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