mirror of
https://github.com/python/cpython.git
synced 2024-11-28 04:15:11 +08:00
154 lines
5.4 KiB
Python
154 lines
5.4 KiB
Python
r"""Utilities to compile possibly incomplete Python source code.
|
|
|
|
This module provides two interfaces, broadly similar to the builtin
|
|
function compile(), which take program text, a filename and a 'mode'
|
|
and:
|
|
|
|
- Return code object if the command is complete and valid
|
|
- Return None if the command is incomplete
|
|
- Raise SyntaxError, ValueError or OverflowError if the command is a
|
|
syntax error (OverflowError and ValueError can be produced by
|
|
malformed literals).
|
|
|
|
The two interfaces are:
|
|
|
|
compile_command(source, filename, symbol):
|
|
|
|
Compiles a single command in the manner described above.
|
|
|
|
CommandCompiler():
|
|
|
|
Instances of this class have __call__ methods identical in
|
|
signature to compile_command; the difference is that if the
|
|
instance compiles program text containing a __future__ statement,
|
|
the instance 'remembers' and compiles all subsequent program texts
|
|
with the statement in force.
|
|
|
|
The module also provides another class:
|
|
|
|
Compile():
|
|
|
|
Instances of this class act like the built-in function compile,
|
|
but with 'memory' in the sense described above.
|
|
"""
|
|
|
|
import __future__
|
|
import warnings
|
|
|
|
_features = [getattr(__future__, fname)
|
|
for fname in __future__.all_feature_names]
|
|
|
|
__all__ = ["compile_command", "Compile", "CommandCompiler"]
|
|
|
|
# The following flags match the values from Include/cpython/compile.h
|
|
# Caveat emptor: These flags are undocumented on purpose and depending
|
|
# on their effect outside the standard library is **unsupported**.
|
|
PyCF_DONT_IMPLY_DEDENT = 0x200
|
|
PyCF_ALLOW_INCOMPLETE_INPUT = 0x4000
|
|
|
|
def _maybe_compile(compiler, source, filename, symbol):
|
|
# Check for source consisting of only blank lines and comments.
|
|
for line in source.split("\n"):
|
|
line = line.strip()
|
|
if line and line[0] != '#':
|
|
break # Leave it alone.
|
|
else:
|
|
if symbol != "eval":
|
|
source = "pass" # Replace it with a 'pass' statement
|
|
|
|
try:
|
|
return compiler(source, filename, symbol)
|
|
except SyntaxError: # Let other compile() errors propagate.
|
|
pass
|
|
|
|
# Catch syntax warnings after the first compile
|
|
# to emit warnings (SyntaxWarning, DeprecationWarning) at most once.
|
|
with warnings.catch_warnings():
|
|
warnings.simplefilter("error")
|
|
|
|
try:
|
|
compiler(source + "\n", filename, symbol)
|
|
except SyntaxError as e:
|
|
if "incomplete input" in str(e):
|
|
return None
|
|
raise
|
|
|
|
def _is_syntax_error(err1, err2):
|
|
rep1 = repr(err1)
|
|
rep2 = repr(err2)
|
|
if "was never closed" in rep1 and "was never closed" in rep2:
|
|
return False
|
|
if rep1 == rep2:
|
|
return True
|
|
return False
|
|
|
|
def _compile(source, filename, symbol):
|
|
return compile(source, filename, symbol, PyCF_DONT_IMPLY_DEDENT | PyCF_ALLOW_INCOMPLETE_INPUT)
|
|
|
|
def compile_command(source, filename="<input>", symbol="single"):
|
|
r"""Compile a command and determine whether it is incomplete.
|
|
|
|
Arguments:
|
|
|
|
source -- the source string; may contain \n characters
|
|
filename -- optional filename from which source was read; default
|
|
"<input>"
|
|
symbol -- optional grammar start symbol; "single" (default), "exec"
|
|
or "eval"
|
|
|
|
Return value / exceptions raised:
|
|
|
|
- Return a code object if the command is complete and valid
|
|
- Return None if the command is incomplete
|
|
- Raise SyntaxError, ValueError or OverflowError if the command is a
|
|
syntax error (OverflowError and ValueError can be produced by
|
|
malformed literals).
|
|
"""
|
|
return _maybe_compile(_compile, source, filename, symbol)
|
|
|
|
class Compile:
|
|
"""Instances of this class behave much like the built-in compile
|
|
function, but if one is used to compile text containing a future
|
|
statement, it "remembers" and compiles all subsequent program texts
|
|
with the statement in force."""
|
|
def __init__(self):
|
|
self.flags = PyCF_DONT_IMPLY_DEDENT | PyCF_ALLOW_INCOMPLETE_INPUT
|
|
|
|
def __call__(self, source, filename, symbol):
|
|
codeob = compile(source, filename, symbol, self.flags, True)
|
|
for feature in _features:
|
|
if codeob.co_flags & feature.compiler_flag:
|
|
self.flags |= feature.compiler_flag
|
|
return codeob
|
|
|
|
class CommandCompiler:
|
|
"""Instances of this class have __call__ methods identical in
|
|
signature to compile_command; the difference is that if the
|
|
instance compiles program text containing a __future__ statement,
|
|
the instance 'remembers' and compiles all subsequent program texts
|
|
with the statement in force."""
|
|
|
|
def __init__(self,):
|
|
self.compiler = Compile()
|
|
|
|
def __call__(self, source, filename="<input>", symbol="single"):
|
|
r"""Compile a command and determine whether it is incomplete.
|
|
|
|
Arguments:
|
|
|
|
source -- the source string; may contain \n characters
|
|
filename -- optional filename from which source was read;
|
|
default "<input>"
|
|
symbol -- optional grammar start symbol; "single" (default) or
|
|
"eval"
|
|
|
|
Return value / exceptions raised:
|
|
|
|
- Return a code object if the command is complete and valid
|
|
- Return None if the command is incomplete
|
|
- Raise SyntaxError, ValueError or OverflowError if the command is a
|
|
syntax error (OverflowError and ValueError can be produced by
|
|
malformed literals).
|
|
"""
|
|
return _maybe_compile(self.compiler, source, filename, symbol)
|