[clang] Add flag to experiment with cold function attributes

.github/new-prs-labeler.yml

@@ -1,3 +1,9 @@
+ClangIR:
+  - clang/include/clang/CIR/**/*
+  - clang/lib/CIR/**/*
+  - clang/tools/cir-*/**/*
+  - clang/test/CIR/**/*
+
 clang:dataflow:
   - clang/include/clang/Analysis/FlowSensitive/**/*
   - clang/lib/Analysis/FlowSensitive/**/*
@@ -938,3 +944,6 @@ openmp:libomptarget:
 
 bazel:
   - utils/bazel/**
+
+offload:
+  - offload/**

bolt/include/bolt/Rewrite/RewriteInstance.h

@@ -368,13 +368,6 @@ class RewriteInstance {
   /// rewritten binary.
   void patchBuildID();
 
-  /// Return file offset corresponding to a given virtual address.
-  uint64_t getFileOffsetFor(uint64_t Address) {
-    assert(Address >= NewTextSegmentAddress &&
-           "address in not in the new text segment");
-    return Address - NewTextSegmentAddress + NewTextSegmentOffset;
-  }
-
   /// Return file offset corresponding to a virtual \p Address.
   /// Return 0 if the address has no mapping in the file, including being
   /// part of .bss section.
@@ -398,9 +391,6 @@ class RewriteInstance {
   /// Return true if the section holds debug information.
   static bool isDebugSection(StringRef SectionName);
 
-  /// Return true if the section holds linux kernel symbol information.
-  static bool isKSymtabSection(StringRef SectionName);
-
   /// Adds Debug section to overwrite.
   static void addToDebugSectionsToOverwrite(const char *Section) {
     DebugSectionsToOverwrite.emplace_back(Section);

bolt/lib/Rewrite/RewriteInstance.cpp

@@ -5767,10 +5767,3 @@ bool RewriteInstance::isDebugSection(StringRef SectionName) {
 
   return false;
 }
-
-bool RewriteInstance::isKSymtabSection(StringRef SectionName) {
-  if (SectionName.starts_with("__ksymtab"))
-    return true;
-
-  return false;
-}

clang-tools-extra/clang-tidy/performance/UnnecessaryValueParamCheck.cpp

@@ -85,10 +85,10 @@ void UnnecessaryValueParamCheck::check(const MatchFinder::MatchResult &Result) {
 
   TraversalKindScope RAII(*Result.Context, TK_AsIs);
 
-  FunctionParmMutationAnalyzer &Analyzer =
-      MutationAnalyzers.try_emplace(Function, *Function, *Result.Context)
-          .first->second;
-  if (Analyzer.isMutated(Param))
+  FunctionParmMutationAnalyzer *Analyzer =
+      FunctionParmMutationAnalyzer::getFunctionParmMutationAnalyzer(
+          *Function, *Result.Context, MutationAnalyzerCache);
+  if (Analyzer->isMutated(Param))
     return;
 
   const bool IsConstQualified =
@@ -169,7 +169,7 @@ void UnnecessaryValueParamCheck::storeOptions(
 }
 
 void UnnecessaryValueParamCheck::onEndOfTranslationUnit() {
-  MutationAnalyzers.clear();
+  MutationAnalyzerCache.clear();
 }
 
 void UnnecessaryValueParamCheck::handleMoveFix(const ParmVarDecl &Var,

clang-tools-extra/clang-tidy/performance/UnnecessaryValueParamCheck.h

@@ -37,8 +37,7 @@ class UnnecessaryValueParamCheck : public ClangTidyCheck {
   void handleMoveFix(const ParmVarDecl &Var, const DeclRefExpr &CopyArgument,
                      const ASTContext &Context);
 
-  llvm::DenseMap<const FunctionDecl *, FunctionParmMutationAnalyzer>
-      MutationAnalyzers;
+  ExprMutationAnalyzer::Memoized MutationAnalyzerCache;
   utils::IncludeInserter Inserter;
   const std::vector<StringRef> AllowedTypes;
 };

clang-tools-extra/docs/ReleaseNotes.rst

@@ -221,6 +221,10 @@ Changes in existing checks
   <clang-tidy/checks/llvm/header-guard>` check by replacing the local
   option `HeaderFileExtensions` by the global option of the same name.
 
