Add info to ObjCPropertyRefExpr to indicate whether the dot syntax property

reference is going to message the setter, the getter, or both.

Having this info on the ObjCPropertyRefExpr node makes it easier for AST
clients (like libclang) to reason about the meaning of the property reference.

[AST/Sema]
-Use 2 bits (with a PointerIntPair) in ObjCPropertyRefExpr to record the above info
-Have ObjCPropertyOpBuilder set the info appropriately.

[libclang]
-When there is an implicit property reference (property syntax using methods)
have clang_getCursorReferenced return a cursor for the method. If the property
reference is going to result in messaging both the getter and the setter choose
to return a cursor for the setter because it is less obvious from source inspection
that the setter is getting called.

The general idea has the seal of approval by John.

rdar://11151621

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@153709 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 57 insertions, 11 deletions

diff --git a/include/clang/AST/ExprObjC.h b/include/clang/AST/ExprObjC.h
index 6e4e5b9a32..4bfd12c069 100644
--- a/include/clang/AST/ExprObjC.h
+++ b/include/clang/AST/ExprObjC.h
@@ -510,7 +510,18 @@ private:
   /// if the bool is false, this is an explicit property reference;
   /// the pointer is an ObjCPropertyDecl and Setter is always null.
   llvm::PointerIntPair<NamedDecl*, 1, bool> PropertyOrGetter;
-  ObjCMethodDecl *Setter;
+
+  /// \brief Indicates whether the property reference will result in a message
+  /// to the getter, the setter, or both.
+  /// This applies to both implicit and explicit property references.
+  enum MethodRefFlags {
+    MethodRef_None = 0,
+    MethodRef_Getter = 0x1,
+    MethodRef_Setter = 0x2
+  };
+
+  /// \brief Contains the Setter method pointer and MethodRefFlags bit flags.
+  llvm::PointerIntPair<ObjCMethodDecl *, 2, unsigned> SetterAndMethodRefFlags;
 
   // FIXME: Maybe we should store the property identifier here,
   // because it's not rederivable from the other data when there's an
@@ -533,7 +544,7 @@ public:
            /*TypeDependent=*/false, base->isValueDependent(),
            base->isInstantiationDependent(),
            base->containsUnexpandedParameterPack()),
-      PropertyOrGetter(PD, false), Setter(0),
+      PropertyOrGetter(PD, false), SetterAndMethodRefFlags(),
       IdLoc(l), ReceiverLoc(), Receiver(base) {
     assert(t->isSpecificPlaceholderType(BuiltinType::PseudoObject));
   }
@@ -544,7 +555,7 @@ public:
     : Expr(ObjCPropertyRefExprClass, t, VK, OK,
            /*TypeDependent=*/false, false, st->isInstantiationDependentType(),
            st->containsUnexpandedParameterPack()),
-      PropertyOrGetter(PD, false), Setter(0),
+      PropertyOrGetter(PD, false), SetterAndMethodRefFlags(),
       IdLoc(l), ReceiverLoc(sl), Receiver(st.getTypePtr()) {
     assert(t->isSpecificPlaceholderType(BuiltinType::PseudoObject));
   }
@@ -555,7 +566,7 @@ public:
     : Expr(ObjCPropertyRefExprClass, T, VK, OK, false,
            Base->isValueDependent(), Base->isInstantiationDependent(),
            Base->containsUnexpandedParameterPack()),
-      PropertyOrGetter(Getter, true), Setter(Setter),
+      PropertyOrGetter(Getter, true), SetterAndMethodRefFlags(Setter, 0),
       IdLoc(IdLoc), ReceiverLoc(), Receiver(Base) {
     assert(T->isSpecificPlaceholderType(BuiltinType::PseudoObject));
   }
@@ -565,7 +576,7 @@ public:
                       SourceLocation IdLoc,
                       SourceLocation SuperLoc, QualType SuperTy)
     : Expr(ObjCPropertyRefExprClass, T, VK, OK, false, false, false, false),
-      PropertyOrGetter(Getter, true), Setter(Setter),
+      PropertyOrGetter(Getter, true), SetterAndMethodRefFlags(Setter, 0),
       IdLoc(IdLoc), ReceiverLoc(SuperLoc), Receiver(SuperTy.getTypePtr()) {
     assert(T->isSpecificPlaceholderType(BuiltinType::PseudoObject));
   }
@@ -575,7 +586,7 @@ public:
                       SourceLocation IdLoc,
                       SourceLocation ReceiverLoc, ObjCInterfaceDecl *Receiver)
     : Expr(ObjCPropertyRefExprClass, T, VK, OK, false, false, false, false),
-      PropertyOrGetter(Getter, true), Setter(Setter),
+      PropertyOrGetter(Getter, true), SetterAndMethodRefFlags(Setter, 0),
       IdLoc(IdLoc), ReceiverLoc(ReceiverLoc), Receiver(Receiver) {
     assert(T->isSpecificPlaceholderType(BuiltinType::PseudoObject));
   }
@@ -598,7 +609,7 @@ public:
 
