scripts/Python/modify-python-lldb.py - lldb - Git at Google

 #
 # modify-python-lldb.py
 #
 # This script modifies the lldb module (which was automatically generated via
 # running swig) to support iteration and/or equality operations for certain lldb
 # objects, implements truth value testing for certain lldb objects, and adds a
 # global variable 'debugger_unique_id' which is initialized to 0.
 #
 # As a cleanup step, it also removes the 'residues' from the autodoc features of
 # swig.  For an example, take a look at SBTarget.h header file, where we take
 # advantage of the already existing doxygen C++-docblock and make it the Python
 # docstring for the same method.  The 'residues' in this context include the
 # '#endif', the '#ifdef SWIG', the c comment marker, the trailing blank (SPC's)
 # line, and the doxygen comment start marker.
 #
 # In addition to the 'residues' removal during the cleanup step, it also
 # transforms the 'char' data type (which was actually 'char *' but the 'autodoc'
 # feature of swig removes ' *' from it) into 'str' (as a Python str type).
 #
 # It also calls SBDebugger.Initialize() to initialize the lldb debugger
 # subsystem.
 #

 import sys, re, StringIO

 if len (sys.argv) != 2:
     output_name = "./lldb.py"
 else:
     output_name = sys.argv[1] + "/lldb.py"

 # print "output_name is '" + output_name + "'"

 #
 # Residues to be removed.
 #
 c_endif_swig = "#endif"
 c_ifdef_swig = "#ifdef SWIG"
 c_comment_marker = "//------------"
 # The pattern for recognizing the doxygen comment block line.
 doxygen_comment_start = re.compile("^\s*(/// ?)")
 # The demarcation point for turning on/off residue removal state.
 # When bracketed by the lines, the CLEANUP_DOCSTRING state (see below) is ON.
 toggle_docstring_cleanup_line = '        """'

 def char_to_str_xform(line):
     """This transforms the 'char', i.e, 'char *' to 'str', Python string."""
     line = line.replace(' char', ' str')
     line = line.replace('char ', 'str ')
     # Special case handling of 'char **argv' and 'char **envp'.
     line = line.replace('str argv', 'list argv')
     line = line.replace('str envp', 'list envp')
     return line

 #
 # The one-liner docstring also needs char_to_str transformation, btw.
 #
 TWO_SPACES = ' ' * 2
 EIGHT_SPACES = ' ' * 8
 one_liner_docstring_pattern = re.compile('^(%s|%s)""".*"""$' % (TWO_SPACES, EIGHT_SPACES))

 #
 # lldb_helpers and lldb_iter() should appear before our first SB* class definition.
 #
 lldb_helpers = '''
 # ==================================
 # Helper function for SBModule class
 # ==================================
 def in_range(symbol, section):
     """Test whether a symbol is within the range of a section."""
     symSA = symbol.GetStartAddress().GetFileAddress()
     symEA = symbol.GetEndAddress().GetFileAddress()
     secSA = section.GetFileAddress()
     secEA = secSA + section.GetByteSize()

     if symEA != LLDB_INVALID_ADDRESS:
         if secSA <= symSA and symEA <= secEA:
             return True
         else:
             return False
     else:
         if secSA <= symSA and symSA < secEA:
             return True
         else:
             return False
 '''

 lldb_iter_def = '''
 # ===================================
 # Iterator for lldb container objects
 # ===================================
 def lldb_iter(obj, getsize, getelem):
     """A generator adaptor to support iteration for lldb container objects."""
     size = getattr(obj, getsize)
     elem = getattr(obj, getelem)
     for i in range(size()):
         yield elem(i)

 # ==============================================================================
 # The modify-python-lldb.py script is responsible for post-processing this SWIG-
 # generated lldb.py module.  It is responsible for adding the above lldb_iter()
 # function definition as well as the supports, in the following, for iteration
 # protocol: __iter__, rich comparison methods: __eq__ and __ne__, truth value
 # testing (and built-in operation bool()): __nonzero__, and built-in function
 # len(): __len__.
 # ==============================================================================
 '''

 #
 # linked_list_iter() is a special purpose iterator to treat the SBValue as the
 # head of a list data structure, where you specify the child member name which
 # points to the next item on the list and you specify the end-of-list function
 # which takes an SBValue and returns True if EOL is reached and False if not.
 #
 linked_list_iter_def = '''
     def __eol_test__(val):
         """Default function for end of list test takes an SBValue object.

