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Tag methods

v5-2
Roberto Ierusalimschy 28 years ago
parent
26c5f56ad1
commit
4b91e9cde6
4 changed files with 378 additions and 417 deletions
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  1. 353
      fallback.c
  2. 64
      fallback.h
  3. 317
      ltm.c
  4. 61
      ltm.h

353
fallback.c
View File

@ -1,353 +0,0 @@
/*
** fallback.c
** TecCGraf - PUC-Rio
*/
char *rcs_fallback="$Id: fallback.c,v 2.10 1997/07/03 22:06:06 roberto Exp $";
#include <stdio.h>
#include <string.h>
#include "auxlib.h"
#include "luamem.h"
#include "fallback.h"
#include "opcode.h"
#include "lua.h"
#include "table.h"
#include "tree.h"
#include "hash.h"
/* -------------------------------------------
** Reference routines
*/
static struct ref {
TObject o;
enum {LOCK, HOLD, FREE, COLLECTED} status;
} *refArray = NULL;
static int refSize = 0;
int luaI_ref (TObject *object, int lock)
{
int i;
int oldSize;
if (ttype(object) == LUA_T_NIL)
return -1; /* special ref for nil */
for (i=0; i<refSize; i++)
if (refArray[i].status == FREE)
goto found;
/* no more empty spaces */
oldSize = refSize;
refSize = growvector(&refArray, refSize, struct ref, refEM, MAX_WORD);
for (i=oldSize; i<refSize; i++)
refArray[i].status = FREE;
i = oldSize;
found:
refArray[i].o = *object;
refArray[i].status = lock ? LOCK : HOLD;
return i;
}
void lua_unref (int ref)
{
if (ref >= 0 && ref < refSize)
refArray[ref].status = FREE;
}
TObject *luaI_getref (int ref)
{
static TObject nul = {LUA_T_NIL, {0}};
if (ref == -1)
return &nul;
if (ref >= 0 && ref < refSize &&
(refArray[ref].status == LOCK || refArray[ref].status == HOLD))
return &refArray[ref].o;
else
return NULL;
}
void luaI_travlock (int (*fn)(TObject *))
{
int i;
for (i=0; i<refSize; i++)
if (refArray[i].status == LOCK)
fn(&refArray[i].o);
}
void luaI_invalidaterefs (void)
{
int i;
for (i=0; i<refSize; i++)
if (refArray[i].status == HOLD && !luaI_ismarked(&refArray[i].o))
refArray[i].status = COLLECTED;
}
/* -------------------------------------------
* Internal Methods
*/
char *luaI_eventname[] = { /* ORDER IM */
"gettable", "settable", "index", "getglobal", "setglobal", "add",
"sub", "mul", "div", "pow", "unm", "lt", "le", "gt", "ge",
"concat", "gc", "function",
NULL
};
static int luaI_checkevent (char *name, char *list[])
{
int e = luaI_findstring(name, list);
if (e < 0)
luaL_verror("`%s' is not a valid event name", name);
return e;
}
struct IM *luaI_IMtable = NULL;
static int IMtable_size = 0;
static int last_tag = LUA_T_NIL; /* ORDER LUA_T */
/* events in LUA_T_LINE are all allowed, since this is used as a
* 'placeholder' for "default" fallbacks
*/
static char validevents[NUM_TYPES][IM_N] = { /* ORDER LUA_T, ORDER IM */
{1, 1, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1}, /* LUA_T_USERDATA */
{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}, /* LUA_T_LINE */
{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, /* LUA_T_CMARK */
{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, /* LUA_T_MARK */
{1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0}, /* LUA_T_CFUNCTION */
{1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0}, /* LUA_T_FUNCTION */
{0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}, /* LUA_T_ARRAY */
{1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1}, /* LUA_T_STRING */
{1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1}, /* LUA_T_NUMBER */
{1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1} /* LUA_T_NIL */
};
static int validevent (lua_Type t, int e)
{ /* ORDER LUA_T */
return (t < LUA_T_NIL) ? 1 : validevents[-t][e];
}
static void init_entry (int tag)
{
int i;
for (i=0; i<IM_N; i++)
ttype(luaI_getim(tag, i)) = LUA_T_NIL;
}
void luaI_initfallbacks (void)
{
if (luaI_IMtable == NULL) {
int i;
IMtable_size = NUM_TYPES+10;
luaI_IMtable = newvector(IMtable_size, struct IM);
for (i=LUA_T_NIL; i<=LUA_T_USERDATA; i++)
init_entry(i);
}
}
int lua_newtag (void)
{
--last_tag;
if ((-last_tag) >= IMtable_size) {
