How to bootstrap GCC with custom flags for libcc1?

[Alex Vong]

Alex Vong <alexvong1995@gmail.com> writes:

> Alex Vong <alexvong1995@gmail.com> writes:
>
>> Alex Vong <alexvong1995@gmail.com> writes:
>>
>> [...]
>>>
>>> I am building GCC 7.3.0 with Guix on Debian 10. I want to add these flags:
>>> '-mindirect-branch=thunk -mfunction-return=thunk -mindirect-branch-register'.
>>> The build log is in the attachment. Thank you.
>>>
>> [...]
>>
>> Turns out the log is too large to be attached, so I put it here:
>>
>> https://notabug.org/alexvong1995/logs/src/master/gcc/dl4kjm4148xrk4zh6r3fx87yj2kg6w-gcc-7.3.0.drv
>
> I understand the problem now. I mistype CXXFLAGS as CPPFLAGS. I will try
> if this resolves the problem.

Yes, it does. So setting BOOT_CFLAGS, CFLAGS_FOR_TARGET and
CXXFLAGS_FOR_TARGET covers everything.