[qt/clang/llvm-project]: Summary of bulk changes made

Git repository change summary for qt/clang/llvm-project
Pushed by mirror-service into branch 'upstream/users/kparzysz/special-clauses-default'.
Changed from 0000000000000000000000000000000000000000 to 9dab3510397947d5041808695bec1c8c41058725
Acknowledgement was received that this change introduces only existing code that has been pushed to another public open source repository.

This change contains the following new commits:

Git commit c4b89858f8f2d52d18007bc66a3a827c6bfa8151 by GitHub (on behalf of Zeyi Xu) on 26/07/2026 at 12:37..
[clang-tidy] Fix nested macro false positives in misc-redundant-expression (#209385)

Apply the existing macro-origin filtering when comparing flattened
operands in nested expressions.

Closes https://github.com/llvm/llvm-project/issues/209373
https://invent.kde.org/qt/clang/llvm-project/-/commit/c4b89858f8f2d52d18007bc66a3a827c6bfa8151

Git commit 0acd2c54da07dceebb78e94d256ed211a82031b9 by GitHub (on behalf of Zeyi Xu) on 26/07/2026 at 12:51..
[clang-tidy] Support Markdown documentation in rename_check.py (#210577)

Part of https://github.com/llvm/llvm-project/issues/201242
https://invent.kde.org/qt/clang/llvm-project/-/commit/0acd2c54da07dceebb78e94d256ed211a82031b9

Git commit 3678fa2b1ef60938ef61228145bb9c138367cf41 by GitHub (on behalf of Yingwei Zheng) on 26/07/2026 at 13:09..
[SimplifyCFG] Don't create new unreachable BB in `turnSwitchRangeIntoICmp` (#212035)

Previously we relied on `createUnreachableSwitchDefault` to remove
incoming edges in phi nodes and update DT. However, it also creates a
new unreachable BB and updates the default destination of the switch
instruction, which is about to be replaced by a branch instruction. This
patch inlines the function and removes logic about the new BB, to make
sure the DT is updated correctly.

This issue cannot be reproduced via
-simplifycfg-require-and-preserve-domtree=1. I just found it by checking
DT in requestResimplify (will be added after fixing all existing
issues). The following test covers this case:

https://github.com/llvm/llvm-project/blob/5bc304c65494702d9d4928ff6cb369e6e6496e53/llvm/test/Transforms/SimplifyCFG/switch-range-to-icmp.ll#L38-L73
https://invent.kde.org/qt/clang/llvm-project/-/commit/3678fa2b1ef60938ef61228145bb9c138367cf41

Git commit 28c8e8931546057c01c517086b99a17230cd4d70 by GitHub (on behalf of Balázs Benics) on 26/07/2026 at 13:58..
[llvm][ADT] Mark llvm::IntrusiveRefCntPtr with the warn_unused attribute (#211795)

IntrusiveRefCntPtr has non-trivial ctor/dtor, thus unused variables
wouldn't trigger a warning by default. However, they should.
https://clang.llvm.org/docs/AttributeReference.html#warn-unused

Let's mark the class with this attribute get warned about them.

This would have helped catching #211518 and #211517.
Supersedes #211647.

Some tests had to be uplifted because some bots used `-Werror` for those tests.
https://invent.kde.org/qt/clang/llvm-project/-/commit/28c8e8931546057c01c517086b99a17230cd4d70

Git commit c94c90b2efaa46520024b2bc8aa2caa30114cd55 by GitHub (on behalf of rdevshp) on 26/07/2026 at 14:08..
[analyzer] Fix _Atomic crashes for Z3 symbolic execution (#212050)

This PR fixes _Atomic crashes for Z3 symbolic execution by passing the
types through getAtomicUnqualifiedType and getCanonicalType and skip
casting in fromCast if `FromTy == ToTy && FromBitWidth == ToBitWidth`.

