[Lldb-commits] [lldb] r335401 - Update cmdtemplate.py to use best pratices.
Jim Ingham via lldb-commits
lldb-commits at lists.llvm.org
Fri Jun 22 17:21:04 PDT 2018
> On Jun 22, 2018, at 5:20 PM, Jim Ingham <jingham at apple.com> wrote:
>
> This is very cool!
>
> Could we make a base class for lldb commands in the lldb module that provides register_lldb_command? Then you wouldn't have to copy and paste this boiler-plate in every command file. Now that you have a generic way to add the commands, we could just do that automatically in "command script import" on every class that derives from this base when we import the module, and you wouldn't need to add the __lldb_init_module either.
>
> We could also provide a table driven way to specify the options, then have the base class actually make them using opt parse. I'd like to hide this bit as much as possible, to prepare for eventually transitioning over to having the options be real lldb command options.
>
> Jim
>
>
>> On Jun 22, 2018, at 4:34 PM, Greg Clayton via lldb-commits <lldb-commits at lists.llvm.org> wrote:
>>
>> Author: gclayton
>> Date: Fri Jun 22 16:34:24 2018
>> New Revision: 335401
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=335401&view=rev
>> Log:
>> Update cmdtemplate.py to use best pratices.
>>
>> Fixes include:
>> - fix all lint errors
>> - add code that will automatically register and LLDB command classes by detecting the classes and any classes that have a "register_lldb_command" function
>> - automatically fill in the correct module name when registering commands
>> - automatically fill in the class name when registering command
>>
>>
>> Modified:
>> lldb/trunk/examples/python/cmdtemplate.py
>>
>> Modified: lldb/trunk/examples/python/cmdtemplate.py
>> URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/examples/python/cmdtemplate.py?rev=335401&r1=335400&r2=335401&view=diff
>> ==============================================================================
>> --- lldb/trunk/examples/python/cmdtemplate.py (original)
>> +++ lldb/trunk/examples/python/cmdtemplate.py Fri Jun 22 16:34:24 2018
>> @@ -1,69 +1,91 @@
>> #!/usr/bin/python
>>
>> -#----------------------------------------------------------------------
>> +# ---------------------------------------------------------------------
>> # Be sure to add the python path that points to the LLDB shared library.
>> #
>> # # To use this in the embedded python interpreter using "lldb" just
>> # import it with the full path using the "command script import"
>> # command
>> # (lldb) command script import /path/to/cmdtemplate.py
>> -#----------------------------------------------------------------------
>> +# ---------------------------------------------------------------------
>>
>> +import inspect
>> import lldb
>> -import commands
>> import optparse
>> import shlex
>> +import sys
>> +
>>
>> class FrameStatCommand:
>> - def create_options(self):
>> + program = 'framestats'
>> +
>> + @classmethod
>> + def register_lldb_command(cls, debugger, module_name):
>> + parser = cls.create_options()
>> + cls.__doc__ = parser.format_help()
>> + # Add any commands contained in this module to LLDB
>> + command = 'command script add -c %s.%s %s' % (module_name,
>> + cls.__name__,
>> + cls.program)
>> + debugger.HandleCommand(command)
>> + print('The "{0}" command has been installed, type "help {0}" or "{0} '
>> + '--help" for detailed help.'.format(cls.program))
>> +
>> + @classmethod
>> + def create_options(cls):
>>
>> usage = "usage: %prog [options]"
>> - description = '''This command is meant to be an example of how to make an LLDB command that
>> -does something useful, follows best practices, and exploits the SB API.
>> -Specifically, this command computes the aggregate and average size of the variables in the current frame
>> -and allows you to tweak exactly which variables are to be accounted in the computation.
>> -'''
>> -
>> - # Pass add_help_option = False, since this keeps the command in line with lldb commands,
>> - # and we wire up "help command" to work by providing the long & short help methods below.
>> - self.parser = optparse.OptionParser(
>> - description = description,
>> - prog = 'framestats',
>> - usage = usage,
>> - add_help_option = False)
>> + description = ('This command is meant to be an example of how to make '
>> + 'an LLDB command that does something useful, follows '
>> + 'best practices, and exploits the SB API. '
>> + 'Specifically, this command computes the aggregate '
>> + 'and average size of the variables in the current '
>> + 'frame and allows you to tweak exactly which variables '
>> + 'are to be accounted in the computation.')
