Problems with __cxa_demangle and the verbose terminate handler

[Andreas Schwab]

Mark Mitchell <mark@codesourcery.com> writes:

> Perhaps most dangerous of all is this code in vterminate.cc:
>
>   # define writestr(str)  write(2, str, __builtin_strlen(str))
>
> This bit of cleverness is designed to let the terminate handler write
> to the standard error stream.  However, there is no way to know that
> file descriptor 2 *is* the standard error stream.  If the process
> closes stderr, and then opens another file (say, "/dev/launch_missle",
> or "/dev/database") that new file descriptor may very well be
> descriptor 2.  Using "fputs" to write to "stderr" does not have this
> problem.

POSIX defines STDERR_FILENO to 2, so both are required to be equivalent.

Andreas.

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Andreas Schwab, SuSE Labs, schwab@suse.de
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