Index: clang/lib/Sema/SemaStmt.cpp =================================================================== --- clang/lib/Sema/SemaStmt.cpp +++ clang/lib/Sema/SemaStmt.cpp @@ -2764,9 +2764,11 @@ SemaRef.Diag(VD->getBeginLoc(), diag::note_use_type_or_non_reference) << NonReferenceType << NewReferenceType << VD->getSourceRange() << FixItHint::CreateRemoval(VD->getTypeSpecEndLoc()); - } else { + } else if (!VariableType->isRValueReferenceType()) { // The range always returns a copy, so a temporary is always created. // Suggest removing the reference from the loop variable. + // If the type is a rvalue reference do not warn since that changes the + // semantic of the code. SemaRef.Diag(VD->getLocation(), diag::warn_for_range_variable_always_copy) << VD << RangeInitType; QualType NonReferenceType = VariableType.getNonReferenceType(); Index: clang/test/SemaCXX/warn-range-loop-analysis.cpp =================================================================== --- clang/test/SemaCXX/warn-range-loop-analysis.cpp +++ clang/test/SemaCXX/warn-range-loop-analysis.cpp @@ -85,34 +85,46 @@ void test1() { Container A; + for (const int &&x : A) {} + // No warning, rvalue-reference to the temporary for (const int &x : A) {} // expected-warning@-1 {{always a copy}} // expected-note@-2 {{'int'}} // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:19}:"" for (const int x : A) {} // No warning, non-reference type indicates copy is made + for (int&& x : A) {} + // No warning, rvalue-reference to the temporary //for (int &x : A) {} // Binding error for (int x : A) {} // No warning, non-reference type indicates copy is made + for (const double &&x : A) {} + // No warning, rvalue-reference to the temporary for (const double &x : A) {} // expected-warning@-1 {{always a copy}} // expected-note@-2 {{'double'}} // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:21-[[@LINE-3]]:22}:"" for (const double x : A) {} // No warning, non-reference type indicates copy is made + for (double &&x : A) {} + // No warning, rvalue-reference to the temporary //for (double &x : A) {} // Binding error for (double x : A) {} // No warning, non-reference type indicates copy is made + for (const Bar &&x : A) {} + // No warning, rvalue-reference to the temporary for (const Bar &x : A) {} // expected-warning@-1 {{always a copy}} // expected-note@-2 {{'Bar'}} // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:19}:"" for (const Bar x : A) {} // No warning, non-reference type indicates copy is made + for (Bar &&x : A) {} + // No warning, rvalue-reference to the temporary //for (Bar &x : A) {} // Binding error for (Bar x : A) {} @@ -122,30 +134,50 @@ void test2() { Container B; + //for (const int &&x : B) {} + // Binding error for (const int &x : B) {} // No warning, this reference is not a temporary for (const int x : B) {} // No warning on POD copy + //for (int &x : B) {} + // Binding error for (int &x : B) {} // No warning for (int x : B) {} // No warning + for (const double &&x : B) {} + // expected-warning@-1 {{resulting in a copy}} + // expected-note-re@-2 {{'double'{{.*}}'const int &'}} + // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:21-[[@LINE-3]]:23}:"" for (const double &x : B) {} // expected-warning@-1 {{resulting in a copy}} // expected-note-re@-2 {{'double'{{.*}}'const int &'}} // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:21-[[@LINE-3]]:22}:"" for (const double x : B) {} + for (double &&x : B) {} + // expected-warning@-1 {{resulting in a copy}} + // expected-note-re@-2 {{'double'{{.