从 gdbinit 脚本步进时如何设置跳过无趣的功能？

Question

我正在尝试设置一组函数，让 gdb 在执行以下命令时跳过这些函数：

skip myfunction

。但是如果我把它们放在 ~/.gdbinit 而不是在终端 gdb 提示符中说，我会得到错误：

No function found named myfunction.

Ignore function pending future shared library load? (y or [n]) [answered N; input not from terminal]

所以我需要 GDB 来获得 Y 答案。我试过 suggested for breakpoints as well as set confirm off suggested in a comment to this question。但是这些对 skip 命令没有帮助。

如何在 .gdbinit 脚本中设置 skip，回答 Y 关于未来库加载的问题？

Answer 1

此处已提出此功能：

https://sourceware.org/ml/gdb-prs/2015-q2/msg00417.html https://sourceware.org/bugzilla/show_bug.cgi?id=18531

到目前为止，activity 已经有 6 个月没有关于该问题的讨论了。在撰写本文时，该功能尚未包含在 GDB 7.10 中。

Answer 2

可以用Python等待执行开始，相当于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()

将此代码保存到 Python 文件 pending_skip.py（或在 .gdbinit 中用 python ... end 包围），然后：

source pending_skip.py
pending_skip fct1
pending_skip fct2 fct3
pending_skip # to list pending skips

文档参考：

从 gdbinit 脚本步进时如何设置跳过无趣的功能？

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

debugging

gdb