Initial support for emitting unwinding information in perf jitdump.

src/factory.cc

Index: src/factory.cc
diff --git a/src/factory.cc b/src/factory.cc
index 3c5f4161fd00f8c162a8c0c21903cceeb8e9260f..0807bd1f2fa2fc4534e84f56431171dcac89e118 100644
--- a/src/factory.cc
+++ b/src/factory.cc
@@ -1427,7 +1427,11 @@ Handle<Code> Factory::NewCode(const CodeDesc& desc,
   Handle<ByteArray> reloc_info = NewByteArray(desc.reloc_size, TENURED);
 
   // Compute size.
-  int body_size = RoundUp(desc.instr_size, kObjectAlignment);
+  int unpadded_body_size = desc.unwinding_info_size > 0

[rmcilroy, 2016/06/21 13:47:43]

nit - just body_size (the RoundUp at the end isn't really padding, just
alignment).

[rmcilroy, 2016/06/21 13:47:43]

Create a local variable for has_unwinding_info and use it here and below (and I
think the check should be desc.unwinding_info != nullptr, with a corresponding
DCHECK that desc.unwinding_info_size is zero if not.

[Stefano Sanfilippo, 2016/06/23 15:23:43]

Done.

[Stefano Sanfilippo, 2016/06/23 15:23:43]

Done.

+                               ? RoundUp(desc.instr_size, kInt64Size) +
+                                     desc.unwinding_info_size + kInt64Size

[rmcilroy, 2016/06/21 13:47:43]

Do this addition in an if block (setting body_size to desc.instr_size outside
the if, and then rounding up and adding in the if has_unwinding_info block.

[Stefano Sanfilippo, 2016/06/23 15:23:43]

Done.

+                               : desc.instr_size;
+  int body_size = RoundUp(unpadded_body_size, kObjectAlignment);
   int obj_size = Code::SizeFor(body_size);
 
   Handle<Code> code = NewCodeRaw(obj_size, immovable);
@@ -1444,6 +1448,7 @@ Handle<Code> Factory::NewCode(const CodeDesc& desc,
   code->set_instruction_size(desc.instr_size);
   code->set_relocation_info(*reloc_info);
   code->set_flags(flags);
+  code->set_has_unwinding_info(desc.unwinding_info_size > 0);
   code->set_raw_kind_specific_flags1(0);
   code->set_raw_kind_specific_flags2(0);
   code->set_is_crankshafted(crankshafted);