Extracted a function transforming path hints to search paths

Given a list of possible paths it returns a list of the existing real
paths and of their 'bin' subdirectories, if they exist.

lib/spack/spack/architecture.py

@@ -58,6 +58,7 @@
 """
 import os
 import inspect
+import itertools
 import platform as py_platform
 
 import llnl.util.multiproc as mp
@@ -231,28 +232,13 @@ def __repr__(self):
     def _cmp_key(self):
         return (self.name, self.version)
 
-    def find_compilers(self, *paths):
+    def find_compilers(self, *path_hints):
         """
         Return a list of compilers found in the supplied paths.
         This invokes the find() method for each Compiler class,
         and appends the compilers detected to a list.
         """
-        if not paths:
-            paths = get_path('PATH')
-        # Make sure path elements exist, and include /bin directories
-        # under prefixes.
-        filtered_path = []
-        for p in paths:
-            # Eliminate symlinks and just take the real directories.
-            p = os.path.realpath(p)
-            if not os.path.isdir(p):
-                continue
-            filtered_path.append(p)
-
-            # Check for a bin directory, add it if it exists
-            bin = os.path.join(p, 'bin')
-            if os.path.isdir(bin):
-                filtered_path.append(os.path.realpath(bin))
+        paths = executable_search_paths(path_hints or get_path('PATH'))
 
         # Once the paths are cleaned up, do a search for each type of
         # compiler.  We can spawn a bunch of parallel searches to reduce
@@ -261,7 +247,7 @@ def find_compilers(self, *paths):
         import spack.compilers
         types = spack.compilers.all_compiler_types()
         compiler_lists = mp.parmap(
-            lambda cmp_cls: self.find_compiler(cmp_cls, *filtered_path),
+            lambda cmp_cls: self.find_compiler(cmp_cls, *paths),
             types)
 
         # ensure all the version calls we made are cached in the parent
@@ -319,10 +305,10 @@ def find_compiler(self, cmp_cls, *path):
         return list(compilers.values())
 
     def to_dict(self):
-        d = {}
-        d['name'] = self.name
-        d['version'] = self.version
-        return d
+        return {
+            'name': self.name,
+            'version': self.version
+        }
 
 
 @key_ordering
@@ -493,3 +479,30 @@ def sys_type():
     """
     arch = Arch(platform(), 'default_os', 'default_target')
     return str(arch)
+
+
+def executable_search_paths(path_hints):
+    """Given a list of path hints returns a list of paths where
+    to search for an executable.
+
+    Args:
+        path_hints (list of paths): list of paths taken into
+            consideration for a search
+
+    Returns:
+        A list containing the real path of every existing directory
+        in `path_hints` and its `bin` subdirectory if it exists.
+    """
+    # Select the realpath of existing directories
+    existing_paths = filter(os.path.isdir, map(os.path.realpath, path_hints))
+
+    # Adding their 'bin' subdirectory
+    def maybe_add_bin(path):
+        bin_subdirectory = os.path.realpath(os.path.join(path, 'bin'))
+        if os.path.isdir(bin_subdirectory):
+            return [path, bin_subdirectory]
+        return [path]
+
+    return list(itertools.chain.from_iterable(
+        map(maybe_add_bin, existing_paths))
+    )

lib/spack/spack/compiler.py

@@ -15,7 +15,6 @@
 import spack.spec
 import spack.architecture
 from spack.util.executable import Executable, ProcessError
-from spack.util.environment import get_path
 
 __all__ = ['Compiler']
 
@@ -263,9 +262,6 @@ def _find_matches_in_path(cls, compiler_names, detect_version, *path):
            suffix, version) tuples.  This can be further organized by
            find().
         """
-        if not path:
-            path = get_path('PATH')
-
         prefixes = [''] + cls.prefixes
         suffixes = [''] + cls.suffixes
 

lib/spack/spack/compilers/__init__.py

@@ -6,6 +6,7 @@
 """This module contains functions related to finding compilers on the
 system and configuring Spack to use multiple compilers.
 """
+import itertools
 import os
 
 from llnl.util.lang import list_modules
@@ -177,17 +178,20 @@ def all_compiler_specs(scope=None, init_config=True):
 
 
 def find_compilers(*paths):
-    """Return a list of compilers found in the supplied paths.
-       This invokes the find_compilers() method for each operating
-       system associated with the host platform, and appends
-       the compilers detected to a list.
+    """List of compilers found in the supplied paths.
+
+    This function invokes the find_compilers() method for each operating
+    system associated with the host platform.
+
+    Args:
+        *paths: paths where to search for compilers
+
+    Returns:
+        List of compilers found in the supplied paths
     """
-    # Find compilers for each operating system class
-    oss = all_os_classes()
-    compiler_lists = []
-    for o in oss:
-        compiler_lists.extend(o.find_compilers(*paths))
-    return compiler_lists
+    return list(itertools.chain.from_iterable(
+        o.find_compilers(*paths) for o in all_os_classes()
+    ))
 
 
 def supported_compilers():