Cool, thanks!
Andreas Schwab <sch...@linux-m68k.org> 于2018年9月29日周六 下午7:57写道：
>
> On Sep 29 2018, bx L <lbxlbxlbxlbx...@gmail.com> wrote:
>
> > I notice that gcc has some predefined macros, which can be
> > obtained with " gcc -dM -E - < /dev/null". I guess many of them are
> > machine-specified, such as __LDBL_MANT_DIG__. However, I can't find
> > where these macros are defined when browsing GCC's source codes. I'm
> > very curious about how these macros are defined.
>
> Look for builtin_define, then inspect the context to see where the macro
> names are constructed. For example, c-family/c-cppbuiltin.c has a lot
> of them.
>
> Andreas.
>
> --
> Andreas Schwab, sch...@linux-m68k.org
> GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1
> "And now for something completely different."
