diff --git a/src/hprof/hprof.cc b/src/hprof/hprof.cc
index eacc73f..02f80c1 100644
--- a/src/hprof/hprof.cc
+++ b/src/hprof/hprof.cc
@@ -201,8 +201,7 @@
 // only true when marking the root set or unreachable
 // objects.  Used to add rootset references to obj.
 int Hprof::MarkRootObject(const Object *obj, jobject jniObj) {
-  HprofRecord *rec = &current_record_;
-  int err; // TODO: we may return this uninitialized
+  HprofRecord* rec = &current_record_;
   HprofHeapTag heapTag = (HprofHeapTag)gc_scan_state_;
 
   if (heapTag == 0) {
@@ -221,9 +220,7 @@
   case HPROF_ROOT_STICKY_CLASS:
   case HPROF_ROOT_MONITOR_USED:
   case HPROF_ROOT_INTERNED_STRING:
-  case HPROF_ROOT_FINALIZING:
   case HPROF_ROOT_DEBUGGER:
-  case HPROF_ROOT_REFERENCE_CLEANUP:
   case HPROF_ROOT_VM_INTERNAL:
     rec->AddU1(heapTag);
     rec->AddId((HprofObjectId)obj);
@@ -268,13 +265,24 @@
     rec->AddU4((uint32_t)-1);    //xxx
     break;
 
-  default:
-    err = 0;
+  case HPROF_CLASS_DUMP:
+  case HPROF_INSTANCE_DUMP:
+  case HPROF_OBJECT_ARRAY_DUMP:
+  case HPROF_PRIMITIVE_ARRAY_DUMP:
+  case HPROF_HEAP_DUMP_INFO:
+  case HPROF_PRIMITIVE_ARRAY_NODATA_DUMP:
+    // Ignored.
+    break;
+
+  case HPROF_ROOT_FINALIZING:
+  case HPROF_ROOT_REFERENCE_CLEANUP:
+  case HPROF_UNREACHABLE:
+    LOG(FATAL) << "obsolete tag " << static_cast<int>(heapTag);
     break;
   }
 
   objects_in_segment_++;
-  return err;
+  return 0;
 }
 
 int Hprof::StackTraceSerialNumber(const void* /*obj*/) {
diff --git a/src/indirect_reference_table.cc b/src/indirect_reference_table.cc
index 14d804b..69f171c 100644
--- a/src/indirect_reference_table.cc
+++ b/src/indirect_reference_table.cc
@@ -60,9 +60,7 @@
   alloc_entries_ = max_entries_ = -1;
 }
 
-/*
- * Make sure that the entry at "idx" is correctly paired with "iref".
- */
+// Make sure that the entry at "idx" is correctly paired with "iref".
 bool IndirectReferenceTable::CheckEntry(const char* what, IndirectRef iref, int idx) const {
   const Object* obj = table_[idx];
   IndirectRef checkRef = ToIndirectRef(obj, idx);
@@ -89,12 +87,11 @@
   DCHECK_GE(segment_state_.parts.numHoles, prevState.parts.numHoles);
 
   if (topIndex == alloc_entries_) {
-    /* reached end of allocated space; did we hit buffer max? */
+    // reached end of allocated space; did we hit buffer max?
     if (topIndex == max_entries_) {
-      LOG(ERROR) << "JNI ERROR (app bug): " << kind_ << " table overflow "
-                 << "(max=" << max_entries_ << ")";
-      Dump();
-      LOG(FATAL); // TODO: operator<< for IndirectReferenceTable
+      LOG(FATAL) << "JNI ERROR (app bug): " << kind_ << " table overflow "
+                 << "(max=" << max_entries_ << ")\n"
+                 << Dumpable<IndirectReferenceTable>(*this);
     }
 
     size_t newSize = alloc_entries_ * 2;
@@ -106,12 +103,11 @@
     table_ = reinterpret_cast<const Object**>(realloc(table_, newSize * sizeof(const Object*)));
     slot_data_ = reinterpret_cast<IndirectRefSlot*>(realloc(slot_data_, newSize * sizeof(IndirectRefSlot)));
     if (table_ == NULL || slot_data_ == NULL) {
-      LOG(ERROR) << "JNI ERROR (app bug): unable to expand "
+      LOG(FATAL) << "JNI ERROR (app bug): unable to expand "
                  << kind_ << " table (from "
                  << alloc_entries_ << " to " << newSize
-                 << ", max=" << max_entries_ << ")";
-      Dump();
-      LOG(FATAL); // TODO: operator<< for IndirectReferenceTable
+                 << ", max=" << max_entries_ << ")\n"
+                 << Dumpable<IndirectReferenceTable>(*this);
     }
 
