From 48ac8018ca0ed7ae9e5bc26c54357cdcb9c87799 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Fri, 27 Jun 2008 18:26:19 +0000
Subject: [PATCH] Improved support for building 32-bit binaries on
 x86_64-linux.

* glibc_multi: a wrapper that combines the 32-bit and 64-bit Glibcs.
  This is necessary so that 64-bit GCC can find gnu/stubs-32.h and the
  32-bit Glibc libraries.

  To build glibc_multi on x86_64-linux, you still need either the
  i686-linux Glibc derivation from a channel, or to have configured
  Nix with support for forwarding the build to a i686-linux machine.
  In the future this may become unnecessary by providing a prebuilt
  binary of 32-bit Glibc somewhere (like the binaries used in the
  stdenvLinux bootstrap).

* With glibc_multi, it becomes possible to build gcc with multilib
  support (i.e. it builds 32-bit and 64-bit versions of libgcc,
  libstdc++, etc.).

svn path=/nixpkgs/trunk/; revision=12203
---
 .../development/compilers/gcc-4.3/default.nix |  6 ++--
 pkgs/top-level/all-packages.nix               | 36 ++++++++++++++++---
 2 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/pkgs/development/compilers/gcc-4.3/default.nix b/pkgs/development/compilers/gcc-4.3/default.nix
index 003433cf65e5..09d7ff7a807d 100644
--- a/pkgs/development/compilers/gcc-4.3/default.nix
+++ b/pkgs/development/compilers/gcc-4.3/default.nix
@@ -5,6 +5,7 @@
 , texinfo ? null
 , gmp, mpfr
 , bison ? null, flex ? null
+, enableMultilib ? false
 }:
 
 assert langC;
@@ -43,6 +44,7 @@ stdenv.mkDerivation {
     ++ optionals langTreelang [bison flex];
 
   configureFlags = "
+    ${if enableMultilib then "" else "--disable-multilib"}
     --disable-libstdcxx-pch
     --with-system-zlib
     --enable-languages=${
@@ -60,8 +62,8 @@ stdenv.mkDerivation {
   NIX_EXTRA_LDFLAGS = if staticCompiler then "-static" else "";
 
   inherit gmp mpfr;
-
-  passthru = { inherit langC langCC langFortran langTreelang; };
+  
+  passthru = { inherit langC langCC langFortran langTreelang enableMultilib; };
 
   meta = {
     homepage = "http://gcc.gnu.org/";
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index daabd8c91a69..574e385d331e 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -1333,10 +1333,16 @@ let pkgs = rec {
     profiledCompiler = true;
   }));
 
-  gcc43 = lowPrio (wrapGCCWith (import ../build-support/gcc-wrapper-new) (import ../development/compilers/gcc-4.3 {
+  gcc43 = lowPrio (wrapGCCWith (import ../build-support/gcc-wrapper-new) glibc (import ../development/compilers/gcc-4.3 {
     inherit fetchurl stdenv texinfo gmp mpfr noSysDirs;
     profiledCompiler = false;
-    #langFortran = true;
+  }));
+
+  gcc43multi = lowPrio (wrapGCCWith (import ../build-support/gcc-wrapper-new) glibc_multi (import ../development/compilers/gcc-4.3 {
+    stdenv = overrideGCC stdenv (wrapGCCWith (import ../build-support/gcc-wrapper) glibc_multi gcc42);
+    inherit fetchurl texinfo gmp mpfr noSysDirs;
+    profiledCompiler = false;
+    enableMultilib = true;
   }));
 
   gccApple = wrapGCC (import ../development/compilers/gcc-apple {
@@ -1748,7 +1754,7 @@ let pkgs = rec {
     inherit fetchurl stdenv visualcpp windowssdk;
   };
 
-  wrapGCCWith = gccWrapper: baseGCC: gccWrapper {
+  wrapGCCWith = gccWrapper: glibc: baseGCC: gccWrapper {
     nativeTools = stdenv ? gcc && stdenv.gcc.nativeTools;
     nativeLibc = stdenv ? gcc && stdenv.gcc.nativeLibc;
     nativePrefix = if stdenv ? gcc then stdenv.gcc.nativePrefix else "";
@@ -1757,7 +1763,7 @@ let pkgs = rec {
     inherit stdenv binutils;
   };
 
-  wrapGCC = wrapGCCWith (import ../build-support/gcc-wrapper);
+  wrapGCC = wrapGCCWith (import ../build-support/gcc-wrapper) glibc;
 
   # FIXME: This is a specific hack for GCC-UPC.  Eventually, we may
   # want to merge `gcc-upc-wrapper' and `gcc-wrapper'.
@@ -2591,6 +2597,28 @@ let pkgs = rec {
       #installLocales = false;
     });
 
+  glibc_multi =
+    assert system == "x86_64-linux";
+    runCommand "${glibc.name}-multi"
+      { glibc64 = glibc;
+        glibc32 = (import ./all-packages.nix {system = "i686-linux";}).glibc;
+      }
+      ''
+        ensureDir $out
+        ln -s $glibc64/* $out/
+        
+        rm $out/lib $out/lib64
+        ensureDir $out/lib
+        ln -s $glibc64/lib/* $out/lib
+        ln -s $glibc32/lib $out/lib/32
+        ln -s lib $out/lib64
+
+        rm $out/include
+        cp -rs $glibc32/include $out
+        chmod -R u+w $out/include
+        cp -rsf $glibc64/include $out
+      ''; # */
+
   gmime = import ../development/libraries/gmime {
     inherit fetchurl stdenv pkgconfig zlib;
     inherit (gtkLibs) glib;