add conan.tools.android.android_abi() (#12873)

* add conan.tools.android.android_abi

* improve unit tests

* improt unit test again

* Dont fall back to settings if context settings are missing

* Fix tests

---------

Co-authored-by: Rubén Rincón Blanco <rubenrb@jfrog.com>

conan/tools/android/__init__.py

@@ -0,0 +1 @@
+from conan.tools.android.utils import android_abi

conan/tools/android/utils.py

@@ -0,0 +1,31 @@
+from conan.errors import ConanException
+
+
+def android_abi(conanfile, context="host"):
+    """
+    Returns Android-NDK ABI
+    :param conanfile: ConanFile instance
+    :param context: either "host", "build" or "target"
+    :return: Android-NDK ABI
+    """
+    if context not in ("host", "build", "target"):
+        raise ConanException(f"context argument must be either 'host', 'build' or 'target', was '{context}'")
+
+    try:
+        settings = getattr(conanfile, f"settings_{context}")
+    except AttributeError:
+        if context == "host":
+            settings = conanfile.settings
+        else:
+            raise ConanException(f"settings_{context} not declared in recipe")
+    arch = settings.get_safe("arch")
+    # https://cmake.org/cmake/help/latest/variable/CMAKE_ANDROID_ARCH_ABI.html
+    return {
+        "armv5el": "armeabi",
+        "armv5hf": "armeabi",
+        "armv5": "armeabi",
+        "armv6": "armeabi-v6",
+        "armv7": "armeabi-v7a",
+        "armv7hf": "armeabi-v7a",
+        "armv8": "arm64-v8a",
+    }.get(arch, arch)

conan/tools/cmake/toolchain/blocks.py

@@ -6,6 +6,7 @@
 from jinja2 import Template
 
 from conan.tools._compilers import architecture_flag, libcxx_flags
+from conan.tools.android.utils import android_abi
 from conan.tools.apple.apple import is_apple_os, to_apple_arch
 from conan.tools.build import build_jobs
 from conan.tools.build.cross_building import cross_building
@@ -301,11 +302,6 @@ def context(self):
         if os_ != "Android":
             return
 
-        android_abi = {"x86": "x86",
-                       "x86_64": "x86_64",
-                       "armv7": "armeabi-v7a",
-                       "armv8": "arm64-v8a"}.get(str(self._conanfile.settings.arch))
-
         # TODO: only 'c++_shared' y 'c++_static' supported?
         #  https://developer.android.com/ndk/guides/cpp-support
         libcxx_str = self._conanfile.settings.get_safe("compiler.libcxx")
@@ -317,7 +313,7 @@ def context(self):
 
         ctxt_toolchain = {
             'android_platform': 'android-' + str(self._conanfile.settings.os.api_level),
-            'android_abi': android_abi,
+            'android_abi': android_abi(self._conanfile),
             'android_stl': libcxx_str,
             'android_ndk_path': android_ndk_path,
         }

conans/test/unittests/tools/android/test_android_tools.py

@@ -0,0 +1,79 @@
+from conans.test.utils.mocks import ConanFileMock, MockSettings
+from conans.errors import ConanException
+from conan.tools.android import android_abi
+
+from pytest import raises
+
+def test_tools_android_abi():
+    settings_linux = MockSettings({"os": "Linux", "arch": "foo"})
+
+    for (arch, expected) in [
+        ("armv5el", "armeabi"),
+        ("armv5hf", "armeabi"),
+        ("armv5", "armeabi"),
+        ("armv6", "armeabi-v6"),
+        ("armv7", "armeabi-v7a"),
+        ("armv7hf", "armeabi-v7a"),
+        ("armv8", "arm64-v8a"),
+        ("x86", "x86"),
+        ("x86_64", "x86_64"),
+        ("mips", "mips"),
+        ("mips_64", "mips_64"),
+    ]:
+        conanfile = ConanFileMock()
+        settings_android = MockSettings({"os": "Android", "arch": arch})
+
+        # 1 profile (legacy native build)
+        conanfile.settings = settings_android
+        assert android_abi(conanfile) == expected
+        assert android_abi(conanfile, context="host") == expected
+
+        with raises(ConanException):
+            assert android_abi(conanfile, context="build") == expected
+
+        with raises(ConanException):
+            assert android_abi(conanfile, context="target") == expected
+
+        # 2 profiles
+        ## native build
+        conanfile.settings = settings_android
+        conanfile.settings_host = settings_android
+        conanfile.settings_build = settings_android
+        assert android_abi(conanfile) == expected
+        assert android_abi(conanfile, context="host") == expected
+        assert android_abi(conanfile, context="build") == expected
+
+        with raises(ConanException):
+            assert android_abi(conanfile, context="target") == expected
+
+        ## cross-build from Android to Linux (quite hypothetical)
+        conanfile.settings = settings_linux
+        conanfile.settings_host = settings_linux
+        conanfile.settings_build = settings_android
+        assert android_abi(conanfile) != expected
+        assert android_abi(conanfile, context="host") != expected
+        assert android_abi(conanfile, context="build") == expected
+
+        with raises(ConanException):
+            assert android_abi(conanfile, context="target")
+
+        ## cross-build a recipe from Linux to Android:
+        ### test android_abi in recipe itself
+        conanfile.settings = settings_android
+        conanfile.settings_host = settings_android
+        conanfile.settings_build = settings_linux
+        assert android_abi(conanfile) == expected
+        assert android_abi(conanfile, context="host") == expected
+        assert android_abi(conanfile, context="build") != expected
+        with raises(ConanException):
+            android_abi(conanfile, context="target")
+
+        ### test android_abi in "compiler recipe" (ie a android-ndk recipe in tool_requires of recipe being cross-build)
+        conanfile.settings = settings_linux
+        conanfile.settings_host = settings_linux
+        conanfile.settings_build = settings_linux
+        conanfile.settings_target = settings_android
+        assert android_abi(conanfile) != expected
+        assert android_abi(conanfile, context="host") != expected
+        assert android_abi(conanfile, context="build") != expected
+        assert android_abi(conanfile, context="target") == expected