[clang-tools-extra] [clang-tidy] add misc-constexpr check (PR #162741)

via cfe-commits cfe-commits at lists.llvm.org
Thu Oct 9 14:39:07 PDT 2025


llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-tidy

Author: Julian Schmidt (5chmidti)

<details>
<summary>Changes</summary>

This check finds all functions and variables that can be declared as `constexpr`, using the specified standard version to check if the requirements are met.

This is part 1/N, adding only the C++11 rule-set.

Fixes #<!-- -->115622

---

Patch is 51.72 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/162741.diff


13 Files Affected:

- (modified) clang-tools-extra/clang-tidy/modernize/CMakeLists.txt (+1) 
- (modified) clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp (+2) 
- (added) clang-tools-extra/clang-tidy/modernize/UseConstexprCheck.cpp (+517) 
- (added) clang-tools-extra/clang-tidy/modernize/UseConstexprCheck.h (+45) 
- (modified) clang-tools-extra/clang-tidy/utils/ASTUtils.cpp (+17) 
- (modified) clang-tools-extra/clang-tidy/utils/ASTUtils.h (+3) 
- (modified) clang-tools-extra/docs/ReleaseNotes.rst (+5) 
- (modified) clang-tools-extra/docs/clang-tidy/checks/list.rst (+1) 
- (added) clang-tools-extra/docs/clang-tidy/checks/modernize/use-constexpr.rst (+73) 
- (added) clang-tools-extra/test/clang-tidy/checkers/modernize/use-constexpr-cxx20.cpp (+36) 
- (added) clang-tools-extra/test/clang-tidy/checkers/modernize/use-constexpr-locals.cpp (+20) 
- (added) clang-tools-extra/test/clang-tidy/checkers/modernize/use-constexpr-replacement-opts.cpp (+32) 
- (added) clang-tools-extra/test/clang-tidy/checkers/modernize/use-constexpr.cpp (+461) 


``````````diff
diff --git a/clang-tools-extra/clang-tidy/modernize/CMakeLists.txt b/clang-tools-extra/clang-tidy/modernize/CMakeLists.txt
index 882f2dc9fb4d8..f7dbc1d7312ee 100644
--- a/clang-tools-extra/clang-tidy/modernize/CMakeLists.txt
+++ b/clang-tools-extra/clang-tidy/modernize/CMakeLists.txt
@@ -32,6 +32,7 @@ add_clang_library(clangTidyModernizeModule STATIC
   UnaryStaticAssertCheck.cpp
   UseAutoCheck.cpp
   UseBoolLiteralsCheck.cpp
+  UseConstexprCheck.cpp
   UseConstraintsCheck.cpp
   UseDefaultMemberInitCheck.cpp
   UseDesignatedInitializersCheck.cpp
diff --git a/clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp b/clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp
index 360e2b8434d0c..1b54adeef9281 100644
--- a/clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp
@@ -33,6 +33,7 @@
 #include "UnaryStaticAssertCheck.h"
 #include "UseAutoCheck.h"
 #include "UseBoolLiteralsCheck.h"
+#include "UseConstexprCheck.h"
 #include "UseConstraintsCheck.h"
 #include "UseDefaultMemberInitCheck.h"
 #include "UseDesignatedInitializersCheck.h"
@@ -82,6 +83,7 @@ class ModernizeModule : public ClangTidyModule {
     CheckFactories.registerCheck<MinMaxUseInitializerListCheck>(
         "modernize-min-max-use-initializer-list");
     CheckFactories.registerCheck<PassByValueCheck>("modernize-pass-by-value");
+    CheckFactories.registerCheck<UseConstexprCheck>("modernize-use-constexpr");
     CheckFactories.registerCheck<UseDesignatedInitializersCheck>(
         "modernize-use-designated-initializers");
     CheckFactories.registerCheck<UseIntegerSignComparisonCheck>(
diff --git a/clang-tools-extra/clang-tidy/modernize/UseConstexprCheck.cpp b/clang-tools-extra/clang-tidy/modernize/UseConstexprCheck.cpp
new file mode 100644
index 0000000000000..9238605b3cb4a
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/modernize/UseConstexprCheck.cpp
@@ -0,0 +1,517 @@
