//===----------------------------------------------------------------------===//
#include "llvm/Support/PrettyStackTrace.h"
+#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/Compiler.h"
#include "llvm/Support/Signals.h"
-#include "llvm/Support/ThreadLocal.h"
#include "llvm/Support/Watchdog.h"
#include "llvm/Support/raw_ostream.h"
-#include "llvm-c/Core.h"
#ifdef HAVE_CRASHREPORTERCLIENT_H
#include <CrashReporterClient.h>
using namespace llvm;
-static ManagedStatic<sys::ThreadLocal<const PrettyStackTraceEntry> > PrettyStackTraceHead;
+// If backtrace support is not enabled, compile out support for pretty stack
+// traces. This has the secondary effect of not requiring thread local storage
+// when backtrace support is disabled.
+#if defined(HAVE_BACKTRACE) && defined(ENABLE_BACKTRACES)
+
+// 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.
+static LLVM_THREAD_LOCAL const PrettyStackTraceEntry *PrettyStackTraceHead =
+ nullptr;
static unsigned PrintStack(const PrettyStackTraceEntry *Entry, raw_ostream &OS){
unsigned NextID = 0;
/// PrintCurStackTrace - Print the current stack trace to the specified stream.
static void PrintCurStackTrace(raw_ostream &OS) {
// Don't print an empty trace.
- if (PrettyStackTraceHead->get() == 0) return;
+ if (!PrettyStackTraceHead) return;
// If there are pretty stack frames registered, walk and emit them.
OS << "Stack dump:\n";
- PrintStack(PrettyStackTraceHead->get(), OS);
+ PrintStack(PrettyStackTraceHead, OS);
OS.flush();
}
#endif
}
+// defined(HAVE_BACKTRACE) && defined(ENABLE_BACKTRACES)
+#endif
+
PrettyStackTraceEntry::PrettyStackTraceEntry() {
+#if defined(HAVE_BACKTRACE) && defined(ENABLE_BACKTRACES)
// Link ourselves.
- NextEntry = PrettyStackTraceHead->get();
- PrettyStackTraceHead->set(this);
+ NextEntry = PrettyStackTraceHead;
+ PrettyStackTraceHead = this;
+#endif
}
PrettyStackTraceEntry::~PrettyStackTraceEntry() {
- // 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 &&
+#if defined(HAVE_BACKTRACE) && defined(ENABLE_BACKTRACES)
+ assert(PrettyStackTraceHead == this &&
"Pretty stack trace entry destruction is out of order");
- PrettyStackTraceHead->set(getNextEntry());
+ PrettyStackTraceHead = getNextEntry();
+#endif
}
void PrettyStackTraceString::print(raw_ostream &OS) const {
OS << '\n';
}
+#if defined(HAVE_BACKTRACE) && defined(ENABLE_BACKTRACES)
static bool RegisterCrashPrinter() {
- sys::AddSignalHandler(CrashHandler, 0);
+ sys::AddSignalHandler(CrashHandler, nullptr);
return false;
}
+#endif
void llvm::EnablePrettyStackTrace() {
+#if defined(HAVE_BACKTRACE) && defined(ENABLE_BACKTRACES)
// The first time this is called, we register the crash printer.
static bool HandlerRegistered = RegisterCrashPrinter();
(void)HandlerRegistered;
+#endif
}
void LLVMEnablePrettyStackTrace() {