gcc: fix building darwin->linux cross compiler

This reverts d9feea5 with some slight modifications to work with
other changes since then.

Fixes #88213.

pkgs/development/compilers/gcc/4.8/default.nix

@@ -10,7 +10,7 @@
 , enableLTO ? true
 , texinfo ? null
 , perl ? null # optional, for texi2pod (then pod2man); required for Java
-, gmp, mpfr, libmpc, gettext, which
+, gmp, mpfr, libmpc, gettext, which, patchelf
 , libelf                      # optional, for link-time optimizations (LTO)
 , cloog ? null, isl ? null # optional, for the Graphite optimization framework.
 , zlib ? null, boehmgc ? null
@@ -159,11 +159,14 @@ stdenv.mkDerivation ({
 
   # For building runtime libs
   depsBuildTarget =
-    if hostPlatform == buildPlatform then [
-      targetPackages.stdenv.cc.bintools # newly-built gcc will be used
-    ] else assert targetPlatform == hostPlatform; [ # build != host == target
-      stdenv.cc
-    ];
+    (
+      if hostPlatform == buildPlatform then [
+        targetPackages.stdenv.cc.bintools # newly-built gcc will be used
+      ] else assert targetPlatform == hostPlatform; [ # build != host == target
+        stdenv.cc
+      ]
+    )
+    ++ optional targetPlatform.isLinux patchelf;
 
   buildInputs = [
     gmp mpfr libmpc libelf

pkgs/development/compilers/gcc/4.9/default.nix

@@ -10,7 +10,7 @@
 , enableLTO ? true
 , texinfo ? null
 , perl ? null # optional, for texi2pod (then pod2man); required for Java
-, gmp, mpfr, libmpc, gettext, which
+, gmp, mpfr, libmpc, gettext, which, patchelf
 , libelf                      # optional, for link-time optimizations (LTO)
 , cloog ? null, isl ? null # optional, for the Graphite optimization framework.
 , zlib ? null, boehmgc ? null
@@ -171,11 +171,14 @@ stdenv.mkDerivation ({
 
   # For building runtime libs
   depsBuildTarget =
-    if hostPlatform == buildPlatform then [
-      targetPackages.stdenv.cc.bintools # newly-built gcc will be used
-    ] else assert targetPlatform == hostPlatform; [ # build != host == target
-      stdenv.cc
-    ];
+    (
+      if hostPlatform == buildPlatform then [
+        targetPackages.stdenv.cc.bintools # newly-built gcc will be used
+      ] else assert targetPlatform == hostPlatform; [ # build != host == target
+        stdenv.cc
+      ]
+    )
+    ++ optional targetPlatform.isLinux patchelf;
 
   buildInputs = [
     gmp mpfr libmpc libelf

pkgs/development/compilers/gcc/6/default.nix

@@ -11,7 +11,7 @@
 , texinfo ? null
 , flex
 , perl ? null # optional, for texi2pod (then pod2man); required for Java
-, gmp, mpfr, libmpc, gettext, which
+, gmp, mpfr, libmpc, gettext, which, patchelf
 , libelf                      # optional, for link-time optimizations (LTO)
 , isl ? null # optional, for the Graphite optimization framework.
 , zlib ? null, boehmgc ? null
@@ -184,11 +184,14 @@ stdenv.mkDerivation ({
 
   # For building runtime libs
   depsBuildTarget =
-    if hostPlatform == buildPlatform then [
-      targetPackages.stdenv.cc.bintools # newly-built gcc will be used
-    ] else assert targetPlatform == hostPlatform; [ # build != host == target
-      stdenv.cc
-    ];
+    (
+      if hostPlatform == buildPlatform then [
+        targetPackages.stdenv.cc.bintools # newly-built gcc will be used
+      ] else assert targetPlatform == hostPlatform; [ # build != host == target
+        stdenv.cc
+      ]
+    )
+    ++ optional targetPlatform.isLinux patchelf;
 
   buildInputs = [
     gmp mpfr libmpc libelf

pkgs/development/compilers/gcc/7/default.nix

@@ -9,7 +9,7 @@
 , enableLTO ? true
 , texinfo ? null
 , perl ? null # optional, for texi2pod (then pod2man)
-, gmp, mpfr, libmpc, gettext, which
+, gmp, mpfr, libmpc, gettext, which, patchelf
 , libelf                      # optional, for link-time optimizations (LTO)
 , isl ? null # optional, for the Graphite optimization framework.
 , zlib ? null
@@ -155,11 +155,14 @@ stdenv.mkDerivation ({
 
