Issue #24619: New approach for tokenizing async/await.
This commit fixes how one-line async-defs and defs are tracked by tokenizer. It allows to correctly parse invalid code such as: >>> async def f(): ... def g(): pass ... async = 10 and valid code such as: >>> async def f(): ... async def g(): pass ... await z As a consequence, is is now possible to have one-line 'async def foo(): await ..' functions: >>> async def foo(): return await bar()
This commit is contained in:
parent
80acc3ebbc
commit
8fb307cd65
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@ -685,9 +685,7 @@ Execution of Python coroutines can be suspended and resumed at many points
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(see :term:`coroutine`). In the body of a coroutine, any ``await`` and
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``async`` identifiers become reserved keywords; :keyword:`await` expressions,
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:keyword:`async for` and :keyword:`async with` can only be used in
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coroutine bodies. However, to simplify the parser, these keywords cannot
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be used on the same line as a function or coroutine (:keyword:`def`
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statement) header.
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coroutine bodies.
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Functions defined with ``async def`` syntax are always coroutine functions,
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even if they do not contain ``await`` or ``async`` keywords.
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@ -369,6 +369,7 @@ def generate_tokens(readline):
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# 'stashed' and 'ctx' are used for async/await parsing
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stashed = None
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ctx = [('sync', 0)]
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in_async = 0
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while 1: # loop over lines in stream
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try:
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@ -436,6 +437,14 @@ def generate_tokens(readline):
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"unindent does not match any outer indentation level",
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("<tokenize>", lnum, pos, line))
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indents = indents[:-1]
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cur_indent = indents[-1]
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while len(ctx) > 1 and ctx[-1][1] >= cur_indent:
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if ctx[-1][0] == 'async':
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in_async -= 1
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assert in_async >= 0
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ctx.pop()
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yield (DEDENT, '', (lnum, pos), (lnum, pos), line)
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else: # continued statement
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@ -499,7 +508,7 @@ def generate_tokens(readline):
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yield (STRING, token, spos, epos, line)
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elif initial in namechars: # ordinary name
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if token in ('async', 'await'):
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if ctx[-1][0] == 'async' and ctx[-1][1] < indents[-1]:
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if in_async:
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yield (ASYNC if token == 'async' else AWAIT,
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token, spos, epos, line)
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continue
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@ -515,6 +524,7 @@ def generate_tokens(readline):
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and stashed[1] == 'async'):
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ctx.append(('async', indents[-1]))
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in_async += 1
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yield (ASYNC, stashed[1],
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stashed[2], stashed[3],
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@ -1,3 +1,2 @@
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async def foo():
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def foo(a=await something()):
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pass
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async def foo(a=await something()):
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pass
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@ -1,3 +1,2 @@
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async def foo():
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def foo(a:await something()):
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pass
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async def foo(a:await something()):
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pass
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@ -1,2 +1,2 @@
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async def foo():
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async def foo(): await something()
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await
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@ -1,2 +0,0 @@
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async def foo():
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await
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@ -67,11 +67,11 @@ def silence_coro_gc():
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class AsyncBadSyntaxTest(unittest.TestCase):
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def test_badsyntax_1(self):
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with self.assertRaisesRegex(SyntaxError, 'invalid syntax'):
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with self.assertRaisesRegex(SyntaxError, "'await' outside"):
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import test.badsyntax_async1
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def test_badsyntax_2(self):
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with self.assertRaisesRegex(SyntaxError, 'invalid syntax'):
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with self.assertRaisesRegex(SyntaxError, "'await' outside"):
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import test.badsyntax_async2
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def test_badsyntax_3(self):
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@ -103,10 +103,6 @@ class AsyncBadSyntaxTest(unittest.TestCase):
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import test.badsyntax_async8
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def test_badsyntax_9(self):
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with self.assertRaisesRegex(SyntaxError, 'invalid syntax'):
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import test.badsyntax_async9
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def test_badsyntax_10(self):
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ns = {}
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for comp in {'(await a for a in b)',
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'[await a for a in b]',
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@ -116,6 +112,221 @@ class AsyncBadSyntaxTest(unittest.TestCase):
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with self.assertRaisesRegex(SyntaxError, 'await.*in comprehen'):
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exec('async def f():\n\t{}'.format(comp), ns, ns)
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def test_badsyntax_10(self):
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# Tests for issue 24619
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samples = [
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"""async def foo():
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def bar(): pass
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await = 1
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""",
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"""async def foo():
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def bar(): pass
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await = 1
