Lua 3.13.1

1 files changed, 263 insertions, 0 deletions

diff --git a/src/ltm.c b/src/ltm.c
new file mode 100644
index 00000000..0bbee22c
--- /dev/null
+++ b/src/ltm.c
@@ -0,0 +1,263 @@
+/*
+** $Id: ltm.c,v 1.16 1998/06/18 16:57:03 roberto Exp $
+** Tag methods
+** See Copyright Notice in lua.h
+*/
+
+
+#include <stdio.h>
+#include <string.h>
+
+#include "lauxlib.h"
+#include "lmem.h"
+#include "lobject.h"
+#include "lstate.h"
+#include "ltm.h"
+
+
+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 = luaL_findstring(name, list);
+  if (e < 0)
+    luaL_verror("`%.50s' is not a valid event name", name);
+  return e;
+}
+
+
+
+/* events in LUA_T_NIL are all allowed, since this is used as a
+*  'placeholder' for "default" fallbacks
+*/
+static char validevents[NUM_TAGS][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, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1},  /* LUA_T_NUMBER */
+{1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1},  /* LUA_T_STRING */
+{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, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0},  /* LUA_T_PROTO */
+{1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0},  /* LUA_T_CPROTO */
+{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}   /* LUA_T_NIL */
+};
+
+
+static int validevent (int 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;
+}
+
+
+void luaT_init (void)
+{
+  int t;
+  L->IMtable_size = NUM_TAGS*2;
+  L->last_tag = -(NUM_TAGS-1);
+  L->IMtable = luaM_newvector(L->IMtable_size, struct IM);
+  for (t=L->last_tag; t<=0; t++)
+    init_entry(t);
+}
+
+
+int lua_newtag (void)
+{
+  --L->last_tag;
+  if ((-L->last_tag) >= L->IMtable_size)
+    L->IMtable_size = luaM_growvector(&L->IMtable, L->IMtable_size,
+                                   struct IM, memEM, MAX_INT);
+  init_entry(L->last_tag);
+  return L->last_tag;
+}
+
+
+static void checktag (int tag)
+{
+  if (!(L->last_tag <= tag && tag <= 0))
+    luaL_verror("%d is not a valid tag", tag);
+}
+
+void luaT_realtag (int tag)
+{
+  if (!(L->last_tag <= tag && tag < LUA_T_NIL))
+    luaL_verror("tag %d is not result of `newtag'", tag);
+}
+
+
+int lua_copytagmethods (int tagto, int tagfrom)
+{
+  int e;
+  checktag(tagto);
+  checktag(tagfrom);
+  for (e=0; e<IM_N; e++) {
+    if (validevent(tagto, e))
+      *luaT_getim(tagto, e) = *luaT_getim(tagfrom, e);
+  }
+  return tagto;
+}
+
+
+int luaT_efectivetag (TObject *o)
+{
+  int t;
+  switch (t = ttype(o)) {
+    case LUA_T_ARRAY:
+      return o->value.a->htag;
+    case LUA_T_USERDATA: {
+      int tag = o->value.ts->u.d.tag;
+      return (tag >= 0) ? LUA_T_USERDATA : tag;
+    }
+    case LUA_T_CLOSURE:
+      return o->value.cl->consts[0].ttype;
+#ifdef DEBUG
+    case LUA_T_PMARK: case LUA_T_CMARK:
+    case LUA_T_CLMARK: case LUA_T_LINE:
+      LUA_INTERNALERROR("invalid type");
+#endif
+    default:
+      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 &luaO_nilobject;
+}
+
+
+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 tag method `%.20s' 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(&L->errorim))
+    return "error";
+  for (e=IM_GETTABLE; e<=IM_FUNCTION; e++) {  /* ORDER IM */
+    int t;
+    for (t=0; t>=L->last_tag; t--)
+      if (fn(luaT_getim(t,e)))
+        return luaT_eventname[e];
+  }
+  return NULL;
+}
+
+
+/*
+* ===================================================================
+* compatibility with old fallback system
+*/
+#ifdef 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 (luaL_findstring(name, oldnames)) {
+    case 0:  /* old error fallback */
+      oldfunc = L->errorim;
+      L->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_NIL, 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 = luaL_findstring(name, luaT_eventname)) >= 0) {
+        oldfunc = *luaT_getim(LUA_T_NIL, 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
+