ReC98/Research/Borland C++ decompilation.md

Limits of decompilability

MOV BX, SP-style functions, no stack frame

These almost certainly weren't compiled from C. By disabling stack frames using #pragma option -k-, it might be possible to still get the exact same code out of Turbo C++ – even though it will most certainly look horrible, and barely more readable than assembly (or even less so), with tons of inline ASM and register pseudovariables. However, it's futile to even try if the function contains one of the following:

• A reference to the DI register. In that case, Turbo C++ always inserts a PUSH DI at the beginning (before the MOV BX, SP), and a POP DI before returning.

  Certainty: Confirmed through reverse-engineering TCC.EXE, no way around it.