[cfe-dev] Proposal: Integrate static analysis test suites

Sun Jan 24 00:58:07 PST 2016

Since that patch landed, I've manually run ~30 of the SAMATE/SARD tests,
and so far, Clang has missed 5 stack buffer overruns, 4 heap buffer
overruns, and a couple of format string issues. Clang seems a bit better
with double-free/use-after-free issues, and leak issues.

So it looks like there's some good stuff here, and we'll have a pretty
specific set of things to work on!

Pretty cool, eh?

Sincerely,
Alexander Riccio
--
"Change the world or go home."
about.me/ariccio

<http://about.me/ariccio>
If left to my own devices, I will build more.
⁂

On Wed, Jan 20, 2016 at 1:11 AM, <Alexander G. Riccio> <test35965 at gmail.com>
wrote:

> A quick update on this project:
>
> I've been slowed by a technical issue, and I lost ~2 weeks as two family
> members were in the hospital (sorry!).
>
> Since I develop on Windows, I quickly hit a testcase that clang didn't
> detect, as I discussed in "Clang on Windows fails to detect trivial
> double free in static analysis".
>
> That resulted in D16245 <http://reviews.llvm.org/D16245>, which (when
> accepted) fixes that issue. I want to ensure that novice can simply pass
> "--analyze", and clang to "just work", so I've intentionally put off
> further testing work. Otherwise, I could hack around it, and subsequently
> forget about the workaround. Once that's dealt with, then I can resume work
> at a faster pace.
>
>
>
> Sincerely,
> Alexander Riccio
> --
> "Change the world or go home."
> about.me/ariccio
>
> <http://about.me/ariccio>
> If left to my own devices, I will build more.
> ⁂
>
> On Mon, Jan 4, 2016 at 3:05 PM, Anna Zaks <ganna at apple.com> wrote:
>
>>
>> On Jan 2, 2016, at 12:45 PM, <Alexander G. Riccio> <test35965 at gmail.com>
>> <Alexander G. Riccio> wrote:
>>
>> Devin has started writing scripts for running additional analyzer tests
>>> as described in this thread:
>>>
>>
>> A buildbot sounds like the perfect idea!
>>
>> The idea was to check out the tests/projects from the existing repos
>>> instead of copying them. Would it be possible to do the same with these
>>> tests?
>>>
>>
>> Eh? What do you mean? Would that stop someone from running them in the
>> clang unit test infrastructure?
>>
>> I believe that these tests WILL need to be modified to run in the Clang
>> testing infrastructure.
>>
>>
>> Currently, the analyzer is only tested with the regression tests.
>> However, those need to be fast (since they effect all clang developers) and
>> they have limited coverage. Internally, we’ve been testing the analyzer
>> with the test scripts Devin described in the email I referenced. We use
>> that testing method to analyze whole projects and long running tests. Those
>> tests can and should be executed separately as they take more than an hour
>> to complete. The plan is to set up an external builedbot running those
>> tests.
>>
>> How long would it take to analyze the tests you are planning to add?
>> Depending on the answer to that question, adding your tests to the new
>> builedbot might be a better fit than adding them to the regression tests.
>>
>> I also prefer not to modify the externally written tests since it would
>> allow us to update them more easily, for example, when a new version of the
>> tests comes out.
>>
>> Is there any way to treat static analyzer warnings as plain old
>> warnings/errors? Dumping them to a plist file from a command line
>> compilation is a bit annoying, and I think is incompatible with the clang
>> unit testing infrastructure?
>>
>>
>> Plist output is one if the outputs that the clang static analyzer
>> supports. It is a much richer format than the textual warning since it
>> contains information about the path on which the error occurred. We did
>> have some lit tests checking plist output as well.
>>
>>
>>
>> Sincerely,
>> Alexander Riccio
>> --
>> "Change the world or go home."
>> about.me/ariccio
>>
>> <http://about.me/ariccio>
>> If left to my own devices, I will build more.
>> ⁂
>>
>> On Mon, Dec 28, 2015 at 12:23 AM, Anna Zaks <ganna at apple.com> wrote:
>>
>>>
>>> On Dec 17, 2015, at 11:01 AM, <Alexander G. Riccio> <
>>> alexander at riccio.com> <Alexander G. Riccio> wrote:
>>>
