diff --git a/.ci/metrics/requirements.lock.txt b/.ci/metrics/requirements.lock.txt
diff --git a/.ci/metrics/requirements.txt b/.ci/metrics/requirements.txt
@@ -0,0 +1 @@
+pygithub==2.5.0
diff --git a/.github/new-issues-labeler.yml b/.github/new-issues-labeler.yml
@@ -30,3 +30,9 @@
 
 'infra:commit-access-request':
   - '/Request Commit Access/'
+
+'false-positive':
+  - '\bfalse[- ]positive\b'
+
+'false-negative':
+  - '\bfalse[- ]negative\b'
diff --git a/.github/workflows/build-metrics-container.yml b/.github/workflows/build-metrics-container.yml
@@ -0,0 +1,78 @@
+name: Build Metrics Container
+
+permissions:
+  contents: read
+
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - .github/workflows/build-metrics-container.yml
+      - '.ci/metrics/**'
+  pull_request:
+    branches:
+      - main
+    paths:
+      - .github/workflows/build-metrics-container.yml
+      - '.ci/metrics/**'
+
+jobs:
+  build-metrics-container:
+    if: github.repository_owner == 'llvm'
+    runs-on: ubuntu-latest
+    outputs:
+      container-name: ${{ steps.vars.outputs.container-name }}
+      container-name-tag: ${{ steps.vars.outputs.container-name-tag }}
+      container-filename: ${{ steps.vars.outputs.container-filename }}
+    steps:
+      - name: Checkout LLVM
+        uses: actions/checkout@v4
+        with:
+          sparse-checkout: .ci/metrics/
+      - name: Write Variables
+        id: vars
+        run: |
+          tag=`date +%s`
+          container_name="ghcr.io/$GITHUB_REPOSITORY_OWNER/metrics"
+          echo "container-name=$container_name" >> $GITHUB_OUTPUT
+          echo "container-name-tag=$container_name:$tag" >> $GITHUB_OUTPUT
+          echo "container-filename=$(echo $container_name:$tag  | sed -e 's/\//-/g' -e 's/:/-/g').tar" >> $GITHUB_OUTPUT
+      - name: Build Container
+        working-directory: ./.ci/metrics
+        run: |
+          podman build -t ${{ steps.vars.outputs.container-name-tag }} -f Dockerfile .
+      # Save the container so we have it in case the push fails.  This also
+      # allows us to separate the push step into a different job so we can
+      # maintain minimal permissions while building the container.
+      - name: Save Container Image
+        run: |
+          podman save  ${{ steps.vars.outputs.container-name-tag }} >  ${{ steps.vars.outputs.container-filename }}
+      - name: Upload Container Image
+        uses: actions/upload-artifact@v4
+        with:
+          name: container
+          path: ${{ steps.vars.outputs.container-filename }}
+          retention-days: 14
+
+  push-metrics-container:
+    if: github.event_name == 'push'
+    needs:
+      - build-metrics-container
+    permissions:
+      packages: write
+    runs-on: ubuntu-24.04
+    env:
+      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+    steps:
+      - name: Download Container
+        uses: actions/download-artifact@v4
+        with:
+          name: container
+      - name: Push Container
+        run: |
+          podman load -i ${{ needs.build-metrics-container.outputs.container-filename }}
+          podman tag ${{ needs.build-metrics-container.outputs.container-name-tag }} ${{ needs.build-metrics-container.outputs.container-name }}:latest
+          podman login -u ${{ github.actor }} -p $GITHUB_TOKEN ghcr.io
+          podman push ${{ needs.build-metrics-container.outputs.container-name-tag }}
+          podman push ${{ needs.build-metrics-container.outputs.container-name }}:latest
diff --git a/.github/workflows/docs.yml b/.github/workflows/docs.yml
@@ -112,58 +112,87 @@ jobs:
           sudo apt-get update
           # swig and graphviz are lldb specific dependencies
           sudo apt-get install -y cmake ninja-build swig graphviz
+      - name: Setup output folder
+        run: mkdir built-docs
       - name: Build LLVM docs
         if: steps.docs-changed-subprojects.outputs.llvm_any_changed == 'true'
         run: |
           cmake -B llvm-build -GNinja -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_SPHINX=ON ./llvm
           TZ=UTC ninja -C llvm-build docs-llvm-html docs-llvm-man
+          mkdir built-docs/llvm
+          cp -r llvm-build/docs/* built-docs/llvm/
       - name: Build Clang docs
         if: steps.docs-changed-subprojects.outputs.clang_any_changed == 'true'
         run: |
           cmake -B clang-build -GNinja -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_PROJECTS="clang" -DLLVM_ENABLE_SPHINX=ON ./llvm
           TZ=UTC ninja -C clang-build docs-clang-html docs-clang-man
+          mkdir built-docs/clang
+          cp -r clang-build/docs/* built-docs/clang/
       - name: Build clang-tools-extra docs
         if: steps.docs-changed-subprojects.outputs.clang-tools-extra_any_changed == 'true'
         run: |
           cmake -B clang-tools-extra-build -GNinja -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_PROJECTS="clang;clang-tools-extra" -DLLVM_ENABLE_SPHINX=ON ./llvm
           TZ=UTC ninja -C clang-tools-extra-build docs-clang-tools-html docs-clang-tools-man
+          mkdir built-docs/clang-tools-extra
+          cp -r clang-tools-extra-build/docs/* built-docs/clang-tools-extra/
       - name: Build LLDB docs
         if: steps.docs-changed-subprojects.outputs.lldb_any_changed == 'true'
         run: |
           cmake -B lldb-build -GNinja -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_PROJECTS="clang;lldb" -DLLVM_ENABLE_SPHINX=ON ./llvm
           TZ=UTC ninja -C lldb-build docs-lldb-html docs-lldb-man
+          mkdir built-docs/lldb
+          cp -r lldb-build/docs/* built-docs/lldb/
       - name: Build libunwind docs
         if: steps.docs-changed-subprojects.outputs.libunwind_any_changed == 'true'
         run: |
           cmake -B libunwind-build -GNinja -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_RUNTIMES="libunwind" -DLLVM_ENABLE_SPHINX=ON ./runtimes
           TZ=UTC ninja -C libunwind-build docs-libunwind-html
+          mkdir built-docs/libunwind
+          cp -r libunwind-build/docs/* built-docs/libunwind
       - name: Build libcxx docs
         if: steps.docs-changed-subprojects.outputs.libcxx_any_changed == 'true'
         run: |
           cmake -B libcxx-build -GNinja -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_RUNTIMES="libcxxabi;libcxx;libunwind" -DLLVM_ENABLE_SPHINX=ON ./runtimes
           TZ=UTC ninja -C libcxx-build docs-libcxx-html
+          mkdir built-docs/libcxx
+          cp -r libcxx-build/docs/* built-docs/libcxx/
       - name: Build libc docs
         if: steps.docs-changed-subprojects.outputs.libc_any_changed == 'true'
         run: |
           cmake -B libc-build -GNinja -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_RUNTIMES="libc" -DLLVM_ENABLE_SPHINX=ON ./runtimes
           TZ=UTC ninja -C libc-build docs-libc-html
+          mkdir built-docs/libc
+          cp -r libc-build/docs/* built-docs/libc/
       - name: Build LLD docs
         if: steps.docs-changed-subprojects.outputs.lld_any_changed == 'true'
         run: |
           cmake -B lld-build -GNinja -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_PROJECTS="lld" -DLLVM_ENABLE_SPHINX=ON ./llvm
           TZ=UTC ninja -C lld-build docs-lld-html
+          mkdir built-docs/lld
+          cp -r lld-build/docs/* built-docs/lld/
       - name: Build OpenMP docs
         if: steps.docs-changed-subprojects.outputs.openmp_any_changed == 'true'
         run: |
           cmake -B openmp-build -GNinja -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_PROJECTS="clang;openmp" -DLLVM_ENABLE_SPHINX=ON ./llvm
           TZ=UTC ninja -C openmp-build docs-openmp-html
+          mkdir built-docs/openmp
+          cp -r openmp-build/docs/* built-docs/openmp/
       - name: Build Polly docs
         if: steps.docs-changed-subprojects.outputs.polly_any_changed == 'true'
         run: |
           cmake -B polly-build -GNinja -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_PROJECTS="polly" -DLLVM_ENABLE_SPHINX=ON ./llvm
           TZ=UTC ninja -C polly-build docs-polly-html docs-polly-man
+          mkdir built-docs/polly
+          cp -r polly-build/docs/* built-docs/polly/
       - name: Build Flang docs
         if: steps.docs-changed-subprojects.outputs.flang_any_changed == 'true'
         run: |
           cmake -B flang-build -GNinja -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_PROJECTS="clang;mlir;flang" -DLLVM_ENABLE_SPHINX=ON ./llvm
           TZ=UTC ninja -C flang-build docs-flang-html
+          mkdir built-docs/flang
+          cp -r flang-build/docs/* built-docs/flang/
+      - name: Upload docs
+        uses: actions/upload-artifact@v4
+        with:
+          name: docs-output
+          path: built-docs/
diff --git a/bolt/CODE_OWNERS.TXT → bolt/Maintainers.txt b/bolt/CODE_OWNERS.TXT → bolt/Maintainers.txt
diff --git a/bolt/include/bolt/Core/BinaryFunction.h b/bolt/include/bolt/Core/BinaryFunction.h
@@ -2407,6 +2407,19 @@ inline raw_ostream &operator<<(raw_ostream &OS,
   return OS;
 }
 
+/// Compare function by index if it is valid, fall back to the original address
+/// otherwise.
+inline bool compareBinaryFunctionByIndex(const BinaryFunction *A,
+                                         const BinaryFunction *B) {
+  if (A->hasValidIndex() && B->hasValidIndex())
+    return A->getIndex() < B->getIndex();
+  if (A->hasValidIndex() && !B->hasValidIndex())
+    return true;
+  if (!A->hasValidIndex() && B->hasValidIndex())
+    return false;
+  return A->getAddress() < B->getAddress();
+}
+
 } // namespace bolt
 
 // GraphTraits specializations for function basic block graphs (CFGs)

diff --git a/bolt/include/bolt/Profile/DataAggregator.h b/bolt/include/bolt/Profile/DataAggregator.h
@@ -170,6 +170,9 @@ class DataAggregator : public DataReader {
   std::string BuildIDBinaryName;
 
   /// Memory map info for a single file as recorded in perf.data
+  /// When a binary has multiple text segments, the Size is computed as the
+  /// difference of the last address of these segments from the BaseAddress.
+  /// The base addresses of all text segments must be the same.
   struct MMapInfo {
     uint64_t BaseAddress{0}; /// Base address of the mapped binary.
     uint64_t MMapAddress{0}; /// Address of the executable segment.
@@ -493,6 +496,11 @@ class DataAggregator : public DataReader {
   /// and return a file name matching a given \p FileBuildID.
   std::optional<StringRef> getFileNameForBuildID(StringRef FileBuildID);
 
+  /// Get a constant reference to the parsed binary mmap entries.
+  const std::unordered_map<uint64_t, MMapInfo> &getBinaryMMapInfo() {
+    return BinaryMMapInfo;
+  }
+
   friend class YAMLProfileWriter;
 };
 } // namespace bolt

diff --git a/bolt/lib/Core/BinaryContext.cpp b/bolt/lib/Core/BinaryContext.cpp
@@ -1607,13 +1607,7 @@ std::vector<BinaryFunction *> BinaryContext::getSortedFunctions() {
                   SortedFunctions.begin(),
                   [](BinaryFunction &BF) { return &BF; });
 
-  llvm::stable_sort(SortedFunctions,
-                    [](const BinaryFunction *A, const BinaryFunction *B) {
-                      if (A->hasValidIndex() && B->hasValidIndex()) {
-                        return A->getIndex() < B->getIndex();
-                      }
-                      return A->hasValidIndex();
-                    });
+  llvm::stable_sort(SortedFunctions, compareBinaryFunctionByIndex);
   return SortedFunctions;
 }
 

diff --git a/bolt/lib/Core/BinaryFunction.cpp b/bolt/lib/Core/BinaryFunction.cpp
@@ -385,16 +385,7 @@ bool BinaryFunction::isForwardCall(const MCSymbol *CalleeSymbol) const {
   if (CalleeBF) {
     if (CalleeBF->isInjected())
       return true;
-
-    if (hasValidIndex() && CalleeBF->hasValidIndex()) {
-      return getIndex() < CalleeBF->getIndex();
-    } else if (hasValidIndex() && !CalleeBF->hasValidIndex()) {
-      return true;
-    } else if (!hasValidIndex() && CalleeBF->hasValidIndex()) {
-      return false;
-    } else {
-      return getAddress() < CalleeBF->getAddress();
-    }
+    return compareBinaryFunctionByIndex(this, CalleeBF);
   } else {
     // Absolute symbol.
     ErrorOr<uint64_t> CalleeAddressOrError = BC.getSymbolValue(*CalleeSymbol);

diff --git a/bolt/lib/Passes/ReorderFunctions.cpp b/bolt/lib/Passes/ReorderFunctions.cpp
@@ -473,16 +473,7 @@ Error ReorderFunctions::runOnFunctions(BinaryContext &BC) {
                     [](BinaryFunction &BF) { return &BF; });
 
     // Sort functions by index.
-    llvm::stable_sort(SortedFunctions,
-                      [](const BinaryFunction *A, const BinaryFunction *B) {
-                        if (A->hasValidIndex() && B->hasValidIndex())
-                          return A->getIndex() < B->getIndex();
-                        if (A->hasValidIndex() && !B->hasValidIndex())
-                          return true;
-                        if (!A->hasValidIndex() && B->hasValidIndex())
-                          return false;
-                        return A->getAddress() < B->getAddress();
-                      });
+    llvm::stable_sort(SortedFunctions, compareBinaryFunctionByIndex);
 
     for (const BinaryFunction *Func : SortedFunctions) {
       if (!Func->hasValidIndex())

diff --git a/bolt/lib/Profile/DataAggregator.cpp b/bolt/lib/Profile/DataAggregator.cpp
@@ -95,6 +95,12 @@ cl::opt<bool> ReadPreAggregated(
     "pa", cl::desc("skip perf and read data from a pre-aggregated file format"),
     cl::cat(AggregatorCategory));
 
+cl::opt<std::string>
+    ReadPerfEvents("perf-script-events",
+                   cl::desc("skip perf event collection by supplying a "
+                            "perf-script output in a textual format"),
+                   cl::ReallyHidden, cl::init(""), cl::cat(AggregatorCategory));
+
 static cl::opt<bool>
 TimeAggregator("time-aggr",
   cl::desc("time BOLT aggregator"),
@@ -167,8 +173,9 @@ void DataAggregator::findPerfExecutable() {
 void DataAggregator::start() {
   outs() << "PERF2BOLT: Starting data aggregation job for " << Filename << "\n";
 
