diff options
| -rw-r--r-- | llvm/lib/Support/PrettyStackTrace.cpp | 39 |
1 files changed, 21 insertions, 18 deletions
diff --git a/llvm/lib/Support/PrettyStackTrace.cpp b/llvm/lib/Support/PrettyStackTrace.cpp index 3483dfc37219..987778a1bde6 100644 --- a/llvm/lib/Support/PrettyStackTrace.cpp +++ b/llvm/lib/Support/PrettyStackTrace.cpp @@ -16,7 +16,9 @@ #include "llvm-c/Core.h" #include "llvm/ADT/SmallString.h" #include "llvm/Config/config.h" // Get autoconf configuration settings +#include "llvm/Support/ManagedStatic.h" #include "llvm/Support/Signals.h" +#include "llvm/Support/ThreadLocal.h" #include "llvm/Support/Watchdog.h" #include "llvm/Support/raw_ostream.h" @@ -26,18 +28,7 @@ using namespace llvm; -// We need a thread local pointer to manage the stack of our stack trace -// objects, but we *really* cannot tolerate destructors running and do not want -// to pay any overhead of synchronizing. As a consequence, we use a raw -// thread-local variable. Some day, we should be able to use a limited subset -// of C++11's thread_local, but compilers aren't up for it today. -// FIXME: This should be moved to a Compiler.h abstraction. -#ifdef _MSC_VER // MSVC supports this with a __declspec. -static __declspec(thread) const PrettyStackTraceEntry - *PrettyStackTraceHead = nullptr; -#else // Clang, GCC, and all compatible compilers tend to use __thread. -static __thread const PrettyStackTraceEntry *PrettyStackTraceHead = nullptr; -#endif +static ManagedStatic<sys::ThreadLocal<const PrettyStackTraceEntry> > PrettyStackTraceHead; static unsigned PrintStack(const PrettyStackTraceEntry *Entry, raw_ostream &OS){ unsigned NextID = 0; @@ -55,12 +46,12 @@ static unsigned PrintStack(const PrettyStackTraceEntry *Entry, raw_ostream &OS){ /// PrintCurStackTrace - Print the current stack trace to the specified stream. static void PrintCurStackTrace(raw_ostream &OS) { // Don't print an empty trace. - if (!PrettyStackTraceHead) return; + if (!PrettyStackTraceHead->get()) return; // If there are pretty stack frames registered, walk and emit them. OS << "Stack dump:\n"; - PrintStack(PrettyStackTraceHead, OS); + PrintStack(PrettyStackTraceHead->get(), OS); OS.flush(); } @@ -110,14 +101,26 @@ static void CrashHandler(void *) { PrettyStackTraceEntry::PrettyStackTraceEntry() { // Link ourselves. - NextEntry = PrettyStackTraceHead; - PrettyStackTraceHead = this; + NextEntry = PrettyStackTraceHead->get(); + PrettyStackTraceHead->set(this); } PrettyStackTraceEntry::~PrettyStackTraceEntry() { - assert(PrettyStackTraceHead == this && + // Do nothing if PrettyStackTraceHead is uninitialized. This can only happen + // if a shutdown occurred after we created the PrettyStackTraceEntry. That + // does occur in the following idiom: + // + // PrettyStackTraceProgram X(...); + // llvm_shutdown_obj Y; + // + // Without this check, we may end up removing ourselves from the stack trace + // after PrettyStackTraceHead has already been destroyed. + if (!PrettyStackTraceHead.isConstructed()) + return; + + assert(PrettyStackTraceHead->get() == this && "Pretty stack trace entry destruction is out of order"); - PrettyStackTraceHead = getNextEntry(); + PrettyStackTraceHead->set(getNextEntry()); } void PrettyStackTraceString::print(raw_ostream &OS) const { |