Support java debugging

The java architecture is a little different:

- the debugger is a jdt.ls extension bundle.
- to start the server, you send a startDebugSession command to jdt.ls
- this returns a tcl port to connect to for DAP

Loading of jdt.ls and the extension are out of scope for vimspector
currently and instead you can tell it to ask you for a port to connect
to.

After connexting to that port, vimspector works as normal.

To support TCP/IP was pretty simple: we provide the same API from
vimscript as the job-based (stdin/out) comms layer, but instead just
directly use a channel.

The only wrinkle was that the java debug adapter broke the protocol on
runInTerminal and didn't return a 'cwd', so we make one up.

autoload/vimspector/internal/channel.vim

@@ -0,0 +1,101 @@
+" vimspector - A multi-language debugging system for Vim
+" Copyright 2018 Ben Jackson
+"
+" Licensed under the Apache License, Version 2.0 (the "License");
+" you may not use this file except in compliance with the License.
+" You may obtain a copy of the License at
+"
+"   http://www.apache.org/licenses/LICENSE-2.0
+"
+" Unless required by applicable law or agreed to in writing, software
+" distributed under the License is distributed on an "AS IS" BASIS,
+" WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+" See the License for the specific language governing permissions and
+" limitations under the License.
+
+
+" Boilerplate {{{
+let s:save_cpo = &cpo
+set cpo&vim
+" }}}
+
+function! s:_OnServerData( channel, data ) abort
+  py3 << EOF
+_vimspector_session.OnChannelData( vim.eval( 'a:data' ) )
+EOF
+endfunction
+
+function! s:_OnServerError( channel, data ) abort
+  echom "Channel received error: " . a:data
+endfunction
+
+function! s:_OnExit( channel, status ) abort
+  echom "Channel exit with status " . a:status
+endfunction
+
+function! s:_OnClose( channel ) abort
+  echom "Channel closed"
+  " py3 _vimspector_session.OnChannelClosed()
+endfunction
+
+function! s:_Send( msg ) abort
+  call ch_sendraw( s:ch, a:msg )
+endfunction
+
+function! vimspector#internal#channel#StartDebugSession( config ) abort
+
+  if exists( 's:ch' )
+    echo "Channel is already running"
+    return v:none
+  endif
+
+  let l:addr = 'localhost:' . a:config[ 'port' ]
+
+  let s:ch = ch_open( l:addr,
+        \             {
+        \                 'mode': 'raw',
+        \                 'callback': funcref( 's:_OnServerData' ),
+        \                 'close_cb': funcref( 's:_OnClose' ),
+        \             }
+        \           )
+
+  if ch_status( s:ch ) != 'open'
+    echom 'Unable to connect to debug adapter'
+    return v:none
+  endif
+
+  return funcref( 's:_Send' )
+endfunction
+
+function! vimspector#internal#channel#StopDebugSession() abort
+  if !exists( 's:ch' )
+    return
+  endif
+
+  if ch_status( s:ch ) == 'open'
+    call ch_close( s:ch )
+  endif
+
+  unlet s:ch
+endfunction
+
+function! vimspector#internal#channel#Reset() abort
+  if exists( 's:ch' )
+    call vimspector#internal#channel#StopDebugSession()
+  endif
+endfunction
+
+function! vimspector#internal#channel#ForceRead() abort
+  if exists( 's:ch' )
+    let data = ch_readraw( s:ch, { 'timeout': 1000 } )
+    if data != ''
+      call s:_OnServerData( s:ch, data )
+    endif
+  endif
+endfunction
+
+" Boilerplate {{{
+let &cpo=s:save_cpo
+unlet s:save_cpo
+" }}}
+

python3/vimspector/debug_session.py

@@ -46,7 +46,7 @@ class DebugSession( object ):
     self._next_sign_id = SIGN_ID_OFFSET
 
     # FIXME: This needs redesigning. There are a number of problems:
-    #  - breakpoints don't have to be line-wisw (e.g. method/exception)
+    #  - breakpoints don't have to be line-wise (e.g. method/exception)
     #  - when the server moves/changes a breakpoint, this is not updated,
     #    leading to them getting out of sync
     #  - the split of responsibility between this object and the CodeView is
@@ -133,8 +133,10 @@ class DebugSession( object ):
     if not configuration:
       return
 
