diff --git a/clang-tools-extra/clang-tidy/modernize/MinMaxUseInitializerListCheck.cpp b/clang-tools-extra/clang-tidy/modernize/MinMaxUseInitializerListCheck.cpp
@@ -129,17 +129,17 @@ generateReplacements(const MatchFinder::MatchResult &Match,
       continue;
     }
 
+    // if the nested call is not the same as the top call
+    if (InnerCall->getDirectCallee()->getQualifiedNameAsString() !=
+        TopCall->getDirectCallee()->getQualifiedNameAsString())
+      continue;
+
     const FindArgsResult InnerResult = findArgs(InnerCall);
 
     // if the nested call doesn't have arguments skip it
     if (!InnerResult.First || !InnerResult.Last)
       continue;
 
-    // if the nested call is not the same as the top call
-    if (InnerCall->getDirectCallee()->getQualifiedNameAsString() !=
-        TopCall->getDirectCallee()->getQualifiedNameAsString())
-      continue;
-
     // if the nested call doesn't have the same compare function
     if ((Result.Compare || InnerResult.Compare) &&
         !utils::areStatementsIdentical(Result.Compare, InnerResult.Compare,

diff --git a/clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp b/clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp
@@ -42,6 +42,7 @@
 #include "UseNullptrCheck.h"
 #include "UseOverrideCheck.h"
 #include "UseStartsEndsWithCheck.h"
+#include "UseStdFormatCheck.h"
 #include "UseStdNumbersCheck.h"
 #include "UseStdPrintCheck.h"
 #include "UseTrailingReturnTypeCheck.h"
@@ -76,6 +77,7 @@ class ModernizeModule : public ClangTidyModule {
         "modernize-use-designated-initializers");
     CheckFactories.registerCheck<UseStartsEndsWithCheck>(
         "modernize-use-starts-ends-with");
+    CheckFactories.registerCheck<UseStdFormatCheck>("modernize-use-std-format");
     CheckFactories.registerCheck<UseStdNumbersCheck>(
         "modernize-use-std-numbers");
     CheckFactories.registerCheck<UseStdPrintCheck>("modernize-use-std-print");

diff --git a/clang-tools-extra/clang-tidy/modernize/UseConstraintsCheck.cpp b/clang-tools-extra/clang-tidy/modernize/UseConstraintsCheck.cpp
@@ -41,6 +41,8 @@ AST_MATCHER(FunctionDecl, hasOtherDeclarations) {
 void UseConstraintsCheck::registerMatchers(MatchFinder *Finder) {
   Finder->addMatcher(
       functionTemplateDecl(
+          // Skip external libraries included as system headers
+          unless(isExpansionInSystemHeader()),
           has(functionDecl(unless(hasOtherDeclarations()), isDefinition(),
                            hasReturnTypeLoc(typeLoc().bind("return")))
                   .bind("function")))
@@ -57,6 +59,8 @@ matchEnableIfSpecializationImplTypename(TypeLoc TheType) {
       return std::nullopt;
     }
     TheType = Dep.getQualifierLoc().getTypeLoc();
+    if (TheType.isNull())
+      return std::nullopt;
   }
 
   if (const auto SpecializationLoc =
@@ -254,7 +258,7 @@ findInsertionForConstraint(const FunctionDecl *Function, ASTContext &Context) {
         return utils::lexer::findPreviousTokenKind(Init->getSourceLocation(),
                                                    SM, LangOpts, tok::colon);
     }
-    if (Constructor->init_begin() != Constructor->init_end())
+    if (!Constructor->inits().empty())
       return std::nullopt;
   }
   if (Function->isDeleted()) {

diff --git a/clang-tools-extra/clang-tidy/modernize/UseStdFormatCheck.cpp b/clang-tools-extra/clang-tidy/modernize/UseStdFormatCheck.cpp
@@ -0,0 +1,107 @@
+//===--- UseStdFormatCheck.cpp - clang-tidy -------------------------------===//
+//
+// 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 "UseStdFormatCheck.h"
+#include "../utils/FormatStringConverter.h"
+#include "../utils/Matchers.h"
+#include "../utils/OptionsUtils.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Lex/Lexer.h"
+#include "clang/Tooling/FixIt.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::modernize {
+
+namespace {
+AST_MATCHER(StringLiteral, isOrdinary) { return Node.isOrdinary(); }
+} // namespace
+
+UseStdFormatCheck::UseStdFormatCheck(StringRef Name, ClangTidyContext *Context)
+    : ClangTidyCheck(Name, Context),
+      StrictMode(Options.getLocalOrGlobal("StrictMode", false)),
+      StrFormatLikeFunctions(utils::options::parseStringList(
+          Options.get("StrFormatLikeFunctions", ""))),
+      ReplacementFormatFunction(
+          Options.get("ReplacementFormatFunction", "std::format")),
+      IncludeInserter(Options.getLocalOrGlobal("IncludeStyle",
+                                               utils::IncludeSorter::IS_LLVM),
+                      areDiagsSelfContained()),
+      MaybeHeaderToInclude(Options.get("FormatHeader")) {
+  if (StrFormatLikeFunctions.empty())
+    StrFormatLikeFunctions.push_back("absl::StrFormat");
+
+  if (!MaybeHeaderToInclude && ReplacementFormatFunction == "std::format")
+    MaybeHeaderToInclude = "<format>";
+}
+
+void UseStdFormatCheck::registerPPCallbacks(const SourceManager &SM,
+                                            Preprocessor *PP,
+                                            Preprocessor *ModuleExpanderPP) {
+  IncludeInserter.registerPreprocessor(PP);
+}
+
+void UseStdFormatCheck::registerMatchers(MatchFinder *Finder) {
+  Finder->addMatcher(
+      callExpr(argumentCountAtLeast(1),
+               hasArgument(0, stringLiteral(isOrdinary())),
+               callee(functionDecl(unless(cxxMethodDecl()),
+                                   matchers::matchesAnyListedName(
+                                       StrFormatLikeFunctions))
+                          .bind("func_decl")))
+          .bind("strformat"),
+      this);
+}
+
+void UseStdFormatCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
+  using utils::options::serializeStringList;
+  Options.store(Opts, "StrictMode", StrictMode);
+  Options.store(Opts, "StrFormatLikeFunctions",
+                serializeStringList(StrFormatLikeFunctions));
+  Options.store(Opts, "ReplacementFormatFunction", ReplacementFormatFunction);
+  Options.store(Opts, "IncludeStyle", IncludeInserter.getStyle());
+  if (MaybeHeaderToInclude)
+    Options.store(Opts, "FormatHeader", *MaybeHeaderToInclude);
+}
+
+void UseStdFormatCheck::check(const MatchFinder::MatchResult &Result) {
+  const unsigned FormatArgOffset = 0;
+  const auto *OldFunction = Result.Nodes.getNodeAs<FunctionDecl>("func_decl");
+  const auto *StrFormat = Result.Nodes.getNodeAs<CallExpr>("strformat");
+
+  utils::FormatStringConverter::Configuration ConverterConfig;
+  ConverterConfig.StrictMode = StrictMode;
+  utils::FormatStringConverter Converter(Result.Context, StrFormat,
+                                         FormatArgOffset, ConverterConfig,
+                                         getLangOpts());
+  const Expr *StrFormatCall = StrFormat->getCallee();
+  if (!Converter.canApply()) {
+    diag(StrFormat->getBeginLoc(),
+         "unable to use '%0' instead of %1 because %2")
+        << StrFormatCall->getSourceRange() << ReplacementFormatFunction
+        << OldFunction->getIdentifier()
+        << Converter.conversionNotPossibleReason();
+    return;
+  }
+
+  DiagnosticBuilder Diag =
+      diag(StrFormatCall->getBeginLoc(), "use '%0' instead of %1")
+      << ReplacementFormatFunction << OldFunction->getIdentifier();
+  Diag << FixItHint::CreateReplacement(
+      CharSourceRange::getTokenRange(StrFormatCall->getSourceRange()),
+      ReplacementFormatFunction);
+  Converter.applyFixes(Diag, *Result.SourceManager);
+
+  if (MaybeHeaderToInclude)
+    Diag << IncludeInserter.createIncludeInsertion(
+        Result.Context->getSourceManager().getFileID(
+            StrFormatCall->getBeginLoc()),
+        *MaybeHeaderToInclude);
+}
+
+} // namespace clang::tidy::modernize
diff --git a/clang-tools-extra/clang-tidy/modernize/UseStdFormatCheck.h b/clang-tools-extra/clang-tidy/modernize/UseStdFormatCheck.h
@@ -0,0 +1,51 @@
+//===--- UseStdFormatCheck.h - clang-tidy -----------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_USESTDFORMATCHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_USESTDFORMATCHECK_H
+
+#include "../ClangTidyCheck.h"
+#include "../utils/IncludeInserter.h"
+
+namespace clang::tidy::modernize {
+
+/// Converts calls to absl::StrFormat, or other functions via configuration
+/// options, to C++20's std::format, or another function via a configuration
+/// option, modifying the format string appropriately and removing
+/// now-unnecessary calls to std::string::c_str() and std::string::data().
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/modernize/use-std-format.html
+class UseStdFormatCheck : public ClangTidyCheck {
+public:
+  UseStdFormatCheck(StringRef Name, ClangTidyContext *Context);
+  bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
+    if (ReplacementFormatFunction == "std::format")
+      return LangOpts.CPlusPlus20;
+    return LangOpts.CPlusPlus;
+  }
+  void registerPPCallbacks(const SourceManager &SM, Preprocessor *PP,
+                           Preprocessor *ModuleExpanderPP) override;
+  void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
+  void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+  void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+  std::optional<TraversalKind> getCheckTraversalKind() const override {
+    return TK_IgnoreUnlessSpelledInSource;
+  }
+
+private:
+  bool StrictMode;
+  std::vector<StringRef> StrFormatLikeFunctions;
+  StringRef ReplacementFormatFunction;
+  utils::IncludeInserter IncludeInserter;
+  std::optional<StringRef> MaybeHeaderToInclude;
+};
+
+} // namespace clang::tidy::modernize
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_USESTDFORMATCHECK_H
diff --git a/clang-tools-extra/clang-tidy/modernize/UseStdPrintCheck.cpp b/clang-tools-extra/clang-tidy/modernize/UseStdPrintCheck.cpp
@@ -129,8 +129,11 @@ void UseStdPrintCheck::check(const MatchFinder::MatchResult &Result) {
     FormatArgOffset = 1;
   }
 
+  utils::FormatStringConverter::Configuration ConverterConfig;
+  ConverterConfig.StrictMode = StrictMode;
+  ConverterConfig.AllowTrailingNewlineRemoval = true;
   utils::FormatStringConverter Converter(
-      Result.Context, Printf, FormatArgOffset, StrictMode, getLangOpts());
+      Result.Context, Printf, FormatArgOffset, ConverterConfig, getLangOpts());
   const Expr *PrintfCall = Printf->getCallee();
   const StringRef ReplacementFunction = Converter.usePrintNewlineFunction()
                                             ? ReplacementPrintlnFunction

diff --git a/clang-tools-extra/clang-tidy/readability/ElseAfterReturnCheck.cpp b/clang-tools-extra/clang-tidy/readability/ElseAfterReturnCheck.cpp
@@ -113,7 +113,7 @@ static bool containsDeclInScope(const Stmt *Node) {
 }
 
 static void removeElseAndBrackets(DiagnosticBuilder &Diag, ASTContext &Context,
-                           const Stmt *Else, SourceLocation ElseLoc) {
+                                  const Stmt *Else, SourceLocation ElseLoc) {
   auto Remap = [&](SourceLocation Loc) {
     return Context.getSourceManager().getExpansionLoc(Loc);
   };
@@ -172,7 +172,7 @@ void ElseAfterReturnCheck::registerMatchers(MatchFinder *Finder) {
       breakStmt().bind(InterruptingStr), cxxThrowExpr().bind(InterruptingStr)));
   Finder->addMatcher(
       compoundStmt(
-          forEach(ifStmt(unless(isConstexpr()),
+          forEach(ifStmt(unless(isConstexpr()), unless(isConsteval()),
                          hasThen(stmt(
                              anyOf(InterruptsControlFlow,
                                    compoundStmt(has(InterruptsControlFlow))))),

diff --git a/clang-tools-extra/clang-tidy/readability/IdentifierNamingCheck.cpp b/clang-tools-extra/clang-tidy/readability/IdentifierNamingCheck.cpp
@@ -1358,7 +1358,7 @@ IdentifierNamingCheck::getFailureInfo(
   std::replace(KindName.begin(), KindName.end(), '_', ' ');
 
   std::string Fixup = fixupWithStyle(Type, Name, Style, HNOption, ND);
-  if (StringRef(Fixup).equals(Name)) {
+  if (StringRef(Fixup) == Name) {
     if (!IgnoreFailedSplit) {
       LLVM_DEBUG(Location.print(llvm::dbgs(), SM);
                  llvm::dbgs()
@@ -1374,6 +1374,10 @@ IdentifierNamingCheck::getFailureInfo(
 std::optional<RenamerClangTidyCheck::FailureInfo>
 IdentifierNamingCheck::getDeclFailureInfo(const NamedDecl *Decl,
                                           const SourceManager &SM) const {
+  // Implicit identifiers cannot be renamed.
+  if (Decl->isImplicit())
+    return std::nullopt;
+
   SourceLocation Loc = Decl->getLocation();
   const FileStyle &FileStyle = getStyleForFile(SM.getFilename(Loc));
   if (!FileStyle.isActive())

diff --git a/clang-tools-extra/clang-tidy/readability/SimplifyBooleanExprCheck.cpp b/clang-tools-extra/clang-tidy/readability/SimplifyBooleanExprCheck.cpp
@@ -7,6 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "SimplifyBooleanExprCheck.h"
+#include "clang/AST/Expr.h"
 #include "clang/AST/RecursiveASTVisitor.h"
 #include "clang/Lex/Lexer.h"
 #include "llvm/Support/SaveAndRestore.h"
@@ -280,9 +281,8 @@ class SimplifyBooleanExprCheck::Visitor : public RecursiveASTVisitor<Visitor> {
     if (!S) {
       return true;
     }
-    if (Check->IgnoreMacros && S->getBeginLoc().isMacroID()) {
+    if (Check->canBeBypassed(S))
       return false;
-    }
     if (!shouldIgnore(S))
       StmtStack.push_back(S);
     return true;
@@ -513,17 +513,23 @@ class SimplifyBooleanExprCheck::Visitor : public RecursiveASTVisitor<Visitor> {
     return true;
   }
 
-  static bool isUnaryLNot(const Expr *E) {
-    return isa<UnaryOperator>(E) &&
+  bool isExpectedUnaryLNot(const Expr *E) {
+    return !Check->canBeBypassed(E) && isa<UnaryOperator>(E) &&
            cast<UnaryOperator>(E)->getOpcode() == UO_LNot;
   }
 