+//===--- UseConstexprCheck.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 "UseConstexprCheck.h"
+#include "../utils/ASTUtils.h"
+#include "../utils/LexerUtils.h"
+#include "clang/AST/RecursiveASTVisitor.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallPtrSet.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::modernize {
+
+namespace {
+AST_MATCHER(FunctionDecl, locationPermitsConstexpr) {
+  const bool IsInMainFile =
+      Finder->getASTContext().getSourceManager().isInMainFile(
+          Node.getLocation());
+
+  if (IsInMainFile && Node.hasExternalFormalLinkage())
+    return false;
+  if (!IsInMainFile && !Node.isInlined())
+    return false;
+
+  return true;
+}
+
+AST_MATCHER(Expr, isCXX11ConstantExpr) {
+  return !Node.isValueDependent() &&
+         Node.isCXX11ConstantExpr(Finder->getASTContext());
+}
+
+AST_MATCHER(DeclaratorDecl, isInMacro) {
+  const SourceRange R =
+      SourceRange(Node.getTypeSpecStartLoc(), Node.getLocation());
+
+  return Node.getLocation().isMacroID() || Node.getEndLoc().isMacroID() ||
+         utils::rangeContainsMacroExpansion(
+             R, &Finder->getASTContext().getSourceManager()) ||
+         utils::rangeIsEntirelyWithinMacroArgument(
+             R, &Finder->getASTContext().getSourceManager());
+}
+
+AST_MATCHER(Decl, hasNoRedecl) {
+  // There is always the actual declaration
+  return !Node.redecls().empty() &&
+         std::next(Node.redecls_begin()) == Node.redecls_end();
+}
+
+AST_MATCHER(Decl, allRedeclsInSameFile) {
+  const SourceManager &SM = Finder->getASTContext().getSourceManager();
+  const SourceLocation L = Node.getLocation();
+  for (const Decl *ReDecl : Node.redecls()) {
+    if (!SM.isWrittenInSameFile(L, ReDecl->getLocation()))
+      return false;
+  }
+  return true;
+}
+} // namespace
+
+static bool
+satisfiesConstructorPropertiesUntil20(const CXXConstructorDecl *Ctor,
+                                      ASTContext &Ctx) {
+  const CXXRecordDecl *Rec = Ctor->getParent();
+  llvm::SmallPtrSet<const RecordDecl *, 8> Bases{};
+  for (const CXXBaseSpecifier Base : Rec->bases())
+    Bases.insert(Base.getType()->getAsRecordDecl());
+
+  llvm::SmallPtrSet<const FieldDecl *, 8> Fields{Rec->field_begin(),
+                                                 Rec->field_end()};
+  llvm::SmallPtrSet<const FieldDecl *, 4> Indirects{};
+
+  for (const CXXCtorInitializer *const Init : Ctor->inits()) {
+    const Type *InitType = Init->getBaseClass();
+    if (InitType && InitType->isRecordType()) {
+      const auto *ConstructingInit =
+          llvm::dyn_cast<CXXConstructExpr>(Init->getInit());
+      if (ConstructingInit &&
+          !ConstructingInit->getConstructor()->isConstexprSpecified())
+        return false;
+    }
+
+    if (Init->isBaseInitializer()) {
+      Bases.erase(Init->getBaseClass()->getAsRecordDecl());
+      continue;
+    }
+
+    if (Init->isMemberInitializer()) {
+      const FieldDecl *Field = Init->getMember();
+
+      if (Field->isAnonymousStructOrUnion())
+        Indirects.insert(Field);
+
+      Fields.erase(Field);
+      continue;
+    }
+  }
+
+  for (const auto &Match :
+       match(cxxRecordDecl(forEach(indirectFieldDecl().bind("indirect"))), *Rec,
+             Ctx)) {
+    const auto *IField = Match.getNodeAs<IndirectFieldDecl>("indirect");
+
+    size_t NumInitializations = false;
+    for (const NamedDecl *ND : IField->chain())
+      NumInitializations += Indirects.erase(llvm::dyn_cast<FieldDecl>(ND));
+
+    if (NumInitializations != 1)
+      return false;
+
+    for (const NamedDecl *ND : IField->chain())