     // Clear the newly-allocated slot_data_ elements.
@@ -120,16 +116,14 @@
     alloc_entries_ = newSize;
   }
 
-  /*
-   * We know there's enough room in the table.  Now we just need to find
-   * the right spot.  If there's a hole, find it and fill it; otherwise,
-   * add to the end of the list.
-   */
+  // We know there's enough room in the table.  Now we just need to find
+  // the right spot.  If there's a hole, find it and fill it; otherwise,
+  // add to the end of the list.
   IndirectRef result;
   int numHoles = segment_state_.parts.numHoles - prevState.parts.numHoles;
   if (numHoles > 0) {
     DCHECK_GT(topIndex, 1U);
-    /* find the first hole; likely to be near the end of the list */
+    // Find the first hole; likely to be near the end of the list.
     const Object** pScan = &table_[topIndex - 1];
     DCHECK(*pScan != NULL);
     while (*--pScan != NULL) {
@@ -140,7 +134,7 @@
     *pScan = obj;
     segment_state_.parts.numHoles--;
   } else {
-    /* add to the end */
+    // Add to the end.
     UpdateSlotAdd(obj, topIndex);
     result = ToIndirectRef(obj, topIndex);
     table_[topIndex++] = obj;
@@ -157,16 +151,13 @@
 
 void IndirectReferenceTable::AssertEmpty() {
   if (begin() != end()) {
-    Dump();
-    LOG(FATAL) << "Internal Error: non-empty local reference table";
+    LOG(FATAL) << "Internal Error: non-empty local reference table\n"
+               << Dumpable<IndirectReferenceTable>(*this);
   }
 }
 
-/*
- * Verify that the indirect table lookup is valid.
- *
- * Returns "false" if something looks bad.
- */
+// Verifies that the indirect table lookup is valid.
+// Returns "false" if something looks bad.
 bool IndirectReferenceTable::GetChecked(IndirectRef iref) const {
   if (iref == NULL) {
     LOG(WARNING) << "Attempt to look up NULL " << kind_;
@@ -181,7 +172,6 @@
   int topIndex = segment_state_.parts.topIndex;
   int idx = ExtractIndex(iref);
   if (idx >= topIndex) {
-    /* bad -- stale reference? */
     LOG(ERROR) << "JNI ERROR (app bug): accessed stale " << kind_ << " "
                << iref << " (index " << idx << " in a table of size " << topIndex << ")";
     AbortMaybe();
@@ -214,19 +204,14 @@
   return Find(direct_pointer, 0, segment_state_.parts.topIndex, table_) != -1;
 }
 
-/*
- * Remove "obj" from "pRef".  We extract the table offset bits from "iref"
- * and zap the corresponding entry, leaving a hole if it's not at the top.
- *
- * If the entry is not between the current top index and the bottom index
- * specified by the cookie, we don't remove anything.  This is the behavior
- * required by JNI's DeleteLocalRef function.
- *
- * Note this is NOT called when a local frame is popped.  This is only used
- * for explicit single removals.
- *
- * Returns "false" if nothing was removed.
- */
+// Removes an object. We extract the table offset bits from "iref"
+// and zap the corresponding entry, leaving a hole if it's not at the top.
+// If the entry is not between the current top index and the bottom index
+// specified by the cookie, we don't remove anything. This is the behavior
+// required by JNI's DeleteLocalRef function.
+// This method is not called when a local frame is popped; this is only used
+// for explicit single removals.
+// Returns "false" if nothing was removed.
 bool IndirectReferenceTable::Remove(uint32_t cookie, IndirectRef iref) {
   IRTSegmentState prevState;
   prevState.all = cookie;
@@ -299,11 +284,9 @@
       }
     }
   } else {
-    /*
-     * Not the top-most entry.  This creates a hole.  We NULL out the
-     * entry to prevent somebody from deleting it twice and screwing up
-     * the hole count.
-     */
+    // Not the top-most entry.  This creates a hole.  We NULL out the
+    // entry to prevent somebody from deleting it twice and screwing up
+    // the hole count.
     if (table_[idx] == NULL) {
       LOG(INFO) << "--- WEIRD: removing null entry " << idx;
       return false;
@@ -329,10 +312,10 @@
   }
 }
 
