[Clang-tidy] Fix for misc-noexcept-move-constructor false triggers on defaulted declarations

[edyp87]

Summary

There is no need for triggering warning when noexcept specifier in move constructor or move-assignment operator is neither evaluated nor uninstantiated.

This fixes bug reported here: bugs.llvm.org/show_bug.cgi?id=24712

[alexfh]

LG

[alexfh]

Do you have commit rights?

[edyp87]

No, please apply this patch for me. Thank you!

clang-tidy/misc/NoexceptMoveConstructorCheck.cpp

if (const auto *Ctor = dyn_cast<CXXConstructorDecl>(Decl)) {
       if (!Ctor->isMoveConstructor())
         return;
       MethodType = "constructor";
     } else if (!Decl->isMoveAssignmentOperator()) {
       return;
     }
 
     const auto *ProtoType = Decl->getType()->getAs<FunctionProtoType>();
+
+    if (isUnresolvedExceptionSpec(ProtoType->getExceptionSpecType()))
+      return;
+
     switch (ProtoType->getNoexceptSpec(*Result.Context)) {
       case FunctionProtoType::NR_NoNoexcept:
         diag(Decl->getLocation(), "move %0s should be marked noexcept")
             << MethodType;
         // FIXME: Add a fixit.
         break;
       case FunctionProtoType::NR_Throw:
         // Don't complain about nothrow(false), but complain on nothrow(expr)

test/clang-tidy/misc-noexcept-move-constructor.cpp

public:
   OK2(OK2 &&) noexcept(true) {}
   OK2 &operator=(OK2 &&) noexcept(kTrue) { return *this; }
 };
 
 struct OK3 {
   OK3(OK3 &&) noexcept(false) {}
   OK3 &operator=(OK3 &&) = delete;
 };
+
+struct OK4 {
+  OK4(OK4 &&) noexcept = default;
+  OK4 &operator=(OK4 &&) noexcept = default;
+};
+
+struct OK5 {
+  OK5(OK5 &&) noexcept(true) = default;
+  OK5 &operator=(OK5 &&) noexcept(true) = default;
+};