cpython: Enable cross-compilation

pkgs/development/interpreters/python/cpython/2.7/cross-compile.patch

@@ -0,0 +1,44 @@
+commit 9ac1104b075ecea6175e2214b81c6538adbb9e84
+Author: Ben Gamari <ben@smart-cactus.org>
+Date:   Tue Oct 17 23:53:25 2017 -0400
+
+    Fix it
+
+diff --git a/Makefile.pre.in b/Makefile.pre.in
+index e288964..ddc7428 100644
+--- a/Makefile.pre.in
++++ b/Makefile.pre.in
+@@ -1120,27 +1120,27 @@ libinstall:	build_all $(srcdir)/Lib/$(PLATDIR) $(srcdir)/Modules/xxmodule.c
+ 		$(INSTALL_DATA) $(srcdir)/Modules/xxmodule.c \
+ 			$(DESTDIR)$(LIBDEST)/distutils/tests ; \
+ 	fi
+-	PYTHONPATH=$(DESTDIR)$(LIBDEST)  $(RUNSHARED) \
++	$(RUNSHARED) \
+ 		$(PYTHON_FOR_BUILD) -Wi -tt $(DESTDIR)$(LIBDEST)/compileall.py \
+ 		-d $(LIBDEST) -f \
+ 		-x 'bad_coding|badsyntax|site-packages|lib2to3/tests/data' \
+ 		$(DESTDIR)$(LIBDEST)
+-	PYTHONPATH=$(DESTDIR)$(LIBDEST) $(RUNSHARED) \
++	$(RUNSHARED) \
+ 		$(PYTHON_FOR_BUILD) -Wi -tt -O $(DESTDIR)$(LIBDEST)/compileall.py \
+ 		-d $(LIBDEST) -f \
+ 		-x 'bad_coding|badsyntax|site-packages|lib2to3/tests/data' \
+ 		$(DESTDIR)$(LIBDEST)
+-	-PYTHONPATH=$(DESTDIR)$(LIBDEST)  $(RUNSHARED) \
++	-$(RUNSHARED) \
+ 		$(PYTHON_FOR_BUILD) -Wi -t $(DESTDIR)$(LIBDEST)/compileall.py \
+ 		-d $(LIBDEST)/site-packages -f \
+ 		-x badsyntax $(DESTDIR)$(LIBDEST)/site-packages
+-	-PYTHONPATH=$(DESTDIR)$(LIBDEST) $(RUNSHARED) \
++	-$(RUNSHARED) \
+ 		$(PYTHON_FOR_BUILD) -Wi -t -O $(DESTDIR)$(LIBDEST)/compileall.py \
+ 		-d $(LIBDEST)/site-packages -f \
+ 		-x badsyntax $(DESTDIR)$(LIBDEST)/site-packages
+-	-PYTHONPATH=$(DESTDIR)$(LIBDEST) $(RUNSHARED) \
++	-$(RUNSHARED) \
+ 		$(PYTHON_FOR_BUILD) -m lib2to3.pgen2.driver $(DESTDIR)$(LIBDEST)/lib2to3/Grammar.txt
+-	-PYTHONPATH=$(DESTDIR)$(LIBDEST) $(RUNSHARED) \
++	-$(RUNSHARED) \
+ 		$(PYTHON_FOR_BUILD) -m lib2to3.pgen2.driver $(DESTDIR)$(LIBDEST)/lib2to3/PatternGrammar.txt
+ 
+ # Create the PLATDIR source directory, if one wasn't distributed..

pkgs/development/interpreters/python/cpython/2.7/default.nix

@@ -1,4 +1,4 @@
-{ stdenv, hostPlatform, fetchurl
+{ stdenv, hostPlatform, buildPlatform, buildPackages, fetchurl
 , bzip2
 , gdbm
 , fetchpatch
@@ -89,6 +89,10 @@ let
       # compiler when needed.
       ./python-2.7-distutils-C++.patch
 
+    ] ++ [
+
+      # Don't use pass host PYTHONPATH to build python
+      #./cross-compile.patch
     ];
 
   preConfigure = ''
@@ -117,6 +121,28 @@ let
     "ac_cv_func_bind_textdomain_codeset=yes"
   ] ++ optionals stdenv.isDarwin [
     "--disable-toolbox-glue"
+  ] ++ optionals (hostPlatform != buildPlatform) [
+    "PYTHON_FOR_BUILD=${getBin buildPackages.python}/bin/python"
+    "ac_cv_buggy_getaddrinfo=no"
+    # Assume little-endian IEEE 754 floating point when cross compiling
+    "ac_cv_little_endian_double=yes"
+    "ac_cv_big_endian_double=no"
+    "ac_cv_mixed_endian_double=no"
+    "ac_cv_x87_double_rounding=yes"
+    "ac_cv_tanh_preserves_zero_sign=yes"
+    # Generally assume that things are present and work
+    "ac_cv_posix_semaphores_enabled=yes"
+    "ac_cv_broken_sem_getvalue=no"
+    "ac_cv_wchar_t_signed=yes"
+    "ac_cv_rshift_extends_sign=yes"
+    "ac_cv_broken_nice=no"
+    "ac_cv_broken_poll=no"
+    "ac_cv_working_tzset=yes"
+    "ac_cv_have_long_long_format=yes"
+    "ac_cv_have_size_t_format=yes"
+    "ac_cv_computed_gotos=yes"
+    "ac_cv_file__dev_ptmx=yes"
+    "ac_cv_file__dev_ptc=yes"
   ];
 