         Return True if val is invalid or it corresponds to a null pointer.
         Otherwise, return False.
         """
         if not val or val.GetValueAsUnsigned() == 0:
             return True
         else:
             return False

     # ==================================================
     # Iterator for lldb.SBValue treated as a linked list
     # ==================================================
     def linked_list_iter(self, next_item_name, end_of_list_test=__eol_test__):
         """Generator adaptor to support iteration for SBValue as a linked list.

         linked_list_iter() is a special purpose iterator to treat the SBValue as
         the head of a list data structure, where you specify the child member
         name which points to the next item on the list and you specify the
         end-of-list test function which takes an SBValue for an item and returns
         True if EOL is reached and False if not.

         linked_list_iter() also detects infinite loop and bails out early.

         The end_of_list_test arg, if omitted, defaults to the __eol_test__
         function above.

         For example,

         # Get Frame #0.
         ...

         # Get variable 'task_head'.
         task_head = frame0.FindVariable('task_head')
         ...

         for t in task_head.linked_list_iter('next'):
             print t
         """
         if end_of_list_test(self):
             return
         item = self
         visited = set()
         try:
             while not end_of_list_test(item) and not item.GetValueAsUnsigned() in visited:
                 visited.add(item.GetValueAsUnsigned())
                 yield item
                 # Prepare for the next iteration.
                 item = item.GetChildMemberWithName(next_item_name)
         except:
             # Exception occurred.  Stop the generator.
             pass

         return
 '''

 # This supports the iteration protocol.
 iter_def = "    def __iter__(self): return lldb_iter(self, '%s', '%s')"
 module_iter = "    def module_iter(self): return lldb_iter(self, '%s', '%s')"
 breakpoint_iter = "    def breakpoint_iter(self): return lldb_iter(self, '%s', '%s')"
 watchpoint_iter = "    def watchpoint_iter(self): return lldb_iter(self, '%s', '%s')"
 section_iter = "    def section_iter(self): return lldb_iter(self, '%s', '%s')"
 compile_unit_iter = "    def compile_unit_iter(self): return lldb_iter(self, '%s', '%s')"

 # Called to implement the built-in function len().
 # Eligible objects are those containers with unambiguous iteration support.
 len_def = "    def __len__(self): return self.%s()"

 # This supports the rich comparison methods of __eq__ and __ne__.
 eq_def = "    def __eq__(self, other): return isinstance(other, %s) and %s"
 ne_def = "    def __ne__(self, other): return not self.__eq__(other)"

 # Called to implement truth value testing and the built-in operation bool();
 # should return False or True, or their integer equivalents 0 or 1.
 # Delegate to self.IsValid() if it is defined for the current lldb object.
 nonzero_def = "    def __nonzero__(self): return self.IsValid()"

 # A convenience iterator for SBSymbol!
 symbol_in_section_iter_def = '''
     def symbol_in_section_iter(self, section):
         """Given a module and its contained section, returns an iterator on the
         symbols within the section."""
         for sym in self:
             if in_range(sym, section):
                 yield sym
 '''

 #
 # This dictionary defines a mapping from classname to (getsize, getelem) tuple.
 #
 d = { 'SBBreakpoint':  ('GetNumLocations',   'GetLocationAtIndex'),
       'SBCompileUnit': ('GetNumLineEntries', 'GetLineEntryAtIndex'),
       'SBDebugger':    ('GetNumTargets',     'GetTargetAtIndex'),
       'SBModule':      ('GetNumSymbols',     'GetSymbolAtIndex'),
       'SBProcess':     ('GetNumThreads',     'GetThreadAtIndex'),
       'SBSection':     ('GetNumSubSections', 'GetSubSectionAtIndex'),
       'SBThread':      ('GetNumFrames',      'GetFrameAtIndex'),

       'SBInstructionList':   ('GetSize', 'GetInstructionAtIndex'),
       'SBStringList':        ('GetSize', 'GetStringAtIndex',),
       'SBSymbolContextList': ('GetSize', 'GetContextAtIndex'),
       'SBTypeList':          ('GetSize', 'GetTypeAtIndex'),
       'SBValueList':         ('GetSize', 'GetValueAtIndex'),

       'SBType':  ('GetNumberChildren', 'GetChildAtIndex'),
       'SBValue': ('GetNumChildren',    'GetChildAtIndex'),