-  // Don't launch perf for pre-aggregated files
-  if (opts::ReadPreAggregated)
+  // Don't launch perf for pre-aggregated files or when perf input is specified
+  // by the user.
+  if (opts::ReadPreAggregated || !opts::ReadPerfEvents.empty())
     return;
 
   findPerfExecutable();
@@ -464,6 +471,13 @@ void DataAggregator::filterBinaryMMapInfo() {
 
 int DataAggregator::prepareToParse(StringRef Name, PerfProcessInfo &Process,
                                    PerfProcessErrorCallbackTy Callback) {
+  if (!opts::ReadPerfEvents.empty()) {
+    outs() << "PERF2BOLT: using pre-processed perf events for '" << Name
+           << "' (perf-script-events)\n";
+    ParsingBuf = opts::ReadPerfEvents;
+    return 0;
+  }
+
   std::string Error;
   outs() << "PERF2BOLT: waiting for perf " << Name
          << " collection to finish...\n";
@@ -2056,15 +2070,6 @@ std::error_code DataAggregator::parseMMapEvents() {
     if (FileMMapInfo.first == "(deleted)")
       continue;
 
-    // Consider only the first mapping of the file for any given PID
-    auto Range = GlobalMMapInfo.equal_range(FileMMapInfo.first);
-    bool PIDExists = llvm::any_of(make_range(Range), [&](const auto &MI) {
-      return MI.second.PID == FileMMapInfo.second.PID;
-    });
-
-    if (PIDExists)
-      continue;
-
     GlobalMMapInfo.insert(FileMMapInfo);
   }
 
@@ -2116,12 +2121,22 @@ std::error_code DataAggregator::parseMMapEvents() {
                << " using file offset 0x" << Twine::utohexstr(MMapInfo.Offset)
                << ". Ignoring profile data for this mapping\n";
         continue;
-      } else {
-        MMapInfo.BaseAddress = *BaseAddress;
       }
+      MMapInfo.BaseAddress = *BaseAddress;
     }
 
-    BinaryMMapInfo.insert(std::make_pair(MMapInfo.PID, MMapInfo));
+    // Try to add MMapInfo to the map and update its size. Large binaries may
+    // span to multiple text segments, so the mapping is inserted only on the
+    // first occurrence.
+    if (!BinaryMMapInfo.insert(std::make_pair(MMapInfo.PID, MMapInfo)).second)
+      assert(MMapInfo.BaseAddress == BinaryMMapInfo[MMapInfo.PID].BaseAddress &&
+             "Base address on multiple segment mappings should match");
+
+    // Update mapping size.
+    const uint64_t EndAddress = MMapInfo.MMapAddress + MMapInfo.Size;
+    const uint64_t Size = EndAddress - BinaryMMapInfo[MMapInfo.PID].BaseAddress;
+    if (Size > BinaryMMapInfo[MMapInfo.PID].Size)
+      BinaryMMapInfo[MMapInfo.PID].Size = Size;
   }
 
   if (BinaryMMapInfo.empty()) {

diff --git a/bolt/lib/Rewrite/RewriteInstance.cpp b/bolt/lib/Rewrite/RewriteInstance.cpp
@@ -2927,6 +2927,23 @@ void RewriteInstance::handleRelocation(const SectionRef &RelocatedSection,
     LLVM_DEBUG(dbgs() << "BOLT-DEBUG: ignoring relocation from data to data\n");
 }
 
+static BinaryFunction *getInitFunctionIfStaticBinary(BinaryContext &BC) {
+  // Workaround for https://github.com/llvm/llvm-project/issues/100096
+  // ("[BOLT] GOT array pointer incorrectly rewritten"). In aarch64
+  // static glibc binaries, the .init section's _init function pointer can
+  // alias with a data pointer for the end of an array. GOT rewriting
+  // currently can't detect this and updates the data pointer to the
+  // moved _init, causing a runtime crash. Skipping _init on the other
+  // hand should be harmless.
+  if (!BC.IsStaticExecutable)
+    return nullptr;
+  const BinaryData *BD = BC.getBinaryDataByName("_init");
+  if (!BD || BD->getSectionName() != ".init")
+    return nullptr;
+  LLVM_DEBUG(dbgs() << "BOLT-DEBUG: skip _init in for GOT workaround.\n");
+  return BC.getBinaryFunctionAtAddress(BD->getAddress());
+}
+
 void RewriteInstance::selectFunctionsToProcess() {
   // Extend the list of functions to process or skip from a file.
   auto populateFunctionNames = [](cl::opt<std::string> &FunctionNamesFile,
@@ -3047,6 +3064,9 @@ void RewriteInstance::selectFunctionsToProcess() {
     return true;
   };
 
+  if (BinaryFunction *Init = getInitFunctionIfStaticBinary(*BC))
+    Init->setIgnored();
+
   for (auto &BFI : BC->getBinaryFunctions()) {
     BinaryFunction &Function = BFI.second;
 

diff --git a/bolt/test/AArch64/check-init-not-moved.s b/bolt/test/AArch64/check-init-not-moved.s
@@ -0,0 +1,43 @@
+# Regression test for https://github.com/llvm/llvm-project/issues/100096
+# static glibc binaries crash on startup because _init is moved and
+# shares its address with an array end pointer. The GOT rewriting can't
+# tell the two pointers apart and incorrectly updates the _array_end
+# address. Test checks that _init is not moved.
+
+# RUN: llvm-mc -filetype=obj -triple aarch64-unknown-unknown %s -o %t.o
+# RUN: %clang %cflags %t.o -o %t.exe -Wl,-q -static -Wl,--section-start=.data=0x1000 -Wl,--section-start=.init=0x1004
+# RUN: llvm-bolt %t.exe -o %t.bolt
+# RUN: llvm-nm %t.exe | FileCheck --check-prefix=CHECK-ORIGINAL %s
+# RUN: llvm-nm %t.bolt | FileCheck --check-prefix=CHECK-BOLTED %s
+
+.section .data
+.globl _array_end
+_array_start:
+    .word 0x0
+
+_array_end:
+.section .init,"ax",@progbits
+.globl _init
+
+# Check that bolt doesn't move _init.
+#
+# CHECK-ORIGINAL: 0000000000001004 T _init
+# CHECK-BOLTED:   0000000000001004 T _init
+_init:
+    ret
+
+.section .text,"ax",@progbits
+.globl _start
+
+# Check that bolt is moving some other functions.
+#
+# CHECK-ORIGINAL:   0000000000001008 T _start
+# CHECK-BOLTED-NOT: 0000000000001008 T _start
+_start:
+    bl _init
+    adrp x0, #:got:_array_end
+    ldr x0, [x0, #:gotpage_lo15:_array_end]
+    adrp x0, #:got:_init
+    ldr x0, [x0, #:gotpage_lo15:_init]
+    ret
+
diff --git a/bolt/test/AArch64/data-at-0-offset.c b/bolt/test/AArch64/data-at-0-offset.c
@@ -1,4 +1,4 @@
-// RUN: %clang %cflags -O2 -fPIE -Wl,-q -pie  %s -o %t.exe
+// RUN: %clang %cflags -O2 -fPIE -std=gnu99 -Wl,-q -pie  %s -o %t.exe
 // RUN: llvm-bolt %t.exe -o %t.bolt 2>&1 | FileCheck %s
 // CHECK-NOT: BOLT-WARNING: unable to disassemble instruction at offset
 

diff --git a/bolt/test/AArch64/double_jump.cpp b/bolt/test/AArch64/double_jump.cpp
@@ -1,6 +1,6 @@
 // A contrived example to test the double jump removal peephole.
 
-// RUN: %clang %cflags -O0 %s -o %t.exe
+// RUN: %clangxx %cxxflags -O0 %s -o %t.exe
 // RUN: llvm-bolt %t.exe -o %t.bolt --peepholes=double-jumps | \
 // RUN:   FileCheck %s -check-prefix=CHECKBOLT
 // RUN: llvm-objdump --no-print-imm-hex -d %t.bolt | FileCheck %s

diff --git a/bolt/test/R_ABS.pic.lld.cpp b/bolt/test/R_ABS.pic.lld.cpp
@@ -6,7 +6,7 @@
  * with libc available.
  * REQUIRES: system-linux
  *
- * RUN: %clang %cflags -fPIC -shared %s -o %t.so -Wl,-q -fuse-ld=lld
+ * RUN: %clangxx %cxxflags -fPIC -shared %s -o %t.so -Wl,-q -fuse-ld=lld
  * RUN: llvm-bolt %t.so -o %t.so.bolt --relocs
  */
 

diff --git a/bolt/test/X86/double-jump.test b/bolt/test/X86/double-jump.test
@@ -4,7 +4,7 @@
 ## correctly on Windows e.g. subshell execution
 REQUIRES: shell
 
-RUN: %clang %cflags %p/Inputs/double_jump.cpp -o %t.exe
+RUN: %clangxx %cxxflags %p/Inputs/double_jump.cpp -o %t.exe
 RUN: (llvm-bolt %t.exe --peepholes=double-jumps \
 RUN:   --eliminate-unreachable -o %t 2>&1 \
 RUN:   && llvm-objdump -d %t --print-imm-hex --no-show-raw-insn) | FileCheck %s

diff --git a/bolt/test/X86/dwarf5-df-inlined-subroutine-gc-sections-range.test b/bolt/test/X86/dwarf5-df-inlined-subroutine-gc-sections-range.test
@@ -6,7 +6,7 @@
 ; RUN: -split-dwarf-file=main.dwo -o main.o
 ; RUN: llvm-mc -dwarf-version=5 -filetype=obj -triple x86_64-unknown-linux %p/Inputs/dwarf5-df-inlined-subroutine-gc-sections-range-helper.s \
 ; RUN: -split-dwarf-file=helper.dwo -o helper.o
-; RUN: %clang --target=x86_64-pc-linux -fuse-ld=lld -Wl,-gc-sections -Wl,-q -gdwarf-5 -gsplit-dwarf=split main.o helper.o -o main.exe
+; RUN: %clang -fuse-ld=lld -Wl,-gc-sections -Wl,-q -gdwarf-5 -gsplit-dwarf=split main.o helper.o -o main.exe
 ; RUN: llvm-bolt main.exe -o main.exe.bolt --update-debug-sections
 ; RUN: llvm-dwarfdump --debug-addr main.exe > log.txt
 ; RUN: llvm-dwarfdump --debug-rnglists --verbose --show-form main.dwo >> log.txt

diff --git a/bolt/test/X86/jmp-optimization.test b/bolt/test/X86/jmp-optimization.test
@@ -4,7 +4,7 @@
 ## correctly on Windows e.g. unsupported parameter expansion
 REQUIRES: shell
 
-RUN: %clang %cflags -O2 %S/Inputs/jmp_opt{,2,3}.cpp -o %t
+RUN: %clangxx %cxxflags -O2 %S/Inputs/jmp_opt{,2,3}.cpp -o %t
 RUN: llvm-bolt -inline-small-functions %t -o %t.bolt
 RUN: llvm-objdump -d %t.bolt --print-imm-hex | FileCheck %s
 

diff --git a/bolt/test/X86/match-functions-with-call-graph.test b/bolt/test/X86/match-functions-with-call-graph.test
@@ -2,7 +2,7 @@
 
 # REQUIRES: system-linux
 # RUN: split-file %s %t
-# RUN: %clang %cflags %t/main.cpp -o %t.exe -Wl,-q -nostdlib
+# RUN: %clangxx %cxxflags %t/main.cpp -o %t.exe -Wl,-q -nostdlib
 # RUN: llvm-bolt %t.exe -o %t.out --data %t/yaml --profile-ignore-hash -v=1 \
 # RUN:   --dyno-stats --print-cfg --infer-stale-profile=1 --match-with-call-graph 2>&1 | FileCheck %s
 

diff --git a/bolt/test/pie.test b/bolt/test/pie.test
@@ -4,7 +4,7 @@
 ## on Linux systems where the host triple matches the target.
 REQUIRES: system-linux
 
-RUN: %clang %cflags -fPIC -pie %p/Inputs/jump_table_icp.cpp -o %t
+RUN: %clangxx %cxxflags -fPIC -pie %p/Inputs/jump_table_icp.cpp -o %t
 RUN: llvm-bolt %t -o %t.null 2>&1 | FileCheck %s
 
 CHECK: BOLT-INFO: shared object or position-independent executable detected
diff --git a/bolt/test/runtime/X86/instrumentation-indirect.c b/bolt/test/runtime/X86/instrumentation-indirect.c
@@ -38,7 +38,7 @@ int main(int argc, char **argv) {
 /*
 REQUIRES: system-linux,bolt-runtime,lit-max-individual-test-time
 
-RUN: %clang %cflags %s -o %t.exe -Wl,-q -pie -fpie
+RUN: %clang %cflags -D_GNU_SOURCE %s -o %t.exe -Wl,-q -pie -fpie
 
 RUN: llvm-bolt %t.exe --instrument --instrumentation-file=%t.fdata \
 RUN:   --instrumentation-wait-forks=1 --conservative-instrumentation \

diff --git a/bolt/test/runtime/bolt-reserved.cpp b/bolt/test/runtime/bolt-reserved.cpp
@@ -5,7 +5,7 @@
  * new sections.
  */
 
-// RUN: %clang %s -o %t.exe -Wl,-q
+// RUN: %clangxx %s -o %t.exe -Wl,-q
 // RUN: llvm-bolt %t.exe -o %t.bolt.exe 2>&1 | FileCheck %s
 // RUN: %t.bolt.exe
 
@@ -16,7 +16,7 @@
  * not enough for allocating new sections.
  */
 
-// RUN: %clang %s -o %t.tiny.exe -Wl,--no-eh-frame-hdr -Wl,-q -DTINY
+// RUN: %clangxx %s -o %t.tiny.exe -Wl,--no-eh-frame-hdr -Wl,-q -DTINY
 // RUN: not llvm-bolt %t.tiny.exe -o %t.tiny.bolt.exe 2>&1 | \
 // RUN:   FileCheck %s --check-prefix=CHECK-TINY
 

diff --git a/bolt/unittests/Core/CMakeLists.txt b/bolt/unittests/Core/CMakeLists.txt
@@ -8,6 +8,7 @@ set(LLVM_LINK_COMPONENTS
 add_bolt_unittest(CoreTests
   BinaryContext.cpp
   MCPlusBuilder.cpp
+  MemoryMaps.cpp
   DynoStats.cpp
 
