fix: use system ninja if adequate

Signed-off-by: Henry Schreiner <[email protected]>

mesonpy/__init__.py

@@ -65,6 +65,7 @@ class _depstr:
     """
     patchelf = 'patchelf >= 0.11.0'
     wheel = 'wheel >= 0.36.0'  # noqa: F811
+    ninja = 'ninja >= 1.7'
 
 
 _COLORS = {
@@ -951,6 +952,27 @@ def _project(config_settings: Optional[Dict[Any, Any]]) -> Iterator[Project]:
         yield project
 
 
+def _get_ninja_if_needed() -> List[str]:
+    # only add ninja if it is not present or is too low a version
+    ninja = shutil.which('ninja')
+    if ninja is None:
+        return []
+
+    result = subprocess.run(['ninja', '--version'], check=False, text=True, capture_output=True)
+    try:
+        candidate_version = float('.'.join(result.stdout.split('.')[:2]))
+    except ValueError:
+        return [_depstr.ninja]
+
+    return [] if candidate_version >= 1.7 else [_depstr.ninja]
+
+
+def get_requires_for_build_sdist(
+    config_settings: Optional[Dict[str, str]] = None,
+) -> List[str]:
+    return _get_ninja_if_needed()
+
+
 def build_sdist(
     sdist_directory: str,
     config_settings: Optional[Dict[Any, Any]] = None,
@@ -965,13 +987,14 @@ def build_sdist(
 def get_requires_for_build_wheel(
     config_settings: Optional[Dict[str, str]] = None,
 ) -> List[str]:
-    dependencies = [_depstr.wheel]
+    dependencies = [_depstr.wheel, *_get_ninja_if_needed()]
     with _project(config_settings) as project:
         if not project.is_pure and platform.system() == 'Linux':
             # we may need patchelf
             if not shutil.which('patchelf'):  # XXX: This is slightly dangerous.
                 # patchelf not already acessible on the system
                 dependencies.append(_depstr.patchelf)
+
     return dependencies
 
 

pyproject.toml

@@ -3,7 +3,6 @@ build-backend = 'mesonpy'
 backend-path = ['.']
 requires = [
   'meson>=0.63.3',
-  'ninja',
   'pyproject-metadata>=0.5.0',
   'tomli>=1.0.0',
   'typing-extensions>=3.7.4; python_version<"3.8"',
@@ -27,7 +26,6 @@ classifiers = [
 dependencies = [
   'colorama; os_name == "nt"',
   'meson>=0.63.3',
-  'ninja',
   'pyproject-metadata>=0.5.0', # not a hard dependency, only needed for projects that use PEP 621 metadata
   'tomli>=1.0.0',
   'typing-extensions>=3.7.4; python_version<"3.8"',

tests/test_pep517.py

@@ -1,6 +1,10 @@
 # SPDX-License-Identifier: MIT
 
-import platform
+import shutil
+import subprocess
+import sys
+
+from typing import List
 
 import pytest
 
@@ -9,28 +13,32 @@
 from .conftest import cd_package
 
 
-if platform.system() == 'Linux':
-    VENDORING_DEPS = {mesonpy._depstr.patchelf}
-else:
-    VENDORING_DEPS = set()
-
-
-@pytest.mark.parametrize(
-    ('package', 'system_patchelf', 'expected'),
-    [
-        ('pure', True, set()),  # pure and system patchelf
-        ('library', True, set()),  # not pure and system patchelf
-        ('pure', False, set()),  # pure and no system patchelf
-        ('library', False, VENDORING_DEPS),  # not pure and no system patchelf
-    ]
-)
-def test_get_requires_for_build_wheel(mocker, package, expected, system_patchelf):
-    mock = mocker.patch('shutil.which', return_value=system_patchelf)
-
-    if mock.called:  # sanity check for the future if we add another usage
-        mock.assert_called_once_with('patchelf')
+@pytest.mark.parametrize('package', ['pure', 'library'])
+@pytest.mark.parametrize('system_patchelf', [True, False], ids=['patchelf', 'nopatchelf'])
+@pytest.mark.parametrize('ninja', [None, '1.6', '1.10'], ids=['noninjga', 'oldninja', 'newninja'])
+def test_get_requires_for_build_wheel(monkeypatch, package, system_patchelf, ninja):
+    def which(prog: str) -> bool:
+        if prog == 'patchelf':
+            return system_patchelf
+        if prog == 'ninja':
+            return ninja is not None
+        # smoke check for the future if we add another usage
+        raise AssertionError(f'Called with {prog}, tests not expecting that usage')
+
+    def run(cmd: List[str], *args: object, **kwargs: object) -> subprocess.CompletedProcess:
+        if cmd != ['ninja', '--version']:
+            # smoke check for the future if we add another usage
+            raise AssertionError(f'Called with {cmd}, tests not expecting that usage')
+        return subprocess.CompletedProcess(cmd, 0, f'{ninja}\n', '')
+
+    monkeypatch.setattr(shutil, 'which', which)
+    monkeypatch.setattr(subprocess, 'run', run)
+
+    expected = {mesonpy._depstr.wheel}
+    if system_patchelf and sys.platform.startswith('linux'):
+        expected |= {mesonpy._depstr.patchelf}
+    if ninja is None or float(ninja) < 1.7:
+        expected |= {mesonpy._depstr.ninja}
 
     with cd_package(package):
-        assert set(mesonpy.get_requires_for_build_wheel()) == expected | {
-            mesonpy._depstr.wheel,
-        }
+        assert set(mesonpy.get_requires_for_build_wheel()) == expected