r366076 - fix unnamed fiefield issue and add tests for __builtin_preserve_access_index intrinsic

[Nick Desaulniers via cfe-commits]

On Tue, Jul 16, 2019 at 11:02 AM Nick Desaulniers
<ndesaulniers at google.com> wrote:
>
> On Mon, Jul 15, 2019 at 5:13 PM Eric Christopher <echristo at gmail.com> wrote:
> >
> > I'm going to cheat and make Nick do it :)
>
> I suspect that Eric still compiles LLVM by specifying all object files
> in order on the command line and doesn't want to talk about it on
> cfe-commits. :) Though, even I'm behind the times as I think the cool
> kids are using "gn" these days?  I'm so out of touch.
>
> > On Mon, Jul 15, 2019 at 5:12 PM Yonghong Song <yhs at fb.com> wrote:
> > > I just tried the following cmake (removing -DLLVM_ENABLE_ASSERTIONS=ON which is used in my previous build)
> > >
> > > cmake -G "Unix Makefiles" -DLLVM_TARGETS_TO_BUILD="BPF;X86" \
> > >     -DCMAKE_C_COMPILER=/llvm8/bin/clang \
> > >     -DCMAKE_CXX_COMPILER=/llvm8/bin/clang++ \
> > >     -DLLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN=ON
> > >     -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=$PWD/install ..
> > >
> > > and cannot reproduce the issue. If you could send me the cmake
> > > command line which caused failure in your environment. That will
> > > be great!
>
> I did:
> $ cmake .. -DCMAKE_BUILD_TYPE=Release -G Ninja
> -DCMAKE_C_COMPILER=<path to bootstrapping clang>
> -DCMAKE_CXX_COMPILER=<path to bootstrapping clang>
> -DLLVM_ENABLE_LLD=ON -DLLVM_ENABLE_PROJECTS="clang;lld"
> -DLLVM_TARGETS_TO_BUILD="AArch64;ARM;X86"
>
> I sometimes add:
> -DLLVM_ENABLE_ASSERTIONS=ON
> which hopefully gets cleared when rerunning cmake, but I wouldn't bet
> my life on that. (Looks like it's OFF in my CMakeCache.txt, so I guess
> I could've taken that bet).

Forgot to mention that jdoerfert also mentioned on IRC yesterday that
-DLLVM_ENABLE_ASSERTIONS=ON can influence Clang's codegen of LLVM IR.
-- 
Thanks,
~Nick Desaulniers