[Python-ideas] pdb / bdb adding watchpoint ability

[Louie Lu]

Hi all,

Current pdb and bdb didn't have the ability to create a watchpoint for variable.

Such in gdb, it have a series of watchpoint function*:

    * watch  : break when expression value changed
    * rwatch : break when read value from expression
    * awatch: breka when read or write value to expression


In Python, there have some problem in rwatch implement, that we
can't directly know what variable is been read or not. This will need
to used the dis module to get the bytecode and to know if the variable
is been read (load) or not.

The b.p.o issue is open at here:
http://bugs.python.org/issue30429

And the current implement is at:
https://github.com/python/cpython/pull/1756

How do you think about this ability to put in pdb/bdb?


-Louie