//! This lint is **warn** by default
use if_chain::if_chain;
+use rustc::declare_lint_pass;
use rustc::lint::{EarlyContext, EarlyLintPass, LintArray, LintPass};
-use rustc::{declare_lint_pass, declare_tool_lint};
+use rustc_session::declare_tool_lint;
use syntax::ast;
use crate::utils::sugg::Sugg;
-use crate::utils::{
- in_macro_or_desugar, snippet_block, snippet_block_with_applicability, span_lint_and_sugg, span_lint_and_then,
-};
+use crate::utils::{snippet_block, snippet_block_with_applicability, span_lint_and_sugg, span_lint_and_then};
use rustc_errors::Applicability;
declare_clippy_lint! {
impl EarlyLintPass for CollapsibleIf {
fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &ast::Expr) {
- if !in_macro_or_desugar(expr.span) {
+ if !expr.span.from_expansion() {
check_if(cx, expr)
}
}
}
fn check_if(cx: &EarlyContext<'_>, expr: &ast::Expr) {
- match expr.node {
- ast::ExprKind::If(ref check, ref then, ref else_) => {
- if let Some(ref else_) = *else_ {
- check_collapsible_maybe_if_let(cx, else_);
- } else {
- check_collapsible_no_if_let(cx, expr, check, then);
- }
- },
- ast::ExprKind::IfLet(_, _, _, Some(ref else_)) => {
+ if let ast::ExprKind::If(check, then, else_) = &expr.kind {
+ if let Some(else_) = else_ {
check_collapsible_maybe_if_let(cx, else_);
- },
- _ => (),
+ } else if let ast::ExprKind::Let(..) = check.kind {
+ // Prevent triggering on `if let a = b { if c { .. } }`.
+ } else {
+ check_collapsible_no_if_let(cx, expr, check, then);
+ }
}
}
fn check_collapsible_maybe_if_let(cx: &EarlyContext<'_>, else_: &ast::Expr) {
if_chain! {
- if let ast::ExprKind::Block(ref block, _) = else_.node;
+ if let ast::ExprKind::Block(ref block, _) = else_.kind;
if !block_starts_with_comment(cx, block);
if let Some(else_) = expr_block(block);
- if !in_macro_or_desugar(else_.span);
+ if !else_.span.from_expansion();
+ if let ast::ExprKind::If(..) = else_.kind;
then {
- match else_.node {
- ast::ExprKind::If(..) | ast::ExprKind::IfLet(..) => {
- let mut applicability = Applicability::MachineApplicable;
- span_lint_and_sugg(
- cx,
- COLLAPSIBLE_IF,
- block.span,
- "this `else { if .. }` block can be collapsed",
- "try",
- snippet_block_with_applicability(cx, else_.span, "..", &mut applicability).into_owned(),
- applicability,
- );
- }
- _ => (),
- }
+ let mut applicability = Applicability::MachineApplicable;
+ span_lint_and_sugg(
+ cx,
+ COLLAPSIBLE_IF,
+ block.span,
+ "this `else { if .. }` block can be collapsed",
+ "try",
+ snippet_block_with_applicability(cx, else_.span, "..", &mut applicability).into_owned(),
+ applicability,
+ );
}
}
}
if_chain! {
if !block_starts_with_comment(cx, then);
if let Some(inner) = expr_block(then);
- if let ast::ExprKind::If(ref check_inner, ref content, None) = inner.node;
+ if let ast::ExprKind::If(ref check_inner, ref content, None) = inner.kind;
then {
+ if let ast::ExprKind::Let(..) = check_inner.kind {
+ // Prevent triggering on `if c { if let a = b { .. } }`.
+ return;
+ }
+
if expr.span.ctxt() != inner.span.ctxt() {
return;
}
let mut it = block.stmts.iter();
if let (Some(stmt), None) = (it.next(), it.next()) {
- match stmt.node {
+ match stmt.kind {
ast::StmtKind::Expr(ref expr) | ast::StmtKind::Semi(ref expr) => Some(expr),
_ => None,
}