-void IndirectReferenceTable::Dump() const {
-  LOG(WARNING) << kind_ << " table dump:";
+void IndirectReferenceTable::Dump(std::ostream& os) const {
+  os << kind_ << " table dump:\n";
   std::vector<const Object*> entries(table_, table_ + Capacity());
-  ReferenceTable::Dump(entries);
+  ReferenceTable::Dump(os, entries);
 }
 
 }  // namespace art
diff --git a/src/indirect_reference_table.h b/src/indirect_reference_table.h
index b0a0d64..710e43f 100644
--- a/src/indirect_reference_table.h
+++ b/src/indirect_reference_table.h
@@ -287,7 +287,7 @@
 
   void AssertEmpty();
 
-  void Dump() const;
+  void Dump(std::ostream& os) const;
 
   /*
    * Return the #of entries in the entire table.  This includes holes, and
diff --git a/src/indirect_reference_table_test.cc b/src/indirect_reference_table_test.cc
index cea4afd..387a2cd 100644
--- a/src/indirect_reference_table_test.cc
+++ b/src/indirect_reference_table_test.cc
@@ -52,7 +52,7 @@
   IndirectRef iref2 = irt.Add(cookie, obj2);
   EXPECT_TRUE(iref2 != NULL);
 
-  irt.Dump();
+  irt.Dump(LOG(DEBUG));
 
   EXPECT_EQ(obj0, irt.Get(iref0));
   EXPECT_EQ(obj1, irt.Get(iref1));
diff --git a/src/jni_internal.cc b/src/jni_internal.cc
index 846a717..a20bcc9 100644
--- a/src/jni_internal.cc
+++ b/src/jni_internal.cc
@@ -90,21 +90,15 @@
 
   uint32_t cookie = env->local_ref_cookie;
   IndirectRef ref = locals.Add(cookie, obj);
-  if (ref == NULL) {
-    // TODO: just change Add's DCHECK to CHECK and lose this?
-    locals.Dump();
-    LOG(FATAL) << "Failed adding to JNI local reference table "
-               << "(has " << locals.Capacity() << " entries)";
-  }
 
 #if 0 // TODO: fix this to understand PushLocalFrame, so we can turn it on.
   if (env->check_jni) {
     size_t entry_count = locals.Capacity();
     if (entry_count > 16) {
       LOG(WARNING) << "Warning: more than 16 JNI local references: "
-                   << entry_count << " (most recent was a " << PrettyTypeOf(obj) << ")";
-      locals.Dump();
-      // TODO: LOG(FATAL) instead.
+                   << entry_count << " (most recent was a " << PrettyTypeOf(obj) << ")\n"
+                   << Dumpable<IndirectReferenceTable>(locals);
+      // TODO: LOG(FATAL) in a later release?
     }
   }
 #endif
@@ -2654,9 +2648,9 @@
   functions = enabled ? GetCheckJniNativeInterface() : &gJniNativeInterface;
 }
 
