| Message ID | 20191216020334.2895591-1-simon.marchi@polymtl.ca |
|---|---|
| State | New |
| Headers | show |
>>>>> "Simon" == Simon Marchi <simon.marchi@polymtl.ca> writes:
Simon> gdb/ChangeLog:
Simon> * tui/tui-layout.h (class tui_layout_base): Add virtual
Simon> destructor.
Thanks for doing this. It looks good to me.
Tom
On 2019-12-17 2:58 p.m., Tom Tromey wrote: >>>>>> "Simon" == Simon Marchi <simon.marchi@polymtl.ca> writes: > > Simon> gdb/ChangeLog: > > Simon> * tui/tui-layout.h (class tui_layout_base): Add virtual > Simon> destructor. > > Thanks for doing this. It looks good to me. > > Tom > Thanks, I pushed it. Simon
diff --git a/gdb/tui/tui-layout.h b/gdb/tui/tui-layout.h index 691d4ad2e22b..cfe807d8690a 100644 --- a/gdb/tui/tui-layout.h +++ b/gdb/tui/tui-layout.h @@ -34,6 +34,8 @@ public: DISABLE_COPY_AND_ASSIGN (tui_layout_base); + virtual ~tui_layout_base () = default; + /* Clone this object. Ordinarily a layout is cloned before it is used, so that any necessary modifications do not affect the "skeleton" layout. */
I stumbled on some ASan failures when using the TUI, when tearing down a TUI layout. The simplest way to trigger it is to run: $ ./gdb --data-directory=data-directory -batch -ex "layout next" The ASan report is: ================================================================= ==2829136==ERROR: AddressSanitizer: new-delete-type-mismatch on 0x608000009a20 in thread T0: object passed to delete has wrong type: size of the allocated type: 88 bytes; size of the deallocated type: 24 bytes. #0 0x7f470fe2507e in operator delete(void*, unsigned long) /build/gcc/src/gcc/libsanitizer/asan/asan_new_delete.cc:177 #1 0x55f88c75700d in std::default_delete<tui_layout_base>::operator()(tui_layout_base*) const /usr/include/c++/9.2.0/bits/unique_ptr.h:81 #2 0x55f88c756328 in std::unique_ptr<tui_layout_base, std::default_delete<tui_layout_base> >::~unique_ptr() /usr/include/c++/9.2.0/bits/unique_ptr.h:284 #3 0x7f470ee536a6 in __run_exit_handlers (/usr/lib/libc.so.6+0x3e6a6) #4 0x7f470ee5385d in __GI_exit (/usr/lib/libc.so.6+0x3e85d) #5 0x55f88c69f2ac in quit_force(int*, int) /home/simark/src/binutils-gdb/gdb/top.c:1766 #6 0x55f88becc29a in captured_main_1 /home/simark/src/binutils-gdb/gdb/main.c:1183 #7 0x55f88becc814 in captured_main /home/simark/src/binutils-gdb/gdb/main.c:1192 #8 0x55f88becc8a9 in gdb_main(captured_main_args*) /home/simark/src/binutils-gdb/gdb/main.c:1217 #9 0x55f88b3159cd in main /home/simark/src/binutils-gdb/gdb/gdb.c:32 #10 0x7f470ee3c152 in __libc_start_main (/usr/lib/libc.so.6+0x27152) #11 0x55f88b31579d in _start (/home/simark/build/binutils-gdb/gdb/gdb+0x11fb79d) 0x608000009a20 is located 0 bytes inside of 88-byte region [0x608000009a20,0x608000009a78) allocated by thread T0 here: #0 0x7f470fe238f8 in operator new(unsigned long) /build/gcc/src/gcc/libsanitizer/asan/asan_new_delete.cc:104 #1 0x55f88c750906 in tui_layout_split::clone() const /home/simark/src/binutils-gdb/gdb/tui/tui-layout.c:515 #2 0x55f88c74e60e in show_layout /home/simark/src/binutils-gdb/gdb/tui/tui-layout.c:90 #3 0x55f88c74e7db in tui_set_layout(tui_layout_type) /home/simark/src/binutils-gdb/gdb/tui/tui-layout.c:116 #4 0x55f88c782f4f in tui_enable() /home/simark/src/binutils-gdb/gdb/tui/tui.c:481 #5 0x55f88c74eeb2 in tui_layout_command /home/simark/src/binutils-gdb/gdb/tui/tui-layout.c:286 #6 0x55f88b6f969b in do_const_cfunc /home/simark/src/binutils-gdb/gdb/cli/cli-decode.c:107 #7 0x55f88b701859 in cmd_func(cmd_list_element*, char const*, int) /home/simark/src/binutils-gdb/gdb/cli/cli-decode.c:1952 #8 0x55f88c69b455 in execute_command(char const*, int) /home/simark/src/binutils-gdb/gdb/top.c:652 #9 0x55f88bec9026 in catch_command_errors /home/simark/src/binutils-gdb/gdb/main.c:400 #10 0x55f88becc1f2 in captured_main_1 /home/simark/src/binutils-gdb/gdb/main.c:1167 #11 0x55f88becc814 in captured_main /home/simark/src/binutils-gdb/gdb/main.c:1192 #12 0x55f88becc8a9 in gdb_main(captured_main_args*) /home/simark/src/binutils-gdb/gdb/main.c:1217 #13 0x55f88b3159cd in main /home/simark/src/binutils-gdb/gdb/gdb.c:32 #14 0x7f470ee3c152 in __libc_start_main (/usr/lib/libc.so.6+0x27152) The problem is that the tui_layout_base is missing a virtual destructor. We allocate a derived object (tui_layout_split), but delete it through a tui_layout_base pointer. Since the tui_layout_base destructor is not virtual, the derived (tui_layout_split) destructor is not called, only the base destructor. That code is not in gdb-9-branch, so I don't think this patch is relevant for the stable branch. Note that this is caught as a diagnostic with clang: In file included from /home/simark/src/binutils-gdb/gdb/tui/tui-layout.c:22: In file included from /home/simark/src/binutils-gdb/gdb/defs.h:28: In file included from /home/simark/src/binutils-gdb/gdb/gdbsupport/common-defs.h:133: In file included from /home/simark/src/binutils-gdb/gdb/gdbsupport/common-exceptions.h:25: In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/9.2.0/../../../../include/c++/9.2.0/memory:80: /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/9.2.0/../../../../include/c++/9.2.0/bits/unique_ptr.h:81:2: error: delete called on 'tui_layout_base' that is abstract but has non-virtual destructor [-Werror,-Wdelete-abstract-non-virtual-dtor] delete __ptr; ^ /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/9.2.0/../../../../include/c++/9.2.0/bits/unique_ptr.h:284:4: note: in instantiation of member function 'std::default_delete<tui_layout_base>::operator()' requested here get_deleter()(std::move(__ptr)); ^ /home/simark/src/binutils-gdb/gdb/tui/tui-layout.c:54:41: note: in instantiation of member function 'std::unique_ptr<tui_layout_base, std::default_delete<tui_layout_base> >::~unique_ptr' requested here static std::unique_ptr<tui_layout_base> applied_layout; ^ 1 error generated. GCC has the similar -Wdelete-non-virtual-dtor, enabled by -Wall, but it doesn't show up because warnings are inhibited for system headers, where std::unique_ptr is defined. There is a bug about it here: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58876 gdb/ChangeLog: * tui/tui-layout.h (class tui_layout_base): Add virtual destructor. --- gdb/tui/tui-layout.h | 2 ++ 1 file changed, 2 insertions(+)