clang/test/SemaCXX/co_await-range-for.cpp

   1 // RUN: %clang_cc1 -triple x86_64-apple-darwin9 %s -std=c++20 \
   2 // RUN:    -fsyntax-only -Wignored-qualifiers -Wno-error=return-type -verify \
   3 // RUN:    -fblocks
   4 #include "Inputs/std-coroutine.h"
   5
   6 using namespace std;
   7
   8 template <class Begin>
   9 struct Awaiter {
  10   bool await_ready();
  11   void await_suspend(coroutine_handle<>);
  12   Begin await_resume();
  13 };
  14
  15 template <class Iter> struct BeginTag { BeginTag() = delete; };
  16 template <class Iter> struct IncTag { IncTag() = delete; };
  17
  18 template <class Iter, bool Delete = false>
  19 struct CoawaitTag { CoawaitTag() = delete; };
  20
  21 template <class T>
  22 struct Iter {
  23   using value_type = T;
  24   using reference = T &;
  25   using pointer = T *;
  26
  27   IncTag<Iter> operator++();
  28   reference operator*();
  29   pointer operator->();
  30 };
  31 template <class T> bool operator==(Iter<T>, Iter<T>);
  32 template <class T> bool operator!=(Iter<T>, Iter<T>);
  33
  34 template <class T>
  35 struct Range {
  36   BeginTag<Iter<T>> begin();
  37   Iter<T> end();
  38 };
  39
  40 struct MyForLoopArrayAwaiter {
  41   struct promise_type {
  42     MyForLoopArrayAwaiter get_return_object() { return {}; }
  43     void return_void();
  44     void unhandled_exception();
  45     suspend_never initial_suspend();
  46     suspend_never final_suspend() noexcept;
  47     template <class T>
  48     Awaiter<T *> await_transform(T *) = delete; // expected-note {{explicitly deleted}}
  49   };
  50 };
  51 MyForLoopArrayAwaiter g() {
  52   int arr[10] = {0};
  53   for co_await(auto i : arr) {} // expected-warning {{'for co_await' belongs to CoroutineTS instead of C++20, which is deprecated}}
  54   // expected-error@-1 {{call to deleted member function 'await_transform'}}
  55   // expected-note@-2 {{'await_transform' implicitly required by 'co_await' here}}
  56 }
  57
  58 struct ForLoopAwaiterBadBeginTransform {
  59   struct promise_type {
  60     ForLoopAwaiterBadBeginTransform get_return_object();
  61     void return_void();
  62     void unhandled_exception();
  63     suspend_never initial_suspend();
  64     suspend_never final_suspend() noexcept;
  65
  66     template <class T>
  67     Awaiter<T> await_transform(BeginTag<T>) = delete; // expected-note 1+ {{explicitly deleted}}
  68
  69     template <class T>
  70     CoawaitTag<T> await_transform(IncTag<T>); // expected-note 1+ {{candidate}}
  71   };
  72 };
  73 ForLoopAwaiterBadBeginTransform bad_begin() {
  74   Range<int> R;
  75   for co_await(auto i : R) {} // expected-warning {{'for co_await' belongs to CoroutineTS instead of C++20, which is deprecated}}
  76   // expected-error@-1 {{call to deleted member function 'await_transform'}}
  77   // expected-note@-2 {{'await_transform' implicitly required by 'co_await' here}}
  78 }
  79 template <class Dummy>
  80 ForLoopAwaiterBadBeginTransform bad_begin_template(Dummy) {
  81   Range<Dummy> R;
  82   for co_await(auto i : R) {} // expected-warning {{'for co_await' belongs to CoroutineTS instead of C++20, which is deprecated}}
  83   // expected-error@-1 {{call to deleted member function 'await_transform'}}
  84   // expected-note@-2 {{'await_transform' implicitly required by 'co_await' here}}
  85 }
  86 template ForLoopAwaiterBadBeginTransform bad_begin_template(int); // expected-note {{requested here}}
