/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╚──────────────────────────────────────────────────────────────────────────────╝
│ │
│ Lua │
│ Copyright © 2004-2021 Lua.org, PUC-Rio. │
│ │
│ 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. │
│ │
╚─────────────────────────────────────────────────────────────────────────────*/
#define lapi_c
#define LUA_CORE
#include "third_party/lua/lapi.h"
#include "third_party/lua/ldebug.h"
#include "third_party/lua/ldo.h"
#include "third_party/lua/lfunc.h"
#include "third_party/lua/lgc.h"
#include "third_party/lua/lmem.h"
#include "third_party/lua/lobject.h"
#include "third_party/lua/lprefix.h"
#include "third_party/lua/lstate.h"
#include "third_party/lua/lstring.h"
#include "third_party/lua/ltable.h"
#include "third_party/lua/ltm.h"
#include "third_party/lua/lua.h"
#include "third_party/lua/lundump.h"
#include "third_party/lua/lvm.h"
// clang-format off
asm(".ident\t\"\\n\\n\
Lua 5.4.3 (MIT License)\\n\
Copyright 1994–2021 Lua.org, PUC-Rio.\"");
asm(".include \"libc/disclaimer.inc\"");
const char lua_ident[] =
"$LuaVersion: " LUA_COPYRIGHT " $"
"$LuaAuthors: " LUA_AUTHORS " $";
/*
** Test for a valid index (one that is not the 'nilvalue').
** '!ttisnil(o)' implies 'o != &G(L)->nilvalue', so it is not needed.
** However, it covers the most common cases in a faster way.
*/
#define isvalid(L, o) (!ttisnil(o) || o != &G(L)->nilvalue)
/* test for pseudo index */
#define ispseudo(i) ((i) <= LUA_REGISTRYINDEX)
/* test for upvalue */
#define isupvalue(i) ((i) < LUA_REGISTRYINDEX)
static TValue *index2value (lua_State *L, int idx) {
CallInfo *ci = L->ci;
if (idx > 0) {
StkId o = ci->func + idx;
api_check(L, idx <= L->ci->top - (ci->func + 1), "unacceptable index");
if (o >= L->top) return &G(L)->nilvalue;
else return s2v(o);
}
else if (!ispseudo(idx)) { /* negative index */
api_check(L, idx != 0 && -idx <= L->top - (ci->func + 1), "invalid index");
return s2v(L->top + idx);
}
else if (idx == LUA_REGISTRYINDEX)
return &G(L)->l_registry;
else { /* upvalues */
idx = LUA_REGISTRYINDEX - idx;
api_check(L, idx <= MAXUPVAL + 1, "upvalue index too large");
if (ttislcf(s2v(ci->func))) /* light C function? */
return &G(L)->nilvalue; /* it has no upvalues */
else {
CClosure *func = clCvalue(s2v(ci->func));
return (idx <= func->nupvalues) ? &func->upvalue[idx-1]
: &G(L)->nilvalue;
}
}
}
static StkId index2stack (lua_State *L, int idx) {
CallInfo *ci = L->ci;
if (idx > 0) {
StkId o = ci->func + idx;
api_check(L, o < L->top, "unacceptable index");
return o;
}
else { /* non-positive index */
api_check(L, idx != 0 && -idx <= L->top - (ci->func + 1), "invalid index");
api_check(L, !ispseudo(idx), "invalid index");
return L->top + idx;
}
}
LUA_API int lua_checkstack (lua_State *L, int n) {
int res;
CallInfo *ci;
lua_lock(L);
ci = L->ci;
api_check(L, n >= 0, "negative 'n'");
if (L->stack_last - L->top > n) /* stack large enough? */
res = 1; /* yes; check is OK */
else { /* no; need to grow stack */
int inuse = cast_int(L->top - L->stack) + EXTRA_STACK;
if (inuse > LUAI_MAXSTACK - n) /* can grow without overflow? */
res = 0; /* no */
else /* try to grow stack */
res = luaD_growstack(L, n, 0);
}
if (res && ci->top < L->top + n)
ci->top = L->top + n; /* adjust frame top */
lua_unlock(L);
return res;
}
/**
* Exchanges values between different threads of the same state.
*
* This funcetion pops n values from the stack from, and pushes them onto
* the stack to.
*/
LUA_API void lua_xmove (lua_State *from, lua_State *to, int n) {
int i;
if (from == to) return;
lua_lock(to);
api_checknelems(from, n);
api_check(from, G(from) == G(to), "moving among independent states");
api_check(from, to->ci->top - to->top >= n, "stack overflow");
from->top -= n;
for (i = 0; i < n; i++) {
setobjs2s(to, to->top, from->top + i);
to->top++; /* stack already checked by previous 'api_check' */
}
lua_unlock(to);
}
/**
* lua_atpanic
*
* [-0, +0, –]
*
* lua_CFunction lua_atpanic (lua_State *L, lua_CFunction panicf);
*
* Sets a new panic function and returns the old one (see §4.4).
*/
LUA_API lua_CFunction lua_atpanic (lua_State *L, lua_CFunction panicf) {
lua_CFunction old;
lua_lock(L);
old = G(L)->panic;
G(L)->panic = panicf;
lua_unlock(L);
return old;
}
/**
* lua_version
*
* [-0, +0, –]
*
* lua_Number lua_version (lua_State *L);
*
* Returns the version number of this core.
*/
LUA_API lua_Number lua_version (lua_State *L) {
UNUSED(L);
return LUA_VERSION_NUM;
}
/*
** basic stack manipulation
*/
/**
* lua_absindex [-0, +0, –]
*
* Converts the acceptable index idx into an equivalent absolute index (that
* is, one that does not depend on the stack size).
*/
LUA_API int lua_absindex (lua_State *L, int idx) {
return (idx > 0 || ispseudo(idx))
? idx
: cast_int(L->top - L->ci->func) + idx;
}
/**
* lua_gettop [-0, +0, –]
*
* Returns the index of the top element in the stack. Because indices start
* at 1, this result is equal to the number of elements in the stack; in
* particular, 0 means an empty stack.
*/
LUA_API int lua_gettop (lua_State *L) {
return cast_int(L->top - (L->ci->func + 1));
}
/**
* lua_settop [-?, +?, e]
*
* Accepts any index, or 0, and sets the stack top to this index. If the new
* top is greater than the old one, then the new elements are filled with
* nil. If index is 0, then all stack elements are removed.
*
* This function can run arbitrary code when removing an index marked as
* to-be-closed from the stack.
