Remove references to Unicode objects being ready

[picnixz]

We have some code referrencing readiness of Unicode objects but this property is deprecated (see #129894 (comment)). Following @encukou's advice, we should address each module with a separate PR so that experts can review them separately.

unicodedata.c

cpython/Modules/unicodedata.c

Lines 594 to 596 in a85eeb9

	/* result is guaranteed to be ready, as it is compact. */
	kind = PyUnicode_KIND(result);
	data = PyUnicode_DATA(result);

cpython/Modules/unicodedata.c

Lines 655 to 661 in a85eeb9

	result = nfd_nfkd(self, input, k);
	if (!result)
	return NULL;
	/* result will be "ready". */
	kind = PyUnicode_KIND(result);
	data = PyUnicode_DATA(result);
	len = PyUnicode_GET_LENGTH(result);

_io/textio.c

cpython/Modules/_io/textio.c

Lines 357 to 363 in a85eeb9

	kind = PyUnicode_KIND(modified);
	out = PyUnicode_DATA(modified);
	PyUnicode_WRITE(kind, out, 0, '\r');
	memcpy(out + kind, PyUnicode_DATA(output), kind * output_len);
	Py_SETREF(output, modified); /* output remains ready */
	self->pendingcr = 0;
	output_len++;

cpython/Modules/_io/textio.c

Lines 1821 to 1824 in a85eeb9

	/* decoded_chars is guaranteed to be "ready". */
	avail = (PyUnicode_GET_LENGTH(self->decoded_chars)
	- self->decoded_chars_used);

Parser files

cpython/Parser/lexer/lexer.c

Lines 311 to 315 in a85eeb9

	/* Verify that the identifier follows PEP 3131.
	All identifier strings are guaranteed to be "ready" unicode objects.
	*/
	static int
	verify_identifier(struct tok_state *tok)

cpython/Parser/pegen.c

Lines 505 to 513 in a85eeb9

	PyObject *
	_PyPegen_new_identifier(Parser *p, const char *n)
	{
	PyObject *id = PyUnicode_DecodeUTF8(n, (Py_ssize_t)strlen(n), NULL);
	if (!id) {
	goto error;
	}
	/* PyUnicode_DecodeUTF8 should always return a ready string. */
	assert(PyUnicode_IS_READY(id));

tracemalloc.c

cpython/Python/tracemalloc.c

Lines 252 to 259 in a85eeb9

	if (!PyUnicode_IS_READY(filename)) {
	/* Don't make a Unicode string ready to avoid reentrant calls
	to tracemalloc_alloc() or tracemalloc_realloc() */
	#ifdef TRACE_DEBUG
	tracemalloc_error("filename is not a ready unicode string");
	#endif
	return;
	}

This one seems to be dead code (cc @vstinner)

Linked PRs

• gh-130790: Remove references about unicode's readiness from comments #130801

[vstinner]

If it's just a few lines in each C file, a single PR would be more convenient.

[sergey-miryanov]

@picnixz Do you plan to work on this, or can I take it?

[picnixz]

I was planning to do it tomorrow, but feel free to take it. It's just that I don't know if we need to split into multiple PRs or in one. I haven't looked at the code exactly to see whether we can safely remove the comment/code so there might be some conditions that still need to be checked.

[sergey-miryanov]

@picnixz I allowed a little bit more to myself and updated the comments to public API. Is this ok?