[llvm-branch-commits] [clang] [analyzer][docs] CSA release notes for clang-21 (PR #154600)
Tobias Hieta via llvm-branch-commits
llvm-branch-commits at lists.llvm.org
Tue Aug 26 05:06:37 PDT 2025
https://github.com/tru updated https://github.com/llvm/llvm-project/pull/154600
>From b81295ef2efe283f87a75fadcf302eba701c3dd9 Mon Sep 17 00:00:00 2001
From: Balazs Benics <benicsbalazs at gmail.com>
Date: Wed, 20 Aug 2025 21:40:26 +0200
Subject: [PATCH] [analyzer][docs] CSA release notes for clang-21
The commits were gathered using:
```sh
git log --reverse --oneline llvmorg-20-init..llvm/main \
clang/{lib/StaticAnalyzer,include/clang/StaticAnalyzer} | grep -v NFC | \
grep -v OpenACC | grep -v -i revert | grep -v -i "webkit"
```
FYI, I also ignored Webkit changes because I assue it's fairly specific
for them, and they likely already know what they ship xD.
I used the `LLVM_ENABLE_SPHINX=ON` and `LLVM_ENABLE_DOXYGEN=ON` cmake
options to enable the `docs-clang-html` build target, which generates
the html into `build/tools/clang/docs/html/ReleaseNotes.html` of which I
attach the screenshots to let you judge if it looks all good or not.
---
clang/docs/ReleaseNotes.rst | 116 +++++++++++++++++++++++++++++++++---
1 file changed, 107 insertions(+), 9 deletions(-)
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 9ef697a14dcce..832ee35587fe3 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -1234,33 +1234,131 @@ Code Completion
Static Analyzer
---------------
-- Fixed a crash when C++20 parenthesized initializer lists are used. This issue
- was causing a crash in clang-tidy. (#GH136041)
New features
^^^^^^^^^^^^
+- A new flag - `-static-libclosure` was introduced to support statically linking
+ the runtime for the Blocks extension on Windows. This flag currently only
+ changes the code generation, and even then, only on Windows. This does not
+ impact the linker behaviour like the other `-static-*` flags.
+- OpenACC support, enabled via `-fopenacc` has reached a level of completeness
+ to finally be at least notionally usable. Currently, the OpenACC 3.4
+ specification has been completely implemented for Sema and AST creation, so
+ nodes will show up in the AST after having been properly checked. Lowering is
+ currently a work in progress, with compute, loop, and combined constructs
+ partially implemented, plus a handful of data and executable constructs
+ implemented. Lowering will only work in Clang-IR mode (so only with a compiler
+ built with Clang-IR enabled, and with `-fclangir` used on the command line).
+ However, note that the Clang-IR implementation status is also quite partial,
+ so frequent 'not yet implemented' diagnostics should be expected. Also, the
+ ACC MLIR dialect does not currently implement any lowering to LLVM-IR, so no
+ code generation is possible for OpenACC.
+- Implemented `P2719R5 Type-aware allocation and deallocation functions <https://wg21.link/P2719>`_
+ as an extension in all C++ language modes.
+
+- Added support for the ``[[clang::assume(cond)]]`` attribute, treating it as
+ ``__builtin_assume(cond)`` for better static analysis. (#GH129234)
+
+- Introduced per-entry-point statistics to provide more detailed analysis metrics.
+ Documentation: :doc:`analyzer/developer-docs/Statistics` (#GH131175)
+
+- Added time-trace scopes for high-level analyzer steps to improve performance
+ debugging. Documentation: :doc:`analyzer/developer-docs/PerformanceInvestigation`
+ (#GH125508, #GH125884)
+
+- Enhanced the ``check::BlockEntrance`` checker callback to provide more granular
+ control over block-level analysis.
+ `Documentation (check::BlockEntrance)
+ <https://clang.llvm.org/doxygen/CheckerDocumentation_8cpp_source.html>`_
+ (#GH140924)
+
+- Added a new checker ``core.FixedAddressDereference`` to detect dereferences
+ of fixed addresses, which can be useful for finding hard-coded memory
+ accesses. (#GH127191, #GH132404)
+
Crash and bug fixes
^^^^^^^^^^^^^^^^^^^
-- Fixed a crash in ``UnixAPIMisuseChecker`` and ``MallocChecker`` when analyzing
+- Fixed a crash when C++20 parenthesized initializer lists are used.
