From 80e74cdc6886b83a24587d86cccde0f057ceda38 Mon Sep 17 00:00:00 2001 From: Devin Coughlin Date: Tue, 6 Sep 2016 23:42:51 +0000 Subject: [scan-build-py] Increase precision of timestamp in report directory name This commit improves compatibility with the perl version of scan-build. The perl version of scan-build produces output report directories with increasing lexicographic ordering. This ordering is relied on by the CmpRuns.py tool in utils/analyzer when comparing results for build commands with multiple steps. That tool tries to line up the output directory for each step between different runs of the analyzer based on the increasing directory name. The python version of scan-build uses file.mkdtemp() with a time stamp prefix to create report directories. The timestamp has a 1-second precision. This means that when analysis of a single build step takes less than a second the ordering property that CmpRuns.py expects will sometimes not hold, depending on the timing and the random suffix generated by mkdtemp(). Ultimately this causes CmpRuns to incorrectly correlate results from build steps and report spurious differences between runs. This commit increases the precision of the timestamp used in scan-build-py to the microsecond level. This approach still has the same underlying issue -- but in practice analysis of any build step is unlikely to take less than a millisecond. Differential Revision: https://reviews.llvm.org/D24163 llvm-svn: 280768 --- clang/tools/scan-build-py/tests/unit/test_report.py | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'clang/tools/scan-build-py/tests/unit') diff --git a/clang/tools/scan-build-py/tests/unit/test_report.py b/clang/tools/scan-build-py/tests/unit/test_report.py index 3f249ce2aa0..c82b5593e0d 100644 --- a/clang/tools/scan-build-py/tests/unit/test_report.py +++ b/clang/tools/scan-build-py/tests/unit/test_report.py @@ -146,3 +146,16 @@ class GetPrefixFromCompilationDatabaseTest(unittest.TestCase): def test_empty(self): self.assertEqual( sut.commonprefix([]), '') + +class ReportDirectoryTest(unittest.TestCase): + + # Test that successive report directory names ascend in lexicographic + # order. This is required so that report directories from two runs of + # scan-build can be easily matched up to compare results. + def test_directory_name_comparison(self): + with libear.TemporaryDirectory() as tmpdir, \ + sut.report_directory(tmpdir, False) as report_dir1, \ + sut.report_directory(tmpdir, False) as report_dir2, \ + sut.report_directory(tmpdir, False) as report_dir3: + self.assertLess(report_dir1, report_dir2) + self.assertLess(report_dir2, report_dir3) -- cgit v1.2.3