Assisted-by: Codex
https://invent.kde.org/qt/clang/llvm-project/-/commit/c94c90b2efaa46520024b2bc8aa2caa30114cd55

Git commit 9d601915fb9d3f4e6f7ee6e369ddff7fc20ad08d by GitHub (on behalf of Nikolas Klauser) on 26/07/2026 at 14:19..
[libc++abi][NFC] Remove some XFAILs which never trigger (#211241)

The oldest library we support is from LLVM 12, so we can remove any
XFAILs for libraries built before that.
https://invent.kde.org/qt/clang/llvm-project/-/commit/9d601915fb9d3f4e6f7ee6e369ddff7fc20ad08d

Git commit a81db64570f94c2ca8ac0f598c0b5bba1a7ae59e by GitHub (on behalf of Jackson Stogel) on 26/07/2026 at 14:25..
[libc][cpp::string] Allocate fewer temp strings in operator= and += (#210895)

This PR generally updates `cpp::string` to avoid incidental allocations.
Specifically, it:

- Updates `opreator=(string_view)` to avoid allocating a temporary
string:
https://github.com/llvm/llvm-project/blob/67ebc4b221c3e94028b33004cd5cd08deee95048/libc/src/__support/CPP/string.h#L106-L108
- Changes `operator+=(const string&)` to accept a `string_view` so that
strings may be appended without allocation.
- Makes the `string(string_view)` constructor explicit. Before, there
were non-obvious allocations because of the implicit conversion.

As a side effect, this PR has to more carefully handle self-assignment
and self-append. This PR updates append and assignment to avoid calling
`realloc` during append / assignment, as this may invalidate input
pointers held by `string_view` if they point to data held by the string.
This also fixes self-assignment, which previously didn't work, eg
`cpp::string s = "abc"; s = s;` would zero out `s`.
https://invent.kde.org/qt/clang/llvm-project/-/commit/a81db64570f94c2ca8ac0f598c0b5bba1a7ae59e

Git commit 150f33ce28956d80fc7617e477bb805ab062a28a by GitHub (on behalf of Michael G. Kazakov) on 26/07/2026 at 14:51..
[libc++][pstl] Implementation of a parallel std::mismatch() based on __pstl::__parallel_find() (#209291)

This PR adds a parallel version of `std::mismatch` as one of the backend
operations.
It also provides an implementation based on `__pstl::__parallel_find()`
which does the heavy lifting.
`libdispatch` and `std_thread` backends expose this implementation under
their backend tags, while the `serial` backend redirects the calls to
the serial `std::mismatch`.

4 flavours of the function are exposed: 3-legged, 3-legged with
predicate, 4-legged, 4-legged with predicate.
3-legged flavours are implemented in the `default` (`composition`)
backend by redirecting the call to the 4-legged flavours.

Included tests check that:

- Semantics of the iterator-only functions is correct.
- Semantics of the predicated functions is correct.
- Custom types are supported by the implementation.
- The functions correctly SFINAE out when the first argument is not an
execution policy.
- The `nodiscard` policy is followed.
- The `noexcept` policy is followed.
- `static_assert` verifies iterators' categories.

Part of #99938.
https://invent.kde.org/qt/clang/llvm-project/-/commit/150f33ce28956d80fc7617e477bb805ab062a28a

Git commit 1196889292e746c68ab3895508cb8eea05c17d15 by Krzysztof Parzyszek on 26/07/2026 at 15:46..
[flang][OpenMP] Split DEFAULT into DEFAULT(dsa) and DEFAULT(variant)

The 5.0 and 5.1 specs used DEFAULT clause for what is now OTHERWISE.
Separate these two claues to be able to specify their properties
independently.
https://invent.kde.org/qt/clang/llvm-project/-/commit/1196889292e746c68ab3895508cb8eea05c17d15

Git commit 9dab3510397947d5041808695bec1c8c41058725 by Krzysztof Parzyszek on 26/07/2026 at 15:53..
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https://invent.kde.org/qt/clang/llvm-project/-/commit/9dab3510397947d5041808695bec1c8c41058725