       # SBTarget needs special processing, see below.
       'SBTarget': {'module':     ('GetNumModules', 'GetModuleAtIndex'),
                    'breakpoint': ('GetNumBreakpoints', 'GetBreakpointAtIndex'),
                    'watchpoint': ('GetNumWatchpoints', 'GetWatchpointAtIndex')
                    },

       # SBModule has an additional section_iter(), see below.
       'SBModule-section': ('GetNumSections', 'GetSectionAtIndex'),
       # And compile_unit_iter().
       'SBModule-compile-unit': ('GetNumCompileUnits', 'GetCompileUnitAtIndex'),
       # As well as symbol_in_section_iter().
       'SBModule-symbol-in-section': symbol_in_section_iter_def
       }

 #
 # This dictionary defines a mapping from classname to equality method name(s).
 #
 e = { 'SBAddress':            ['GetFileAddress', 'GetModule'],
       'SBBreakpoint':         ['GetID'],
       'SBWatchpoint':         ['GetID'],
       'SBFileSpec':           ['GetFilename', 'GetDirectory'],
       'SBModule':             ['GetFileSpec', 'GetUUIDString'],
       'SBType':               ['GetByteSize', 'GetName']
       }

 def list_to_frag(list):
     """Transform a list to equality program fragment.

     For example, ['GetID'] is transformed to 'self.GetID() == other.GetID()',
     and ['GetFilename', 'GetDirectory'] to 'self.GetFilename() == other.GetFilename()
     and self.GetDirectory() == other.GetDirectory()'.
     """
     if not list:
         raise Exception("list should be non-empty")
     frag = StringIO.StringIO()
     for i in range(len(list)):
         if i > 0:
             frag.write(" and ")
         frag.write("self.{0}() == other.{0}()".format(list[i]))
     return frag.getvalue()

 class NewContent(StringIO.StringIO):
     """Simple facade to keep track of the previous line to be committed."""
     def __init__(self):
         StringIO.StringIO.__init__(self)
         self.prev_line = None
     def add_line(self, a_line):
         """Add a line to the content, if there is a previous line, commit it."""
         if self.prev_line != None:
             print >> self, self.prev_line
         self.prev_line = a_line
     def del_line(self):
         """Forget about the previous line, do not commit it."""
         self.prev_line = None
     def del_blank_line(self):
         """Forget about the previous line if it is a blank line."""
         if self.prev_line != None and not self.prev_line.strip():
             self.prev_line = None
     def finish(self):
         """Call this when you're finished with populating content."""
         if self.prev_line != None:
             print >> self, self.prev_line
         self.prev_line = None

 # The new content will have the iteration protocol defined for our lldb objects.
 new_content = NewContent()

 with open(output_name, 'r') as f_in:
     content = f_in.read()

 # The pattern for recognizing the beginning of an SB class definition.
 class_pattern = re.compile("^class (SB.*)\(_object\):$")

 # The pattern for recognizing the beginning of the __init__ method definition.
 init_pattern = re.compile("^    def __init__\(self.*\):")

 # The pattern for recognizing the beginning of the IsValid method definition.
 isvalid_pattern = re.compile("^    def IsValid\(")

 # These define the states of our finite state machine.
 NORMAL = 0
 DEFINING_ITERATOR = 1
 DEFINING_EQUALITY = 2
 CLEANUP_DOCSTRING = 4

 # The lldb_iter_def only needs to be inserted once.
 lldb_iter_defined = False;

 # Our FSM begins its life in the NORMAL state, and transitions to the
 # DEFINING_ITERATOR and/or DEFINING_EQUALITY state whenever it encounters the
 # beginning of certain class definitions, see dictionaries 'd' and 'e' above.
 #
 # Note that the two states DEFINING_ITERATOR and DEFINING_EQUALITY are
 # orthogonal in that our FSM can be in one, the other, or both states at the
 # same time.  During such time, the FSM is eagerly searching for the __init__
 # method definition in order to insert the appropriate method(s) into the lldb
 # module.
 #
 # The state CLEANUP_DOCSTRING can be entered from either the NORMAL or the
 # DEFINING_ITERATOR/EQUALITY states.  While in this state, the FSM is fixing/
 # cleaning the Python docstrings generated by the swig docstring features.
 #
 # The FSM, in all possible states, also checks the current input for IsValid()
 # definition, and inserts a __nonzero__() method definition to implement truth
 # value testing and the built-in operation bool().
 state = NORMAL
 for line in content.splitlines():
     # Handle the state transition into CLEANUP_DOCSTRING state as it is possible
     # to enter this state from either NORMAL or DEFINING_ITERATOR/EQUALITY.
     #
     # If '        """' is the sole line, prepare to transition to the
     # CLEANUP_DOCSTRING state or out of it.
     if line == toggle_docstring_cleanup_line:
         if state & CLEANUP_DOCSTRING:
             # Special handling of the trailing blank line right before the '"""'
             # end docstring marker.
             new_content.del_blank_line()
             state ^= CLEANUP_DOCSTRING
         else:
             state |= CLEANUP_DOCSTRING

