Reference data created in other patches

[avncharlie]

Is there a way to define data in one patch that can be used in another patch? I've tried to do like so:

context.register_insert(
    SingleBlockScope(module.entry_point, BlockPosition.ENTRY),
        Patch.from_function(lambda _:'''
            nop

            .data
            __variable:   .quad 0
    ''', Constraints(x86_syntax=X86Syntax.INTEL))
)

context.register_insert_function(
    'inserted_function_that_uses_var',
    Patch.from_function(lambda _: '''
        mov rdi, [rip + __variable]
    ''', Constraints(x86_syntax=X86Syntax.INTEL))
)

This causes this error:

    gtirb_rewriting.driver.main(AddAFLPass)
  File "/usr/local/lib/python3.9/dist-packages/gtirb_rewriting/driver.py", line 350, in main
    _driver_core([entrypoint], False, argv)
  File "/usr/local/lib/python3.9/dist-packages/gtirb_rewriting/driver.py", line 316, in _driver_core
    pass_man.run(ir)
  File "/usr/local/lib/python3.9/dist-packages/gtirb_rewriting/passes.py", line 116, in run
    context.apply()
  File "/usr/local/lib/python3.9/dist-packages/gtirb_rewriting/rewriting.py", line 1039, in apply
    self._apply_function_insertion(
  File "/usr/local/lib/python3.9/dist-packages/gtirb_rewriting/rewriting.py", line 732, in _apply_function_insertion
    assembler_result = self._invoke_patch(
  File "/usr/local/lib/python3.9/dist-packages/gtirb_rewriting/rewriting.py", line 404, in _invoke_patch
    assembler.assemble(asm, patch.constraints.x86_syntax)
  File "/usr/local/lib/python3.9/dist-packages/gtirb_rewriting/assembler/assembler.py", line 333, in assemble
    assembler.assemble(_Streamer(self._state), asm)
  File "/usr/local/lib/python3.9/dist-packages/gtirb_rewriting/assembler/assembler.py", line 122, in impl
    return func(self, *args, **kwargs)
  File "/usr/local/lib/python3.9/dist-packages/gtirb_rewriting/assembler/assembler.py", line 998, in emit_instruction
    ] = self._fixup_to_symbolic_operand(
  File "/usr/local/lib/python3.9/dist-packages/gtirb_rewriting/assembler/assembler.py", line 1584, in _fixup_to_symbolic_operand
    return self._mcexpr_to_symbolic_operand(expr, is_branch, loc)
  File "/usr/local/lib/python3.9/dist-packages/gtirb_rewriting/assembler/assembler.py", line 1552, in _mcexpr_to_symbolic_operand
    sym = self._resolve_symbol_ref(expr)
  File "/usr/local/lib/python3.9/dist-packages/gtirb_rewriting/assembler/assembler.py", line 1447, in _resolve_symbol_ref
    return self._resolve_symbol(expr.symbol, expr.location)
  File "/usr/local/lib/python3.9/dist-packages/gtirb_rewriting/assembler/assembler.py", line 1432, in _resolve_symbol
    raise UndefSymbolError._make(
gtirb_rewriting.assembler.assembler.UndefSymbolError: __variable is an undefined symbol reference

I've also tried to add the data in a seperate pass before it gets used but this also doesn't seem to work. Thanks

[avncharlie]

Using one pass to add the data and another to reference ended up working, I just wasn't doing it correctly. Closing as resolved

[jranieri-grammatech]

Could you re-open this? I think gtirb-rewriting could handle this better at some point.