*/
LUA_API void lua_settop (lua_State *L, int idx) {
CallInfo *ci;
StkId func, newtop;
ptrdiff_t diff; /* difference for new top */
lua_lock(L);
ci = L->ci;
func = ci->func;
if (idx >= 0) {
api_check(L, idx <= ci->top - (func + 1), "new top too large");
diff = ((func + 1) + idx) - L->top;
for (; diff > 0; diff--)
setnilvalue(s2v(L->top++)); /* clear new slots */
}
else {
api_check(L, -(idx+1) <= (L->top - (func + 1)), "invalid new top");
diff = idx + 1; /* will "subtract" index (as it is negative) */
}
api_check(L, L->tbclist < L->top, "previous pop of an unclosed slot");
newtop = L->top + diff;
if (diff < 0 && L->tbclist >= newtop) {
lua_assert(hastocloseCfunc(ci->nresults));
luaF_close(L, newtop, CLOSEKTOP, 0);
}
L->top = newtop; /* correct top only after closing any upvalue */
lua_unlock(L);
}
LUA_API void lua_closeslot (lua_State *L, int idx) {
StkId level;
lua_lock(L);
level = index2stack(L, idx);
api_check(L, hastocloseCfunc(L->ci->nresults) && L->tbclist == level,
"no variable to close at given level");
luaF_close(L, level, CLOSEKTOP, 0);
level = index2stack(L, idx); /* stack may be moved */
setnilvalue(s2v(level));
lua_unlock(L);
}
/*
** Reverse the stack segment from 'from' to 'to'
** (auxiliary to 'lua_rotate')
** Note that we move(copy) only the value inside the stack.
** (We do not move additional fields that may exist.)
*/
static void reverse (lua_State *L, StkId from, StkId to) {
for (; from < to; from++, to--) {
TValue temp;
setobj(L, &temp, s2v(from));
setobjs2s(L, from, to);
setobj2s(L, to, &temp);
}
}
/*
** Let x = AB, where A is a prefix of length 'n'. Then,
** rotate x n == BA. But BA == (A^r . B^r)^r.
*/
LUA_API void lua_rotate (lua_State *L, int idx, int n) {
StkId p, t, m;
lua_lock(L);
t = L->top - 1; /* end of stack segment being rotated */
p = index2stack(L, idx); /* start of segment */
api_check(L, (n >= 0 ? n : -n) <= (t - p + 1), "invalid 'n'");
m = (n >= 0 ? t - n : p - n - 1); /* end of prefix */
reverse(L, p, m); /* reverse the prefix with length 'n' */
reverse(L, m + 1, t); /* reverse the suffix */
reverse(L, p, t); /* reverse the entire segment */
lua_unlock(L);
}
LUA_API void lua_copy (lua_State *L, int fromidx, int toidx) {
TValue *fr, *to;
lua_lock(L);
fr = index2value(L, fromidx);
to = index2value(L, toidx);
api_check(L, isvalid(L, to), "invalid index");
setobj(L, to, fr);
if (isupvalue(toidx)) /* function upvalue? */
luaC_barrier(L, clCvalue(s2v(L->ci->func)), fr);
/* LUA_REGISTRYINDEX does not need gc barrier
(collector revisits it before finishing collection) */
lua_unlock(L);
}
LUA_API void lua_pushvalue (lua_State *L, int idx) {
lua_lock(L);
setobj2s(L, L->top, index2value(L, idx));
api_incr_top(L);
lua_unlock(L);
}
/*
** access functions (stack -> C)
*/
LUA_API int lua_type (lua_State *L, int idx) {
const TValue *o = index2value(L, idx);
return (isvalid(L, o) ? ttype(o) : LUA_TNONE);
}
LUA_API const char *lua_typename (lua_State *L, int t) {
UNUSED(L);
api_check(L, LUA_TNONE <= t && t < LUA_NUMTYPES, "invalid type");
return ttypename(t);
}
LUA_API int lua_iscfunction (lua_State *L, int idx) {
const TValue *o = index2value(L, idx);
return (ttislcf(o) || (ttisCclosure(o)));
}
LUA_API int lua_isinteger (lua_State *L, int idx) {
const TValue *o = index2value(L, idx);
return ttisinteger(o);
}
LUA_API int lua_isnumber (lua_State *L, int idx) {
lua_Number n;
const TValue *o = index2value(L, idx);
return tonumber(o, &n);
}
LUA_API int lua_isstring (lua_State *L, int idx) {
const TValue *o = index2value(L, idx);
return (ttisstring(o) || cvt2str(o));
}
LUA_API int lua_isuserdata (lua_State *L, int idx) {
const TValue *o = index2value(L, idx);
return (ttisfulluserdata(o) || ttislightuserdata(o));
}
LUA_API int lua_rawequal (lua_State *L, int index1, int index2) {
const TValue *o1 = index2value(L, index1);
const TValue *o2 = index2value(L, index2);
return (isvalid(L, o1) && isvalid(L, o2)) ? luaV_rawequalobj(o1, o2) : 0;
}
LUA_API void lua_arith (lua_State *L, int op) {
lua_lock(L);
if (op != LUA_OPUNM && op != LUA_OPBNOT)
api_checknelems(L, 2); /* all other operations expect two operands */
else { /* for unary operations, add fake 2nd operand */
api_checknelems(L, 1);
setobjs2s(L, L->top, L->top - 1);
api_incr_top(L);
}
/* first operand at top - 2, second at top - 1; result go to top - 2 */
luaO_arith(L, op, s2v(L->top - 2), s2v(L->top - 1), L->top - 2);
L->top--; /* remove second operand */
lua_unlock(L);
}
LUA_API int lua_compare (lua_State *L, int index1, int index2, int op) {
const TValue *o1;
const TValue *o2;
int i = 0;
lua_lock(L); /* may call tag method */
o1 = index2value(L, index1);
o2 = index2value(L, index2);
if (isvalid(L, o1) && isvalid(L, o2)) {
switch (op) {
case LUA_OPEQ: i = luaV_equalobj(L, o1, o2); break;
case LUA_OPLT: i = luaV_lessthan(L, o1, o2); break;
case LUA_OPLE: i = luaV_lessequal(L, o1, o2); break;
default: api_check(L, 0, "invalid option");
}
}
lua_unlock(L);
return i;
}
LUA_API size_t lua_stringtonumber (lua_State *L, const char *s) {
size_t sz = luaO_str2num(s, s2v(L->top));
if (sz != 0)
api_incr_top(L);
return sz;
}
LUA_API lua_Number lua_tonumberx (lua_State *L, int idx, int *pisnum) {
lua_Number n = 0;
const TValue *o = index2value(L, idx);
int isnum = tonumber(o, &n);
if (pisnum)
*pisnum = isnum;
return n;
}
LUA_API lua_Integer lua_tointegerx (lua_State *L, int idx, int *pisnum) {
lua_Integer res = 0;
const TValue *o = index2value(L, idx);
int isnum = tointeger(o, &res);
if (pisnum)
*pisnum = isnum;
return res;
}
LUA_API int lua_toboolean (lua_State *L, int idx) {
const TValue *o = index2value(L, idx);
return !l_isfalse(o);
}
LUA_API const char *lua_tolstring (lua_State *L, int idx, size_t *len) {
TValue *o;
lua_lock(L);
o = index2value(L, idx);
if (!ttisstring(o)) {
if (!cvt2str(o)) { /* not convertible? */
if (len != NULL) *len = 0;
lua_unlock(L);
return NULL;
}
luaO_tostring(L, o);
luaC_checkGC(L);
o = index2value(L, idx); /* previous call may reallocate the stack */
}
if (len != NULL)
*len = vslen(o);
lua_unlock(L);
return svalue(o);
}
LUA_API lua_Unsigned lua_rawlen (lua_State *L, int idx) {
const TValue *o = index2value(L, idx);
switch (ttypetag(o)) {
case LUA_VSHRSTR: return tsvalue(o)->shrlen;
case LUA_VLNGSTR: return tsvalue(o)->u.lnglen;
case LUA_VUSERDATA: return uvalue(o)->len;
case LUA_VTABLE: return luaH_getn(hvalue(o));
default: return 0;
}
}
LUA_API lua_CFunction lua_tocfunction (lua_State *L, int idx) {
const TValue *o = index2value(L, idx);
if (ttislcf(o)) return fvalue(o);
else if (ttisCclosure(o))
return clCvalue(o)->f;
else return NULL; /* not a C function */
}
static void *touserdata (const TValue *o) {
switch (ttype(o)) {
case LUA_TUSERDATA: return getudatamem(uvalue(o));
case LUA_TLIGHTUSERDATA: return pvalue(o);
default: return NULL;
}
}
/**
* lua_touserdata [-0, +0, –]
*
* If the value at the given index is a full userdata, returns its
* memory-block address. If the value is a light userdata, returns its value
* (a pointer). Otherwise, returns NULL.