+      Fields.erase(llvm::dyn_cast<FieldDecl>(ND));
+  }
+
+  if (!Fields.empty())
+    return false;
+
+  return true;
+}
+
+static bool isLiteralType(QualType QT, const ASTContext &Ctx,
+                          bool ConservativeLiteralType);
+
+static bool isLiteralType(const Type *T, const ASTContext &Ctx,
+                          const bool ConservativeLiteralType) {
+  if (!T)
+    return false;
+
+  if (!T->isLiteralType(Ctx))
+    return false;
+
+  if (!ConservativeLiteralType)
+    return T->isLiteralType(Ctx) && !T->isVoidType();
+
+  if (T->isIncompleteType() || T->isIncompleteArrayType())
+    return false;
+
+  T = utils::unwrapPointee(T);
+  if (!T)
+    return false;
+
+  assert(!T->isPointerOrReferenceType());
+
+  if (T->isIncompleteType() || T->isIncompleteArrayType())
+    return false;
+
+  if (T->isLiteralType(Ctx))
+    return true;
+
+  if (const CXXRecordDecl *Rec = T->getAsCXXRecordDecl()) {
+    if (llvm::any_of(Rec->ctors(), [](const CXXConstructorDecl *Ctor) {
+          return !Ctor->isCopyOrMoveConstructor() &&
+                 Ctor->isConstexprSpecified();
+        }))
+      return false;
+
+    for (const CXXBaseSpecifier Base : Rec->bases()) {
+      if (!isLiteralType(Base.getType(), Ctx, ConservativeLiteralType))
+        return false;
+    }
+  }
+
+  if (const Type *ArrayElementType = T->getArrayElementTypeNoTypeQual())
+    return isLiteralType(ArrayElementType, Ctx, ConservativeLiteralType);
+
+  return false;
+}
+
+static bool isLiteralType(QualType QT, const ASTContext &Ctx,
+                          const bool ConservativeLiteralType) {
+  return !QT.isVolatileQualified() &&
+         isLiteralType(QT.getTypePtr(), Ctx, ConservativeLiteralType);
+}
+
+static bool satisfiesProperties11(
+    const FunctionDecl *FDecl, ASTContext &Ctx,
+    const bool ConservativeLiteralType,
+    const bool AddConstexprToMethodOfClassWithoutConstexprConstructor) {
+  if (FDecl->isConstexprSpecified())
+    return true;
+
+  const LangOptions LO = Ctx.getLangOpts();
+  const auto *Method = llvm::dyn_cast<CXXMethodDecl>(FDecl);
+  if (Method && !Method->isStatic() &&
+      !Method->getParent()->hasConstexprNonCopyMoveConstructor() &&
+      !AddConstexprToMethodOfClassWithoutConstexprConstructor)
+    return false;
+
+  if (Method &&
+      (Method->isVirtual() ||
+       !match(cxxMethodDecl(hasBody(cxxTryStmt())), *Method, Ctx).empty()))
+    return false;
+
+  if (const auto *Ctor = llvm::dyn_cast<CXXConstructorDecl>(FDecl);
+      Ctor && (!satisfiesConstructorPropertiesUntil20(Ctor, Ctx) ||
+               llvm::any_of(Ctor->getParent()->bases(),
+                            [](const CXXBaseSpecifier &Base) {
+                              return Base.isVirtual();
+                            })))
+    return false;
+
+  if (const auto *Dtor = llvm::dyn_cast<CXXDestructorDecl>(FDecl);
+      Dtor && !Dtor->isTrivial())
+    return false;
+
+  if (!isLiteralType(FDecl->getReturnType(), Ctx, ConservativeLiteralType))
+    return false;
+
+  for (const ParmVarDecl *Param : FDecl->parameters())
+    if (!isLiteralType(Param->getType(), Ctx, ConservativeLiteralType))
+      return false;
+
+  class Visitor11 : public clang::RecursiveASTVisitor<Visitor11> {
+  public:
+    using Base = clang::RecursiveASTVisitor<Visitor11>;
+    bool shouldVisitImplicitCode() const { return true; }
+
+    Visitor11(ASTContext &Ctx, bool ConservativeLiteralType)
+        : Ctx(Ctx), ConservativeLiteralType(ConservativeLiteralType) {}
+
+    bool WalkUpFromNullStmt(NullStmt *) {
+      Possible = false;
