llvm-6502/lib/Support/ThreadLocal.cpp
Hans Wennborg 837d6ed3ea Make sys::ThreadLocal<> zero-initialized on non-thread builds (PR18205)
According to the docs, ThreadLocal<>::get() should return NULL
if no object has been set. This patch makes that the case also for non-thread
builds and adds a very basic unit test to check it.

(This was causing PR18205 because PrettyStackTraceHead didn't get zero-
initialized and we'd crash trying to read past the end of that list. We didn't
notice this so much on Linux since we'd crash after printing all the entries,
but on Mac we print into a SmallString, and would crash before printing that.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@197718 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-19 20:32:44 +00:00

93 lines
2.7 KiB
C++

//===- ThreadLocal.cpp - Thread Local Data ----------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the llvm::sys::ThreadLocal class.
//
//===----------------------------------------------------------------------===//
#include "llvm/Config/config.h"
#include "llvm/Support/ThreadLocal.h"
//===----------------------------------------------------------------------===//
//=== WARNING: Implementation here must contain only TRULY operating system
//=== independent code.
//===----------------------------------------------------------------------===//
#if !defined(LLVM_ENABLE_THREADS) || LLVM_ENABLE_THREADS == 0
// Define all methods as no-ops if threading is explicitly disabled
namespace llvm {
using namespace sys;
ThreadLocalImpl::ThreadLocalImpl() : data() { }
ThreadLocalImpl::~ThreadLocalImpl() { }
void ThreadLocalImpl::setInstance(const void* d) {
typedef int SIZE_TOO_BIG[sizeof(d) <= sizeof(data) ? 1 : -1];
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
#if defined(HAVE_PTHREAD_H) && defined(HAVE_PTHREAD_GETSPECIFIC)
#include <cassert>
#include <pthread.h>
#include <stdlib.h>
namespace llvm {
using namespace sys;
ThreadLocalImpl::ThreadLocalImpl() : data() {
typedef int SIZE_TOO_BIG[sizeof(pthread_key_t) <= sizeof(data) ? 1 : -1];
pthread_key_t* key = reinterpret_cast<pthread_key_t*>(&data);
int errorcode = pthread_key_create(key, NULL);
assert(errorcode == 0);
(void) errorcode;
}
ThreadLocalImpl::~ThreadLocalImpl() {
pthread_key_t* key = reinterpret_cast<pthread_key_t*>(&data);
int errorcode = pthread_key_delete(*key);
assert(errorcode == 0);
(void) errorcode;
}
void ThreadLocalImpl::setInstance(const void* d) {
pthread_key_t* key = reinterpret_cast<pthread_key_t*>(&data);
int errorcode = pthread_setspecific(*key, d);
assert(errorcode == 0);
(void) errorcode;
}
const void* ThreadLocalImpl::getInstance() {
pthread_key_t* key = reinterpret_cast<pthread_key_t*>(&data);
return pthread_getspecific(*key);
}
void ThreadLocalImpl::removeInstance() {
setInstance(0);
}
}
#elif defined(LLVM_ON_UNIX)
#include "Unix/ThreadLocal.inc"
#elif defined( LLVM_ON_WIN32)
#include "Windows/ThreadLocal.inc"
#else
#warning Neither LLVM_ON_UNIX nor LLVM_ON_WIN32 set in Support/ThreadLocal.cpp
#endif
#endif