From 36c7a9cf9e51bd6d3f903204d5ea6e90901a8378 Mon Sep 17 00:00:00 2001
From: Ben Huntsman <ben@huntsmans.net>
Date: Tue, 30 May 2023 16:45:12 -0700
Subject: [PATCH] fix: add support for AIX (#988)

* fix: add support for AIX

* fix: Update README.rst with known issue on AIX

AIX support requires a version of CMake newer than the 3.22.0 version that
IBM supplies in their AIX Toolbox for Open Source Software.  IBM is aware
of the issue and will be providing a newer build soon, but for now we
should note that users will need to build their own copy of a newer CMake
on AIX at this time.
---
 README.rst                                    |  3 ++
 docs/skbuild.platform_specifics.rst           |  8 ++++++
 skbuild/platform_specifics/aix.py             | 28 +++++++++++++++++++
 .../platform_specifics/platform_factory.py    |  5 ++++
 tests/test_platform.py                        |  3 +-
 5 files changed, 46 insertions(+), 1 deletion(-)
 create mode 100644 skbuild/platform_specifics/aix.py

diff --git a/README.rst b/README.rst
index 91b3b30c..89631766 100644
--- a/README.rst
+++ b/README.rst
@@ -83,6 +83,9 @@ already addressed in `scikit-build-core`_.
   currently.
 * The cache directory (``_skbuild``) may need to be deleted between builds in
   some cases (like rebuilding with a different Python interpreter).
+* AIX requires a newer version of CMake than the IBM-supplied CMake 3.22.0
+  from the AIX Toolbox for Open Source Software.  We currently recommend
+  building CMake from source on AIX.
 
 We are also working on improving scikit-build, so there are some upcoming
 changes and deprecations:
diff --git a/docs/skbuild.platform_specifics.rst b/docs/skbuild.platform_specifics.rst
index de00c284..ac4af0fe 100644
--- a/docs/skbuild.platform_specifics.rst
+++ b/docs/skbuild.platform_specifics.rst
@@ -49,6 +49,14 @@ skbuild.platform\_specifics.osx module
    :undoc-members:
    :show-inheritance:
 
+skbuild.platform\_specifics.aix module
+----------------------------------------
+
+.. automodule:: skbuild.platform_specifics.aix
+   :members:
+   :undoc-members:
+   :show-inheritance:
+
 skbuild.platform\_specifics.platform\_factory module
 ----------------------------------------------------
 
diff --git a/skbuild/platform_specifics/aix.py b/skbuild/platform_specifics/aix.py
new file mode 100644
index 00000000..1d4ee1a2
--- /dev/null
+++ b/skbuild/platform_specifics/aix.py
@@ -0,0 +1,28 @@
+"""This module defines object specific to AIX platform."""
+
+from __future__ import annotations
+
+import sys
+import textwrap
+
+from . import unix
+
+
+class AIXPlatform(unix.UnixPlatform):
+    """AIX implementation of :class:`.abstract.CMakePlatform`."""
+
+    @property
+    def generator_installation_help(self) -> str:
+        """Return message guiding the user for installing a valid toolchain."""
+        return (
+            textwrap.dedent(
+                """
+            Building AIX wheels for Python {pyver} requires IBM XL C/C++.
+            Get it here:
+
+              https://www.ibm.com/products/xl-c-aix-compiler-power
+            """
+            )
+            .format(pyver=".".join(str(v) for v in sys.version_info[:2]))
+            .strip()
+        )
diff --git a/skbuild/platform_specifics/platform_factory.py b/skbuild/platform_specifics/platform_factory.py
index 9242cf70..d0740c06 100644
--- a/skbuild/platform_specifics/platform_factory.py
+++ b/skbuild/platform_specifics/platform_factory.py
@@ -45,5 +45,10 @@ def get_platform() -> abstract.CMakePlatform:
 
         return sunos.SunOSPlatform()
 
+    if this_platform == "aix":
+        from . import aix
+
+        return aix.AIXPlatform()
+
     msg = f"Unsupported platform: {this_platform:s}. Please contact the scikit-build team."
     raise RuntimeError(msg)
diff --git a/tests/test_platform.py b/tests/test_platform.py
index 3a35085f..5554a960 100644
--- a/tests/test_platform.py
+++ b/tests/test_platform.py
@@ -83,7 +83,7 @@ def test_generator_cleanup():
 
 
 @pytest.mark.parametrize(
-    "supported_platform", ["darwin", "freebsd", "openbsd", "linux", "windows", "os400", "cygwin", "sunos"]
+    "supported_platform", ["darwin", "freebsd", "openbsd", "linux", "windows", "os400", "cygwin", "sunos", "aix"]
 )
 def test_known_platform(supported_platform, mocker):
     mocker.patch("platform.system", return_value=supported_platform)
@@ -96,6 +96,7 @@ def test_known_platform(supported_platform, mocker):
         "os400": "BSD",
         "cygwin": "Cygwin",
         "sunos": "SunOS",
+        "aix": "AIX",
     }
     expected_platform_classname = f"{platforms[supported_platform]}Platform"
     assert get_platform().__class__.__name__ == expected_platform_classname