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21d3294c | 1 | /* |
2 | ** $Id: lfunc.c,v 2.12.1.2 2007/12/28 14:58:43 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 nelems, Table *e) { | |
24 | Closure *c = cast(Closure *, luaM_malloc(L, sizeCclosure(nelems))); | |
25 | luaC_link(L, obj2gco(c), LUA_TFUNCTION); | |
26 | c->c.isC = 1; | |
27 | c->c.env = e; | |
28 | c->c.nupvalues = cast_byte(nelems); | |
29 | return c; | |
30 | } | |
31 | ||
32 | ||
33 | Closure *luaF_newLclosure (lua_State *L, int nelems, Table *e) { | |
34 | Closure *c = cast(Closure *, luaM_malloc(L, sizeLclosure(nelems))); | |
35 | luaC_link(L, obj2gco(c), LUA_TFUNCTION); | |
36 | c->l.isC = 0; | |
37 | c->l.env = e; | |
38 | c->l.nupvalues = cast_byte(nelems); | |
39 | while (nelems--) c->l.upvals[nelems] = NULL; | |
40 | return c; | |
41 | } | |
42 | ||
43 | ||
44 | UpVal *luaF_newupval (lua_State *L) { | |
45 | UpVal *uv = luaM_new(L, UpVal); | |
46 | luaC_link(L, obj2gco(uv), LUA_TUPVAL); | |
47 | uv->v = &uv->u.value; | |
48 | setnilvalue(uv->v); | |
49 | return uv; | |
50 | } | |
51 | ||
52 | ||
53 | UpVal *luaF_findupval (lua_State *L, StkId level) { | |
54 | global_State *g = G(L); | |
55 | GCObject **pp = &L->openupval; | |
56 | UpVal *p; | |
57 | UpVal *uv; | |
58 | while (*pp != NULL && (p = ngcotouv(*pp))->v >= level) { | |
59 | lua_assert(p->v != &p->u.value); | |
60 | if (p->v == level) { /* found a corresponding upvalue? */ | |
61 | if (isdead(g, obj2gco(p))) /* is it dead? */ | |
62 | changewhite(obj2gco(p)); /* ressurect it */ | |
63 | return p; | |
64 | } | |
65 | pp = &p->next; | |
66 | } | |
67 | uv = luaM_new(L, UpVal); /* not found: create a new one */ | |
68 | uv->tt = LUA_TUPVAL; | |
69 | uv->marked = luaC_white(g); | |
70 | uv->v = level; /* current value lives in the stack */ | |
71 | uv->next = *pp; /* chain it in the proper position */ | |
72 | *pp = obj2gco(uv); | |
73 | uv->u.l.prev = &g->uvhead; /* double link it in `uvhead' list */ | |
74 | uv->u.l.next = g->uvhead.u.l.next; | |
75 | uv->u.l.next->u.l.prev = uv; | |
76 | g->uvhead.u.l.next = uv; | |
77 | lua_assert(uv->u.l.next->u.l.prev == uv && uv->u.l.prev->u.l.next == uv); | |
78 | return uv; | |
79 | } | |
80 | ||
81 | ||
82 | static void unlinkupval (UpVal *uv) { | |
83 | lua_assert(uv->u.l.next->u.l.prev == uv && uv->u.l.prev->u.l.next == uv); | |
84 | uv->u.l.next->u.l.prev = uv->u.l.prev; /* remove from `uvhead' list */ | |
85 | uv->u.l.prev->u.l.next = uv->u.l.next; | |
86 | } | |
87 | ||
88 | ||
89 | void luaF_freeupval (lua_State *L, UpVal *uv) { | |
90 | if (uv->v != &uv->u.value) /* is it open? */ | |
91 | unlinkupval(uv); /* remove from open list */ | |
92 | luaM_free(L, uv); /* free upvalue */ | |
93 | } | |
94 | ||
95 | ||
96 | void luaF_close (lua_State *L, StkId level) { | |
97 | UpVal *uv; | |
98 | global_State *g = G(L); | |
99 | while (L->openupval != NULL && (uv = ngcotouv(L->openupval))->v >= level) { | |
100 | GCObject *o = obj2gco(uv); | |
101 | lua_assert(!isblack(o) && uv->v != &uv->u.value); | |
102 | L->openupval = uv->next; /* remove from `open' list */ | |
103 | if (isdead(g, o)) | |
104 | luaF_freeupval(L, uv); /* free upvalue */ | |
105 | else { | |
106 | unlinkupval(uv); | |
107 | setobj(L, &uv->u.value, uv->v); | |
108 | uv->v = &uv->u.value; /* now current value lives here */ | |
109 | luaC_linkupval(L, uv); /* link upvalue into `gcroot' list */ | |
110 | } | |
111 | } | |
112 | } | |
113 | ||
114 | ||
115 | Proto *luaF_newproto (lua_State *L) { | |
116 | Proto *f = luaM_new(L, Proto); | |
117 | luaC_link(L, obj2gco(f), LUA_TPROTO); | |
118 | f->k = NULL; | |
119 | f->sizek = 0; | |
120 | f->p = NULL; | |
121 | f->sizep = 0; | |
122 | f->code = NULL; | |
123 | f->sizecode = 0; | |
124 | f->sizelineinfo = 0; | |
125 | f->sizeupvalues = 0; | |
126 | f->nups = 0; | |
127 | f->upvalues = NULL; | |
128 | f->numparams = 0; | |
129 | f->is_vararg = 0; | |
130 | f->maxstacksize = 0; | |
131 | f->lineinfo = NULL; | |
132 | f->sizelocvars = 0; | |
133 | f->locvars = NULL; | |
134 | f->linedefined = 0; | |
135 | f->lastlinedefined = 0; | |
136 | f->source = NULL; | |
137 | return f; | |
138 | } | |
139 | ||
140 | ||
141 | void luaF_freeproto (lua_State *L, Proto *f) { | |
142 | luaM_freearray(L, f->code, f->sizecode, Instruction); | |
143 | luaM_freearray(L, f->p, f->sizep, Proto *); | |
144 | luaM_freearray(L, f->k, f->sizek, TValue); | |
145 | luaM_freearray(L, f->lineinfo, f->sizelineinfo, int); | |
146 | luaM_freearray(L, f->locvars, f->sizelocvars, struct LocVar); | |
147 | luaM_freearray(L, f->upvalues, f->sizeupvalues, TString *); | |
148 | luaM_free(L, f); | |
149 | } | |
150 | ||
151 | ||
152 | void luaF_freeclosure (lua_State *L, Closure *c) { | |
153 | int size = (c->c.isC) ? sizeCclosure(c->c.nupvalues) : | |
154 | sizeLclosure(c->l.nupvalues); | |
155 | luaM_freemem(L, c, size); | |
156 | } | |
157 | ||
158 | ||
159 | /* | |
160 | ** Look for n-th local variable at line `line' in function `func'. | |
161 | ** Returns NULL if not found. | |
162 | */ | |
163 | const char *luaF_getlocalname (const Proto *f, int local_number, int pc) { | |
164 | int i; | |
165 | for (i = 0; i<f->sizelocvars && f->locvars[i].startpc <= pc; i++) { | |
166 | if (pc < f->locvars[i].endpc) { /* is variable active? */ | |
167 | local_number--; | |
168 | if (local_number == 0) | |
169 | return getstr(f->locvars[i].varname); | |
170 | } | |
171 | } | |
172 | return NULL; /* not found */ | |
173 | } | |
174 |