Code formatting #1336

dNechita · 2025-08-13T11:38:07Z

PR Description

This PR continues the effort to introduce code formatting rules, initially discussed in #397 and further developed in #413 by @rgetz.
Additionally, this PR provides a script that enables users to format the entire codebase.

PR Type

Bug fix (a change that fixes an issue)
New feature (a change that adds new functionality)
Breaking change (a change that affects other repos or cause CIs to fail)

PR Checklist

I have conducted a self-review of my own code changes
I have commented new code, particularly complex or unclear areas
I have checked that I did not introduce new warnings or errors (CI output)
I have checked that components that use libiio did not get broken
I have updated the documentation accordingly (GitHub Pages, READMEs, etc)

mhennerich · 2025-08-13T12:07:34Z

.clang-format

+BreakConstructorInitializers: BeforeComma
+BreakAfterJavaFieldAnnotations: false
+BreakStringLiterals: false
+ColumnLimit: 80


Looking through the diff. There are lots of excessive line breaks!
I think we should go for al least 100.
https://lkml.org/lkml/2020/5/29/1317

I will change to 100 and see how it looks. If there aren't any outstanding issues that would require a wider limit, we could settle for 100.

At one time - I made a loop, that incremented by 5's and then saved off where the min diff was - I don't remember what the results were - but it would be easy to do it again...

I tested with a similar loop and noticed that the larger the ColumnLimit, the fewer changes are generated. But the decrease in changes isn’t linear. The biggest impact is switching from 80 to 85, then the next big impact is from 85-90 and so on. Looking at the graph, it looks like the "elbow" is around value 100, after which the curve flattens a bit.

Testing ColumnLimit values from 80 to 140 (step 5) in .clang-format... This script will modify .clang-format, run format.sh, count changes, and revert them. Starting tests... Testing ColumnLimit: 80 Updated ColumnLimit to: 80 Running format.sh... Changes detected - Files: 103, Lines: 13583 Reverting changes... Testing ColumnLimit: 85 Updated ColumnLimit to: 85 Running format.sh... Changes detected - Files: 103, Lines: 12988 Reverting changes... Testing ColumnLimit: 90 Updated ColumnLimit to: 90 Running format.sh... Changes detected - Files: 103, Lines: 12588 Reverting changes... Testing ColumnLimit: 95 Updated ColumnLimit to: 95 Running format.sh... Changes detected - Files: 103, Lines: 12450 Reverting changes... Testing ColumnLimit: 100 Updated ColumnLimit to: 100 Running format.sh... Changes detected - Files: 102, Lines: 12337 Reverting changes... Testing ColumnLimit: 105 Updated ColumnLimit to: 105 Running format.sh... Changes detected - Files: 103, Lines: 12223 Reverting changes... Testing ColumnLimit: 110 Updated ColumnLimit to: 110 Running format.sh... Changes detected - Files: 103, Lines: 12149 Reverting changes... Testing ColumnLimit: 115 Updated ColumnLimit to: 115 Running format.sh... Changes detected - Files: 103, Lines: 12119 Reverting changes... Testing ColumnLimit: 120 Updated ColumnLimit to: 120 Running format.sh... Changes detected - Files: 103, Lines: 12044 Reverting changes... Testing ColumnLimit: 125 Updated ColumnLimit to: 125 Running format.sh... Changes detected - Files: 103, Lines: 11990 Reverting changes... Testing ColumnLimit: 130 Updated ColumnLimit to: 130 Running format.sh... Changes detected - Files: 103, Lines: 11947 Reverting changes... Testing ColumnLimit: 135 Updated ColumnLimit to: 135 Running format.sh... Changes detected - Files: 103, Lines: 11914 Reverting changes... Testing ColumnLimit: 140 Updated ColumnLimit to: 140 Running format.sh... Changes detected - Files: 103, Lines: 11909 Reverting changes... Restoring original ColumnLimit: 100 Updated ColumnLimit to: 100 ================================================================================= RESULTS SUMMARY ================================================================================= ColumnLimit | Modified Files | Total Line Changes ------------ | -------------- | ------------------ 80 | 103 | 13583 85 | 103 | 12988 90 | 103 | 12588 95 | 103 | 12450 100 | 102 | 12337 105 | 103 | 12223 110 | 103 | 12149 115 | 103 | 12119 120 | 103 | 12044 125 | 103 | 11990 130 | 103 | 11947 135 | 103 | 11914 140 | 103 | 11909 ================================================================================= Minimum changes found with ColumnLimit: 140 (11909 line changes)

