[Clang][Doc] Edit the Clang release notes

[royjacobson]

Summary

Do a large edit of the Clang release notes.

This is meant to be merged into the Clang 16.x branch.

[rymiel]

I don't know sphinx enough to know if the trailing underscore is needed in links, but there's about 5 links that don't have the underscore (Search for

>`)

)

clang/docs/ReleaseNotes.rst

570

810

812

[erichkeane]

A handful of suggestions as I spot-checked. This looks great, thank you for doing this! I'd like Aaron to take a look though.

clang/docs/ReleaseNotes.rst

46

no-ops read awkwardly to me, so I'm hopeful that 'silently ignored' is a little more descriptive.

Perhaps, "deprecated and ignored" if that isn't accurate?

48–51

49

166

[royjacobson]

• Address comments from Erich and Emilia
• Validate that the rst actually builds an html file
• Fix some missing backticks and underscores

[royjacobson]

Thanks Erich and Emilia!

The html file is attached here, I think it's probably easier to proof read that way. (Took me a bit to figure out the CMake magic...)

ReleaseNotes.html110 KBDownload

[rymiel]

I think it's worthwhile to mark comments with the "Done" checkmark in Phrabricator if they have been addressed

[aaron.ballman]

clang/docs/ReleaseNotes.rst

447–449

Assuming https://github.com/llvm/llvm-project/issues/60337 gets ported to the 16.0 branch, this bullet can be removed entirely.

[aaron.ballman]

clang/docs/ReleaseNotes.rst

447–449

and that did land in 84f3164c1d9ce024f59221dcfbc8ab050de73748

[tschuett]

I am not the only one who has a different background. If the introduction says this is the introduction of the release notes, I am not super motivated to read on. I would prefer to see some highlights to motivate the readers to continue reading.

[royjacobson]

In D142578#4087974, @tschuett wrote:

I am not the only one who has a different background. If the introduction says this is the introduction of the release notes, I am not super motivated to read on. I would prefer to see some highlights to motivate the readers to continue reading.

You've mentioned what I think are separate issues - that this document is difficult to read for readers from different backgrounds and that the introduction might be too long or unengaging.

I mostly agree about the first point - I've tried to do what I could to make it more accessible but I don't think it's enough.

About the second point - I'm not really sure what to change. I think the 'potentially breaking changes' section is more important than the 'what's new' section, but the 'what's new' section IS the second section (and there's a table of contents). Are there specific topics you think we should remove from the introduction or move into the intro from the 'what's new' section? I'd like to avoid duplicating information if we can.

[tschuett]

IDK. Clang 16 is fully is a fully conformant C++20 except for some DRs. Or beginning with Clang 16, we start a long-term project to overhaul the diagnostics.

I agree that breaking changes are important.

[royjacobson]

• Remove redundant paragraph from the intro
• Remove outdated bug fix bullet

[royjacobson]

clang/docs/ReleaseNotes.rst

447–449

done.

[royjacobson]

In D142578#4088011, @tschuett wrote:

IDK. Clang 16 is fully is a fully conformant C++20 except for some DRs. Or beginning with Clang 16, we start a long-term project to overhaul the diagnostics.

I agree that breaking changes are important.

I contemplated on this for a bit, and I don't have anything that I feel is representative enough and fits into one paragraph. I'm still not against the general idea though.

[aaron.ballman]

Thank you for working on this, it is really shaping up nicely!

In D142578#4088769, @royjacobson wrote:

In D142578#4088011, @tschuett wrote:

IDK. Clang 16 is fully is a fully conformant C++20 except for some DRs. Or beginning with Clang 16, we start a long-term project to overhaul the diagnostics.

I agree that breaking changes are important.

I contemplated on this for a bit, and I don't have anything that I feel is representative enough and fits into one paragraph. I'm still not against the general idea though.

I think "major announcements" should be limited to things almost everyone will want to know about, like "we're changing our license" or "we've finished support for <major language revision>". So not every release will have major announcements, and that's fine -- we can remove any empty sections from the release notes.

clang/docs/ReleaseNotes.rst

16

Are you planning to merge the changes in generic text over to the trunk once this lands?

43

Do we want to mention that this may also impact build-time performance of projects relying on the default language standard mode, because C++17 pulls in a lot more compile-time-intensive APIs like constexpr and more template metaprogramming?

46

I don't know if we want to standardize on Clang-15 or Clang 15, etc. Feel free to edit as you see fit.

[royjacobson]

15 -> Clang 15

clang/docs/ReleaseNotes.rst

16

Yeah, absolutely!

43

I agree this change is annoying and has real life impact - I'm not trying to minimize it - but I think newer language versions bring enough benefits that we shouldn't warn users about using them in the Clang release notes. Especially since this doesn't come with any balancing context (like 'you can now use template variables instead of instantiating a struct every time you check if two types are equal' ;) )

46

Changed to Clang 15

[aaron.ballman]

clang/docs/ReleaseNotes.rst

43

That's fair! I was thinking of it from the perspective of whether we'll get bug reports or not. When we made the switch in-tree, some folks thought we introduced a compile time perf regression bad enough to warrant reverting the changes, which made me think users may probably think the same thing.

However, on reflection, I doubt that mentioning it in the release notes will actually mean less bug reports about it. :-P

[royjacobson]

Rebase to include the RISC-V changes.

[royjacobson]

friendly ping :)

[aaron.ballman]

LGTM, thank you for this, the new layout is a big improvement!

[royjacobson]

Landed in https://github.com/llvm/llvm-project/commit/be701ab08f12daf9437c2db6d08a1731cf1df34c

clang/docs/ReleaseNotes.rst

 ===========================================
 Clang |release| |ReleaseNotesTitle|
 ===========================================
 
 .. contents::
    :local:
    :depth: 2
 
 Written by the `LLVM Team <https://llvm.org/>`_
 
 .. only:: PreRelease
 
   .. warning::
      These are in-progress notes for the upcoming Clang |version| release.
      Release notes for previous releases can be found on
-     `the Download Page <https://releases.llvm.org/download.html>`_.
+     `the Releases Page <https://llvm.org/releases>`_.
 
 Introduction
 ============
 
 This document contains the release notes for the Clang C/C++/Objective-C
 frontend, part of the LLVM Compiler Infrastructure, release |release|. Here we
 describe the status of Clang in some detail, including major
 improvements from the previous release and new feature work. For the
 general LLVM release notes, see `the LLVM
-documentation <https://llvm.org/docs/ReleaseNotes.html>`_. All LLVM
-releases may be downloaded from the `LLVM releases web
-site <https://llvm.org/releases/>`_.
+documentation <https://llvm.org/docs/ReleaseNotes.html>`_. For the libc++ release notes,
+see `this page <https://libcxx.llvm.org/ReleaseNotes.html>`_. All LLVM releases
+may be downloaded from the `LLVM releases web site <https://llvm.org/releases/>`_.
 
 For more information about Clang or LLVM, including information about the
 latest release, please see the `Clang Web Site <https://clang.llvm.org>`_ or the
 `LLVM Web Site <https://llvm.org>`_.
 
-Note that if you are reading this file from a Git checkout or the
-main Clang web page, this document applies to the *next* release, not
-the current one. To see the release notes for a specific release, please
-see the `releases page <https://llvm.org/releases/>`_.
-
 Potentially Breaking Changes
 ============================
 These changes are ones which we think may surprise users when upgrading to
 Clang |release| because of the opportunity they pose for disruption to existing
 code bases.
 
-- Clang will now correctly diagnose as ill-formed a constant expression where an
-  enum without a fixed underlying type is set to a value outside the range of
-  the enumeration's values.
-
-  .. code-block:: c++
+- Clang's default C++/ObjC++ standard is now ``gnu++17`` instead of ``gnu++14``.
+  This means Clang will by default accept code using features from C++17 and
+  conforming GNU extensions. Projects incompatible with C++17 can add
+  ``-std=gnu++14`` to their build settings to restore the previous behaviour.
 
-    enum E { Zero, One, Two, Three, Four };
-    constexpr E Val1 = (E)3;  // Ok
-    constexpr E Val2 = (E)7;  // Ok
-    constexpr E Val3 = (E)8;  // Now diagnosed as out of the range [0, 7]
-    constexpr E Val4 = (E)-1; // Now diagnosed as out of the range [0, 7]
+- The ``-fexperimental-new-pass-manager`` and ``-fno-legacy-pass-manager``
+  flags have been removed. These flags have been silently ignored since 15.
 
-  Due to the extended period of time this bug was present in major C++
-  implementations (including Clang), this error has the ability to be
-  downgraded into a warning (via: ``-Wno-error=enum-constexpr-conversion``) to
-  provide a transition period for users. This diagnostic is expected to turn
-  into an error-only diagnostic in the next Clang release. Fixes
-  `Issue 50055 <https://github.com/llvm/llvm-project/issues/50055>`_.
+- Clang's resource directory path previously included the full clang version.
+  It now includes only the major version. The new resource directory is
+  ``$prefix/lib/clang/$CLANG_MAJOR_VERSION`` and can be queried using
+  ``clang -print-resource-dir``, just like before.
 
 - The ``-Wimplicit-function-declaration`` and ``-Wimplicit-int`` warnings
   now default to an error in C99, C11, and C17. As of C2x,
   support for implicit function declarations and implicit int has been removed,
   and the warning options will have no effect. Specifying ``-Wimplicit-int`` in
   C89 mode will now issue warnings instead of being a noop.
 
   **NOTE**: We recommend that projects using configure scripts verify that the
- ``-Wincompatible-function-pointer-types`` now defaults to an error in all C
 
   .. code-block:: c
 
     void func(const int *i);
     void other(void) {
       void (*fp)(int *) = func; // Previously a warning, now a downgradable error.
     }
 
+- To match GCC, ``__ppc64__`` is no longer defined on PowerPC64 targets. Use
+  ``__powerpc64__`` instead.
+
+- ``-p`` is rejected for all targets which are not AIX or OpenBSD. ``-p`` led
+  to an ``-Wunused-command-line-argument`` warning in previous releases.
+
+C/C++ Language Potentially Breaking Changes
+-------------------------------------------
+
 - Clang now disallows types whose sizes aren't a multiple of their alignments
   to be used as the element type of arrays.
 
   .. code-block:: c
 
     typedef char int8_a16 __attribute__((aligned(16)));
     int8_a16 array[4]; // Now diagnosed as the element size not being a multiple of the array alignment.
 