*/
LUA_API void *lua_touserdata (lua_State *L, int idx) {
const TValue *o = index2value(L, idx);
return touserdata(o);
}
/**
* lua_tothread [-0, +0, –]
*
* Converts the value at the given index to a Lua thread (represented as
* lua_State*). This value must be a thread; otherwise, the function returns
* NULL.
*/
LUA_API lua_State *lua_tothread (lua_State *L, int idx) {
const TValue *o = index2value(L, idx);
return (!ttisthread(o)) ? NULL : thvalue(o);
}
/**
* lua_topointer [-0, +0, –]
*
* Converts the value at the given index to a generic C pointer (void*). The
* value can be a userdata, a table, a thread, a string, or a function;
* otherwise, lua_topointer returns NULL. Different objects will give
* different pointers. There is no way to convert the pointer back to its
* original value.
*
* Typically this function is used only for hashing and debug information.
*/
LUA_API const void *lua_topointer (lua_State *L, int idx) {
/*
** Returns a pointer to the internal representation of an object.
** Note that ANSI C does not allow the conversion of a pointer to
** function to a 'void*', so the conversion here goes through
** a 'size_t'. (As the returned pointer is only informative, this
** conversion should not be a problem.)
*/
const TValue *o = index2value(L, idx);
switch (ttypetag(o)) {
case LUA_VLCF: return cast_voidp(cast_sizet(fvalue(o)));
case LUA_VUSERDATA: case LUA_VLIGHTUSERDATA:
return touserdata(o);
default: {
if (iscollectable(o))
return gcvalue(o);
else
return NULL;
}
}
}
/*
** push functions (C -> stack)
*/
/**
* lua_pushnil [-0, +1, –]
*
* Pushes a nil value onto the stack.
*/
LUA_API void lua_pushnil (lua_State *L) {
lua_lock(L);
setnilvalue(s2v(L->top));
api_incr_top(L);
lua_unlock(L);
}
/**
* lua_pushnumber [-0, +1, –]
*
* Pushes a float with value n onto the stack.
*/
LUA_API void lua_pushnumber (lua_State *L, lua_Number n) {
lua_lock(L);
setfltvalue(s2v(L->top), n);
api_incr_top(L);
lua_unlock(L);
}
/**
* lua_pushinteger [-0, +1, –]
*
* void lua_pushinteger (lua_State *L, lua_Integer n);
*
* Pushes an integer with value n onto the stack.
*/
LUA_API void lua_pushinteger (lua_State *L, lua_Integer n) {
lua_lock(L);
setivalue(s2v(L->top), n);
api_incr_top(L);
lua_unlock(L);
}
/*
** Pushes on the stack a string with given length. Avoid using 's' when
** 'len' == 0 (as 's' can be NULL in that case), due to later use of
** 'memcmp' and 'memcpy'.
*/
LUA_API const char *lua_pushlstring (lua_State *L, const char *s, size_t len) {
TString *ts;
lua_lock(L);
ts = (len == 0) ? luaS_new(L, "") : luaS_newlstr(L, s, len);
setsvalue2s(L, L->top, ts);
api_incr_top(L);
luaC_checkGC(L);
lua_unlock(L);
return getstr(ts);
}
/**
* lua_pushstring [-0, +1, m]
*
* Pushes the zero-terminated string pointed to by s onto the stack. Lua will
* make or reuse an internal copy of the given string, so the memory at s can
* be freed or reused immediately after the function returns.
*
* Returns a pointer to the internal copy of the string (see §4.1.3).
*
* If s is NULL, pushes nil and returns NULL.
*/
LUA_API const char *lua_pushstring (lua_State *L, const char *s) {
lua_lock(L);
if (s == NULL)
setnilvalue(s2v(L->top));
else {
TString *ts;
ts = luaS_new(L, s);
setsvalue2s(L, L->top, ts);
s = getstr(ts); /* internal copy's address */
}
api_incr_top(L);
luaC_checkGC(L);
lua_unlock(L);
return s;
}
/**
* lua_pushvfstring [-0, +1, v]
*
* Equivalent to lua_pushfstring, except that it receives a va_list instead
* of a variable number of arguments.
*/
LUA_API const char *lua_pushvfstring (lua_State *L, const char *fmt,
va_list argp) {
const char *ret;
lua_lock(L);
ret = luaO_pushvfstring(L, fmt, argp);
luaC_checkGC(L);
lua_unlock(L);
return ret;
}
/**
* lua_pushfstring [-0, +1, v]
*
* Pushes onto the stack a formatted string and returns a pointer to this
* string (see §4.1.3). It is similar to the ISO C function sprintf, but has
* two important differences. First, you do not have to allocate space for
* the result; the result is a Lua string and Lua takes care of memory
* allocation (and deallocation, through garbage collection). Second, the
* conversion specifiers are quite restricted. There are no flags, widths, or
* precisions. The conversion specifiers can only be '%%' (inserts the
* character '%'), '%s' (inserts a zero-terminated string, with no size
* restrictions), '%f' (inserts a lua_Number), '%I' (inserts a lua_Integer),
* '%p' (inserts a pointer), '%d' (inserts an int), '%c' (inserts an int as a
* one-byte character), and '%U' (inserts a long int as a UTF-8 byte
* sequence).
*
* This function may raise errors due to memory overflow or an invalid
* conversion specifier.
*/
LUA_API const char *lua_pushfstring (lua_State *L, const char *fmt, ...) {
const char *ret;
va_list argp;
lua_lock(L);
va_start(argp, fmt);
ret = luaO_pushvfstring(L, fmt, argp);
va_end(argp);
luaC_checkGC(L);
lua_unlock(L);
return ret;
}
/**
* lua_pushcclosure [-n, +1, m]
*
* Pushes a new C closure onto the stack. This function receives a pointer to
* a C function and pushes onto the stack a Lua value of type function that,
* when called, invokes the corresponding C function. The parameter n tells
* how many upvalues this function will have (see §4.2).
