Fix #1695: Handle IDE, launcher, debug server, and no-debug disconnect

Fix #1721 "runInTerminal" is broken on non-Windows platforms.

Fix #1722: Output is not captured in "noDebug" with "runInTerminal"

Groundwork for #1713: adapter: multiple concurrent sessions

Move "launch" request parsing and debuggee process spawning, PID reporting and tracking, stdio "output" capture, and exit code reporting into launcher. Launcher now communicates to the adapter via a full-fledged message channel.

Refactor adapter. Add an abstraction for a debug session, and treat IDE, launcher, and debug server as separate components managed by that session.

Improve adapter logging to capture information about current debug session, and current message handler if any.

Fix reporting exceptions from message handlers.

Various test fixes.

setup.py

@@ -114,8 +114,9 @@ def finalize_options(self):
         package_dir={'': 'src'},
         packages=[
             'ptvsd',
-            'ptvsd.common',
             'ptvsd.adapter',
+            'ptvsd.common',
+            'ptvsd.launcher',
             'ptvsd.server',
             'ptvsd._vendored',
         ],

src/ptvsd/adapter/__main__.py

@@ -6,59 +6,44 @@
 
 import argparse
 import locale
+import os
 import sys
 
 # WARNING: ptvsd and submodules must not be imported on top level in this module,
 # and should be imported locally inside main() instead.
 
+# Force absolute path on Python 2.
+__file__ = os.path.abspath(__file__)
+
 
 def main(args):
-    import ptvsd
-    from ptvsd.common import log, options
-    from ptvsd.adapter import channels
+    from ptvsd.common import log, options as common_options
+    from ptvsd.adapter import session, options as adapter_options
 
-    if args.cls and args.debug_server is not None:
-        print("\033c")
+    if args.cls:
+        sys.stderr.write("\033c")
+    if args.log_stderr:
+        adapter_options.log_stderr = True
+    if args.log_dir is not None:
+        common_options.log_dir = args.log_dir
 
-    options.log_dir = args.log_dir
-    log.stderr_levels |= {"info"}
     log.filename_prefix = "ptvsd.adapter"
+    log.stderr_levels |= {"info"}
     log.to_file()
     log.describe_environment("ptvsd.adapter startup environment:")
 
+    session = session.Session()
     if args.debug_server is None:
-        address = None
+        session.connect_to_ide()
     else:
-        address = ("localhost", args.debug_server)
-        # If in debugServer mode, log "debug" to stderr as well.
-        log.stderr_levels |= {"debug"}
-
-    chan = channels.Channels()
-    ide = chan.connect_to_ide(address)
-
-    ide.start()
-    ide.send_event(
-        "output",
-        {
-            "category": "telemetry",
-            "output": "ptvsd.adapter",
-            "data": {"version": ptvsd.__version__},
-        },
-    )
-
-    # Wait until the IDE debug session is over - everything interesting is going to
-    # be happening on the background threads running the IDE and the server message
-    # loops from here on.
-    ide.wait()
+        # If in debugServer mode, log everything to stderr.
+        log.stderr_levels |= set(log.LEVELS)
+        with session.accept_connection_from_ide(("localhost", args.debug_server)):
+            pass
+    session.wait_for_completion()
 
-    # Make sure the server message loop is also done, but only if the server connection
-    # has been established.
-    server = chan.server()
-    if server is not None:
-        server.wait()
 
-
-def _parse_argv():
+def _parse_argv(argv):
     parser = argparse.ArgumentParser()
 
     parser.add_argument(
@@ -83,7 +68,14 @@ def _parse_argv():
         help="enable logging and use DIR to save adapter logs",
     )
 
-    return parser.parse_args()
+    parser.add_argument(
+        "--log-stderr", action="store_true", help="enable logging to stderr"
+    )
+
+    args = parser.parse_args(argv[1:])
+    if args.debug_server is None and args.log_stderr:
+        parser.error("--log-stderr can only be used with --debug-server")
+    return args
 
 
 if __name__ == "__main__":
@@ -117,4 +109,4 @@ def _parse_argv():
     # Load locale settings.
     locale.setlocale(locale.LC_ALL, "")
 
-    main(_parse_argv())
+    main(_parse_argv(sys.argv))