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// RUN: %clang_cc1 -fsyntax-only -std=c++11 -Wloop-analysis -verify %s
// RUN: %clang_cc1 -fsyntax-only -std=c++11 -Wrange-loop-analysis -verify %s
template <typename return_type>
struct Iterator {
return_type operator*();
Iterator operator++();
bool operator!=(const Iterator);
};
template <typename T>
struct Container {
typedef Iterator<T> I;
I begin();
I end();
};
struct Foo {};
struct Bar {
Bar(Foo);
Bar(int);
operator int();
};
// Testing notes:
// test0 checks that the full text of the warnings and notes is correct. The
// rest of the tests checks a smaller portion of the text.
// test1-6 are set in pairs, the odd numbers are the non-reference returning
// versions of the even numbers.
// test7-9 use an array instead of a range object
// tests use all four versions of the loop variable, const &T, const T, T&, and
// T. Versions producing errors and are commented out.
//
// Conversion chart:
// double <=> int
// int <=> Bar
// double => Bar
// Foo => Bar
//
// Conversions during tests:
// test1-2
// int => int
// int => double
// int => Bar
// test3-4
// Bar => Bar
// Bar => int
// test5-6
// Foo => Bar
// test7
// double => double
// double => int
// double => Bar
// test8
// Foo => Foo
// Foo => Bar
// test9
// Bar => Bar
// Bar => int
void test0() {
Container<int> int_non_ref_container;
Container<int&> int_container;
Container<Bar&> bar_container;
for (const int &x : int_non_ref_container) {}
// expected-warning@-1 {{loop variable 'x' is always a copy because the range of type 'Container<int>' does not return a reference}}
// expected-note@-2 {{use non-reference type 'int'}}
for (const double &x : int_container) {}
// expected-warning@-1 {{loop variable 'x' has type 'const double &' but is initialized with type 'int' resulting in a copy}}
// expected-note@-2 {{use non-reference type 'double' to keep the copy or type 'const int &' to prevent copying}}
for (const Bar x : bar_container) {}
// expected-warning@-1 {{loop variable 'x' of type 'const Bar' creates a copy from type 'const Bar'}}
// expected-note@-2 {{use reference type 'const Bar &' to prevent copying}}
}
void test1() {
Container<int> A;
for (const int &x : A) {}
// expected-warning@-1 {{always a copy}}
// expected-note@-2 {{'int'}}
for (const int x : A) {}
// No warning, non-reference type indicates copy is made
//for (int &x : A) {}
// Binding error
for (int x : A) {}
// No warning, non-reference type indicates copy is made
for (const double &x : A) {}
// expected-warning@-1 {{always a copy}}
// expected-note@-2 {{'double'}}
for (const double x : A) {}
// No warning, non-reference type indicates copy is made
//for (double &x : A) {}
// Binding error
for (double x : A) {}
// No warning, non-reference type indicates copy is made
for (const Bar &x : A) {}
// expected-warning@-1 {{always a copy}}
// expected-note@-2 {{'Bar'}}
for (const Bar x : A) {}
// No warning, non-reference type indicates copy is made
//for (Bar &x : A) {}
// Binding error
for (Bar x : A) {}
// No warning, non-reference type indicates copy is made
}
void test2() {
Container<int&> B;
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) {}
// 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 &'}}
for (const double x : B) {}
//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'}}
for (const Bar x : B) {}
//for (Bar &x : B) {}
// Binding error
for (Bar x : B) {}
// No warning
}
void test3() {
Container<Bar> C;
for (const Bar &x : C) {}
// expected-warning@-1 {{always a copy}}
// expected-note@-2 {{'Bar'}}
for (const Bar x : C) {}
// No warning, non-reference type indicates copy is made
//for (Bar &x : C) {}
// Binding error
for (Bar x : C) {}
// No warning, non-reference type indicates copy is made
for (const int &x : C) {}
// expected-warning@-1 {{always a copy}}
// expected-note@-2 {{'int'}}
for (const int x : C) {}
// No warning, copy made
//for (int &x : C) {}
// Binding error
for (int x : C) {}
// No warning, copy made
}
void test4() {
Container<Bar&> D;
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 &'}}
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 &'}}
for (const int x : D) {}
// No warning
//for (int &x : D) {}
// Binding error
for (int x : D) {}
// No warning
}
void test5() {
Container<Foo> E;
for (const Bar &x : E) {}
// expected-warning@-1 {{always a copy}}
// expected-note@-2 {{'Bar'}}
for (const Bar x : E) {}
// No warning, non-reference type indicates copy is made
//for (Bar &x : E) {}
// Binding error
for (Bar x : E) {}
// No warning, non-reference type indicates copy is made
}
void test6() {
Container<Foo&> F;
for (const Bar &x : F) {}
// expected-warning@-1 {{resulting in a copy}}
// expected-note-re@-2 {{'Bar'{{.*}}'const Foo &'}}
for (const Bar x : F) {}
// No warning.
//for (Bar &x : F) {}
// Binding error
for (Bar x : F) {}
// No warning
}
void test7() {
double G[2];
for (const double &x : G) {}
// No warning
for (const double x : G) {}
// No warning on POD copy
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 &'}}
for (const int x : G) {}
// No warning
//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 &'}}
for (const Bar x : G) {}
// No warning
//for (int &Bar : G) {}
// Binding error
for (int Bar : G) {}
// No warning
}
void test8() {
Foo H[2];
for (const Foo &x : H) {}
// No warning
for (const Foo x : H) {}
// No warning on POD copy
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 &'}}
for (const Bar x : H) {}
// No warning
//for (Bar &x: H) {}
// Binding error
for (Bar x: H) {}
// No warning
}
void test9() {
Bar I[2] = {1,2};
for (const Bar &x : I) {}
// No warning
for (const Bar x : I) {}
// expected-warning@-1 {{creates a copy}}
// expected-note@-2 {{'const Bar &'}}
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 &'}}
for (const int x : I) {}
// No warning
//for (int &x : I) {}
// Binding error
for (int x : I) {}
// No warning
}
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