Re: nyacc 0.73.0 released

[Matt Wette]

> On Dec 31, 2016, at 6:15 AM, Jan Nieuwenhuizen <address@hidden> wrote:
> 
> Matt Wette writes:
> 
>> I believe C99 parser is complete.  There may be errors, but I think
>> all the elements are there.
> 
> Great!  As it turns out, I was using some GNU extensions (anonymous
> unions inside structs.
> 
> I have now picked-up my work on Mes's simple C compiler backend, using
> Nyacc.  I have already replaced my LALR parser with Nyacc's AST[0].
> 
> How far is the Nyacc's C99 preprocessor?  I have two problems with it.
> 
> It would be very helpful if it would disregard anything inside a false
> conditional directive.  It seems I cannot conditionally comment things
> out that Nyacc does not parse, like
> 
> --8<---------------cut here---------------start------------->8---
>    #if __GNUC__
>    void
>    _start ()
>    {
>      puts ("Hello micro-mes!\n");
> 
>      ///int r = main (0,0);
>      int r;
>      asm (
>           "push $0\n\t"
>           "push $0\n\t"
>           "call main\n\t"
>           "movl %%eax,%0\n\t"
>           : "=r" (r)
>           : //no inputs "" (&main)
>           );
>    #endif // GNUC
> --8<---------------cut here---------------end--------------->8---
> 
> ==>  micro-mes.c:199: parse failed at state 379, on input “:"

I need to document better.  There is an argument to handle this.  I think this 
may accomplish what you want:

(define (my-xdef? name mode) (if (equal? name “__GNUC__”) #f (env? mode ‘code))

(parse-c99 #:xdef? my-xdef? …)

> headers that Nyacc does not parse, like <assert.h>, which is
> a bit of a pain.

(define my-td-dict ‘((“assert.h”)))

(parse-c99 #:td-dict my-td-dict …)

See std-dict in nyacc/lang/c99/body.scm.  This is added by default, but should 
probably not be.
td-dict is an a-list of include files with typedefs in those files.


> 
> Also, it seems like it doesn't like it if an #includ'ed file is meant to
> go inside a function, like (simplified example)
> 
> --8<---------------cut here---------------start------------->8---
>    // main.i
>    r = 3;
> --8<---------------cut here---------------end--------------->8---
> 
> --8<---------------cut here---------------start------------->8---
>    // main.c
>    int
>    main ()
>    {
>      int r;
>      #include "main.i"
>      return r;
>    } 
> --8<---------------cut here---------------end--------------->8---
> 
> 
> ==> ./main.i:2: parse failed at state 43, on input “r"

This seems like a bug to me.  I will check it out.