Force a load when creating a reference to a temporary copied from a bitfield.

For this source:
  const int &ref = someStruct.bitfield;

We used to generate this AST:

  DeclStmt [...]
  `-VarDecl [...] ref 'const int &'
    `-MaterializeTemporaryExpr [...] 'const int' lvalue
      `-ImplicitCastExpr [...] 'const int' lvalue <NoOp>
        `-MemberExpr [...] 'int' lvalue bitfield .bitfield [...]
          `-DeclRefExpr [...] 'struct X' lvalue ParmVar [...] 'someStruct' 'struct X'

Notice the lvalue inside the MaterializeTemporaryExpr, which is very
confusing (and caused an assertion to fire in the analyzer - PR15694).

We now generate this:

  DeclStmt [...]
  `-VarDecl [...] ref 'const int &'
    `-MaterializeTemporaryExpr [...] 'const int' lvalue
      `-ImplicitCastExpr [...] 'int' <LValueToRValue>
        `-MemberExpr [...] 'int' lvalue bitfield .bitfield [...]
          `-DeclRefExpr [...] 'struct X' lvalue ParmVar [...] 'someStruct' 'struct X'

Which makes a lot more sense. This allows us to remove code in both
CodeGen and AST that hacked around this special case.

The commit also makes Clang accept this (legal) C++11 code:

  int &&ref = std::move(someStruct).bitfield

PR15694 / <rdar://problem/13600396>

llvm-svn: 179250

diff --git a/clang/include/clang/Sema/Initialization.h b/clang/include/clang/Sema/Initialization.h
index 8459be1..9740318 100644 (file)
--- a/clang/include/clang/Sema/Initialization.h
+++ b/clang/include/clang/Sema/Initialization.h
@@ -594,6 +594,8 @@ public:
     SK_QualificationConversionXValue,
     /// \brief Perform a qualification conversion, producing an lvalue.
     SK_QualificationConversionLValue,
+    /// \brief Perform a load from a glvalue, producing an rvalue.
+    SK_LValueToRValue,
     /// \brief Perform an implicit conversion sequence.
     SK_ConversionSequence,
     /// \brief Perform list-initialization without a constructor
@@ -911,6 +913,12 @@ public:
   void AddQualificationConversionStep(QualType Ty,
                                      ExprValueKind Category);
   
+  /// \brief Add a new step that performs a load of the given type.
+  ///
+  /// Although the term "LValueToRValue" is conventional, this applies to both
+  /// lvalues and xvalues.
+  void AddLValueToRValueStep(QualType Ty);
+
   /// \brief Add a new step that applies an implicit conversion sequence.
   void AddConversionSequenceStep(const ImplicitConversionSequence &ICS,
                                  QualType T);

diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index ae86150..d7abe30 100644 (file)
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -2865,25 +2865,12 @@ bool LValueExprEvaluator::VisitVarDecl(const Expr *E, const VarDecl *VD) {
 
 bool LValueExprEvaluator::VisitMaterializeTemporaryExpr(
     const MaterializeTemporaryExpr *E) {
-  if (E->GetTemporaryExpr()->isRValue()) {
-    if (E->getType()->isRecordType())
-      return EvaluateTemporary(E->GetTemporaryExpr(), Result, Info);
+  if (E->getType()->isRecordType())
+    return EvaluateTemporary(E->GetTemporaryExpr(), Result, Info);
 
-    Result.set(E, Info.CurrentCall->Index);
-    return EvaluateInPlace(Info.CurrentCall->Temporaries[E], Info,
-                           Result, E->GetTemporaryExpr());
-  }
-
-  // Materialization of an lvalue temporary occurs when we need to force a copy
-  // (for instance, if it's a bitfield).
-  // FIXME: The AST should contain an lvalue-to-rvalue node for such cases.
-  if (!Visit(E->GetTemporaryExpr()))
-    return false;
-  if (!HandleLValueToRValueConversion(Info, E, E->getType(), Result,
-                                      Info.CurrentCall->Temporaries[E]))
-    return false;
   Result.set(E, Info.CurrentCall->Index);
-  return true;
+  return EvaluateInPlace(Info.CurrentCall->Temporaries[E], Info,
+                         Result, E->GetTemporaryExpr());
 }
 
 bool

diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index a0dd158..fe0d070 100644 (file)
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -228,157 +228,152 @@ EmitExprForReferenceBinding(CodeGenFunction &CGF, const Expr *E,
                                        InitializedDecl);
   }
 
