From 89f3bcf0b526ebc0ebee949554c3f9b5bd199182 Mon Sep 17 00:00:00 2001
From: Matthias Braun <matze@braunis.de>
Date: Fri, 19 May 2017 22:37:01 +0000
Subject: [PATCH] Verifier: Check wchar_size module flag.

Differential Revision: https://reviews.llvm.org/D32974

llvm-svn: 303460
---
 llvm/lib/IR/Verifier.cpp | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index 3b68d6365872..4b9bdcf81a39 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -1317,6 +1317,15 @@ Verifier::visitModuleFlag(const MDNode *Op,
     Assert(Inserted,
            "module flag identifiers must be unique (or of 'require' type)", ID);
   }
+
+  if (ID->getString() == "wchar_size") {
+    ConstantInt *Value
+      = mdconst::dyn_extract_or_null<ConstantInt>(Op->getOperand(2));
+    Assert(Value, "wchar_size metadata requires constant integer argument");
+    uint64_t WCharSize = Value->getZExtValue();
+    Assert(WCharSize == 0 || WCharSize == 2 || WCharSize == 4,
+           "wchar_size should be 0, 2 or 4");
+  }
 }
 
 /// Return true if this attribute kind only applies to functions.