P1286R2: Remove restriction that the exception specification of a

defaulted special member matches the implicit exception specification.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@360011 91177308-0d34-0410-b5e6-96231b3b80d8

6 files changed, 76 insertions, 26 deletions

diff --git a/test/CXX/dcl.decl/dcl.fct.def/dcl.fct.def.default/p2.cpp b/test/CXX/dcl.decl/dcl.fct.def/dcl.fct.def.default/p2.cpp
index c2f3b5a045..2b7886d383 100644
--- a/test/CXX/dcl.decl/dcl.fct.def/dcl.fct.def.default/p2.cpp
+++ b/test/CXX/dcl.decl/dcl.fct.def/dcl.fct.def.default/p2.cpp
@@ -56,8 +56,8 @@ constexpr S5::S5() = default;
 static_assert(S5().m == 4, "");
 
 
-// An explicitly-defaulted function may have an exception specification only if
-// it is compatible with the exception specification on an implicit declaration.
+// An explicitly-defaulted function may have a different exception specification
+// from the exception specification on an implicit declaration.
 struct E1 {
   E1() noexcept = default;
   E1(const E1&) noexcept = default;
@@ -67,13 +67,24 @@ struct E1 {
   ~E1() noexcept = default;
 };
 struct E2 {
-  E2() noexcept(false) = default; // expected-error {{exception specification of explicitly defaulted default constructor does not match the calculated one}}
-  E2(const E2&) noexcept(false) = default; // expected-error {{exception specification of explicitly defaulted copy constructor does not match the calculated one}}
-  E2(E2&&) noexcept(false) = default; // expected-error {{exception specification of explicitly defaulted move constructor does not match the calculated one}}
-  E2 &operator=(const E2&) noexcept(false) = default; // expected-error {{exception specification of explicitly defaulted copy assignment operator does not match the calculated one}}
-  E2 &operator=(E2&&) noexcept(false) = default; // expected-error {{exception specification of explicitly defaulted move assignment operator does not match the calculated one}}
-  ~E2() noexcept(false) = default; // expected-error {{exception specification of explicitly defaulted destructor does not match the calculated one}}
+  E2() noexcept(false) = default;
+  E2(const E2&) noexcept(false) = default;
+  E2(E2&&) noexcept(false) = default;
+  E2 &operator=(const E2&) noexcept(false) = default;
+  E2 &operator=(E2&&) noexcept(false) = default;
+  ~E2() noexcept(false) = default;
 };
+E2 e2;
+E2 make_e2() noexcept;
+void take_e2(E2&&) noexcept;
+static_assert(!noexcept(E2()), "");
+static_assert(!noexcept(E2(e2)), "");
+static_assert(!noexcept(E2(static_cast<E2&&>(e2))), "");
+static_assert(!noexcept(e2 = e2), "");
+static_assert(!noexcept(e2 = static_cast<E2&&>(e2)), "");
+// FIXME: This expression results in destruction of an E2 temporary; the
+// noexcept expression should evaluate to false.
+static_assert(noexcept(take_e2(make_e2())), "");
 
 // If a function is explicitly defaulted on its first declaration
 //   -- it is implicitly considered to have the same exception-specification as
diff --git a/test/CXX/drs/dr17xx.cpp b/test/CXX/drs/dr17xx.cpp
index bf7458ea81..ca55c42977 100644
--- a/test/CXX/drs/dr17xx.cpp
+++ b/test/CXX/drs/dr17xx.cpp
@@ -88,3 +88,18 @@ void f() {
 }
 #endif
 } // namespace dr1722
+
+namespace dr1778 { // dr1778: 9
+  // Superseded by P1286R2.
+#if __cplusplus >= 201103L
+  struct A { A() noexcept(true) = default; };
+  struct B { B() noexcept(false) = default; };
+  static_assert(noexcept(A()), "");
+  static_assert(!noexcept(B()), "");
+
+  struct C { A a; C() noexcept(false) = default; };
+  struct D { B b; D() noexcept(true) = default; };
+  static_assert(!noexcept(C()), "");
+  static_assert(noexcept(D()), "");
+#endif
+}
diff --git a/test/CXX/except/except.spec/p14.cpp b/test/CXX/except/except.spec/p14.cpp
index c717d97797..b1c8b207b4 100644
--- a/test/CXX/except/except.spec/p14.cpp
+++ b/test/CXX/except/except.spec/p14.cpp
@@ -83,7 +83,12 @@ namespace PR14141 {
     Derived &operator=(const Derived&) noexcept(false) = default;
     Derived &operator=(Derived&&) noexcept(false) = default;
     ~Derived() noexcept(false) = default;
-  };
+  } d1;
+  static_assert(!noexcept(Derived()), "");
+  static_assert(!noexcept(Derived(static_cast<Derived&&>(d1))), "");
+  static_assert(!noexcept(Derived(d1)), "");
+  static_assert(!noexcept(d1 = static_cast<Derived&&>(d1)), "");
+  static_assert(!noexcept(d1 = d1), "");
   struct Derived2 : ThrowingBase {
     Derived2() = default;
     Derived2(const Derived2&) = default;
@@ -91,15 +96,21 @@ namespace PR14141 {
     Derived2 &operator=(const Derived2&) = default;
     Derived2 &operator=(Derived2&&) = default;
     ~Derived2() = default;
-  };
+  } d2;
+  static_assert(!noexcept(Derived2()), "");
+  static_assert(!noexcept(Derived2(static_cast<Derived2&&>(d2))), "");
+  static_assert(!noexcept(Derived2(d2)), "");
+  static_assert(!noexcept(d2 = static_cast<Derived2&&>(d2)), "");
+  static_assert(!noexcept(d2 = d2), "");
   struct Derived3 : ThrowingBase {
-    Derived3() noexcept(true) = default; // expected-error {{does not match the calculated}}
-    Derived3(const Derived3&) noexcept(true) = default; // expected-error {{does not match the calculated}}
-    Derived3(Derived3&&) noexcept(true) = default; // expected-error {{does not match the calculated}}
-    Derived3 &operator=(const Derived3&) noexcept(true) = default; // expected-error {{does not match the calculated}}
-    Derived3 &operator=(Derived3&&) noexcept(true) = default; // expected-error {{does not match the calculated}}
-    ~Derived3() noexcept(true) = default; // expected-error {{does not match the calculated}}
-  };
+    Derived3() noexcept(true) = default;
+    Derived3(const Derived3&) noexcept(true) = default;
+    Derived3(Derived3&&) noexcept(true) = default;
+    Derived3 &operator=(const Derived3&) noexcept(true) = default;
+    Derived3 &operator=(Derived3&&) noexcept(true) = default;
+    ~Derived3() noexcept(true) = default;
+  } d3;
+  static_assert(noexcept(Derived3(), Derived3(Derived3()), Derived3(d3), d3 = Derived3(), d3 = d3), "");
 }
 
