Add more instrumentation for Code::CopyFrom crasher.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 9b7e0a76c3948ebcdf0ffe59856f997bd12bde39..c0de3606c628899d16c7689352f66c9a570e1d03 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -8813,10 +8813,13 @@ void Code::CopyFrom(const CodeDesc& desc) {
   ASSERT(Marking::Color(this) == Marking::WHITE_OBJECT);
 
   // copy code
+  CHECK(IsCode());
+  CHECK(relocation_info()->IsByteArray());
   memmove(instruction_start(), desc.buffer, desc.instr_size);

[Jakob Kummerow, 2013/03/19 16:32:05]

Let's add (before the memmove):
CHECK(reinterpret_cast<intptr_t>(instruction_start()) ==
reinterpret_cast<intptr_t>(this) + Code::kHeaderSize)

[Michael Starzinger, 2013/03/19 16:43:54]

Done.

 
   // copy reloc info
   // TODO(mstarzinger): Remove once we found the bug.
+  CHECK(IsCode());
   CHECK(relocation_info()->IsByteArray());
   memmove(relocation_start(),
           desc.buffer + desc.buffer_size - desc.reloc_size,