Fix HTML5 lib LTO build with PTHREADS (#20275) #20858
Conversation
|
I think this shouldn't be need, but currently is due a bug in the linker. Can you add a comment mentioning that this is workaround for what a bug in wasm-ld? And perhaps add "Fixes #20275" to the PR description? |
ifiddynine
changed the title
|
Totally forgot about this change, merged in latest + updated the title! Came across it again just now in 3.1.51 |
tools/system_libs.py
Outdated
| path='system/lib/html5', | ||
| filenames=['callback.c']) | ||
|
|
||
| return math_files + exit_files + other_files + iprintf_files + errno_files + html5_files |
There was a problem hiding this comment.
IIUC this move html5/callback.c from libhtml to libc.. or actually it seems maybe duplicates it in the two libraries?
|
Sorry for the delay, I revisited this just now - I believe this fix is the current correct way of doing it. |
| @@ -2038,7 +2038,7 @@ class libhtml5(Library): | |||
| cflags = ['-Oz', '-fno-inline-functions'] | |||
| src_dir = 'system/lib/html5' | |||
| src_glob = '*.c' | |||
|
|
|||
| force_object_files = True | |||
There was a problem hiding this comment.
Could you add a comment here with a link LTO bug so we know to remove it when its no longer needed?
There was a problem hiding this comment.
Would that be the same as the one below, or a new ticket?
There was a problem hiding this comment.
#20275 (can you also add it to the PR description)
|
This change should no longer be needed since llvm/llvm-project#101894 landed in llvm. Can you confirm this is no longer needed at your end? |
|
Yup! I merged latest into our fork over the weekend but ran into other LTO issues - I'll get back to it soon and let you know. I think this fixed worked, but something else was acting up. Will let you know if it's our fault or not when I have time! |
|
I think we can safely close this PR now |
This is workaround for a bug in wasm-ld.
We use WebGPU, pthread and PROXY_TO_PTHREAD and noticed a linker error in our release builds where we enable LTO:
wasm-ld: error: C:\Dev\emsdk\upstream\emscripten\cache\sysroot\lib\wasm32-emscripten\lto\libhtml5.a(callback.o): attempt to add bitcode file after LTO (_emscripten_run_callback_on_thread)
Judging by other tickets this seems like the place to fix it, but let me know if that's wrong.