1/*	$NetBSD$	*/
2
3/*
4** Id: lfunc.c,v 2.12.1.2 2007/12/28 14:58:43 roberto Exp
5** Auxiliary functions to manipulate prototypes and closures
6** See Copyright Notice in lua.h
7*/
8
9
10#include <stddef.h>
11
12#define lfunc_c
13#define LUA_CORE
14
15#include "lua.h"
16
17#include "lfunc.h"
18#include "lgc.h"
19#include "lmem.h"
20#include "lobject.h"
21#include "lstate.h"
22
23
24
25Closure *luaF_newCclosure (lua_State *L, int nelems, Table *e) {
26  Closure *c = cast(Closure *, luaM_malloc(L, sizeCclosure(nelems)));
27  luaC_link(L, obj2gco(c), LUA_TFUNCTION);
28  c->c.isC = 1;
29  c->c.env = e;
30  c->c.nupvalues = cast_byte(nelems);
31  return c;
32}
33
34
35Closure *luaF_newLclosure (lua_State *L, int nelems, Table *e) {
36  Closure *c = cast(Closure *, luaM_malloc(L, sizeLclosure(nelems)));
37  luaC_link(L, obj2gco(c), LUA_TFUNCTION);
38  c->l.isC = 0;
39  c->l.env = e;
40  c->l.nupvalues = cast_byte(nelems);
41  while (nelems--) c->l.upvals[nelems] = NULL;
42  return c;
43}
44
45
46UpVal *luaF_newupval (lua_State *L) {
47  UpVal *uv = luaM_new(L, UpVal);
48  luaC_link(L, obj2gco(uv), LUA_TUPVAL);
49  uv->v = &uv->u.value;
50  setnilvalue(uv->v);
51  return uv;
52}
53
54
55UpVal *luaF_findupval (lua_State *L, StkId level) {
56  global_State *g = G(L);
57  GCObject **pp = &L->openupval;
58  UpVal *p;
59  UpVal *uv;
60  while (*pp != NULL && (p = ngcotouv(*pp))->v >= level) {
61    lua_assert(p->v != &p->u.value);
62    if (p->v == level) {  /* found a corresponding upvalue? */
63      if (isdead(g, obj2gco(p)))  /* is it dead? */
64        changewhite(obj2gco(p));  /* ressurect it */
65      return p;
66    }
67    pp = &p->next;
68  }
69  uv = luaM_new(L, UpVal);  /* not found: create a new one */
70  uv->tt = LUA_TUPVAL;
71  uv->marked = luaC_white(g);
72  uv->v = level;  /* current value lives in the stack */
73  uv->next = *pp;  /* chain it in the proper position */
74  *pp = obj2gco(uv);
75  uv->u.l.prev = &g->uvhead;  /* double link it in `uvhead' list */
76  uv->u.l.next = g->uvhead.u.l.next;
77  uv->u.l.next->u.l.prev = uv;
78  g->uvhead.u.l.next = uv;
79  lua_assert(uv->u.l.next->u.l.prev == uv && uv->u.l.prev->u.l.next == uv);
80  return uv;
81}
82
83
84static void unlinkupval (UpVal *uv) {
85  lua_assert(uv->u.l.next->u.l.prev == uv && uv->u.l.prev->u.l.next == uv);
86  uv->u.l.next->u.l.prev = uv->u.l.prev;  /* remove from `uvhead' list */
87  uv->u.l.prev->u.l.next = uv->u.l.next;
88}
89
90
91void luaF_freeupval (lua_State *L, UpVal *uv) {
92  if (uv->v != &uv->u.value)  /* is it open? */
93    unlinkupval(uv);  /* remove from open list */
94  luaM_free(L, uv);  /* free upvalue */
95}
96
97
98void luaF_close (lua_State *L, StkId level) {
99  UpVal *uv;
100  global_State *g = G(L);
101  while (L->openupval != NULL && (uv = ngcotouv(L->openupval))->v >= level) {
102    GCObject *o = obj2gco(uv);
103    lua_assert(!isblack(o) && uv->v != &uv->u.value);
104    L->openupval = uv->next;  /* remove from `open' list */
105    if (isdead(g, o))
106      luaF_freeupval(L, uv);  /* free upvalue */
107    else {
108      unlinkupval(uv);
109      setobj(L, &uv->u.value, uv->v);
110      uv->v = &uv->u.value;  /* now current value lives here */
111      luaC_linkupval(L, uv);  /* link upvalue into `gcroot' list */
112    }
113  }
114}
115
116
117Proto *luaF_newproto (lua_State *L) {
118  Proto *f = luaM_new(L, Proto);
119  luaC_link(L, obj2gco(f), LUA_TPROTO);
120  f->k = NULL;
121  f->sizek = 0;
122  f->p = NULL;
123  f->sizep = 0;
124  f->code = NULL;
125  f->sizecode = 0;
126  f->sizelineinfo = 0;
127  f->sizeupvalues = 0;
128  f->nups = 0;
129  f->upvalues = NULL;
130  f->numparams = 0;
131  f->is_vararg = 0;
132  f->maxstacksize = 0;
133  f->lineinfo = NULL;
134  f->sizelocvars = 0;
135  f->locvars = NULL;
136  f->linedefined = 0;
137  f->lastlinedefined = 0;
138  f->source = NULL;
139  return f;
140}
141
142
143void luaF_freeproto (lua_State *L, Proto *f) {
144  luaM_freearray(L, f->code, f->sizecode, Instruction);
145  luaM_freearray(L, f->p, f->sizep, Proto *);
146  luaM_freearray(L, f->k, f->sizek, TValue);
147  luaM_freearray(L, f->lineinfo, f->sizelineinfo, int);
148  luaM_freearray(L, f->locvars, f->sizelocvars, struct LocVar);
149  luaM_freearray(L, f->upvalues, f->sizeupvalues, TString *);
150  luaM_free(L, f);
151}
152
153
154void luaF_freeclosure (lua_State *L, Closure *c) {
155  int size = (c->c.isC) ? sizeCclosure(c->c.nupvalues) :
156                          sizeLclosure(c->l.nupvalues);
157  luaM_freemem(L, c, size);
158}
159
160
161/*
162** Look for n-th local variable at line `line' in function `func'.
163** Returns NULL if not found.
164*/
165const char *luaF_getlocalname (const Proto *f, int local_number, int pc) {
166  int i;
167  for (i = 0; i<f->sizelocvars && f->locvars[i].startpc <= pc; i++) {
168    if (pc < f->locvars[i].endpc) {  /* is variable active? */
169      local_number--;
170      if (local_number == 0)
171        return getstr(f->locvars[i].varname);
172    }
173  }
174  return NULL;  /* not found */
175}
176
177