Cray support: use linux platform for newer craype versions (#29392)

Newer versions of the CrayPE for EX systems have standalone compiler executables for CCE and compiler wrappers for Cray MPICH. With those, we can treat the cray systems as part of the linux platform rather than having a separate cray platform.

This PR:
- [x] Changes cray platform detection to ignore EX systems with Craype version 21.10 or later
- [x] Changes the cce compiler to be detectable via paths
- [x] Changes the spack compiler wrapper to understand the executable names for the standalone cce compiler (`craycc`, `crayCC`, `crayftn`).

7 files changed, 105 insertions, 30 deletions

diff --git a/lib/spack/env/cc b/lib/spack/env/cc
index bef7209bfa..ffdddfc0df 100755
--- a/lib/spack/env/cc
+++ b/lib/spack/env/cc
@@ -241,28 +241,28 @@ case "$command" in
         mode=cpp
         debug_flags="-g"
         ;;
-    cc|c89|c99|gcc|clang|armclang|icc|icx|pgcc|nvc|xlc|xlc_r|fcc|amdclang|cl.exe)
+    cc|c89|c99|gcc|clang|armclang|icc|icx|pgcc|nvc|xlc|xlc_r|fcc|amdclang|cl.exe|craycc)
         command="$SPACK_CC"
         language="C"
         comp="CC"
         lang_flags=C
         debug_flags="-g"
         ;;
-    c++|CC|g++|clang++|armclang++|icpc|icpx|dpcpp|pgc++|nvc++|xlc++|xlc++_r|FCC|amdclang++)
+    c++|CC|g++|clang++|armclang++|icpc|icpx|dpcpp|pgc++|nvc++|xlc++|xlc++_r|FCC|amdclang++|crayCC)
         command="$SPACK_CXX"
         language="C++"
         comp="CXX"
         lang_flags=CXX
         debug_flags="-g"
         ;;
-    ftn|f90|fc|f95|gfortran|flang|armflang|ifort|ifx|pgfortran|nvfortran|xlf90|xlf90_r|nagfor|frt|amdflang)
+    ftn|f90|fc|f95|gfortran|flang|armflang|ifort|ifx|pgfortran|nvfortran|xlf90|xlf90_r|nagfor|frt|amdflang|crayftn)
         command="$SPACK_FC"
         language="Fortran 90"
         comp="FC"
         lang_flags=F
         debug_flags="-g"
         ;;
-    f77|xlf|xlf_r|pgf77|amdflang)
+    f77|xlf|xlf_r|pgf77)
         command="$SPACK_F77"
         language="Fortran 77"
         comp="F77"
diff --git a/lib/spack/env/cce/case-insensitive/crayCC b/lib/spack/env/cce/case-insensitive/crayCC
new file mode 120000
index 0000000000..e2deb67f3b
--- /dev/null
+++ b/lib/spack/env/cce/case-insensitive/crayCC
@@ -0,0 +1 @@
+../../cc
\ No newline at end of file
diff --git a/lib/spack/env/cce/craycc b/lib/spack/env/cce/craycc
new file mode 120000
index 0000000000..82c2b8e90a
--- /dev/null
+++ b/lib/spack/env/cce/craycc
@@ -0,0 +1 @@
+../cc
\ No newline at end of file
diff --git a/lib/spack/env/cce/crayftn b/lib/spack/env/cce/crayftn
new file mode 120000
index 0000000000..82c2b8e90a
--- /dev/null
+++ b/lib/spack/env/cce/crayftn
@@ -0,0 +1 @@
+../cc
\ No newline at end of file
diff --git a/lib/spack/spack/compilers/cce.py b/lib/spack/spack/compilers/cce.py
index d572a31ff4..3ecbcdc3d6 100644
--- a/lib/spack/spack/compilers/cce.py
+++ b/lib/spack/spack/compilers/cce.py
@@ -2,7 +2,6 @@
 # Spack Project Developers. See the top-level COPYRIGHT file for details.
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
-
 import os
 
 from spack.compiler import Compiler, UnsupportedCompilerFlag
@@ -12,17 +11,25 @@ from spack.version import ver
 class Cce(Compiler):
     """Cray compiler environment compiler."""
 
+    def __init__(self, *args, **kwargs):
+        super(Cce, self).__init__(*args, **kwargs)
+        # For old cray compilers on module based systems we replace
+        # ``version_argument`` with the old value. Cannot be a property
+        # as the new value is used in classmethods for path-based detection
+        if not self.is_clang_based:
+            self.version_argument = "-V"
+
     # Subclasses use possible names of C compiler
-    cc_names = ["cc"]
+    cc_names = ["craycc", "cc"]
 
     # Subclasses use possible names of C++ compiler
-    cxx_names = ["CC"]
+    cxx_names = ["crayCC", "CC"]
 
     # Subclasses use possible names of Fortran 77 compiler
-    f77_names = ["ftn"]
+    f77_names = ["crayftn", "ftn"]
 
     # Subclasses use possible names of Fortran 90 compiler
-    fc_names = ["ftn"]
+    fc_names = ["crayftn", "ftn"]
 
     # MacPorts builds gcc versions with prefixes and -mp-X.Y suffixes.
     suffixes = [r"-mp-\d\.\d"]
@@ -30,24 +37,30 @@ class Cce(Compiler):
     PrgEnv = "PrgEnv-cray"
     PrgEnv_compiler = "cce"
 
