sepavloff added inline comments.

================
Comment at: clang/test/Driver/config-file3.c:27
 
-//--- Invocation qqq-clang-g++ tries to find config file qqq-clang-g++.cfg 
first.
+//--- Invocation x86_64-unknown-linux-gnu-clang-g++ tries 
x86_64-unknown-linux-gnu-clang++.cfg first.
 //
----------------
mgorny wrote:
> sepavloff wrote:
> > mgorny wrote:
> > > sepavloff wrote:
> > > > mgorny wrote:
> > > > > sepavloff wrote:
> > > > > > mgorny wrote:
> > > > > > > arichardson wrote:
> > > > > > > > sepavloff wrote:
> > > > > > > > > Tests must check the case when target prefix is not a real 
> > > > > > > > > triple as in the original test (qqq-clang).
> > > > > > > > It would be quite important for me that this continues to work. 
> > > > > > > > I made use of that in the CheriBSD toolchain when creating [[ 
> > > > > > > > https://github.com/CTSRD-CHERI/cheribuild/blob/master/pycheribuild/projects/cross/llvm.py#L499
> > > > > > > >  | symlinked binaries to easily build for different ABIs]] such 
> > > > > > > > as `cheribsd-riscv64-hybrid-clang++` and 
> > > > > > > > `cheribsd-riscv64-purecap-clang-cpp`. It appears this 
> > > > > > > > previously only worked if the prefix did not start with a valid 
> > > > > > > > triple (which is why I put the OS before the architecture). I 
> > > > > > > > think it would also be nice if the whole prefix was checked 
> > > > > > > > even if it starts with a valid triple, but this does not need 
> > > > > > > > to be changed in this patch (haven't looked at it in detail so 
> > > > > > > > this might actually work).
> > > > > > > If the prefix is not a valid triple, then clang ignores it and 
> > > > > > > uses host triple instead. And now we're back to square one. If I 
> > > > > > > check both variants, it's too complex. If I don't, it's bad too.
> > > > > > Our customers use this feature. Target prefix may designate, for 
> > > > > > example, debug build or build with specific framework.
> > > > > How are we supposed to avoid the "absurd" case where x86_64 configs 
> > > > > are loaded for `-m32` invocation then?
> > > > In this case overloading target does not makes sense. You need to 
> > > > analyze `RealTriple` in `Driver::loadDefaultConfigFiles` and if it is 
> > > > wrong, use target prefix as if it is real target.
> > > What do you mean by "wrong"? The target triple is always a correct triple.
> > Not triple, sorry. Target prefix taken from `ClangNameParts.TargetPrefix`.
> Now I'm confused. Are you suggesting that we use prefix instead of target if 
> it's… incorrect?
Basically yes.

We need to support arbitrary target prefixes, because they are used now. If 
`ClangNameParts.TargetPrefix` is not a valid triple, use it to build config 
file names.

We also need to use config files like `x86_64.cfg` where middle components are 
dropped, they are also used. They also need to support target overloading.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D134337/new/

https://reviews.llvm.org/D134337

_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

Reply via email to