-void JNIEnvExt::DumpReferenceTables() {
-  locals.Dump();
-  monitors.Dump();
+void JNIEnvExt::DumpReferenceTables(std::ostream& os) {
+  locals.Dump(os);
+  monitors.Dump(os);
 }
 
 void JNIEnvExt::PushFrame(int /*capacity*/) {
@@ -2826,18 +2820,18 @@
   }
 }
 
-void JavaVMExt::DumpReferenceTables() {
+void JavaVMExt::DumpReferenceTables(std::ostream& os) {
   {
     MutexLock mu(globals_lock);
-    globals.Dump();
+    globals.Dump(os);
   }
   {
     MutexLock mu(weak_globals_lock);
-    weak_globals.Dump();
+    weak_globals.Dump(os);
   }
   {
     MutexLock mu(pins_lock);
-    pin_table.Dump();
+    pin_table.Dump(os);
   }
 }
 
diff --git a/src/jni_internal.h b/src/jni_internal.h
index e12a7cd..0d97aa4 100644
--- a/src/jni_internal.h
+++ b/src/jni_internal.h
@@ -100,7 +100,7 @@
 
   void DumpForSigQuit(std::ostream& os);
 
-  void DumpReferenceTables();
+  void DumpReferenceTables(std::ostream& os);
 
   void SetCheckJniEnabled(bool enabled);
 
@@ -145,7 +145,7 @@
   JNIEnvExt(Thread* self, JavaVMExt* vm);
   ~JNIEnvExt();
 
-  void DumpReferenceTables();
+  void DumpReferenceTables(std::ostream& os);
 
   void SetCheckJniEnabled(bool enabled);
 
diff --git a/src/native/dalvik_system_VMDebug.cc b/src/native/dalvik_system_VMDebug.cc
index f125272..49ef593 100644
--- a/src/native/dalvik_system_VMDebug.cc
+++ b/src/native/dalvik_system_VMDebug.cc
@@ -201,8 +201,8 @@
   LOG(INFO) << "--- reference table dump ---";
 
   JNIEnvExt* e = reinterpret_cast<JNIEnvExt*>(env);
-  e->DumpReferenceTables();
-  e->vm->DumpReferenceTables();
+  e->DumpReferenceTables(LOG(INFO));
+  e->vm->DumpReferenceTables(LOG(INFO));
 
   LOG(INFO) << "---";
 }
diff --git a/src/reference_table.cc b/src/reference_table.cc
index dd32765..ee1760b 100644
--- a/src/reference_table.cc
+++ b/src/reference_table.cc
@@ -52,7 +52,7 @@
 
 // If "obj" is an array, return the number of elements in the array.
 // Otherwise, return zero.
-size_t GetElementCount(const Object* obj) {
+static size_t GetElementCount(const Object* obj) {
   if (obj == NULL || obj == kClearedJniWeakGlobal || !obj->IsArrayInstance()) {
     return 0;
   }
@@ -97,13 +97,13 @@
 // Pass in the number of elements in the array (or 0 if this is not an
 // array object), and the number of additional objects that are identical
 // or equivalent to the original.
-void LogSummaryLine(const Object* obj, size_t elems, int identical, int equiv) {
+static void DumpSummaryLine(std::ostream& os, const Object* obj, size_t element_count, int identical, int equiv) {
   if (obj == NULL) {
-    LOG(WARNING) << "    NULL reference (count=" << equiv << ")";
+    os << "    NULL reference (count=" << equiv << ")\n";
     return;
   }
   if (obj == kClearedJniWeakGlobal) {
-    LOG(WARNING) << "    cleared jweak (count=" << equiv << ")";
+    os << "    cleared jweak (count=" << equiv << ")\n";
     return;
   }
 
@@ -113,8 +113,8 @@
     // Class' type parameter here would be misleading.
     className = "java.lang.Class";
   }
-  if (elems != 0) {
-    StringAppendF(&className, " (%zd elements)", elems);
+  if (element_count != 0) {
+    StringAppendF(&className, " (%zd elements)", element_count);
   }
 
   size_t total = identical + equiv + 1;
@@ -122,21 +122,21 @@
   if (identical + equiv != 0) {
     StringAppendF(&msg, " (%d unique instances)", equiv + 1);
   }
-  LOG(WARNING) << "    " << msg;
+  os << "    " << msg << "\n";
 }
 
 size_t ReferenceTable::Size() const {
   return entries_.size();
 }
 
-void ReferenceTable::Dump() const {
-  LOG(WARNING) << name_ << " reference table dump:";
-  Dump(entries_);
+void ReferenceTable::Dump(std::ostream& os) const {
+  os << name_ << " reference table dump:\n";
+  Dump(os, entries_);
 }
 
