1 files changed, 203 insertions, 23 deletions

diff --git a/include/clang/Sema/ScopeInfo.h b/include/clang/Sema/ScopeInfo.h
index b4752f5..feda9c9 100644
--- a/include/clang/Sema/ScopeInfo.h
+++ b/include/clang/Sema/ScopeInfo.h
@@ -7,7 +7,8 @@
 //
 //===----------------------------------------------------------------------===//
 //
-//  This file defines FunctionScopeInfo and BlockScopeInfo.
+// This file defines FunctionScopeInfo and its subclasses, which contain
+// information about a single function, block, lambda, or method body.
 //
 //===----------------------------------------------------------------------===//
 
@@ -21,14 +22,20 @@
 
 namespace clang {
 
+class Decl;
 class BlockDecl;
 class CXXMethodDecl;
+class ObjCPropertyDecl;
 class IdentifierInfo;
 class LabelDecl;
 class ReturnStmt;
 class Scope;
 class SwitchStmt;
 class VarDecl;
+class DeclRefExpr;
+class ObjCIvarRefExpr;
+class ObjCPropertyRefExpr;
+class ObjCMessageExpr;
 
 namespace sema {
 
@@ -84,13 +91,10 @@ public:
   /// \brief Whether this function contains any indirect gotos.
   bool HasIndirectGoto;
 
-  /// A flag that is set when parsing a -dealloc method and no [super dealloc]
-  /// call was found yet.
-  bool ObjCShouldCallSuperDealloc;
-
-  /// A flag that is set when parsing a -finalize method and no [super finalize]
-  /// call was found yet.
-  bool ObjCShouldCallSuperFinalize;
+  /// A flag that is set when parsing a method that must call super's
+  /// implementation, such as \c -dealloc, \c -finalize, or any method marked
+  /// with \c __attribute__((objc_requires_super)).
+  bool ObjCShouldCallSuper;
 
   /// \brief Used to determine if errors occurred in this function or block.
   DiagnosticErrorTrap ErrorTrap;
@@ -113,6 +117,164 @@ public:
   /// prior to being emitted.
   SmallVector<PossiblyUnreachableDiag, 4> PossiblyUnreachableDiags;
 
