Add a new clang-tidy check (misc-move-constructor-init) that diagnoses move constructor initializations that call copy constructors instead of move constructors.
llvm-svn: 245571
diff --git a/clang-tools-extra/clang-tidy/misc/MoveConstructorInitCheck.cpp b/clang-tools-extra/clang-tidy/misc/MoveConstructorInitCheck.cpp
new file mode 100644
index 0000000..b1ec6da
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/misc/MoveConstructorInitCheck.cpp
@@ -0,0 +1,77 @@
+//===--- MoveConstructorInitCheck.cpp - clang-tidy-------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "MoveConstructorInitCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+
+void MoveConstructorInitCheck::registerMatchers(MatchFinder *Finder) {
+ Finder->addMatcher(
+ constructorDecl(unless(isImplicit()), allOf(
+ isMoveConstructor(),
+ hasAnyConstructorInitializer(
+ ctorInitializer(withInitializer(constructExpr(hasDeclaration(
+ constructorDecl(isCopyConstructor()).bind("ctor")
+ )))).bind("init")
+ )
+ )), this);
+}
+
+void MoveConstructorInitCheck::check(const MatchFinder::MatchResult &Result) {
+ const auto *CopyCtor = Result.Nodes.getNodeAs<CXXConstructorDecl>("ctor");
+ const auto *Initializer = Result.Nodes.getNodeAs<CXXCtorInitializer>("init");
+
+ // Do not diagnose if the expression used to perform the initialization is a
+ // trivially-copyable type.
+ QualType QT = Initializer->getInit()->getType();
+ if (QT.isTriviallyCopyableType(*Result.Context))
+ return;
+
+ const auto *RD = QT->getAsCXXRecordDecl();
+ if (RD && RD->isTriviallyCopyable())
+ return;
+
+ // Diagnose when the class type has a move constructor available, but the
+ // ctor-initializer uses the copy constructor instead.
+ const CXXConstructorDecl *Candidate = nullptr;
+ for (const auto *Ctor : CopyCtor->getParent()->ctors()) {
+ if (Ctor->isMoveConstructor() && Ctor->getAccess() <= AS_protected &&
+ !Ctor->isDeleted()) {
+ // The type has a move constructor that is at least accessible to the
+ // initializer.
+ //
+ // FIXME: Determine whether the move constructor is a viable candidate
+ // for the ctor-initializer, perhaps provide a fixit that suggests
+ // using std::move().
+ Candidate = Ctor;
+ break;
+ }
+ }
+
+ if (Candidate) {
+ // There's a move constructor candidate that the caller probably intended
+ // to call instead.
+ diag(Initializer->getSourceLocation(),
+ "move constructor initializes %0 by calling a copy constructor")
+ << (Initializer->isBaseInitializer() ? "base class" : "class member");
+ diag(CopyCtor->getLocation(), "copy constructor being called",
+ DiagnosticIDs::Note);
+ diag(Candidate->getLocation(), "candidate move constructor here",
+ DiagnosticIDs::Note);
+ }
+}
+
+} // namespace tidy
+} // namespace clang
+