merge main into amd-staging

Author: ronlieb

clang-tools-extra/clang-tidy/modernize/CMakeLists.txt

@@ -42,6 +42,7 @@ add_clang_library(clangTidyModernizeModule STATIC
   UseNullptrCheck.cpp
   UseOverrideCheck.cpp
   UseRangesCheck.cpp
+  UseScopedLockCheck.cpp
   UseStartsEndsWithCheck.cpp
   UseStdFormatCheck.cpp
   UseStdNumbersCheck.cpp

clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp

@@ -43,6 +43,7 @@
 #include "UseNullptrCheck.h"
 #include "UseOverrideCheck.h"
 #include "UseRangesCheck.h"
+#include "UseScopedLockCheck.h"
 #include "UseStartsEndsWithCheck.h"
 #include "UseStdFormatCheck.h"
 #include "UseStdNumbersCheck.h"
@@ -80,6 +81,8 @@ class ModernizeModule : public ClangTidyModule {
     CheckFactories.registerCheck<UseIntegerSignComparisonCheck>(
         "modernize-use-integer-sign-comparison");
     CheckFactories.registerCheck<UseRangesCheck>("modernize-use-ranges");
+    CheckFactories.registerCheck<UseScopedLockCheck>(
+        "modernize-use-scoped-lock");
     CheckFactories.registerCheck<UseStartsEndsWithCheck>(
         "modernize-use-starts-ends-with");
     CheckFactories.registerCheck<UseStdFormatCheck>("modernize-use-std-format");