   # For building runtime libs
   depsBuildTarget =
-    if hostPlatform == buildPlatform then [
-      targetPackages.stdenv.cc.bintools # newly-built gcc will be used
-    ] else assert targetPlatform == hostPlatform; [ # build != host == target
-      stdenv.cc
-    ];
+    (
+      if hostPlatform == buildPlatform then [
+        targetPackages.stdenv.cc.bintools # newly-built gcc will be used
+      ] else assert targetPlatform == hostPlatform; [ # build != host == target
+        stdenv.cc
+      ]
+    )
+    ++ optional targetPlatform.isLinux patchelf;
 
   buildInputs = [
     gmp mpfr libmpc libelf

pkgs/development/compilers/gcc/8/default.nix

@@ -9,7 +9,7 @@
 , enableLTO ? true
 , texinfo ? null
 , perl ? null # optional, for texi2pod (then pod2man)
-, gmp, mpfr, libmpc, gettext, which
+, gmp, mpfr, libmpc, gettext, which, patchelf
 , libelf                      # optional, for link-time optimizations (LTO)
 , isl ? null # optional, for the Graphite optimization framework.
 , zlib ? null
@@ -147,11 +147,14 @@ stdenv.mkDerivation ({
 
   # For building runtime libs
   depsBuildTarget =
-    if hostPlatform == buildPlatform then [
-      targetPackages.stdenv.cc.bintools # newly-built gcc will be used
-    ] else assert targetPlatform == hostPlatform; [ # build != host == target
-      stdenv.cc
-    ];
+    (
+      if hostPlatform == buildPlatform then [
+        targetPackages.stdenv.cc.bintools # newly-built gcc will be used
+      ] else assert targetPlatform == hostPlatform; [ # build != host == target
+        stdenv.cc
+      ]
+    )
+    ++ optional targetPlatform.isLinux patchelf;
 
   buildInputs = [
     gmp mpfr libmpc libelf

pkgs/development/compilers/gcc/9/default.nix

@@ -9,7 +9,7 @@
 , enableLTO ? true
 , texinfo ? null
 , perl ? null # optional, for texi2pod (then pod2man)
-, gmp, mpfr, libmpc, gettext, which
+, gmp, mpfr, libmpc, gettext, which, patchelf
 , libelf                      # optional, for link-time optimizations (LTO)
 , isl ? null # optional, for the Graphite optimization framework.
 , zlib ? null
@@ -146,11 +146,14 @@ stdenv.mkDerivation ({
 
   # For building runtime libs
   depsBuildTarget =
-    if hostPlatform == buildPlatform then [
-      targetPackages.stdenv.cc.bintools # newly-built gcc will be used
-    ] else assert targetPlatform == hostPlatform; [ # build != host == target
-      stdenv.cc
-    ];
+    (
+      if hostPlatform == buildPlatform then [
+        targetPackages.stdenv.cc.bintools # newly-built gcc will be used
+      ] else assert targetPlatform == hostPlatform; [ # build != host == target
+        stdenv.cc
+      ]
+    )
+    ++ optional targetPlatform.isLinux patchelf;
 
   buildInputs = [
     gmp mpfr libmpc libelf

pkgs/development/compilers/gcc/builder.sh

@@ -240,7 +240,7 @@ postInstall() {
     # More dependencies with the previous gcc or some libs (gccbug stores the build command line)
     rm -rf $out/bin/gccbug
 
-    if type "patchelf"; then
+    if [[ buildConfig == *"linux"* ]]; then
         # Take out the bootstrap-tools from the rpath, as it's not needed at all having $out
         for i in $(find "$out"/libexec/gcc/*/*/* -type f -a \! -name '*.la'); do
             PREV_RPATH=`patchelf --print-rpath "$i"`
@@ -249,6 +249,16 @@ postInstall() {
         done
     fi
 
+    if [[ targetConfig == *"linux"* ]]; then
+        # For some reason, when building for linux on darwin, the libs retain
+	# RPATH to $out.
+        for i in "$lib"/"$targetConfig"/lib/{libtsan,libasan,libubsan}.so.*.*.*; do
+            PREV_RPATH=`patchelf --print-rpath "$i"`
+            NEW_RPATH=`echo "$PREV_RPATH" | sed "s,:${out}[^:]*,,g"`
+            patchelf --set-rpath "$NEW_RPATH" "$i" && echo OK
+        done
+    fi
+
     if type "install_name_tool"; then
         for i in "$lib"/lib/*.*.dylib; do
             install_name_tool -id "$i" "$i" || true