Beebasm macro scoping

[hjalfi]

Is there any way to make Beebasm macros without having them create an automatic scope? I want to do something like this:

Code: Select all

macro startthing
    {
endmacro

macro endthing
    }
endmacro

(simplified example, of course. I'm intending to do something more complex than this, honest.)

[Rich Talbot-Watkins]

Not unless something has changed recently. BeebAsm macros are really better described as functions - they are instanced with a fake scope so that the parameter symbols disappear on exit.

[hjalfi]

I'm just wondering if there's a way to suppress that scope creation, to make them work like (conventional!) text substitution macros.

[Rich Talbot-Watkins]

The way that BeebAsm works internally means that when you call

MACRO BLAH var1, var2

like this:

BLAH 1, 2

it really just creates a new scope, assigns var1 and var2 to the passed parameters, and then instances the macro body:

{
var1=1
var2=2
; rest of macro
}

So the scope is kind of an important part of how parameters are assigned. I know this is not like the more regular text substitution which most assemblers perform, but it was what seemed easiest and most useful to me when I knocked this together all those years ago.

From distant memory, it might just be possible to allow a new scope to be opened (but not closed) inside a macro, with no bad side-effects. It just seemed like ill-defined behaviour at the time which I made a point of checking for, and prohibiting!

[TobyLobster]

I'm just wondering if there's a way to suppress that scope creation, to make them work like (conventional!) text substitution macros.

Alternatively, If you have some coding ability it should be possible to write a preprocessor that handles text substitution, whose output is then fed into beebasm.

[hjalfi]

I've looked at using a preprocessor, but unfortunately beebasm doesn't seem to have a way to set the current file and line number (equivalent to C's

Code: Select all

# "filename" 1234

directives), which means that error messages are always reported at the wrong place.

[tricky]

You should be able to sneak, or sledgehammer a label out of a macro with .*label but without the text concatenation from the other thread it probably won't help.
If you made your macros a single line, the CPP should work ok shouldn't it?

[TobyLobster]

I've looked at using a preprocessor, but unfortunately beebasm doesn't seem to have a way to set the current file and line number (equivalent to C's

Code: Select all

# "filename" 1234

directives), which means that error messages are always reported at the wrong place.

Sounds like a useful future feature for Beebasm...?