*
* Any function to be callable by Lua must follow the correct protocol to
* receive its parameters and return its results (see lua_CFunction).
*
* When a C function is created, it is possible to associate some values with
* it, the so called upvalues; these upvalues are then accessible to the
* function whenever it is called. This association is called a C closure
* (see §4.2). To create a C closure, first the initial values for its
* upvalues must be pushed onto the stack. (When there are multiple upvalues,
* the first value is pushed first.) Then lua_pushcclosure is called to
* create and push the C function onto the stack, with the argument n telling
* how many values will be associated with the function. lua_pushcclosure
* also pops these values from the stack.
*
* The maximum value for n is 255.
*
* When n is zero, this function creates a light C function, which is just a
* pointer to the C function. In that case, it never raises a memory error.
*/
LUA_API void lua_pushcclosure (lua_State *L, lua_CFunction fn, int n) {
lua_lock(L);
if (n == 0) {
setfvalue(s2v(L->top), fn);
api_incr_top(L);
}
else {
CClosure *cl;
api_checknelems(L, n);
api_check(L, n <= MAXUPVAL, "upvalue index too large");
cl = luaF_newCclosure(L, n);
cl->f = fn;
L->top -= n;
while (n--) {
setobj2n(L, &cl->upvalue[n], s2v(L->top + n));
/* does not need barrier because closure is white */
lua_assert(iswhite(cl));
}
setclCvalue(L, s2v(L->top), cl);
api_incr_top(L);
luaC_checkGC(L);
}
lua_unlock(L);
}
/**
* lua_pushboolean [-0, +1, –]
*
* Pushes a boolean value with value b onto the stack.
*/
LUA_API void lua_pushboolean (lua_State *L, int b) {
lua_lock(L);
/* a.k.a. L->top->val.tt_ = b ? LUA_VTRUE : LUA_VFALSE; */
if (b)
setbtvalue(s2v(L->top));
else
setbfvalue(s2v(L->top));
api_incr_top(L);
lua_unlock(L);
}
/**
* lua_pushlightuserdata [-0, +1, –]
*
* Pushes a light userdata onto the stack.
*
* Userdata represent C values in Lua. A light userdata represents a pointer,
* a void*. It is a value (like a number): you do not create it, it has no
* individual metatable, and it is not collected (as it was never created). A
* light userdata is equal to "any" light userdata with the same C address.
*/
LUA_API void lua_pushlightuserdata (lua_State *L, void *p) {
lua_lock(L);
setpvalue(s2v(L->top), p);
api_incr_top(L);
lua_unlock(L);
}
/**
* lua_pushthread [-0, +1, –]
*
* Pushes the thread represented by L onto the stack. Returns 1 if this
* thread is the main thread of its state.
*/
LUA_API int lua_pushthread (lua_State *L) {
lua_lock(L);
setthvalue(L, s2v(L->top), L);
api_incr_top(L);
lua_unlock(L);
return (G(L)->mainthread == L);
}
/*
** get functions (Lua -> stack)
*/
static int auxgetstr (lua_State *L, const TValue *t, const char *k) {
const TValue *slot;
TString *str = luaS_new(L, k);
if (luaV_fastget(L, t, str, slot, luaH_getstr)) {
setobj2s(L, L->top, slot);
api_incr_top(L);
}
else {
setsvalue2s(L, L->top, str);
api_incr_top(L);
luaV_finishget(L, t, s2v(L->top - 1), L->top - 1, slot);
}
lua_unlock(L);
return ttype(s2v(L->top - 1));
}
/*
** Get the global table in the registry. Since all predefined
** indices in the registry were inserted right when the registry
** was created and never removed, they must always be in the array
** part of the registry.
*/
#define getGtable(L) \
(&hvalue(&G(L)->l_registry)->array[LUA_RIDX_GLOBALS - 1])
LUA_API int lua_getglobal (lua_State *L, const char *name) {
const TValue *G;
lua_lock(L);
G = getGtable(L);
return auxgetstr(L, G, name);
}
LUA_API int lua_gettable (lua_State *L, int idx) {
const TValue *slot;
TValue *t;
lua_lock(L);
t = index2value(L, idx);
if (luaV_fastget(L, t, s2v(L->top - 1), slot, luaH_get)) {
setobj2s(L, L->top - 1, slot);
}
else
luaV_finishget(L, t, s2v(L->top - 1), L->top - 1, slot);
lua_unlock(L);
return ttype(s2v(L->top - 1));
}
LUA_API int lua_getfield (lua_State *L, int idx, const char *k) {
lua_lock(L);
return auxgetstr(L, index2value(L, idx), k);
}
LUA_API int lua_geti (lua_State *L, int idx, lua_Integer n) {
TValue *t;
const TValue *slot;
lua_lock(L);
t = index2value(L, idx);
if (luaV_fastgeti(L, t, n, slot)) {
setobj2s(L, L->top, slot);
}
else {
TValue aux;
setivalue(&aux, n);
luaV_finishget(L, t, &aux, L->top, slot);
}
api_incr_top(L);
lua_unlock(L);
return ttype(s2v(L->top - 1));
}
static int finishrawget (lua_State *L, const TValue *val) {
if (isempty(val)) /* avoid copying empty items to the stack */
setnilvalue(s2v(L->top));
else
setobj2s(L, L->top, val);
api_incr_top(L);
lua_unlock(L);
return ttype(s2v(L->top - 1));
}
static Table *gettable (lua_State *L, int idx) {
TValue *t = index2value(L, idx);
api_check(L, ttistable(t), "table expected");
return hvalue(t);
}
/**
* lua_rawget [-1, +1, –]
*
* Similar to lua_gettable, but does a raw access (i.e., without
* metamethods).
*/
LUA_API int lua_rawget (lua_State *L, int idx) {
Table *t;
const TValue *val;
lua_lock(L);
api_checknelems(L, 1);
t = gettable(L, idx);
val = luaH_get(t, s2v(L->top - 1));
L->top--; /* remove key */
return finishrawget(L, val);
}
LUA_API int lua_rawgeti (lua_State *L, int idx, lua_Integer n) {
Table *t;
lua_lock(L);
t = gettable(L, idx);
return finishrawget(L, luaH_getint(t, n));
}
/**
* lua_rawgetp [-0, +1, –]
*
* Pushes onto the stack the value t[k], where t is the table at the given
* index and k is the pointer p represented as a light userdata. The access
* is raw; that is, it does not use the __index metavalue.
*
* Returns the type of the pushed value.
*/
LUA_API int lua_rawgetp (lua_State *L, int idx, const void *p) {
Table *t;
TValue k;
lua_lock(L);
t = gettable(L, idx);
setpvalue(&k, cast_voidp(p));
return finishrawget(L, luaH_get(t, &k));
}
/**
* lua_createtable [-0, +1, m]
*
* Creates a new empty table and pushes it onto the stack. Parameter narr is
* a hint for how many elements the table will have as a sequence; parameter
* nrec is a hint for how many other elements the table will have. Lua may
* use these hints to preallocate memory for the new table. This
* preallocation may help performance when you know in advance how many
* elements the table will have. Otherwise you can use the function
* lua_newtable.
