A decompiled switch drops values: run the function for every case instead

Symptoms

A function chooses a few constants by a two-level switch (here: by menu, then by the selected item) and passes them on in registers. The decompiler shows two of the four values, merged across cases, and the port draws boxes in the wrong places.

Cause

Watcom passes arguments in EAX, EDX, EBX and ECX. Ghidra loses register arguments it cannot type, and merges the cases of a jump table whose blocks only load registers. The values are in the binary, but reading each case by hand is slow and error-prone.

What to do

Run the function under Unicorn once per input that selects a case, with the structures it reads laid out in scratch memory, and stop at the call it makes: the registers there are the answer. In POD, measure/menu_outline.py runs draw_outline (FUN_0043873c) for all 503 menu items and records x, y, width, height and the style (the style is on the stack above the return address). The port's table is generated from that file.