#5958 New tool: cppstd minimum version required (#5997)

* #5958 New tool: cppstd minimum version required

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* #5958 Fix bad indentation

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* #5958 Add gnu cppstd to the tests

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* #5958 Add gnu extensions

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* #5958 Mock distro for Linux

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* #5958 Fix tests on MacOS

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* #5958 Validate cppstd by str

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* #5958 Add valid_minimum_cppstd

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* Update conans/client/tools/settings.py

Co-Authored-By: Javier G. Sogo <jgsogo@gmail.com>

* Update conans/client/tools/settings.py

Co-Authored-By: Javier G. Sogo <jgsogo@gmail.com>

* Update conans/tools.py

Co-Authored-By: Javier G. Sogo <jgsogo@gmail.com>

* #5958 Apply @jgsogo suggestions

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* #5958 Fix broken tests for cppstd

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* Update conans/tools.py

Co-Authored-By: Javier G. Sogo <jgsogo@gmail.com>

* #5958 Remove duplicated import

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* #5958 Fix C++98 comparison

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* #5958 Add unit tests for check_min_cppstd

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* #5958 Fix Conanfile test

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* #5958 Add unit tests for valid_min_cppstd

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* #5958 Remove duplicated functional tests

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* #5958 Test improvements from code review

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* #5958 remove unused import

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* #5958 cppstd must be a number

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* #5958 Dont use assert for production code

- Raise ConanExcetion when some input is incorrect

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* #5958 Validate target OS using ConanFile settings

- The target OS should be considered as important for cpp version

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* #5958 Use default compiler cppstd when not included in settings

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* #5958 Fix functional test

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* Review

* Fix bug

* #5958 Detect temporary C++ standard

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* #5958 Remove temporary C++ standard

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* #5958 Do not validate OS for GNU extensions

Signed-off-by: Uilian Ries <uilianries@gmail.com>

* #5958 Update GNU extensions description

Signed-off-by: Uilian Ries <uilianries@gmail.com>

conans/client/tools/__init__.py

@@ -15,6 +15,8 @@
 # noinspection PyUnresolvedReferences
 from .scm import *
 # noinspection PyUnresolvedReferences
+from .settings import *
+# noinspection PyUnresolvedReferences
 from .system_pm import *
 # noinspection PyUnresolvedReferences
 from .win import *

conans/client/tools/settings.py

@@ -0,0 +1,71 @@
+from conans.client.build.cppstd_flags import cppstd_default
+from conans.errors import ConanInvalidConfiguration, ConanException
+
+
+def check_min_cppstd(conanfile, cppstd, gnu_extensions=False):
+    """ Check if current cppstd fits the minimal version required.
+
+        In case the current cppstd doesn't fit the minimal version required
+        by cppstd, a ConanInvalidConfiguration exception will be raised.
+
+        1. If settings.compiler.cppstd, the tool will use settings.compiler.cppstd to compare
+        2. It not settings.compiler.cppstd, the tool will use compiler to compare (reading the
+           default from cppstd_default)
+        3. If not settings.compiler is present (not declared in settings) will raise because it
+           cannot compare.
+
+    :param conanfile: ConanFile instance with cppstd to be compared
+    :param cppstd: Minimal cppstd version required
+    :param gnu_extensions: GNU extension is required (e.g gnu17)
+    """
+    if not str(cppstd).isdigit():
+        raise ConanException("cppstd parameter must be a number")
+
+    def less_than(lhs, rhs):
+        def extract_cpp_version(_cppstd):
+            return str(_cppstd).replace("gnu", "")
+
+        def add_millennium(_cppstd):
+            return "19%s" % _cppstd if _cppstd == "98" else "20%s" % _cppstd
+
+        lhs = add_millennium(extract_cpp_version(lhs))
+        rhs = add_millennium(extract_cpp_version(rhs))
+        return lhs < rhs
+
+    def check_required_gnu_extension(_cppstd):
+        if gnu_extensions and "gnu" not in _cppstd:
+            raise ConanInvalidConfiguration("The cppstd GNU extension is required")
+
+    def deduced_cppstd():
+        cppstd = conanfile.settings.get_safe("compiler.cppstd")
+        if cppstd:
+            return cppstd
+
+        compiler = conanfile.settings.get_safe("compiler")
+        compiler_version = conanfile.settings.get_safe("compiler.version")
+        if not compiler or not compiler_version:
+            raise ConanException("Could not obtain cppstd because there is no declared "
+                                 "compiler in the 'settings' field of the recipe.")
+        return cppstd_default(compiler, compiler_version)
+
+    current_cppstd = deduced_cppstd()
+    check_required_gnu_extension(current_cppstd)
+
+    if less_than(current_cppstd, cppstd):
+        raise ConanInvalidConfiguration("Current cppstd ({}) is lower than the required C++ "
+                                        "standard ({}).".format(current_cppstd, cppstd))
+
+
+def valid_min_cppstd(conanfile, cppstd, gnu_extensions=False):
+    """ Validate if current cppstd fits the minimal version required.
+
+    :param conanfile: ConanFile instance with cppstd to be compared
+    :param cppstd: Minimal cppstd version required
+    :param gnu_extensions: GNU extension is required (e.g gnu17). This option ONLY works on Linux.
+    :return: True, if current cppstd matches the required cppstd version. Otherwise, False.
+    """
+    try:
+        check_min_cppstd(conanfile, cppstd, gnu_extensions)
+    except ConanInvalidConfiguration:
+        return False
+    return True

