The default for nasm-mode seems to be to format labels fully left-aligned (starting in the first column), like so:

foo:
    xor eax, eax

So far, so good. If a label contains a % character, however, the indentation changes - the labels are now aligned one tab in, same as assembly instructions, like so:

    foo%1:
    xor eax, eax

Probably this happens because nasm-mode doesn't detect it as a valid label - but such labels are common, for example, in macro definitions.

Is this intended?

I'm not sure if this is a nasm-mode issue, or just a quirk of emacs comment handling, but when using the nasm mode, I can no longer add a ; character in the middle of a line.

For example, I often have something like:

xor eax, dword [ebx + ecx + 123]

and I want to comment out everything after and including dword, like:

xor eax, ebx ; dword [ebx + ecx + 123]

When I enter the ; in that location there, the cursor instead jumps to the end of the line and adds the ; there. In some cases this is helpful, but in this case not. I have to delete everything I want to comment out, and then write the comment.

nasm-mode issue or emacs quirk?

Hi,

As you might know, I'm the NASM maintainer. I'm also a pretty avid Emacs user. I thought I might help by making it possible for the token lists to be automatically generated, so I added a Perl script to do so (misc/emacstbl.pl) and put it in the "emacs" branch of the main NASM repository, https://github.com/netwide-assembler/nasm.

It probably takes a bit of hacking to accept the output of this file, and I would certainly accept changes to the script as needed, but I would suggest using (require) to load this file separately from the actual code, to decouple it from maintaining your code.

I have attached a sample output.
nasmtbl.el.txt

After installing nasm-mode and load it, completion-at-point in sh-mode no longer give code completion, but giving this error instead:

user-error: No items suitable for an index found in this buffer

@charliegreen seems to have done some useful development in October 2016 at https://github.com/charliegreen/nasm-mode

It would be cool to merge the changes into mainline. @skeeto do you have time to look at them?

One bug that the changes fix for me is font-lock highlighting of 'cpu_whatever:' labels (in mainline, 'cpu' is highlighted as a keyword even though it's part of the label name).