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""",
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"""async def foo():
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def bar(): pass
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if 1:
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await = 1
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""",
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"""def foo():
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async def bar(): pass
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if 1:
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await a
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""",
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"""def foo():
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async def bar(): pass
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await a
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""",
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"""def foo():
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def baz(): pass
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async def bar(): pass
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await a
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""",
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"""def foo():
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def baz(): pass
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# 456
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async def bar(): pass
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# 123
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await a
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""",
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"""async def foo():
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def baz(): pass
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# 456
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async def bar(): pass
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# 123
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await = 2
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""",
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"""def foo():
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def baz(): pass
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async def bar(): pass
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await a
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""",
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"""async def foo():
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def baz(): pass
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async def bar(): pass
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await = 2
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""",
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"""async def foo():
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def async(): pass
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""",
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"""async def foo():
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def await(): pass
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""",
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"""async def foo():
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def bar():
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await
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""",
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"""async def foo():
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return lambda async: await
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""",
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"""async def foo():
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return lambda a: await
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""",
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"""async def foo(a: await b):
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pass
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""",
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"""def baz():
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async def foo(a: await b):
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pass
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""",
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"""async def foo(async):
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pass
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""",
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"""async def foo():
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def bar():
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def baz():
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async = 1
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""",
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"""async def foo():
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def bar():
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def baz():
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pass
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async = 1
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""",
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"""def foo():
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async def bar():
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async def baz():
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pass
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def baz():
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42
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async = 1
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""",
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"""async def foo():
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def bar():
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def baz():
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pass\nawait foo()
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""",
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"""def foo():
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def bar():
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async def baz():
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pass\nawait foo()
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""",
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"""async def foo(await):
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pass
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""",
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"""def foo():
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async def bar(): pass
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await a
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""",
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"""def foo():
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async def bar():
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pass\nawait a
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"""]
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ns = {}
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for code in samples:
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with self.subTest(code=code), self.assertRaises(SyntaxError):
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exec(code, ns, ns)
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def test_goodsyntax_1(self):
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# Tests for issue 24619
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def foo(await):
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async def foo(): pass
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async def foo():
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pass
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return await + 1
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self.assertEqual(foo(10), 11)
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def foo(await):
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async def foo(): pass
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async def foo(): pass
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return await + 2
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self.assertEqual(foo(20), 22)
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def foo(await):
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async def foo(): pass
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async def foo(): pass
