Bug 202346 – [GTK] 2.26.1: webkitgtk is not LTO optimisation ready

• Status: RESOLVED
• Resolution: DUPLICATE
• Component: WebKitGTK

[Tomasz Kłoczko]

When webkitgtk is build with LTO optimisation linking fails

[Tomasz Kłoczko]

Created attachment 379787 [details]
linking fail

[Adrian Perez]

*** Bug 172356 has been marked as a duplicate of this bug. ***

[Adrian Perez]

Tomasz, I have successfully built WebKitGTK (and WPE) many times
with LTO enabled, with different combinations of compilers and
linkers (GCC, Clang, lld, Gold) and it has always worked fine.
LLVM's ThinLTO works as well.

I see that “-Wl,--no-undefined” is being passed to the linker,
and that is the most likely cause for the linker failure.

[Tomasz Kłoczko]

Despite fact that you've been able to build WebKitGTK (I have no problems with libwpe, wpebackend-fdo and LTO) looks like 2.26.1 *is* broken.

WebKitGTK compiles and links correctly when using LTO is disabled.

I'm not fiddling in linker options to add -Wl,--no-undefined.
I'm using now as linker options:

$ rpm -E %build_ldflags
-Wl,-z,relro -Wl,--as-needed  -Wl,-z,now -specs=/usr/lib/rpm/redhat/redhat-hardened-ld -flto -flto-partition=none -fuse-linker-plugin

If -Wl,--no-undefined is causing the issue it must be added by cmake.

Any suggestions?

[Tomasz Kłoczko]

Just tested 2.27.1 and looks like still it is not possible to build it as long as LTO optimisation is in use.

[Tomasz Kłoczko]

Issue still is not resolved in 2.28.2 :(

[Michael Catanzaro]

Should be fixed by 240354@main. Please try again and reopen if not.

*** This bug has been marked as a duplicate of bug 228865 ***