1 files changed, 87 insertions, 0 deletions
diff --git a/src/tools/clippy/clippy_lints/src/functions/too_many_lines.rs b/src/tools/clippy/clippy_lints/src/functions/too_many_lines.rs
new file mode 100644
index 000000000..54bdea7ea
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/functions/too_many_lines.rs
@@ -0,0 +1,87 @@
+use rustc_hir as hir;
+use rustc_hir::intravisit::FnKind;
+use rustc_lint::{LateContext, LintContext};
+use rustc_middle::lint::in_external_macro;
+use rustc_span::Span;
+
+use clippy_utils::diagnostics::span_lint;
+use clippy_utils::source::snippet_opt;
+
+use super::TOO_MANY_LINES;
+
+pub(super) fn check_fn(
+    cx: &LateContext<'_>,
+    kind: FnKind<'_>,
+    span: Span,
+    body: &hir::Body<'_>,
+    too_many_lines_threshold: u64,
+) {
+    // Closures must be contained in a parent body, which will be checked for `too_many_lines`.
+    // Don't check closures for `too_many_lines` to avoid duplicated lints.
+    if matches!(kind, FnKind::Closure) || in_external_macro(cx.sess(), span) {
+        return;
+    }
+
+    let code_snippet = match snippet_opt(cx, body.value.span) {
+        Some(s) => s,
+        _ => return,
+    };
+    let mut line_count: u64 = 0;
+    let mut in_comment = false;
+    let mut code_in_line;
+
+    let function_lines = if matches!(body.value.kind, hir::ExprKind::Block(..))
+        && code_snippet.as_bytes().first().copied() == Some(b'{')
+        && code_snippet.as_bytes().last().copied() == Some(b'}')
+    {
+        // Removing the braces from the enclosing block
+        &code_snippet[1..code_snippet.len() - 1]
+    } else {
+        &code_snippet
+    }
+    .trim() // Remove leading and trailing blank lines
+    .lines();
+
+    for mut line in function_lines {
+        code_in_line = false;
+        loop {
+            line = line.trim_start();
+            if line.is_empty() {
+                break;
+            }
+            if in_comment {
+                if let Some(i) = line.find("*/") {
+                    line = &line[i + 2..];
+                    in_comment = false;
+                    continue;
+                }
+            } else {
+                let multi_idx = line.find("/*").unwrap_or(line.len());
+                let single_idx = line.find("//").unwrap_or(line.len());
+                code_in_line |= multi_idx > 0 && single_idx > 0;
+                // Implies multi_idx is below line.len()
+                if multi_idx < single_idx {
+                    line = &line[multi_idx + 2..];
+                    in_comment = true;
+                    continue;
+                }
+            }
+            break;
+        }
+        if code_in_line {
+            line_count += 1;
+        }
+    }
+
+    if line_count > too_many_lines_threshold {
+        span_lint(
+            cx,
+            TOO_MANY_LINES,
+            span,
+            &format!(
+                "this function has too many lines ({}/{})",
+                line_count, too_many_lines_threshold
+            ),
+        );
+    }
+}