-  RValue RV;
   if (E->isGLValue()) {
     // Emit the expression as an lvalue.
     LValue LV = CGF.EmitLValue(E);
+    assert(LV.isSimple());
+    return LV.getAddress();
+  }
+  
+  if (!ObjCARCReferenceLifetimeType.isNull()) {
+    ReferenceTemporary = CreateReferenceTemporary(CGF, 
+                                                ObjCARCReferenceLifetimeType, 
+                                                  InitializedDecl);
     
-    if (LV.isSimple())
-      return LV.getAddress();
     
-    // We have to load the lvalue.
-    RV = CGF.EmitLoadOfLValue(LV);
-  } else {
-    if (!ObjCARCReferenceLifetimeType.isNull()) {
-      ReferenceTemporary = CreateReferenceTemporary(CGF, 
-                                                  ObjCARCReferenceLifetimeType, 
-                                                    InitializedDecl);
-      
-      
-      LValue RefTempDst = CGF.MakeAddrLValue(ReferenceTemporary, 
-                                             ObjCARCReferenceLifetimeType);
+    LValue RefTempDst = CGF.MakeAddrLValue(ReferenceTemporary, 
+                                           ObjCARCReferenceLifetimeType);
 
-      CGF.EmitScalarInit(E, dyn_cast_or_null<ValueDecl>(InitializedDecl),
-                         RefTempDst, false);
-      
-      bool ExtendsLifeOfTemporary = false;
-      if (const VarDecl *Var = dyn_cast_or_null<VarDecl>(InitializedDecl)) {
-        if (Var->extendsLifetimeOfTemporary())
-          ExtendsLifeOfTemporary = true;
-      } else if (InitializedDecl && isa<FieldDecl>(InitializedDecl)) {
+    CGF.EmitScalarInit(E, dyn_cast_or_null<ValueDecl>(InitializedDecl),
+                       RefTempDst, false);
+    
+    bool ExtendsLifeOfTemporary = false;
+    if (const VarDecl *Var = dyn_cast_or_null<VarDecl>(InitializedDecl)) {
+      if (Var->extendsLifetimeOfTemporary())
         ExtendsLifeOfTemporary = true;
-      }
-      
-      if (!ExtendsLifeOfTemporary) {
-        // Since the lifetime of this temporary isn't going to be extended,
-        // we need to clean it up ourselves at the end of the full expression.
-        switch (ObjCARCReferenceLifetimeType.getObjCLifetime()) {
-        case Qualifiers::OCL_None:
-        case Qualifiers::OCL_ExplicitNone:
-        case Qualifiers::OCL_Autoreleasing:
-          break;
-            
-        case Qualifiers::OCL_Strong: {
-          assert(!ObjCARCReferenceLifetimeType->isArrayType());
-          CleanupKind cleanupKind = CGF.getARCCleanupKind();
-          CGF.pushDestroy(cleanupKind, 
-                          ReferenceTemporary,
-                          ObjCARCReferenceLifetimeType,
-                          CodeGenFunction::destroyARCStrongImprecise,
-                          cleanupKind & EHCleanup);
-          break;
-        }
+    } else if (InitializedDecl && isa<FieldDecl>(InitializedDecl)) {
+      ExtendsLifeOfTemporary = true;
+    }
+    
+    if (!ExtendsLifeOfTemporary) {
+      // Since the lifetime of this temporary isn't going to be extended,
+      // we need to clean it up ourselves at the end of the full expression.
+      switch (ObjCARCReferenceLifetimeType.getObjCLifetime()) {
+      case Qualifiers::OCL_None:
+      case Qualifiers::OCL_ExplicitNone:
+      case Qualifiers::OCL_Autoreleasing:
+        break;
           
