Description

Fixes #1224

compile() read mode only after converting and checking the source, so an invalid source hid an invalid mode. The func_type mode's PyCF_ONLY_AST requirement was checked later still, so an AST source with that mode and no flag reached obj2sst and failed with ShouldNotReachHere. CPython's builtin_compile_impl dispatches on mode right after the flags and optimize checks (bltinmodule.c#L776-L798), before it converts the source (#L826).

AS-IS

>>> compile(None, 'f', 'x')
TypeError: compile() arg 1 must be a string, bytes or AST object
>>> compile('\x00', 'f', 'x')
SyntaxError: source code string cannot contain null bytes
>>> compile(b'\xff', 'f', 'x')
SyntaxError: (unicode error) 'utf-8' codec can't decode byte 0xff in position 0: malformed input (f, line 1)
>>> compile(ast.parse('1'), 'f', 'func_type')
com.oracle.truffle.api.CompilerDirectives$ShouldNotReachHere

TO-BE

>>> compile(None, 'f', 'x')
ValueError: compile() mode must be 'exec', 'eval' or 'single'
>>> compile('\x00', 'f', 'x')
ValueError: compile() mode must be 'exec', 'eval' or 'single'
>>> compile(b'\xff', 'f', 'x')
ValueError: compile() mode must be 'exec', 'eval' or 'single'
>>> compile(ast.parse('1'), 'f', 'func_type')
ValueError: compile() mode 'func_type' requires flag PyCF_ONLY_AST

(matching CPython)

Changes

• In CompileNode.generic, resolve the input type with getParserInputType right after checkOptimize and reuse it for the AST path.
• In CompileNode.compile, call getParserInputType before checkSource, which covers a str source that arrives through doCompile.
• Move the func_type requires PyCF_ONLY_AST check from compile into getParserInputType, so both paths raise it with the other mode errors.
• Add test_compile_checks_mode_before_source to tests/test_parser.py, with the file's first assert_raises helper.

Testing

mx python-jvm on linux-aarch64, then mx graalpytest test_parser.py test_exec.py test_ast.py test_code.py (108 passed). test.test_compile, test.test_builtin and test.test_ast from lib-python report the same failures and errors as on master. The new test fails on the unpatched build. Twenty compile() call shapes, including valid exec, eval, single and func_type compiles, AST sources, and func_type without the flag, print the same as CPython 3.12.13 except compile(None, 'f', 'x', optimize=5), which raises TypeError instead of ValueError before and after this change.