   DISABLE_LLVM_LINK_LLVM_DYLIB
@@ -17,6 +18,8 @@ target_link_libraries(CoreTests
   PRIVATE
   LLVMBOLTCore
   LLVMBOLTRewrite
+  LLVMBOLTProfile
+  LLVMTestingSupport
   )
 
 foreach (tgt ${BOLT_TARGETS_TO_BUILD})

diff --git a/bolt/unittests/Core/MCPlusBuilder.cpp b/bolt/unittests/Core/MCPlusBuilder.cpp
@@ -90,14 +90,15 @@ INSTANTIATE_TEST_SUITE_P(AArch64, MCPlusBuilderTester,
                          ::testing::Values(Triple::aarch64));
 
 TEST_P(MCPlusBuilderTester, AliasX0) {
-  uint64_t AliasesX0[] = {AArch64::W0, AArch64::X0, AArch64::W0_W1,
+  uint64_t AliasesX0[] = {AArch64::W0,    AArch64::W0_HI,
+                          AArch64::X0,    AArch64::W0_W1,
                           AArch64::X0_X1, AArch64::X0_X1_X2_X3_X4_X5_X6_X7};
   size_t AliasesX0Count = sizeof(AliasesX0) / sizeof(*AliasesX0);
   testRegAliases(Triple::aarch64, AArch64::X0, AliasesX0, AliasesX0Count);
 }
 
 TEST_P(MCPlusBuilderTester, AliasSmallerX0) {
-  uint64_t AliasesX0[] = {AArch64::W0, AArch64::X0};
+  uint64_t AliasesX0[] = {AArch64::W0, AArch64::W0_HI, AArch64::X0};
   size_t AliasesX0Count = sizeof(AliasesX0) / sizeof(*AliasesX0);
   testRegAliases(Triple::aarch64, AArch64::X0, AliasesX0, AliasesX0Count, true);
 }

diff --git a/bolt/unittests/Core/MemoryMaps.cpp b/bolt/unittests/Core/MemoryMaps.cpp
@@ -0,0 +1,142 @@
+//===- bolt/unittest/Core/MemoryMaps.cpp ----------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "bolt/Core/BinaryContext.h"
+#include "bolt/Profile/DataAggregator.h"
+#include "llvm/BinaryFormat/ELF.h"
+#include "llvm/DebugInfo/DWARF/DWARFContext.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/TargetSelect.h"
+#include "llvm/Testing/Support/Error.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+using namespace llvm::object;
+using namespace llvm::ELF;
+using namespace bolt;
+
+namespace opts {
+extern cl::opt<std::string> ReadPerfEvents;
+} // namespace opts
+
+namespace {
+
+/// Perform checks on memory map events normally captured in perf. Tests use
+/// the 'opts::ReadPerfEvents' flag to emulate these events, passing a custom
+/// 'perf script' output to DataAggregator.
+struct MemoryMapsTester : public testing::TestWithParam<Triple::ArchType> {
+  void SetUp() override {
+    initalizeLLVM();
+    prepareElf();
+    initializeBOLT();
+  }
+
+protected:
+  void initalizeLLVM() {
+    llvm::InitializeAllTargetInfos();
+    llvm::InitializeAllTargetMCs();
+    llvm::InitializeAllAsmParsers();
+    llvm::InitializeAllDisassemblers();
+    llvm::InitializeAllTargets();
+    llvm::InitializeAllAsmPrinters();
+  }
+
+  void prepareElf() {
+    memcpy(ElfBuf, "\177ELF", 4);
+    ELF64LE::Ehdr *EHdr = reinterpret_cast<typename ELF64LE::Ehdr *>(ElfBuf);
+    EHdr->e_ident[llvm::ELF::EI_CLASS] = llvm::ELF::ELFCLASS64;
+    EHdr->e_ident[llvm::ELF::EI_DATA] = llvm::ELF::ELFDATA2LSB;
+    EHdr->e_machine = GetParam() == Triple::aarch64 ? EM_AARCH64 : EM_X86_64;
+    MemoryBufferRef Source(StringRef(ElfBuf, sizeof(ElfBuf)), "ELF");
+    ObjFile = cantFail(ObjectFile::createObjectFile(Source));
+  }
+
+  void initializeBOLT() {
+    Relocation::Arch = ObjFile->makeTriple().getArch();
+    BC = cantFail(BinaryContext::createBinaryContext(
+        ObjFile->makeTriple(), ObjFile->getFileName(), nullptr, true,
+        DWARFContext::create(*ObjFile.get()), {llvm::outs(), llvm::errs()}));
+    ASSERT_FALSE(!BC);
+  }
+
+  char ElfBuf[sizeof(typename ELF64LE::Ehdr)] = {};
+  std::unique_ptr<ObjectFile> ObjFile;
+  std::unique_ptr<BinaryContext> BC;
+};
+} // namespace
+
+#ifdef X86_AVAILABLE
+
+INSTANTIATE_TEST_SUITE_P(X86, MemoryMapsTester,
+                         ::testing::Values(Triple::x86_64));
+
+#endif
+
+#ifdef AARCH64_AVAILABLE
+
+INSTANTIATE_TEST_SUITE_P(AArch64, MemoryMapsTester,
+                         ::testing::Values(Triple::aarch64));
+
+#endif
+
+/// Check that the correct mmap size is computed when we have multiple text
+/// segment mappings.
+TEST_P(MemoryMapsTester, ParseMultipleSegments) {
+  const int Pid = 1234;
+  StringRef Filename = "BINARY";
+  opts::ReadPerfEvents = formatv(
+      "name       0 [000]     0.000000: PERF_RECORD_MMAP2 {0}/{0}: "
+      "[0xabc0000000(0x1000000) @ 0x11c0000 103:01 1573523 0]: r-xp {1}\n"
+      "name       0 [000]     0.000000: PERF_RECORD_MMAP2 {0}/{0}: "
+      "[0xabc2000000(0x8000000) @ 0x31d0000 103:01 1573523 0]: r-xp {1}\n",
+      Pid, Filename);
+
+  BC->SegmentMapInfo[0x11da000] =
+      SegmentInfo{0x11da000, 0x10da000, 0x11ca000, 0x10da000, 0x10000, true};
+  BC->SegmentMapInfo[0x31d0000] =
+      SegmentInfo{0x31d0000, 0x51ac82c, 0x31d0000, 0x3000000, 0x200000, true};
+
+  DataAggregator DA("");
+  BC->setFilename(Filename);
+  Error Err = DA.preprocessProfile(*BC);
+
+  // Ignore errors from perf2bolt when parsing memory events later on.
+  ASSERT_THAT_ERROR(std::move(Err), Succeeded());
+
+  auto &BinaryMMapInfo = DA.getBinaryMMapInfo();
+  auto El = BinaryMMapInfo.find(Pid);
+  // Check that memory mapping is present and has the expected size.
+  ASSERT_NE(El, BinaryMMapInfo.end());
+  ASSERT_EQ(El->second.Size, static_cast<uint64_t>(0xb1d0000));
+}
+
+/// Check that DataAggregator aborts when pre-processing an input binary
+/// with multiple text segments that have different base addresses.
+TEST_P(MemoryMapsTester, MultipleSegmentsMismatchedBaseAddress) {
+  const int Pid = 1234;
+  StringRef Filename = "BINARY";
+  opts::ReadPerfEvents = formatv(
+      "name       0 [000]     0.000000: PERF_RECORD_MMAP2 {0}/{0}: "
+      "[0xabc0000000(0x1000000) @ 0x11c0000 103:01 1573523 0]: r-xp {1}\n"
+      "name       0 [000]     0.000000: PERF_RECORD_MMAP2 {0}/{0}: "
+      "[0xabc2000000(0x8000000) @ 0x31d0000 103:01 1573523 0]: r-xp {1}\n",
+      Pid, Filename);
+
+  BC->SegmentMapInfo[0x11da000] =
+      SegmentInfo{0x11da000, 0x10da000, 0x11ca000, 0x10da000, 0x10000, true};
+  // Using '0x31d0fff' FileOffset which triggers a different base address
+  // for this second text segment.
+  BC->SegmentMapInfo[0x31d0000] =
+      SegmentInfo{0x31d0000, 0x51ac82c, 0x31d0fff, 0x3000000, 0x200000, true};
+
+  DataAggregator DA("");
+  BC->setFilename(Filename);
+  ASSERT_DEBUG_DEATH(
+      { Error Err = DA.preprocessProfile(*BC); },
+      "Base address on multiple segment mappings should match");
+}
diff --git a/bolt/utils/bughunter.sh b/bolt/utils/bughunter.sh
@@ -131,7 +131,7 @@ if [[ $FAIL -eq "0" ]]; then
         fi
     else
         echo "Did it pass? Type the return code [0 = pass, 1 = fail]"
-        read -n1 PASS
+        read -n1 FAIL
     fi
     if [[ $FAIL -eq "0" ]] ; then
         echo "  Warning: optimized binary passes."
@@ -205,7 +205,7 @@ while [[ "$CONTINUE" -ne "0" ]] ; do
             echo "  OPTIMIZED_BINARY failure=$FAIL"
         else
             echo "Did it pass? Type the return code [0 = pass, 1 = fail]"
-            read -n1 PASS
+            read -n1 FAIL
         fi
     else
         FAIL=1

diff --git a/clang-tools-extra/CODE_OWNERS.TXT b/clang-tools-extra/CODE_OWNERS.TXT
diff --git a/clang-tools-extra/Maintainers.txt b/clang-tools-extra/Maintainers.txt
@@ -0,0 +1,75 @@
+=============================
+Clang Tools Extra Maintainers
+=============================
+
+This file is a list of the maintainers
+(https://llvm.org/docs/DeveloperPolicy.html#maintainers) for clang-tools-extra.
+
+
+Active Maintainers
+==================
+The following people are the active maintainers for the project. Please reach
+out to them for code reviews, questions about their area of expertise, or other
+assistance.
+
+Lead Maintainer
+---------------
+| Aaron Ballman
+| aaron@aaronballman.com (email), aaron.ballman (Phabricator), AaronBallman (GitHub), AaronBallman (Discourse), aaronballman (Discord), AaronBallman (IRC)
+
+
+clang-tidy
+----------
+| Congcong Cai
+| congcongcai0907@163.com (email), HerrCai0907 (GitHub), HerrCai0907 (Discourse)
+
+| Julian Schmidt
+| git.julian.schmidt@gmail.com (email), 5chmidti (GitHub), 5chmidti (Discourse), 5chmidti (Discord)
+
+| Piotr Zegar
+| me@piotrzegar.pl (email), PiotrZSL (GitHub), PiotrZSL (Discourse), PiotrZSL (Discord)
+
+
+clang-query
+-----------
+| Aaron Ballman
+| aaron@aaronballman.com (email), aaron.ballman (Phabricator), AaronBallman (GitHub), AaronBallman (Discourse), aaronballman (Discord), AaronBallman (IRC)
+
+
+clang-doc
+---------
+| Paul Kirth
+| paulkirth@google.com (email), ilovepi (GitHub), ilovepi (Discourse)
+
+| Peter Chou
+| peterchou411@gmail.com (email), PeterChou1 (GitHub), PeterChou1 (Discourse), .peterchou (Discord)
+
+
+clangd
+------
+| Nathan Ridge
+| zeratul976@hotmail.com (email), HighCommander4 (GitHub), HighCommander4 (Discourse), nridge (Discord)
+
+| Chris Bieneman
+| chris.bieneman@gmail.com (email), llvm-beanz (GitHub), beanz (Discord), beanz (Discourse)
+
+| Kadir Çetinkaya
+| kadircet@google.com (email), kadircet (GitHub) kadircet (Discourse), kadircet (Discord)
+
+
+Inactive Maintainers
+====================
+The following people have graciously spent time performing maintainership
+responsibilities but are no longer active in that role. Thank you for all your
+help with the success of the project!
+
+Emeritus Lead Maintainers
+-------------------------
+| Manuel Klimek (klimek@google.com (email), r4nt (GitHub))
+
+
+Inactive component maintainers
+------------------------------
+| Nathan James (n.james93@hotmail.co.uk) -- clang-tidy
+| Julie Hockett (juliehockett@google.com) -- clang-doc
+| Sam McCall (sammccall@google.com (email), sam-mccall (GitHub, Discourse, Discord)) -- clangd
diff --git a/clang-tools-extra/clang-reorder-fields/ReorderFieldsAction.cpp b/clang-tools-extra/clang-reorder-fields/ReorderFieldsAction.cpp
@@ -116,6 +116,28 @@ findMembersUsedInInitExpr(const CXXCtorInitializer *Initializer,
   return Results;
 }
 
