X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FSupport%2FPrettyStackTrace.cpp;h=d6782a70e1a4906877151d34767e3a113b07931f;hb=34509ffd82b5929133008e234c490cee8ca5d4b9;hp=cd7c097d35dcd42fc8400a1bf3ec38d597478759;hpb=481d402ab03e163e180d2650fae13704858f8d81;p=oota-llvm.git

diff --git a/lib/Support/PrettyStackTrace.cpp b/lib/Support/PrettyStackTrace.cpp
index cd7c097d35d..d6782a70e1a 100644
--- a/lib/Support/PrettyStackTrace.cpp
+++ b/lib/Support/PrettyStackTrace.cpp
@@ -8,16 +8,18 @@
 //===----------------------------------------------------------------------===//
 //
 // This file defines some helpful functions for dealing with the possibility of
-// Unix signals occuring while your program is running.
+// Unix signals occurring while your program is running.
 //
 //===----------------------------------------------------------------------===//
 
-#include "llvm/Config/config.h"     // Get autoconf configuration settings
 #include "llvm/Support/PrettyStackTrace.h"
-#include "llvm/Support/raw_ostream.h"
-#include "llvm/Support/Signals.h"
-#include "llvm/Support/ThreadLocal.h"
+#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"
 
 #ifdef HAVE_CRASHREPORTERCLIENT_H
 #include <CrashReporterClient.h>
@@ -25,19 +27,27 @@
 
 using namespace llvm;
 
-namespace llvm {
-  bool DisablePrettyStackTrace = false;
-}
+// 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)
 
-// FIXME: This should be thread local when llvm supports threads.
-static sys::ThreadLocal<const PrettyStackTraceEntry> PrettyStackTraceHead;
+// 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;
   if (Entry->getNextEntry())
     NextID = PrintStack(Entry->getNextEntry(), OS);
   OS << NextID << ".\t";
-  Entry->print(OS);
+  {
+    sys::Watchdog W(5);
+    Entry->print(OS);
+  }
   
   return NextID+1;
 }
@@ -45,12 +55,12 @@ 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.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();
 }
 
@@ -62,7 +72,7 @@ extern "C" {
 CRASH_REPORTER_CLIENT_HIDDEN 
 struct crashreporter_annotations_t gCRAnnotations 
         __attribute__((section("__DATA," CRASHREPORTER_ANNOTATIONS_SECTION))) 
-        = { CRASHREPORTER_ANNOTATIONS_VERSION, 0, 0, 0, 0 };
+        = { CRASHREPORTER_ANNOTATIONS_VERSION, 0, 0, 0, 0, 0, 0 };
 }
 #elif defined (__APPLE__) && HAVE_CRASHREPORTER_INFO
 static const char *__crashreporter_info__ = 0;
@@ -98,26 +108,23 @@ static void CrashHandler(void *) {
 #endif
 }
 
-static bool RegisterCrashPrinter() {
-  if (!DisablePrettyStackTrace)
-    sys::AddSignalHandler(CrashHandler, 0);
-  return false;
-}
+// defined(HAVE_BACKTRACE) && defined(ENABLE_BACKTRACES)
+#endif
 
 PrettyStackTraceEntry::PrettyStackTraceEntry() {
-  // The first time this is called, we register the crash printer.
-  static bool HandlerRegistered = RegisterCrashPrinter();
-  HandlerRegistered = HandlerRegistered;
-    
+#if defined(HAVE_BACKTRACE) && defined(ENABLE_BACKTRACES)
   // Link ourselves.
-  NextEntry = PrettyStackTraceHead.get();
-  PrettyStackTraceHead.set(this);
+  NextEntry = PrettyStackTraceHead;
+  PrettyStackTraceHead = this;
+#endif
 }
 
 PrettyStackTraceEntry::~PrettyStackTraceEntry() {
-  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 {
@@ -132,3 +139,35 @@ void PrettyStackTraceProgram::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
+}
+
+const void* llvm::SavePrettyStackState() {
+#if defined(HAVE_BACKTRACE) && defined(ENABLE_BACKTRACES)
+  return PrettyStackTraceHead;
+#else
+  return nullptr;
+#endif
+}
+
+void llvm::RestorePrettyStackState(const void* Top) {
+#if defined(HAVE_BACKTRACE) && defined(ENABLE_BACKTRACES)
+  PrettyStackTraceHead = (const PrettyStackTraceEntry*)Top;
+#endif
+}
+
+void LLVMEnablePrettyStackTrace() {
+  EnablePrettyStackTrace();
+}