-    link_paths = {
-        "cc": os.path.join("cce", "cc"),
-        "cxx": os.path.join("cce", "case-insensitive", "CC"),
-        "f77": os.path.join("cce", "ftn"),
-        "fc": os.path.join("cce", "ftn"),
-    }
+    @property
+    def link_paths(self):
+        if self.PrgEnv in self.modules:
+            # Old module-based interface to cray compilers
+            return {
+                "cc": os.path.join("cce", "cc"),
+                "cxx": os.path.join("case-insensitive", "CC"),
+                "f77": os.path.join("cce", "ftn"),
+                "fc": os.path.join("cce", "ftn"),
+            }
+
+        return {
+            "cc": os.path.join("cce", "craycc"),
+            "cxx": os.path.join("cce", "case-insensitive", "crayCC"),
+            "f77": os.path.join("cce", "crayftn"),
+            "fc": os.path.join("cce", "crayftn"),
+        }
 
     @property
     def is_clang_based(self):
         version = self._real_version or self.version
         return version >= ver("9.0") and "classic" not in str(version)
 
-    @property
-    def version_argument(self):
-        if self.is_clang_based:
-            return "--version"
-        return "-V"
-
+    version_argument = "--version"
     version_regex = r"[Vv]ersion.*?(\d+(\.\d+)+)"
 
     @property
diff --git a/lib/spack/spack/platforms/cray.py b/lib/spack/spack/platforms/cray.py
index 8f87740e4c..dadf114d90 100644
--- a/lib/spack/spack/platforms/cray.py
+++ b/lib/spack/spack/platforms/cray.py
@@ -12,6 +12,7 @@ import archspec.cpu
 import llnl.util.tty as tty
 
 import spack.target
+import spack.version
 from spack.operating_systems.cray_backend import CrayBackend
 from spack.operating_systems.cray_frontend import CrayFrontend
 from spack.paths import build_env_path
@@ -31,6 +32,9 @@ _craype_name_to_target_name = {
     "abudhabi": "piledriver",
 }
 
+_ex_craype_dir = "/opt/cray/pe/cpe"
+_xc_craype_dir = "/opt/cray/pe/cdt"
+
 
 def _target_name_from_craype_target_name(name):
     return _craype_name_to_target_name.get(name, name)
@@ -110,18 +114,47 @@ class Cray(Platform):
             env.prepend_path("LD_LIBRARY_PATH", os.environ["CRAY_LD_LIBRARY_PATH"])
 
     @classmethod
+    def craype_type_and_version(cls):
+        if os.path.isdir(_ex_craype_dir):
+            craype_dir = _ex_craype_dir
+            craype_type = "EX"
+        elif os.path.isdir(_xc_craype_dir):
+            craype_dir = _xc_craype_dir
+            craype_type = "XC"
+        else:
+            return (None, None)
+
+        # Take the default version from known symlink path
+        default_path = os.path.join(craype_dir, "default")
+        if os.path.islink(default_path):
+            version = spack.version.Version(os.readlink(default_path))
+            return (craype_type, version)
+
+        # If no default version, sort available versions and return latest
+        versions_available = [spack.version.Version(v) for v in os.listdir(craype_dir)]
+        versions_available.sort(reverse=True)
+        return (craype_type, versions_available[0])
+
+    @classmethod
     def detect(cls):
         """
-        Detect whether this system is a Cray machine.
-
-        We detect the Cray platform based on the availability through `module`
-        of the Cray programming environment. If this environment is available,
-        we can use it to find compilers, target modules, etc. If the Cray
-        programming environment is not available via modules, then we will
-        treat it as a standard linux system, as the Cray compiler wrappers
-        and other components of the Cray programming environment are
-        irrelevant without module support.
+        Detect whether this system requires CrayPE module support.
+
+        Systems with newer CrayPE (21.10 for EX systems, future work for CS and
+        XC systems) have compilers and MPI wrappers that can be used directly
+        by path. These systems are considered ``linux`` platforms.
+
+        For systems running an older CrayPE, we detect the Cray platform based
+        on the availability through `module` of the Cray programming
+        environment. If this environment is available, we can use it to find
+        compilers, target modules, etc. If the Cray programming environment is
+        not available via modules, then we will treat it as a standard linux
+        system, as the Cray compiler wrappers and other components of the Cray
+        programming environment are irrelevant without module support.
         """
+        craype_type, craype_version = cls.craype_type_and_version()
+        if craype_type == "EX" and craype_version >= spack.version.Version("21.10"):
+            return False
         return "opt/cray" in os.environ.get("MODULEPATH", "")
 
     def _default_target_from_env(self):
diff --git a/lib/spack/spack/test/architecture.py b/lib/spack/spack/test/architecture.py
index 746be0c8be..92914be685 100644
--- a/lib/spack/spack/test/architecture.py
+++ b/lib/spack/spack/test/architecture.py
@@ -8,6 +8,8 @@ import sys
 
 import pytest
 
+import llnl.util.filesystem as fs
+
 import spack.concretize
 import spack.operating_systems
 import spack.platforms
@@ -214,3 +216,27 @@ def test_concretize_target_ranges(root_target_range, dep_target_range, result, m
         spec.concretize()
 
     assert str(spec).count("arch=test-debian6-%s" % result) == 2
+
+
+@pytest.mark.parametrize(
+    "versions,default,expected",
+    [
+        (["21.11", "21.9"], "21.11", False),
+        (["21.11", "21.9"], "21.9", True),
+        (["21.11", "21.9"], None, False),
+    ],
+)
+def test_cray_platform_detection(versions, default, expected, tmpdir, monkeypatch, working_env):
+    ex_path = str(tmpdir.join("fake_craype_dir"))
+    fs.mkdirp(ex_path)
+
+    with fs.working_dir(ex_path):
+        for version in versions:
+            fs.touch(version)
+        if default:
+            os.symlink(default, "default")
+
+    monkeypatch.setattr(spack.platforms.cray, "_ex_craype_dir", ex_path)
+    os.environ["MODULEPATH"] = "/opt/cray/pe"
+
+    assert spack.platforms.cray.Cray.detect() == expected