- Issue #14330: For cross builds, don't use host python, use host search paths

  for host compiler.

Lib/distutils/util.py

@@ -53,6 +53,10 @@ def get_platform ():
             return 'win-ia64'
         return sys.platform
 
+    # Set for cross builds explicitly
+    if "_PYTHON_HOST_PLATFORM" in os.environ:
+        return os.environ["_PYTHON_HOST_PLATFORM"]
+
     if os.name != "posix" or not hasattr(os, 'uname'):
         # XXX what about the architecture? NT is Intel or Alpha,
         # Mac OS is M68k or PPC, etc.

Lib/sysconfig.py

@@ -138,6 +138,10 @@ if os.name == "nt" and "\\pc\\v" in _PROJECT_BASE[-10:].lower():
 if os.name == "nt" and "\\pcbuild\\amd64" in _PROJECT_BASE[-14:].lower():
     _PROJECT_BASE = _safe_realpath(os.path.join(_PROJECT_BASE, pardir, pardir))
 
+# set for cross builds
+if "_PROJECT_BASE" in os.environ:
+    _PROJECT_BASE = _safe_realpath(os.environ["_PROJECT_BASE"])
+
 def _is_python_source_dir(d):
     for fn in ("Setup.dist", "Setup.local"):
         if os.path.isfile(os.path.join(d, "Modules", fn)):
@@ -673,6 +677,10 @@ def get_platform():
         # Mac OS is M68k or PPC, etc.
         return sys.platform
 
+    # Set for cross builds explicitly
+    if "_PYTHON_HOST_PLATFORM" in os.environ:
+        return os.environ["_PYTHON_HOST_PLATFORM"]
+
     # Try to distinguish various flavours of Unix
     osname, host, release, version, machine = os.uname()
 

Makefile.pre.in

@@ -194,6 +194,10 @@ LIBOBJS=	@LIBOBJS@
 PYTHON=		python$(EXE)
 BUILDPYTHON=	python$(BUILDEXE)
 
+PYTHON_FOR_BUILD=@PYTHON_FOR_BUILD@
+_PYTHON_HOST_PLATFORM=@_PYTHON_HOST_PLATFORM@
+HOST_GNU_TYPE=  @host@
+
 # The task to run while instrument when building the profile-opt target
 PROFILE_TASK=	$(srcdir)/Tools/pybench/pybench.py -n 2 --with-gc --with-syscheck
 #PROFILE_TASK=	$(srcdir)/Lib/test/regrtest.py
@@ -446,6 +450,7 @@ build_all_generate_profile:
 	$(MAKE) all CFLAGS="$(CFLAGS) -fprofile-generate" LIBS="$(LIBS) -lgcov"
 
 run_profile_task:
+	: # FIXME: can't run for a cross build
 	$(RUNSHARED) ./$(BUILDPYTHON) $(PROFILE_TASK)
 
 build_all_use_profile:
@@ -462,18 +467,17 @@ $(BUILDPYTHON):	Modules/python.o $(LIBRARY) $(LDLIBRARY) $(PY3LIBRARY)
 	$(LINKCC) $(PY_LDFLAGS) $(LINKFORSHARED) -o $@ Modules/python.o $(BLDLIBRARY) $(LIBS) $(MODLIBS) $(SYSLIBS) $(LDLAST)
 
 platform: $(BUILDPYTHON) $(SYSCONFIGDATA)
-	$(RUNSHARED) ./$(BUILDPYTHON) -E -c 'import sys ; from sysconfig import get_platform ; print(get_platform()+"-"+sys.version[0:3])' >platform
+	$(RUNSHARED) $(PYTHON_FOR_BUILD) -c 'import sys ; from sysconfig import get_platform ; print(get_platform()+"-"+sys.version[0:3])' >platform
 
 # Generate the sysconfig build-time data
 $(SYSCONFIGDATA): $(BUILDPYTHON)
-	$(RUNSHARED) ./$(BUILDPYTHON) -SE -m sysconfig --generate-posix-vars
+	$(RUNSHARED) $(PYTHON_FOR_BUILD) -S -m sysconfig --generate-posix-vars
 