+/// Returns the full source range for the field declaration up to (not
+/// including) the trailing semicolumn, including potential macro invocations,
+/// e.g. `int a GUARDED_BY(mu);`.
+static SourceRange getFullFieldSourceRange(const FieldDecl &Field,
+                                           const ASTContext &Context) {
+  SourceRange Range = Field.getSourceRange();
+  SourceLocation End = Range.getEnd();
+  const SourceManager &SM = Context.getSourceManager();
+  const LangOptions &LangOpts = Context.getLangOpts();
+  while (true) {
+    std::optional<Token> CurrentToken = Lexer::findNextToken(End, SM, LangOpts);
+
+    if (!CurrentToken || CurrentToken->is(tok::semi))
+      break;
+
+    if (CurrentToken->is(tok::eof))
+      return Range; // Something is wrong, return the original range.
+    End = CurrentToken->getLastLoc();
+  }
+  return SourceRange(Range.getBegin(), End);
+}
+
 /// Reorders fields in the definition of a struct/class.
 ///
 /// At the moment reordering of fields with
@@ -145,9 +167,10 @@ static bool reorderFieldsInDefinition(
     const auto FieldIndex = Field->getFieldIndex();
     if (FieldIndex == NewFieldsOrder[FieldIndex])
       continue;
-    addReplacement(Field->getSourceRange(),
-                   Fields[NewFieldsOrder[FieldIndex]]->getSourceRange(),
-                   Context, Replacements);
+    addReplacement(
+        getFullFieldSourceRange(*Field, Context),
+        getFullFieldSourceRange(*Fields[NewFieldsOrder[FieldIndex]], Context),
+        Context, Replacements);
   }
   return true;
 }

diff --git a/clang-tools-extra/clang-tidy/bugprone/BranchCloneCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/BranchCloneCheck.cpp
@@ -102,6 +102,212 @@ void BranchCloneCheck::registerMatchers(MatchFinder *Finder) {
       this);
   Finder->addMatcher(switchStmt().bind("switch"), this);
   Finder->addMatcher(conditionalOperator().bind("condOp"), this);
+  Finder->addMatcher(
+      ifStmt((hasThen(hasDescendant(ifStmt())))).bind("ifWithDescendantIf"),
+      this);
+}
+
+/// Determines whether two statement trees are identical regarding
+/// operators and symbols.
+///
+/// Exceptions: expressions containing macros or functions with possible side
+/// effects are never considered identical.
+/// Limitations: (t + u) and (u + t) are not considered identical.
+/// t*(u + t) and t*u + t*t are not considered identical.
+///
+static bool isIdenticalStmt(const ASTContext &Ctx, const Stmt *Stmt1,
+                            const Stmt *Stmt2, bool IgnoreSideEffects) {
+
+  if (!Stmt1 || !Stmt2)
+    return !Stmt1 && !Stmt2;
+
+  // If Stmt1 & Stmt2 are of different class then they are not
+  // identical statements.
+  if (Stmt1->getStmtClass() != Stmt2->getStmtClass())
+    return false;
+
+  const auto *Expr1 = dyn_cast<Expr>(Stmt1);
+  const auto *Expr2 = dyn_cast<Expr>(Stmt2);
+
+  if (Expr1 && Expr2) {
+    // If Stmt1 has side effects then don't warn even if expressions
+    // are identical.
+    if (!IgnoreSideEffects && Expr1->HasSideEffects(Ctx) &&
+        Expr2->HasSideEffects(Ctx))
+      return false;
+    // If either expression comes from a macro then don't warn even if
+    // the expressions are identical.
+    if ((Expr1->getExprLoc().isMacroID()) || (Expr2->getExprLoc().isMacroID()))
+      return false;
+
+    // If all children of two expressions are identical, return true.
+    Expr::const_child_iterator I1 = Expr1->child_begin();
+    Expr::const_child_iterator I2 = Expr2->child_begin();
+    while (I1 != Expr1->child_end() && I2 != Expr2->child_end()) {
+      if (!isIdenticalStmt(Ctx, *I1, *I2, IgnoreSideEffects))
+        return false;
+      ++I1;
+      ++I2;
+    }
+    // If there are different number of children in the statements, return
+    // false.
+    if (I1 != Expr1->child_end())
+      return false;
+    if (I2 != Expr2->child_end())
+      return false;
+  }
+
+  switch (Stmt1->getStmtClass()) {
+  default:
+    return false;
+  case Stmt::CallExprClass:
+  case Stmt::ArraySubscriptExprClass:
+  case Stmt::ArraySectionExprClass:
+  case Stmt::OMPArrayShapingExprClass:
+  case Stmt::OMPIteratorExprClass:
+  case Stmt::ImplicitCastExprClass:
+  case Stmt::ParenExprClass:
+  case Stmt::BreakStmtClass:
+  case Stmt::ContinueStmtClass:
+  case Stmt::NullStmtClass:
+    return true;
+  case Stmt::CStyleCastExprClass: {
+    const auto *CastExpr1 = cast<CStyleCastExpr>(Stmt1);
+    const auto *CastExpr2 = cast<CStyleCastExpr>(Stmt2);
+
+    return CastExpr1->getTypeAsWritten() == CastExpr2->getTypeAsWritten();
+  }
+  case Stmt::ReturnStmtClass: {
+    const auto *ReturnStmt1 = cast<ReturnStmt>(Stmt1);
+    const auto *ReturnStmt2 = cast<ReturnStmt>(Stmt2);
+
+    return isIdenticalStmt(Ctx, ReturnStmt1->getRetValue(),
+                           ReturnStmt2->getRetValue(), IgnoreSideEffects);
+  }
+  case Stmt::ForStmtClass: {
+    const auto *ForStmt1 = cast<ForStmt>(Stmt1);
+    const auto *ForStmt2 = cast<ForStmt>(Stmt2);
+
+    if (!isIdenticalStmt(Ctx, ForStmt1->getInit(), ForStmt2->getInit(),
+                         IgnoreSideEffects))
+      return false;
+    if (!isIdenticalStmt(Ctx, ForStmt1->getCond(), ForStmt2->getCond(),
+                         IgnoreSideEffects))
+      return false;
+    if (!isIdenticalStmt(Ctx, ForStmt1->getInc(), ForStmt2->getInc(),
+                         IgnoreSideEffects))
+      return false;
+    if (!isIdenticalStmt(Ctx, ForStmt1->getBody(), ForStmt2->getBody(),
+                         IgnoreSideEffects))
+      return false;
+    return true;
+  }
+  case Stmt::DoStmtClass: {
+    const auto *DStmt1 = cast<DoStmt>(Stmt1);
+    const auto *DStmt2 = cast<DoStmt>(Stmt2);
+
+    if (!isIdenticalStmt(Ctx, DStmt1->getCond(), DStmt2->getCond(),
+                         IgnoreSideEffects))
+      return false;
+    if (!isIdenticalStmt(Ctx, DStmt1->getBody(), DStmt2->getBody(),
+                         IgnoreSideEffects))
+      return false;
+    return true;
+  }
+  case Stmt::WhileStmtClass: {
+    const auto *WStmt1 = cast<WhileStmt>(Stmt1);
+    const auto *WStmt2 = cast<WhileStmt>(Stmt2);
+
+    if (!isIdenticalStmt(Ctx, WStmt1->getCond(), WStmt2->getCond(),
+                         IgnoreSideEffects))
+      return false;
+    if (!isIdenticalStmt(Ctx, WStmt1->getBody(), WStmt2->getBody(),
+                         IgnoreSideEffects))
+      return false;
+    return true;
+  }
+  case Stmt::IfStmtClass: {
+    const auto *IStmt1 = cast<IfStmt>(Stmt1);
+    const auto *IStmt2 = cast<IfStmt>(Stmt2);
+
+    if (!isIdenticalStmt(Ctx, IStmt1->getCond(), IStmt2->getCond(),
+                         IgnoreSideEffects))
+      return false;
+    if (!isIdenticalStmt(Ctx, IStmt1->getThen(), IStmt2->getThen(),
+                         IgnoreSideEffects))
+      return false;
+    if (!isIdenticalStmt(Ctx, IStmt1->getElse(), IStmt2->getElse(),
+                         IgnoreSideEffects))
+      return false;
+    return true;
+  }
+  case Stmt::CompoundStmtClass: {
+    const auto *CompStmt1 = cast<CompoundStmt>(Stmt1);
+    const auto *CompStmt2 = cast<CompoundStmt>(Stmt2);
+
+    if (CompStmt1->size() != CompStmt2->size())
+      return false;
+
+    if (!llvm::all_of(llvm::zip(CompStmt1->body(), CompStmt2->body()),
+                      [&Ctx, IgnoreSideEffects](
+                          std::tuple<const Stmt *, const Stmt *> stmtPair) {
+                        const Stmt *stmt0 = std::get<0>(stmtPair);
+                        const Stmt *stmt1 = std::get<1>(stmtPair);
+                        return isIdenticalStmt(Ctx, stmt0, stmt1,
+                                               IgnoreSideEffects);
+                      })) {
+      return false;
+    }
+
+    return true;
+  }
+  case Stmt::CompoundAssignOperatorClass:
+  case Stmt::BinaryOperatorClass: {
+    const auto *BinOp1 = cast<BinaryOperator>(Stmt1);
+    const auto *BinOp2 = cast<BinaryOperator>(Stmt2);
+    return BinOp1->getOpcode() == BinOp2->getOpcode();
+  }
+  case Stmt::CharacterLiteralClass: {
+    const auto *CharLit1 = cast<CharacterLiteral>(Stmt1);
+    const auto *CharLit2 = cast<CharacterLiteral>(Stmt2);
+    return CharLit1->getValue() == CharLit2->getValue();
+  }
+  case Stmt::DeclRefExprClass: {
+    const auto *DeclRef1 = cast<DeclRefExpr>(Stmt1);
+    const auto *DeclRef2 = cast<DeclRefExpr>(Stmt2);
+    return DeclRef1->getDecl() == DeclRef2->getDecl();
+  }
+  case Stmt::IntegerLiteralClass: {
+    const auto *IntLit1 = cast<IntegerLiteral>(Stmt1);
+    const auto *IntLit2 = cast<IntegerLiteral>(Stmt2);
+
+    llvm::APInt I1 = IntLit1->getValue();
+    llvm::APInt I2 = IntLit2->getValue();
+    if (I1.getBitWidth() != I2.getBitWidth())
+      return false;
+    return I1 == I2;
+  }
+  case Stmt::FloatingLiteralClass: {
+    const auto *FloatLit1 = cast<FloatingLiteral>(Stmt1);
+    const auto *FloatLit2 = cast<FloatingLiteral>(Stmt2);
+    return FloatLit1->getValue().bitwiseIsEqual(FloatLit2->getValue());
+  }
+  case Stmt::StringLiteralClass: {
+    const auto *StringLit1 = cast<StringLiteral>(Stmt1);
+    const auto *StringLit2 = cast<StringLiteral>(Stmt2);
+    return StringLit1->getBytes() == StringLit2->getBytes();
+  }
+  case Stmt::MemberExprClass: {
+    const auto *MemberStmt1 = cast<MemberExpr>(Stmt1);
+    const auto *MemberStmt2 = cast<MemberExpr>(Stmt2);
+    return MemberStmt1->getMemberDecl() == MemberStmt2->getMemberDecl();
+  }
+  case Stmt::UnaryOperatorClass: {
+    const auto *UnaryOp1 = cast<UnaryOperator>(Stmt1);
+    const auto *UnaryOp2 = cast<UnaryOperator>(Stmt2);
+    return UnaryOp1->getOpcode() == UnaryOp2->getOpcode();
+  }
+  }
 }
 
 void BranchCloneCheck::check(const MatchFinder::MatchResult &Result) {
@@ -269,6 +475,21 @@ void BranchCloneCheck::check(const MatchFinder::MatchResult &Result) {
     return;
   }
 
+  if (const auto *IS = Result.Nodes.getNodeAs<IfStmt>("ifWithDescendantIf")) {
+    const Stmt *Then = IS->getThen();
+    auto CS = dyn_cast<CompoundStmt>(Then);
+    if (CS && (!CS->body_empty())) {
+      const auto *InnerIf = dyn_cast<IfStmt>(*CS->body_begin());
+      if (InnerIf && isIdenticalStmt(Context, IS->getCond(), InnerIf->getCond(),
+                                     /*IgnoreSideEffects=*/false)) {
+        diag(IS->getBeginLoc(), "if with identical inner if statement");
+        diag(InnerIf->getBeginLoc(), "inner if starts here",
+             DiagnosticIDs::Note);
+      }
+    }
+    return;
+  }
+
   llvm_unreachable("No if statement and no switch statement.");
 }
 

diff --git a/clang-tools-extra/clang-tidy/bugprone/ReturnConstRefFromParameterCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/ReturnConstRefFromParameterCheck.cpp
@@ -21,11 +21,13 @@ void ReturnConstRefFromParameterCheck::registerMatchers(MatchFinder *Finder) {
           to(parmVarDecl(hasType(hasCanonicalType(
                              qualType(lValueReferenceType(pointee(
                                           qualType(isConstQualified()))))
-                                 .bind("type"))))
+                                 .bind("type"))),
+                         hasDeclContext(functionDecl().bind("owner")))
                  .bind("param")))
           .bind("dref"));
   const auto Func =
-      functionDecl(hasReturnTypeLoc(loc(
+      functionDecl(equalsBoundNode("owner"),
+                   hasReturnTypeLoc(loc(
                        qualType(hasCanonicalType(equalsBoundNode("type"))))))
           .bind("func");
 

diff --git a/clang-tools-extra/clang-tidy/misc/RedundantExpressionCheck.cpp b/clang-tools-extra/clang-tidy/misc/RedundantExpressionCheck.cpp
@@ -855,9 +855,6 @@ static bool areExprsMacroAndNonMacro(const Expr *&LhsExpr,
 } // namespace
 
 void RedundantExpressionCheck::registerMatchers(MatchFinder *Finder) {
-  const auto AnyLiteralExpr = ignoringParenImpCasts(
-      anyOf(cxxBoolLiteral(), characterLiteral(), integerLiteral()));
-
   const auto BannedIntegerLiteral =
       integerLiteral(expandedByMacro(KnownBannedMacroNames));
   const auto IsInUnevaluatedContext = expr(anyOf(
@@ -866,19 +863,16 @@ void RedundantExpressionCheck::registerMatchers(MatchFinder *Finder) {
   // Binary with equivalent operands, like (X != 2 && X != 2).
   Finder->addMatcher(
       traverse(TK_AsIs,
-               binaryOperator(
-                   anyOf(isComparisonOperator(),
-                         hasAnyOperatorName("-", "/", "%", "|", "&", "^", "&&",
-                                            "||", "=")),
-                   operandsAreEquivalent(),
-                   // Filter noisy false positives.
-                   unless(isInTemplateInstantiation()),
-                   unless(binaryOperatorIsInMacro()),
-                   unless(hasType(realFloatingPointType())),
-                   unless(hasEitherOperand(hasType(realFloatingPointType()))),
-                   unless(hasLHS(AnyLiteralExpr)),
-                   unless(hasDescendant(BannedIntegerLiteral)),
-                   unless(IsInUnevaluatedContext))
+               binaryOperator(anyOf(isComparisonOperator(),
+                                    hasAnyOperatorName("-", "/", "%", "|", "&",
+                                                       "^", "&&", "||", "=")),
+                              operandsAreEquivalent(),
+                              // Filter noisy false positives.
+                              unless(isInTemplateInstantiation()),
+                              unless(binaryOperatorIsInMacro()),
+                              unless(hasAncestor(arraySubscriptExpr())),
+                              unless(hasDescendant(BannedIntegerLiteral)),
+                              unless(IsInUnevaluatedContext))
                    .bind("binary")),
       this);
 