*}}'const int &'}} + // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:15-[[@LINE-3]]:17}:"" //for (double &x : B) {} // Binding error for (double x : B) {} // No warning + for (const Bar &&x : B) {} + // expected-warning@-1 {{resulting in a copy}} + // expected-note@-2 {{'Bar'}} + // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:20}:"" for (const Bar &x : B) {} // expected-warning@-1 {{resulting in a copy}} // expected-note@-2 {{'Bar'}} // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:19}:"" for (const Bar x : B) {} + for (Bar &&x : B) {} + // expected-warning@-1 {{resulting in a copy}} + // expected-note@-2 {{'Bar'}} + // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:12-[[@LINE-3]]:14}:"" //for (Bar &x : B) {} // Binding error for (Bar x : B) {} @@ -155,23 +187,31 @@ void test3() { Container C; + for (const Bar &&x : C) {} + // No warning, rvalue-reference to the temporary for (const Bar &x : C) {} // expected-warning@-1 {{always a copy}} // expected-note@-2 {{'Bar'}} // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:19}:"" for (const Bar x : C) {} // No warning, non-reference type indicates copy is made + for (Bar &&x : C) {} + // No warning, rvalue-reference to the temporary //for (Bar &x : C) {} // Binding error for (Bar x : C) {} // No warning, non-reference type indicates copy is made + for (const int &&x : C) {} + // No warning, rvalue-reference to the temporary for (const int &x : C) {} // expected-warning@-1 {{always a copy}} // expected-note@-2 {{'int'}} // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:19}:"" for (const int x : C) {} // No warning, copy made + for (int &&x : C) {} + // No warning, rvalue-reference to the temporary //for (int &x : C) {} // Binding error for (int x : C) {} @@ -181,23 +221,35 @@ void test4() { Container D; + //for (const Bar &&x : D) {} + // Binding error for (const Bar &x : D) {} // No warning, this reference is not a temporary for (const Bar x : D) {} // expected-warning@-1 {{creates a copy}} // expected-note@-2 {{'const Bar &'}} // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:18}:"&" + //for (Bar &&x : D) {} + // Binding error for (Bar &x : D) {} // No warning for (Bar x : D) {} // No warning + for (const int &&x : D) {} + // expected-warning@-1 {{resulting in a copy}} + // expected-note-re@-2 {{'int'{{.*}}'const Bar &'}} + // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:20}:"" for (const int &x : D) {} // expected-warning@-1 {{resulting in a copy}} // expected-note-re@-2 {{'int'{{.*}}'const Bar &'}} // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:19}:"" for (const int x : D) {} // No warning + for (int &&x : D) {} + // expected-warning@-1 {{resulting in a copy}} + // expected-note-re@-2 {{'int'{{.*}}'const Bar &'}} + // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:12-[[@LINE-3]]:14}:"" //for (int &x : D) {} // Binding error for (int x : D) {} @@ -207,12 +259,16 @@ void test5() { Container E; + for (const Bar &&x : E) {} + // No warning, rvalue-reference to the temporary for (const Bar &x : E) {} // expected-warning@-1 {{always a copy}} // expected-note@-2 {{'Bar'}} // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:19}:"" for (const Bar x : E) {} // No warning, non-reference type indicates copy is made + for (Bar &&x : E) {} + // No warning, rvalue-reference to the temporary //for (Bar &x : E) {} // Binding error for (Bar x : E) {} @@ -222,12 +278,20 @@ void test6() { Container F; + for (const Bar &&x : F) {} + // expected-warning@-1 {{resulting in a copy}} + // expected-note-re@-2 {{'Bar'{{.*}}'const Foo &'}} + // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:20}:"" for (const Bar &x : F) {} // expected-warning@-1 {{resulting in a copy}} // expected-note-re@-2 {{'Bar'{{.*}}'const Foo &'}} // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:19}:"" for (const Bar x : F) {} // No warning. + for (Bar &&x : F) {} + // expected-warning@-1 {{resulting in a copy}} + // expected-note-re@-2 {{'Bar'{{.