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/*
** $Id: ltm.c $
** Tag methods
** See Copyright Notice in lua.h
*/

#define ltm_c
#define LUA_CORE

#include "lprefix.h"


#include <string.h>

#include "lua.h"

#include "ldebug.h"
#include "ldo.h"
#include "lgc.h"
#include "lobject.h"
#include "lstate.h"
#include "lstring.h"
#include "ltable.h"
#include "ltm.h"
#include "lvm.h"


static const char udatatypename[] = "userdata";

LUAI_DDEF const char *const luaT_typenames_[LUA_TOTALTYPES] = {
  "no value",
  "nil", "boolean", udatatypename, "number",
  "string", "table", "function", udatatypename, "thread",
  "upvalue", "proto" /* these last cases are used for tests only */
};


void luaT_init (lua_State *L) {
  static const char *const luaT_eventname[] = {  /* ORDER TM */
    "__index", "__newindex",
    "__gc", "__mode", "__len", "__eq",
    "__add", "__sub", "__mul", "__mod", "__pow",
    "__div", "__idiv",
    "__band", "__bor", "__bxor", "__shl", "__shr",
    "__unm", "__bnot", "__lt", "__le",
    "__concat", "__call", "__close"
  };
  int i;
  for (i=0; i<TM_N; i++) {
    G(L)->tmname[i] = luaS_new(L, luaT_eventname[i]);
    luaC_fix(L, obj2gco(G(L)->tmname[i]));  /* never collect these names */
  }
}


/*
** function to be used with macro "fasttm": optimized for absence of
** tag methods
*/
const TValue *luaT_gettm (Table *events, TMS event, TString *ename) {
  const TValue *tm = luaH_getshortstr(events, ename);
  lua_assert(event <= TM_EQ);
  if (notm(tm)) {  /* no tag method? */
    events->flags |= cast_byte(1u<<event);  /* cache this fact */
    return NULL;
  }
  else return tm;
}


const TValue *luaT_gettmbyobj (lua_State *L, const TValue *o, TMS event) {
  Table *mt;
  switch (ttype(o)) {
    case LUA_TTABLE:
      mt = hvalue(o)->metatable;
      break;
    case LUA_TUSERDATA:
      mt = uvalue(o)->metatable;
      break;
    default:
      mt = G(L)->mt[ttype(o)];
  }
  return (mt ? luaH_getshortstr(mt, G(L)->tmname[event]) : &G(L)->nilvalue);
}


/*
** Return the name of the type of an object. For tables and userdata
** with metatable, use their '__name' metafield, if present.
*/
const char *luaT_objtypename (lua_State *L, const TValue *o) {
  Table *mt;
  if ((ttistable(o) && (mt = hvalue(o)->metatable) != NULL) ||
      (ttisfulluserdata(o) && (mt = uvalue(o)->metatable) != NULL)) {
    const TValue *name = luaH_getshortstr(mt, luaS_new(L, "__name"));
    if (ttisstring(name))  /* is '__name' a string? */
      return getstr(tsvalue(name));  /* use it as type name */
  }
  return ttypename(ttype(o));  /* else use standard type name */
}


void luaT_callTM (lua_State *L, const TValue *f, const TValue *p1,
                  const TValue *p2, const TValue *p3) {
  StkId func = L->top.p;
  setobj2s(L, func, f);  /* push function (assume EXTRA_STACK) */
  setobj2s(L, func + 1, p1);  /* 1st argument */
  setobj2s(L, func + 2, p2);  /* 2nd argument */
  setobj2s(L, func + 3, p3);  /* 3rd argument */
  L->top.p = func + 4;
  /* metamethod may yield only when called from Lua code */
  if (isLuacode(L->ci))
    luaD_call(L, func, 0);
  else
    luaD_callnoyield(L, func, 0);
}


