X64: Implement InstanceofStub. Prohibit zero-size code objects.

src/x64/assembler-x64.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 255 matching lines @@
 
 void Assembler::GetCode(CodeDesc* desc) {
   // finalize code
   // (at this point overflow() may be true, but the gap ensures that
   // we are still not overlapping instructions and relocation info)
   ASSERT(pc_ <= reloc_info_writer.pos());  // no overlap
   // setup desc
   desc->buffer = buffer_;
   desc->buffer_size = buffer_size_;
   desc->instr_size = pc_offset();
+  ASSERT(desc->instr_size > 0);  // Zero-size code objects upset the system.
   desc->reloc_size = (buffer_ + buffer_size_) - reloc_info_writer.pos();
   desc->origin = this;
 
   Counters::reloc_info_size.Increment(desc->reloc_size);
 }
 
 
 void Assembler::Align(int m) {
   ASSERT(IsPowerOf2(m));
   while ((pc_offset() & (m - 1)) != 0) {
@@ skipping 1837 matching lines @@
 bool BreakLocationIterator::IsDebugBreakAtReturn()  {
   UNIMPLEMENTED();
   return false;
 }
 
 void BreakLocationIterator::SetDebugBreakAtReturn()  {
   UNIMPLEMENTED();
 }
 
 } }  // namespace v8::internal