When writing the Windows dbgeng driver for Dexter, I couldn't work out why it
would either launch a process and leave it free running, or if I started the
process suspended, never do anything with it. The result was a hack to create
and attach processes manually. This has been flaking out on Reids Windows
buildbot, and clearly wasn't a good solution.
Digging into this, it turns out that the "normal" cdb / windbg behaviour of
breaking whenever we attach to a process is not the default: it has to be
explicitly requested from the debug engine. This patch does so (by setting
DEBUG_ENGOPT_INITIAL_BREAK in the engine options), after which we can simply
call "CreateProcessAndAttach2" and everything automagically works.
No test for this behaviour: everything was just broken before.
Differential Revision: https://reviews.llvm.org/D74409
This reverts commit cb935f345683194e42e6e883d79c5a16479acd74.
Discussion in D68708 advises that green dragon is being briskly
refurbished, and it's good to have this patch up testing it.
Dexter (Debug Experience Tester) is a test-driver for our debug info
integration tests, reading a set of debug experience expectations and
comparing them with the actual behaviour of a program under a debugger.
More about Dexter can be found in the RFC:
http://lists.llvm.org/pipermail/llvm-dev/2019-October/135773.html
and the phab review in D68708. Not all the debuginfo tests have been
transformed into Dexter tests, and we look forwards to doing that
incrementally.
This commit mostly aims to flush out buildbots that are running
debuginfo-tests but don't have python 3 installed, possibly
green-dragon and some windows bots.