+public:
+  /// Represents a simple identification of a weak object.
+  ///
+  /// Part of the implementation of -Wrepeated-use-of-weak.
+  ///
+  /// This is used to determine if two weak accesses refer to the same object.
+  /// Here are some examples of how various accesses are "profiled":
+  ///
+  /// Access Expression |     "Base" Decl     |          "Property" Decl
+  /// :---------------: | :-----------------: | :------------------------------:
+  /// self.property     | self (VarDecl)      | property (ObjCPropertyDecl)
+  /// self.implicitProp | self (VarDecl)      | -implicitProp (ObjCMethodDecl)
+  /// self->ivar.prop   | ivar (ObjCIvarDecl) | prop (ObjCPropertyDecl)
+  /// cxxObj.obj.prop   | obj (FieldDecl)     | prop (ObjCPropertyDecl)
+  /// [self foo].prop   | 0 (unknown)         | prop (ObjCPropertyDecl)
+  /// self.prop1.prop2  | prop1 (ObjCPropertyDecl)    | prop2 (ObjCPropertyDecl)
+  /// MyClass.prop      | MyClass (ObjCInterfaceDecl) | -prop (ObjCMethodDecl)
+  /// weakVar           | 0 (known)           | weakVar (VarDecl)
+  /// self->weakIvar    | self (VarDecl)      | weakIvar (ObjCIvarDecl)
+  ///
+  /// Objects are identified with only two Decls to make it reasonably fast to
+  /// compare them.
+  class WeakObjectProfileTy {
+    /// The base object decl, as described in the class documentation.
+    ///
+    /// The extra flag is "true" if the Base and Property are enough to uniquely
+    /// identify the object in memory.
+    ///
+    /// \sa isExactProfile()
+    typedef llvm::PointerIntPair<const NamedDecl *, 1, bool> BaseInfoTy;
+    BaseInfoTy Base;
+
+    /// The "property" decl, as described in the class documentation.
+    ///
+    /// Note that this may not actually be an ObjCPropertyDecl, e.g. in the
+    /// case of "implicit" properties (regular methods accessed via dot syntax).
+    const NamedDecl *Property;
+
+    /// Used to find the proper base profile for a given base expression.
+    static BaseInfoTy getBaseInfo(const Expr *BaseE);
+
+    // For use in DenseMap.
+    friend class DenseMapInfo;
+    inline WeakObjectProfileTy();
+    static inline WeakObjectProfileTy getSentinel();
+
+  public:
+    WeakObjectProfileTy(const ObjCPropertyRefExpr *RE);
+    WeakObjectProfileTy(const Expr *Base, const ObjCPropertyDecl *Property);
+    WeakObjectProfileTy(const DeclRefExpr *RE);
+    WeakObjectProfileTy(const ObjCIvarRefExpr *RE);
+
+    const NamedDecl *getBase() const { return Base.getPointer(); }
+    const NamedDecl *getProperty() const { return Property; }
+
+    /// Returns true if the object base specifies a known object in memory,
+    /// rather than, say, an instance variable or property of another object.
+    ///
+    /// Note that this ignores the effects of aliasing; that is, \c foo.bar is
+    /// considered an exact profile if \c foo is a local variable, even if
+    /// another variable \c foo2 refers to the same object as \c foo.
+    ///
+    /// For increased precision, accesses with base variables that are
+    /// properties or ivars of 'self' (e.g. self.prop1.prop2) are considered to
+    /// be exact, though this is not true for arbitrary variables
+    /// (foo.prop1.prop2).
+    bool isExactProfile() const {
+      return Base.getInt();
+    }
+
+    bool operator==(const WeakObjectProfileTy &Other) const {
+      return Base == Other.Base && Property == Other.Property;
+    }
+
+    // For use in DenseMap.
+    // We can't specialize the usual llvm::DenseMapInfo at the end of the file
+    // because by that point the DenseMap in FunctionScopeInfo has already been
+    // instantiated.
+    class DenseMapInfo {
+    public:
+      static inline WeakObjectProfileTy getEmptyKey() {
+        return WeakObjectProfileTy();
+      }
+      static inline WeakObjectProfileTy getTombstoneKey() {
+        return WeakObjectProfileTy::getSentinel();
+      }
+
+      static unsigned getHashValue(const WeakObjectProfileTy &Val) {
+        typedef std::pair<BaseInfoTy, const NamedDecl *> Pair;
+        return llvm::DenseMapInfo<Pair>::getHashValue(Pair(Val.Base,
+                                                           Val.Property));
+      }
+
+      static bool isEqual(const WeakObjectProfileTy &LHS,
+                          const WeakObjectProfileTy &RHS) {
+        return LHS == RHS;
+      }
+    };
+  };
+
+  /// Represents a single use of a weak object.
+  ///
+  /// Stores both the expression and whether the access is potentially unsafe
+  /// (i.e. it could potentially be warned about).
+  ///
+  /// Part of the implementation of -Wrepeated-use-of-weak.
+  class WeakUseTy {
+    llvm::PointerIntPair<const Expr *, 1, bool> Rep;
+  public:
+    WeakUseTy(const Expr *Use, bool IsRead) : Rep(Use, IsRead) {}
+
+    const Expr *getUseExpr() const { return Rep.getPointer(); }
+    bool isUnsafe() const { return Rep.getInt(); }
+    void markSafe() { Rep.setInt(false); }
+
+    bool operator==(const WeakUseTy &Other) const {
+      return Rep == Other.Rep;
+    }
+  };
+
+  /// Used to collect uses of a particular weak object in a function body.
+  ///
+  /// Part of the implementation of -Wrepeated-use-of-weak.
+  typedef SmallVector<WeakUseTy, 4> WeakUseVector;
+
+  /// Used to collect all uses of weak objects in a function body.
+  ///
+  /// Part of the implementation of -Wrepeated-use-of-weak.
+  typedef llvm::SmallDenseMap<WeakObjectProfileTy, WeakUseVector, 8,
+                              WeakObjectProfileTy::DenseMapInfo>
+          WeakObjectUseMap;
+
+private:
+  /// Used to collect all uses of weak objects in this function body.
+  ///
+  /// Part of the implementation of -Wrepeated-use-of-weak.
+  WeakObjectUseMap WeakObjectUses;
+
+public:
+  /// Record that a weak object was accessed.
+  ///
+  /// Part of the implementation of -Wrepeated-use-of-weak.
+  template <typename ExprT>
+  inline void recordUseOfWeak(const ExprT *E, bool IsRead = true);
+
+  void recordUseOfWeak(const ObjCMessageExpr *Msg,
+                       const ObjCPropertyDecl *Prop);
+
+  /// Record that a given expression is a "safe" access of a weak object (e.g.
+  /// assigning it to a strong variable.)
+  ///
+  /// Part of the implementation of -Wrepeated-use-of-weak.
+  void markSafeWeakUse(const Expr *E);
+
+  const WeakObjectUseMap &getWeakObjectUses() const {
+    return WeakObjectUses;
+  }
+
   void setHasBranchIntoScope() {
     HasBranchIntoScope = true;
   }
@@ -135,8 +297,7 @@ public:
       HasBranchProtectedScope(false),
       HasBranchIntoScope(false),
       HasIndirectGoto(false),
-      ObjCShouldCallSuperDealloc(false),
-      ObjCShouldCallSuperFinalize(false),
+      ObjCShouldCallSuper(false),
       ErrorTrap(Diag) { }
 
