Allow mojo_debug gdb attach to search symbols in multiple directories.

mojo/devtools/common/android_gdb/session.py

 # Copyright 2015 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.
 
 """
 Manages a debugging session with GDB.
 
 This module is meant to be imported from inside GDB. Once loaded, the
 |DebugSession| attaches GDB to a running Mojo Shell process on an Android
 device using a remote gdbserver.
@@ skipping 53 matching lines @@
                _gdb_execute("info proc map").split('\n')]
               if len(x) == 5 and x[4][0] == '/']
   res = {}
   for m in mappings:
     libname = m.filename[m.filename.rfind('/') + 1:]
     res[libname] = res.get(libname, []) + [m]
   return res.values()
 
 
 class DebugSession(object):
-  def __init__(self, build_directory, package_name, pyelftools_dir, adb):
-    self._build_directory = build_directory
-    if not os.path.exists(self._build_directory):
-      logging.fatal("Please pass a valid build directory")
+  def __init__(self, build_directory_list, package_name, pyelftools_dir, adb):
+    build_directories = build_directory_list.split(',')
+    if len(build_directories) == 0 or not all(map(os.path.exists,
+                                                  build_directories)):
+      logging.fatal("Please pass a list of valid build directories")
       sys.exit(1)
     self._package_name = package_name
     self._adb = adb
     self._remote_file_cache = os.path.join(os.getenv('HOME'), '.mojosymbols')
 
     if pyelftools_dir != None:
       sys.path.append(pyelftools_dir)
     try:
       import elftools.elf.elffile as elffile
     except ImportError:
       logging.fatal("Unable to find elftools module; please install pyelftools "
                     "and specify its path on the command line using "
                     "--pyelftools-dir.")
       sys.exit(1)
 
     self._elffile_module = elffile
 
-    self._libraries = self._find_libraries(build_directory)
+    self._libraries = self._find_libraries(build_directories)
     self._rfc = RemoteFileConnection('localhost', 10000)
     self._remote_file_reader_process = None
     if not os.path.exists(self._remote_file_cache):
       os.makedirs(self._remote_file_cache)
     self._done_mapping = set()
     self._downloaded_files = []
 
   def __del__(self):
     # Note that, per python interpreter documentation, __del__ is not
     # guaranteed to be called when the interpreter (GDB, in our case) quits.
     # Also, most (all?) globals are no longer available at this time (launching
     # a subprocess does not work).
     self.stop()
 
   def stop(self, _unused_return_value=None):
     if self._remote_file_reader_process != None:
       self._remote_file_reader_process.kill()
 
-  def _find_libraries(self, lib_dir):
-    """Finds all libraries in |lib_dir| and key them by their signatures.
+  def _find_libraries(self, lib_dirs):
+    """Finds all libraries in |lib_dirs| and key them by their signatures.
     """
     res = {}
-    for fn in glob.glob('%s/*.so' % lib_dir):
-      with open(fn, 'r') as f:
-        s = get_signature(f, self._elffile_module)
-        if s is not None:
-          res[s] = fn
+    for lib_dir in lib_dirs:
+      for fn in glob.glob('%s/*.so' % lib_dir):
+        with open(fn, 'r') as f:
+          s = get_signature(f, self._elffile_module)
+          if s is not None:
+            res[s] = fn
     return res
 
   def _associate_symbols(self, mapping, local_file):
     with open(local_file, "r") as f:
       elf = self._elffile_module.ELFFile(f)
       s = elf.get_section_by_name(".text")
       text_address = mapping[0].start + s['sh_offset']
       _gdb_execute("add-symbol-file %s 0x%x" % (local_file, text_address))
 
   def _download_file(self, signature, remote):
@@ skipping 175 matching lines @@
 
   def complete(self, text, _unused_word):
     if text == self._UPDATE_COMMAND:
       return ('all', 'current')
     elif text in self._UPDATE_COMMAND + ' all':
       return ['all']
     elif text in self._UPDATE_COMMAND + ' current':
       return ['current']
     else:
       return []