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This allows Rust code to be profiled and optimized based on= the >> >> > profile. >> >> > >> >> > This was verified by inspecting the object files and confirming tha= t >> >> > they look correct. It was also verified in conjuction with my helpe= rs >> >> > inlining series, and it also appears to have worked correctly when >> >> > combined with that series once one missing thing [1] was fixed in t= he >> >> > helpers inlining series. >> >> > >> >> > Link: https://lore.kernel.org/all/aasPsbMEsX6iGUl8@google.com/ [1] >> >> > Signed-off-by: Alice Ryhl >> >> > --- >> >> > scripts/Makefile.autofdo | 6 +++++- >> >> > scripts/Makefile.lib | 3 +++ >> >> > 2 files changed, 8 insertions(+), 1 deletion(-) >> >> > >> >> > diff --git a/scripts/Makefile.autofdo b/scripts/Makefile.autofdo >> >> > index 1caf2457e585..3f08acab4549 100644 >> >> > --- a/scripts/Makefile.autofdo >> >> > +++ b/scripts/Makefile.autofdo >> >> > @@ -3,14 +3,18 @@ >> >> > # Enable available and selected Clang AutoFDO features. >> >> > >> >> > CFLAGS_AUTOFDO_CLANG :=3D -fdebug-info-for-profiling -mllvm -enabl= e-fs-discriminator=3Dtrue -mllvm -improved-fs-discriminator=3Dtrue >> >> > +RUSTFLAGS_AUTOFDO_CLANG :=3D -Zdebug-info-for-profiling -Cllvm-arg= s=3D-enable-fs-discriminator=3Dtrue -Cllvm-args=3D-improved-fs-discriminato= r=3Dtrue >> >> >> >> I get that it's currently named as AUTOFDO_CLANG, but this really oug= ht to be >> >> AUTOFDO_LLVM... >> >> >> >> The flag translations look correct to me. >> > >> > Do you think it's worth having Rust not match the CFLAGS here? >> > >> >> I think the C flags should probably be renamed AUTOFDO_LLVM too. After c= all, all >> the perf tools involved here are called llvm-foobar as well. > > But isn't it just called this because the config option is > CONFIG_AUTOFDO_CLANG? So it's the CFLAGS or RUSTFLAGS related to that > particular config option. It may make sense to rename > CONFIG_AUTOFDO_CLANG to CONFIG_AUTOFDO, but that's out-of-scope for > this change, in my opinion. I get that it's an existing config name, but previously it is a correct description, while after this change it is no longer accurate. I don't know if there's an established practice on renaming CONFIG options = when this sort thing happens though. Perhaps one way is to have add CONFIG_AUTOFDO_CLANG that selects CONFIG_AUTOFDO. Best, Gary