*/
LUA_API void lua_createtable (lua_State *L, int narray, int nrec) {
Table *t;
lua_lock(L);
t = luaH_new(L);
sethvalue2s(L, L->top, t);
api_incr_top(L);
if (narray > 0 || nrec > 0)
luaH_resize(L, t, narray, nrec);
luaC_checkGC(L);
lua_unlock(L);
}
/**
* lua_getmetatable [-0, +(0|1), –]
*
* int lua_getmetatable (lua_State *L, int index);
*
* If the value at the given index has a metatable, the function pushes that
* metatable onto the stack and returns 1. Otherwise, the function returns 0
* and pushes nothing on the stack.
*/
LUA_API int lua_getmetatable (lua_State *L, int objindex) {
const TValue *obj;
Table *mt;
int res = 0;
lua_lock(L);
obj = index2value(L, objindex);
switch (ttype(obj)) {
case LUA_TTABLE:
mt = hvalue(obj)->metatable;
break;
case LUA_TUSERDATA:
mt = uvalue(obj)->metatable;
break;
default:
mt = G(L)->mt[ttype(obj)];
break;
}
if (mt != NULL) {
sethvalue2s(L, L->top, mt);
api_incr_top(L);
res = 1;
}
lua_unlock(L);
return res;
}
/**
* lua_getiuservalue [-0, +1, –]
*
* int lua_getiuservalue (lua_State *L, int index, int n);
*
* Pushes onto the stack the n-th user value associated with the full
* userdata at the given index and returns the type of the pushed value.
*
* If the userdata does not have that value, pushes nil and returns
* LUA_TNONE.
*/
LUA_API int lua_getiuservalue (lua_State *L, int idx, int n) {
TValue *o;
int t;
lua_lock(L);
o = index2value(L, idx);
api_check(L, ttisfulluserdata(o), "full userdata expected");
if (n <= 0 || n > uvalue(o)->nuvalue) {
setnilvalue(s2v(L->top));
t = LUA_TNONE;
}
else {
setobj2s(L, L->top, &uvalue(o)->uv[n - 1].uv);
t = ttype(s2v(L->top));
}
api_incr_top(L);
lua_unlock(L);
return t;
}
/*
** set functions (stack -> Lua)
*/
/*
** t[k] = value at the top of the stack (where 'k' is a string)
*/
static void auxsetstr (lua_State *L, const TValue *t, const char *k) {
const TValue *slot;
TString *str = luaS_new(L, k);
api_checknelems(L, 1);
if (luaV_fastget(L, t, str, slot, luaH_getstr)) {
luaV_finishfastset(L, t, slot, s2v(L->top - 1));
L->top--; /* pop value */
}
else {
setsvalue2s(L, L->top, str); /* push 'str' (to make it a TValue) */
api_incr_top(L);
luaV_finishset(L, t, s2v(L->top - 1), s2v(L->top - 2), slot);
L->top -= 2; /* pop value and key */
}
lua_unlock(L); /* lock done by caller */
}
LUA_API void lua_setglobal (lua_State *L, const char *name) {
const TValue *G;
lua_lock(L); /* unlock done in 'auxsetstr' */
G = getGtable(L);
auxsetstr(L, G, name);
}
LUA_API void lua_settable (lua_State *L, int idx) {
TValue *t;
const TValue *slot;
lua_lock(L);
api_checknelems(L, 2);
t = index2value(L, idx);
if (luaV_fastget(L, t, s2v(L->top - 2), slot, luaH_get)) {
luaV_finishfastset(L, t, slot, s2v(L->top - 1));
}
else
luaV_finishset(L, t, s2v(L->top - 2), s2v(L->top - 1), slot);
L->top -= 2; /* pop index and value */
lua_unlock(L);
}
LUA_API void lua_setfield (lua_State *L, int idx, const char *k) {
lua_lock(L); /* unlock done in 'auxsetstr' */
auxsetstr(L, index2value(L, idx), k);
}
/**
* lua_seti [-1, +0, e]
*
* Does the equivalent to t[n] = v, where t is the value at the given index
* and v is the value on the top of the stack.
*
* This function pops the value from the stack. As in Lua, this function may
* trigger a metamethod for the "newindex" event (see §2.4).
*/
LUA_API void lua_seti (lua_State *L, int idx, lua_Integer n) {
TValue *t;
const TValue *slot;
lua_lock(L);
api_checknelems(L, 1);
t = index2value(L, idx);
if (luaV_fastgeti(L, t, n, slot)) {
luaV_finishfastset(L, t, slot, s2v(L->top - 1));
}
else {
TValue aux;
setivalue(&aux, n);
luaV_finishset(L, t, &aux, s2v(L->top - 1), slot);
}
L->top--; /* pop value */
lua_unlock(L);
}
static void aux_rawset (lua_State *L, int idx, TValue *key, int n) {
Table *t;
lua_lock(L);
api_checknelems(L, n);
t = gettable(L, idx);
luaH_set(L, t, key, s2v(L->top - 1));
invalidateTMcache(t);
luaC_barrierback(L, obj2gco(t), s2v(L->top - 1));
L->top -= n;
lua_unlock(L);
}
/**
* lua_rawset [-2, +0, m]
*
* Similar to lua_settable, but does a raw assignment (i.e., without
* metamethods).
*/
LUA_API void lua_rawset (lua_State *L, int idx) {
aux_rawset(L, idx, s2v(L->top - 2), 2);
}
/**
* lua_rawsetp [-1, +0, m]
*
* Does the equivalent of t[p] = v, where t is the table at the given index,
* p is encoded as a light userdata, and v is the value on the top of the
* stack.
*
* This function pops the value from the stack. The assignment is raw, that
* is, it does not use the __newindex metavalue.
*/
LUA_API void lua_rawsetp (lua_State *L, int idx, const void *p) {
TValue k;
setpvalue(&k, cast_voidp(p));
aux_rawset(L, idx, &k, 1);
}
/**
* lua_rawseti [-1, +0, m]
*
* Does the equivalent of t[i] = v, where t is the table at the given index
* and v is the value on the top of the stack.
*
* This function pops the value from the stack. The assignment is raw, that
* is, it does not use the __newindex metavalue.
*/
LUA_API void lua_rawseti (lua_State *L, int idx, lua_Integer n) {
Table *t;
lua_lock(L);
api_checknelems(L, 1);
t = gettable(L, idx);
luaH_setint(L, t, n, s2v(L->top - 1));
luaC_barrierback(L, obj2gco(t), s2v(L->top - 1));
L->top--;
lua_unlock(L);
}
/**
* lua_setmetatable [-1, +0, –]
*
* Pops a table or nil from the stack and sets that value as the new
* metatable for the value at the given index. (nil means no metatable.)
*
* (For historical reasons, this function returns an int, which now is always
* 1.)
