upcxx: Update the UPC++ package to 2021.9.0 (#26996)

* upcxx: Update the UPC++ package to 2021.9.0

* Add the new release, and a missing older one.

* Remove the spack package cruft for supporting the obsolete build system that
  was present in older versions that are no longer supported.

* General cleanups.

Support for library versions older than 2020.3.0 is officially retired,
for two reasons:

1. Releases prior to 2020.3.0 had a required dependency on Python 2,
   which is [officially EOL](https://www.python.org/doc/sunset-python-2/)
   as of Jan 1 2020, and is no longer considered secure.
2. (Most importantly) The UPC++ development team is unable/unwilling to
   support releases more than two years old.  UPC++ provides robust
   backwards-compatibility to earlier releases of UPC++ v1.0, with very
   rare well-documented/well-motivated exceptions.  Users are strongly
   encouraged to update to a current version of UPC++.

NOTE: Most of the lines changed in this commit are simply re-indentation,
and thus might be best reviewed in a diff that ignores whitespace.

* upcxx: Detect Cray XC more explicitly

This change is necessary to prevent false matches occuring on new Cray Shasta
systems, which do not use the aries network but were incorrectly being treated
as a Cray XC + aries platform.

UPC++ has not yet deployed official native support for Cray Shasta, but this
change is sufficient to allow building the portable backends there.

var/spack/repos/builtin/packages/upcxx/package.py

@@ -3,11 +3,18 @@
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
+import os
+
 from spack import *
 
 
+def is_CrayXC():
+    return (spack.platforms.host().name == 'cray') and \
+           (os.environ.get('CRAYPE_NETWORK_TARGET') == "aries")
+
+
 def cross_detect():
-    if spack.platforms.host().name == 'cray':
+    if is_CrayXC():
         if which('srun'):
             return 'cray-aries-slurm'
         if which('aprun'):
@@ -24,6 +31,7 @@ class Upcxx(Package):
 
     homepage = "https://upcxx.lbl.gov"
     maintainers = ['bonachea']
+    url = "https://bitbucket.org/berkeleylab/upcxx/downloads/upcxx-2021.3.0.tar.gz"
     git = 'https://bitbucket.org/berkeleylab/upcxx.git'
 
     tags = ['e4s']
@@ -31,13 +39,15 @@ class Upcxx(Package):
     version('develop', branch='develop')
     version('master',  branch='master')
 
+    version('2021.9.0', sha256='9299e17602bcc8c05542cdc339897a9c2dba5b5c3838d6ef2df7a02250f42177')
     version('2021.3.0', sha256='3433714cd4162ffd8aad9a727c12dbf1c207b7d6664879fc41259a4b351595b7')
     version('2020.11.0', sha256='f6f212760a485a9f346ca11bb4751e7095bbe748b8e5b2389ff9238e9e321317',
             url='https://bitbucket.org/berkeleylab/upcxx/downloads/upcxx-2020.11.0-memory_kinds_prototype.tar.gz')
     version('2020.10.0', sha256='623e074b512bf8cad770a04040272e1cc660d2749760398b311f9bcc9d381a37')
+    version('2020.3.2', sha256='978adc315d21089c739d5efda764b77fc9a2a7c5860f169fe5cd2ca1d840620f')
     version('2020.3.0', sha256='01be35bef4c0cfd24e9b3d50c88866521b9cac3ad4cbb5b1fc97aea55078810f')
-    version('2019.9.0', sha256='7d67ccbeeefb59de9f403acc719f52127a30801a2c2b9774a1df03f850f8f1d4')
+    # Do NOT add older versions here.
-    version('2019.3.2', sha256='dcb0b337c05a0feb2ed5386f5da6c60342412b49cab10f282f461e74411018ad')
+    # UPC++ releases over 2 years old are not supported.
 
     variant('mpi', default=False,
             description='Enables MPI-based spawners and mpi-conduit')
@@ -48,8 +58,8 @@ class Upcxx(Package):
     variant('cross', default=cross_detect(),
             description="UPC++ cross-compile target (autodetect by default)")
 
-    conflicts('cross=none', when='platform=cray',
+    conflicts('cross=none', when=is_CrayXC(),
-              msg='cross=none is unacceptable on Cray.' +
+              msg='cross=none is unacceptable on Cray XC.' +
                   'Please specify an appropriate "cross" value')
 
     # UPC++ always relies on GASNet-EX.
@@ -61,47 +71,15 @@ class Upcxx(Package):
 
     depends_on('mpi', when='+mpi')
     depends_on('cuda', when='+cuda')
-    # Require Python2 2.7.5+ up to v2019.9.0
+    depends_on('python@2.7.5:', type=("build", "run"))
-    depends_on('python@2.7.5:2',
-               type=("build", "run"), when='@:2019.9.0')
-    # v2020.3.0 and later also permit Python3
-    depends_on('python@2.7.5:', type=("build", "run"), when='@2020.3.0:')
 
