#6063: GHC's build-time ld-flag checks are problematic --------------------------------------+------------------------------------- Reporter: parcs | Owner: thoughtpolice Type: bug | Status: new Priority: high | Milestone: 7.8.1 Component: Compiler | Version: 7.4.1 Resolution: | Keywords: Os: Linux | Architecture: Unknown/Multiple Failure: GHC doesn't work at all | Difficulty: Unknown Testcase: | Blockedby: Blocking: | Related: #4862 --------------------------------------+------------------------------------- Comment(by aseipp@…): commit 71a194d8ca2efd075a5c000be0b378c8706ca0b3 {{{ Author: Austin Seipp <aseipp@pobox.com> Date: Sat May 4 16:07:22 2013 -0500 Detect linker information at runtime. Fixes Trac #6063 Previously, we did ./configure time checks to see if 'GNU ld' supported certain options. If it does, we bake those options into the link step. See Trac #5240. Unfortunately, the linker we use at runtime can change for several reasons. One is that the user specifies -pgml 'foo'. The other is if /usr/bin/ld or whatnot changes from when GHC was built. Those options mentioned earlier are specific to GNU ld, but many systems support GNU gold too. This is Trac #6063. So we need to check at runtime what linker we're using. This is actually a little bit complicated because we normally use the C compiler as our linker. Windows and OS X are also special here. Finally, this patch also unconditionally gives '--hash-size=31' and '--reduce-memory-overheads' to the system linker if it's GNU ld. These options have been supported for 8+ years from what I can see, and there are probably a lot of other reasons why GHC would not work with such an ancient binutils, all things considered. See Note [Run-time linker info] in SysTools for details. There are plenty of comments as well in the surrounding code. Signed-off-by: Austin Seipp <aseipp@pobox.com> aclocal.m4 | 33 ------------ compiler/main/DynFlags.hs | 26 +++++++++- compiler/main/SysTools.lhs | 117 ++++++++++++++++++++++++++++++++++++++++++- configure.ac | 2 - distrib/configure.ac.in | 2 - 5 files changed, 137 insertions(+), 43 deletions(-) }}} -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/6063#comment:19> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler