From c240556a24f6e358992a0c7169592c2ccc3c4e60 Mon Sep 17 00:00:00 2001
From: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
Date: Fri, 12 Jun 2015 10:33:59 +0300
Subject: [PATCH] gmp: Fix build on ARM
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The config.guess script tries to detect various ARM optimization flags
via /proc/cpuinfo. This is not only impure, but the detection is also
broken on multicore machines; on my quad-core system the machine type is
autodetected as 'neon neon neon neon-unknown-linux-gnueabihf':

checking build system type... Invalid configuration `neon': machine `neon' not recognized
configure: error: /nix/store/bafimhdj1yaxj6m1hvq7wvhwwizc939x-bootstrap-tools/bin/sh ./config.sub neon
neon
neon
neon-unknown-linux-gnueabihf failed
builder for ‘/nix/store/1npm2358bpvclj5w7fqjjwg72vbb0d79-gmp-6.0.0a.drv’ failed with exit code 1

Override the system type with the output of GNU config.guess to avoid
the autodetection.
---
 pkgs/development/libraries/gmp/5.1.x.nix | 9 ++++++++-
 pkgs/development/libraries/gmp/6.x.nix   | 9 ++++++++-
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/pkgs/development/libraries/gmp/5.1.x.nix b/pkgs/development/libraries/gmp/5.1.x.nix
index 0df1a4f8cd83..7b393067ff52 100644
--- a/pkgs/development/libraries/gmp/5.1.x.nix
+++ b/pkgs/development/libraries/gmp/5.1.x.nix
@@ -1,6 +1,6 @@
 { stdenv, fetchurl, m4, cxx ? true, withStatic ? true }:
 
-with { inherit (stdenv.lib) optional; };
+with { inherit (stdenv.lib) optional optionalString; };
 
 stdenv.mkDerivation rec {
   name = "gmp-5.1.3";
@@ -28,6 +28,13 @@ stdenv.mkDerivation rec {
     ++ optional stdenv.is64bit "--with-pic"
     ;
 
+  # The config.guess in GMP tries to runtime-detect various
+  # ARM optimization flags via /proc/cpuinfo (and is also
+  # broken on multicore CPUs). Avoid this impurity.
+  preConfigure = optionalString stdenv.isArm ''
+      configureFlagsArray+=("--build=$(./configfsf.guess)")
+    '';
+
   doCheck = true;
 
   dontDisableStatic = withStatic;
diff --git a/pkgs/development/libraries/gmp/6.x.nix b/pkgs/development/libraries/gmp/6.x.nix
index b7350c19960a..171611e12498 100644
--- a/pkgs/development/libraries/gmp/6.x.nix
+++ b/pkgs/development/libraries/gmp/6.x.nix
@@ -1,6 +1,6 @@
 { stdenv, fetchurl, m4, cxx ? true, withStatic ? true }:
 
-with { inherit (stdenv.lib) optional; };
+with { inherit (stdenv.lib) optional optionalString; };
 
 stdenv.mkDerivation rec {
   name = "gmp-6.0.0a";
@@ -26,6 +26,13 @@ stdenv.mkDerivation rec {
     ++ optional stdenv.is64bit "--with-pic"
     ;
 
+  # The config.guess in GMP tries to runtime-detect various
+  # ARM optimization flags via /proc/cpuinfo (and is also
+  # broken on multicore CPUs). Avoid this impurity.
+  preConfigure = optionalString stdenv.isArm ''
+      configureFlagsArray+=("--build=$(./configfsf.guess)")
+    '';
+
   doCheck = true;
 
   dontDisableStatic = withStatic;