clang-tools-extra/clang-tidy/modernize/UseScopedLockCheck.cpp

@@ -0,0 +1,311 @@
+//===--- UseScopedLockCheck.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 "UseScopedLockCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/Decl.h"
+#include "clang/AST/Stmt.h"
+#include "clang/AST/Type.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+#include "clang/Basic/SourceLocation.h"
+#include "clang/Lex/Lexer.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/Twine.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::modernize {
+
+static bool isLockGuardDecl(const NamedDecl *Decl) {
+  return Decl->getDeclName().isIdentifier() &&
+         Decl->getName() == "lock_guard" && Decl->isInStdNamespace();
+}
+
+static bool isLockGuard(const QualType &Type) {
+  if (const auto *Record = Type->getAs<RecordType>())
+    if (const RecordDecl *Decl = Record->getDecl())
+      return isLockGuardDecl(Decl);
+
+  if (const auto *TemplateSpecType = Type->getAs<TemplateSpecializationType>())
+    if (const TemplateDecl *Decl =
+            TemplateSpecType->getTemplateName().getAsTemplateDecl())
+      return isLockGuardDecl(Decl);
+
+  return false;
+}
+
+static llvm::SmallVector<const VarDecl *>
+getLockGuardsFromDecl(const DeclStmt *DS) {
+  llvm::SmallVector<const VarDecl *> LockGuards;
+
+  for (const Decl *Decl : DS->decls()) {
+    if (const auto *VD = dyn_cast<VarDecl>(Decl)) {
+      const QualType Type =
+          VD->getType().getCanonicalType().getUnqualifiedType();
+      if (isLockGuard(Type))
+        LockGuards.push_back(VD);
+    }
+  }
+
+  return LockGuards;
+}
+
+// Scans through the statements in a block and groups consecutive
+// 'std::lock_guard' variable declarations together.
+static llvm::SmallVector<llvm::SmallVector<const VarDecl *>>
+findLocksInCompoundStmt(const CompoundStmt *Block,
+                        const ast_matchers::MatchFinder::MatchResult &Result) {
+  // store groups of consecutive 'std::lock_guard' declarations
+  llvm::SmallVector<llvm::SmallVector<const VarDecl *>> LockGuardGroups;
+  llvm::SmallVector<const VarDecl *> CurrentLockGuardGroup;
+
+  auto AddAndClearCurrentGroup = [&]() {
+    if (!CurrentLockGuardGroup.empty()) {
+      LockGuardGroups.push_back(CurrentLockGuardGroup);
+      CurrentLockGuardGroup.clear();
+    }
+  };
+
+  for (const Stmt *Stmt : Block->body()) {
+    if (const auto *DS = dyn_cast<DeclStmt>(Stmt)) {
+      llvm::SmallVector<const VarDecl *> LockGuards = getLockGuardsFromDecl(DS);
+
+      if (!LockGuards.empty()) {
+        CurrentLockGuardGroup.append(LockGuards);
+        continue;
+      }
+    }
+    AddAndClearCurrentGroup();
+  }
+
+  AddAndClearCurrentGroup();
+
+  return LockGuardGroups;
+}
+
+static TemplateSpecializationTypeLoc
+getTemplateLockGuardTypeLoc(const TypeSourceInfo *SourceInfo) {
+  const TypeLoc Loc = SourceInfo->getTypeLoc();
+
+  const auto ElaboratedLoc = Loc.getAs<ElaboratedTypeLoc>();
+  if (!ElaboratedLoc)
+    return {};
+
+  return ElaboratedLoc.getNamedTypeLoc().getAs<TemplateSpecializationTypeLoc>();
+}
+
+// Find the exact source range of the 'lock_guard' token
+static SourceRange getLockGuardRange(const TypeSourceInfo *SourceInfo) {
+  const TypeLoc LockGuardTypeLoc = SourceInfo->getTypeLoc();
+
+  return SourceRange(LockGuardTypeLoc.getBeginLoc(),
+                     LockGuardTypeLoc.getEndLoc());
+}
+
+// Find the exact source range of the 'lock_guard' name token
+static SourceRange getLockGuardNameRange(const TypeSourceInfo *SourceInfo) {
+  const TemplateSpecializationTypeLoc TemplateLoc =
+      getTemplateLockGuardTypeLoc(SourceInfo);
+  if (!TemplateLoc)
+    return {};
+
+  return SourceRange(TemplateLoc.getTemplateNameLoc(),
+                     TemplateLoc.getLAngleLoc().getLocWithOffset(-1));
+}
+
+const static StringRef UseScopedLockMessage =
+    "use 'std::scoped_lock' instead of 'std::lock_guard'";
+
+UseScopedLockCheck::UseScopedLockCheck(StringRef Name,
+                                       ClangTidyContext *Context)
+    : ClangTidyCheck(Name, Context),
+      WarnOnSingleLocks(Options.get("WarnOnSingleLocks", true)),
+      WarnOnUsingAndTypedef(Options.get("WarnOnUsingAndTypedef", true)) {}
+
+void UseScopedLockCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
+  Options.store(Opts, "WarnOnSingleLocks", WarnOnSingleLocks);
+  Options.store(Opts, "WarnOnUsingAndTypedef", WarnOnUsingAndTypedef);
+}
+
+void UseScopedLockCheck::registerMatchers(MatchFinder *Finder) {
+  const auto LockGuardClassDecl =
+      namedDecl(hasName("lock_guard"), isInStdNamespace());
+
+  const auto LockGuardType = qualType(anyOf(
+      hasUnqualifiedDesugaredType(
+          recordType(hasDeclaration(LockGuardClassDecl))),
+      elaboratedType(namesType(hasUnqualifiedDesugaredType(
+          templateSpecializationType(hasDeclaration(LockGuardClassDecl)))))));
+
+  const auto LockVarDecl = varDecl(hasType(LockGuardType));
+
+  if (WarnOnSingleLocks) {
+    Finder->addMatcher(
+        compoundStmt(
+            unless(isExpansionInSystemHeader()),
+            has(declStmt(has(LockVarDecl)).bind("lock-decl-single")),
+            unless(has(declStmt(unless(equalsBoundNode("lock-decl-single")),
+                                has(LockVarDecl))))),
+        this);
+  }
+
+  Finder->addMatcher(
+      compoundStmt(unless(isExpansionInSystemHeader()),
+                   has(declStmt(has(LockVarDecl)).bind("lock-decl-multiple")),