-        case Qualifiers::OCL_Weak:
-          assert(!ObjCARCReferenceLifetimeType->isArrayType());
-          CGF.pushDestroy(NormalAndEHCleanup, 
-                          ReferenceTemporary,
-                          ObjCARCReferenceLifetimeType,
-                          CodeGenFunction::destroyARCWeak,
-                          /*useEHCleanupForArray*/ true);
-          break;
-        }
+      case Qualifiers::OCL_Strong: {
+        assert(!ObjCARCReferenceLifetimeType->isArrayType());
+        CleanupKind cleanupKind = CGF.getARCCleanupKind();
+        CGF.pushDestroy(cleanupKind, 
+                        ReferenceTemporary,
+                        ObjCARCReferenceLifetimeType,
+                        CodeGenFunction::destroyARCStrongImprecise,
+                        cleanupKind & EHCleanup);
+        break;
+      }
         
-        ObjCARCReferenceLifetimeType = QualType();
+      case Qualifiers::OCL_Weak:
+        assert(!ObjCARCReferenceLifetimeType->isArrayType());
+        CGF.pushDestroy(NormalAndEHCleanup, 
+                        ReferenceTemporary,
+                        ObjCARCReferenceLifetimeType,
+                        CodeGenFunction::destroyARCWeak,
+                        /*useEHCleanupForArray*/ true);
+        break;
       }
       
-      return ReferenceTemporary;
-    }
-
-    SmallVector<SubobjectAdjustment, 2> Adjustments;
-    E = E->skipRValueSubobjectAdjustments(Adjustments);
-    if (const OpaqueValueExpr *opaque = dyn_cast<OpaqueValueExpr>(E))
-      if (opaque->getType()->isRecordType())
-        return CGF.EmitOpaqueValueLValue(opaque).getAddress();
-
-    // Create a reference temporary if necessary.
-    AggValueSlot AggSlot = AggValueSlot::ignored();
-    if (CGF.hasAggregateEvaluationKind(E->getType())) {
-      ReferenceTemporary = CreateReferenceTemporary(CGF, E->getType(), 
-                                                    InitializedDecl);
-      CharUnits Alignment = CGF.getContext().getTypeAlignInChars(E->getType());
-      AggValueSlot::IsDestructed_t isDestructed
-        = AggValueSlot::IsDestructed_t(InitializedDecl != 0);
-      AggSlot = AggValueSlot::forAddr(ReferenceTemporary, Alignment,
-                                      Qualifiers(), isDestructed,
-                                      AggValueSlot::DoesNotNeedGCBarriers,
-                                      AggValueSlot::IsNotAliased);
+      ObjCARCReferenceLifetimeType = QualType();
     }
     
-    if (InitializedDecl) {
-      if (const InitListExpr *ILE = dyn_cast<InitListExpr>(E)) {
-        if (ILE->initializesStdInitializerList()) {
-          ReferenceInitializerList = ILE;
-        }
-      }
-      else if (const RecordType *RT =
-                 E->getType()->getBaseElementTypeUnsafe()->getAs<RecordType>()){
-        // Get the destructor for the reference temporary.
-        CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
-        if (!ClassDecl->hasTrivialDestructor())
-          ReferenceTemporaryDtor = ClassDecl->getDestructor();
+    return ReferenceTemporary;
+  }
+
+  SmallVector<SubobjectAdjustment, 2> Adjustments;
+  E = E->skipRValueSubobjectAdjustments(Adjustments);
+  if (const OpaqueValueExpr *opaque = dyn_cast<OpaqueValueExpr>(E))
+    if (opaque->getType()->isRecordType())
+      return CGF.EmitOpaqueValueLValue(opaque).getAddress();
+
+  // Create a reference temporary if necessary.
+  AggValueSlot AggSlot = AggValueSlot::ignored();
+  if (CGF.hasAggregateEvaluationKind(E->getType())) {
+    ReferenceTemporary = CreateReferenceTemporary(CGF, E->getType(), 
+                                                  InitializedDecl);
+    CharUnits Alignment = CGF.getContext().getTypeAlignInChars(E->getType());
+    AggValueSlot::IsDestructed_t isDestructed
+      = AggValueSlot::IsDestructed_t(InitializedDecl != 0);
+    AggSlot = AggValueSlot::forAddr(ReferenceTemporary, Alignment,
+                                    Qualifiers(), isDestructed,
+                                    AggValueSlot::DoesNotNeedGCBarriers,
+                                    AggValueSlot::IsNotAliased);
+  }
+  
+  if (InitializedDecl) {
+    if (const InitListExpr *ILE = dyn_cast<InitListExpr>(E)) {
+      if (ILE->initializesStdInitializerList()) {
+        ReferenceInitializerList = ILE;
       }
     }
+    else if (const RecordType *RT =
+               E->getType()->getBaseElementTypeUnsafe()->getAs<RecordType>()){
+      // Get the destructor for the reference temporary.
+      CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
+      if (!ClassDecl->hasTrivialDestructor())
+        ReferenceTemporaryDtor = ClassDecl->getDestructor();
+    }
+  }
 
