initial mips platform support, import from issue 48

The target mips32r2_dyn is tested to fully compile, but untested to
run.  Target mips32r2_static reaches kiwix-lib and fails linking
pthread.  For further details see the comments in #48.

Some known problems:

* hardcoded values of icudt58l in some dependent packages
  unnoticable during compile, but will affect runtimes

* the libdir name problem
  x86_64-linux-gnu <> mips-linux-gnu

* pthread linking problem when compiling kiwix-lib statically
  may be a meson issue, since it somewhat claims to properly
  handle pthread linking in cross-compile situations; there
  are some url links in #48 laying out a proper workaround.

kiwixbuild/dependencies/icu4c.py

@@ -20,7 +20,8 @@ class Icu(Dependency):
                    "icu4c_custom_data.patch",
                    "icu4c_noxlocale.patch",
                    "icu4c_rpath.patch",
-                   "icu4c_build_config.patch"]
+                   "icu4c_build_config.patch",
+                   "icu4c_run_tools_w_qemu_if_endianess_differs.patch"]
 
 
     class Builder(MakeBuilder):
@@ -41,8 +42,10 @@ class Icu(Dependency):
                 icu_native_builder = get_target_step(
                     'icu4c',
                     'native_static' if platformInfo.static else 'native_dyn')
-                options += " --with-cross-build={} --disable-tools".format(
+                options += " --with-cross-build={}".format(
                     icu_native_builder.build_path)
+                if platformInfo.build == 'iOS':
+                    options += " --disable-tools"
             if platformInfo.build == 'android':
                 options += " --with-data-packaging=archive"
             return options

kiwixbuild/patches/icu4c_run_tools_w_qemu_if_endianess_differs.patch

@@ -0,0 +1,42 @@
+diff -ur icu4c/source/data/Makefile.in icu4c.patched/source/data/Makefile.in
+--- icu4c/source/data/Makefile.in	2018-06-17 03:28:46.646446362 +0200
++++ icu4c.patched/source/data/Makefile.in	2018-06-17 03:30:44.072860064 +0200
+@@ -577,9 +577,9 @@
+ #          There must be a nicer way to do this.
+ 
+ $(CFU_FILES): $(ALL_CFU_SOURCE) $(TOOLBINDIR)/gencfu$(TOOLEXEEXT) $(DAT_FILES)
+-	$(INVOKE) echo ALL_CFU_SOURCE: $(ALL_CFU_SOURCE)
+-	$(INVOKE) echo CFU_FILES: $(CFU_FILES)
+-	$(INVOKE) echo CFU_FILES_SHORT: $(CFU_FILES_SHORT)
++	echo ALL_CFU_SOURCE: $(ALL_CFU_SOURCE)
++	echo CFU_FILES: $(CFU_FILES)
++	echo CFU_FILES_SHORT: $(CFU_FILES_SHORT)
+ 	$(INVOKE) $(TOOLBINDIR)/gencfu -c -i $(BUILDDIR) -r $(word 1,$(ALL_CFU_SOURCE)) -w $(word 2,$(ALL_CFU_SOURCE)) -o $@
+ 
+ 
+diff -ur icu4c/source/Makefile.in icu4c.patched/source/Makefile.in
+--- icu4c/source/Makefile.in	2018-06-17 03:28:45.222465606 +0200
++++ icu4c.patched/source/Makefile.in	2018-06-17 03:29:33.757809798 +0200
+@@ -243,9 +243,20 @@
+ 	@(echo "CROSS_ICU_VERSION=$(VERSION)" ;\
+ 	  echo "TOOLEXEEXT=$(EXEEXT)" \
+ 	   ) > $@
+-	@(echo 'TOOLBINDIR=$$(cross_buildroot)/bin' ;\
++	@(echo '' ;\
++	  echo 'ifneq ($$(ICUDATA_PLATFORM_NAME),$(ICUDATA_PLATFORM_NAME))' ;\
++	  echo 'cross_buildroot=$$(top_builddir)' ;\
++	  echo 'endif' ;\
++	  echo '' ;\
++	  echo 'TOOLBINDIR=$$(cross_buildroot)/bin' ;\
+ 	  echo 'TOOLLIBDIR=$$(cross_buildroot)/lib' ;\
+ 	  echo "INVOKE=$(LDLIBRARYPATH_ENVVAR)=$(LIBRARY_PATH_PREFIX)"'$$(TOOLLIBDIR):$$(cross_buildroot)/stubdata:$$(cross_buildroot)/tools/ctestfw:$$$$'"$(LDLIBRARYPATH_ENVVAR)" ;\
+ 	  echo "PKGDATA_INVOKE=$(LDLIBRARYPATH_ENVVAR)=$(LIBRARY_PATH_PREFIX)"'$$(cross_buildroot)/stubdata:$$(cross_buildroot)/tools/ctestfw:$$(TOOLLIBDIR):$$$$'"$(LDLIBRARYPATH_ENVVAR) " ;\
++	  echo '' ;\
++	  echo 'ifneq ($$(ICUDATA_PLATFORM_NAME),$(ICUDATA_PLATFORM_NAME))' ;\
++	  echo 'export QEMU_SET_ENV:=$$(strip $$(subst $$$$'"$(LDLIBRARYPATH_ENVVAR)"',,$$(INVOKE)))$$(strip $$(subst LD_LIBRARY_PATH=,,$$(QEMU_SET_ENV)))' ;\
++	  echo '$$(eval $$(shell grep host_cpu $$(top_builddir)/config/Makefile.inc))' ;\
++	  echo 'INVOKE=qemu-$$(host_cpu)-static' ;\
++	  echo 'endif' ;\
+ 	  echo ) >> $@
+ 
+ config/icucross.inc: $(top_builddir)/icudefs.mk  $(top_builddir)/Makefile @platform_make_fragment@

