Improve tidy's license validation logic

fixes https://github.com/servo/servo/issues/10716

I took the lazy way out and hardcoded the size of block we examine for
licenses.

fixes https://github.com/servo/servo/issues/10719

Includes tests for new functionality.

6 files changed, 75 insertions, 105 deletions

diff --git a/python/tidy/HISTORY.rst b/python/tidy/HISTORY.rst
index 1e02962afa0..bc36c7e908f 100644
--- a/python/tidy/HISTORY.rst
+++ b/python/tidy/HISTORY.rst
@@ -1,6 +1,17 @@
 Release History
 ---------------
 
+0.1.0 (2016-08-09)
+++++++++++++++++++
+
+- Improve license checking to disregard comments and line breaks
+- License checking verifies that COPYRIGHT is specified when apache2 is used
+
+0.0.3 (2016-04-19)
+++++++++++++++++++
+
+- Add alternate wording of apache2 license
+
 0.0.2 (2016-04-17)
 ++++++++++++++++++
 - Cleanup Tidy to work on external deps
diff --git a/python/tidy/servo_tidy/licenseck.py b/python/tidy/servo_tidy/licenseck.py
index 3a17f1fdf04..a9fe9077f21 100644
--- a/python/tidy/servo_tidy/licenseck.py
+++ b/python/tidy/servo_tidy/licenseck.py
@@ -7,97 +7,29 @@
 # option. This file may not be copied, modified, or distributed
 # except according to those terms.
 
-
-# These licenses are valid for use in Servo
-licenses = [
-
-"""\
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-""",
-
-"""\
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, You can obtain one at http://mozilla.org/MPL/2.0/.
-""",
-
-"""\
-#!/usr/bin/env bash
-
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, You can obtain one at http://mozilla.org/MPL/2.0/.
-""",
-
-"""\
-#!/usr/bin/env python
-
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, You can obtain one at http://mozilla.org/MPL/2.0/.
-""",
-
-"""\
-#!/usr/bin/env python3
-
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, You can obtain one at http://mozilla.org/MPL/2.0/.
-""",
-
-"""\
-// This Source Code Form is subject to the terms of the Mozilla Public
-// License, v. 2.0. If a copy of the MPL was not distributed with this
-// file, You can obtain one at http://mozilla.org/MPL/2.0/.
-""",
-
-"""\
-// Copyright 2013 The Servo Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-""",
-
-"""\
-# Copyright 2013 The Servo Project Developers. See the COPYRIGHT
-# file at the top-level directory of this distribution.
-#
-# Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-# http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-# <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-# option. This file may not be copied, modified, or distributed
-# except according to those terms.
-""",
-
-"""\
-// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-""",
-
-"""\
-// Copyright 2012-2014 The Rust Project Developers.
-// See http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-""",
-]  # noqa: Indicate to flake8 that we do not want to check indentation here
+# when wrapped to 80 chars, the longest license is 10 lines.
+# TODO actually grab whatever commented block is before the second blank line
+# of the file instead of hard-coding this.
+MAX_LICENSE_LINESPAN = 12
+
+MPL = """\
+This Source Code Form is subject to the terms of the Mozilla Public \
+License, v. 2.0. If a copy of the MPL was not distributed with this \
+file, You can obtain one at http://mozilla.org/MPL/2.0/.\
+"""
+
+APACHE = """\
+Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or \
+http://www.apache.org/licenses/LICENSE-2.0> or the MIT license \
+<LICENSE-MIT or http://opensource.org/licenses/MIT>, at your \
+option. This file may not be copied, modified, or distributed \
+except according to those terms.\
+"""
+
+COPYRIGHT = [
+    "See the COPYRIGHT file at the top-level directory of this distribution",
+    "See http://rust-lang.org/COPYRIGHT",
+]
 
 # The valid licenses, in the form we'd expect to see them in a Cargo.toml file.
 licenses_toml = [
diff --git a/python/tidy/servo_tidy/tidy.py b/python/tidy/servo_tidy/tidy.py
index 3433e8265ed..fac5f8e7063 100644
--- a/python/tidy/servo_tidy/tidy.py
+++ b/python/tidy/servo_tidy/tidy.py
@@ -17,12 +17,9 @@ import site
 import StringIO
 import subprocess
 import sys
-from licenseck import licenses, licenses_toml, licenses_dep_toml
+from licenseck import MPL, APACHE, COPYRIGHT, licenses_toml, licenses_dep_toml
 
-# License and header checks
-EMACS_HEADER = "/* -*- Mode:"
-VIM_HEADER = "/* vim:"
-MAX_LICENSE_LINESPAN = max(len(license.splitlines()) for license in licenses)
+COMMENTS = ["// ", "# ", " *", "/* "]
 