     if state == NORMAL:
         match = class_pattern.search(line)
         # Inserts lldb_helpers and the lldb_iter() definition before the first
         # class definition.
         if not lldb_iter_defined and match:
             new_content.add_line(lldb_helpers)
             new_content.add_line(lldb_iter_def)
             lldb_iter_defined = True

         # If we are at the beginning of the class definitions, prepare to
         # transition to the DEFINING_ITERATOR/DEFINING_EQUALITY state for the
         # right class names.
         if match:
             cls = match.group(1)
             if cls in d:
                 # Adding support for iteration for the matched SB class.
                 state |= DEFINING_ITERATOR
             if cls in e:
                 # Adding support for eq and ne for the matched SB class.
                 state |= DEFINING_EQUALITY

     if (state & DEFINING_ITERATOR) or (state & DEFINING_EQUALITY):
         match = init_pattern.search(line)
         if match:
             # We found the beginning of the __init__ method definition.
             # This is a good spot to insert the iter and/or eq-ne support.
             #
             # But note that SBTarget has three types of iterations.
             if cls == "SBTarget":
                 new_content.add_line(module_iter % (d[cls]['module']))
                 new_content.add_line(breakpoint_iter % (d[cls]['breakpoint']))
                 new_content.add_line(watchpoint_iter % (d[cls]['watchpoint']))
             else:
                 if (state & DEFINING_ITERATOR):
                     new_content.add_line(iter_def % d[cls])
                     new_content.add_line(len_def % d[cls][0])
                 if (state & DEFINING_EQUALITY):
                     new_content.add_line(eq_def % (cls, list_to_frag(e[cls])))
                     new_content.add_line(ne_def)

             # SBModule has extra SBSection, SBCompileUnit iterators and symbol_in_section_iter()!
             if cls == "SBModule":
                 new_content.add_line(section_iter % d[cls+'-section'])
                 new_content.add_line(compile_unit_iter % d[cls+'-compile-unit'])
                 new_content.add_line(d[cls+'-symbol-in-section'])

             # This special purpose iterator is for SBValue only!!!
             if cls == "SBValue":
                 new_content.add_line(linked_list_iter_def)

             # Next state will be NORMAL.
             state = NORMAL

     if (state & CLEANUP_DOCSTRING):
         # Cleanse the lldb.py of the autodoc'ed residues.
         if c_ifdef_swig in line or c_endif_swig in line:
             continue
         # As well as the comment marker line.
         if c_comment_marker in line:
             continue

         # Also remove the '\a ' and '\b 'substrings.
         line = line.replace('\a ', '')
         line = line.replace('\b ', '')
         # And the leading '///' substring.
         doxygen_comment_match = doxygen_comment_start.match(line)
         if doxygen_comment_match:
             line = line.replace(doxygen_comment_match.group(1), '', 1)

         line = char_to_str_xform(line)

         # Note that the transition out of CLEANUP_DOCSTRING is handled at the
         # beginning of this function already.

     # This deals with one-liner docstring, for example, SBThread.GetName:
     # """GetName(self) -> char""".
     if one_liner_docstring_pattern.match(line):
         line = char_to_str_xform(line)

     # Look for 'def IsValid(*args):', and once located, add implementation
     # of truth value testing for this object by delegation.
     if isvalid_pattern.search(line):
         new_content.add_line(nonzero_def)

