Ark Bytecode (.abc) 010Editor Template

010Editor template for .abc (Open/HarmonyOS Ark Bytecode) files

Note: this is NOT a disassembler for the bytecode, but a parser for the file format that contains the bytecode. (Think .dex vs Dalvik bytecode)

For a disassembler, see https://gitee.com/openharmony/arkcompiler_runtime_core/blob/master/README.md#disassembler-ark_disasm.

Known issues

• Parsing of LiteralArray can be flawed due to poor documentation. By the documentation (see References section for a link), a LiteralArray has two fields: num_literals which indicates the number of literals this LiteralArray contains (somehow the number must be divided by 2 to get the actual number), and literals which is an array of Literal. The Literal struct, as it turns out, follows a Tag-Value format, which means the first field is a tag determining how the second field should be interpreted. Unfortunately, the tags are not documented at all. I had to extract them from the source code, but I'm not 100% sure if I understood everything in the relevant code correctly, especially the LiteralTag::ARRAY_* tags, given that this is such a huge project.
• Parsing of methods referred to by MethodRegionIndex is still problematic, so this part of code has been commented out.
• Parsing of Proto and MethodHandle is not implemented yet.
• Parsing of LineNumberProgram is flawed too, as the operands in a line number program are not handled at all, and as such a 0x0 operand would be misinterpreted as marking the end of the program.
• Should be fixed already (if I was looking at the right place in the code!). Parsing of Value of any type is not implemented. The Value struct is used when a Field, in its field_data, has a TaggedValue with the tag VALUE (bit of a tongue twister). Value follows a Tag-Value format too (but the "tag" is indicated by a field named type_idx in Field), whose tag is - surprise surprise - poorly documented. Luckily, this time the code is simpler, except for the 0x0b tag, which means the type of the value is any. I have no idea what this type means and how it should be interpreted.

References

• Official documentation for the .abc format (Careful, a few things in it are not accurate or up-to-date)
• arkcompiler\runtime_core\libpandafile\literal_data_accessor.h
• arkcompiler\ets_runtime\ecmascript\jspandafile\js_pandafile.cpp
• FieldTag: arkcompiler\runtime_core\libpandafile\field_data_accessor.cpp
• LiteralTag: arkcompiler\runtime_core\libpandafile\literal_data_accessor-inl.h
• Official ABC static defect scanner

Changelog

• 2024/7/27: Added support for abc version >= 12.0.1.0