*/
LUA_API int lua_setmetatable (lua_State *L, int objindex) {
TValue *obj;
Table *mt;
lua_lock(L);
api_checknelems(L, 1);
obj = index2value(L, objindex);
if (ttisnil(s2v(L->top - 1)))
mt = NULL;
else {
api_check(L, ttistable(s2v(L->top - 1)), "table expected");
mt = hvalue(s2v(L->top - 1));
}
switch (ttype(obj)) {
case LUA_TTABLE: {
hvalue(obj)->metatable = mt;
if (mt) {
luaC_objbarrier(L, gcvalue(obj), mt);
luaC_checkfinalizer(L, gcvalue(obj), mt);
}
break;
}
case LUA_TUSERDATA: {
uvalue(obj)->metatable = mt;
if (mt) {
luaC_objbarrier(L, uvalue(obj), mt);
luaC_checkfinalizer(L, gcvalue(obj), mt);
}
break;
}
default: {
G(L)->mt[ttype(obj)] = mt;
break;
}
}
L->top--;
lua_unlock(L);
return 1;
}
/**
* lua_setiuservalue [-1, +0, –]
*
* Pops a value from the stack and sets it as the new n-th user value
* associated to the full userdata at the given index. Returns 0 if the
* userdata does not have that value.
*/
LUA_API int lua_setiuservalue (lua_State *L, int idx, int n) {
TValue *o;
int res;
lua_lock(L);
api_checknelems(L, 1);
o = index2value(L, idx);
api_check(L, ttisfulluserdata(o), "full userdata expected");
if (!(cast_uint(n) - 1u < cast_uint(uvalue(o)->nuvalue)))
res = 0; /* 'n' not in [1, uvalue(o)->nuvalue] */
else {
setobj(L, &uvalue(o)->uv[n - 1].uv, s2v(L->top - 1));
luaC_barrierback(L, gcvalue(o), s2v(L->top - 1));
res = 1;
}
L->top--;
lua_unlock(L);
return res;
}
/*
** 'load' and 'call' functions (run Lua code)
*/
#define checkresults(L,na,nr) \
api_check(L, (nr) == LUA_MULTRET || (L->ci->top - L->top >= (nr) - (na)), \
"results from function overflow current stack size")
LUA_API void lua_callk (lua_State *L, int nargs, int nresults,
lua_KContext ctx, lua_KFunction k) {
StkId func;
lua_lock(L);
api_check(L, k == NULL || !isLua(L->ci),
"cannot use continuations inside hooks");
api_checknelems(L, nargs+1);
api_check(L, L->status == LUA_OK, "cannot do calls on non-normal thread");
checkresults(L, nargs, nresults);
func = L->top - (nargs+1);
if (k != NULL && yieldable(L)) { /* need to prepare continuation? */
L->ci->u.c.k = k; /* save continuation */
L->ci->u.c.ctx = ctx; /* save context */
luaD_call(L, func, nresults); /* do the call */
}
else /* no continuation or no yieldable */
luaD_callnoyield(L, func, nresults); /* just do the call */
adjustresults(L, nresults);
lua_unlock(L);
}
/*
** Execute a protected call.
*/
struct CallS { /* data to 'f_call' */
StkId func;
int nresults;
};
static void f_call (lua_State *L, void *ud) {
struct CallS *c = cast(struct CallS *, ud);
luaD_callnoyield(L, c->func, c->nresults);
}
LUA_API int lua_pcallk (lua_State *L, int nargs, int nresults, int errfunc,
lua_KContext ctx, lua_KFunction k) {
struct CallS c;
int status;
ptrdiff_t func;
lua_lock(L);
api_check(L, k == NULL || !isLua(L->ci),
"cannot use continuations inside hooks");
api_checknelems(L, nargs+1);
api_check(L, L->status == LUA_OK, "cannot do calls on non-normal thread");
checkresults(L, nargs, nresults);
if (errfunc == 0)
func = 0;
else {
StkId o = index2stack(L, errfunc);
api_check(L, ttisfunction(s2v(o)), "error handler must be a function");
func = savestack(L, o);
}
c.func = L->top - (nargs+1); /* function to be called */
if (k == NULL || !yieldable(L)) { /* no continuation or no yieldable? */
c.nresults = nresults; /* do a 'conventional' protected call */
status = luaD_pcall(L, f_call, &c, savestack(L, c.func), func);
}
else { /* prepare continuation (call is already protected by 'resume') */
CallInfo *ci = L->ci;
ci->u.c.k = k; /* save continuation */
ci->u.c.ctx = ctx; /* save context */
/* save information for error recovery */
ci->u2.funcidx = cast_int(savestack(L, c.func));
ci->u.c.old_errfunc = L->errfunc;
L->errfunc = func;
setoah(ci->callstatus, L->allowhook); /* save value of 'allowhook' */
ci->callstatus |= CIST_YPCALL; /* function can do error recovery */
luaD_call(L, c.func, nresults); /* do the call */
ci->callstatus &= ~CIST_YPCALL;
L->errfunc = ci->u.c.old_errfunc;
status = LUA_OK; /* if it is here, there were no errors */
}
adjustresults(L, nresults);
lua_unlock(L);
return status;
}
LUA_API int lua_load (lua_State *L, lua_Reader reader, void *data,
const char *chunkname, const char *mode) {
ZIO z;
int status;
lua_lock(L);
if (!chunkname) chunkname = "?";
luaZ_init(L, &z, reader, data);
status = luaD_protectedparser(L, &z, chunkname, mode);
if (status == LUA_OK) { /* no errors? */
LClosure *f = clLvalue(s2v(L->top - 1)); /* get newly created function */
if (f->nupvalues >= 1) { /* does it have an upvalue? */
/* get global table from registry */
const TValue *gt = getGtable(L);
/* set global table as 1st upvalue of 'f' (may be LUA_ENV) */
setobj(L, f->upvals[0]->v, gt);
luaC_barrier(L, f->upvals[0], gt);
}
}
lua_unlock(L);
return status;
}
LUA_API int lua_dump (lua_State *L, lua_Writer writer, void *data, int strip) {
int status;
TValue *o;
lua_lock(L);
api_checknelems(L, 1);
o = s2v(L->top - 1);
if (isLfunction(o))
status = luaU_dump(L, getproto(o), writer, data, strip);
else
status = 1;
lua_unlock(L);
return status;
}
LUA_API int lua_status (lua_State *L) {
return L->status;
}
/*
** Garbage-collection function
*/
LUA_API int lua_gc (lua_State *L, int what, ...) {
va_list argp;
int res = 0;
global_State *g;
lua_lock(L);
g = G(L);
va_start(argp, what);
switch (what) {
case LUA_GCSTOP: {
g->gcrunning = 0;
break;
}
case LUA_GCRESTART: {
luaE_setdebt(g, 0);
g->gcrunning = 1;
break;
}
case LUA_GCCOLLECT: {
luaC_fullgc(L, 0);
break;
}
case LUA_GCCOUNT: {
/* GC values are expressed in Kbytes: #bytes/2^10 */
res = cast_int(gettotalbytes(g) >> 10);
break;
}
case LUA_GCCOUNTB: {
res = cast_int(gettotalbytes(g) & 0x3ff);
break;
}
case LUA_GCSTEP: {
int data = va_arg(argp, int);
l_mem debt = 1; /* =1 to signal that it did an actual step */
lu_byte oldrunning = g->gcrunning;
g->gcrunning = 1; /* allow GC to run */
if (data == 0) {
luaE_setdebt(g, 0); /* do a basic step */
luaC_step(L);
}
else { /* add 'data' to total debt */