 # File patterns to include in the non-WPT tidy check.
 FILE_PATTERNS_TO_CHECK = ["*.rs", "*.rc", "*.cpp", "*.c",
@@ -55,7 +52,6 @@ IGNORED_FILES = [
 IGNORED_DIRS = [
     # Upstream
     os.path.join(".", "support", "android", "apk"),
-    os.path.join(".", "support", "rust-task_info"),
     os.path.join(".", "tests", "wpt", "css-tests"),
     os.path.join(".", "tests", "wpt", "harness"),
     os.path.join(".", "tests", "wpt", "update"),
@@ -147,13 +143,35 @@ def filter_files(start_dir, only_changed_files, progress):
         yield file_name
 
 
+def uncomment(line):
+    for c in COMMENTS:
+        if line.startswith(c):
+            if line.endswith("*/"):
+                return line[len(c):(len(line) - 3)].strip()
+            return line[len(c):].strip()
+
+
+def licensed_mpl(header):
+    return MPL in header
+
+
+def licensed_apache(header):
+    if APACHE in header:
+        return any(c in header for c in COPYRIGHT)
+
+
 def check_license(file_name, lines):
     if any(file_name.endswith(ext) for ext in (".toml", ".lock", ".json")):
         raise StopIteration
-    while lines and (lines[0].startswith(EMACS_HEADER) or lines[0].startswith(VIM_HEADER)):
-        lines = lines[1:]
-    contents = "".join(lines[:MAX_LICENSE_LINESPAN])
-    valid_license = any(contents.startswith(license) for license in licenses)
+    block = min(len(lines), licenseck.MAX_LICENSE_LINESPAN)
+    license_block = []
+    for l in lines[:block]:
+        l = l.rstrip('\n')
+        line = uncomment(l)
+        if line is not None:
+            license_block += [line]
+    contents = " ".join(license_block)
+    valid_license = licensed_mpl(contents) or licensed_apache(contents)
     acknowledged_bad_license = "xfail-license" in contents
     if not (valid_license or acknowledged_bad_license):
         yield (1, "incorrect license")
@@ -305,8 +323,8 @@ def check_toml(file_name, lines):
     for idx, line in enumerate(lines):
         if line.find("*") != -1:
             yield (idx + 1, "found asterisk instead of minimum version number")
-        for license in licenses_toml:
-            ok_licensed |= (license in line)
+        for license_line in licenses_toml:
+            ok_licensed |= (license_line in line)
     if not ok_licensed:
         yield (0, ".toml file should contain a valid license.")
 
diff --git a/python/tidy/servo_tidy_tests/apache2_license.rs b/python/tidy/servo_tidy_tests/apache2_license.rs
new file mode 100644
index 00000000000..c9fed89cf73
--- /dev/null
+++ b/python/tidy/servo_tidy_tests/apache2_license.rs
@@ -0,0 +1,5 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
diff --git a/python/tidy/servo_tidy_tests/test_tidy.py b/python/tidy/servo_tidy_tests/test_tidy.py
index 92b304a5c1a..888c0faf693 100644
--- a/python/tidy/servo_tidy_tests/test_tidy.py
+++ b/python/tidy/servo_tidy_tests/test_tidy.py
@@ -58,6 +58,10 @@ class CheckTidiness(unittest.TestCase):
         self.assertEqual('script should use `[[` instead of `[` for conditional testing', errors.next()[2])
         self.assertNoMoreErrors(errors)
 
+    def test_apache2_incomplete(self):
+        errors = tidy.collect_errors_for_files(iterFile('apache2_license.rs'), [], [tidy.check_license])
+        self.assertEqual('incorrect license', errors.next()[2])
+
     def test_rust(self):
         errors = tidy.collect_errors_for_files(iterFile('rust_tidy.rs'), [], [tidy.check_rust], print_text=False)
         self.assertEqual('use statement spans multiple lines', errors.next()[2])
diff --git a/python/tidy/setup.py b/python/tidy/setup.py
index a1af7d88465..dbff59e7964 100644
--- a/python/tidy/setup.py
+++ b/python/tidy/setup.py
@@ -11,7 +11,7 @@ import os
 from setuptools import setup, find_packages
 
 
-VERSION = '0.0.3'
+VERSION = '0.1.0'
 
 install_requires = [
     "flake8==2.4.1",
@@ -51,7 +51,7 @@ if __name__ == '__main__':
         zip_safe=False,
         entry_points={
             'console_scripts': [
-                'servo-tidy=servo_tidy.tidy:scan'
+                'servo-tidy=servo_tidy.tidy:scan',
             ],
         },
     )