How to verify clang-tidy checks applied to headers?

Clang Frontend
1

Hi,

I'm trying to write a test for this bug:
<https://bugs.llvm.org/show_bug.cgi?id=26332&gt;

Namely, that clang-tidy check readability-simplify-boolean-expr
doesn't apply to the user's header files correctly.

So I wrote a cpp file like this:

2

Maybe you could first generate the preprocessed file, use the
preprocessed file as the test input and add the "CHECK-MESSAGES" lines
to the preprocessed file?

3

You probably need to extend the test framework to accept
the -header-filter command line and pass it through.

Thanks,

Stephen.

4

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In article <q02pmi$6qf$1@blaine.gmane.org>,
    Stephen Kelly via cfe-dev <cfe-dev@lists.llvm.org> writes:

You probably need to extend the test framework to accept
the -header-filter command line and pass it through.

Yeah, I think check_clang_tidy.py will need to be augmented in order
to support that. However, that's just a wrapper around running
clang-tidy in a convenient manner, so I thought I could prototype it
with // RUN: clang-tidy ..., but didn't manage to find the right
incantation. I find it hard to believe I'm the first person to try
and do this, so I was hoping there was an accepted recipe for doing
this.

5

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In article <CAJ0ZJHTd=4RwyU3Nh+wNfETYO7D=dd4kCnL5QTRqX9qEL8vq1Q@mail.gmail.com>,
    Hongbin Zheng <etherzhhb@gmail.com> writes:

Maybe you could first generate the preprocessed file, use the
preprocessed file as the test input and add the "CHECK-MESSAGES" lines
to the preprocessed file?

If I do that, then I'm not testing the actual mechanism.

6

I don't know much about clang-tidy tests, but i had a quick look.

Because clang-tidy checks are FileCheck-based, it should be trivial to specify in the main file that the warning needs to come from another file, from a specific line, by simply matching the output. Matching that it *doesn't* appear in a certain file on a certain line is more fragile though, because the other file may change and you won't notice how your test breaks.

So, yeah, i guess it's better to put CHECK: lines into the header itself, and then tell FileCheck to use the *header* as the input file.

I'm not sure if %check_clang_tidy aka check_clang_tidy.py supports such behavior. If not, you should be able to do that manually, but of course you'll also need to pipe it into FileCheck manually for any checks to happen.

7

Hi,

did you try something similar to `// RUN: clang-tidy -checks='-*,
abseil-no-namespace' -header-filter='.*' %s -- -I %S/Inputs 2>&1 |
FileCheck %s`?

This pattern occurs multiple times in the test-framework: `git grep "|
FileCheck" *.cpp` shows quite a view places, maybe there are other
places that are more specific to your requirement?

Best, Jonas

8

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In article <bdfd9306-7233-6712-ad2c-85cfe61c47ab@jonas-toth.eu>,
    Jonas Toth via cfe-dev <cfe-dev@lists.llvm.org> writes:

did you try something similar to `// RUN: clang-tidy -checks='-*,
abseil-no-namespace' -header-filter='.*' %s -- -I %S/Inputs 2>&1 |
FileCheck %s`?

Yeah, I tried something like that, but I didn't get it to work
properly. I will look at it again to see if I can get the right
command-line. It's been a couple years since I worked on clang-tidy
and some of my clang-fu has decayed away. If I can find a pattern that
works, I'll enhance the helper script to support this directly.

This pattern occurs multiple times in the test-framework: `git grep "|
FileCheck" *.cpp` shows quite a view places, maybe there are other
places that are more specific to your requirement?

Thanks for the pointer.

9

[Please reply *only* to the list and do not include my email directly
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In article <bdfd9306-7233-6712-ad2c-85cfe61c47ab@jonas-toth.eu>,
    Jonas Toth via cfe-dev <cfe-dev@lists.llvm.org> writes:

did you try something similar to `// RUN: clang-tidy -checks='-*,
abseil-no-namespace' -header-filter='.*' %s -- -I %S/Inputs 2>&1 |
FileCheck %s`?

This pattern occurs multiple times in the test-framework: `git grep "|
FileCheck" *.cpp` shows quite a view places, maybe there are other
places that are more specific to your requirement?

Well, it seems that I already had a patch that did this from 2 years
ago that never made it through the exhausting process that is
phabricator.

Right now I have a Compose Method refactor in phabricator that needs
approval. After that, I'll rebase my old changes on top of that.

So I need a little review love in phabricator, please...