   postConfigure = if hostPlatform.isCygwin then ''
@@ -131,6 +157,9 @@ let
     ++ [ db gdbm ncurses sqlite readline ]
     ++ optionals x11Support [ tcl tk xlibsWrapper libX11 ]
     ++ optionals stdenv.isDarwin ([ CF ] ++ optional (configd != null) configd);
+  nativeBuildInputs =
+    optionals (hostPlatform != buildPlatform)
+    [ buildPackages.stdenv.cc buildPackages.python ];
 
   mkPaths = paths: {
     C_INCLUDE_PATH = makeSearchPathOutput "dev" "include" paths;
@@ -144,7 +173,7 @@ in stdenv.mkDerivation {
     name = "python-${version}";
     pythonVersion = majorVersion;
 
-    inherit majorVersion version src patches buildInputs
+    inherit majorVersion version src patches buildInputs nativeBuildInputs
             preConfigure configureFlags;
 
     LDFLAGS = stdenv.lib.optionalString (!stdenv.isDarwin) "-lgcc_s";
@@ -187,7 +216,8 @@ in stdenv.mkDerivation {
         # Determinism: Windows installers were not deterministic.
         # We're also not interested in building Windows installers.
         find "$out" -name 'wininst*.exe' | xargs -r rm -f
-
+      '' + optionalString (stdenv.hostPlatform == stdenv.buildPlatform)
+      ''
         # Determinism: rebuild all bytecode
         # We exclude lib2to3 because that's Python 2 code which fails
         # We rebuild three times, once for each optimization level

pkgs/development/interpreters/python/cpython/3.6/default.nix

@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, fetchpatch
+{ stdenv, fetchurl, fetchpatch, buildPackages
 , glibc
 , bzip2
 , expat
@@ -39,12 +39,15 @@ let
     ++ optionals x11Support [ tcl tk libX11 xproto ]
     ++ optionals stdenv.isDarwin [ CF configd ];
 
+  nativeBuildInputs =
+    optional (stdenv.hostPlatform != stdenv.buildPlatform) buildPackages.python3;
+
 in stdenv.mkDerivation {
   name = "python3-${version}";
   pythonVersion = majorVersion;
   inherit majorVersion version;
 
-  inherit buildInputs;
+  inherit buildInputs nativeBuildInputs;
 
   src = fetchurl {
     url = "https://www.python.org/ftp/python/${majorVersion}.${minorVersion}/Python-${version}.tar.xz";
@@ -87,6 +90,27 @@ in stdenv.mkDerivation {
     "--without-ensurepip"
     "--with-system-expat"
     "--with-system-ffi"
+  ] ++ optionals (stdenv.hostPlatform != stdenv.buildPlatform) [
+    "ac_cv_buggy_getaddrinfo=no"
+    # Assume little-endian IEEE 754 floating point when cross compiling
+    "ac_cv_little_endian_double=yes"
+    "ac_cv_big_endian_double=no"
+    "ac_cv_mixed_endian_double=no"
+    "ac_cv_x87_double_rounding=yes"
+    "ac_cv_tanh_preserves_zero_sign=yes"
+    # Generally assume that things are present and work
+    "ac_cv_posix_semaphores_enabled=yes"
+    "ac_cv_broken_sem_getvalue=no"
+    "ac_cv_wchar_t_signed=yes"
+    "ac_cv_rshift_extends_sign=yes"
+    "ac_cv_broken_nice=no"
+    "ac_cv_broken_poll=no"
+    "ac_cv_working_tzset=yes"
+    "ac_cv_have_long_long_format=yes"
+    "ac_cv_have_size_t_format=yes"
+    "ac_cv_computed_gotos=yes"
+    "ac_cv_file__dev_ptmx=yes"
+    "ac_cv_file__dev_ptc=yes"
   ];
 
   preConfigure = ''
@@ -139,7 +163,7 @@ in stdenv.mkDerivation {
     for i in $out/lib/python${majorVersion}/_sysconfigdata*.py $out/lib/python${majorVersion}/config-${majorVersion}m*/Makefile; do
       sed -i $i -e "s|-I/nix/store/[^ ']*||g" -e "s|-L/nix/store/[^ ']*||g" -e "s|$TMPDIR|/no-such-path|g"
     done
-
+  '' + optionalString (stdenv.hostPlatform == stdenv.buildPlatform) ''
     # Determinism: rebuild all bytecode
     # We exclude lib2to3 because that's Python 2 code which fails
     # We rebuild three times, once for each optimization level