Repository navigation
Expand file tree
/
Copy pathcodeop.py
More file actions
143 lines (111 loc) · 5.25 KB
/
Copy pathcodeop.py
File metadata and controls
143 lines (111 loc) · 5.25 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
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
# Disable compiler warnings when checking for incomplete input.
with warnings.catch_warnings():
warnings.simplefilter("ignore", (SyntaxWarning, DeprecationWarning))
try:
compiler(source, filename, symbol)
except SyntaxError: # Let other compile() errors propagate.
try:
compiler(source + "\n", filename, symbol)
return None
except SyntaxError as e:
if "incomplete input" in str(e):
return None
# fallthrough
return compiler(source, filename, symbol)
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)