[CMake][NewPM] Move ENABLE_EXPERIMENTAL_NEW_PASS_MANAGER into llvm/

[aeubanks]

Summary

This allows us to use its value everywhere, rather than just clang. Some
other places, like opt and lld, will use its value soon.

The #define for it is now in llvm-config.h.

[hans]

Seems like a good idea to me.

From the change description:

This allows us to use its value everywhere, rather than just llvm.

Do you mean rather than just clang?

[rnk]

llvm/include/llvm/Config/llvm-config.h.cmake

92

This is unrelated, but appears to be in the wrong header, it should be in config.h. It isn't namespaced, and could conflict with another project's config header.

95

This should be namespaced in LLVM_*.

Can we drop "experimental" now to shorten it? LLVM_ENABLE_NEW_PASS_MANAGER?

[aeubanks]

In D92072#2425025, @hans wrote:

Seems like a good idea to me.

From the change description:

This allows us to use its value everywhere, rather than just llvm.

Do you mean rather than just clang?

Whoops, yup.

llvm/include/llvm/Config/llvm-config.h.cmake

95

That would mean changing the CMake variable name which would break everybody using the flag. I can add a #define alias if you want.

[rnk]

llvm/include/llvm/Config/llvm-config.h.cmake

95

You can leave the cmake option as it is, and make a new variable with the right name before the call to configure_file:

set(LLVM_ENABLE_NEW_PASS_MANAGER ENABLE_EXPERIMENTAL_NEW_PASS_MANAGER)

[aeubanks]

rename to LLVM_ENABLE_NEW_PASS_MANAGER

[rnk]

lgtm

[nikic]

It looks like this change has also enabled the new pass manager by default.

[aeubanks]

In D92072#2426511, @nikic wrote:

It looks like this change has also enabled the new pass manager by default.

Whoops, I'll revert and see what went wrong.

[aeubanks]

set LLVM_ENABLE_NEW_PASS_MANAGER to the value of ENABLE_EXPERIMENTAL_NEW_PASS_MANAGER, not the string itself