misc/liblua/lfunc.c
changeset 2812 0a24853de796
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/misc/liblua/lfunc.c	Mon Feb 15 19:49:20 2010 +0000
@@ -0,0 +1,174 @@
+/*
+** $Id: lfunc.c,v 2.12.1.2 2007/12/28 14:58:43 roberto Exp $
+** Auxiliary functions to manipulate prototypes and closures
+** See Copyright Notice in lua.h
+*/
+
+
+#include <stddef.h>
+
+#define lfunc_c
+#define LUA_CORE
+
+#include "lua.h"
+
+#include "lfunc.h"
+#include "lgc.h"
+#include "lmem.h"
+#include "lobject.h"
+#include "lstate.h"
+
+
+
+Closure *luaF_newCclosure (lua_State *L, int nelems, Table *e) {
+  Closure *c = cast(Closure *, luaM_malloc(L, sizeCclosure(nelems)));
+  luaC_link(L, obj2gco(c), LUA_TFUNCTION);
+  c->c.isC = 1;
+  c->c.env = e;
+  c->c.nupvalues = cast_byte(nelems);
+  return c;
+}
+
+
+Closure *luaF_newLclosure (lua_State *L, int nelems, Table *e) {
+  Closure *c = cast(Closure *, luaM_malloc(L, sizeLclosure(nelems)));
+  luaC_link(L, obj2gco(c), LUA_TFUNCTION);
+  c->l.isC = 0;
+  c->l.env = e;
+  c->l.nupvalues = cast_byte(nelems);
+  while (nelems--) c->l.upvals[nelems] = NULL;
+  return c;
+}
+
+
+UpVal *luaF_newupval (lua_State *L) {
+  UpVal *uv = luaM_new(L, UpVal);
+  luaC_link(L, obj2gco(uv), LUA_TUPVAL);
+  uv->v = &uv->u.value;
+  setnilvalue(uv->v);
+  return uv;
+}
+
+
+UpVal *luaF_findupval (lua_State *L, StkId level) {
+  global_State *g = G(L);
+  GCObject **pp = &L->openupval;
+  UpVal *p;
+  UpVal *uv;
+  while (*pp != NULL && (p = ngcotouv(*pp))->v >= level) {
+    lua_assert(p->v != &p->u.value);
+    if (p->v == level) {  /* found a corresponding upvalue? */
+      if (isdead(g, obj2gco(p)))  /* is it dead? */
+        changewhite(obj2gco(p));  /* ressurect it */
+      return p;
+    }
+    pp = &p->next;
+  }
+  uv = luaM_new(L, UpVal);  /* not found: create a new one */
+  uv->tt = LUA_TUPVAL;
+  uv->marked = luaC_white(g);
+  uv->v = level;  /* current value lives in the stack */
+  uv->next = *pp;  /* chain it in the proper position */
+  *pp = obj2gco(uv);
+  uv->u.l.prev = &g->uvhead;  /* double link it in `uvhead' list */
+  uv->u.l.next = g->uvhead.u.l.next;
+  uv->u.l.next->u.l.prev = uv;
+  g->uvhead.u.l.next = uv;
+  lua_assert(uv->u.l.next->u.l.prev == uv && uv->u.l.prev->u.l.next == uv);
+  return uv;
+}
+
+
+static void unlinkupval (UpVal *uv) {
+  lua_assert(uv->u.l.next->u.l.prev == uv && uv->u.l.prev->u.l.next == uv);
+  uv->u.l.next->u.l.prev = uv->u.l.prev;  /* remove from `uvhead' list */
+  uv->u.l.prev->u.l.next = uv->u.l.next;
+}
+
+
+void luaF_freeupval (lua_State *L, UpVal *uv) {
+  if (uv->v != &uv->u.value)  /* is it open? */
+    unlinkupval(uv);  /* remove from open list */
+  luaM_free(L, uv);  /* free upvalue */
+}
+
+
+void luaF_close (lua_State *L, StkId level) {
+  UpVal *uv;
+  global_State *g = G(L);
+  while (L->openupval != NULL && (uv = ngcotouv(L->openupval))->v >= level) {
+    GCObject *o = obj2gco(uv);
+    lua_assert(!isblack(o) && uv->v != &uv->u.value);
+    L->openupval = uv->next;  /* remove from `open' list */
+    if (isdead(g, o))
+      luaF_freeupval(L, uv);  /* free upvalue */
+    else {
+      unlinkupval(uv);
+      setobj(L, &uv->u.value, uv->v);
+      uv->v = &uv->u.value;  /* now current value lives here */
+      luaC_linkupval(L, uv);  /* link upvalue into `gcroot' list */
+    }
+  }
+}
+
+
+Proto *luaF_newproto (lua_State *L) {
+  Proto *f = luaM_new(L, Proto);
+  luaC_link(L, obj2gco(f), LUA_TPROTO);
+  f->k = NULL;
+  f->sizek = 0;
+  f->p = NULL;
+  f->sizep = 0;
+  f->code = NULL;
+  f->sizecode = 0;
+  f->sizelineinfo = 0;
+  f->sizeupvalues = 0;
+  f->nups = 0;
+  f->upvalues = NULL;
+  f->numparams = 0;
+  f->is_vararg = 0;
+  f->maxstacksize = 0;
+  f->lineinfo = NULL;
+  f->sizelocvars = 0;
+  f->locvars = NULL;
+  f->linedefined = 0;
+  f->lastlinedefined = 0;
+  f->source = NULL;
+  return f;
+}
+
+
+void luaF_freeproto (lua_State *L, Proto *f) {
+  luaM_freearray(L, f->code, f->sizecode, Instruction);
+  luaM_freearray(L, f->p, f->sizep, Proto *);
+  luaM_freearray(L, f->k, f->sizek, TValue);
+  luaM_freearray(L, f->lineinfo, f->sizelineinfo, int);
+  luaM_freearray(L, f->locvars, f->sizelocvars, struct LocVar);
+  luaM_freearray(L, f->upvalues, f->sizeupvalues, TString *);
+  luaM_free(L, f);
+}
+
+
+void luaF_freeclosure (lua_State *L, Closure *c) {
+  int size = (c->c.isC) ? sizeCclosure(c->c.nupvalues) :
+                          sizeLclosure(c->l.nupvalues);
+  luaM_freemem(L, c, size);
+}
+
+
+/*
+** Look for n-th local variable at line `line' in function `func'.
+** Returns NULL if not found.
+*/
+const char *luaF_getlocalname (const Proto *f, int local_number, int pc) {
+  int i;
+  for (i = 0; i<f->sizelocvars && f->locvars[i].startpc <= pc; i++) {
+    if (pc < f->locvars[i].endpc) {  /* is variable active? */
+      local_number--;
+      if (local_number == 0)
+        return getstr(f->locvars[i].varname);
+    }
+  }
+  return NULL;  /* not found */
+}
+