2 files changed, 70 insertions, 0 deletions
diff --git a/meta/lib/oe/license.py b/meta/lib/oe/license.py
new file mode 100644
index 0000000000..b230d3ef45
--- /dev/null
+++ b/meta/lib/oe/license.py
@@ -0,0 +1,32 @@
+# vi:sts=4:sw=4:et
+"""Code for parsing OpenEmbedded license strings"""
+
+import ast
+import re
+
+class InvalidLicense(StandardError):
+    def __init__(self, license):
+        self.license = license
+        StandardError.__init__(self)
+
+    def __str__(self):
+        return "invalid license '%s'" % self.license
+
+license_operator = re.compile('([&|() ])')
+license_pattern = re.compile('[a-zA-Z0-9.+_\-]+$')
+
+class LicenseVisitor(ast.NodeVisitor):
+    """Syntax tree visitor which can accept OpenEmbedded license strings"""
+    def visit_string(self, licensestr):
+        new_elements = []
+        elements = filter(lambda x: x.strip(), license_operator.split(licensestr))
+        for pos, element in enumerate(elements):
+            if license_pattern.match(element):
+                if pos > 0 and license_pattern.match(elements[pos-1]):
+                    new_elements.append('&')
+                element = '"' + element + '"'
+            elif not license_operator.match(element):
+                raise InvalidLicense(element)
+            new_elements.append(element)
+
+        self.visit(ast.parse(' '.join(new_elements)))
diff --git a/meta/lib/oe/tests/test_license.py b/meta/lib/oe/tests/test_license.py
new file mode 100644
index 0000000000..cb949fc76f
--- /dev/null
+++ b/meta/lib/oe/tests/test_license.py
@@ -0,0 +1,38 @@
+import unittest
+import oe.license
+
+class SeenVisitor(oe.license.LicenseVisitor):
+    def __init__(self):
+        self.seen = []
+        oe.license.LicenseVisitor.__init__(self)
+
+    def visit_Str(self, node):
+        self.seen.append(node.s)
+
+class TestSingleLicense(unittest.TestCase):
+    licenses = [
+        "GPLv2",
+        "LGPL-2.0",
+        "Artistic",
+        "MIT",
+        "GPLv3+",
+        "FOO_BAR",
+    ]
+    invalid_licenses = ["GPL/BSD"]
+
+    @staticmethod
+    def parse(licensestr):
+        visitor = SeenVisitor()
+        visitor.visit_string(licensestr)
+        return visitor.seen
+
+    def test_single_licenses(self):
+        for license in self.licenses:
+            licenses = self.parse(license)
+            self.assertListEqual(licenses, [license])
+
+    def test_invalid_licenses(self):
+        for license in self.invalid_licenses:
+            with self.assertRaises(oe.license.InvalidLicense) as cm:
+                self.parse(license)
+            self.assertEqual(cm.exception.license, license)