@@ -1238,6 +1232,50 @@ void RedundantExpressionCheck::check(const MatchFinder::MatchResult &Result) {
   if (const auto *BinOp = Result.Nodes.getNodeAs<BinaryOperator>("binary")) {
     // If the expression's constants are macros, check whether they are
     // intentional.
+
+    //
+    // Special case for floating-point representation.
+    //
+    // If expressions on both sides of comparison operator are of type float,
+    // then for some comparison operators no warning shall be
+    // reported even if the expressions are identical from a symbolic point of
+    // view. Comparison between expressions, declared variables and literals
+    // are treated differently.
+    //
+    // != and == between float literals that have the same value should NOT
+    // warn. < > between float literals that have the same value SHOULD warn.
+    //
+    // != and == between the same float declaration should NOT warn.
+    // < > between the same float declaration SHOULD warn.
+    //
+    // != and == between eq. expressions that evaluates into float
+    //           should NOT warn.
+    // < >       between eq. expressions that evaluates into float
+    //           should NOT warn.
+    //
+    const Expr *LHS = BinOp->getLHS()->IgnoreParenImpCasts();
+    const Expr *RHS = BinOp->getRHS()->IgnoreParenImpCasts();
+    const BinaryOperator::Opcode Op = BinOp->getOpcode();
+    const bool OpEqualEQorNE = ((Op == BO_EQ) || (Op == BO_NE));
+
+    const auto *DeclRef1 = dyn_cast<DeclRefExpr>(LHS);
+    const auto *DeclRef2 = dyn_cast<DeclRefExpr>(RHS);
+    const auto *FloatLit1 = dyn_cast<FloatingLiteral>(LHS);
+    const auto *FloatLit2 = dyn_cast<FloatingLiteral>(RHS);
+
+    if (DeclRef1 && DeclRef2 &&
+        DeclRef1->getType()->hasFloatingRepresentation() &&
+        DeclRef2->getType()->hasFloatingRepresentation() &&
+        (DeclRef1->getDecl() == DeclRef2->getDecl()) && OpEqualEQorNE) {
+      return;
+    }
+
+    if (FloatLit1 && FloatLit2 &&
+        FloatLit1->getValue().bitwiseIsEqual(FloatLit2->getValue()) &&
+        OpEqualEQorNE) {
+      return;
+    }
+
     if (areSidesBinaryConstExpressions(BinOp, Result.Context)) {
       const Expr *LhsConst = nullptr, *RhsConst = nullptr;
       BinaryOperatorKind MainOpcode{}, SideOpcode{};

diff --git a/clang-tools-extra/clang-tidy/misc/UseInternalLinkageCheck.cpp b/clang-tools-extra/clang-tidy/misc/UseInternalLinkageCheck.cpp
@@ -15,7 +15,9 @@
 #include "clang/Basic/SourceLocation.h"
 #include "clang/Basic/Specifiers.h"
 #include "clang/Lex/Token.h"
+#include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallVector.h"
 
 using namespace clang::ast_matchers;
 
@@ -78,6 +80,22 @@ AST_POLYMORPHIC_MATCHER(isExternStorageClass,
   return Node.getStorageClass() == SC_Extern;
 }
 
+AST_MATCHER(FunctionDecl, isAllocationOrDeallocationOverloadedFunction) {
+  // [basic.stc.dynamic.allocation]
+  // An allocation function that is not a class member function shall belong to
+  // the global scope and not have a name with internal linkage.
+  // [basic.stc.dynamic.deallocation]
+  // A deallocation function that is not a class member function shall belong to
+  // the global scope and not have a name with internal linkage.
+  static const llvm::DenseSet<OverloadedOperatorKind> OverloadedOperators{
+      OverloadedOperatorKind::OO_New,
+      OverloadedOperatorKind::OO_Array_New,
+      OverloadedOperatorKind::OO_Delete,
+      OverloadedOperatorKind::OO_Array_Delete,
+  };
+  return OverloadedOperators.contains(Node.getOverloadedOperator());
+}
+
 } // namespace
 
 UseInternalLinkageCheck::UseInternalLinkageCheck(StringRef Name,
@@ -100,10 +118,16 @@ void UseInternalLinkageCheck::registerMatchers(MatchFinder *Finder) {
                 isExternStorageClass(), isExternC(),
                 // 3. template
                 isExplicitTemplateSpecialization(),
-                // 4. friend
-                hasAncestor(friendDecl()))));
+                hasAncestor(decl(anyOf(
+                    // 4. friend
+                    friendDecl(),
+                    // 5. module export decl
+                    exportDecl()))))));
   Finder->addMatcher(
-      functionDecl(Common, hasBody(), unless(cxxMethodDecl()), unless(isMain()))
+      functionDecl(Common, hasBody(),
+                   unless(anyOf(cxxMethodDecl(),
+                                isAllocationOrDeallocationOverloadedFunction(),
+                                isMain())))
           .bind("fn"),
       this);
   Finder->addMatcher(varDecl(Common, hasGlobalStorage()).bind("var"), this);

diff --git a/clang-tools-extra/clang-tidy/modernize/UseStartsEndsWithCheck.cpp b/clang-tools-extra/clang-tidy/modernize/UseStartsEndsWithCheck.cpp
@@ -18,6 +18,21 @@
 using namespace clang::ast_matchers;
 
 namespace clang::tidy::modernize {
+
+static bool isNegativeComparison(const Expr *ComparisonExpr) {
+  if (const auto *Op = llvm::dyn_cast<BinaryOperator>(ComparisonExpr))
+    return Op->getOpcode() == BO_NE;
+
+  if (const auto *Op = llvm::dyn_cast<CXXOperatorCallExpr>(ComparisonExpr))
+    return Op->getOperator() == OO_ExclaimEqual;
+
+  if (const auto *Op =
+          llvm::dyn_cast<CXXRewrittenBinaryOperator>(ComparisonExpr))
+    return Op->getOperator() == BO_NE;
+
+  return false;
+}
+
 struct NotLengthExprForStringNode {
   NotLengthExprForStringNode(std::string ID, DynTypedNode Node,
                              ASTContext *Context)
@@ -171,10 +186,26 @@ void UseStartsEndsWithCheck::registerMatchers(MatchFinder *Finder) {
                              hasRHS(lengthExprForStringNode("needle")))))
           .bind("expr"),
       this);
+
+  // Case 6: X.substr(0, LEN(Y)) [!=]= Y -> starts_with.
+  Finder->addMatcher(
+      binaryOperation(
+          hasAnyOperatorName("==", "!="),
+          hasOperands(
+              expr().bind("needle"),
+              cxxMemberCallExpr(
+                  argumentCountIs(2), hasArgument(0, ZeroLiteral),
+                  hasArgument(1, lengthExprForStringNode("needle")),
+                  callee(cxxMethodDecl(hasName("substr"),
+                                       ofClass(OnClassWithStartsWithFunction))
+                             .bind("find_fun")))
+                  .bind("find_expr")))
+          .bind("expr"),
+      this);
 }
 
 void UseStartsEndsWithCheck::check(const MatchFinder::MatchResult &Result) {
-  const auto *ComparisonExpr = Result.Nodes.getNodeAs<BinaryOperator>("expr");
+  const auto *ComparisonExpr = Result.Nodes.getNodeAs<Expr>("expr");
   const auto *FindExpr = Result.Nodes.getNodeAs<CXXMemberCallExpr>("find_expr");
   const auto *FindFun = Result.Nodes.getNodeAs<CXXMethodDecl>("find_fun");
   const auto *SearchExpr = Result.Nodes.getNodeAs<Expr>("needle");
@@ -183,39 +214,42 @@ void UseStartsEndsWithCheck::check(const MatchFinder::MatchResult &Result) {
   const auto *EndsWithFunction =
       Result.Nodes.getNodeAs<CXXMethodDecl>("ends_with_fun");
   assert(bool(StartsWithFunction) != bool(EndsWithFunction));
+
   const CXXMethodDecl *ReplacementFunction =
       StartsWithFunction ? StartsWithFunction : EndsWithFunction;
 
-  if (ComparisonExpr->getBeginLoc().isMacroID())
+  if (ComparisonExpr->getBeginLoc().isMacroID() ||
+      FindExpr->getBeginLoc().isMacroID())
     return;
 
-  const bool Neg = ComparisonExpr->getOpcode() == BO_NE;
+  // Make sure FindExpr->getArg(0) can be used to make a range in the FitItHint.
+  if (FindExpr->getNumArgs() == 0)
+    return;
 
-  auto Diagnostic =
-      diag(FindExpr->getExprLoc(), "use %0 instead of %1() %select{==|!=}2 0")
-      << ReplacementFunction->getName() << FindFun->getName() << Neg;
+  // Retrieve the source text of the search expression.
+  const auto SearchExprText = Lexer::getSourceText(
+      CharSourceRange::getTokenRange(SearchExpr->getSourceRange()),
+      *Result.SourceManager, Result.Context->getLangOpts());
 
-  // Remove possible arguments after search expression and ' [!=]= .+' suffix.
-  Diagnostic << FixItHint::CreateReplacement(
-      CharSourceRange::getTokenRange(
-          Lexer::getLocForEndOfToken(SearchExpr->getEndLoc(), 0,
-                                     *Result.SourceManager, getLangOpts()),
-          ComparisonExpr->getEndLoc()),
-      ")");
+  auto Diagnostic = diag(FindExpr->getExprLoc(), "use %0 instead of %1")
+                    << ReplacementFunction->getName() << FindFun->getName();
 
-  // Remove possible '.+ [!=]= ' prefix.
+  // Remove everything before the function call.
   Diagnostic << FixItHint::CreateRemoval(CharSourceRange::getCharRange(
       ComparisonExpr->getBeginLoc(), FindExpr->getBeginLoc()));
 
-  // Replace method name by '(starts|ends)_with'.
-  // Remove possible arguments before search expression.
+  // Rename the function to `starts_with` or `ends_with`.
+  Diagnostic << FixItHint::CreateReplacement(FindExpr->getExprLoc(),
+                                             ReplacementFunction->getName());
+
+  // Replace arguments and everything after the function call.
   Diagnostic << FixItHint::CreateReplacement(
-      CharSourceRange::getCharRange(FindExpr->getExprLoc(),
-                                    SearchExpr->getBeginLoc()),
-      (ReplacementFunction->getName() + "(").str());
+      CharSourceRange::getTokenRange(FindExpr->getArg(0)->getBeginLoc(),
+                                     ComparisonExpr->getEndLoc()),
+      (SearchExprText + ")").str());
 
-  // Add possible negation '!'.
-  if (Neg)
+  // Add negation if necessary.
+  if (isNegativeComparison(ComparisonExpr))
     Diagnostic << FixItHint::CreateInsertion(FindExpr->getBeginLoc(), "!");
 }
 

diff --git a/clang-tools-extra/clangd/refactor/tweaks/DefineOutline.cpp b/clang-tools-extra/clangd/refactor/tweaks/DefineOutline.cpp
@@ -467,18 +467,9 @@ class DefineOutline : public Tweak {
       }
     }
 
-    // For function templates, the same limitations as for class templates
-    // apply.
-    if (const TemplateParameterList *Params =
-            MD->getDescribedTemplateParams()) {
-      // FIXME: Is this really needed? It inhibits application on
-      //        e.g. std::enable_if.
-      for (NamedDecl *P : *Params) {
-        if (!P->getIdentifier())
-          return false;
-      }
+    // Function templates must be defined in the same file.
+    if (MD->getDescribedTemplate())
       SameFile = true;
-    }
 
     // The refactoring is meaningless for unnamed classes and namespaces,
     // unless we're outlining in the same file

diff --git a/clang-tools-extra/clangd/unittests/tweaks/DefineOutlineTests.cpp b/clang-tools-extra/clangd/unittests/tweaks/DefineOutlineTests.cpp
@@ -118,12 +118,6 @@ TEST_F(DefineOutlineTest, TriggersOnFunctionDecl) {
     template <> void fo^o<int>() {}
   )cpp");
 
-  // Not available on member function templates with unnamed template
-  // parameters.
-  EXPECT_UNAVAILABLE(R"cpp(
-    struct Foo { template <typename> void ba^r() {} };
-  )cpp");
-
   // Not available on methods of unnamed classes.
   EXPECT_UNAVAILABLE(R"cpp(
     struct Foo {
@@ -410,14 +404,14 @@ inline typename O1<T, U...>::template O2<V, A>::E O1<T, U...>::template O2<V, A>
       {
           R"cpp(
             struct Foo {
-              template <typename T, bool B = true>
+              template <typename T, typename, bool B = true>
               T ^bar() { return {}; }
             };)cpp",
           R"cpp(
             struct Foo {
-              template <typename T, bool B = true>
+              template <typename T, typename, bool B = true>
               T bar() ;
-            };template <typename T, bool B>
+            };template <typename T, typename, bool B>
 inline T Foo::bar() { return {}; }
 )cpp",
           ""},
@@ -426,13 +420,13 @@ inline T Foo::bar() { return {}; }
       {
           R"cpp(
             template <typename T> struct Foo {
-              template <typename U> T ^bar(const T& t, const U& u) { return {}; }
+              template <typename U, bool> T ^bar(const T& t, const U& u) { return {}; }
             };)cpp",
           R"cpp(
             template <typename T> struct Foo {
-              template <typename U> T bar(const T& t, const U& u) ;
+              template <typename U, bool> T bar(const T& t, const U& u) ;
             };template <typename T>
-template <typename U>
+template <typename U, bool>
 inline T Foo<T>::bar(const T& t, const U& u) { return {}; }
 )cpp",
           ""},

diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -73,6 +73,8 @@ Hover
 Code completion
 ^^^^^^^^^^^^^^^
 
+- Added completion for C++20 keywords.
+
 Code actions
 ^^^^^^^^^^^^
 
@@ -154,6 +156,10 @@ Changes in existing checks
   <clang-tidy/checks/altera/id-dependent-backward-branch>` check by fixing
   crashes from invalid code.
 
+- Improved :doc:`bugprone-branch-clone
+  <clang-tidy/checks/bugprone/branch-clone>` check to improve detection of
+  branch clones by now detecting duplicate inner and outer if statements.
+
 - Improved :doc:`bugprone-casting-through-void
   <clang-tidy/checks/bugprone/casting-through-void>` check to suggest replacing
   the offending code with ``reinterpret_cast``, to more clearly express intent.
@@ -177,7 +183,8 @@ Changes in existing checks
 - Improved :doc:`bugprone-return-const-ref-from-parameter
   <clang-tidy/checks/bugprone/return-const-ref-from-parameter>` check to
   diagnose potential dangling references when returning a ``const &`` parameter
-  by using the conditional operator ``cond ? var1 : var2``.
+  by using the conditional operator ``cond ? var1 : var2`` and no longer giving
+  false positives for functions which contain lambda.
 
 - Improved :doc:`bugprone-sizeof-expression
   <clang-tidy/checks/bugprone/sizeof-expression>` check to find suspicious
@@ -228,14 +235,21 @@ Changes in existing checks
   <clang-tidy/checks/misc/definitions-in-headers>` check by rewording the
   diagnostic note that suggests adding ``inline``.
 
+- Improved :doc:`misc-redundant-expression
+  <clang-tidy/checks/misc/redundant-expression>` check by extending the
+  checker to detect floating point and integer literals in redundant
+  expressions.
+
 - Improved :doc:`misc-unconventional-assign-operator
   <clang-tidy/checks/misc/unconventional-assign-operator>` check to avoid
   false positive for C++23 deducing this.
 
