How to set skipping of uninteresting functions while stepping from gdbinit script? - debugging

Question

I'm trying to setup a set of functions to be skipped by gdb from stepping in by commands like:
skip myfunction
. But if I place them in ~/.gdbinit instead of just saying in the terminal gdb prompt, I get the error:
No function found named myfunction.
Ignore function pending future shared library load? (y or [n]) [answered N; input not from terminal]
So I need GDB to get Y answer. I've tried what was suggested for breakpoints as well as set confirm off suggested in a comment to this question. But these don't help with skip command.
How can I set skip in a .gdbinit script, answering Y about future library load?

Answer 1

you can use Python to wait for the execution to start, which is equivalent to pending on:
import gdb
to_skip = []
def try_pending_skips(evt=None):
for skip in list(to_skip): # make a copy for safe remove
try:
# test if the function (aka symbol is defined)
symb, _ = gdb.lookup_symbol(skip)
if not symb:
continue
except gdb.error:
# no frame ?
continue
# yes, we can skip it
gdb.execute("skip {}".format(skip))
to_skip.remove(skip)
if not to_skip:
# no more functions to skip
try:
gdb.events.new_objfile.disconnect(try_pending_skips) # event fired when the binary is loaded
except ValueError:
pass # was not connected
class cmd_pending_skip(gdb.Command):
self = None
def __init__ (self):
gdb.Command.__init__(self, "pending_skip", gdb.COMMAND_OBSCURE)
def invoke (self, args, from_tty):
global to_skip
if not args:
if not to_skip:
print("No pending skip.")
else:
print("Pending skips:")
for skip in to_skip:
print("\t{}".format(skip))
return
new_skips = args.split()
to_skip += new_skips
for skip in new_skips:
print("Pending skip for function '{}' registered.".format(skip))
try:
gdb.events.new_objfile.disconnect(try_pending_skips)
except ValueError: pass # was not connected
# new_objfile event fired when the binary and libraries are loaded in memory
gdb.events.new_objfile.connect(try_pending_skips)
# try right away, just in case
try_pending_skips()
cmd_pending_skip()
Save this code into a Python file pending_skip.py (or surrounded with python ... end in your .gdbinit), then:
source pending_skip.py
pending_skip fct1
pending_skip fct2 fct3
pending_skip # to list pending skips
Documentation references:
GDB Python TOC
Basic Python
Events in Python
Symbols in Python

Answer 2

This feature has been proposed here:
https://sourceware.org/ml/gdb-prs/2015-q2/msg00417.html
https://sourceware.org/bugzilla/show_bug.cgi?id=18531
So far, there's been no activity on that issue for 6 months though. As of writing this, the feature is not included in GDB 7.10.