+      return false;
+    }
+    bool WalkUpFromDeclStmt(DeclStmt *DS) {
+      for (const Decl *D : DS->decls())
+        if (!llvm::isa<StaticAssertDecl, TypedefNameDecl, UsingDecl,
+                       UsingDirectiveDecl>(D)) {
+          Possible = false;
+          return false;
+        }
+      return true;
+    }
+
+    bool WalkUpFromExpr(Expr *) { return true; }
+    bool WalkUpFromCompoundStmt(CompoundStmt *S) {
+      for (const DynTypedNode &Node : Ctx.getParents(*S))
+        if (Node.get<FunctionDecl>() != nullptr)
+          return true;
+
+      Possible = false;
+      return false;
+    }
+    bool WalkUpFromStmt(Stmt *) {
+      Possible = false;
+      return false;
+    }
+
+    bool WalkUpFromReturnStmt(ReturnStmt *) {
+      ++NumReturns;
+      if (NumReturns != 1U) {
+        Possible = false;
+        return false;
+      }
+      return true;
+    }
+
+    bool WalkUpFromCastExpr(CastExpr *CE) {
+      if (llvm::is_contained(
+              {
+                  CK_LValueBitCast,
+                  CK_IntegralToPointer,
+                  CK_PointerToIntegral,
+              },
+              CE->getCastKind())) {
+        Possible = false;
+        return false;
+      }
+      return true;
+    }
+
+    bool TraverseCXXDynamicCastExpr(CXXDynamicCastExpr *) {
+      Possible = false;
+      return false;
+    }
+
+    bool TraverseCXXReinterpretCastExpr(CXXReinterpretCastExpr *) {
+      Possible = false;
+      return false;
+    }
+
+    bool TraverseType(QualType QT, const bool TraverseQualifier = true) {
+      if (QT.isNull())
+        return true;
+      if (!isLiteralType(QT, Ctx, ConservativeLiteralType)) {
+        Possible = false;
+        return false;
+      }
+      return Base::TraverseType(QT, TraverseQualifier);
+    }
+
+    bool WalkUpFromCXXConstructExpr(CXXConstructExpr *CE) {
+      if (const CXXConstructorDecl *Ctor = CE->getConstructor();
+          Ctor && !Ctor->isConstexprSpecified()) {
+        Possible = false;
+        return false;
+      }
+
+      return true;
+    }
+    bool WalkUpFromCallExpr(CallExpr *CE) {
+      if (const auto *FDecl =
+              llvm::dyn_cast_if_present<FunctionDecl>(CE->getCalleeDecl());
+          FDecl && !FDecl->isConstexprSpecified()) {
+        Possible = false;
+        return false;
+      }
+      return true;
+    }
+
+    bool TraverseCXXNewExpr(CXXNewExpr *) {
+      Possible = false;
+      return false;
+    }
+
+    bool TraverseDeclRefExpr(DeclRefExpr *DRef) {
+      if (DRef->getType().isVolatileQualified()) {
+        Possible = false;
+        return false;
+      }
+      return Base::TraverseDeclRefExpr(DRef);
+    }
+
+    ASTContext &Ctx;
+    const bool ConservativeLiteralType;
+    bool Possible = true;
+    size_t NumReturns = 0;
+  };
+
+  Visitor11 V{Ctx, ConservativeLiteralType};
+  V.TraverseDecl(const_cast<FunctionDecl *>(FDecl));
+  if (!V.Possible)
+    return false;
+
+  return true;
+}
+
+namespace {
+AST_MATCHER_P2(FunctionDecl, satisfiesProperties, bool, ConservativeLiteralType,
+               bool, AddConstexprToMethodOfClassWithoutConstexprConstructor) {
+  ASTContext &Ctx = Finder->getASTContext();
+  const LangOptions LO = Ctx.getLangOpts();
+
+  if (LO.CPlusPlus11)
+    return satisfiesProperties11(
+        &Node, Ctx, ConservativeLiteralType,
+        AddConstexprToMethodOfClassWithoutConstexprConstructor);
+
+  return false;
+}
+
+AST_MATCHER_P(VarDecl, satisfiesVariableProperties, bool,
+              ConservativeLiteralType) {
+  ASTContext &Ctx = Finder->getASTContext();