+  bool isExpectedBinaryOp(const Expr *E) {
+    const auto *BinaryOp = dyn_cast<BinaryOperator>(E);
+    return !Check->canBeBypassed(E) && BinaryOp && BinaryOp->isLogicalOp() &&
+           BinaryOp->getType()->isBooleanType();
+  }
+
   template <typename Functor>
   static bool checkEitherSide(const BinaryOperator *BO, Functor Func) {
     return Func(BO->getLHS()) || Func(BO->getRHS());
   }
 
-  static bool nestedDemorgan(const Expr *E, unsigned NestingLevel) {
+  bool nestedDemorgan(const Expr *E, unsigned NestingLevel) {
     const auto *BO = dyn_cast<BinaryOperator>(E->IgnoreUnlessSpelledInSource());
     if (!BO)
       return false;
@@ -539,15 +545,13 @@ class SimplifyBooleanExprCheck::Visitor : public RecursiveASTVisitor<Visitor> {
       return true;
     case BO_LAnd:
     case BO_LOr:
-      if (checkEitherSide(BO, isUnaryLNot))
-        return true;
-      if (NestingLevel) {
-        if (checkEitherSide(BO, [NestingLevel](const Expr *E) {
-              return nestedDemorgan(E, NestingLevel - 1);
-            }))
-          return true;
-      }
-      return false;
+      return checkEitherSide(
+                 BO,
+                 [this](const Expr *E) { return isExpectedUnaryLNot(E); }) ||
+             (NestingLevel &&
+              checkEitherSide(BO, [this, NestingLevel](const Expr *E) {
+                return nestedDemorgan(E, NestingLevel - 1);
+              }));
     default:
       return false;
     }
@@ -556,19 +560,19 @@ class SimplifyBooleanExprCheck::Visitor : public RecursiveASTVisitor<Visitor> {
   bool TraverseUnaryOperator(UnaryOperator *Op) {
     if (!Check->SimplifyDeMorgan || Op->getOpcode() != UO_LNot)
       return Base::TraverseUnaryOperator(Op);
-    Expr *SubImp = Op->getSubExpr()->IgnoreImplicit();
-    auto *Parens = dyn_cast<ParenExpr>(SubImp);
-    auto *BinaryOp =
-        Parens
-            ? dyn_cast<BinaryOperator>(Parens->getSubExpr()->IgnoreImplicit())
-            : dyn_cast<BinaryOperator>(SubImp);
-    if (!BinaryOp || !BinaryOp->isLogicalOp() ||
-        !BinaryOp->getType()->isBooleanType())
+    const Expr *SubImp = Op->getSubExpr()->IgnoreImplicit();
+    const auto *Parens = dyn_cast<ParenExpr>(SubImp);
+    const Expr *SubExpr =
+        Parens ? Parens->getSubExpr()->IgnoreImplicit() : SubImp;
+    if (!isExpectedBinaryOp(SubExpr))
       return Base::TraverseUnaryOperator(Op);
+    const auto *BinaryOp = cast<BinaryOperator>(SubExpr);
     if (Check->SimplifyDeMorganRelaxed ||
-        checkEitherSide(BinaryOp, isUnaryLNot) ||
-        checkEitherSide(BinaryOp,
-                        [](const Expr *E) { return nestedDemorgan(E, 1); })) {
+        checkEitherSide(
+            BinaryOp,
+            [this](const Expr *E) { return isExpectedUnaryLNot(E); }) ||
+        checkEitherSide(
+            BinaryOp, [this](const Expr *E) { return nestedDemorgan(E, 1); })) {
       if (Check->reportDeMorgan(Context, Op, BinaryOp, !IsProcessing, parent(),
                                 Parens) &&
           !Check->areDiagsSelfContained()) {
@@ -694,6 +698,10 @@ void SimplifyBooleanExprCheck::check(const MatchFinder::MatchResult &Result) {
   Visitor(this, *Result.Context).traverse();
 }
 
+bool SimplifyBooleanExprCheck::canBeBypassed(const Stmt *S) const {
+  return IgnoreMacros && S->getBeginLoc().isMacroID();
+}
+
 void SimplifyBooleanExprCheck::issueDiag(const ASTContext &Context,
                                          SourceLocation Loc,
                                          StringRef Description,

diff --git a/clang-tools-extra/clang-tidy/readability/SimplifyBooleanExprCheck.h b/clang-tools-extra/clang-tidy/readability/SimplifyBooleanExprCheck.h
@@ -64,6 +64,8 @@ class SimplifyBooleanExprCheck : public ClangTidyCheck {
                  StringRef Description, SourceRange ReplacementRange,
                  StringRef Replacement);
 
+  bool canBeBypassed(const Stmt *S) const;
+
   const bool IgnoreMacros;
   const bool ChainedConditionalReturn;
   const bool ChainedConditionalAssignment;

diff --git a/clang-tools-extra/clang-tidy/readability/StaticAccessedThroughInstanceCheck.cpp b/clang-tools-extra/clang-tidy/readability/StaticAccessedThroughInstanceCheck.cpp
@@ -59,10 +59,6 @@ void StaticAccessedThroughInstanceCheck::check(
 
   const Expr *BaseExpr = MemberExpression->getBase();
 
-  // Do not warn for overloaded -> operators.
-  if (isa<CXXOperatorCallExpr>(BaseExpr))
-    return;
-
   const QualType BaseType =
       BaseExpr->getType()->isPointerType()
           ? BaseExpr->getType()->getPointeeType().getUnqualifiedType()
@@ -89,17 +85,30 @@ void StaticAccessedThroughInstanceCheck::check(
     return;
 
   SourceLocation MemberExprStartLoc = MemberExpression->getBeginLoc();
-  auto Diag =
-      diag(MemberExprStartLoc, "static member accessed through instance");
-
-  if (BaseExpr->HasSideEffects(*AstContext) ||
-      getNameSpecifierNestingLevel(BaseType) > NameSpecifierNestingThreshold)
-    return;
+  auto CreateFix = [&] {
+    return FixItHint::CreateReplacement(
+        CharSourceRange::getCharRange(MemberExprStartLoc,
+                                      MemberExpression->getMemberLoc()),
+        BaseTypeName + "::");
+  };
+
+  {
+    auto Diag =
+        diag(MemberExprStartLoc, "static member accessed through instance");
+
+    if (getNameSpecifierNestingLevel(BaseType) > NameSpecifierNestingThreshold)
+      return;
+
+    if (!BaseExpr->HasSideEffects(*AstContext,
+                                  /* IncludePossibleEffects =*/true)) {
+      Diag << CreateFix();
+      return;
+    }
+  }
 
-  Diag << FixItHint::CreateReplacement(
-      CharSourceRange::getCharRange(MemberExprStartLoc,
-                                    MemberExpression->getMemberLoc()),
-      BaseTypeName + "::");
+  diag(MemberExprStartLoc, "member base expression may carry some side effects",
+       DiagnosticIDs::Level::Note)
+      << BaseExpr->getSourceRange() << CreateFix();
 }
 
 } // namespace clang::tidy::readability
diff --git a/clang-tools-extra/clang-tidy/readability/StringCompareCheck.cpp b/clang-tools-extra/clang-tidy/readability/StringCompareCheck.cpp
@@ -7,24 +7,43 @@
 //===----------------------------------------------------------------------===//
 
 #include "StringCompareCheck.h"
-#include "../utils/FixItHintUtils.h"
+#include "../utils/OptionsUtils.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
 #include "clang/Tooling/FixIt.h"
+#include "llvm/ADT/StringRef.h"
 
 using namespace clang::ast_matchers;
+namespace optutils = clang::tidy::utils::options;
 
 namespace clang::tidy::readability {
 
 static const StringRef CompareMessage = "do not use 'compare' to test equality "
                                         "of strings; use the string equality "
                                         "operator instead";
 
+static const StringRef DefaultStringLikeClasses = "::std::basic_string;"
+                                                  "::std::basic_string_view";
+
+StringCompareCheck::StringCompareCheck(StringRef Name,
+                                       ClangTidyContext *Context)
+    : ClangTidyCheck(Name, Context),
+      StringLikeClasses(optutils::parseStringList(
+          Options.get("StringLikeClasses", DefaultStringLikeClasses))) {}
+
+void StringCompareCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
+  Options.store(Opts, "StringLikeClasses",
+                optutils::serializeStringList(StringLikeClasses));
+}
+
 void StringCompareCheck::registerMatchers(MatchFinder *Finder) {
+  if (StringLikeClasses.empty()) {
+    return;
+  }
   const auto StrCompare = cxxMemberCallExpr(
-      callee(cxxMethodDecl(hasName("compare"),
-                           ofClass(classTemplateSpecializationDecl(
-                               hasName("::std::basic_string"))))),
+      callee(cxxMethodDecl(hasName("compare"), ofClass(cxxRecordDecl(hasAnyName(
+                                                   StringLikeClasses))))),
       hasArgument(0, expr().bind("str2")), argumentCountIs(1),
       callee(memberExpr().bind("str1")));
 

diff --git a/clang-tools-extra/clang-tidy/readability/StringCompareCheck.h b/clang-tools-extra/clang-tidy/readability/StringCompareCheck.h
@@ -10,6 +10,7 @@
 #define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_STRINGCOMPARECHECK_H
 
 #include "../ClangTidyCheck.h"
+#include <vector>
 
 namespace clang::tidy::readability {
 
@@ -20,13 +21,18 @@ namespace clang::tidy::readability {
 /// http://clang.llvm.org/extra/clang-tidy/checks/readability/string-compare.html
 class StringCompareCheck : public ClangTidyCheck {
 public:
-  StringCompareCheck(StringRef Name, ClangTidyContext *Context)
-      : ClangTidyCheck(Name, Context) {}
+  StringCompareCheck(StringRef Name, ClangTidyContext *Context);
+
   bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
     return LangOpts.CPlusPlus;
   }
+
   void registerMatchers(ast_matchers::MatchFinder *Finder) override;
   void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+  void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
+
+private:
+  const std::vector<StringRef> StringLikeClasses;
 };
 
 } // namespace clang::tidy::readability

diff --git a/clang-tools-extra/clang-tidy/readability/SuspiciousCallArgumentCheck.cpp b/clang-tools-extra/clang-tidy/readability/SuspiciousCallArgumentCheck.cpp
@@ -138,11 +138,11 @@ static bool applyAbbreviationHeuristic(
     const llvm::StringMap<std::string> &AbbreviationDictionary, StringRef Arg,
     StringRef Param) {
   if (AbbreviationDictionary.contains(Arg) &&
-      Param.equals(AbbreviationDictionary.lookup(Arg)))
+      Param == AbbreviationDictionary.lookup(Arg))
     return true;
 
   if (AbbreviationDictionary.contains(Param) &&
-      Arg.equals(AbbreviationDictionary.lookup(Param)))
+      Arg == AbbreviationDictionary.lookup(Param))
     return true;
 
   return false;

diff --git a/clang-tools-extra/clang-tidy/tool/ClangTidyMain.cpp b/clang-tools-extra/clang-tidy/tool/ClangTidyMain.cpp
@@ -53,6 +53,7 @@ Configuration files:
   Checks                       - Same as '--checks'. Additionally, the list of
                                  globs can be specified as a list instead of a
                                  string.
+  ExcludeHeaderFilterRegex     - Same as '--exclude-header-filter'.
   ExtraArgs                    - Same as '--extra-args'.
   ExtraArgsBefore              - Same as '--extra-args-before'.
   FormatStyle                  - Same as '--format-style'.
@@ -132,6 +133,20 @@ option in .clang-tidy file, if any.
                                          cl::init(""),
                                          cl::cat(ClangTidyCategory));
 
+static cl::opt<std::string> ExcludeHeaderFilter("exclude-header-filter",
+                                                desc(R"(
+Regular expression matching the names of the
+headers to exclude diagnostics from. Diagnostics
+from the main file of each translation unit are
+always displayed.
+Must be used together with --header-filter.
+Can be used together with -line-filter.
+This option overrides the 'ExcludeHeaderFilterRegex'
+option in .clang-tidy file, if any.
+)"),
+                                                cl::init(""),
+                                                cl::cat(ClangTidyCategory));
+
 static cl::opt<bool> SystemHeaders("system-headers", desc(R"(
 Display the errors from system headers.
 This option overrides the 'SystemHeaders' option
@@ -353,6 +368,7 @@ static std::unique_ptr<ClangTidyOptionsProvider> createOptionsProvider(
   DefaultOptions.Checks = DefaultChecks;
   DefaultOptions.WarningsAsErrors = "";
   DefaultOptions.HeaderFilterRegex = HeaderFilter;
+  DefaultOptions.ExcludeHeaderFilterRegex = ExcludeHeaderFilter;
   DefaultOptions.SystemHeaders = SystemHeaders;
   DefaultOptions.FormatStyle = FormatStyle;
   DefaultOptions.User = llvm::sys::Process::GetEnv("USER");
@@ -367,6 +383,8 @@ static std::unique_ptr<ClangTidyOptionsProvider> createOptionsProvider(
     OverrideOptions.WarningsAsErrors = WarningsAsErrors;
   if (HeaderFilter.getNumOccurrences() > 0)
     OverrideOptions.HeaderFilterRegex = HeaderFilter;
+  if (ExcludeHeaderFilter.getNumOccurrences() > 0)
+    OverrideOptions.ExcludeHeaderFilterRegex = ExcludeHeaderFilter;
   if (SystemHeaders.getNumOccurrences() > 0)
     OverrideOptions.SystemHeaders = SystemHeaders;
   if (FormatStyle.getNumOccurrences() > 0)

diff --git a/clang-tools-extra/clang-tidy/tool/run-clang-tidy.py b/clang-tools-extra/clang-tidy/tool/run-clang-tidy.py
@@ -106,11 +106,14 @@ def get_tidy_invocation(
     use_color,
     plugins,
     warnings_as_errors,
+    exclude_header_filter,
 ):
     """Gets a command line for clang-tidy."""
     start = [clang_tidy_binary]
     if allow_enabling_alpha_checkers:
         start.append("-allow-enabling-analyzer-alpha-checkers")
+    if exclude_header_filter is not None:
+        start.append("--exclude-header-filter=" + exclude_header_filter)
     if header_filter is not None:
         start.append("-header-filter=" + header_filter)
     if line_filter is not None:
@@ -228,6 +231,7 @@ def run_tidy(args, clang_tidy_binary, tmpdir, build_path, queue, lock, failed_fi
             args.use_color,
             args.plugins,
             args.warnings_as_errors,
+            args.exclude_header_filter,
         )
 
         proc = subprocess.Popen(
@@ -292,6 +296,14 @@ def main():
         "-config option after reading specified config file. "
         "Use either -config-file or -config, not both.",
     )
+    parser.add_argument(
+        "-exclude-header-filter",
+        default=None,
+        help="Regular expression matching the names of the "
+        "headers to exclude diagnostics from. Diagnostics from "
+        "the main file of each translation unit are always "
+        "displayed.",
+    )
     parser.add_argument(
         "-header-filter",
         default=None,
@@ -450,6 +462,7 @@ def main():
             args.use_color,
             args.plugins,
             args.warnings_as_errors,
+            args.exclude_header_filter,
         )
         invocation.append("-list-checks")
         invocation.append("-")

diff --git a/clang-tools-extra/clang-tidy/utils/FormatStringConverter.cpp b/clang-tools-extra/clang-tidy/utils/FormatStringConverter.cpp
@@ -198,10 +198,11 @@ static bool castMismatchedIntegerTypes(const CallExpr *Call, bool StrictMode) {
 FormatStringConverter::FormatStringConverter(ASTContext *ContextIn,
                                              const CallExpr *Call,
                                              unsigned FormatArgOffset,
-                                             bool StrictMode,
+                                             const Configuration ConfigIn,
                                              const LangOptions &LO)
-    : Context(ContextIn),
-      CastMismatchedIntegerTypes(castMismatchedIntegerTypes(Call, StrictMode)),
+    : Context(ContextIn), Config(ConfigIn),
+      CastMismatchedIntegerTypes(
+          castMismatchedIntegerTypes(Call, ConfigIn.StrictMode)),
       Args(Call->getArgs()), NumArgs(Call->getNumArgs()),
       ArgsOffset(FormatArgOffset + 1), LangOpts(LO) {
   assert(ArgsOffset <= NumArgs);
@@ -627,9 +628,12 @@ void FormatStringConverter::finalizeFormatText() {
 