     # All flags should be passed to the build-env in autoconf-like vars
     flag_handler = env_flags
 
-    def url_for_version(self, version):
-        if version > Version('2019.3.2'):
-            url = "https://bitbucket.org/berkeleylab/upcxx/downloads/upcxx-{0}.tar.gz"
-        else:
-            url = "https://bitbucket.org/berkeleylab/upcxx/downloads/upcxx-{0}-offline.tar.gz"
-        return url.format(version)
-
-    def setup_build_environment(self, env):
-        # ensure we use the correct python
-        env.set('UPCXX_PYTHON', self.spec['python'].command.path)
-
-        if '+mpi' in self.spec:
-            env.set('GASNET_CONFIGURE_ARGS',
-                    '--enable-mpi --enable-mpi-compat')
-        else:
-            env.set('GASNET_CONFIGURE_ARGS', '--without-mpicc')
-
-        if 'cross=none' not in self.spec:
-            env.set('CROSS', self.spec.variants['cross'].value)
-
-        if '+cuda' in self.spec:
-            env.set('UPCXX_CUDA', '1')
-            env.set('UPCXX_CUDA_NVCC', self.spec['cuda'].prefix.bin.nvcc)
-
     def setup_run_environment(self, env):
-        # ensure we use the correct python
-        env.set('UPCXX_PYTHON', self.spec['python'].command.path)
-
         env.set('UPCXX_INSTALL', self.prefix)
         env.set('UPCXX', self.prefix.bin.upcxx)
-        if 'platform=cray' in self.spec:
+        if is_CrayXC():
-            env.set('UPCXX_GASNET_CONDUIT', 'aries')
             env.set('UPCXX_NETWORK', 'aries')
 
     def setup_dependent_package(self, module, dep_spec):
@@ -110,97 +88,91 @@ def setup_dependent_package(self, module, dep_spec):
     def setup_dependent_build_environment(self, env, dependent_spec):
         env.set('UPCXX_INSTALL', self.prefix)
         env.set('UPCXX', self.prefix.bin.upcxx)
-        if 'platform=cray' in self.spec:
+        if is_CrayXC():
-            env.set('UPCXX_GASNET_CONDUIT', 'aries')
             env.set('UPCXX_NETWORK', 'aries')
 
     def install(self, spec, prefix):
+        env = os.environ
         # UPC++ follows autoconf naming convention for LDLIBS, which is 'LIBS'
         if (env.get('LDLIBS')):
             env['LIBS'] = env['LDLIBS']
 
-        if spec.version <= Version('2019.9.0'):
+        options = ["--prefix=%s" % prefix]
-            env['CC'] = self.compiler.cc
+
-            if '+mpi' in self.spec:
+        if 'cross=none' in spec:
-                if 'platform=cray' in self.spec:
+            options.append('--without-cross')
-                    env['GASNET_CONFIGURE_ARGS'] += \
-                        " --with-mpicc=" + self.compiler.cc
-                else:
-                    env['CXX'] = spec['mpi'].mpicxx
-            else:
-                env['CXX'] = self.compiler.cxx
-            if '+gasnet' in self.spec:
-                env['GASNET'] = spec['gasnet'].prefix.src
-            installsh = Executable("./install")
-            installsh(prefix)
         else:
-            if 'platform=cray' in self.spec:
+            options.append('--with-cross=' + spec.variants['cross'].value)
-                # Spack loads the cray-libsci module incorrectly on ALCF theta,
-                # breaking the Cray compiler wrappers
-                # cray-libsci is irrelevant to our build, so disable it
-                for var in ['PE_PKGCONFIG_PRODUCTS', 'PE_PKGCONFIG_LIBS']:
-                    env[var] = ":".join(
-                        filter(lambda x: "libsci" not in x.lower(),
-                               env[var].split(":")))
-                # Undo spack compiler wrappers:
-                # the C/C++ compilers must work post-install
-                # hack above no longer works after the fix to UPC++ issue #287
-                real_cc = join_path(env['CRAYPE_DIR'], 'bin', 'cc')
-                real_cxx = join_path(env['CRAYPE_DIR'], 'bin', 'CC')
-                # workaround a bug in the UPC++ installer: (issue #346)
-                env['GASNET_CONFIGURE_ARGS'] += \
-                    " --with-cc=" + real_cc + " --with-cxx=" + real_cxx
-                if '+mpi' in self.spec:
-                    env['GASNET_CONFIGURE_ARGS'] += " --with-mpicc=" + real_cc
-            else:
-                real_cc = self.compiler.cc
-                real_cxx = self.compiler.cxx
-                if '+mpi' in self.spec:
-                    real_cxx = spec['mpi'].mpicxx
 
