Fix CodeFlusher::ProcessOptimizedCodeMaps stale fields.

This makes sure that all pointer fields in an entry in the optimized
code map are considered weak, not just the code object. If just one
field of an entry dies, then the whole entry dies.

R=hpayer@chromium.org

Review URL: https://codereview.chromium.org/1217813013

Cr-Commit-Position: refs/heads/master@{#29417}

src/heap/mark-compact.cc

@@ -950,25 +950,40 @@ void CodeFlusher::ProcessOptimizedCodeMaps() {
     int old_length = code_map->length();
     for (int i = SharedFunctionInfo::kEntriesStart; i < old_length;
          i += SharedFunctionInfo::kEntryLength) {
+      // Each entry contains [ context, code, literals, ast-id ] as fields.
+      STATIC_ASSERT(SharedFunctionInfo::kEntryLength == 4);
+      Context* context =
+          Context::cast(code_map->get(i + SharedFunctionInfo::kContextOffset));
       Code* code =
           Code::cast(code_map->get(i + SharedFunctionInfo::kCachedCodeOffset));
+      FixedArray* literals = FixedArray::cast(
+          code_map->get(i + SharedFunctionInfo::kLiteralsOffset));
+      Smi* ast_id =
+          Smi::cast(code_map->get(i + SharedFunctionInfo::kOsrAstIdOffset));
+      if (Marking::IsWhite(Marking::MarkBitFrom(context))) continue;
+      DCHECK(Marking::IsBlack(Marking::MarkBitFrom(context)));
       if (Marking::IsWhite(Marking::MarkBitFrom(code))) continue;
       DCHECK(Marking::IsBlack(Marking::MarkBitFrom(code)));
-      // Move every slot in the entry.
-      for (int j = 0; j < SharedFunctionInfo::kEntryLength; j++) {
-        int dst_index = new_length++;
-        Object** slot = code_map->RawFieldOfElementAt(dst_index);
-        Object* object = code_map->get(i + j);
-        code_map->set(dst_index, object);
-        if (j == SharedFunctionInfo::kOsrAstIdOffset) {
-          DCHECK(object->IsSmi());
-        } else {
-          DCHECK(
-              Marking::IsBlack(Marking::MarkBitFrom(HeapObject::cast(*slot))));
-          isolate_->heap()->mark_compact_collector()->RecordSlot(slot, slot,
-                                                                 *slot);
-        }
-      }
+      if (Marking::IsWhite(Marking::MarkBitFrom(literals))) continue;
+      DCHECK(Marking::IsBlack(Marking::MarkBitFrom(literals)));
+      // Move every slot in the entry and record slots when needed.
+      code_map->set(new_length + SharedFunctionInfo::kCachedCodeOffset, code);
+      code_map->set(new_length + SharedFunctionInfo::kContextOffset, context);
+      code_map->set(new_length + SharedFunctionInfo::kLiteralsOffset, literals);
+      code_map->set(new_length + SharedFunctionInfo::kOsrAstIdOffset, ast_id);
+      Object** code_slot = code_map->RawFieldOfElementAt(
+          new_length + SharedFunctionInfo::kCachedCodeOffset);
+      isolate_->heap()->mark_compact_collector()->RecordSlot(
+          code_slot, code_slot, *code_slot);
+      Object** context_slot = code_map->RawFieldOfElementAt(
+          new_length + SharedFunctionInfo::kContextOffset);
+      isolate_->heap()->mark_compact_collector()->RecordSlot(
+          context_slot, context_slot, *context_slot);
+      Object** literals_slot = code_map->RawFieldOfElementAt(
+          new_length + SharedFunctionInfo::kLiteralsOffset);
+      isolate_->heap()->mark_compact_collector()->RecordSlot(
+          literals_slot, literals_slot, *literals_slot);
+      new_length += SharedFunctionInfo::kEntryLength;
     }
 
     // Process context-independent entry in the optimized code map.