Help: GOLD unable to find logf() in libm.so when sysroot is enabled

[Nick Clifton <nickc at redhat dot com>]

Hi Ian, Hi Cary,

  Do you have a minute to help me with a Fedora binutils bug which I
  think might be a generic GOLD problem ?

    https://bugzilla.redhat.com/show_bug.cgi?id=1386126

  The problem appears to be that an ARM native GOLD linker built with
  --with-sysroot=/ enabled reports that it cannot resolve a reference to
  the logf symbol (in libm.so), despite the fact that it has found the
  library:

  SYSROOT GOLD
/usr/lib/ghc-7.10.3/text_HmqVQnZSpjaC156ABqPhne/libHStext-1.2.2.1-HmqVQnZSpjaC156ABqPhne-ghc7.10.3.so: reference to logf
/usr/lib/ghc-7.10.3/base_HQfYBxpPvuw8OunzQu6JGM/libHSbase-4.8.2.0-HQfYBxpPvuw8OunzQu6JGM-ghc7.10.3.so: reference to logf
/usr/lib/ghc-7.10.3/ghcpr_8TmvWUcS1U1IKHT0levwg3/libHSghc-prim-0.4.0.0-8TmvWUcS1U1IKHT0levwg3-ghc7.10.3.so: reference to logf
/usr/lib/gcc/armv7hl-redhat-linux-gnueabi/6.2.1/../../../libm.so: definition of logf
/usr/lib/ghc-7.10.3/text_HmqVQnZSpjaC156ABqPhne/libHStext-1.2.2.1-HmqVQnZSpjaC156ABqPhne-ghc7.10.3.so: error: undefined reference to 'logf'

  NON-SYSROOT GOLD
/usr/lib/ghc-7.10.3/text_HmqVQnZSpjaC156ABqPhne/libHStext-1.2.2.1-HmqVQnZSpjaC156ABqPhne-ghc7.10.3.so: reference to logf
/usr/lib/ghc-7.10.3/base_HQfYBxpPvuw8OunzQu6JGM/libHSbase-4.8.2.0-HQfYBxpPvuw8OunzQu6JGM-ghc7.10.3.so: reference to logf
/usr/lib/ghc-7.10.3/ghcpr_8TmvWUcS1U1IKHT0levwg3/libHSghc-prim-0.4.0.0-8TmvWUcS1U1IKHT0levwg3-ghc7.10.3.so: reference to logf
/usr/lib/gcc/armv7hl-redhat-linux-gnueabi/6.2.1/../../../libm.so: definition of logf

  Apparently this problem is restricted to the ARM and AARCH64 targets,
  although I have not verified this.  It may be a factor of the build
  systems involved, in that the build for non-arm targets might use a
  different location for the application libraries.  That is just a
  guess however.

  Also I do not know if the logf symbol is special, or it just happens
  that this is the only symbol in libm.so that is needed by the
  libHStext-1.2.2.1-HmqVQnZSpjaC156ABqPhne-ghc7.10.3.so library.  I
  suspect the latter however.
  
  I have found that if I add a second reference to logf in an ordinary
  object file that the link then works.

  I am currently using the 2.27 gold sources to reproduce this problem.
  I am about to start a test using the mainline sources, but it takes a
  day to spin up a new linker and as far as I can see there have no
  changes to sysroot handling since 2.27 anyway, so I doubt it this will
  resolve the issue.

  Do you have any suggestions or insights ?

  Thanks.

Cheers
  Nick