luaI_initfallbacks();
IMtable_size = growvector(&luaI_IMtable, IMtable_size,
struct IM, memEM, MAX_INT);
}
init_entry(last_tag);
return last_tag;
}
static void checktag (int tag)
{
if (!(last_tag <= tag && tag <= 0))
luaL_verror("%d is not a valid tag", tag);
}
void luaI_realtag (int tag)
{
if (!(last_tag <= tag && tag < LUA_T_NIL))
luaL_verror("tag %d is not result of `newtag'", tag);
}
void luaI_settag (int tag, TObject *o)
{
luaI_realtag(tag);
switch (ttype(o)) {
case LUA_T_ARRAY:
o->value.a->htag = tag;
break;
case LUA_T_USERDATA:
o->value.ts->tag = tag;
break;
default:
luaL_verror("cannot change the tag of a %s", luaI_typenames[-ttype(o)]);
}
}
int luaI_efectivetag (TObject *o)
{
lua_Type t = ttype(o);
if (t == LUA_T_USERDATA) {
int tag = o->value.ts->tag;
return (tag >= 0) ? LUA_T_USERDATA : tag;
}
else if (t == LUA_T_ARRAY)
return o->value.a->htag;
else return t;
}
void luaI_gettagmethod (void)
{
int t = (int)luaL_check_number(1);
int e = luaI_checkevent(luaL_check_string(2), luaI_eventname);
checktag(t);
if (validevent(t, e))
luaI_pushobject(luaI_getim(t,e));
}
void luaI_settagmethod (void)
{
int t = (int)luaL_check_number(1);
int e = luaI_checkevent(luaL_check_string(2), luaI_eventname);
lua_Object func = lua_getparam(3);
checktag(t);
if (!validevent(t, e))
luaL_verror("cannot change internal method `%s' for tag %d",
luaI_eventname[e], t);
luaL_arg_check(lua_isnil(func) || lua_isfunction(func),
3, "function expected");
luaI_pushobject(luaI_getim(t,e));
*luaI_getim(t, e) = *luaI_Address(func);
}
void luaI_seterrormethod (void)
{
lua_Object func = lua_getparam(1);
luaL_arg_check(lua_isnil(func) || lua_isfunction(func),
1, "function expected");
luaI_pushobject(&luaI_errorim);
luaI_errorim = *luaI_Address(func);
}
char *luaI_travfallbacks (int (*fn)(TObject *))
{
int e;
if (fn(&luaI_errorim))
return "error";
for (e=IM_GETTABLE; e<=IM_FUNCTION; e++) { /* ORDER IM */
int t;
for (t=0; t>=last_tag; t--)
if (fn(luaI_getim(t,e)))
return luaI_eventname[e];
}
return NULL;
}
/*
* ===================================================================
* compatibility with old fallback system
*/
#if LUA_COMPAT2_5
static void errorFB (void)
{
lua_Object o = lua_getparam(1);
if (lua_isstring(o))
fprintf (stderr, "lua: %s\n", lua_getstring(o));
else
fprintf(stderr, "lua: unknown error\n");
}
static void nilFB (void) { }
static void typeFB (void)
{
lua_error("unexpected type");
}
static void fillvalids (IMS e, TObject *func)
{
int t;
for (t=LUA_T_NIL; t<=LUA_T_USERDATA; t++)
if (validevent(t, e))
*luaI_getim(t, e) = *func;
}
void luaI_setfallback (void)
{
static char *oldnames [] = {"error", "getglobal", "arith", "order", NULL};
TObject oldfunc;
lua_CFunction replace;
char *name = luaL_check_string(1);
lua_Object func = lua_getparam(2);
luaI_initfallbacks();
luaL_arg_check(lua_isfunction(func), 2, "function expected");
switch (luaI_findstring(name, oldnames)) {
case 0: /* old error fallback */
oldfunc = luaI_errorim;
luaI_errorim = *luaI_Address(func);
replace = errorFB;
break;
case 1: /* old getglobal fallback */
oldfunc = *luaI_getim(LUA_T_NIL, IM_GETGLOBAL);
*luaI_getim(LUA_T_NIL, IM_GETGLOBAL) = *luaI_Address(func);
replace = nilFB;
break;
case 2: { /* old arith fallback */
int i;
oldfunc = *luaI_getim(LUA_T_NUMBER, IM_POW);
for (i=IM_ADD; i<=IM_UNM; i++) /* ORDER IM */
fillvalids(i, luaI_Address(func));
replace = typeFB;
break;
}
case 3: { /* old order fallback */
int i;
oldfunc = *luaI_getim(LUA_T_LINE, IM_LT);
for (i=IM_LT; i<=IM_GE; i++) /* ORDER IM */
fillvalids(i, luaI_Address(func));
replace = typeFB;
break;
}
default: {
int e;
if ((e = luaI_findstring(name, luaI_eventname)) >= 0) {
oldfunc = *luaI_getim(LUA_T_LINE, e);
fillvalids(e, luaI_Address(func));
replace = (e == IM_GC || e == IM_INDEX) ? nilFB : typeFB;
}
else {
luaL_verror("`%s' is not a valid fallback name", name);
replace = NULL; /* to avoid warnings */
}
}
}
if (oldfunc.ttype != LUA_T_NIL)
luaI_pushobject(&oldfunc);
else
lua_pushcfunction(replace);
}
#endif

