apilint: Allow parsing 3.0 signature files

Test: python apilint_test.py
Change-Id: I59df950229c05329afde93f94efc13adb4640ad7
diff --git a/tools/apilint/apilint.py b/tools/apilint/apilint.py
index 75c3eba..59e89f5 100644
--- a/tools/apilint/apilint.py
+++ b/tools/apilint/apilint.py
@@ -223,6 +223,7 @@
 class V2Tokenizer(object):
     __slots__ = ["raw"]
 
+    SIGNATURE_PREFIX = "// Signature format: "
     DELIMITER = re.compile(r'\s+|[()@<>;,={}/"!?]|\[\]|\.\.\.')
     STRING_SPECIAL = re.compile(r'["\\]')
 
@@ -610,8 +611,12 @@
         else:
             blame = None
 
-        if line == 1 and raw == "// Signature format: 2.0":
-            sig_format = 2
+        if line == 1 and raw.startswith("// Signature format: "):
+            sig_format_string = raw[len(V2Tokenizer.SIGNATURE_PREFIX):]
+            if sig_format_string in ["2.0", "3.0"]:
+                sig_format = 2
+            else:
+                raise ValueError("Unknown format: %s" % (sig_format_string,))
         elif raw.startswith("package"):
             pkg = Package(line, raw, blame)
         elif raw.startswith("  ") and raw.endswith("{"):
diff --git a/tools/apilint/apilint_test.py b/tools/apilint/apilint_test.py
index 9c261d5..3716bf9 100644
--- a/tools/apilint/apilint_test.py
+++ b/tools/apilint/apilint_test.py
@@ -164,6 +164,23 @@
         self.assertEquals(api['android.SomeEnum'].ctors[0].split[0], 'ctor')
         self.assertEquals(api['android.SomeEnum'].methods[0].split[0], 'method')
 
+class ParseV3Stream(unittest.TestCase):
+    def test_field_kinds(self):
+        api = apilint._parse_stream("""
+// Signature format: 3.0
+package a {
+
+  public final class ContextKt {
+    method public static inline <reified T> T! getSystemService(android.content.Context);
+    method public static inline void withStyledAttributes(android.content.Context, android.util.AttributeSet? set = null, int[] attrs, @AttrRes int defStyleAttr = 0, @StyleRes int defStyleRes = 0, kotlin.jvm.functions.Function1<? super android.content.res.TypedArray,kotlin.Unit> block);
+  }
+}
+        """.strip().split('\n'))
+        self.assertEquals(api['a.ContextKt'].methods[0].name, 'getSystemService')
+        self.assertEquals(api['a.ContextKt'].methods[0].split[:4], ['method', 'public', 'static', 'inline'])
+        self.assertEquals(api['a.ContextKt'].methods[1].name, 'withStyledAttributes')
+        self.assertEquals(api['a.ContextKt'].methods[1].split[:4], ['method', 'public', 'static', 'inline'])
+
 class V2TokenizerTests(unittest.TestCase):
     def _test(self, raw, expected):
         self.assertEquals(apilint.V2Tokenizer(raw).tokenize(), expected)