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return await + 2
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self.assertEqual(foo(20), 22)
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def foo(await):
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"""spam"""
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async def foo(): \
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pass
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# 123
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async def foo(): pass
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# 456
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return await + 2
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self.assertEqual(foo(20), 22)
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def foo(await):
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def foo(): pass
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def foo(): pass
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async def bar(): return await_
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await_ = await
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try:
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bar().send(None)
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except StopIteration as ex:
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return ex.args[0]
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self.assertEqual(foo(42), 42)
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async def f():
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async def g(): pass
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await z
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self.assertTrue(inspect.iscoroutinefunction(f))
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class TokenizerRegrTest(unittest.TestCase):
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@ -461,8 +672,7 @@ class CoroutineTest(unittest.TestCase):
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class Awaitable:
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pass
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async def foo():
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return (await Awaitable())
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async def foo(): return await Awaitable()
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with self.assertRaisesRegex(
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TypeError, "object Awaitable can't be used in 'await' expression"):
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@ -1051,10 +1051,7 @@ class GrammarTests(unittest.TestCase):
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async def test():
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def sum():
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async = 1
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await = 41
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return async + await
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pass
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if 1:
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await someobj()
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@ -786,12 +786,12 @@ Async/await extension:
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NAME 'def' (2, 2) (2, 5)
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NAME 'foo' (2, 6) (2, 9)
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OP '(' (2, 9) (2, 10)
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NAME 'await' (2, 10) (2, 15)
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AWAIT 'await' (2, 10) (2, 15)
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OP ')' (2, 15) (2, 16)
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OP ':' (2, 16) (2, 17)
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NEWLINE '\\n' (2, 17) (2, 18)
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INDENT ' ' (3, 0) (3, 4)
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NAME 'await' (3, 4) (3, 9)
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AWAIT 'await' (3, 4) (3, 9)
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OP '=' (3, 10) (3, 11)
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NUMBER '1' (3, 12) (3, 13)
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NEWLINE '\\n' (3, 13) (3, 14)
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@ -829,6 +829,17 @@ Async/await extension:
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OP ':' (2, 18) (2, 19)
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NAME 'pass' (2, 20) (2, 24)
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DEDENT '' (3, 0) (3, 0)
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>>> dump_tokens('''async def foo(async): await''')
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ENCODING 'utf-8' (0, 0) (0, 0)
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ASYNC 'async' (1, 0) (1, 5)
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NAME 'def' (1, 6) (1, 9)
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NAME 'foo' (1, 10) (1, 13)
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OP '(' (1, 13) (1, 14)
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ASYNC 'async' (1, 14) (1, 19)
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OP ')' (1, 19) (1, 20)
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OP ':' (1, 20) (1, 21)
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AWAIT 'await' (1, 22) (1, 27)
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"""
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from test import support
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@ -501,6 +501,7 @@ def _tokenize(readline, encoding):
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# 'stashed' and 'ctx' are used for async/await parsing
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stashed = None
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ctx = [('sync', 0)]
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in_async = 0
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if encoding is not None:
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if encoding == "utf-8-sig":
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@ -580,6 +581,9 @@ def _tokenize(readline, encoding):
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cur_indent = indents[-1]
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while len(ctx) > 1 and ctx[-1][1] >= cur_indent:
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if ctx[-1][0] == 'async':
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in_async -= 1
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assert in_async >= 0
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ctx.pop()
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yield TokenInfo(DEDENT, '', (lnum, pos), (lnum, pos), line)
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@ -640,7 +644,7 @@ def _tokenize(readline, encoding):
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yield TokenInfo(STRING, token, spos, epos, line)
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elif initial.isidentifier(): # ordinary name
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if token in ('async', 'await'):
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if ctx[-1][0] == 'async' and ctx[-1][1] < indents[-1]:
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if in_async:
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yield TokenInfo(
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ASYNC if token == 'async' else AWAIT,
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token, spos, epos, line)
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@ -657,6 +661,7 @@ def _tokenize(readline, encoding):
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and stashed.string == 'async'):
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ctx.append(('async', indents[-1]))
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in_async += 1
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yield TokenInfo(ASYNC, stashed.string,
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stashed.start, stashed.end,
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@ -19,6 +19,9 @@ Core and Builtins
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- Issue #24407: Fix crash when dict is mutated while being updated.
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- Issue #24619: New approach for tokenizing async/await. As a consequence,
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is is now possible to have one-line 'async def foo(): await ..' functions.
