1 //! lint on if expressions with an else if, but without a final else branch
3 use rustc::lint::{in_external_macro, EarlyContext, EarlyLintPass, LintArray, LintContext, LintPass};
4 use rustc::{declare_tool_lint, lint_array};
7 use crate::utils::span_help_and_lint;
10 /// **What it does:** Checks for usage of if expressions with an `else if` branch,
11 /// but without a final `else` branch.
13 /// **Why is this bad?** Some coding guidelines require this (e.g. MISRA-C:2004 Rule 14.10).
15 /// **Known problems:** None.
19 /// if x.is_positive() {
21 /// } else if x.is_negative() {
29 /// if x.is_positive() {
31 /// } else if x.is_negative() {
34 /// // we don't care about zero
37 pub ELSE_IF_WITHOUT_ELSE,
39 "if expression with an `else if`, but without a final `else` branch"
42 #[derive(Copy, Clone)]
43 pub struct ElseIfWithoutElse;
45 impl LintPass for ElseIfWithoutElse {
46 fn get_lints(&self) -> LintArray {
47 lint_array!(ELSE_IF_WITHOUT_ELSE)
50 fn name(&self) -> &'static str {
55 impl EarlyLintPass for ElseIfWithoutElse {
56 fn check_expr(&mut self, cx: &EarlyContext<'_>, mut item: &Expr) {
57 if in_external_macro(cx.sess(), item.span) {
61 while let ExprKind::If(_, _, Some(ref els)) = item.node {
62 if let ExprKind::If(_, _, None) = els.node {
67 "if expression with an `else if`, but without a final `else`",
68 "add an `else` block here",