Index: lib/Sema/SemaInit.cpp =================================================================== --- lib/Sema/SemaInit.cpp +++ lib/Sema/SemaInit.cpp @@ -5988,6 +5988,18 @@ if (!VD->getType()->isRecordType()) return; + // If we're returning a function parameter, copy elision + // is not possible. + if (const FunctionDecl *FD = + dyn_cast_or_null(VD->getParentFunctionOrMethod())) { + for (const auto *Param : FD->params()) { + if (Param == VD) { + DiagID = diag::warn_redundant_move_on_return; + break; + } + } + } + if (DiagID == 0) { DiagID = S.Context.hasSameUnqualifiedType(DestType, VD->getType()) ? diag::warn_pessimizing_move_on_return Index: test/SemaCXX/warn-pessmizing-move.cpp =================================================================== --- test/SemaCXX/warn-pessmizing-move.cpp +++ test/SemaCXX/warn-pessmizing-move.cpp @@ -23,10 +23,6 @@ return a1; return a2; return std::move(a1); - // expected-warning@-1{{prevents copy elision}} - // expected-note@-2{{remove std::move call}} - // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:10-[[@LINE-3]]:20}:"" - // CHECK: fix-it:"{{.*}}":{[[@LINE-4]]:22-[[@LINE-4]]:23}:"" return std::move(a2); // expected-warning@-1{{prevents copy elision}} // expected-note@-2{{remove std::move call}} @@ -46,10 +42,6 @@ return b1; return b2; return std::move(b1); - // expected-warning@-1{{prevents copy elision}} - // expected-note@-2{{remove std::move call}} - // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:10-[[@LINE-3]]:20}:"" - // CHECK: fix-it:"{{.*}}":{[[@LINE-4]]:22-[[@LINE-4]]:23}:"" return std::move(b2); // expected-warning@-1{{prevents copy elision}} // expected-note@-2{{remove std::move call}} @@ -163,24 +155,11 @@ #define wrap1(x) x #define wrap2(x) x -// Macro test. Since the std::move call is outside the macro, it is -// safe to suggest a fix-it. +// Macro tests. A test8(A a) { return std::move(a); - // expected-warning@-1{{prevents copy elision}} - // expected-note@-2{{remove std::move call}} - // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:10-[[@LINE-3]]:20}:"" - // CHECK: fix-it:"{{.*}}":{[[@LINE-4]]:21-[[@LINE-4]]:22}:"" return std::move(wrap1(a)); - // expected-warning@-1{{prevents copy elision}} - // expected-note@-2{{remove std::move call}} - // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:10-[[@LINE-3]]:20}:"" - // CHECK: fix-it:"{{.*}}":{[[@LINE-4]]:28-[[@LINE-4]]:29}:"" return std::move(wrap1(wrap2(a))); - // expected-warning@-1{{prevents copy elision}} - // expected-note@-2{{remove std::move call}} - // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:10-[[@LINE-3]]:20}:"" - // CHECK: fix-it:"{{.*}}":{[[@LINE-4]]:35-[[@LINE-4]]:36}:"" } #define test9 \ @@ -188,16 +167,11 @@ return std::move(a); \ } -// Macro test. The std::call is inside the macro, so no fix-it is suggested. test9 -// expected-warning@-1{{prevents copy elision}} -// CHECK-NOT: fix-it #define return_a return std::move(a) // Macro test. The std::call is inside the macro, so no fix-it is suggested. A test10(A a) { return_a; - // expected-warning@-1{{prevents copy elision}} - // CHECK-NOT: fix-it } Index: test/SemaCXX/warn-redundant-move.cpp =================================================================== --- test/SemaCXX/warn-redundant-move.cpp +++ test/SemaCXX/warn-redundant-move.cpp @@ -90,3 +90,10 @@ return std::move(b1); return std::move(b2); } + +//PR23819 +struct X {}; +X g(); +void h(X&&); +X f(X x) { return std::move(x); } //expected-warning{{redundant move in return statement}} \ + //expected-note{{remove std::move call here}}