1 files changed, 40 insertions, 43 deletions

diff --git a/pkgs/development/compilers/gcc/7/default.nix b/pkgs/development/compilers/gcc/7/default.nix
index 48b245c1006f5..032a20271ee05 100644
--- a/pkgs/development/compilers/gcc/7/default.nix
+++ b/pkgs/development/compilers/gcc/7/default.nix
@@ -35,6 +35,7 @@
 , darwin ? null
 , flex ? null
 , buildPlatform, hostPlatform, targetPlatform
+, buildPackages
 }:
 
 assert langJava     -> zip != null && unzip != null
@@ -323,6 +324,8 @@ stdenv.mkDerivation ({
       "--with-mpc=${libmpc}"
     ] ++
     optional (libelf != null) "--with-libelf=${libelf}" ++
+    optional (!(crossMingw && crossStageStatic))
+      "--with-native-system-header-dir=${getDev stdenv.cc.libc}/include" ++
 
     # Basic configuration
     [
@@ -374,14 +377,6 @@ stdenv.mkDerivation ({
     # Ada
     optional langAda "--enable-libada" ++
 
-    # Cross-compilation
-    optional (targetPlatform == hostPlatform) (
-      let incDir = if hostPlatform.isDarwin
-                     then "${darwin.usr-include}"
-                     else "${getDev stdenv.cc.libc}/include";
-      in "--with-native-system-header-dir=${incDir}"
-    ) ++
-
     platformFlags ++
     optional (targetPlatform != hostPlatform) crossConfigureFlags ++
     optional (!bootstrap) "--disable-bootstrap" ++
@@ -446,12 +441,12 @@ stdenv.mkDerivation ({
     STRIP_FOR_TARGET = "${targetPlatform.config}-strip";
     CC_FOR_TARGET = "${targetPlatform.config}-gcc";
     CXX_FOR_TARGET = "${targetPlatform.config}-g++";
-    # If we are making a cross compiler, targetPlatform != hostPlatform
-    NIX_CC_CROSS = optionalString (targetPlatform == hostPlatform) builtins.toString stdenv.cc;
+
     dontStrip = true;
     buildFlags = "";
   };
 
+  NIX_BUILD_CC = buildPackages.stdenv.cc;
 
   # Needed for the cross compilation to work
   AR = "ar";
@@ -459,18 +454,21 @@ stdenv.mkDerivation ({
   # http://gcc.gnu.org/install/specific.html#x86-64-x-solaris210
   CC = if stdenv.system == "x86_64-solaris" then "gcc -m64" else "gcc";
 
-  # Setting $CPATH and $LIBRARY_PATH to make sure both `gcc' and `xgcc' find
-  # the library headers and binaries, regarless of the language being
-  # compiled.
-
-  # Note: When building the Java AWT GTK+ peer, the build system doesn't
-  # honor `--with-gmp' et al., e.g., when building
-  # `libjava/classpath/native/jni/java-math/gnu_java_math_GMP.c', so we just
-  # add them to $CPATH and $LIBRARY_PATH in this case.
+  # Setting $CPATH and $LIBRARY_PATH to make sure both `gcc' and `xgcc' find the
+  # library headers and binaries, regarless of the language being compiled.
+  #
+  # Note: When building the Java AWT GTK+ peer, the build system doesn't honor
+  # `--with-gmp' et al., e.g., when building
+  # `libjava/classpath/native/jni/java-math/gnu_java_math_GMP.c', so we just add
+  # them to $CPATH and $LIBRARY_PATH in this case.
   #
   # Likewise, the LTO code doesn't find zlib.
+  #
+  # Cross-compiling, we need gcc not to read ./specs in order to build the g++
+  # compiler (after the specs for the cross-gcc are created). Having
+  # LIBRARY_PATH= makes gcc read the specs from ., and the build breaks.
 
-  CPATH = makeSearchPathOutput "dev" "include" ([]
+  CPATH = optionals (targetPlatform == hostPlatform) (makeSearchPathOutput "dev" "include" ([]
     ++ optional (zlib != null) zlib
     ++ optional langJava boehmgc
     ++ optionals javaAwtGtk xlibs
@@ -481,39 +479,38 @@ stdenv.mkDerivation ({
     # On GNU/Hurd glibc refers to Mach & Hurd
     # headers.
     ++ optionals (libcCross != null && libcCross ? propagatedBuildInputs)
-                 libcCross.propagatedBuildInputs);
+                 libcCross.propagatedBuildInputs
+  ));
 
-  LIBRARY_PATH = makeLibraryPath ([]
+  LIBRARY_PATH = optionals (targetPlatform == hostPlatform) (makeLibraryPath ([]
     ++ optional (zlib != null) zlib
     ++ optional langJava boehmgc
     ++ optionals javaAwtGtk xlibs
     ++ optionals javaAwtGtk [ gmp mpfr ]
-    ++ optional (libpthread != null) libpthread);
-
-  EXTRA_TARGET_CFLAGS =
-    if targetPlatform != hostPlatform && libcCross != null then [
-        "-idirafter ${getDev libcCross}/include"
-      ]
-      ++ optionals (! crossStageStatic) [
-        "-B${libcCross.out}/lib"
-      ]
-    else null;
-
-  EXTRA_TARGET_LDFLAGS =
-    if targetPlatform != hostPlatform && libcCross != null then [
-        "-Wl,-L${libcCross.out}/lib"
-      ]
-      ++ (if crossStageStatic then [
+    ++ optional (libpthread != null) libpthread)
+  );
+
+  EXTRA_TARGET_FLAGS = optionals
+    (targetPlatform != hostPlatform && libcCross != null)
+    ([
+      "-idirafter ${getDev libcCross}/include"
+    ] ++ optionals (! crossStageStatic) [
+      "-B${libcCross.out}/lib"
+    ]);
+
+  EXTRA_TARGET_LDFLAGS = optionals
+    (targetPlatform != hostPlatform && libcCross != null)
+    ([
+      "-Wl,-L${libcCross.out}/lib"
+    ] ++ (if crossStageStatic then [
         "-B${libcCross.out}/lib"
       ] else [
         "-Wl,-rpath,${libcCross.out}/lib"
         "-Wl,-rpath-link,${libcCross.out}/lib"
-      ])
-      ++ optionals (libpthreadCross != null) [
-        "-L${libpthreadCross}/lib"
-        "-Wl,${libpthreadCross.TARGET_LDFLAGS}"
-      ]
-    else null;
+    ]) ++ optionals (libpthreadCross != null) [
+      "-L${libpthreadCross}/lib"
+      "-Wl,${libpthreadCross.TARGET_LDFLAGS}"
+    ]);
 
   passthru =
     { inherit langC langCC langObjC langObjCpp langAda langFortran langVhdl langGo version; isGNU = true; };