Add looking up of build systems by name

2 files changed, 37 insertions, 4 deletions

diff --git a/morphlib/buildsystem.py b/morphlib/buildsystem.py
index 0ac27387..9ee62d03 100644
--- a/morphlib/buildsystem.py
+++ b/morphlib/buildsystem.py
@@ -45,6 +45,8 @@ class BuildSystem(object):
 class ManualBuildSystem(BuildSystem):
 
     '''A manual build system where the morphology must specify all commands.'''
+
+    name = 'manual'
     
     def used_by_project(self, srcdir):
         return False
@@ -53,6 +55,8 @@ class ManualBuildSystem(BuildSystem):
 class AutotoolsBuildSystem(BuildSystem):
 
     '''The automake/autoconf/libtool holy trinity.'''
+
+    name = 'autotools'
     
     def used_by_project(self, srcdir):
         indicators = [
@@ -66,6 +70,12 @@ class AutotoolsBuildSystem(BuildSystem):
                    for x in indicators)
 
 
+build_systems = [
+    ManualBuildSystem(),
+    AutotoolsBuildSystem(),
+]
+    
+
 def detect_build_system(srcdir):
     '''Automatically detect the build system, if possible.
     
@@ -74,12 +84,22 @@ def detect_build_system(srcdir):
     
     '''
     
-    build_systems = [
-        AutotoolsBuildSystem(),
-    ]
-    
     for bs in build_systems:
         if bs.used_by_project(srcdir):
             return bs
     return ManualBuildSystem()
 
+
+
+def lookup_build_system(name):
+    '''Return build system that corresponds to the name.
+    
+    If the name does not match any build system, raise ``KeyError``.
+    
+    '''
+    
+    for bs in build_systems:
+        if bs.name == name:
+            return bs
+    raise KeyError(name)
+
diff --git a/morphlib/buildsystem_tests.py b/morphlib/buildsystem_tests.py
index c8e9058f..362b85dd 100644
--- a/morphlib/buildsystem_tests.py
+++ b/morphlib/buildsystem_tests.py
@@ -90,3 +90,16 @@ class DetectBuildSystemTests(unittest.TestCase):
         bs = morphlib.buildsystem.detect_build_system(self.tempdir)
         self.assertEqual(type(bs), morphlib.buildsystem.AutotoolsBuildSystem)
 
+
+class LookupBuildSystemTests(unittest.TestCase):
+
+    def lookup(self, name):
+        return morphlib.buildsystem.lookup_build_system(name)
+
+    def test_raises_keyerror_for_unknown_name(self):
+        self.assertRaises(KeyError, self.lookup, 'unkonwn')
+
+    def test_looks_up_manual(self):
+        self.assertEqual(type(self.lookup('manual')),
+                         morphlib.buildsystem.ManualBuildSystem)
+