diff --git a/clang.xcodeproj/project.pbxproj b/clang.xcodeproj/project.pbxproj
index 1b3f147..4ae76ef 100644
--- a/clang.xcodeproj/project.pbxproj
+++ b/clang.xcodeproj/project.pbxproj
@@ -10,6 +10,7 @@
 		035611E20DB40C8100D2EF2A /* RewriteObjC.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 035611E10DB40C8100D2EF2A /* RewriteObjC.cpp */; };
 		03F50AC60D416EAA00B9CF60 /* Targets.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 03F50AC50D416EAA00B9CF60 /* Targets.cpp */; };
 		1A30A9E90B93A4C800201A91 /* ExprCXX.h in CopyFiles */ = {isa = PBXBuildFile; fileRef = 1A30A9E80B93A4C800201A91 /* ExprCXX.h */; };
+		1A32C17F0E1C87AD00A6B483 /* ExprConstant.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 1A32C17E0E1C87AD00A6B483 /* ExprConstant.cpp */; };
 		1A376A2D0D4AED9B002A1C52 /* CGExprConstant.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 1A376A2C0D4AED9B002A1C52 /* CGExprConstant.cpp */; };
 		1A7342480C7B57D500122F56 /* CGObjC.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 1A7342470C7B57D500122F56 /* CGObjC.cpp */; };
 		1A869A700BA2164C008DA07A /* LiteralSupport.h in CopyFiles */ = {isa = PBXBuildFile; fileRef = 1A869A6E0BA2164C008DA07A /* LiteralSupport.h */; };
@@ -260,6 +261,7 @@
 		035611E10DB40C8100D2EF2A /* RewriteObjC.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = RewriteObjC.cpp; path = Driver/RewriteObjC.cpp; sourceTree = "<group>"; };
 		03F50AC50D416EAA00B9CF60 /* Targets.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = Targets.cpp; sourceTree = "<group>"; };
 		1A30A9E80B93A4C800201A91 /* ExprCXX.h */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.c.h; name = ExprCXX.h; path = clang/AST/ExprCXX.h; sourceTree = "<group>"; };
+		1A32C17E0E1C87AD00A6B483 /* ExprConstant.cpp */ = {isa = PBXFileReference; fileEncoding = 4; indentWidth = 2; lastKnownFileType = sourcecode.cpp.cpp; name = ExprConstant.cpp; path = lib/AST/ExprConstant.cpp; sourceTree = "<group>"; tabWidth = 2; };
 		1A376A2C0D4AED9B002A1C52 /* CGExprConstant.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = CGExprConstant.cpp; path = lib/CodeGen/CGExprConstant.cpp; sourceTree = "<group>"; };
 		1A68BC110D0CADDD001A28C8 /* PPCBuiltins.def */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text; name = PPCBuiltins.def; path = clang/AST/PPCBuiltins.def; sourceTree = "<group>"; };
 		1A68BC120D0CADDD001A28C8 /* TargetBuiltins.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = TargetBuiltins.h; path = clang/AST/TargetBuiltins.h; sourceTree = "<group>"; };
@@ -406,7 +408,7 @@
 		DE5932CE0AD60FF400BC794C /* clang.h */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.c.h; name = clang.h; path = Driver/clang.h; sourceTree = "<group>"; };
 		DE5932CF0AD60FF400BC794C /* PrintParserCallbacks.cpp */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.cpp.cpp; name = PrintParserCallbacks.cpp; path = Driver/PrintParserCallbacks.cpp; sourceTree = "<group>"; };
 		DE5932D00AD60FF400BC794C /* PrintPreprocessedOutput.cpp */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.cpp.cpp; name = PrintPreprocessedOutput.cpp; path = Driver/PrintPreprocessedOutput.cpp; sourceTree = "<group>"; };
-		DE613EF30E0E148D00B05B79 /* APValue.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = APValue.h; path = clang/AST/APValue.h; sourceTree = "<group>"; };
+		DE613EF30E0E148D00B05B79 /* APValue.h */ = {isa = PBXFileReference; fileEncoding = 4; indentWidth = 2; lastKnownFileType = sourcecode.c.h; name = APValue.h; path = clang/AST/APValue.h; sourceTree = "<group>"; tabWidth = 2; };
 		DE67E70A0C020EC500F66BC5 /* SemaType.cpp */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.cpp.cpp; name = SemaType.cpp; path = lib/Sema/SemaType.cpp; sourceTree = "<group>"; };
 		DE67E70C0C020ECA00F66BC5 /* SemaStmt.cpp */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.cpp.cpp; name = SemaStmt.cpp; path = lib/Sema/SemaStmt.cpp; sourceTree = "<group>"; };
 		DE67E70E0C020ECF00F66BC5 /* SemaExprCXX.cpp */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.cpp.cpp; name = SemaExprCXX.cpp; path = lib/Sema/SemaExprCXX.cpp; sourceTree = "<group>"; };
@@ -826,6 +828,7 @@
 				DE38CF260D8C9E6C00A273B6 /* DeclObjC.cpp */,
 				3513185F0CD14468006B66F7 /* DeclSerialization.cpp */,
 				DE0FCB330A9C21F100248FD5 /* Expr.cpp */,
+				1A32C17E0E1C87AD00A6B483 /* ExprConstant.cpp */,
 				35260CA40C7F75C000D66CE9 /* ExprCXX.cpp */,
 				DE3452400AEF1A2D00DBC861 /* Stmt.cpp */,
 				DEF2EDA60C6A4252000C4259 /* StmtDumper.cpp */,
@@ -1121,6 +1124,7 @@
 				3534A01D0E129849002709B2 /* ParseCXXInlineMethods.cpp in Sources */,
 				DE22BCF20E14197E0094DC60 /* SemaDeclAttr.cpp in Sources */,
 				359DBBD40E1AC9CC00F43FA0 /* AnalysisConsumer.cpp in Sources */,
+				1A32C17F0E1C87AD00A6B483 /* ExprConstant.cpp in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
diff --git a/include/clang/AST/APValue.h b/include/clang/AST/APValue.h
index 626019c..ba3d86b 100644
--- a/include/clang/AST/APValue.h
+++ b/include/clang/AST/APValue.h
@@ -18,9 +18,10 @@
 #include "llvm/ADT/APFloat.h"
 