+- Improved :doc:`misc-const-correctness
+  <clang-tidy/checks/misc/const-correctness>` check by avoiding infinite recursion
+  for recursive forwarding reference.
+
 - Improved :doc:`misc-definitions-in-headers
   <clang-tidy/checks/misc/definitions-in-headers>` check by replacing the local
   option `HeaderFileExtensions` by the global option of the same name.

clang-tools-extra/docs/clang-tidy/checks/bugprone/sizeof-expression.rst

@@ -190,6 +190,6 @@ Options
 
 .. option:: WarnOnSizeOfPointerToAggregate
 
-   When `true, the check will warn on an expression like
+   When `true`, the check will warn on an expression like
    ``sizeof(expr)`` where the expression is a pointer
    to aggregate. Default is `true`.

clang-tools-extra/test/clang-tidy/checkers/misc/const-correctness-templates.cpp

@@ -58,3 +58,18 @@ void concatenate3(Args... args)
     (..., (stream << args));
 }
 } // namespace gh70323
+
+namespace gh60895 {
+
+template <class T> void f1(T &&a);
+template <class T> void f2(T &&a);
+template <class T> void f1(T &&a) { f2<T>(a); }
+template <class T> void f2(T &&a) { f1<T>(a); }
+void f() {
+  int x = 0;
+  // CHECK-MESSAGES:[[@LINE-1]]:3: warning: variable 'x' of type 'int' can be declared 'const'
+  // CHECK-FIXES: int const x = 0;
+  f1(x);
+}
+
+} // namespace gh60895

clang/docs/LanguageExtensions.rst

@@ -3466,6 +3466,54 @@ Query for this feature with ``__has_builtin(__builtin_trap)``.
 
 ``__builtin_arm_trap`` is lowered to the ``llvm.aarch64.break`` builtin, and then to ``brk #payload``.
 
+``__builtin_allow_runtime_check``
+---------------------------------
+
+``__builtin_allow_runtime_check`` return true if the check at the current
+program location should be executed. It is expected to be used to implement
+``assert`` like checks which can be safely removed by optimizer.
+
+**Syntax**:
+
+.. code-block:: c++
+
+    bool __builtin_allow_runtime_check(const char* kind)
+
+**Example of use**:
+
+.. code-block:: c++
+
+  if (__builtin_allow_runtime_check("mycheck") && !ExpensiveCheck()) {
+     abort();
+  }
+
+**Description**
+
+``__builtin_allow_runtime_check`` is lowered to ` ``llvm.allow.runtime.check``
+<https://llvm.org/docs/LangRef.html#llvm-allow-runtime-check-intrinsic>`_
+builtin.
+
+The ``__builtin_allow_runtime_check()`` is expected to be used with control
+flow conditions such as in ``if`` to guard expensive runtime checks. The
+specific rules for selecting permitted checks can differ and are controlled by
+the compiler options.
+
+Flags to control checks:
+* ``-mllvm -lower-allow-check-percentile-cutoff-hot=N`` where N is PGO hotness
+cutoff in range ``[0, 999999]`` to disallow checks in hot code.
+* ``-mllvm -lower-allow-check-random-rate=P`` where P is number in range
+``[0.0, 1.0]`` representation probability of keeping a check.
+* If both flags are specified, ``-lower-allow-check-random-rate`` takes
+precedence.
+* If none is specified, ``__builtin_allow_runtime_check`` is lowered as
+``true``, allowing all checks.
+
+Parameter ``kind`` is a string literal representing a user selected kind for
+guarded check. It's unused now. It will enable kind-specific lowering in future.
+E.g. a higher hotness cutoff can be used for more expensive kind of check.
+
+Query for this feature with ``__has_builtin(__builtin_allow_runtime_check)``.
+
 ``__builtin_nondeterministic_value``
 ------------------------------------
 

clang/docs/ReleaseNotes.rst

@@ -68,7 +68,7 @@ AST Dumping Potentially Breaking Changes
 
 Clang Frontend Potentially Breaking Changes
 -------------------------------------------
-- Removed support for constructing on-stack ``TemplateArgumentList``s; interfaces should instead
+- Removed support for constructing on-stack ``TemplateArgumentList``\ s; interfaces should instead
   use ``ArrayRef<TemplateArgument>`` to pass template arguments. Transitioning internal uses to
   ``ArrayRef<TemplateArgument>`` reduces AST memory usage by 0.4% when compiling clang, and is
   expected to show similar improvements on other workloads.
@@ -104,8 +104,7 @@ C++20 Feature Support
 
 - Clang now implements [module.import]p7 fully. Clang now will import module
   units transitively for the module units coming from the same module of the
-  current module units.
-  Fixes `#84002 <https://github.com/llvm/llvm-project/issues/84002>`_.
+  current module units. Fixes #GH84002
 
