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-rw-r--r--src/lauxlib.c161
1 files changed, 116 insertions, 45 deletions
diff --git a/src/lauxlib.c b/src/lauxlib.c
index 1c41d6a8eaf4c..f7a383663e19f 100644
--- a/src/lauxlib.c
+++ b/src/lauxlib.c
@@ -1,5 +1,5 @@
/*
-** $Id: lauxlib.c,v 1.279 2014/12/14 18:32:26 roberto Exp $
+** $Id: lauxlib.c,v 1.289 2016/12/20 18:37:00 roberto Exp $
** Auxiliary functions for building Lua libraries
** See Copyright Notice in lua.h
*/
@@ -17,7 +17,8 @@
#include <string.h>
-/* This file uses only the official API of Lua.
+/*
+** This file uses only the official API of Lua.
** Any function declared here could be written as an application function.
*/
@@ -33,8 +34,8 @@
*/
-#define LEVELS1 12 /* size of the first part of the stack */
-#define LEVELS2 10 /* size of the second part of the stack */
+#define LEVELS1 10 /* size of the first part of the stack */
+#define LEVELS2 11 /* size of the second part of the stack */
@@ -68,12 +69,11 @@ static int findfield (lua_State *L, int objidx, int level) {
/*
** Search for a name for a function in all loaded modules
-** (registry._LOADED).
*/
static int pushglobalfuncname (lua_State *L, lua_Debug *ar) {
int top = lua_gettop(L);
lua_getinfo(L, "f", ar); /* push function */
- lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED");
+ lua_getfield(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE);
if (findfield(L, top + 1, 2)) {
const char *name = lua_tostring(L, -1);
if (strncmp(name, "_G.", 3) == 0) { /* name start with '_G.'? */
@@ -107,7 +107,7 @@ static void pushfuncname (lua_State *L, lua_Debug *ar) {
}
-static int countlevels (lua_State *L) {
+static int lastlevel (lua_State *L) {
lua_Debug ar;
int li = 1, le = 1;
/* find an upper bound */
@@ -126,14 +126,16 @@ LUALIB_API void luaL_traceback (lua_State *L, lua_State *L1,
const char *msg, int level) {
lua_Debug ar;
int top = lua_gettop(L);
- int numlevels = countlevels(L1);
- int mark = (numlevels > LEVELS1 + LEVELS2) ? LEVELS1 : 0;
- if (msg) lua_pushfstring(L, "%s\n", msg);
+ int last = lastlevel(L1);
+ int n1 = (last - level > LEVELS1 + LEVELS2) ? LEVELS1 : -1;
+ if (msg)
+ lua_pushfstring(L, "%s\n", msg);
+ luaL_checkstack(L, 10, NULL);
lua_pushliteral(L, "stack traceback:");
while (lua_getstack(L1, level++, &ar)) {
- if (level == mark) { /* too many levels? */
+ if (n1-- == 0) { /* too many levels? */
lua_pushliteral(L, "\n\t..."); /* add a '...' */
- level = numlevels - LEVELS2; /* and skip to last ones */
+ level = last - LEVELS2 + 1; /* and skip to last ones */
}
else {
lua_getinfo(L1, "Slnt", &ar);
@@ -196,6 +198,10 @@ static void tag_error (lua_State *L, int arg, int tag) {
}
+/*
+** The use of 'lua_pushfstring' ensures this function does not
+** need reserved stack space when called.
+*/
LUALIB_API void luaL_where (lua_State *L, int level) {
lua_Debug ar;
if (lua_getstack(L, level, &ar)) { /* check function at level */
@@ -205,10 +211,15 @@ LUALIB_API void luaL_where (lua_State *L, int level) {
return;
}
}
- lua_pushliteral(L, ""); /* else, no information available... */
+ lua_pushfstring(L, ""); /* else, no information available... */
}
+/*
+** Again, the use of 'lua_pushvfstring' ensures this function does
+** not need reserved stack space when called. (At worst, it generates
+** an error with "stack overflow" instead of the given message.)
+*/
LUALIB_API int luaL_error (lua_State *L, const char *fmt, ...) {
va_list argp;
va_start(argp, fmt);
@@ -286,10 +297,10 @@ LUALIB_API int luaL_execresult (lua_State *L, int stat) {
*/
LUALIB_API int luaL_newmetatable (lua_State *L, const char *tname) {
- if (luaL_getmetatable(L, tname)) /* name already in use? */
+ if (luaL_getmetatable(L, tname) != LUA_TNIL) /* name already in use? */
return 0; /* leave previous value on top, but return 0 */
lua_pop(L, 1);
- lua_newtable(L); /* create metatable */
+ lua_createtable(L, 0, 2); /* create metatable */
lua_pushstring(L, tname);
lua_setfield(L, -2, "__name"); /* metatable.__name = tname */
lua_pushvalue(L, -1);
@@ -347,10 +358,15 @@ LUALIB_API int luaL_checkoption (lua_State *L, int arg, const char *def,
}
+/*
+** Ensures the stack has at least 'space' extra slots, raising an error
+** if it cannot fulfill the request. (The error handling needs a few
+** extra slots to format the error message. In case of an error without
+** this extra space, Lua will generate the same 'stack overflow' error,
+** but without 'msg'.)
