FixUp: make sure that we copy templates rather than end up updating them

This adds some templates to the gadget config, organised by "category"
(human-readable) and presented in a menu. The configuration thus created
is just run normally through the variable replacements.

Also:
- Fix default value replacements which come from the calculus
- Add default-value _lists_. This uses select-from-list UI. Useful for
  enumerated values. Allow specifying a default.

autoload/vimspector.vim

@@ -296,7 +296,7 @@ function! vimspector#GetConfigurations() abort
     return
   endif
   let configurations = py3eval(
-        \ 'list( _vimspector_session.GetConfigurations( {} )[ 1 ].keys() )'
+        \ 'list( _vimspector_session.GetConfigurations().keys() )'
         \ . ' if _vimspector_session else []' )
   return configurations
 endfunction

python3/vimspector/debug_session.py

@@ -13,7 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import glob
 import json
 import logging
 import os
@@ -32,15 +31,11 @@ from vimspector import ( breakpoints,
                          variables,
                          settings,
                          terminal,
-                         installer )
-from vimspector.vendor.json_minify import minify
+                         launch )
 
 # We cache this once, and don't allow it to change (FIXME?)
 VIMSPECTOR_HOME = utils.GetVimspectorBase()
 
-# cache of what the user entered for any option we ask them
-USER_CHOICES = {}
-
 
 class DebugSession( object ):
   def __init__( self, api_prefix ):
@@ -80,24 +75,11 @@ class DebugSession( object ):
     self._server_capabilities = {}
     self.ClearTemporaryBreakpoints()
 
-  def GetConfigurations( self, adapters ):
+  def GetConfigurations( self ):
     current_file = utils.GetBufferFilepath( vim.current.buffer )
     filetypes = utils.GetBufferFiletypes( vim.current.buffer )
-    configurations = {}
+    return launch.GetConfigurations( {}, current_file, filetypes )[ 1 ]
 
-    for launch_config_file in PathsToAllConfigFiles( VIMSPECTOR_HOME,
-                                                     current_file,
-                                                     filetypes ):
-      self._logger.debug( f'Reading configurations from: {launch_config_file}' )
-      if not launch_config_file or not os.path.exists( launch_config_file ):
-        continue
-
-      with open( launch_config_file, 'r' ) as f:
-        database = json.loads( minify( f.read() ) )
-        configurations.update( database.get( 'configurations' ) or {} )
-        adapters.update( database.get( 'adapters' ) or {} )
-
-    return launch_config_file, configurations
 
   def Start( self, launch_variables = None ):
     # We mutate launch_variables, so don't mutate the default argument.
@@ -112,161 +94,48 @@ class DebugSession( object ):
     self._launch_config = None
 
     current_file = utils.GetBufferFilepath( vim.current.buffer )
-    adapters = {}
-    launch_config_file, configurations = self.GetConfigurations( adapters )
-
-    if not configurations:
-      utils.UserMessage( 'Unable to find any debug configurations. '
-                         'You need to tell vimspector how to launch your '
-                         'application.' )
-      return
-
-    glob.glob( install.GetGadgetDir( VIMSPECTOR_HOME ) )
-    for gadget_config_file in PathsToAllGadgetConfigs( VIMSPECTOR_HOME,
-                                                       current_file ):
-      self._logger.debug( f'Reading gadget config: {gadget_config_file}' )
-      if not gadget_config_file or not os.path.exists( gadget_config_file ):
-        continue
-
-      with open( gadget_config_file, 'r' ) as f:
-        a =  json.loads( minify( f.read() ) ).get( 'adapters' ) or {}
-        adapters.update( a )
-
-    if 'configuration' in launch_variables:
-      configuration_name = launch_variables.pop( 'configuration' )
-    elif ( len( configurations ) == 1 and
-           next( iter( configurations.values() ) ).get( "autoselect", True ) ):
-      configuration_name = next( iter( configurations.keys() ) )
-    else:
-      # Find a single configuration with 'default' True and autoselect not False
-      defaults = { n: c for n, c in configurations.items()
-                   if c.get( 'default', False ) is True
-                   and c.get( 'autoselect', True ) is not False }
-
-      if len( defaults ) == 1:
-        configuration_name = next( iter( defaults.keys() ) )
-      else:
-        configuration_name = utils.SelectFromList(
-          'Which launch configuration?',
-          sorted( configurations.keys() ) )
-
-    if not configuration_name or configuration_name not in configurations:
-      return
+    filetypes = utils.GetBufferFiletypes( vim.current.buffer )
+    adapters = launch.GetAdapters( current_file )
+    launch_config_file, configurations = launch.GetConfigurations( adapters,
+                                                                   current_file,
+                                                                   filetypes )
 
     if launch_config_file:
       self._workspace_root = os.path.dirname( launch_config_file )
     else:
       self._workspace_root = os.path.dirname( current_file )
 
