3 files changed, 40 insertions, 10 deletions

diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 9132b0a1903..3caca9d7e6c 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -1379,15 +1379,20 @@ EvaluatedStmt *VarDecl::ensureEvaluatedStmt() const {
   return Eval;
 }
 
-bool VarDecl::evaluateValue(
-                      llvm::SmallVectorImpl<PartialDiagnosticAt> &Notes) const {
+APValue *VarDecl::evaluateValue() const {
+  llvm::SmallVector<PartialDiagnosticAt, 8> Notes;
+  return evaluateValue(Notes);
+}
+
+APValue *VarDecl::evaluateValue(
+    llvm::SmallVectorImpl<PartialDiagnosticAt> &Notes) const {
   EvaluatedStmt *Eval = ensureEvaluatedStmt();
 
   // We only produce notes indicating why an initializer is non-constant the
   // first time it is evaluated. FIXME: The notes won't always be emitted the
   // first time we try evaluation, so might not be produced at all.
   if (Eval->WasEvaluated)
-    return !Eval->Evaluated.isUninit();
+    return Eval->Evaluated.isUninit() ? 0 : &Eval->Evaluated;
 
   const Expr *Init = cast<Expr>(Eval->Value);
   assert(!Init->isValueDependent());
@@ -1396,7 +1401,7 @@ bool VarDecl::evaluateValue(
     // FIXME: Produce a diagnostic for self-initialization.
     Eval->CheckedICE = true;
     Eval->IsICE = false;
-    return false;
+    return 0;
   }
 
   Eval->IsEvaluating = true;
@@ -1418,7 +1423,7 @@ bool VarDecl::evaluateValue(
     Eval->IsICE = Notes.empty();
   }
 
-  return Result;
+  return Result ? &Eval->Evaluated : 0;
 }
 
 bool VarDecl::checkInitIsICE() const {
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 912b111d617..ec5111579a2 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -5413,15 +5413,12 @@ bool Expr::EvaluateAsRValue(EvalResult &Result, const ASTContext &Ctx) const {
     return true;
   }
 
-  // FIXME: Evaluating initializers for large arrays can cause performance
-  // problems, and we don't use such values yet. Once we have a more efficient
-  // array representation, this should be reinstated, and used by CodeGen.
-  // The same problem affects large records.
+  // FIXME: Evaluating values of large array and record types can cause
+  // performance problems. Only do so in C++11 for now.
   if (isRValue() && (getType()->isArrayType() || getType()->isRecordType()) &&
       !Ctx.getLangOptions().CPlusPlus0x)
     return false;
 
-  // FIXME: If this is the initializer for an lvalue, pass that in.
   EvalInfo Info(Ctx, Result);
   return ::EvaluateAsRValue(Info, this, Result.Val);
 }
@@ -5461,6 +5458,12 @@ bool Expr::EvaluateAsLValue(EvalResult &Result, const ASTContext &Ctx) const {
 bool Expr::EvaluateAsInitializer(APValue &Value, const ASTContext &Ctx,
                                  const VarDecl *VD,
                       llvm::SmallVectorImpl<PartialDiagnosticAt> &Notes) const {
+  // FIXME: Evaluating initializers for large array and record types can cause
+  // performance problems. Only do so in C++11 for now.
+  if (isRValue() && (getType()->isArrayType() || getType()->isRecordType()) &&
+      !Ctx.getLangOptions().CPlusPlus0x)
+    return false;
+
   Expr::EvalStatus EStatus;
   EStatus.Diag = &Notes;
 
diff --git a/clang/lib/AST/RecordLayoutBuilder.cpp b/clang/lib/AST/RecordLayoutBuilder.cpp
index 5223219a306..d094461dc35 100644
--- a/clang/lib/AST/RecordLayoutBuilder.cpp
+++ b/clang/lib/AST/RecordLayoutBuilder.cpp
@@ -2153,6 +2153,28 @@ const CXXMethodDecl *ASTContext::getKeyFunction(const CXXRecordDecl *RD) {
   return Entry;
 }
 
+static uint64_t getFieldOffset(const ASTContext &C, const FieldDecl *FD) {
+  const ASTRecordLayout &Layout = C.getASTRecordLayout(FD->getParent());
+  return Layout.getFieldOffset(FD->getFieldIndex());
+}
+
+uint64_t ASTContext::getFieldOffset(const ValueDecl *VD) const {
+  uint64_t OffsetInBits;
+  if (const FieldDecl *FD = dyn_cast<FieldDecl>(VD)) {
+    OffsetInBits = ::getFieldOffset(*this, FD);
+  } else {
+    const IndirectFieldDecl *IFD = cast<IndirectFieldDecl>(VD);
+
+    OffsetInBits = 0;
+    for (IndirectFieldDecl::chain_iterator CI = IFD->chain_begin(),
+                                           CE = IFD->chain_end();
+         CI != CE; ++CI)
+      OffsetInBits += ::getFieldOffset(*this, cast<FieldDecl>(*CI));
+  }
+
+  return OffsetInBits;
+}
+
 /// getObjCLayout - Get or compute information about the layout of the
 /// given interface.
 ///