-    RV = CGF.EmitAnyExpr(E, AggSlot);
-
-    // Check if need to perform derived-to-base casts and/or field accesses, to
-    // get from the temporary object we created (and, potentially, for which we
-    // extended the lifetime) to the subobject we're binding the reference to.
-    if (!Adjustments.empty()) {
-      llvm::Value *Object = RV.getAggregateAddr();
-      for (unsigned I = Adjustments.size(); I != 0; --I) {
-        SubobjectAdjustment &Adjustment = Adjustments[I-1];
-        switch (Adjustment.Kind) {
-        case SubobjectAdjustment::DerivedToBaseAdjustment:
-          Object = 
-              CGF.GetAddressOfBaseClass(Object, 
-                                        Adjustment.DerivedToBase.DerivedClass, 
-                              Adjustment.DerivedToBase.BasePath->path_begin(),
-                              Adjustment.DerivedToBase.BasePath->path_end(),
-                                        /*NullCheckValue=*/false);
-          break;
-            
-        case SubobjectAdjustment::FieldAdjustment: {
-          LValue LV = CGF.MakeAddrLValue(Object, E->getType());
-          LV = CGF.EmitLValueForField(LV, Adjustment.Field);
-          if (LV.isSimple()) {
-            Object = LV.getAddress();
-            break;
-          }
+  RValue RV = CGF.EmitAnyExpr(E, AggSlot);
+
+  // Check if need to perform derived-to-base casts and/or field accesses, to
+  // get from the temporary object we created (and, potentially, for which we
+  // extended the lifetime) to the subobject we're binding the reference to.
+  if (!Adjustments.empty()) {
+    llvm::Value *Object = RV.getAggregateAddr();
+    for (unsigned I = Adjustments.size(); I != 0; --I) {
+      SubobjectAdjustment &Adjustment = Adjustments[I-1];
+      switch (Adjustment.Kind) {
+      case SubobjectAdjustment::DerivedToBaseAdjustment:
+        Object = 
+            CGF.GetAddressOfBaseClass(Object, 
+                                      Adjustment.DerivedToBase.DerivedClass, 
+                            Adjustment.DerivedToBase.BasePath->path_begin(),
+                            Adjustment.DerivedToBase.BasePath->path_end(),
+                                      /*NullCheckValue=*/false);
+        break;
           
