From: titzer <titzer@chromium.org>
Date: Tue, 25 Aug 2015 10:17:26 +0000 (-0700)
Subject: Add a PLACEHOLDER code kind.
X-Git-Tag: upstream/4.7.83~692
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=e4bcc3363f2db15bbc0ba57b91676ce7f1c4adb1;p=platform%2Fupstream%2Fv8.git

Add a PLACEHOLDER code kind.

The PLACEHOLDER code kind is used when compiling a code object that has
direct calls to other code objects, but those other code objects do not
yet exist because they have not yet been compiled. It serves as a
placeholder to break the cycle, e.g. in WASM.

R=yangguo@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1308393003

Cr-Commit-Position: refs/heads/master@{#30348}
---

diff --git a/src/log.cc b/src/log.cc
index 2bf27da14..0e932cfad 100644
--- a/src/log.cc
+++ b/src/log.cc
@@ -1643,6 +1643,10 @@ void Logger::LogCodeObject(Object* object) {
       description = "A keyed store IC from the snapshot";
       tag = Logger::KEYED_STORE_IC_TAG;
       break;
+    case Code::PLACEHOLDER:
+      description = "A placeholder for linking later code";
+      tag = Logger::STUB_TAG;
+      break;
     case Code::NUMBER_OF_KINDS:
       break;
   }
diff --git a/src/objects.h b/src/objects.h
index eafa6c157..f93f52189 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -4461,7 +4461,8 @@ class Code: public HeapObject {
   V(STUB)                   \
   V(HANDLER)                \
   V(BUILTIN)                \
-  V(REGEXP)
+  V(REGEXP)                 \
+  V(PLACEHOLDER)
 
 #define IC_KIND_LIST(V) \
   V(LOAD_IC)            \
diff --git a/src/snapshot/serialize.cc b/src/snapshot/serialize.cc
index 0e672760b..9097dba2c 100644
--- a/src/snapshot/serialize.cc
+++ b/src/snapshot/serialize.cc
@@ -2478,6 +2478,8 @@ void CodeSerializer::SerializeObject(HeapObject* obj, HowToCode how_to_code,
           SerializeGeneric(code_object, how_to_code, where_to_point);
         }
         return;
+      case Code::PLACEHOLDER:
+        UNREACHABLE();
     }
     UNREACHABLE();
   }