[Sema] Don't crash when recovering from a misspelled pseudo destructor call to an incomplete type.

When attempting to correct a misspelled pseudo destructor call as in:

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

a call is made in canRecoverDotPseudoDestructorCallsOnPointerObjects
to LookupDestructor without checking that the record has a definition.

This causes an assertion later in LookupSpecialMember which assumes that
the record has a definition.

Patch By Roman Zhikharevich!

Differential Revision: https://reviews.llvm.org/D57111

Reviewed By: riccibruno

llvm-svn: 352047

1 files changed, 3 insertions, 2 deletions

diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index d54696bbef7..5ac248d36b4 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -6854,8 +6854,9 @@ canRecoverDotPseudoDestructorCallsOnPointerObjects(Sema &SemaRef,
                                                    QualType DestructedType) {
   // If this is a record type, check if its destructor is callable.
   if (auto *RD = DestructedType->getAsCXXRecordDecl()) {
-    if (CXXDestructorDecl *D = SemaRef.LookupDestructor(RD))
-      return SemaRef.CanUseDecl(D, /*TreatUnavailableAsInvalid=*/false);
+    if (RD->hasDefinition())
+      if (CXXDestructorDecl *D = SemaRef.LookupDestructor(RD))
+        return SemaRef.CanUseDecl(D, /*TreatUnavailableAsInvalid=*/false);
     return false;
   }