-void ReferenceTable::Dump(const Table& entries) {
+void ReferenceTable::Dump(std::ostream& os, const Table& entries) {
   if (entries.empty()) {
-    LOG(WARNING) << "  (empty)";
+    os << "  (empty)\n";
     return;
   }
 
@@ -147,50 +147,39 @@
   if (first < 0) {
     first = 0;
   }
-  LOG(WARNING) << "  Last " << (count - first) << " entries (of " << count << "):";
+  os << "  Last " << (count - first) << " entries (of " << count << "):\n";
   for (int idx = count - 1; idx >= first; --idx) {
     const Object* ref = entries[idx];
     if (ref == NULL) {
       continue;
     }
     if (ref == kClearedJniWeakGlobal) {
-      LOG(WARNING) << StringPrintf("    %5d: cleared jweak", idx);
+      os << StringPrintf("    %5d: cleared jweak\n", idx);
       continue;
     }
     if (ref->GetClass() == NULL) {
       // should only be possible right after a plain dvmMalloc().
       size_t size = ref->SizeOf();
-      LOG(WARNING) << StringPrintf("    %5d: %p (raw) (%zd bytes)", idx, ref, size);
+      os << StringPrintf("    %5d: %p (raw) (%zd bytes)\n", idx, ref, size);
       continue;
     }
 
     std::string className(PrettyTypeOf(ref));
 
     std::string extras;
-    size_t elems = GetElementCount(ref);
-    if (elems != 0) {
-      StringAppendF(&extras, " (%zd elements)", elems);
-    }
-#if 0
-    // TODO: support dumping string data.
-    else if (ref->GetClass() == gDvm.classJavaLangString) {
-      const StringObject* str = reinterpret_cast<const StringObject*>(ref);
-      extras += " \"";
-      size_t count = 0;
-      char* s = dvmCreateCstrFromString(str);
-      char* p = s;
-      for (; *p && count < 16; ++p, ++count) {
-        extras += *p;
-      }
-      if (*p == 0) {
-        extras += "\"";
+    size_t element_count = GetElementCount(ref);
+    if (element_count != 0) {
+      StringAppendF(&extras, " (%zd elements)", element_count);
+    } else if (ref->GetClass()->IsStringClass()) {
+      String* s = const_cast<Object*>(ref)->AsString();
+      std::string utf8(s->ToModifiedUtf8());
+      if (s->GetLength() <= 16) {
+        StringAppendF(&extras, " \"%s\"", utf8.c_str());
       } else {
-        StringAppendF(&extras, "... (%d chars)", str->length());
+        StringAppendF(&extras, " \"%.16s... (%d chars)", utf8.c_str(), s->GetLength());
       }
-      free(s);
     }
-#endif
-    LOG(WARNING) << StringPrintf("    %5d: ", idx) << ref << " " << className << extras;
+    os << StringPrintf("    %5d: ", idx) << ref << " " << className << extras << "\n";
   }
 
   // Make a copy of the table and sort it.
@@ -209,27 +198,27 @@
   }
 
   // Dump a summary of the whole table.
-  LOG(WARNING) << "  Summary:";
+  os << "  Summary:\n";
   size_t equiv = 0;
   size_t identical = 0;
   for (size_t idx = 1; idx < count; idx++) {
     const Object* prev = sorted_entries[idx-1];
     const Object* current = sorted_entries[idx];
-    size_t elems = GetElementCount(prev);
+    size_t element_count = GetElementCount(prev);
     if (current == prev) {
       // Same reference, added more than once.
       identical++;
-    } else if (current->GetClass() == prev->GetClass() && GetElementCount(current) == elems) {
+    } else if (current->GetClass() == prev->GetClass() && GetElementCount(current) == element_count) {
       // Same class / element count, different object.
       equiv++;
     } else {
       // Different class.
-      LogSummaryLine(prev, elems, identical, equiv);
+      DumpSummaryLine(os, prev, element_count, identical, equiv);
       equiv = identical = 0;
     }
   }
   // Handle the last entry.
-  LogSummaryLine(sorted_entries.back(), GetElementCount(sorted_entries.back()), identical, equiv);
+  DumpSummaryLine(os, sorted_entries.back(), GetElementCount(sorted_entries.back()), identical, equiv);
 }
 
 void ReferenceTable::VisitRoots(Heap::RootVisitor* visitor, void* arg) {
diff --git a/src/reference_table.h b/src/reference_table.h
index 9142b7c..28af887 100644
--- a/src/reference_table.h
+++ b/src/reference_table.h
@@ -43,13 +43,13 @@
 
   size_t Size() const;
 
