Line data Source code
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 : #include <stddef.h>
9 :
10 : #define lfunc_c
11 : #define LUA_CORE
12 :
13 : #include "lua.h"
14 :
15 : #include "lfunc.h"
16 : #include "lgc.h"
17 : #include "lmem.h"
18 : #include "lobject.h"
19 : #include "lstate.h"
20 :
21 :
22 :
23 535 : Closure *luaF_newCclosure (lua_State *L, int n) {
24 535 : Closure *c = &luaC_newobj(L, LUA_TCCL, sizeCclosure(n), NULL, 0)->cl;
25 535 : c->c.nupvalues = cast_byte(n);
26 535 : return c;
27 : }
28 :
29 :
30 3408 : Closure *luaF_newLclosure (lua_State *L, int n) {
31 3408 : Closure *c = &luaC_newobj(L, LUA_TLCL, sizeLclosure(n), NULL, 0)->cl;
32 3408 : c->l.p = NULL;
33 3408 : c->l.nupvalues = cast_byte(n);
34 13802 : while (n--) c->l.upvals[n] = NULL;
35 3408 : return c;
36 : }
37 :
38 :
39 464 : UpVal *luaF_newupval (lua_State *L) {
40 464 : UpVal *uv = &luaC_newobj(L, LUA_TUPVAL, sizeof(UpVal), NULL, 0)->uv;
41 464 : uv->v = &uv->u.value;
42 464 : setnilvalue(uv->v);
43 464 : return uv;
44 : }
45 :
46 :
47 6871 : UpVal *luaF_findupval (lua_State *L, StkId level) {
48 6871 : global_State *g = G(L);
49 6871 : GCObject **pp = &L->openupval;
50 : UpVal *p;
51 : UpVal *uv;
52 15166 : while (*pp != NULL && (p = gco2uv(*pp))->v >= level) {
53 9459 : GCObject *o = obj2gco(p);
54 : lua_assert(p->v != &p->u.value);
55 : lua_assert(!isold(o) || isold(obj2gco(L)));
56 9459 : if (p->v == level) { /* found a corresponding upvalue? */
57 1164 : if (isdead(g, o)) /* is it dead? */
58 1 : changewhite(o); /* resurrect it */
59 1164 : return p;
60 : }
61 8295 : pp = &p->next;
62 : }
63 : /* not found: create a new one */
64 5707 : uv = &luaC_newobj(L, LUA_TUPVAL, sizeof(UpVal), pp, 0)->uv;
65 5707 : uv->v = level; /* current value lives in the stack */
66 5707 : uv->u.l.prev = &g->uvhead; /* double link it in `uvhead' list */
67 5707 : uv->u.l.next = g->uvhead.u.l.next;
68 5707 : uv->u.l.next->u.l.prev = uv;
69 5707 : g->uvhead.u.l.next = uv;
70 : lua_assert(uv->u.l.next->u.l.prev == uv && uv->u.l.prev->u.l.next == uv);
71 5707 : return uv;
72 : }
73 :
74 :
75 5707 : static void unlinkupval (UpVal *uv) {
76 : lua_assert(uv->u.l.next->u.l.prev == uv && uv->u.l.prev->u.l.next == uv);
77 5707 : uv->u.l.next->u.l.prev = uv->u.l.prev; /* remove from `uvhead' list */
78 5707 : uv->u.l.prev->u.l.next = uv->u.l.next;
79 5707 : }
80 :
81 :
82 6048 : void luaF_freeupval (lua_State *L, UpVal *uv) {
83 6048 : if (uv->v != &uv->u.value) /* is it open? */
84 4 : unlinkupval(uv); /* remove from open list */
85 6048 : luaM_free(L, uv); /* free upvalue */
86 6048 : }
87 :
88 :
89 2059 : void luaF_close (lua_State *L, StkId level) {
90 : UpVal *uv;
91 2059 : global_State *g = G(L);
92 7765 : while (L->openupval != NULL && (uv = gco2uv(L->openupval))->v >= level) {
93 5706 : GCObject *o = obj2gco(uv);
94 : lua_assert(!isblack(o) && uv->v != &uv->u.value);
95 5706 : L->openupval = uv->next; /* remove from `open' list */
96 5706 : if (isdead(g, o))
97 3 : luaF_freeupval(L, uv); /* free upvalue */
98 : else {
99 5703 : unlinkupval(uv); /* remove upvalue from 'uvhead' list */
100 5703 : setobj(L, &uv->u.value, uv->v); /* move value to upvalue slot */
101 5703 : uv->v = &uv->u.value; /* now current value lives here */
102 5703 : gch(o)->next = g->allgc; /* link upvalue into 'allgc' list */
103 5703 : g->allgc = o;
104 5703 : luaC_checkupvalcolor(g, uv);
105 : }
106 : }
107 2059 : }
108 :
109 :
110 2211 : Proto *luaF_newproto (lua_State *L) {
111 2211 : Proto *f = &luaC_newobj(L, LUA_TPROTO, sizeof(Proto), NULL, 0)->p;
112 2211 : f->k = NULL;
113 2211 : f->sizek = 0;
114 2211 : f->p = NULL;
115 2211 : f->sizep = 0;
116 2211 : f->code = NULL;
117 2211 : f->cache = NULL;
118 2211 : f->sizecode = 0;
119 2211 : f->lineinfo = NULL;
120 2211 : f->sizelineinfo = 0;
121 2211 : f->upvalues = NULL;
122 2211 : f->sizeupvalues = 0;
123 2211 : f->numparams = 0;
124 2211 : f->is_vararg = 0;
125 2211 : f->maxstacksize = 0;
126 2211 : f->locvars = NULL;
127 2211 : f->sizelocvars = 0;
128 2211 : f->linedefined = 0;
129 2211 : f->lastlinedefined = 0;
130 2211 : f->source = NULL;
131 2211 : return f;
132 : }
133 :
134 :
135 2056 : void luaF_freeproto (lua_State *L, Proto *f) {
136 2056 : luaM_freearray(L, f->code, f->sizecode);
137 2056 : luaM_freearray(L, f->p, f->sizep);
138 2056 : luaM_freearray(L, f->k, f->sizek);
139 2056 : luaM_freearray(L, f->lineinfo, f->sizelineinfo);
140 2056 : luaM_freearray(L, f->locvars, f->sizelocvars);
141 2056 : luaM_freearray(L, f->upvalues, f->sizeupvalues);
142 2056 : luaM_free(L, f);
143 2056 : }
144 :
145 :
146 : /*
147 : ** Look for n-th local variable at line `line' in function `func'.
148 : ** Returns NULL if not found.
149 : */
150 152 : const char *luaF_getlocalname (const Proto *f, int local_number, int pc) {
151 : int i;
152 191 : for (i = 0; i<f->sizelocvars && f->locvars[i].startpc <= pc; i++) {
153 50 : if (pc < f->locvars[i].endpc) { /* is variable active? */
154 33 : local_number--;
155 33 : if (local_number == 0)
156 11 : return getstr(f->locvars[i].varname);
157 : }
158 : }
159 141 : return NULL; /* not found */
160 : }
161 :
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