Thanks Duncan.

Adding code owners and more relevant folks

LGTM

Looks like this patch causes a number of issues for us, I will work with @jansvoboda11 to see if there's some way to resolve them.

LGTM! @ChuanqiXu wdyt?

Apply last round of reviews before landing

Add release notes entry.

Address last round of review

Put dependency in place for D145641

LGTM!

... I think in general we want feature testing macros to be treated as our signal to the user that we think something is complete, not that we think something is in progress but pretty usable.

@bruno, @ChuanqiXu please let us know if you have any objections, otherwise we will land the revert in ~2 hours.

Update after reviewer comments

Good catch, thanks! LGTM

Test failures are unrelated, thanks for the review @ChuanqiXu

Thanks for working on this Wei!

Only test failing is ClangScanDeps/modules-full.cpp on Windoes, which is unrelated to this change.

Update checks that rely on coroutine_traits in std-coroutine.h

Thanks for the review, will push once all tests pass!

Update patch to reuse std-coroutine.h and add a few more other bits there.

Test failure is unrelated.

Nice new testcase snippets, LGTM

Additionally, this likely deserves an entry in ./clang/docs/ReleaseNotes.rst.

Nice, thanks for adding the builtin layer.

Also not using this at Meta, LGTM.

Very nice how this has improved since the version I worked on in the past, thanks!

LGTM

LGTM with minor nitpick: can you reflect in the title that this is related to header maps?

Nice cleanup, before landing please capitalize remove in the title and also add [NFC] to it!

Nice catch, thanks for improving this.

Looks great, some minor suggestions.

Thanks for the detailed explanations, LGTM!

Great to see both this and D130325 landing, LGTM too.

Thanks for working on this Troy, nice speed up.

LGTM! Should we also add a release note or do we think this isn't enough of a compile-time performance improvement to warrant that?

LGTM

Hi Troy, thanks for working on this, nice compile time perf savings. Can you update the diff to contain more context? If anything, -U 999999 or similar would do the job.

I'm not sure how to deal with missing env -u.

• We could do env CLANG_MODULE_CACHE_PATH= and change the compiler's interpretation of empty string for this variable. I'm not sure if the current behaviour (there will be no module cache in the cc1 at all) is intentional or useful. Hesitant to change this behaviour.

Awesome!

Thanks for the fast review! Good suggestions, will apply and land.

LGTM

Empty lines handling should also make it skipped, fix the 3 failures.

LGTM, thanks for the detailed explanation/comments. One minor nitpick inline.

Just noticed that 3 test cases failed. Please fix them before landing.

Hi, nice to see this getting in. Comments inline!

Nice!

Forgot to ask, is there anything preventing a testcase to be added here?

LGTM

This is pretty cool, I enjoy the idea of getting a tar out of a crash. I'm also a +1 for having this group of behaviors as a more official -femit-reproducer=<option> flag. In future work, do you plan to change the default crash mode to output a tar instead of multiple files?

Why isn't D23934 sufficient? What do these flags with very long names do that ffixed-date-time doesn't?

It would be nice to have some mechanism to notify developers that includes are still performed regardless of requires

LGTM

Nice cleanup, fixes and testcases, just pending test failures and this looks good.

LGTM

LGTM

Could the test be tagged with keywords that would prevent the linting to kick in? The amount of changes for this and following patches seems too big to be worth the reformatting.

The right solution to the paren problem is to add some notion of precedence (and associativity) to Nodes, but that's a larger change that would become simpler once the refactoring I'm doing is completed.

LGTM

LGTM!

Given context from further patches in the set, I believe ptrauth operand bundle has been a good way to represent this and works well. LGTM

This is good to go, sorry for the delay.

LGTM