 # Build the shared modules
 sharedmods: $(BUILDPYTHON) $(SYSCONFIGDATA)
-	@case $$MAKEFLAGS in \
-	*s*) $(RUNSHARED) CC='$(CC)' LDSHARED='$(BLDSHARED)' OPT='$(OPT)' ./$(BUILDPYTHON) -E $(srcdir)/setup.py -q build;; \
-	*) $(RUNSHARED) CC='$(CC)' LDSHARED='$(BLDSHARED)' OPT='$(OPT)' ./$(BUILDPYTHON) -E $(srcdir)/setup.py build;; \
-	esac
+	case $$MAKEFLAGS in *s*) quiet=-q; esac; \
+	$(RUNSHARED) CC='$(CC)' LDSHARED='$(BLDSHARED)' OPT='$(OPT)' \
+		$(PYTHON_FOR_BUILD) $(srcdir)/setup.py $$quiet build
 
 # Build static library
 # avoid long command lines, same as LIBRARY_OBJS
@@ -1073,25 +1077,25 @@ libinstall:	build_all $(srcdir)/Lib/$(PLATDIR) $(srcdir)/Modules/xxmodule.c
 			$(DESTDIR)$(LIBDEST)/distutils/tests ; \
 	fi
 	-PYTHONPATH=$(DESTDIR)$(LIBDEST)  $(RUNSHARED) \
-		./$(BUILDPYTHON) -Wi $(DESTDIR)$(LIBDEST)/compileall.py \
+		$(PYTHON_FOR_BUILD) -Wi $(DESTDIR)$(LIBDEST)/compileall.py \
 		-d $(LIBDEST) -f \
 		-x 'bad_coding|badsyntax|site-packages|lib2to3/tests/data' \
 		$(DESTDIR)$(LIBDEST)
 	-PYTHONPATH=$(DESTDIR)$(LIBDEST) $(RUNSHARED) \
-		./$(BUILDPYTHON) -Wi -O $(DESTDIR)$(LIBDEST)/compileall.py \
+		$(PYTHON_FOR_BUILD) -Wi -O $(DESTDIR)$(LIBDEST)/compileall.py \
 		-d $(LIBDEST) -f \
 		-x 'bad_coding|badsyntax|site-packages|lib2to3/tests/data' \
 		$(DESTDIR)$(LIBDEST)
 	-PYTHONPATH=$(DESTDIR)$(LIBDEST)  $(RUNSHARED) \
-		./$(BUILDPYTHON) -Wi $(DESTDIR)$(LIBDEST)/compileall.py \
+		$(PYTHON_FOR_BUILD) -Wi $(DESTDIR)$(LIBDEST)/compileall.py \
 		-d $(LIBDEST)/site-packages -f \
 		-x badsyntax $(DESTDIR)$(LIBDEST)/site-packages
 	-PYTHONPATH=$(DESTDIR)$(LIBDEST) $(RUNSHARED) \
-		./$(BUILDPYTHON) -Wi -O $(DESTDIR)$(LIBDEST)/compileall.py \
+		$(PYTHON_FOR_BUILD) -Wi -O $(DESTDIR)$(LIBDEST)/compileall.py \
 		-d $(LIBDEST)/site-packages -f \
 		-x badsyntax $(DESTDIR)$(LIBDEST)/site-packages
 	-PYTHONPATH=$(DESTDIR)$(LIBDEST) $(RUNSHARED) \
-		./$(BUILDPYTHON) -Wi -c "import lib2to3.pygram, lib2to3.patcomp;lib2to3.patcomp.PatternCompiler()"
+		$(PYTHON_FOR_BUILD) -Wi -c "import lib2to3.pygram, lib2to3.patcomp;lib2to3.patcomp.PatternCompiler()"
 
 # Create the PLATDIR source directory, if one wasn't distributed..
 $(srcdir)/Lib/$(PLATDIR):
@@ -1185,7 +1189,7 @@ libainstall:	all python-config
 # Install the dynamically loadable modules
 # This goes into $(exec_prefix)
 sharedinstall: sharedmods
-	$(RUNSHARED) ./$(BUILDPYTHON) -E $(srcdir)/setup.py install \
+	$(RUNSHARED) $(PYTHON_FOR_BUILD) $(srcdir)/setup.py install \
 	   	--prefix=$(prefix) \
 		--install-scripts=$(BINDIR) \
 		--install-platlib=$(DESTSHARED) \
@@ -1257,7 +1261,7 @@ frameworkinstallextras:
 # This installs a few of the useful scripts in Tools/scripts
 scriptsinstall:
 	SRCDIR=$(srcdir) $(RUNSHARED) \
-	./$(BUILDPYTHON) $(srcdir)/Tools/scripts/setup.py install \
+	$(PYTHON_FOR_BUILD) $(srcdir)/Tools/scripts/setup.py install \
 	--prefix=$(prefix) \
 	--install-scripts=$(BINDIR) \
 	--root=$(DESTDIR)/

