From dca75df926e48f2a6f3b5ab2c3077d7c21696054 Mon Sep 17 00:00:00 2001
From: Joel Dice <joel.dice@gmail.com>
Date: Tue, 9 Apr 2013 17:45:19 -0600
Subject: [PATCH] add vmfPrintTrace method for dumping traces to a specific
 stream

---
 src/avian/machine.h |  3 +++
 src/machine.cpp     | 25 ++++++++++++++++---------
 2 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/src/avian/machine.h b/src/avian/machine.h
index 5c57bc18e2..a53d4c98f2 100644
--- a/src/avian/machine.h
+++ b/src/avian/machine.h
@@ -2699,6 +2699,9 @@ popResources(Thread* t);
 JNIEXPORT void
 vmPrintTrace(vm::Thread* t);
 
+JNIEXPORT void
+vmfPrintTrace(vm::Thread* t, FILE* out);
+
 namespace vm {
 
 void
diff --git a/src/machine.cpp b/src/machine.cpp
index 098a60130a..0f5bf55291 100644
--- a/src/machine.cpp
+++ b/src/machine.cpp
@@ -5171,11 +5171,11 @@ noop()
 
 // for debugging
 JNIEXPORT void
-vmPrintTrace(Thread* t)
+vmfPrintTrace(Thread* t, FILE* out)
 {
   class Visitor: public Processor::StackVisitor {
    public:
-    Visitor(Thread* t): t(t) { }
+    Visitor(Thread* t, FILE* out): t(t), out(out) { }
 
     virtual bool visit(Processor::StackWalker* walker) {
       const int8_t* class_ = &byteArrayBody
@@ -5185,30 +5185,37 @@ vmPrintTrace(Thread* t)
       int line = t->m->processor->lineNumber
         (t, walker->method(), walker->ip());
 
-      fprintf(stderr, "  at %s.%s ", class_, method);
+      fprintf(out, "  at %s.%s ", class_, method);
 
       switch (line) {
       case NativeLine:
-        fprintf(stderr, "(native)\n");
+        fprintf(out, "(native)\n");
         break;
       case UnknownLine:
-        fprintf(stderr, "(unknown line)\n");
+        fprintf(out, "(unknown line)\n");
         break;
       default:
-        fprintf(stderr, "(line %d)\n", line);
+        fprintf(out, "(line %d)\n", line);
       }
 
       return true;
     }
 
     Thread* t;
-  } v(t);
+    FILE* out;
+  } v(t, out);
 
-  fprintf(stderr, "debug trace for thread %p\n", t);
+  fprintf(out, "debug trace for thread %p\n", t);
 
   t->m->processor->walkStack(t, &v);
 
-  fflush(stderr);
+  fflush(out);
+}
+
+JNIEXPORT void
+vmPrintTrace(Thread* t)
+{
+  vmfPrintTrace(t, stderr);
 }
 
 // also for debugging