/src/middleware/lua/lfunc.c
C | 174 lines | 136 code | 29 blank | 9 comment | 28 complexity | 20bdd3463590fa03c54ed57e2168485f MD5 | raw file
1/* 2** $Id: lfunc.c,v 2.12.1.2 2007/12/28 14:58:43 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 23Closure *luaF_newCclosure (lua_State *L, int nelems, Table *e) { 24 Closure *c = cast(Closure *, luaM_malloc(L, sizeCclosure(nelems))); 25 luaC_link(L, obj2gco(c), LUA_TFUNCTION); 26 c->c.isC = 1; 27 c->c.env = e; 28 c->c.nupvalues = cast_byte(nelems); 29 return c; 30} 31 32 33Closure *luaF_newLclosure (lua_State *L, int nelems, Table *e) { 34 Closure *c = cast(Closure *, luaM_malloc(L, sizeLclosure(nelems))); 35 luaC_link(L, obj2gco(c), LUA_TFUNCTION); 36 c->l.isC = 0; 37 c->l.env = e; 38 c->l.nupvalues = cast_byte(nelems); 39 while (nelems--) c->l.upvals[nelems] = NULL; 40 return c; 41} 42 43 44UpVal *luaF_newupval (lua_State *L) { 45 UpVal *uv = luaM_new(L, UpVal); 46 luaC_link(L, obj2gco(uv), LUA_TUPVAL); 47 uv->v = &uv->u.value; 48 setnilvalue(uv->v); 49 return uv; 50} 51 52 53UpVal *luaF_findupval (lua_State *L, StkId level) { 54 global_State *g = G(L); 55 GCObject **pp = &L->openupval; 56 UpVal *p; 57 UpVal *uv; 58 while (*pp != NULL && (p = ngcotouv(*pp))->v >= level) { 59 lua_assert(p->v != &p->u.value); 60 if (p->v == level) { /* found a corresponding upvalue? */ 61 if (isdead(g, obj2gco(p))) /* is it dead? */ 62 changewhite(obj2gco(p)); /* ressurect it */ 63 return p; 64 } 65 pp = &p->next; 66 } 67 uv = luaM_new(L, UpVal); /* not found: create a new one */ 68 uv->tt = LUA_TUPVAL; 69 uv->marked = luaC_white(g); 70 uv->v = level; /* current value lives in the stack */ 71 uv->next = *pp; /* chain it in the proper position */ 72 *pp = obj2gco(uv); 73 uv->u.l.prev = &g->uvhead; /* double link it in `uvhead' list */ 74 uv->u.l.next = g->uvhead.u.l.next; 75 uv->u.l.next->u.l.prev = uv; 76 g->uvhead.u.l.next = uv; 77 lua_assert(uv->u.l.next->u.l.prev == uv && uv->u.l.prev->u.l.next == uv); 78 return uv; 79} 80 81 82static void unlinkupval (UpVal *uv) { 83 lua_assert(uv->u.l.next->u.l.prev == uv && uv->u.l.prev->u.l.next == uv); 84 uv->u.l.next->u.l.prev = uv->u.l.prev; /* remove from `uvhead' list */ 85 uv->u.l.prev->u.l.next = uv->u.l.next; 86} 87 88 89void luaF_freeupval (lua_State *L, UpVal *uv) { 90 if (uv->v != &uv->u.value) /* is it open? */ 91 unlinkupval(uv); /* remove from open list */ 92 luaM_free(L, uv); /* free upvalue */ 93} 94 95 96void luaF_close (lua_State *L, StkId level) { 97 UpVal *uv; 98 global_State *g = G(L); 99 while (L->openupval != NULL && (uv = ngcotouv(L->openupval))->v >= level) { 100 GCObject *o = obj2gco(uv); 101 lua_assert(!isblack(o) && uv->v != &uv->u.value); 102 L->openupval = uv->next; /* remove from `open' list */ 103 if (isdead(g, o)) 104 luaF_freeupval(L, uv); /* free upvalue */ 105 else { 106 unlinkupval(uv); 107 setobj(L, &uv->u.value, uv->v); 108 uv->v = &uv->u.value; /* now current value lives here */ 109 luaC_linkupval(L, uv); /* link upvalue into `gcroot' list */ 110 } 111 } 112} 113 114 115Proto *luaF_newproto (lua_State *L) { 116 Proto *f = luaM_new(L, Proto); 117 luaC_link(L, obj2gco(f), LUA_TPROTO); 118 f->k = NULL; 119 f->sizek = 0; 120 f->p = NULL; 121 f->sizep = 0; 122 f->code = NULL; 123 f->sizecode = 0; 124 f->sizelineinfo = 0; 125 f->sizeupvalues = 0; 126 f->nups = 0; 127 f->upvalues = NULL; 128 f->numparams = 0; 129 f->is_vararg = 0; 130 f->maxstacksize = 0; 131 f->lineinfo = NULL; 132 f->sizelocvars = 0; 133 f->locvars = NULL; 134 f->linedefined = 0; 135 f->lastlinedefined = 0; 136 f->source = NULL; 137 return f; 138} 139 140 141void luaF_freeproto (lua_State *L, Proto *f) { 142 luaM_freearray(L, f->code, f->sizecode, Instruction); 143 luaM_freearray(L, f->p, f->sizep, Proto *); 144 luaM_freearray(L, f->k, f->sizek, TValue); 145 luaM_freearray(L, f->lineinfo, f->sizelineinfo, int); 146 luaM_freearray(L, f->locvars, f->sizelocvars, struct LocVar); 147 luaM_freearray(L, f->upvalues, f->sizeupvalues, TString *); 148 luaM_free(L, f); 149} 150 151 152void luaF_freeclosure (lua_State *L, Closure *c) { 153 int size = (c->c.isC) ? sizeCclosure(c->c.nupvalues) : 154 sizeLclosure(c->l.nupvalues); 155 luaM_freemem(L, c, size); 156} 157 158 159/* 160** Look for n-th local variable at line `line' in function `func'. 161** Returns NULL if not found. 162*/ 163const char *luaF_getlocalname (const Proto *f, int local_number, int pc) { 164 int i; 165 for (i = 0; i<f->sizelocvars && f->locvars[i].startpc <= pc; i++) { 166 if (pc < f->locvars[i].endpc) { /* is variable active? */ 167 local_number--; 168 if (local_number == 0) 169 return getstr(f->locvars[i].varname); 170 } 171 } 172 return NULL; /* not found */ 173} 174