 - When compiling for Windows in MSVC compatibility mode (for example by using
   clang-cl), the compiler will now propagate dllimport/export declspecs in
-  explicit specializations of class template member functions (`Issue 54717
+  explicit specializations of class template member functions (`#54717
   <https://github.com/llvm/llvm-project/issues/54717>`_):
 
   .. code-block:: c++
 
     template <typename> struct __declspec(dllexport) S {
       void f();
     };
     template<> void S<int>::f() {}  // clang-cl will now dllexport this.
.. code-block:: c++
 
     void func(void *p) {
       *p; // Now diagnosed as a warning-as-error.
     }
 
 - Clang now diagnoses use of a bit-field as an instruction operand in Microsoft
   style inline asm blocks as an error. Previously, a bit-field operand yielded
   the address of the allocation unit the bit-field was stored within; reads or
-  writes therefore had the potential to read or write nearby bit-fields. This
-  change fixes `issue 57791 <https://github.com/llvm/llvm-project/issues/57791>`_.
+  writes therefore had the potential to read or write nearby bit-fields.
+  (`#57791 <https://github.com/llvm/llvm-project/issues/57791>`_)
 
   .. code-block:: c++
 
     typedef struct S {
       unsigned bf:1;
     } S;
     void f(S s) {
       __asm {
         mov eax, s.bf // Now diagnosed as an error.
         mov s.bf, eax // Now diagnosed as an error.
       }
     }
 
-- The ``-fexperimental-new-pass-manager`` and ``-fno-legacy-pass-manager``
-  flags have been removed. These have been no-ops since 15.0.0.
+- Clang now diagnoses if structs/unions with the same name are different in
+  different used modules. Behavior in C and Objective-C language modes now is
+  the same as in C++.
+
+C++ Specific Potentially Breaking Changes
+-----------------------------------------
+- Clang now prohibits non-inline externally-visible definitions in C++
+  standard header units as per ``[module.import/6]``.  In Clang-15,
+  these definitions were allowed.  Note that such definitions are ODR
+  violations if the header is included more than once.
+
+- Clang will now correctly diagnose as ill-formed a constant expression where an
+  enum without a fixed underlying type is set to a value outside the range of
+  the enumeration's values.
+
+  .. code-block:: c++
+
+    enum E { Zero, One, Two, Three, Four };
+    constexpr E Val1 = (E)3;  // Ok
+    constexpr E Val2 = (E)7;  // Ok
+    constexpr E Val3 = (E)8;  // Now diagnosed as out of the range [0, 7]
+    constexpr E Val4 = (E)-1; // Now diagnosed as out of the range [0, 7]
+
+  Due to the extended period of time this bug was present in major C++
+  implementations (including Clang), this error has the ability to be
+  downgraded into a warning (via: ``-Wno-error=enum-constexpr-conversion``) to
+  provide a transition period for users. This diagnostic is expected to turn
+  into an error-only diagnostic in the next Clang release.
+  (`#50055 <https://github.com/llvm/llvm-project/issues/50055>`_)
 
 - As a side effect of implementing DR692/DR1395/DR1432, Clang now rejects some
   overloaded function templates as ambiguous when one of the candidates has a
   trailing parameter pack.
 
   .. code-block:: c++
 
     template <typename T> void g(T, T = T());
     template <typename T, typename... U> void g(T, U...);
     void h() {
       // This is rejected due to ambiguity between the pack and the
       // default argument. Only parameters with arguments are considered during
       // partial ordering of function templates.
       g(42);
     }
 
-- Clang's resource dir used to include the full clang version. It will now
-  include only the major version. The new resource directory is
-  ``$prefix/lib/clang/$CLANG_MAJOR_VERSION`` and can be queried using
-  ``clang -print-resource-dir``, just like before.
-
-- To match GCC, ``__ppc64__`` is no longer defined on PowerPC64 targets. Use
-  ``__powerpc64__`` instead.
-
-- ``-p`` is rejected for all targets which are not AIX or OpenBSD. ``-p`` led
-  to an ``-Wunused-command-line-argument`` warning in previous releases.
-
-- Clang now diagnoses non-inline externally-visible definitions in C++
-  standard header units as per ``[module.import/6]``.  Previously, in Clang-15,
-  these definitions were allowed.  Note that such definitions are ODR
-  violations if the header is included more than once.
-
-- Clang now diagnoses if structs/unions with the same name are different in
-  different used modules. Behavior in C and Objective-C language modes now is
-  the same as in C++.
+ABI Changes in This Version
+---------------------------
+- GCC doesn't pack non-POD members in packed structs unless the packed
+  attribute is also specified on the member. Clang historically did perform
+  such packing. Clang now matches the gcc behavior
+  (except on Darwin, PS4 and AIX).
+  You can switch back to the old ABI behavior with the flag:
+  ``-fclang-abi-compat=15.0``.
+- GCC allows POD types to have defaulted special members. Clang historically
+  classified such types as non-POD (for the purposes of Itanium ABI). Clang now
+  matches the gcc behavior (except on Darwin, PS4, AIX and z/OS). You can switch
+  back to the old ABI behavior with the flag: ``-fclang-abi-compat=15.0``.
 
 What's New in Clang |release|?
 ==============================
 Some of the major new features and improvements to Clang are listed
 here. Generic improvements to Clang as a whole or to its underlying
 infrastructure are described first, followed by language-specific
 sections with improvements to Clang's support for those languages.
 
-Major New Features
-------------------
+C++ Language Changes
+--------------------
 
-Bug Fixes
----------
-- ``stdatomic.h`` will use the internal declarations when targeting pre-C++-23
-  on Windows platforms as the MSVC support requires newer C++ standard.
-- Correct ``_Static_assert`` to accept the same set of extended integer
-  constant expressions as is accpted in other contexts that accept them.
-  This fixes `Issue 57687 <https://github.com/llvm/llvm-project/issues/57687>`_.
-- Fixes an accepts-invalid bug in C when using a ``_Noreturn`` function
-  specifier on something other than a function declaration. This fixes
-  `Issue 56800 <https://github.com/llvm/llvm-project/issues/56800>`_.
-- Fix `#56772 <https://github.com/llvm/llvm-project/issues/56772>`_ - invalid
-  destructor names were incorrectly accepted on template classes.
-- Improve compile-times with large dynamic array allocations with trivial
-  constructors. This fixes
-  `Issue 56774 <https://github.com/llvm/llvm-project/issues/56774>`_.
-- No longer assert/miscompile when trying to make a vectorized ``_BitInt`` type
-  using the ``ext_vector_type`` attribute (the ``vector_size`` attribute was
-  already properly diagnosing this case).
-- Fix clang not properly diagnosing the failing subexpression when chained
-  binary operators are used in a ``static_assert`` expression.
-- Fix a crash when evaluating a multi-dimensional array's array filler
-  expression is element-dependent. This fixes
-  `Issue 50601 <https://github.com/llvm/llvm-project/issues/56016>`_.
-- Fixed a crash-on-valid with consteval evaluation of a list-initialized
-  constructor for a temporary object. This fixes
-  `Issue 55871 <https://github.com/llvm/llvm-project/issues/55871>`_.
-- Fix `#57008 <https://github.com/llvm/llvm-project/issues/57008>`_ - Builtin
-  C++ language extension type traits instantiated by a template with unexpected
-  number of arguments cause an assertion fault.
-- Fix multi-level pack expansion of undeclared function parameters.
-  This fixes `Issue 56094 <https://github.com/llvm/llvm-project/issues/56094>`_.
-- Fix `#57151 <https://github.com/llvm/llvm-project/issues/57151>`_.
-  ``-Wcomma`` is emitted for void returning functions.
-- ``-Wtautological-compare`` missed warnings for tautological comparisons
-  involving a negative integer literal. This fixes
-  `Issue 42918 <https://github.com/llvm/llvm-project/issues/42918>`_.
-- Fix a crash when generating code coverage information for an
-  ``if consteval`` statement. This fixes
-  `Issue 57377 <https://github.com/llvm/llvm-project/issues/57377>`_.
-- Fix assert that triggers a crash during template name lookup when a type was
-  incomplete but was not also a TagType. This fixes
-  `Issue 57387 <https://github.com/llvm/llvm-project/issues/57387>`_.
-- Fix a crash when emitting a concept-related diagnostic. This fixes
-  `Issue 57415 <https://github.com/llvm/llvm-project/issues/57415>`_.
-- Fix a crash when attempting to default a virtual constexpr non-special member
-  function in a derived class. This fixes
-  `Issue 57431 <https://github.com/llvm/llvm-project/issues/57431>`_
-- Fix a crash where we attempt to define a deleted destructor. This fixes
-  `Issue 57516 <https://github.com/llvm/llvm-project/issues/57516>`_
-- Fix ``__builtin_assume_aligned`` crash when the 1st arg is array type. This fixes
-  `Issue 57169 <https://github.com/llvm/llvm-project/issues/57169>`_
-- Clang configuration files are now read through the virtual file system
-  rather than the physical one, if these are different.
-- Clang will now no longer treat a C 'overloadable' function without a prototype as
-  a variadic function with the attribute.  This should make further diagnostics more
-  clear.
-- Fixes to builtin template emulation of regular templates.
-  `Issue 42102 <https://github.com/llvm/llvm-project/issues/42102>`_
-  `Issue 51928 <https://github.com/llvm/llvm-project/issues/51928>`_
-- A SubstTemplateTypeParmType can now represent the pack index for a
-  substitution from an expanded pack.
-  `Issue 56099 <https://github.com/llvm/llvm-project/issues/56099>`_
-- Fix `-Wpre-c++17-compat` crashing Clang when compiling C++20 code which
-  contains deduced template specializations. This Fixes
-  `Issue 57369 <https://github.com/llvm/llvm-project/issues/57369>`_
-  `Issue 57643 <https://github.com/llvm/llvm-project/issues/57643>`_
-  `Issue 57793 <https://github.com/llvm/llvm-project/issues/57793>`_
-- Respect constructor constraints during class template argument deduction (CTAD).
-  This is the suggested resolution to CWG DR2628.
-  `Issue 57646 <https://github.com/llvm/llvm-project/issues/57646>`_
-  `Issue 43829 <https://github.com/llvm/llvm-project/issues/43829>`_
-- Fixed a crash in C++20 mode in Clang and Clangd when compile source
-  with compilation errors.
-  `Issue 53628 <https://github.com/llvm/llvm-project/issues/53628>`_
-- The template arguments of a variable template being accessed as a
-  member will now be represented in the AST.
-- Fix incorrect handling of inline builtins with asm labels.
-- Finished implementing C++ DR2565, which results in a requirement becoming
-  not satisfied in the event of an instantiation failures in a requires expression's
-  parameter list. We previously handled this correctly in a constraint evaluation
-  context, but not in a requires clause evaluated as a boolean.
-- Address the thread identification problems in coroutines.
-  `Issue 47177 <https://github.com/llvm/llvm-project/issues/47177>`_
-  `Issue 47179 <https://github.com/llvm/llvm-project/issues/47179>`_
-- Fix a crash upon stray coloncolon token in C2x mode.
-- Reject non-type template arguments formed by casting a non-zero integer
-  to a pointer in pre-C++17 modes, instead of treating them as null
-  pointers.
-- Fix template arguments of pointer and reference not taking the type as
-  part of their identity.
-  `Issue 47136 <https://github.com/llvm/llvm-project/issues/47136>`_
-- Fix a crash when trying to form a recovery expression on a call inside a
-  constraint, which re-evaluated the same constraint.
-  `Issue 53213 <https://github.com/llvm/llvm-project/issues/53213>`_
-  `Issue 45736 <https://github.com/llvm/llvm-project/issues/45736>`_
-- Fix an issue when performing constraints partial ordering on non-template
-  functions. `Issue 56154 <https://github.com/llvm/llvm-project/issues/56154>`_
-- Fix handling of unexpanded packs in template argument expressions.
-  `Issue 58679 <https://github.com/llvm/llvm-project/issues/58679>`_
-- Fix a crash when a ``btf_type_tag`` attribute is applied to the pointee of
-  a function pointer.
-- Fix a number of recursively-instantiated constraint issues, which would possibly
-  result in a stack overflow.
-  `Issue 44304 <https://github.com/llvm/llvm-project/issues/44304>`_
-  `Issue 50891 <https://github.com/llvm/llvm-project/issues/50891>`_
-- Clang 14 predeclared some builtin POSIX library functions in ``gnu2x`` mode,
-  and Clang 15 accidentally stopped predeclaring those functions in that
-  language mode. Clang 16 now predeclares those functions again. This fixes
-  `Issue 56607 <https://github.com/llvm/llvm-project/issues/56607>`_.
-- GNU attributes being applied prior to standard attributes would be handled
-  improperly, which was corrected to match the behaviour exhibited by GCC.
-  `Issue 58229 <https://github.com/llvm/llvm-project/issues/58229>`_
-- The builtin type trait ``__is_aggregate`` now returns ``true`` for arrays of incomplete
-  types in accordance with the suggested fix for `LWG3823 <https://cplusplus.github.io/LWG/issue3823>`_
-- Fix bug with using enum that could lead to enumerators being treated as if
-  they were part of an overload set. This fixes
-  `Issue 58067 <https://github.com/llvm/llvm-project/issues/58057>`_
-  `Issue 59014 <https://github.com/llvm/llvm-project/issues/59014>`_
-  `Issue 54746 <https://github.com/llvm/llvm-project/issues/54746>`_
-- Fix assert that triggers a crash during some types of list initialization that
-  generate a CXXTemporaryObjectExpr instead of a InitListExpr. This fixes
-  `Issue 58302 <https://github.com/llvm/llvm-project/issues/58302>`_
-  `Issue 58753 <https://github.com/llvm/llvm-project/issues/58753>`_
-  `Issue 59100 <https://github.com/llvm/llvm-project/issues/59100>`_
-- Fix issue using __attribute__((format)) on non-variadic functions that expect
-  more than one formatted argument.
-- Fix bug where constant evaluation treated a pointer to member that points to
-  a weak member as never being null. Such comparisons are now treated as
-  non-constant.
-- Fix sanity check when value initializing an empty union so that it takes into
-  account anonymous structs which is a GNU extension. This fixes
-  `Issue 58800 <https://github.com/llvm/llvm-project/issues/58800>`_
-- Fix an issue that triggers a crash if we instantiate a hidden friend functions.
-  This fixes `Issue 54457 <https://github.com/llvm/llvm-project/issues/54457>`_
-- Fix an issue where -frewrite-includes generated line control directives with
-  incorrect line numbers in some cases when a header file used an end of line
-  character sequence that differed from the primary source file.
-  `Issue 59736 <https://github.com/llvm/llvm-project/issues/59736>`_
-- In C mode, when ``e1`` has ``__attribute__((noreturn))`` but ``e2`` doesn't,
-  ``(c ? e1 : e2)`` is no longer considered noreturn.
-  `Issue 59792 <https://github.com/llvm/llvm-project/issues/59792>`_
-- Fix an issue that makes Clang crash on lambda template parameters. This fixes
-  `Issue 57960 <https://github.com/llvm/llvm-project/issues/57960>`_
-- Fix issue that the standard C++ modules importer will call global
-  constructor/destructor for the global varaibles in the importing modules.
-  This fixes `Issue 59765 <https://github.com/llvm/llvm-project/issues/59765>`_
-- Reject in-class defaulting of previosly declared comparison operators. Fixes
-  `Issue 51227 <https://github.com/llvm/llvm-project/issues/51227>`_.
-- Fix the bug of inserting the ``ZeroInitializationFixit`` before the template
-  argument list of ``VarTemplateSpecializationDecl``.
+C++20 Feature Support
+^^^^^^^^^^^^^^^^^^^^^
 
