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

   1 /*      $NetBSD: lfunc.c,v 1.3 2015/02/02 14:03:05 lneto Exp $  */
   2
   3 /*
   4 ** Id: lfunc.c,v 2.45 2014/11/02 19:19:04 roberto Exp
   5 ** Auxiliary functions to manipulate prototypes and closures
   6 ** See Copyright Notice in lua.h
   7 */
   8
   9 #define lfunc_c
  10 #define LUA_CORE
  11
  12 #include "lprefix.h"
  13
  14
  15 #ifndef _KERNEL
  16 #include <stddef.h>
  17 #endif
  18
  19 #include "lua.h"
  20
  21 #include "lfunc.h"
  22 #include "lgc.h"
  23 #include "lmem.h"
  24 #include "lobject.h"
  25 #include "lstate.h"
  26
  27
  28
  29 CClosure *luaF_newCclosure (lua_State *L, int n) {
  30   GCObject *o = luaC_newobj(L, LUA_TCCL, sizeCclosure(n));
  31   CClosure *c = gco2ccl(o);
  32   c->nupvalues = cast_byte(n);
  33   return c;
  34 }
  35
  36
  37 LClosure *luaF_newLclosure (lua_State *L, int n) {
  38   GCObject *o = luaC_newobj(L, LUA_TLCL, sizeLclosure(n));
  39   LClosure *c = gco2lcl(o);
  40   c->p = NULL;
  41   c->nupvalues = cast_byte(n);
  42   while (n--) c->upvals[n] = NULL;
  43   return c;
  44 }
  45
  46 /*
  47 ** fill a closure with new closed upvalues
  48 */
  49 void luaF_initupvals (lua_State *L, LClosure *cl) {
  50   int i;
  51   for (i = 0; i < cl->nupvalues; i++) {
  52     UpVal *uv = luaM_new(L, UpVal);
  53     uv->refcount = 1;
  54     uv->v = &uv->u.value;  /* make it closed */
  55     setnilvalue(uv->v);
  56     cl->upvals[i] = uv;
  57   }
  58 }
  59
  60
  61 UpVal *luaF_findupval (lua_State *L, StkId level) {
  62   UpVal **pp = &L->openupval;
  63   UpVal *p;
  64   UpVal *uv;
  65   lua_assert(isintwups(L) || L->openupval == NULL);
  66   while (*pp != NULL && (p = *pp)->v >= level) {
  67     lua_assert(upisopen(p));
  68     if (p->v == level)  /* found a corresponding upvalue? */
  69       return p;  /* return it */
  70     pp = &p->u.open.next;
  71   }
  72   /* not found: create a new upvalue */
  73   uv = luaM_new(L, UpVal);
  74   uv->refcount = 0;
  75   uv->u.open.next = *pp;  /* link it to list of open upvalues */
  76   uv->u.open.touched = 1;
  77   *pp = uv;
  78   uv->v = level;  /* current value lives in the stack */
  79   if (!isintwups(L)) {  /* thread not in list of threads with upvalues? */
  80     L->twups = G(L)->twups;  /* link it to the list */
  81     G(L)->twups = L;
  82   }
  83   return uv;
  84 }
  85
  86
  87 void luaF_close (lua_State *L, StkId level) {
  88   UpVal *uv;
  89   while (L->openupval != NULL && (uv = L->openupval)->v >= level) {
  90     lua_assert(upisopen(uv));
  91     L->openupval = uv->u.open.next;  /* remove from 'open' list */
  92     if (uv->refcount == 0)  /* no references? */
  93       luaM_free(L, uv);  /* free upvalue */
  94     else {
  95       setobj(L, &uv->u.value, uv->v);  /* move value to upvalue slot */
  96       uv->v = &uv->u.value;  /* now current value lives here */
  97       luaC_upvalbarrier(L, uv);
  98     }
  99   }
 100 }
 101
 102
 103 Proto *luaF_newproto (lua_State *L) {
 104   GCObject *o = luaC_newobj(L, LUA_TPROTO, sizeof(Proto));
 105   Proto *f = gco2p(o);
 106   f->k = NULL;
 107   f->sizek = 0;
 108   f->p = NULL;
 109   f->sizep = 0;
 110   f->code = NULL;
 111   f->cache = NULL;
 112   f->sizecode = 0;
 113   f->lineinfo = NULL;
 114   f->sizelineinfo = 0;
 115   f->upvalues = NULL;
 116   f->sizeupvalues = 0;
 117   f->numparams = 0;
 118   f->is_vararg = 0;
 119   f->maxstacksize = 0;
 120   f->locvars = NULL;
 121   f->sizelocvars = 0;
 122   f->linedefined = 0;
 123   f->lastlinedefined = 0;
 124   f->source = NULL;
 125   return f;
 126 }
 127
 128
 129 void luaF_freeproto (lua_State *L, Proto *f) {
 130   luaM_freearray(L, f->code, f->sizecode);
 131   luaM_freearray(L, f->p, f->sizep);
 132   luaM_freearray(L, f->k, f->sizek);
 133   luaM_freearray(L, f->lineinfo, f->sizelineinfo);
 134   luaM_freearray(L, f->locvars, f->sizelocvars);
 135   luaM_freearray(L, f->upvalues, f->sizeupvalues);
 136   luaM_free(L, f);
 137 }
 138
 139
 140 /*
 141 ** Look for n-th local variable at line 'line' in function 'func'.
 142 ** Returns NULL if not found.
 143 */
 144 const char *luaF_getlocalname (const Proto *f, int local_number, int pc) {
 145   int i;
 146   for (i = 0; i<f->sizelocvars && f->locvars[i].startpc <= pc; i++) {
 147     if (pc < f->locvars[i].endpc) {  /* is variable active? */
 148       local_number--;
 149       if (local_number == 0)
 150         return getstr(f->locvars[i].varname);
 151     }
 152   }
 153   return NULL;  /* not found */
 154 }
 155