root: make X11 really optional on macOS (#32661)

* root: make X11 really optional on macOS
* Update var/spack/repos/builtin/packages/root/package.py
* remove when clauses in provides

Co-authored-by: Hadrien G. <knights_of_ni@gmx.com>

1 files changed, 57 insertions, 0 deletions

diff --git a/var/spack/repos/builtin/packages/apple-gl/package.py b/var/spack/repos/builtin/packages/apple-gl/package.py
new file mode 100644
index 0000000000..4f30d11b3d
--- /dev/null
+++ b/var/spack/repos/builtin/packages/apple-gl/package.py
@@ -0,0 +1,57 @@
+# Copyright 2013-2022 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+
+from spack.package import *
+
+
+class AppleGl(Package):
+    """Shim package for the core OpenGL library from Apple"""
+
+    homepage = "https://developer.apple.com/library/archive/documentation/GraphicsImaging/Conceptual/OpenGL-MacProgGuide/opengl_intro/opengl_intro.html"
+
+    maintainers = ["aphecetche"]
+
+    has_code = False
+
+    version("4.1.0")
+
+    provides("gl@4.1")
+
+    # Only supported on 'platform=darwin' and compiler=apple-clang
+    conflicts("platform=linux")
+    conflicts("platform=cray")
+    conflicts("%gcc")
+    conflicts("%clang")
+
+    phases = []
+
+    sdk_base = (
+        "/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/"
+        "Developer/SDKs/MacOSX"
+    )
+
+    def setup_dependent_build_environment(self, env, dependent_spec):
+        # we try to setup a build environment with enough hints
+        # for the build system to pick up on the Apple framework version
+        # of OpenGL.
+        # - for a cmake build we actually needs nothing at all as
+        # find_package(OpenGL) will do the right thing
+        # - for the rest of the build systems we'll assume that
+        # setting the C_INCLUDE_PATH will be enough for the compilation phase
+        # and *** for the link phase.
+        env.prepend_path("C_INCLUDE_PATH", self.sdk_base)
+
+    @property
+    def headers(self):
+        return HeaderList(
+            "{}.sdk/System/Library/Frameworks/OpenGL.framework/Headers".format(self.sdk_base)
+        )
+
+    @property
+    def libs(self):
+        return LibraryList(
+            "{}.sdk/System/Library/Frameworks/OpenGL.framework".format(self.sdk_base)
+        )