64
fallback.h
View File

@ -1,64 +0,0 @@
/*
** $Id: fallback.h,v 1.24 1997/07/03 22:06:06 roberto Exp $
*/
#ifndef fallback_h
#define fallback_h
#include "lua.h"
#include "opcode.h"
/*
* WARNING: if you change the order of this enumeration,
* grep "ORDER IM"
*/
typedef enum {
IM_GETTABLE = 0,
IM_SETTABLE,
IM_INDEX,
IM_GETGLOBAL,
IM_SETGLOBAL,
IM_ADD,
IM_SUB,
IM_MUL,
IM_DIV,
IM_POW,
IM_UNM,
IM_LT,
IM_LE,
IM_GT,
IM_GE,
IM_CONCAT,
IM_GC,
IM_FUNCTION
} IMS;
#define IM_N 18
extern struct IM {
TObject int_method[IM_N];
} *luaI_IMtable;
extern char *luaI_eventname[];
#define luaI_getim(tag,event) (&luaI_IMtable[-(tag)].int_method[event])
#define luaI_getimbyObj(o,e) (luaI_getim(luaI_efectivetag(o),(e)))
void luaI_setfallback (void);
int luaI_ref (TObject *object, int lock);
TObject *luaI_getref (int ref);
void luaI_travlock (int (*fn)(TObject *));
void luaI_invalidaterefs (void);
char *luaI_travfallbacks (int (*fn)(TObject *));
void luaI_settag (int tag, TObject *o);
void luaI_realtag (int tag);
int luaI_efectivetag (TObject *o);
void luaI_settagmethod (void);
void luaI_gettagmethod (void);
void luaI_seterrormethod (void);
void luaI_initfallbacks (void);
#endif