+    self._workspace_root = os.path.dirname( launch_config_file )
+
     utils.ExpandReferencesInDict( launch_config[ configuration ], {
-      'workspaceRoot': os.path.dirname( launch_config_file )
+      'workspaceRoot': self._workspace_root
     } )
 
     adapter = launch_config[ configuration ].get( 'adapter' )
@@ -207,7 +209,8 @@ class DebugSession( object ):
       vim.current.tabpage = self._uiTab
       vim.command( 'tabclose!' )
 
-    vim.eval( 'vimspector#internal#job#Reset()' )
+    vim.eval( 'vimspector#internal#{}#Reset()'.format(
+      self._connection_type ) )
     vim.eval( 'vimspector#internal#state#Reset()' )
 
     # make sure that we're displaying signs in any still-open buffers
@@ -347,8 +350,17 @@ class DebugSession( object ):
     self._logger.info( 'Starting debug adapter with: {0}'.format( json.dumps(
       self._adapter ) ) )
 
+    self._connection_type = 'job'
+    if 'port' in self._adapter:
+      self._connection_type = 'channel'
+
+      if self._adapter[ 'port' ] == 'ask':
+        port = utils.AskForInput( 'Enter port to connect to: ' )
+        self._adapter[ 'port' ] = port
+
     channel_send_func = vim.bindeval(
-      "vimspector#internal#job#StartDebugSession( {0} )".format(
+      "vimspector#internal#{}#StartDebugSession( {} )".format(
+        self._connection_type,
         json.dumps( self._adapter ) ) )
 
     if channel_send_func is None:
@@ -385,13 +397,16 @@ class DebugSession( object ):
     tries = 0
     while not state[ 'done' ] and tries < 10:
       tries = tries + 1
-      vim.eval( 'vimspector#internal#job#ForceRead()' )
+      vim.eval( 'vimspector#internal#{}#ForceRead()'.format(
+        self._connection_type ) )
 
-    vim.eval( 'vimspector#internal#job#StopDebugSession()' )
+    vim.eval( 'vimspector#internal#{}#StopDebugSession()'.format(
+      self._connection_type ) )
 
   def _StopDebugAdapter( self, callback = None ):
     def handler( message ):
-      vim.eval( 'vimspector#internal#job#StopDebugSession()' )
+      vim.eval( 'vimspector#internal#{}#StopDebugSession()'.format(
+        self._connection_type ) )
 
       vim.command( 'au! vimspector_cleanup' )
 
@@ -489,6 +504,9 @@ class DebugSession( object ):
   def OnRequest_runInTerminal( self, message ):
     params = message[ 'arguments' ]
 
+    if 'cwd' not in params:
+      params[ 'cwd' ] = self._workspace_root
+
     buffer_number = self._codeView.LaunchTerminal( params )
 
     response = {

support/test/java/test_project/.gitignore

@@ -0,0 +1,4 @@
+.classpath
+.project
+.settings/
+target/

support/test/java/test_project/.vimspector.json

@@ -0,0 +1,22 @@
+{
+  "adapters": {
+    "java-debug-server": {
+      "name": "vscode-java",
+      "port": "ask"
+    }
+  },
+  "configurations": {
+    "Java Launch": {
+      "adapter": "java-debug-server",
+      "configuration": {
+        "request": "launch",
+        "mainClass": "com.vimspector.test.TestApplication",
+        "sourcePaths": [ "${workspaceRoot}/src/main/java" ],
+        "classPaths": [ "${workspaceRoot}/target/classes" ],
+        "args": "hello world!",
+        "stopOnEntry": true,
+        "console": "integratedTerminal"
+      }
+    }
+  }
+}

support/test/java/test_project/pom.xml

@@ -0,0 +1,10 @@
+<project>
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>com.vimspector.test</groupId>
+  <artifactId>TestApplication</artifactId>
+  <version>1</version>
+  <properties>
+    <maven.compiler.source>1.8</maven.compiler.source>
+    <maven.compiler.target>1.8</maven.compiler.target>
+  </properties>
+</project>

support/test/java/test_project/src/main/java/com/vimspector/test/TestApplication.java

@@ -0,0 +1,11 @@
+package com.vimspector.test;
+
+public class TestApplication {
+  public static void main( String[] args ) {
+    for ( String s : args ) {
+      System.out.println( "Arg: " + s );
+    }
+  }
+}
+
+