     # Pass the original line of content to new_content.
     new_content.add_line(line)

 # We are finished with recording new content.
 new_content.finish()

 with open(output_name, 'w') as f_out:
     f_out.write(new_content.getvalue())
     f_out.write('''debugger_unique_id = 0
 SBDebugger.Initialize()
 debugger = None
 target = SBTarget()
 process = SBProcess()
 thread = SBThread()
 frame = SBFrame()''')
	#
	# modify-python-lldb.py
	#
	# This script modifies the lldb module (which was automatically generated via
	# running swig) to support iteration and/or equality operations for certain lldb
	# objects, implements truth value testing for certain lldb objects, and adds a
	# global variable 'debugger_unique_id' which is initialized to 0.
	#
	# As a cleanup step, it also removes the 'residues' from the autodoc features of
	# swig. For an example, take a look at SBTarget.h header file, where we take
	# advantage of the already existing doxygen C++-docblock and make it the Python
	# docstring for the same method. The 'residues' in this context include the
	# '#endif', the '#ifdef SWIG', the c comment marker, the trailing blank (SPC's)
	# line, and the doxygen comment start marker.
	#
	# In addition to the 'residues' removal during the cleanup step, it also
	# transforms the 'char' data type (which was actually 'char *' but the 'autodoc'
	# feature of swig removes ' *' from it) into 'str' (as a Python str type).
	#
	# It also calls SBDebugger.Initialize() to initialize the lldb debugger
	# subsystem.
	#

	import sys, re, StringIO

	if len (sys.argv) != 2:
	output_name = "./lldb.py"
	else:
	output_name = sys.argv[1] + "/lldb.py"

	# print "output_name is '" + output_name + "'"

	#
	# Residues to be removed.
	#
	c_endif_swig = "#endif"
	c_ifdef_swig = "#ifdef SWIG"
	c_comment_marker = "//------------"
	# The pattern for recognizing the doxygen comment block line.
	doxygen_comment_start = re.compile("^\s*(/// ?)")
	# The demarcation point for turning on/off residue removal state.
	# When bracketed by the lines, the CLEANUP_DOCSTRING state (see below) is ON.
	toggle_docstring_cleanup_line = ' """'

	def char_to_str_xform(line):
	"""This transforms the 'char', i.e, 'char *' to 'str', Python string."""
	line = line.replace(' char', ' str')
	line = line.replace('char ', 'str ')
	# Special case handling of 'char argv' and 'char envp'.
	line = line.replace('str argv', 'list argv')
	line = line.replace('str envp', 'list envp')
	return line

	#
	# The one-liner docstring also needs char_to_str transformation, btw.
	#
	TWO_SPACES = ' ' * 2
	EIGHT_SPACES = ' ' * 8
	one_liner_docstring_pattern = re.compile('^(%s\|%s)""".*"""$' % (TWO_SPACES, EIGHT_SPACES))

	#
	# lldb_helpers and lldb_iter() should appear before our first SB* class definition.
	#
	lldb_helpers = '''
	# ==================================
	# Helper function for SBModule class
	# ==================================
	def in_range(symbol, section):
	"""Test whether a symbol is within the range of a section."""
	symSA = symbol.GetStartAddress().GetFileAddress()
	symEA = symbol.GetEndAddress().GetFileAddress()
	secSA = section.GetFileAddress()
	secEA = secSA + section.GetByteSize()

	if symEA != LLDB_INVALID_ADDRESS:
	if secSA <= symSA and symEA <= secEA:
	return True
	else:
	return False
	else:
	if secSA <= symSA and symSA < secEA:
	return True
	else:
	return False
	'''

	lldb_iter_def = '''
	# ===================================
	# Iterator for lldb container objects
	# ===================================
	def lldb_iter(obj, getsize, getelem):
	"""A generator adaptor to support iteration for lldb container objects."""
	size = getattr(obj, getsize)
	elem = getattr(obj, getelem)
	for i in range(size()):
	yield elem(i)

	# ==============================================================================
	# The modify-python-lldb.py script is responsible for post-processing this SWIG-
	# generated lldb.py module. It is responsible for adding the above lldb_iter()
	# function definition as well as the supports, in the following, for iteration
	# protocol: __iter__, rich comparison methods: __eq__ and __ne__, truth value
	# testing (and built-in operation bool()): __nonzero__, and built-in function
	# len(): __len__.
	# ==============================================================================
	'''

	#
	# linked_list_iter() is a special purpose iterator to treat the SBValue as the
	# head of a list data structure, where you specify the child member name which
	# points to the next item on the list and you specify the end-of-list function
	# which takes an SBValue and returns True if EOL is reached and False if not.
	#
	linked_list_iter_def = '''
	def __eol_test__(val):
	"""Default function for end of list test takes an SBValue object.

