1 files changed, 88 insertions, 1 deletions
diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
index 34eefc0dcc..305c41c51c 100644
--- a/lib/AST/Decl.cpp
+++ b/lib/AST/Decl.cpp
@@ -1337,6 +1337,94 @@ void VarDecl::setInit(Expr *I) {
   Init = I;
 }
 
+/// Convert the initializer for this declaration to the elaborated EvaluatedStmt
+/// form, which contains extra information on the evaluated value of the
+/// initializer.
+EvaluatedStmt *VarDecl::ensureEvaluatedStmt() const {
+  EvaluatedStmt *Eval = Init.dyn_cast<EvaluatedStmt *>();
+  if (!Eval) {
+    Stmt *S = Init.get<Stmt *>();
+    Eval = new (getASTContext()) EvaluatedStmt;
+    Eval->Value = S;
+    Init = Eval;
+  }
+  return Eval;
+}
+
+bool 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();
+
+  const Expr *Init = cast<Expr>(Eval->Value);
+  assert(!Init->isValueDependent());
+
+  if (Eval->IsEvaluating) {
+    // FIXME: Produce a diagnostic for self-initialization.
+    Eval->CheckedICE = true;
+    Eval->IsICE = false;
+    return false;
+  }
+
+  Eval->IsEvaluating = true;
+
+  bool Result = Init->EvaluateAsInitializer(Eval->Evaluated, getASTContext(),
+                                            this, Notes);
+
+  // Ensure the result is an uninitialized APValue if evaluation fails.
+  if (!Result)
+    Eval->Evaluated = APValue();
+
+  Eval->IsEvaluating = false;
+  Eval->WasEvaluated = true;
+
+  // In C++11, we have determined whether the initializer was a constant
+  // expression as a side-effect.
+  if (getASTContext().getLangOptions().CPlusPlus0x && !Eval->CheckedICE) {
+    Eval->CheckedICE = true;
+    Eval->IsICE = Notes.empty();
+  }
+
+  return Result;
+}
+
+bool VarDecl::checkInitIsICE() const {
+  EvaluatedStmt *Eval = ensureEvaluatedStmt();
+  if (Eval->CheckedICE)
+    // We have already checked whether this subexpression is an
+    // integral constant expression.
+    return Eval->IsICE;
+
+  const Expr *Init = cast<Expr>(Eval->Value);
+  assert(!Init->isValueDependent());
+
+  // In C++11, evaluate the initializer to check whether it's a constant
+  // expression.
+  if (getASTContext().getLangOptions().CPlusPlus0x) {
+    llvm::SmallVector<PartialDiagnosticAt, 8> Notes;
+    evaluateValue(Notes);
+    return Eval->IsICE;
+  }
+
+  // It's an ICE whether or not the definition we found is
+  // out-of-line.  See DR 721 and the discussion in Clang PR
+  // 6206 for details.
+
+  if (Eval->CheckingICE)
+    return false;
+  Eval->CheckingICE = true;
+
+  Eval->IsICE = Init->isIntegerConstantExpr(getASTContext());
+  Eval->CheckingICE = false;
+  Eval->CheckedICE = true;
+  return Eval->IsICE;
+}
+
 bool VarDecl::extendsLifetimeOfTemporary() const {
   assert(getType()->isReferenceType() &&"Non-references never extend lifetime");
   
@@ -2687,4 +2775,3 @@ SourceRange ImportDecl::getSourceRange() const {
   
   return SourceRange(getLocation(), getIdentifierLocs().back());
 }
-