aboutsummaryrefslogtreecommitdiffstats
path: root/bruiser/lua-5.3.4/src/lfunc.c
blob: 67967dab3fc89e638e99247186d8181ac7af957a (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
/*
** $Id: lfunc.c,v 2.45 2014/11/02 19:19:04 roberto Exp $
** Auxiliary functions to manipulate prototypes and closures
** See Copyright Notice in lua.h
*/

#define lfunc_c
#define LUA_CORE

#include "lprefix.h"


#include <stddef.h>

#include "lua.h"

#include "lfunc.h"
#include "lgc.h"
#include "lmem.h"
#include "lobject.h"
#include "lstate.h"



CClosure *luaF_newCclosure (lua_State *L, int n) {
  GCObject *o = luaC_newobj(L, LUA_TCCL, sizeCclosure(n));
  CClosure *c = gco2ccl(o);
  c->nupvalues = cast_byte(n);
  return c;
}


LClosure *luaF_newLclosure (lua_State *L, int n) {
  GCObject *o = luaC_newobj(L, LUA_TLCL, sizeLclosure(n));
  LClosure *c = gco2lcl(o);
  c->p = NULL;
  c->nupvalues = cast_byte(n);
  while (n--) c->upvals[n] = NULL;
  return c;
}

/*
** fill a closure with new closed upvalues
*/
void luaF_initupvals (lua_State *L, LClosure *cl) {
  int i;
  for (i = 0; i < cl->nupvalues; i++) {
    UpVal *uv = luaM_new(L, UpVal);
    uv->refcount = 1;
    uv->v = &uv->u.value;  /* make it closed */
    setnilvalue(uv->v);
    cl->upvals[i] = uv;
  }
}


UpVal *luaF_findupval (lua_State *L, StkId level) {
  UpVal **pp = &L->openupval;
  UpVal *p;
  UpVal *uv;
  lua_assert(isintwups(L) || L->openupval == NULL);
  while (*pp != NULL && (p = *pp)->v >= level) {
    lua_assert(upisopen(p));
    if (p->v == level)  /* found a corresponding upvalue? */
      return p;  /* return it */
    pp = &p->u.open.next;
  }
  /* not found: create a new upvalue */
  uv = luaM_new(L, UpVal);
  uv->refcount = 0;
  uv->u.open.next = *pp;  /* link it to list of open upvalues */
  uv->u.open.touched = 1;
  *pp = uv;
  uv->v = level;  /* current value lives in the stack */
  if (!isintwups(L)) {  /* thread not in list of threads with upvalues? */
    L->twups = G(L)->twups;  /* link it to the list */
    G(L)->twups = L;
  }
  return uv;
}


void luaF_close (lua_State *L, StkId level) {
  UpVal *uv;
  while (L->openupval != NULL && (uv = L->openupval)->v >= level) {
    lua_assert(upisopen(uv));
    L->openupval = uv->u.open.next;  /* remove from 'open' list */
    if (uv->refcount == 0)  /* no references? */
      luaM_free(L, uv);  /* free upvalue */
    else {
      setobj(L, &uv->u.value, uv->v);  /* move value to upvalue slot */
      uv->v = &uv->u.value;  /* now current value lives here */
      luaC_upvalbarrier(L, uv);
    }
  }
}


Proto *luaF_newproto (lua_State *L) {
  GCObject *o = luaC_newobj(L, LUA_TPROTO, sizeof(Proto));
  Proto *f = gco2p(o);
  f->k = NULL;
  f->sizek = 0;
  f->p = NULL;
  f->sizep = 0;
  f->code = NULL;
  f->cache = NULL;
  f->sizecode = 0;
  f->lineinfo = NULL;
  f->sizelineinfo = 0;
  f->upvalues = NULL;
  f->sizeupvalues = 0;
  f->numparams = 0;
  f->is_vararg = 0;
  f->maxstacksize = 0;
  f->locvars = NULL;
  f->sizelocvars = 0;
  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);
  luaM_freearray(L, f->p, f->sizep);
  luaM_freearray(L, f->k, f->sizek);
  luaM_freearray(L, f->lineinfo, f->sizelineinfo);
  luaM_freearray(L, f->locvars, f->sizelocvars);
  luaM_freearray(L, f->upvalues, f->sizeupvalues);
  luaM_free(L, f);
}


/*
** 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 */
}