 - Initial support for class template argument deduction (CTAD) for type alias
   templates (`P1814R0 <https://wg21.link/p1814r0>`_).
@@ -135,8 +134,7 @@ C++2c Feature Support
 Resolutions to C++ Defect Reports
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 - Substitute template parameter pack, when it is not explicitly specified
-  in the template parameters, but is deduced from a previous argument.
-  (`#78449: <https://github.com/llvm/llvm-project/issues/78449>`_).
+  in the template parameters, but is deduced from a previous argument. (#GH78449)
 
 - Type qualifications are now ignored when evaluating layout compatibility
   of two types.
@@ -176,8 +174,7 @@ C23 Feature Support
 
 - Clang now generates predefined macros of the form ``__TYPE_FMTB__`` and
   ``__TYPE_FMTb__`` (e.g., ``__UINT_FAST64_FMTB__``) in C23 mode for use with
-  macros typically exposed from ``<inttypes.h>``, such as ``PRIb8``.
-  (`#81896: <https://github.com/llvm/llvm-project/issues/81896>`_).
+  macros typically exposed from ``<inttypes.h>``, such as ``PRIb8``. (#GH81896)
 
 - Clang now supports `N3018 The constexpr specifier for object definitions`
   <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3018.htm>`_.
@@ -215,7 +212,10 @@ New Compiler Flags
 
 - ``-Wmissing-designated-field-initializers``, grouped under ``-Wmissing-field-initializers``.
   This diagnostic can be disabled to make ``-Wmissing-field-initializers`` behave
-  like it did before Clang 18.x. Fixes (`#56628 <https://github.com/llvm/llvm-project/issues/68933>`_)
+  like it did before Clang 18.x. Fixes #GH56628
+
+- ``-fexperimental-modules-reduced-bmi`` enables the Reduced BMI for C++20 named modules.
+  See the document of standard C++ modules for details.
 
 Deprecated Compiler Flags
 -------------------------
@@ -254,8 +254,7 @@ Removed Compiler Flags
 
 - The ``-freroll-loops`` flag has been removed. It had no effect since Clang 13.
 - ``-m[no-]unaligned-access`` is removed for RISC-V and LoongArch.
-  ``-m[no-]strict-align``, also supported by GCC, should be used instead.
-  (`#85350 <https://github.com/llvm/llvm-project/pull/85350>`_.)
+  ``-m[no-]strict-align``, also supported by GCC, should be used instead. (#GH85350)
 
 Attribute Changes in Clang
 --------------------------
@@ -325,8 +324,7 @@ Improvements to Clang's diagnostics
   Fixes #GH82512.
 
 - Clang now provides improved warnings for the ``cleanup`` attribute to detect misuse scenarios,
-  such as attempting to call ``free`` on an unallocated object. Fixes
-  `#79443 <https://github.com/llvm/llvm-project/issues/79443>`_.
+  such as attempting to call ``free`` on an unallocated object. Fixes #GH79443.
 
 - Clang no longer warns when the ``bitand`` operator is used with boolean
   operands, distinguishing it from potential typographical errors or unintended
@@ -366,17 +364,18 @@ Improvements to Clang's diagnostics
 - Clang now uses the correct type-parameter-key (``class`` or ``typename``) when printing
   template template parameter declarations.
 
+- Clang now diagnoses requires expressions with explicit object parameters.
+
 Improvements to Clang's time-trace
 ----------------------------------
 
 Bug Fixes in This Version
 -------------------------
 - Clang's ``-Wundefined-func-template`` no longer warns on pure virtual
-  functions.
-  (`#74016 <https://github.com/llvm/llvm-project/issues/74016>`_)
+  functions. (#GH74016)
 
 - Fixed missing warnings when comparing mismatched enumeration constants
-  in C (`#29217 <https://github.com/llvm/llvm-project/issues/29217>`).
+  in C (#GH29217)
 
 - Clang now accepts elaborated-type-specifiers that explicitly specialize
   a member class template for an implicit instantiation of a class template.
@@ -415,14 +414,16 @@ Bug Fixes in This Version
   type only rather than to the complex type (e.g. ``_Complex float / int`` is now evaluated
   as ``_Complex float / float`` rather than ``_Complex float / _Complex float``), as mandated
   by the C standard. This significantly improves codegen of `*` and `/` especially.
-  Fixes (`#31205 <https://github.com/llvm/llvm-project/issues/31205>`_).
+  Fixes #GH31205.
 
