Make --gdb work for android

sky/tools/skydb

 #!/usr/bin/env python
 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 from skypy.skyserver import SkyServer
 import argparse
 import json
 import logging
 import os
 import pipes
 import requests
 import signal
 import skypy.paths
 import StringIO
 import subprocess
 import sys
 import time
 import urlparse
+import re
 
 SRC_ROOT = skypy.paths.Paths('ignored').src_root
 sys.path.insert(0, os.path.join(SRC_ROOT, 'build', 'android'))
 from pylib import android_commands
 from pylib import constants
 from pylib import forwarder
 
 
 SUPPORTED_MIME_TYPES = [
     'text/html',
     'text/sky',
     'text/plain',
 ]
 
 DEFAULT_SKY_COMMAND_PORT = 7777
 GDB_PORT = 8888
 SKY_SERVER_PORT = 9999
 PID_FILE_PATH = "/tmp/skydb.pids"
 DEFAULT_URL = "https://raw.githubusercontent.com/domokit/mojo/master/sky/examples/home.sky"
 
 ANDROID_PACKAGE = "org.chromium.mojo.shell"
 ANDROID_ACTIVITY = "%s/.MojoShellActivity" % ANDROID_PACKAGE
 
+
 # FIXME: Move this into mopy.config
 def gn_args_from_build_dir(build_dir):
     gn_cmd = [
         'gn', 'args',
         build_dir,
         '--list', '--short'
     ]
     config = {}
     for line in subprocess.check_output(gn_cmd).strip().split('\n'):
         # FIXME: This doesn't handle = in values.
@@ skipping 37 matching lines @@
             'am', 'start',
             '-W',
             '-S',
             '-a', 'android.intent.action.VIEW',
             '-n', ANDROID_ACTIVITY,
             # FIXME: This quoting is very error-prone.  Perhaps we should read
             # our args from a file instead?
             '--esa', 'parameters', ','.join(escaped_args),
         ]
 
-    def _build_mojo_shell_command(self, args):
+    def _build_mojo_shell_command(self, args, is_android):
         content_handlers = ['%s,%s' % (mime_type, 'mojo:sky_viewer')
             for mime_type in SUPPORTED_MIME_TYPES]
 
         remote_command_port = self.pids.get('remote_sky_command_port', self.pids['sky_command_port'])
 
         shell_args = [
             '--v=1',
             '--content-handlers=%s' % ','.join(content_handlers),
             '--url-mappings=mojo:window_manager=mojo:sky_debugger',
             '--args-for=mojo:sky_debugger_prompt %d' % remote_command_port,
             'mojo:window_manager',
         ]
 
+        # Desktop-only work-around for mojo crashing under chromoting.
+        if not is_android and args.use_osmesa:
+            shell_args.append(
+                '--args-for=mojo:native_viewport_service --use-osmesa')
+
+        if is_android and args.gdb:
+            shell_args.append('--wait_for_debugger')
+
         if 'remote_sky_server_port' in self.pids:
             shell_command = self._wrap_for_android(shell_args)
         else:
             shell_command = [self.paths.mojo_shell_path] + shell_args
 
         return shell_command
 
     def _connect_to_device(self):
         device = android_commands.AndroidCommands(
             android_commands.GetAttachedDevices()[0])
         device.EnableAdbRoot()
         return device
 
     def sky_server_for_args(self, args):
         # FIXME: This is a hack.  sky_server should just take a build_dir
         # not a magical "configuration" name.
         configuration = os.path.basename(os.path.normpath(args.build_dir))
         server_root = self._server_root_for_url(args.url_or_path)
         sky_server = SkyServer(self.paths, SKY_SERVER_PORT,
             configuration, server_root)
         return sky_server
 
     def _create_paths_for_build_dir(self, build_dir):
         # skypy.paths.Paths takes a root-relative build_dir argument. :(
         abs_build_dir = os.path.abspath(build_dir)
         root_relative_build_dir = os.path.relpath(abs_build_dir, SRC_ROOT)
         return skypy.paths.Paths(root_relative_build_dir)
 
+    def _find_remote_pid_for_package(self, package):
+        ps_output = subprocess.check_output(['adb', 'shell', 'ps'])
+        for line in ps_output.split('\n'):
+            fields = line.split()
+            if fields and fields[-1] == package:
+                return fields[1]
+        return None
+
+    def _find_install_location_for_package(self, package):
+        pm_command = ['adb', 'shell', 'pm', 'path', package]
+        pm_output = subprocess.check_output(pm_command)
+        # e.g. package:/data/app/org.chromium.mojo.shell-1/base.apk
+        return pm_output.split(':')[-1]
+
     def start_command(self, args):
         # FIXME: Lame that we use self for a command-specific variable.
         self.paths = self._create_paths_for_build_dir(args.build_dir)
         self.stop_command(None) # Quit any existing process.
         self.pids = {} # Clear out our pid file.
 