-          // For non-simple lvalues, we actually have to create a copy of
-          // the object we're binding to.
-          QualType T = Adjustment.Field->getType().getNonReferenceType()
-                                                  .getUnqualifiedType();
-          Object = CreateReferenceTemporary(CGF, T, InitializedDecl);
-          LValue TempLV = CGF.MakeAddrLValue(Object,
-                                             Adjustment.Field->getType());
-          CGF.EmitStoreThroughLValue(CGF.EmitLoadOfLValue(LV), TempLV);
-          break;
-        }
-
-        case SubobjectAdjustment::MemberPointerAdjustment: {
-          llvm::Value *Ptr = CGF.EmitScalarExpr(Adjustment.Ptr.RHS);
-          Object = CGF.CGM.getCXXABI().EmitMemberDataPointerAddress(
-                        CGF, Object, Ptr, Adjustment.Ptr.MPT);
+      case SubobjectAdjustment::FieldAdjustment: {
+        LValue LV = CGF.MakeAddrLValue(Object, E->getType());
+        LV = CGF.EmitLValueForField(LV, Adjustment.Field);
+        if (LV.isSimple()) {
+          Object = LV.getAddress();
           break;
         }
-        }
+        
+        // For non-simple lvalues, we actually have to create a copy of
+        // the object we're binding to.
+        QualType T = Adjustment.Field->getType().getNonReferenceType()
+                                                .getUnqualifiedType();
+        Object = CreateReferenceTemporary(CGF, T, InitializedDecl);
+        LValue TempLV = CGF.MakeAddrLValue(Object,
+                                           Adjustment.Field->getType());
+        CGF.EmitStoreThroughLValue(CGF.EmitLoadOfLValue(LV), TempLV);
+        break;
       }
 
-      return Object;
+      case SubobjectAdjustment::MemberPointerAdjustment: {
+        llvm::Value *Ptr = CGF.EmitScalarExpr(Adjustment.Ptr.RHS);
+        Object = CGF.CGM.getCXXABI().EmitMemberDataPointerAddress(
+                      CGF, Object, Ptr, Adjustment.Ptr.MPT);
+        break;
+      }
+      }
     }
+
+    return Object;
   }
 
   if (RV.isAggregate())

diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index 63309e3..cd59a32 100644 (file)
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/clang/lib/Sema/SemaInit.cpp
@@ -2409,6 +2409,7 @@ void InitializationSequence::Step::Destroy() {
   case SK_QualificationConversionRValue:
   case SK_QualificationConversionXValue:
   case SK_QualificationConversionLValue:
+  case SK_LValueToRValue:
   case SK_ListInitialization:
   case SK_ListConstructorCall:
   case SK_UnwrapInitList:
@@ -2555,6 +2556,15 @@ void InitializationSequence::AddQualificationConversionStep(QualType Ty,
   Steps.push_back(S);
 }
 
+void InitializationSequence::AddLValueToRValueStep(QualType Ty) {
+  assert(!Ty.hasQualifiers() && "rvalues may not have qualifiers");
+
+  Step S;
+  S.Kind = SK_LValueToRValue;
+  S.Type = Ty;
+  Steps.push_back(S);
+}
+
 void InitializationSequence::AddConversionSequenceStep(
                                        const ImplicitConversionSequence &ICS,
                                                        QualType T) {
@@ -3351,6 +3361,57 @@ static void TryReferenceInitialization(Sema &S,
                                  T1Quals, cv2T2, T2, T2Quals, Sequence);
 }
 
+/// Converts the target of reference initialization so that it has the
+/// appropriate qualifiers and value kind.
+///
+/// In this case, 'x' is an 'int' lvalue, but it needs to be 'const int'.
+/// \code
+///   int x;
+///   const int &r = x;
+/// \endcode
+///
+/// In this case the reference is binding to a bitfield lvalue, which isn't
+/// valid. Perform a load to create a lifetime-extended temporary instead.
+/// \code
+///   const int &r = someStruct.bitfield;
+/// \endcode
+static ExprValueKind
+convertQualifiersAndValueKindIfNecessary(Sema &S,
+                                         InitializationSequence &Sequence,
+                                         Expr *Initializer,
+                                         QualType cv1T1,
+                                         Qualifiers T1Quals,
+                                         Qualifiers T2Quals,
+                                         bool IsLValueRef) {
+  bool IsNonAddressableType = Initializer->getBitField() ||
+                              Initializer->refersToVectorElement();
+
+  if (IsNonAddressableType) {
+    // C++11 [dcl.init.ref]p5: [...] Otherwise, the reference shall be an
+    // lvalue reference to a non-volatile const type, or the reference shall be
+    // an rvalue reference.
+    //
+    // If not, we can't make a temporary and bind to that. Give up and allow the
+    // error to be diagnosed later.
+    if (IsLValueRef && (!T1Quals.hasConst() || T1Quals.hasVolatile())) {
+      assert(Initializer->isGLValue());
+      return Initializer->getValueKind();
+    }
+
+    // Force a load so we can materialize a temporary.
+    Sequence.AddLValueToRValueStep(cv1T1.getUnqualifiedType());
+    return VK_RValue;
+  }
+
+  if (T1Quals != T2Quals) {
+    Sequence.AddQualificationConversionStep(cv1T1,
+                                            Initializer->getValueKind());
+  }
+
+  return Initializer->getValueKind();
+}
+
+
 /// \brief Reference initialization without resolving overloaded functions.
 static void TryReferenceInitializationCore(Sema &S,
                                            const InitializedEntity &Entity,
@@ -3406,11 +3467,11 @@ static void TryReferenceInitializationCore(Sema &S,
         Sequence.AddObjCObjectConversionStep(
                                      S.Context.getQualifiedType(T1, T2Quals));
 
