license: split license parsing into oe.license

In addition to moving this functionality to oe.license, makes the string
preparation more picky before passing it off to the ast compilation. This
ensures that LICENSE entries like 'GPL/BSD' are seen as invalid (due to the
presence of the unsupported '/').

Signed-off-by: Christopher Larson <kergoth@gmail.com>

3 files changed, 90 insertions, 39 deletions

diff --git a/meta/classes/license.bbclass b/meta/classes/license.bbclass
index 4d036b171..8c6e2d2c9 100644
--- a/meta/classes/license.bbclass
+++ b/meta/classes/license.bbclass
@@ -1,17 +1,17 @@
 # Populates LICENSE_DIRECTORY as set in distro config with the license files as set by
-# LIC_FILES_CHKSUM. 
+# LIC_FILES_CHKSUM.
 # TODO:
 # - We should also enable the ability to put the generated license directory onto the
 #  rootfs
 # - Gather up more generic licenses
-# - There is a real issue revolving around license naming standards. See license names 
+# - There is a real issue revolving around license naming standards. See license names
 #  licenses.conf and compare them to the license names in the recipes. You'll see some
 #  differences and that should be corrected.
 
 LICENSE_DIRECTORY ??= "${DEPLOY_DIR}/licenses"
 LICSSTATEDIR = "${WORKDIR}/license-destdir/"
 
-addtask populate_lic after do_patch before do_package 
+addtask populate_lic after do_patch before do_package
 do_populate_lic[dirs] = "${LICSSTATEDIR}/${PN}"
 do_populate_lic[cleandirs] = "${LICSSTATEDIR}"
 
@@ -20,7 +20,7 @@ do_populate_lic[cleandirs] = "${LICSSTATEDIR}"
 # break the non-standardized license names that we find in LICENSE, we'll set
 # up a bunch of VarFlags to accomodate non-SPDX license names.
 #
-# We should really discuss standardizing this field, but that's a longer term goal. 
+# We should really discuss standardizing this field, but that's a longer term goal.
 # For now, we can do this and it should grab the most common LICENSE naming variations.
 
 #GPL variations
@@ -57,37 +57,25 @@ python do_populate_lic() {
     import os
     import bb
     import shutil
-    import ast
-
-    class LicenseVisitor(ast.NodeVisitor):
-        def generic_visit(self, node):
-            ast.NodeVisitor.generic_visit(self, node)
+    import oe.license
 
+    class FindVisitor(oe.license.LicenseVisitor):
         def visit_Str(self, node):
             #
             # Until I figure out what to do with
             # the two modifiers I support (or greater = +
             # and "with exceptions" being *
-            # we'll just strip out the modifier and put 
+            # we'll just strip out the modifier and put
             # the base license.
             find_license(node.s.replace("+", "").replace("*", ""))
-            ast.NodeVisitor.generic_visit(self, node)
-
-        def visit_BinOp(self, node):
-            op = node.op
-            if isinstance(op, ast.BitOr): 
-                x = LicenseVisitor()
-                x.visit(node.left)
-                x.visit(node.right)
-            else:               
-                ast.NodeVisitor.generic_visit(self, node)
+            self.generic_visit(node)
 
     def copy_license(source, destination, file_name):
         try:
             bb.copyfile(os.path.join(source, file_name), os.path.join(destination, file_name))
         except:
             bb.warn("%s: No generic license file exists for: %s at %s" % (pn, file_name, source))
-            pass 
+            pass
 
     def link_license(source, destination, file_name):
         try:
@@ -108,8 +96,8 @@ python do_populate_lic() {
                 # Great, there is an SPDXLICENSEMAP. We can copy!
                 bb.note("We need to use a SPDXLICENSEMAP for %s" % (license_type))
                 spdx_generic = d.getVarFlag('SPDXLICENSEMAP', license_type)
-                copy_license(generic_directory, gen_lic_dest, spdx_generic)            
-                link_license(gen_lic_dest, destdir, spdx_generic)            
+                copy_license(generic_directory, gen_lic_dest, spdx_generic)
+                link_license(gen_lic_dest, destdir, spdx_generic)
             else:
                 # And here is where we warn people that their licenses are lousy
                 bb.warn("%s: No generic license file exists for: %s at %s" % (pn, license_type, generic_directory))
@@ -117,7 +105,7 @@ python do_populate_lic() {
                 pass
         elif os.path.isfile(os.path.join(generic_directory, license_type)):
             copy_license(generic_directory, gen_lic_dest, license_type)
-            link_license(gen_lic_dest, destdir, license_type)            
+            link_license(gen_lic_dest, destdir, license_type)
 
     # All the license types for the package
     license_types = d.getVar('LICENSE', True)
@@ -130,7 +118,7 @@ python do_populate_lic() {
     srcdir = d.getVar('S', True)
     # Directory we store the generic licenses as set in the distro configuration
     generic_directory = d.getVar('COMMON_LICENSE_DIR', True)
-    
+
     try:
         bb.mkdirhier(destdir)
     except:
@@ -153,21 +141,14 @@ python do_populate_lic() {
         # If the copy didn't occur, something horrible went wrong and we fail out
         if ret is False or ret == 0:
             bb.warn("%s could not be copied for some reason. It may not exist. WARN for now." % srclicfile)
- 
+
     gen_lic_dest = os.path.join(d.getVar('LICENSE_DIRECTORY', True), "common-licenses")
-    
-    clean_licenses = ""
-
-    for x in license_types.replace("(", " ( ").replace(")", " ) ").split():
-        if ((x != "(") and (x != ")") and (x != "&") and (x != "|")):
-            clean_licenses += "'" + x + "'"
-        else:
-            clean_licenses += " " + x + " "
-
-    # lstrip any possible indents, since ast needs python syntax.
-    node = ast.parse(clean_licenses.lstrip())
-    v = LicenseVisitor()
-    v.visit(node)
+
+    v = FindVisitor()
+    try:
+        v.visit_string(license_types)
+    except oe.license.InvalidLicense as exc:
+        bb.fatal("%s: %s" % (d.getVar('PF', True), exc))
 }
 
 SSTATETASKS += "do_populate_lic"
diff --git a/meta/lib/oe/license.py b/meta/lib/oe/license.py
new file mode 100644
index 000000000..b230d3ef4
--- /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 000000000..cb949fc76
--- /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)