Bug 200987 – [GTK][WPE] Gtk-Doc fails with build options which need cooperation between CFLAGS and LDFLAGS

• Status: RESOLVED
• Resolution: FIXED
• Component: Tools / Tests

[Adrian Perez]

This can be reproduced with a recent enough version of Clang with
support for ThinLTO, which *requires* passing -fuse-ld=lld to the
linker, and -flto=thin to *both* the compiler and the linker.
Failing to pass the linker options results in lld not being used
and the GNU Binutils linkers don't understand LLVM bitcode, or
in lld being used (if it's the default) but -flto=thin will be
missing from the linker command line (not good either).

This has gone unnoticed even when some distributions use LTO becase
it just *happens* to work with the Binutils linkers: linking object
built with -flto wors even if the flag is not passed to the linker.

[Adrian Perez]

This can be reproduced by trying to build with the following
CMake incantation:

  CC=clang CXX=clang \
  LDFLAGS='-fuse-ld=lld -flto=thin'
  CFLAGS='-flto=thin' CXXFLAGS='-flto=thin'
  cmake -DPORT=GTK -DENABLE_GTKDOC=ON <…>

[Adrian Perez]

Created attachment 376897 [details]
Patch

[Philippe Normand]

Comment on attachment 376897 [details]
Patch

Looks legit :)

[WebKit Commit Bot]

Comment on attachment 376897 [details]
Patch

Clearing flags on attachment: 376897

Committed r248954: <https://trac.webkit.org/changeset/248954>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Radar WebKit Bug Importer]

<rdar://problem/54565709>