[dist] Implement GuestPythonRecipe.should_build

To do so, we also create new class properties, so we can do a little refactor:
  - `link_version`: the python link version, eg: `3.7m`
  - `lib_name`: the python library name, eg: `libpython3.7m.so`

Note: Those new properties are created because, I needed those values to create `should_build`

Author: opacam

pythonforandroid/python.py

@@ -103,6 +103,24 @@ def __init__(self, *args, **kwargs):
         self._ctx = None
         super(GuestPythonRecipe, self).__init__(*args, **kwargs)
 
+    @property
+    def link_version(self):
+        py_version = self.major_minor_version_string
+        if py_version[0] == '3':
+            py_version += 'm'
+        return py_version
+
+    @property
+    def lib_name(self):
+        return 'libpython{version}.so'.format(version=self.link_version)
+
+    def should_build(self, arch):
+        if not exists(self.link_root(arch.arch)):
+            return True
+        if exists(join(self.link_root(arch.arch), self.lib_name)):
+            return False
+        return True
+
     def get_recipe_env(self, arch=None, with_flags_in_cc=True):
         env = environ.copy()
 
@@ -244,12 +262,9 @@ def build_arch(self, arch):
                     _env=env)
 
             if not exists('python'):
-                py_version = self.major_minor_version_string
-                if self.major_minor_version_string[0] == '3':
-                    py_version += 'm'
                 shprint(sh.make, 'all', '-j', str(cpu_count()),
-                        'INSTSONAME=libpython{version}.so'.format(
-                            version=py_version), _env=env)
+                        'INSTSONAME={lib_name}'.format(lib_name=self.lib_name),
+                        _env=env)
 
             # TODO: Look into passing the path to pyconfig.h in a
             # better way, although this is probably acceptable
@@ -335,12 +350,7 @@ def create_python_bundle(self, dirn, arch):
                 copy2(filen, join(dirn, 'site-packages', filen))
 
         # copy the python .so files into place
-        python_build_dir = join(self.get_build_dir(arch.arch),
-                                'android-build')
-        python_lib_name = 'libpython' + self.major_minor_version_string
-        if self.major_minor_version_string[0] == '3':
-            python_lib_name += 'm'
-        shprint(sh.cp, join(python_build_dir, python_lib_name + '.so'),
+        shprint(sh.cp, join(self.link_root(arch.arch), self.lib_name),
                 join(self.ctx.dist_dir, self.ctx.dist_name, 'libs', arch.arch))
 
         info('Renaming .so files to reflect cross-compile')

pythonforandroid/recipe.py

@@ -690,9 +690,8 @@ def get_recipe_env(self, arch=None, with_flags_in_cc=True, with_python=False):
         env['PYTHON_INCLUDE_ROOT'] = self.ctx.python_recipe.include_root(arch.arch)
         env['PYTHON_LINK_ROOT'] = self.ctx.python_recipe.link_root(arch.arch)
         env['EXTRA_LDLIBS'] = ' -lpython{}'.format(
-            self.ctx.python_recipe.major_minor_version_string)
-        if 'python3' in self.ctx.python_recipe.name:
-            env['EXTRA_LDLIBS'] += 'm'
+            self.ctx.python_recipe.link_version
+        )
         return env
 
 
@@ -833,16 +832,13 @@ def get_recipe_env(self, arch=None, with_flags_in_cc=True):
         env['LANG'] = "en_GB.UTF-8"
 
         if not self.call_hostpython_via_targetpython:
-            python_name = self.ctx.python_recipe.name
             env['CFLAGS'] += ' -I{}'.format(
                 self.ctx.python_recipe.include_root(arch.arch)
             )
             env['LDFLAGS'] += ' -L{} -lpython{}'.format(
                 self.ctx.python_recipe.link_root(arch.arch),
-                self.ctx.python_recipe.major_minor_version_string,
+                self.ctx.python_recipe.link_version,
             )
-            if python_name == 'python3':
-                env['LDFLAGS'] += 'm'
 
             hppath = []
             hppath.append(join(dirname(self.hostpython_location), 'Lib'))

pythonforandroid/recipes/boost/__init__.py

@@ -91,9 +91,7 @@ def get_recipe_env(self, arch):
         env['PYTHON_ROOT'] = self.ctx.python_recipe.link_root(arch.arch)
         env['PYTHON_INCLUDE'] = self.ctx.python_recipe.include_root(arch.arch)
         env['PYTHON_MAJOR_MINOR'] = self.ctx.python_recipe.version[:3]
-        env['PYTHON_LINK_VERSION'] = self.ctx.python_recipe.major_minor_version_string
-        if 'python3' in self.ctx.python_recipe.name:
-            env['PYTHON_LINK_VERSION'] += 'm'
+        env['PYTHON_LINK_VERSION'] = self.ctx.python_recipe.link_version
 
         env['ARCH'] = self.select_build_arch(arch)
         env['CROSSHOST'] = env['ARCH'] + '-linux-androideabi'

pythonforandroid/recipes/cffi/__init__.py

@@ -44,9 +44,9 @@ def get_recipe_env(self, arch=None):
             env['BUILDLIB_PATH'],
         ])
         env['LDFLAGS'] += ' -L{}'.format(self.ctx.python_recipe.link_root(arch.arch))
-        env['LDFLAGS'] += ' -lpython{}'.format(self.ctx.python_recipe.major_minor_version_string)
-        if 'python3' in self.ctx.python_recipe.name:
-            env['LDFLAGS'] += 'm'
+        env['LDFLAGS'] += ' -lpython{}'.format(
+            self.ctx.python_recipe.link_version
+        )
         return env
 
 

pythonforandroid/recipes/numpy/__init__.py

@@ -38,13 +38,11 @@ def get_recipe_env(self, arch):
             self.ctx.ndk_platform
         )
 
-        py_ver = self.ctx.python_recipe.major_minor_version_string
+        py_ver = self.ctx.python_recipe.link_version
         py_inc_dir = self.ctx.python_recipe.include_root(arch.arch)
         py_lib_dir = self.ctx.python_recipe.link_root(arch.arch)
         flags += ' -I{}'.format(py_inc_dir)
         flags += ' -L{} -lpython{}'.format(py_lib_dir, py_ver)
-        if 'python3' in self.ctx.python_recipe.name:
-            flags += 'm'
 
         if flags not in env['CC']:
             env['CC'] += flags

pythonforandroid/recipes/opencv/__init__.py

@@ -53,11 +53,10 @@ def build_arch(self, arch):
             python_include_root = self.ctx.python_recipe.include_root(arch.arch)
             python_site_packages = self.ctx.get_site_packages_dir()
             python_link_root = self.ctx.python_recipe.link_root(arch.arch)
-            python_link_version = self.ctx.python_recipe.major_minor_version_string
-            if 'python3' in self.ctx.python_recipe.name:
-                python_link_version += 'm'
-            python_library = join(python_link_root,
-                                  'libpython{}.so'.format(python_link_version))
+            python_link_version = self.ctx.python_recipe.link_version
+            python_library = join(
+                python_link_root, self.ctx.python_recipe.lib_name
+            )
             python_include_numpy = join(python_site_packages,
                                         'numpy', 'core', 'include')