>>> However, if the goal is to have the tests
>>>> because you would like to make efforts to have the compiler diagnose
>>>> their cases properly, that's far more interesting and a good reason to
>>>> bring in the tests.
>>>
>>>
>>> That's exactly my intention. Improving the static analyzer to detect
>>> these cases, that will be interesting.
>>> placeholder text
>>>
>>> If the other tests are not clearly licensed, we
>>>> should try to get NIST to clarify the license of them before
>>>> inclusion.
>>>
>>>
>>> That sounds like the best idea, as a government agency, they almost
>>> certainly have lawyers.
>>>
>>> I think the next step is to integrate the working (error correctly
>>> diagnosed) tests, only those that are obviously in the public domain, and
>>> propose them as a big batched patch. This shouldn't itself be
>>> controversial.
>>>
>>> How exactly do I submit a patch? I see that the LLVM developer policy
>>> says to send it to the mailing list (cfe-commits), but I also see that Phabricator
>>> comes into this somewhere
>>> <http://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20151214/145026.html>
>>> ?
>>>
>>>
>>> Devin has started writing scripts for running additional analyzer tests
>>> as described in this thread:
>>>
>>> http://clang-developers.42468.n3.nabble.com/analyzer-Adding-build-bot-for-static-analyzer-reference-results-td4047770.html
>>>
>>> The idea was to check out the tests/projects from the existing repos
>>> instead of copying them. Would it be possible to do the same with these
>>> tests?
>>>
>>> Sorry for not replying sooner!
>>> Anna.
>>>
>>> Sincerely,
>>> Alexander Riccio
>>> --
>>> "Change the world or go home."
>>> about.me/ariccio
>>>
>>> <http://about.me/ariccio>
>>> If left to my own devices, I will build more.
>>> ⁂
>>>
>>> On Thu, Dec 10, 2015 at 4:04 PM, Aaron Ballman <aaron at aaronballman.com>
>>> wrote:
>>>
>>>> On Mon, Dec 7, 2015 at 9:50 PM, <Alexander G. Riccio> via cfe-dev
>>>> <cfe-dev at lists.llvm.org> wrote:
>>>> > First time Clang contributor here,
>>>> >
>>>> > I'd like to add the "C Test Suite for Source Code Analyzer v2", a
>>>> > relatively small test suite (102 cases/flaws), some of which Clang
>>>> > doesn't yet detect*. See link at bottom.
>>>> >
>>>> > Immediate questions:
>>>> > 0. Does the Clang community/project like the idea?
>>>>
>>>> I've included a few other devs (CCed) to get further opinions.
>>>>
>>>> I like the idea of being able to diagnose the issues covered by the
>>>> test suite, but I don't think including the test suite by itself is
>>>> particularly useful without that goal in mind. Also, one question I
>>>> would have has to do with the licensing of the tests themselves and
>>>> whether we would need to do anything special there.
>>>>
>>>> > 1. What's the procedure for including new tests? (not the technical,
>>>> > but the community/project).
>>>>
>>>> Getting the discussion going about the desired goal (as you are doing)
>>>> is the right first step.
>>>>
>>>> > 2. How do I include failing tests without breaking things? Some of
>>>> > these tests will fail - that's why I'm proposing their inclusion - but
>>>> > they shouldn't yet cause the regression testing system to complain.
>>>>
>>>> Agreed, any test cases that are failing would have to fail gracefully.
>>>> I assume that by failure, you mean "should diagnose in some way, but
>>>> currently does not". I would probably split the tests into two types:
>>>> one set of tests that properly diagnose the issue (can be checked with
>>>> FileCheck or -verify, depending on the kind of tests we're talking
>>>> about), and one set of tests where we do not diagnose, but want to see
>>>> them someday (which can be tested with expect-no-diagnostics, for
>>>> example). This way, we can ensure test cases continue to diagnose when
>>>> we want them to, and we can be alerted when new diagnostics start to
>>>> catch previously uncaught tests. This is assuming that it makes sense
>>>> to include all of the tests at once, which may not make sense in
>>>> practice.
>>>>
>>>> > 3. How does Clang handle licensing of third party code? Some of these
>>>> > tests are clearly in the public domain (developed at NIST, says "in
>>>> > the public domain"), but others are less clearly licensed.
