Add EGL support to ParaView and Glew (#39800)

* Add EGL support to ParaView and Glew

add a package for egl that provides GL but also adds
EGL libs and headers for projects that need them

Fix a header problem with the opengl package

Format files using black

* better description for egl variant description

Co-authored-by: Vicente Bolea <vicente.bolea@gmail.com>

* better check/setup of non egl variant dependencies

Co-authored-by: Vicente Bolea <vicente.bolea@gmail.com>

* Add biddisco as maintainer

* Fix unused var style warning

* Add egl conflicts for other gl providers

---------

Co-authored-by: Vicente Bolea <vicente.bolea@gmail.com>

1 files changed, 92 insertions, 0 deletions

diff --git a/var/spack/repos/builtin/packages/egl/package.py b/var/spack/repos/builtin/packages/egl/package.py
new file mode 100644
index 0000000000..d79f1e30db
--- /dev/null
+++ b/var/spack/repos/builtin/packages/egl/package.py
@@ -0,0 +1,92 @@
+# Copyright 2013-2023 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)
+
+import re
+import sys
+
+from spack.package import *
+
+
+class Egl(BundlePackage):
+    """Placeholder for external EGL(OpenGL) libraries from hardware vendors"""
+
+    homepage = "https://www.khronos.org/egl"
+    maintainers("biddisco")
+
+    version("1.5")
+
+    # This should really be when='platform=linux' but can't because of a
+    # current bug in when and how ArchSpecs are constructed
+    if sys.platform.startswith("linux"):
+        provides("gl@4.5")
+
+    # conflict with GLX
+    conflicts("glx")
+
+    # not always available, but sometimes
+    executables = ["^eglinfo$"]
+
+    @classmethod
+    def determine_version(cls, exe):
+        if exe:
+            output = Executable(exe)(output=str, error=str)
+            match = re.search(r"EGL version string: (\S+)", output)
+            return match.group(1) if match else None
+        else:
+            return None
+
+    # Override the fetcher method to throw a useful error message;
+    # fixes GitHub issue (#7061) in which this package threw a
+    # generic, uninformative error during the `fetch` step,
+    @property
+    def fetcher(self):
+        msg = """This package is intended to be a placeholder for
+        system-provided EGL(OpenGL) libraries from hardware vendors.  Please
+        download and install EGL drivers/libraries for your graphics
+        hardware separately, and then set that up as an external package.
+        An example of a working packages.yaml:
+
+        packages:
+          egl:
+            buildable: False
+            externals:
+            - spec: egl@1.5.0
+              prefix: /usr/
+
+        In that case, /usr/ should contain these two folders:
+
+        include/EGL/      (egl headers, including "egl.h")
+        lib               (egl libraries, including "libEGL.so")
+
+        """
+        raise InstallError(msg)
+
+    @fetcher.setter  # Since fetcher is read-write, must override both
+    def fetcher(self):
+        _ = self.fetcher
+
+    @property
+    def headers(self):
+        return self.egl_headers
+
+    @property
+    def libs(self):
+        return self.egl_libs
+
+    @property
+    def egl_headers(self):
+        header_name = "GL/gl"
+        gl_header = find_headers(header_name, root=self.prefix, recursive=True)
+        header_name = "EGL/egl"
+        egl_header = find_headers(header_name, root=self.prefix, recursive=True)
+        return gl_header + egl_header
+
+    @property
+    def egl_libs(self):
+        lib_name = "libGL"
+        gl_lib = find_libraries(lib_name, root=self.prefix, recursive=True)
+        lib_name = "libEGL"
+        egl_lib = find_libraries(lib_name, root=self.prefix, recursive=True)
+        return gl_lib + egl_lib