Re: Merge cpplib and front end hashtables, part 1

[Daniel Berlin <dan at cgsoftware dot com>]

Neil Booth <neil@daikokuya.demon.co.uk> writes:

> Daniel Berlin wrote:-
> 
> > But it wouldn't have compiled, right?
> 
> Sure it would have.
> 
> #define ADD(X,Y) X+Y
> ADD(2,3)
> 
> for a trivial example.  I assume you'd like to be able to handle
> these?  In GDB, I'd like to be able to use a lot of the GCC macros for
> trees, say, which get way more complex.
> 
> > Remember, we get the macros from the *debug info*.
> 
> My understanding is that (Dwarf2) debug info is the same as a #define
> line without the #define, so it's no different to where cpplib gets
> them from.  Or are we talking about stabs or Dwarf1 (which I know
> nothing about).
> 
> Incidentally, if you really want something expanded to text, you could
> write a subroutine that looped calling cpp_get_token() until it got a
> CPP_EOF token, calling cpp_spell_token() on each token it receives.
> cpp_token_len() gives you (an upper bound on) the amount of space you
> need to spell the token, so I reckon you could write a simple loop to
> get what you want into an expandable buffer with 3 cpplib calls and
> around a dozen lines.  Another loop to add the macro definitions with
> a call to cpp_define is say 5 lines.  Initialization of the library
> and pushing thedyour text buffer you want expanded is maybe another 10
> say.  I think you could do everything in 50 to 100 lines max.
> 

My main problem is getting the defines into cpplib, from the dwarf2
info.
Sigh, I think i know how to do it just once.
The rest I already have done, it took about 10 minutes.

> cpplib has to do something very similar when evaluating the #
> preprocessing operator to convert an arbitrary sequence of tokens to
> text, after all.
> 
> Neil.

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