[lldb-dev] Editline Rewrite : issues surround wide character handling on different platforms

[jingham at apple.com]

I hadn't seen that.  That looks pretty useful for things like reintroducing the "size" method for std::vectors that hold the size in an easily accessible field, or something else like that.  It involves re-implementing the guts of the library you are patching up in Python using debugger API's so it isn't entirely straight-forward.  Note we already do a similar sort of thing in the data formatters to produce nice summaries and "synthetic children" for std & Foundation types that can avoid running code.  I think gdb also has some formatter infrastructure like this, IIRC, but I haven't used gdb much for a few years now.

Anyway, you'd be hard pressed to use something like these Xmethods to do more science fiction'y things like "I wish that I had std::vector<T> around for some experiment I want to do in the debugger, but the program never used std::vector<T>, please make it for me".  Not sure how often you'd really use that, but the point is that if we had the C++ modules around, we would get it pretty much for free.

Jim


> On Oct 29, 2014, at 10:44 AM, Siva Chandra <sivachandra at google.com> wrote:
> 
> On Wed, Oct 29, 2014 at 10:33 AM,  <jingham at apple.com> wrote:
>> And for instance, if we ever get good support for modules in C++,
>> we could presumably then use that to do things like instantiate template
>> classes for types that weren't instantiated in the current program, and
>> other cool'o things like that which would be hard to do with some
>> hand-built C++ parser, a la gdb.
> 
> GDB's solution for such cases currently is XMethods:
> https://sourceware.org/gdb/current/onlinedocs/gdb/Xmethods-In-Python.html
> 
> There are a bunch of XMethods available for container classes in
> libstdc++: https://gcc.gnu.org/svn/gcc/trunk/libstdc++-v3/python/libstdcxx/v6/xmethods.py