llvm-project/lldb/scripts/Python/modify-python-lldb.py

434 lines
17 KiB
Python

#
# 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')"
# 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'),
# 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 an extra SBSection iterator and symbol_in_section_iter()!
if cls == "SBModule":
new_content.add_line(section_iter % d[cls+'-section'])
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\n")
f_out.write("SBDebugger.Initialize()\n")