+
+  const QualType QT = Node.getType();
+  const Type *T = QT.getTypePtr();
+  if (!T)
+    return false;
+
+  if (!isLiteralType(QT, Ctx, ConservativeLiteralType))
+    return false;
+
+  const bool IsDeclaredInsideConstexprFunction = std::invoke([&Node]() {
+    const auto *Func = llvm::dyn_cast<FunctionDecl>(Node.getDeclContext());
+    if (!Func)
+      return false;
+    return Func->isConstexpr();
+  });
+
+  if (Node.isStaticLocal() && IsDeclaredInsideConstexprFunction)
+    return false;
+
+  if (!Ctx.getLangOpts().CPlusPlus20)
+    return true;
+
+  const CXXRecordDecl *RDecl = T->getAsCXXRecordDecl();
+  const Type *const ArrayOrPtrElement = T->getPointeeOrArrayElementType();
+  if (ArrayOrPtrElement)
+    RDecl = ArrayOrPtrElement->getAsCXXRecordDecl();
+
+  if (RDecl && (!RDecl->hasDefinition() || !RDecl->hasConstexprDestructor()))
+    return false;
+
+  return true;
+}
+} // namespace
+
+void UseConstexprCheck::registerMatchers(MatchFinder *Finder) {
+  Finder->addMatcher(
+      functionDecl(
+          isDefinition(),
+          unless(anyOf(isConstexpr(), isImplicit(), hasExternalFormalLinkage(),
+                       isInMacro(), isMain(), isInStdNamespace(),
+                       isExpansionInSystemHeader(), isExternC(),
+                       cxxMethodDecl(ofClass(cxxRecordDecl(isLambda()))))),
+          locationPermitsConstexpr(), allRedeclsInSameFile(),
+          satisfiesProperties(
+              ConservativeLiteralType,
+              AddConstexprToMethodOfClassWithoutConstexprConstructor))
+          .bind("func"),
+      this);
+
+  const auto CallToNonConstexprFunction =
+      callExpr(callee(functionDecl(unless(isConstexpr()))));
+
+  const auto VarSupportingConstexpr =
+      varDecl(
+          unless(anyOf(parmVarDecl(), isImplicit(), isInStdNamespace(),
+                       isExpansionInSystemHeader(), isConstexpr(), isExternC(),
+                       hasExternalFormalLinkage(), isInMacro())),
+          hasNoRedecl(), hasType(qualType(isConstQualified())),
+          satisfiesVariableProperties(ConservativeLiteralType),
+          hasInitializer(
+              expr(isCXX11ConstantExpr(), unless(CallToNonConstexprFunction),
+                   unless(hasDescendant(CallToNonConstexprFunction)))))
+          .bind("var");
+  Finder->addMatcher(mapAnyOf(translationUnitDecl, namespaceDecl)
+                         .with(forEach(VarSupportingConstexpr)),
+                     this);
+  Finder->addMatcher(declStmt(hasSingleDecl(VarSupportingConstexpr)), this);
+}
+
+static const FunctionDecl *
+maybeResolveToTemplateDecl(const FunctionDecl *Func) {
+  if (Func && Func->isTemplateInstantiation())
+    Func = Func->getTemplateInstantiationPattern();
+  return Func;
+}
+
+void UseConstexprCheck::check(const MatchFinder::MatchResult &Result) {
+  if (const auto *Func = Result.Nodes.getNodeAs<FunctionDecl>("func")) {
+    Func = maybeResolveToTemplateDecl(Func);
+    if (Func)
+      Functions.insert(Func);
+    return;
+  }
+
+  if (const auto *Var = Result.Nodes.getNodeAs<VarDecl>("var")) {
+    if (const VarDecl *VarTemplate = Var->getTemplateInstantiationPattern())
+      Var = VarTemplate;
+
+    Variables.insert(Var);
+    return;
+  }
+}
+
+void UseConstexprCheck::onEndOfTranslationUnit() {
+  const std::string FunctionReplacement = ConstexprString + " ";
+
+  for (const FunctionDecl *Func : Functions) {
+    const SourceRange R =
+        SourceRange(Func->getTypeSpecStartLoc(), Func->getLocation());
+    auto Diag = diag(Func->getLocation(), "declare function %0 as 'constexpr'")