-      if (T1Quals != T2Quals)
-        Sequence.AddQualificationConversionStep(cv1T1, VK_LValue);
-      bool BindingTemporary = T1Quals.hasConst() && !T1Quals.hasVolatile() &&
-        (Initializer->getBitField() || Initializer->refersToVectorElement());
-      Sequence.AddReferenceBindingStep(cv1T1, BindingTemporary);
+      ExprValueKind ValueKind =
+        convertQualifiersAndValueKindIfNecessary(S, Sequence, Initializer,
+                                                 cv1T1, T1Quals, T2Quals,
+                                                 isLValueRef);
+      Sequence.AddReferenceBindingStep(cv1T1, ValueKind == VK_RValue);
       return;
     }
 
@@ -3493,10 +3554,12 @@ static void TryReferenceInitializationCore(Sema &S,
       Sequence.AddObjCObjectConversionStep(
                                        S.Context.getQualifiedType(T1, T2Quals));
 
-    if (T1Quals != T2Quals)
-      Sequence.AddQualificationConversionStep(cv1T1, ValueKind);
-    Sequence.AddReferenceBindingStep(cv1T1,
-                                 /*bindingTemporary=*/InitCategory.isPRValue());
+    ValueKind = convertQualifiersAndValueKindIfNecessary(S, Sequence,
+                                                         Initializer, cv1T1,
+                                                         T1Quals, T2Quals,
+                                                         isLValueRef);
+
+    Sequence.AddReferenceBindingStep(cv1T1, ValueKind == VK_RValue);
     return;
   }
 
@@ -4988,6 +5051,7 @@ InitializationSequence::Perform(Sema &S,
   case SK_QualificationConversionLValue:
   case SK_QualificationConversionXValue:
   case SK_QualificationConversionRValue:
+  case SK_LValueToRValue:
   case SK_ConversionSequence:
   case SK_ListInitialization:
   case SK_UnwrapInitList:
@@ -5104,6 +5168,9 @@ InitializationSequence::Perform(Sema &S,
       break;
 
     case SK_BindReferenceToTemporary:
+      // Make sure the "temporary" is actually an rvalue.
+      assert(CurInit.get()->isRValue() && "not a temporary");
+
       // Check exception specifications
       if (S.CheckExceptionSpecCompatibility(CurInit.get(), DestType))
         return ExprError();
@@ -5241,6 +5308,16 @@ InitializationSequence::Perform(Sema &S,
       break;
     }
 
+    case SK_LValueToRValue: {
+      assert(CurInit.get()->isGLValue() && "cannot load from a prvalue");
+      CurInit = S.Owned(ImplicitCastExpr::Create(S.Context, Step->Type,
+                                                 CK_LValueToRValue,
+                                                 CurInit.take(),
+                                                 /*BasePath=*/0,
+                                                 VK_RValue));
+      break;
+    }
+
     case SK_ConversionSequence: {
       Sema::CheckedConversionKind CCK 
         = Kind.isCStyleCast()? Sema::CCK_CStyleCast
@@ -6185,6 +6262,10 @@ void InitializationSequence::dump(raw_ostream &OS) const {
       OS << "qualification conversion (lvalue)";
       break;
 
