def invoke(self, n=1):
for frame in FrameIterator(gdb.selected_frame()):
if n <= 0:
frame.select()
break
n = n - 1
return 1
def invoke(self, name, limit):
name = str(name)
for frame in FrameIterator(gdb.selected_frame()):
if limit <= 0:
return gdb.Value(0)
limit = limit - 1
val = find_var(frame, name)
if val is not None:
return val
raise gdb.GdbError("couldn't find %s" % name)
def execute_frame_filters(frame, frame_low, frame_high):
""" Internal function called from GDB that will execute the chain
of frame filters. Each filter is executed in priority order.
After the execution completes, slice the iterator to frame_low -
frame_high range.
Arguments:
frame: The initial frame.
frame_low: The low range of the slice. If this is a negative
integer then it indicates a backward slice (ie bt -4) which
counts backward from the last frame in the backtrace.
frame_high: The high range of the slice. If this is -1 then
it indicates all frames until the end of the stack from
frame_low.
Returns:
frame_iterator: The sliced iterator after all frame
filters have had a change to execute, or None if no frame
filters are registered.
"""
# Get a sorted list of frame filters.
sorted_list = list(_sort_list())
# Check to see if there are any frame-filters. If not, just
# return None and let default backtrace printing occur.
if len(sorted_list) == 0:
return None
frame_iterator = FrameIterator(frame)
# Apply a basic frame decorator to all gdb.Frames. This unifies
# the interface. Python 3.x moved the itertools.imap
# functionality to map(), so check if it is available.
if hasattr(itertools, "imap"):
frame_iterator = itertools.imap(FrameDecorator, frame_iterator)
else:
frame_iterator = map(FrameDecorator, frame_iterator)
for ff in sorted_list:
frame_iterator = ff.filter(frame_iterator)
# Slicing
# Is this a slice from the end of the backtrace, ie bt -2?
if frame_low < 0:
count = 0
slice_length = abs(frame_low)
# We cannot use MAXLEN argument for deque as it is 2.6 onwards
# and some GDB versions might be < 2.6.
sliced = collections.deque()
for frame_item in frame_iterator:
if count >= slice_length:
sliced.popleft()
count = count + 1
sliced.append(frame_item)
return iter(sliced)
# -1 for frame_high means until the end of the backtrace. Set to
# None if that is the case, to indicate to itertools.islice to
# slice to the end of the iterator.
if frame_high == -1:
frame_high = None
else:
# As frames start from 0, add one to frame_high so islice
# correctly finds the end
frame_high = frame_high + 1
sliced = itertools.islice(frame_iterator, frame_low, frame_high)
return sliced