gdbsupport/new-op.cc

   1 /* Replace operator new/new[], for GDB, the GNU debugger.
   2
   3    Copyright (C) 2016-2020 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 /* GCC does not understand __has_feature.  */
  21 #if !defined(__has_feature)
  22 # define __has_feature(x) 0
  23 #endif
  24
  25 #if !__has_feature(address_sanitizer) && !defined(__SANITIZE_ADDRESS__)
  26 #include "common-defs.h"
  27 #include "host-defs.h"
  28 #include <new>
  29
  30 /* Override operator new / operator new[], in order to internal_error
  31    on allocation failure and thus query the user for abort/core
  32    dump/continue, just like xmalloc does.  We don't do this from a
  33    new-handler function instead (std::set_new_handler) because we want
  34    to catch allocation errors from within global constructors too.
  35
  36    Skip overriding if building with -fsanitize=address though.
  37    Address sanitizer wants to override operator new/delete too in
  38    order to detect malloc+delete and new+free mismatches.  Our
  39    versions would mask out ASan's, with the result of losing that
  40    useful mismatch detection.
  41
  42    Note that C++ implementations could either have their throw
  43    versions call the nothrow versions (libstdc++), or the other way
  44    around (clang/libc++).  For that reason, we replace both throw and
  45    nothrow variants and call malloc directly.  */
  46
  47 void *
  48 operator new (std::size_t sz)
  49 {
  50   /* malloc (0) is unpredictable; avoid it.  */
  51   if (sz == 0)
  52     sz = 1;
  53
  54   void *p = malloc (sz);        /* ARI: malloc */
  55   if (p == NULL)
  56     {
  57       /* If the user decides to continue debugging, throw a
  58          gdb_quit_bad_alloc exception instead of a regular QUIT
  59          gdb_exception.  The former extends both std::bad_alloc and a
  60          QUIT gdb_exception.  This is necessary because operator new
  61          can only ever throw std::bad_alloc, or something that extends
  62          it.  */
  63       try
  64         {
  65           malloc_failure (sz);
  66         }
  67       catch (gdb_exception &ex)
  68         {
  69           throw gdb_quit_bad_alloc (std::move (ex));
  70         }
  71     }
  72   return p;
  73 }
  74
  75 void *
  76 operator new (std::size_t sz, const std::nothrow_t&) noexcept
  77 {
  78   /* malloc (0) is unpredictable; avoid it.  */
  79   if (sz == 0)
  80     sz = 1;
  81   return malloc (sz);           /* ARI: malloc */
  82 }
  83
  84 void *
  85 operator new[] (std::size_t sz)
  86 {
  87    return ::operator new (sz);
  88 }
  89
  90 void*
  91 operator new[] (std::size_t sz, const std::nothrow_t&) noexcept
  92 {
  93   return ::operator new (sz, std::nothrow);
  94 }
  95 #endif