gdb: allow gdbclient.py to find local files.

gdbclient.py is always downloading the stripped version of executable
files from the device. This CL first tries to find the unstripped local
file before falling back to the stripped version.

Bug: http://b/24947939
Change-Id: I7a49d0d8b28590ee99ce892d3e3476921f4ae974

scripts/gdbclient.py

@@ -106,7 +106,7 @@ def ensure_linker(device, sysroot, is64bit):
         device.pull(remote_path, local_path)
 
 
-def handle_switches(args):
+def handle_switches(args, sysroot):
     """Fetch the targeted binary and determine how to attach gdb.
 
     Args:
@@ -135,14 +135,20 @@ def handle_switches(args):
         if not args.run_cmd[0].startswith("/"):
             sys.exit("commands passed to -r must use absolute paths")
         run_cmd = args.run_cmd
-        binary_file = gdbrunner.pull_file(device, run_cmd[0], user=args.user)
+        binary_file, local = gdbrunner.find_file(device, run_cmd[0], sysroot,
+                                                 user=args.user)
     if binary_file is None:
         assert pid is not None
         try:
-            binary_file = gdbrunner.pull_binary(device, pid=pid, user=args.user)
+            binary_file, local = gdbrunner.find_binary(device, pid, sysroot,
+                                                       user=args.user)
         except adb.ShellError:
             sys.exit("failed to pull binary for PID {}".format(pid))
 
+    if not local:
+        logging.warning("Couldn't find local unstripped executable in {},"
+                        " symbols may not be available.".format(sysroot))
+
     return (binary_file, pid, run_cmd)
 
 def generate_gdb_script(sysroot, binary_file, is64bit, port, connect_timeout=5):
@@ -216,7 +222,7 @@ def main():
     run_cmd = None
 
     # Fetch binary for -p, -n.
-    binary_file, pid, run_cmd = handle_switches(args)
+    binary_file, pid, run_cmd = handle_switches(args, sysroot)
 
     with binary_file:
         arch = gdbrunner.get_binary_arch(binary_file)
@@ -249,6 +255,9 @@ def main():
         gdb_path = os.path.join(root, "prebuilts", "gdb", platform_name, "bin",
                                 "gdb")
 
+        # Print a newline to separate our messages from the GDB session.
+        print("")
+
         # Start gdb.
         gdbrunner.start_gdb(gdb_path, gdb_commands)