debt = cast(l_mem, data) * 1024 + g->GCdebt;
luaE_setdebt(g, debt);
luaC_checkGC(L);
}
g->gcrunning = oldrunning; /* restore previous state */
if (debt > 0 && g->gcstate == GCSpause) /* end of cycle? */
res = 1; /* signal it */
break;
}
case LUA_GCSETPAUSE: {
int data = va_arg(argp, int);
res = getgcparam(g->gcpause);
setgcparam(g->gcpause, data);
break;
}
case LUA_GCSETSTEPMUL: {
int data = va_arg(argp, int);
res = getgcparam(g->gcstepmul);
setgcparam(g->gcstepmul, data);
break;
}
case LUA_GCISRUNNING: {
res = g->gcrunning;
break;
}
case LUA_GCGEN: {
int minormul = va_arg(argp, int);
int majormul = va_arg(argp, int);
res = isdecGCmodegen(g) ? LUA_GCGEN : LUA_GCINC;
if (minormul != 0)
g->genminormul = minormul;
if (majormul != 0)
setgcparam(g->genmajormul, majormul);
luaC_changemode(L, KGC_GEN);
break;
}
case LUA_GCINC: {
int pause = va_arg(argp, int);
int stepmul = va_arg(argp, int);
int stepsize = va_arg(argp, int);
res = isdecGCmodegen(g) ? LUA_GCGEN : LUA_GCINC;
if (pause != 0)
setgcparam(g->gcpause, pause);
if (stepmul != 0)
setgcparam(g->gcstepmul, stepmul);
if (stepsize != 0)
g->gcstepsize = stepsize;
luaC_changemode(L, KGC_INC);
break;
}
default: res = -1; /* invalid option */
}
va_end(argp);
lua_unlock(L);
return res;
}
/*
** miscellaneous functions
*/
/**
* lua_error [-1, +0, v]
*
* Raises a Lua error, using the value on the top of the stack as the error
* object. This function does a long jump, and therefore never returns (see
* luaL_error).
*/
LUA_API int lua_error (lua_State *L) {
TValue *errobj;
lua_lock(L);
errobj = s2v(L->top - 1);
api_checknelems(L, 1);
/* error object is the memory error message? */
if (ttisshrstring(errobj) && eqshrstr(tsvalue(errobj), G(L)->memerrmsg))
luaM_error(L); /* raise a memory error */
else
luaG_errormsg(L); /* raise a regular error */
/* code unreachable; will unlock when control actually leaves the kernel */
unreachable;
}
/**
* lua_next [-1, +(2|0), v]
*
* Pops a key from the stack, and pushes a key–value pair from the table at
* the given index, the "next" pair after the given key. If there are no more
* elements in the table, then lua_next returns 0 and pushes nothing.
*
* A typical table traversal looks like this:
*
* // table is in the stack at index 't'
* lua_pushnil(L); // first key
* while (lua_next(L, t) != 0) {
* // uses 'key' (at index -2) and 'value' (at index -1)
* printf("%s - %s\n",
* lua_typename(L, lua_type(L, -2)),
* lua_typename(L, lua_type(L, -1)));
* // removes 'value'; keeps 'key' for next iteration
* lua_pop(L, 1);
* }
*
* While traversing a table, avoid calling lua_tolstring directly on a key,
* unless you know that the key is actually a string. Recall that
* lua_tolstring may change the value at the given index; this confuses the
* next call to lua_next.
*
* This function may raise an error if the given key is neither nil nor
* present in the table. See function next for the caveats of modifying the
* table during its traversal.
*/
LUA_API int lua_next (lua_State *L, int idx) {
Table *t;
int more;
lua_lock(L);
api_checknelems(L, 1);
t = gettable(L, idx);
more = luaH_next(L, t, L->top - 1);
if (more) {
api_incr_top(L);
}
else /* no more elements */
L->top -= 1; /* remove key */
lua_unlock(L);
return more;
}
/**
* lua_toclose [-0, +0, m]
*
* Marks the given index in the stack as a to-be-closed slot (see §3.3.8).
* Like a to-be-closed variable in Lua, the value at that slot in the stack
* will be closed when it goes out of scope. Here, in the context of a C
* function, to go out of scope means that the running function returns to
* Lua, or there is an error, or the slot is removed from the stack through
* lua_settop or lua_pop, or there is a call to lua_closeslot. A slot marked
* as to-be-closed should not be removed from the stack by any other function
* in the API except lua_settop or lua_pop, unless previously deactivated by
* lua_closeslot.
*
* This function should not be called for an index that is equal to or below
* an active to-be-closed slot.
*
* Note that, both in case of errors and of a regular return, by the time the
* __close metamethod runs, the C stack was already unwound, so that any
* automatic C variable declared in the calling function (e.g., a buffer)
* will be out of scope.
*/
LUA_API void lua_toclose (lua_State *L, int idx) {
int nresults;
StkId o;
lua_lock(L);
o = index2stack(L, idx);
nresults = L->ci->nresults;
api_check(L, L->tbclist < o, "given index below or equal a marked one");
luaF_newtbcupval(L, o); /* create new to-be-closed upvalue */
if (!hastocloseCfunc(nresults)) /* function not marked yet? */
L->ci->nresults = codeNresults(nresults); /* mark it */
lua_assert(hastocloseCfunc(L->ci->nresults));
lua_unlock(L);
}
/**
* lua_concat [-n, +1, e]
*
* Concatenates the n values at the top of the stack, pops them, and leaves
* the result on the top. If n is 1, the result is the single value on the
* stack (that is, the function does nothing); if n is 0, the result is the
* empty string. Concatenation is performed following the usual semantics of
* Lua (see §3.4.6).
*/
LUA_API void lua_concat (lua_State *L, int n) {
lua_lock(L);
api_checknelems(L, n);
if (n > 0)
luaV_concat(L, n);
else { /* nothing to concatenate */
setsvalue2s(L, L->top, luaS_newlstr(L, "", 0)); /* push empty string */
api_incr_top(L);
}
luaC_checkGC(L);
lua_unlock(L);
}
/**
* lua_len [-0, +1, e]
*
* Returns the length of the value at the given index. It is equivalent to
* the '#' operator in Lua (see §3.4.7) and may trigger a metamethod for the
* "length" event (see §2.4). The result is pushed on the stack.
*/
LUA_API void lua_len (lua_State *L, int idx) {
TValue *t;
lua_lock(L);
t = index2value(L, idx);
luaV_objlen(L, L->top, t);
api_incr_top(L);
lua_unlock(L);
}
/**
* lua_getallocf [-0, +0, –]
*
* Returns the memory-allocation function of a given state. If ud is not
* NULL, Lua stores in *ud the opaque pointer given when the memory-allocator
* function was set.