void luaT_callTMres (lua_State *L, const TValue *f, const TValue *p1,
                     const TValue *p2, StkId res) {
  ptrdiff_t result = savestack(L, res);
  StkId func = L->top.p;
  setobj2s(L, func, f);  /* push function (assume EXTRA_STACK) */
  setobj2s(L, func + 1, p1);  /* 1st argument */
  setobj2s(L, func + 2, p2);  /* 2nd argument */
  L->top.p += 3;
  /* metamethod may yield only when called from Lua code */
  if (isLuacode(L->ci))
    luaD_call(L, func, 1);
  else
    luaD_callnoyield(L, func, 1);
  res = restorestack(L, result);
  setobjs2s(L, res, --L->top.p);  /* move result to its place */
}


static int callbinTM (lua_State *L, const TValue *p1, const TValue *p2,
                      StkId res, TMS event) {
  const TValue *tm = luaT_gettmbyobj(L, p1, event);  /* try first operand */
  if (notm(tm))
    tm = luaT_gettmbyobj(L, p2, event);  /* try second operand */
  if (notm(tm)) return 0;
  luaT_callTMres(L, tm, p1, p2, res);
  return 1;
}


void luaT_trybinTM (lua_State *L, const TValue *p1, const TValue *p2,
                    StkId res, TMS event) {
  if (l_unlikely(!callbinTM(L, p1, p2, res, event))) {
    switch (event) {
      case TM_BAND: case TM_BOR: case TM_BXOR:
      case TM_SHL: case TM_SHR: case TM_BNOT: {
        if (ttisnumber(p1) && ttisnumber(p2))
          luaG_tointerror(L, p1, p2);
        else
          luaG_opinterror(L, p1, p2, "perform bitwise operation on");
      }
      /* calls never return, but to avoid warnings: *//* FALLTHROUGH */
      default:
        luaG_opinterror(L, p1, p2, "perform arithmetic on");
    }
  }
}


void luaT_tryconcatTM (lua_State *L) {
  StkId top = L->top.p;
  if (l_unlikely(!callbinTM(L, s2v(top - 2), s2v(top - 1), top - 2,
                               TM_CONCAT)))
    luaG_concaterror(L, s2v(top - 2), s2v(top - 1));
}


void luaT_trybinassocTM (lua_State *L, const TValue *p1, const TValue *p2,
                                       int flip, StkId res, TMS event) {
  if (flip)
    luaT_trybinTM(L, p2, p1, res, event);
  else
    luaT_trybinTM(L, p1, p2, res, event);
}


void luaT_trybiniTM (lua_State *L, const TValue *p1, lua_Integer i2,
                                   int flip, StkId res, TMS event) {
  TValue aux;
  setivalue(&aux, i2);
  luaT_trybinassocTM(L, p1, &aux, flip, res, event);
}


/*
** Calls an order tag method.
** For lessequal, LUA_COMPAT_LT_LE keeps compatibility with old
** behavior: if there is no '__le', try '__lt', based on l <= r iff
** !(r < l) (assuming a total order). If the metamethod yields during
** this substitution, the continuation has to know about it (to negate
** the result of r<l); bit CIST_LEQ in the call status keeps that
** information.
*/
int luaT_callorderTM (lua_State *L, const TValue *p1, const TValue *p2,
                      TMS event) {
  if (callbinTM(L, p1, p2, L->top.p, event))  /* try original event */
    return !l_isfalse(s2v(L->top.p));
#if defined(LUA_COMPAT_LT_LE)
  else if (event == TM_LE) {
      /* try '!(p2 < p1)' for '(p1 <= p2)' */
      L->ci->callstatus |= CIST_LEQ;  /* mark it is doing 'lt' for 'le' */
      if (callbinTM(L, p2, p1, L->top.p, TM_LT)) {
        L->ci->callstatus ^= CIST_LEQ;  /* clear mark */
        return l_isfalse(s2v(L->top.p));
      }
      /* else error will remove this 'ci'; no need to clear mark */
  }
#endif
  luaG_ordererror(L, p1, p2);  /* no metamethod found */
  return 0;  /* to avoid warnings */
}


