From 8b66d829fbcc37eeb8a2a2e14dfc7bf40ee067e1 Mon Sep 17 00:00:00 2001 From: Renato Golin Date: Mon, 1 Jun 2026 21:35:58 +0100 Subject: [PATCH] [Docs] Update coding standard for TD files (#200848) This PR proposes an update to the coding standards document to make explicit that we do not want unnecessary formatting changes to TD files. This is in response to this merged PR (#199346), which lead to this RFC (https://discourse.llvm.org/t/80-column-limit-for-td-files/90950/). --------- Co-authored-by: Vlad Serebrennikov --- .clang-format-ignore | 3 +++ clang/.clang-format-ignore | 3 --- llvm/docs/CodingStandards.rst | 9 +++++++++ 3 files changed, 12 insertions(+), 3 deletions(-) delete mode 100644 clang/.clang-format-ignore diff --git a/.clang-format-ignore b/.clang-format-ignore index e69de29bb2d1..1fb0c9558af8 100644 --- a/.clang-format-ignore +++ b/.clang-format-ignore @@ -0,0 +1,3 @@ +# Do not attempt to format .td files; we have too many formatting needs across +# the various files to allow automatic formatting. +**/*.td diff --git a/clang/.clang-format-ignore b/clang/.clang-format-ignore deleted file mode 100644 index 1fb0c9558af8..000000000000 --- a/clang/.clang-format-ignore +++ /dev/null @@ -1,3 +0,0 @@ -# Do not attempt to format .td files; we have too many formatting needs across -# the various files to allow automatic formatting. -**/*.td diff --git a/llvm/docs/CodingStandards.rst b/llvm/docs/CodingStandards.rst index 12704ce606e0..2cffcdd96b1d 100644 --- a/llvm/docs/CodingStandards.rst +++ b/llvm/docs/CodingStandards.rst @@ -463,6 +463,15 @@ for it (vs something else, like 90 columns). However, documentation files are not source code files, and instead of fitting into 80 columns, they must be formatted to one sentence per line. This way a change in the middle of a paragraph doesn't cause unnecessary changes in subsequent lines, making it easier for reviewers to see what has changed when documentation is updated. +Another exception are TableGen files (.td). +There are no tools that can parse, verify and edit them to match our coding style, including clang-format, so they are excluded from this limit. +It is still good practice to try to fit them into 80 columns, but it is not a requirement. +As with other changes, if you patch a TD file, do not reformat the entire file, but only the lines you are changing. + +If your reformatting is causing unnecessary changes in subsequent lines, please just follow the existing formatting. +Unecessary changes in TD files cause unnecessary churn in the file history and force recompilation of many unnecessary files. +It also causes unnecessary changes in forks working on the same TD files, which makes it harder to rebase and merge later. + Whitespace ^^^^^^^^^^