	Return True if val is invalid or it corresponds to a null pointer.
	Otherwise, return False.
	"""
	if not val or val.GetValueAsUnsigned() == 0:
	return True
	else:
	return False

	# ==================================================
	# Iterator for lldb.SBValue treated as a linked list
	# ==================================================
	def linked_list_iter(self, next_item_name, end_of_list_test=__eol_test__):
	"""Generator adaptor to support iteration for SBValue as a linked list.

	linked_list_iter() is a special purpose iterator to treat the SBValue as
	the head of a list data structure, where you specify the child member
	name which points to the next item on the list and you specify the
	end-of-list test function which takes an SBValue for an item and returns
	True if EOL is reached and False if not.

	linked_list_iter() also detects infinite loop and bails out early.

	The end_of_list_test arg, if omitted, defaults to the __eol_test__
	function above.

	For example,

	# Get Frame #0.
	...

	# Get variable 'task_head'.
	task_head = frame0.FindVariable('task_head')
	...

	for t in task_head.linked_list_iter('next'):
	print t
	"""
	if end_of_list_test(self):
	return
	item = self
	visited = set()
	try:
	while not end_of_list_test(item) and not item.GetValueAsUnsigned() in visited:
	visited.add(item.GetValueAsUnsigned())
	yield item
	# Prepare for the next iteration.
	item = item.GetChildMemberWithName(next_item_name)
	except:
	# Exception occurred. Stop the generator.
	pass

	return
	'''

	# This supports the iteration protocol.
	iter_def = " def __iter__(self): return lldb_iter(self, '%s', '%s')"
	module_iter = " def module_iter(self): return lldb_iter(self, '%s', '%s')"
	breakpoint_iter = " def breakpoint_iter(self): return lldb_iter(self, '%s', '%s')"
	watchpoint_iter = " def watchpoint_iter(self): return lldb_iter(self, '%s', '%s')"
	section_iter = " def section_iter(self): return lldb_iter(self, '%s', '%s')"
	compile_unit_iter = " def compile_unit_iter(self): return lldb_iter(self, '%s', '%s')"

	# Called to implement the built-in function len().
	# Eligible objects are those containers with unambiguous iteration support.
	len_def = " def __len__(self): return self.%s()"

	# This supports the rich comparison methods of __eq__ and __ne__.
	eq_def = " def __eq__(self, other): return isinstance(other, %s) and %s"
	ne_def = " def __ne__(self, other): return not self.__eq__(other)"

	# Called to implement truth value testing and the built-in operation bool();
	# should return False or True, or their integer equivalents 0 or 1.
	# Delegate to self.IsValid() if it is defined for the current lldb object.
	nonzero_def = " def __nonzero__(self): return self.IsValid()"

	# A convenience iterator for SBSymbol!
	symbol_in_section_iter_def = '''
	def symbol_in_section_iter(self, section):
	"""Given a module and its contained section, returns an iterator on the
	symbols within the section."""
	for sym in self:
	if in_range(sym, section):
	yield sym
	'''

	#
	# This dictionary defines a mapping from classname to (getsize, getelem) tuple.
	#
	d = { 'SBBreakpoint': ('GetNumLocations', 'GetLocationAtIndex'),
	'SBCompileUnit': ('GetNumLineEntries', 'GetLineEntryAtIndex'),
	'SBDebugger': ('GetNumTargets', 'GetTargetAtIndex'),
	'SBModule': ('GetNumSymbols', 'GetSymbolAtIndex'),
	'SBProcess': ('GetNumThreads', 'GetThreadAtIndex'),
	'SBSection': ('GetNumSubSections', 'GetSubSectionAtIndex'),
	'SBThread': ('GetNumFrames', 'GetFrameAtIndex'),

	'SBInstructionList': ('GetSize', 'GetInstructionAtIndex'),
	'SBStringList': ('GetSize', 'GetStringAtIndex',),
	'SBSymbolContextList': ('GetSize', 'GetContextAtIndex'),
	'SBTypeList': ('GetSize', 'GetTypeAtIndex'),
	'SBValueList': ('GetSize', 'GetValueAtIndex'),

	'SBType': ('GetNumberChildren', 'GetChildAtIndex'),
	'SBValue': ('GetNumChildren', 'GetChildAtIndex'),

