[Lldb-commits] [lldb] Add the ability to define a Python based command that uses CommandObjectParsed (PR #70734)

[David Spickett via lldb-commits]

================
@@ -0,0 +1,313 @@
+"""
+This module implements a couple of utility classes to make writing
+lldb parsed commands more Pythonic.
+The way to use it is to make a class for your command that inherits from ParsedCommandBase.
+That will make an LLDBOVParser which you will use for your
+option definition, and to fetch option values for the current invocation
+of your command.  Access to the OV parser is through:
+
+ParsedCommandBase.get_parser()
+
+Next, implement setup_command_definition() in your new command class, and call:
+
+  self.get_parser().add_option()
+
+to add all your options.  The order doesn't matter for options, lldb will sort them
+alphabetically for you when it prints help.
+
+Similarly you can define the arguments with:
+
+  self.get_parser().add_argument()
+
+At present, lldb doesn't do as much work as it should verifying arguments, it
+only checks that commands that take no arguments don't get passed arguments.
+
+Then implement the execute function for your command as:
+
+    def __call__(self, debugger, args_list, exe_ctx, result):
+
+The arguments will be a list of strings.  
+
+You can access the option values using the 'dest' string you passed in when defining the option.
+
+If you need to know whether a given option was set by the user or not, you can
+use the was_set API.
+
+There are example commands in the lldb testsuite at:
+
+llvm-project/lldb/test/API/commands/command/script/add/test_commands.py
+"""
+import inspect
+import lldb
+import sys
+from abc import abstractmethod
+
+class LLDBOVParser:
+    def __init__(self):
+        # This is a dictionary of dictionaries.  The key is the long option
+        # name, and the value is the rest of the definition.
+        self.options_dict = {}
+        self.args_array = []
+
+    # Some methods to translate common value types.  Should return a
+    # tuple of the value and an error value (True => error) if the
+    # type can't be converted.
+    # FIXME: Need a way to push the conversion error string back to lldb.
+    @staticmethod
+    def to_bool(in_value):
+        error = True
+        value = False
+        if type(in_value) != str or len(in_value) == 0:
+            return (value, error)
+
+        low_in = in_value.lower()
+        if low_in == "y" or low_in == "yes" or low_in == "t" or low_in == "true" or low_in == "1":
+            value = True
+            error = False
+            
+        if not value and low_in == "n" or low_in == "no" or low_in == "f" or low_in == "false" or low_in == "0":
+            value = False
+            error = False
+
+        return (value, error)
+
+    @staticmethod
+    def to_int(in_value):
+        #FIXME: Not doing errors yet...
+        return (int(in_value), False)
+
+    @staticmethod
+    def to_unsigned(in_value):
+        # FIXME: find an unsigned converter...
+        # And handle errors.
+        return (int(in_value), False)
+
+    translators = {
+        lldb.eArgTypeBoolean : to_bool,
+        lldb.eArgTypeBreakpointID : to_unsigned,
+        lldb.eArgTypeByteSize : to_unsigned,
+        lldb.eArgTypeCount : to_unsigned,
+        lldb.eArgTypeFrameIndex : to_unsigned,
+        lldb.eArgTypeIndex : to_unsigned,
+        lldb.eArgTypeLineNum : to_unsigned,
+        lldb.eArgTypeNumLines : to_unsigned,
+        lldb.eArgTypeNumberPerLine : to_unsigned,
+        lldb.eArgTypeOffset : to_int,
+        lldb.eArgTypeThreadIndex : to_unsigned,
+        lldb.eArgTypeUnsignedInteger : to_unsigned,
+        lldb.eArgTypeWatchpointID : to_unsigned,
+        lldb.eArgTypeColumnNum : to_unsigned,
+        lldb.eArgTypeRecognizerID : to_unsigned,
+        lldb.eArgTypeTargetID : to_unsigned,
+        lldb.eArgTypeStopHookID : to_unsigned
+    }
+
+    @classmethod
+    def translate_value(cls, value_type, value):
+        try:
+            return cls.translators[value_type](value)
+        except KeyError:
+            # If we don't have a translator, return the string value.
+            return (value, False)
+
+    # FIXME: would this be better done on the C++ side?
