1 /* $NetBSD: lfunc.c,v 1.1.1.1 2010/10/31 11:16:56 mbalmer Exp $ */ 2 3 /* 4 ** Id: lfunc.c,v 2.12.1.2 2007/12/28 14:58:43 roberto Exp 5 ** Auxiliary functions to manipulate prototypes and closures 6 ** See Copyright Notice in lua.h 7 */ 8 9 10 #include <stddef.h> 11 12 #define lfunc_c 13 #define LUA_CORE 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 25 Closure *luaF_newCclosure (lua_State *L, int nelems, Table *e) { 26 Closure *c = cast(Closure *, luaM_malloc(L, sizeCclosure(nelems))); 27 luaC_link(L, obj2gco(c), LUA_TFUNCTION); 28 c->c.isC = 1; 29 c->c.env = e; 30 c->c.nupvalues = cast_byte(nelems); 31 return c; 32 } 33 34 35 Closure *luaF_newLclosure (lua_State *L, int nelems, Table *e) { 36 Closure *c = cast(Closure *, luaM_malloc(L, sizeLclosure(nelems))); 37 luaC_link(L, obj2gco(c), LUA_TFUNCTION); 38 c->l.isC = 0; 39 c->l.env = e; 40 c->l.nupvalues = cast_byte(nelems); 41 while (nelems--) c->l.upvals[nelems] = NULL; 42 return c; 43 } 44 45 46 UpVal *luaF_newupval (lua_State *L) { 47 UpVal *uv = luaM_new(L, UpVal); 48 luaC_link(L, obj2gco(uv), LUA_TUPVAL); 49 uv->v = &uv->u.value; 50 setnilvalue(uv->v); 51 return uv; 52 } 53 54 55 UpVal *luaF_findupval (lua_State *L, StkId level) { 56 global_State *g = G(L); 57 GCObject **pp = &L->openupval; 58 UpVal *p; 59 UpVal *uv; 60 while (*pp != NULL && (p = ngcotouv(*pp))->v >= level) { 61 lua_assert(p->v != &p->u.value); 62 if (p->v == level) { /* found a corresponding upvalue? */ 63 if (isdead(g, obj2gco(p))) /* is it dead? */ 64 changewhite(obj2gco(p)); /* ressurect it */ 65 return p; 66 } 67 pp = &p->next; 68 } 69 uv = luaM_new(L, UpVal); /* not found: create a new one */ 70 uv->tt = LUA_TUPVAL; 71 uv->marked = luaC_white(g); 72 uv->v = level; /* current value lives in the stack */ 73 uv->next = *pp; /* chain it in the proper position */ 74 *pp = obj2gco(uv); 75 uv->u.l.prev = &g->uvhead; /* double link it in `uvhead' list */ 76 uv->u.l.next = g->uvhead.u.l.next; 77 uv->u.l.next->u.l.prev = uv; 78 g->uvhead.u.l.next = uv; 79 lua_assert(uv->u.l.next->u.l.prev == uv && uv->u.l.prev->u.l.next == uv); 80 return uv; 81 } 82 83 84 static void unlinkupval (UpVal *uv) { 85 lua_assert(uv->u.l.next->u.l.prev == uv && uv->u.l.prev->u.l.next == uv); 86 uv->u.l.next->u.l.prev = uv->u.l.prev; /* remove from `uvhead' list */ 87 uv->u.l.prev->u.l.next = uv->u.l.next; 88 } 89 90 91 void luaF_freeupval (lua_State *L, UpVal *uv) { 92 if (uv->v != &uv->u.value) /* is it open? */ 93 unlinkupval(uv); /* remove from open list */ 94 luaM_free(L, uv); /* free upvalue */ 95 } 96 97 98 void luaF_close (lua_State *L, StkId level) { 99 UpVal *uv; 100 global_State *g = G(L); 101 while (L->openupval != NULL && (uv = ngcotouv(L->openupval))->v >= level) { 102 GCObject *o = obj2gco(uv); 103 lua_assert(!isblack(o) && uv->v != &uv->u.value); 104 L->openupval = uv->next; /* remove from `open' list */ 105 if (isdead(g, o)) 106 luaF_freeupval(L, uv); /* free upvalue */ 107 else { 108 unlinkupval(uv); 109 setobj(L, &uv->u.value, uv->v); 110 uv->v = &uv->u.value; /* now current value lives here */ 111 luaC_linkupval(L, uv); /* link upvalue into `gcroot' list */ 112 } 113 } 114 } 115 116 117 Proto *luaF_newproto (lua_State *L) { 118 Proto *f = luaM_new(L, Proto); 119 luaC_link(L, obj2gco(f), LUA_TPROTO); 120 f->k = NULL; 121 f->sizek = 0; 122 f->p = NULL; 123 f->sizep = 0; 124 f->code = NULL; 125 f->sizecode = 0; 126 f->sizelineinfo = 0; 127 f->sizeupvalues = 0; 128 f->nups = 0; 129 f->upvalues = NULL; 130 f->numparams = 0; 131 f->is_vararg = 0; 132 f->maxstacksize = 0; 133 f->lineinfo = NULL; 134 f->sizelocvars = 0; 135 f->locvars = NULL; 136 f->linedefined = 0; 137 f->lastlinedefined = 0; 138 f->source = NULL; 139 return f; 140 } 141 142 143 void luaF_freeproto (lua_State *L, Proto *f) { 144 luaM_freearray(L, f->code, f->sizecode, Instruction); 145 luaM_freearray(L, f->p, f->sizep, Proto *); 146 luaM_freearray(L, f->k, f->sizek, TValue); 147 luaM_freearray(L, f->lineinfo, f->sizelineinfo, int); 148 luaM_freearray(L, f->locvars, f->sizelocvars, struct LocVar); 149 luaM_freearray(L, f->upvalues, f->sizeupvalues, TString *); 150 luaM_free(L, f); 151 } 152 153 154 void luaF_freeclosure (lua_State *L, Closure *c) { 155 int size = (c->c.isC) ? sizeCclosure(c->c.nupvalues) : 156 sizeLclosure(c->l.nupvalues); 157 luaM_freemem(L, c, size); 158 } 159 160 161 /* 162 ** Look for n-th local variable at line `line' in function `func'. 163 ** Returns NULL if not found. 164 */ 165 const char *luaF_getlocalname (const Proto *f, int local_number, int pc) { 166 int i; 167 for (i = 0; i<f->sizelocvars && f->locvars[i].startpc <= pc; i++) { 168 if (pc < f->locvars[i].endpc) { /* is variable active? */ 169 local_number--; 170 if (local_number == 0) 171 return getstr(f->locvars[i].varname); 172 } 173 } 174 return NULL; /* not found */ 175 } 176 177