#include "llvm-c/Core.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Config/config.h" // Get autoconf configuration settings
+#include "llvm/Support/Compiler.h"
#include "llvm/Support/Signals.h"
#include "llvm/Support/Watchdog.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
+// 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. 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.
-#define LLVM_THREAD_LOCAL __declspec(thread)
-#else
-// Clang, GCC, and all compatible compilers tend to use __thread. But we need
-// to work aronud a bug in the combination of Clang's compilation of
-// local-dynamic TLS and the ppc64 linker relocations which we do by forcing to
-// global-dynamic (called in most documents "general dynamic").
-// FIXME: Make this conditional on the Clang version once this is fixed in
-// top-of-tree.
-#if defined(__clang__) && defined(__powerpc64__)
-#define LLVM_THREAD_LOCAL __thread __attribute__((tls_model("global-dynamic")))
-#else
-#define LLVM_THREAD_LOCAL __thread
-#endif
-#endif
-
+// thread-local variable.
static LLVM_THREAD_LOCAL const PrettyStackTraceEntry *PrettyStackTraceHead =
nullptr;
#endif
}
+// defined(HAVE_BACKTRACE) && defined(ENABLE_BACKTRACES)
+#endif
+
PrettyStackTraceEntry::PrettyStackTraceEntry() {
+#if defined(HAVE_BACKTRACE) && defined(ENABLE_BACKTRACES)
// Link ourselves.
NextEntry = PrettyStackTraceHead;
PrettyStackTraceHead = this;
+#endif
}
PrettyStackTraceEntry::~PrettyStackTraceEntry() {
+#if defined(HAVE_BACKTRACE) && defined(ENABLE_BACKTRACES)
assert(PrettyStackTraceHead == this &&
"Pretty stack trace entry destruction is out of order");
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, 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() {