*/
LUA_API lua_Alloc lua_getallocf (lua_State *L, void **ud) {
lua_Alloc f;
lua_lock(L);
if (ud) *ud = G(L)->ud;
f = G(L)->frealloc;
lua_unlock(L);
return f;
}
/**
* lua_setallocf [-0, +0, –]
*
* void lua_setallocf (lua_State *L, lua_Alloc f, void *ud);
*
* Changes the allocator function of a given state to f with user data ud.
*/
LUA_API void lua_setallocf (lua_State *L, lua_Alloc f, void *ud) {
lua_lock(L);
G(L)->ud = ud;
G(L)->frealloc = f;
lua_unlock(L);
}
/**
* lua_setwarnf [-0, +0, –]
*
* Sets the warning function to be used by Lua to emit warnings (see
* lua_WarnFunction). The ud parameter sets the value ud passed to the
* warning function.
*/
void lua_setwarnf (lua_State *L, lua_WarnFunction f, void *ud) {
lua_lock(L);
G(L)->ud_warn = ud;
G(L)->warnf = f;
lua_unlock(L);
}
/**
* lua_warning [-0, +0, –]
*
* Emits a warning with the given message. A message in a call with tocont
* true should be continued in another call to this function.
*
* See warn for more details about warnings.
*/
void lua_warning (lua_State *L, const char *msg, int tocont) {
lua_lock(L);
luaE_warning(L, msg, tocont);
lua_unlock(L);
}
/**
* lua_newuserdatauv [-0, +1, m]
*
* This function creates and pushes on the stack a new full userdata, with
* nuvalue associated Lua values, called user values, plus an associated
* block of raw memory with size bytes. (The user values can be set and read
* with the functions lua_setiuservalue and lua_getiuservalue.)
*
* The function returns the address of the block of memory. Lua ensures that
* this address is valid as long as the corresponding userdata is alive (see
* §2.5). Moreover, if the userdata is marked for finalization (see §2.5.3),
* its address is valid at least until the call to its finalizer.
*/
LUA_API void *lua_newuserdatauv (lua_State *L, size_t size, int nuvalue) {
Udata *u;
lua_lock(L);
api_check(L, 0 <= nuvalue && nuvalue < USHRT_MAX, "invalid value");
u = luaS_newudata(L, size, nuvalue);
setuvalue(L, s2v(L->top), u);
api_incr_top(L);
luaC_checkGC(L);
lua_unlock(L);
return getudatamem(u);
}
static const char *aux_upvalue (TValue *fi, int n, TValue **val,
GCObject **owner) {
switch (ttypetag(fi)) {
case LUA_VCCL: { /* C closure */
CClosure *f = clCvalue(fi);
if (!(cast_uint(n) - 1u < cast_uint(f->nupvalues)))
return NULL; /* 'n' not in [1, f->nupvalues] */
*val = &f->upvalue[n-1];
if (owner) *owner = obj2gco(f);
return "";
}
case LUA_VLCL: { /* Lua closure */
LClosure *f = clLvalue(fi);
TString *name;
Proto *p = f->p;
if (!(cast_uint(n) - 1u < cast_uint(p->sizeupvalues)))
return NULL; /* 'n' not in [1, p->sizeupvalues] */
*val = f->upvals[n-1]->v;
if (owner) *owner = obj2gco(f->upvals[n - 1]);
name = p->upvalues[n-1].name;
return (name == NULL) ? "(no name)" : getstr(name);
}
default: return NULL; /* not a closure */
}
}
/**
* lua_getupvalue [-0, +(0|1), –]
*
* Gets information about the n-th upvalue of the closure at index funcindex.
* It pushes the upvalue's value onto the stack and returns its name. Returns
* NULL (and pushes nothing) when the index n is greater than the number of
* upvalues.
*
* See debug.getupvalue for more information about upvalues.
*/
LUA_API const char *lua_getupvalue (lua_State *L, int funcindex, int n) {
const char *name;
TValue *val = NULL; /* to avoid warnings */
lua_lock(L);
name = aux_upvalue(index2value(L, funcindex), n, &val, NULL);
if (name) {
setobj2s(L, L->top, val);
api_incr_top(L);
}
lua_unlock(L);
return name;
}
/**
* lua_setupvalue [-(0|1), +0, –]
*
* Sets the value of a closure's upvalue. It assigns the value on the top of
* the stack to the upvalue and returns its name. It also pops the value from
* the stack.
*
* Returns NULL (and pops nothing) when the index n is greater than the
* number of upvalues.
*
* Parameters funcindex and n are as in the function lua_getupvalue.
*/
LUA_API const char *lua_setupvalue (lua_State *L, int funcindex, int n) {
const char *name;
TValue *val = NULL; /* to avoid warnings */
GCObject *owner = NULL; /* to avoid warnings */
TValue *fi;
lua_lock(L);
fi = index2value(L, funcindex);
api_checknelems(L, 1);
name = aux_upvalue(fi, n, &val, &owner);
if (name) {
L->top--;
setobj(L, val, s2v(L->top));
luaC_barrier(L, owner, val);
}
lua_unlock(L);
return name;
}
static UpVal **getupvalref (lua_State *L, int fidx, int n, LClosure **pf) {
static const UpVal *const nullup = NULL;
LClosure *f;
TValue *fi = index2value(L, fidx);
api_check(L, ttisLclosure(fi), "Lua function expected");
f = clLvalue(fi);
if (pf) *pf = f;
if (1 <= n && n <= f->p->sizeupvalues)
return &f->upvals[n - 1]; /* get its upvalue pointer */
else
return (UpVal**)&nullup;
}
/**
* lua_upvalueid [-0, +0, –]
*
* Returns a unique identifier for the upvalue numbered n from the closure at
* index funcindex.
*
* These unique identifiers allow a program to check whether different
* closures share upvalues. Lua closures that share an upvalue (that is, that
* access a same external local variable) will return identical ids for those
* upvalue indices.
*
* Parameters funcindex and n are as in the function lua_getupvalue, but n
* cannot be greater than the number of upvalues.
*/
LUA_API void *lua_upvalueid (lua_State *L, int fidx, int n) {
TValue *fi = index2value(L, fidx);
switch (ttypetag(fi)) {
case LUA_VLCL: { /* lua closure */
return *getupvalref(L, fidx, n, NULL);
}
case LUA_VCCL: { /* C closure */
CClosure *f = clCvalue(fi);
if (1 <= n && n <= f->nupvalues)
return &f->upvalue[n - 1];
/* else */
} /* FALLTHROUGH */
case LUA_VLCF:
return NULL; /* light C functions have no upvalues */
default: {
api_check(L, 0, "function expected");
return NULL;
}
}
}
/**
* lua_upvaluejoin [-0, +0, –]
*
* Make the n1-th upvalue of the Lua closure at index funcindex1 refer to the
* n2-th upvalue of the Lua closure at index funcindex2.
*/
LUA_API void lua_upvaluejoin (lua_State *L, int fidx1, int n1,
int fidx2, int n2) {
LClosure *f1;
UpVal **up1 = getupvalref(L, fidx1, n1, &f1);
UpVal **up2 = getupvalref(L, fidx2, n2, NULL);
api_check(L, *up1 != NULL && *up2 != NULL, "invalid upvalue index");
*up1 = *up2;
luaC_objbarrier(L, f1, *up1);
}