Externalize deoptimization reasons.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 9ec776ddafdbe4b463ce158307192bbd97948479..187e2ba0f2d55f929022ccb592869277ad61c2fa 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -10531,6 +10531,7 @@ void Code::CopyFrom(const CodeDesc& desc) {
   // unbox handles and relocate
   intptr_t delta = instruction_start() - desc.buffer;
   int mode_mask = RelocInfo::kCodeTargetMask |
+                  RelocInfo::ModeMask(RelocInfo::DEOPT_REASON) |
                   RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT) |
                   RelocInfo::ModeMask(RelocInfo::CELL) |
                   RelocInfo::ModeMask(RelocInfo::RUNTIME_ENTRY) |
@@ -10984,14 +10985,18 @@ Code* Code::GetCodeAgeStub(Isolate* isolate, Age age, MarkingParity parity) {
 
 
 void Code::PrintDeoptLocation(FILE* out, int bailout_id) {
-  const char* last_comment = NULL;
-  int mask = RelocInfo::ModeMask(RelocInfo::COMMENT)
-      | RelocInfo::ModeMask(RelocInfo::RUNTIME_ENTRY);
+  int last_position = 0;
+  Deoptimizer::DeoptReason last_reason = Deoptimizer::kNoReason;
+  int mask = RelocInfo::ModeMask(RelocInfo::DEOPT_REASON) |
+             RelocInfo::ModeMask(RelocInfo::POSITION) |
+             RelocInfo::ModeMask(RelocInfo::RUNTIME_ENTRY);
   for (RelocIterator it(this, mask); !it.done(); it.next()) {
     RelocInfo* info = it.rinfo();
-    if (info->rmode() == RelocInfo::COMMENT) {
-      last_comment = reinterpret_cast<const char*>(info->data());
-    } else if (last_comment != NULL) {
+    if (info->rmode() == RelocInfo::POSITION) {
+      last_position = reinterpret_cast<int>(info->data());
+    } else if (info->rmode() == RelocInfo::DEOPT_REASON) {
+      last_reason = static_cast<Deoptimizer::DeoptReason>(info->data());
+    } else if (last_reason != Deoptimizer::kNoReason) {
       if ((bailout_id == Deoptimizer::GetDeoptimizationId(
               GetIsolate(), info->target_address(), Deoptimizer::EAGER)) ||
           (bailout_id == Deoptimizer::GetDeoptimizationId(
@@ -10999,7 +11004,8 @@ void Code::PrintDeoptLocation(FILE* out, int bailout_id) {
           (bailout_id == Deoptimizer::GetDeoptimizationId(
               GetIsolate(), info->target_address(), Deoptimizer::LAZY))) {
         CHECK(RelocInfo::IsRuntimeEntry(info->rmode()));
-        PrintF(out, "            %s\n", last_comment);
+        PrintF(out, "            ;;; deoptimize at %d: %s\n", last_position,
+               Deoptimizer::GetDeoptReason(last_reason));
         return;
       }
     }