Implement support for equality comparisons (!=, ==) of member

pointers, by extending the "composite pointer type" logic to include
member pointer types.

Introduce test cases for member pointer comparisons, including those
that involve the builtin operator candidates implemented earlier. 

llvm-svn: 79925

1 files changed, 62 insertions, 19 deletions

diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index 0434f304d87..d89a0909aa1 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -1510,15 +1510,20 @@ QualType Sema::CXXCheckConditionalOperands(Expr *&Cond, Expr *&LHS, Expr *&RHS,
 
 /// \brief Find a merged pointer type and convert the two expressions to it.
 ///
-/// This finds the composite pointer type for @p E1 and @p E2 according to
-/// C++0x 5.9p2. It converts both expressions to this type and returns it.
+/// This finds the composite pointer type (or member pointer type) for @p E1
+/// and @p E2 according to C++0x 5.9p2. It converts both expressions to this
+/// type and returns it.
 /// It does not emit diagnostics.
 QualType Sema::FindCompositePointerType(Expr *&E1, Expr *&E2) {
   assert(getLangOptions().CPlusPlus && "This function assumes C++");
   QualType T1 = E1->getType(), T2 = E2->getType();
-  if(!T1->isAnyPointerType() && !T2->isAnyPointerType())
-    return QualType();
+  
+  if (!T1->isPointerType() && !T1->isMemberPointerType() &&
+      !T2->isPointerType() && !T2->isMemberPointerType())
+   return QualType();
 
+  // FIXME: Do we need to work on the canonical types?
+  
   // C++0x 5.9p2
   //   Pointer conversions and qualification conversions are performed on
   //   pointer operands to bring them to their composite pointer type. If
@@ -1532,8 +1537,10 @@ QualType Sema::FindCompositePointerType(Expr *&E1, Expr *&E2) {
     ImpCastExprToType(E2, T1);
     return T1;
   }
-  // Now both have to be pointers.
-  if(!T1->isPointerType() || !T2->isPointerType())
+  
+  // Now both have to be pointers or member pointers.
+  if (!T1->isPointerType() && !T1->isMemberPointerType() &&
+      !T2->isPointerType() && !T2->isMemberPointerType())
     return QualType();
 
   //   Otherwise, of one of the operands has type "pointer to cv1 void," then
@@ -1547,20 +1554,56 @@ QualType Sema::FindCompositePointerType(Expr *&E1, Expr *&E2) {
   // conversions in both directions. If only one works, or if the two composite
   // types are the same, we have succeeded.
   llvm::SmallVector<unsigned, 4> QualifierUnion;
+  llvm::SmallVector<std::pair<const Type *, const Type *>, 4> MemberOfClass;
   QualType Composite1 = T1, Composite2 = T2;
-  const PointerType *Ptr1, *Ptr2;
-  while ((Ptr1 = Composite1->getAs<PointerType>()) &&
-         (Ptr2 = Composite2->getAs<PointerType>())) {
-    Composite1 = Ptr1->getPointeeType();
-    Composite2 = Ptr2->getPointeeType();
-    QualifierUnion.push_back(
-      Composite1.getCVRQualifiers() | Composite2.getCVRQualifiers());
-  }
-  // Rewrap the composites as pointers with the union CVRs.
-  for (llvm::SmallVector<unsigned, 4>::iterator I = QualifierUnion.begin(),
-       E = QualifierUnion.end(); I != E; ++I) {
-    Composite1 = Context.getPointerType(Composite1.getQualifiedType(*I));
-    Composite2 = Context.getPointerType(Composite2.getQualifiedType(*I));
+  do {
+    const PointerType *Ptr1, *Ptr2;
+    if ((Ptr1 = Composite1->getAs<PointerType>()) &&
+        (Ptr2 = Composite2->getAs<PointerType>())) {
+      Composite1 = Ptr1->getPointeeType();
+      Composite2 = Ptr2->getPointeeType();
+      QualifierUnion.push_back(
+                 Composite1.getCVRQualifiers() | Composite2.getCVRQualifiers());
+      MemberOfClass.push_back(std::make_pair((const Type *)0, (const Type *)0));
+      continue;
+    }
+    
+    const MemberPointerType *MemPtr1, *MemPtr2;
+    if ((MemPtr1 = Composite1->getAs<MemberPointerType>()) &&
+        (MemPtr2 = Composite2->getAs<MemberPointerType>())) {
+      Composite1 = MemPtr1->getPointeeType();
+      Composite2 = MemPtr2->getPointeeType();
+      QualifierUnion.push_back(
+                 Composite1.getCVRQualifiers() | Composite2.getCVRQualifiers());
+      MemberOfClass.push_back(std::make_pair(MemPtr1->getClass(),
+                                             MemPtr2->getClass()));
+      continue;
+    }
+    
+    // FIXME: block pointer types?
+    
+    // Cannot unwrap any more types.
+    break;
+  } while (true);
+  
+  // Rewrap the composites as pointers or member pointers with the union CVRs.
+  llvm::SmallVector<std::pair<const Type *, const Type *>, 4>::iterator MOC
+    = MemberOfClass.begin();
+  for (llvm::SmallVector<unsigned, 4>::iterator 
+         I = QualifierUnion.begin(),
+         E = QualifierUnion.end(); 
+       I != E; (void)++I, ++MOC) {
+    if (MOC->first && MOC->second) {
+      // Rebuild member pointer type
+      Composite1 = Context.getMemberPointerType(Composite1.getQualifiedType(*I),
+                                                MOC->first);
+      Composite2 = Context.getMemberPointerType(Composite2.getQualifiedType(*I),
+                                                MOC->second);
+    } else {
+      // Rebuild pointer type
+      Composite1 = Context.getPointerType(Composite1.getQualifiedType(*I));
+      Composite2 = Context.getPointerType(Composite2.getQualifiedType(*I));
+    }
   }
 
   ImplicitConversionSequence E1ToC1 = TryImplicitConversion(E1, Composite1);