 namespace clang {
+  class Expr;
 
 /// APValue - This class implements a discriminated union of [uninitialized]
-/// [APSInt] [APFloat], [Complex APSInt] [Complex APFloat].
+/// [APSInt] [APFloat], [Complex APSInt] [Complex APFloat], [Expr + Offset].
 class APValue {
   typedef llvm::APSInt APSInt;
   typedef llvm::APFloat APFloat;
@@ -30,7 +31,8 @@
     SInt,
     Float,
     ComplexSInt,
-    ComplexFloat
+    ComplexFloat,
+    LValue
   };
 private:
   ValueKind Kind;
@@ -44,6 +46,11 @@
     ComplexAPFloat() : Real(0.0), Imag(0.0) {}
   };
   
+  struct LValue {
+    Expr* Base;
+    uint64_t Offset;
+  };
+  
   enum {
     MaxSize = (sizeof(ComplexAPSInt) > sizeof(ComplexAPFloat) ? 
                sizeof(ComplexAPSInt) : sizeof(ComplexAPFloat))
diff --git a/include/clang/AST/Expr.h b/include/clang/AST/Expr.h
index b207186..e821cc3 100644
--- a/include/clang/AST/Expr.h
+++ b/include/clang/AST/Expr.h
@@ -29,7 +29,8 @@
   class Selector;
   class Decl;
   class ASTContext;
-  
+  class APValue;
+    
 /// Expr - This represents one expression.  Note that Expr's are subclasses of
 /// Stmt.  This allows an expression to be transparently used any place a Stmt
 /// is required.
@@ -108,6 +109,8 @@
   /// isConstantExpr - Return true if this expression is a valid constant expr.
   bool isConstantExpr(ASTContext &Ctx, SourceLocation *Loc) const;
   
+  bool tryEvaluate(APValue& Result, ASTContext &Ctx) const;
+
   /// hasGlobalStorage - Return true if this expression has static storage
   /// duration.  This means that the address of this expression is a link-time
   /// constant.
diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index 58dadb0..de0c740 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -13,6 +13,7 @@
 
