1/*
2** $Id: lfunc.c,v 2.30.1.1 2013/04/12 18:48:47 roberto Exp $
3** Auxiliary functions to manipulate prototypes and closures
4** See Copyright Notice in lua.h
5*/
6
7
8#define lfunc_c
9#define LUA_CORE
10
11#include <sys/lua/lua.h>
12
13#include "lfunc.h"
14#include "lgc.h"
15#include "lmem.h"
16#include "lobject.h"
17#include "lstate.h"
18
19
20
21Closure *luaF_newCclosure (lua_State *L, int n) {
22  Closure *c = &luaC_newobj(L, LUA_TCCL, sizeCclosure(n), NULL, 0)->cl;
23  c->c.nupvalues = cast_byte(n);
24  return c;
25}
26
27
28Closure *luaF_newLclosure (lua_State *L, int n) {
29  Closure *c = &luaC_newobj(L, LUA_TLCL, sizeLclosure(n), NULL, 0)->cl;
30  c->l.p = NULL;
31  c->l.nupvalues = cast_byte(n);
32  while (n--) c->l.upvals[n] = NULL;
33  return c;
34}
35
36
37UpVal *luaF_newupval (lua_State *L) {
38  UpVal *uv = &luaC_newobj(L, LUA_TUPVAL, sizeof(UpVal), NULL, 0)->uv;
39  uv->v = &uv->u.value;
40  setnilvalue(uv->v);
41  return uv;
42}
43
44
45UpVal *luaF_findupval (lua_State *L, StkId level) {
46  global_State *g = G(L);
47  GCObject **pp = &L->openupval;
48  UpVal *p;
49  UpVal *uv;
50  while (*pp != NULL && (p = gco2uv(*pp))->v >= level) {
51    GCObject *o = obj2gco(p);
52    lua_assert(p->v != &p->u.value);
53    lua_assert(!isold(o) || isold(obj2gco(L)));
54    if (p->v == level) {  /* found a corresponding upvalue? */
55      if (isdead(g, o))  /* is it dead? */
56        changewhite(o);  /* resurrect it */
57      return p;
58    }
59    pp = &p->next;
60  }
61  /* not found: create a new one */
62  uv = &luaC_newobj(L, LUA_TUPVAL, sizeof(UpVal), pp, 0)->uv;
63  uv->v = level;  /* current value lives in the stack */
64  uv->u.l.prev = &g->uvhead;  /* double link it in `uvhead' list */
65  uv->u.l.next = g->uvhead.u.l.next;
66  uv->u.l.next->u.l.prev = uv;
67  g->uvhead.u.l.next = uv;
68  lua_assert(uv->u.l.next->u.l.prev == uv && uv->u.l.prev->u.l.next == uv);
69  return uv;
70}
71
72
73static void unlinkupval (UpVal *uv) {
74  lua_assert(uv->u.l.next->u.l.prev == uv && uv->u.l.prev->u.l.next == uv);
75  uv->u.l.next->u.l.prev = uv->u.l.prev;  /* remove from `uvhead' list */
76  uv->u.l.prev->u.l.next = uv->u.l.next;
77}
78
79
80void luaF_freeupval (lua_State *L, UpVal *uv) {
81  if (uv->v != &uv->u.value)  /* is it open? */
82    unlinkupval(uv);  /* remove from open list */
83  luaM_free(L, uv);  /* free upvalue */
84}
85
86
87void luaF_close (lua_State *L, StkId level) {
88  UpVal *uv;
89  global_State *g = G(L);
90  while (L->openupval != NULL && (uv = gco2uv(L->openupval))->v >= level) {
91    GCObject *o = obj2gco(uv);
92    lua_assert(!isblack(o) && uv->v != &uv->u.value);
93    L->openupval = uv->next;  /* remove from `open' list */
94    if (isdead(g, o))
95      luaF_freeupval(L, uv);  /* free upvalue */
96    else {
97      unlinkupval(uv);  /* remove upvalue from 'uvhead' list */
98      setobj(L, &uv->u.value, uv->v);  /* move value to upvalue slot */
99      uv->v = &uv->u.value;  /* now current value lives here */
100      gch(o)->next = g->allgc;  /* link upvalue into 'allgc' list */
101      g->allgc = o;
102      luaC_checkupvalcolor(g, uv);
103    }
104  }
105}
106
107
108Proto *luaF_newproto (lua_State *L) {
109  Proto *f = &luaC_newobj(L, LUA_TPROTO, sizeof(Proto), NULL, 0)->p;
110  f->k = NULL;
111  f->sizek = 0;
112  f->p = NULL;
113  f->sizep = 0;
114  f->code = NULL;
115  f->cache = NULL;
116  f->sizecode = 0;
117  f->lineinfo = NULL;
118  f->sizelineinfo = 0;
119  f->upvalues = NULL;
120  f->sizeupvalues = 0;
121  f->numparams = 0;
122  f->is_vararg = 0;
123  f->maxstacksize = 0;
124  f->locvars = NULL;
125  f->sizelocvars = 0;
126  f->linedefined = 0;
127  f->lastlinedefined = 0;
128  f->source = NULL;
129  return f;
130}
131
132
133void luaF_freeproto (lua_State *L, Proto *f) {
134  luaM_freearray(L, f->code, f->sizecode);
135  luaM_freearray(L, f->p, f->sizep);
136  luaM_freearray(L, f->k, f->sizek);
137  luaM_freearray(L, f->lineinfo, f->sizelineinfo);
138  luaM_freearray(L, f->locvars, f->sizelocvars);
139  luaM_freearray(L, f->upvalues, f->sizeupvalues);
140  luaM_free(L, f);
141}
142
143
144/*
145** Look for n-th local variable at line `line' in function `func'.
146** Returns NULL if not found.
147*/
148const char *luaF_getlocalname (const Proto *f, int local_number, int pc) {
149  int i;
150  for (i = 0; i<f->sizelocvars && f->locvars[i].startpc <= pc; i++) {
151    if (pc < f->locvars[i].endpc) {  /* is variable active? */
152      local_number--;
153      if (local_number == 0)
154        return getstr(f->locvars[i].varname);
155    }
156  }
157  return NULL;  /* not found */
158}
159