>> +
>> + # Pass add_help_option = False, since this keeps the command in line
>> + # with lldb commands, and we wire up "help command" to work by
>> + # providing the long & short help methods below.
>> + parser = optparse.OptionParser(
>> + description=description,
>> + prog=cls.program,
>> + usage=usage,
>> + add_help_option=False)
>>
>> - self.parser.add_option(
>> + parser.add_option(
>> '-i',
>> '--in-scope',
>> - action = 'store_true',
>> - dest = 'inscope',
>> - help = 'in_scope_only = True',
>> - default = True)
>> + action='store_true',
>> + dest='inscope',
>> + help='in_scope_only = True',
>> + default=True)
>>
>> - self.parser.add_option(
>> + parser.add_option(
>> '-a',
>> '--arguments',
>> - action = 'store_true',
>> - dest = 'arguments',
>> - help = 'arguments = True',
>> - default = True)
>> + action='store_true',
>> + dest='arguments',
>> + help='arguments = True',
>> + default=True)
>>
>> - self.parser.add_option(
>> + parser.add_option(
>> '-l',
>> '--locals',
>> - action = 'store_true',
>> - dest = 'locals',
>> - help = 'locals = True',
>> - default = True)
>> + action='store_true',
>> + dest='locals',
>> + help='locals = True',
>> + default=True)
>>
>> - self.parser.add_option(
>> + parser.add_option(
>> '-s',
>> '--statics',
>> - action = 'store_true',
>> - dest = 'statics',
>> - help = 'statics = True',
>> - default = True)
>> -
>> + action='store_true',
>> + dest='statics',
>> + help='statics = True',
>> + default=True)
>> +
>> + return parser
>> +
>> def get_short_help(self):
>> return "Example command for use in debugging"
>>
>> @@ -71,23 +93,25 @@ and allows you to tweak exactly which va
>> return self.help_string
>>
>> def __init__(self, debugger, unused):
>> - self.create_options()
>> + self.parser = self.create_options()
>> self.help_string = self.parser.format_help()
>>
>> def __call__(self, debugger, command, exe_ctx, result):
>> # Use the Shell Lexer to properly parse up command options just like a
>> # shell would
>> command_args = shlex.split(command)
>> -
>> +
>> try:
>> (options, args) = self.parser.parse_args(command_args)
>> except:
>> - # if you don't handle exceptions, passing an incorrect argument to the OptionParser will cause LLDB to exit
>> - # (courtesy of OptParse dealing with argument errors by throwing SystemExit)
>> + # if you don't handle exceptions, passing an incorrect argument to
>> + # the OptionParser will cause LLDB to exit (courtesy of OptParse
>> + # dealing with argument errors by throwing SystemExit)
>> result.SetError("option parsing failed")
>> return
>>
>> - # Always get program state from the SBExecutionContext passed in as exe_ctx
>> + # Always get program state from the lldb.SBExecutionContext passed
>> + # in as exe_ctx
>> frame = exe_ctx.GetFrame()
>> if not frame.IsValid():
>> result.SetError("invalid frame")
>> @@ -108,15 +132,16 @@ and allows you to tweak exactly which va
>> variable_type = variable.GetType()
>> total_size = total_size + variable_type.GetByteSize()
>> average_size = float(total_size) / variables_count
>> - print >>result, "Your frame has %d variables. Their total size is %d bytes. The average size is %f bytes" % (
>> - variables_count, total_size, average_size)
>> - # not returning anything is akin to returning success
>> + print >>result, ("Your frame has %d variables. Their total size "
>> + "is %d bytes. The average size is %f bytes") % (
>> + variables_count, total_size, average_size)
>> + # not returning anything is akin to returning success
>>
>>
>> def __lldb_init_module(debugger, dict):
>> - # This initializer is being run from LLDB in the embedded command interpreter
>> -
>> - # Add any commands contained in this module to LLDB
>> - debugger.HandleCommand(
>> - 'command script add -c cmdtemplate.FrameStatCommand framestats')
>> - print 'The "framestats" command has been installed, type "help framestats" for detailed help.'
>> + # Register all classes that have a register_lldb_command method
>> + for _name, cls in inspect.getmembers(sys.modules[__name__]):
>> + if inspect.isclass(cls) and callable(getattr(cls,
>> + "register_lldb_command",
>> + None)):
>> + cls.register_lldb_command(debugger, __name__)
>>
>>
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