[llvm-dev] [RFC] Semi-Automatic clang-format of files with low frequency

[Michael Kruse via llvm-dev]

In my experience clang-format helps avoiding spurious merge conflicts
when both parents are clang-formatted. For instance, one source made a
change (e.g. add an assert), undo it again, but a whitespace change
remains.

Another example was libclang, especially Index.h which up until
recently was not clang-formatted at all. It contains large enums. When
adding a value, `git clang-format` would re-format the entire enum,
mostly adding indentation to every line. The problem disappeared when
Index.h was clang-formatted.

Michael


Am Di., 30. Juni 2020 um 12:55 Uhr schrieb Matt Arsenault via llvm-dev
<llvm-dev at lists.llvm.org>:
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> On Jun 28, 2020, at 11:30, MyDeveloper Day via llvm-dev <llvm-dev at lists.llvm.org> wrote:
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> I’m a contributor to clang-format and would like to see LLVM 100% clang formatted so we can use LLVM as a massive test-suite for clang-format when we make changes.
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> My main issue with this would be that clang-format does things that I don’t believe are stated in the LLVM style guide and I also disagree with. There’s a whole set of cases where it makes unwelcome changes to put things that were on separate lines on a single line. Whenever I run clang-format, I typically git checkout -p to discard all of these.
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> For example, it likes to take member initializer lists and pack them into as few lines as possible. This is just asking for merge conflicts (e.g. AMDGPUSubtarget has a ton of fields in it, and out of tree code is constantly adding new fields for unreleased subtargets). It also mangles BuildMI calls, where I believe every .add() should be on its own line, and stringing this into BuildMI().addFoo().addBar() is way less readable.
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> I also believe it’s 4 space indent on line wraps differs from the stated 2 space indent level (and this also disagrees with emacs llvm-style)
>
> -Matt
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