-    configuration = configurations[ configuration_name ]
-    adapter = configuration.get( 'adapter' )
-    if isinstance( adapter, str ):
-      adapter_dict = adapters.get( adapter )
 
-      if adapter_dict is None:
-        suggested_gadgets = installer.FindGadgetForAdapter( adapter )
-        if suggested_gadgets:
-          response = utils.AskForInput(
-            f"The specified adapter '{adapter}' is not "
-            "installed. Would you like to install the following gadgets? ",
-            ' '.join( suggested_gadgets ) )
-          if response:
-            new_launch_variables = dict( launch_variables )
-            new_launch_variables[ 'configuration' ] = configuration_name
+    if not configurations:
+      configuration_name, configuration = launch.SuggestConfiguration(
+        current_file,
+        filetypes )
+    else:
+      configuration_name, configuration = launch.SelectConfiguration(
+        launch_variables,
+        configurations )
 
-            installer.RunInstaller(
-              self._api_prefix,
-              False, # Don't leave open
-              *shlex.split( response ),
-              then = lambda: self.Start( new_launch_variables ) )
-            return
-          elif response is None:
-            return
+    if not configuration:
+      utils.UserMessage( 'Unable to find any debug configurations. '
+                         'You need to tell vimspector how to launch your '
+                         'application.' )
+      return
 
-        utils.UserMessage( f"The specified adapter '{adapter}' is not "
-                           "available. Did you forget to run "
-                           "'install_gadget.py'?",
-                           persist = True,
-                           error = True )
-        return
-
-      adapter = adapter_dict
-
-    # Additional vars as defined by VSCode:
-    #
-    # ${workspaceFolder} - the path of the folder opened in VS Code
-    # ${workspaceFolderBasename} - the name of the folder opened in VS Code
-    #                              without any slashes (/)
-    # ${file} - the current opened file
-    # ${relativeFile} - the current opened file relative to workspaceFolder
-    # ${fileBasename} - the current opened file's basename
-    # ${fileBasenameNoExtension} - the current opened file's basename with no
-    #                              file extension
-    # ${fileDirname} - the current opened file's dirname
-    # ${fileExtname} - the current opened file's extension
-    # ${cwd} - the task runner's current working directory on startup
-    # ${lineNumber} - the current selected line number in the active file
-    # ${selectedText} - the current selected text in the active file
-    # ${execPath} - the path to the running VS Code executable
-
-    def relpath( p, relative_to ):
-      if not p:
-        return ''
-      return os.path.relpath( p, relative_to )
-
-    def splitext( p ):
-      if not p:
-        return [ '', '' ]
-      return os.path.splitext( p )
-
-    variables = {
-      'dollar': '$', # HACK. Hote '$$' also works.
-      'workspaceRoot': self._workspace_root,
-      'workspaceFolder': self._workspace_root,
-      'gadgetDir': install.GetGadgetDir( VIMSPECTOR_HOME ),
-      'file': current_file,
-    }
-
-    calculus = {
-      'relativeFile': lambda: relpath( current_file,
-                                       self._workspace_root ),
-      'fileBasename': lambda: os.path.basename( current_file ),
-      'fileBasenameNoExtension':
-        lambda: splitext( os.path.basename( current_file ) )[ 0 ],
-      'fileDirname': lambda: os.path.dirname( current_file ),
-      'fileExtname': lambda: splitext( os.path.basename( current_file ) )[ 1 ],
-      # NOTE: this is the window-local cwd for the current window, *not* Vim's
-      # working directory.
-      'cwd': os.getcwd,
-      'unusedLocalPort': utils.GetUnusedLocalPort,
-    }
-
-    # Pretend that vars passed to the launch command were typed in by the user
-    # (they may have been in theory)
-    USER_CHOICES.update( launch_variables )
-    variables.update( launch_variables )
+    adapter = launch.SelectAdapter( self._api_prefix,
+                                    self,
+                                    configuration_name,
+                                    configuration,
+                                    adapters,
+                                    launch_variables )
+    if not adapter:
+      return
 
