[recipe-stl] Rework of protobuf_cpp recipe

In here we do:
  - inherit from CppCompiledComponentsPythonRecipe Because depends on android's STL library
  - make use of the base class methods for library recipes
  - Split build_arch into proper methods
  - Shorten some long lines (to be PEP8 friendly)
  - make generated library shared
  - remove recipe from CI/constants

ci/constants.py

@@ -67,7 +67,6 @@ class TargetPython(Enum):
     'ffpyplayer',
     # requires `libpq-dev` system dependency e.g. for `pg_config` binary
     'psycopg2',
-    'protobuf_cpp',
     # most likely some setup in the Docker container, because it works in host
     'pyjnius', 'pyopenal',
     # SyntaxError: invalid syntax (Python2)

pythonforandroid/recipes/protobuf_cpp/__init__.py

@@ -1,6 +1,6 @@
-from pythonforandroid.recipe import PythonRecipe
+from pythonforandroid.recipe import CppCompiledComponentsPythonRecipe
 from pythonforandroid.logger import shprint, info_notify
-from pythonforandroid.util import current_directory, shutil
+from pythonforandroid.util import current_directory
 from os.path import exists, join
 import sh
 from multiprocessing import cpu_count
@@ -9,13 +9,19 @@
 import os
 
 
-class ProtobufCppRecipe(PythonRecipe):
+class ProtobufCppRecipe(CppCompiledComponentsPythonRecipe):
+    """This is a two-in-one recipe:
+      - build labraru `libprotobuf.so`
+      - build and install python binding for protobuf_cpp
+    """
     name = 'protobuf_cpp'
     version = '3.6.1'
     url = 'https://github.com/google/protobuf/releases/download/v{version}/protobuf-python-{version}.tar.gz'
     call_hostpython_via_targetpython = False
     depends = ['cffi', 'setuptools']
     site_packages_name = 'google/protobuf/pyext'
+    setup_extra_args = ['--cpp_implementation']
+    built_libraries = {'libprotobuf.so': 'src/.libs'}
     protoc_dir = None
 
     def prebuild_arch(self, arch):
@@ -65,42 +71,37 @@ def prebuild_arch(self, arch):
     def build_arch(self, arch):
         env = self.get_recipe_env(arch)
 
-        # Build libproto.a
+        # Build libproto.so
         with current_directory(self.get_build_dir(arch.arch)):
-            env['HOSTARCH'] = 'arm-eabi'
-            env['BUILDARCH'] = shprint(sh.gcc, '-dumpmachine').stdout.decode('utf-8').split('\n')[0]
+            build_arch = (
+                shprint(sh.gcc, '-dumpmachine')
+                .stdout.decode('utf-8')
+                .split('\n')[0]
+            )
 
             if not exists('configure'):
                 shprint(sh.Command('./autogen.sh'), _env=env)
 
             shprint(sh.Command('./configure'),
-                    '--host={}'.format(env['HOSTARCH']),
+                    '--build={}'.format(build_arch),
+                    '--host={}'.format(arch.command_prefix),
+                    '--target={}'.format(arch.command_prefix),
+                    '--disable-static',
                     '--enable-shared',
                     _env=env)
 
             with current_directory(join(self.get_build_dir(arch.arch), 'src')):
                 shprint(sh.make, 'libprotobuf.la', '-j'+str(cpu_count()), _env=env)
-                shprint(sh.cp, '.libs/libprotobuf.a', join(self.ctx.get_libs_dir(arch.arch), 'libprotobuf.a'))
-
-                # Copy stl library
-                shutil.copyfile(
-                    self.ctx.ndk_dir + '/sources/cxx-stl/gnu-libstdc++/' + self.ctx.toolchain_version + '/libs/' + arch.arch + '/libgnustl_shared.so',
-                    join(self.ctx.get_libs_dir(arch.arch), 'libgnustl_shared.so'))
 
+    def build_compiled_components(self, arch):
         # Build python bindings and _message.so
+        env = self.get_recipe_env(arch)
         with current_directory(join(self.get_build_dir(arch.arch), 'python')):
             hostpython = sh.Command(self.hostpython_location)
             shprint(hostpython,
                     'setup.py',
                     'build_ext',
-                    '--cpp_implementation', _env=env)
-
-        # Install python bindings
-        self.install_python_package(arch)
-
-        # Create __init__.py which is missing (cf. https://github.com/protocolbuffers/protobuf/issues/1296
-        # and https://stackoverflow.com/questions/13862562/google-protocol-buffers-not-found-when-trying-to-freeze-python-app)
-        open(join(self.ctx.get_site_packages_dir(), 'google', '__init__.py'), 'a').close()
+                    _env=env, *self.setup_extra_args)
 
     def install_python_package(self, arch):
         env = self.get_recipe_env(arch)
@@ -114,32 +115,25 @@ def install_python_package(self, arch):
             shprint(hostpython, 'setup.py', 'install', '-O2',
                     '--root={}'.format(self.ctx.get_python_install_dir()),
                     '--install-lib=.',
-                    '--cpp_implementation',
                     _env=hpenv, *self.setup_extra_args)
 
+        # Create __init__.py which is missing, see also:
+        #   - https://github.com/protocolbuffers/protobuf/issues/1296
+        #   - https://stackoverflow.com/questions/13862562/
+        #   google-protocol-buffers-not-found-when-trying-to-freeze-python-app
+        open(
+            join(self.ctx.get_site_packages_dir(), 'google', '__init__.py'),
+            'a',
+        ).close()
+
     def get_recipe_env(self, arch):
         env = super(ProtobufCppRecipe, self).get_recipe_env(arch)
         if self.protoc_dir is not None:
             # we need protoc with binary for host platform
             env['PROTOC'] = join(self.protoc_dir, 'bin', 'protoc')
         env['TARGET_OS'] = 'OS_ANDROID_CROSSCOMPILE'
-        env['CFLAGS'] += (
-            ' -I' + self.ctx.ndk_dir + '/platforms/android-' +
-            str(self.ctx.android_api) +
-            '/arch-' + arch.arch.replace('eabi', '') + '/usr/include' +
-            ' -I' + self.ctx.ndk_dir + '/sources/cxx-stl/gnu-libstdc++/' +
-            self.ctx.toolchain_version + '/include' +
-            ' -I' + self.ctx.ndk_dir + '/sources/cxx-stl/gnu-libstdc++/' +
-            self.ctx.toolchain_version + '/libs/' + arch.arch + '/include')
-        env['CFLAGS'] += ' -std=gnu++11'
-        env['CXXFLAGS'] = env['CFLAGS']
-        env['CXXFLAGS'] += ' -frtti'
-        env['CXXFLAGS'] += ' -fexceptions'
-        env['LDFLAGS'] += (
-            ' -lgnustl_shared -landroid -llog' +
-            ' -L' + self.ctx.ndk_dir +
-            '/sources/cxx-stl/gnu-libstdc++/' + self.ctx.toolchain_version +
-            '/libs/' + arch.arch)
+        env['CXXFLAGS'] += ' -std=c++11'
+        env['LDFLAGS'] += ' -lm -landroid -llog'
         return env