   // It's clearer to convert printf("Hello\r\n"); to std::print("Hello\r\n")
   // than to std::println("Hello\r");
-  if (StringRef(StandardFormatString).ends_with("\\n") &&
-      !StringRef(StandardFormatString).ends_with("\\\\n") &&
-      !StringRef(StandardFormatString).ends_with("\\r\\n")) {
+  // Use StringRef until C++20 std::string::ends_with() is available.
+  const auto StandardFormatStringRef = StringRef(StandardFormatString);
+  if (Config.AllowTrailingNewlineRemoval &&
+      StandardFormatStringRef.ends_with("\\n") &&
+      !StandardFormatStringRef.ends_with("\\\\n") &&
+      !StandardFormatStringRef.ends_with("\\r\\n")) {
     UsePrintNewlineFunction = true;
     FormatStringNeededRewriting = true;
     StandardFormatString.erase(StandardFormatString.end() - 2,

diff --git a/clang-tools-extra/clang-tidy/utils/FormatStringConverter.h b/clang-tools-extra/clang-tidy/utils/FormatStringConverter.h
@@ -32,8 +32,14 @@ class FormatStringConverter
 public:
   using ConversionSpecifier = clang::analyze_format_string::ConversionSpecifier;
   using PrintfSpecifier = analyze_printf::PrintfSpecifier;
+
+  struct Configuration {
+    bool StrictMode = false;
+    bool AllowTrailingNewlineRemoval = false;
+  };
+
   FormatStringConverter(ASTContext *Context, const CallExpr *Call,
-                        unsigned FormatArgOffset, bool StrictMode,
+                        unsigned FormatArgOffset, Configuration Config,
                         const LangOptions &LO);
 
   bool canApply() const { return ConversionNotPossibleReason.empty(); }
@@ -45,6 +51,7 @@ class FormatStringConverter
 
 private:
   ASTContext *Context;
+  const Configuration Config;
   const bool CastMismatchedIntegerTypes;
   const Expr *const *Args;
   const unsigned NumArgs;

diff --git a/clang-tools-extra/clang-tidy/utils/IncludeSorter.cpp b/clang-tools-extra/clang-tidy/utils/IncludeSorter.cpp
@@ -88,8 +88,7 @@ determineIncludeKind(StringRef CanonicalFile, StringRef IncludeFile,
     if (FileCopy.consume_front(Parts.first) &&
         FileCopy.consume_back(Parts.second)) {
       // Determine the kind of this inclusion.
-      if (FileCopy.equals("/internal/") ||
-          FileCopy.equals("/proto/")) {
+      if (FileCopy == "/internal/" || FileCopy == "/proto/") {
         return IncludeSorter::IK_MainTUInclude;
       }
     }

diff --git a/clang-tools-extra/clang-tidy/utils/RenamerClangTidyCheck.cpp b/clang-tools-extra/clang-tidy/utils/RenamerClangTidyCheck.cpp
@@ -61,6 +61,7 @@ struct DenseMapInfo<clang::tidy::RenamerClangTidyCheck::NamingCheckId> {
 namespace clang::tidy {
 
 namespace {
+
 class NameLookup {
   llvm::PointerIntPair<const NamedDecl *, 1, bool> Data;
 
@@ -78,19 +79,58 @@ class NameLookup {
   operator bool() const { return !hasMultipleResolutions(); }
   const NamedDecl *operator*() const { return getDecl(); }
 };
+
 } // namespace
 
 static const NamedDecl *findDecl(const RecordDecl &RecDecl,
                                  StringRef DeclName) {
   for (const Decl *D : RecDecl.decls()) {
     if (const auto *ND = dyn_cast<NamedDecl>(D)) {
-      if (ND->getDeclName().isIdentifier() && ND->getName().equals(DeclName))
+      if (ND->getDeclName().isIdentifier() && ND->getName() == DeclName)
         return ND;
     }
   }
   return nullptr;
 }
 
+/// Returns the function that \p Method is overridding. If There are none or
+/// multiple overrides it returns nullptr. If the overridden function itself is
+/// overridding then it will recurse up to find the first decl of the function.
+static const CXXMethodDecl *getOverrideMethod(const CXXMethodDecl *Method) {
+  if (Method->size_overridden_methods() != 1)
+    return nullptr;
+
+  while (true) {
+    Method = *Method->begin_overridden_methods();
+    assert(Method && "Overridden method shouldn't be null");
+    unsigned NumOverrides = Method->size_overridden_methods();
+    if (NumOverrides == 0)
+      return Method;
+    if (NumOverrides > 1)
+      return nullptr;
+  }
+}
+
+static bool hasNoName(const NamedDecl *Decl) {
+  return !Decl->getIdentifier() || Decl->getName().empty();
+}
+
+static const NamedDecl *getFailureForNamedDecl(const NamedDecl *ND) {
+  const auto *Canonical = cast<NamedDecl>(ND->getCanonicalDecl());
+  if (Canonical != ND)
+    return Canonical;
+
+  if (const auto *Method = dyn_cast<CXXMethodDecl>(ND)) {
+    if (const CXXMethodDecl *Overridden = getOverrideMethod(Method))
+      Canonical = cast<NamedDecl>(Overridden->getCanonicalDecl());
+
+    if (Canonical != ND)
+      return Canonical;
+  }
+
+  return ND;
+}
+
 /// Returns a decl matching the \p DeclName in \p Parent or one of its base
 /// classes. If \p AggressiveTemplateLookup is `true` then it will check
 /// template dependent base classes as well.
@@ -132,24 +172,6 @@ static NameLookup findDeclInBases(const CXXRecordDecl &Parent,
   return NameLookup(Found); // If nullptr, decl wasn't found.
 }
 
-/// Returns the function that \p Method is overridding. If There are none or
-/// multiple overrides it returns nullptr. If the overridden function itself is
-/// overridding then it will recurse up to find the first decl of the function.
-static const CXXMethodDecl *getOverrideMethod(const CXXMethodDecl *Method) {
-  if (Method->size_overridden_methods() != 1)
-    return nullptr;
-
-  while (true) {
-    Method = *Method->begin_overridden_methods();
-    assert(Method && "Overridden method shouldn't be null");
-    unsigned NumOverrides = Method->size_overridden_methods();
-    if (NumOverrides == 0)
-      return Method;
-    if (NumOverrides > 1)
-      return nullptr;
-  }
-}
-
 namespace {
 
 /// Callback supplies macros to RenamerClangTidyCheck::checkMacro
@@ -192,10 +214,6 @@ class RenamerClangTidyVisitor
       : Check(Check), SM(SM),
         AggressiveDependentMemberLookup(AggressiveDependentMemberLookup) {}
 
-  static bool hasNoName(const NamedDecl *Decl) {
-    return !Decl->getIdentifier() || Decl->getName().empty();
-  }
-
   bool shouldVisitTemplateInstantiations() const { return true; }
 
   bool shouldVisitImplicitCode() const { return false; }
@@ -246,29 +264,10 @@ class RenamerClangTidyVisitor
   }
 
   bool VisitNamedDecl(NamedDecl *Decl) {
-    if (hasNoName(Decl))
-      return true;
-
-    const auto *Canonical = cast<NamedDecl>(Decl->getCanonicalDecl());
-    if (Canonical != Decl) {
-      Check->addUsage(Canonical, Decl->getLocation(), SM);
-      return true;
-    }
-
-    // Fix overridden methods
-    if (const auto *Method = dyn_cast<CXXMethodDecl>(Decl)) {
-      if (const CXXMethodDecl *Overridden = getOverrideMethod(Method)) {
-        Check->addUsage(Overridden, Method->getLocation(), SM);
-        return true; // Don't try to add the actual decl as a Failure.
-      }
-    }
-
-    // Ignore ClassTemplateSpecializationDecl which are creating duplicate
-    // replacements with CXXRecordDecl.
-    if (isa<ClassTemplateSpecializationDecl>(Decl))
-      return true;
-
-    Check->checkNamedDecl(Decl, SM);
+    SourceRange UsageRange =
+        DeclarationNameInfo(Decl->getDeclName(), Decl->getLocation())
+            .getSourceRange();
+    Check->addUsage(Decl, UsageRange, SM);
     return true;
   }
 
@@ -413,82 +412,97 @@ void RenamerClangTidyCheck::registerPPCallbacks(
       std::make_unique<RenamerClangTidyCheckPPCallbacks>(SM, this));
 }
 
-void RenamerClangTidyCheck::addUsage(
-    const RenamerClangTidyCheck::NamingCheckId &Decl, SourceRange Range,
-    const SourceManager &SourceMgr) {
+std::pair<RenamerClangTidyCheck::NamingCheckFailureMap::iterator, bool>
+RenamerClangTidyCheck::addUsage(
+    const RenamerClangTidyCheck::NamingCheckId &FailureId,
+    SourceRange UsageRange, const SourceManager &SourceMgr) {
   // Do nothing if the provided range is invalid.
-  if (Range.isInvalid())
-    return;
+  if (UsageRange.isInvalid())
+    return {NamingCheckFailures.end(), false};
 
-  // If we have a source manager, use it to convert to the spelling location for
-  // performing the fix. This is necessary because macros can map the same
-  // spelling location to different source locations, and we only want to fix
-  // the token once, before it is expanded by the macro.
-  SourceLocation FixLocation = Range.getBegin();
+  // Get the spelling location for performing the fix. This is necessary because
+  // macros can map the same spelling location to different source locations,
+  // and we only want to fix the token once, before it is expanded by the macro.
+  SourceLocation FixLocation = UsageRange.getBegin();
   FixLocation = SourceMgr.getSpellingLoc(FixLocation);
   if (FixLocation.isInvalid())
-    return;
+    return {NamingCheckFailures.end(), false};
+
+  auto EmplaceResult = NamingCheckFailures.try_emplace(FailureId);
+  NamingCheckFailure &Failure = EmplaceResult.first->second;
 
   // Try to insert the identifier location in the Usages map, and bail out if it
   // is already in there
-  RenamerClangTidyCheck::NamingCheckFailure &Failure =
-      NamingCheckFailures[Decl];
   if (!Failure.RawUsageLocs.insert(FixLocation).second)
-    return;
+    return EmplaceResult;
 
-  if (!Failure.shouldFix())
-    return;
+  if (Failure.FixStatus != RenamerClangTidyCheck::ShouldFixStatus::ShouldFix)
+    return EmplaceResult;
 
   if (SourceMgr.isWrittenInScratchSpace(FixLocation))
     Failure.FixStatus = RenamerClangTidyCheck::ShouldFixStatus::InsideMacro;
 
-  if (!utils::rangeCanBeFixed(Range, &SourceMgr))
+  if (!utils::rangeCanBeFixed(UsageRange, &SourceMgr))
     Failure.FixStatus = RenamerClangTidyCheck::ShouldFixStatus::InsideMacro;
+
+  return EmplaceResult;
 }
 
-void RenamerClangTidyCheck::addUsage(const NamedDecl *Decl, SourceRange Range,
+void RenamerClangTidyCheck::addUsage(const NamedDecl *Decl,
+                                     SourceRange UsageRange,
                                      const SourceManager &SourceMgr) {
-  // Don't keep track for non-identifier names.
-  auto *II = Decl->getIdentifier();
-  if (!II)
+  if (hasNoName(Decl))
+    return;
+
+  // Ignore ClassTemplateSpecializationDecl which are creating duplicate
+  // replacements with CXXRecordDecl.
+  if (isa<ClassTemplateSpecializationDecl>(Decl))
     return;
-  if (const auto *Method = dyn_cast<CXXMethodDecl>(Decl)) {
-    if (const CXXMethodDecl *Overridden = getOverrideMethod(Method))
-      Decl = Overridden;
-  }
-  Decl = cast<NamedDecl>(Decl->getCanonicalDecl());
-  return addUsage(
-      RenamerClangTidyCheck::NamingCheckId(Decl->getLocation(), II->getName()),
-      Range, SourceMgr);
-}
 
-void RenamerClangTidyCheck::checkNamedDecl(const NamedDecl *Decl,
-                                           const SourceManager &SourceMgr) {
-  std::optional<FailureInfo> MaybeFailure = getDeclFailureInfo(Decl, SourceMgr);
+  // We don't want to create a failure for every NamedDecl we find. Ideally
+  // there is just one NamedDecl in every group of "related" NamedDecls that
+  // becomes the failure. This NamedDecl and all of its related NamedDecls
+  // become usages. E.g. Since NamedDecls are Redeclarable, only the canonical
+  // NamedDecl becomes the failure and all redeclarations become usages.
+  const NamedDecl *FailureDecl = getFailureForNamedDecl(Decl);
+
+  std::optional<FailureInfo> MaybeFailure =
+      getDeclFailureInfo(FailureDecl, SourceMgr);
   if (!MaybeFailure)
     return;
 
