[PATCH] D54943: [clang-tidy] implement const-transformation for cppcoreguidelines-const-correctness

[Florin Iucha via Phabricator via cfe-commits]

0x8000-0000 added a comment.

In D54943#1815473 <https://reviews.llvm.org/D54943#1815473>, @JonasToth wrote:

> In D54943#1815358 <https://reviews.llvm.org/D54943#1815358>, @0x8000-0000 wrote:
>
> > Here is a minimal example that shows the problem:
>
>
> I can not reproduce that case :(
>  It gives me a compilation error in `const DoGooder anInstanceOf...`, because `DoGooder` requires an template parameter. I then add `DoGooder<int>` and the variable gets no transformation.
>  Did you reproduce the error with exactly that code?
>
> And which version did you run? Maybe that was a previous false positive, that might be fixed right now?


The way I am testing is that I am fetching the current master branch of https://github.com/llvm/llvm-project.git, then downloading the latest patch from here and applying on top, then building.

This is the state of the tree right as of last night:

  commit 1c8ab48028cc39429a392691ef2e66968460d782 (HEAD -> D54943.diff12)
  Author: Florin Iucha <florin at signbit.net>
  Date:   Fri Jan 10 18:52:54 2020 -0500
  
      D54943.diff12
  
  commit 1b8c84b8dd5a4a294943a6a6f0631d2d3a1f9f27 (origin/master, origin/HEAD, master)
  Author: Richard Smith <richard at metafoo.co.uk>
  Date:   Fri Jan 10 15:47:29 2020 -0800
  
      Improve precision of documentation comment.

CTAD takes care of the missing template parameter, that's why I'm passing "-std=c++17" to clang-tidy.

  /tmp$ /opt/clang10/bin/clang-tidy -checks="-*,cppcoreguidelines-const-correctness" -header-filter=".*" test.cpp -- -std=c++17 -Wall
  54 warnings generated.
  /tmp/test.cpp:22:9: warning: variable 'anInstanceOf' of type '<dependent type>' can be declared 'const' [cppcoreguidelines-const-correctness]
          const DoGooder anInstanceOf{nullptr, Foo::someRandomConstant};
          ^
                         const 
  Suppressed 53 warnings (53 in non-user code).
  Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
  /tmp$ /opt/clang10/bin/clang++ -c test.cpp
  test.cpp:22:15: error: use of class template 'DoGooder' requires template arguments
          const DoGooder anInstanceOf{nullptr, Foo::someRandomConstant};
                ^
  test.cpp:4:8: note: template is declared here
  struct DoGooder
         ^
  1 error generated.
  /tmp$ /opt/clang10/bin/clang++ -std=c++17 -c test.cpp
  -rw-r--r-- 1 florin florin 432 Jan 11 09:48 test.cpp
  -rw-r--r-- 1 florin florin 744 Jan 11 09:52 test.o


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D54943/new/

https://reviews.llvm.org/D54943