+                   has(declStmt(unless(equalsBoundNode("lock-decl-multiple")),
+                                has(LockVarDecl))))
+          .bind("block-multiple"),
+      this);
+
+  if (WarnOnUsingAndTypedef) {
+    // Match 'typedef std::lock_guard<std::mutex> Lock'
+    Finder->addMatcher(typedefDecl(unless(isExpansionInSystemHeader()),
+                                   hasUnderlyingType(LockGuardType))
+                           .bind("lock-guard-typedef"),
+                       this);
+
+    // Match 'using Lock = std::lock_guard<std::mutex>'
+    Finder->addMatcher(
+        typeAliasDecl(
+            unless(isExpansionInSystemHeader()),
+            hasType(elaboratedType(namesType(templateSpecializationType(
+                hasDeclaration(LockGuardClassDecl))))))
+            .bind("lock-guard-using-alias"),
+        this);
+
+    // Match 'using std::lock_guard'
+    Finder->addMatcher(
+        usingDecl(unless(isExpansionInSystemHeader()),
+                  hasAnyUsingShadowDecl(hasTargetDecl(LockGuardClassDecl)))
+            .bind("lock-guard-using-decl"),
+        this);
+  }
+}
+
+void UseScopedLockCheck::check(const MatchFinder::MatchResult &Result) {
+  if (const auto *DS = Result.Nodes.getNodeAs<DeclStmt>("lock-decl-single")) {
+    llvm::SmallVector<const VarDecl *> Decls = getLockGuardsFromDecl(DS);
+    diagOnMultipleLocks({Decls}, Result);
+    return;
+  }
+
+  if (const auto *Compound =
+          Result.Nodes.getNodeAs<CompoundStmt>("block-multiple")) {
+    diagOnMultipleLocks(findLocksInCompoundStmt(Compound, Result), Result);
+    return;
+  }
+
+  if (const auto *Typedef =
+          Result.Nodes.getNodeAs<TypedefDecl>("lock-guard-typedef")) {
+    diagOnSourceInfo(Typedef->getTypeSourceInfo(), Result);
+    return;
+  }
+
+  if (const auto *UsingAlias =
+          Result.Nodes.getNodeAs<TypeAliasDecl>("lock-guard-using-alias")) {
+    diagOnSourceInfo(UsingAlias->getTypeSourceInfo(), Result);
+    return;
+  }
+
+  if (const auto *Using =
+          Result.Nodes.getNodeAs<UsingDecl>("lock-guard-using-decl")) {
+    diagOnUsingDecl(Using, Result);
+  }
+}
+
+void UseScopedLockCheck::diagOnSingleLock(
+    const VarDecl *LockGuard, const MatchFinder::MatchResult &Result) {
+  auto Diag = diag(LockGuard->getBeginLoc(), UseScopedLockMessage);
+
+  const SourceRange LockGuardTypeRange =
+      getLockGuardRange(LockGuard->getTypeSourceInfo());
+
+  if (LockGuardTypeRange.isInvalid())
+    return;
+
+  // Create Fix-its only if we can find the constructor call to properly handle
+  // 'std::lock_guard l(m, std::adopt_lock)' case.
+  const auto *CtorCall = dyn_cast<CXXConstructExpr>(LockGuard->getInit());
+  if (!CtorCall)
+    return;
+
+  if (CtorCall->getNumArgs() == 1) {
+    Diag << FixItHint::CreateReplacement(LockGuardTypeRange,
+                                         "std::scoped_lock");
+    return;
+  }
+
+  if (CtorCall->getNumArgs() == 2) {
+    const Expr *const *CtorArgs = CtorCall->getArgs();
+
+    const Expr *MutexArg = CtorArgs[0];
+    const Expr *AdoptLockArg = CtorArgs[1];
+
+    const StringRef MutexSourceText = Lexer::getSourceText(
+        CharSourceRange::getTokenRange(MutexArg->getSourceRange()),
+        *Result.SourceManager, Result.Context->getLangOpts());
+    const StringRef AdoptLockSourceText = Lexer::getSourceText(
+        CharSourceRange::getTokenRange(AdoptLockArg->getSourceRange()),
+        *Result.SourceManager, Result.Context->getLangOpts());
+
+    Diag << FixItHint::CreateReplacement(LockGuardTypeRange, "std::scoped_lock")
+         << FixItHint::CreateReplacement(
+                SourceRange(MutexArg->getBeginLoc(), AdoptLockArg->getEndLoc()),
+                (llvm::Twine(AdoptLockSourceText) + ", " + MutexSourceText)
+                    .str());
+    return;
+  }
+
+  llvm_unreachable("Invalid argument number of std::lock_guard constructor");
+}
+
+void UseScopedLockCheck::diagOnMultipleLocks(
+    const llvm::SmallVector<llvm::SmallVector<const VarDecl *>> &LockGroups,
+    const ast_matchers::MatchFinder::MatchResult &Result) {
+  for (const llvm::SmallVector<const VarDecl *> &Group : LockGroups) {
+    if (Group.size() == 1) {
+      if (WarnOnSingleLocks)
+        diagOnSingleLock(Group[0], Result);
+    } else {
+      diag(Group[0]->getBeginLoc(),
+           "use single 'std::scoped_lock' instead of multiple "
+           "'std::lock_guard'");
+
+      for (const VarDecl *Lock : llvm::drop_begin(Group))
+        diag(Lock->getLocation(), "additional 'std::lock_guard' declared here",
+             DiagnosticIDs::Note);
+    }
+  }
+}
+
+void UseScopedLockCheck::diagOnSourceInfo(
+    const TypeSourceInfo *LockGuardSourceInfo,
+    const ast_matchers::MatchFinder::MatchResult &Result) {
+  const TypeLoc TL = LockGuardSourceInfo->getTypeLoc();
+
+  if (const auto ElaboratedTL = TL.getAs<ElaboratedTypeLoc>()) {
+    auto Diag = diag(ElaboratedTL.getBeginLoc(), UseScopedLockMessage);
+
+    const SourceRange LockGuardRange =
+        getLockGuardNameRange(LockGuardSourceInfo);
+    if (LockGuardRange.isInvalid())
+      return;
+
+    Diag << FixItHint::CreateReplacement(LockGuardRange, "scoped_lock");
+  }
+}
+
+void UseScopedLockCheck::diagOnUsingDecl(
+    const UsingDecl *UsingDecl,
+    const ast_matchers::MatchFinder::MatchResult &Result) {
+  diag(UsingDecl->getLocation(), UseScopedLockMessage)
+      << FixItHint::CreateReplacement(UsingDecl->getLocation(), "scoped_lock");
+}
+
+} // namespace clang::tidy::modernize

