[Lldb-commits] [lldb] Add the ability to define custom completers to the parsed_cmd template. (PR #109062)

[via lldb-commits]

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@@ -587,8 +587,150 @@ say
 SBCommandReturnObject and SBStream both support this file-like behavior by
 providing write() and flush() calls at the Python layer.
 
+The commands that are added using this Class definition are what lldb calls
+"raw" commands.  The command interpreter doesn't attempt to parse the command,
+doesn't handle option values, neither generating help for them, or their
+completion.  Raw commands are useful when the arguments passed to the command
+are unstructured, and having to protect them against lldb command parsing would
+be onerous.  For instance, "expr" is a raw command.
+
+You can also add scripted commands that implement the "parsed command", where
+the options and their types are specified, as well as the argument and argument
+types.  These commands look and act like the majority of lldb commands, and you
+can also add custom completions for the options and/or the arguments if you have
+special needs.
+
+The easiest way to do this is to derive your new command from the lldb.ParsedCommand
+class.  That responds in the same way to the help & repeat command interfaces, and
+provides some convenience methods, and most importantly an LLDBOptionValueParser,
+accessed throught lldb.ParsedCommand.get_parser().  The parser is used to set
+your command definitions, and to retrieve option values in the __call__ method.
+
+To set the command definition, implement the ParsedCommand abstract method:
+
+::
+
+   def setup_command_definition(self):
+
+This is called when your command is added to lldb.  In this method you add the
+options and their types, the option help strings, etc. to the command using the API:
+
+::
+
+    def add_option(self, short_option, long_option, help, default,
+                   dest = None, required=False, groups = None,
+                   value_type=lldb.eArgTypeNone, completion_type=None,
+                   enum_values=None):
+        """
+        short_option: one character, must be unique, not required
+        long_option:  no spaces, must be unique, required
+        help:         a usage string for this option, will print in the command help
+        default:      the initial value for this option (if it has a value)
+        dest:         the name of the property that gives you access to the value for
+                      this value.  Defaults to the long option if not provided.
+        required: if true, this option must be provided or the command will error out
+        groups: Which "option groups" does this option belong to.  This can either be
+                a simple list (e.g. [1, 3, 4, 5]) or you can specify ranges by sublists:
+                so [1, [3,5]] is the same as [1, 3, 4, 5].
+        value_type: one of the lldb.eArgType enum values.  Some of the common arg
+                    types also have default completers, which will be applied automatically.
+        completion_type: currently these are values form the lldb.CompletionType enum.	If
+                         you need custom completions, implement	handle_option_argument_completion.
+        enum_values: An array of duples: ["element_name", "element_help"].  If provided,
+                     only one of the enum elements is allowed.  The value will be the
+                     element_name for the chosen enum element as a string.
+        """
+
+Similarly, you can add argument types to the command:
+
+::
+
+    def make_argument_element(self, arg_type, repeat = "optional", groups = None):
+        """
+      	arg_type: The argument type, one of the	lldb.eArgType enum values.
+      	repeat:	Choose from the	following options:
+      	      	"plain"	- one value
+      	      	"optional" - zero or more values
+      	      	"plus" - one or	more values
+      	groups:	As with	add_option.
+        """
+
+Then implement the body of the command by defining:
+
+::
+
+    def __call__(self, debugger, args_array, exe_ctx, result):
+        """This is the command callback.  The option values are
+        provided by the 'dest' properties on the parser.
+
+        args_array: This is the list of arguments provided.
+        exe_ctx: Gives the SBExecutionContext on which the
+                 command should operate.
+        result:  Any results of the command should be
+                 written into this SBCommandReturnObject.
+        """
+
+This differs from the "raw" command's __call__ in that the arguments are already
+parsed into the args_array, and the option values are set in the parser, and
+can be accessed using their property name.  The LLDBOptionValueParser class has
+a couple of other handy methods:
+
+::
+    def was_set(self, long_option_name):
+
+returns True if the option was specified on the command line.
+
+::
+    def dest_for_option(self, long_option_name):
+    """
+    This will return the value of the dest variable you defined for opt_name.
+    Mostly useful for handle_completion where you get passed the long option.
+    """
+
+lldb will handle completing your option names, and all your enum values
+automatically.  If your option or argument types have associated built-in completers,
+then lldb will also handle that completion for you.  But if you have a need for
+custom completions, either in your arguments or option values, you can handle
+completion by hand as well.  To handle completion of option value arguments,
+your lldb.ParsedCommand subclass should implement:
+
+::
+    def handle_option_argument_completion(self, args, arg_pos, cursor_pos):
+    """
+    args: A list of the arguments to the command
+    arg_pos: An index into the args list of the argument with the cursor
+    cursor_pos: The cursor position in the arg specified by arg_pos
+    """
----------------
jimingham wrote:

Oops, I stopped half way through...

https://github.com/llvm/llvm-project/pull/109062