-  FailureInfo &Info = *MaybeFailure;
-  NamingCheckFailure &Failure =
-      NamingCheckFailures[NamingCheckId(Decl->getLocation(), Decl->getName())];
-  SourceRange Range =
-      DeclarationNameInfo(Decl->getDeclName(), Decl->getLocation())
-          .getSourceRange();
-
-  const IdentifierTable &Idents = Decl->getASTContext().Idents;
-  auto CheckNewIdentifier = Idents.find(Info.Fixup);
+  NamingCheckId FailureId(FailureDecl->getLocation(), FailureDecl->getName());
+
+  auto [FailureIter, NewFailure] = addUsage(FailureId, UsageRange, SourceMgr);
+
+  if (FailureIter == NamingCheckFailures.end()) {
+    // Nothing to do if the usage wasn't accepted.
+    return;
+  }
+  if (!NewFailure) {
+    // FailureInfo has already been provided.
+    return;
+  }
+
+  // Update the stored failure with info regarding the FailureDecl.
+  NamingCheckFailure &Failure = FailureIter->second;
+  Failure.Info = std::move(*MaybeFailure);
+
+  // Don't overwritte the failure status if it was already set.
+  if (!Failure.shouldFix()) {
+    return;
+  }
+  const IdentifierTable &Idents = FailureDecl->getASTContext().Idents;
+  auto CheckNewIdentifier = Idents.find(Failure.Info.Fixup);
   if (CheckNewIdentifier != Idents.end()) {
     const IdentifierInfo *Ident = CheckNewIdentifier->second;
     if (Ident->isKeyword(getLangOpts()))
       Failure.FixStatus = ShouldFixStatus::ConflictsWithKeyword;
     else if (Ident->hasMacroDefinition())
       Failure.FixStatus = ShouldFixStatus::ConflictsWithMacroDefinition;
-  } else if (!isValidAsciiIdentifier(Info.Fixup)) {
+  } else if (!isValidAsciiIdentifier(Failure.Info.Fixup)) {
     Failure.FixStatus = ShouldFixStatus::FixInvalidIdentifier;
   }
-
-  Failure.Info = std::move(Info);
-  addUsage(Decl, Range, SourceMgr);
 }
 
 void RenamerClangTidyCheck::check(const MatchFinder::MatchResult &Result) {

diff --git a/clang-tools-extra/clang-tidy/utils/RenamerClangTidyCheck.h b/clang-tools-extra/clang-tidy/utils/RenamerClangTidyCheck.h
@@ -115,15 +115,9 @@ class RenamerClangTidyCheck : public ClangTidyCheck {
   void expandMacro(const Token &MacroNameTok, const MacroInfo *MI,
                    const SourceManager &SourceMgr);
 
-  void addUsage(const RenamerClangTidyCheck::NamingCheckId &Decl,
-                SourceRange Range, const SourceManager &SourceMgr);
-
-  /// Convenience method when the usage to be added is a NamedDecl.
   void addUsage(const NamedDecl *Decl, SourceRange Range,
                 const SourceManager &SourceMgr);
 
-  void checkNamedDecl(const NamedDecl *Decl, const SourceManager &SourceMgr);
-
 protected:
   /// Overridden by derived classes, returns information about if and how a Decl
   /// failed the check. A 'std::nullopt' result means the Decl did not fail the
@@ -158,6 +152,14 @@ class RenamerClangTidyCheck : public ClangTidyCheck {
                                const NamingCheckFailure &Failure) const = 0;
 
 private:
+  // Manage additions to the Failure/usage map
+  //
+  // return the result of NamingCheckFailures::try_emplace() if the usage was
+  // accepted.
+  std::pair<NamingCheckFailureMap::iterator, bool>
+  addUsage(const RenamerClangTidyCheck::NamingCheckId &FailureId,
+           SourceRange UsageRange, const SourceManager &SourceMgr);
+
   NamingCheckFailureMap NamingCheckFailures;
   const bool AggressiveDependentMemberLookup;
 };

diff --git a/clang-tools-extra/clangd/AST.cpp b/clang-tools-extra/clangd/AST.cpp
@@ -50,16 +50,11 @@ getTemplateSpecializationArgLocs(const NamedDecl &ND) {
     if (const ASTTemplateArgumentListInfo *Args =
             Func->getTemplateSpecializationArgsAsWritten())
       return Args->arguments();
-  } else if (auto *Cls =
-                 llvm::dyn_cast<ClassTemplatePartialSpecializationDecl>(&ND)) {
+  } else if (auto *Cls = llvm::dyn_cast<ClassTemplateSpecializationDecl>(&ND)) {
     if (auto *Args = Cls->getTemplateArgsAsWritten())
       return Args->arguments();
-  } else if (auto *Var =
-                 llvm::dyn_cast<VarTemplatePartialSpecializationDecl>(&ND)) {
-    if (auto *Args = Var->getTemplateArgsAsWritten())
-      return Args->arguments();
   } else if (auto *Var = llvm::dyn_cast<VarTemplateSpecializationDecl>(&ND)) {
-    if (auto *Args = Var->getTemplateArgsInfo())
+    if (auto *Args = Var->getTemplateArgsAsWritten())
       return Args->arguments();
   }
   // We return std::nullopt for ClassTemplateSpecializationDecls because it does
@@ -270,22 +265,10 @@ std::string printTemplateSpecializationArgs(const NamedDecl &ND) {
           getTemplateSpecializationArgLocs(ND)) {
     printTemplateArgumentList(OS, *Args, Policy);
   } else if (auto *Cls = llvm::dyn_cast<ClassTemplateSpecializationDecl>(&ND)) {
-    if (const TypeSourceInfo *TSI = Cls->getTypeAsWritten()) {
-      // ClassTemplateSpecializationDecls do not contain
-      // TemplateArgumentTypeLocs, they only have TemplateArgumentTypes. So we
-      // create a new argument location list from TypeSourceInfo.
-      auto STL = TSI->getTypeLoc().getAs<TemplateSpecializationTypeLoc>();
-      llvm::SmallVector<TemplateArgumentLoc> ArgLocs;
-      ArgLocs.reserve(STL.getNumArgs());
-      for (unsigned I = 0; I < STL.getNumArgs(); ++I)
-        ArgLocs.push_back(STL.getArgLoc(I));
-      printTemplateArgumentList(OS, ArgLocs, Policy);
-    } else {
-      // FIXME: Fix cases when getTypeAsWritten returns null inside clang AST,
-      // e.g. friend decls. Currently we fallback to Template Arguments without
-      // location information.
-      printTemplateArgumentList(OS, Cls->getTemplateArgs().asArray(), Policy);
-    }
+    // FIXME: Fix cases when getTypeAsWritten returns null inside clang AST,
+    // e.g. friend decls. Currently we fallback to Template Arguments without
+    // location information.
+    printTemplateArgumentList(OS, Cls->getTemplateArgs().asArray(), Policy);
   }
   OS.flush();
   return TemplateArgs;
@@ -453,10 +436,12 @@ bool hasReservedScope(const DeclContext &DC) {
 }
 
 QualType declaredType(const TypeDecl *D) {
+  ASTContext &Context = D->getASTContext();
   if (const auto *CTSD = llvm::dyn_cast<ClassTemplateSpecializationDecl>(D))
-    if (const auto *TSI = CTSD->getTypeAsWritten())
-      return TSI->getType();
-  return D->getASTContext().getTypeDeclType(D);
+    if (const auto *Args = CTSD->getTemplateArgsAsWritten())
+      return Context.getTemplateSpecializationType(
+          TemplateName(CTSD->getSpecializedTemplate()), Args->arguments());
+  return Context.getTypeDeclType(D);
 }
 
 namespace {

diff --git a/clang-tools-extra/clangd/Preamble.cpp b/clang-tools-extra/clangd/Preamble.cpp
@@ -918,7 +918,9 @@ void PreamblePatch::apply(CompilerInvocation &CI) const {
   // no guarantees around using arbitrary options when reusing PCHs, and
   // different target opts can result in crashes, see
   // ParsedASTTest.PreambleWithDifferentTarget.
-  CI.TargetOpts = Baseline->TargetOpts;
+  // Make sure this is a deep copy, as the same Baseline might be used
+  // concurrently.
+  *CI.TargetOpts = *Baseline->TargetOpts;
 
   // No need to map an empty file.
   if (PatchContents.empty())

diff --git a/clang-tools-extra/clangd/SemanticHighlighting.cpp b/clang-tools-extra/clangd/SemanticHighlighting.cpp
@@ -693,17 +693,22 @@ class CollectExtraHighlightings
     return true;
   }
 
+  bool
+  VisitClassTemplateSpecializationDecl(ClassTemplateSpecializationDecl *D) {
+    if (auto *Args = D->getTemplateArgsAsWritten())
+      H.addAngleBracketTokens(Args->getLAngleLoc(), Args->getRAngleLoc());
+    return true;
+  }
+
   bool VisitClassTemplatePartialSpecializationDecl(
       ClassTemplatePartialSpecializationDecl *D) {
     if (auto *TPL = D->getTemplateParameters())
       H.addAngleBracketTokens(TPL->getLAngleLoc(), TPL->getRAngleLoc());
-    if (auto *Args = D->getTemplateArgsAsWritten())
-      H.addAngleBracketTokens(Args->getLAngleLoc(), Args->getRAngleLoc());
     return true;
   }
 
   bool VisitVarTemplateSpecializationDecl(VarTemplateSpecializationDecl *D) {
-    if (auto *Args = D->getTemplateArgsInfo())
+    if (auto *Args = D->getTemplateArgsAsWritten())
       H.addAngleBracketTokens(Args->getLAngleLoc(), Args->getRAngleLoc());
     return true;
   }
@@ -712,8 +717,6 @@ class CollectExtraHighlightings
       VarTemplatePartialSpecializationDecl *D) {
     if (auto *TPL = D->getTemplateParameters())
       H.addAngleBracketTokens(TPL->getLAngleLoc(), TPL->getRAngleLoc());
-    if (auto *Args = D->getTemplateArgsAsWritten())
-      H.addAngleBracketTokens(Args->getLAngleLoc(), Args->getRAngleLoc());
     return true;
   }
 

diff --git a/clang-tools-extra/clangd/refactor/Rename.cpp b/clang-tools-extra/clangd/refactor/Rename.cpp
@@ -1090,11 +1090,10 @@ llvm::Expected<RenameResult> rename(const RenameInputs &RInputs) {
     return MainFileRenameEdit.takeError();
 
   llvm::DenseSet<Range> RenamedRanges;
-  if (const auto *MD = dyn_cast<ObjCMethodDecl>(&RenameDecl)) {
+  if (!isa<ObjCMethodDecl>(RenameDecl)) {
     // TODO: Insert the ranges from the ObjCMethodDecl/ObjCMessageExpr selector
     // pieces which are being renamed. This will require us to make changes to
     // locateDeclAt to preserve this AST node.
-  } else {
     RenamedRanges.insert(CurrentIdentifier);
   }
 

diff --git a/clang-tools-extra/clangd/unittests/FindTargetTests.cpp b/clang-tools-extra/clangd/unittests/FindTargetTests.cpp
@@ -642,10 +642,7 @@ TEST_F(TargetDeclTest, RewrittenBinaryOperator) {
     bool x = (Foo(1) [[!=]] Foo(2));
   )cpp";
   EXPECT_DECLS("CXXRewrittenBinaryOperator",
-               {"std::strong_ordering operator<=>(const Foo &) const = default",
-                Rel::TemplatePattern},
-               {"bool operator==(const Foo &) const noexcept = default",
-                Rel::TemplateInstantiation});
+               {"bool operator==(const Foo &) const noexcept = default"});
 }
 
 TEST_F(TargetDeclTest, FunctionTemplate) {

diff --git a/clang-tools-extra/clangd/unittests/HoverTests.cpp b/clang-tools-extra/clangd/unittests/HoverTests.cpp
@@ -965,6 +965,19 @@ class Foo final {})cpp";
          // Bindings are in theory public members of an anonymous struct.
          HI.AccessSpecifier = "public";
        }},
+      {// Don't crash on invalid decl with invalid init expr.
+       R"cpp(
+          Unknown [[^abc]] = invalid;
+          // error-ok
+          )cpp",
+       [](HoverInfo &HI) {
+         HI.Name = "abc";
+         HI.Kind = index::SymbolKind::Variable;
+         HI.NamespaceScope = "";
+         HI.Definition = "int abc = <recovery - expr>()";
+         HI.Type = "int";
+         HI.AccessSpecifier = "public";
+       }},
       {// Extra info for function call.
        R"cpp(
           void fun(int arg_a, int &arg_b) {};
@@ -3078,7 +3091,7 @@ TEST(Hover, All) {
             HI.NamespaceScope = "";
             HI.Definition =
                 "bool operator==(const Foo &) const noexcept = default";
-            HI.Documentation = "Foo spaceship";
+            HI.Documentation = "";
           }},
   };
 
@@ -3881,7 +3894,7 @@ TEST(Hover, SpaceshipTemplateNoCrash) {
   TU.ExtraArgs.push_back("-std=c++20");
   auto AST = TU.build();
   auto HI = getHover(AST, T.point(), format::getLLVMStyle(), nullptr);
-  EXPECT_EQ(HI->Documentation, "Foo bar baz");
+  EXPECT_EQ(HI->Documentation, "");
 }
 
 TEST(Hover, ForwardStructNoCrash) {

diff --git a/clang-tools-extra/clangd/unittests/SelectionTests.cpp b/clang-tools-extra/clangd/unittests/SelectionTests.cpp
@@ -589,6 +589,12 @@ TEST(SelectionTest, CommonAncestor) {
         auto x = [[ns::^C<int>]];
       )cpp",
        "ConceptReference"},
+      {R"cpp(
+        template <typename T, typename K>
+        concept D = true;
+        template <typename T> void g(D<[[^T]]> auto abc) {}
+      )cpp",
+       "TemplateTypeParmTypeLoc"},
   };
 
   for (const Case &C : Cases) {

diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -90,7 +90,11 @@ Improvements to clang-doc
 Improvements to clang-query
 ---------------------------
 
-The improvements are...
+- Added the `file` command to dynamically load a list of commands and matchers
+  from an external file, allowing the cost of reading the compilation database
+  and building the AST to be imposed just once for faster prototyping.
+
+- Removed support for ``enable output srcloc``. Fixes #GH82591
 
 Improvements to clang-rename
 ----------------------------
@@ -113,6 +117,9 @@ Improvements to clang-tidy
 - Fixed `--verify-config` option not properly parsing checks when using the
   literal operator in the `.clang-tidy` config.
 
+- Added argument `--exclude-header-filter` and config option `ExcludeHeaderFilterRegex`
+  to exclude headers from analysis via a RegEx.
+
 New checks
 ^^^^^^^^^^
 
@@ -148,6 +155,15 @@ New checks
   Finds initializer lists for aggregate types that could be
   written as designated initializers instead.
 
+- New :doc:`modernize-use-std-format
+  <clang-tidy/checks/modernize/use-std-format>` check.
+
+  Converts calls to ``absl::StrFormat``, or other functions via
+  configuration options, to C++20's ``std::format``, or another function
+  via a configuration option, modifying the format string appropriately and
+  removing now-unnecessary calls to ``std::string::c_str()`` and
+  ``std::string::data()``.
+
 - New :doc:`readability-enum-initial-value
   <clang-tidy/checks/readability/enum-initial-value>` check.
 
@@ -202,6 +218,10 @@ Changes in existing checks
   eliminating false positives resulting from direct usage of bitwise operators
   within parentheses.
 
