release/21.x: [libclang/python] Return None instead of null cursors from Token.cursor (#163183)

[DeinAlptraum]

Backport 38a5282

[DeinAlptraum]

From #163183

[llvmbot]

@llvm/pr-subscribers-clang

Author: Jannick Kremer (DeinAlptraum)

Changes

Backport 38a5282

---

Full diff: https://github.com/llvm/llvm-project/pull/163961.diff

3 Files Affected:

• (modified) clang/bindings/python/clang/cindex.py (+2)
• (modified) clang/bindings/python/tests/cindex/test_tokens.py (+6)
• (modified) clang/docs/ReleaseNotes.rst (+1)

diff --git a/clang/bindings/python/clang/cindex.py b/clang/bindings/python/clang/cindex.py index 824674309d262..5ce7b5781bcb4 100644 --- a/clang/bindings/python/clang/cindex.py +++ b/clang/bindings/python/clang/cindex.py @@ -3853,6 +3853,8 @@ def cursor(self): cursor._tu = self._tu conf.lib.clang_annotateTokens(self._tu, byref(self), 1, byref(cursor)) + if cursor.is_null(): + return None return cursor diff --git a/clang/bindings/python/tests/cindex/test_tokens.py b/clang/bindings/python/tests/cindex/test_tokens.py index b6c1fc8b83600..6658579c63835 100644 --- a/clang/bindings/python/tests/cindex/test_tokens.py +++ b/clang/bindings/python/tests/cindex/test_tokens.py @@ -53,3 +53,9 @@ def test_token_extent(self): self.assertEqual(extent.start.offset, 4) self.assertEqual(extent.end.offset, 7) + + def test_null_cursor(self): + """Ensure that the cursor property converts null cursors to None""" + tu = get_tu("int i = 5;") + tokens = list(tu.get_tokens(extent=tu.cursor.extent)) + self.assertEqual(tokens[-1].cursor, None) diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 43529b0f28c3d..364ea632b40cb 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -94,6 +94,7 @@ Clang Frontend Potentially Breaking Changes Clang Python Bindings Potentially Breaking Changes -------------------------------------------------- +- Return ``None`` instead of null cursors from ``Token.cursor`` - ``Cursor.from_location`` now returns ``None`` instead of a null cursor. This eliminates the last known source of null cursors. - Almost all ``Cursor`` methods now assert that they are called on non-null cursors. 

[AaronBallman]

LGTM!

[DeinAlptraum]

I get
"Merging is blocked
Cannot update this protected ref."
Can one of you merge this?

[Endilll]

I get "Merging is blocked Cannot update this protected ref." Can one of you merge this?

No, it's up to the release managers to merge it.

[github-actions]

@DeinAlptraum (or anyone else). If you would like to add a note about this fix in the release notes (completely optional). Please reply to this comment with a one or two sentence description of the fix. When you are done, please add the release:note label to this PR.

[DeinAlptraum]

Return None instead of null cursors from Token.cursor. This fixes a bug in version 21 where cursors obtained via Token.Cursor were sometimes null cursors that produce errors when used.