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

llvm-svn: 153709

7 files changed, 110 insertions, 18 deletions

diff --git a/clang/include/clang/AST/ExprObjC.h b/clang/include/clang/AST/ExprObjC.h
index 6e4e5b9a325..4bfd12c0693 100644
--- a/clang/include/clang/AST/ExprObjC.h
+++ b/clang/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.
diff --git a/clang/lib/AST/StmtDumper.cpp b/clang/lib/AST/StmtDumper.cpp
index aea4c395d5c..b5e298c0c94 100644
--- a/clang/lib/AST/StmtDumper.cpp
+++ b/clang/lib/AST/StmtDumper.cpp
@@ -686,6 +686,14 @@ void StmtDumper::VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *Node) {
 
   if (Node->isSuperReceiver())
     OS << " super";
+
+  OS << " Messaging=";
+  if (Node->isMessagingGetter() && Node->isMessagingSetter())
+    OS << "Getter&Setter";
+  else if (Node->isMessagingGetter())
+    OS << "Getter";
+  else if (Node->isMessagingSetter())
+    OS << "Setter";
 }
 
 void StmtDumper::VisitObjCSubscriptRefExpr(ObjCSubscriptRefExpr *Node) {
diff --git a/clang/lib/Sema/SemaPseudoObject.cpp b/clang/lib/Sema/SemaPseudoObject.cpp
index aebc0eb6084..d52c912457a 100644
--- a/clang/lib/Sema/SemaPseudoObject.cpp
+++ b/clang/lib/Sema/SemaPseudoObject.cpp
@@ -208,6 +208,7 @@ namespace {
   /// A PseudoOpBuilder for Objective-C @properties.
   class ObjCPropertyOpBuilder : public PseudoOpBuilder {
     ObjCPropertyRefExpr *RefExpr;
+    ObjCPropertyRefExpr *SyntacticRefExpr;
     OpaqueValueExpr *InstanceReceiver;
     ObjCMethodDecl *Getter;
 
@@ -217,7 +218,7 @@ namespace {
   public:
     ObjCPropertyOpBuilder(Sema &S, ObjCPropertyRefExpr *refExpr) :
       PseudoOpBuilder(S, refExpr->getLocation()), RefExpr(refExpr),
-      InstanceReceiver(0), Getter(0), Setter(0) {
+      SyntacticRefExpr(0), InstanceReceiver(0), Getter(0), Setter(0) {
     }
 
     ExprResult buildRValueOperation(Expr *op);
@@ -538,6 +539,10 @@ Expr *ObjCPropertyOpBuilder::rebuildAndCaptureObject(Expr *syntacticBase) {
       ObjCPropertyRefRebuilder(S, InstanceReceiver).rebuild(syntacticBase);
   }
 
+  if (ObjCPropertyRefExpr *
+        refE = dyn_cast<ObjCPropertyRefExpr>(syntacticBase->IgnoreParens()))
+    SyntacticRefExpr = refE;
+
   return syntacticBase;
 }
 
@@ -545,7 +550,10 @@ Expr *ObjCPropertyOpBuilder::rebuildAndCaptureObject(Expr *syntacticBase) {
 ExprResult ObjCPropertyOpBuilder::buildGet() {
   findGetter();
   assert(Getter);
-  
+
+  if (SyntacticRefExpr)
+    SyntacticRefExpr->setIsMessagingGetter();
+
   QualType receiverType;
   if (RefExpr->isClassReceiver()) {
     receiverType = S.Context.getObjCInterfaceType(RefExpr->getClassReceiver());
@@ -581,6 +589,9 @@ ExprResult ObjCPropertyOpBuilder::buildSet(Expr *op, SourceLocation opcLoc,
   bool hasSetter = findSetter();
   assert(hasSetter); (void) hasSetter;
 
+  if (SyntacticRefExpr)
+    SyntacticRefExpr->setIsMessagingSetter();
+
   QualType receiverType;
   if (RefExpr->isClassReceiver()) {
     receiverType = S.Context.getObjCInterfaceType(RefExpr->getClassReceiver());
diff --git a/clang/lib/Serialization/ASTReaderStmt.cpp b/clang/lib/Serialization/ASTReaderStmt.cpp
index d8289f227f5..1c9817b955d 100644
--- a/clang/lib/Serialization/ASTReaderStmt.cpp
+++ b/clang/lib/Serialization/ASTReaderStmt.cpp
@@ -887,13 +887,15 @@ void ASTStmtReader::VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
 