configure

@@ -682,6 +682,7 @@ CC
 EXPORT_MACOSX_DEPLOYMENT_TARGET
 CONFIGURE_MACOSX_DEPLOYMENT_TARGET
 SGI_ABI
+_PYTHON_HOST_PLATFORM
 MACHDEP
 FRAMEWORKINSTALLAPPSPREFIX
 FRAMEWORKUNIXTOOLSPREFIX
@@ -700,6 +701,7 @@ UNIVERSALSDK
 CONFIG_ARGS
 SOVERSION
 VERSION
+PYTHON_FOR_BUILD
 host_os
 host_vendor
 host_cpu
@@ -2880,6 +2882,29 @@ case $host_os in *\ *) host_os=`echo "$host_os" | sed 's/ /-/g'`;; esac
 
 
 
+if test "$cross_compiling" = yes; then
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for python interpreter for cross build" >&5
+$as_echo_n "checking for python interpreter for cross build... " >&6; }
+    if test -z "$PYTHON_FOR_BUILD"; then
+        for interp in python$PACKAGE_VERSION python3 python; do
+	    which $interp >/dev/null 2>&1 || continue
+	    if $interp -c 'import sys;sys.exit(not sys.version_info[:2] >= (3,3))'; then
+	        break
+	    fi
+            interp=
+	done
+        if test x$interp = x; then
+	    as_fn_error $? "python$PACKAGE_VERSION interpreter not found" "$LINENO" 5
+	fi
+        { $as_echo "$as_me:${as_lineno-$LINENO}: result: $interp" >&5
+$as_echo "$interp" >&6; }
+	PYTHON_FOR_BUILD="_PROJECT_BASE=$srcdir"' _PYTHON_HOST_PLATFORM=$(_PYTHON_HOST_PLATFORM) PYTHONPATH=$(srcdir)/Lib:$(srcdir)/Lib/plat-$(MACHDEP) '$interp
+    fi
+else
+    PYTHON_FOR_BUILD='./$(BUILDPYTHON) -E'
+fi
+
+
 
 if test "$prefix" != "/"; then
     prefix=`echo "$prefix" | sed -e 's/\/$//g'`
@@ -3218,6 +3243,29 @@ then
     esac
 fi
 
+
+if test "$cross_compiling" = yes; then
+	case "$host" in
+	*-*-linux*)
+		case "$host_cpu" in
+		arm*)
+			_host_cpu=arm
+			;;
+		*)
+			_host_cpu=$host_cpu
+		esac
+		;;
+	*-*-cygwin*)
+		_host_cpu=
+		;;
+	*)
+		# for now, limit cross builds to known configurations
+		MACHDEP="unknown"
+		as_fn_error $? "cross build not supported for $host" "$LINENO" 5
+	esac
+	_PYTHON_HOST_PLATFORM="$MACHDEP${_host_cpu:+-$_host_cpu}"
+fi
+
 # Some systems cannot stand _XOPEN_SOURCE being defined at all; they
 # disable features if it is defined, without any means to access these
 # features as extensions. For these systems, we skip the definition of
@@ -5540,6 +5588,10 @@ else # shared is disabled
   esac
 fi
 
+if test "$cross_compiling" = yes; then
+	RUNSHARED=
+fi
+
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $LDLIBRARY" >&5
 $as_echo "$LDLIBRARY" >&6; }
 

configure.ac

@@ -35,6 +35,27 @@ AC_CONFIG_HEADER(pyconfig.h)
 
