dynarmic/externals/zydis/assets/porting-guide-v3-v4.md

Porting Guide v3 -> v4

General

• Zydis now requires a C11 capable compiler
• Type renamed: ZydisAddressWidth -> ZydisStackWidth
• Enum changed: ZydisMemoryOperandType
  • Constants added: ZYDIS_MEMOP_TYPE_VSIB
• Decoding behavior changed:
  • In case of vector SIB addressing memory operands, ZYDIS_MEMOP_TYPE_VSIB will be reported by the decoder instead of ZYDIS_MEMOP_TYPE_MEM (in ZydisDecodedOperand.mem.type)
• Constants renamed:
  • ZYDIS_STATIC_DEFINE -> ZYDIS_STATIC_BUILD
  • Zydis_EXPORTS -> ZYDIS_SHOULD_EXPORT
  • ZYDIS_ADDRESS_WIDTH_XXX -> ZYDIS_STACK_WIDTH_XXX
• ZydisCPUFlagAction got replaced by ZydisAccessedFlagsMask
• ZydisAccessedFlags was added as a replacement for the CPU flag arrays
• ZYDIS_CPUFLAG_C[0-3] were replaced with ZYDIS_FPUFLAG_C[0-3]
• The segment API (ZydisGetInstructionSegments and corresponding types) was moved to a separate header file

Decoder

• Added functions to decode instructions and operands individually, allowing for improved performance when the operands are not actually needed.
  • ZydisDecoderDecodeInstruction
  • ZydisDecoderDecodeOperands
• ZydisDecoderDecodeBuffer got replaced by ZydisDecoderDecodeFull
• ZydisDecodedInstruction struct was changed
  • Removed field operands
    • The operands array is passed to the desired decoder function as a separate argument instead
  • Added field operand_count_visible
    • Contains the number of visible (explicit and implicit) operands
  • The cpu_flags_read and cpu_flags_written fields are replaced with the cpu_flags field
  • The fpu_flags_read and fpu_flags_read fields are replaced with the fpu_flags field
  • The older accessed_flags array is replaced by the cpu_flags and fpu_flags fields

Formatter

• Added arguments to accommodate the new decoder API changes
• Arguments from Ex variants of various functions were integrated into the non-Ex variant
  • All of these varied by only a single argument and didn't warrant the additional complexity
• As a result, the signature of the following functions changed:
  • ZydisFormatterFormatInstruction
  • ZydisFormatterFormatOperand
  • ZydisFormatterTokenizeInstruction
  • ZydisFormatterTokenizeOperand

Utils

• Removed flag helpers (no longer needed with new flags format!)
  • ZydisGetAccessedFlagsByAction
  • ZydisGetAccessedFlagsRead
  • ZydisGetAccessedFlagsWritten

Changes relevant for language bindings

• Encoder added
  • Encoder.h, various new types and functions
• Type ZydisRegisterKind added
• The ZYDIS_ATTRIB_ defines were rebased (underlying bits were changed)
• New type ZydisDecodingFlags
• New type ZydisDecoderContext
• An anonymous union was added around some fields in the raw part of ZydisDecodedInstruction
• An anonymous union was added around the operand type specific fields in ZydisDecodedOperand
• The previously anonymous sub-structs in ZydisDecodedOperand were lifted to the top level scope and are proper types now
• Some of the previously anonymous sub-structs in ZydisDecodedInstruction were lifted to the top level scope as well
• ZydisDecodedOperand::type was moved to a different location in the struct
• Unions were added around fields in ZydisDecodedOperand and ZydisDecodedInstruction