SERVER-5702: Add ability to register unit tests in SCons.

Tests are registered with env.RegisterUnitTest(), or by compiling a C++ unit
test with
    env.CppUnitTest('test_name', [test_source_list], LIBDEPS=[...])

The result is that SCons knows how to build a file "build/unittests.txt", one line per test.

1 files changed, 33 insertions, 0 deletions

diff --git a/site_scons/site_tools/unittest.py b/site_scons/site_tools/unittest.py
new file mode 100644
index 00000000000..0ce0ae582c1
--- /dev/null
+++ b/site_scons/site_tools/unittest.py
@@ -0,0 +1,33 @@
+"""Pseudo-builders for building and registering unit tests.
+"""
+
+def exists(env):
+    return True
+
+def register_unit_test(env, test):
+    env._UnitTestList('$UNITTEST_LIST', test)
+    env.Alias('$UNITTEST_ALIAS', test)
+
+def unit_test_list_builder_action(env, target, source):
+    print "Generating " + str(target[0])
+    ofile = open(str(target[0]), 'wb')
+    try:
+        for s in source:
+            print '\t' + str(s)
+            ofile.write('%s\n' % s)
+    finally:
+        ofile.close()
+
+def build_cpp_unit_test(env, target, source, **kwargs):
+    kwargs['LIBDEPS'] = kwargs.get('LIBDEPS', []) + ['$BUILD_DIR/mongo/unittest/unittest_main',
+                                                     '$BUILD_DIR/mongo/unittest/unittest_crutch']
+    result = env.Program(target, source, **kwargs)
+    env.RegisterUnitTest(result[0])
+    return result
+
+def generate(env):
+    unit_test_list_builder = env.Builder(action=unit_test_list_builder_action, multi=True)
+    env.Append(BUILDERS=dict(_UnitTestList=unit_test_list_builder))
+    env.AddMethod(register_unit_test, 'RegisterUnitTest')
+    env.AddMethod(build_cpp_unit_test, 'CppUnitTest')
+    env.Alias('$UNITTEST_ALIAS', '$UNITTEST_LIST')