Creating a DWARF stack-based variable with LLVM

Variable.cpp

Variable& Variable::set_stack_offset(uint64_t offset) {
  llvm::BumpPtrAllocator& allocator = editor_->allocator();
  auto* loc = new (allocator) llvm::DIELoc{};
  loc->addValue(allocator, (llvm::dwarf::Attribute)0, llvm::dwarf::DW_FORM_data1,
                llvm::DIEInteger(llvm::dwarf::DW_OP_fbreg));

  loc->addValue(allocator, (llvm::dwarf::Attribute)0, llvm::dwarf::DW_FORM_sdata,
                llvm::DIEInteger(-offset));

  loc->computeSize(editor_->streamer().getAsmPrinter().getDwarfFormParams());
  die_->addValue(allocator, llvm::dwarf::DW_AT_location,
                 llvm::dwarf::DW_FORM_exprloc, loc);

  return *this;
}