-Improvements to Clang's diagnostics
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-- Disabled FIT-IT suggested for a case of bad conversion in system headers.
-- Clang will now check compile-time determinable string literals as format strings.
-  Fixes `Issue 55805: <https://github.com/llvm/llvm-project/issues/55805>`_.
-- ``-Wformat`` now recognizes ``%b`` for the ``printf``/``scanf`` family of
-  functions and ``%B`` for the ``printf`` family of functions. Fixes
-  `Issue 56885: <https://github.com/llvm/llvm-project/issues/56885>`_.
-- Introduced ``-Wsingle-bit-bitfield-constant-conversion``, grouped under
-  ``-Wbitfield-constant-conversion``, which diagnoses implicit truncation when
-  ``1`` is assigned to a 1-bit signed integer bitfield. This fixes
-  `Issue 53253 <https://github.com/llvm/llvm-project/issues/53253>`_. To reduce
-  potential false positives, this diagnostic will not diagnose use of the
-  ``true`` macro (from ``<stdbool.h>>`) in C language mode despite the macro
-  being defined to expand to ``1``.
-- Clang will now print more information about failed static assertions. In
-  particular, simple static assertion expressions are evaluated to their
-  compile-time value and printed out if the assertion fails.
-- Diagnostics about uninitialized ``constexpr`` varaibles have been improved
-  to mention the missing constant initializer.
-- Correctly diagnose a future keyword if it exist as a keyword in the higher
-  language version and specifies in which version it will be a keyword. This
-  supports both c and c++ language.
-- When diagnosing multi-level pack expansions of mismatched lengths, Clang will
-  now, in most cases, be able to point to the relevant outer parameter.
-- ``no_sanitize("...")`` on a global variable for known but not relevant
-  sanitizers is now just a warning. It now says that this will be ignored
-  instead of incorrectly saying no_sanitize only applies to functions and
-  methods.
-- No longer mention ``reinterpet_cast`` in the invalid constant expression
-  diagnostic note when in C mode.
-- Clang will now give a more suitale diagnostic for declaration of block
-  scope identifiers that have external/internal linkage that has an initializer.
-  Fixes `Issue 57478: <https://github.com/llvm/llvm-project/issues/57478>`_.
-- New analysis pass will now help preserve sugar when combining deductions, in an
-  order agnostic way. This will be in effect when deducing template arguments,
-  when deducing function return type from multiple return statements, for the
-  conditional operator, and for most binary operations. Type sugar is combined
-  in a way that strips the sugar which is different between terms, and preserves
-  those which are common.
-- Correctly diagnose use of an integer literal without a suffix whose
-  underlying type is ``long long`` or ``unsigned long long`` as an extension in
-  C89 mode . Clang previously only diagnosed if the literal had an explicit
-  ``LL`` suffix.
-- Clang now correctly diagnoses index that refers past the last possible element
-  of FAM-like arrays.
-- Clang now correctly diagnoses a warning when defercencing a void pointer in C mode.
-  This fixes `Issue 53631 <https://github.com/llvm/llvm-project/issues/53631>`_
-- Clang will now diagnose an overload set where a candidate has a constraint that
-  refers to an expression with a previous error as nothing viable, so that it
-  doesn't generate strange cascading errors, particularly in cases where a
-  subsuming constraint fails, which would result in a less-specific overload to
-  be selected.
-- Add a fix-it hint for the ``-Wdefaulted-function-deleted`` warning to
-  explicitly delete the function.
-- Fixed an accidental duplicate diagnostic involving the declaration of a
-  function definition without a prototype which is preceded by a static
-  declaration of the function with a prototype. Fixes
-  `Issue 58181 <https://github.com/llvm/llvm-project/issues/58181>`_.
-- Copy-elided initialization of lock scopes is now handled differently in
-  ``-Wthread-safety-analysis``: annotations on the move constructor are no
-  longer taken into account, in favor of annotations on the function returning
-  the lock scope by value. This could result in new warnings if code depended
-  on the previous undocumented behavior. As a side effect of this change,
-  constructor calls outside of initializer expressions are no longer ignored,
-  which can result in new warnings (or make existing warnings disappear).
-- The wording of diagnostics regarding arithmetic on fixed-sized arrays and
-  pointers is improved to include the type of the array and whether it's cast
-  to another type. This should improve comprehension for why an index is
-  out-of-bounds.
-- Clang now correctly points to the problematic parameter for the ``-Wnonnull``
-  warning. This fixes
-  `Issue 58273 <https://github.com/llvm/llvm-project/issues/58273>`_.
-- Introduced ``-Wcast-function-type-strict`` and
-  ``-Wincompatible-function-pointer-types-strict`` to warn about function type
-  mismatches in casts and assignments that may result in runtime indirect call
-  `Control-Flow Integrity (CFI)
-  <https://clang.llvm.org/docs/ControlFlowIntegrity.html>`_ failures. The
-  ``-Wcast-function-type-strict`` diagnostic is grouped under
-  ``-Wcast-function-type`` as it identifies a more strict set of potentially
-  problematic function type casts.
-- Clang will now disambiguate NTTP types when printing diagnostic that contain NTTP types.
-  Fixes `Issue 57562 <https://github.com/llvm/llvm-project/issues/57562>`_.
-- Better error recovery for pack expansion of expressions.
-  `Issue 58673 <https://github.com/llvm/llvm-project/issues/58673>`_.
-- Better diagnostics when the user has missed `auto` in a declaration.
-  `Issue 49129 <https://github.com/llvm/llvm-project/issues/49129>`_.
-- Clang now diagnoses use of invalid or reserved module names in a module
-  export declaration. Both are diagnosed as an error, but the diagnostic is
-  suppressed for use of reserved names in a system header.
-- ``-Winteger-overflow`` will diagnose overflow in more cases. This fixes
-  `Issue 58944 <https://github.com/llvm/llvm-project/issues/58944>`_.
-- Clang has an internal limit of 2GB of preprocessed source code per
-  compilation, including source reachable through imported AST files such as
-  PCH or modules. When Clang hits this limit, it now produces notes mentioning
-  which header and source files are consuming large amounts of this space.
-  ``#pragma clang __debug sloc_usage`` can also be used to request this report.
-- Clang no longer permits the keyword 'bool' in a concept declaration as a
-  concepts-ts compatibility extension.
-- Clang now diagnoses overflow undefined behavior in a constant expression while
-  evaluating a compound assignment with remainder as operand.
-- Add ``-Wreturn-local-addr``, a GCC alias for ``-Wreturn-stack-address``.
-- Clang now suppresses ``-Wlogical-op-parentheses`` on ``(x && a || b)`` and ``(a || b && x)``
-  only when ``x`` is a string literal.
-- Clang will now reject the GNU extension address of label in coroutines explicitly.
-  This fixes `Issue 56436 <https://github.com/llvm/llvm-project/issues/56436>`_.
-- Clang now automatically adds ``[[clang::lifetimebound]]`` to the parameters of
-  ``std::move, std::forward`` et al, this enables Clang to diagnose more cases
-  where the returned reference outlives the object.
+Newly implemented papers:
+
+- Implemented `P0848: Conditionally Trivial Special Member Functions <https://wg21.link/p0848r3>`_.
+  Note: The handling of deleted functions is not yet compliant, as Clang
+  does not implement `DR1496 <https://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#1496>`_
+  and `DR1734 <https://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#1734>`_.
+
+- Implemented `P1091R3 <https://wg21.link/p1091r3>`_ and `P1381R1 <https://wg21.link/P1381R1>`_ to
+  support capturing structured bindings in lambdas (`#52720 <https://github.com/llvm/llvm-project/issues/52720>`_,
+  `#54300 <https://github.com/llvm/llvm-project/issues/54300>`_,
+  `#54301 <https://github.com/llvm/llvm-project/issues/54301>`_,
+  `#49430 <https://github.com/llvm/llvm-project/issues/49430>`_).
+
+- Implemented `P2468R2: The Equality Operator You Are Looking For <http://wg21.link/p2468r2>`_.
+
+- Implemented `P2113R0: Proposed resolution for 2019 comment CA 112 <https://wg21.link/P2113R0>`_
+  ([temp.func.order]p6.2.1 is not implemented, matching GCC).
+
+- Implemented `P0634R3: Down with typename! <https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0634r3.html>`_,
+  which removes the requirement for the ``typename`` keyword in certain contexts.
+
+- Implemented `P0857R0: Fixing small-ish functionality gaps in constraints <https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0857r0.html>`_,
+  which specifies constrained lambdas and constrained template *template-parameter*\s.
+
+- Implemented `P0960R3 <https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0960r3.html>`_
+  and `P1975R0 <https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1975r0.html>`_,
+  which allow parenthesized aggregate-initialization.
+
+Notable Bug Fixes to C++20 Features:
+
+- Clang now correctly delays the instantiation of function constraints until
+  the time of checking, which should now allow the libstdc++ ranges implementation
+  to work for at least trivial examples.
+  (`#44178 <https://github.com/llvm/llvm-project/issues/44178>`_)
+
+- Consider explicitly defaulted constexpr/consteval special member function
+  template instantiation to be constexpr/consteval even though a call to such
+  a function cannot appear in a constant expression.
+  (C++14 [dcl.constexpr]p6 (CWG DR647/CWG DR1358))
+
+- Correctly defer dependent immediate function invocations until template instantiation.
+  (`#55601 <https://github.com/llvm/llvm-project/issues/55601>`_)
+
+- Correctly set expression evaluation context as 'immediate function context' in
+  consteval functions.
+  (`#51182 <https://github.com/llvm/llvm-project/issues/51182>`_)
+
+- Skip rebuilding lambda expressions in arguments of immediate invocations.
+  (`#56183 <https://github.com/llvm/llvm-project/issues/56183>`_,
+  `#51695 <https://github.com/llvm/llvm-project/issues/51695>`_,
+  `#50455 <https://github.com/llvm/llvm-project/issues/50455>`_,
+  `#54872 <https://github.com/llvm/llvm-project/issues/54872>`_,
+  `#54587 <https://github.com/llvm/llvm-project/issues/54587>`_)
+
+- Clang implements DR2621, correcting a defect in ``using enum`` handling.  The
+  name is found via ordinary lookup so typedefs are found.
+
+- Implemented CWG2635 as a Defect Report, which prohibits structured bindings from being constrained.
 