317
ltm.c
View File

@ -0,0 +1,317 @@
/*
** $Id: $
** Tag methods
** See Copyright Notice in lua.h
*/
#include <stdio.h>
#include <string.h>
#include "lauxlib.h"
#include "ldo.h"
#include "lmem.h"
#include "lobject.h"
#include "ltm.h"
static struct IM init_IM[NUM_TYPES] = {
{{{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}}},
{{{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}}},
{{{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}}},
{{{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}}},
{{{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}}},
{{{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}}},
{{{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}}},
{{{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}}},
{{{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}}},
{{{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}}},
{{{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}},
{LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}, {LUA_T_NIL, {NULL}}}}
};
char *luaT_eventname[] = { /* ORDER IM */
"gettable", "settable", "index", "getglobal", "setglobal", "add",
"sub", "mul", "div", "pow", "unm", "lt", "le", "gt", "ge",
"concat", "gc", "function",
NULL
};
static int luaI_checkevent (char *name, char *list[])
{
int e = luaO_findstring(name, list);
if (e < 0)
luaL_verror("`%.50s' is not a valid event name", name);
return e;
}
struct IM *luaT_IMtable = init_IM;
static int IMtable_size = NUM_TYPES;
static int last_tag = -(NUM_TYPES-1);
/* events in LUA_T_LINE are all allowed, since this is used as a
* 'placeholder' for "default" fallbacks
*/
static char validevents[NUM_TYPES][IM_N] = { /* ORDER LUA_T, ORDER IM */
{1, 1, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1}, /* LUA_T_USERDATA */
{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}, /* LUA_T_LINE */
{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, /* LUA_T_CMARK */
{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, /* LUA_T_MARK */
{1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0}, /* LUA_T_CFUNCTION */
{1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0}, /* LUA_T_FUNCTION */
{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, /* LUA_T_PROTO */
{0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}, /* LUA_T_ARRAY */
{1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1}, /* LUA_T_STRING */
{1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1}, /* LUA_T_NUMBER */
{1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1} /* LUA_T_NIL */
};
static int validevent (lua_Type t, int e)
{ /* ORDER LUA_T */
return (t < LUA_T_NIL) ? 1 : validevents[-t][e];
}
static void init_entry (int tag)
{
int i;
for (i=0; i<IM_N; i++)
ttype(luaT_getim(tag, i)) = LUA_T_NIL;
}
int lua_newtag (void)
{
--last_tag;
if ((-last_tag) >= IMtable_size) {
if (luaT_IMtable == init_IM) { /* fist time? */
IMtable_size *= 2;
luaT_IMtable = luaM_newvector(IMtable_size, struct IM);
memcpy(luaT_IMtable, init_IM, sizeof(init_IM));
}
else
IMtable_size = luaM_growvector(&luaT_IMtable, IMtable_size,
struct IM, memEM, MAX_INT);
}
init_entry(last_tag);
return last_tag;
}
static void checktag (int tag)
{ /* ORDER LUA_T */
if (!(last_tag <= tag && tag <= 0))
luaL_verror("%d is not a valid tag", tag);
}
void luaT_realtag (int tag)
{
if (!(last_tag <= tag && tag < LUA_T_NIL))
luaL_verror("tag %d is not result of `newtag'", tag);
}
int luaT_efectivetag (TObject *o)
{
lua_Type t = ttype(o);
if (t == LUA_T_USERDATA) {
int tag = o->value.ts->tag;
return (tag >= 0) ? LUA_T_USERDATA : tag;
}
else if (t == LUA_T_ARRAY)
return o->value.a->htag;
else return t;
}
TObject *luaT_gettagmethod (int t, char *event)
{
int e = luaI_checkevent(event, luaT_eventname);
checktag(t);
if (validevent(t, e))
return luaT_getim(t,e);
else
return luaT_getim(LUA_T_CMARK, IM_GETTABLE); /* always nil */
}
void luaT_settagmethod (int t, char *event, TObject *func)
{
TObject temp = *func;
int e = luaI_checkevent(event, luaT_eventname);
checktag(t);
if (!validevent(t, e))
luaL_verror("settagmethod: cannot change internal method `%s' for tag %d",
luaT_eventname[e], t);
*func = *luaT_getim(t,e);
*luaT_getim(t, e) = temp;
}
char *luaT_travtagmethods (int (*fn)(TObject *))
{
int e;
if (fn(&luaD_errorim))
return "error";
for (e=IM_GETTABLE; e<=IM_FUNCTION; e++) { /* ORDER IM */
int t;
for (t=0; t>=last_tag; t--)
if (fn(luaT_getim(t,e)))
return luaT_eventname[e];
}
return NULL;
}
/*
* ===================================================================
* compatibility with old fallback system
*/
#if LUA_COMPAT2_5
#include "lapi.h"
static void errorFB (void)
{
lua_Object o = lua_getparam(1);
if (lua_isstring(o))
fprintf(stderr, "lua: %s\n", lua_getstring(o));
else
fprintf(stderr, "lua: unknown error\n");
}
static void nilFB (void) { }
static void typeFB (void)
{
lua_error("unexpected type");
}
static void fillvalids (IMS e, TObject *func)
{
int t;
for (t=LUA_T_NIL; t<=LUA_T_USERDATA; t++)
if (validevent(t, e))
*luaT_getim(t, e) = *func;
}
void luaT_setfallback (void)
{
static char *oldnames [] = {"error", "getglobal", "arith", "order", NULL};
TObject oldfunc;
lua_CFunction replace;
char *name = luaL_check_string(1);
lua_Object func = lua_getparam(2);
luaL_arg_check(lua_isfunction(func), 2, "function expected");
switch (luaO_findstring(name, oldnames)) {
case 0: /* old error fallback */
oldfunc = luaD_errorim;
luaD_errorim = *luaA_Address(func);
replace = errorFB;
break;
case 1: /* old getglobal fallback */
oldfunc = *luaT_getim(LUA_T_NIL, IM_GETGLOBAL);
*luaT_getim(LUA_T_NIL, IM_GETGLOBAL) = *luaA_Address(func);
replace = nilFB;
break;
case 2: { /* old arith fallback */
int i;
oldfunc = *luaT_getim(LUA_T_NUMBER, IM_POW);
for (i=IM_ADD; i<=IM_UNM; i++) /* ORDER IM */
fillvalids(i, luaA_Address(func));
replace = typeFB;
break;
}
case 3: { /* old order fallback */
int i;
oldfunc = *luaT_getim(LUA_T_LINE, IM_LT);
for (i=IM_LT; i<=IM_GE; i++) /* ORDER IM */
fillvalids(i, luaA_Address(func));
replace = typeFB;
break;
}
default: {
int e;
if ((e = luaO_findstring(name, luaT_eventname)) >= 0) {
oldfunc = *luaT_getim(LUA_T_LINE, e);
fillvalids(e, luaA_Address(func));
replace = (e == IM_GC || e == IM_INDEX) ? nilFB : typeFB;
}
else {
luaL_verror("`%.50s' is not a valid fallback name", name);
replace = NULL; /* to avoid warnings */
}
}
}
if (oldfunc.ttype != LUA_T_NIL)
luaA_pushobject(&oldfunc);
else
lua_pushcfunction(replace);
}
#endif