 - Improved :doc:`misc-use-internal-linkage
   <clang-tidy/checks/misc/use-internal-linkage>` check to insert ``static``
   keyword before type qualifiers such as ``const`` and ``volatile`` and fix
-  false positives for function declaration without body.
+  false positives for function declaration without body and fix false positives
+  for C++20 export declarations and fix false positives for global scoped
+  overloaded ``operator new`` and ``operator delete``.
 
 - Improved :doc:`modernize-avoid-c-arrays
   <clang-tidy/checks/modernize/avoid-c-arrays>` check to suggest using 
@@ -260,8 +274,9 @@ Changes in existing checks
   ``NULL``/``__null`` (but not ``0``) when used with a templated type.
 
 - Improved :doc:`modernize-use-starts-ends-with
-  <clang-tidy/checks/modernize/use-starts-ends-with>` check to handle two cases
-  that can be replaced with ``ends_with``
+  <clang-tidy/checks/modernize/use-starts-ends-with>` check to handle two new
+  cases from ``rfind`` and ``compare`` to ``ends_with``, and one new case from
+  ``substr`` to ``starts_with``, and a small adjustment to the  diagnostic message.
 
 - Improved :doc:`modernize-use-std-format
   <clang-tidy/checks/modernize/use-std-format>` check to support replacing

diff --git a/clang-tools-extra/docs/clang-tidy/checks/bugprone/branch-clone.rst b/clang-tools-extra/docs/clang-tidy/checks/bugprone/branch-clone.rst
@@ -32,9 +32,28 @@ If this is the intended behavior, then there is no reason to use a conditional
 statement; otherwise the issue can be solved by fixing the branch that is
 handled incorrectly.
 
-The check also detects repeated branches in longer ``if/else if/else`` chains
+The check detects repeated branches in longer ``if/else if/else`` chains
 where it would be even harder to notice the problem.
 
+The check also detects repeated inner and outer ``if`` statements that may
+be a result of a copy-paste error. This check cannot currently detect
+identical inner and outer ``if`` statements if code is between the ``if``
+conditions. An example is as follows.
+
+.. code-block:: c++
+
+    void test_warn_inner_if_1(int x) {
+      if (x == 1) {    // warns, if with identical inner if
+        if (x == 1)    // inner if is here
+          ;
+      if (x == 1) {    // does not warn, cannot detect
+        int y = x;
+        if (x == 1)
+          ;
+      }
+    }
+
+
 In ``switch`` statements the check only reports repeated branches when they are
 consecutive, because it is relatively common that the ``case:`` labels have
 some natural ordering and rearranging them would decrease the readability of

diff --git a/clang-tools-extra/docs/clang-tidy/checks/misc/redundant-expression.rst b/clang-tools-extra/docs/clang-tidy/checks/misc/redundant-expression.rst
@@ -23,3 +23,22 @@ Examples:
   (p->x == p->x)              // always true
   (p->x < p->x)               // always false
   (speed - speed + 1 == 12)   // speed - speed is always zero
+  int b = a | 4 | a           // identical expr on both sides
+  ((x=1) | (x=1))             // expression is identical
+
+Floats are handled except in the case that NaNs are checked like so:
+
+.. code-block:: c++
+
+  int TestFloat(float F) {
+    if (F == F)               // Identical float values used
+      return 1;
+    return 0;
+  }
+
+  int TestFloat(float F) {
+    // Testing NaN.
+    if (F != F && F == F)     // does not warn
+      return 1;
+    return 0;
+  }
diff --git a/clang-tools-extra/docs/clang-tidy/checks/misc/use-internal-linkage.rst b/clang-tools-extra/docs/clang-tidy/checks/misc/use-internal-linkage.rst
@@ -29,6 +29,11 @@ Example:
   void fn3(); // without function body in all declaration, maybe external linkage
   void fn3();
 
+  // export declarations
+  export void fn4() {}
+  export namespace t { void fn5() {} }
+  export int v2;
+
 Options
 -------
 

diff --git a/clang-tools-extra/docs/clang-tidy/checks/modernize/use-starts-ends-with.rst b/clang-tools-extra/docs/clang-tidy/checks/modernize/use-starts-ends-with.rst
@@ -7,26 +7,16 @@ Checks for common roundabout ways to express ``starts_with`` and ``ends_with``
 and suggests replacing with the simpler method when it is available. Notably, 
 this will work with ``std::string`` and ``std::string_view``.
 
-.. code-block:: c++
+Covered scenarios:
 
-  std::string s = "...";
-  if (s.find("prefix") == 0) { /* do something */ }
-  if (s.rfind("prefix", 0) == 0) { /* do something */ }
-  if (s.compare(0, strlen("prefix"), "prefix") == 0) { /* do something */ }
-  if (s.compare(s.size() - strlen("suffix"), strlen("suffix"), "suffix") == 0) {
-    /* do something */
-  }
-  if (s.rfind("suffix") == (s.length() - 6)) {
-    /* do something */
-  }
-
-becomes
-
-.. code-block:: c++
-
-  std::string s = "...";
-  if (s.starts_with("prefix")) { /* do something */ }
-  if (s.starts_with("prefix")) { /* do something */ }
-  if (s.starts_with("prefix")) { /* do something */ }
-  if (s.ends_with("suffix")) { /* do something */ }
-  if (s.ends_with("suffix")) { /* do something */ }
+==================================================== =====================
+Expression                                           Replacement
+---------------------------------------------------- ---------------------
+``u.find(v) == 0``                                   ``u.starts_with(v)``
+``u.rfind(v, 0) != 0``                               ``!u.starts_with(v)``
+``u.compare(0, v.size(), v) == 0``                   ``u.starts_with(v)``
+``u.substr(0, v.size()) == v``                       ``u.starts_with(v)``
+``v != u.substr(0, v.size())``                       ``!u.starts_with(v)``
+``u.compare(u.size() - v.size(), v.size(), v) == 0`` ``u.ends_with(v)``
+``u.rfind(v) == u.size() - v.size()``                ``u.ends_with(v)``
+==================================================== =====================
diff --git a/clang-tools-extra/test/clang-reorder-fields/FieldAnnotationsInMacros.cpp b/clang-tools-extra/test/clang-reorder-fields/FieldAnnotationsInMacros.cpp
@@ -0,0 +1,9 @@
+// RUN: clang-reorder-fields -record-name Foo -fields-order y,x %s -- | FileCheck %s
+
+#define GUARDED_BY(x) __attribute__((guarded_by(x)))
+
+class Foo {
+  int x GUARDED_BY(x); // CHECK: {{^  int y;}}
+  int y;               // CHECK-NEXT: {{^  int x GUARDED_BY\(x\);}}
+};
+
diff --git a/clang-tools-extra/test/clang-tidy/checkers/Inputs/Headers/string b/clang-tools-extra/test/clang-tidy/checkers/Inputs/Headers/string
@@ -60,6 +60,8 @@ struct basic_string {
   _Type& insert(size_type pos, const C* s);
   _Type& insert(size_type pos, const C* s, size_type n);
 
+  _Type substr(size_type pos = 0, size_type count = npos) const;
+
   constexpr bool starts_with(std::basic_string_view<C, T> sv) const noexcept;
   constexpr bool starts_with(C ch) const noexcept;
   constexpr bool starts_with(const C* s) const;
@@ -134,10 +136,6 @@ bool operator==(const std::string&, const std::string&);
 bool operator==(const std::string&, const char*);
 bool operator==(const char*, const std::string&);
 
-bool operator!=(const std::string&, const std::string&);
-bool operator!=(const std::string&, const char*);
-bool operator!=(const char*, const std::string&);
-
 bool operator==(const std::wstring&, const std::wstring&);
 bool operator==(const std::wstring&, const wchar_t*);
 bool operator==(const wchar_t*, const std::wstring&);
@@ -146,9 +144,15 @@ bool operator==(const std::string_view&, const std::string_view&);
 bool operator==(const std::string_view&, const char*);
 bool operator==(const char*, const std::string_view&);
 
+#if __cplusplus < 202002L
+bool operator!=(const std::string&, const std::string&);
+bool operator!=(const std::string&, const char*);
+bool operator!=(const char*, const std::string&);
+
 bool operator!=(const std::string_view&, const std::string_view&);
 bool operator!=(const std::string_view&, const char*);
 bool operator!=(const char*, const std::string_view&);
+#endif
 
 size_t strlen(const char* str);
 }

diff --git a/...g/test/Analysis/identical-expressions.cpp → ...ers/bugprone/alpha-core-identicalexpr.cpp b/...g/test/Analysis/identical-expressions.cpp → ...ers/bugprone/alpha-core-identicalexpr.cpp
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/return-const-ref-from-parameter.cpp b/clang-tools-extra/test/clang-tidy/checkers/bugprone/return-const-ref-from-parameter.cpp
@@ -76,6 +76,9 @@ struct C {
 // CHECK-MESSAGES: :[[@LINE-1]]:38: warning: returning a constant reference parameter
 };
 
+const auto Lf1 = [](const T& t) -> const T& { return t; };
+// CHECK-MESSAGES: :[[@LINE-1]]:54: warning: returning a constant reference parameter
+
 } // namespace invalid
 
 namespace false_negative_because_dependent_and_not_instantiated {
@@ -151,6 +154,14 @@ void instantiate(const int &param, const float &paramf, int &mut_param, float &m
         itf6(mut_paramf);
 }
 
+template<class T>
+void f(const T& t) {
+    const auto get = [&t] -> const T& { return t; };
+    return T{};
+}
+
+const auto Lf1 = [](T& t) -> const T& { return t; };
+
 } // namespace valid
 
 namespace overload {

diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/use-internal-linkage-func.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/use-internal-linkage-func.cpp
@@ -85,3 +85,13 @@ void func_with_body() {}
 void func_without_body();
 void func_without_body();
 }
+
+// gh117489 start
+namespace std {
+using size_t = decltype(sizeof(int));
+}
+void * operator new(std::size_t) { return nullptr; }
+void * operator new[](std::size_t) { return nullptr; }
+void operator delete(void*) noexcept {}
+void operator delete[](void*) noexcept {}
+// gh117489 end
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/use-internal-linkage-module.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/use-internal-linkage-module.cpp
@@ -0,0 +1,20 @@
+// RUN: %check_clang_tidy -std=c++20 %s misc-use-internal-linkage %t -- -- -I%S/Inputs/use-internal-linkage
+
+module;
+
+export module test;
+
+export void single_export_fn() {}
+export int single_export_var;
+
+export {
+  void group_export_fn1() {}
+  void group_export_fn2() {}
+  int group_export_var1;
+  int group_export_var2;
+}
+
+export namespace aa {
+void namespace_export_fn() {}
+int namespace_export_var;
+} // namespace aa
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-starts-ends-with.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-starts-ends-with.cpp
@@ -36,7 +36,7 @@ void test(std::string s, std::string_view sv, sub_string ss, sub_sub_string sss,
           string_like sl, string_like_camel slc, prefer_underscore_version puv,
           prefer_underscore_version_flip puvf) {
   s.find("a") == 0;
-  // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use starts_with instead of find() == 0
+  // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use starts_with instead of find [modernize-use-starts-ends-with]
   // CHECK-FIXES: s.starts_with("a");
 
   (((((s)).find("a")))) == ((0));
@@ -68,7 +68,7 @@ void test(std::string s, std::string_view sv, sub_string ss, sub_sub_string sss,
   // CHECK-FIXES: !s.starts_with("a");
 
   s.rfind("a", 0) == 0;
-  // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use starts_with instead of rfind() == 0
+  // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use starts_with instead of rfind [modernize-use-starts-ends-with]
   // CHECK-FIXES: s.starts_with("a");
 
   s.rfind(s, 0) == 0;
@@ -91,16 +91,6 @@ void test(std::string s, std::string_view sv, sub_string ss, sub_sub_string sss,
   // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use starts_with
   // CHECK-FIXES: !s.starts_with("a");
 
-  #define STR(x) std::string(x)
-  0 == STR(s).find("a");
-  // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use starts_with
-  // CHECK-FIXES: STR(s).starts_with("a");
-
-  #define STRING s
-  if (0 == STRING.find("ala")) { /* do something */}
-  // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use starts_with
-  // CHECK-FIXES: if (STRING.starts_with("ala"))
-
   #define FIND find
   s.FIND("a") == 0;
   // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use starts_with
@@ -149,11 +139,11 @@ void test(std::string s, std::string_view sv, sub_string ss, sub_sub_string sss,
   // CHECK-FIXES: puvf.starts_with("a");
 
   s.compare(0, 1, "a") == 0;
-  // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use starts_with instead of compare() == 0
+  // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use starts_with instead of compare [modernize-use-starts-ends-with]
   // CHECK-FIXES: s.starts_with("a");
 
   s.compare(0, 1, "a") != 0;
-  // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use starts_with instead of compare() != 0
+  // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use starts_with instead of compare [modernize-use-starts-ends-with]
   // CHECK-FIXES: !s.starts_with("a");
 
   s.compare(0, strlen("a"), "a") == 0;
@@ -265,4 +255,78 @@ void test(std::string s, std::string_view sv, sub_string ss, sub_sub_string sss,
 
   s.compare(0, 1, "ab") == 0;
   s.rfind(suffix, 1) == s.size() - suffix.size();
+
+  #define STR(x) std::string(x)
+  0 == STR(s).find("a");
+
+  #define STRING s
+  if (0 == STRING.find("ala")) { /* do something */}
+}
+
+void test_substr() {
+    std::string str("hello world");
+    std::string prefix = "hello";
+
+    // Basic pattern
+    str.substr(0, 5) == "hello";
+    // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use starts_with instead of substr [modernize-use-starts-ends-with]
+    // CHECK-FIXES: str.starts_with("hello");
+
+    // With string literal on left side
+    "hello" == str.substr(0, 5);
+    // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use starts_with instead of substr [modernize-use-starts-ends-with]
+    // CHECK-FIXES: str.starts_with("hello");
+
+    // Inequality comparison
+    str.substr(0, 5) != "world";
+    // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use starts_with instead of substr [modernize-use-starts-ends-with]
+    // CHECK-FIXES: !str.starts_with("world");
+
+    // Ensure non-zero start position is not transformed
+    str.substr(1, 5) == "hello";
+    str.substr(0, 4) == "hello"; // Length mismatch
+
+    size_t len = 5;
+    str.substr(0, len) == "hello"; // Non-constant length
+
+    // String literal with size calculation
+    str.substr(0, strlen("hello")) == "hello";
+    // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use starts_with instead of substr [modernize-use-starts-ends-with]
+    // CHECK-FIXES: str.starts_with("hello");
+
+    str.substr(0, prefix.size()) == prefix;
+    // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use starts_with instead of substr [modernize-use-starts-ends-with]
+    // CHECK-FIXES: str.starts_with(prefix);
+
+    str.substr(0, prefix.length()) == prefix;
+    // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use starts_with instead of substr [modernize-use-starts-ends-with]
+    // CHECK-FIXES: str.starts_with(prefix);
+
+    // Tests to verify macro behavior
+    #define MSG "hello"
+    str.substr(0, strlen(MSG)) == MSG;
+    // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use starts_with instead of substr [modernize-use-starts-ends-with]
+    // CHECK-FIXES: str.starts_with(MSG);
+
+    #define STARTS_WITH(X, Y) (X).substr(0, (Y).size()) == (Y)
+    STARTS_WITH(str, prefix);
+
+    #define SUBSTR(X, A, B) (X).substr((A), (B))
+    SUBSTR(str, 0, 6) == "prefix";
+
+    #define STR() str
+    SUBSTR(STR(), 0, 6) == "prefix";
+    "prefix" == SUBSTR(STR(), 0, 6);
+
+    str.substr(0, strlen("hello123")) == "hello";
+}
+
+void test_operator_rewriting(std::string str, std::string prefix) {
+  str.substr(0, prefix.size()) == prefix;
+  // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use starts_with instead of substr
+  // CHECK-FIXES: str.starts_with(prefix);
+
+  str.substr(0, prefix.size()) != prefix;
+  // CHECK-MESSAGES: :[[@LINE-1]]:{{[0-9]+}}: warning: use starts_with instead of substr
+  // CHECK-FIXES: !str.starts_with(prefix);
 }
diff --git a/clang/docs/ClangFormat.rst b/clang/docs/ClangFormat.rst
@@ -33,7 +33,7 @@ to format C/C++/Java/JavaScript/JSON/Objective-C/Protobuf/C# code.
   Clang-format options:
 