per discussion in #397, The clang-format is the linux kernel code formatting template with a few minor tweaks: indent continuation more: -ContinuationIndentWidth: 8 +ContinuationIndentWidth: 16 remove the kernel's ForEachMacros Sort the include paths, like Lars suggested in #411 -SortIncludes: false +SortIncludes: true In this order: -#IncludeBlocks: Preserve # Unknown to clang-format-5.0 +IncludeBlocks: Regroup IncludeCategories: - - Regex: '.*' - Priority: 1 -IncludeIsMainRegex: '(Test)?$' + - Regex: '^<.*\.h>' + Priority: 1 + - Regex: '^<.*' + Priority: 2 + - Regex: '.*' + Priority: 3 +IncludeIsMainRegex: 'xxx' The cmake-format.py file is from the doc, with tabs set to 4 spaces https://cmake-format.readthedocs.io/en/latest/configuration.html This is something for discussion, This is expected to have clang-format version 7.0.1-8 (tags/RELEASE_701/final) or higher. Signed-off-by: Robin Getz <robin.getz@analog.com>

Signed-off-by: Robin Getz <robin.getz@analog.com>

The script supports ignoring specific files and directories by reading their paths from a list, ensuring that any files or folders specified will be excluded from formatting. Signed-off-by: Dan Nechita <dan.nechita@analog.com>

On Windows, the include order matters so turn off clang-format to preserve the include order. Otherwise the windows build will fail. Signed-off-by: Dan Nechita <dan.nechita@analog.com>

Format all .c and .h files using rules from .clang-format but ignore paths defined in .clangformatignore file. Format all .cmake and CMakeLists.txt files using rules from cmake-format.py but ignore paths defined in .cmakeformatignore file. The current changes result from executing: ./format.sh in the repository's top-level directory. Signed-off-by: Dan Nechita <dan.nechita@analog.com>

dNechita · 2025-08-13T13:44:51Z

V1:

Extended the maximum line length from 80 to 100
Prevented clang-format from reordering the includes on some files which was causing windows builds to fail (dns_sd.h, dns_sd_windows.c)
Fixed 2 spelling errors in cmake-format.py

rgetz · 2025-08-30T18:25:31Z

Eventually (after this is merged), you will want to add something like this also here

 # Example .git-blame-ignore-revs file
    a926bba49c89a5b882cd298be3af2570b1e6252c # Formatting changes
    237de8a6367a88649a3f161112492d0d70d83707 # Automated refactor

rgetz · 2025-08-30T18:26:34Z

After fixing things - a pre-commit hook/check is needed to ensure that all future patches keep the style - or it will just start diverting...

dNechita · 2025-09-01T11:54:09Z

After fixing things - a pre-commit hook/check is needed to ensure that all future patches keep the style - or it will just start diverting...

I have an active PR (#1338) that implements a CI job that checks if code is formatted. The job will fail if it's not. Specifically, the job checks all changed files, applies formatting, and fails if even one is not properly formatted.
The job is triggered on pull requests.

dNechita requested a review from nunojsa August 13, 2025 11:38

dNechita requested review from cristina-suteu and mhennerich as code owners August 13, 2025 11:38

mhennerich reviewed Aug 13, 2025

View reviewed changes

rgetz and others added 5 commits August 13, 2025 15:08

general tweaks for code updates - no functional changes

d5d5ff2

Signed-off-by: Robin Getz <robin.getz@analog.com>

code-format: Add script that formats entire code base

2bdb030

The script supports ignoring specific files and directories by reading their paths from a list, ensuring that any files or folders specified will be excluded from formatting. Signed-off-by: Dan Nechita <dan.nechita@analog.com>

code-format: Don't let formatter alter the include order for dns files

1c9bf8f

On Windows, the include order matters so turn off clang-format to preserve the include order. Otherwise the windows build will fail. Signed-off-by: Dan Nechita <dan.nechita@analog.com>

dNechita force-pushed the code-formatting branch from c3de091 to ad79729 Compare August 13, 2025 13:15

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dNechita commented Aug 13, 2025

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