source/libs/gmp/gmp-src/tal-debug.c

   1 /* TMP_ALLOC routines for debugging.
   2
   3 Copyright 2000, 2001, 2004 Free Software Foundation, Inc.
   4
   5 This file is part of the GNU MP Library.
   6
   7 The GNU MP Library is free software; you can redistribute it and/or modify
   8 it under the terms of either:
   9
  10   * the GNU Lesser General Public License as published by the Free
  11     Software Foundation; either version 3 of the License, or (at your
  12     option) any later version.
  13
  14 or
  15
  16   * the GNU General Public License as published by the Free Software
  17     Foundation; either version 2 of the License, or (at your option) any
  18     later version.
  19
  20 or both in parallel, as here.
  21
  22 The GNU MP Library is distributed in the hope that it will be useful, but
  23 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  24 or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  25 for more details.
  26
  27 You should have received copies of the GNU General Public License and the
  28 GNU Lesser General Public License along with the GNU MP Library.  If not,
  29 see https://www.gnu.org/licenses/.  */
  30
  31 #include <stdio.h>
  32 #include <stdlib.h>
  33 #include <string.h>
  34 #include "gmp.h"
  35 #include "gmp-impl.h"
  36
  37
  38 /* This method aims to help a malloc debugger find problems.  A linked list
  39    of allocated block is kept for TMP_FREE to release.  This is reentrant
  40    and thread safe.
  41
  42    Each TMP_ALLOC is a separate malloced block, so redzones or sentinels
  43    applied by a malloc debugger either above or below can guard against
  44    accesses outside the allocated area.
  45
  46    A marker is a "struct tmp_debug_t *" so that TMP_DECL can initialize it
  47    to NULL and we can detect TMP_ALLOC without TMP_MARK.
  48
  49    It will work to realloc an MPZ_TMP_INIT variable, but when TMP_FREE comes
  50    to release the memory it will have the old size, thereby triggering an
  51    error from tests/memory.c.
  52
  53    Possibilities:
  54
  55    It'd be possible to keep a global list of active "struct tmp_debug_t"
  56    records, so at the end of a program any TMP leaks could be printed.  But
  57    if only a couple of routines are under test at any one time then the
  58    likely culprit should be easy enough to spot.  */
  59
  60
  61 void
  62 __gmp_tmp_debug_mark (const char *file, int line,
  63                       struct tmp_debug_t **markp, struct tmp_debug_t *mark,
  64                       const char *decl_name, const char *mark_name)
  65 {
  66   if (strcmp (mark_name, decl_name) != 0)
  67     {
  68       __gmp_assert_header (file, line);
  69       fprintf (stderr, "GNU MP: TMP_MARK(%s) but TMP_DECL(%s) is in scope\n",
  70                mark_name, decl_name);
  71       abort ();
  72     }
  73
  74   if (*markp != NULL)
  75     {
  76       __gmp_assert_header (file, line);
  77       fprintf (stderr, "GNU MP: Repeat of TMP_MARK(%s)\n", mark_name);
  78       if (mark->file != NULL && mark->file[0] != '\0' && mark->line != -1)
  79         {
  80           __gmp_assert_header (mark->file, mark->line);
  81           fprintf (stderr, "previous was here\n");
  82         }
  83       abort ();
  84     }
  85
  86   *markp = mark;
  87   mark->file = file;
  88   mark->line = line;
  89   mark->list = NULL;
  90 }
  91
  92 void *
  93 __gmp_tmp_debug_alloc (const char *file, int line, int dummy,
  94                        struct tmp_debug_t **markp,
  95                        const char *decl_name, size_t size)
  96 {
  97   struct tmp_debug_t        *mark = *markp;
  98   struct tmp_debug_entry_t  *p;
  99
 100   ASSERT_ALWAYS (size >= 1);
 101
 102   if (mark == NULL)
 103     {
 104       __gmp_assert_header (file, line);
 105       fprintf (stderr, "GNU MP: TMP_ALLOC without TMP_MARK(%s)\n", decl_name);
 106       abort ();
 107     }
 108
 109   p = __GMP_ALLOCATE_FUNC_TYPE (1, struct tmp_debug_entry_t);
 110   p->size = size;
 111   p->block = (*__gmp_allocate_func) (size);
 112   p->next = mark->list;
 113   mark->list = p;
 114   return p->block;
 115 }
 116
 117 void
 118 __gmp_tmp_debug_free (const char *file, int line, int dummy,
 119                       struct tmp_debug_t **markp,
 120                       const char *decl_name, const char *free_name)
 121 {
 122   struct tmp_debug_t        *mark = *markp;
 123   struct tmp_debug_entry_t  *p, *next;
 124
 125   if (mark == NULL)
 126     {
 127       __gmp_assert_header (file, line);
 128       fprintf (stderr, "GNU MP: TMP_FREE(%s) without TMP_MARK(%s)\n",
 129                free_name, decl_name);
 130       abort ();
 131     }
 132
 133   if (strcmp (free_name, decl_name) != 0)
 134     {
 135       __gmp_assert_header (file, line);
 136       fprintf (stderr, "GNU MP: TMP_FREE(%s) when TMP_DECL(%s) is in scope\n",
 137                free_name, decl_name);
 138       abort ();
 139     }
 140
 141   p = mark->list;
 142   while (p != NULL)
 143     {
 144       next = p->next;
 145       (*__gmp_free_func) (p->block, p->size);
 146       __GMP_FREE_FUNC_TYPE (p, 1, struct tmp_debug_entry_t);
 147       p = next;
 148     }
 149
 150   *markp = NULL;
 151 }