[c++2a] P0515R3: Support for overloaded operator<=>.

No CodeGen support for MSABI yet, we don't know how to mangle this there.

llvm-svn: 319513

3 files changed, 39 insertions, 2 deletions

diff --git a/clang/test/CodeGenCXX/cxx2a-three-way-comparison.cpp b/clang/test/CodeGenCXX/cxx2a-three-way-comparison.cpp
new file mode 100644
index 00000000000..08ab41b1eaa
--- /dev/null
+++ b/clang/test/CodeGenCXX/cxx2a-three-way-comparison.cpp
@@ -0,0 +1,13 @@
+// RUN: %clang_cc1 -std=c++2a -emit-llvm %s -o - -triple %itanium_abi_triple | FileCheck %s --check-prefix=ITANIUM
+// RUN: not %clang_cc1 -std=c++2a -emit-llvm %s -o - -triple %ms_abi_triple 2>&1 | FileCheck %s --check-prefix=MSABI
+// MSABI: cannot mangle this three-way comparison operator yet
+
+struct A {
+  void operator<=>(int);
+};
+
+// ITANIUM: define {{.*}}@_ZN1AssEi(
+void A::operator<=>(int) {}
+
+// ITANIUM: define {{.*}}@_Zssi1A(
+void operator<=>(int, A) {}
diff --git a/clang/test/Lexer/cxx2a-spaceship.cpp b/clang/test/Lexer/cxx2a-spaceship.cpp
index f407937c4e3..604575ee976 100644
--- a/clang/test/Lexer/cxx2a-spaceship.cpp
+++ b/clang/test/Lexer/cxx2a-spaceship.cpp
@@ -10,7 +10,7 @@ namespace N {
 struct A {};
 void operator<=(A, A);
 #if __cplusplus > 201703L
-void operator<=>(A, A); // expected-error {{}}
+void operator<=>(A, A);
 #ifdef COMPAT
 // expected-warning@-2 {{'<=>' operator is incompatible with C++ standards before C++2a}}
 #endif
@@ -21,7 +21,7 @@ X<operator<=>
 #if __cplusplus <= 201703L
   // expected-warning@-2 {{'<=>' is a single token in C++2a; add a space to avoid a change in behavior}}
 #else
-  > // expected-error@-4 {{}}
+  >
 #endif
 #ifdef COMPAT
 // expected-warning@-7 {{'<=>' operator is incompatible with C++ standards before C++2a}}
diff --git a/clang/test/SemaCXX/cxx2a-three-way-comparison.cpp b/clang/test/SemaCXX/cxx2a-three-way-comparison.cpp
new file mode 100644
index 00000000000..eb1480ce610
--- /dev/null
+++ b/clang/test/SemaCXX/cxx2a-three-way-comparison.cpp
@@ -0,0 +1,24 @@
+// RUN: %clang_cc1 -std=c++2a -verify %s
+
+struct A {};
+constexpr int operator<=>(A a, A b) { return 42; }
+static_assert(operator<=>(A(), A()) == 42);
+
+int operator<=>(); // expected-error {{overloaded 'operator<=>' must have at least one parameter of class or enumeration type}}
+int operator<=>(A); // expected-error {{overloaded 'operator<=>' must be a binary operator}}
+int operator<=>(int, int); // expected-error {{overloaded 'operator<=>' must have at least one parameter of class or enumeration type}}
+int operator<=>(A, A, A); // expected-error {{overloaded 'operator<=>' must be a binary operator}}
+int operator<=>(A, A, ...); // expected-error {{overloaded 'operator<=>' cannot be variadic}}
+int operator<=>(int, A = {}); // expected-error {{parameter of overloaded 'operator<=>' cannot have a default argument}}
+
+struct B {
+  int &operator<=>(int);
+  friend int operator<=>(A, B);
+
+  friend int operator<=>(int, int); // expected-error {{overloaded 'operator<=>' must have at least one parameter of class or enumeration type}}
+  void operator<=>(); // expected-error {{overloaded 'operator<=>' must be a binary operator}};
+  void operator<=>(A, ...); // expected-error {{overloaded 'operator<=>' cannot be variadic}}
+  void operator<=>(A, A); // expected-error {{overloaded 'operator<=>' must be a binary operator}};
+};
+
+int &r = B().operator<=>(0);