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Don't override operator new if GDB is built with -fsanitize=address
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Nowadays, if we build GDB with -fsanitize=address, we can get the asan
error below,

(gdb) quit
=================================================================
==9723==ERROR: AddressSanitizer: alloc-dealloc-mismatch (malloc vs operator delete) on 0x60200003bf70
    #0 0x7f88f3837527 in operator delete(void*) (/usr/lib/x86_64-linux-gnu/libasan.so.1+0x55527)
    tromey#1 0xac8e13 in __gnu_cxx::new_allocator<void (*)()>::deallocate(void (**)(), unsigned long) /usr/include/c++/4.9/ext/new_allocator.h:110
    tromey#2 0xac8cc2 in __gnu_cxx::__alloc_traits<std::allocator<void (*)()> >::deallocate(std::allocator<void (*)()>&, void (**)(), unsigned long) /usr/include/c++/4.9/ext/alloc_traits.h:185
....
0x60200003bf70 is located 0 bytes inside of 8-byte region [0x60200003bf70,0x60200003bf78)
allocated by thread T0 here:
    #0 0x7f88f38367ef in __interceptor_malloc (/usr/lib/x86_64-linux-gnu/libasan.so.1+0x547ef)
    tromey#1 0xbd2762 in operator new(unsigned long) /home/yao/SourceCode/gnu/gdb/git/gdb/common/new-op.c:42
    tromey#2 0xac8edc in __gnu_cxx::new_allocator<void (*)()>::allocate(unsigned long, void const*) /usr/include/c++/4.9/ext/new_allocator.h:104
    tromey#3 0xac8d81 in __gnu_cxx::__alloc_traits<std::allocator<void (*)()> >::allocate(std::allocator<void (*)()>&, unsigned long) /usr/include/c++/4.9/ext/alloc_traits.h:182

The reason for this is that we override operator new but don't override
operator delete.  This patch does the override if the code is NOT
compiled with asan.

gdb:

2016-10-25  Yao Qi  <yao.qi@linaro.org>

	PR gdb/20716
	* common/new-op.c (__has_feature): New macro.
	Don't override operator new if asan is used.
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Yao Qi committed Oct 25, 2016
1 parent a18a2a3 commit 3ef9d66
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6 changes: 6 additions & 0 deletions gdb/ChangeLog
Original file line number Diff line number Diff line change
@@ -1,3 +1,9 @@
2016-10-25 Yao Qi <yao.qi@linaro.org>

PR gdb/20716
* common/new-op.c (__has_feature): New macro.
Don't override operator new if asan is used.

2016-10-24 Luis Machado <lgustavo@codesourcery.com>

* exec.c (exec_file_locate_attach): Prevent NULL pointer dereference
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7 changes: 7 additions & 0 deletions gdb/common/new-op.c
Original file line number Diff line number Diff line change
Expand Up @@ -17,6 +17,12 @@
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */

/* GCC does not understand __has_feature. */
#if !defined(__has_feature)
# define __has_feature(x) 0
#endif

#if !__has_feature(address_sanitizer) && !defined(__SANITIZE_ADDRESS__)
#include "common-defs.h"
#include "host-defs.h"
#include <new>
Expand Down Expand Up @@ -83,3 +89,4 @@ operator new[] (std::size_t sz, const std::nothrow_t&)
{
return ::operator new (sz, std::nothrow);
}
#endif

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