Hi,

I was wondering, whats the downside to using a macro in another macro eg:

think of this code:

steps:

1. preprocessor finds macro "a" declaration and saves it

2. same for macro "b" declaration

3. preprocessor finds macro "b" used, so it replaces this line with body of macro "b", and continues preprocessing this body.

4. as next thing, it finds usage of macro "a" (generated by macro "b" body), so it again expands this macro (replaces "a" line with body of macro "a")

5. it continues to preprocess new lines, finds line with "macro_a_body", which is not any kind of preprocessor directive, so it lets it be. So result is one line containing "macro_a_body"

PS: It doesn't work exactly as i described, but it is enough to understand behavior in such cases.

additional thoughts:
The problem is that with some tricky code that includes nested macros, matches etc. the assembler does more and more passes to resolve the code. When you have no nestings and everything is in correct order, there are fewer passes and the job gets done quicker.

This is not really so straightforward related. Especially when you use matches and not if's, it's unlikely to get more passes because of it.

these passes have nothing to do with macros.... multiple passes happen duing assembling (if, repeat), after all preprocessing (macro, match) is done.

Yea i understand, thanks for the info guys.

Thanks,
Sarge

@vid:
Don't say it has *nothing to do* with macros etc.
Like Tomasz said, it is not that straigh-forward:

This one takes 64 passes and as I understand there is little related to assembly... :/ ...only the dword

But it is not related to preprocessor either. And in fact, in fasm's meaning of this term, this is exactly the "assembly" what happens here.

Well, I still need to finish that "Understanding fasm" text to cover the preprocessor layer and then all the possible interactions between various layers...

You do that! And then we'll come back on this topic to clear out what "macro in macro" means

Sorry for confusion I've made :$

i think reading my preprossesor tutorial may clear it for you _what_ is preprocessor (eg. just some textual substitutions)/