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Library
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-------
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@ -31,6 +31,12 @@
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|| c == '_'\
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|| (c >= 128))
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/* The following DEFTYPE* flags are used in 'tok_state->deftypestack',
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and should be removed in 3.7, when async/await are regular
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keywords. */
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#define DEFTYPE_ASYNC 1
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#define DEFTYPE_HAS_NL 2
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extern char *PyOS_Readline(FILE *, FILE *, const char *);
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/* Return malloc'ed string including trailing \n;
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empty malloc'ed string for EOF;
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@ -130,6 +136,8 @@ tok_new(void)
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tok->def = 0;
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tok->defstack[0] = 0;
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tok->deftypestack[0] = 0;
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tok->def_async_behind = 0;
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tok->def_in_async = 0;
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tok->atbol = 1;
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tok->pendin = 0;
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@ -1436,7 +1444,12 @@ tok_get(struct tok_state *tok, char **p_start, char **p_end)
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tok->pendin++;
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while (tok->def && tok->defstack[tok->def] >= tok->indent) {
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if (tok->deftypestack[tok->def] & DEFTYPE_ASYNC) {
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tok->def_in_async--;
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assert(tok->def_in_async >= 0);
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}
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tok->def--;
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assert(tok->def >= 0);
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}
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return DEDENT;
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@ -1447,6 +1460,22 @@ tok_get(struct tok_state *tok, char **p_start, char **p_end)
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}
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}
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if (!blankline && tok->level == 0
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&& tok->def && tok->deftypestack[tok->def] & DEFTYPE_HAS_NL
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&& tok->defstack[tok->def] >= tok->indent)
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{
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/* The top function on the stack did have a NEWLINE
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token, but didn't have an INDENT. That means that
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it's a one-line function and it should now be removed
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from the stack. */
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if (tok->deftypestack[tok->def] & DEFTYPE_ASYNC) {
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tok->def_in_async--;
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assert(tok->def_in_async >= 0);
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}
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tok->def--;
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assert(tok->def >= 0);
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}
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again:
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tok->start = NULL;
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/* Skip spaces */
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@ -1501,59 +1530,58 @@ tok_get(struct tok_state *tok, char **p_start, char **p_end)
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tok_len = tok->cur - tok->start;
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if (tok_len == 3 && memcmp(tok->start, "def", 3) == 0) {
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if (tok->def && tok->deftypestack[tok->def] == 3) {
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tok->deftypestack[tok->def] = 2;
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/* The current token is 'def'. */
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if (tok->def + 1 >= MAXINDENT) {
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tok->done = E_TOODEEP;
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tok->cur = tok->inp;
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return ERRORTOKEN;
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}