         if not os.path.exists(self.paths.mojo_shell_path):
             print "mojo_shell not found in build_dir '%s'" % args.build_dir
             print "Are you sure you sure that's a valid build_dir location?"
             print "See skydb start --help for more info"
@@ skipping 23 matching lines @@
             device_http_port = forwarder.Forwarder.DevicePortForHostPort(
                 sky_server.port)
             self.pids['remote_sky_server_port'] = device_http_port
 
             port_string = 'tcp:%s' % args.command_port
             subprocess.check_call([
                 'adb', 'forward', port_string, port_string
             ])
             self.pids['remote_sky_command_port'] = args.command_port
 
-        shell_command = self._build_mojo_shell_command(args)
+        shell_command = self._build_mojo_shell_command(args, is_android)
 
-        if not is_android:
-            # Desktop-only work-around for mojo crashing under chromoting.
-            if args.use_osmesa:
-                shell_args.append(
-                    '--args-for=mojo:native_viewport_service --use-osmesa')
-
-            # On android we can't launch inside gdb, but rather have to attach.
-            if args.gdb:
-                shell_command = ['gdbserver', ':%s' % GDB_PORT] + shell_command
+        # On android we can't launch inside gdb, but rather have to attach.
+        if not is_android and args.gdb:
+            shell_command = ['gdbserver', ':%d' % GDB_PORT] + shell_command
 
         print ' '.join(map(pipes.quote, shell_command))
-        self.pids['mojo_shell_pid'] = subprocess.Popen(shell_command).pid
+        # This pid is meaningless on android (it's the adb shell pid)
+        start_command_pid = subprocess.Popen(shell_command).pid
+
+        if is_android:
+            # TODO(eseidel): am start -W does not seem to work?
+            pid_tries = 0
+            while True:
+                pid = self._find_remote_pid_for_package(ANDROID_PACKAGE)
+                if pid or pid_tries > 3:
+                    break
+                logging.warn('No pid for %s yet, waiting' % ANDROID_PACKAGE)
+                time.sleep(5)
+                pid_tries += 1
+
+            if not pid:
+                logging.error('Failed to find mojo_shell pid on device!')
+                return
+            self.pids['mojo_shell_pid'] = pid
+        else:
+            self.pids['mojo_shell_pid'] = start_command_pid
 
         if args.gdb and is_android:
-            gdbserver_cmd = ['gdbserver', '--attach', ':%s' % GDB_PORT]
-            self.pids['remote_gdbserver_pid'] = subprocess.Popen(shell_command).pid
+            # We push our own copy of gdbserver with the package since
+            # the default gdbserver is a different version from our gdb.
+            package_path = \
+                self._find_install_location_for_package(ANDROID_PACKAGE)
+            gdb_server_path = os.path.join(
+                os.path.dirname(package_path), 'lib/arm/gdbserver')
+            gdbserver_cmd = [
+                'adb', 'shell',
+                gdb_server_path, '--attach',
+                ':%s' % GDB_PORT,

[qsr, 2015/01/16 00:46:40]

%d ?

[eseidel, 2015/01/16 19:17:18]

I think this makes the code needlessly fragile for no real benefit.  But I've
changed this one since it happens to be OK.  I agree it's nice to know the types
of things, but python doesn't have types, so what I"m asking here is for the
string value of the thing and if the thing quacks like a string, it's gonna be
OK. :)

I don't have any unit-testing for this code which is probably the real reason
for any fragility... :(  (and well over due).

+                str(self.pids['mojo_shell_pid'])
+            ]
+            print ' '.join(map(pipes.quote, gdbserver_cmd))
+            self.pids['adb_shell_gdbserver_pid'] = \
+                subprocess.Popen(gdbserver_cmd).pid
 
             port_string = 'tcp:%s' % GDB_PORT
             subprocess.check_call([
                 'adb', 'forward', port_string, port_string
             ])
             self.pids['remote_gdbserver_port'] = GDB_PORT
 
         if not args.gdb:
             if not self._wait_for_sky_command_port():
                 logging.error('Failed to start sky')
@@ skipping 10 matching lines @@
             return
         logging.info('Killing %s (%s).' % (name, pid))
         try:
             os.kill(pid, signal.SIGTERM)
         except OSError:
             logging.info('%s (%s) already gone.' % (name, pid))
 
     def stop_command(self, args):
         # TODO(eseidel): mojo_shell crashes when attempting graceful shutdown.
         # self._send_command_to_sky('/quit')
-        self._kill_if_exists('mojo_shell_pid', 'mojo_shell')
 
         self._kill_if_exists('sky_server_pid', 'sky_server')
+
         # We could be much more surgical here:
         if 'remote_sky_server_port' in self.pids:
             device = android_commands.AndroidCommands(
                 self.pids['device_serial'])
             forwarder.Forwarder.UnmapAllDevicePorts(device)
 
