clang-format: align brace-after-struct and *-class formatting

l0rinc commented at 3:40 pm on June 25, 2025: contributor

Updates .clang-format file to reflect latest supported Clang-Format standards while preserving most of the existing formatting behavior, except for the very last commit which aligns AfterStruct brace placement with AfterClass for code formatting.

The first commit reformats a file containing a C++ struct, the second one modifies the formatting and reformats the same file to show the difference.

DrahtBot commented at 3:40 pm on June 25, 2025: contributor

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in src/.clang-format:49 in a666d8ab6f outdated

44 SpacesInCStyleCastParentheses: false
45 SpacesInParentheses: false
46-BreakBeforeConceptDeclarations: Always
47-RequiresExpressionIndentation: OuterScope
48-Standard: c++20
49-UseTab:          Never

maflcko commented at 3:49 pm on June 25, 2025:

a666d8ab6f3c019a9f7e184beb9b90affbb8075c: not sure about removing the default values. I don’t think there is any harm in having them. In fact, we don’t want this to silently change from down under with the next clang update.

l0rinc commented at 3:58 pm on June 25, 2025:

What about the other default values, what if those change?

maflcko commented at 4:17 pm on June 25, 2025:

I’d say the others are probably edge cases to not matter much, but no strong opinion. Seems fine to add them as well to avoid silent changes. However, I don’t think the config is forward compatible, so it can probably only contain keys of the minimum required clang version.

l0rinc commented at 9:53 pm on June 25, 2025:

I’ve added all of them, this was the simplest change with fewest commits and explanations

maflcko commented at 4:37 pm on June 26, 2025:

Again, as said in my previous comment this doesn’t work, because older clang-formats will just error out:

0$ clang-format-16 -i src/bench/prevector.cpp
1/b-c/src/.clang-format:12:3: error: unknown key 'AlignFunctionPointers'
2  AlignFunctionPointers: false
3  ^~~~~~~~~~~~~~~~~~~~~
4Error reading /b-c/src/.clang-format: Invalid argument

l0rinc commented at 9:35 am on June 27, 2025:

Thanks, managed to install an older version and redid the changes for maximal compatibility.

in src/.clang-format:3 in 7dda3d2c0e outdated

0@@ -1,26 +1,40 @@
1 AccessModifierOffset: -4
2-AlignAfterOpenBracket: true
3+AlignAfterOpenBracket: Align

maflcko commented at 3:52 pm on June 25, 2025:

7dda3d2c0e65ac1fa08ac3b24a13f2005c6bef1a: not sure about changing the values. seems fine to just keep the old value, which will likely work forever in a backward compatible way

l0rinc commented at 4:00 pm on June 25, 2025:

Many of these keys aren’t even listed in the documentation and the IDE shows that many are invalid since it doesn’t match the allowed schema.

maflcko commented at 3:53 pm on June 25, 2025: member

last commit seems fine, but the others i am not sure. at a minimum you’ll have to drop the scripted diffs from executing, because they can’t be reproduced anyway with different clang-format versions

DrahtBot added the label CI failed on Jun 25, 2025

DrahtBot commented at 5:06 pm on June 25, 2025: contributor

🚧 At least one of the CI tasks failed. Task lint: https://github.com/bitcoin/bitcoin/runs/44780552247 LLM reason (✨ experimental): The CI failure is caused by errors in the lint check, related to code style or formatting issues.

Try to run the tests locally, according to the documentation. However, a CI failure may still happen due to a number of reasons, for example:

Possibly due to a silent merge conflict (the changes in this pull request being incompatible with the current code in the target branch). If so, make sure to rebase on the latest commit of the target branch.
A sanitizer issue, which can only be found by compiling with the sanitizer and running the affected test.
An intermittent issue.

Leave a comment here, if you need help tracking down a confusing failure.

l0rinc force-pushed on Jun 25, 2025

DrahtBot removed the label CI failed on Jun 26, 2025

clang-format: regenerate configs

Regenerated `.clang-format` from current configs to replace deprecated keys with up-to-date equivalents.
Also added all current formatter default values to guard against version differences.

The configs were updated with the following command (using v16 for maximal compatibility):
   $(brew --prefix llvm@16)/bin/clang-format -dump-config -style=file:src/.clang-format

The new config was tested with:
   $(brew --prefix llvm@16)/bin/clang-format -i src/deploymentinfo.h

Co-authored-by: MarcoFalke <*~=`'#}+{/-|&$^_@721217.xyz>

7c9b3e1eae

clang-format: align `AfterStruct` with `AfterClass` in `BraceWrapping`

The new config was tested with the same file as the previous commit to showcase the changes:
  $(brew --prefix llvm@16)/bin/clang-format -i src/deploymentinfo.h

94364a7d54

l0rinc force-pushed on Jun 27, 2025

l0rinc marked this as ready for review on Jun 29, 2025

l0rinc renamed this:
~~clang-format: modernize and realign clang-format configuration~~
clang-format: align brace-after-struct and *-class formatting
on Jun 29, 2025

clang-format: align brace-after-struct and *-class formatting #32813

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