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[mingw gdb/mi] Separating debuggee output from MI


I'm currently writing a gdb frontend using the GDB/MI interface, but I have
been experiencing difficulties with differentiating between output by the
debuggee and output from gdb itself.

The documentation mentions target-stream-output, which is prefixed with "@",
but it seems it is not actually being used. Instead, target output appears
interleaved with gdb output.

This can cause various problems, so I would like to be able to safely separate
target output/input from gdb output/input. Searching for a bit revealed that
this is quite a common problem when writing gdb frontends on windows due to
various limitations of the OS, but I was unable to find a good solution.


I implemented a workaround to this which seems to work, however I am not quite
sure whether it is safe to use.


What I'm doing right now is start the debuggee process in suspended mode from
the frontend (with CreateProcess and CREATE_SUSPENDED flag), create the gdb
process separately, attach it to the suspended process and then resume it
with ResumeThread (assuming a single-threaded program).


Something like this:

/* Start debug process */
CreateProcess(...)

/* Start gdb */
 gdb.exe -i mi
>> -target-attach pid
<< *stopped
>> -exec-continue
<< *running,thread-id="all"

/* Resume suspended process */
ResumeThread(...)

This seems to work, as I now have the debuggee input/output and the gdb
input/output in separate pipes. However, I have not had the chance to test this
any further, so I'm wondering - could this setup could cause any problems?
Especially the fact that I'm doing -exec-continue on a suspended process seems
like asking for trouble.


Thanks!
Benedikt Bitterli


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