Re-commit r347417 "Re-Reinstate 347294 with a fix for the failures."

This was reverted in r347656 due to me thinking it caused a miscompile of
Chromium. Turns out it was the Chromium code that was broken.

llvm-svn: 347756

1 files changed, 4 insertions, 2 deletions

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 5c003ed6093..5c31589e0b2 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -5575,11 +5575,13 @@ static QualType TryToFixInvalidVariablyModifiedType(QualType T,
   if (VLATy->getElementType()->isVariablyModifiedType())
     return QualType();
 
-  llvm::APSInt Res;
+  Expr::EvalResult Result;
   if (!VLATy->getSizeExpr() ||
-      !VLATy->getSizeExpr()->EvaluateAsInt(Res, Context))
+      !VLATy->getSizeExpr()->EvaluateAsInt(Result, Context))
     return QualType();
 
+  llvm::APSInt Res = Result.Val.getInt();
+
   // Check whether the array size is negative.
   if (Res.isSigned() && Res.isNegative()) {
     SizeIsNegative = true;