4

I'm wondering if someone knows why gcc tends to be so conservative about the versions of the libraries to use to compile and build gcc itself .

The main reasons why I'm asking this are :

  1. I think that there is a big shift between the "implicitly suggested" versions listed here ( they also appear named in some scripts inside the gcc sources ) and the latest milestones available
  2. I think that at some point being that conservative can only increase the chances of carrying bugged and sub-optimal versions of the given library

latest releases available at the moment vs the "implicitly suggested" ones :

      latest     considered by gcc
MPFR  3.1.2      2.4.2
GMP   6.0.0a     4.3.2
MPC   1.0.2      0.8.1

This is just for the vital ones, there are also others like cloog and isl, but here you can see a big difference, those releases are just old .

Does anyone happens to know about some good reasons to do that ? Breaking changes in this 3 libraries ? Stability ? Portability ?

user2485710
  • 9,451
  • 13
  • 58
  • 102
  • 2
    Never judge a compiler you didn't write. If it doesn't suit you, write your own. – Igor Pejic Oct 04 '14 at 17:25
  • 1
    @Igor I'm not judging anything, I'm also more then interested in getting this right and get the most out of gcc, quite the opposite of being judgemental just to make an argument on the internet . – user2485710 Oct 04 '14 at 17:26
  • I was just kidding. Your question is more than correct +1. – Igor Pejic Oct 04 '14 at 17:29
  • The latest versions do work just fine. You guessed the reasons: those older versions have been tested for years and no significant defect affecting gcc has been found, and newer releases of those dependencies have dropped support for some horrible platforms that gcc is still trying to support. – Marc Glisse Oct 04 '14 at 17:40
  • @MarcGlisse can you give some names for those platforms ? – user2485710 Oct 04 '14 at 17:43
  • Please have a look at this conversation: https://gcc.gnu.org/ml/gcc-patches/2014-04/msg01512.html and other conversations at the same period on the gmp lists and in gcc's bugzilla. I don't have time to go through them right now, but they should contain your answer and you can post your findings here (I would gladly +1 that). – Marc Glisse Oct 04 '14 at 20:11
  • Went through that conversation and found "GMP 5.x is problematic on SPARC, don't know about 6.x", as well as some mention of problems on Solaris. – semi-extrinsic May 18 '15 at 08:17

1 Answers1

2

The answer is in GCC PR/60933 Comment 2 by Jonathan Wakely:

We've had situations in the past where the minimum suggested versions work and the latest versions prevented GCC from building. The suggested versions are known to work and have been thoroughly tested, which might not be true of the latest versions.

vinc17
  • 2,829
  • 17
  • 23