lib/malloc/watch.c

   1 /* watch.c - watchpoint functions for malloc */
   2
   3 /* Copyright (C) 2001 Free Software Foundation, Inc.
   4
   5    This file is part of GNU Bash, the Bourne Again SHell.
   6
   7    Bash is free software; you can redistribute it and/or modify it under
   8    the terms of the GNU General Public License as published by the Free
   9    Software Foundation; either version 2, or (at your option) any later
  10    version.
  11
  12    Bash is distributed in the hope that it will be useful, but WITHOUT ANY
  13    WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15    for more details.
  16
  17    You should have received a copy of the GNU General Public License along
  18    with Bash; see the file COPYING.  If not, write to the Free Software
  19    Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA. */
  20 #ifdef HAVE_CONFIG_H
  21 #  include <config.h>
  22 #endif
  23
  24 #include <stdio.h>
  25
  26 #include "imalloc.h"
  27
  28 #ifdef MALLOC_WATCH
  29 #include "watch.h"
  30
  31 #define WATCH_MAX       32
  32
  33 int             _malloc_nwatch;
  34 static PTR_T    _malloc_watch_list[WATCH_MAX];
  35
  36 static void
  37 watch_warn (addr, file, line, type, data)
  38      PTR_T addr;
  39      const char *file;
  40      int line, type;
  41      unsigned long data;
  42 {
  43   char *tag;
  44
  45   if (type == W_ALLOC)
  46     tag = "allocated";
  47   else if (type == W_FREE)
  48     tag = "freed";
  49   else if (type == W_REALLOC)
  50     tag = "requesting resize";
  51   else if (type == W_RESIZED)
  52     tag = "just resized";
  53   else
  54     tag = "bug: unknown operation";
  55
  56   fprintf (stderr, "malloc: watch alert: %p %s ", addr, tag);
  57   if (data != (unsigned long)-1)
  58     fprintf (stderr, "(size %lu) ", data);
  59   fprintf (stderr, "from '%s:%d'\n", file ? file : "unknown", line);
  60 }
  61
  62 void
  63 _malloc_ckwatch (addr, file, line, type, data)
  64      PTR_T addr;
  65      const char *file;
  66      int line, type;
  67      unsigned long data;
  68 {
  69   register int i;
  70
  71   for (i = _malloc_nwatch - 1; i >= 0; i--)
  72     {
  73       if (_malloc_watch_list[i] == addr)
  74         {
  75           watch_warn (addr, file, line, type, data);
  76           return;
  77         }
  78     }
  79 }
  80 #endif /* MALLOC_WATCH */
  81
  82 PTR_T
  83 malloc_watch (addr)
  84      PTR_T addr;
  85 {
  86   register int i;
  87   PTR_T ret;
  88
  89   if (addr == 0)
  90     return addr;
  91   ret = (PTR_T)0;
  92
  93 #ifdef MALLOC_WATCH
  94   for (i = _malloc_nwatch - 1; i >= 0; i--)
  95     {
  96       if (_malloc_watch_list[i] == addr)
  97         break;
  98     }
  99   if (i < 0)
 100     {
 101       if (_malloc_nwatch == WATCH_MAX)  /* full, take out first */
 102         {
 103           ret = _malloc_watch_list[0];
 104           _malloc_nwatch--;
 105           for (i = 0; i < _malloc_nwatch; i++)
 106             _malloc_watch_list[i] = _malloc_watch_list[i+1];
 107         }
 108       _malloc_watch_list[_malloc_nwatch++] = addr;
 109     }
 110 #endif
 111
 112   return ret;
 113 }
 114
 115 /* Remove a watchpoint set on ADDR.  If ADDR is NULL, remove all
 116    watchpoints.  Returns ADDR if everything went OK, NULL if ADDR was
 117    not being watched. */
 118 PTR_T
 119 malloc_unwatch (addr)
 120      PTR_T addr;
 121 {
 122 #ifdef MALLOC_WATCH
 123   register int i;
 124
 125   if (addr == 0)
 126     {
 127       for (i = 0; i < _malloc_nwatch; i++)
 128         _malloc_watch_list[i] = (PTR_T)0;
 129       _malloc_nwatch = 0;
 130       return ((PTR_T)0);
 131     }
 132   else
 133     {
 134       for (i = 0; i < _malloc_nwatch; i++)
 135         {
 136           if (_malloc_watch_list[i] == addr)
 137             break;
 138         }
 139       if (i == _malloc_nwatch)
 140         return ((PTR_T)0);              /* not found */
 141       /* shuffle everything from i+1 to end down 1 */
 142       _malloc_nwatch--;
 143       for ( ; i < _malloc_nwatch; i++)
 144         _malloc_watch_list[i] = _malloc_watch_list[i+1];
 145       return addr;
 146     }
 147 #else
 148   return ((PTR_T)0);
 149 #endif
 150 }