Op Parse Syntax Bug for Parenthesized Operands

[shalebridge]

I've added this here for archival purposes, as I've fixed this bug in my own fork of EASy68k.

There are a few syntax cases that trigger a false error due to how opparse.cpp handles parenthesized cases. For example:

LEA ($CFFF).w,A0 ; OK
LEA ($7FFF).w,A0 ; syntax error
LEA ($7FFF).w, A0 ; OK

The line that checks for (d,An) or (d,An,Xi) allows for some undefined behavior in syntax.

if (p[0] == '(' && p[1] != 'P' && p[2] != 'C') {    // CK 2018-2-7
    n = strchr(p,',');

This will find any comma in the line, even if it's outside the parenthesis. This also has a side effect of only filtering hex numbers that start with 'C':

LEA ($0FFF).w,A0 ; ERROR
LEA ($1FFF).w,A0 ; ERROR
...
LEA ($CFFF).w,A0 ; OK
LEA ($DFFF).w,A0 ; ERROR

Then:

if (n) {
    if((n[1] == 'A' && isRegNum(n[2])) || (n[1] == 'S' && n[2] == 'P') ) {

This will directly point to the destination 'A0' if there is no space before the operand, and prematurely send the data off to 'eval':

        p++;                  // skip (
        // evaluate displacement, p points to ','
        p = eval(p, &(d->data), &(d->backRef), errorPtr);
    }
}

When a space is added to the destination after the comma, it just happens to work since n[1] != 'A'.

The easy fix is to add a check for the index of ')' and see if the comma found is inside before continuing:

     n = strchr(p,',');
     pn = strchr(p, ')');
     if (n && n < pn) { ...

[shalebridge]

Forked version bug fixes