Re: [Tinycc-devel] va_* broken on x86-64: any volonteer?

[Michael Matz]

Hi,

[bah, resent again because of suse.de not being the subscribed address 
here :-/ ]

On Thu, 9 Jan 2014, Thomas Preud'homme wrote:

> Oh I see. I compiled with --with-libgcc and gcc doesn't provide __va_* 
> like libtcc1 does. So I guess either libgcc should not be proposed for 
> x86-64 systems or libtcc1 should always be linked in as well as to fill 
> in the blank.

Yeah.  tcc meanwhile also emits references to other symbols that aren't in 
libgcc.  E.g. __floatundixf.

> Or maybe now that arm can uses libtcc1 this option could be just 
> removed. If there is some value in keeping it, it could also be nice 
> that tcc can work directly with libgcc (and thus have va_* macros 
> builtin, see stdarg.h from gcc and gcc's source code).

You can't without providing the implementation currently residing in 
libtcc directly as inline variant in the code generator (as libgcc doesn't 
contain any implementation of that stuff).  As the x86_64 variant of 
stdargs is a bit convoluted (as in, more that three/four instructions) 
that doesn't seem like the best solution.  So, ...

> Dear users, does any of you see value in the --with-libgcc switch of 
> configure?

... if the possibility of using libgcc should be retained, then yes, 
libtcc needs to be linked in additionally.  Which seems to make sense as 
that lib indeed is supposed to provide the runtime parts that the compiler 
(here tcc) specifically wants to rely on.


Ciao,
Michael.