     try:
-      variables.update(
-        utils.ParseVariables( adapter.get( 'variables', {} ),
-                              variables,
-                              calculus,
-                              USER_CHOICES ) )
-      variables.update(
-        utils.ParseVariables( configuration.get( 'variables', {} ),
-                              variables,
-                              calculus,
-                              USER_CHOICES ) )
-
-
-      utils.ExpandReferencesInDict( configuration,
-                                    variables,
-                                    calculus,
-                                    USER_CHOICES )
-      utils.ExpandReferencesInDict( adapter,
-                                    variables,
-                                    calculus,
-                                    USER_CHOICES )
+      launch.ResolveConfiguration( adapter,
+                                   configuration,
+                                   launch_variables,
+                                   self._workspace_root,
+                                   current_file )
     except KeyboardInterrupt:
       self._Reset()
       return
@@ -398,6 +267,9 @@ class DebugSession( object ):
 
   def _Reset( self ):
     self._logger.info( "Debugging complete." )
+
+    launch.SaveConfiguration( self._configuration )
+
     if self._uiTab:
       self._logger.debug( "Clearing down UI" )
 
@@ -1277,29 +1149,3 @@ class DebugSession( object ):
 
   def AddFunctionBreakpoint( self, function, options ):
     return self._breakpoints.AddFunctionBreakpoint( function, options )
-
-
-def PathsToAllGadgetConfigs( vimspector_base, current_file ):
-  yield install.GetGadgetConfigFile( vimspector_base )
-  for p in sorted( glob.glob(
-    os.path.join( install.GetGadgetConfigDir( vimspector_base ),
-                  '*.json' ) ) ):
-    yield p
-
-  yield utils.PathToConfigFile( '.gadgets.json',
-                                os.path.dirname( current_file ) )
-
-
-def PathsToAllConfigFiles( vimspector_base, current_file, filetypes ):
-  for ft in filetypes + [ '_all' ]:
-    for p in sorted( glob.glob(
-      os.path.join( install.GetConfigDirForFiletype( vimspector_base, ft ),
-                    '*.json' ) ) ):
-      yield p
-
-  for ft in filetypes:
-    yield utils.PathToConfigFile( f'.vimspector.{ft}.json',
-                                  os.path.dirname( current_file ) )
-
-  yield utils.PathToConfigFile( '.vimspector.json',
-                                os.path.dirname( current_file ) )

python3/vimspector/gadgets.py

@@ -49,6 +49,40 @@ GADGETS = {
           }
         },
       },
+      'templates': [
+        {
+          'description': 'gdb/lldb local debugging with vscode-cpptools',
+          'filetypes': ( 'c', 'cpp', 'objc', 'rust' ),
+          'configurations': [
+            {
+              'description': 'Launch local process',
+              'launch_configuration': {
+                'adapter': 'vscode-cpptools',
+                'configuration': {
+                  'request': 'launch',
+                  'program': '${Binary:${fileBasenameNoExtension\\}}',
+                  'args': [ '*${CommandLineArguments}' ],
+                  'cwd': '${WorkingDir:${fileDirname\\}}',
+                  'externalConsole#json': '${UseExternalConsole:true\nfalse}',
+                  'stopAtEntry#json': '${StopAtEntry:true\nfalse}',
+                  'MIMode': '${Debugger:gdb\nlldb}',
+                }
+              }
+            },
+            {
+              'description': 'Attach to local process by PID',
+              'launch_configuration': {
+                'adapter': 'vscode-cpptools',
+                'configuration': {
+                  'request': 'attach',
+                  'program': '${Binary:${fileBasenameNoExtension\\}}',
+                  'MIMode': '${Debugger:gdb\nlldb}',
+                }
+              }
+            }
+          ]
+        }
+      ]
     },
     'linux': {
       'file_name': 'cpptools-linux.vsix',
@@ -452,6 +486,42 @@ GADGETS = {
     },
     'all': {
       'version': 'v1.5.3',
+      'templates': [
+        {
+          'description': 'LLDB local debugging with CodeLLDB',
+          'filetypes': ( 'c', 'cpp', 'objc', 'rust' ),
+          'configurations': [
+            {
+              'description': 'Launch local process',
+              'launch_configuration': {
+                'adapter': 'CodeLLDB',
+                'configuration': {
+                  'request': 'launch',
+                  'program': '${Binary:${fileBasenameNoExtension\\}}',
+                  'args': [ '*${CommandLineArguments}' ],
+                  'cwd': '${WorkingDir:${fileDirname\\}}',
+                  'terminal': '${Console:integrated\nexternal}',
+                  'stopOnEntry#json': '${StopOnEntry:true\nfalse}',
+                  'expressions': '${ExpressionType:native\nsimple\npython}'
+                }
+              }
+            },
+            {
+              'description': 'Attach to local process by PID',
+              'launch_configuration': {
+                'adapter': 'CodeLLDB',
+                'configuration': {
+                  'request': 'attach',
+                  'program': '${Binary:${fileBasenameNoExtension\\}}',
+                  'pid#json': "${pid}",
+                  'stopOnEntry#json': '${StopOnEntry:true\nfalse}',
+                  'expressions': '${ExpressionType:native\nsimple\npython}'
+                }
+              }
+            }
+          ]
+        }
+      ]
     },
     'macos': {
       'file_name': 'codelldb-x86_64-darwin.vsix',
@@ -486,6 +556,7 @@ GADGETS = {
         'name': 'CodeLLDB',
         'type': 'CodeLLDB',
         "command": [
+          # FIXME: This probably doesn't work on windows.
           "${gadgetDir}/CodeLLDB/adapter/codelldb",
           "--port", "${unusedLocalPort}"
         ],