         if 'remote_sky_command_port' in self.pids:
             # adb forward --remove takes the *host* port, not the remote port.
             port_string = 'tcp:%s' % self.pids['sky_command_port']
             subprocess.call(['adb', 'forward', '--remove', port_string])
 
             subprocess.call([
                 'adb', 'shell', 'am', 'force-stop', ANDROID_PACKAGE])
+        else:
+            # Only try to kill mojo_shell if it's running locally.
+            self._kill_if_exists('mojo_shell_pid', 'mojo_shell')
 
         if 'remote_gdbserver_port' in self.pids:
+            self._kill_if_exists('adb_shell_gdbserver_pid',
+                'adb shell gdbserver')
+
             port_string = 'tcp:%s' % self.pids['remote_gdbserver_port']
             subprocess.call(['adb', 'forward', '--remove', port_string])
 
+        self._kill_if_exists('mojo_cache_linker_pid', 'mojo cache linker')
+
     def load_command(self, args):
         if not urlparse.urlparse(args.url_or_path).scheme:
             # The load happens on the remote device, use the remote port.
             remote_sky_server_port = self.pids.get('remote_sky_server_port',
                 self.pids['sky_server_port'])
             url = SkyServer.url_for_path(remote_sky_server_port,
                     self.pids['sky_server_root'], args.url_or_path)
         else:
             url = args.url_or_path
         self._send_command_to_sky('/load', url)
@@ skipping 52 matching lines @@
             'AndroidHandler',
             'MojoMain',
             'MojoShellActivity',
             'MojoShellApplication',
             'chromium',
         ]
         subprocess.call(['adb', 'logcat', '-d', '-s'] + TAGS)
 
     def gdb_attach_command(self, args):
         self.paths = self._create_paths_for_build_dir(self.pids['build_dir'])
+
+        self._kill_if_exists('mojo_cache_linker_pid', 'mojo cache linker')
+
+        links_path = '/tmp/mojo_cache_links'
+        if not os.path.exists(links_path):
+            os.makedirs(links_path)
+        shell_link_path = os.path.join(links_path, 'libmojo_shell.so')
+        if os.path.lexists(shell_link_path):
+            os.unlink(shell_link_path)
+        os.symlink(self.paths.mojo_shell_path, shell_link_path)
+
+        logcat_cmd = ['adb', 'logcat']
+        logcat = subprocess.Popen(logcat_cmd, stdout=subprocess.PIPE)
+
+        mojo_cache_linker_path = os.path.join(
+            self.paths.sky_tools_directory, 'mojo_cache_linker.py')
+        cache_linker_cmd = [
+            mojo_cache_linker_path,
+            links_path,
+            self.pids['build_dir'],
+            'http://localhost:%s' % self.pids['remote_sky_server_port']
+        ]
+        self.pids['mojo_cache_linker_pid'] = \
+            subprocess.Popen(cache_linker_cmd, stdin=logcat.stdout).pid
+
+        # Write out our pid file before we exec ourselves.
+        self._write_pid_file(PID_FILE_PATH, self.pids)
+
+        # TODO(eseidel): Need to sync down system libraries into a directory.
+        symbol_search_paths = [
+            links_path,
+            self.pids['build_dir'],
+        ]
+        # TODO(eseidel): We need to look up the toolchain somehow?
+        gdb_path = os.path.join(SRC_ROOT, 'third_party/android_tools/ndk/'
+            'toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64/'
+            'bin/arm-linux-androideabi-gdb')
         gdb_command = [
-            '/usr/bin/gdb', self.paths.mojo_shell_path,
-            '--eval-command', 'target remote localhost:%s' % GDB_PORT
+            gdb_path,
+            '--eval-command', 'file %s' % self.paths.mojo_shell_path,
+            '--eval-command', 'directory %s' % self.paths.src_root,
+            '--eval-command', 'target remote localhost:%s' % GDB_PORT,
+            '--eval-command', 'set solib-search-path %s' %
+                ':'.join(symbol_search_paths),
         ]
         print " ".join(gdb_command)
         # We don't want python listenting for signals or anything, so exec
         # gdb and let it take the entire process.
         os.execv(gdb_command[0], gdb_command)
 
     def print_crash_command(self, args):
         logcat_cmd = ['adb', 'logcat', '-d']
         logcat = subprocess.Popen(logcat_cmd, stdout=subprocess.PIPE)
 
@@ skipping 55 matching lines @@
         load_parser.set_defaults(func=self.load_command)
 
         args = parser.parse_args()
         args.func(args)
 
         self._write_pid_file(PID_FILE_PATH, self.pids)
 
 
 if __name__ == '__main__':
     SkyDebugger().main()