[PATCH] D45050: [clang-tidy] New checker for not null-terminated result caused by strlen(), size() or equal length

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In https://reviews.llvm.org/D45050#1280831, @dyung wrote:

> I have attached a bzipped preprocessed file that I can confirm will show the failure if built with clang++ version 3.7.1, specifically the version that shipped with ubuntu 14.04.5 LTS. Here is the full version information:
>
> Ubuntu clang version 3.7.1-svn253742-1~exp1 (branches/release_37) (based on LLVM 3.7.1)
>
> Target: x86_64-pc-linux-gnu
>  Thread model: posix
>
> If you build it with “clang++ -std=c++11 NotNullTerminatedResultCheck.preproc.cpp” you should see the failure.


I have installed said Ubuntu in a virtual machine for testing this, but unfortunately only the following Clangs are available in the package manager for `Trusty`:

  clang - C, C++ and Objective-C compiler (LLVM based)
  clang-3.3 - C, C++ and Objective-C compiler (LLVM based)
  clang-3.4 - C, C++ and Objective-C compiler (LLVM based)
  clang-3.5 - C, C++ and Objective-C compiler (LLVM based)
  clang-3.6 - C, C++ and Objective-C compiler (LLVM based)
  clang-3.8 - C, C++ and Objective-C compiler (LLVM based)
  clang-3.9 - C, C++ and Objective-C compiler (LLVM based)

(Where `clang` is just a synonym for `clang-3.4`.) **There is no Clang 3.7 in the package upstream, it seems.**

------

However, **`16.04 LTS (Xenial)`** at the time of writing this comment has an `clang-3.7` package, specifically this version:

  Ubuntu clang version 3.7.1-2ubuntu2 (tags/RELEASE_371/final) (based on LLVM 3.7.1)
  Target: x86_64-pc-linux-gnu
  Thread model: posix

With this I can confirm I get a huge trace and the template depth overflow failure.

However, from the filename-line mappings of the preprocessed output, I can see that the `type_traits` header comes from `/usr/include/c++/4.8/type_traits`, which is a version **4.8** standard library, but installing the `clang-3.7` package (through some transitivity in `libasan` and such) depended on `gcc-`**`5`**`-base`, upgrading it from the system-default `5.3.1` to `5.4.0`.

Isn't this a discrepancy, relying on an older standard library than what is seemingly available on the system?


https://reviews.llvm.org/D45050