-Non-comprehensive list of changes in this release
--------------------------------------------------
-- It's now possible to set the crash diagnostics directory through
-  the environment variable ``CLANG_CRASH_DIAGNOSTICS_DIR``.
-  The ``-fcrash-diagnostics-dir`` flag takes precedence.
 - When using header modules, inclusion of a private header and violations of
   the `use-declaration rules
   <https://clang.llvm.org/docs/Modules.html#use-declaration>`_ are now
   diagnosed even when the includer is a textual header. This change can be
   temporarily reversed with ``-Xclang
   -fno-modules-validate-textual-header-includes``, but this flag will be
   removed in a future Clang release.
+
+C++2b Feature Support
+^^^^^^^^^^^^^^^^^^^^^
+- Implemented `P2324R2: Support label at end of compound statement <https://wg21.link/p2324r2>`_.
+- Implemented `P1169R4: static operator() <https://wg21.link/P1169R4>`_ and `P2589R1: static operator[] <https://wg21.link/P2589R1>`_.
+- Implemented `P2513R3: char8_t Compatibility and Portability Fix <https://wg21.link/P2513R3>`_.
+  This change was applied to C++20 as a Defect Report.
+- Implemented `P2647R1: Permitting static constexpr variables in constexpr functions <https://wg21.link/P2647R1>`_.
+- Implemented `CWG2640: Allow more characters in an n-char sequence <https://wg21.link/CWG2640>`_.
+
+Resolutions to C++ Defect Reports
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+- Implemented `DR692 <https://wg21.link/cwg692>`_, `DR1395 <https://wg21.link/cwg1395>`_,
+  and `DR1432 <https://wg21.link/cwg1432>`_. The fix for DR1432 is speculative since the
+  issue is still open and has no proposed resolution at this time. A speculative fix
+  for DR1432 is needed to prevent regressions that would otherwise occur due to DR692.
+- Implemented `DR2358 <https://wg21.link/cwg2358>`_, which allows init captures in lambdas in default arguments.
+- Implemented `DR2654 <https://wg21.link/cwg2654>`_ which undeprecates
+  all compound assignments operations on volatile qualified variables.
+- Implemented `DR2631 <https://wg21.link/cwg2631>`_. Invalid ``consteval`` calls in default arguments and default
+  member initializers are diagnosed when and if the default is used.
+  This changes the value of ``std::source_location::current()``
+  used in default parameters calls compared to previous versions of Clang.
+  (`#56379 <https://github.com/llvm/llvm-project/issues/56379>`_)
+
+C Language Changes
+------------------
+- Adjusted ``-Wformat`` warnings according to `WG14 N2562 <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2562.pdf>`_.
+  Clang will now consider default argument promotions in ``printf``, and remove
+  unnecessary warnings. Especially ``int`` argument with specifier ``%hhd`` and
+  ``%hd``.
+
+C2x Feature Support
+^^^^^^^^^^^^^^^^^^^
+- Implemented `WG14 N2662 <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2662.pdf>`_,
+  so the ``[[maybe_unused]]`` attribute may be applied to a label to silence an
+  ``-Wunused-label`` warning.
+- Implemented `WG14 N2508 <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2508.pdf>`_,
+  so labels can placed everywhere inside a compound statement.
+- Implemented `WG14 N2927 <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2927.htm>`_,
+  the Not-so-magic ``typeof`` operator. Also implemented
+  `WG14 N2930 <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2930.pdf>`_,
+  renaming ``remove_quals``, so the ``typeof_unqual`` operator is also
+  supported. Both of these operators are supported only in C2x mode. The
+  ``typeof`` operator specifies the type of the given parenthesized expression
+  operand or type name, including all qualifiers. The ``typeof_unqual``
+  operator is similar to ``typeof`` except that all qualifiers are removed,
+  including atomic type qualification and type attributes which behave like a
+  qualifier, such as an address space attribute.
+
+  .. code-block:: c
+
+    __attribute__((address_space(1))) const _Atomic int Val;
+    typeof(Val) OtherVal; // type is '__attribute__((address_space(1))) const _Atomic int'
+    typeof_unqual(Val) OtherValUnqual; // type is 'int'
+
+- Implemented `WG14 N3042 <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3042.htm>`_,
+  Introduce the nullptr constant. This introduces a new type ``nullptr_t``,
+  declared in ``<stddef.h>`` which represents the type of the null pointer named
+  constant, ``nullptr``. This constant is implicitly convertible to any pointer
+  type and represents a type-safe null value.
+
+  Note, there are some known incompatibilities with this same feature in C++.
+  The following examples were discovered during implementation and are subject
+  to change depending on how national body comments are resolved by WG14 (C
+  status is based on standard requirements, not necessarily implementation
+  behavior):
+
+  .. code-block:: c
+
+    nullptr_t null_val;
+    (nullptr_t)nullptr;       // Rejected in C, accepted in C++, Clang accepts
+    (void)(1 ? nullptr : 0);  // Rejected in C, accepted in C++, Clang rejects
+    (void)(1 ? null_val : 0); // Rejected in C, accepted in C++, Clang rejects
+    bool b1 = nullptr;        // Accepted in C, rejected in C++, Clang rejects
+    b1 = null_val;            // Accepted in C, rejected in C++, Clang rejects
+    null_val = 0;             // Rejected in C, accepted in C++, Clang rejects
+
+    void func(nullptr_t);
+    func(0);                  // Rejected in C, accepted in C++, Clang rejects
+
+- Implemented `WG14 N2975 <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2975.pdf>`_,
+  Relax requirements for va_start. In C2x mode, functions can now be declared
+  fully variadic and the ``va_start`` macro no longer requires passing a second
+  argument (though it accepts a second argument for backwards compatibility).
+  If a second argument is passed, it is neither expanded nor evaluated in C2x
+  mode.
+
+  .. code-block:: c
+
+    void func(...) {  // Invalid in C17 and earlier, valid in C2x and later.
+      va_list list;
+      va_start(list); // Invalid in C17 and earlier, valid in C2x and later.
+      va_end(list);
+    }
+
+- Diagnose type definitions in the ``type`` argument of ``__builtin_offsetof``
+  as a conforming C extension according to
+  `WG14 N2350 <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2350.htm>`_.
+  Also documents the builtin appropriately. Note, a type definition in C++
+  continues to be rejected.
+
+Non-comprehensive list of changes in this release
+-------------------------------------------------
+- It's now possible to set the crash diagnostics directory through
+  the environment variable ``CLANG_CRASH_DIAGNOSTICS_DIR``.
+  The ``-fcrash-diagnostics-dir`` flag takes precedence.
+
 - Unicode support has been updated to support Unicode 15.0.
   New unicode codepoints are supported as appropriate in diagnostics,
   C and C++ identifiers, and escape sequences.
+
 - In identifiers, Clang allows a restricted set of additional mathematical symbols
   as an extension. These symbols correspond to a proposed Unicode
   `Mathematical notation profile for default identifiers
   <https://www.unicode.org/L2/L2022/22230-math-profile.pdf>`_.
-  This resolves `Issue 54732 <https://github.com/llvm/llvm-project/issues/54732>`_.
+  (`#54732 <https://github.com/llvm/llvm-project/issues/54732>`_)
+
 - Clang now supports loading multiple configuration files. The files from
   default configuration paths are loaded first, unless ``--no-default-config``
   option is used. All files explicitly specified using ``--config=`` option
   are loaded afterwards.
+
 - When loading default configuration files, clang now unconditionally uses
   the real target triple (respecting options such as ``--target=`` and ``-m32``)
   rather than the executable prefix. The respective configuration files are
   also loaded when clang is called via an executable without a prefix (e.g.
   plain ``clang``).
+
 - Default configuration paths were partially changed. Clang now attempts to load
   ``<triple>-<driver>.cfg`` first, and falls back to loading both
   ``<driver>.cfg`` and ``<triple>.cfg`` if the former is not found. `Triple`
   is the target triple and `driver` first tries the canonical name
   for the driver (respecting ``--driver-mode=``), and then the name found
   in the executable.
+
 - If the environment variable ``SOURCE_DATE_EPOCH`` is set, it specifies a UNIX
   timestamp to be used in replacement of the current date and time in
   the ``__DATE__``, ``__TIME__``, and ``__TIMESTAMP__`` macros. See
   `<https://reproducible-builds.org/docs/source-date-epoch/>`_.
+
 - Clang now supports ``__has_constexpr_builtin`` function-like macro that
   evaluates to 1 if the builtin is supported and can be constant evaluated.
   It can be used to writing conditionally constexpr code that uses builtins.
+
 - The time profiler (using ``-ftime-trace`` option) now traces various constant
   evaluation events.
+
 - Clang can now generate a PCH when using ``-fdelayed-template-parsing`` for
   code with templates containing loop hint pragmas, OpenMP pragmas, and
   ``#pragma unused``.
-- Now diagnoses use of a member access expression or array subscript expression
-  within ``__builtin_offsetof`` and ``offsetof`` as being a Clang extension.
 
