For llvm::sys::ThreadLocalImpl instead of malloc'ing the platform-specific

thread local data, embed them in the class using a uint64_t and make sure
we get compiler errors if there's a platform where this is not big enough.

This makes ThreadLocal more safe for using it in conjunction with CrashRecoveryContext.

Related to crash in rdar://11434201.

llvm-svn: 158342

1 files changed, 6 insertions, 7 deletions

diff --git a/llvm/lib/Support/Windows/ThreadLocal.inc b/llvm/lib/Support/Windows/ThreadLocal.inc
index 512462d8900..99c6f4f63b3 100644
--- a/llvm/lib/Support/Windows/ThreadLocal.inc
+++ b/llvm/lib/Support/Windows/ThreadLocal.inc
@@ -22,26 +22,25 @@
 namespace llvm {
 using namespace sys;
 
-ThreadLocalImpl::ThreadLocalImpl() {
-  DWORD* tls = new DWORD;
+ThreadLocalImpl::ThreadLocalImpl() : data(0) {
+  typedef int SIZE_TOO_BIG[sizeof(DWORD) <= sizeof(data) ? 1 : -1];
+  DWORD* tls = reinterpret_cast<DWORD*>(&data);
   *tls = TlsAlloc();
   assert(*tls != TLS_OUT_OF_INDEXES);
-  data = tls;
 }
 
 ThreadLocalImpl::~ThreadLocalImpl() {
-  DWORD* tls = static_cast<DWORD*>(data);
+  DWORD* tls = reinterpret_cast<DWORD*>(&data);
   TlsFree(*tls);
-  delete tls;
 }
 
 const void* ThreadLocalImpl::getInstance() {
-  DWORD* tls = static_cast<DWORD*>(data);
+  DWORD* tls = reinterpret_cast<DWORD*>(&data);
   return TlsGetValue(*tls);
 }
 
 void ThreadLocalImpl::setInstance(const void* d){
-  DWORD* tls = static_cast<DWORD*>(data);
+  DWORD* tls = reinterpret_cast<DWORD*>(&data);
   int errorcode = TlsSetValue(*tls, const_cast<void*>(d));
   assert(errorcode != 0);
   (void)errorcode;