Check in LLVM r95781.
diff --git a/lib/Support/PrettyStackTrace.cpp b/lib/Support/PrettyStackTrace.cpp
new file mode 100644
index 0000000..68b41a7
--- /dev/null
+++ b/lib/Support/PrettyStackTrace.cpp
@@ -0,0 +1,114 @@
+//===- PrettyStackTrace.cpp - Pretty Crash Handling -----------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines some helpful functions for dealing with the possibility of
+// Unix signals occuring while your program is running.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/PrettyStackTrace.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/System/Signals.h"
+#include "llvm/System/ThreadLocal.h"
+#include "llvm/ADT/SmallString.h"
+using namespace llvm;
+
+namespace llvm {
+ bool DisablePrettyStackTrace = false;
+}
+
+// FIXME: This should be thread local when llvm supports threads.
+static sys::ThreadLocal<const PrettyStackTraceEntry> PrettyStackTraceHead;
+
+static unsigned PrintStack(const PrettyStackTraceEntry *Entry, raw_ostream &OS){
+ unsigned NextID = 0;
+ if (Entry->getNextEntry())
+ NextID = PrintStack(Entry->getNextEntry(), OS);
+ OS << NextID << ".\t";
+ Entry->print(OS);
+
+ return NextID+1;
+}
+
+/// 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 there are pretty stack frames registered, walk and emit them.
+ OS << "Stack dump:\n";
+
+ PrintStack(PrettyStackTraceHead.get(), OS);
+ OS.flush();
+}
+
+// Integrate with crash reporter.
+#ifdef __APPLE__
+extern "C" const char *__crashreporter_info__;
+const char *__crashreporter_info__ = 0;
+#endif
+
+
+/// CrashHandler - This callback is run if a fatal signal is delivered to the
+/// process, it prints the pretty stack trace.
+static void CrashHandler(void *Cookie) {
+#ifndef __APPLE__
+ // On non-apple systems, just emit the crash stack trace to stderr.
+ PrintCurStackTrace(errs());
+#else
+ // Otherwise, emit to a smallvector of chars, send *that* to stderr, but also
+ // put it into __crashreporter_info__.
+ SmallString<2048> TmpStr;
+ {
+ raw_svector_ostream Stream(TmpStr);
+ PrintCurStackTrace(Stream);
+ }
+
+ if (!TmpStr.empty()) {
+ __crashreporter_info__ = strdup(std::string(TmpStr.str()).c_str());
+ errs() << TmpStr.str();
+ }
+
+#endif
+}
+
+static bool RegisterCrashPrinter() {
+ if (!DisablePrettyStackTrace)
+ sys::AddSignalHandler(CrashHandler, 0);
+ return false;
+}
+
+PrettyStackTraceEntry::PrettyStackTraceEntry() {
+ // The first time this is called, we register the crash printer.
+ static bool HandlerRegistered = RegisterCrashPrinter();
+ HandlerRegistered = HandlerRegistered;
+
+ // Link ourselves.
+ NextEntry = PrettyStackTraceHead.get();
+ PrettyStackTraceHead.set(this);
+}
+
+PrettyStackTraceEntry::~PrettyStackTraceEntry() {
+ assert(PrettyStackTraceHead.get() == this &&
+ "Pretty stack trace entry destruction is out of order");
+ PrettyStackTraceHead.set(getNextEntry());
+}
+
+void PrettyStackTraceString::print(raw_ostream &OS) const {
+ OS << Str << "\n";
+}
+
+void PrettyStackTraceProgram::print(raw_ostream &OS) const {
+ OS << "Program arguments: ";
+ // Print the argument list.
+ for (unsigned i = 0, e = ArgC; i != e; ++i)
+ OS << ArgV[i] << ' ';
+ OS << '\n';
+}
+