+- Improved :doc:`bugprone-optional-value-conversion
+  <clang-tidy/checks/bugprone/optional-value-conversion>` check by eliminating
+  false positives resulting from use of optionals in unevaluated context.
+
 - Improved :doc:`bugprone-suspicious-include
   <clang-tidy/checks/bugprone/suspicious-include>` check by replacing the local
   options `HeaderFileExtensions` and `ImplementationFileExtensions` by the
@@ -244,6 +264,12 @@ Changes in existing checks
   <clang-tidy/checks/cppcoreguidelines/use-default-member-init>`. Fixed
   incorrect hints when using list-initialization.
 
+- Improved :doc:`cppcoreguidelines-special-member-functions
+  <clang-tidy/checks/cppcoreguidelines/special-member-functions>` check with a
+  new option `AllowImplicitlyDeletedCopyOrMove`, which removes the requirement
+  for explicit copy or move special member functions when they are already
+  implicitly deleted.
+
 - Improved :doc:`google-build-namespaces
   <clang-tidy/checks/google/build-namespaces>` check by replacing the local
   option `HeaderFileExtensions` by the global option of the same name.
@@ -259,6 +285,10 @@ Changes in existing checks
 - Improved :doc:`google-runtime-int <clang-tidy/checks/google/runtime-int>`
   check performance through optimizations.
 
+- Improved :doc:`hicpp-signed-bitwise <clang-tidy/checks/hicpp/signed-bitwise>`
+  check by ignoring false positives involving positive integer literals behind
+  implicit casts when `IgnorePositiveIntegerLiterals` is enabled.
+
 - Improved :doc:`hicpp-ignored-remove-result <clang-tidy/checks/hicpp/ignored-remove-result>`
   check by ignoring other functions with same prefixes as the target specific
   functions.
@@ -300,6 +330,10 @@ Changes in existing checks
   don't remove parentheses used in ``sizeof`` calls when they have array index
   accesses as arguments.
 
+- Improved :doc:`modernize-use-constraints
+  <clang-tidy/checks/modernize/use-constraints>` check by fixing a crash that
+  occurred in some scenarios and excluding system headers from analysis.
+
 - Improved :doc:`modernize-use-nullptr
   <clang-tidy/checks/modernize/use-nullptr>` check to include support for C23,
   which also has introduced the ``nullptr`` keyword.
@@ -333,6 +367,10 @@ Changes in existing checks
   <clang-tidy/checks/readability/duplicate-include>` check by excluding include
   directives that form the filename using macro.
 
+- Improved :doc:`readability-else-after-return
+  <clang-tidy/checks/readability/else-after-return>` check to ignore
+  `if consteval` statements, for which the `else` branch must not be removed.
+
 - Improved :doc:`readability-identifier-naming
   <clang-tidy/checks/readability/identifier-naming>` check in `GetConfigPerFile`
   mode by resolving symbolic links to header files. Fixed handling of Hungarian
@@ -348,11 +386,25 @@ Changes in existing checks
   <clang-tidy/checks/readability/redundant-inline-specifier>` check to properly
   emit warnings for static data member with an in-class initializer.
 
+- Improved :doc:`readability-static-accessed-through-instance
+  <clang-tidy/checks/readability/static-accessed-through-instance>` check to
+  support calls to overloaded operators as base expression and provide fixes to
+  expressions with side-effects.
+
+- Improved :doc:`readability-simplify-boolean-expr
+  <clang-tidy/checks/readability/simplify-boolean-expr>` check to avoid to emit
+  warning for macro when IgnoreMacro option is enabled.
+
 - Improved :doc:`readability-static-definition-in-anonymous-namespace
   <clang-tidy/checks/readability/static-definition-in-anonymous-namespace>`
   check by resolving fix-it overlaps in template code by disregarding implicit
   instances.
 
+- Improved :doc:`readability-string-compare
+  <clang-tidy/checks/readability/string-compare>` check to also detect
+  usages of ``std::string_view::compare``. Added a `StringLikeClasses` option
+  to detect usages of ``compare`` method in custom string-like classes.
+
 Removed checks
 ^^^^^^^^^^^^^^
 

diff --git a/...ols-extra/docs/clang-tidy/checks/cppcoreguidelines/special-member-functions.rst b/...ols-extra/docs/clang-tidy/checks/cppcoreguidelines/special-member-functions.rst
@@ -45,9 +45,10 @@ Options
 
 .. option:: AllowMissingMoveFunctions
 
-   When set to `true` (default is `false`), this check doesn't flag classes which define no move
-   operations at all. It still flags classes which define only one of either
-   move constructor or move assignment operator. With this option enabled, the following class won't be flagged:
+   When set to `true` (default is `false`), this check doesn't flag classes
+   which define no move operations at all. It still flags classes which define
+   only one of either move constructor or move assignment operator. With this
+   option enabled, the following class won't be flagged:
 
    .. code-block:: c++
 
@@ -59,10 +60,11 @@ Options
 
 .. option:: AllowMissingMoveFunctionsWhenCopyIsDeleted
 
-   When set to `true` (default is `false`), this check doesn't flag classes which define deleted copy
-   operations but don't define move operations. This flag is related to Google C++ Style Guide
-   https://google.github.io/styleguide/cppguide.html#Copyable_Movable_Types. With this option enabled, the
-   following class won't be flagged:
+   When set to `true` (default is `false`), this check doesn't flag classes
+   which define deleted copy operations but don't define move operations. This
+   flag is related to Google C++ Style Guide `Copyable and Movable Types
+   <https://google.github.io/styleguide/cppguide.html#Copyable_Movable_Types>`_.
+   With this option enabled, the following class won't be flagged:
 
    .. code-block:: c++
 
@@ -71,3 +73,15 @@ Options
        A& operator=(const A&) = delete;
        ~A();
      };
+
+.. option:: AllowImplicitlyDeletedCopyOrMove
+
+   When set to `true` (default is `false`), this check doesn't flag classes
+   which implicitly delete copy or move operations.
+   With this option enabled, the following class won't be flagged:
+
+   .. code-block:: c++
+
+      struct A : boost::noncopyable {
+        ~A() { std::cout << "dtor\n"; }
+      };
diff --git a/clang-tools-extra/docs/clang-tidy/checks/list.rst b/clang-tools-extra/docs/clang-tidy/checks/list.rst
@@ -300,6 +300,7 @@ Clang-Tidy Checks
    :doc:`modernize-use-nullptr <modernize/use-nullptr>`, "Yes"
    :doc:`modernize-use-override <modernize/use-override>`, "Yes"
    :doc:`modernize-use-starts-ends-with <modernize/use-starts-ends-with>`, "Yes"
+   :doc:`modernize-use-std-format <modernize/use-std-format>`, "Yes"
    :doc:`modernize-use-std-numbers <modernize/use-std-numbers>`, "Yes"
    :doc:`modernize-use-std-print <modernize/use-std-print>`, "Yes"
    :doc:`modernize-use-trailing-return-type <modernize/use-trailing-return-type>`, "Yes"

diff --git a/clang-tools-extra/docs/clang-tidy/checks/modernize/use-constraints.rst b/clang-tools-extra/docs/clang-tidy/checks/modernize/use-constraints.rst
@@ -68,3 +68,7 @@ The tool will replace the above code with,
   // The tool will not emit a diagnostic or attempt to replace the code.
   template <typename T, std::enable_if_t<T::some_trait, int> = 0>
   struct my_class {};
+
+.. note::
+
+  System headers are not analyzed by this check.
diff --git a/clang-tools-extra/docs/clang-tidy/checks/modernize/use-std-format.rst b/clang-tools-extra/docs/clang-tidy/checks/modernize/use-std-format.rst
@@ -0,0 +1,84 @@
+.. title:: clang-tidy - modernize-use-std-format
+
+modernize-use-std-format
+========================
+
+Converts calls to ``absl::StrFormat``, or other functions via
+configuration options, to C++20's ``std::format``, or another function
+via a configuration option, modifying the format string appropriately and
+removing now-unnecessary calls to ``std::string::c_str()`` and
+``std::string::data()``.
+
+For example, it turns lines like
+
+.. code-block:: c++
+
+  return absl::StrFormat("The %s is %3d", description.c_str(), value);
+
+into:
+
+.. code-block:: c++
+
+  return std::format("The {} is {:3}", description, value);
+
+The check uses the same format-string-conversion algorithm as
+`modernize-use-std-print <../modernize/use-std-print.html>`_ and its
+shortcomings are described in the documentation for that check.
+
+Options
+-------
+
+.. option:: StrictMode
+
+   When `true`, the check will add casts when converting from variadic
+   functions and printing signed or unsigned integer types (including
+   fixed-width integer types from ``<cstdint>``, ``ptrdiff_t``, ``size_t``
+   and ``ssize_t``) as the opposite signedness to ensure that the output
+   would matches that of a simple wrapper for ``std::sprintf`` that
+   accepted a C-style variable argument list. For example, with
+   `StrictMode` enabled,
+
+  .. code-block:: c++
+
+    extern std::string strprintf(const char *format, ...);
+    int i = -42;
+    unsigned int u = 0xffffffff;
+    return strprintf("%d %u\n", i, u);
+
+  would be converted to
+
+  .. code-block:: c++
+
+    return std::format("{} {}\n", static_cast<unsigned int>(i), static_cast<int>(u));
+
+  to ensure that the output will continue to be the unsigned representation
+  of -42 and the signed representation of 0xffffffff (often 4294967254
+  and -1 respectively). When `false` (which is the default), these casts
+  will not be added which may cause a change in the output. Note that this
+  option makes no difference for the default value of
+  `StrFormatLikeFunctions` since ``absl::StrFormat`` takes a function
+  parameter pack and is not a variadic function.
+
+.. option:: StrFormatLikeFunctions
+
+   A semicolon-separated list of (fully qualified) function names to
+   replace, with the requirement that the first parameter contains the
+   printf-style format string and the arguments to be formatted follow
+   immediately afterwards. The default value for this option is
+   `absl::StrFormat`.
+
+.. option:: ReplacementFormatFunction
+
+   The function that will be used to replace the function set by the
+   `StrFormatLikeFunctions` option rather than the default
+   `std::format`. It is expected that the function provides an interface
+   that is compatible with ``std::format``. A suitable candidate would be
+   `fmt::format`.
+
+.. option:: FormatHeader
+
+   The header that must be included for the declaration of
+   `ReplacementFormatFunction` so that a ``#include`` directive can be added if
+   required. If `ReplacementFormatFunction` is `std::format` then this option will
+   default to ``<format>``, otherwise this option will default to nothing
+   and no ``#include`` directive will be added.
diff --git a/...s-extra/docs/clang-tidy/checks/readability/static-accessed-through-instance.rst b/...s-extra/docs/clang-tidy/checks/readability/static-accessed-through-instance.rst
@@ -35,3 +35,6 @@ is changed to:
   C::E1;
   C::E2;
 
+The `--fix` commandline option provides default support for safe fixes, whereas
+`--fix-notes` enables fixes that may replace expressions with side effects,
+potentially altering the program's behavior.
diff --git a/clang-tools-extra/docs/clang-tidy/checks/readability/string-compare.rst b/clang-tools-extra/docs/clang-tidy/checks/readability/string-compare.rst
@@ -14,10 +14,12 @@ recommended to avoid the risk of incorrect interpretation of the return value
 and to simplify the code. The string equality and inequality operators can
 also be faster than the ``compare`` method due to early termination.
 
-Examples:
+Example
+-------
 
 .. code-block:: c++
 
+  // The same rules apply to std::string_view.
   std::string str1{"a"};
   std::string str2{"b"};
 
@@ -50,5 +52,36 @@ Examples:
   }
 
 The above code examples show the list of if-statements that this check will
-give a warning for. All of them uses ``compare`` to check if equality or
+give a warning for. All of them use ``compare`` to check equality or
 inequality of two strings instead of using the correct operators.
+
+Options
+-------
+
+.. option:: StringLikeClasses
+
+   A string containing semicolon-separated names of string-like classes.
+   By default contains only ``::std::basic_string``
+   and ``::std::basic_string_view``. If a class from this list has
+   a ``compare`` method similar to that of ``std::string``, it will be checked
+   in the same way.
+
+Example
+^^^^^^^
+
+.. code-block:: c++
+
+  struct CustomString {
+  public:
+    int compare (const CustomString& other) const;
+  }
+
+  CustomString str1;
+  CustomString str2;
+
+  // use str1 != str2 instead.
+  if (str1.compare(str2)) {
+  }
+
+If `StringLikeClasses` contains ``CustomString``, the check will suggest
+replacing ``compare`` with equality operator.
diff --git a/clang-tools-extra/docs/clang-tidy/index.rst b/clang-tools-extra/docs/clang-tidy/index.rst
diff --git a/clang-tools-extra/include-cleaner/lib/WalkAST.cpp b/clang-tools-extra/include-cleaner/lib/WalkAST.cpp
@@ -267,18 +267,21 @@ class ASTWalker : public RecursiveASTVisitor<ASTWalker> {
     return true;
   }
 
-  // Report a reference from explicit specializations to the specialized
-  // template. Implicit ones are filtered out by RAV and explicit instantiations
-  // are already traversed through typelocs.
+  // Report a reference from explicit specializations/instantiations to the
+  // specialized template. Implicit ones are filtered out by RAV.
   bool
   VisitClassTemplateSpecializationDecl(ClassTemplateSpecializationDecl *CTSD) {
-    if (CTSD->isExplicitSpecialization())
+    // if (CTSD->isExplicitSpecialization())
+    if (clang::isTemplateExplicitInstantiationOrSpecialization(
+            CTSD->getTemplateSpecializationKind()))
       report(CTSD->getLocation(),
              CTSD->getSpecializedTemplate()->getTemplatedDecl());
     return true;
   }
   bool VisitVarTemplateSpecializationDecl(VarTemplateSpecializationDecl *VTSD) {
-    if (VTSD->isExplicitSpecialization())
+    // if (VTSD->isExplicitSpecialization())
+    if (clang::isTemplateExplicitInstantiationOrSpecialization(
+            VTSD->getTemplateSpecializationKind()))
       report(VTSD->getLocation(),
              VTSD->getSpecializedTemplate()->getTemplatedDecl());
     return true;

diff --git a/clang-tools-extra/test/clang-query/Inputs/empty.script b/clang-tools-extra/test/clang-query/Inputs/empty.script
@@ -0,0 +1 @@
+# This file intentionally has no queries
diff --git a/clang-tools-extra/test/clang-query/Inputs/file.script b/clang-tools-extra/test/clang-query/Inputs/file.script
@@ -0,0 +1 @@
+f DIRECTORY/runtime_file.script
diff --git a/clang-tools-extra/test/clang-query/Inputs/runtime_file.script b/clang-tools-extra/test/clang-query/Inputs/runtime_file.script
@@ -0,0 +1,5 @@
+set bind-root false
+
+l func functionDecl(hasName("bar"))
+m func.bind("f")
+m varDecl().bind("v")
diff --git a/clang-tools-extra/test/clang-query/errors.c b/clang-tools-extra/test/clang-query/errors.c
@@ -1,10 +1,12 @@
 // RUN: not clang-query -c foo -c bar %s -- | FileCheck %s
 // RUN: not clang-query -f %S/Inputs/foo.script %s -- | FileCheck %s
 // RUN: not clang-query -f %S/Inputs/nonexistent.script %s -- 2>&1 | FileCheck --check-prefix=CHECK-NONEXISTENT %s
+// RUN: not clang-query -c 'file %S/Inputs/nonexistent.script' %s -- 2>&1 | FileCheck --check-prefix=CHECK-NONEXISTENT-FILEQUERY %s
 // RUN: not clang-query -c foo -f foo %s -- 2>&1 | FileCheck --check-prefix=CHECK-BOTH %s
 
