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
luaF_newCclosure(lua_State * L,int n)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
luaF_newLclosure(lua_State * L,int n)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
luaF_newupval(lua_State * L)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
luaF_findupval(lua_State * L,StkId level)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
unlinkupval(UpVal * uv)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
luaF_freeupval(lua_State * L,UpVal * uv)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
luaF_close(lua_State * L,StkId level)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
luaF_newproto(lua_State * L)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
luaF_freeproto(lua_State * L,Proto * f)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 */
luaF_getlocalname(const Proto * f,int local_number,int pc)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
162