+                << Func << R;
+
+    for (const Decl *D : Func->redecls())
+      if (const auto *FDecl = llvm::dyn_cast<FunctionDecl>(D))
+        Diag << FixItHint::CreateInsertion(FDecl->getTypeSpecStartLoc(),
+                                           FunctionReplacement);
+  }
+
+  const auto MaybeRemoveConst = [&, this](DiagnosticBuilder &Diag,
+                                          const VarDecl *Var) {
+    // Since either of the locs can be in a macro, use `makeFileCharRange` to be
+    // sure that we have a consistent `CharSourceRange`, located entirely in the
+    // source file.
+    const CharSourceRange FileRange = Lexer::makeFileCharRange(
+        CharSourceRange::getCharRange(Var->getInnerLocStart(),
+                                      Var->getLocation()),
+        Var->getASTContext().getSourceManager(), getLangOpts());
+    if (const std::optional<Token> ConstToken =
+            utils::lexer::getQualifyingToken(
+                tok::TokenKind::kw_const, FileRange, Var->getASTContext(),
+                Var->getASTContext().getSourceManager())) {
+      Diag << FixItHint::CreateRemoval(ConstToken->getLocation());
+    }
+  };
+
+  for (const auto *Var : Variables) {
+    const SourceRange R =
+        SourceRange(Var->getTypeSpecStartLoc(), Var->getLocation());
+    auto Diag = diag(Var->getLocation(), "declare variable %0 as 'constexpr'")
+                << Var << R
+                << FixItHint::CreateInsertion(Var->getTypeSpecStartLoc(),
+                                              FunctionReplacement);
+    MaybeRemoveConst(Diag, Var);
+  }
+
+  Functions.clear();
+  Variables.clear();
+}
+
+UseConstexprCheck::UseConstexprCheck(StringRef Name, ClangTidyContext *Context)
+    : ClangTidyCheck(Name, Context),
+      ConservativeLiteralType(Options.get("ConservativeLiteralType", true)),
+      AddConstexprToMethodOfClassWithoutConstexprConstructor(Options.get(
+          "AddConstexprToMethodOfClassWithoutConstexprConstructor", false)),
+      ConstexprString(Options.get("ConstexprString", "constexpr")),
+      StaticConstexprString(
+          Options.get("StaticConstexprString", "static " + ConstexprString)) {}
+
+void UseConstexprCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
+  Options.store(Opts, "ConservativeLiteralType", ConservativeLiteralType);
+  Options.store(Opts, "AddConstexprToMethodOfClassWithoutConstexprConstructor",
+                AddConstexprToMethodOfClassWithoutConstexprConstructor);
+  Options.store(Opts, "ConstexprString", ConstexprString);
+  Options.store(Opts, "StaticConstexprString", StaticConstexprString);
+}
+} // namespace clang::tidy::modernize
diff --git a/clang-tools-extra/clang-tidy/modernize/UseConstexprCheck.h b/clang-tools-extra/clang-tidy/modernize/UseConstexprCheck.h
new file mode 100644
index 0000000000000..bfb206d40ba47
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/modernize/UseConstexprCheck.h
@@ -0,0 +1,45 @@
+//===--- UseUseConstexprCheck.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_USECONSTEXPRCHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_USECONSTEXPRCHECK_H
+
+#include "../ClangTidyCheck.h"
+#include "clang/AST/Decl.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallPtrSet.h"
+
+namespace clang::tidy::modernize {
+
+/// Finds functions and variables that can be declared 'constexpr'.
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-...
[truncated]

``````````

</details>


https://github.com/llvm/llvm-project/pull/162741


More information about the cfe-commits mailing list