Here's what's to be done for maintaining GNU Binutils.

As these tools primarily deal with low-level parts of the target architecture and the object file format (ELF ABI), which are essentially (at least meant to be) the same, there shouldn't be many differences comparing the binutils between the GNU/Hurd and GNU/Linux ports, for example. There are a few, though, as explained below.

General information
Sources
Configuration
Build
1. Analysis
Install
1. Analysis
Testsuite
1. Analysis

General information

Sources

Configuration

Last reviewed up to the Git mirror's 5c3ec1ded654250e0ac27df79998b32b2403e81f (2013-04-29) sources.

Globally
- a.out (such as ld/emulparams/i386linux.sh, ld/emultempl/linux.em, etc.), COFF, PE image support and 64-bit support are not interesting.
- In the testsuites, .exp and .d files very likely should not only care for *-*-linux*, but also *-*-gnu*. (If they need to be conditionalized like this at all.)
bfd/
- config.bfd
  - i[3-7]86-*-gnu*
    
    Comparing to i[3-7]86-*-linux-*:
    - i386linux_vec -- a.out.
    - i386pei_vec -- PE.
    - 64 bit.
- configure.host
  
  Souldn't need anything. x86 Linux neither.
- configure.in
  
  Linux:
  - COREFILE=trad-core.lo with TRAD_HEADER='"hosts/i386linux.h"'
    
    We don't have any such core file support configured. TODO: should we? Where is this core file reading exactly used? GDB?
  - i386linux_vec -- a.out.
  - i386pei_vec -- PE.
binutils/
- configure.tgt
gas/
- config/te-gnu.h
  
  C.f. te-linux.h; search tree for TE_LINUX vs. TE_GNU usage.
  - tc-i386.h
    
    Sole TE_LINUX usage is for a.out.
- configure.tgt
ld/
- configure.host
  - *-*-gnu*
    
    TODO: resolve crt0.o vs. crt1.o issue. Testsuite failures.
    - configure.tgt
    - i[3-7]86-*-gnu*
    Compare to i[3-7]86-*-linux-*, but don't need a.out (i386linux) and 64 bit support.
__ehdr_start symbol, c84ed8d89d0b8bf5a2968d465f77ac24bcfc40c2 -- can this be helpful in the exec server, glibc, or elsewhere? Used in GDB (BFD) commit bdbd9758806ed855af89244870fdc52cf3ff09bc.
Add HOSTING_SCRT0 for PIE test, 49cc20aa5c416ea4307931cccf6353247368187d -- is for GNU/Linux only; but also seems unused.

Build

Here's a log of a binutils build run; this is from our Git repository's tschwinge/Paul_Desmond branch, commit 5c3ec1ded654250e0ac27df79998b32b2403e81f (2013-04-29), run on kepler.SCHWINGE and coulomb.SCHWINGE.

$ export LC_ALL=C
$ ../Paul_Desmond/configure --prefix="$PWD".install --enable-gold --with-sysroot=/ SHELL=/bin/dash CC=gcc-4.7 CXX=g++-4.7 2>&1 | tee log_build
[...]
$ make 2>&1 | tee log_build_
[...]

Different hosts may default to different shells and compiler versions; thus harmonized. Debian GCC (which is used in binutils' testsuite) likes to pass --sysroot=/ to ld, so we need to configure binutils with support for sysroots.

This takes up around 950 MiB, and needs roughly 13 min on kepler.SCHWINGE and 45 min on coulomb.SCHWINGE.

Analysis

x86 GNU/Linux' and GNU/Hurd's configurations are slightly different, thus mask out most of the differences that are due to GNU/Linux supporting more core file formats, and more emulation vectors.

$ toolchain/logs/process binutils build

gold GNU/Linux vs. GNU/Hurd

-checking for glibc ifunc support... both
+checking for glibc ifunc support... dyn

Missing IFUNC support on GNU/Hurd.

944a6010b676b9f80f0a16c65183102b187822c5..a5e5fda5f96d5b881a354bd8666fdbb1496ee8da:

 gcc-4.6 -c -DHAVE_CONFIG_H -g -O2  -I. -I../../Paul_Desmond/libiberty/../include  -W -Wall -Wwrite-strings -Wc++-compat -Wstrict-prototypes -pedantic  ../../Paul_Desmond/libiberty/hashtab.c -o hashtab.o
+../../Paul_Desmond/libiberty/hashtab.c: In function 'hash_pointer':
+../../Paul_Desmond/libiberty/hashtab.c:1001:7: warning: right shift count >= width of type [enabled by default]

Install

$ make install 2>&1 | tee log_install
[...]

This takes up around 150 MiB, and needs roughly 1 min on kepler.SCHWINGE and 3 min on coulomb.SCHWINGE.

Analysis

$ toolchain/logs/process binutils install

libtool: finish: ldconfig is not run for the Hurd.

Testsuite

$ make -k check 2>&1 | tee log_test
[...]

This needs roughly 6 min on kepler.SCHWINGE and 45 min on coulomb.SCHWINGE.

Analysis

$ toolchain/logs/process binutils test

FAIL: static [...]

The testsuite isn't prepared for using crt0.o instead of crt1.o depending on whether a static or dynamic executable is created. Documented in ld/configure.host. Perhaps we should finally rewrite this messy code in glibc? Or, something similar to commit 49cc20aa5c416ea4307931cccf6353247368187d Add HOSTING_SCRT0 for PIE test can be used.

Same issue for FAIL: Common symbol override ifunc * ones?
FAIL: ld-elf/64ksec

On the idle grubber, this one takes a few minutes wall time to complete successfully (I/O system weakness), so assuming some system load variation, the testsuite's timeout may trigger.
FAIL: ELF weak [...]

I suppose this is due to us having an override w.r.t. weak symbol handling in glibc, needed for our external libpthread. TODO: document properly.
FAIL: gas/i386/rept

Added in commit 06f1247c54126b9f1e6acb8ff8c7be35aec6f44c (2012-06-07) as part of the fix for sourceware [BZ #14201], renamed in commit d654e24bbc2f601df4dc43b26049b0339528b93a (2012-06-07):
```
WARNING: program timed out.
FAIL: gas/i386/rept
```
ld IFUNC execution tests

Missing IFUNC support on GNU/Hurd.

Added in commit 82c5587db078581cfe94a4385ed99de1d1fa6657 (2012-09-19):
```
FAIL: Common symbol override ifunc test 1a
FAIL: Common symbol override ifunc test 1b
```

gold GNU/Linux vs. GNU/Hurd

-FAIL: relro_test.sh
+PASS: relro_test.sh


-PASS: ver_matching_test.sh
+FAIL: ver_matching_test.sh


-PASS: script_test_3
+FAIL: script_test_3


-PASS: tls_phdrs_script_test
+FAIL: tls_phdrs_script_test


-PASS: ifuncmain1static
-PASS: ifuncmain1picstatic
-PASS: ifuncmain2static
-PASS: ifuncmain2picstatic
-PASS: ifuncmain4static
-PASS: ifuncmain4picstatic
-PASS: ifuncmain5static
-PASS: ifuncmain5picstatic
-PASS: ifuncmain7static
-PASS: ifuncmain7picstatic