external/mit/lua/dist/src/lfunc.c

   1 /*      $NetBSD: lfunc.c,v 1.1.1.2 2012/03/15 00:08:10 alnsn Exp $      */
   2
   3 /*
   4 ** $Id: lfunc.c,v 1.1.1.2 2012/03/15 00:08:10 alnsn 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