[sqlite] Converted extract_sqlite_api to python3.

Required changes:

1. Python 3 exceptions no longer have a message attribute so
   created a new ExtractError exception.
2. Switched from the imp to the importlib module.

Bug: none
Change-Id: I5c8b08dca1534e235309464cf5e054578b9ed2f8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2000981
Commit-Queue: Victor Costan <pwnall@chromium.org>
Reviewed-by: Darwin Huang <huangdarwin@chromium.org>
Reviewed-by: Victor Costan <pwnall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#731718}

third_party/sqlite/PRESUBMIT.py

@@ -13,6 +13,6 @@ def CheckChangeOnUpload(input_api, output_api):
   results += input_api.RunTests(
       input_api.canned_checks.GetUnitTests(input_api, output_api, [
           'scripts/extract_sqlite_api_unittest.py'
-      ]))
+      ], env=None, run_on_python2=False, run_on_python3=True))
 
   return results

third_party/sqlite/scripts/extract_sqlite_api.py

-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Copyright 2018 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
@@ -18,6 +18,10 @@ For example, the following renaming macro is produced for sqlite3_initialize().
 import re
 import sys
 
+class ExtractError(ValueError):
+  def __init__(self, message):
+    self.message = message
+
 def ExtractLineTuples(string):
   '''Returns a list of lines, with start/end whitespace stripped.
 
@@ -197,7 +201,7 @@ IDENTIFIER_RE = re.compile(r'^[a-zA-Z_0-9]+$')
 def ExtractApiExport(macro_names, api_export_macro, statement):
   '''Extracts the symbol name from a statement exporting a function.
 
-  Returns None if the statement does not export a symbol. Throws ValueError if
+  Returns None if the statement does not export a symbol. Throws ExtractError if
   the parser cannot understand the statement.
   '''
   # See http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1256.pdf, section 6.7
@@ -237,7 +241,7 @@ def ExtractApiExport(macro_names, api_export_macro, statement):
   seen_simple_type = False
   for word in words:
     if word in UNSUPPORTED_KEYWORDS:
-      raise ValueError("Unsupported keyword %s" % word)
+      raise ExtractError("Unsupported keyword %s" % word)
 
     if word in QUALIFIER_KEYWORDS:
       continue
@@ -249,7 +253,7 @@ def ExtractApiExport(macro_names, api_export_macro, statement):
 
     if word in COMPOSITE_TYPE_SPECIFIERS:
       if seen_simple_type:
-        raise ValueError('Mixed simple (struct_name) and composite (int) types')
+        raise ExtractError('Mixed simple (struct_name) and composite (int) types')
       seen_composite_type = True
       continue
 
@@ -260,16 +264,16 @@ def ExtractApiExport(macro_names, api_export_macro, statement):
     if not seen_composite_type and not seen_simple_type:
       seen_simple_type = True
       if IDENTIFIER_RE.match(word) is None:
-        raise ValueError(
+        raise ExtractError(
             "%s parsed as type name, which doesn't make sense" % word)
       continue
 
     if IDENTIFIER_RE.match(word) is None:
-      raise ValueError(
+      raise ExtractError(
           "%s parsed as symbol name, which doesn't make sense" % word)
     return word
 
-  raise ValueError('Failed to find symbol name')
+  raise ExtractError('Failed to find symbol name')
 
 
 def ExportedSymbolLine(symbol_prefix, symbol, statement_tuple):
@@ -311,7 +315,7 @@ def ProcessSource(api_export_macro, symbol_prefix, header_line, footer_line,
       if symbol_name:
         output_lines.append(
             ExportedSymbolLine(symbol_prefix, symbol_name, statement_tuple))
-    except ValueError as exception:
+    except ExtractError as exception:
       output_lines.append(ExportedExceptionLine(exception, statement_tuple))
 
   output_lines.sort()

third_party/sqlite/scripts/extract_sqlite_api_unittest.py

-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # Copyright 2018 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
@@ -8,7 +8,7 @@
 These tests should be getting picked up by the PRESUBMIT.py in this directory.
 """
 
-import imp
+from importlib.machinery import SourceFileLoader
 import os
 import shutil
 import sys
@@ -20,7 +20,7 @@ class ExtractSqliteApiUnittest(unittest.TestCase):
     self.test_root = tempfile.mkdtemp()
     source_path = os.path.join(
         os.path.dirname(os.path.realpath(__file__)), 'extract_sqlite_api.py')
-    self.extractor = imp.load_source('extract_api', source_path)
+    self.extractor = SourceFileLoader('extract_api', source_path).load_module()
 
   def tearDown(self):
     if self.test_root:
@@ -198,17 +198,21 @@ class ExtractSqliteApiUnittest(unittest.TestCase):
             set(['SQLITE_DEPRECATED']), 'SQLITE_API',
             'NOT_SQLITE_API struct sqlite_type sqlite3_sleep(int ms)'))
 
-    with self.assertRaisesRegexp(ValueError, 'Mixed simple .* and composite'):
+    with self.assertRaisesRegex(self.extractor.ExtractError,
+                                'Mixed simple .* and composite'):
       self.extractor.ExtractApiExport(
           set(), 'SQLITE_API', 'SQLITE_API void int sqlite3_sleep(int ms)')
-    with self.assertRaisesRegexp(ValueError, 'Unsupported keyword struct'):
+    with self.assertRaisesRegex(self.extractor.ExtractError,
+                                'Unsupported keyword struct'):
       self.extractor.ExtractApiExport(
           set(), 'SQLITE_API',
           'SQLITE_API struct sqlite_type sqlite3_sleep(int ms)')
-    with self.assertRaisesRegexp(ValueError, 'int\+\+ parsed as type name'):
+    with self.assertRaisesRegex(self.extractor.ExtractError,
+                                'int\+\+ parsed as type name'):
       self.extractor.ExtractApiExport(
           set(), 'SQLITE_API', 'SQLITE_API int++ sqlite3_sleep(int ms)')
-    with self.assertRaisesRegexp(ValueError, 'sqlite3\+sleep parsed as symbol'):
+    with self.assertRaisesRegex(self.extractor.ExtractError,
+                                'sqlite3\+sleep parsed as symbol'):
       self.extractor.ExtractApiExport(
           set(), 'SQLITE_API', 'SQLITE_API int sqlite3+sleep(int ms)')
 
@@ -228,7 +232,7 @@ class ExtractSqliteApiUnittest(unittest.TestCase):
     self.assertEqual(
         '// TODO: Lines 42-44 -- Something went wrong',
         self.extractor.ExportedExceptionLine(
-            ValueError('Something went wrong'),
+            self.extractor.ExtractError('Something went wrong'),
             (42, 44, 'SQLITE_API int chrome_sqlite3_sleep(int ms)')))
 
   def testProcessSource(self):