 namespace rdar13017229 {
diff --git a/test/SemaCXX/cxx0x-defaulted-functions.cpp b/test/SemaCXX/cxx0x-defaulted-functions.cpp
index 6346e1c235..45a65440d5 100644
--- a/test/SemaCXX/cxx0x-defaulted-functions.cpp
+++ b/test/SemaCXX/cxx0x-defaulted-functions.cpp
@@ -189,11 +189,11 @@ namespace PR15597 {
     ~A() noexcept(true) = default;
   };
   template<typename T> struct B {
-    B() noexcept(false) = default; // expected-error {{does not match the calculated one}}
-    ~B() noexcept(false) = default; // expected-error {{does not match the calculated one}}
+    B() noexcept(false) = default;
+    ~B() noexcept(false) = default;
   };
   A<int> a;
-  B<int> b; // expected-note {{here}}
+  B<int> b;
 }
 
 namespace PR27941 {
@@ -242,3 +242,20 @@ template <typename Type>
 E<Type>::E(const int&) {}  // expected-error {{definition of explicitly defaulted function}}
 
 }
+
+namespace P1286R2 {
+  struct X {
+    X();
+  };
+  struct A {
+    struct B {
+      B() noexcept(A::value) = default;
+      X x;
+    };
+    decltype(B()) b;
+    static constexpr bool value = true;
+  };
+  A::B b;
+
+  static_assert(noexcept(A::B()), "");
+}
diff --git a/test/SemaCXX/member-init.cpp b/test/SemaCXX/member-init.cpp
index 2c4659afa3..3fcee50e63 100644
--- a/test/SemaCXX/member-init.cpp
+++ b/test/SemaCXX/member-init.cpp
@@ -51,7 +51,7 @@ struct CheckExcSpec {
   int n = 0;
 };
 struct CheckExcSpecFail {
-  CheckExcSpecFail() noexcept(true) = default; // expected-error {{exception specification of explicitly defaulted default constructor does not match the calculated one}}
+  CheckExcSpecFail() noexcept(true) = default; // ok, but calls terminate() on exception
   ThrowCtor tc = 123;
 };
 
diff --git a/test/SemaTemplate/exception-spec-crash.cpp b/test/SemaTemplate/exception-spec-crash.cpp
index ebbb30a2c2..1418ba65e1 100644
--- a/test/SemaTemplate/exception-spec-crash.cpp
+++ b/test/SemaTemplate/exception-spec-crash.cpp
@@ -1,5 +1,6 @@
 // RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s -Wno-defaulted-function-deleted
 // RUN: %clang_cc1 -std=c++11 -fcxx-exceptions -DCXX_EXCEPTIONS -fsyntax-only -verify %s -Wno-defaulted-function-deleted
+// expected-no-diagnostics
 
 template <class _Tp> struct is_nothrow_move_constructible {
   static const bool value = false;
@@ -20,11 +21,6 @@ class basic_string {
 
 class Foo {
   Foo(Foo &&) noexcept = default;
-#ifdef CXX_EXCEPTIONS
-// expected-error@-2 {{does not match the calculated}}
-#else
-// expected-no-diagnostics
-#endif
   Foo &operator=(Foo &&) noexcept = default;
   basic_string<allocator<char> > vectorFoo_;
 };