The compile ignores constant statements and emit a SyntaxWarning warning.
Don't emit the warning for string statement because triple quoted string is a
common syntax for multiline comments.
Don't emit the warning on ellipis neither: 'def f(): ...' is a legit syntax for
abstract functions.
Changes:
* test_ast: ignore SyntaxWarning when compiling test statements. Modify
test_load_const() to use assignment expressions rather than constant
expression.
* test_code: add more kinds of constant statements, ignore SyntaxWarning when
testing that the compiler removes constant statements.
* test_grammar: ignore SyntaxWarning on the statement "1"
obj2ast_constant() code is baesd on obj2ast_object() which has a special case
for Py_None. But in practice, we don't need to have a special case for
constants.
Issue noticed by Joseph Jevnik on a review.
Issue #26146: Add a new kind of AST node: ast.Constant. It can be used by
external AST optimizers, but the compiler does not emit directly such node.
An optimizer can replace the following AST nodes with ast.Constant:
* ast.NameConstant: None, False, True
* ast.Num: int, float, complex
* ast.Str: str
* ast.Bytes: bytes
* ast.Tuple if items are constants too: tuple
* frozenset
Update code to accept ast.Constant instead of ast.Num and/or ast.Str:
* compiler
* docstrings
* ast.literal_eval()
* Tools/parser/unparse.py
with no known parent package.
Previously SystemError was raised if the parent package didn't exist
(e.g., __package__ was set to '').
Thanks to Florent Xicluna and Yongzhi Pan for reporting the issue.
