llvm_tools: make the lexan 4c uploader ignore old clang(s)

Lexan saw a crash from clang 9.0.0 uploaded to their bucket. There's
~nothing we care to do about these crashes, and 4c even fails to parse
the header of them. Seems best to warn & ignore these cases
automatically (if an actual _user_ wants this functionality, 4c can
easily be fixed, but I doubt anyone cares)

No test is provided since submit_test_case has quite a few side-effects.
Doesn't seem worth splitting it or mocking a lot to add an automated
test for this peephole.

BUG=None
TEST=manually ran on chrotomation

Change-Id: Iae131913e7b9494015262e41af8ad4193c9d62f6
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/2657875
Reviewed-by: Manoj Gupta <manojgupta@chromium.org>
Tested-by: George Burgess <gbiv@chromium.org>

2 files changed, 46 insertions, 7 deletions

diff --git a/llvm_tools/upload_lexan_crashes_to_forcey.py b/llvm_tools/upload_lexan_crashes_to_forcey.py
index b93f51a7..486fe664 100755
--- a/llvm_tools/upload_lexan_crashes_to_forcey.py
+++ b/llvm_tools/upload_lexan_crashes_to_forcey.py
@@ -101,21 +101,29 @@ def temp_dir() -> Generator[str, None, None]:
     shutil.rmtree(loc)
 
 
+def download_and_unpack_test_case(gs_url: str, tempdir: str) -> None:
+  suffix = os.path.splitext(gs_url)[1]
+  target_name = 'test_case' + suffix
+  target = os.path.join(tempdir, target_name)
+  subprocess.run(['gsutil.py', 'cp', gs_url, target], check=True)
+  subprocess.run(['tar', 'xaf', target_name], check=True, cwd=tempdir)
+  os.unlink(target)
+
+
 def submit_test_case(gs_url: str, cr_tool: str) -> None:
   logging.info('Submitting %s', gs_url)
-  suffix = os.path.splitext(gs_url)[1]
   with temp_dir() as tempdir:
-    target_name = 'test_case' + suffix
-    target = os.path.join(tempdir, target_name)
-    subprocess.run(['gsutil.py', 'cp', gs_url, target], check=True)
-    subprocess.run(['tar', 'xaf', target_name], check=True, cwd=tempdir)
-    os.unlink(target)
+    download_and_unpack_test_case(gs_url, tempdir)
 
     # Sometimes (e.g., in
     # gs://chrome-clang-crash-reports/v1/2020/03/27/
     # chromium.clang-ToTiOS-12754-GTXToolKit-2bfcde.tgz)
     # we'll get `.crash` files. Unclear why, but let's filter them out anyway.
-    repro_files = [x for x in os.listdir(tempdir) if not x.endswith('.crash')]
+    repro_files = [
+        os.path.join(tempdir, x)
+        for x in os.listdir(tempdir)
+        if not x.endswith('.crash')
+    ]
     assert len(repro_files) == 2, repro_files
     if repro_files[0].endswith('.sh'):
       sh_file, src_file = repro_files
@@ -124,6 +132,13 @@ def submit_test_case(gs_url: str, cr_tool: str) -> None:
       src_file, sh_file = repro_files
       assert sh_file.endswith('.sh'), repro_files
 
+    # Peephole: lexan got a crash upload with a way old clang. Ignore it.
+    with open(sh_file, encoding='utf-8') as f:
+      if 'Crash reproducer for clang version 9.0.0' in f.read():
+        logging.warning('Skipping upload for %s; seems to be with an old clang',
+                        gs_url)
+        return
+
     subprocess.run(
         [
             cr_tool,
diff --git a/llvm_tools/upload_lexan_crashes_to_forcey_test.py b/llvm_tools/upload_lexan_crashes_to_forcey_test.py
index 3c9c0d4b..937cbf8e 100755
--- a/llvm_tools/upload_lexan_crashes_to_forcey_test.py
+++ b/llvm_tools/upload_lexan_crashes_to_forcey_test.py
@@ -7,6 +7,7 @@
 """Tests for upload_lexan_crashes_to_forcey."""
 
 import datetime
+import os
 import unittest
 import unittest.mock
 
@@ -117,6 +118,29 @@ class Test(unittest.TestCase):
         ),
     ])
 
+  @unittest.mock.patch(
+      'upload_lexan_crashes_to_forcey.download_and_unpack_test_case')
+  @unittest.mock.patch('subprocess.run')
+  def test_test_case_submission_functions(self, subprocess_run_mock,
+                                          download_and_unpack_mock):
+    mock_gs_url = 'gs://foo/bar/baz'
+
+    def side_effect(gs_url: str, tempdir: str) -> None:
+      self.assertEqual(gs_url, mock_gs_url)
+
+      with open(os.path.join(tempdir, 'test_case.c'), 'w') as f:
+        # All we need is an empty file here.
+        pass
+
+      with open(
+          os.path.join(tempdir, 'test_case.sh'), 'w', encoding='utf-8') as f:
+        f.write('# Crash reproducer for clang version 9.0.0 (...)\n')
+        f.write('clang something or other\n')
+
+    download_and_unpack_mock.side_effect = side_effect
+    upload_lexan_crashes_to_forcey.submit_test_case(mock_gs_url, '4c')
+    subprocess_run_mock.assert_not_called()
+
 
 if __name__ == '__main__':
   unittest.main()