Index: cfe/trunk/include/clang/AST/ASTContext.h
===================================================================
--- cfe/trunk/include/clang/AST/ASTContext.h
+++ cfe/trunk/include/clang/AST/ASTContext.h
@@ -1441,6 +1441,10 @@
   /// The sizeof operator requires this (C99 6.5.3.4p4).
   CanQualType getSizeType() const;
 
+  /// \brief Return the unique signed counterpart of 
+  /// the integer type corresponding to size_t.
+  CanQualType getSignedSizeType() const;
+
   /// \brief Return the unique type for "intmax_t" (C99 7.18.1.5), defined in
   /// <stdint.h>.
   CanQualType getIntMaxType() const;
Index: cfe/trunk/include/clang/Basic/TargetInfo.h
===================================================================
--- cfe/trunk/include/clang/Basic/TargetInfo.h
+++ cfe/trunk/include/clang/Basic/TargetInfo.h
@@ -226,6 +226,20 @@
 
 public:
   IntType getSizeType() const { return SizeType; }
+  IntType getSignedSizeType() const {
+    switch (SizeType) {
+    case UnsignedShort:
+      return SignedShort;
+    case UnsignedInt:
+      return SignedInt;
+    case UnsignedLong:
+      return SignedLong;
+    case UnsignedLongLong:
+      return SignedLongLong;
+    default:
+      llvm_unreachable("Invalid SizeType");
+    }
+  }
   IntType getIntMaxType() const { return IntMaxType; }
   IntType getUIntMaxType() const {
     return getCorrespondingUnsignedType(IntMaxType);
Index: cfe/trunk/lib/AST/ASTContext.cpp
===================================================================
--- cfe/trunk/lib/AST/ASTContext.cpp
+++ cfe/trunk/lib/AST/ASTContext.cpp
@@ -4525,6 +4525,12 @@
   return getFromTargetType(Target->getSizeType());
 }
 
+/// Return the unique signed counterpart of the integer type 
+/// corresponding to size_t.
+CanQualType ASTContext::getSignedSizeType() const {
+  return getFromTargetType(Target->getSignedSizeType());
+}
+
 /// getIntMaxType - Return the unique type for "intmax_t" (C99 7.18.1.5).
 CanQualType ASTContext::getIntMaxType() const {
   return getFromTargetType(Target->getIntMaxType());