clang/test/SemaCXX/nothrow-vs-exception-specs.cpp

   1 // RUN: %clang_cc1 %s -fcxx-exceptions -fdeclspec -fsyntax-only -Wexceptions -verify -std=c++14
   2 // RUN: %clang_cc1 %s -fcxx-exceptions -fdeclspec -fsyntax-only -Wexceptions -verify -std=c++17 -DCPP17
   3
   4 __attribute__((nothrow)) void f1();
   5 static_assert(noexcept(f1()), "");
   6 void f1() noexcept;
   7 // expected-error@+2 {{exception specification in declaration does not match previous declaration}}
   8 // expected-note@-2 {{previous declaration is here}}
   9 void f1() noexcept(false);
  10
  11 __attribute__((nothrow)) void f2();
  12 static_assert(noexcept(f2()), "");
  13 // expected-error@+2 {{exception specification in declaration does not match previous declaration}}
  14 // expected-note@-3 {{previous declaration is here}}
  15 void f2() noexcept(false);
  16
  17 void f3() __attribute__((nothrow));
  18 static_assert(noexcept(f3()), "");
  19 void f3() noexcept;
  20 // expected-error@+2 {{exception specification in declaration does not match previous declaration}}
  21 // expected-note@-2 {{previous declaration is here}}
  22 void f3() noexcept(false);
  23
  24 // Still noexcept due to throw()
  25 __attribute__((nothrow)) void f4() throw();
  26 static_assert(noexcept(f4()), "");
  27
  28 // Still noexcept due to noexcept
  29 __attribute__((nothrow)) void f5() noexcept;
  30 static_assert(noexcept(f5()), "");
  31
  32 // Still noexcept due to noexcept(true)
  33 __attribute__((nothrow)) void f6() noexcept(true);
  34 static_assert(noexcept(f6()), "");
  35
  36 #ifndef CPP17
  37 // Doesn't override C++ implementation.
  38 // expected-warning@+1{{'nothrow' attribute conflicts with exception specification; attribute ignored}}
  39 __attribute__((nothrow)) void f7() throw(int);
  40 static_assert(!noexcept(f7()), "");
  41 #endif
  42
  43 // Doesn't override C++ implementation.
  44 // expected-warning@+1{{'nothrow' attribute conflicts with exception specification; attribute ignored}}
  45 __attribute__((nothrow)) void f8() noexcept(false);
  46 static_assert(!noexcept(f8()), "");
  47
  48 __declspec(nothrow) void foo1() noexcept;
  49 __declspec(nothrow) void foo2() noexcept(true);
  50 // expected-warning@+1{{'nothrow' attribute conflicts with exception specification; attribute ignored}}
  51 __declspec(nothrow) void foo3() noexcept(false);
  52 __declspec(nothrow) void foo4() noexcept(noexcept(foo1()));
  53 __declspec(nothrow) void foo5() noexcept(noexcept(foo2()));
  54 // expected-warning@+1{{'nothrow' attribute conflicts with exception specification; attribute ignored}}
  55 __declspec(nothrow) void foo6() noexcept(noexcept(foo3()));
  56
  57 template<typename F>
  58 __declspec(nothrow) void foo7() noexcept(noexcept(F()));
  59
  60 // FIXME: It would be nice to be able to warn on these, however at the time we
  61 // evaluate the nothrow, these have yet to be parsed, so the data is not yet
  62 // there.
  63 struct S {
  64   __declspec(nothrow) void f1();
  65 #ifndef CPP17
  66   __declspec(nothrow) void f2() throw();
  67   __declspec(nothrow) void f3() throw(int);
  68 #endif
  69   __declspec(nothrow) void f4() noexcept(true);
  70   __declspec(nothrow) void f5() noexcept(false);
  71 };
  72
  73 namespace PR42100 {
  74 class Base {
  75 public:
  76   // expected-note@+1{{overridden virtual function is here}}
  77   virtual __declspec(nothrow) void foo() = 0;
  78   // expected-note@+1{{previous declaration is here}}
  79   __declspec(nothrow) void bar();
  80 };
  81
  82 // expected-warning@+1{{'bar' is missing exception specification '__attribute__((nothrow))'}}
  83 void Base::bar() {}
  84
  85 class Sub : public Base {
  86 public:
  87   // expected-warning@+1{{exception specification of overriding function is more lax than base version}}
  88   void foo() {}
  89 };
  90 }
  91
  92 namespace FuncPointerReferenceConverts {
  93 void FuncToBeRefed();
  94
  95 #ifndef CPP17
  96 // expected-error@+6{{target exception specification is not superset of source}}
  97 // expected-error@+6{{target exception specification is not superset of source}}
  98 #else
  99 // expected-error@+3{{non-const lvalue reference to type 'void () __attribute__((nothrow))' cannot bind to a value of unrelated type 'void ()'}}
 100 // expected-error@+3{{cannot initialize a variable of type 'void (*)() __attribute__((nothrow))' with an lvalue of type 'void ()': different exception specifications}}
 101 #endif
 102 __declspec(nothrow) void (&FuncRef)() = FuncToBeRefed;
 103 __declspec(nothrow) void (*FuncPtr)() = FuncToBeRefed;
 104 }