  87
  88 template <class Iter>
  89 Awaiter<Iter> operator co_await(CoawaitTag<Iter, true>) = delete;
  90 // expected-note@-1 1+ {{explicitly deleted}}
  91
  92 struct ForLoopAwaiterBadIncTransform {
  93   struct promise_type {
  94     ForLoopAwaiterBadIncTransform get_return_object();
  95     void return_void();
  96     void unhandled_exception();
  97     suspend_never initial_suspend();
  98     suspend_never final_suspend() noexcept;
  99
 100     template <class T>
 101     Awaiter<T> await_transform(BeginTag<T> e);
 102
 103     template <class T>
 104     CoawaitTag<T, true> await_transform(IncTag<T>);
 105   };
 106 };
 107 ForLoopAwaiterBadIncTransform bad_inc_transform() {
 108   Range<float> R;
 109   for co_await(auto i : R) {} // expected-warning {{'for co_await' belongs to CoroutineTS instead of C++20, which is deprecated}}
 110   // expected-error@-1 {{overload resolution selected deleted operator 'co_await'}}
 111   // expected-note@-2 {{in implicit call to 'operator++' for iterator of type 'Range<float>'}}
 112 }
 113
 114 template <class Dummy>
 115 ForLoopAwaiterBadIncTransform bad_inc_transform_template(Dummy) {
 116   Range<Dummy> R;
 117   for co_await(auto i : R) {} // expected-warning {{'for co_await' belongs to CoroutineTS instead of C++20, which is deprecated}}
 118   // expected-error@-1 {{overload resolution selected deleted operator 'co_await'}}
 119   // expected-note@-2 {{in implicit call to 'operator++' for iterator of type 'Range<long>'}}
 120 }
 121 template ForLoopAwaiterBadIncTransform bad_inc_transform_template(long); // expected-note {{requested here}}
 122
 123 // Ensure we mark and check the function as a coroutine even if it's
 124 // never instantiated.
 125 template <class T>
 126 constexpr void never_instant(T) {
 127   static_assert(sizeof(T) != sizeof(T), "function should not be instantiated");
 128   for co_await(auto i : foo(T{})) {} // expected-warning {{'for co_await' belongs to CoroutineTS instead of C++20, which is deprecated}}
 129   // expected-error@-1 {{'co_await' cannot be used in a constexpr function}}
 130 }
 131
 132 namespace NS {
 133 struct ForLoopAwaiterCoawaitLookup {
 134   struct promise_type {
 135     ForLoopAwaiterCoawaitLookup get_return_object();
 136     void return_void();
 137     void unhandled_exception();
 138     suspend_never initial_suspend();
 139     suspend_never final_suspend() noexcept;
 140     template <class T>
 141     CoawaitTag<T, false> await_transform(BeginTag<T> e);
 142     template <class T>
 143     Awaiter<T> await_transform(IncTag<T>);
 144   };
 145 };
 146 } // namespace NS
 147 using NS::ForLoopAwaiterCoawaitLookup;
 148
 149 template <class T>
 150 ForLoopAwaiterCoawaitLookup test_coawait_lookup(T) {
 151   Range<T> R;
 152   for co_await(auto i : R) {} // expected-warning {{'for co_await' belongs to CoroutineTS instead of C++20, which is deprecated}}
 153   // expected-error@-1 {{no member named 'await_ready' in 'CoawaitTag<Iter<int>>'}}
 154 }
 155 template ForLoopAwaiterCoawaitLookup test_coawait_lookup(int); // expected-note {{requested here}}
 156
 157 // FIXME: This test should fail as well since the newly declared operator co_await
 158 // should not be found by lookup.
 159 namespace NS2 {
 160 template <class Iter>
 161 Awaiter<Iter> operator co_await(CoawaitTag<Iter, false>);
 162 }
 163 using NS2::operator co_await;
 164 template ForLoopAwaiterCoawaitLookup test_coawait_lookup(long);