From c420d14b29e991b234e1ac3ad5f8d00abd0ed1dc Mon Sep 17 00:00:00 2001
From: Vedant Kumar <vsk@apple.com>
Date: Fri, 16 Jun 2017 03:27:36 +0000
Subject: [ubsan] PR33081: Skip the standard type checks for volatile

Skip checks for null dereference, alignment violation, object size
violation, and dynamic type violation if the pointer points to volatile
data.

Differential Revision: https://reviews.llvm.org/D34262

llvm-svn: 305546
---
 clang/lib/CodeGen/CGExpr.cpp | 5 +++++
 1 file changed, 5 insertions(+)

(limited to 'clang/lib/CodeGen/CGExpr.cpp')

diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index 15829888ead..7359006677f 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -549,6 +549,11 @@ void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
   if (Ptr->getType()->getPointerAddressSpace())
     return;
 
+  // Don't check pointers to volatile data. The behavior here is implementation-
+  // defined.
+  if (Ty.isVolatileQualified())
+    return;
+
   SanitizerScope SanScope(this);
 
   SmallVector<std::pair<llvm::Value *, SanitizerMask>, 3> Checks;
-- 
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