 - Fixes an assertion failure on invalid code when trying to define member
   functions in lambdas.
 
 - Fixed a regression in CTAD that a friend declaration that befriends itself may cause
   incorrect constraint substitution. (#GH86769).
 
+- Fixed an assertion failure on invalid InitListExpr in C89 mode (#GH88008).
+
 Bug Fixes to Compiler Builtins
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
@@ -464,8 +465,7 @@ Bug Fixes to C++ Support
 - Fix a crash when trying to call a varargs function that also has an explicit object parameter. (#GH80971)
 - Fixed a bug where abbreviated function templates would append their invented template parameters to
   an empty template parameter lists.
-- Fix parsing of abominable function types inside type traits.
-  Fixes (`#77585 <https://github.com/llvm/llvm-project/issues/77585>`_)
+- Fix parsing of abominable function types inside type traits. Fixes #GH77585
 - Clang now classifies aggregate initialization in C++17 and newer as constant
   or non-constant more accurately. Previously, only a subset of the initializer
   elements were considered, misclassifying some initializers as constant. Partially fixes
@@ -506,9 +506,7 @@ Bug Fixes to C++ Support
 - Fix a bug where overload resolution falsely reported an ambiguity when it was comparing
   a member-function against a non member function or a member-function with an
   explicit object parameter against a member function with no explicit object parameter
-  when one of the function had more specialized templates.
-  Fixes (`#82509 <https://github.com/llvm/llvm-project/issues/82509>`_)
-  and (`#74494 <https://github.com/llvm/llvm-project/issues/74494>`_)
+  when one of the function had more specialized templates. Fixes #GH82509 and #GH74494
 - Clang now supports direct lambda calls inside of a type alias template declarations.
   This addresses (#GH70601), (#GH76674), (#GH79555), (#GH81145) and (#GH82104).
 - Allow access to a public template alias declaration that refers to friend's
@@ -530,14 +528,14 @@ Bug Fixes to C++ Support
 - Fixed a bug that prevented member function templates of class templates declared with a deduced return type
   from being explicitly specialized for a given implicit instantiation of the class template.
 
-- Fix crash when inheriting from a cv-qualified type. Fixes:
-  (`#35603 <https://github.com/llvm/llvm-project/issues/35603>`_)
+- Fix crash when inheriting from a cv-qualified type. Fixes #GH35603
 - Fix a crash when the using enum declaration uses an anonymous enumeration. Fixes (#GH86790).
 - Handled an edge case in ``getFullyPackExpandedSize`` so that we now avoid a false-positive diagnostic. (#GH84220)
 - Clang now correctly tracks type dependence of by-value captures in lambdas with an explicit
   object parameter.
   Fixes (#GH70604), (#GH79754), (#GH84163), (#GH84425), (#GH86054), (#GH86398), and (#GH86399).
 - Fix a crash when deducing ``auto`` from an invalid dereference (#GH88329).
+- Fix a crash in requires expression with templated base class member function. Fixes (#GH84020).
 
 Bug Fixes to AST Handling
 ^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -551,8 +549,7 @@ Miscellaneous Clang Crashes Fixed
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 - Do not attempt to dump the layout of dependent types or invalid declarations
-  when ``-fdump-record-layouts-complete`` is passed.
-  Fixes (`#83684 <https://github.com/llvm/llvm-project/issues/83684>`_).
+  when ``-fdump-record-layouts-complete`` is passed. Fixes #GH83684.
 
 OpenACC Specific Changes
 ------------------------
@@ -602,8 +599,7 @@ Windows Support
   would only be included if AVX was enabled at compile time. This was done to work
   around include times from MSVC STL including ``intrin.h`` under clang-cl.
   Clang-cl now provides ``intrin0.h`` for MSVC STL and therefore all intrinsic
-  features without requiring enablement at compile time.
-  Fixes: (`#53520 <https://github.com/llvm/llvm-project/issues/53520>`_)
+  features without requiring enablement at compile time. Fixes #GH53520
 
 - Improved compile times with MSVC STL. MSVC provides ``intrin0.h`` which is a
   header that only includes intrinsics that are used by MSVC STL to avoid the
@@ -684,6 +680,8 @@ Static Analyzer
   but not under any case blocks if ``unroll-loops=true`` analyzer config is
   set. (#GH68819)
 - Support C++23 static operator calls. (#GH84972)
+- Fixed a crash in ``security.cert.env.InvalidPtr`` checker when accidentally
+  matched user-defined ``strerror`` and similar library functions. (GH#88181)
 
 New features
 ^^^^^^^^^^^^