     --Werror                       - If set, changes formatting warnings to errors
-    --Wno-error=<value>            - If set don't error out on the specified warning type.
+    --Wno-error=<value>            - If set, don't error out on the specified warning type.
       =unknown                     -   If set, unknown format options are only warned about.
                                        This can be used to enable formatting, even if the
                                        configuration contains unknown (newer) options.

diff --git a/clang/docs/ClangFormatStyleOptions.rst b/clang/docs/ClangFormatStyleOptions.rst
@@ -3759,9 +3759,9 @@ the configuration (without a prefix: ``Auto``).
   lists.
 
   Important differences:
-  - No spaces inside the braced list.
-  - No line break before the closing brace.
-  - Indentation with the continuation indent, not with the block indent.
+  * No spaces inside the braced list.
+  * No line break before the closing brace.
+  * Indentation with the continuation indent, not with the block indent.
 
   Fundamentally, C++11 braced lists are formatted exactly like function
   calls would be formatted in their place. If the braced list follows a name
@@ -4104,10 +4104,10 @@ the configuration (without a prefix: ``Auto``).
   When guessing whether a #include is the "main" include (to assign
   category 0, see above), use this regex of allowed suffixes to the header
   stem. A partial match is done, so that:
-  - "" means "arbitrary suffix"
-  - "$" means "no suffix"
+  * ``""`` means "arbitrary suffix"
+  * ``"$"`` means "no suffix"
 
-  For example, if configured to "(_test)?$", then a header a.h would be seen
+  For example, if configured to ``"(_test)?$"``, then a header a.h would be seen
   as the "main" include in both a.cc and a_test.cc.
 
 .. _IncludeIsMainSourceRegex:
@@ -5313,21 +5313,21 @@ the configuration (without a prefix: ``Auto``).
 
 **QualifierOrder** (``List of Strings``) :versionbadge:`clang-format 14` :ref:`¶ <QualifierOrder>`
   The order in which the qualifiers appear.
-  Order is an array that can contain any of the following:
+  The order is an array that can contain any of the following:
 
-    * const
-    * inline
-    * static
-    * friend
-    * constexpr
-    * volatile
-    * restrict
-    * type
+    * ``const``
+    * ``inline``
+    * ``static``
+    * ``friend``
+    * ``constexpr``
+    * ``volatile``
+    * ``restrict``
+    * ``type``
 
 
   .. note::
 
-   It **must** contain ``type``.
+   It must contain ``type``.
 
   Items to the left of ``type`` will be placed to the left of the type and
   aligned in the order supplied. Items to the right of ``type`` will be
@@ -6645,12 +6645,11 @@ the configuration (without a prefix: ``Auto``).
 .. _StatementMacros:
 
 **StatementMacros** (``List of Strings``) :versionbadge:`clang-format 8` :ref:`¶ <StatementMacros>`
-  A vector of macros that should be interpreted as complete
-  statements.
+  A vector of macros that should be interpreted as complete statements.
 
-  Typical macros are expressions, and require a semi-colon to be
-  added; sometimes this is not the case, and this allows to make
-  clang-format aware of such cases.
+  Typical macros are expressions and require a semicolon to be added.
+  Sometimes this is not the case, and this allows to make clang-format aware
+  of such cases.
 
   For example: Q_UNUSED
 

diff --git a/clang/docs/LanguageExtensions.rst b/clang/docs/LanguageExtensions.rst
@@ -647,6 +647,9 @@ elementwise to the input.
 
 Unless specified otherwise operation(±0) = ±0 and operation(±infinity) = ±infinity
 
+The integer elementwise intrinsics, including ``__builtin_elementwise_popcount``,
+can be called in a ``constexpr`` context.
+
 ============================================== ====================================================================== =========================================
          Name                                   Operation                                                             Supported element types
 ============================================== ====================================================================== =========================================

diff --git a/clang/docs/LibASTMatchersReference.html b/clang/docs/LibASTMatchersReference.html
@@ -804,6 +804,17 @@ <h2 id="decl-matchers">Node Matchers</h2>
 </pre></td></tr>
 
 
+<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1Decl.html">Decl</a>&gt;</td><td class="name" onclick="toggle('exportDecl0')"><a name="exportDecl0Anchor">exportDecl</a></td><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1ExportDecl.html">ExportDecl</a>&gt;...</td></tr>
+<tr><td colspan="4" class="doc" id="exportDecl0"><pre>Matches any export declaration.
+
+Example matches following declarations.
+  export void foo();
+  export { void foo(); }
+  export namespace { void foo(); }
+  export int v;
+</pre></td></tr>
+
+
 <tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1Decl.html">Decl</a>&gt;</td><td class="name" onclick="toggle('fieldDecl0')"><a name="fieldDecl0Anchor">fieldDecl</a></td><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1FieldDecl.html">FieldDecl</a>&gt;...</td></tr>
 <tr><td colspan="4" class="doc" id="fieldDecl0"><pre>Matches field declarations.
 

diff --git a/clang/docs/OpenMPSupport.rst b/clang/docs/OpenMPSupport.rst
@@ -290,7 +290,7 @@ implementation.
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | memory management            | changes to omp_alloctrait_key enum                           | :none:`unclaimed`        |                                                                       |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| memory model                 | seq_cst clause on flush construct                            | :none:`unclaimed`        |                                                                       |
+| memory model                 | seq_cst clause on flush construct                            | :good:`done`             | https://github.com/llvm/llvm-project/pull/114072                      |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | misc                         | 'omp_all_memory' keyword and use in 'depend' clause          | :good:`done`             | D125828, D126321                                                      |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+

diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
@@ -158,6 +158,35 @@ C++ Specific Potentially Breaking Changes
 
   Previously, this code was erroneously accepted.
 
+- Clang will now consider the implicitly deleted destructor of a union or
+  a non-union class without virtual base class to be ``constexpr`` in C++20
+  mode (Clang 19 only did so in C++23 mode but the standard specification for
+  this changed in C++20). (#GH85550)
+
+  .. code-block:: c++
+
+    struct NonLiteral {
+      NonLiteral() {}
+      ~NonLiteral() {}
+    };
+
+    template <class T>
+    struct Opt {
+      union {
+        char c;
+        T data;
+      };
+      bool engaged = false;
+
+      constexpr Opt() {}
+      constexpr ~Opt() {
+        if (engaged)
+          data.~T();
+      }
+    };
+
+    // Previously only accepted in C++23 and later, now also accepted in C++20.
+    consteval void foo() { Opt<NonLiteral>{}; }
 
 ABI Changes in This Version
 ---------------------------
@@ -227,6 +256,8 @@ C++2c Feature Support
 - Added the ``__builtin_is_within_lifetime`` builtin, which supports
   `P2641R4 Checking if a union alternative is active <https://wg21.link/p2641r4>`_
 
+- Implemented `P3176R1 The Oxford variadic comma <https://wg21.link/P3176R1>`_
+
 C++23 Feature Support
 ^^^^^^^^^^^^^^^^^^^^^
 - Removed the restriction to literal types in constexpr functions in C++23 mode.
@@ -332,6 +363,8 @@ C23 Feature Support
 
 - Clang now supports `N3029 <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3029.htm>`_ Improved Normal Enumerations.
 - Clang now officially supports `N3030 <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3030.htm>`_ Enhancements to Enumerations. Clang already supported it as an extension, so there were no changes to compiler behavior.
+- Fixed the value of ``BOOL_WIDTH`` in ``<limits.h>`` to return ``1``
+  explicitly, as mandated by the standard. Fixes #GH117348
 
 Non-comprehensive list of changes in this release
 -------------------------------------------------
@@ -370,6 +403,7 @@ Non-comprehensive list of changes in this release
 - ``__builtin_reduce_mul`` function can now be used in constant expressions.
 - ``__builtin_reduce_and`` function can now be used in constant expressions.
 - ``__builtin_reduce_or`` and ``__builtin_reduce_xor`` functions can now be used in constant expressions.
+- ``__builtin_elementwise_popcount`` function can now be used in constant expressions.
 
 New Compiler Flags
 ------------------
@@ -404,10 +438,10 @@ Modified Compiler Flags
   to utilize these vector libraries. The behavior for all other vector function
   libraries remains unchanged.
 
-- The ``-Wnontrivial-memaccess`` warning has been updated to also warn about
+- The ``-Wnontrivial-memcall`` warning has been added to warn about
   passing non-trivially-copyable destrination parameter to ``memcpy``,
   ``memset`` and similar functions for which it is a documented undefined
-  behavior.
+  behavior. It is implied by ``-Wnontrivial-memaccess``
 
 Removed Compiler Flags
 -------------------------
@@ -441,6 +475,11 @@ Attribute Changes in Clang
 - The ``hybrid_patchable`` attribute is now supported on ARM64EC targets. It can be used to specify
   that a function requires an additional x86-64 thunk, which may be patched at runtime.
 
+- The attribute ``[[clang::no_specializations]]`` has been added to warn
+  users that a specific template shouldn't be specialized. This is useful for
+  e.g. standard library type traits, where adding a specialization results in
+  undefined behaviour.
+
 - ``[[clang::lifetimebound]]`` is now explicitly disallowed on explicit object member functions
   where they were previously silently ignored.
 
@@ -471,6 +510,8 @@ Attribute Changes in Clang
 - Clang now supports ``[[clang::lifetime_capture_by(X)]]``. Similar to lifetimebound, this can be
   used to specify when a reference to a function parameter is captured by another capturing entity ``X``.
 
+- The ``target_version`` attribute is now only supported for AArch64 and RISC-V architectures.
+
 Improvements to Clang's diagnostics
 -----------------------------------
 
@@ -583,6 +624,10 @@ Improvements to Clang's diagnostics
 - For an rvalue reference bound to a temporary struct with an integer member, Clang will detect constant integer overflow
   in the initializer for the integer member (#GH46755).
 
+- Fixed a false negative ``-Wunused-private-field`` diagnostic when a defaulted comparison operator is defined out of class (#GH116961).
+
+- Clang now diagnoses dangling references for C++20's parenthesized aggregate initialization (#101957).
+
 Improvements to Clang's time-trace
 ----------------------------------
 
@@ -714,6 +759,10 @@ Bug Fixes to C++ Support
   assumption if they also occur inside of a dependent lambda. (#GH114787)
 - Clang now uses valid deduced type locations when diagnosing functions with trailing return type
   missing placeholder return type. (#GH78694)
+- Fixed a bug where bounds of partially expanded pack indexing expressions were checked too early. (#GH116105)
+- Fixed an assertion failure caused by using ``consteval`` in condition in consumed analyses. (#GH117385)
+- Fix a crash caused by incorrect argument position in merging deduced template arguments. (#GH113659)
+- Fixed an assertion failure caused by mangled names with invalid identifiers. (#GH112205)
 
 Bug Fixes to AST Handling
 ^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -723,6 +772,9 @@ Bug Fixes to AST Handling
   sometimes incorrectly return null even if a comment was present. (#GH108145)
 - Clang now correctly parses the argument of the ``relates``, ``related``, ``relatesalso``,
   and ``relatedalso`` comment commands.
+- Clang now uses the location of the begin of the member expression for ``CallExpr``
+  involving deduced ``this``. (#GH116928)
+- Fixed printout of AST that uses pack indexing expression. (#GH116486)
 
 Miscellaneous Bug Fixes
 ^^^^^^^^^^^^^^^^^^^^^^^
@@ -913,6 +965,8 @@ AST Matchers
 - Ensure ``hasName`` matches template specializations across inline namespaces,
   making `matchesNodeFullSlow` and `matchesNodeFullFast` consistent.
 
+- Add ``exportDecl`` matcher to match export declaration.
+
 clang-format
 ------------
 
@@ -964,6 +1018,10 @@ Improvements
 Moved checkers
 ^^^^^^^^^^^^^^
 
+- The checker ``alpha.core.IdenticalExpr`` was deleted because it was
+  duplicated in the clang-tidy checkers ``misc-redundant-expression`` and
+  ``bugprone-branch-clone``.
+
 - The checker ``alpha.security.MallocOverflow`` was deleted because it was
   badly implemented and its agressive logic produced too many false positives.
   To detect too large arguments passed to malloc, consider using the checker
@@ -975,6 +1033,16 @@ Moved checkers
   original checkers were implemented only using AST matching and make more
   sense as a single clang-tidy check.
 