conans/test/functional/tools/cppstd_minimum_version_test.py

@@ -0,0 +1,51 @@
+import unittest
+from parameterized import parameterized
+from textwrap import dedent
+
+from conans.test.utils.tools import TestClient
+
+
+class CppStdMinimumVersionTests(unittest.TestCase):
+
+    CONANFILE = dedent("""
+        import os
+        from conans import ConanFile
+        from conans.tools import check_min_cppstd, valid_min_cppstd
+
+        class Fake(ConanFile):
+            name = "fake"
+            version = "0.1"
+            settings = "compiler"
+
+            def configure(self):
+                check_min_cppstd(self, "17", False)
+                self.output.info("valid standard")
+                assert valid_min_cppstd(self, "17", False)
+        """)
+
+    PROFILE = dedent("""
+        [settings]
+        compiler=gcc
+        compiler.version=9
+        compiler.libcxx=libstdc++
+        {}
+        """)
+
+    def setUp(self):
+        self.client = TestClient()
+        self.client.save({"conanfile.py": CppStdMinimumVersionTests.CONANFILE})
+
+    @parameterized.expand(["17", "gnu17"])
+    def test_cppstd_from_settings(self, cppstd):
+        profile = CppStdMinimumVersionTests.PROFILE.replace("{}", "compiler.cppstd=%s" % cppstd)
+        self.client.save({"myprofile":  profile})
+        self.client.run("create . user/channel -pr myprofile")
+        self.assertIn("valid standard", self.client.out)
+
+    @parameterized.expand(["11", "gnu11"])
+    def test_invalid_cppstd_from_settings(self, cppstd):
+        profile = CppStdMinimumVersionTests.PROFILE.replace("{}", "compiler.cppstd=%s" % cppstd)
+        self.client.save({"myprofile": profile})
+        self.client.run("create . user/channel -pr myprofile", assert_error=True)
+        self.assertIn("Invalid configuration: Current cppstd (%s) is lower than the required C++ "
+                      "standard (17)." % cppstd, self.client.out)

