Skip to main content

MAINT007-return-complexity — Excessive Return Statements

Dimension: Maintainability Default severity: Low Languages: All CWE: CWE-1121 Last reviewed: 2026-05-06

What it detects​

Flags functions with more return statements than a configurable threshold (default 4). A high return count often signals a function that is trying to do too many things; restructuring with guard clauses or helper functions typically improves readability and testability.

Configuration​

[rules."MAINT007-return-complexity"]
threshold = 4   # default

Example — flagged​

Rust:

pub fn classify(x: i32, y: i32, z: i32) -> &'static str {
    if x < 0 { return "negative x"; }
    if y < 0 { return "negative y"; }
    if z < 0 { return "negative z"; }
    if x == y { return "equal xy"; }
    if y == z { return "equal yz"; }
    "default"
    // 5 effective returns → flagged at default threshold of 4
}

Example — not flagged​

pub fn check(x: i32) -> &'static str {
    if x < 0 { return "negative"; }
    "non-negative"
    // 2 returns → clean
}

Fix guidance​

  • Extract early-exit guards into a validation helper.
  • Use match / pattern-matching to collapse multiple branches.
  • Split the function into smaller focused callables.

Implementation​

References​