Detect FE compilers automatically on Cray (#17267)

* cray: detect frontend compilers automatically

This commit permits to detect frontend compilers
automatically, with the exception of cce.

Co-authored-by: Gregory Becker <becker33.llnl.gov>

lib/spack/spack/operating_systems/cray_frontend.py

@@ -5,8 +5,11 @@
 
 import contextlib
 import os
+import re
 
 import llnl.util.filesystem as fs
+import llnl.util.lang
+import llnl.util.tty as tty
 
 from spack.operating_systems.linux_distro import LinuxDistro
 from spack.util.environment import get_path
@@ -60,6 +63,42 @@ def compiler_search_paths(self):
         This prevents from detecting Cray compiler wrappers and avoids
         possible false detections.
         """
+        import spack.compilers
+
         with unload_programming_environment():
-            search_paths = fs.search_paths_for_executables(*get_path('PATH'))
-        return search_paths
+            search_paths = get_path('PATH')
+
+        extract_path_re = re.compile(r'prepend-path[\s]*PATH[\s]*([/\w\.:-]*)')
+
+        for compiler_cls in spack.compilers.all_compiler_types():
+            # Check if the compiler class is supported on Cray
+            prg_env = getattr(compiler_cls, 'PrgEnv', None)
+            compiler_module = getattr(compiler_cls, 'PrgEnv_compiler', None)
+            if not (prg_env and compiler_module):
+                continue
+
+            # It is supported, check which versions are available
+            output = module('avail', compiler_cls.PrgEnv_compiler)
+            version_regex = r'({0})/([\d\.]+[\d]-?[\w]*)'.format(
+                compiler_cls.PrgEnv_compiler
+            )
+            matches = re.findall(version_regex, output)
+            versions = tuple(version for _, version in matches)
+
+            # Now inspect the modules and add to paths
+            msg = "[CRAY FE] Detected FE compiler [name={0}, versions={1}]"
+            tty.debug(msg.format(compiler_module, versions))
+            for v in versions:
+                try:
+                    current_module = compiler_module + '/' + v
+                    out = module('show', current_module)
+                    match = extract_path_re.search(out)
+                    search_paths += match.group(1).split(':')
+                except Exception as e:
+                    msg = ("[CRAY FE] An unexpected error occurred while "
+                           "detecting FE compiler [compiler={0}, "
+                           " version={1}, error={2}]")
+                    tty.debug(msg.format(compiler_cls.name, v, str(e)))
+
+        search_paths = list(llnl.util.lang.dedupe(search_paths))
+        return fs.search_paths_for_executables(*search_paths)

lib/spack/spack/test/compilers/detection.py

@@ -4,6 +4,9 @@
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 """Test detection of compiler version"""
 import pytest
+import os
+
+import llnl.util.filesystem as fs
 
 import spack.compilers.arm
 import spack.compilers.cce
@@ -16,6 +19,9 @@
 import spack.compilers.xl
 import spack.compilers.xl_r
 
+from spack.operating_systems.cray_frontend import CrayFrontend
+import spack.util.module_cmd
+
 
 @pytest.mark.parametrize('version_str,expected_version', [
     ('Arm C/C++/Fortran Compiler version 19.0 (build number 73) (based on LLVM 7.0.2)\n' # NOQA
@@ -189,3 +195,41 @@ def test_xl_version_detection(version_str, expected_version):
 
     version = spack.compilers.xl_r.XlR.extract_version_from_output(version_str)
     assert version == expected_version
+
+
+@pytest.mark.parametrize('compiler,version', [
+    ('gcc', '8.1.0'),
+    ('gcc', '1.0.0-foo'),
+    ('pgi', '19.1'),
+    ('pgi', '19.1a'),
+    ('intel', '9.0.0'),
+    ('intel', '0.0.0-foobar')
+])
+def test_cray_frontend_compiler_detection(
+        compiler, version, tmpdir, monkeypatch, working_env
+):
+    """Test that the Cray frontend properly finds compilers form modules"""
+    # setup the fake compiler directory
+    compiler_dir = tmpdir.join(compiler)
+    compiler_exe = compiler_dir.join('cc').ensure()
+    fs.set_executable(str(compiler_exe))
+
+    # mock modules
+    def _module(cmd, *args):
+        module_name = '%s/%s' % (compiler, version)
+        module_contents = 'prepend-path PATH %s' % compiler_dir
+        if cmd == 'avail':
+            return module_name if compiler in args[0] else ''
+        if cmd == 'show':
+            return module_contents if module_name in args else ''
+    monkeypatch.setattr(spack.operating_systems.cray_frontend, 'module',
+                        _module)
+
+    # remove PATH variable
+    os.environ.pop('PATH', None)
+
+    # get a CrayFrontend object
+    cray_fe_os = CrayFrontend()
+
+    paths = cray_fe_os.compiler_search_paths
+    assert paths == [str(compiler_dir)]