conans/test/unittests/client/tools/cppstd_required_test.py

@@ -0,0 +1,158 @@
+import unittest
+from mock import mock
+from parameterized import parameterized
+
+from conans.test.utils.conanfile import MockConanfile, MockSettings
+from conans.client.tools import OSInfo
+from conans.errors import ConanInvalidConfiguration, ConanException
+
+from conans.tools import check_min_cppstd, valid_min_cppstd
+
+
+class UserInputTests(unittest.TestCase):
+
+    def test_check_cppstd_type(self):
+        """ cppstd must be a number
+        """
+        conanfile = MockConanfile(MockSettings({}))
+        with self.assertRaises(ConanException) as raises:
+            check_min_cppstd(conanfile, "gnu17", False)
+        self.assertEqual("cppstd parameter must be a number", str(raises.exception))
+
+
+class CheckMinCppStdTests(unittest.TestCase):
+
+    def _create_conanfile(self, compiler, version, os, cppstd, libcxx=None):
+        settings = MockSettings({"arch": "x86_64",
+                                 "build_type": "Debug",
+                                 "os": os,
+                                 "compiler": compiler,
+                                 "compiler.version": version,
+                                 "compiler.cppstd": cppstd})
+        if libcxx:
+            settings.values["compiler.libcxx"] = libcxx
+        conanfile = MockConanfile(settings)
+        return conanfile
+
+    @parameterized.expand(["98", "11", "14", "17"])
+    def test_check_min_cppstd_from_settings(self, cppstd):
+        """ check_min_cppstd must accept cppstd less/equal than cppstd in settings
+        """
+        conanfile = self._create_conanfile("gcc", "9", "Linux", "17", "libstdc++")
+        check_min_cppstd(conanfile, cppstd, False)
+
+    @parameterized.expand(["98", "11", "14"])
+    def test_check_min_cppstd_from_outdated_settings(self, cppstd):
+        """ check_min_cppstd must raise when cppstd is greater when supported on settings
+        """
+        conanfile = self._create_conanfile("gcc", "9", "Linux", cppstd, "libstdc++")
+        with self.assertRaises(ConanInvalidConfiguration) as raises:
+            check_min_cppstd(conanfile, "17", False)
+        self.assertEqual("Current cppstd ({}) is lower than the required C++ standard "
+                         "(17).".format(cppstd), str(raises.exception))
+
+    @parameterized.expand(["98", "11", "14", "17"])
+    def test_check_min_cppstd_from_settings_with_extension(self, cppstd):
+        """ current cppstd in settings must has GNU extension when extensions is enabled
+        """
+        conanfile = self._create_conanfile("gcc", "9", "Linux", "gnu17", "libstdc++")
+        check_min_cppstd(conanfile, cppstd, True)
+
+        conanfile.settings.values["compiler.cppstd"] = "17"
+        with self.assertRaises(ConanException) as raises:
+            check_min_cppstd(conanfile, cppstd, True)
+        self.assertEqual("The cppstd GNU extension is required", str(raises.exception))
+
+    def test_check_min_cppstd_unsupported_standard(self):
+        """ check_min_cppstd must raise when the compiler does not support a standard
+        """
+        conanfile = self._create_conanfile("gcc", "9", "Linux", None, "libstdc++")
+        with self.assertRaises(ConanInvalidConfiguration) as raises:
+            check_min_cppstd(conanfile, "42", False)
+        self.assertEqual("Current cppstd (gnu14) is lower than the required C++ standard (42).",
+                         str(raises.exception))
+
+    def test_check_min_cppstd_gnu_compiler_extension(self):
+        """ Current compiler must support GNU extension on Linux when extensions is required
+        """
+        conanfile = self._create_conanfile("gcc", "9", "Linux", None, "libstdc++")
+        with mock.patch("platform.system", mock.MagicMock(return_value="Linux")):
+            with mock.patch.object(OSInfo, '_get_linux_distro_info'):
+                with mock.patch("conans.client.tools.settings.cppstd_default", return_value="17"):
+                    with self.assertRaises(ConanException) as raises:
+                        check_min_cppstd(conanfile, "17", True)
+                    self.assertEqual("The cppstd GNU extension is required", str(raises.exception))
+
+    def test_no_compiler_declared(self):