*}}'const Foo &'}} + // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:12-[[@LINE-3]]:14}:"" //for (Bar &x : F) {} // Binding error for (Bar x : F) {} @@ -237,56 +301,88 @@ void test7() { double G[2]; + //for (const double &&x : G) {} + // Binding error for (const double &x : G) {} // No warning for (const double x : G) {} // No warning on POD copy + //for (double &&x : G) {} + // Binding error for (double &x : G) {} // No warning for (double x : G) {} // No warning + for (const int &&x : G) {} + // expected-warning@-1 {{resulting in a copy}} + // expected-note-re@-2 {{'int'{{.*}}'const double &'}} + // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:20}:"" for (const int &x : G) {} // expected-warning@-1 {{resulting in a copy}} // expected-note-re@-2 {{'int'{{.*}}'const double &'}} // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:19}:"" for (const int x : G) {} // No warning + for (int &&x : G) {} + // expected-warning@-1 {{resulting in a copy}} + // expected-note-re@-2 {{'int'{{.*}}'const double &'}} + // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:12-[[@LINE-3]]:14}:"" //for (int &x : G) {} // Binding error for (int x : G) {} // No warning + for (const Bar &&x : G) {} + // expected-warning@-1 {{resulting in a copy}} + // expected-note-re@-2 {{'Bar'{{.*}}'const double &'}} + // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:20}:"" for (const Bar &x : G) {} // expected-warning@-1 {{resulting in a copy}} // expected-note-re@-2 {{'Bar'{{.*}}'const double &'}} // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:19}:"" for (const Bar x : G) {} // No warning - //for (int &Bar : G) {} + for (Bar &&x : G) {} + // expected-warning@-1 {{resulting in a copy}} + // expected-note-re@-2 {{'Bar'{{.*}}'const double &'}} + // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:12-[[@LINE-3]]:14}:"" + //for (Bar &x : G) {} // Binding error - for (int Bar : G) {} + for (Bar x : G) {} // No warning } void test8() { Foo H[2]; + //for (const Foo &&x : H) {} + // Binding error for (const Foo &x : H) {} // No warning for (const Foo x : H) {} // No warning on POD copy + //for (Foo &&x : H) {} + // Binding error for (Foo &x : H) {} // No warning for (Foo x : H) {} // No warning + for (const Bar &&x : H) {} + // expected-warning@-1 {{resulting in a copy}} + // expected-note-re@-2 {{'Bar'{{.*}}'const Foo &'}} + // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:20}:"" for (const Bar &x : H) {} // expected-warning@-1 {{resulting in a copy}} // expected-note-re@-2 {{'Bar'{{.*}}'const Foo &'}} // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:19}:"" for (const Bar x : H) {} // No warning + for (Bar &&x: H) {} + // expected-warning@-1 {{resulting in a copy}} + // expected-note-re@-2 {{'Bar'{{.*}}'const Foo &'}} + // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:12-[[@LINE-3]]:14}:"" //for (Bar &x: H) {} // Binding error for (Bar x: H) {} @@ -296,23 +392,35 @@ void test9() { Bar I[2] = {1,2}; + //for (const Bar &&x : I) {} + // Binding error for (const Bar &x : I) {} // No warning for (const Bar x : I) {} // expected-warning@-1 {{creates a copy}} // expected-note@-2 {{'const Bar &'}} // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:18}:"&" + //for (Bar &&x : I) {} + // Binding error for (Bar &x : I) {} // No warning for (Bar x : I) {} // No warning + for (const int &&x : I) {} + // expected-warning@-1 {{resulting in a copy}} + // expected-note-re@-2 {{'int'{{.*}}'const Bar &'}} + // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:20}:"" for (const int &x : I) {} // expected-warning@-1 {{resulting in a copy}} // expected-note-re@-2 {{'int'{{.*}}'const Bar &'}} // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:19}:"" for (const int x : I) {} // No warning + for (int &&x : I) {} + // expected-warning@-1 {{resulting in a copy}} + // expected-note-re@-2 {{'int'{{.*}}'const Bar &'}} + // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:12-[[@LINE-3]]:14}:"" //for (int &x : I) {} // Binding error for (int x : I) {}