Update autoconf test for gcc to require 4.7 and up
authorPeter Trommler <ptrommler@acm.org>
Mon, 6 Nov 2017 20:35:30 +0000 (15:35 -0500)
committerBen Gamari <ben@smart-cactus.org>
Mon, 6 Nov 2017 21:39:20 +0000 (16:39 -0500)
commit59de290928e6903337f31c1f8107ac8a98ea145d
tree7c8cd1ebd75bd1bb0f11b0ac24965f82cc4d74f8
parent8613e61de62178e76cd0f8915bd1fbe9c200a039
Update autoconf test for gcc to require 4.7 and up

Fixing #14244 required the newer gcc atomic built-ins that are provided
from 4.7 and up. This updates the test to check for minimum gcc version
4.7.

The version tests for 3.4 (!), 4.4, and 4.6 are no longer needed and can
be removed. This makes the build system simpler.

Test Plan: validate

Reviewers: austin, bgamari, hvr, simonmar

Reviewed By: bgamari

Subscribers: rwbarton, thomie, erikd

Differential Revision: https://phabricator.haskell.org/D4165
aclocal.m4
mk/config.mk.in
mk/warnings.mk
rts/ghc.mk