 AC_CANONICAL_HOST
 
+if test "$cross_compiling" = yes; then
+    AC_MSG_CHECKING([for python interpreter for cross build])
+    if test -z "$PYTHON_FOR_BUILD"; then
+        for interp in python$PACKAGE_VERSION python3 python; do
+	    which $interp >/dev/null 2>&1 || continue
+	    if $interp -c 'import sys;sys.exit(not sys.version_info@<:@:2@:>@ >= (3,3))'; then
+	        break
+	    fi
+            interp=
+	done
+        if test x$interp = x; then
+	    AC_MSG_ERROR([python$PACKAGE_VERSION interpreter not found])
+	fi
+        AC_MSG_RESULT($interp)
+	PYTHON_FOR_BUILD="_PROJECT_BASE=$srcdir"' _PYTHON_HOST_PLATFORM=$(_PYTHON_HOST_PLATFORM) PYTHONPATH=$(srcdir)/Lib:$(srcdir)/Lib/plat-$(MACHDEP) '$interp
+    fi
+else
+    PYTHON_FOR_BUILD='./$(BUILDPYTHON) -E'
+fi
+AC_SUBST(PYTHON_FOR_BUILD)
+
 dnl Ensure that if prefix is specified, it does not end in a slash. If
 dnl it does, we get path names containing '//' which is both ugly and
 dnl can cause trouble.
@@ -352,6 +373,29 @@ then
 	'')	MACHDEP="unknown";;
     esac
 fi
+
+AC_SUBST(_PYTHON_HOST_PLATFORM)
+if test "$cross_compiling" = yes; then
+	case "$host" in
+	*-*-linux*)
+		case "$host_cpu" in
+		arm*)
+			_host_cpu=arm
+			;;
+		*)
+			_host_cpu=$host_cpu
+		esac
+		;;
+	*-*-cygwin*)
+		_host_cpu=
+		;;
+	*)
+		# for now, limit cross builds to known configurations
+		MACHDEP="unknown"
+		AC_MSG_ERROR([cross build not supported for $host])
+	esac
+	_PYTHON_HOST_PLATFORM="$MACHDEP${_host_cpu:+-$_host_cpu}"
+fi
 	
 # Some systems cannot stand _XOPEN_SOURCE being defined at all; they
 # disable features if it is defined, without any means to access these
@@ -913,6 +957,10 @@ else # shared is disabled
   esac
 fi
 
+if test "$cross_compiling" = yes; then
+	RUNSHARED=
+fi
+
 AC_MSG_RESULT($LDLIBRARY)
 
 AC_PROG_RANLIB

setup.py

@@ -15,7 +15,12 @@ from distutils.command.install_lib import install_lib
 from distutils.command.build_scripts import build_scripts
 from distutils.spawn import find_executable
 
+cross_compiling = "_PYTHON_HOST_PLATFORM" in os.environ
+
 def get_platform():
+    # cross build
+    if "_PYTHON_HOST_PLATFORM" in os.environ:
+        return os.environ["_PYTHON_HOST_PLATFORM"]
     # Get value of sys.platform
     if sys.platform.startswith('osf1'):
         return 'osf1'
@@ -23,7 +28,7 @@ def get_platform():
 host_platform = get_platform()
 
 # Were we compiled --with-pydebug or with #define Py_DEBUG?
-COMPILED_WITH_PYDEBUG = hasattr(sys, 'gettotalrefcount')
+COMPILED_WITH_PYDEBUG = ('--with-pydebug' in sysconfig.get_config_var("CONFIG_ARGS"))
 
 # This global variable is used to hold the list of modules to be disabled.
 disabled_module_list = []
@@ -334,6 +339,10 @@ class PyBuildExt(build_ext):
         # cached.  Clear that cache before trying to import.
         sys.path_importer_cache.clear()
 
+        # Don't try to load extensions for cross builds
+        if cross_compiling:
+            return
+
         try:
             imp.load_dynamic(ext.name, ext_filename)
         except ImportError as why:
@@ -370,12 +379,15 @@ class PyBuildExt(build_ext):
         # https://wiki.ubuntu.com/MultiarchSpec
         if not find_executable('dpkg-architecture'):
             return
+        opt = ''
+        if cross_compiling:
+            opt = '-t' + sysconfig.get_config_var('HOST_GNU_TYPE')
         tmpfile = os.path.join(self.build_temp, 'multiarch')
         if not os.path.exists(self.build_temp):
             os.makedirs(self.build_temp)
         ret = os.system(
-            'dpkg-architecture -qDEB_HOST_MULTIARCH > %s 2> /dev/null' %
-            tmpfile)
+            'dpkg-architecture %s -qDEB_HOST_MULTIARCH > %s 2> /dev/null' %
+            (opt, tmpfile))
         try:
             if ret >> 8 == 0:
                 with open(tmpfile) as fp:
@@ -387,12 +399,46 @@ class PyBuildExt(build_ext):
         finally:
             os.unlink(tmpfile)
 