 // CHECK: unknown command: foo
 // CHECK-NOT: unknown command: bar
 
 // CHECK-NONEXISTENT: cannot open {{.*}}nonexistent.script
+// CHECK-NONEXISTENT-FILEQUERY: cannot open {{.*}}nonexistent.script
 // CHECK-BOTH: cannot specify both -c and -f
diff --git a/clang-tools-extra/test/clang-query/file-empty.c b/clang-tools-extra/test/clang-query/file-empty.c
@@ -0,0 +1,2 @@
+// RUN: clang-query -c 'file %S/Inputs/empty.script' %s --
+// COM: no output expected; nothing to CHECK
diff --git a/clang-tools-extra/test/clang-query/file-query.c b/clang-tools-extra/test/clang-query/file-query.c
@@ -0,0 +1,14 @@
+// RUN: rm -rf %/t
+// RUN: mkdir %/t
+// RUN: cp %/S/Inputs/file.script %/t/file.script
+// RUN: cp %/S/Inputs/runtime_file.script %/t/runtime_file.script
+// Need to embed the correct temp path in the actual JSON-RPC requests.
+// RUN: sed -e "s|DIRECTORY|%/t|" %/t/file.script > %/t/file.script.temp
+
+// RUN: clang-query -c 'file %/t/file.script.temp' %s -- | FileCheck %s
+
+// CHECK: file-query.c:11:1: note: "f" binds here
+void bar(void) {}
+
+// CHECK: file-query.c:14:1: note: "v" binds here
+int baz{1};
diff --git a/clang-tools-extra/test/clang-tidy/check_clang_tidy.py b/clang-tools-extra/test/clang-tidy/check_clang_tidy.py
@@ -99,6 +99,7 @@ def __init__(self, args, extra_args):
         self.has_check_fixes = False
         self.has_check_messages = False
         self.has_check_notes = False
+        self.expect_no_diagnosis = False
         self.export_fixes = args.export_fixes
         self.fixes = MessagePrefix("CHECK-FIXES")
         self.messages = MessagePrefix("CHECK-MESSAGES")
@@ -172,12 +173,21 @@ def get_prefixes(self):
                 )
 
             if not has_check_fix and not has_check_message and not has_check_note:
-                sys.exit(
-                    "%s, %s or %s not found in the input"
-                    % (self.fixes.prefix, self.messages.prefix, self.notes.prefix)
-                )
+                self.expect_no_diagnosis = True
 
-        assert self.has_check_fixes or self.has_check_messages or self.has_check_notes
+        expect_diagnosis = (
+            self.has_check_fixes or self.has_check_messages or self.has_check_notes
+        )
+        if self.expect_no_diagnosis and expect_diagnosis:
+            sys.exit(
+                "%s, %s or %s not found in the input"
+                % (
+                    self.fixes.prefix,
+                    self.messages.prefix,
+                    self.notes.prefix,
+                )
+            )
+        assert expect_diagnosis or self.expect_no_diagnosis
 
     def prepare_test_inputs(self):
         # Remove the contents of the CHECK lines to avoid CHECKs matching on
@@ -226,6 +236,10 @@ def run_clang_tidy(self):
         print("------------------------------------------------------------------")
         return clang_tidy_output
 
+    def check_no_diagnosis(self, clang_tidy_output):
+        if clang_tidy_output != "":
+            sys.exit("No diagnostics were expected, but found the ones above")
+
     def check_fixes(self):
         if self.has_check_fixes:
             try_run(
@@ -277,7 +291,9 @@ def run(self):
             self.get_prefixes()
         self.prepare_test_inputs()
         clang_tidy_output = self.run_clang_tidy()
-        if self.export_fixes is None:
+        if self.expect_no_diagnosis:
+            self.check_no_diagnosis(clang_tidy_output)
+        elif self.export_fixes is None:
             self.check_fixes()
             self.check_messages(clang_tidy_output)
             self.check_notes(clang_tidy_output)

diff --git a/clang-tools-extra/test/clang-tidy/checkers/Inputs/Headers/string b/clang-tools-extra/test/clang-tidy/checkers/Inputs/Headers/string
@@ -108,6 +108,8 @@ struct basic_string_view {
   constexpr bool starts_with(C ch) const noexcept;
   constexpr bool starts_with(const C* s) const;
 
+  constexpr int compare(basic_string_view sv) const noexcept;
+
   static constexpr size_t npos = -1;
 };
 
@@ -132,6 +134,14 @@ bool operator==(const std::wstring&, const std::wstring&);
 bool operator==(const std::wstring&, const wchar_t*);
 bool operator==(const wchar_t*, const std::wstring&);
 
+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&);
+
+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&);
+
 size_t strlen(const char* str);
 }
 

diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/optional-value-conversion.cpp b/clang-tools-extra/test/clang-tidy/checkers/bugprone/optional-value-conversion.cpp
@@ -210,4 +210,6 @@ void correct(std::optional<int> param)
   std::optional<long>* p2 = &p;
   takeOptionalValue(p2->value_or(5U));
   takeOptionalRef(p2->value_or(5U));
+
+  using Type = decltype(takeOptionalValue(*param));
 }
diff --git a/...ols-extra/test/clang-tidy/checkers/cppcoreguidelines/special-member-functions-relaxed.cpp b/...ols-extra/test/clang-tidy/checkers/cppcoreguidelines/special-member-functions-relaxed.cpp
@@ -1,4 +1,4 @@
-// RUN: %check_clang_tidy %s cppcoreguidelines-special-member-functions %t -- -config="{CheckOptions: {cppcoreguidelines-special-member-functions.AllowMissingMoveFunctions: true, cppcoreguidelines-special-member-functions.AllowSoleDefaultDtor: true}}" --
+// RUN: %check_clang_tidy %s cppcoreguidelines-special-member-functions %t -- -config="{CheckOptions: {cppcoreguidelines-special-member-functions.AllowMissingMoveFunctions: true, cppcoreguidelines-special-member-functions.AllowSoleDefaultDtor: true, cppcoreguidelines-special-member-functions.AllowImplicitlyDeletedCopyOrMove: true}}" --
 
 // Don't warn on destructors without definitions, they might be defaulted in another TU.
 class DeclaresDestructor {
@@ -34,12 +34,13 @@ class DefinesCopyAssignment {
 class DefinesMoveConstructor {
   DefinesMoveConstructor(DefinesMoveConstructor &&);
 };
-// CHECK-MESSAGES: [[@LINE-3]]:7: warning: class 'DefinesMoveConstructor' defines a move constructor but does not define a destructor, a copy constructor, a copy assignment operator or a move assignment operator [cppcoreguidelines-special-member-functions]
+// CHECK-MESSAGES: [[@LINE-3]]:7: warning: class 'DefinesMoveConstructor' defines a move constructor but does not define a destructor or a move assignment operator [cppcoreguidelines-special-member-functions]
 
 class DefinesMoveAssignment {
   DefinesMoveAssignment &operator=(DefinesMoveAssignment &&);
 };
-// CHECK-MESSAGES: [[@LINE-3]]:7: warning: class 'DefinesMoveAssignment' defines a move assignment operator but does not define a destructor, a copy constructor, a copy assignment operator or a move constructor [cppcoreguidelines-special-member-functions]
+// CHECK-MESSAGES: [[@LINE-3]]:7: warning: class 'DefinesMoveAssignment' defines a move assignment operator but does not define a destructor or a move constructor [cppcoreguidelines-special-member-functions]
+
 class DefinesNothing {
 };
 
@@ -81,3 +82,22 @@ struct TemplateClass {
 // This should not cause problems.
 TemplateClass<int> InstantiationWithInt;
 TemplateClass<double> InstantiationWithDouble;
+
+struct NoCopy
+{
+  NoCopy() = default;
+  ~NoCopy() = default;
+
+  NoCopy(const NoCopy&) = delete;
+  NoCopy(NoCopy&&) = delete;
+
+  NoCopy& operator=(const NoCopy&) = delete;
+  NoCopy& operator=(NoCopy&&) = delete;
+};
+
+// CHECK-MESSAGES: [[@LINE+1]]:8: warning: class 'NonCopyable' defines a copy constructor but does not define a destructor or a copy assignment operator [cppcoreguidelines-special-member-functions]
+struct NonCopyable : NoCopy
+{
+  NonCopyable() = default;
+  NonCopyable(const NonCopyable&) = delete;
+};
diff --git a/clang-tools-extra/test/clang-tidy/checkers/hicpp/signed-bitwise-integer-literals.cpp b/clang-tools-extra/test/clang-tidy/checkers/hicpp/signed-bitwise-integer-literals.cpp
@@ -11,6 +11,7 @@ void examples() {
   // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use of a signed integer operand with a binary bitwise operator
 
   unsigned URes2 = URes << 1; //Ok
+  unsigned URes3 = URes & 1; //Ok
 
   int IResult;
   IResult = 10 & 2; //Ok
@@ -21,6 +22,8 @@ void examples() {
   IResult = Int << 1;
   // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: use of a signed integer operand with a binary bitwise operator
   IResult = ~0; //Ok
+  IResult = -1 & 1;
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: use of a signed integer operand with a binary bitwise operator [hicpp-signed-bitwise]
 }
 
 enum EnumConstruction {

diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/unused-using-decls.hpp b/clang-tools-extra/test/clang-tidy/checkers/misc/unused-using-decls.hpp
@@ -0,0 +1,6 @@
+// RUN: %check_clang_tidy %s misc-unused-using-decls %t
+
+// Verify that we don't generate the warnings on header files.
+namespace foo { class Foo {}; }
+
+using foo::Foo;
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/unused-using-decls.hxx b/clang-tools-extra/test/clang-tidy/checkers/misc/unused-using-decls.hxx
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/make-unique.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/make-unique.cpp
@@ -606,11 +606,8 @@ void invoke_template() {
   template_fun(foo);
 }
 
-void no_fix_for_invalid_new_loc() {
-  // FIXME: Although the code is valid, the end location of `new struct Base` is
-  // invalid. Correct it once https://bugs.llvm.org/show_bug.cgi?id=35952 is
-  // fixed.
+void fix_for_c_style_struct() {
   auto T = std::unique_ptr<Base>(new struct Base);
   // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: use std::make_unique instead
-  // CHECK-FIXES: auto T = std::unique_ptr<Base>(new struct Base);
+  // CHECK-FIXES: auto T = std::make_unique<Base>();
 }
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/min-max-use-initializer-list.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/min-max-use-initializer-list.cpp
@@ -300,6 +300,27 @@ B maxTT2 = std::max(B(), std::max(B(), B()));
 B maxTT3 = std::max(B(), std::max(B(), B()), [](const B &lhs, const B &rhs) { return lhs.a[0] < rhs.a[0]; });
 // CHECK-FIXES: B maxTT3 = std::max(B(), std::max(B(), B()), [](const B &lhs, const B &rhs) { return lhs.a[0] < rhs.a[0]; });
 
+struct GH91982 {
+  int fun0Args();
+  int fun1Arg(int a);
+  int fun2Args(int a, int b);
+  int fun3Args(int a, int b, int c);
+  int fun4Args(int a, int b, int c, int d);
+
+  int foo() {
+    return std::max(
+        fun0Args(),
+        std::max(fun1Arg(0),
+                 std::max(fun2Args(0, 1),
+                          std::max(fun3Args(0, 1, 2), fun4Args(0, 1, 2, 3)))));
+// CHECK-MESSAGES: :[[@LINE-5]]:12: warning: do not use nested 'std::max' calls, use an initializer list instead [modernize-min-max-use-initializer-list]
+// CHECK-FIXES: return std::max(
+// CHECK-FIXES-NEXT: {fun0Args(),
+// CHECK-FIXES-NEXT: fun1Arg(0),
+// CHECK-FIXES-NEXT: fun2Args(0, 1),
+// CHECK-FIXES-NEXT: fun3Args(0, 1, 2), fun4Args(0, 1, 2, 3)});
+  }
+};
 
 } // namespace
 
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-constraints.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-constraints.cpp
@@ -724,3 +724,35 @@ void not_last_param() {
 }
 