+        conanfile = self._create_conanfile(None, None, "Linux", None, "libstdc++")
+        with self.assertRaises(ConanException) as raises:
+            check_min_cppstd(conanfile, "14", False)
+        self.assertEqual("Could not obtain cppstd because there is no declared compiler in the "
+                         "'settings' field of the recipe.", str(raises.exception))
+
+
+class ValidMinCppstdTests(unittest.TestCase):
+
+    def _create_conanfile(self, compiler, version, os, cppstd, libcxx=None):
+        settings = MockSettings({"arch": "x86_64",
+                                 "build_type": "Debug",
+                                 "os": os,
+                                 "compiler": compiler,
+                                 "compiler.version": version,
+                                 "compiler.cppstd": cppstd})
+        if libcxx:
+            settings.values["compiler.libcxx"] = libcxx
+        conanfile = MockConanfile(settings)
+        return conanfile
+
+    @parameterized.expand(["98", "11", "14", "17"])
+    def test_valid_min_cppstd_from_settings(self, cppstd):
+        """ valid_min_cppstd must accept cppstd less/equal than cppstd in settings
+        """
+        conanfile = self._create_conanfile("gcc", "9", "Linux", "17", "libstdc++")
+        self.assertTrue(valid_min_cppstd(conanfile, cppstd, False))
+
+    @parameterized.expand(["98", "11", "14"])
+    def test_valid_min_cppstd_from_outdated_settings(self, cppstd):
+        """ valid_min_cppstd returns False when cppstd is greater when supported on settings
+        """
+        conanfile = self._create_conanfile("gcc", "9", "Linux", cppstd, "libstdc++")
+        self.assertFalse(valid_min_cppstd(conanfile, "17", False))
+
+    @parameterized.expand(["98", "11", "14", "17"])
+    def test_valid_min_cppstd_from_settings_with_extension(self, cppstd):
+        """ valid_min_cppstd must returns True when current cppstd in settings has GNU extension and
+            extensions is enabled
+        """
+        conanfile = self._create_conanfile("gcc", "9", "Linux", "gnu17", "libstdc++")
+        self.assertTrue(valid_min_cppstd(conanfile, cppstd, True))
+
+        conanfile.settings.values["compiler.cppstd"] = "17"
+        self.assertFalse(valid_min_cppstd(conanfile, cppstd, True))
+
+    def test_valid_min_cppstd_unsupported_standard(self):
+        """ valid_min_cppstd must returns False when the compiler does not support a standard
+        """
+        conanfile = self._create_conanfile("gcc", "9", "Linux", None, "libstdc++")
+        self.assertFalse(valid_min_cppstd(conanfile, "42", False))
+
+    def test_valid_min_cppstd_gnu_compiler_extension(self):
+        """ valid_min_cppstd must returns False when current compiler does not support GNU extension
+            on Linux and extensions is required
+        """
+        conanfile = self._create_conanfile("gcc", "9", "Linux", None, "libstdc++")
+        with mock.patch("platform.system", mock.MagicMock(return_value="Linux")):
+            with mock.patch.object(OSInfo, '_get_linux_distro_info'):
+                with mock.patch("conans.client.tools.settings.cppstd_default", return_value="gnu1z"):
+                    self.assertFalse(valid_min_cppstd(conanfile, "20", True))
+
+    @parameterized.expand(["98", "11", "14", "17"])
+    def test_min_cppstd_mingw_windows(self, cppstd):
+        """ GNU extensions HAS effect on Windows when running a cross-building for Linux
+        """
+        with mock.patch("platform.system", mock.MagicMock(return_value="Windows")):
+            conanfile = self._create_conanfile("gcc", "9", "Linux", "gnu17", "libstdc++")
+            self.assertTrue(valid_min_cppstd(conanfile, cppstd, True))
+
+            conanfile.settings.values["compiler.cppstd"] = "17"
+            self.assertFalse(valid_min_cppstd(conanfile, cppstd, True))

conans/tools.py

@@ -19,6 +19,7 @@
 from conans.client.tools.env import *  # pylint: disable=unused-import
 from conans.client.tools.pkg_config import *  # pylint: disable=unused-import
 from conans.client.tools.scm import *  # pylint: disable=unused-import
+from conans.client.tools.settings import *  # pylint: disable=unused-import
 from conans.client.tools.apple import *
 from conans.client.tools.android import *
 # Tools form conans.util