python3/vimspector/launch.py

@@ -0,0 +1,335 @@
+# vimspector - A multi-language debugging system for Vim
+# Copyright 2020 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.
+
+import os
+import logging
+import json
+import glob
+import shlex
+import copy
+
+from vimspector import install, installer, utils, gadgets
+from vimspector.vendor.json_minify import minify
+
+_logger = logging.getLogger( __name__ )
+utils.SetUpLogging( _logger )
+
+# We cache this once, and don't allow it to change (FIXME?)
+VIMSPECTOR_HOME = utils.GetVimspectorBase()
+
+# cache of what the user entered for any option we ask them
+USER_CHOICES = {}
+
+
+
+def GetAdapters( current_file ):
+  adapters = {}
+  for gadget_config_file in PathsToAllGadgetConfigs( VIMSPECTOR_HOME,
+                                                     current_file ):
+    _logger.debug( f'Reading gadget config: {gadget_config_file}' )
+    if not gadget_config_file or not os.path.exists( gadget_config_file ):
+      continue
+
+    with open( gadget_config_file, 'r' ) as f:
+      a =  json.loads( minify( f.read() ) ).get( 'adapters' ) or {}
+      adapters.update( a )
+
+  return adapters
+
+
+def PathsToAllGadgetConfigs( vimspector_base, current_file ):
+  yield install.GetGadgetConfigFile( vimspector_base )
+  for p in sorted( glob.glob(
+    os.path.join( install.GetGadgetConfigDir( vimspector_base ),
+                  '*.json' ) ) ):
+    yield p
+
+  yield utils.PathToConfigFile( '.gadgets.json',
+                                os.path.dirname( current_file ) )
+
+
+def GetConfigurations( adapters, current_file, filetypes ):
+  configurations = {}
+  for launch_config_file in PathsToAllConfigFiles( VIMSPECTOR_HOME,
+                                                   current_file,
+                                                   filetypes ):
+    _logger.debug( f'Reading configurations from: {launch_config_file}' )
+    if not launch_config_file or not os.path.exists( launch_config_file ):
+      continue
+
+    with open( launch_config_file, 'r' ) as f:
+      database = json.loads( minify( f.read() ) )
+      configurations.update( database.get( 'configurations' ) or {} )
+      adapters.update( database.get( 'adapters' ) or {} )
+
+  # We return the last config file inspected which is the most specific one
+  # (i.e. the project-local one)
+  return launch_config_file, configurations
+
+
+def PathsToAllConfigFiles( vimspector_base, current_file, filetypes ):
+  for ft in filetypes + [ '_all' ]:
+    for p in sorted( glob.glob(
+      os.path.join( install.GetConfigDirForFiletype( vimspector_base, ft ),
+                    '*.json' ) ) ):
+      yield p
+
+  for ft in filetypes:
+    yield utils.PathToConfigFile( f'.vimspector.{ft}.json',
+                                  os.path.dirname( current_file ) )
+
+  yield utils.PathToConfigFile( '.vimspector.json',
+                                os.path.dirname( current_file ) )
+
+
+def SelectConfiguration( launch_variables, configurations ):
+  if 'configuration' in launch_variables:
+    configuration_name = launch_variables.pop( 'configuration' )
+  elif ( len( configurations ) == 1 and
+         next( iter( configurations.values() ) ).get( "autoselect", True ) ):
+    configuration_name = next( iter( configurations.keys() ) )
+  else:
+    # Find a single configuration with 'default' True and autoselect not False
+    defaults = { n: c for n, c in configurations.items()
+                 if c.get( 'default', False ) is True
+                 and c.get( 'autoselect', True ) is not False }
+
+    if len( defaults ) == 1:
+      configuration_name = next( iter( defaults.keys() ) )
+    else:
+      configuration_name = utils.SelectFromList(
+        'Which launch configuration?',
+        sorted( configurations.keys() ) )
+
+  if not configuration_name or configuration_name not in configurations:
+    return None, None
+
+  configuration = configurations[ configuration_name ]
+
+  return configuration_name, configuration
+
+
+def SuggestConfiguration( current_file, filetypes ):
+  nothing = None, None
+  templates = []
+  filetypes = set( filetypes )
+
+  for gadget_name, gadget in gadgets.GADGETS.items():
+    spec = {}
+    spec.update( gadget.get( 'all', {} ) )
+    spec.update( gadget.get( install.GetOS(), {} ) )
+
+    for template in spec.get( 'templates', [] ):
+      if filetypes.intersection( template.get( 'filetypes', set() ) ):
+        # We _must_ copy the template as we end up taking bits out of it to
+        # assign to the resulting config. Python... references... mutabiliy..
+        # fun.
+        templates.append( copy.deepcopy( template ) )
+
+  if not templates:
+    return nothing
+
+  template_idx = utils.SelectFromList(
+    'No debug configurations were found for this project, '
+    'Would you like to use one of the following templates?',
+    [ t[ 'description' ] for t in templates ],
+    ret = 'index' )
+
+  if template_idx is None:
+    return nothing
+
+  template = templates[ template_idx ]
+
+  config_index = utils.SelectFromList(
+    'Which configuration?',
+    [ c[ 'description' ] for c in template[ 'configurations' ] ],
+    ret = 'index' )
+
+  if config_index is None:
+    return nothing
+
+  configuration = template[ 'configurations' ][ config_index ]
+  configuration_name = utils.AskForInput( 'Give the config a name: ',
+                                          configuration[ 'description' ] )
+
+  configuration[ 'launch_configuration' ][ 'generated' ] = {
+    'name': configuration_name,
+    'path': os.path.join( os.path.dirname( current_file ), '.vimspector.json' ),
+  }
+
+  return configuration_name, configuration[ 'launch_configuration' ]
+
+
+def SaveConfiguration( configuration ):
+  gen = configuration.pop( 'generated', None )
+  if not gen:
+    return
+
+  if utils.Confirm(
+    f'Would you like to save the configuration named "{ gen[ "name" ] }"',
+    '&Yes\n&No' ) != 1:
+    return
+
+  config_path = utils.AskForInput( 'Enter the path to save to: ',
+                                   gen[ 'path' ] )
+
+  if not config_path:
+    return
+
+  os.makedirs( os.path.dirname( config_path ), exist_ok = True )
+  current_contents = {}
+
+  if os.path.exists( config_path ):
+    if utils.Confirm( 'File exists, merge with this configuration?\n'
+                      '(NOTE: comments and formatting in the existing file '
+                      'will be LOST!!)',
+                      '&Yes\n&No' ) != 1:
+      return
+
+    with open( config_path, 'r' ) as f:
+      current_contents = json.loads( minify( f.read() ) )
+
+  # TODO: how much of configuration is mangled at this point ?
+  # TODO: how about the defaulted arguments? All the refs are replaced at this
+  # point?
+  current_contents.setdefault( 'configurations', {} )
+  current_contents[ 'configurations' ][ gen[ 'name' ] ] = configuration
+
+  with open( config_path, 'w' ) as f:
+    json.dump( current_contents, f, indent=2 )
+
+  utils.UserMessage( f'Wrote { config_path }', persist = True )
+
+
+def SelectAdapter( api_prefix,
+                   debug_session,
+                   configuration_name,
+                   configuration,
+                   adapters,
+                   launch_variables ):
+  adapter = configuration.get( 'adapter' )
+
+  if isinstance( adapter, str ):
+    adapter_dict = adapters.get( adapter )
+
+    if adapter_dict is None:
+      suggested_gadgets = installer.FindGadgetForAdapter( adapter )
+      if suggested_gadgets:
+        response = utils.AskForInput(
+          f"The specified adapter '{adapter}' is not "
+           "installed. Would you like to install the following gadgets? ",
+          ' '.join( suggested_gadgets ) )
+        if response:
+          new_launch_variables = dict( launch_variables )
+          new_launch_variables[ 'configuration' ] = configuration_name
+
+          installer.RunInstaller(
+            api_prefix,
+            False, # Don't leave open
+            *shlex.split( response ),
+            then = debug_session.Start( new_launch_variables ) )
+          return None
+        elif response is None:
+          return None
+
+      utils.UserMessage( f"The specified adapter '{adapter}' is not "
+                         "available. Did you forget to run "
+                         "'install_gadget.py'?",
+                         persist = True,
+                         error = True )
+      return None
+
+    adapter = adapter_dict
+
+  return adapter
+
+
+def ResolveConfiguration( adapter,
+                          configuration,
+                          launch_variables,
+                          workspace_root,
+                          current_file ):
+  # Additional vars as defined by VSCode:
+  #
+  # ${workspaceFolder} - the path of the folder opened in VS Code
+  # ${workspaceFolderBasename} - the name of the folder opened in VS Code
+  #                              without any slashes (/)
+  # ${file} - the current opened file
+  # ${relativeFile} - the current opened file relative to workspaceFolder
+  # ${fileBasename} - the current opened file's basename
+  # ${fileBasenameNoExtension} - the current opened file's basename with no
+  #                              file extension
+  # ${fileDirname} - the current opened file's dirname
+  # ${fileExtname} - the current opened file's extension
+  # ${cwd} - the task runner's current working directory on startup
+  # ${lineNumber} - the current selected line number in the active file
+  # ${selectedText} - the current selected text in the active file
+  # ${execPath} - the path to the running VS Code executable
+  def relpath( p, relative_to ):
+    if not p:
+      return ''
+    return os.path.relpath( p, relative_to )
+
+  def splitext( p ):
+    if not p:
+      return [ '', '' ]
+    return os.path.splitext( p )
+
+  variables = {
+    'dollar': '$', # HACK. Hote '$$' also works.
+    'workspaceRoot': workspace_root,
+    'workspaceFolder': workspace_root,
+    'gadgetDir': install.GetGadgetDir( VIMSPECTOR_HOME ),
+    'file': current_file,
+  }
+
+  calculus = {
+    'relativeFile': lambda: relpath( current_file, workspace_root ),
+    'fileBasename': lambda: os.path.basename( current_file ),
+    'fileBasenameNoExtension':
+      lambda: splitext( os.path.basename( current_file ) )[ 0 ],
+    'fileDirname': lambda: os.path.dirname( current_file ),
+    'fileExtname': lambda: splitext( os.path.basename( current_file ) )[ 1 ],
+    # NOTE: this is the window-local cwd for the current window, *not* Vim's
+    # working directory.
+    'cwd': os.getcwd,
+    'unusedLocalPort': utils.GetUnusedLocalPort,
+  }
+
+  # Pretend that vars passed to the launch command were typed in by the user
+  # (they may have been in theory)
+  USER_CHOICES.update( launch_variables )
+  variables.update( launch_variables )
+
+  variables.update(
+    utils.ParseVariables( adapter.get( 'variables', {} ),
+                          variables,
+                          calculus,
+                          USER_CHOICES ) )
+  variables.update(
+    utils.ParseVariables( configuration.get( 'variables', {} ),
+                          variables,
+                          calculus,
+                          USER_CHOICES ) )
+
+
+  utils.ExpandReferencesInDict( configuration,
+                                variables,
+                                calculus,
+                                USER_CHOICES )
+  utils.ExpandReferencesInDict( adapter,
+                                variables,
+                                calculus,
+                                USER_CHOICES )