+*/
LUALIB_API void luaL_checkstack (lua_State *L, int space, const char *msg) {
- /* keep some extra space to run error routines, if needed */
- const int extra = LUA_MINSTACK;
- if (!lua_checkstack(L, space + extra)) {
+ if (!lua_checkstack(L, space)) {
if (msg)
luaL_error(L, "stack overflow (%s)", msg);
else
@@ -435,6 +451,47 @@ LUALIB_API lua_Integer luaL_optinteger (lua_State *L, int arg,
** =======================================================
*/
+/* userdata to box arbitrary data */
+typedef struct UBox {
+ void *box;
+ size_t bsize;
+} UBox;
+
+
+static void *resizebox (lua_State *L, int idx, size_t newsize) {
+ void *ud;
+ lua_Alloc allocf = lua_getallocf(L, &ud);
+ UBox *box = (UBox *)lua_touserdata(L, idx);
+ void *temp = allocf(ud, box->box, box->bsize, newsize);
+ if (temp == NULL && newsize > 0) { /* allocation error? */
+ resizebox(L, idx, 0); /* free buffer */
+ luaL_error(L, "not enough memory for buffer allocation");
+ }
+ box->box = temp;
+ box->bsize = newsize;
+ return temp;
+}
+
+
+static int boxgc (lua_State *L) {
+ resizebox(L, 1, 0);
+ return 0;
+}
+
+
+static void *newbox (lua_State *L, size_t newsize) {
+ UBox *box = (UBox *)lua_newuserdata(L, sizeof(UBox));
+ box->box = NULL;
+ box->bsize = 0;
+ if (luaL_newmetatable(L, "LUABOX")) { /* creating metatable? */
+ lua_pushcfunction(L, boxgc);
+ lua_setfield(L, -2, "__gc"); /* metatable.__gc = boxgc */
+ }
+ lua_setmetatable(L, -2);
+ return resizebox(L, -1, newsize);
+}
+
+
/*
** check whether buffer is using a userdata on the stack as a temporary
** buffer
@@ -455,11 +512,12 @@ LUALIB_API char *luaL_prepbuffsize (luaL_Buffer *B, size_t sz) {
if (newsize < B->n || newsize - B->n < sz)
luaL_error(L, "buffer too large");
/* create larger buffer */
- newbuff = (char *)lua_newuserdata(L, newsize * sizeof(char));
- /* move content to new buffer */
- memcpy(newbuff, B->b, B->n * sizeof(char));
if (buffonstack(B))
- lua_remove(L, -2); /* remove old buffer */
+ newbuff = (char *)resizebox(L, -1, newsize);
+ else { /* no buffer yet */
+ newbuff = (char *)newbox(L, newsize);
+ memcpy(newbuff, B->b, B->n * sizeof(char)); /* copy original content */
+ }
B->b = newbuff;
B->size = newsize;
}
@@ -468,9 +526,11 @@ LUALIB_API char *luaL_prepbuffsize (luaL_Buffer *B, size_t sz) {
LUALIB_API void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l) {
- char *b = luaL_prepbuffsize(B, l);
- memcpy(b, s, l * sizeof(char));
- luaL_addsize(B, l);
+ if (l > 0) { /* avoid 'memcpy' when 's' can be NULL */
+ char *b = luaL_prepbuffsize(B, l);
+ memcpy(b, s, l * sizeof(char));
+ luaL_addsize(B, l);
+ }
}
@@ -482,8 +542,10 @@ LUALIB_API void luaL_addstring (luaL_Buffer *B, const char *s) {
LUALIB_API void luaL_pushresult (luaL_Buffer *B) {
lua_State *L = B->L;
lua_pushlstring(L, B->b, B->n);
- if (buffonstack(B))
- lua_remove(L, -2); /* remove old buffer */
+ if (buffonstack(B)) {
+ resizebox(L, -2, 0); /* delete old buffer */
+ lua_remove(L, -2); /* remove its header from the stack */
+ }
}
@@ -605,7 +667,7 @@ static int errfile (lua_State *L, const char *what, int fnameindex) {
static int skipBOM (LoadF *lf) {
- const char *p = "\xEF\xBB\xBF"; /* Utf8 BOM mark */
+ const char *p = "\xEF\xBB\xBF"; /* UTF-8 BOM mark */
int c;
lf->n = 0;
do {
@@ -630,7 +692,7 @@ static int skipcomment (LoadF *lf, int *cp) {
if (c == '#') { /* first line is a comment (Unix exec. file)? */
do { /* skip first line */
c = getc(lf->f);
- } while (c != EOF && c != '\n') ;
+ } while (c != EOF && c != '\n');
*cp = getc(lf->f); /* skip end-of-line, if present */
return 1; /* there was a comment */
}
@@ -746,13 +808,17 @@ LUALIB_API lua_Integer luaL_len (lua_State *L, int idx) {
LUALIB_API const char *luaL_tolstring (lua_State *L, int idx, size_t *len) {
- if (!luaL_callmeta(L, idx, "__tostring")) { /* no metafield? */
