22.214.171.124 Writing new convenience functions
You can implement new convenience functions (see Convenience Vars)
in Python. A convenience function is an instance of a subclass of the
The initializer for
Functionregisters the new function with gdb. The argument name is the name of the function, a string. The function will be visible to the user as a convenience variable of type
internal function, whose name is the same as the given name.
The documentation for the new function is taken from the documentation string for the new class.
When a convenience function is evaluated, its arguments are converted to instances of
gdb.Value, and then the function's
invokemethod is called. Note that gdb does not predetermine the arity of convenience functions. Instead, all available arguments are passed to
invoke, following the standard Python calling convention. In particular, a convenience function can have default values for parameters without ill effect.
The return value of this method is used as its value in the enclosing expression. If an ordinary Python value is returned, it is converted to a
gdb.Valuefollowing the usual rules.
The following code snippet shows how a trivial convenience function can be implemented in Python:
class Greet (gdb.Function): """Return string to greet someone. Takes a name as argument.""" def __init__ (self): super (Greet, self).__init__ ("greet") def invoke (self, name): return "Hello, %s!" % name.string () Greet ()
The last line instantiates the class, and is necessary to trigger the
registration of the function with gdb. Depending on how the
Python code is read into gdb, you may need to import the
gdb module explicitly.