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| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 */ |
| 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 |
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