+    case SK_LValueToRValue:
+      OS << "load (lvalue to rvalue)";
+      break;
+
     case SK_ConversionSequence:
       OS << "implicit conversion sequence (";
       S->ICS->DebugPrint(); // FIXME: use OS

diff --git a/clang/test/Analysis/reference.cpp b/clang/test/Analysis/reference.cpp
index 8dd0baf..bcab80b 100644 (file)
--- a/clang/test/Analysis/reference.cpp
+++ b/clang/test/Analysis/reference.cpp
@@ -224,3 +224,13 @@ namespace rdar11212286 {
     return *x; // no-warning
   }
 }
+
+namespace PR15694 {
+  class C {
+    bool bit : 1;
+    template <class T> void bar(const T &obj) {}
+    void foo() {
+      bar(bit); // don't crash
+    }
+  };
+}

diff --git a/clang/test/CXX/dcl.decl/dcl.init/dcl.init.ref/p5-0x.cpp b/clang/test/CXX/dcl.decl/dcl.init/dcl.init.ref/p5-0x.cpp
index 812d0de..fdfa678 100644 (file)
--- a/clang/test/CXX/dcl.decl/dcl.init/dcl.init.ref/p5-0x.cpp
+++ b/clang/test/CXX/dcl.decl/dcl.init/dcl.init.ref/p5-0x.cpp
@@ -200,3 +200,37 @@ namespace rdar13278115 {
   X &&f1(Y &y) { return y; } // expected-error{{rvalue reference to type 'rdar13278115::X' cannot bind to lvalue of type 'rdar13278115::Y'}}
   const X &&f2(Y &y) { return y; } // expected-error{{rvalue reference to type 'const rdar13278115::X' cannot bind to lvalue of type 'rdar13278115::Y'}}
 }
+
+namespace bitfields {
+  struct IntBitfield {
+    int i : 17; // expected-note 3 {{bit-field is declared here}}
+  };
+
+  // A simplified version of std::move.
+  template <typename T>
+  T &&move(T &obj) {
+    return static_cast<T &&>(obj);
+  }
+
+  void test() {
+    int & ir1 = (lvalue<IntBitfield>().i); // expected-error{{non-const reference cannot bind to bit-field 'i'}}
+    int & ir2 = (xvalue<IntBitfield>().i); // expected-error{{non-const lvalue reference to type 'int' cannot bind to a temporary of type 'int'}}
+    int && ir3 = (xvalue<IntBitfield>().i); // no-warning
+    int && ir4 = move(lvalue<IntBitfield>()).i; // no-warning
+
+    volatile int & vir1 = (lvalue<IntBitfield>().i); // expected-error{{non-const reference cannot bind to bit-field 'i'}}
+    volatile int & vir2 = (xvalue<IntBitfield>().i); // expected-error{{volatile lvalue reference to type 'volatile int' cannot bind to a temporary of type 'int'}}
+    volatile int && vir3 = (xvalue<IntBitfield>().i); // no-warning
+    volatile int && vir4 = move(lvalue<IntBitfield>()).i; // no-warning
+
+    const int & cir1 = (lvalue<IntBitfield>().i); // no-warning
+    const int & cir2 = (xvalue<IntBitfield>().i); // no-warning
+    const int && cir3 = (xvalue<IntBitfield>().i); // no-warning
+    const int && cir4 = move(lvalue<IntBitfield>()).i; // no-warning
+
+    const volatile int & cvir1 = (lvalue<IntBitfield>().i); // expected-error{{non-const reference cannot bind to bit-field 'i'}}
+    const volatile int & cvir2 = (xvalue<IntBitfield>().i); // expected-error{{volatile lvalue reference to type 'const volatile int' cannot bind to a temporary of type 'int'}}
+    const volatile int && cvir3 = (xvalue<IntBitfield>().i); // no-warning
+    const volatile int && cvir4 = move(lvalue<IntBitfield>()).i; // no-warning
+  }
+}