int luaT_callorderiTM (lua_State *L, const TValue *p1, int v2,
                       int flip, int isfloat, TMS event) {
  TValue aux; const TValue *p2;
  if (isfloat) {
    setfltvalue(&aux, cast_num(v2));
  }
  else
    setivalue(&aux, v2);
  if (flip) {  /* arguments were exchanged? */
    p2 = p1; p1 = &aux;  /* correct them */
  }
  else
    p2 = &aux;
  return luaT_callorderTM(L, p1, p2, event);
}


void luaT_adjustvarargs (lua_State *L, int nfixparams, CallInfo *ci,
                         const Proto *p) {
  int i;
  int actual = cast_int(L->top.p - ci->func.p) - 1;  /* number of arguments */
  int nextra = actual - nfixparams;  /* number of extra arguments */
  ci->u.l.nextraargs = nextra;
  luaD_checkstack(L, p->maxstacksize + 1);
  /* copy function to the top of the stack */
  setobjs2s(L, L->top.p++, ci->func.p);
  /* move fixed parameters to the top of the stack */
  for (i = 1; i <= nfixparams; i++) {
    setobjs2s(L, L->top.p++, ci->func.p + i);
    setnilvalue(s2v(ci->func.p + i));  /* erase original parameter (for GC) */
  }
  ci->func.p += actual + 1;
  ci->top.p += actual + 1;
  lua_assert(L->top.p <= ci->top.p && ci->top.p <= L->stack_last.p);
}


void luaT_getvarargs (lua_State *L, CallInfo *ci, StkId where, int wanted) {
  int i;
  int nextra = ci->u.l.nextraargs;
  if (wanted < 0) {
    wanted = nextra;  /* get all extra arguments available */
    checkstackGCp(L, nextra, where);  /* ensure stack space */
    L->top.p = where + nextra;  /* next instruction will need top */
  }
  for (i = 0; i < wanted && i < nextra; i++)
    setobjs2s(L, where + i, ci->func.p - nextra + i);
  for (; i < wanted; i++)   /* complete required results with nil */
    setnilvalue(s2v(where + i));
}

	/*
	** $Id: ltm.c $
	** Tag methods
	** See Copyright Notice in lua.h
	*/

	#define ltm_c
	#define LUA_CORE

	#include "lprefix.h"


	#include <string.h>

	#include "lua.h"

	#include "ldebug.h"
	#include "ldo.h"
	#include "lgc.h"
	#include "lobject.h"
	#include "lstate.h"
	#include "lstring.h"
	#include "ltable.h"
	#include "ltm.h"
	#include "lvm.h"


	static const char udatatypename[] = "userdata";

	LUAI_DDEF const char *const luaT_typenames_[LUA_TOTALTYPES] = {
	"no value",
	"nil", "boolean", udatatypename, "number",
	"string", "table", "function", udatatypename, "thread",
	"upvalue", "proto" /* these last cases are used for tests only */
	};


	void luaT_init (lua_State *L) {
	static const char const luaT_eventname[] = { / ORDER TM */
	"__index", "__newindex",
	"__gc", "__mode", "__len", "__eq",
	"__add", "__sub", "__mul", "__mod", "__pow",
	"__div", "__idiv",
	"__band", "__bor", "__bxor", "__shl", "__shr",
	"__unm", "__bnot", "__lt", "__le",
	"__concat", "__call", "__close"
	};
	int i;
	for (i=0; i<TM_N; i++) {
	G(L)->tmname[i] = luaS_new(L, luaT_eventname[i]);
	luaC_fix(L, obj2gco(G(L)->tmname[i])); /* never collect these names */
	}
	}