 New Compiler Flags
 ------------------
 
-- Implemented `-fcoro-aligned-allocation` flag. This flag implements
+- Implemented ``-fcoro-aligned-allocation`` flag. This flag implements
   Option 2 of P2014R0 aligned allocation of coroutine frames
   (`P2014R0 <https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p2014r0.pdf>`_).
   With this flag, the coroutines will try to lookup aligned allocation
   function all the time. The compiler will emit an error if it fails to
   find aligned allocation function. So if the user code implemented self
   defined allocation function for coroutines, the existing code will be
   broken. A little divergence with P2014R0 is that clang will lookup
-  `::operator new(size_­t, std::aligned_val_t, nothrow_­t)` if there is
-  `get_­return_­object_­on_­allocation_­failure`. We feel this is more consistent
+  ``::operator new(size_­t, std::aligned_val_t, nothrow_­t)`` if there is
+  ``get_­return_­object_­on_­allocation_­failure``. We feel this is more consistent
   with the intention.
 
 - Added ``--no-default-config`` to disable automatically loading configuration
   files using default paths.
 
 - Added the new level, ``3``, to the ``-fstrict-flex-arrays=`` flag. The new
   level is the strict, standards-conforming mode for flexible array members. It
   recognizes only incomplete arrays as flexible array members (which is how the
- The option ``-rtlib=platform`` can now be used for all targets to override
   built-in hardcoded default). (Previously the MSVC and Darwin targets didn't
   allow this parameter combination.)
 
 Removed Compiler Flags
 -------------------------
 - Clang now no longer supports ``-cc1 -fconcepts-ts``.  This flag has been deprecated
   and encouraged use of ``-std=c++20`` since Clang 10, so we're now removing it.
 
-New Pragmas in Clang
---------------------
-- ...
-
 Attribute Changes in Clang
 --------------------------
 - Added support for ``__attribute__((guard(nocf)))`` and C++-style
   ``[[clang::guard(nocf)]]``, which is equivalent to ``__declspec(guard(nocf))``
   when using the MSVC environment. This is to support enabling Windows Control
   Flow Guard checks with the ability to disable them for specific functions when
   using the MinGW environment. This attribute is only available for Windows
   targets.
- Introduced new attribute ``__attribute__((target_version("cpu_features")))``
   and expanded the functionality of the existing attribute
   ``__attribute__((target_clones("cpu_features1","cpu_features2",...)))`` to
   support Function Multi Versioning on AArch64 target. It detects at runtime
   which function versions are supported by CPU and calls the one with highest
   priority. Refer to `clang attributes
   <https://clang.llvm.org/docs/AttributeReference.html#target-version>`_ for
   more details.
 
-Windows Support
----------------
-- For the MinGW driver, added the options ``-mguard=none``, ``-mguard=cf`` and
-  ``-mguard=cf-nochecks`` (equivalent to ``/guard:cf-``, ``/guard:cf`` and
-  ``/guard:cf,nochecks`` in clang-cl) for enabling Control Flow Guard checks
-  and generation of address-taken function table.
+Improvements to Clang's diagnostics
+-----------------------------------
+- Disabled a FIX-IT suggested for a case of bad conversion in system headers.
 
-- Switched from SHA1 to BLAKE3 for PDB type hashing / ``-gcodeview-ghash``
+- Clang will now check compile-time determinable string literals as format strings.
+  (`#55805 <https://github.com/llvm/llvm-project/issues/55805>`_)
 
-- Fixed code generation with emulated TLS, when the emulated TLS is enabled
-  by default (with downstream patches; no upstream configurations default
-  to this configuration, but some mingw downstreams change the default
-  in this way).
+- ``-Wformat`` now recognizes ``%b`` for the ``printf``/``scanf`` family of
+  functions and ``%B`` for the ``printf`` family of functions.
+  (`#56885 <https://github.com/llvm/llvm-project/issues/56885>`_)
 
-- Improved detection of MinGW cross sysroots for finding sysroots provided
-  by Linux distributions such as Fedora. Also improved such setups by
-  avoiding to include ``/usr/include`` among the include paths when cross
-  compiling with a cross sysroot based in ``/usr``.
+- Introduced ``-Wsingle-bit-bitfield-constant-conversion``, grouped under
+  ``-Wbitfield-constant-conversion``, which diagnoses implicit truncation when
+  ``1`` is assigned to a 1-bit signed integer bitfield. To reduce
+  potential false positives, this diagnostic will not diagnose use of the
+  ``true`` macro (from ``<stdbool.h>``) in C language mode despite the macro
+  being defined to expand to ``1``. (`#53253 <https://github.com/llvm/llvm-project/issues/53253>`_)
 
-AIX Support
------------
-* When using ``-shared``, the clang driver now invokes llvm-nm to create an
-  export list if the user doesn't specify one via linker flag or pass an
-  alternative export control option.
+- Clang will now print more information about failed static assertions. In
+  particular, simple static assertion expressions are evaluated to their
+  compile-time value and printed out if the assertion fails.
 
-C Language Changes in Clang
----------------------------
-- Adjusted ``-Wformat`` warnings according to `WG14 N2562 <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2562.pdf>`_.
-  Clang will now consider default argument promotions in ``printf``, and remove
-  unnecessary warnings. Especially ``int`` argument with specifier ``%hhd`` and
-  ``%hd``.
+- Diagnostics about uninitialized ``constexpr`` variables have been improved
+  to mention the missing constant initializer.
 
-C2x Feature Support
--------------------
-- Implemented `WG14 N2662 <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2662.pdf>`_,
-  so the [[maybe_unused]] attribute may be applied to a label to silence an
-  ``-Wunused-label`` warning.
-- Implemented `WG14 N2508 <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2508.pdf>`_,
-  so labels can placed everywhere inside a compound statement.
-- Implemented `WG14 N2927 <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2927.htm>`_,
-  the Not-so-magic ``typeof`` operator. Also implemented
-  `WG14 N2930 <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2930.pdf>`_,
-  renaming ``remove_quals``, so the ``typeof_unqual`` operator is also
-  supported. Both of these operators are supported only in C2x mode. The
-  ``typeof`` operator specifies the type of the given parenthesized expression
-  operand or type name, including all qualifiers. The ``typeof_unqual``
-  operator is similar to ``typeof`` except that all qualifiers are removed,
-  including atomic type qualification and type attributes which behave like a
-  qualifier, such as an address space attribute.
+- Correctly diagnose a future keyword if it exists as a keyword in the higher
+  language version and specifies in which version it will be a keyword. This
+  supports both C and C++.
 
-  .. code-block:: c
+- When diagnosing multi-level pack expansions of mismatched lengths, Clang will
+  now, in most cases, be able to point to the relevant outer parameter.
 
-    __attribute__((address_space(1))) const _Atomic int Val;
-    typeof(Val) OtherVal; // type is '__attribute__((address_space(1))) const _Atomic int'
-    typeof_unqual(Val) OtherValUnqual; // type is 'int'
+- ``no_sanitize("...")`` on a global variable for known but not relevant
+  sanitizers is now just a warning. It now says that this will be ignored
+  instead of incorrectly saying no_sanitize only applies to functions and
+  methods.
 
-- Implemented `WG14 N3042 <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3042.htm>`_,
-  Introduce the nullptr constant. This introduces a new type ``nullptr_t``,
-  declared in ``<stddef.h>`` which represents the type of the null pointer named
-  constant, ``nullptr``. This constant is implicitly convertible to any pointer
-  type and represents a type-safe null value.
+- No longer mention ``reinterpet_cast`` in the invalid constant expression
+  diagnostic note when in C mode.
 
-  Note, there are some known incompatibilities with this same feature in C++.
-  The following examples were discovered during implementation and are subject
-  to change depending on how national body comments are resolved by WG14 (C
-  status is based on standard requirements, not necessarily implementation
-  behavior):
+- Clang will now give a more suitale diagnostic for declaration of block
+  scope identifiers that have external/internal linkage that has an initializer.
+  (`#57478 <https://github.com/llvm/llvm-project/issues/57478>`_)
 
-  .. code-block:: c
+- A new analysis pass will helps preserve sugar when combining deductions, in an
+  order agnostic way. This will be in effect when deducing template arguments,
+  when deducing function return type from multiple return statements, for the
+  conditional operator, and for most binary operations. Type sugar is combined
+  in a way that strips the sugar which is different between terms, and preserves
+  those which are common.
 
-    nullptr_t null_val;
-    (nullptr_t)nullptr;       // Rejected in C, accepted in C++, Clang accepts
-    (void)(1 ? nullptr : 0);  // Rejected in C, accepted in C++, Clang rejects
-    (void)(1 ? null_val : 0); // Rejected in C, accepted in C++, Clang rejects
-    bool b1 = nullptr;        // Accepted in C, rejected in C++, Clang rejects
-    b1 = null_val;            // Accepted in C, rejected in C++, Clang rejects
-    null_val = 0;             // Rejected in C, accepted in C++, Clang rejects
+- Correctly diagnose the use of an integer literal without a suffix whose
+  underlying type is ``long long`` or ``unsigned long long`` as an extension in
+  C89 mode . Clang previously only diagnosed if the literal had an explicit
+  ``LL`` suffix.
 
-    void func(nullptr_t);
-    func(0);                  // Rejected in C, accepted in C++, Clang rejects
+- Clang now correctly diagnoses index that refers past the last possible element
+  of FAM-like arrays.
 
-- Implemented `WG14 N2975 <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2975.pdf>`_,
-  Relax requirements for va_start. In C2x mode, functions can now be declared
-  fully variadic and the ``va_start`` macro no longer requires passing a second
-  argument (though it accepts a second argument for backwards compatibility).
-  If a second argument is passed, it is neither expanded nor evaluated in C2x
-  mode.
+- Clang now correctly emits a warning when dereferencing a void pointer in C mode.
+  (`#53631 <https://github.com/llvm/llvm-project/issues/53631>`_)
 
-  .. code-block:: c
+- Clang will now diagnose an overload set where a candidate has a constraint that
+  refers to an expression with a previous error as nothing viable, so that it
+  doesn't generate strange cascading errors, particularly in cases where a
+  subsuming constraint fails, which would result in a less-specific overload to
+  be selected.
 
-    void func(...) {  // Invalid in C17 and earlier, valid in C2x and later.
-      va_list list;
-      va_start(list); // Invalid in C17 and earlier, valid in C2x and later.
-      va_end(list);
-    }
+- Add a fix-it hint for the ``-Wdefaulted-function-deleted`` warning to
+  explicitly delete the function.
 
