Make Clang not crash on calls to destructors on incomplete pointer types

[rzhikharevich]

Summary

This patch fixes handling of code like this:

struct Foo;

void foo(Foo *p) {
  p.~Foo();
}

[riccibruno]

Upload patches with full context please.
Also the diagnostic seems to be wrong ?
And finally is there a bug report for this ?

[rzhikharevich]

In D57111#1368224, @riccibruno wrote:

Upload patches with full context please.
Also the diagnostic seems to be wrong ?

I don't think so, the valid code would be 'p->~C()'.

And finally is there a bug report for this ?

No. Should I file one?

[riccibruno]

In D57111#1368230, @rzhikharevich wrote:

In D57111#1368224, @riccibruno wrote:

Upload patches with full context please.
Also the diagnostic seems to be wrong ?

I don't think so, the valid code would be 'p->~C()'.

You are right, my bad!

And finally is there a bug report for this ?

No. Should I file one?

No, it is just so that we can close the corresponding bug report if there is one.
Your fix seems reasonable to me. Thanks for the patch!

I guess you will want someone to commit it ?

[rzhikharevich]

In D57111#1368256, @riccibruno wrote:

I guess you will want someone to commit it ?

Yes, if the fix is correct.

[riccibruno]

In D57111#1368277, @rzhikharevich wrote:

In D57111#1368256, @riccibruno wrote:

I guess you will want someone to commit it ?

Yes, if the fix is correct.

It looks to be correct to me since the problem is that LookupDestructor will dispatch to
Sema::LookupSpecialMember, which assumes that the CXXRecordDecl has a definition.

cfe/trunk/lib/Sema/SemaExprCXX.cpp

 
 /// Check if it's ok to try and recover dot pseudo destructor calls on
 /// pointer objects.
 static bool
 canRecoverDotPseudoDestructorCallsOnPointerObjects(Sema &SemaRef,
                                                    QualType DestructedType) {
   // If this is a record type, check if its destructor is callable.
   if (auto *RD = DestructedType->getAsCXXRecordDecl()) {
+    if (RD->hasDefinition())
       if (CXXDestructorDecl *D = SemaRef.LookupDestructor(RD))
         return SemaRef.CanUseDecl(D, /*TreatUnavailableAsInvalid=*/false);
     return false;
   }
 
   // Otherwise, check if it's a type for which it's valid to use a pseudo-dtor.
   return DestructedType->isDependentType() || DestructedType->isScalarType() ||
          DestructedType->isVectorType();
 }
 

cfe/trunk/test/SemaCXX/incomplete-call.cpp

 
 
 struct C; // expected-note{{forward declaration}}
 
 void test_incomplete_object_call(C& c) {
   c(); // expected-error{{incomplete type in call to object of type}}
 }
 
+void test_incomplete_object_dtor(C *p) {
+  p.~C(); // expected-error{{member reference type 'C *' is a pointer; did you mean to use '->'?}}
+}
+
 namespace pr18542 {
   struct X {
     int count;
     template<typename CharT> class basic_istream;
     template<typename CharT>
       void basic_istream<CharT>::read() { // expected-error{{out-of-line definition of 'read' from class 'basic_istream<CharT>' without definition}}
         count = 0;
       }
   };
 }