ba8b5c17 |
1 | /* |
2 | ** $Id: lfunc.c,v 2.30 2012/10/03 12:36:46 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 | Closure *luaF_newCclosure (lua_State *L, int n) { |
24 | Closure *c = &luaC_newobj(L, LUA_TCCL, sizeCclosure(n), NULL, 0)->cl; |
25 | c->c.nupvalues = cast_byte(n); |
26 | return c; |
27 | } |
28 | |
29 | |
30 | Closure *luaF_newLclosure (lua_State *L, int n) { |
31 | Closure *c = &luaC_newobj(L, LUA_TLCL, sizeLclosure(n), NULL, 0)->cl; |
32 | c->l.p = NULL; |
33 | c->l.nupvalues = cast_byte(n); |
34 | while (n--) c->l.upvals[n] = NULL; |
35 | return c; |
36 | } |
37 | |
38 | |
39 | UpVal *luaF_newupval (lua_State *L) { |
40 | UpVal *uv = &luaC_newobj(L, LUA_TUPVAL, sizeof(UpVal), NULL, 0)->uv; |
41 | uv->v = &uv->u.value; |
42 | setnilvalue(uv->v); |
43 | return uv; |
44 | } |
45 | |
46 | |
47 | UpVal *luaF_findupval (lua_State *L, StkId level) { |
48 | global_State *g = G(L); |
49 | GCObject **pp = &L->openupval; |
50 | UpVal *p; |
51 | UpVal *uv; |
52 | while (*pp != NULL && (p = gco2uv(*pp))->v >= level) { |
53 | GCObject *o = obj2gco(p); |
54 | lua_assert(p->v != &p->u.value); |
55 | lua_assert(!isold(o) || isold(obj2gco(L))); |
56 | if (p->v == level) { /* found a corresponding upvalue? */ |
57 | if (isdead(g, o)) /* is it dead? */ |
58 | changewhite(o); /* resurrect it */ |
59 | return p; |
60 | } |
61 | pp = &p->next; |
62 | } |
63 | /* not found: create a new one */ |
64 | uv = &luaC_newobj(L, LUA_TUPVAL, sizeof(UpVal), pp, 0)->uv; |
65 | uv->v = level; /* current value lives in the stack */ |
66 | uv->u.l.prev = &g->uvhead; /* double link it in `uvhead' list */ |
67 | uv->u.l.next = g->uvhead.u.l.next; |
68 | uv->u.l.next->u.l.prev = uv; |
69 | 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 | return uv; |
72 | } |
73 | |
74 | |
75 | 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 | uv->u.l.next->u.l.prev = uv->u.l.prev; /* remove from `uvhead' list */ |
78 | uv->u.l.prev->u.l.next = uv->u.l.next; |
79 | } |
80 | |
81 | |
82 | void luaF_freeupval (lua_State *L, UpVal *uv) { |
83 | if (uv->v != &uv->u.value) /* is it open? */ |
84 | unlinkupval(uv); /* remove from open list */ |
85 | luaM_free(L, uv); /* free upvalue */ |
86 | } |
87 | |
88 | |
89 | void luaF_close (lua_State *L, StkId level) { |
90 | UpVal *uv; |
91 | global_State *g = G(L); |
92 | while (L->openupval != NULL && (uv = gco2uv(L->openupval))->v >= level) { |
93 | GCObject *o = obj2gco(uv); |
94 | lua_assert(!isblack(o) && uv->v != &uv->u.value); |
95 | L->openupval = uv->next; /* remove from `open' list */ |
96 | if (isdead(g, o)) |
97 | luaF_freeupval(L, uv); /* free upvalue */ |
98 | else { |
99 | unlinkupval(uv); /* remove upvalue from 'uvhead' list */ |
100 | setobj(L, &uv->u.value, uv->v); /* move value to upvalue slot */ |
101 | uv->v = &uv->u.value; /* now current value lives here */ |
102 | gch(o)->next = g->allgc; /* link upvalue into 'allgc' list */ |
103 | g->allgc = o; |
104 | luaC_checkupvalcolor(g, uv); |
105 | } |
106 | } |
107 | } |
108 | |
109 | |
110 | Proto *luaF_newproto (lua_State *L) { |
111 | Proto *f = &luaC_newobj(L, LUA_TPROTO, sizeof(Proto), NULL, 0)->p; |
112 | f->k = NULL; |
113 | f->sizek = 0; |
114 | f->p = NULL; |
115 | f->sizep = 0; |
116 | f->code = NULL; |
117 | f->cache = NULL; |
118 | f->sizecode = 0; |
119 | f->lineinfo = NULL; |
120 | f->sizelineinfo = 0; |
121 | f->upvalues = NULL; |
122 | f->sizeupvalues = 0; |
123 | f->numparams = 0; |
124 | f->is_vararg = 0; |
125 | f->maxstacksize = 0; |
126 | f->locvars = NULL; |
127 | f->sizelocvars = 0; |
128 | f->linedefined = 0; |
129 | f->lastlinedefined = 0; |
130 | f->source = NULL; |
131 | return f; |
132 | } |
133 | |
134 | |
135 | void luaF_freeproto (lua_State *L, Proto *f) { |
136 | luaM_freearray(L, f->code, f->sizecode); |
137 | luaM_freearray(L, f->p, f->sizep); |
138 | luaM_freearray(L, f->k, f->sizek); |
139 | luaM_freearray(L, f->lineinfo, f->sizelineinfo); |
140 | luaM_freearray(L, f->locvars, f->sizelocvars); |
141 | luaM_freearray(L, f->upvalues, f->sizeupvalues); |
142 | luaM_free(L, f); |
143 | } |
144 | |
145 | |
146 | /* |
147 | ** Look for n-th local variable at line `line' in function `func'. |
148 | ** Returns NULL if not found. |
149 | */ |
150 | const char *luaF_getlocalname (const Proto *f, int local_number, int pc) { |
151 | int i; |
152 | for (i = 0; i<f->sizelocvars && f->locvars[i].startpc <= pc; i++) { |
153 | if (pc < f->locvars[i].endpc) { /* is variable active? */ |
154 | local_number--; |
155 | if (local_number == 0) |
156 | return getstr(f->locvars[i].varname); |
157 | } |
158 | } |
159 | return NULL; /* not found */ |
160 | } |
161 | |