1 /*
2 ** $Id: lfunc.c,v 2.45.1.1 2017/04/19 17:39:34 roberto Exp $
3 ** Auxiliary functions to manipulate prototypes and closures
4 ** See Copyright Notice in lua.h
5 */
6
7 #define lfunc_c
8 #define LUA_CORE
9
10 #include "lprefix.h"
11
12
13 #include <stddef.h>
14
15 #include "lua.h"
16
17 #include "lfunc.h"
18 #include "lgc.h"
19 #include "lmem.h"
20 #include "lobject.h"
21 #include "lstate.h"
22
23
24
luaF_newCclosure(lua_State * L,int n)25 CClosure *luaF_newCclosure (lua_State *L, int n) {
26 GCObject *o = luaC_newobj(L, LUA_TCCL, sizeCclosure(n));
27 CClosure *c = gco2ccl(o);
28 c->nupvalues = cast_byte(n);
29 return c;
30 }
31
32
luaF_newLclosure(lua_State * L,int n)33 LClosure *luaF_newLclosure (lua_State *L, int n) {
34 GCObject *o = luaC_newobj(L, LUA_TLCL, sizeLclosure(n));
35 LClosure *c = gco2lcl(o);
36 c->p = NULL;
37 c->nupvalues = cast_byte(n);
38 while (n--) c->upvals[n] = NULL;
39 return c;
40 }
41
42 /*
43 ** fill a closure with new closed upvalues
44 */
luaF_initupvals(lua_State * L,LClosure * cl)45 void luaF_initupvals (lua_State *L, LClosure *cl) {
46 int i;
47 for (i = 0; i < cl->nupvalues; i++) {
48 UpVal *uv = luaM_new(L, UpVal);
49 uv->refcount = 1;
50 uv->v = &uv->u.value; /* make it closed */
51 setnilvalue(uv->v);
52 cl->upvals[i] = uv;
53 }
54 }
55
56
luaF_findupval(lua_State * L,StkId level)57 UpVal *luaF_findupval (lua_State *L, StkId level) {
58 UpVal **pp = &L->openupval;
59 UpVal *p;
60 UpVal *uv;
61 lua_assert(isintwups(L) || L->openupval == NULL);
62 while (*pp != NULL && (p = *pp)->v >= level) {
63 lua_assert(upisopen(p));
64 if (p->v == level) /* found a corresponding upvalue? */
65 return p; /* return it */
66 pp = &p->u.open.next;
67 }
68 /* not found: create a new upvalue */
69 uv = luaM_new(L, UpVal);
70 uv->refcount = 0;
71 uv->u.open.next = *pp; /* link it to list of open upvalues */
72 uv->u.open.touched = 1;
73 *pp = uv;
74 uv->v = level; /* current value lives in the stack */
75 if (!isintwups(L)) { /* thread not in list of threads with upvalues? */
76 L->twups = G(L)->twups; /* link it to the list */
77 G(L)->twups = L;
78 }
79 return uv;
80 }
81
82
luaF_close(lua_State * L,StkId level)83 void luaF_close (lua_State *L, StkId level) {
84 UpVal *uv;
85 while (L->openupval != NULL && (uv = L->openupval)->v >= level) {
86 lua_assert(upisopen(uv));
87 L->openupval = uv->u.open.next; /* remove from 'open' list */
88 if (uv->refcount == 0) /* no references? */
89 luaM_free(L, uv); /* free upvalue */
90 else {
91 setobj(L, &uv->u.value, uv->v); /* move value to upvalue slot */
92 uv->v = &uv->u.value; /* now current value lives here */
93 luaC_upvalbarrier(L, uv);
94 }
95 }
96 }
97
98
luaF_newproto(lua_State * L)99 Proto *luaF_newproto (lua_State *L) {
100 GCObject *o = luaC_newobj(L, LUA_TPROTO, sizeof(Proto));
101 Proto *f = gco2p(o);
102 f->k = NULL;
103 f->sizek = 0;
104 f->p = NULL;
105 f->sizep = 0;
106 f->code = NULL;
107 f->cache = NULL;
108 f->sizecode = 0;
109 f->lineinfo = NULL;
110 f->sizelineinfo = 0;
111 f->upvalues = NULL;
112 f->sizeupvalues = 0;
113 f->numparams = 0;
114 f->is_vararg = 0;
115 f->maxstacksize = 0;
116 f->locvars = NULL;
117 f->sizelocvars = 0;
118 f->linedefined = 0;
119 f->lastlinedefined = 0;
120 f->source = NULL;
121 return f;
122 }
123
124
luaF_freeproto(lua_State * L,Proto * f)125 void luaF_freeproto (lua_State *L, Proto *f) {
126 luaM_freearray(L, f->code, f->sizecode);
127 luaM_freearray(L, f->p, f->sizep);
128 luaM_freearray(L, f->k, f->sizek);
129 luaM_freearray(L, f->lineinfo, f->sizelineinfo);
130 luaM_freearray(L, f->locvars, f->sizelocvars);
131 luaM_freearray(L, f->upvalues, f->sizeupvalues);
132 luaM_free(L, f);
133 }
134
135
136 /*
137 ** Look for n-th local variable at line 'line' in function 'func'.
138 ** Returns NULL if not found.
139 */
luaF_getlocalname(const Proto * f,int local_number,int pc)140 const char *luaF_getlocalname (const Proto *f, int local_number, int pc) {
141 int i;
142 for (i = 0; i<f->sizelocvars && f->locvars[i].startpc <= pc; i++) {
143 if (pc < f->locvars[i].endpc) { /* is variable active? */
144 local_number--;
145 if (local_number == 0)
146 return getstr(f->locvars[i].varname);
147 }
148 }
149 return NULL; /* not found */
150 }
151
152