	# SBTarget needs special processing, see below.
	'SBTarget': {'module': ('GetNumModules', 'GetModuleAtIndex'),
	'breakpoint': ('GetNumBreakpoints', 'GetBreakpointAtIndex'),
	'watchpoint': ('GetNumWatchpoints', 'GetWatchpointAtIndex')
	},

	# SBModule has an additional section_iter(), see below.
	'SBModule-section': ('GetNumSections', 'GetSectionAtIndex'),
	# And compile_unit_iter().
	'SBModule-compile-unit': ('GetNumCompileUnits', 'GetCompileUnitAtIndex'),
	# As well as symbol_in_section_iter().
	'SBModule-symbol-in-section': symbol_in_section_iter_def
	}

	#
	# This dictionary defines a mapping from classname to equality method name(s).
	#
	e = { 'SBAddress': ['GetFileAddress', 'GetModule'],
	'SBBreakpoint': ['GetID'],
	'SBWatchpoint': ['GetID'],
	'SBFileSpec': ['GetFilename', 'GetDirectory'],
	'SBModule': ['GetFileSpec', 'GetUUIDString'],
	'SBType': ['GetByteSize', 'GetName']
	}

	def list_to_frag(list):
	"""Transform a list to equality program fragment.

	For example, ['GetID'] is transformed to 'self.GetID() == other.GetID()',
	and ['GetFilename', 'GetDirectory'] to 'self.GetFilename() == other.GetFilename()
	and self.GetDirectory() == other.GetDirectory()'.
	"""
	if not list:
	raise Exception("list should be non-empty")
	frag = StringIO.StringIO()
	for i in range(len(list)):
	if i > 0:
	frag.write(" and ")
	frag.write("self.{0}() == other.{0}()".format(list[i]))
	return frag.getvalue()

	class NewContent(StringIO.StringIO):
	"""Simple facade to keep track of the previous line to be committed."""
	def __init__(self):
	StringIO.StringIO.__init__(self)
	self.prev_line = None
	def add_line(self, a_line):
	"""Add a line to the content, if there is a previous line, commit it."""
	if self.prev_line != None:
	print >> self, self.prev_line
	self.prev_line = a_line
	def del_line(self):
	"""Forget about the previous line, do not commit it."""
	self.prev_line = None
	def del_blank_line(self):
	"""Forget about the previous line if it is a blank line."""
	if self.prev_line != None and not self.prev_line.strip():
	self.prev_line = None
	def finish(self):
	"""Call this when you're finished with populating content."""
	if self.prev_line != None:
	print >> self, self.prev_line
	self.prev_line = None

	# The new content will have the iteration protocol defined for our lldb objects.
	new_content = NewContent()

	with open(output_name, 'r') as f_in:
	content = f_in.read()

	# The pattern for recognizing the beginning of an SB class definition.
	class_pattern = re.compile("^class (SB.*)\(_object\):$")

	# The pattern for recognizing the beginning of the __init__ method definition.
	init_pattern = re.compile("^ def __init__\(self.*\):")

	# The pattern for recognizing the beginning of the IsValid method definition.
	isvalid_pattern = re.compile("^ def IsValid\(")

	# These define the states of our finite state machine.
	NORMAL = 0
	DEFINING_ITERATOR = 1
	DEFINING_EQUALITY = 2
	CLEANUP_DOCSTRING = 4

	# The lldb_iter_def only needs to be inserted once.
	lldb_iter_defined = False;

	# Our FSM begins its life in the NORMAL state, and transitions to the
	# DEFINING_ITERATOR and/or DEFINING_EQUALITY state whenever it encounters the
	# beginning of certain class definitions, see dictionaries 'd' and 'e' above.
	#
	# Note that the two states DEFINING_ITERATOR and DEFINING_EQUALITY are
	# orthogonal in that our FSM can be in one, the other, or both states at the
	# same time. During such time, the FSM is eagerly searching for the __init__
	# method definition in order to insert the appropriate method(s) into the lldb
	# module.
	#
	# The state CLEANUP_DOCSTRING can be entered from either the NORMAL or the
	# DEFINING_ITERATOR/EQUALITY states. While in this state, the FSM is fixing/
	# cleaning the Python docstrings generated by the swig docstring features.
	#
	# The FSM, in all possible states, also checks the current input for IsValid()
	# definition, and inserts a __nonzero__() method definition to implement truth
	# value testing and the built-in operation bool().
	state = NORMAL
	for line in content.splitlines():
	# Handle the state transition into CLEANUP_DOCSTRING state as it is possible
	# to enter this state from either NORMAL or DEFINING_ITERATOR/EQUALITY.
	#
	# If ' """' is the sole line, prepare to transition to the
	# CLEANUP_DOCSTRING state or out of it.
	if line == toggle_docstring_cleanup_line:
	if state & CLEANUP_DOCSTRING:
	# Special handling of the trailing blank line right before the '"""'
	# end docstring marker.
	new_content.del_blank_line()
	state ^= CLEANUP_DOCSTRING
	else:
	state \|= CLEANUP_DOCSTRING

