Re: GCC testing on FreeBSD

[Gerald Pfeifer <gerald@pfeifer.com>]

Hi Jonathan,

On Fri, 26 Apr 2024, Jonathan Wakely wrote:
> How are you testing on FreeBSD?
> 
> When I build GCC trunk on FreeBSD 14.0 and try to run the libstdc++
> testsuite it fails due to lots of these errors:
> 
> Excess errors:
> /usr/local/bin/ld: /tmp//ccev946q.o: relocation R_X86_64_32 against
> symbol `_ZTIN10__cxxabiv115__forced_unwindE@@CXXABI_1.3.2' can not be
> used when making a PDE object; recompile with -fPIE
> /usr/local/bin/ld: failed to set dynamic section sizes: bad value

my first reaction was to recommend using binutils instead of /usr/bin/ld 
which is LLD 16.0.6 or similar (since a while ago FreeBSD switched to that
toolchain as part of the base system).

My nightly tester has been using GNU ld since

  # 2012-03-11  Configure using --with-as=$localbase/bin/as and
  #             --with-ld=$localbase/bin/ld on *.freebsd.org.

in the script invoked by cron, even before FreeBSD made that switch.

Seeing /usr/local/bin/ld in the error message it appears you are doing 
that already, though?

> Which suggests that -fPIE is missing from the default test flags.
> 
> Have you seen this? Do you do something locally to work around it?

All I have in terms of adjustments to the FreeBSD systems I build on via 
that script are the following

  CONFIGUREFLAGS="--with-gmp=$LOCALBASE --with-as=$LOCALBASE/bin/as $CONFIGUREFLAGS"
  LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$LOCALBASE/lib
  PATH=$LOCALBASE/bin:$PATH

where LOCALBASE looks like it would be /usr/local in your case. Nothing 
explicit around PIE there.

Looking at the logs of a serialized build I triggered manually where I 
remove the --with-ld configure option, I see 

  checking linker PIE support with copy reloc... no
  checking for -fno-PIE option... yes
  checking for -no-pie option... yes

and then build invocations like

  c++ -std=c++11  -fno-PIE -c ...

during all-stage1-target-libgcc which ultimately fails with - mystery?! -

  ld: error: unable to find library -lc
  collect2: error: ld returned 1 exit status
  gmake[3]: *** [Makefile:1005: libgcc_s.so] Error 1

(Disclaimer: all my tests on FreeBSD 13.2, not FreeBSD 14 as in your 
case.)


Looking at the lang/gcc* ports that I maintained for two decades until 
Lorenzo (copied now) kindly took them over two years ago I see the 
following change among others for newer versions:

  % git show b6a5871a0cf40
  commit b6a5871a0cf40dfc194217704e2dc03e2e91fb62
  Author: Lorenzo Salvadore <salvadore@FreeBSD.org>
  Date:   Fri Feb 3 20:12:49 2023 +0100

    lang/gcc10: Mark PIE_UNSAFE
    
    Building the port with WITH_PIE fails if the BOOTSTRAP option is
    enabled. Mark PIE_UNSAFE when this option is enabled until a better
    solution is found.
    
    PR:             268901

where https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=268901 is the PR 
referenced.

PIE_UNSAFE=yes in a port's Makefile (the equivalent to a spec file in RPM 
land) is used as follows in ports/Mk/Features/pie.mk:

  .  if !defined(PIE_UNSAFE)
  PIE_CFLAGS?=    -fPIE -fPIC
  CFLAGS+=        ${PIE_CFLAGS}
  CXXFLAGS+=      ${PIE_CFLAGS}
  LDFLAGS+=       -pie
  STATIC_PIE_ARGS+=       -static-pie
  .  endif


You are not using the Ports Infrastructure, I believe, so the above does 
not directly apply, may provide some additional background, though?


Hope this helps - and please chime in Lorenzo and Andreas!

Gerald