Fix an off by 1 bug that prevented SmallPtrSet from using all of its 'small' capacity...

[oota-llvm.git] / lib / Support / ThreadLocal.cpp

diff --git a/lib/Support/ThreadLocal.cpp b/lib/Support/ThreadLocal.cpp
index 1030a2b97db4694b1028c6bfccb3c01f41a9fb81..2dec9eb417f5bf4324e7b014c825a16c2664e9c8 100644 (file)
--- a/lib/Support/ThreadLocal.cpp
+++ b/lib/Support/ThreadLocal.cpp
@@ -12,6 +12,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Config/config.h"
+#include "llvm/Support/Compiler.h"
 #include "llvm/Support/ThreadLocal.h"
 
 //===----------------------------------------------------------------------===//
@@ -23,11 +24,20 @@
 // Define all methods as no-ops if threading is explicitly disabled
 namespace llvm {
 using namespace sys;
-ThreadLocalImpl::ThreadLocalImpl() { }
+ThreadLocalImpl::ThreadLocalImpl() : data() { }
 ThreadLocalImpl::~ThreadLocalImpl() { }
-void ThreadLocalImpl::setInstance(const void* d) { data = const_cast<void*>(d);}
-const void* ThreadLocalImpl::getInstance() { return data; }
-void ThreadLocalImpl::removeInstance() { data = 0; }
+void ThreadLocalImpl::setInstance(const void* d) {
+  static_assert(sizeof(d) <= sizeof(data), "size too big");
+  void **pd = reinterpret_cast<void**>(&data);
+  *pd = const_cast<void*>(d);
+}
+const void* ThreadLocalImpl::getInstance() {
+  void **pd = reinterpret_cast<void**>(&data);
+  return *pd;
+}
+void ThreadLocalImpl::removeInstance() {
+  setInstance(0);
+}
 }
 #else
 
@@ -40,10 +50,10 @@ void ThreadLocalImpl::removeInstance() { data = 0; }
 namespace llvm {
 using namespace sys;
 
-ThreadLocalImpl::ThreadLocalImpl() : data(0) {
-  typedef int SIZE_TOO_BIG[sizeof(pthread_key_t) <= sizeof(data) ? 1 : -1];
+ThreadLocalImpl::ThreadLocalImpl() : data() {
+  static_assert(sizeof(pthread_key_t) <= sizeof(data), "size too big");
   pthread_key_t* key = reinterpret_cast<pthread_key_t*>(&data);
-  int errorcode = pthread_key_create(key, NULL);
+  int errorcode = pthread_key_create(key, nullptr);
   assert(errorcode == 0);
   (void) errorcode;
 }
@@ -68,7 +78,7 @@ const void* ThreadLocalImpl::getInstance() {
 }
 
 void ThreadLocalImpl::removeInstance() {
-  setInstance(0);
+  setInstance(nullptr);
 }
 
 }