+ This affected a crash of the well-known lambda overloaded pattern.
+ (#GH136041, #GH135665)
+
+- Dropped an unjustified assertion, that was triggered in ``BugReporterVisitors.cpp``
+ for variable initialization detection. (#GH125044)
+
+- Fixed a crash in ``unix.API`` and ``unix.Malloc`` when analyzing
code with non-standard ``getline`` or ``getdelim`` function signatures. (#GH144884)
+- Fixed crashes involving ``__builtin_bit_cast``. (#GH139188)
+
+- ``__datasizeof`` (C++) and ``_Countof`` (C) no longer cause a failed assertion
+ when given an operand of VLA type. (#GH151711)
+
+- Fixed a crash in ``alpha.core.CastSize``. (#GH134387)
+
+- Some ``cplusplus.PlacementNew`` false positives were fixed. (#GH150161)
+
Improvements
^^^^^^^^^^^^
+- Added option to assume at least one iteration in loops to reduce false positives.
+ (#GH125494)
+
- The checker option ``optin.cplusplus.VirtualCall:PureOnly`` was removed,
- because it had been deprecated since 2019 and it is completely useless (it
- was kept only for compatibility with pre-2019 versions, setting it to true is
- equivalent to completely disabling the checker).
+ because it had been deprecated since 2019. (#GH131823)
+
+- Enhanced the ``core.StackAddressEscape`` to detect more cases of stack address
+ escapes, including return values for child stack frames. (#GH126620, #GH126986)
+
+- Improved the ``unix.BlockInCriticalSection`` to recognize ``O_NONBLOCK``
+ streams and suppress reports in those cases. (#GH127049)
+
+- Better support for lambda-converted function pointers in analysis. (#GH144906)
+
+- Improved modeling of ``getcwd`` function in ``unix.StdCLibraryFunctions`` checker.
+ (#GH141076)
+
+- Enhanced the ``optin.core.EnumCastOutOfRange`` checker to ignore ``[[clang::flag_enum]]``
+ enums. (#GH141232)
+
+- Improved handling of structured bindings captured by lambdas. (#GH132579, #GH91835)
+
+- Fixed unnamed bitfield handling in ``optin.cplusplus.UninitializedObject``. (#GH132427, #GH132001)
+
+- Enhanced iterator checker modeling for ``insert`` operations. (#GH132596)
+
+- Improved ``format`` attribute handling in ``optin.taint.GenericTaint``. (#GH132765)
+
+- Added support for ``consteval`` in ``ConditionBRVisitor::VisitTerminator``.
+ (#GH146859, #GH139130)
+
+- C standard streams are no longer invalidated by all C library function calls.
+ (#GH147766)
+
+- Enhanced store management with region-store-binding-limit to improve performance.
+ See `region-store-max-binding-fanout
+ <https://clang.llvm.org/docs/analyzer/user-docs/Options.html#region-store-max-binding-fanout>`_
+ config option. Overriding these options are discouraged, unless you know what you do.
+ (#GH127602)
+
+- Updated undefined assignment checker (``core.uninitialized.Assign``) diagnostics
+ to avoid using the term ``garbage``. (#GH126596)
+
+- Fixed false memory leak reports involving placement new. (#GH144341)
+
+- Avoided unnecessary super region invalidation in ``unix.cstring.*`` checkers.
+ (#GH146212, #GH143807)
+
+- Enhanced handling of tainted division-by-zero error paths in the
+ ``optin.taint.TaintedDiv`` checker. (#GH144491)
Moved checkers
^^^^^^^^^^^^^^
-- After lots of improvements, the checker ``alpha.security.ArrayBoundV2`` is
+- After lots of improvements, the checker ``alpha.security.ArrayBoundV2`` was
renamed to ``security.ArrayBound``. As this checker is stable now, the old
- checker ``alpha.security.ArrayBound`` (which was searching for the same kind
- of bugs with an different, simpler and less accurate algorithm) is removed.
+ checker ``alpha.security.ArrayBound`` was removed.
.. _release-notes-sanitizers:
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