+    def add_gcc_paths(self):
+        gcc = sysconfig.get_config_var('CC')
+        tmpfile = os.path.join(self.build_temp, 'gccpaths')
+        if not os.path.exists(self.build_temp):
+            os.makedirs(self.build_temp)
+        ret = os.system('%s -E -v - </dev/null 2>%s 1>/dev/null' % (gcc, tmpfile))
+        is_gcc = False
+        in_incdirs = False
+        inc_dirs = []
+        lib_dirs = []
+        try:
+            if ret >> 8 == 0:
+                with open(tmpfile) as fp:
+                    for line in fp.readlines():
+                        if line.startswith("gcc version"):
+                            is_gcc = True
+                        elif line.startswith("#include <...>"):
+                            in_incdirs = True
+                        elif line.startswith("End of search list"):
+                            in_incdirs = False
+                        elif is_gcc and line.startswith("LIBRARY_PATH"):
+                            for d in line.strip().split("=")[1].split(":"):
+                                d = os.path.normpath(d)
+                                if '/gcc/' not in d:
+                                    add_dir_to_list(self.compiler.library_dirs,
+                                                    d)
+                        elif is_gcc and in_incdirs and '/gcc/' not in line:
+                            add_dir_to_list(self.compiler.include_dirs,
+                                            line.strip())
+        finally:
+            os.unlink(tmpfile)
+
     def detect_modules(self):
         # Ensure that /usr/local is always used, but the local build
         # directories (i.e. '.' and 'Include') must be first.  See issue
         # 10520.
-        add_dir_to_list(self.compiler.library_dirs, '/usr/local/lib')
-        add_dir_to_list(self.compiler.include_dirs, '/usr/local/include')
+        if not cross_compiling:
+            add_dir_to_list(self.compiler.library_dirs, '/usr/local/lib')
+            add_dir_to_list(self.compiler.include_dirs, '/usr/local/include')
+        self.add_gcc_paths()
         self.add_multiarch_paths()
 
         # Add paths specified in the environment variables LDFLAGS and
@@ -443,11 +489,18 @@ class PyBuildExt(build_ext):
         # lib_dirs and inc_dirs are used to search for files;
         # if a file is found in one of those directories, it can
         # be assumed that no additional -I,-L directives are needed.
-        lib_dirs = self.compiler.library_dirs + [
-            '/lib64', '/usr/lib64',
-            '/lib', '/usr/lib',
-            ]
-        inc_dirs = self.compiler.include_dirs + ['/usr/include']
+        inc_dirs = self.compiler.include_dirs[:]
+        lib_dirs = self.compiler.library_dirs[:]
+        if not cross_compiling:
+            for d in (
+                '/usr/include',
+                ):
+                add_dir_to_list(inc_dirs, d)
+            for d in (
+                '/lib64', '/usr/lib64',
+                '/lib', '/usr/lib',
+                ):
+                add_dir_to_list(lib_dirs, d)
         exts = []
         missing = []
 
@@ -596,8 +649,6 @@ class PyBuildExt(build_ext):
             os.makedirs(self.build_temp)
         # Determine if readline is already linked against curses or tinfo.
         if do_readline:
-            # FIXME: needs patch from issue #14330
-            cross_compiling = False
             if cross_compiling:
                 ret = os.system("%s -d %s | grep '(NEEDED)' > %s" \
                                 % (sysconfig.get_config_var('READELF'),
@@ -839,6 +890,9 @@ class PyBuildExt(build_ext):
             db_inc_paths.append('/pkg/db-3.%d/include' % x)
             db_inc_paths.append('/opt/db-3.%d/include' % x)
 
+        if cross_compiling:
+            db_inc_paths = []
+
         # Add some common subdirectories for Sleepycat DB to the list,
         # based on the standard include directories. This way DB3/4 gets
         # picked up when it is installed in a non-standard prefix and
@@ -975,7 +1029,9 @@ class PyBuildExt(build_ext):
                              '/usr/local/include',
                              '/usr/local/include/sqlite',
                              '/usr/local/include/sqlite3',
-                           ]
+                             ]
+        if cross_compiling:
+            sqlite_inc_paths = []
         MIN_SQLITE_VERSION_NUMBER = (3, 0, 8)
         MIN_SQLITE_VERSION = ".".join([str(x)
                                     for x in MIN_SQLITE_VERSION_NUMBER])
@@ -1710,7 +1766,8 @@ class PyBuildExt(build_ext):
                                          ffi_configfile):
                 from distutils.dir_util import mkpath
                 mkpath(ffi_builddir)
-                config_args = []
+                config_args = [arg for arg in sysconfig.get_config_var("CONFIG_ARGS").split()
+                               if (('--host=' in arg) or ('--build=' in arg))]
 
                 # Pass empty CFLAGS because we'll just append the resulting
                 # CFLAGS to Python's; -g or -O2 is to be avoided.