On Tue, 2023-11-21 at 08:00 +0800, Xi Ruoyao wrote:

/* snip */

> > This has broken libgcc builds when target libc isn't yet available.
> > 
> > In file included from /scratch/jmyers/glibc-bot/src/gcc/libgcc/../gcc/config/loongarch/loongarch-def.h:49,
> >                  from /scratch/jmyers/glibc-bot/src/gcc/libgcc/../gcc/config/loongarch/loongarch-opts.h:24,
> >                  from ../.././gcc/options.h:8,
> >                  from ../.././gcc/tm.h:49,
> >                  from /scratch/jmyers/glibc-bot/src/gcc/libgcc/libgcc2.c:29:
> > /scratch/jmyers/glibc-bot/build/compilers/loongarch64-linux-gnu-lp64d/gcc-first/gcc/include/stdint.h:9:16: fatal error: stdint.h: No such file or directory
> >     9 | # include_next <stdint.h>
> >       |                ^~~~~~~~~~
> > compilation terminated.
> > make[3]: *** [Makefile:505: _muldi3.o] Error 1
> > 
> > https://sourceware.org/pipermail/libc-testresults/2023q4/012109.html
> > 
> > My guess would be that the definitions needing <stdint.h> are not actually 
> > needed in code built for the target, and so there should be more
> > 
> > #if !defined(IN_LIBGCC2) && !defined(IN_TARGET_LIBS) && !defined(IN_RTS)
> > 
> > conditions like the one already present in loongarch-opts.h, to avoid 
> > depending on a target header like this being present.
> 
> Ah, makes sense.  I thought stdint.h was usable without libc but it's
> not true.
> 
> The only use for stdint.h is in struct loongarch_isa (using int64_t for
> a 64-bit bitset).  This struct is not used by target code.
> 
> I'll test building a cross compiler from x86_64 with stdint.h and struct
> loongarch_isa guarded with the ifdef.

Pushed the attached patch r14-5634.  Tested building a cross compiler
from x86_64 with cross Binutils but not target libc.  Also tested
bootstrapping on loongarch64-linux-gnu.

-- 
Xi Ruoyao <xry111@xry111.site>
School of Aerospace Science and Technology, Xidian University