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 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 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 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 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 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 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 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 } 106 107 108 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 } 131 132 133 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 */ 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