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else if (tok->defstack[tok->def] < tok->indent) {
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/* We advance defs stack only when we see "def" *and*
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the indentation level was increased relative to the
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previous "def". */
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if (tok->def + 1 >= MAXINDENT) {
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tok->done = E_TOODEEP;
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tok->cur = tok->inp;
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return ERRORTOKEN;
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}
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/* Advance defs stack. */
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tok->def++;
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tok->defstack[tok->def] = tok->indent;
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tok->def++;
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tok->defstack[tok->def] = tok->indent;
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tok->deftypestack[tok->def] = 1;
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if (tok->def_async_behind) {
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/* The previous token was 'async'. */
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tok->def_async_behind = 0;
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tok->deftypestack[tok->def] = DEFTYPE_ASYNC;
|
||||
tok->def_in_async++;
|
||||
}
|
||||
else {
|
||||
/* This is a regular function (not async def). */
|
||||
tok->deftypestack[tok->def] = 0;
|
||||
}
|
||||
}
|
||||
else if (tok_len == 5) {
|
||||
if (memcmp(tok->start, "async", 5) == 0) {
|
||||
/* The current token is 'async'. */
|
||||
memcpy(&ahead_tok, tok, sizeof(ahead_tok));
|
||||
|
||||
/* Try to look ahead one token. */
|
||||
ahead_tok_kind = tok_get(&ahead_tok, &ahead_tok_start,
|
||||
&ahead_top_end);
|
||||
|
||||
if (ahead_tok_kind == NAME &&
|
||||
ahead_tok.cur - ahead_tok.start == 3 &&
|
||||
memcmp(ahead_tok.start, "def", 3) == 0) {
|
||||
|
||||
if (tok->def + 1 >= MAXINDENT) {
|
||||
tok->done = E_TOODEEP;
|
||||
tok->cur = tok->inp;
|
||||
return ERRORTOKEN;
|
||||
}
|
||||
|
||||
tok->def++;
|
||||
tok->defstack[tok->def] = tok->indent;
|
||||
tok->deftypestack[tok->def] = 3;
|
||||
|
||||
if (ahead_tok_kind == NAME
|
||||
&& ahead_tok.cur - ahead_tok.start == 3
|
||||
&& memcmp(ahead_tok.start, "def", 3) == 0)
|
||||
{
|
||||
/* The next token is going to be 'def', so instead of
|
||||
returning 'async' NAME token, we return ASYNC. */
|
||||
tok->def_async_behind = 1;
|
||||
return ASYNC;
|
||||
}
|
||||
else if (tok->def && tok->deftypestack[tok->def] == 2
|
||||
&& tok->defstack[tok->def] < tok->indent) {
|
||||
|
||||
else if (tok->def_in_async)
|
||||
{
|
||||
/* We're inside an 'async def' function, so we treat
|
||||
'async' token as ASYNC, instead of NAME. */
|
||||
return ASYNC;
|
||||
}
|
||||
|
||||
}
|
||||
else if (memcmp(tok->start, "await", 5) == 0
|
||||
&& tok->def && tok->deftypestack[tok->def] == 2
|
||||
&& tok->defstack[tok->def] < tok->indent) {
|
||||
|
||||
else if (memcmp(tok->start, "await", 5) == 0 && tok->def_in_async)
|
||||
{
|
||||
/* We're inside an 'async def' function, so we treat
|
||||
'await' token as AWAIT, instead of NAME. */
|
||||
return AWAIT;
|
||||
}
|
||||
}
|
||||
|
@ -1569,6 +1597,13 @@ tok_get(struct tok_state *tok, char **p_start, char **p_end)
|
|||
*p_start = tok->start;
|
||||
*p_end = tok->cur - 1; /* Leave '\n' out of the string */
|
||||
tok->cont_line = 0;
|
||||
if (tok->def) {
|
||||
/* Mark the top function on the stack that it had
|
||||
at least one NEWLINE. That will help us to
|
||||
distinguish one-line functions from functions
|
||||
with multiple statements. */
|
||||
tok->deftypestack[tok->def] |= DEFTYPE_HAS_NL;
|
||||
}
|
||||
return NEWLINE;
|
||||
}
|
||||
|
||||
|
|
|
@ -66,12 +66,21 @@ struct tok_state {
|
|||
const char* str;
|
||||
const char* input; /* Tokenizer's newline translated copy of the string. */
|
||||
|
||||
int defstack[MAXINDENT]; /* stack if funcs & indents where they
|
||||
were defined */
|
||||
int deftypestack[MAXINDENT]; /* stack of func types
|
||||
(0 not func; 1: "def name";
|
||||
2: "async def name") */
|
||||
int def; /* Length of stack of func types */
|
||||
/* `def*` fields are for parsing async/await in a backwards compatible
|
||||
way. They should be removed in 3.7, when they will become
|
||||
regular constants. See PEP 492 for more details. */
|
||||
int defstack[MAXINDENT]; /* Stack of funcs & indents where they
|
||||
were defined. */
|
||||
int deftypestack[MAXINDENT]; /* Stack of func flags, see DEFTYPE_*
|
||||
constants. */
|
||||
int def; /* Length of stack of func types/flags. */
|
||||
int def_async_behind; /* 1 if there was an 'async' token before
|
||||
a 'def' token. */
|
||||
int def_in_async; /* Counter of how deep 'async def's
|
||||
are nested. If greater than 0,
|
||||
we are somewhere in an 'async def'
|
||||
body, so 'async' and 'await' should
|
||||
be parsed as keywords.*/
|
||||
};
|
||||
|
||||
extern struct tok_state *PyTokenizer_FromString(const char *, int);
|
||||
|
|
Loading…
Reference in New Issue