Automate source code formatting with clang-format

[iamazeem]

Hi,

To automate the source code formatting and to keep it consistent throughout, clang-format can be configured for zsv:

• https://clang.llvm.org/docs/ClangFormat.html
• https://clang.llvm.org/docs/ClangFormatStyleOptions.html

https://zed0.co.uk/clang-format-configurator/ may be used to generate the .clang-format file.
Once .clang-format is added, the users can configure their editors, e.g. VS Code, to format source files automatically (on demand or on save).

The same can be integrated in the CI pipeline as well to enforce a consistent style.
The CI may fail if code is not formatted or it can reformat and commit the formatted files back to repo.
LMK what would be the preferred workflow. I'll update the CI accordingly.

Thanks!

[liquidaty]

Will review and comment shortly

[liquidaty]

Is it possible to start with CI failing if changed code does not conform-- but only for changed code? If so, let's do that.

If not, can we start with having the CI fail if code does not conform, but only for certain specified files? If so, let's do that, starting with src/*.*. We can broaden the scope later.

If none of the above is feasible, will review further and get back to you.

[iamazeem]

Both are feasible.

However, I'll recommend to create one single PR first with formatted source code in one go excluding externals libs.
After that, it'll just be the conformance of the new code only.

[iamazeem]

UPDATE

For future changes, https://clang-format-configurator.site/ should be used instead of https://zed0.co.uk/clang-format-configurator.

It supports newer versions and includes other bug fixes.
See its README for a detailed overview.

[iamazeem]

UPDATE: By default, clang-format-15 is being used in CI.
It includes the pointer alignment bug fix for struct observed with clang-format-14.
PR: #194