From 49a5456606967babaa319954a9710dc2eac6c4f0 Mon Sep 17 00:00:00 2001
From: est31 <MTest31@outlook.com>
Date: Sun, 20 Feb 2022 03:17:44 +0100
Subject: [PATCH] tidy: fire less "ignoring file length unneccessarily"
 warnings

This avoids a situation where a file is at the border of the limit,
and alternates between hitting the limit and not hitting it, causing
a back and forth of addition of the ignore-tidy-linelength directive.

As an example, consider the ignore-tidy-filelength of compiler/rustc_typeck/src/collect.rs.

It was added in 2ca4964db5d263a8f9222846bd70a7f26cf414cf, removed in
37354ebc9794b0eb14b08c02177e3094c8fe91cd, added again in 448d07683a6defd567996114793a09c9a8aef5df,
removed in 3171bd5bf54fb91f7f7df7c40df5adc7d8bd5dea, added in 438826fd1a9a119d00992ede948cdd479431ecbb,
and #94142 is going to remove it again.

To avoid this back and forth, we exempt files from the unneccessary
ignoring warning that have length of at least 70% of the limit.
---
 src/tools/tidy/src/style.rs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/tools/tidy/src/style.rs b/src/tools/tidy/src/style.rs
index ca79c835b9fa1..c197acd4828a1 100644
--- a/src/tools/tidy/src/style.rs
+++ b/src/tools/tidy/src/style.rs
@@ -395,6 +395,9 @@ pub fn check(path: &Path, bad: &mut bool) {
                 );
             };
             suppressible_tidy_err!(err, skip_file_length, "");
+        } else if lines > (LINES * 7) / 10 {
+            // Just set it to something that doesn't trigger the "unneccessarily ignored" warning.
+            skip_file_length = Directive::Ignore(true);
         }
 
         if let Directive::Ignore(false) = skip_cr {