[cfe-dev] Clang Static Analyzer Inter-File Analysis

[Artem Dergachev via cfe-dev]

Yup, Kristof is right: there's a difference between "files" and 
"translation units". Your #includes may be different files on disk, but 
every .c/.cpp file is compiled together with all of its includes in a 
single Clang process, therefore there never were any technical barriers 
to produce reports that jump from .c to .h and back in this scenario. 
The minor difficulties to present the bug report to the user (either as 
.plist or as .html) were indeed resolved recently (like, a few years ago).

The actual cross-translation-unit analysis challenge is to exchange 
information between multiple instances of Clang that compile different 
translation units, either by serializing intermediate analysis results 
on disk, or by passing them around through an IPC interface. We have a 
solution that attempts to do the former, but it's not enabled by default 
yet.

I don't think our .plist format is documented anywhere. It's probably a 
very good idea to get it documented so that people who rely on it didn't 
have to continuously monitor the upstream commits. I don't think we had 
any breaking changes since multi-file plists were introduced, but we did 
add a few extra fields since then (issue hashes, opt-in performance 
statistics, executed lines, macro expansions(?)).

On 3/13/19 2:43 PM, Kristóf Umann via cfe-dev wrote:
> Hi!
>
> CTU is off by default -- isn't it possible that those filenames are 
> headers and other included files?
>
> > Is there another place where I might be able to find this sort 
> of information in the future? Thank you.
> Enable the checker debug.ConfigDumper, that might tell a couple 
> things, coupled with the frontend flag -analyzer-config-help. Mind 
> you, we are currently working on a lot nicer user interface ;)
>
> Cheers,
> Kristóf Umann
>
> Gianluca Gross via cfe-dev <cfe-dev at lists.llvm.org 
> <mailto:cfe-dev at lists.llvm.org>> ezt írta (időpont: 2019. márc. 13., 
> Sze, 20:35):
>
>     Hello all,
>
>     Just a quick question. Is it true that the latest version of clang
>     runs
>     inter-file analysis (using the cross translation unit) by default? We
>     were working with an older version of clang, and after updating it
>     seems
>     that the output plist files contain multiple file paths. Apologies if
>     this question is too simple or not appropriate for this mailing
>     list. Is
>     there another place where I might be able to find this sort of
>     information in the future? Thank you.
>
>     Best,
>     Gianluca Gross
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