   ObjCMethodDecl *getImplicitPropertySetter() const {
     assert(isImplicitProperty());
-    return Setter;
+    return SetterAndMethodRefFlags.getPointer();
   }
 
   Selector getGetterSelector() const {
@@ -613,6 +624,28 @@ public:
     return getExplicitProperty()->getSetterName();
   }
 
+  /// \brief True if the property reference will result in a message to the
+  /// getter.
+  /// This applies to both implicit and explicit property references.
+  bool isMessagingGetter() const {
+    return SetterAndMethodRefFlags.getInt() & MethodRef_Getter;
+  }
+
+  /// \brief True if the property reference will result in a message to the
+  /// setter.
+  /// This applies to both implicit and explicit property references.
+  bool isMessagingSetter() const {
+    return SetterAndMethodRefFlags.getInt() & MethodRef_Setter;
+  }
+
+  void setIsMessagingGetter(bool val = true) {
+    setMethodRefFlag(MethodRef_Getter, val);
+  }
+
+  void setIsMessagingSetter(bool val = true) {
+    setMethodRefFlag(MethodRef_Setter, val);
+  }
+
   const Expr *getBase() const { 
     return cast<Expr>(Receiver.get<Stmt*>()); 
   }
@@ -689,15 +722,19 @@ public:
 
 private:
   friend class ASTStmtReader;
-  void setExplicitProperty(ObjCPropertyDecl *D) {
+  friend class ASTStmtWriter;
+  void setExplicitProperty(ObjCPropertyDecl *D, unsigned methRefFlags) {
     PropertyOrGetter.setPointer(D);
     PropertyOrGetter.setInt(false);
-    Setter = 0;
+    SetterAndMethodRefFlags.setPointer(0);
+    SetterAndMethodRefFlags.setInt(methRefFlags);
   }
-  void setImplicitProperty(ObjCMethodDecl *Getter, ObjCMethodDecl *Setter) {
+  void setImplicitProperty(ObjCMethodDecl *Getter, ObjCMethodDecl *Setter,
+                           unsigned methRefFlags) {
     PropertyOrGetter.setPointer(Getter);
     PropertyOrGetter.setInt(true);
-    this->Setter = Setter;
+    SetterAndMethodRefFlags.setPointer(Setter);
+    SetterAndMethodRefFlags.setInt(methRefFlags);
   }
   void setBase(Expr *Base) { Receiver = Base; }
   void setSuperReceiver(QualType T) { Receiver = T.getTypePtr(); }
@@ -705,6 +742,15 @@ private:
 
   void setLocation(SourceLocation L) { IdLoc = L; }
   void setReceiverLocation(SourceLocation Loc) { ReceiverLoc = Loc; }
+
+  void setMethodRefFlag(MethodRefFlags flag, bool val) {
+    unsigned f = SetterAndMethodRefFlags.getInt();
+    if (val)
+      f |= flag;
+    else
+      f &= ~flag;
+    SetterAndMethodRefFlags.setInt(f);
+  }
 };
   
 /// ObjCSubscriptRefExpr - used for array and dictionary subscripting.