strace changes behavior of the traced process

[Andreas Schwab]

Yuri <yuri-WD5pMP1oN6wAvxtiuMwx3w at public.gmane.org> writes:

> When I run 'gdb printf' with and without strace, the output of gdb is 
> different in that with strace "Inferior exited" message disappears.
> It looks like strace maybe consumes the exit signal of the debugged 
> process before gdb does?
>
> $ gdb printf
> <...skipped...>
> (gdb) r "Hello\n"
> Starting program: /usr/bin/printf "Hello\n"
> Hello
> [Inferior 1 (process 3057) exited normally]
> (gdb)
>
>
> $ strace -f 2>/dev/null gdb printf
> <...skipped...>
> (gdb) r "Hello\n"
> Starting program: /usr/bin/printf "Hello\n"
> Hello
> (gdb)

That's because gdb never gets a chance to trace the inferior (there can
be only one tracer).  A newer gdb complains that the program exited
during startup.

Andreas.

-- 
Andreas Schwab, schwab at linux-m68k.org
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