1 // SPDX-License-Identifier: MIT
2 /*
3 ** $Id: lfunc.c,v 2.30.1.1 2013/04/12 18:48:47 roberto Exp $
4 ** Auxiliary functions to manipulate prototypes and closures
5 ** See Copyright Notice in lua.h
6 */
7
8
9 #define lfunc_c
10 #define LUA_CORE
11
12 #include <sys/lua/lua.h>
13
14 #include "lfunc.h"
15 #include "lgc.h"
16 #include "lmem.h"
17 #include "lobject.h"
18 #include "lstate.h"
19
20
21
luaF_newCclosure(lua_State * L,int n)22 Closure *luaF_newCclosure (lua_State *L, int n) {
23 Closure *c = &luaC_newobj(L, LUA_TCCL, sizeCclosure(n), NULL, 0)->cl;
24 c->c.nupvalues = cast_byte(n);
25 return c;
26 }
27
28
luaF_newLclosure(lua_State * L,int n)29 Closure *luaF_newLclosure (lua_State *L, int n) {
30 Closure *c = &luaC_newobj(L, LUA_TLCL, sizeLclosure(n), NULL, 0)->cl;
31 c->l.p = NULL;
32 c->l.nupvalues = cast_byte(n);
33 while (n--) c->l.upvals[n] = NULL;
34 return c;
35 }
36
37
luaF_newupval(lua_State * L)38 UpVal *luaF_newupval (lua_State *L) {
39 UpVal *uv = &luaC_newobj(L, LUA_TUPVAL, sizeof(UpVal), NULL, 0)->uv;
40 uv->v = &uv->u.value;
41 setnilvalue(uv->v);
42 return uv;
43 }
44
45
luaF_findupval(lua_State * L,StkId level)46 UpVal *luaF_findupval (lua_State *L, StkId level) {
47 global_State *g = G(L);
48 GCObject **pp = &L->openupval;
49 UpVal *p;
50 UpVal *uv;
51 while (*pp != NULL && (p = gco2uv(*pp))->v >= level) {
52 GCObject *o = obj2gco(p);
53 lua_assert(p->v != &p->u.value);
54 lua_assert(!isold(o) || isold(obj2gco(L)));
55 if (p->v == level) { /* found a corresponding upvalue? */
56 if (isdead(g, o)) /* is it dead? */
57 changewhite(o); /* resurrect it */
58 return p;
59 }
60 pp = &p->next;
61 }
62 /* not found: create a new one */
63 uv = &luaC_newobj(L, LUA_TUPVAL, sizeof(UpVal), pp, 0)->uv;
64 uv->v = level; /* current value lives in the stack */
65 uv->u.l.prev = &g->uvhead; /* double link it in `uvhead' list */
66 uv->u.l.next = g->uvhead.u.l.next;
67 uv->u.l.next->u.l.prev = uv;
68 g->uvhead.u.l.next = uv;
69 lua_assert(uv->u.l.next->u.l.prev == uv && uv->u.l.prev->u.l.next == uv);
70 return uv;
71 }
72
73
unlinkupval(UpVal * uv)74 static void unlinkupval (UpVal *uv) {
75 lua_assert(uv->u.l.next->u.l.prev == uv && uv->u.l.prev->u.l.next == uv);
76 uv->u.l.next->u.l.prev = uv->u.l.prev; /* remove from `uvhead' list */
77 uv->u.l.prev->u.l.next = uv->u.l.next;
78 }
79
80
luaF_freeupval(lua_State * L,UpVal * uv)81 void luaF_freeupval (lua_State *L, UpVal *uv) {
82 if (uv->v != &uv->u.value) /* is it open? */
83 unlinkupval(uv); /* remove from open list */
84 luaM_free(L, uv); /* free upvalue */
85 }
86
87
luaF_close(lua_State * L,StkId level)88 void luaF_close (lua_State *L, StkId level) {
89 UpVal *uv;
90 global_State *g = G(L);
91 while (L->openupval != NULL && (uv = gco2uv(L->openupval))->v >= level) {
92 GCObject *o = obj2gco(uv);
93 lua_assert(!isblack(o) && uv->v != &uv->u.value);
94 L->openupval = uv->next; /* remove from `open' list */
95 if (isdead(g, o))
96 luaF_freeupval(L, uv); /* free upvalue */
97 else {
98 unlinkupval(uv); /* remove upvalue from 'uvhead' list */
99 setobj(L, &uv->u.value, uv->v); /* move value to upvalue slot */
100 uv->v = &uv->u.value; /* now current value lives here */
101 gch(o)->next = g->allgc; /* link upvalue into 'allgc' list */
102 g->allgc = o;
103 luaC_checkupvalcolor(g, uv);
104 }
105 }
106 }
107
108
luaF_newproto(lua_State * L)109 Proto *luaF_newproto (lua_State *L) {
110 Proto *f = &luaC_newobj(L, LUA_TPROTO, sizeof(Proto), NULL, 0)->p;
111 f->k = NULL;
112 f->sizek = 0;
113 f->p = NULL;
114 f->sizep = 0;
115 f->code = NULL;
116 f->cache = NULL;
117 f->sizecode = 0;
118 f->lineinfo = NULL;
119 f->sizelineinfo = 0;
120 f->upvalues = NULL;
121 f->sizeupvalues = 0;
122 f->numparams = 0;
123 f->is_vararg = 0;
124 f->maxstacksize = 0;
125 f->locvars = NULL;
126 f->sizelocvars = 0;
127 f->linedefined = 0;
128 f->lastlinedefined = 0;
129 f->source = NULL;
130 return f;
131 }
132
133
luaF_freeproto(lua_State * L,Proto * f)134 void luaF_freeproto (lua_State *L, Proto *f) {
135 luaM_freearray(L, f->code, f->sizecode);
136 luaM_freearray(L, f->p, f->sizep);
137 luaM_freearray(L, f->k, f->sizek);
138 luaM_freearray(L, f->lineinfo, f->sizelineinfo);
139 luaM_freearray(L, f->locvars, f->sizelocvars);
140 luaM_freearray(L, f->upvalues, f->sizeupvalues);
141 luaM_free(L, f);
142 }
143
144
145 /*
146 ** Look for n-th local variable at line `line' in function `func'.
147 ** Returns NULL if not found.
148 */
luaF_getlocalname(const Proto * f,int local_number,int pc)149 const char *luaF_getlocalname (const Proto *f, int local_number, int pc) {
150 int i;
151 for (i = 0; i<f->sizelocvars && f->locvars[i].startpc <= pc; i++) {
152 if (pc < f->locvars[i].endpc) { /* is variable active? */
153 local_number--;
154 if (local_number == 0)
155 return getstr(f->locvars[i].varname);
156 }
157 }
158 return NULL; /* not found */
159 }
160