>>>>
>>>> Oh look, you asked the same question I asked. ;-) If the tests are in
>>>> the public domain and clearly state as such, I think we can go ahead
>>>> and include them. If the other tests are not clearly licensed, we
>>>> should try to get NIST to clarify the license of them before
>>>> inclusion. Depending on the license, we may be able to include them
>>>> under their original license. If we cannot clarify the license, I
>>>> would guess that we simply should not include those tests as part of
>>>> our test suite. Note: I could be totally wrong, IANAL. :-)
>>>>
>>>> > Should the community accept that testsuite, and I successfully add
>>>> > that test suite, then I'd like to step it up a bit, and include the
>>>> > "Juliet Test Suite for C/C++". "Juliet" is a huge test suite by the
>>>> > NSA Center for Assured Software & NIST's Software Assurance Metrics
>>>> > And Tool Evaluation project, which has 25,477 test cases (!!) for 118
>>>> > CWEs. I don't think any other open source compiler could compete with
>>>> > Clang after this. There's a ton of literature on the "Juliet" suite,
>>>> > and listing it here is not necessary.
>>>> >
>>>> > This project would be my first Clang contribution :)
>>>> >
>>>> > Personally, I'm interested in static analysis, and this is the first
>>>> > step in understanding & improving Clang's static analysis
>>>> > capabilities.
>>>> >
>>>> > I have some ideas on how to detect the currently undetected bugs, and
>>>> > I'm curious to see where things lead.
>>>>
>>>> Adding the tests by themselves is not necessarily interesting to the
>>>> project unless they exercise the compiler in ways it's not currently
>>>> being exercised. So just having tests for the sake of having the tests
>>>> is not too useful (IMO). However, if the goal is to have the tests
>>>> because you would like to make efforts to have the compiler diagnose
>>>> their cases properly, that's far more interesting and a good reason to
>>>> bring in the tests.
>>>>
>>>> One possible approach if you are interested in having the compiler
>>>> diagnose the cases is to bring the tests in one at a time. Start with
>>>> the initial batch of "these are diagnosed properly", then move on to
>>>> "this test is diagnosed properly because of this patch." Eventually
>>>> we'll get to the stage where all of the tests are diagnosed properly.
>>>>
>>>> > Secondary questions:
>>>> > 1. How should I break the new tests up into patches? Should I just
>>>> > whack the whole 102 case suite into a single patch, or a bunch of
>>>> > smaller ones?
>>>>
>>>> See comments above.
>>>>
>>>> > 2. How does the Clang/LLVM static analysis testing infrastructure
>>>> > work? I'm going to have to figure this out myself anyways, but where
>>>> > should I start? Any tips on adding new tests?
>>>>
>>>> http://clang-analyzer.llvm.org/checker_dev_manual.html
>>>>
>>>> Another good place for some of these checkers may be clang-tidy, or
>>>> the compiler frontend itself. It's likely to depend on case-by-case
>>>> code patterns.
>>>>
>>>> http://clang.llvm.org/extra/clang-tidy/
>>>>
>>>> Thank you for looking into this!
>>>>
>>>> ~Aaron
>>>>
>>>> >
>>>> > *If I remember correctly,
>>>> > https://samate.nist.gov/SRD/view_testcase.php?tID=149055 passes
>>>> > analysis without complaint. I manually spot checked a very small
>>>> > number of tests.
>>>> >
>>>> > "C Test Suite for Source Code Analyzer v2" (valid code):
>>>> > https://samate.nist.gov/SRD/view.php?tsID=101
>>>> > "C Test Suite for Source Code Analyzer v2" (invalid code):
>>>> > https://samate.nist.gov/SRD/view.php?tsID=100
>>>> >
>>>> > "Juliet Test Suite for C/C++" (files):
>>>> >
>>>> https://samate.nist.gov/SRD/testsuites/juliet/Juliet_Test_Suite_v1.2_for_C_Cpp.zip
>>>> > "Juliet Test Suite for C/C++" (docs):
>>>> >
>>>> https://samate.nist.gov/SRD/resources/Juliet_Test_Suite_v1.2_for_C_Cpp_-_User_Guide.pdf
>>>> >
>>>> >
>>>> > Sincerely,
>>>> > Alexander Riccio
>>>> > _______________________________________________
>>>> > cfe-dev mailing list
>>>> > cfe-dev at lists.llvm.org
>>>> > http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev
>>>>
>>>
>>>
>>>
>>
>>
>
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