 #include "clang/AST/ExprObjC.h"
 #include "clang/AST/ASTContext.h"
+#include "clang/AST/APValue.h"
 #include "clang/AST/StmtVisitor.h"
 #include "clang/Basic/IdentifierTable.h"
 #include "clang/Basic/TargetInfo.h"
diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
new file mode 100644
index 0000000..ea9b106
--- /dev/null
+++ b/lib/AST/ExprConstant.cpp
@@ -0,0 +1,60 @@
+//===--- Expr.cpp - Expression Constant Evaluator -------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the Expr constant evaluator.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/AST/APValue.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/Expr.h"
+
+using namespace clang;
+
+
+static bool CalcFakeICEVal(const Expr* Expr,
+                           llvm::APSInt& Result,
+                           ASTContext& Context) {
+  // Calculate the value of an expression that has a calculatable
+  // value, but isn't an ICE. Currently, this only supports
+  // a very narrow set of extensions, but it can be expanded if needed.
+  if (const ParenExpr *PE = dyn_cast<ParenExpr>(Expr))
+    return CalcFakeICEVal(PE->getSubExpr(), Result, Context);
+  
+  if (const CastExpr *CE = dyn_cast<CastExpr>(Expr)) {
+    QualType CETy = CE->getType();
+    if ((CETy->isIntegralType() && !CETy->isBooleanType()) ||
+        CETy->isPointerType()) {
+      if (CalcFakeICEVal(CE->getSubExpr(), Result, Context)) {
+        Result.extOrTrunc(Context.getTypeSize(CETy));
+        // FIXME: This assumes pointers are signed.
+        Result.setIsSigned(CETy->isSignedIntegerType() ||
+                           CETy->isPointerType());
+        return true;
+      }
+    }
+  }
+  
+  if (Expr->getType()->isIntegralType())
+    return Expr->isIntegerConstantExpr(Result, Context);
+  
+  return false;
+}
+
+bool Expr::tryEvaluate(APValue& Result, ASTContext &Ctx) const
+{
+  llvm::APSInt sInt(1);
+  
+  if (CalcFakeICEVal(this, sInt, Ctx)) {
+    Result = APValue(sInt);
+    return true;
+  }
+  
+  return false;
+}
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index c0c3f09..80c37b9 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -12,6 +12,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "Sema.h"
+#include "clang/AST/APValue.h"
 #include "clang/AST/ASTConsumer.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/Attr.h"
@@ -1799,48 +1800,20 @@
   CollectIvars(Class, Decls);
 }
 
-
-static bool CalcFakeICEVal(const Expr* Expr,
-                           llvm::APSInt& Result,
-                           ASTContext& Context) {
-  // Calculate the value of an expression that has a calculatable
-  // value, but isn't an ICE. Currently, this only supports
-  // a very narrow set of extensions, but it can be expanded if needed.
-  if (const ParenExpr *PE = dyn_cast<ParenExpr>(Expr))
-    return CalcFakeICEVal(PE->getSubExpr(), Result, Context);
-
-  if (const CastExpr *CE = dyn_cast<CastExpr>(Expr)) {
-    QualType CETy = CE->getType();
-    if ((CETy->isIntegralType() && !CETy->isBooleanType()) ||
-        CETy->isPointerType()) {
-      if (CalcFakeICEVal(CE->getSubExpr(), Result, Context)) {
-        Result.extOrTrunc(Context.getTypeSize(CETy));
-        // FIXME: This assumes pointers are signed.
-        Result.setIsSigned(CETy->isSignedIntegerType() ||
-                           CETy->isPointerType());
-        return true;
-      }
-    }
-  }
-
-  if (Expr->getType()->isIntegralType())
-    return Expr->isIntegerConstantExpr(Result, Context);
-
-  return false;
-}
-
 QualType Sema::TryFixInvalidVariablyModifiedType(QualType T) {
   // This method tries to turn a variable array into a constant
   // array even when the size isn't an ICE.  This is necessary
   // for compatibility with code that depends on gcc's buggy
   // constant expression folding, like struct {char x[(int)(char*)2];}
   if (const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T)) {
-    llvm::APSInt Result(32);
+    APValue Result;
     if (VLATy->getSizeExpr() &&
-        CalcFakeICEVal(VLATy->getSizeExpr(), Result, Context) &&
-        Result > llvm::APSInt(Result.getBitWidth(), Result.isUnsigned())) {
+        VLATy->getSizeExpr()->tryEvaluate(Result, Context) && Result.isSInt() &&
+        Result.getSInt() > llvm::APSInt(Result.getSInt().getBitWidth(), 
+                                        Result.getSInt().isUnsigned())) {
       return Context.getConstantArrayType(VLATy->getElementType(),
-                                          Result, ArrayType::Normal, 0);
+                                          Result.getSInt(), 
+                                          ArrayType::Normal, 0);
     }
   }
   return QualType();