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SWORD25: Remove more unused loadlib code + use of fopen
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The functions loader_C and loader_Croot provably did not do anything
besides returning an error, so removing them was safe.

For loader_Lua, this was using luaL_loadfile. But that in turn now
uses Sword25FileProxy, which only supports loading config.lua,
and config.lua is not used via the loadlib mechanism.
Therefore, I deemed it safe to also remove this third loader.

This leaves loader_preload as only remaining loader. It is probably
unused, too, but I did not both to investigate further, as I already
achieved my primary goal (getting rid of fopen/fclose use).

All other removed functions were unused due to the removal of the
first three loader_* functions.
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@fingolfin
fingolfin committed May 25, 2011
1 parent 0aa6aca commit fdf12c5
Showing 1 changed file with 18 additions and 140 deletions.
158 changes: 18 additions & 140 deletions engines/sword25/util/lua/loadlib.cpp
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Expand Up @@ -8,19 +8,6 @@
** implementation for Windows, and a stub for other systems.
*/

// FIXME: Avoid using these APIs.
// Actually, this could be achieved by removing 80% of the remaining
// code in this file. Most of it is an elaborate way of expressing
// something like "return ERROR;" anyway, as we don't support loading
// dynamic libs
#define FORBIDDEN_SYMBOL_EXCEPTION_FILE
#define FORBIDDEN_SYMBOL_EXCEPTION_fopen
#define FORBIDDEN_SYMBOL_EXCEPTION_fclose


#include <stdlib.h>
#include <string.h>


#define loadlib_c
#define LUA_LIB
Expand All @@ -44,11 +31,6 @@
#define LIB_FAIL "open"


/* error codes for ll_loadfunc */
#define ERRLIB 1
#define ERRFUNC 2


/*
** {======================================================
** Fallback for other systems
Expand Down Expand Up @@ -97,29 +79,28 @@ static int gctm (lua_State *L) {
}


static int ll_loadfunc (lua_State *L, const char *path, const char *sym) {
void **reg = ll_register(L, path);
if (*reg == NULL) {
lua_pushliteral(L, DLMSG); // loading not supported, just push an error msg
return ERRLIB; /* unable to load library */
} else {
return ERRFUNC; /* unable to find function */
}
}
/* error codes for ll_loadfunc */
#define ERRLIB 1
#define ERRFUNC 2


static int ll_loadlib (lua_State *L) {
const char *path = luaL_checkstring(L, 1);
const char *init = luaL_checkstring(L, 2);
int stat = ll_loadfunc(L, path, init);
if (stat == 0) /* no errors? */
return 1; /* return the loaded function */
else { /* error; error message is on stack top */
lua_pushnil(L);
lua_insert(L, -2);
lua_pushstring(L, (stat == ERRLIB) ? LIB_FAIL : "init");
return 3; /* return nil, error message, and where */
// const char *init = luaL_checkstring(L, 2);
int stat;
void **reg = ll_register(L, path);
if (*reg == NULL) {
stat = ERRLIB; /* unable to load library */
} else {
stat = ERRFUNC; /* unable to find function */
}
lua_pushliteral(L, DLMSG);

/* error; error message is on stack top */
lua_pushnil(L);
lua_insert(L, -2);
lua_pushstring(L, (stat == ERRLIB) ? LIB_FAIL : "init");
return 3; /* return nil, error message, and where */
}


Expand All @@ -131,109 +112,6 @@ static int ll_loadlib (lua_State *L) {
*/


static int readable (const char *filename) {
FILE *f = fopen(filename, "r"); /* try to open file */
if (f == NULL) return 0; /* open failed */
fclose(f);
return 1;
}


static const char *pushnexttemplate (lua_State *L, const char *path) {
const char *l;
while (*path == *LUA_PATHSEP) path++; /* skip separators */
if (*path == '\0') return NULL; /* no more templates */
l = strchr(path, *LUA_PATHSEP); /* find next separator */
if (l == NULL) l = path + strlen(path);
lua_pushlstring(L, path, l - path); /* template */
return l;
}


static const char *findfile (lua_State *L, const char *name,
const char *pname) {
const char *path;
name = luaL_gsub(L, name, ".", LUA_DIRSEP);
lua_getfield(L, LUA_ENVIRONINDEX, pname);
path = lua_tostring(L, -1);
if (path == NULL)
luaL_error(L, LUA_QL("package.%s") " must be a string", pname);
lua_pushliteral(L, ""); /* error accumulator */
while ((path = pushnexttemplate(L, path)) != NULL) {
const char *filename;
filename = luaL_gsub(L, lua_tostring(L, -1), LUA_PATH_MARK, name);
lua_remove(L, -2); /* remove path template */
if (readable(filename)) /* does file exist and is readable? */
return filename; /* return that file name */
lua_pushfstring(L, "\n\tno file " LUA_QS, filename);
lua_remove(L, -2); /* remove file name */
lua_concat(L, 2); /* add entry to possible error message */
}
return NULL; /* not found */
}


static void loaderror (lua_State *L, const char *filename) {
luaL_error(L, "error loading module " LUA_QS " from file " LUA_QS ":\n\t%s",
lua_tostring(L, 1), filename, lua_tostring(L, -1));
}


static int loader_Lua (lua_State *L) {
const char *filename;
const char *name = luaL_checkstring(L, 1);
filename = findfile(L, name, "path");
if (filename == NULL) return 1; /* library not found in this path */
if (luaL_loadfile(L, filename) != 0)
loaderror(L, filename);
return 1; /* library loaded successfully */
}


static const char *mkfuncname (lua_State *L, const char *modname) {
const char *funcname;
const char *mark = strchr(modname, *LUA_IGMARK);
if (mark) modname = mark + 1;
funcname = luaL_gsub(L, modname, ".", LUA_OFSEP);
funcname = lua_pushfstring(L, POF"%s", funcname);
lua_remove(L, -2); /* remove 'gsub' result */
return funcname;
}


static int loader_C (lua_State *L) {
const char *funcname;
const char *name = luaL_checkstring(L, 1);
const char *filename = findfile(L, name, "cpath");
if (filename == NULL) return 1; /* library not found in this path */
funcname = mkfuncname(L, name);
if (ll_loadfunc(L, filename, funcname) != 0)
loaderror(L, filename);
return 1; /* library loaded successfully */
}


static int loader_Croot (lua_State *L) {
const char *funcname;
const char *filename;
const char *name = luaL_checkstring(L, 1);
const char *p = strchr(name, '.');
int stat;
if (p == NULL) return 0; /* is root */
lua_pushlstring(L, name, p - name);
filename = findfile(L, lua_tostring(L, -1), "cpath");
if (filename == NULL) return 1; /* root not found */
funcname = mkfuncname(L, name);
if ((stat = ll_loadfunc(L, filename, funcname)) != 0) {
if (stat != ERRFUNC) loaderror(L, filename); /* real error */
lua_pushfstring(L, "\n\tno module " LUA_QS " in file " LUA_QS,
name, filename);
return 1; /* function not found */
}
return 1;
}


static int loader_preload (lua_State *L) {
const char *name = luaL_checkstring(L, 1);
lua_getfield(L, LUA_ENVIRONINDEX, "preload");
Expand Down Expand Up @@ -409,7 +287,7 @@ static const luaL_Reg ll_funcs[] = {


static const lua_CFunction loaders[] =
{loader_preload, loader_Lua, loader_C, loader_Croot, NULL};
{loader_preload, NULL};


LUALIB_API int luaopen_package (lua_State *L) {
Expand Down

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