Add very basic support for symboled debugging on 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
@@ skipping 119 matching lines @@
 
     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))
+        configuration = os.path.basename(os.path.normpath(self.paths.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)
@@ skipping 18 matching lines @@
         self.stop_command(None) # Quit any existing process.
 
         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"
             sys.exit(2)
 
         # FIXME: This is probably not the right way to compute is_android
         # from the build directory?
-        gn_args = gn_args_from_build_dir(args.build_dir)
+        gn_args = gn_args_from_build_dir(self.paths.build_dir)
         is_android = 'android_sdk_version' in gn_args
 
         sky_server = self.sky_server_for_args(args)
         self.pids['sky_server_pid'] = sky_server.start()
         self.pids['sky_server_port'] = sky_server.port
         self.pids['sky_server_root'] = sky_server.root
 
-        self.pids['build_dir'] = args.build_dir
+        self.pids['build_dir'] = self.paths.build_dir
         self.pids['sky_command_port'] = args.command_port
 
         if is_android:
             # Pray to the build/android gods in their misspelled tongue.
-            constants.SetOutputDirectort(args.build_dir)
+            constants.SetOutputDirectort(self.paths.build_dir)
 
             device = self._connect_to_device()
             self.pids['device_serial'] = device.GetDevice()
 
             forwarder.Forwarder.Map([(0, sky_server.port)], device)
             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
@@ skipping 199 matching lines @@
             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)
 
+        # Pull down the system libraries this pid has already mapped in.
+        # TODO(eseidel): This does not handle dynamic loads well.
+        system_libs_root = '/tmp/device_libs'
+        library_cacher_path = os.path.join(
+            self.paths.sky_tools_directory, 'android_library_cacher.py')
+        subprocess.call([
+            library_cacher_path, system_libs_root, self.pids['mojo_shell_pid']
+        ])
+
+        # TODO(eseidel): adb_gdb does, this, unclear why solib-absolute-prefix
+        # doesn't make this explicit listing not necessary?
+        system_lib_dirs = subprocess.check_output([
+            'find', system_libs_root,
+            '-mindepth', '1',
+            '-maxdepth', '4',
+            '-type', 'd',
+        ]).strip().split('\n')
+
         # TODO(eseidel): Need to sync down system libraries into a directory.
-        symbol_search_paths = [
+        symbol_search_paths = system_lib_dirs + [
             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 = [
             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),
+            '--eval-command', 'set solib-absolute-prefix %s' % system_libs_root,
         ]
         print " ".join(gdb_command)
         # We don't want python listening 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 59 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()