-- Diagnose type definitions in the ``type`` argument of ``__builtin_offsetof``
-  as a conforming C extension according to
-  `WG14 N2350 <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2350.htm>`_.
-  Also documents the builtin appropriately. Note, a type definition in C++
-  continues to be rejected.
+- Fixed an accidental duplicate diagnostic involving the declaration of a
+  function definition without a prototype which is preceded by a static
+  declaration of the function with a prototype.
+  (`#58181 <https://github.com/llvm/llvm-project/issues/58181>`_)
 
-C++ Language Changes in Clang
------------------------------
-- Implemented `DR692 <https://wg21.link/cwg692>`_, `DR1395 <https://wg21.link/cwg1395>`_,
-  and `DR1432 <https://wg21.link/cwg1432>`_. The fix for DR1432 is speculative since the
-  issue is still open and has no proposed resolution at this time. A speculative fix
-  for DR1432 is needed to prevent regressions that would otherwise occur due to DR692.
-- Clang's default C++/ObjC++ standard is now ``gnu++17`` instead of ``gnu++14``.
-  This means Clang will by default accept code using features from C++17 and
-  conforming GNU extensions. Projects incompatible with C++17 can add
-  ``-std=gnu++14`` to their build settings to restore the previous behaviour.
-- Implemented DR2358 allowing init captures in lambdas in default arguments.
-- implemented `DR2654 <https://wg21.link/cwg2654>`_ which undeprecates
-  all compound assignements operations on volatile qualified variables.
-- Implemented DR2631. Invalid ``consteval`` calls in default arguments and default
-  member initializers are diagnosed when and if the default is used.
-  This Fixes `Issue 56379 <https://github.com/llvm/llvm-project/issues/56379>`_
-  and changes the value of ``std::source_location::current()``
-  used in default parameters calls compared to previous versions of Clang.
+- Copy-elided initialization of lock scopes is now handled differently in
+  ``-Wthread-safety-analysis``: annotations on the move constructor are no
+  longer taken into account, in favor of annotations on the function returning
+  the lock scope by value. This could result in new warnings if code depended
+  on the previous undocumented behavior. As a side effect of this change,
+  constructor calls outside of initializer expressions are no longer ignored,
+  which can result in new warnings (or make existing warnings disappear).
 
-C++20 Feature Support
-^^^^^^^^^^^^^^^^^^^^^
-- Support capturing structured bindings in lambdas
-  (`P1091R3 <https://wg21.link/p1091r3>`_ and `P1381R1 <https://wg21.link/P1381R1>`_).
-  This fixes issues `Issue 52720 <https://github.com/llvm/llvm-project/issues/52720>`_,
-  `Issue 54300 <https://github.com/llvm/llvm-project/issues/54300>`_,
-  `Issue 54301 <https://github.com/llvm/llvm-project/issues/54301>`_,
-  and `Issue 49430 <https://github.com/llvm/llvm-project/issues/49430>`_.
-- Consider explicitly defaulted constexpr/consteval special member function
-  template instantiation to be constexpr/consteval even though a call to such
-  a function cannot appear in a constant expression.
-  (C++14 [dcl.constexpr]p6 (CWG DR647/CWG DR1358))
-- Correctly defer dependent immediate function invocations until template instantiation.
-  This fixes `Issue 55601 <https://github.com/llvm/llvm-project/issues/55601>`_.
-- Implemented "Conditionally Trivial Special Member Functions" (`P0848 <https://wg21.link/p0848r3>`_).
-  Note: The handling of deleted functions is not yet compliant, as Clang
-  does not implement `DR1496 <https://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#1496>`_
-  and `DR1734 <https://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#1734>`_.
-- Class member variables are now in scope when parsing a ``requires`` clause. Fixes
-  `Issue 55216 <https://github.com/llvm/llvm-project/issues/55216>`_.
-- Correctly set expression evaluation context as 'immediate function context' in
-  consteval functions.
-  This fixes `Issue 51182 <https://github.com/llvm/llvm-project/issues/51182>`_.
-- Fixes an assert crash caused by looking up missing vtable information on ``consteval``
-  virtual functions. Fixes `Issue 55065 <https://github.com/llvm/llvm-project/issues/55065>`_.
-- Skip rebuilding lambda expressions in arguments of immediate invocations.
-  This fixes `Issue 56183 <https://github.com/llvm/llvm-project/issues/56183>`_,
-  `Issue 51695 <https://github.com/llvm/llvm-project/issues/51695>`_,
-  `Issue 50455 <https://github.com/llvm/llvm-project/issues/50455>`_,
-  `Issue 54872 <https://github.com/llvm/llvm-project/issues/54872>`_,
-  `Issue 54587 <https://github.com/llvm/llvm-project/issues/54587>`_.
-- Clang now correctly delays the instantiation of function constraints until
-  the time of checking, which should now allow the libstdc++ ranges implementation
-  to work for at least trivial examples.  This fixes
-  `Issue 44178 <https://github.com/llvm/llvm-project/issues/44178>`_.
-- Clang implements DR2621, correcting a defect in ``using enum`` handling.  The
-  name is found via ordinary lookup so typedefs are found.
-- Implemented `P0634r3 <https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0634r3.html>`_,
-  which removes the requirement for the ``typename`` keyword in certain contexts.
-- Implemented The Equality Operator You Are Looking For (`P2468 <http://wg21.link/p2468r2>`_).
-- Implemented `P2113R0: Proposed resolution for 2019 comment CA 112 <https://wg21.link/P2113R0>`_
-  ([temp.func.order]p6.2.1 is not implemented, matching GCC).
-- Implemented `P0857R0 <https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0857r0.html>`_,
-  which specifies constrained lambdas and constrained template *template-parameter*\s.
-- Required parameter pack to be provided at the end of the concept parameter list. This
-  fixes `Issue 48182 <https://github.com/llvm/llvm-project/issues/48182>`_.
+- The wording of diagnostics regarding arithmetic on fixed-sized arrays and
+  pointers is improved to include the type of the array and whether it's cast
+  to another type. This should improve comprehension for why an index is
+  out-of-bounds.
+
+- Clang now correctly points to the problematic parameter for the ``-Wnonnull``
+  warning. (`#58273 <https://github.com/llvm/llvm-project/issues/58273>`_)
+
+- Introduced ``-Wcast-function-type-strict`` and
+  ``-Wincompatible-function-pointer-types-strict`` to warn about function type
+  mismatches in casts and assignments that may result in runtime indirect call
+  `Control-Flow Integrity (CFI)
+  <https://clang.llvm.org/docs/ControlFlowIntegrity.html>`_ failures. The
+  ``-Wcast-function-type-strict`` diagnostic is grouped under
+  ``-Wcast-function-type`` as it identifies a more strict set of potentially
+  problematic function type casts.
+
+- Clang will now disambiguate NTTP types when printing diagnostic that contain NTTP types.
+  (`#57562 <https://github.com/llvm/llvm-project/issues/57562>`_)
+
+- Better error recovery for pack expansion of expressions.
+  (`#58673 <https://github.com/llvm/llvm-project/issues/58673>`_)
+
+- Better diagnostics when the user has missed ``auto`` in a declaration.
+  (`#49129 <https://github.com/llvm/llvm-project/issues/49129>`_)
+
+- Clang now diagnoses use of invalid or reserved module names in a module
+  export declaration. Both are diagnosed as an error, but the diagnostic is
+  suppressed for use of reserved names in a system header.
+
+- ``-Winteger-overflow`` will diagnose overflow in more cases.
+  (`#58944 <https://github.com/llvm/llvm-project/issues/58944>`_)
+
+- Clang has an internal limit of 2GB of preprocessed source code per
+  compilation, including source reachable through imported AST files such as
+  PCH or modules. When Clang hits this limit, it now produces notes mentioning
+  which header and source files are consuming large amounts of this space.
+  ``#pragma clang __debug sloc_usage`` can also be used to request this report.
+
+- Clang no longer permits the keyword 'bool' in a concept declaration as a
+  concepts-ts compatibility extension.
+
+- Clang now diagnoses overflow undefined behavior in a constant expression while
+  evaluating a compound assignment with remainder as operand.
+
+- Add ``-Wreturn-local-addr``, a GCC alias for ``-Wreturn-stack-address``.
+
+- Clang now suppresses ``-Wlogical-op-parentheses`` on ``(x && a || b)`` and ``(a || b && x)``
+  only when ``x`` is a string literal.
+
+- Clang will now reject the GNU extension address of label in coroutines explicitly.
+  (`#56436 <https://github.com/llvm/llvm-project/issues/56436>`_)
+
+- Clang now automatically adds ``[[clang::lifetimebound]]`` to the parameters of
+  ``std::move, std::forward`` et al, this enables Clang to diagnose more cases
+  where the returned reference outlives the object.
+
+- Fix clang not properly diagnosing the failing subexpression when chained
+  binary operators are used in a ``static_assert`` expression.
+
+- ``-Wtautological-compare`` missed warnings for tautological comparisons
+  involving a negative integer literal.
+  (`#42918 <https://github.com/llvm/llvm-project/issues/42918>`_)
+
+- ``-Wcomma`` is no longer emitted for void returning functions.
+  (`#57151 <https://github.com/llvm/llvm-project/issues/57151>`_)
+
+Bug Fixes in This Version
+-------------------------
+
+Bug Fixes to Compiler Builtins
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+- ``stdatomic.h`` will use the internal declarations when targeting pre-C++-23
+  on Windows platforms as the MSVC support requires newer C++ standard.
+
+- Correct ``_Static_assert`` to accept the same set of extended integer
+  constant expressions as is accpted in other contexts that accept them.
+  (`#57687 <https://github.com/llvm/llvm-project/issues/57687>`_)
+
+- Fix crashes caused when builtin C++ language extension type traits were
+  instantiated by templates with an unexpected number of arguments.
+  (`#57008 <https://github.com/llvm/llvm-project/issues/57008>`_)
+
+- Fix ``__builtin_assume_aligned`` crash when the 1st arg is array type.
+  (`#57169 <https://github.com/llvm/llvm-project/issues/57169>`_)
+
+- Fixes to builtin template emulation of regular templates.
+  (`#42102 <https://github.com/llvm/llvm-project/issues/42102>`_,
+  `#51928 <https://github.com/llvm/llvm-project/issues/51928>`_)
+
+- Fix incorrect handling of inline builtins with asm labels.
+
+- The builtin type trait ``__is_aggregate`` now returns ``true`` for arrays of incomplete
+  types in accordance with the suggested fix for `LWG3823 <https://cplusplus.github.io/LWG/issue3823>`_
+
+Bug Fixes to Attribute Support
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+- Fixes an accepts-invalid bug in C when using a ``_Noreturn`` function
+  specifier on something other than a function declaration.
+  (`#56800 <https://github.com/llvm/llvm-project/issues/56800>`_)
+
+- No longer assert/miscompile when trying to make a vectorized ``_BitInt`` type
+  using the ``ext_vector_type`` attribute (the ``vector_size`` attribute was
+  already properly diagnosing this case).
+
+- Invalid destructor names are no longer accepted on template classes.
+  (`#56772 <https://github.com/llvm/llvm-project/issues/56772>`_)
+
+- Improve compile-times with large dynamic array allocations with trivial
+  constructors.
+  (`#56774 <https://github.com/llvm/llvm-project/issues/56774>`_)
+
+- Fix a crash when a ``btf_type_tag`` attribute is applied to the pointee of
+  a function pointer.
+
+- In C mode, when ``e1`` has ``__attribute__((noreturn))`` but ``e2`` doesn't,
+  ``(c ? e1 : e2)`` is no longer considered noreturn.
+  (`#59792 <https://github.com/llvm/llvm-project/issues/59792>`_)
+
+- GNU attributes being applied prior to standard attributes would be handled
+  improperly, which was corrected to match the behaviour exhibited by GCC.
+  (`#58229 <https://github.com/llvm/llvm-project/issues/58229>`_)
+
+- Fix issue using __attribute__((format)) on non-variadic functions that expect
+  more than one formatted argument.
+
+- Clang will now no longer treat a C 'overloadable' function without a prototype as
+  a variadic function with the attribute.  This should make further diagnostics more
+  clear.
+
+Bug Fixes to C++ Support
+^^^^^^^^^^^^^^^^^^^^^^^^
+- Fix multi-level pack expansion of undeclared function parameters.
+  (`#56094 <https://github.com/llvm/llvm-project/issues/56094>`_)
+
+- Address the thread identification problems in coroutines.
+  (`#47177 <https://github.com/llvm/llvm-project/issues/47177>`_,
+  `#47179 <https://github.com/llvm/llvm-project/issues/47179>`_)
+
+- Reject non-type template arguments formed by casting a non-zero integer
+  to a pointer in pre-C++17 modes, instead of treating them as null
+  pointers.
+
+- Fix template arguments of pointer and reference not taking the type as
+  part of their identity.
+  (`#47136 <https://github.com/llvm/llvm-project/issues/47136>`_)
+
+- Fix handling of unexpanded packs in template argument expressions.
+  (`#58679 <https://github.com/llvm/llvm-project/issues/58679>`_)
+
+- Fix bug with ``using enum`` that could lead to enumerators being treated as if
+  they were part of an overload set.
+  (`#58067 <https://github.com/llvm/llvm-project/issues/58057>`_,
+  `#59014 <https://github.com/llvm/llvm-project/issues/59014>`_,
+  `#54746 <https://github.com/llvm/llvm-project/issues/54746>`_)
+
+- Fix bug where constant evaluation treated a pointer to member that points to
+  a weak member as never being null. Such comparisons are now treated as
+  non-constant.
+
+- Fix issue that the standard C++ modules importer will call global
+  constructor/destructor for the global variables in the importing modules.
+  (`#59765 <https://github.com/llvm/llvm-project/issues/59765>`_)
+
+- Reject in-class defaulting of previously declared comparison operators.
+  (`#51227 <https://github.com/llvm/llvm-project/issues/51227>`_)
 
