Allow pexpect tests to work in remote testsuite runs

[friss]

Summary

This commit adds platform selection/connection commands to the base
PExpectTest class. I doesn't look like any of the current tests are
really interesting to test remotely, but it's easy enough to get
them to work.

[labath]

I don't see harm in adding this, but I am curious about what are you planning to use this for. My takeaway from all of the pexpect discussions we've had in the past was that pexpect should only be used for stuff that really, really needs an interactive terminal to work (i.e., stuff like batch mode, the "gui" command, interactive command line editing/libedit stuff, etc.). All of these seem like innately host-related stuff, and I am having trouble imagining a feature/test that requires an interactive terminal, but only works on remote targets.

[friss]

In D68727#1703073, @labath wrote:

I don't see harm in adding this, but I am curious about what are you planning to use this for. My takeaway from all of the pexpect discussions we've had in the past was that pexpect should only be used for stuff that really, really needs an interactive terminal to work (i.e., stuff like batch mode, the "gui" command, interactive command line editing/libedit stuff, etc.). All of these seem like innately host-related stuff, and I am having trouble imagining a feature/test that requires an interactive terminal, but only works on remote targets.

I don't have any specific plans. I was going through our test suite and cleaning up the remote on-device runs. Those tests were failing because they had never been exercised in this configuration, so I took a look at what it would take to get them to work, and it was easy enough. I'm no opposed to skipping those tests if we're running with a remote platform, if we don't think they'll ever be useful in this config.

lldb/packages/Python/lldbsuite/test/lldbpexpect.py

 from __future__ import print_function
 from __future__ import absolute_import
 
 # System modules
 import sys
 
 # Third-party modules
 import six
 
 # LLDB Modules
 import lldb
 from .lldbtest import *
 from . import lldbutil
+from lldbsuite.test import configuration
 
 if sys.platform.startswith('win32'):
     # llvm.org/pr22274: need a pexpect replacement for windows
     class PExpectTest(object):
         pass
 else:
     import pexpect
 
     class PExpectTest(TestBase):
 
         NO_DEBUG_INFO_TESTCASE = True
         PROMPT = "(lldb) "
 
         def expect_prompt(self):
             self.child.expect_exact(self.PROMPT)
 
         def launch(self, executable=None, extra_args=None, timeout=30, dimensions=None):
             logfile = getattr(sys.stdout, 'buffer',
                               sys.stdout) if self.TraceOn() else None
             args = ['--no-lldbinit', '--no-use-colors']
             for cmd in self.setUpCommands():
                 args += ['-O', cmd]
-            if executable is not None:
-                args += ['--file', executable]
             if extra_args is not None:
                 args.extend(extra_args)
             self.child = pexpect.spawn(
                     lldbtest_config.lldbExec, args=args, logfile=logfile,
                     timeout=timeout, dimensions=dimensions)
             self.expect_prompt()
             for cmd in self.setUpCommands():
                 self.child.expect_exact(cmd)
                 self.expect_prompt()
+
+            if configuration.lldb_platform_name:
+                self.child.sendline("platform select " + configuration.lldb_platform_name)
+                self.child.expect_exact("Platform: " + configuration.lldb_platform_name)
+                self.expect_prompt()
+                self.child.sendline("platform connect " + configuration.lldb_platform_url)
+                self.child.expect_exact("Connected: yes")
+                self.expect_prompt()
+
+                if configuration.lldb_platform_working_dir:
+                    self.child.sendline("platform mkdir " + configuration.lldb_platform_working_dir)
+                    self.expect_prompt()
+                    self.child.sendline("platform settings -w " + configuration.lldb_platform_working_dir)
+                    self.expect_prompt()
+
             if executable is not None:
-                self.child.expect_exact("target create")
+                self.child.sendline("target create " + executable)
                 self.child.expect_exact("Current executable set to")
                 self.expect_prompt()
 
         def expect(self, cmd, substrs=None):
             self.child.sendline(cmd)
             if substrs is not None:
                 for s in substrs:
                     self.child.expect_exact(s)
             self.expect_prompt()
 
         def quit(self, gracefully=True):
             self.child.sendeof()
             self.child.close(force=not gracefully)
             self.child = None