python3/vimspector/utils.py

@@ -333,25 +333,41 @@ def UserMessage( msg, persist=False, error=False ):
 
 
 @contextlib.contextmanager
-def InputSave():
+def AskingForUserInput():
   vim.eval( 'inputsave()' )
   try:
     yield
   finally:
     vim.eval( 'inputrestore()' )
+    # Clear the command line so that subsequent
+    vim.command( 'redraw' )
 
 
-def SelectFromList( prompt, options ):
-  with InputSave():
+def SelectFromList( prompt,
+                    options,
+                    ret = 'text',
+                    default_index = None ):
+  with AskingForUserInput():
     display_options = [ prompt ]
-    display_options.extend( [ '{0}: {1}'.format( i + 1, v )
-                              for i, v in enumerate( options ) ] )
+    display_options.extend( [
+      '{0}{1}: {2}'.format( '*' if i == default_index else ' ',
+                            i + 1,
+                            v )
+      for i, v in enumerate( options )
+    ] )
     try:
       selection = int( vim.eval(
         'inputlist( ' + json.dumps( display_options ) + ' )' ) ) - 1
       if selection < 0 or selection >= len( options ):
-        return None
-      return options[ selection ]
+        if default_index is not None:
+          selection = default_index
+        else:
+          return None
+
+      if ret == 'text':
+        return options[ selection ]
+      else:
+        return selection
     except ( KeyboardInterrupt, vim.error ):
       return None
 
@@ -362,7 +378,7 @@ def AskForInput( prompt, default_value = None ):
   else:
     default_option = ", '{}'".format( Escape( default_value ) )
 
-  with InputSave():
+  with AskingForUserInput():
     try:
       return vim.eval( "input( '{}' {} )".format( Escape( prompt ),
                                                   default_option ) )
@@ -370,6 +386,14 @@ def AskForInput( prompt, default_value = None ):
       return None
 
 
+def Confirm( msg, *args ):
+  with AskingForUserInput():
+    try:
+      return int( Call( 'confirm', msg, *args ) )
+    except ( KeyboardInterrupt, vim.error ):
+      return 0
+
+
 def AppendToBuffer( buf, line_or_lines, modified=False ):
   line = 1
   try:
@@ -512,10 +536,7 @@ def ExpandReferencesInString( orig_s,
 
   # Parse any variables passed in in mapping, and ask for any that weren't,
   # storing the result in mapping
-  bug_catcher = 0
-  while bug_catcher < 100:
-    ++bug_catcher
-
+  while True:
     try:
       s = _Substitute( s, mapping )
       break
@@ -531,11 +552,25 @@ def ExpandReferencesInString( orig_s,
         if default_value is None and e.default_value is not None:
           try:
             default_value = _Substitute( e.default_value, mapping )
-          except MissingSubstitution:
-            default_value = e.default_value
+          except MissingSubstitution as f:
+            if f.name in calculus:
+              default_value = calculus[ f.name ]()
+            else:
+              default_value = e.default_value
 
-        mapping[ key ] = AskForInput( 'Enter value for {}: '.format( key ),
-                                      default_value )
+        value_list = None
+        if default_value:
+          default_value_list = default_value.split( '\n' )
+          if len( default_value_list ) > 1:
+            value_list = default_value_list
+
+        if value_list:
+          mapping[ key ] = SelectFromList( f'Select value for { key }: ',
+                                           default_value_list,
+                                           default_index = 0 )
+        else:
+          mapping[ key ] = AskForInput( 'Enter value for {}: '.format( key ),
+                                        default_value )
 
         if mapping[ key ] is None:
           raise KeyboardInterrupt
@@ -570,8 +605,6 @@ def CoerceType( mapping: typing.Dict[ str, typing.Any ], key: str ):
     mapping[ key ] = DICT_TYPES[ new_type ]( value )
 
 
-# TODO: Should we just run the substitution on the whole JSON string instead?
-# That woul dallow expansion in bool and number values, such as ports etc. ?
 def ExpandReferencesInDict( obj, mapping, calculus, user_choices ):
   for k in list( obj.keys() ):
     obj[ k ] = ExpandReferencesInObject( obj[ k ],
@@ -787,6 +820,7 @@ def WindowID( window, tab=None ):
   return int( Call( 'win_getid', window.number, tab.number ) )
 
 
+@memoize
 def UseWinBar():
   # Buggy neovim doesn't render correctly when the WinBar is defined:
   # https://github.com/neovim/neovim/issues/12689