src/lfunc.c

   1 /*
   2 ** $Id: lfunc.c,v 1.9 1998/06/19 16:14:09 roberto Exp $
   3 ** Auxiliary functions to manipulate prototypes and closures
   4 ** See Copyright Notice in lua.h
   5 */
   6
   7
   8 #include <stdlib.h>
   9
  10 #include "lfunc.h"
  11 #include "lmem.h"
  12 #include "lstate.h"
  13
  14 #define gcsizeproto(p)  5  /* approximate "weight" for a prototype */
  15 #define gcsizeclosure(c) 1  /* approximate "weight" for a closure */
  16
  17
  18
  19 Closure *luaF_newclosure (int nelems)
  20 {
  21   Closure *c = (Closure *)luaM_malloc(sizeof(Closure)+nelems*sizeof(TObject));
  22   luaO_insertlist(&(L->rootcl), (GCnode *)c);
  23   L->nblocks += gcsizeclosure(c);
  24   c->nelems = nelems;
  25   return c;
  26 }
  27
  28
  29 TProtoFunc *luaF_newproto (void)
  30 {
  31   TProtoFunc *f = luaM_new(TProtoFunc);
  32   f->code = NULL;
  33   f->lineDefined = 0;
  34   f->fileName = NULL;
  35   f->consts = NULL;
  36   f->nconsts = 0;
  37   f->locvars = NULL;
  38   luaO_insertlist(&(L->rootproto), (GCnode *)f);
  39   L->nblocks += gcsizeproto(f);
  40   return f;
  41 }
  42
  43
  44
  45 static void freefunc (TProtoFunc *f)
  46 {
  47   luaM_free(f->code);
  48   luaM_free(f->locvars);
  49   luaM_free(f->consts);
  50   luaM_free(f);
  51 }
  52
  53
  54 void luaF_freeproto (TProtoFunc *l)
  55 {
  56   while (l) {
  57     TProtoFunc *next = (TProtoFunc *)l->head.next;
  58     L->nblocks -= gcsizeproto(l);
  59     freefunc(l);
  60     l = next;
  61   }
  62 }
  63
  64
  65 void luaF_freeclosure (Closure *l)
  66 {
  67   while (l) {
  68     Closure *next = (Closure *)l->head.next;
  69     L->nblocks -= gcsizeclosure(l);
  70     luaM_free(l);
  71     l = next;
  72   }
  73 }
  74
  75
  76 /*
  77 ** Look for n-th local variable at line "line" in function "func".
  78 ** Returns NULL if not found.
  79 */
  80 char *luaF_getlocalname (TProtoFunc *func, int local_number, int line)
  81 {
  82   int count = 0;
  83   char *varname = NULL;
  84   LocVar *lv = func->locvars;
  85   if (lv == NULL)
  86     return NULL;
  87   for (; lv->line != -1 && lv->line < line; lv++) {
  88     if (lv->varname) {  /* register */
  89       if (++count == local_number)
  90         varname = lv->varname->str;
  91     }
  92     else  /* unregister */
  93       if (--count < local_number)
  94         varname = NULL;
  95   }
  96   return varname;
  97 }
  98