from __future__ import generators
from bisect import bisect_right
import sys
import inspect, tokenize
import py
from types import ModuleType
cpy_compile = compile
try:
import _ast
from _ast import PyCF_ONLY_AST as _AST_FLAG
except ImportError:
_AST_FLAG = 0
_ast = None
[docs]class Source(object):
""" a immutable object holding a source code fragment,
possibly deindenting it.
"""
_compilecounter = 0
def __init__(self, *parts, **kwargs):
self.lines = lines = []
de = kwargs.get('deindent', True)
rstrip = kwargs.get('rstrip', True)
for part in parts:
if not part:
partlines = []
if isinstance(part, Source):
partlines = part.lines
elif isinstance(part, (tuple, list)):
partlines = [x.rstrip("\n") for x in part]
elif isinstance(part, py.builtin._basestring):
partlines = part.split('\n')
if rstrip:
while partlines:
if partlines[-1].strip():
break
partlines.pop()
else:
partlines = getsource(part, deindent=de).lines
if de:
partlines = deindent(partlines)
lines.extend(partlines)
def __eq__(self, other):
try:
return self.lines == other.lines
except AttributeError:
if isinstance(other, str):
return str(self) == other
return False
def __getitem__(self, key):
if isinstance(key, int):
return self.lines[key]
else:
if key.step not in (None, 1):
raise IndexError("cannot slice a Source with a step")
return self.__getslice__(key.start, key.stop)
def __len__(self):
return len(self.lines)
def __getslice__(self, start, end):
newsource = Source()
newsource.lines = self.lines[start:end]
return newsource
[docs] def strip(self):
""" return new source object with trailing
and leading blank lines removed.
"""
start, end = 0, len(self)
while start < end and not self.lines[start].strip():
start += 1
while end > start and not self.lines[end-1].strip():
end -= 1
source = Source()
source.lines[:] = self.lines[start:end]
return source
[docs] def putaround(self, before='', after='', indent=' ' * 4):
""" return a copy of the source object with
'before' and 'after' wrapped around it.
"""
before = Source(before)
after = Source(after)
newsource = Source()
lines = [ (indent + line) for line in self.lines]
newsource.lines = before.lines + lines + after.lines
return newsource
[docs] def indent(self, indent=' ' * 4):
""" return a copy of the source object with
all lines indented by the given indent-string.
"""
newsource = Source()
newsource.lines = [(indent+line) for line in self.lines]
return newsource
[docs] def getstatement(self, lineno, assertion=False):
""" return Source statement which contains the
given linenumber (counted from 0).
"""
start, end = self.getstatementrange(lineno, assertion)
return self[start:end]
[docs] def getstatementrange(self, lineno, assertion=False):
""" return (start, end) tuple which spans the minimal
statement region which containing the given lineno.
"""
if not (0 <= lineno < len(self)):
raise IndexError("lineno out of range")
ast, start, end = getstatementrange_ast(lineno, self)
return start, end
[docs] def deindent(self, offset=None):
""" return a new source object deindented by offset.
If offset is None then guess an indentation offset from
the first non-blank line. Subsequent lines which have a
lower indentation offset will be copied verbatim as
they are assumed to be part of multilines.
"""
# XXX maybe use the tokenizer to properly handle multiline
# strings etc.pp?
newsource = Source()
newsource.lines[:] = deindent(self.lines, offset)
return newsource
[docs] def isparseable(self, deindent=True):
""" return True if source is parseable, heuristically
deindenting it by default.
"""
try:
import parser
except ImportError:
syntax_checker = lambda x: compile(x, 'asd', 'exec')
else:
syntax_checker = parser.suite
if deindent:
source = str(self.deindent())
else:
source = str(self)
try:
#compile(source+'\n', "x", "exec")
syntax_checker(source+'\n')
except KeyboardInterrupt:
raise
except Exception:
return False
else:
return True
def __str__(self):
return "\n".join(self.lines)
[docs] def compile(self, filename=None, mode='exec',
flag=generators.compiler_flag,
dont_inherit=0, _genframe=None):
""" return compiled code object. if filename is None
invent an artificial filename which displays
the source/line position of the caller frame.
"""
if not filename or py.path.local(filename).check(file=0):
if _genframe is None:
_genframe = sys._getframe(1) # the caller
fn,lineno = _genframe.f_code.co_filename, _genframe.f_lineno
base = "<%d-codegen " % self._compilecounter
self.__class__._compilecounter += 1
if not filename:
filename = base + '%s:%d>' % (fn, lineno)
else:
filename = base + '%r %s:%d>' % (filename, fn, lineno)
source = "\n".join(self.lines) + '\n'
try:
co = cpy_compile(source, filename, mode, flag)
except SyntaxError:
ex = sys.exc_info()[1]
# re-represent syntax errors from parsing python strings
msglines = self.lines[:ex.lineno]
if ex.offset:
msglines.append(" "*ex.offset + '^')
msglines.append("(code was compiled probably from here: %s)" % filename)
newex = SyntaxError('\n'.join(msglines))
newex.offset = ex.offset
newex.lineno = ex.lineno
newex.text = ex.text
raise newex
else:
if flag & _AST_FLAG:
return co
lines = [(x + "\n") for x in self.lines]
import linecache
linecache.cache[filename] = (1, None, lines, filename)
return co
#
# public API shortcut functions
#
def compile_(source, filename=None, mode='exec', flags=
generators.compiler_flag, dont_inherit=0):
""" compile the given source to a raw code object,
and maintain an internal cache which allows later
retrieval of the source code for the code object
and any recursively created code objects.