 - Do not hide templated base members introduced via using-decl in derived class
-  (useful specially for constrained members). Fixes `GH50886 <https://github.com/llvm/llvm-project/issues/50886>`_.
-- Implemented CWG2635 as a Defect Report, which prohibits structured bindings from being constrained.
-- Correctly handle access-checks in requires expression. Fixes `GH53364 <https://github.com/llvm/llvm-project/issues/53364>`_,
-  `GH53334 <https://github.com/llvm/llvm-project/issues/53334>`_.
+  (useful specially for constrained members). (`#50886 <https://github.com/llvm/llvm-project/issues/50886>`_)
+
+Concepts Specific Fixes:
+
+- Class member variables are now in scope when parsing a ``requires`` clause.
+  (`#55216 <https://github.com/llvm/llvm-project/issues/55216>`_)
+
+- Required parameter pack to be provided at the end of the concept parameter list.
+  (`#48182 <https://github.com/llvm/llvm-project/issues/48182>`_)
 
-- Implemented `P0960R3: <https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0960r3.html>`_
-  and `P1975R0: <https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1975r0.html>`_,
-  which allows parenthesized aggregate-initialization.
+- Correctly handle access-checks in requires expression. (`#53364 <https://github.com/llvm/llvm-project/issues/53364>`_,
+  `#53334 <https://github.com/llvm/llvm-project/issues/53334>`_)
 
 - Fixed an issue with concept requirement evaluation, where we incorrectly allowed implicit
-  conversions to bool for a requirement.  This fixes `GH54524 <https://github.com/llvm/llvm-project/issues/54524>`_.
+  conversions to bool for a requirement.  (`#54524 <https://github.com/llvm/llvm-project/issues/54524>`_)
 
-C++2b Feature Support
-^^^^^^^^^^^^^^^^^^^^^
+- Respect constructor constraints during class template argument deduction (CTAD).
+  This is the suggested resolution to CWG DR2628.
+  (`#57646 <https://github.com/llvm/llvm-project/issues/57646>`_,
+  `#43829 <https://github.com/llvm/llvm-project/issues/43829>`_)
 
-- Support label at end of compound statement (`P2324 <https://wg21.link/p2324r2>`_).
-- Implemented `P1169R4: static operator() <https://wg21.link/P1169R4>`_ and `P2589R1: static operator[] <https://wg21.link/P2589R1>`_.
-- Implemented "char8_t Compatibility and Portability Fix" (`P2513R3 <https://wg21.link/P2513R3>`_).
-  This change was applied to C++20 as a Defect Report.
-- Implemented "Permitting static constexpr variables in constexpr functions" (`P2647R1 <https://wg21.link/P2647R1>_`).
-- Implemented `CWG2640 Allow more characters in an n-char sequence <https://wg21.link/CWG2640>_`.
+- Fix a crash when emitting a concept-related diagnostic.
+  (`#57415 <https://github.com/llvm/llvm-project/issues/57415>`_)
 
-CUDA/HIP Language Changes in Clang
-----------------------------------
+- Fix a crash when trying to form a recovery expression on a call inside a
+  constraint, which re-evaluated the same constraint.
+  (`#53213 <https://github.com/llvm/llvm-project/issues/53213>`_,
+  `#45736 <https://github.com/llvm/llvm-project/issues/45736>`_)
 
- - Allow the use of ``__noinline__`` as a keyword (instead of ``__attribute__((noinline))``)
-   in lambda declarations.
+- Fix an issue when performing constraints partial ordering on non-template
+  functions. (`#56154 <https://github.com/llvm/llvm-project/issues/56154>`_)
 
-Objective-C Language Changes in Clang
--------------------------------------
+- Fix a number of recursively-instantiated constraint issues, which would possibly
+  result in a stack overflow.
+  (`#44304 <https://github.com/llvm/llvm-project/issues/44304>`_,
+  `#50891 <https://github.com/llvm/llvm-project/issues/50891>`_)
 
-OpenCL C Language Changes in Clang
-----------------------------------
+- Finished implementing C++ DR2565, which results in a requirement becoming
+  not satisfied in the event of an instantiation failures in a requires expression's
+  parameter list. We previously handled this correctly in a constraint evaluation
+  context, but not in a requires clause evaluated as a boolean.
 
-...
+Consteval Specific Fixes:
 
-ABI Changes in Clang
---------------------
+- Fix a crash when generating code coverage information for an
+  ``if consteval`` statement.
+  (`#57377 <https://github.com/llvm/llvm-project/issues/57377>`_)
 
-- GCC doesn't pack non-POD members in packed structs unless the packed
-  attribute is also specified on the member. Clang historically did perform
-  such packing. Clang now matches the gcc behavior
-  (except on Darwin, PS4 and AIX).
-  You can switch back to the old ABI behavior with the flag:
-  ``-fclang-abi-compat=15.0``.
-- GCC allows POD types to have defaulted special members. Clang historically
-  classified such types as non-POD (for the purposes of Itanium ABI). Clang now
-  matches the gcc behavior (except on Darwin, PS4, AIX and z/OS). You can switch
-  back to the old ABI behavior with the flag: ``-fclang-abi-compat=15.0``.
+- Fixed a crash-on-valid with consteval evaluation of a list-initialized
+  constructor for a temporary object.
+  (`#55871 <https://github.com/llvm/llvm-project/issues/55871>`_)
 
-OpenMP Support in Clang
------------------------
+- Fixes an assert crash caused by looking up missing vtable information on ``consteval``
+  virtual functions. (`#55065 <https://github.com/llvm/llvm-project/issues/55065>`_)
 
-...
+Bug Fixes to AST Handling
+^^^^^^^^^^^^^^^^^^^^^^^^^
+- A SubstTemplateTypeParmType can now represent the pack index for a
+  substitution from an expanded pack.
+  (`#56099 <https://github.com/llvm/llvm-project/issues/56099>`_)
 
-CUDA Support in Clang
----------------------
+- The template arguments of a variable template being accessed as a
+  member will now be represented in the AST.
 
-- Clang now supports CUDA SDK up to 11.8
-- Added support for targeting sm_{87,89,90} GPUs.
+Miscellaneous Bug Fixes
+^^^^^^^^^^^^^^^^^^^^^^^
+- Clang configuration files are now read through the virtual file system
+  rather than the physical one, if these are different.
 
-LoongArch Support in Clang
---------------------------
-- Clang now supports LoongArch. Along with the backend, clang is able to build a
-  large corpus of Linux applications. Test-suite 100% pass.
-- Support basic option ``-march=`` which is used to select the target
-  architecture, i.e. the basic set of ISA modules to be enabled. Possible values
-  are ``loongarch64`` and ``la464``.
-- Support basic option ``-mabi=`` which is used to select the base ABI type.
-  Possible values are ``lp64d``, ``lp64f``, ``lp64s``, ``ilp32d``, ``ilp32f``
-  and ``ilp32s``.
-- Support extended options: ``-msoft-float``, ``-msingle-float``, ``-mdouble-float`` and ``mfpu=``.
-  See `LoongArch toolchain conventions <https://loongson.github.io/LoongArch-Documentation/LoongArch-toolchain-conventions-EN.html>`_.
+- Fix an issue where -frewrite-includes generated line control directives with
+  incorrect line numbers in some cases when a header file used an end of line
+  character sequence that differed from the primary source file.
+  (`#59736 <https://github.com/llvm/llvm-project/issues/59736>`_)
+
+- Clang 14 predeclared some builtin POSIX library functions in ``gnu2x`` mode,
+  and Clang 15 accidentally stopped predeclaring those functions in that
+  language mode. Clang 16 now predeclares those functions again.
+  (`#56607 <https://github.com/llvm/llvm-project/issues/56607>`_)
+
+- Fix the bug of inserting the ``ZeroInitializationFixit`` before the template
+  argument list of ``VarTemplateSpecializationDecl``.
+
+Miscellaneous Clang Crashes Fixed
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+- Fix a crash when evaluating a multi-dimensional array's array filler
+  expression is element-dependent.
+  (`#50601 <https://github.com/llvm/llvm-project/issues/56016>`_)
+
+- Fix an assert that triggers a crash during template name lookup when a type is
+  incomplete but was not also a TagType.
+  (`#57387 <https://github.com/llvm/llvm-project/issues/57387>`_)
+
+- Fix a crash when attempting to default a virtual constexpr non-special member
+  function in a derived class.
+  (`#57431 <https://github.com/llvm/llvm-project/issues/57431>`_)
+
+- Fix ``-Wpre-c++17-compat`` crashing Clang when compiling C++20 code which
+  contains deduced template specializations.
+  (`#57369 <https://github.com/llvm/llvm-project/issues/57369>`_,
+  `#57643 <https://github.com/llvm/llvm-project/issues/57643>`_,
+  `#57793 <https://github.com/llvm/llvm-project/issues/57793>`_)
+
+- Fix a crash upon stray coloncolon token in C2x mode.
+
+- Fix assert that triggers a crash during some types of list initialization that
+  generate a CXXTemporaryObjectExpr instead of a InitListExpr.
+  (`#58302 <https://github.com/llvm/llvm-project/issues/58302>`_,
+  `#58753 <https://github.com/llvm/llvm-project/issues/58753>`_,
+  `#59100 <https://github.com/llvm/llvm-project/issues/59100>`_)
+
+- Fix a crash where we attempt to define a deleted destructor.
+  (`#57516 <https://github.com/llvm/llvm-project/issues/57516>`_)
+
+- Fix an issue that triggers a crash if we instantiate a hidden friend functions.
+  (`#54457 <https://github.com/llvm/llvm-project/issues/54457>`_)
 
-RISC-V Support in Clang
+- Fix an issue that makes Clang crash on lambda template parameters.
+  (`#57960 <https://github.com/llvm/llvm-project/issues/57960>`_)
+
+- Fixed a crash in C++20 mode in Clang and Clangd when compile source
+  with compilation errors.
+  (`#53628 <https://github.com/llvm/llvm-project/issues/53628>`_)
+
+- Fix sanity check when value initializing an empty union so that it takes into
+  account anonymous structs which is a GNU extension.
+  (`#58800 <https://github.com/llvm/llvm-project/issues/58800>`_)
+
+
+Target Specific Changes
 -----------------------
-- ``sifive-7-rv32`` and ``sifive-7-rv64`` are no longer supported for ``-mcpu``.
-  Use ``sifive-e76``, ``sifive-s76``, or ``sifive-u74`` instead.
-- Native detections via ``-mcpu=native`` and ``-mtune=native`` are supported.
-- Fix interaction of ``-mcpu`` and ``-march``, RISC-V backend will take the
-  architecture extension union of ``-mcpu`` and ``-march`` before, and now will
-  take architecture extensions from ``-march`` if both are given.
-- An ABI mismatch between GCC and Clang that related to the
-  sign/zero-extension of integer scalars was fixed.
 