	if state == NORMAL:
	match = class_pattern.search(line)
	# Inserts lldb_helpers and the lldb_iter() definition before the first
	# class definition.
	if not lldb_iter_defined and match:
	new_content.add_line(lldb_helpers)
	new_content.add_line(lldb_iter_def)
	lldb_iter_defined = True

	# If we are at the beginning of the class definitions, prepare to
	# transition to the DEFINING_ITERATOR/DEFINING_EQUALITY state for the
	# right class names.
	if match:
	cls = match.group(1)
	if cls in d:
	# Adding support for iteration for the matched SB class.
	state \|= DEFINING_ITERATOR
	if cls in e:
	# Adding support for eq and ne for the matched SB class.
	state \|= DEFINING_EQUALITY

	if (state & DEFINING_ITERATOR) or (state & DEFINING_EQUALITY):
	match = init_pattern.search(line)
	if match:
	# We found the beginning of the __init__ method definition.
	# This is a good spot to insert the iter and/or eq-ne support.
	#
	# But note that SBTarget has three types of iterations.
	if cls == "SBTarget":
	new_content.add_line(module_iter % (d[cls]['module']))
	new_content.add_line(breakpoint_iter % (d[cls]['breakpoint']))
	new_content.add_line(watchpoint_iter % (d[cls]['watchpoint']))
	else:
	if (state & DEFINING_ITERATOR):
	new_content.add_line(iter_def % d[cls])
	new_content.add_line(len_def % d[cls][0])
	if (state & DEFINING_EQUALITY):
	new_content.add_line(eq_def % (cls, list_to_frag(e[cls])))
	new_content.add_line(ne_def)

	# SBModule has extra SBSection, SBCompileUnit iterators and symbol_in_section_iter()!
	if cls == "SBModule":
	new_content.add_line(section_iter % d[cls+'-section'])
	new_content.add_line(compile_unit_iter % d[cls+'-compile-unit'])
	new_content.add_line(d[cls+'-symbol-in-section'])

	# This special purpose iterator is for SBValue only!!!
	if cls == "SBValue":
	new_content.add_line(linked_list_iter_def)

	# Next state will be NORMAL.
	state = NORMAL

	if (state & CLEANUP_DOCSTRING):
	# Cleanse the lldb.py of the autodoc'ed residues.
	if c_ifdef_swig in line or c_endif_swig in line:
	continue
	# As well as the comment marker line.
	if c_comment_marker in line:
	continue

	# Also remove the '\a ' and '\b 'substrings.
	line = line.replace('\a ', '')
	line = line.replace('\b ', '')
	# And the leading '///' substring.
	doxygen_comment_match = doxygen_comment_start.match(line)
	if doxygen_comment_match:
	line = line.replace(doxygen_comment_match.group(1), '', 1)

	line = char_to_str_xform(line)

	# Note that the transition out of CLEANUP_DOCSTRING is handled at the
	# beginning of this function already.

	# This deals with one-liner docstring, for example, SBThread.GetName:
	# """GetName(self) -> char""".
	if one_liner_docstring_pattern.match(line):
	line = char_to_str_xform(line)

	# Look for 'def IsValid(*args):', and once located, add implementation
	# of truth value testing for this object by delegation.
	if isvalid_pattern.search(line):
	new_content.add_line(nonzero_def)

	# Pass the original line of content to new_content.
	new_content.add_line(line)

	# We are finished with recording new content.
	new_content.finish()

	with open(output_name, 'w') as f_out:
	f_out.write(new_content.getvalue())
	f_out.write('''debugger_unique_id = 0
	SBDebugger.Initialize()
	debugger = None
	target = SBTarget()
	process = SBProcess()
	thread = SBThread()
	frame = SBFrame()''')