 } // namespace enable_if_trailing_type_parameter
+
+
+// Issue fixes:
+
+namespace PR91872 {
+
+enum expression_template_option { value1, value2 };
+
+template <typename T> struct number_category {
+  static const int value = 0;
+};
+
+constexpr int number_kind_complex = 1;
+
+template <typename T, expression_template_option ExpressionTemplates>
+struct number {
+  using type = T;
+};
+
+template <typename T> struct component_type {
+  using type = T;
+};
+
+template <class T, expression_template_option ExpressionTemplates>
+inline typename std::enable_if<
+    number_category<T>::value == number_kind_complex,
+    component_type<number<T, ExpressionTemplates>>>::type::type
+abs(const number<T, ExpressionTemplates> &v) {
+  return {};
+}
+
+}
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-std-format-custom.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-std-format-custom.cpp
@@ -0,0 +1,52 @@
+// RUN: %check_clang_tidy -check-suffixes=,STRICT                       \
+// RUN:   -std=c++20 %s modernize-use-std-format %t --                  \
+// RUN:   -config="{CheckOptions: {                                     \
+// RUN:              modernize-use-std-format.StrictMode: true,         \
+// RUN:              modernize-use-std-format.StrFormatLikeFunctions: '::strprintf; mynamespace::strprintf2', \
+// RUN:              modernize-use-std-format.ReplacementFormatFunction: 'fmt::format', \
+// RUN:              modernize-use-std-format.FormatHeader: '<fmt/core.h>' \
+// RUN:            }}"                                                  \
+// RUN:   -- -isystem %clang_tidy_headers
+// RUN: %check_clang_tidy -check-suffixes=,NOTSTRICT                    \
+// RUN:   -std=c++20 %s modernize-use-std-format %t --                  \
+// RUN:   -config="{CheckOptions: {                                     \
+// RUN:              modernize-use-std-format.StrFormatLikeFunctions: '::strprintf; mynamespace::strprintf2', \
+// RUN:              modernize-use-std-format.ReplacementFormatFunction: 'fmt::format', \
+// RUN:              modernize-use-std-format.FormatHeader: '<fmt/core.h>' \
+// RUN:            }}"                                                  \
+// RUN:   -- -isystem %clang_tidy_headers
+
+#include <cstdio>
+#include <string>
+// CHECK-FIXES: #include <fmt/core.h>
+
+std::string strprintf(const char *, ...);
+
+namespace mynamespace {
+  std::string strprintf2(const char *, ...);
+}
+
+std::string strprintf_test(const std::string &name, double value) {
+  return strprintf("'%s'='%f'\n", name.c_str(), value);
+  // CHECK-MESSAGES: [[@LINE-1]]:10: warning: use 'fmt::format' instead of 'strprintf' [modernize-use-std-format]
+  // CHECK-FIXES: return fmt::format("'{}'='{:f}'\n", name, value);
+
+  return mynamespace::strprintf2("'%s'='%f'\n", name.c_str(), value);
+  // CHECK-MESSAGES: [[@LINE-1]]:10: warning: use 'fmt::format' instead of 'strprintf2' [modernize-use-std-format]
+  // CHECK-FIXES: return fmt::format("'{}'='{:f}'\n", name, value);
+}
+
+std::string StrFormat_strict_conversion() {
+  const unsigned char uc = 'A';
+  return strprintf("Integer %hhd from unsigned char\n", uc);
+  // CHECK-MESSAGES: [[@LINE-1]]:10: warning: use 'fmt::format' instead of 'strprintf' [modernize-use-std-format]
+  // CHECK-FIXES-NOTSTRICT: return fmt::format("Integer {} from unsigned char\n", uc);
+  // CHECK-FIXES-STRICT: return fmt::format("Integer {} from unsigned char\n", static_cast<signed char>(uc));
+}
+
+// Ensure that MatchesAnyListedNameMatcher::NameMatcher::match() can cope with a
+// NamedDecl that has no name when we're trying to match unqualified_strprintf.
+std::string A(const std::string &in)
+{
+    return "_" + in;
+}
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-std-format-fmt.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-std-format-fmt.cpp
@@ -0,0 +1,24 @@
+// RUN: %check_clang_tidy %s modernize-use-std-format %t -- \
+// RUN:   -config="{CheckOptions: { \
+// RUN:              StrictMode: true, \
+// RUN:              modernize-use-std-format.StrFormatLikeFunctions: 'fmt::sprintf', \
+// RUN:              modernize-use-std-format.ReplacementFormatFunction: 'fmt::format', \
+// RUN:              modernize-use-std-format.FormatHeader: '<fmt/core.h>' \
+// RUN:            }}" \
+// RUN:   -- -isystem %clang_tidy_headers
+
+// CHECK-FIXES: #include <fmt/core.h>
+#include <string>
+
+namespace fmt
+{
+// Use const char * for the format since the real type is hard to mock up.
+template <typename... Args>
+std::string sprintf(const char *format, const Args&... args);
+} // namespace fmt
+
+std::string fmt_sprintf_simple() {
+  return fmt::sprintf("Hello %s %d", "world", 42);
+  // CHECK-MESSAGES: [[@LINE-1]]:10: warning: use 'fmt::format' instead of 'sprintf' [modernize-use-std-format]
+  // CHECK-FIXES: fmt::format("Hello {} {}", "world", 42);
+}
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-std-format.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-std-format.cpp
@@ -0,0 +1,120 @@
+// RUN: %check_clang_tidy \
+// RUN:   -std=c++20 %s modernize-use-std-format %t -- \
+// RUN:   -config="{CheckOptions: {StrictMode: true}}" \
+// RUN:   -- -isystem %clang_tidy_headers
+// RUN: %check_clang_tidy \
+// RUN:   -std=c++20 %s modernize-use-std-format %t -- \
+// RUN:   -config="{CheckOptions: {StrictMode: false}}" \
+// RUN:   -- -isystem %clang_tidy_headers
+#include <string>
+// CHECK-FIXES: #include <format>
+
+namespace absl
+{
+// Use const char * for the format since the real type is hard to mock up.
+template <typename... Args>
+std::string StrFormat(const char *format, const Args&... args);
+} // namespace absl
+
+template <typename T>
+struct iterator {
+  T *operator->();
+  T &operator*();
+};
+
+std::string StrFormat_simple() {
+  return absl::StrFormat("Hello");
+  // CHECK-MESSAGES: [[@LINE-1]]:10: warning: use 'std::format' instead of 'StrFormat' [modernize-use-std-format]
+  // CHECK-FIXES: return std::format("Hello");
+}
+
+std::string StrFormat_complex(const char *name, double value) {
+  return absl::StrFormat("'%s'='%f'", name, value);
+  // CHECK-MESSAGES: [[@LINE-1]]:10: warning: use 'std::format' instead of 'StrFormat' [modernize-use-std-format]
+  // CHECK-FIXES: return std::format("'{}'='{:f}'", name, value);
+}
+
+std::string StrFormat_integer_conversions() {
+  return absl::StrFormat("int:%d int:%d char:%c char:%c", 65, 'A', 66, 'B');
+  // CHECK-MESSAGES: [[@LINE-1]]:10: warning: use 'std::format' instead of 'StrFormat' [modernize-use-std-format]
+  // CHECK-FIXES: return std::format("int:{} int:{:d} char:{:c} char:{}", 65, 'A', 66, 'B');
+}
+
+// FormatConverter is capable of removing newlines from the end of the format
+// string. Ensure that isn't incorrectly happening for std::format.
+std::string StrFormat_no_newline_removal() {
+  return absl::StrFormat("a line\n");
+  // CHECK-MESSAGES: [[@LINE-1]]:10: warning: use 'std::format' instead of 'StrFormat' [modernize-use-std-format]
+  // CHECK-FIXES: return std::format("a line\n");
+}
+
+// FormatConverter is capable of removing newlines from the end of the format
+// string. Ensure that isn't incorrectly happening for std::format.
+std::string StrFormat_cstr_removal(const std::string &s1, const std::string *s2) {
+  return absl::StrFormat("%s %s %s %s", s1.c_str(), s1.data(), s2->c_str(), s2->data());
+  // CHECK-MESSAGES: [[@LINE-1]]:10: warning: use 'std::format' instead of 'StrFormat' [modernize-use-std-format]
+  // CHECK-FIXES: return std::format("{} {} {} {}", s1, s1, *s2, *s2);
+}
+
+std::string StrFormat_strict_conversion() {
+  const unsigned char uc = 'A';
+  return absl::StrFormat("Integer %hhd from unsigned char\n", uc);
+  // CHECK-MESSAGES: [[@LINE-1]]:10: warning: use 'std::format' instead of 'StrFormat' [modernize-use-std-format]
+  // CHECK-FIXES: return std::format("Integer {} from unsigned char\n", uc);
+}
+
+std::string StrFormat_field_width_and_precision() {
+  auto s1 = absl::StrFormat("width only:%*d width and precision:%*.*f precision only:%.*f", 3, 42, 4, 2, 3.14159265358979323846, 5, 2.718);
+  // CHECK-MESSAGES: [[@LINE-1]]:13: warning: use 'std::format' instead of 'StrFormat' [modernize-use-std-format]
+  // CHECK-FIXES: std::format("width only:{:{}} width and precision:{:{}.{}f} precision only:{:.{}f}", 42, 3, 3.14159265358979323846, 4, 2, 2.718, 5);
+
+  auto s2 = absl::StrFormat("width and precision positional:%1$*2$.*3$f after", 3.14159265358979323846, 4, 2);
+  // CHECK-MESSAGES: [[@LINE-1]]:13: warning: use 'std::format' instead of 'StrFormat' [modernize-use-std-format]
+  // CHECK-FIXES: std::format("width and precision positional:{0:{1}.{2}f} after", 3.14159265358979323846, 4, 2);
+
+  const int width = 10, precision = 3;
+  const unsigned int ui1 = 42, ui2 = 43, ui3 = 44;
+  auto s3 = absl::StrFormat("casts width only:%*d width and precision:%*.*d precision only:%.*d\n", 3, ui1, 4, 2, ui2, 5, ui3);
+  // CHECK-MESSAGES: [[@LINE-1]]:13: warning: use 'std::format' instead of 'StrFormat' [modernize-use-std-format]
+  // CHECK-FIXES-NOTSTRICT: std::format("casts width only:{:{}} width and precision:{:{}.{}} precision only:{:.{}}", ui1, 3, ui2, 4, 2, ui3, 5);
+  // CHECK-FIXES-STRICT: std::format("casts width only:{:{}} width and precision:{:{}.{}} precision only:{:.{}}", static_cast<int>(ui1), 3, static_cast<int>(ui2), 4, 2, static_cast<int>(ui3), 5);
+
+  auto s4 = absl::StrFormat("c_str removal width only:%*s width and precision:%*.*s precision only:%.*s", 3, s1.c_str(), 4, 2, s2.c_str(), 5, s3.c_str());
+  // CHECK-MESSAGES: [[@LINE-1]]:13: warning: use 'std::format' instead of 'StrFormat' [modernize-use-std-format]
+  // CHECK-FIXES: std::format("c_str removal width only:{:>{}} width and precision:{:>{}.{}} precision only:{:.{}}", s1, 3, s2, 4, 2, s3, 5);
+
+  const std::string *ps1 = &s1, *ps2 = &s2, *ps3 = &s3;
+  auto s5 = absl::StrFormat("c_str() removal pointer width only:%-*s width and precision:%-*.*s precision only:%-.*s", 3, ps1->c_str(), 4, 2, ps2->c_str(), 5, ps3->c_str());
+  // CHECK-MESSAGES: [[@LINE-1]]:13: warning: use 'std::format' instead of 'StrFormat' [modernize-use-std-format]
+  // CHECK-FIXES: std::format("c_str() removal pointer width only:{:{}} width and precision:{:{}.{}} precision only:{:.{}}", *ps1, 3, *ps2, 4, 2, *ps3, 5);
+
+  iterator<std::string> is1, is2, is3;
+  auto s6 = absl::StrFormat("c_str() removal iterator width only:%-*s width and precision:%-*.*s precision only:%-.*s", 3, is1->c_str(), 4, 2, is2->c_str(), 5, is3->c_str());
+  // CHECK-MESSAGES: [[@LINE-1]]:13: warning: use 'std::format' instead of 'StrFormat' [modernize-use-std-format]
+  // CHECK-FIXES: std::format("c_str() removal iterator width only:{:{}} width and precision:{:{}.{}} precision only:{:.{}}", *is1, 3, *is2, 4, 2, *is3, 5);
+
+  return s1 + s2 + s3 + s4 + s5 + s6;
+}
+
+std::string StrFormat_macros() {
+  // The function call is replaced even though it comes from a macro.
+#define FORMAT absl::StrFormat
+  auto s1 = FORMAT("Hello %d", 42);
+  // CHECK-MESSAGES: [[@LINE-1]]:13: warning: use 'std::format' instead of 'StrFormat' [modernize-use-std-format]
+  // CHECK-FIXES: std::format("Hello {}", 42);
+
+  // The format string is replaced even though it comes from a macro, this
+  // behaviour is required so that that <inttypes.h> macros are replaced.
+#define FORMAT_STRING "Hello %s"
+  auto s2 = absl::StrFormat(FORMAT_STRING, 42);
+  // CHECK-MESSAGES: [[@LINE-1]]:13: warning: use 'std::format' instead of 'StrFormat' [modernize-use-std-format]
+  // CHECK-FIXES: std::format("Hello {}", 42);
+
+  // Arguments that are macros aren't replaced with their value, even if they are rearranged.
+#define VALUE 3.14159265358979323846
+#define WIDTH 10
+#define PRECISION 4
+  auto s3 = absl::StrFormat("Hello %*.*f", WIDTH, PRECISION, VALUE);
+  // CHECK-MESSAGES: [[@LINE-1]]:13: warning: use 'std::format' instead of 'StrFormat' [modernize-use-std-format]
+  // CHECK-FIXES: std::format("Hello {:{}.{}f}", VALUE, WIDTH, PRECISION);
+}
diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/else-after-return-if-consteval.cpp b/clang-tools-extra/test/clang-tidy/checkers/readability/else-after-return-if-consteval.cpp
@@ -0,0 +1,17 @@
+// RUN: %check_clang_tidy -std=c++23 %s readability-else-after-return %t 
+
+// Consteval if is an exception to the rule, we cannot remove the else.
+void f() {
+  if (sizeof(int) > 4) {
+    return;
+  } else {
+    return;
+  }
+  // CHECK-MESSAGES: [[@LINE-3]]:5: warning: do not use 'else' after 'return'
+
+  if consteval {
+    return;
+  } else {
+    return;
+  }
+}
diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/magic-numbers-todo.cpp b/clang-tools-extra/test/clang-tidy/checkers/readability/magic-numbers-todo.cpp
diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/simplify-boolean-expr-macros.cpp b/clang-tools-extra/test/clang-tidy/checkers/readability/simplify-boolean-expr-macros.cpp
@@ -6,15 +6,25 @@
 // RUN:     --
 
 #define NEGATE(expr) !(expr)
+#define NOT_AND_NOT(a, b) (!a && !b)
 
 bool without_macro(bool a, bool b) {
     return !(!a && b);
     // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: boolean expression can be simplified by DeMorgan's theorem
     // CHECK-FIXES: return a || !b;
 }
 
-bool macro(bool a, bool b) {
-    return NEGATE(!a && b);
-    // CHECK-MESSAGES-MACROS: :[[@LINE-1]]:12: warning: boolean expression can be simplified by DeMorgan's theorem
-    // CHECK-FIXES: return NEGATE(!a && b);
+void macro(bool a, bool b) {
+    NEGATE(!a && b);
+    // CHECK-MESSAGES-MACROS: :[[@LINE-1]]:5: warning: boolean expression can be simplified by DeMorgan's theorem
+    // CHECK-FIXES: NEGATE(!a && b);
+    !NOT_AND_NOT(a, b);
+    // CHECK-MESSAGES-MACROS: :[[@LINE-1]]:5: warning: boolean expression can be simplified by DeMorgan's theorem
+    // CHECK-FIXES: !NOT_AND_NOT(a, b);
+    !(NEGATE(a) && b);
+    // CHECK-MESSAGES-MACROS: :[[@LINE-1]]:5: warning: boolean expression can be simplified by DeMorgan's theorem
+    // CHECK-FIXES: !(NEGATE(a) && b);
+    !(a && NEGATE(b));
+    // CHECK-MESSAGES-MACROS: :[[@LINE-1]]:5: warning: boolean expression can be simplified by DeMorgan's theorem
+    // CHECK-FIXES: !(a && NEGATE(b));
 }
diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/static-accessed-through-instance.cpp b/clang-tools-extra/test/clang-tidy/checkers/readability/static-accessed-through-instance.cpp
@@ -1,4 +1,4 @@
-// RUN: %check_clang_tidy %s readability-static-accessed-through-instance %t -- -- -isystem %S/Inputs/static-accessed-through-instance
+// RUN: %check_clang_tidy %s readability-static-accessed-through-instance %t -- --fix-notes -- -isystem %S/Inputs/static-accessed-through-instance
 #include <__clang_cuda_builtin_vars.h>
 
 enum OutEnum {
@@ -47,7 +47,8 @@ C &f(int, int, int, int);
 void g() {
   f(1, 2, 3, 4).x;
   // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: static member accessed through instance  [readability-static-accessed-through-instance]
-  // CHECK-FIXES: {{^}}  f(1, 2, 3, 4).x;{{$}}
+  // CHECK-MESSAGES: :[[@LINE-2]]:3: note: member base expression may carry some side effects
+  // CHECK-FIXES: {{^}}  C::x;{{$}}
 }
 
 int i(int &);
@@ -59,20 +60,23 @@ int k(bool);
 void f(C c) {
   j(i(h().x));
   // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: static member
-  // CHECK-FIXES: {{^}}  j(i(h().x));{{$}}
+  // CHECK-MESSAGES: :[[@LINE-2]]:7: note: member base expression may carry some side effects
+  // CHECK-FIXES: {{^}}  j(i(C::x));{{$}}
 
