BlockEncoder option to return all offsets, including for rewritten instructions #643
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Adds a new
BlockEncoderOption,ReturnAllNewInstructionOffsets, which enablesReturnNewInstructionOffsetsand also changes its behavior regarding instructions that were rewritten (e.g. by branch fixups) to output the offset of the rewritten block of instructions, as opposed tou32::MAXwithReturnNewInstructionOffsets.I am not really happy about the name, but can't think of anything better at the moment so please let me know if you have other suggestions.
The particular use-case I need this for is for live instrumentation where I will be hooking thousands of individual instructions, some of which may be in the middle of functions. In such cases it becomes necessary to maintain a CFG to fixup branch targets as code is relocated. To do so, I need to know where control flow instructions were moved, regardless of whether they had to be rewritten as multiple instructions. Without this feature, I would have to perform the
BlockEncoder's branch fixups myself, which seems counterproductive.