	/*
	** function to be used with macro "fasttm": optimized for absence of
	** tag methods
	*/
	const TValue luaT_gettm (Table events, TMS event, TString *ename) {
	const TValue *tm = luaH_getshortstr(events, ename);
	lua_assert(event <= TM_EQ);
	if (notm(tm)) { /* no tag method? */
	events->flags \|= cast_byte(1u<<event); /* cache this fact */
	return NULL;
	}
	else return tm;
	}


	const TValue luaT_gettmbyobj (lua_State L, const TValue *o, TMS event) {
	Table *mt;
	switch (ttype(o)) {
	case LUA_TTABLE:
	mt = hvalue(o)->metatable;
	break;
	case LUA_TUSERDATA:
	mt = uvalue(o)->metatable;
	break;
	default:
	mt = G(L)->mt[ttype(o)];
	}
	return (mt ? luaH_getshortstr(mt, G(L)->tmname[event]) : &G(L)->nilvalue);
	}


	/*
	** Return the name of the type of an object. For tables and userdata
	** with metatable, use their '__name' metafield, if present.
	*/
	const char luaT_objtypename (lua_State L, const TValue *o) {
	Table *mt;
	if ((ttistable(o) && (mt = hvalue(o)->metatable) != NULL) \|\|
	(ttisfulluserdata(o) && (mt = uvalue(o)->metatable) != NULL)) {
	const TValue *name = luaH_getshortstr(mt, luaS_new(L, "__name"));
	if (ttisstring(name)) /* is '__name' a string? */
	return getstr(tsvalue(name)); /* use it as type name */
	}
	return ttypename(ttype(o)); /* else use standard type name */
	}


	void luaT_callTM (lua_State L, const TValue f, const TValue *p1,
	const TValue p2, const TValue p3) {
	StkId func = L->top.p;
	setobj2s(L, func, f); /* push function (assume EXTRA_STACK) */
	setobj2s(L, func + 1, p1); /* 1st argument */
	setobj2s(L, func + 2, p2); /* 2nd argument */
	setobj2s(L, func + 3, p3); /* 3rd argument */
	L->top.p = func + 4;
	/* metamethod may yield only when called from Lua code */
	if (isLuacode(L->ci))
	luaD_call(L, func, 0);
	else
	luaD_callnoyield(L, func, 0);
	}


	void luaT_callTMres (lua_State L, const TValue f, const TValue *p1,
	const TValue *p2, StkId res) {
	ptrdiff_t result = savestack(L, res);
	StkId func = L->top.p;
	setobj2s(L, func, f); /* push function (assume EXTRA_STACK) */
	setobj2s(L, func + 1, p1); /* 1st argument */
	setobj2s(L, func + 2, p2); /* 2nd argument */
	L->top.p += 3;
	/* metamethod may yield only when called from Lua code */
	if (isLuacode(L->ci))
	luaD_call(L, func, 1);
	else
	luaD_callnoyield(L, func, 1);
	res = restorestack(L, result);
	setobjs2s(L, res, --L->top.p); /* move result to its place */
	}


	static int callbinTM (lua_State L, const TValue p1, const TValue *p2,
	StkId res, TMS event) {
	const TValue tm = luaT_gettmbyobj(L, p1, event); / try first operand */
	if (notm(tm))
	tm = luaT_gettmbyobj(L, p2, event); /* try second operand */
	if (notm(tm)) return 0;
	luaT_callTMres(L, tm, p1, p2, res);
	return 1;
	}


	void luaT_trybinTM (lua_State L, const TValue p1, const TValue *p2,
	StkId res, TMS event) {
	if (l_unlikely(!callbinTM(L, p1, p2, res, event))) {
	switch (event) {
	case TM_BAND: case TM_BOR: case TM_BXOR:
	case TM_SHL: case TM_SHR: case TM_BNOT: {
	if (ttisnumber(p1) && ttisnumber(p2))
	luaG_tointerror(L, p1, p2);
	else
	luaG_opinterror(L, p1, p2, "perform bitwise operation on");
	}
	/* calls never return, but to avoid warnings: // FALLTHROUGH */
	default:
	luaG_opinterror(L, p1, p2, "perform arithmetic on");
	}
	}
	}


	void luaT_tryconcatTM (lua_State *L) {
	StkId top = L->top.p;
	if (l_unlikely(!callbinTM(L, s2v(top - 2), s2v(top - 1), top - 2,
	TM_CONCAT)))
	luaG_concaterror(L, s2v(top - 2), s2v(top - 1));
	}


