Initial support for emitting unwinding information in perf jitdump.

src/objects.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/objects.h"
 
 #include <cmath>
 #include <iomanip>
 #include <sstream>
 
@@ skipping 13435 matching lines @@
   }
   Assembler::FlushICache(GetIsolate(), instruction_start(), instruction_size());
 }
 
 
 void Code::CopyFrom(const CodeDesc& desc) {
   // copy code
   CopyBytes(instruction_start(), desc.buffer,
             static_cast<size_t>(desc.instr_size));
 
+  // copy unwinding info, if any
+  if (desc.unwinding_info) {
+    DCHECK_GT(desc.unwinding_info_size, 0);
+    set_unwinding_info_size(desc.unwinding_info_size);
+    CopyBytes(unwinding_info_start(), desc.unwinding_info,
+              static_cast<size_t>(desc.unwinding_info_size));
+  }
+
   // copy reloc info
   CopyBytes(relocation_start(),
             desc.buffer + desc.buffer_size - desc.reloc_size,
             static_cast<size_t>(desc.reloc_size));
 
   // unbox handles and relocate
   intptr_t delta = instruction_start() - desc.buffer;
   int mode_mask = RelocInfo::kCodeTargetMask |
                   RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT) |
                   RelocInfo::ModeMask(RelocInfo::CELL) |
@@ skipping 5389 matching lines @@
   } else {
     // Old-style generators.
     int offset = continuation();
     CHECK(0 <= offset && offset < function()->code()->instruction_size());
     return function()->code()->SourcePosition(offset);
   }
 }
 
 }  // namespace internal
 }  // namespace v8