Re: [PATCH 3/3] Introduce gdbsupport/cxx-thread.h and use it

[Simon Marchi <simark@simark.ca>]

On 10/1/25 2:57 PM, Tom Tromey wrote:
> This introduces a new file, gdbsupport/cxx-thread.h, which provides
> stubs for the C++ threading functionality on systems that don't
> support it.
> 
> On fully-working ports, this header just supplies a number of aliases
> in the gdb namespace.  So, for instance, gdb::mutex is just an alias
> for std::mutex.
> 
> For non-working ports, compatibility stubs are provided for the subset
> of threading functionality that's used in gdb.  These generally do
> nothing and assume single-threaded operation.
> 
> The idea behind this is to reduce the number of checks of
> CXX_STD_THREAD, making the code cleaner.
> 
> Not all spots using CXX_STD_THREAD could readily be converted.
> In particular:
> 
> * Unit tests
> * --config output
> * Code manipulating threads themselves
> * The extension interrupting handling code
> 
> These all seem fine to me.
> 
> Note there's also a check in py-dap.c.  This one is perhaps slightly
> subtle: DAP starts threads on the Python side, but it relies on gdb
> itself being thread-savvy, for instance in gdb.post_event.

I think this looks good.  The remaining uses of CXX_STD_THREAD appear to
be in areas we don't touch often.  I like that we no longer need to wrap
all uses of std::mutex:w

Did you get a chance to validate your change on one of those toolchains
that don't have std::thread support?

Approved-By: Simon Marchi <simon.marchi@efficios.com>

Simon