Re: [PATCH 0/4] Save target description in tfile.

Yao Qi
2016-02-11T17:36:58Z

Marcin Kościelnicki <koriakin@0x04.net> writes:

> 1. target.xml is read from the target.
> 2. Includes are processed, resulting in a single in-memory XML file
> containing all the data.
> 3. The resulting file is stored in tfile header by prefixing every line
> with "tdesc ". We may insert a spurious newline at the end of file
> with this encoding, but that won't matter for XML.
> 4. When tfile is read, the XML is stored in an allocated buffer, and
> xfer for TARGET_OBJECT_AVAILABLE_FEATURES is implemented, reading
> from it.
> 5. target_find_description is called to force reading it.

The target description is a global state in trace file, so it doesn't
work tracepoints have different target descriptions, for example in
multi-inferior case, one is x86 and the other one is x86_64 (and arm vs
aarch64 too), and we have tracepoints set in two processes.

I know tracepoint doesn't support multi-inferior/multi-process, but we
may support that in the future. Since we are changing tracepoint file
format, we'd better think about this a little bit. Can we save multiple
target descriptions in trace file, and associate the tracepoints to the
right target description in trace file?

--
Yao (齐尧)