Tidy should not check line lengths

Author: Anthuang

src/tools/compiletest/src/runtest.rs

@@ -3534,6 +3534,8 @@ impl<'test> TestCx<'test> {
 
         // Remove test annotations like `//~ ERROR text` from the output,
         // since they duplicate actual errors and make the output hard to read.
+        // This mirrors the regex in src/tools/tidy/src/style.rs, please update
+        // both if either are changed.
         normalized =
             Regex::new("\\s*//(\\[.*\\])?~.*").unwrap().replace_all(&normalized, "").into_owned();
 

src/tools/tidy/src/style.rs

@@ -16,6 +16,7 @@
 //! A number of these checks can be opted-out of with various directives of the form:
 //! `// ignore-tidy-CHECK-NAME`.
 
+use regex::Regex;
 use std::path::Path;
 
 const ERROR_CODE_COLS: usize = 80;
@@ -39,6 +40,19 @@ C++ code used llvm_unreachable, which triggers undefined behavior
 when executed when assertions are disabled.
 Use llvm::report_fatal_error for increased robustness.";
 
+const ANNOTATIONS_TO_IGNORE: &[&str] = &[
+    "// @!has",
+    "// @has",
+    "// @matches",
+    "// CHECK",
+    "// EMIT_MIR",
+    "// compile-flags",
+    "// error-pattern",
+    "// gdb",
+    "// lldb",
+    "// normalize-stderr-test",
+];
+
 /// Parser states for `line_is_url`.
 #[derive(Clone, Copy, PartialEq)]
 #[allow(non_camel_case_types)]
@@ -90,11 +104,21 @@ fn line_is_url(columns: usize, line: &str) -> bool {
     state == EXP_END
 }
 
+/// Returns `true` if `line` can be ignored. This is the case when it contains
+/// an annotation that is explicitly ignored.
+fn should_ignore(line: &str) -> bool {
+    // Matches test annotations like `//~ ERROR text`.
+    // This mirrors the regex in src/tools/compiletest/src/runtest.rs, please
+    // update both if either are changed.
+    let re = Regex::new("\\s*//(\\[.*\\])?~.*").unwrap();
+    re.is_match(line) || ANNOTATIONS_TO_IGNORE.iter().any(|a| line.contains(a))
+}
+
 /// Returns `true` if `line` is allowed to be longer than the normal limit.
-/// Currently there is only one exception, for long URLs, but more
-/// may be added in the future.
+/// This is the case when the `line` is a long URL, or it contains an
+/// annotation that is explicitly ignored.
 fn long_line_is_ok(max_columns: usize, line: &str) -> bool {
-    if line_is_url(max_columns, line) {
+    if line_is_url(max_columns, line) || should_ignore(line) {
         return true;
     }