 void ASTStmtReader::VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) {
   VisitExpr(E);
+  unsigned MethodRefFlags = Record[Idx++];
   bool Implicit = Record[Idx++] != 0;
   if (Implicit) {
     ObjCMethodDecl *Getter = ReadDeclAs<ObjCMethodDecl>(Record, Idx);
     ObjCMethodDecl *Setter = ReadDeclAs<ObjCMethodDecl>(Record, Idx);
-    E->setImplicitProperty(Getter, Setter);
+    E->setImplicitProperty(Getter, Setter, MethodRefFlags);
   } else {
-    E->setExplicitProperty(ReadDeclAs<ObjCPropertyDecl>(Record, Idx));
+    E->setExplicitProperty(ReadDeclAs<ObjCPropertyDecl>(Record, Idx),
+                           MethodRefFlags);
   }
   E->setLocation(ReadSourceLocation(Record, Idx));
   E->setReceiverLocation(ReadSourceLocation(Record, Idx));
diff --git a/clang/lib/Serialization/ASTWriterStmt.cpp b/clang/lib/Serialization/ASTWriterStmt.cpp
index 791403b5a22..eac7e1fb730 100644
--- a/clang/lib/Serialization/ASTWriterStmt.cpp
+++ b/clang/lib/Serialization/ASTWriterStmt.cpp
@@ -851,6 +851,7 @@ void ASTStmtWriter::VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
 
 void ASTStmtWriter::VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) {
   VisitExpr(E);
+  Record.push_back(E->SetterAndMethodRefFlags.getInt());
   Record.push_back(E->isImplicitProperty());
   if (E->isImplicitProperty()) {
     Writer.AddDeclRef(E->getImplicitPropertyGetter(), Record);
diff --git a/clang/test/Index/get-cursor.m b/clang/test/Index/get-cursor.m
index d343e66a003..ead18de0c01 100644
--- a/clang/test/Index/get-cursor.m
+++ b/clang/test/Index/get-cursor.m
@@ -41,6 +41,17 @@ struct S { int x; };
 }
 @end
 
+@interface Test2
+-(int)implicitProp;
+-(void)setImplicitProp:(int)x;
+@end
+
+void foo1(Test2 *test2) {
+  int x = test2.implicitProp;
+  test2.implicitProp = x;
+  ++test2.implicitProp;
+}
+
 // RUN: c-index-test -cursor-at=%s:4:28 -cursor-at=%s:5:28 %s | FileCheck -check-prefix=CHECK-PROP %s
 // CHECK-PROP: ObjCPropertyDecl=foo1:4:26
 // CHECK-PROP: ObjCPropertyDecl=foo2:5:27
@@ -54,6 +65,10 @@ struct S { int x; };
 // RUN: c-index-test -cursor-at=%s:37:17 %s | FileCheck -check-prefix=CHECK-IN-IMPL %s
 // CHECK-IN-IMPL: VarDecl=i:37:17
 
-// RUN: c-index-test -cursor-at=%s:38:6 -cursor-at=%s:40:11 %s | FileCheck -check-prefix=CHECK-MEMBERREF %s
+// RUN: c-index-test -cursor-at=%s:38:6 -cursor-at=%s:40:11 \
+// RUN:   -cursor-at=%s:50:20 -cursor-at=%s:51:15 -cursor-at=%s:52:20 %s | FileCheck -check-prefix=CHECK-MEMBERREF %s
 // CHECK-MEMBERREF: 38:6 MemberRefExpr=x:34:16 SingleRefName=[38:6 - 38:7] RefName=[38:6 - 38:7] Extent=[38:3 - 38:7]
 // CHECK-MEMBERREF: 40:9 MemberRefExpr=name:23:21 Extent=[40:3 - 40:13] Spelling=name
+// CHECK-MEMBERREF: 50:17 MemberRefExpr=implicitProp:45:7 Extent=[50:11 - 50:29] Spelling=implicitProp
+// CHECK-MEMBERREF: 51:9 MemberRefExpr=setImplicitProp::46:8 Extent=[51:3 - 51:21]
+// CHECK-MEMBERREF: 52:11 MemberRefExpr=setImplicitProp::46:8 Extent=[52:5 - 52:23]
diff --git a/clang/tools/libclang/CIndex.cpp b/clang/tools/libclang/CIndex.cpp
index 972beaf9e75..2a05b1b6f72 100644
--- a/clang/tools/libclang/CIndex.cpp
+++ b/clang/tools/libclang/CIndex.cpp
@@ -2901,8 +2901,17 @@ static Decl *getDeclFromExpr(Stmt *E) {
     return ME->getMemberDecl();
   if (ObjCIvarRefExpr *RE = dyn_cast<ObjCIvarRefExpr>(E))
     return RE->getDecl();
-  if (ObjCPropertyRefExpr *PRE = dyn_cast<ObjCPropertyRefExpr>(E))
-    return PRE->isExplicitProperty() ? PRE->getExplicitProperty() : 0;
+  if (ObjCPropertyRefExpr *PRE = dyn_cast<ObjCPropertyRefExpr>(E)) {
+    if (PRE->isExplicitProperty())
+      return PRE->getExplicitProperty();
+    // It could be messaging both getter and setter as in:
+    // ++myobj.myprop;
+    // in which case prefer to associate the setter since it is less obvious
+    // from inspecting the source that the setter is going to get called.
+    if (PRE->isMessagingSetter())
+      return PRE->getImplicitPropertySetter();
+    return PRE->getImplicitPropertyGetter();
+  }
   if (PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(E))
     return getDeclFromExpr(POE->getSyntacticForm());
   if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E))