Re: [Tinycc-devel] tcc as compiler for tccboot

[Michael Matz]

Hi,

On Wed, 20 Apr 2016, Sergey Korshunoff wrote:

> > Just checked. I used a hex editor to replace a 0x20 bytes in mem-2.o with 
> > 0x04.
> > This helped.
> 
> diff --git a/libtcc.c b/libtcc.c
> index 5aebd32..a8e109c 100644
> --- a/libtcc.c
> +++ b/libtcc.c
> @@ -514,7 +514,11 @@ ST_FUNC Section *new_section(TCCState *s1, const
> char *name, int sh_type, int sh
>          sec->sh_addralign = 1;
>          break;
>      default:
> +        #ifdef TCC_TARGET_I386
> +        sec->sh_addralign =  4; /* gcc/pcc default alignment for i386 */
> +        #else
>          sec->sh_addralign = 32; /* default conservative alignment */
> +        #endif
>          break;

A nicer default that will work for all our architectures is 'PTR_SIZE'.

The 32 comes from Fabrices original tcc implementation, at which point you 
couldn't yet specify alignment for decls (or sections) explicitely, and 
some needed larger alignment than pointer sizes.  This isn't the case 
anymore, section alignment is updated as needed.  So reducing to something 
sensible is possible now.

Please go with PTR_SIZE and no #ifdefery.


Ciao,
Michael.