.

nxdbom/__init__.py

@@ -491,6 +491,42 @@ def removesuffix(s, suffix):
         s = s[:len(s)-len(suffix)]
     return s
 
+
+# spdx_license_canon returns canonical SPDX license ID for license_name.
+#
+# it is an error is license_name cannot be recognized.
+_licdb = {  # spdx -> variants
+    'Apache-2.0':    'Apache License 2.0 | Apache License, Version 2.0 | http://www.apache.org/licenses/LICENSE-2.0',
+    'EPL-1.0':       'Eclipse Public License 1.0',
+    'GPL-2.0+':      'GPL 2+',
+    'GPL-3.0+':      'GNU GPLv3+',
+    'GPL-3.0':       'GPLv3 | GNU General Public License Version 3',
+    'MIT':           '',
+    'PSF':           'Python Software Foundation License',  # XXX no ver
+    'ZPL-2.1':       '',
+
+    'GPL-3.0+-with-NXD-exception':   'GPLv3+ with wide exception for FOSS',
+}
+_licrevdb = {}  # variant -> spdx
+for lic, variants in _licdb.items():
+    vv = []
+    if variants:
+        vv = variants.split('|')
+    vv.append(lic)                      # e.g. MIT -> MIT
+    licsp = lic.replace('-', ' ')
+    if licsp != lic:
+        vv.append(licsp)                # e.g. ZPL 2.1 -> ZPL-2.1
+    for v in vv:
+        v = v.strip()
+        assert v not in _licrevdb, repr(v)
+        _licrevdb[v] = lic
+def spdx_license_canon(license_name):
+    spdx = _licrevdb.get(license_name)
+    if spdx is None:
+        raise ValueError('unknown license %r' % license_name)
+    return spdx
+
+
 # ----------------------------------------
 
 # fmt_bom formats BOM into text.

nxdbom/nxdbom_test.py

@@ -486,6 +486,29 @@ def test_bom_software_eexist():
     with pytest.raises(RuntimeError, match="Cannot load '%s/.installed.cfg'" % ne):
         nxdbom.bom_software(ne)
 
+# ---- licenses ----
+
+@pytest.mark.parametrize('license,spdxok', [
+#   ('3-clause BSD',                XXX
+    ('Apache 2.0',                              'Apache-2.0'),
+    ('Apache License 2.0',                      'Apache-2.0'),
+    ('Apache License, Version 2.0',             'Apache-2.0'),
+    ('Eclipse Public License 1.0',              'EPL-1.0'),
+    ('GNU GPLv3+',                              'GPL-3.0+'),
+    ('GNU General Public License Version 3',    'GPL-3.0'),
+    ('GPL 2+',                                  'GPL-2.0+'),
+    ('GPLv3',                                   'GPL-3.0'),
+    ('GPLv3+ with wide exception for FOSS',     'GPL-3.0+-with-NXD-exception'),
+    ('Python Software Foundation License',      'PSF'),     # no version
+    ('ZPL 2.1',                                 'ZPL-2.1'),
+
+    ('http://www.apache.org/licenses/LICENSE-2.0',  'Apache-2.0'),
+    # XXX ASL 2             (roman)
+    # XXX New BSD License   (scandir)
+    # XXX Modified BSD      (scikit_image)
+])
+def test_spdx_license_canon(license,spdxok):
+    assert nxdbom.spdx_license_canon(license) == spdxok
 
 # ---- txtar ----