[ASan] Move the shadow range on 32-bit iOS (and iOS Simulator)

to 0x40000000-0x60000000 to avoid address space clash with system libraries.
The solution has been proposed by tahabekireren@gmail.com in https://code.google.com/p/address-sanitizer/issues/detail?id=210
This is also known to fix some Chromium iOS tests.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207002 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index ed4f999b88317bbd8639072e8e720418ba0eb89b..27e5c83a4dc84ae7c20ac4d2f00524ac3f7a36b0 100644 (file)
--- a/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -55,6 +55,7 @@ using namespace llvm;
 
 static const uint64_t kDefaultShadowScale = 3;
 static const uint64_t kDefaultShadowOffset32 = 1ULL << 29;
+static const uint64_t kIOSShadowOffset32 = 1ULL << 30;
 static const uint64_t kDefaultShadowOffset64 = 1ULL << 44;
 static const uint64_t kSmallX86_64ShadowOffset = 0x7FFF8000;  // < 2G.
 static const uint64_t kPPC64_ShadowOffset64 = 1ULL << 41;
@@ -250,7 +251,7 @@ struct ShadowMapping {
 static ShadowMapping getShadowMapping(const Module &M, int LongSize) {
   llvm::Triple TargetTriple(M.getTargetTriple());
   bool IsAndroid = TargetTriple.getEnvironment() == llvm::Triple::Android;
-  // bool IsMacOSX = TargetTriple.getOS() == llvm::Triple::MacOSX;
+  bool IsIOS = TargetTriple.getOS() == llvm::Triple::IOS;
   bool IsFreeBSD = TargetTriple.getOS() == llvm::Triple::FreeBSD;
   bool IsLinux = TargetTriple.getOS() == llvm::Triple::Linux;
   bool IsPPC64 = TargetTriple.getArch() == llvm::Triple::ppc64 ||
@@ -268,6 +269,8 @@ static ShadowMapping getShadowMapping(const Module &M, int LongSize) {
       Mapping.Offset = kMIPS32_ShadowOffset32;
     else if (IsFreeBSD)
       Mapping.Offset = kFreeBSD_ShadowOffset32;
+    else if (IsIOS)
+      Mapping.Offset = kIOSShadowOffset32;
     else
       Mapping.Offset = kDefaultShadowOffset32;
   } else {  // LongSize == 64