, -1, "insert");
lua_getfield(L, -3, "searchers");
lua_pushinteger(L, 2);
lua_pushlightuserdata(L, fpSelf);
lua_pushcclosure(L, &lua_loadentry, 1);
lua_call(L, 3, 0);
lua_pop(L, 2);

// Load the first entry
lua_pushcclosure(L, lua_getbacktrace, 0);
lua_rawgeti(L, -2, 1);
int re = loadentry(L, fpSelf, lua_tostring(L, -1));
if (re) fprintf(stderr, "%d! %s\n", re, lua_tostring(L, -1));

for (int i=1; i<argc; i++) lua_pushstring(L, argv[i]);
if (lua_pcall(L, argc -1, 1, 1-argc)) {
fprintf(stderr, "%s\n", lua_tostring(L, -1));
}
else if (lua_gettop(L)>=1 && lua_isnumber(L,-1)) return lua_tointeger(L,-1);
else return 0;

end:
return 1;
#undef fail
}