add 'allgroutines <cmd>' to gdb (e.g. `(gdb) allgroutines bt`)

go-gdb-extra.py

from __future__ import print_function

""" GDB 'allgoroutines' command for executing gdb command within the context of every goroutine at once """

class GoroutineStacks(gdb.Command):
    "Print stacktrace for all goroutines."

    def __init__(self):
        gdb.Command.__init__(self, "allgoroutines", gdb.COMMAND_STACK, gdb.COMPLETE_NONE)

    def invoke(self, arg, _from_tty):
        command = arg

        def onGoRoutine(g, pc, sp):
            try:
                pc = int(pc)
            except gdb.error:
                pc = int(str(pc).split(None, 1)[0], 16)

            save_frame = gdb.selected_frame()
            gdb.parse_and_eval('$save_sp = $sp')
            gdb.parse_and_eval('$save_pc = $pc')
            gdb.parse_and_eval('$sp = {0}'.format(str(sp)))
            gdb.parse_and_eval('$pc = {0}'.format(str(pc)))
            try:
                print("goroutine {} {} {}".format(g['goid'], command, 20*"="))
                gdb.execute(command)
            finally:
                gdb.parse_and_eval('$sp = $save_sp')
                gdb.parse_and_eval('$pc = $save_pc')
                save_frame.select()

        eachGoRoutine(onGoRoutine)


def eachGoRoutine(cb):
    vp = gdb.lookup_type('void').pointer()
    allgs = SliceValue(gdb.parse_and_eval("'runtime.allgs'"))
    for ptr in allgs:
        if ptr['atomicstatus'] == 6:  # 'gdead'
            continue

        pc, sp = ptr['sched']['pc'], ptr['sched']['sp']
        if sp != 0:
            # goroutine is stopped -> report pc/sp as is stored in workqueue
            cb(ptr, pc.cast(vp), sp.cast(vp))
            continue

        pc, sp = ptr['syscallpc'], ptr['syscallsp']
        if sp != 0:
            # goroutine waiting for syscall completion
            cb(ptr, pc.cast(vp), sp.cast(vp))
            continue

        # Otherwise, the goroutine is running, so it doesn't have
        # saved scheduler state. Find G's OS thread.
        m = ptr['m']
        if m == 0:
            continue  # hmmm.... No OS thread assigned

        for thr in gdb.selected_inferior().threads():
            if thr.ptid[1] == m['procid']:
                break
        else:
            continue  # can not find OS thread in gdb

        curthr = gdb.selected_thread()
        try:
            thr.switch()
            pc = gdb.parse_and_eval('$pc')
            sp = gdb.parse_and_eval('$sp')
        finally:
            curthr.switch()
        cb(ptr, pc.cast(vp), sp.cast(vp))

GoroutineStacks()