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 } 161 162
