clang/test/Lexer/cxx2a-spaceship.cpp

   1 // RUN: %clang_cc1 -std=c++17 %s -verify
   2 // RUN: %clang_cc1 -std=c++20 %s -verify
   3 // RUN: %clang_cc1 -std=c++20 %s -verify -Wc++17-compat -DCOMPAT
   4 //
   5 // RUN: %clang_cc1 -std=c++17 %s -E -o - | FileCheck %s --check-prefix=CXX17
   6 // RUN: %clang_cc1 -std=c++20 %s -E -o - | FileCheck %s --check-prefix=CXX20
   7
   8 namespace N {
   9
  10 struct A {};
  11 void operator<=(A, A);
  12 #if __cplusplus > 201703L
  13 void operator<=>(A, A);
  14 #ifdef COMPAT
  15 // expected-warning@-2 {{'<=>' operator is incompatible with C++ standards before C++20}}
  16 #endif
  17 #endif
  18
  19 template<auto> struct X {};
  20 X<operator<=>
  21 #if __cplusplus <= 201703L
  22   // expected-warning@-2 {{'<=>' is a single token in C++20; add a space to avoid a change in behavior}}
  23 #else
  24   >
  25 #endif
  26 #ifdef COMPAT
  27 // expected-warning@-7 {{'<=>' operator is incompatible with C++ standards before C++20}}
  28 #endif
  29   x;
  30 }
  31
  32 // <=> can be formed by pasting other comparison operators.
  33 #if __cplusplus > 201703L
  34 #define STR(x) #x
  35 #define STR_EXPANDED(x) STR(x)
  36 #define PASTE(x, y) x ## y
  37 constexpr char a[] = STR_EXPANDED(PASTE(<, =>));
  38 constexpr char b[] = STR_EXPANDED(PASTE(<=, >));
  39 static_assert(__builtin_strcmp(a, "<=>") == 0);
  40 static_assert(__builtin_strcmp(b, "<=>") == 0);
  41 #endif
  42
  43 // -E must not accidentally form a <=> token.
  44
  45 // CXX17: preprocess1: < =>
  46 // CXX17: preprocess2: <=>
  47 // CXX17: preprocess3: < =>
  48 // CXX17: preprocess4: <=>=
  49 // CXX17: preprocess5: <=>>
  50 // CXX17: preprocess6: <=>>=
  51 // CXX17: preprocess7: <=>
  52 // CXX17: preprocess8: <=>=
  53 //
  54 // CXX20: preprocess1: < =>
  55 // CXX20: preprocess2: <= >
  56 // CXX20: preprocess3: < =>
  57 // CXX20: preprocess4: <= >=
  58 // CXX20: preprocess5: <= >>
  59 // CXX20: preprocess6: <= >>=
  60 // CXX20: preprocess7: <=>
  61 // CXX20: preprocess8: <=>=
  62
  63 #define ID(x) x
  64 [[some_vendor::some_attribute( // expected-warning {{unknown attribute}}
  65 preprocess1: ID(<)ID(=>),
  66 preprocess2: ID(<=)ID(>),
  67 preprocess3: ID(<)ID(=)ID(>),
  68 preprocess4: ID(<=)ID(>=),
  69 preprocess5: ID(<=)ID(>>),
  70 preprocess6: ID(<=)ID(>>=),
  71 preprocess7: ID(<=>) // expected-warning 0-1{{'<=>'}}
  72 preprocess8: ID(<=>=) // expected-warning 0-1{{'<=>'}}
  73 )]];