-            env['CC'] = real_cc
+        if is_CrayXC():
-            env['CXX'] = real_cxx
+            # Spack loads the cray-libsci module incorrectly on ALCF theta,
+            # breaking the Cray compiler wrappers
+            # cray-libsci is irrelevant to our build, so disable it
+            for var in ['PE_PKGCONFIG_PRODUCTS', 'PE_PKGCONFIG_LIBS']:
+                env[var] = ":".join(
+                    filter(lambda x: "libsci" not in x.lower(),
+                           env[var].split(":")))
+            # Undo spack compiler wrappers:
+            # the C/C++ compilers must work post-install
+            real_cc = join_path(env['CRAYPE_DIR'], 'bin', 'cc')
+            real_cxx = join_path(env['CRAYPE_DIR'], 'bin', 'CC')
+            # workaround a bug in the UPC++ installer: (issue #346)
+            if (env.get('GASNET_CONFIGURE_ARGS') is None):
+                env['GASNET_CONFIGURE_ARGS'] = ''
+            env['GASNET_CONFIGURE_ARGS'] += \
+                " --with-cc=" + real_cc + " --with-cxx=" + real_cxx
+            if '+mpi' in spec:
+                env['GASNET_CONFIGURE_ARGS'] += " --with-mpicc=" + real_cc
+        else:
+            real_cc = self.compiler.cc
+            real_cxx = self.compiler.cxx
+            if '+mpi' in spec:
+                real_cxx = spec['mpi'].mpicxx
 
-            options = ["--prefix=%s" % prefix]
+        options.append('--with-cc=' + real_cc)
+        options.append('--with-cxx=' + real_cxx)
 
-            if '+gasnet' in self.spec:
+        if '+gasnet' in spec:
-                options.append('--with-gasnet=' + spec['gasnet'].prefix.src)
+            options.append('--with-gasnet=' + spec['gasnet'].prefix.src)
 
-            configure(*options)
+        options.append('--with-python=' + spec['python'].command.path)
 
-            make()
+        if '+mpi' in spec:
+            options.append('--enable-mpi')
+            options.append('--enable-mpi-compat')
+        else:
+            options.append('--without-mpicc')
 
-            make('install')
+        if '+cuda' in spec:
+            options.append('--with-cuda')
+            options.append('--with-nvcc=' + spec['cuda'].prefix.bin.nvcc)
+
+        configure(*options)
+
+        make()
+
+        make('install')
 
         install_tree('example', prefix.example)
 
     @run_after('install')
     @on_package_attributes(run_tests=True)
     def test_install(self):
-        if self.spec.version <= Version('2019.9.0'):
+        # enable testing of unofficial conduits (mpi)
-            spack.main.send_warning_to_tty(
+        test_networks = 'NETWORKS=$(CONDUITS)'
-                "run_tests not supported in UPC++ version " +
+        # build hello world against installed tree in all configurations
-                self.spec.version.string + " -- SKIPPED")
+        make('test_install', test_networks)
-        else:
+        make('tests-clean')  # cleanup
-            # enable testing of unofficial conduits (mpi)
+        # build all tests for all networks in debug mode
-            test_networks = 'NETWORKS=$(CONDUITS)'
+        make('tests', test_networks)
-            # build hello world against installed tree in all configurations
+        if 'cross=none' in self.spec:
-            make('test_install', test_networks)
+            make('run-tests', 'NETWORKS=smp')  # runs tests for smp backend
-            make('tests-clean')  # cleanup
+        make('tests-clean')  # cleanup
-            # build all tests for all networks in debug mode
-            make('tests', test_networks)
-            if 'cross=none' in self.spec:
-                make('run-tests', 'NETWORKS=smp')  # runs tests for smp backend
-            make('tests-clean')  # cleanup
 
     def test(self):
-        if self.spec.version <= Version('2019.9.0'):
+        # run post-install smoke test:
-            spack.main.send_warning_to_tty(
+        test_install = join_path(self.prefix.bin, 'test-upcxx-install.sh')
-                "post-install tests not supported in UPC++ version " +
+        self.run_test(test_install, expected=['SUCCESS'], status=0,
-                self.spec.version.string + " -- SKIPPED")
+                      installed=True,
-        else:   # run post-install smoke test:
+                      purpose='Checking UPC++ compile+link ' +
-            test_install = join_path(self.prefix.bin, 'test-upcxx-install.sh')
+                              'for all installed backends')
-            self.run_test(test_install, expected=['SUCCESS'], status=0,
-                          installed=True,
-                          purpose='Checking UPC++ compile+link ' +
-                                  'for all installed backends')