BLD: enable building NumPy with Meson

This enables building with NumPy on Linux and macOS. Windows support
should be complete to, but is untested as of now and may need a few
tweaks. This contains:
- A set of `meson.build` files and related code generation script
  tweaks, header templates, etc.
- One CI job on Linux
- Basic docs on using Meson to build NumPy (not yet integrated in the
  html docs, it's too early for that - this is for early adopters right
  now).

The build should be complete, with the major exception of SIMD support.
The full test suite passes. See gh-22546 for the tracking issue with
detailed notes on the plan for switching NumPy to Meson as its build
system.

Co-authored-by: Stefan van der Walt <stefanv@berkeley.edu>

1 files changed, 86 insertions, 0 deletions

diff --git a/tools/check_installed_files.py b/tools/check_installed_files.py
new file mode 100644
index 000000000..f15ca7969
--- /dev/null
+++ b/tools/check_installed_files.py
@@ -0,0 +1,86 @@
+"""
+Check if all the test and .pyi files are installed after building.
+
+Examples::
+
+    $ python check_installed_files.py install_dirname
+
+        install_dirname:
+            the relative path to the directory where NumPy is installed after
+            building and running `meson install`.
+
+Notes
+=====
+
+The script will stop on encountering the first missing file in the install dir,
+it will not give a full listing. This should be okay, because the script is
+meant for use in CI so it's not like many files will be missing at once.
+
+"""
+
+import os
+import glob
+import sys
+
+
+CUR_DIR = os.path.abspath(os.path.join(os.path.dirname(__file__)))
+ROOT_DIR = os.path.dirname(CUR_DIR)
+NUMPY_DIR = os.path.join(ROOT_DIR, 'numpy')
+
+
+# Files whose installation path will be different from original one
+changed_installed_path = {
+    #'numpy/_build_utils/some_file.py': 'numpy/lib/some_file.py'
+}
+
+
+def main(install_dir):
+    INSTALLED_DIR = os.path.join(ROOT_DIR, install_dir)
+    if not os.path.exists(INSTALLED_DIR):
+        raise ValueError(
+            f"Provided install dir {INSTALLED_DIR} does not exist"
+        )
+
+    numpy_test_files = get_files(NUMPY_DIR, kind='test')
+    installed_test_files = get_files(INSTALLED_DIR, kind='test')
+
+    # Check test files detected in repo are installed
+    for test_file in numpy_test_files.keys():
+        if test_file not in installed_test_files.keys():
+            raise Exception(
+                "%s is not installed" % numpy_test_files[test_file]
+            )
+
+    print("----------- All the test files were installed --------------")
+
+    numpy_pyi_files = get_files(NUMPY_DIR, kind='stub')
+    installed_pyi_files = get_files(INSTALLED_DIR, kind='stub')
+
+    # Check *.pyi files detected in repo are installed
+    for pyi_file in numpy_pyi_files.keys():
+        if pyi_file not in installed_pyi_files.keys():
+            raise Exception("%s is not installed" % numpy_pyi_files[pyi_file])
+
+    print("----------- All the .pyi files were installed --------------")
+
+
+def get_files(dir_to_check, kind='test'):
+    files = dict()
+    patterns = {
+        'test': f'{dir_to_check}/**/test_*.py',
+        'stub': f'{dir_to_check}/**/*.pyi',
+    }
+    for path in glob.glob(patterns[kind], recursive=True):
+        relpath = os.path.relpath(path, dir_to_check)
+        files[relpath] = path
+
+    return files
+
+
+if __name__ == '__main__':
+    if not len(sys.argv) == 2:
+        raise ValueError("Incorrect number of input arguments, need "
+                         "check_installation.py relpath/to/installed/numpy")
+
+    install_dir = sys.argv[1]
+    main(install_dir)