	void luaT_trybinassocTM (lua_State L, const TValue p1, const TValue *p2,
	int flip, StkId res, TMS event) {
	if (flip)
	luaT_trybinTM(L, p2, p1, res, event);
	else
	luaT_trybinTM(L, p1, p2, res, event);
	}


	void luaT_trybiniTM (lua_State L, const TValue p1, lua_Integer i2,
	int flip, StkId res, TMS event) {
	TValue aux;
	setivalue(&aux, i2);
	luaT_trybinassocTM(L, p1, &aux, flip, res, event);
	}


	/*
	** Calls an order tag method.
	** For lessequal, LUA_COMPAT_LT_LE keeps compatibility with old
	** behavior: if there is no '__le', try '__lt', based on l <= r iff
	** !(r < l) (assuming a total order). If the metamethod yields during
	** this substitution, the continuation has to know about it (to negate
	** the result of r<l); bit CIST_LEQ in the call status keeps that
	** information.
	*/
	int luaT_callorderTM (lua_State L, const TValue p1, const TValue *p2,
	TMS event) {
	if (callbinTM(L, p1, p2, L->top.p, event)) /* try original event */
	return !l_isfalse(s2v(L->top.p));
	#if defined(LUA_COMPAT_LT_LE)
	else if (event == TM_LE) {
	/* try '!(p2 < p1)' for '(p1 <= p2)' */
	L->ci->callstatus \|= CIST_LEQ; /* mark it is doing 'lt' for 'le' */
	if (callbinTM(L, p2, p1, L->top.p, TM_LT)) {
	L->ci->callstatus ^= CIST_LEQ; /* clear mark */
	return l_isfalse(s2v(L->top.p));
	}
	/* else error will remove this 'ci'; no need to clear mark */
	}
	#endif
	luaG_ordererror(L, p1, p2); /* no metamethod found */
	return 0; /* to avoid warnings */
	}


	int luaT_callorderiTM (lua_State L, const TValue p1, int v2,
	int flip, int isfloat, TMS event) {
	TValue aux; const TValue *p2;
	if (isfloat) {
	setfltvalue(&aux, cast_num(v2));
	}
	else
	setivalue(&aux, v2);
	if (flip) { /* arguments were exchanged? */
	p2 = p1; p1 = &aux; /* correct them */
	}
	else
	p2 = &aux;
	return luaT_callorderTM(L, p1, p2, event);
	}


	void luaT_adjustvarargs (lua_State L, int nfixparams, CallInfo ci,
	const Proto *p) {
	int i;
	int actual = cast_int(L->top.p - ci->func.p) - 1; /* number of arguments */
	int nextra = actual - nfixparams; /* number of extra arguments */
	ci->u.l.nextraargs = nextra;
	luaD_checkstack(L, p->maxstacksize + 1);
	/* copy function to the top of the stack */
	setobjs2s(L, L->top.p++, ci->func.p);
	/* move fixed parameters to the top of the stack */
	for (i = 1; i <= nfixparams; i++) {
	setobjs2s(L, L->top.p++, ci->func.p + i);
	setnilvalue(s2v(ci->func.p + i)); /* erase original parameter (for GC) */
	}
	ci->func.p += actual + 1;
	ci->top.p += actual + 1;
	lua_assert(L->top.p <= ci->top.p && ci->top.p <= L->stack_last.p);
	}


	void luaT_getvarargs (lua_State L, CallInfo ci, StkId where, int wanted) {
	int i;
	int nextra = ci->u.l.nextraargs;
	if (wanted < 0) {
	wanted = nextra; /* get all extra arguments available */
	checkstackGCp(L, nextra, where); /* ensure stack space */
	L->top.p = where + nextra; /* next instruction will need top */
	}
	for (i = 0; i < wanted && i < nextra; i++)
	setobjs2s(L, where + i, ci->func.p - nextra + i);
	for (; i < wanted; i++) /* complete required results with nil */
	setnilvalue(s2v(where + i));
	}