2 files changed, 27 insertions, 10 deletions

diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 768947d00ac..e836135cf2f 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -6226,10 +6226,6 @@ bool RecordExprEvaluator::VisitInitListExpr(const InitListExpr *E) {
     // the initializer list.
     ImplicitValueInitExpr VIE(HaveInit ? Info.Ctx.IntTy : Field->getType());
     const Expr *Init = HaveInit ? E->getInit(ElementNo++) : &VIE;
-    if (Init->isValueDependent()) {
-      Success = false;
-      continue;
-    }
 
     // Temporarily override This, in case there's a CXXDefaultInitExpr in here.
     ThisOverrideRAII ThisOverride(*Info.CurrentCall, &This,
@@ -9940,8 +9936,7 @@ static bool EvaluateAsRValue(EvalInfo &Info, const Expr *E, APValue &Result) {
 }
 
 static bool FastEvaluateAsRValue(const Expr *Exp, Expr::EvalResult &Result,
-                                 const ASTContext &Ctx, bool &IsConst,
-                                 bool IsCheckingForOverflow) {
+                                 const ASTContext &Ctx, bool &IsConst) {
   // Fast-path evaluations of integer literals, since we sometimes see files
   // containing vast quantities of these.
   if (const IntegerLiteral *L = dyn_cast<IntegerLiteral>(Exp)) {
@@ -9962,7 +9957,7 @@ static bool FastEvaluateAsRValue(const Expr *Exp, Expr::EvalResult &Result,
   // performance problems. Only do so in C++11 for now.
   if (Exp->isRValue() && (Exp->getType()->isArrayType() ||
                           Exp->getType()->isRecordType()) &&
-      !Ctx.getLangOpts().CPlusPlus11 && !IsCheckingForOverflow) {
+      !Ctx.getLangOpts().CPlusPlus11) {
     IsConst = false;
     return true;
   }
@@ -9977,7 +9972,7 @@ static bool FastEvaluateAsRValue(const Expr *Exp, Expr::EvalResult &Result,
 /// will be applied to the result.
 bool Expr::EvaluateAsRValue(EvalResult &Result, const ASTContext &Ctx) const {
   bool IsConst;
-  if (FastEvaluateAsRValue(this, Result, Ctx, IsConst, false))
+  if (FastEvaluateAsRValue(this, Result, Ctx, IsConst))
     return IsConst;
   
   EvalInfo Info(Ctx, Result, EvalInfo::EM_IgnoreSideEffects);
@@ -10102,7 +10097,7 @@ APSInt Expr::EvaluateKnownConstInt(const ASTContext &Ctx,
 void Expr::EvaluateForOverflow(const ASTContext &Ctx) const {
   bool IsConst;
   EvalResult EvalResult;
-  if (!FastEvaluateAsRValue(this, EvalResult, Ctx, IsConst, true)) {
+  if (!FastEvaluateAsRValue(this, EvalResult, Ctx, IsConst)) {
     EvalInfo Info(Ctx, EvalResult, EvalInfo::EM_EvaluateForOverflow);
     (void)::EvaluateAsRValue(Info, this, EvalResult.Val);
   }
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 5201796adbb..845c4bf61b7 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -9936,6 +9936,28 @@ void Sema::CheckBoolLikeConversion(Expr *E, SourceLocation CC) {
   ::CheckBoolLikeConversion(*this, E, CC);
 }
 
+/// Diagnose when expression is an integer constant expression and its evaluation
+/// results in integer overflow
+void Sema::CheckForIntOverflow (Expr *E) {
+  // Use a work list to deal with nested struct initializers.
+  SmallVector<Expr *, 2> Exprs(1, E);
+
+  do {
+    Expr *E = Exprs.pop_back_val();
+
+    if (isa<BinaryOperator>(E->IgnoreParenCasts())) {
+      E->IgnoreParenCasts()->EvaluateForOverflow(Context);
+      continue;
+    }
+
+    if (auto InitList = dyn_cast<InitListExpr>(E))
+      Exprs.append(InitList->inits().begin(), InitList->inits().end());
+
+    if (isa<ObjCBoxedExpr>(E))
+      E->IgnoreParenCasts()->EvaluateForOverflow(Context);
+  } while (!Exprs.empty());
+}
+
 namespace {
 /// \brief Visitor for expressions which looks for unsequenced operations on the
 /// same object.
@@ -10437,7 +10459,7 @@ void Sema::CheckCompletedExpr(Expr *E, SourceLocation CheckLoc,
   if (!E->isInstantiationDependent())
     CheckUnsequencedOperations(E);
   if (!IsConstexpr && !E->isValueDependent())
-    E->EvaluateForOverflow(Context);
+    CheckForIntOverflow(E);
   DiagnoseMisalignedMembers();
 }