+    # The common completers are missing some useful ones.
+    # For instance there really should be a common Type completer
+    # And an "lldb command name" completer.
+    completion_table = {
+        lldb.eArgTypeAddressOrExpression : lldb.eVariablePathCompletion,
+        lldb.eArgTypeArchitecture : lldb.eArchitectureCompletion,
+        lldb.eArgTypeBreakpointID : lldb.eBreakpointCompletion,
+        lldb.eArgTypeBreakpointIDRange : lldb.eBreakpointCompletion,
+        lldb.eArgTypeBreakpointName : lldb.eBreakpointNameCompletion,
+        lldb.eArgTypeClassName : lldb.eSymbolCompletion,
+        lldb.eArgTypeDirectoryName : lldb.eDiskDirectoryCompletion,
+        lldb.eArgTypeExpression : lldb.eVariablePathCompletion,
+        lldb.eArgTypeExpressionPath : lldb.eVariablePathCompletion,
+        lldb.eArgTypeFilename : lldb.eDiskFileCompletion,
+        lldb.eArgTypeFrameIndex : lldb.eFrameIndexCompletion,
+        lldb.eArgTypeFunctionName : lldb.eSymbolCompletion,
+        lldb.eArgTypeFunctionOrSymbol : lldb.eSymbolCompletion,
+        lldb.eArgTypeLanguage : lldb.eTypeLanguageCompletion,
+        lldb.eArgTypePath : lldb.eDiskFileCompletion,
+        lldb.eArgTypePid : lldb.eProcessIDCompletion,
+        lldb.eArgTypeProcessName : lldb.eProcessNameCompletion,
+        lldb.eArgTypeRegisterName : lldb.eRegisterCompletion,
+        lldb.eArgTypeRunArgs : lldb.eDiskFileCompletion,
+        lldb.eArgTypeShlibName : lldb.eModuleCompletion,
+        lldb.eArgTypeSourceFile : lldb.eSourceFileCompletion,
+        lldb.eArgTypeSymbol : lldb.eSymbolCompletion,
+        lldb.eArgTypeThreadIndex : lldb.eThreadIndexCompletion,
+        lldb.eArgTypeVarName : lldb.eVariablePathCompletion,
+        lldb.eArgTypePlatform : lldb.ePlatformPluginCompletion,
+        lldb.eArgTypeWatchpointID : lldb.eWatchpointIDCompletion,
+        lldb.eArgTypeWatchpointIDRange : lldb.eWatchpointIDCompletion,
+        lldb.eArgTypeModuleUUID : lldb.eModuleUUIDCompletion,
+        lldb.eArgTypeStopHookID : lldb.eStopHookIDCompletion
+    }
+
+    @classmethod
+    def determine_completion(cls, arg_type):
+        try:
+            return cls.completion_table[arg_type]
+        except KeyError:
+            return lldb.eNoCompletion
+
+    def get_option_element(self, long_name):
+        # Fixme: Is it worth making a long_option dict holding the rest of
+        # the options dict so this lookup is faster?
+        return self.options_dict.get(long_name, None)
+            
+    def option_parsing_started(self):
+        # This makes the ivars for all the "dest" values in the array and gives them
+        # their default values.
+        for key, elem in self.options_dict.items():
+            elem['_value_set'] = False
+            try:
+                object.__setattr__(self, elem["dest"], elem["default"])
+            except AttributeError:
+            # It isn't an error not to have a target, you'll just have to set and
+            # get this option value on your own.
+                continue
+
+    def set_enum_value(self, enum_values, input):
+        candidates = []
+        for candidate in enum_values:
+            # The enum_values are a two element list of value & help string.
+            value = candidate[0]
+            if value.startswith(input):
+                candidates.append(value)
+
+        if len(candidates) == 1:
+            return (candidates[0], False)
+        else:
+            return (input, True)
+        
+    def set_option_value(self, exe_ctx, opt_name, opt_value):
+        elem = self.get_option_element(opt_name)
+        if not elem:
+            return False
+        
+        if "enum_values" in elem:
+            (value, error) = self.set_enum_value(elem["enum_values"], opt_value)
+        else:
+            (value, error)  = __class__.translate_value(elem["value_type"], opt_value)
+
+        if not error:
+            object.__setattr__(self, elem["dest"], value)
+            elem["_value_set"] = True
+            return True
+        return False
----------------
DavidSpickett wrote:

```
if error:
  return False

object.__setattr__(self, elem["dest"], value)
elem["_value_set"] = True
return True
```
Seems simpler to me.

https://github.com/llvm/llvm-project/pull/70734