61
ltm.h
View File

@ -0,0 +1,61 @@
/*
** $Id: $
** Tag methods
** See Copyright Notice in lua.h
*/
#ifndef ltm_h
#define ltm_h
#include "lobject.h"
/*
* WARNING: if you change the order of this enumeration,
* grep "ORDER IM"
*/
typedef enum {
IM_GETTABLE = 0,
IM_SETTABLE,
IM_INDEX,
IM_GETGLOBAL,
IM_SETGLOBAL,
IM_ADD,
IM_SUB,
IM_MUL,
IM_DIV,
IM_POW,
IM_UNM,
IM_LT,
IM_LE,
IM_GT,
IM_GE,
IM_CONCAT,
IM_GC,
IM_FUNCTION
} IMS;
#define IM_N 18
extern struct IM {
TObject int_method[IM_N];
} *luaT_IMtable;
#define luaT_getim(tag,event) (&luaT_IMtable[-(tag)].int_method[event])
#define luaT_getimbyObj(o,e) (luaT_getim(luaT_efectivetag(o),(e)))
extern char *luaT_eventname[];
void luaT_settag (int tag, TObject *o);
void luaT_realtag (int tag);
int luaT_efectivetag (TObject *o);
void luaT_settagmethod (int t, char *event, TObject *func);
TObject *luaT_gettagmethod (int t, char *event);
char *luaT_travtagmethods (int (*fn)(TObject *));
void luaT_setfallback (void); /* only if LUA_COMPAT2_5 */
#endif
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