+ if (luaL_callmeta(L, idx, "__tostring")) { /* metafield? */
+ if (!lua_isstring(L, -1))
+ luaL_error(L, "'__tostring' must return a string");
+ }
+ else {
switch (lua_type(L, idx)) {
case LUA_TNUMBER: {
if (lua_isinteger(L, idx))
- lua_pushfstring(L, "%I", lua_tointeger(L, idx));
+ lua_pushfstring(L, "%I", (LUAI_UACINT)lua_tointeger(L, idx));
else
- lua_pushfstring(L, "%f", lua_tonumber(L, idx));
+ lua_pushfstring(L, "%f", (LUAI_UACNUMBER)lua_tonumber(L, idx));
break;
}
case LUA_TSTRING:
@@ -764,10 +830,15 @@ LUALIB_API const char *luaL_tolstring (lua_State *L, int idx, size_t *len) {
case LUA_TNIL:
lua_pushliteral(L, "nil");
break;
- default:
- lua_pushfstring(L, "%s: %p", luaL_typename(L, idx),
- lua_topointer(L, idx));
+ default: {
+ int tt = luaL_getmetafield(L, idx, "__name"); /* try name */
+ const char *kind = (tt == LUA_TSTRING) ? lua_tostring(L, -1) :
+ luaL_typename(L, idx);
+ lua_pushfstring(L, "%s: %p", kind, lua_topointer(L, idx));
+ if (tt != LUA_TNIL)
+ lua_remove(L, -2); /* remove '__name' */
break;
+ }
}
}
return lua_tolstring(L, -1, len);
@@ -819,23 +890,23 @@ static int libsize (const luaL_Reg *l) {
/*
** Find or create a module table with a given name. The function
-** first looks at the _LOADED table and, if that fails, try a
+** first looks at the LOADED table and, if that fails, try a
** global variable with that name. In any case, leaves on the stack
** the module table.
*/
LUALIB_API void luaL_pushmodule (lua_State *L, const char *modname,
int sizehint) {
- luaL_findtable(L, LUA_REGISTRYINDEX, "_LOADED", 1); /* get _LOADED table */
- if (lua_getfield(L, -1, modname) != LUA_TTABLE) { /* no _LOADED[modname]? */
+ luaL_findtable(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE, 1);
+ if (lua_getfield(L, -1, modname) != LUA_TTABLE) { /* no LOADED[modname]? */
lua_pop(L, 1); /* remove previous result */
/* try global variable (and create one if it does not exist) */
lua_pushglobaltable(L);
if (luaL_findtable(L, 0, modname, sizehint) != NULL)
luaL_error(L, "name conflict for module '%s'", modname);
lua_pushvalue(L, -1);
- lua_setfield(L, -3, modname); /* _LOADED[modname] = new table */
+ lua_setfield(L, -3, modname); /* LOADED[modname] = new table */
}
- lua_remove(L, -2); /* remove _LOADED table */
+ lua_remove(L, -2); /* remove LOADED table */
}
@@ -899,17 +970,17 @@ LUALIB_API int luaL_getsubtable (lua_State *L, int idx, const char *fname) {
*/
LUALIB_API void luaL_requiref (lua_State *L, const char *modname,
lua_CFunction openf, int glb) {
- luaL_getsubtable(L, LUA_REGISTRYINDEX, "_LOADED");
- lua_getfield(L, -1, modname); /* _LOADED[modname] */
+ luaL_getsubtable(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE);
+ lua_getfield(L, -1, modname); /* LOADED[modname] */
if (!lua_toboolean(L, -1)) { /* package not already loaded? */
lua_pop(L, 1); /* remove field */
lua_pushcfunction(L, openf);
lua_pushstring(L, modname); /* argument to open function */
lua_call(L, 1, 1); /* call 'openf' to open module */
lua_pushvalue(L, -1); /* make copy of module (call result) */
- lua_setfield(L, -3, modname); /* _LOADED[modname] = module */
+ lua_setfield(L, -3, modname); /* LOADED[modname] = module */
}
- lua_remove(L, -2); /* remove _LOADED table */
+ lua_remove(L, -2); /* remove LOADED table */
if (glb) {
lua_pushvalue(L, -1); /* copy of module */
lua_setglobal(L, modname); /* _G[modname] = module */
@@ -967,6 +1038,6 @@ LUALIB_API void luaL_checkversion_ (lua_State *L, lua_Number ver, size_t sz) {
luaL_error(L, "multiple Lua VMs detected");
else if (*v != ver)
luaL_error(L, "version mismatch: app. needs %f, Lua core provides %f",
- ver, *v);
+ (LUAI_UACNUMBER)ver, (LUAI_UACNUMBER)*v);
}
generated by cgit v1.2.3 (git 2.25.1) at 2025-06-25 22:24:16 +0000