#3275 Undocumented instructions not working in z80 assembler

[Philipp Klaus Krause]

This code

.z80
.allow_undocumented
ld  a, iyl

gives the error

test.s:2: Error: <o> .org in REL area or directive / mnemonic error
test.s:3: Error: <a> machine specific addressing or addressing mode error
removing

Interestingly, it works with .z180 instead of .z80 (where it is less useful - AFAIK the z180 does trap on undocumented instructions).

[Ragozini Arturo]

The bug is unresolved, the .allow_undocumented directive is not working.

[Sebastian Riedel]

Yes, it looks broken.
Since Z80N looks like being a superset of Z80, you could use .zxn as a workaround for handwritten asm.
.zxn and .ez80 enable undocumented instructions by default.

[Sebastian Riedel]

Now it says:

test.asm:2: Error: <o> Internal Opcode Error.
test.asm:3: Error: <a> Invalid Addressing Mode.

I had to fix the error printing first for tracking it down. sdas printed general error messages instead of using the strings actually thrown.

Internal Opcode Error means case X_UNDOCD: does not trigger at all.

[Sebastian Riedel]

        case X_Z80:
                if (rf > S_CPU)
                        rf = 0;
                break;

#define S_CPU   83
#define S_RL_UNDOCD  85
#define X_UNDOCD 89

.allow_undocumented and sll were intentionally or accidentally disabled for z80.

[Sebastian Riedel]

Should be fixed in [r13287]

    .z80
    .allow_undocumented
    sll a
    ld  a, iyl

$ sdasz80 test.asm

    .z80
    ;.allow_undocumented
    sll a
    ld  a, iyl

$ sdasz80 test.asm
test.asm:3: Error: <a> Undocumented instructions not enabled.
test.asm:4: Error: <a> Invalid Addressing Mode.

[Sebastian Riedel]

AFAIK the z180 does trap on undocumented instructions).

What does hd64180 on undocumented instructions? I could throw an error if one tries to enable .allow_undocumented on these targets.

But only if that’s the case on hd64180 and z180, because they are the same for asz80.

[Sebastian Riedel]

Since they both trap, I disabled it in [r13296]

[Aoineko]

I didn't understand if .allow_undocumented is supposed to work or not after all?
Anyway, if I try to add this directive to my assembler code, I get this error:
Error: <o> .org in REL area or directive / mnemonic error

[Philipp Klaus Krause]

AFAIK, it is working in current snaphots (or SDCC built from source) since late March. It works for me. In SDCC 4.2.0 it AFAIK was still broken.

[Sebastian Riedel]

Though for 4.2.0 the .zxn workaround described above should work.

[Philipp Klaus Krause]

Can you confirm that this works for you in a current snapshot?