Add ignore command (from #1257) (#1276)

* Add ignore command (from #1257)

* Fix lint

* Apply changes suggested by disconnect3d on ignore command

* Add tests for ignore command

pwndbg/commands/__init__.py

@@ -54,7 +54,7 @@ GDB_BUILTIN_COMMANDS = list_current_commands()
 class Command(gdb.Command):
     """Generic command wrapper"""
 
-    builtin_override_whitelist = {"up", "down", "search", "pwd", "start"}
+    builtin_override_whitelist = {"up", "down", "search", "pwd", "start", "ignore"}
     history = {}  # type: Dict[int,str]
 
     def __init__(self, function, prefix=False, command_name=None, shell=False):
@@ -476,6 +476,7 @@ def load_commands():
     import pwndbg.commands.heap
     import pwndbg.commands.hexdump
     import pwndbg.commands.ida
+    import pwndbg.commands.ignore
     import pwndbg.commands.ipython_interactive
     import pwndbg.commands.leakfind
     import pwndbg.commands.memoize

pwndbg/commands/ignore.py

@@ -0,0 +1,44 @@
+"""
+Ignoring a breakpoint
+"""
+
+import argparse
+
+import gdb
+
+import pwndbg.color.message as message
+import pwndbg.commands
+
+parser = argparse.ArgumentParser()
+parser.description = """Set ignore-count of breakpoint number N to COUNT.
+
+While the ignore count is positive, execution will not stop on the breakpoint.
+
+By default, if `N' is ommitted, the last breakpoint (i.e. greatest breakpoint number) will be used."""
+parser.formatter_class = argparse.RawDescriptionHelpFormatter
+parser.add_argument(
+    "bpnum", metavar="N", type=int, default=None, nargs="?", help="The breakpoint number N."
+)
+parser.add_argument("count", metavar="COUNT", type=int, help="The number to set COUNT.")
+
+
+@pwndbg.commands.ArgparsedCommand(parser)
+def ignore(bpnum, count):
+    bps = gdb.breakpoints()
+
+    if not bps:
+        print(message.error("No breakpoints set."))
+        return
+
+    if bpnum is None:
+        bp = max(bps, key=lambda bp: bp.number)
+    else:
+        bp = next((bp for bp in bps if bp.number == bpnum), None)
+
+        if bp is None:
+            print(message.error("No breakpoint number %d." % bpnum))
+            return
+
+    count = max(0, int(count))
+    bp.ignore_count = count
+    print("Will ignore next %d crossings of breakpoint %d." % (count, bp.number))

tests/test_command_ignore.py

@@ -0,0 +1,58 @@
+import gdb
+
+import pwndbg
+import tests
+
+REFERENCE_BINARY = tests.binaries.get("reference-binary.out")
+
+
+def test_command_ignore_no_breakpoint_set():
+    out = gdb.execute("ignore 1001", to_string=True)
+    assert out == "No breakpoints set.\n"
+
+
+def test_command_ignore_no_breakpoint_set_remove():
+    gdb.execute("file " + REFERENCE_BINARY)
+    gdb.execute("break break_here")
+    gdb.execute("delete 1")
+    out = gdb.execute("ignore 1001", to_string=True)
+    assert out == "No breakpoints set.\n"
+
+
+def test_command_ignore_no_breakpoint_found(start_binary):
+    start_binary(REFERENCE_BINARY)
+
+    gdb.execute("break main")
+    out = gdb.execute("ignore 2 1001", to_string=True)
+    assert out == "No breakpoint number 2.\n"
+
+
+def test_command_ignore_breakpoint_last_found_one():
+    gdb.execute("file " + REFERENCE_BINARY)
+    gdb.execute("break break_here")
+
+    out = gdb.execute("ignore 1", to_string=True)
+    assert out == "Will ignore next 1 crossings of breakpoint 1.\n"
+
+    gdb.execute("run")
+    assert not pwndbg.gdblib.proc.alive
+
+    gdb.execute("run")
+    assert pwndbg.gdblib.proc.alive
+
+
+def test_command_ignore_breakpoint_last_found_two():
+    gdb.execute("file " + REFERENCE_BINARY)
+    gdb.execute("break break_here")
+    gdb.execute("break main")
+
+    out = gdb.execute("ignore 15", to_string=True)
+    assert out == "Will ignore next 15 crossings of breakpoint 2.\n"
+
+
+def test_command_ignore_breakpoint_last_negative():
+    gdb.execute("file " + REFERENCE_BINARY)
+    gdb.execute("break break_here")
+
+    out = gdb.execute("ignore -100", to_string=True)
+    assert out == "Will ignore next 0 crossings of breakpoint 1.\n"