-  void Dump() const;
+  void Dump(std::ostream& os) const;
 
   void VisitRoots(Heap::RootVisitor* visitor, void* arg);
 
  private:
   typedef std::vector<const Object*> Table;
-  static void Dump(const Table& entries);
+  static void Dump(std::ostream& os, const Table& entries);
   friend class IndirectReferenceTable; // For Dump.
 
   std::string name_;
diff --git a/src/reference_table_test.cc b/src/reference_table_test.cc
index 4c1e67f..c7c1cc6 100644
--- a/src/reference_table_test.cc
+++ b/src/reference_table_test.cc
@@ -27,10 +27,10 @@
   Object* o1 = String::AllocFromModifiedUtf8("hello");
   Object* o2 = ShortArray::Alloc(0);
 
-  // TODO: rewrite Dump to take a std::ostream& so we can test it better.
-
   ReferenceTable rt("test", 0, 4);
-  rt.Dump();
+  std::ostringstream oss1;
+  rt.Dump(oss1);
+  EXPECT_TRUE(oss1.str().find("(empty)") != std::string::npos) << oss1.str();
   EXPECT_EQ(0U, rt.Size());
   rt.Remove(NULL);
   EXPECT_EQ(0U, rt.Size());
@@ -40,8 +40,16 @@
   EXPECT_EQ(1U, rt.Size());
   rt.Add(o2);
   EXPECT_EQ(2U, rt.Size());
-  rt.Dump();
+  rt.Add(o2);
+  EXPECT_EQ(3U, rt.Size());
+  std::ostringstream oss2;
+  rt.Dump(oss2);
+  EXPECT_TRUE(oss2.str().find("Last 3 entries (of 3):") != std::string::npos) << oss2.str();
+  EXPECT_TRUE(oss2.str().find("1 of java.lang.String") != std::string::npos) << oss2.str();
+  EXPECT_TRUE(oss2.str().find("2 of short[] (1 unique instances)") != std::string::npos) << oss2.str();
   rt.Remove(o1);
+  EXPECT_EQ(2U, rt.Size());
+  rt.Remove(o2);
   EXPECT_EQ(1U, rt.Size());
   rt.Remove(o2);
   EXPECT_EQ(0U, rt.Size());
diff --git a/src/timing_logger.h b/src/timing_logger.h
index 594ae98..d713edf 100644
--- a/src/timing_logger.h
+++ b/src/timing_logger.h
@@ -38,15 +38,19 @@
     labels_.push_back(label);
   }
 
-  void Dump() {
-    LOG(INFO) << name_ << ": begin";
-    for (size_t i = 1; i < times_.size(); ++i) {
-      LOG(INFO) << name_ << StringPrintf(": %8lld ms, ", NsToMs(times_[i] - times_[i-1])) << labels_[i];
-    }
-    LOG(INFO) << name_ << ": end, " << NsToMs(GetTotalNs()) << " ms";
+  void Dump() const {
+    Dump(LOG(INFO));
   }
 
-  uint64_t GetTotalNs() {
+  void Dump(std::ostream& os) const {
+    os << name_ << ": begin";
+    for (size_t i = 1; i < times_.size(); ++i) {
+      os << name_ << StringPrintf(": %8lld ms, ", NsToMs(times_[i] - times_[i-1])) << labels_[i];
+    }
+    os << name_ << ": end, " << NsToMs(GetTotalNs()) << " ms";
+  }
+
+  uint64_t GetTotalNs() const {
     return times_.back() - times_.front();
   }