-X86 Support in Clang
---------------------
+X86 Support
+^^^^^^^^^^^
 - Support ``-mindirect-branch-cs-prefix`` for call and jmp to indirect thunk.
 - Fix 32-bit ``__fastcall`` and ``__vectorcall`` ABI mismatch with MSVC.
 - Add ISA of ``AMX-FP16`` which support ``_tile_dpfp16ps``.
 - Switch ``AVX512-BF16`` intrinsics types from ``short`` to ``__bf16``.
 - Add support for ``PREFETCHI`` instructions.
 - Support ISA of ``CMPCCXADD``.
   * Support intrinsic of ``_cmpccxadd_epi32``.
   * Support intrinsic of ``_cmpccxadd_epi64``.
- Support ISA of ``AVX-NE-CONVERT``.
   * Support intrinsic of ``_mm(256)_cvtneoph_ps``.
   * Support intrinsic of ``_mm(256)_cvtneps_avx_pbh``.
 - ``-march=raptorlake``, ``-march=meteorlake`` and ``-march=emeraldrapids`` are now supported.
 - ``-march=sierraforest``, ``-march=graniterapids`` and ``-march=grandridge`` are now supported.
 - Lift _BitInt() supported max width from 128 to 8388608.
 - Support intrinsics of ``_mm(256)_reduce_(add|mul|or|and)_epi8/16``.
 - Support intrinsics of ``_mm(256)_reduce_(max|min)_ep[i|u]8/16``.
 
-WebAssembly Support in Clang
-----------------------------
-
-The -mcpu=generic configuration now enables sign-ext and mutable-globals. These
-proposals are standardized and available in all major engines.
-
-DWARF Support in Clang
-----------------------
-
-Previously when emitting DWARFv4 and tuning for GDB, Clang would use DWARF v2's
-``DW_AT_bit_offset`` and ``DW_AT_data_member_location``. Clang now uses DWARF v4's
-``DW_AT_data_bit_offset`` regardless of tuning.
-
-Support for ``DW_AT_data_bit_offset`` was added in GDB 8.0. For earlier versions,
-you can use the ``-gdwarf-3`` option to emit compatible DWARF.
-
-Arm and AArch64 Support in Clang
---------------------------------
-
+Arm and AArch64 Support
+^^^^^^^^^^^^^^^^^^^^^^^
 - The target(..) function attributes for AArch64 now accept:
-
   * ``"arch=<arch>"`` strings, that specify the architecture for a function as per the ``-march`` option.
   * ``"cpu=<cpu>"`` strings, that specify the cpu for a function as per the ``-mcpu`` option.
   * ``"tune=<cpu>"`` strings, that specify the tune cpu for a function as per ``-mtune``.
   * ``"+<feature>"``, ``"+no<feature>"`` enables/disables the specific feature, for compatibility with GCC target attributes.
   * ``"<feature>"``, ``"no-<feature>"`` enabled/disables the specific feature, for backward compatibility with previous releases.
 - ``-march`` values for targeting armv2, armv2A, armv3 and armv3M have been removed.
   Their presence gave the impression that Clang can correctly generate code for
   them, which it cannot.
 - Support has been added for the following processors (-mcpu identifiers in parenthesis):
-
   * Arm Cortex-A715 (cortex-a715).
   * Arm Cortex-X3 (cortex-x3).
   * Arm Neoverse V2 (neoverse-v2)
 - Strict floating point has been enabled for AArch64, which means that
   ``-ftrapping-math``, ``-frounding-math``, ``-ffp-model=strict``, and
   ``-ffp-exception-behaviour=<arg>`` are now accepted.
 
+Windows Support
+^^^^^^^^^^^^^^^
+- For the MinGW driver, added the options ``-mguard=none``, ``-mguard=cf`` and
+  ``-mguard=cf-nochecks`` (equivalent to ``/guard:cf-``, ``/guard:cf`` and
+  ``/guard:cf,nochecks`` in clang-cl) for enabling Control Flow Guard checks
+  and generation of address-taken function table.
+- Switched from SHA1 to BLAKE3 for PDB type hashing / ``-gcodeview-ghash``
+- Fixed code generation with emulated TLS, when the emulated TLS is enabled
+  by default (with downstream patches; no upstream configurations default
+  to this configuration, but some mingw downstreams change the default
+  in this way).
+- Improved detection of MinGW cross sysroots for finding sysroots provided
+  by Linux distributions such as Fedora. Also improved such setups by
+  avoiding to include ``/usr/include`` among the include paths when cross
+  compiling with a cross sysroot based in ``/usr``.
+
+LoongArch Support
+^^^^^^^^^^^^^^^^^
+- Clang now supports LoongArch. Along with the backend, clang is able to build a
+  large corpus of Linux applications. Test-suite 100% pass.
+- Support basic option ``-march=`` which is used to select the target
+  architecture, i.e. the basic set of ISA modules to be enabled. Possible values
+  are ``loongarch64`` and ``la464``.
+- Support basic option ``-mabi=`` which is used to select the base ABI type.
+  Possible values are ``lp64d``, ``lp64f``, ``lp64s``, ``ilp32d``, ``ilp32f``
+  and ``ilp32s``.
+- Support extended options: ``-msoft-float``, ``-msingle-float``, ``-mdouble-float`` and ``mfpu=``.
+  See `LoongArch toolchain conventions <https://loongson.github.io/LoongArch-Documentation/LoongArch-toolchain-conventions-EN.html>`_.
+
+RISC-V Support
+^^^^^^^^^^^^^^
+- ``sifive-7-rv32`` and ``sifive-7-rv64`` are no longer supported for ``-mcpu``.
+  Use ``sifive-e76``, ``sifive-s76``, or ``sifive-u74`` instead.
+- Native detections via ``-mcpu=native`` and ``-mtune=native`` are supported.
+- Fix interaction of ``-mcpu`` and ``-march``, RISC-V backend will take the
+  architecture extension union of ``-mcpu`` and ``-march`` before, and now will
+  take architecture extensions from ``-march`` if both are given.
+- An ABI mismatch between GCC and Clang that related to the
+  sign/zero-extension of integer scalars was fixed.
+
+CUDA/HIP Language Changes in Clang
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ - Allow the use of ``__noinline__`` as a keyword (instead of ``__attribute__((noinline))``)
+   in lambda declarations.
+
+CUDA Support
+^^^^^^^^^^^^
+- Clang now supports CUDA SDK up to 11.8
+- Added support for targeting sm_{87,89,90} GPUs.
+
+AIX Support
+^^^^^^^^^^^
+* When using ``-shared``, the clang driver now invokes llvm-nm to create an
+  export list if the user doesn't specify one via linker flag or pass an
+  alternative export control option.
+
+WebAssembly Support
+^^^^^^^^^^^^^^^^^^^
+- The -mcpu=generic configuration now enables sign-ext and mutable-globals. These
+  proposals are standardized and available in all major engines.
+
+DWARF Support in Clang
+----------------------
+Previously when emitting DWARFv4 and tuning for GDB, Clang would use DWARF v2's
+``DW_AT_bit_offset`` and ``DW_AT_data_member_location``. Clang now uses DWARF v4's
+``DW_AT_data_bit_offset`` regardless of tuning.
+
+Support for ``DW_AT_data_bit_offset`` was added in GDB 8.0. For earlier versions,
+you can use the ``-gdwarf-3`` option to emit compatible DWARF.
+
 Floating Point Support in Clang
 -------------------------------
 - The driver option ``-menable-unsafe-fp-math`` has been removed. To enable
   unsafe floating-point optimizations use ``-funsafe-math-optimizations`` or
   ``-ffast-math`` instead.
 - Add ``__builtin_elementwise_sin`` and ``__builtin_elementwise_cos`` builtins for floating point types only.
 
-Internal API Changes
---------------------
-
-Build System Changes
---------------------
-
 AST Matchers
 ------------
 - Add ``isInAnoymousNamespace`` matcher to match declarations in an anonymous namespace.
 
 clang-format
 ------------
 - Add ``RemoveSemicolon`` option for removing ``;`` after a non-empty function definition.
 - Add ``RequiresExpressionIndentation`` option for configuring the alignment of requires-expressions.
   The default value of this option is ``OuterScope``, which differs in behavior from clang-format 15.
   To match the default behavior of clang-format 15, use the ``Keyword`` value.
 - Add ``IntegerLiteralSeparator`` option for fixing integer literal separators
   in C++, C#, Java, and JavaScript.
 - Add ``BreakAfterAttributes`` option for breaking after a group of C++11
   attributes before a function declaration/definition name.
 - Add ``InsertNewlineAtEOF`` option for inserting a newline at EOF if missing.
 - Add ``LineEnding`` option to deprecate ``DeriveLineEnding`` and ``UseCRLF``.
 
-clang-extdef-mapping
---------------------
-
 libclang
 --------
 - Introduced the new function ``clang_getUnqualifiedType``, which mimics
   the behavior of ``QualType::getUnqualifiedType`` for ``CXType``.
 - Introduced the new function ``clang_getNonReferenceType``, which mimics
   the behavior of ``QualType::getNonReferenceType`` for ``CXType``.
 - Introduced the new function ``clang_CXXMethod_isDeleted``, which queries
   whether the method is declared ``= delete``.

 Sanitizers
 ----------
 - ``-fsanitize-memory-param-retval`` is turned on by default. With
   ``-fsanitize=memory``, passing uninitialized variables to functions and
   returning uninitialized variables from functions is more aggressively
   reported. ``-fno-sanitize-memory-param-retval`` restores the previous
   behavior.
 
-Core Analysis Improvements
-==========================
-
-- ...
-
-New Issues Found
-================
-
-- ...
-
-Python Binding Changes
-----------------------
-
-The following methods have been added:
-
--  ...
-
-Significant Known Problems
-==========================
-
 Additional Information
 ======================
 
 A wide variety of additional information is available on the `Clang web
 page <https://clang.llvm.org/>`_. The web page contains versions of the
 API documentation which are up-to-date with the Git version of
 the source code. You can access versions of these documents specific to
 this release by going into the "``clang/docs/``" directory in the Clang
 tree.
 
 If you have any questions or comments about Clang, please feel free to
-contact us on the Discourse forums (Clang Frontend category)
+contact us on the `Discourse forums (Clang Frontend category)
 <https://discourse.llvm.org/c/clang/6>`_.