Parser/node.c

   1 /***********************************************************
   2 Copyright (c) 2000, BeOpen.com.
   3 Copyright (c) 1995-2000, Corporation for National Research Initiatives.
   4 Copyright (c) 1990-1995, Stichting Mathematisch Centrum.
   5 All rights reserved.
   6
   7 See the file "Misc/COPYRIGHT" for information on usage and
   8 redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
   9 ******************************************************************/
  10
  11 #ifdef HAVE_LIMITS_H
  12 #include <limits.h>
  13 #endif
  14 #ifndef INT_MAX
  15 #define INT_MAX 2147483647
  16 #endif
  17
  18 /* Parse tree node implementation */
  19
  20 #include "pgenheaders.h"
  21 #include "node.h"
  22 #include "errcode.h"
  23
  24 node *
  25 PyNode_New(int type)
  26 {
  27         node *n = PyMem_NEW(node, 1);
  28         if (n == NULL)
  29                 return NULL;
  30         n->n_type = type;
  31         n->n_str = NULL;
  32         n->n_lineno = 0;
  33         n->n_nchildren = 0;
  34         n->n_child = NULL;
  35         return n;
  36 }
  37
  38 #define XXX 3 /* Node alignment factor to speed up realloc */
  39 #define XXXROUNDUP(n) ((n) == 1 ? 1 : ((n) + XXX - 1) / XXX * XXX)
  40
  41 int
  42 PyNode_AddChild(register node *n1, int type, char *str, int lineno)
  43 {
  44         register int nch = n1->n_nchildren;
  45         register int nch1 = nch+1;
  46         register node *n;
  47         if (nch == INT_MAX || nch < 0)
  48                 return E_OVERFLOW;
  49         if (XXXROUNDUP(nch) < nch1) {
  50                 n = n1->n_child;
  51                 nch1 = XXXROUNDUP(nch1);
  52                 PyMem_RESIZE(n, node, nch1);
  53                 if (n == NULL)
  54                         return E_NOMEM;
  55                 n1->n_child = n;
  56         }
  57         n = &n1->n_child[n1->n_nchildren++];
  58         n->n_type = type;
  59         n->n_str = str;
  60         n->n_lineno = lineno;
  61         n->n_nchildren = 0;
  62         n->n_child = NULL;
  63         return 0;
  64 }
  65
  66 /* Forward */
  67 static void freechildren(node *);
  68
  69
  70 void
  71 PyNode_Free(node *n)
  72 {
  73         if (n != NULL) {
  74                 freechildren(n);
  75                 PyMem_DEL(n);
  76         }
  77 }
  78
  79 static void
  80 freechildren(node *n)
  81 {
  82         int i;
  83         for (i = NCH(n); --i >= 0; )
  84                 freechildren(CHILD(n, i));
  85         if (n->n_child != NULL)
  86                 PyMem_DEL(n->n_child);
  87         if (STR(n) != NULL)
  88                 PyMem_DEL(STR(n));
  89 }