Remove abuse of mirror::Object* to reference special values.

Remove kInvalidIndirectRefObject, kClearedJniWeakGlobal and
ObjectRegistry::kInvalidObject. Handle error conditions by passing in or
returning an error value.
GetObjectRefType is simplified to be faster and not return invalid references
that are not expected according to the spec. Adjust check JNI and
jni_internal_test appropriately.
Fix cases in the debugger/JDWP of out arguments being passed by reference.
Bug: 17376993

Change-Id: I3ce8a28c01827e163f4dc288449959464da788b1

1 files changed, 11 insertions, 6 deletions

diff --git a/runtime/reference_table.cc b/runtime/reference_table.cc
index 70aba9b..01c5070 100644
--- a/runtime/reference_table.cc
+++ b/runtime/reference_table.cc
@@ -24,6 +24,7 @@
 #include "mirror/class-inl.h"
 #include "mirror/object-inl.h"
 #include "mirror/string-inl.h"
+#include "runtime-inl.h"
 #include "thread.h"
 #include "utils.h"
 
@@ -62,7 +63,9 @@ void ReferenceTable::Remove(mirror::Object* obj) {
 // If "obj" is an array, return the number of elements in the array.
 // Otherwise, return zero.
 static size_t GetElementCount(mirror::Object* obj) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  if (obj == NULL || obj == kClearedJniWeakGlobal || !obj->IsArrayInstance()) {
+  // We assume the special cleared value isn't an array in the if statement below.
+  DCHECK(!Runtime::Current()->GetClearedJniWeakGlobal()->IsArrayInstance());
+  if (obj == nullptr || !obj->IsArrayInstance()) {
     return 0;
   }
   return obj->AsArray()->GetLength();
@@ -81,9 +84,10 @@ struct ObjectComparator {
     } else if (obj2 == NULL) {
       return false;
     }
-    if (obj1 == kClearedJniWeakGlobal) {
+    Runtime* runtime = Runtime::Current();
+    if (runtime->IsClearedJniWeakGlobal(obj1)) {
       return true;
-    } else if (obj2 == kClearedJniWeakGlobal) {
+    } else if (runtime->IsClearedJniWeakGlobal(obj2)) {
       return false;
     }
 
@@ -116,7 +120,7 @@ static void DumpSummaryLine(std::ostream& os, mirror::Object* obj, size_t elemen
     os << "    NULL reference (count=" << equiv << ")\n";
     return;
   }
-  if (obj == kClearedJniWeakGlobal) {
+  if (Runtime::Current()->IsClearedJniWeakGlobal(obj)) {
     os << "    cleared jweak (count=" << equiv << ")\n";
     return;
   }
@@ -167,7 +171,7 @@ void ReferenceTable::Dump(std::ostream& os, Table& entries) {
     if (ref == NULL) {
       continue;
     }
-    if (ref == kClearedJniWeakGlobal) {
+    if (Runtime::Current()->IsClearedJniWeakGlobal(ref)) {
       os << StringPrintf("    %5d: cleared jweak\n", idx);
       continue;
     }
@@ -209,7 +213,8 @@ void ReferenceTable::Dump(std::ostream& os, Table& entries) {
     sorted_entries.pop_back();
   }
   while (!sorted_entries.empty() &&
-         sorted_entries.back().Read<kWithoutReadBarrier>() == kClearedJniWeakGlobal) {
+         Runtime::Current()->IsClearedJniWeakGlobal(
+             sorted_entries.back().Read<kWithoutReadBarrier>())) {
     sorted_entries.pop_back();
   }
   if (sorted_entries.empty()) {