clang++ -flto fails to work unless -B /usr/lib/gold-ld is given

[Matthias Andree]

clang++ -flto does not seem to configure everything properly:

$ clang++ -stdlib=libc++ try.cpp -O3 -flto -Wall -Wextra
/tmp/try-1083b9.o: file not recognized: Dateiformat nicht erkannt
clang: error: linker command failed with exit code 1 (use -v to see invocation)

$ clang++ -stdlib=libc++ try.cpp -O3 -flto -Wall -Wextra -B/usr/lib/gold-ld
however, works properly.

See the attached files for output from the same commands with "-v" added on the respective command lines.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: clang-3.4 1:3.4-1ubuntu3
ProcVersionSignature: Ubuntu 3.13.0-35.62-generic 3.13.11.6
Uname: Linux 3.13.0-35-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.4
Architecture: amd64
CurrentDesktop: KDE
Date: Sat Sep 20 12:53:53 2014
SourcePackage: llvm-toolchain-3.4
UpgradeStatus: Upgraded to trusty on 2014-08-29 (21 days ago)

[Matthias Andree (matthias-andree)]

The only difference that -B makes is running /usr/lib/gold-ld/ld instead of /usr/bin/ld

[Matthias Andree (matthias-andree)]

More importantly, -fuse-ld=gold per apt-get changelog binutils, here, does NOT work:

binutils (2.23.52.20130722-1) unstable; urgency=low

  * New upstream snapshot.
    - Fix PR ld/15762, glibc being built without warning sections.
  * Set the libdir for arm64 to lib, not lib64.
  * Stop building the binutils-gold package, let binutils provide
    binutils-gold. Packages requiring gold should explicity pass
    -fuse-ld=gold to the compiler, packages requiring the bfd linker
    should pass -fuse-ld=bfd to the compiler.
  * Refresh patches.

 -- Matthias Klose <email address hidden> Mon, 22 Jul 2013 21:13:32 +0200

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.