Xcode 14 beta. Can not Not link _objc_msgSend

Question

Xcode 14 beta. Can not Not link _objc_msgSend

Closed this issue 2 years ago · 12 comments

I compiled my project with Xcode14 beta and found that the.a static library could not link to its own library symbols。

Example Like This：
Undefined symbols for architecture arm64:
"_objc_msgSend$setOffsetFromCenter:", referenced from:
+[SVProgressHUD setOffsetFromCenter:] in libSVProgressHUD.a(SVProgressHUD.o)
+[SVProgressHUD resetOffsetFromCenter] in libSVProgressHUD.a(SVProgressHUD.o)
"_objc_msgSend$unreachableBlock", referenced from:
-[Reachability reachabilityChanged:] in libReachability.a(Reachability.o)

SetOffsetFromCenter is a symbol in the SVProgressHUD library, but cannot be linked using ZLD。

Answer 1 · 2022-06-13T19:22:37.000Z

You can pass -fno-objc-msgsend-selector-stubs to your compiles to avoid this

Answer 2 · 2022-06-13T20:01:48.000Z

Perhaps I'll just make that the default for now

Answer 3 · 2022-06-13T20:02:52.000Z

You have to do that to clang for each object compile, not ld unfortunately

Answer 4 · 2022-06-13T20:05:35.000Z

Do you know if lld has a plan for fixing this?

Answer 5 · 2022-06-13T20:35:49.000Z

I started looking at it this morning, not sure how far i'll get

Answer 6 · 2022-08-05T13:37:09.000Z

👋, is there any progress regarding this issue? 👀

Answer 7 · 2022-08-05T15:55:48.000Z

Sorry to be clear I started working on this for LLD, tracked here llvm/llvm-project#56034, for zld to get this it would either require @michaeleisel to implement it entirely, or apple to update their open source dump of ld64 and zld rebase on it. I would suggest disabling it with -fno-objc-msgsend-selector-stubs in the meantime

Answer 8 · 2022-08-05T15:59:05.000Z

i may just turn that flag on by default

Answer 9 · 2022-08-05T15:59:24.000Z

oh wait, right, it's a clang flag, not an ld one

Answer 10 · 2022-09-05T11:03:37.000Z

I noticed that even if you put -fno-objc-msgsend-selector-stubs for all clang invocations, if -miphoneos-version-min=8.0 is presented in the linker command, the _objc_msgSend issue will happen too.

The linker passes after changing the flag to -miphoneos-version-min=10.0

Answer 11 · 2022-09-05T17:17:15.000Z

so, my plan is that i will not be fixing this bug. instead, i will detect when it occurs, and in the error message tell the user either to add the -fno-objc-msgsend-selector-stubs flag to their compilations, or else switch to lld. i am working with the lld people to make user-friendly lld install docs to send people to

Answer 12 · 2022-09-07T16:08:43.000Z

1.3.6 has a better error message for this, including a link to the new mach-o lld docs