Clang crashed while checking for deletion of copy and move ctors

[oontvoo]

Summary

Repro:
template <class> class __attribute__((trivial_abi)) a { a(a &&); };

Crash:

@     0x559d129463fc  clang::CXXRecordDecl::defaultedCopyConstructorIsDeleted()
 @     0x559d1288d3e5  clang::Sema::checkIllFormedTrivialABIStruct()::$_7::operator()()
 @     0x559d12884c34  clang::Sema::checkIllFormedTrivialABIStruct()
 @     0x559d1288412e  clang::Sema::CheckCompletedCXXClass()
 @     0x559d1288d843  clang::Sema::ActOnFinishCXXMemberSpecification()
 @     0x559d12020109  clang::Parser::ParseCXXMemberSpecification()
 @     0x559d1201e80c  clang::Parser::ParseClassSpecifier()
 @     0x559d1204e807  clang::Parser::ParseDeclarationSpecifiers()
 @     0x559d120e9aa9  clang::Parser::ParseSingleDeclarationAfterTemplate()
 @     0x559d120e8f21  clang::Parser::ParseTemplateDeclarationOrSpecialization()
 @     0x559d120e8886  clang::Parser::ParseDeclarationStartingWithTemplate()
 @     0x559d1204a1d4  clang::Parser::ParseDeclaration()
 @     0x559d12004b1d  clang::Parser::ParseExternalDeclaration()
 @     0x559d12017689  clang::Parser::ParseInnerNamespace()
 @     0x559d12017024  clang::Parser::ParseNamespace()
 @     0x559d1204a29b  clang::Parser::ParseDeclaration()
 @     0x559d12004c74  clang::Parser::ParseExternalDeclaration()

[oontvoo]

add test

[oontvoo]

Dont skip checking even for templated type

[oontvoo]

Add more tests

[oontvoo]

updated diff

[oontvoo]

updated diff

[rsmith]

clang/lib/Sema/SemaDeclCXX.cpp

9731

This is not the right fallback answer if the class is a dependent type -- we don't yet know if there's a non-deleted copy or move constructor if one might be implicitly declared, so we should conservatively assume that there might be one. It'd probably be easiest to return true from this function at the very start if the type is dependent (because we don't know if there's a non-deleted copy or move constructor).

clang/test/SemaObjCXX/attr-trivial-abi.mm

59–62 ↗

(On Diff #275899)

We should not diagnose this, because instantiations of this template might have non-deleted copy or move constructors. (We don't know yet when parsing the template definition.)

[oontvoo]

prevent diagnostics for dependent types

[oontvoo]

lint

[oontvoo]

one more test

clang/lib/Sema/SemaDeclCXX.cpp

if (const CXXDestructorDecl *dtor = Record->getDestructor()) {
         Diag(Record->getLocation(),
              diag::note_final_dtor_non_final_class_silence)
             << Context.getRecordType(Record) << FA->isSpelledAsSealed();
       }
     }
   }
 
   // See if trivial_abi has to be dropped.
-  if (Record->hasAttr<TrivialABIAttr>())
+  if (!Record->isDependentType() && Record->hasAttr<TrivialABIAttr>())
     checkIllFormedTrivialABIStruct(*Record);
 
   // Set HasTrivialSpecialMemberForCall if the record has attribute
   // "trivial_abi".
   bool HasTrivialABI = Record->hasAttr<TrivialABIAttr>();
 
   if (HasTrivialABI)
     Record->setHasTrivialSpecialMemberForCall();
if (RD.needsImplicitCopyConstructor() &&
         !RD.defaultedCopyConstructorIsDeleted())
       return true;
     if (RD.needsImplicitMoveConstructor() &&
         !RD.defaultedMoveConstructorIsDeleted())
       return true;
     for (const CXXConstructorDecl *CD : RD.ctors())
       if (CD->isCopyOrMoveConstructor() && !CD->isDeleted())
         return true;
     return false;
   };
 
   if (!HasNonDeletedCopyOrMoveConstructor()) {
     PrintDiagAndRemoveAttr(0);
     return;
   }
 
   // Ill-formed if the struct has virtual functions.

clang/test/SemaCXX/trivial-abi-templated-type.cpp

+// RUN: %clang_cc1 -fsyntax-only -verify %s -std=c++11
+// expected-no-diagnostics
+
+template <class>
+class __attribute__((trivial_abi)) a { a(a &&); };