   virtual ~FunctionScopeInfo();
@@ -144,8 +305,6 @@ public:
   /// \brief Clear out the information in this function scope, making it
   /// suitable for reuse.
   void Clear();
-
-  static bool classof(const FunctionScopeInfo *FSI) { return true; }
 };
 
 class CapturingScopeInfo : public FunctionScopeInfo {
@@ -262,11 +421,7 @@ public:
   }
 
   void addThisCapture(bool isNested, SourceLocation Loc, QualType CaptureType,
-                      Expr *Cpy) {
-    Captures.push_back(Capture(Capture::ThisCapture, isNested, Loc, CaptureType,
-                               Cpy));
-    CXXThisCaptureIndex = Captures.size();
-  }
+                      Expr *Cpy);
 
   /// \brief Determine whether the C++ 'this' is captured.
   bool isCXXThisCaptured() const { return CXXThisCaptureIndex != 0; }
@@ -299,7 +454,6 @@ public:
   static bool classof(const FunctionScopeInfo *FSI) { 
     return FSI->Kind == SK_Block || FSI->Kind == SK_Lambda; 
   }
-  static bool classof(const CapturingScopeInfo *BSI) { return true; }
 };
 
 /// \brief Retains information about a block that is currently being parsed.
@@ -327,7 +481,6 @@ public:
   static bool classof(const FunctionScopeInfo *FSI) { 
     return FSI->Kind == SK_Block; 
   }
-  static bool classof(const BlockScopeInfo *BSI) { return true; }
 };
 
 class LambdaScopeInfo : public CapturingScopeInfo {
@@ -379,15 +532,42 @@ public:
   void finishedExplicitCaptures() {
     NumExplicitCaptures = Captures.size();
   }
-  
-  static bool classof(const FunctionScopeInfo *FSI) { 
+
+  static bool classof(const FunctionScopeInfo *FSI) {
     return FSI->Kind == SK_Lambda; 
   }
-  static bool classof(const LambdaScopeInfo *BSI) { return true; }
-
 };
 
+
+FunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy()
+  : Base(0, false), Property(0) {}
+
+FunctionScopeInfo::WeakObjectProfileTy
+FunctionScopeInfo::WeakObjectProfileTy::getSentinel() {
+  FunctionScopeInfo::WeakObjectProfileTy Result;
+  Result.Base.setInt(true);
+  return Result;
+}
+
+template <typename ExprT>
+void FunctionScopeInfo::recordUseOfWeak(const ExprT *E, bool IsRead) {
+  assert(E);
+  WeakUseVector &Uses = WeakObjectUses[WeakObjectProfileTy(E)];
+  Uses.push_back(WeakUseTy(E, IsRead));
 }
+
+inline void
+CapturingScopeInfo::addThisCapture(bool isNested, SourceLocation Loc,
+                                   QualType CaptureType, Expr *Cpy) {
+  Captures.push_back(Capture(Capture::ThisCapture, isNested, Loc, CaptureType,
+                             Cpy));
+  CXXThisCaptureIndex = Captures.size();
+
+  if (LambdaScopeInfo *LSI = dyn_cast<LambdaScopeInfo>(this))
+    LSI->ArrayIndexStarts.push_back(LSI->ArrayIndexVars.size());
 }
 
+} // end namespace sema
+} // end namespace clang
+
 #endif