OpenEuphoria

Re: BREAKing into Euphoria

• Posted by abuaf Feb 26, 2022
• 1481 views

[quote ghaberek]

See my quote below. This is *not* how my code works. Essentially in the eu source, trace(1) sets the C var "TraceOn=1;" . This then triggers the debugger to be invoked when the existing "trace on" eu byte code is next hit (what i referred to as "pop up the debugger when the next trace'able code is encounterred"). My code patches the C var "TraceOn=1;" in the eu binary in virtual memory (because there's no api exposing access to this). You can then refer to my comments to provide this access via trivial additions to allow_break() in interpreter's C source; this is then the implementaion - nothing to do with the problematic mission of patching eu byte code; i dont think there is any way to locate at runtime where in the bytecode to patch and how to revector the old byte code to allow continuity. Me thinks I'd have to parse eu's symbolic debug stream wind forward to the next eu instruction bytecode address falling on the next eu source line and patch that ... ugly, and not needed, this is not how eu's debugger works; basically the bytecode has the 'trace on' opcode preceeding each new eu source line (keeping in mind each line corresponds to many byte codes which would be un-atomic otherwise), that the interpreter then polls the C "TraceOn" var and invokes the debugger if true, so all the machinery to internally (via a API to the eu app to) trigger the debugger at an abitrary moment is there; which my code does without an exposed API.

Anyone who wants to wrap their head around my code, pls read my comments very carefully. Anyway i reimplemented it without ASM with eu equivalent and some fluff, but the 'hack' is the same methodology.