v1.4.4

source/extern/lua/ltm.c

@@ -0,0 +1,144 @@
+/*
+** $Id: ltm.c,v 2.34 2015/03/30 15:42:27 roberto Exp $
+** 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 "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_TOTALTAGS] = {
+  "no value",
+  "nil", "boolean", udatatypename, "number",
+  "string", "table", "function", udatatypename, "thread",
+  "proto" /* this last case is 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"
+  };
+  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_getstr(events, ename);
+  lua_assert(event <= TM_EQ);
+  if (ttisnil(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 (ttnov(o)) {
+    case LUA_TTABLE:
+      mt = hvalue(o)->metatable;
+      break;
+    case LUA_TUSERDATA:
+      mt = uvalue(o)->metatable;
+      break;
+    default:
+      mt = G(L)->mt[ttnov(o)];
+  }
+  return (mt ? luaH_getstr(mt, G(L)->tmname[event]) : luaO_nilobject);
+}
+
+
+void luaT_callTM (lua_State *L, const TValue *f, const TValue *p1,
+                  const TValue *p2, TValue *p3, int hasres) {
+  ptrdiff_t result = savestack(L, p3);
+  setobj2s(L, L->top++, f);  /* push function (assume EXTRA_STACK) */
+  setobj2s(L, L->top++, p1);  /* 1st argument */
+  setobj2s(L, L->top++, p2);  /* 2nd argument */
+  if (!hasres)  /* no result? 'p3' is third argument */
+    setobj2s(L, L->top++, p3);  /* 3rd argument */
+  /* metamethod may yield only when called from Lua code */
+  luaD_call(L, L->top - (4 - hasres), hasres, isLua(L->ci));
+  if (hasres) {  /* if has result, move it to its place */
+    p3 = restorestack(L, result);
+    setobjs2s(L, p3, --L->top);
+  }
+}
+
+
+int luaT_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 (ttisnil(tm))
+    tm = luaT_gettmbyobj(L, p2, event);  /* try second operand */
+  if (ttisnil(tm)) return 0;
+  luaT_callTM(L, tm, p1, p2, res, 1);
+  return 1;
+}
+
+
+void luaT_trybinTM (lua_State *L, const TValue *p1, const TValue *p2,
+                    StkId res, TMS event) {
+  if (!luaT_callbinTM(L, p1, p2, res, event)) {
+    switch (event) {
+      case TM_CONCAT:
+        luaG_concaterror(L, p1, p2);
+      /* call never returns, but to avoid warnings: *//* FALLTHROUGH */
+      case TM_BAND: case TM_BOR: case TM_BXOR:
+      case TM_SHL: case TM_SHR: case TM_BNOT: {
+        lua_Number dummy;
+        if (tonumber(p1, &dummy) && tonumber(p2, &dummy))
+          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");
+    }
+  }
+}
+
+
+int luaT_callorderTM (lua_State *L, const TValue *p1, const TValue *p2,
+                      TMS event) {
+  if (!luaT_callbinTM(L, p1, p2, L->top, event))
+    return -1;  /* no metamethod */
+  else
+    return !l_isfalse(L->top);
+}
+