+- The checker ``alpha.unix.Chroot`` was modernized, improved and moved to
+  ``unix.Chroot``. Testing was done on open source projects that use chroot(),
+  and false issues addressed in the improvements based on real use cases. Open
+  source projects used for testing include nsjail, lxroot, dive and ruri.
+  This checker conforms to SEI Cert C recommendation `POS05-C. Limit access to
+  files by creating a jail
+  <https://wiki.sei.cmu.edu/confluence/display/c/POS05-C.+Limit+access+to+files+by+creating+a+jail>`_.
+  Fixes (#GH34697).
+  (#GH117791) [Documentation](https://clang.llvm.org/docs/analyzer/checkers.html#unix-chroot-c).
+
 .. _release-notes-sanitizers:
 
 Sanitizers

diff --git a/clang/docs/SanitizerCoverage.rst b/clang/docs/SanitizerCoverage.rst
@@ -385,6 +385,20 @@ Users need to implement a single function to capture the CF table at startup:
     // the collected control flow.
   }
 
+Gated Trace Callbacks
+=====================
+
+Gate the invocation of the tracing callbacks with
+``-sanitizer-coverage-gated-trace-callbacks``.
+
+When this option is enabled, the instrumentation will not call into the
+runtime-provided callbacks for tracing, thus only incurring in a trivial
+branch without going through a function call.
+
+It is up to the runtime to toggle the value of the global variable in order to
+enable tracing.
+
+This option is only supported for trace-pc-guard and trace-cmp.
 
 Disabling instrumentation with ``__attribute__((no_sanitize("coverage")))``
 ===========================================================================

diff --git a/clang/docs/UsersManual.rst b/clang/docs/UsersManual.rst
@@ -2660,7 +2660,7 @@ usual build cycle when using sample profilers for optimization:
 
      > clang-cl /O2 -gdwarf -gline-tables-only ^
        /clang:-fdebug-info-for-profiling /clang:-funique-internal-linkage-names ^
-       /fprofile-sample-use=code.prof code.cc /Fe:code /fuse-ld=lld /link /debug:dwarf
+       -fprofile-sample-use=code.prof code.cc /Fe:code -fuse-ld=lld /link /debug:dwarf
 
    [OPTIONAL] Sampling-based profiles can have inaccuracies or missing block/
    edge counters. The profile inference algorithm (profi) can be used to infer
@@ -2679,7 +2679,7 @@ usual build cycle when using sample profilers for optimization:
 
      > clang-cl /clang:-fsample-profile-use-profi /O2 -gdwarf -gline-tables-only ^
        /clang:-fdebug-info-for-profiling /clang:-funique-internal-linkage-names ^
-       /fprofile-sample-use=code.prof code.cc /Fe:code /fuse-ld=lld /link /debug:dwarf
+       -fprofile-sample-use=code.prof code.cc /Fe:code -fuse-ld=lld /link /debug:dwarf
 
 Sample Profile Formats
 """"""""""""""""""""""

diff --git a/clang/docs/analyzer/checkers.rst b/clang/docs/analyzer/checkers.rst
@@ -1750,6 +1750,37 @@ Critical section handling functions modeled by this checker:
    }
  }
 
+.. _unix-Chroot:
+
+unix.Chroot (C)
+"""""""""""""""
+Check improper use of chroot described by SEI Cert C recommendation `POS05-C.
+Limit access to files by creating a jail
+<https://wiki.sei.cmu.edu/confluence/display/c/POS05-C.+Limit+access+to+files+by+creating+a+jail>`_.
+The checker finds usage patterns where ``chdir("/")`` is not called immediately
+after a call to ``chroot(path)``.
+
+.. code-block:: c
+
+ void f();
+
+ void test_bad() {
+   chroot("/usr/local");
+   f(); // warn: no call of chdir("/") immediately after chroot
+ }
+
+  void test_bad_path() {
+    chroot("/usr/local");
+    chdir("/usr"); // warn: no call of chdir("/") immediately after chroot
+    f();
+  }
+
+ void test_good() {
+   chroot("/usr/local");
+   chdir("/"); // no warning
+   f();
+ }
+
 .. _unix-Errno:
 
 unix.Errno (C)
@@ -1899,6 +1930,29 @@ Check the size argument passed into C string functions for common erroneous patt
      // warn: potential buffer overflow
  }
 
+.. _unix-cstring-NotNullTerminated:
+
+unix.cstring.NotNullTerminated (C)
+""""""""""""""""""""""""""""""""""
+Check for arguments which are not null-terminated strings;
+applies to the ``strlen``, ``strcpy``, ``strcat``, ``strcmp`` family of functions.
+
+Only very fundamental cases are detected where the passed memory block is
+absolutely different from a null-terminated string. This checker does not
+find if a memory buffer is passed where the terminating zero character
+is missing.
+
+.. code-block:: c
+
+ void test1() {
+   int l = strlen((char *)&test1); // warn
+ }
+
+ void test2() {
+ label:
+   int l = strlen((char *)&&label); // warn
+ }
+
 .. _unix-cstring-NullArg:
 
 unix.cstring.NullArg (C)
@@ -2788,36 +2842,6 @@ Check for assignment of a fixed address to a pointer.
    p = (int *) 0x10000; // warn
  }
 
-.. _alpha-core-IdenticalExpr:
-
-alpha.core.IdenticalExpr (C, C++)
-"""""""""""""""""""""""""""""""""
-Warn about unintended use of identical expressions in operators.
-
-.. code-block:: cpp
-
- // C
- void test() {
-   int a = 5;
-   int b = a | 4 | a; // warn: identical expr on both sides
- }
-
- // C++
- bool f(void);
-
- void test(bool b) {
-   int i = 10;
-   if (f()) { // warn: true and false branches are identical
-     do {
-       i--;
-     } while (f());
-   } else {
-     do {
-       i--;
-     } while (f());
-   }
- }
-
 .. _alpha-core-PointerArithm:
 
 alpha.core.PointerArithm (C)
@@ -3275,21 +3299,6 @@ SEI CERT checkers which tries to find errors based on their `C coding rules <htt
 alpha.unix
 ^^^^^^^^^^
 
-.. _alpha-unix-Chroot:
-
-alpha.unix.Chroot (C)
-"""""""""""""""""""""
-Check improper use of chroot.
-
-.. code-block:: c
-
- void f();
-
- void test() {
-   chroot("/usr/local");
-   f(); // warn: no call of chdir("/") immediately after chroot
- }
-
 .. _alpha-unix-PthreadLock:
 
 alpha.unix.PthreadLock (C)
@@ -3367,29 +3376,6 @@ Checks for overlap in two buffer arguments. Applies to:  ``memcpy, mempcpy, wmem
    memcpy(a + 2, a + 1, 8); // warn
  }
 
-.. _alpha-unix-cstring-NotNullTerminated:
-
-alpha.unix.cstring.NotNullTerminated (C)
-""""""""""""""""""""""""""""""""""""""""
-Check for arguments which are not null-terminated strings;
-applies to the ``strlen``, ``strcpy``, ``strcat``, ``strcmp`` family of functions.
-
-Only very fundamental cases are detected where the passed memory block is
-absolutely different from a null-terminated string. This checker does not
-find if a memory buffer is passed where the terminating zero character
-is missing.
-
-.. code-block:: c
-
- void test1() {
-   int l = strlen((char *)&test); // warn
- }
-
- void test2() {
- label:
-   int l = strlen((char *)&&label); // warn
- }
-
 .. _alpha-unix-cstring-OutOfBounds:
 
 alpha.unix.cstring.OutOfBounds (C)

diff --git a/clang/include/clang/AST/DeclCXX.h b/clang/include/clang/AST/DeclCXX.h
@@ -890,6 +890,13 @@ class CXXRecordDecl : public RecordDecl {
             needsOverloadResolutionForDestructor()) &&
            "destructor should not be deleted");
     data().DefaultedDestructorIsDeleted = true;
+    // C++23 [dcl.constexpr]p3.2:
+    //   if the function is a constructor or destructor, its class does not have
+    //   any virtual base classes.
+    // C++20 [dcl.constexpr]p5:
+    //   The definition of a constexpr destructor whose function-body is
+    //   not = delete shall additionally satisfy...
+    data().DefaultedDestructorIsConstexpr = data().NumVBases == 0;
   }
 
   /// Determine whether this class should get an implicit move

diff --git a/clang/include/clang/AST/ExprCXX.h b/clang/include/clang/AST/ExprCXX.h
@@ -4390,17 +4390,17 @@ class PackIndexingExpr final
   unsigned TransformedExpressions : 31;
 
   LLVM_PREFERRED_TYPE(bool)
-  unsigned ExpandedToEmptyPack : 1;
+  unsigned FullySubstituted : 1;
 
   PackIndexingExpr(QualType Type, SourceLocation EllipsisLoc,
                    SourceLocation RSquareLoc, Expr *PackIdExpr, Expr *IndexExpr,
                    ArrayRef<Expr *> SubstitutedExprs = {},
-                   bool ExpandedToEmptyPack = false)
+                   bool FullySubstituted = false)
       : Expr(PackIndexingExprClass, Type, VK_LValue, OK_Ordinary),
         EllipsisLoc(EllipsisLoc), RSquareLoc(RSquareLoc),
         SubExprs{PackIdExpr, IndexExpr},
         TransformedExpressions(SubstitutedExprs.size()),
-        ExpandedToEmptyPack(ExpandedToEmptyPack) {
+        FullySubstituted(FullySubstituted) {
 
     auto *Exprs = getTrailingObjects<Expr *>();
     std::uninitialized_copy(SubstitutedExprs.begin(), SubstitutedExprs.end(),
@@ -4424,12 +4424,16 @@ class PackIndexingExpr final
                                   SourceLocation RSquareLoc, Expr *PackIdExpr,
                                   Expr *IndexExpr, std::optional<int64_t> Index,
                                   ArrayRef<Expr *> SubstitutedExprs = {},
-                                  bool ExpandedToEmptyPack = false);
+                                  bool FullySubstituted = false);
   static PackIndexingExpr *CreateDeserialized(ASTContext &Context,
                                               unsigned NumTransformedExprs);
 
+  bool isFullySubstituted() const { return FullySubstituted; }
+
   /// Determine if the expression was expanded to empty.
-  bool expandsToEmptyPack() const { return ExpandedToEmptyPack; }
+  bool expandsToEmptyPack() const {
+    return isFullySubstituted() && TransformedExpressions == 0;
+  }
 
   /// Determine the location of the 'sizeof' keyword.
   SourceLocation getEllipsisLoc() const { return EllipsisLoc; }

diff --git a/clang/include/clang/AST/OpenMPClause.h b/clang/include/clang/AST/OpenMPClause.h
@@ -2670,8 +2670,8 @@ class OMPCompareClause final : public OMPClause {
   }
 };
 
-/// This represents 'seq_cst' clause in the '#pragma omp atomic'
-/// directive.
+/// This represents 'seq_cst' clause in the '#pragma omp atomic|flush'
+/// directives.
 ///
 /// \code
 /// #pragma omp atomic seq_cst

diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
@@ -5922,12 +5922,12 @@ class PackIndexingType final
   unsigned Size : 31;
 
   LLVM_PREFERRED_TYPE(bool)
-  unsigned ExpandsToEmptyPack : 1;
+  unsigned FullySubstituted : 1;
 
 protected:
   friend class ASTContext; // ASTContext creates these.
   PackIndexingType(const ASTContext &Context, QualType Canonical,
-                   QualType Pattern, Expr *IndexExpr, bool ExpandsToEmptyPack,
+                   QualType Pattern, Expr *IndexExpr, bool FullySubstituted,
                    ArrayRef<QualType> Expansions = {});
 
 public:
@@ -5951,7 +5951,9 @@ class PackIndexingType final
 
   bool hasSelectedType() const { return getSelectedIndex() != std::nullopt; }
 
-  bool expandsToEmptyPack() const { return ExpandsToEmptyPack; }
+  bool isFullySubstituted() const { return FullySubstituted; }
+
+  bool expandsToEmptyPack() const { return isFullySubstituted() && Size == 0; }
 
   ArrayRef<QualType> getExpansions() const {
     return {getExpansionsPtr(), Size};
@@ -5965,10 +5967,10 @@ class PackIndexingType final
     if (hasSelectedType())
       getSelectedType().Profile(ID);
     else
-      Profile(ID, Context, getPattern(), getIndexExpr(), expandsToEmptyPack());
+      Profile(ID, Context, getPattern(), getIndexExpr(), isFullySubstituted());
   }
   static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
-                      QualType Pattern, Expr *E, bool ExpandsToEmptyPack);
+                      QualType Pattern, Expr *E, bool FullySubstituted);
 
 private:
   const QualType *getExpansionsPtr() const {

diff --git a/clang/include/clang/AST/TypeProperties.td b/clang/include/clang/AST/TypeProperties.td
@@ -473,12 +473,12 @@ let Class = PackIndexingType in {
   def : Property<"indexExpression", ExprRef> {
     let Read = [{ node->getIndexExpr() }];
   }
-  def : Property<"expandsToEmptyPack", Bool> {
-    let Read = [{ node->expandsToEmptyPack() }];
+  def : Property<"isFullySubstituted", Bool> {
+    let Read = [{ node->isFullySubstituted() }];
   }
 
   def : Creator<[{
-    return ctx.getPackIndexingType(pattern, indexExpression, expandsToEmptyPack);
+    return ctx.getPackIndexingType(pattern, indexExpression, isFullySubstituted);
   }]>;
 }
 

diff --git a/clang/include/clang/ASTMatchers/ASTMatchers.h b/clang/include/clang/ASTMatchers/ASTMatchers.h
@@ -1236,6 +1236,17 @@ AST_MATCHER_P(TemplateArgument, equalsIntegralValue,
 extern const internal::VariadicDynCastAllOfMatcher<Stmt,
        ObjCAutoreleasePoolStmt> autoreleasePoolStmt;
 
+/// Matches any export declaration.
+///
+/// Example matches following declarations.
+/// \code
+///   export void foo();
+///   export { void foo(); }
+///   export namespace { void foo(); }
+///   export int v;
+/// \endcode
+extern const internal::VariadicDynCastAllOfMatcher<Decl, ExportDecl> exportDecl;
+
 /// Matches any value declaration.
 ///
 /// Example matches A, B, C and F

diff --git a/clang/include/clang/Analysis/FlowSensitive/ASTOps.h b/clang/include/clang/Analysis/FlowSensitive/ASTOps.h
@@ -146,6 +146,10 @@ struct ReferencedDecls {
   /// Free functions and member functions which are referenced (but not
   /// necessarily called).
   llvm::DenseSet<const FunctionDecl *> Functions;
+  /// When analyzing a lambda's call operator, the set of all parameters (from
+  /// the surrounding function) that the lambda captures. Captured local
+  /// variables are already included in `Locals` above.
+  llvm::DenseSet<const ParmVarDecl *> LambdaCapturedParams;
 };
 
 /// Returns declarations that are declared in or referenced from `FD`.