   // The execution of h() depends on the return value of a().
   j(k(a() && h().x));
   // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: static member
-  // CHECK-FIXES: {{^}}  j(k(a() && h().x));{{$}}
+  // CHECK-MESSAGES: :[[@LINE-2]]:14: note: member base expression may carry some side effects
+  // CHECK-FIXES: {{^}}  j(k(a() && C::x));{{$}}
 
   if ([c]() {
         c.ns();
         return c;
       }().x == 15)
     ;
   // CHECK-MESSAGES: :[[@LINE-5]]:7: warning: static member
-  // CHECK-FIXES: {{^}}  if ([c]() {{{$}}
+  // CHECK-MESSAGES: :[[@LINE-6]]:7: note: member base expression may carry some side effects
+  // CHECK-FIXES: {{^}}  if (C::x == 15){{$}}
 }
 
 // Nested specifiers
@@ -261,8 +265,11 @@ struct Qptr {
 };
 
 int func(Qptr qp) {
-  qp->y = 10; // OK, the overloaded operator might have side-effects.
-  qp->K = 10; //
+  qp->y = 10;
+  qp->K = 10;
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: static member accessed through instance [readability-static-accessed-through-instance]
+  // CHECK-MESSAGES: :[[@LINE-2]]:3: note: member base expression may carry some side effects
+  // CHECK-FIXES: {{^}}  Q::K = 10;
 }
 
 namespace {
@@ -380,3 +387,20 @@ namespace PR51861 {
     // CHECK-FIXES: {{^}}    PR51861::Foo::getBar();{{$}}
   }
 }
+
+namespace PR75163 {
+  struct Static {
+    static void call();
+  };
+
+  struct Ptr {
+    Static* operator->();
+  };
+
+  void test(Ptr& ptr) {
+    ptr->call();
+    // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: static member accessed through instance [readability-static-accessed-through-instance]
+    // CHECK-MESSAGES: :[[@LINE-2]]:5: note: member base expression may carry some side effects
+    // CHECK-FIXES: {{^}}    PR75163::Static::call();{{$}}
+  }
+}
diff --git a/...tools-extra/test/clang-tidy/checkers/readability/string-compare-custom-string-classes.cpp b/...tools-extra/test/clang-tidy/checkers/readability/string-compare-custom-string-classes.cpp
@@ -0,0 +1,35 @@
+// RUN: %check_clang_tidy %s readability-string-compare %t -- -config='{CheckOptions: {readability-string-compare.StringLikeClasses: "CustomStringTemplateBase;CustomStringNonTemplateBase"}}' -- -isystem %clang_tidy_headers
+#include <string>
+
+struct CustomStringNonTemplateBase {
+  int compare(const CustomStringNonTemplateBase& Other) const {
+    return 123;  // value is not important for check
+  }
+};
+
+template <typename T>
+struct CustomStringTemplateBase {
+  int compare(const CustomStringTemplateBase& Other) const {
+    return 123;
+  }
+};
+
+struct CustomString1 : CustomStringNonTemplateBase {};
+struct CustomString2 : CustomStringTemplateBase<char> {};
+
+void CustomStringClasses() {
+  std::string_view sv1("a");
+  std::string_view sv2("b");
+  if (sv1.compare(sv2)) {  // No warning - if a std class is not listed in StringLikeClasses, it won't be checked.
+  }
+
+  CustomString1 custom1;
+  if (custom1.compare(custom1)) {
+  }
+  // CHECK-MESSAGES: [[@LINE-2]]:7: warning: do not use 'compare' to test equality of strings; use the string equality operator instead [readability-string-compare]
+
+  CustomString2 custom2;
+  if (custom2.compare(custom2)) {
+  }
+  // CHECK-MESSAGES: [[@LINE-2]]:7: warning: do not use 'compare' to test equality of strings; use the string equality operator instead [readability-string-compare]
+}
diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/string-compare.cpp b/clang-tools-extra/test/clang-tidy/checkers/readability/string-compare.cpp
@@ -67,11 +67,27 @@ void Test() {
   if (str1.compare(comp())) {
   }
   // CHECK-MESSAGES: [[@LINE-2]]:7: warning: do not use 'compare' to test equality of strings;
+
+  std::string_view sv1("a");
+  std::string_view sv2("b");
+  if (sv1.compare(sv2)) {
+  }
+  // CHECK-MESSAGES: [[@LINE-2]]:7: warning: do not use 'compare' to test equality of strings; use the string equality operator instead [readability-string-compare]
+}
+
+struct DerivedFromStdString : std::string {};
+
+void TestDerivedClass() {
+  DerivedFromStdString derived;
+  if (derived.compare(derived)) {
+  }
+  // CHECK-MESSAGES: [[@LINE-2]]:7: warning: do not use 'compare' to test equality of strings; use the string equality operator instead [readability-string-compare]
 }
 
 void Valid() {
   std::string str1("a", 1);
   std::string str2("b", 1);
+
   if (str1 == str2) {
   }
   if (str1 != str2) {
@@ -96,4 +112,11 @@ void Valid() {
   }
   if (str1.compare(str2) == -1) {
   }
+
+  std::string_view sv1("a");
+  std::string_view sv2("b");
+  if (sv1 == sv2) {
+  }
+  if (sv1.compare(sv2) > 0) {
+  }
 }
diff --git a/clang-tools-extra/test/clang-tidy/infrastructure/Inputs/config-files/.clang-tidy b/clang-tools-extra/test/clang-tidy/infrastructure/Inputs/config-files/.clang-tidy
@@ -1,2 +1,3 @@
 Checks: 'from-parent'
 HeaderFilterRegex: 'parent'
+ExcludeHeaderFilterRegex: 'exc-parent'
diff --git a/clang-tools-extra/test/clang-tidy/infrastructure/Inputs/config-files/1/.clang-tidy b/clang-tools-extra/test/clang-tidy/infrastructure/Inputs/config-files/1/.clang-tidy
@@ -1,2 +1,3 @@
 Checks: 'from-child1'
 HeaderFilterRegex: 'child1'
+ExcludeHeaderFilterRegex: 'exc-child1'
diff --git a/clang-tools-extra/test/clang-tidy/infrastructure/Inputs/config-files/3/.clang-tidy b/clang-tools-extra/test/clang-tidy/infrastructure/Inputs/config-files/3/.clang-tidy
@@ -1,3 +1,4 @@
 InheritParentConfig: true
 Checks: 'from-child3'
 HeaderFilterRegex: 'child3'
+ExcludeHeaderFilterRegex: 'exc-child3'
diff --git a/clang-tools-extra/test/clang-tidy/infrastructure/config-files.cpp b/clang-tools-extra/test/clang-tidy/infrastructure/config-files.cpp
@@ -1,18 +1,23 @@
 // RUN: clang-tidy -dump-config %S/Inputs/config-files/- -- | FileCheck %s -check-prefix=CHECK-BASE
 // CHECK-BASE: Checks: {{.*}}from-parent
 // CHECK-BASE: HeaderFilterRegex: parent
+// CHECK-BASE: ExcludeHeaderFilterRegex: exc-parent
 // RUN: clang-tidy -dump-config %S/Inputs/config-files/1/- -- | FileCheck %s -check-prefix=CHECK-CHILD1
 // CHECK-CHILD1: Checks: {{.*}}from-child1
 // CHECK-CHILD1: HeaderFilterRegex: child1
+// CHECK-CHILD1: ExcludeHeaderFilterRegex: exc-child1
 // RUN: clang-tidy -dump-config %S/Inputs/config-files/2/- -- | FileCheck %s -check-prefix=CHECK-CHILD2
 // CHECK-CHILD2: Checks: {{.*}}from-parent
 // CHECK-CHILD2: HeaderFilterRegex: parent
+// CHECK-CHILD2: ExcludeHeaderFilterRegex: exc-parent
 // RUN: clang-tidy -dump-config %S/Inputs/config-files/3/- -- | FileCheck %s -check-prefix=CHECK-CHILD3
 // CHECK-CHILD3: Checks: {{.*}}from-parent,from-child3
 // CHECK-CHILD3: HeaderFilterRegex: child3
-// RUN: clang-tidy -dump-config -checks='from-command-line' -header-filter='from command line' %S/Inputs/config-files/- -- | FileCheck %s -check-prefix=CHECK-COMMAND-LINE
+// CHECK-CHILD3: ExcludeHeaderFilterRegex: exc-child3
+// RUN: clang-tidy -dump-config -checks='from-command-line' -header-filter='from command line' -exclude-header-filter='from_command_line' %S/Inputs/config-files/- -- | FileCheck %s -check-prefix=CHECK-COMMAND-LINE
 // CHECK-COMMAND-LINE: Checks: {{.*}}from-parent,from-command-line
 // CHECK-COMMAND-LINE: HeaderFilterRegex: from command line
+// CHECK-COMMAND-LINE: ExcludeHeaderFilterRegex: from_command_line
 
 // For this test we have to use names of the real checks because otherwise values are ignored.
 // Running with the old key: <Key>, value: <value> CheckOptions
@@ -68,3 +73,11 @@
 // Dumped config does not overflow for unsigned options
 // RUN: clang-tidy --dump-config %S/Inputs/config-files/5/- -- | FileCheck %s -check-prefix=CHECK-OVERFLOW
 // CHECK-OVERFLOW: misc-throw-by-value-catch-by-reference.MaxSize: '1152921504606846976'
+
+// RUN: clang-tidy -dump-config -checks='readability-function-size' -header-filter='foo/*' -exclude-header-filter='bar*' %S/Inputs/config-files/- -- | FileCheck %s -check-prefix=CHECK-EXCLUDE-HEADERS
+// CHECK-EXCLUDE-HEADERS: HeaderFilterRegex: 'foo/*'
+// CHECK-EXCLUDE-HEADERS: ExcludeHeaderFilterRegex: 'bar*'
+
+// RUN: clang-tidy -dump-config -checks='readability-function-size' -header-filter='' -exclude-header-filter='' %S/Inputs/config-files/- -- | FileCheck %s -check-prefix=EMPTY-CHECK-EXCLUDE-HEADERS
+// EMPTY-CHECK-EXCLUDE-HEADERS: HeaderFilterRegex: ''
+// EMPTY-CHECK-EXCLUDE-HEADERS: ExcludeHeaderFilterRegex: ''
diff --git a/clang-tools-extra/test/clang-tidy/infrastructure/file-filter.cpp b/clang-tools-extra/test/clang-tidy/infrastructure/file-filter.cpp
@@ -11,6 +11,7 @@
 // RUN: clang-tidy -checks='-*,google-explicit-constructor' -header-filter='.*' -system-headers -quiet %s -- -I %S/Inputs/file-filter/system/.. -isystem %S/Inputs/file-filter/system 2>&1 | FileCheck --check-prefix=CHECK4-QUIET %s
 // RUN: clang-tidy -checks='-*,cppcoreguidelines-pro-type-cstyle-cast' -header-filter='.*' -system-headers %s -- -I %S/Inputs/file-filter/system/.. -isystem %S/Inputs/file-filter/system 2>&1 | FileCheck --check-prefix=CHECK5 %s
 // RUN: clang-tidy -checks='-*,cppcoreguidelines-pro-type-cstyle-cast' -header-filter='.*' %s -- -I %S/Inputs/file-filter/system/.. -isystem %S/Inputs/file-filter/system 2>&1 | FileCheck --check-prefix=CHECK5-NO-SYSTEM-HEADERS %s
+// RUN: clang-tidy -checks='-*,google-explicit-constructor' -header-filter='.*' -exclude-header-filter='header1\.h' %s -- -I %S/Inputs/file-filter/ -isystem %S/Inputs/file-filter/system 2>&1 | FileCheck --check-prefix=CHECK6 %s
 
 #include "header1.h"
 // CHECK-NOT: warning:
@@ -21,6 +22,7 @@
 // CHECK3-QUIET-NOT: warning:
 // CHECK4: header1.h:1:12: warning: single-argument constructors
 // CHECK4-QUIET: header1.h:1:12: warning: single-argument constructors
+// CHECK6-NOT: warning:
 
 #include "header2.h"
 // CHECK-NOT: warning:
@@ -31,6 +33,7 @@
 // CHECK3-QUIET: header2.h:1:12: warning: single-argument constructors
 // CHECK4: header2.h:1:12: warning: single-argument constructors
 // CHECK4-QUIET: header2.h:1:12: warning: single-argument constructors
+// CHECK6: header2.h:1:12: warning: single-argument constructors
 
 #include <system-header.h>
 // CHECK-NOT: warning:
@@ -41,6 +44,7 @@
 // CHECK3-QUIET-NOT: warning:
 // CHECK4: system-header.h:1:12: warning: single-argument constructors
 // CHECK4-QUIET: system-header.h:1:12: warning: single-argument constructors
+// CHECK6-NOT: warning:
 
 class A { A(int); };
 // CHECK: :[[@LINE-1]]:11: warning: single-argument constructors
@@ -51,6 +55,7 @@ class A { A(int); };
 // CHECK3-QUIET: :[[@LINE-6]]:11: warning: single-argument constructors
 // CHECK4: :[[@LINE-7]]:11: warning: single-argument constructors
 // CHECK4-QUIET: :[[@LINE-8]]:11: warning: single-argument constructors
+// CHECK6: :[[@LINE-9]]:11: warning: single-argument constructors
 
 // CHECK-NOT: warning:
 // CHECK-QUIET-NOT: warning:
@@ -73,6 +78,8 @@ class A { A(int); };
 // CHECK4-NOT: Suppressed {{.*}} warnings
 // CHECK4-NOT: Use -header-filter=.* {{.*}}
 // CHECK4-QUIET-NOT: Suppressed
+// CHECK6: Suppressed 2 warnings (2 in non-user code)
+// CHECK6: Use -header-filter=.* {{.*}}
 
 int x = 123;
 auto x_ptr = TO_FLOAT_PTR(&x);
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		// RUN: clang-query -c 'file %S/Inputs/empty.script' %s --
		// COM: no output expected; nothing to CHECK