Description

sobolevn

opened on Mar 23, 2023

Issue body actions

Example:

This looks like a false-positive, because subobj is always initialized in stringlib_parse_args_finds(function_name, args, &subobj, &start, &end):

cpython/Objects/bytes_methods.c

Lines 770 to 786 in 87be8d9

	static PyObject *
	_Py_bytes_tailmatch(const char *str, Py_ssize_t len,
	const char *function_name, PyObject *args,
	int direction)
	{
	Py_ssize_t start = 0;
	Py_ssize_t end = PY_SSIZE_T_MAX;
	PyObject *subobj;
	int result;
	if (!stringlib_parse_args_finds(function_name, args, &subobj, &start, &end))
	return NULL;
	if (PyTuple_Check(subobj)) {
	Py_ssize_t i;
	for (i = 0; i < PyTuple_GET_SIZE(subobj); i++) {
	result = tailmatch(str, len, PyTuple_GET_ITEM(subobj, i),
	start, end, direction);

Morever, it is used before in PyTuple_Check(subobj).

Any ideas on how to fix / silence it?
And why we get this warning only now? The code was not changed for 10 months.

Linked PRs

• gh-102941: Fix "‘subobj’ may be used uninitialized in this function" warning in bytes_methods.c #102942

Activity

1. sobolevn

   added

   type-bugAn unexpected behavior, bug, or errorAn unexpected behavior, bug, or error

   interpreter-core(Objects, Python, Grammar, and Parser dirs)(Objects, Python, Grammar, and Parser dirs)

   on Mar 23, 2023
2. sobolevn commented on Mar 23, 2023

   

   sobolevn

   on Mar 23, 2023

   MemberAuthor

   More actions

   Maybe adding = NULL?
3. sobolevn

   self-assigned this

   on Mar 23, 2023
4. sobolevn

   added a commit that references this issue on Mar 23, 2023

   pythongh-102941: Fix "‘subobj’ may be used uninitialized in this func…

   f360cec
5. sobolevn

   changed the title [-]New warning: "‘subobj’ may be used uninitialized in this function" in ` Objects/bytes_methods.c`[/-] [+]New warning: "‘subobj’ may be used uninitialized in this function" in `Objects/bytes_methods.c`[/+] on Mar 23, 2023
6. JelleZijlstra

   added a commit that references this issue on Mar 27, 2023

   gh-102941: Fix "‘subobj’ may be used uninitialized in this function" …

   2cdc518
7. sobolevn

   closed this as completedon Mar 27, 2023
8. Fidget-Spinner

   added a commit that references this issue on Mar 27, 2023

   pythongh-102941: Fix "‘subobj’ may be used uninitialized in this func…

   0f312ec
9. warsaw

   added a commit that references this issue on Apr 11, 2023

   pythongh-102941: Fix "‘subobj’ may be used uninitialized in this func…

   0e351ba

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