Generate SBOM of .kcm files in layoutlib.

Bug: 303905932
Test: CIs; m layoutlib dist
Change-Id: Iab35c44bdfff7ea82734a8efd37dfa005bae2664
diff --git a/tools/sbom/Android.bp b/tools/sbom/Android.bp
index 27a160e..2b2b573 100644
--- a/tools/sbom/Android.bp
+++ b/tools/sbom/Android.bp
@@ -80,15 +80,15 @@
 
 python_binary_host {
     name: "generate-sbom-framework_res",
-        srcs: [
-            "generate-sbom-framework_res.py",
-        ],
-        version: {
-            py3: {
-                embedded_launcher: true,
-            },
+    srcs: [
+        "generate-sbom-framework_res.py",
+    ],
+    version: {
+        py3: {
+            embedded_launcher: true,
         },
-        libs: [
-            "sbom_lib",
-        ],
+    },
+    libs: [
+        "sbom_lib",
+    ],
 }
\ No newline at end of file
diff --git a/tools/sbom/generate-sbom-framework_res.py b/tools/sbom/generate-sbom-framework_res.py
index d6be734..e637d53 100644
--- a/tools/sbom/generate-sbom-framework_res.py
+++ b/tools/sbom/generate-sbom-framework_res.py
@@ -20,6 +20,13 @@
 import sbom_data
 import sbom_writers
 
+'''
+This script generates SBOM of framework_res.jar of layoutlib shipped with Android Studio.
+
+The generated SBOM contains some placeholders which should be substituted by release_layoutlib.sh.
+The placeholders include: document name, document namespace, organization, created timestamp and 
+the SHA1 checksum of framework_res.jar.
+'''
 
 def get_args():
   parser = argparse.ArgumentParser()
diff --git a/tools/sbom/generate-sbom.py b/tools/sbom/generate-sbom.py
index a2b33b5..5eae262 100755
--- a/tools/sbom/generate-sbom.py
+++ b/tools/sbom/generate-sbom.py
@@ -130,6 +130,7 @@
   parser.add_argument('--metadata', required=True, help='The SBOM metadata file path.')
   parser.add_argument('--build_version', required=True, help='The build version.')
   parser.add_argument('--product_mfr', required=True, help='The product manufacturer.')
+  parser.add_argument('--module_name', help='The module name. If specified, the generated SBOM is for the module.')
   parser.add_argument('--json', action='store_true', default=False, help='Generated SBOM file in SPDX JSON format')
   parser.add_argument('--unbundled_apk', action='store_true', default=False, help='Generate SBOM for unbundled APKs')
   parser.add_argument('--unbundled_apex', action='store_true', default=False, help='Generate SBOM for unbundled APEXs')
@@ -483,16 +484,25 @@
   global metadata_file_protos
   metadata_file_protos = {}
 
-  product_package = sbom_data.Package(id=sbom_data.SPDXID_PRODUCT,
-                                      name=sbom_data.PACKAGE_NAME_PRODUCT,
+  product_package_id = sbom_data.SPDXID_PRODUCT
+  product_package_name = sbom_data.PACKAGE_NAME_PRODUCT
+  if args.module_name:
+    # Build SBOM of a module so use the module name instead.
+    product_package_id = f'SPDXRef-{sbom_data.encode_for_spdxid(args.module_name)}'
+    product_package_name = args.module_name
+  product_package = sbom_data.Package(id=product_package_id,
+                                      name=product_package_name,
                                       download_location=sbom_data.VALUE_NONE,
                                       version=args.build_version,
                                       supplier='Organization: ' + args.product_mfr,
                                       files_analyzed=True)
-
-  doc = sbom_data.Document(name=args.build_version,
-                           namespace=f'https://www.google.com/sbom/spdx/android/{args.build_version}',
-                           creators=['Organization: ' + args.product_mfr])
+  doc_name = args.build_version
+  if args.module_name:
+    doc_name = f'{args.build_version}/{args.module_name}'
+  doc = sbom_data.Document(name=doc_name,
+                           namespace=f'https://www.google.com/sbom/spdx/android/{doc_name}',
+                           creators=['Organization: ' + args.product_mfr],
+                           describes=product_package_id)
   if not args.unbundled_apex:
     doc.packages.append(product_package)