Re: [Tinycc-devel] Tinycc from git still can't compile fossil-scm

[Michael Matz]

Hello,

On Fri, 28 Mar 2014, Domingo Alvarez Duarte wrote:

> I found that on X86_64 linux if I do not free the memory on __va_end(), the
> compiled fossil-scm server works, I suspect is something with the
> fork/threads.---
> void __va_end(struct __va_list_struct *ap)
> {
>     //free(ap);
> }
>
> Cheers !

Errr.  I see you now fiddled with that on mob.  Commit c025478d7c03, 
rewriting va* to not use malloc.  That's completely wrong.  You've 
effectively changed the ABI of stdarg, and hence interoperability with 
every non-TCC compiler.  The public va_list on x86_64 _must_ be a pointer.
To see it breaking try e.g. this:

% cat vatest.c
#include <stdio.h>
#include <stdarg.h>

static int passdown (const char *str, va_list ap)
{
  int ret;
  va_list ap2;
  va_copy (ap2, ap);
  ret = vprintf (str, ap2);
  va_end (ap2);
  return ret;
}

static int myprintf (const char *str, ...)
{
  va_list ap;
  va_start (ap, str);
  passdown (str, ap);
  va_end (ap);
}

int main ()
{
  myprintf ("%s %i %f\n", "bla", 42, 0.4);
  return 0;
}

When executed it must print:
bla 42 0.400000

Before your patch it does, after your patch it prints garbage (on my 
system " 134514261 0.000000") (without the va_copy and ap2 it even just 
segfaults now, though strictly speaking that's invalid stdarg usage). 
Please revert.

If you could please _discuss_ changes in parts you don't completely 
understand on the list before making nilly-willy changes?  Just because 
fossil-scm "works" after your patching doesn't mean much if you don't know 
_why_ fossil-scm didn't work before, and especially doesn't mean that the 
change was even correct.


Ciao,
Michael.