diff --git a/clang-tools-extra/clang-tidy/performance/MoveConstArgCheck.cpp b/clang-tools-extra/clang-tidy/performance/MoveConstArgCheck.cpp index aa54cf284f627b..d29b9e91f2e35d 100644 --- a/clang-tools-extra/clang-tidy/performance/MoveConstArgCheck.cpp +++ b/clang-tools-extra/clang-tidy/performance/MoveConstArgCheck.cpp @@ -44,7 +44,13 @@ void MoveConstArgCheck::registerMatchers(MatchFinder *Finder) { unless(isInTemplateInstantiation())) .bind("call-move"); - Finder->addMatcher(MoveCallMatcher, this); + Finder->addMatcher( + expr(anyOf( + castExpr(hasSourceExpression(MoveCallMatcher)), + cxxConstructExpr(hasDeclaration(cxxConstructorDecl(anyOf( + isCopyConstructor(), isMoveConstructor()))), + hasArgument(0, MoveCallMatcher)))), + this); auto ConstTypeParmMatcher = qualType(references(isConstQualified())).bind("invocation-parm-type"); diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst index 5d5aecd67b2d70..7092d0b6fdb02d 100644 --- a/clang-tools-extra/docs/ReleaseNotes.rst +++ b/clang-tools-extra/docs/ReleaseNotes.rst @@ -387,6 +387,10 @@ Changes in existing checks - Improved :doc:`modernize-use-using ` check by adding support for detection of typedefs declared on function level. +- Improved :doc:`performance-move-const-arg + ` check by ignoring + ``std::move()`` calls when their target is used as an rvalue. + - Improved :doc:`performance-unnecessary-copy-initialization ` check by detecting more cases of constant access. In particular, pointers can be diff --git a/clang-tools-extra/test/clang-tidy/checkers/performance/move-const-arg.cpp b/clang-tools-extra/test/clang-tidy/checkers/performance/move-const-arg.cpp index 4d90c124ad72cd..4505eef6df24bd 100644 --- a/clang-tools-extra/test/clang-tidy/checkers/performance/move-const-arg.cpp +++ b/clang-tools-extra/test/clang-tidy/checkers/performance/move-const-arg.cpp @@ -114,14 +114,18 @@ void f8() { int f9() { return M2(1); } template -T f10(const int x10) { +T f_unknown_target(const int x10) { return std::move(x10); - // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: std::move of the const variable 'x10' of the trivially-copyable type 'const int' has no effect; remove std::move() [performance-move-const-arg] - // CHECK-FIXES: return x10; } + void f11() { - f10(1); - f10(1); + f_unknown_target(1); + f_unknown_target(1); +} + +A&& f_return_right_ref() { + static A a{}; + return std::move(a); } class NoMoveSemantics {