[llvm-dev] How to print what -Wall represents?

[Peng Yu via llvm-dev]

> diagtool show-enabled a.c
>
> diagtool is a tool in clang-tools-extra. On Debian (I think) it is packaged in clang-tools.

I see these. Why it has the suffix -11 or -9?

$ apt-file search diagtool | grep /bin/
clang-tools-11: /usr/bin/diagtool-11
clang-tools-11: /usr/lib/llvm-11/bin/diagtool
clang-tools-9: /usr/bin/diagtool-9
clang-tools-9: /usr/lib/llvm-9/bin/diagtool

But the command clang has one that doesn't have the suffix?

$ ls -lgG $(which clang)
lrwxrwxrwx 1 24 2021/01/14-10:39:00 /usr/bin/clang -> ../lib/llvm-11/bin/clang
$ apt-file search clang | grep '/bin/\(clang-11\|clang\)$'
clang: /usr/bin/clang
clang-11: /usr/bin/clang-11
clang-11: /usr/lib/llvm-11/bin/clang
clang-11: /usr/lib/llvm-11/bin/clang-11
clang-9: /usr/lib/llvm-9/bin/clang
icecc: /usr/lib/icecc/bin/clang

Where is diagtool on macOS? I don't want to use clang via homebrew as
I am afraid of potential conflict with the default system clang.

Or there is some other way to get the same info on macOS?

-- 
Regards,
Peng