"""
if _ast is not None and isinstance(source, _ast.AST):
# XXX should Source support having AST?
return cpy_compile(source, filename, mode, flags, dont_inherit)
_genframe = sys._getframe(1) # the caller
s = Source(source)
co = s.compile(filename, mode, flags, _genframe=_genframe)
return co
def getfslineno(obj):
""" Return source location (path, lineno) for the given object.
If the source cannot be determined return ("", -1)
"""
try:
code = py.code.Code(obj)
except TypeError:
try:
fn = (inspect.getsourcefile(obj) or
inspect.getfile(obj))
except TypeError:
return "", -1
fspath = fn and py.path.local(fn) or None
lineno = -1
if fspath:
try:
_, lineno = findsource(obj)
except IOError:
pass
else:
fspath = code.path
lineno = code.firstlineno
assert isinstance(lineno, int)
return fspath, lineno
#
# helper functions
#
def findsource(obj):
try:
sourcelines, lineno = inspect.findsource(obj)
except py.builtin._sysex:
raise
except:
return None, -1
source = Source()
source.lines = [line.rstrip() for line in sourcelines]
return source, lineno
def getsource(obj, **kwargs):
obj = py.code.getrawcode(obj)
try:
strsrc = inspect.getsource(obj)
except IndentationError:
strsrc = "\"Buggy python version consider upgrading, cannot get source\""
assert isinstance(strsrc, str)
return Source(strsrc, **kwargs)
def deindent(lines, offset=None):
if offset is None:
for line in lines:
line = line.expandtabs()
s = line.lstrip()
if s:
offset = len(line)-len(s)
break
else:
offset = 0
if offset == 0:
return list(lines)
newlines = []
def readline_generator(lines):
for line in lines:
yield line + '\n'
while True:
yield ''
it = readline_generator(lines)
try:
for _, _, (sline, _), (eline, _), _ in tokenize.generate_tokens(lambda: next(it)):
if sline > len(lines):
break # End of input reached
if sline > len(newlines):
line = lines[sline - 1].expandtabs()
if line.lstrip() and line[:offset].isspace():
line = line[offset:] # Deindent
newlines.append(line)
for i in range(sline, eline):
# Don't deindent continuing lines of
# multiline tokens (i.e. multiline strings)
newlines.append(lines[i])
except (IndentationError, tokenize.TokenError):
pass
# Add any lines we didn't see. E.g. if an exception was raised.
newlines.extend(lines[len(newlines):])
return newlines
def get_statement_startend2(lineno, node):
import ast
# flatten all statements and except handlers into one lineno-list
# AST's line numbers start indexing at 1
l = []
for x in ast.walk(node):
if isinstance(x, _ast.stmt) or isinstance(x, _ast.ExceptHandler):
l.append(x.lineno - 1)
for name in "finalbody", "orelse":
val = getattr(x, name, None)
if val:
# treat the finally/orelse part as its own statement
l.append(val[0].lineno - 1 - 1)
l.sort()
insert_index = bisect_right(l, lineno)
start = l[insert_index - 1]
if insert_index >= len(l):
end = None
else:
end = l[insert_index]
return start, end
def getstatementrange_ast(lineno, source, assertion=False, astnode=None):
if astnode is None:
content = str(source)
try:
astnode = compile(content, "source", "exec", 1024) # 1024 for AST
except ValueError:
start, end = getstatementrange_old(lineno, source, assertion)
return None, start, end
start, end = get_statement_startend2(lineno, astnode)
# we need to correct the end:
# - ast-parsing strips comments
# - there might be empty lines
# - we might have lesser indented code blocks at the end
if end is None:
end = len(source.lines)
if end > start + 1:
# make sure we don't span differently indented code blocks
# by using the BlockFinder helper used which inspect.getsource() uses itself
block_finder = inspect.BlockFinder()
# if we start with an indented line, put blockfinder to "started" mode
block_finder.started = source.lines[start][0].isspace()
it = ((x + "\n") for x in source.lines[start:end])
try:
for tok in tokenize.generate_tokens(lambda: next(it)):
block_finder.tokeneater(*tok)
except (inspect.EndOfBlock, IndentationError):
end = block_finder.last + start
except Exception:
pass
# the end might still point to a comment or empty line, correct it
while end:
line = source.lines[end - 1].lstrip()
if line.startswith("#") or not line:
end -= 1
else:
break
return astnode, start, end
def getstatementrange_old(lineno, source, assertion=False):
""" return (start, end) tuple which spans the minimal
statement region which containing the given lineno.
raise an IndexError if no such statementrange can be found.
"""
# XXX this logic is only used on python2.4 and below
# 1. find the start of the statement
from codeop import compile_command
for start in range(lineno, -1, -1):
if assertion:
line = source.lines[start]
# the following lines are not fully tested, change with care
if 'super' in line and 'self' in line and '__init__' in line:
raise IndexError("likely a subclass")
if "assert" not in line and "raise" not in line:
continue
trylines = source.lines[start:lineno+1]
# quick hack to prepare parsing an indented line with
# compile_command() (which errors on "return" outside defs)
trylines.insert(0, 'def xxx():')
trysource = '\n '.join(trylines)
# ^ space here
try:
compile_command(trysource)
except (SyntaxError, OverflowError, ValueError):
continue
# 2. find the end of the statement
for end in range(lineno+1, len(source)+1):
trysource = source[start:end]
if trysource.isparseable():
return start, end
raise SyntaxError("no valid source range around line %d " % (lineno,))