kiwixbuild/platforms/__init__.py

@@ -6,6 +6,7 @@ from . import (
     armhf,
     i586,
     ios,
+    mips32r2,
     native,
     neutral,
     win32

kiwixbuild/platforms/mips32r2.py

@@ -0,0 +1,95 @@
+from .base import PlatformInfo
+
+from kiwixbuild.utils import pj
+from kiwixbuild._global import get_target_step
+
+
+class MIPS32R2PlatformInfo(PlatformInfo):
+    build = 'mips'
+    arch_full = 'mips-linux-gnu'
+    compatible_hosts = ['fedora', 'debian']
+
+    def get_cross_config(self):
+        return {
+            'binaries': self.binaries,
+            'exec_wrapper_def': '',
+            'root_path': self.root_path,
+            'extra_libs': [],
+            'extra_cflags': [],
+            'host_machine': {
+                'system': 'linux',
+                'lsystem': 'linux',
+                'cpu_family': 'mips32r2',
+                'cpu': '24kc',
+                'endian': 'big',
+                'abi': ''
+            }
+        }
+
+    @property
+    def root_path(self):
+        return '/usr/mips-linux-gnu'
+
+    @property
+    def binaries(self):
+        binaries = ((k,'{}-{}'.format(self.arch_full, v))
+                for k, v in (('CC', 'gcc'),
+                             ('CXX', 'g++'),
+                             ('AR', 'ar'),
+                             ('STRIP', 'strip'),
+                             ('WINDRES', 'windres'),
+                             ('RANLIB', 'ranlib'),
+                             ('LD', 'ld'))
+               )
+        return {k:pj('/usr', 'bin', v)
+                for k,v in binaries}
+
+    @property
+    def exec_wrapper_def(self):
+        try:
+            which('qemu-mips-static')
+        except subprocess.CalledProcessError:
+            return ""
+        else:
+            return "exec_wrapper = 'qemu-mips-static'"
+
+    @property
+    def configure_option(self):
+        return '--host={}'.format(self.arch_full)
+
+    def get_bin_dir(self):
+        return [pj(self.root_path, 'bin')]
+
+    def set_env(self, env):
+        env['PKG_CONFIG_LIBDIR'] = pj(self.root_path, 'lib', 'pkgconfig')
+        # soft float is another abi and thus unsupported by current maintained (apt-get'able) debian/ubuntu tcs,
+        # additionally these are (gnu) libc only; if uclibc is needed, see https://buildroot.org/downloads/ and
+        # make a toolchain and rootfs, then checkout and use kiwixbuild --target_platform native_* within chroot env
+        # (it needs qemu-mips-static from host copied to rootfs/usr/bin, in order to chroot into using a non-mips-host)
+        #env['CFLAGS'] = " -march=mips32r2 -mtune=24kc -msoft-float "+env['CFLAGS']
+        #env['CXXFLAGS'] = " -march=mips32r2 -mtune=24kc -msoft-float "+env['CXXFLAGS']
+        env['CFLAGS'] = " -march=mips32r2 -mtune=24kc "+env['CFLAGS']
+        env['CXXFLAGS'] = " -march=mips32r2 -mtune=24kc "+env['CXXFLAGS']
+        env['QEMU_LD_PREFIX'] = pj(self.root_path)
+        env['QEMU_SET_ENV'] = "LD_LIBRARY_PATH={}".format(
+            ':'.join([
+                pj(self.root_path, "lib"),
+                env['LD_LIBRARY_PATH']
+        ]))
+
+    def set_compiler(self, env):
+        env['CC'] = self.binaries['CC']
+        env['CXX'] = self.binaries['CXX']
+
+    def finalize_setup(self):
+        super().finalize_setup()
+        self.buildEnv.cmake_crossfile = self._gen_crossfile('cmake_cross_file.txt')
+        self.buildEnv.meson_crossfile = self._gen_crossfile('meson_cross_file.txt')
+
+class MIPS32R2Dyn(MIPS32R2PlatformInfo):
+    name = 'mips32r2_dyn'
+    static = False
+
+class MIPS32R2Static(MIPS32R2PlatformInfo):
+    name = 'mips32r2_static'
+    static = True