[Lldb-commits] [lldb] r316740 - Fix a use-after-free in lldb-server

[Pavel Labath via lldb-commits]

libstdc++-4.8

I think the newest versions have a conformant implementation, but I
don't know the full details (I know it was a complicated change
because of the need to maintain binary compatibility).

Our android tests are now runinng lldb-server built with libc++ (which
is how I found the bug). Eventually (= probably not this year) I may
switch the host lldb as well.

On 31 October 2017 at 15:41, Zachary Turner <zturner at google.com> wrote:
>
>
> On Tue, Oct 31, 2017 at 8:20 AM Pavel Labath <labath at google.com> wrote:
>>
>> On 31 October 2017 at 15:12, Zachary Turner via lldb-commits
>> <lldb-commits at lists.llvm.org> wrote:
>> > The takeaway from this example is nothing we don't already know.  We
>> > need
>> > better test coverage.
>> Actually, this was caught by a test (pretty much all of them), but
>> only when building with libc++, as the code was "safe" with libstdc++
>> due to the copy-on-write implementation of std::string (the temporary
>> object shared storage with the longer-lived string it was copied
>> from).
>
>
> What version of libstdc++?  AFAIK copy-on-write std::string is no longer
> conformant in C++11.
>
> If this was really being masked due to a CoW string implementation, we need
> to make absolutely sure we are running tests on a bot with a conformant
> standard library.