clang-tools-extra/clang-tidy/modernize/UseScopedLockCheck.h

@@ -0,0 +1,54 @@
+//===--- UseScopedLockCheck.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_USESCOPEDLOCKCHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_USESCOPEDLOCKCHECK_H
+
+#include "../ClangTidyCheck.h"
+#include "clang/AST/ASTTypeTraits.h"
+#include "clang/AST/Stmt.h"
+#include <optional>
+
+namespace clang::tidy::modernize {
+
+/// Finds uses of ``std::lock_guard`` and suggests replacing them with C++17's
+/// alternative ``std::scoped_lock``.
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/modernize/use-scoped-lock.html
+class UseScopedLockCheck : public ClangTidyCheck {
+public:
+  UseScopedLockCheck(StringRef Name, ClangTidyContext *Context);
+  void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+  void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
+  void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+  bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
+    return LangOpts.CPlusPlus17;
+  }
+  std::optional<TraversalKind> getCheckTraversalKind() const override {
+    return TK_IgnoreUnlessSpelledInSource;
+  }
+
+private:
+  void diagOnSingleLock(const VarDecl *LockGuard,
+                        const ast_matchers::MatchFinder::MatchResult &Result);
+  void diagOnMultipleLocks(
+      const llvm::SmallVector<llvm::SmallVector<const VarDecl *>> &LockGroups,
+      const ast_matchers::MatchFinder::MatchResult &Result);
+  void diagOnSourceInfo(const TypeSourceInfo *LockGuardSourceInfo,
+                        const ast_matchers::MatchFinder::MatchResult &Result);
+  void diagOnUsingDecl(const UsingDecl *UsingDecl,
+                       const ast_matchers::MatchFinder::MatchResult &Result);
+
+  const bool WarnOnSingleLocks;
+  const bool WarnOnUsingAndTypedef;
+};
+
+} // namespace clang::tidy::modernize
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_USESCOPEDLOCKCHECK_H