Impossible to create a label with name starting with dot

[SEt-t]

Is there a way to create a label with name starting with . ?
Based on syntax I expected $.text would do that as $ is documented as an escape symbol to prevent special interpretation, but it doesn't work for such cases.

[maciejwieczorretman]

Can you provide more details on the circumstances when this issue happens?
I tried making labels starting with dots and the code seems to assemble just fine; for example:

	jmp $.text
	jmp .text

section .text
	db 'Some text'
.text:

Assembles into:

     1 00000000 EB0B                    	jmp $.text
     2 00000002 EB09                    	jmp .text
     3
     4                                  section .text
     5 00000004 536F6D652074657874      	db 'Some text'
     6                                  .text:

In this case for example I don't think you can jump to a section name so the $ sign doesn't have any effect.

[SEt-t]

I'm talking about code like this:

	section .text
a:
	jmp $.xyz
b:
$.xyz ret

Here I want a label named exactly .xyz, not a.xyz or b.xyz.

Label .text was needed during debugging generation of debug information so that section names and labels are not mixed there, nothing special about it here.

[maciejwieczorretman]

Okay, so the dot in the front of the label name makes it a local label:
https://www.nasm.us/docs/3.01/nasm03.html#section-3.9

So that will always want to prepend the local name with the outer label. I believe the dollar sign you mentioned is used for reserved names if you wanted to use them for something else - such as turn eax into a label name. To get the behavior you specified above I'd use the special symbol that NASM defines for such occasions - ..@
Then the code above would look like this:

	section .text
a:
	jmp ..@xyz
b:
..@xyz ret

That being said I see the inconsistency in using $ to ditch the reserved name but not convert local label name to a regular label. If the ..@ doesn't satisfy your use cases I can take a look around at how hard it would be to make $ and ..@ synonymous for example.

[SEt-t]

..@ doesn't do what I need at all: the label becomes ..@xyz and it's still impossible to create one named .xyz or .text ("named" as "name in object file", not "name in source text").

As $ is already removed as first symbol on labels and documented to mean "the rest of the word is literal without special meaning" elsewhere, I think it should work here the same as well.

[maciejwieczorretman]

So we discussed adding this functionality and right now it would be a pretty complex change so we can't really prioritize it for the next release. But we'll be planning a rework to the '..' special backend that would allow an easy addition of the non-local dot-starting labels.