-use crate::utils::sugg::Sugg;
use if_chain::if_chain;
-use rustc::hir::def::Def;
-use rustc::hir::*;
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::{declare_tool_lint, lint_array};
-use syntax::ptr::P;
+use rustc_errors::Applicability;
+use rustc_hir::def::{DefKind, Res};
+use rustc_hir::*;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
use crate::utils::paths::*;
-use crate::utils::{match_def_path, match_type, span_lint_and_then, SpanlessEq};
-use rustc_errors::Applicability;
+use crate::utils::sugg::Sugg;
+use crate::utils::{higher, match_def_path, match_type, span_lint_and_then, SpanlessEq};
declare_clippy_lint! {
- /// **What it does:** Checks for expressions that could be replaced by the question mark operator
+ /// **What it does:** Checks for expressions that could be replaced by the question mark operator.
///
- /// **Why is this bad?** Question mark usage is more idiomatic
+ /// **Why is this bad?** Question mark usage is more idiomatic.
///
/// **Known problems:** None
///
/// **Example:**
- /// ```rust
+ /// ```ignore
/// if option.is_none() {
/// return None;
/// }
///
/// Could be written:
///
- /// ```rust
+ /// ```ignore
/// option?;
/// ```
pub QUESTION_MARK,
"checks for expressions that could be replaced by the question mark operator"
}
-#[derive(Copy, Clone)]
-pub struct Pass;
-
-impl LintPass for Pass {
- fn get_lints(&self) -> LintArray {
- lint_array!(QUESTION_MARK)
- }
-
- fn name(&self) -> &'static str {
- "QuestionMark"
- }
-}
+declare_lint_pass!(QuestionMark => [QUESTION_MARK]);
-impl Pass {
- /// Check if the given expression on the given context matches the following structure:
+impl QuestionMark {
+ /// Checks if the given expression on the given context matches the following structure:
///
/// ```ignore
/// if option.is_none() {
/// ```
///
/// If it matches, it will suggest to use the question mark operator instead
- fn check_is_none_and_early_return_none(cx: &LateContext<'_, '_>, expr: &Expr) {
+ fn check_is_none_and_early_return_none(cx: &LateContext<'_, '_>, expr: &Expr<'_>) {
if_chain! {
- if let ExprKind::If(if_expr, body, else_) = &expr.node;
- if let ExprKind::MethodCall(segment, _, args) = &if_expr.node;
- if segment.ident.name == "is_none";
+ if let Some((if_expr, body, else_)) = higher::if_block(&expr);
+ if let ExprKind::MethodCall(segment, _, args) = &if_expr.kind;
+ if segment.ident.name == sym!(is_none);
if Self::expression_returns_none(cx, body);
if let Some(subject) = args.get(0);
if Self::is_option(cx, subject);
let mut replacement: Option<String> = None;
if let Some(else_) = else_ {
if_chain! {
- if let ExprKind::Block(block, None) = &else_.node;
- if block.stmts.len() == 0;
+ if let ExprKind::Block(block, None) = &else_.kind;
+ if block.stmts.is_empty();
if let Some(block_expr) = &block.expr;
if SpanlessEq::new(cx).ignore_fn().eq_expr(subject, block_expr);
then {
}
}
- fn moves_by_default(cx: &LateContext<'_, '_>, expression: &Expr) -> bool {
+ fn moves_by_default(cx: &LateContext<'_, '_>, expression: &Expr<'_>) -> bool {
let expr_ty = cx.tables.expr_ty(expression);
!expr_ty.is_copy_modulo_regions(cx.tcx, cx.param_env, expression.span)
}
- fn is_option(cx: &LateContext<'_, '_>, expression: &Expr) -> bool {
+ fn is_option(cx: &LateContext<'_, '_>, expression: &Expr<'_>) -> bool {
let expr_ty = cx.tables.expr_ty(expression);
match_type(cx, expr_ty, &OPTION)
}
- fn expression_returns_none(cx: &LateContext<'_, '_>, expression: &Expr) -> bool {
- match expression.node {
+ fn expression_returns_none(cx: &LateContext<'_, '_>, expression: &Expr<'_>) -> bool {
+ match expression.kind {
ExprKind::Block(ref block, _) => {
if let Some(return_expression) = Self::return_expression(block) {
return Self::expression_returns_none(cx, &return_expression);
},
ExprKind::Ret(Some(ref expr)) => Self::expression_returns_none(cx, expr),
ExprKind::Path(ref qp) => {
- if let Def::VariantCtor(def_id, _) = cx.tables.qpath_def(qp, expression.hir_id) {
- return match_def_path(cx.tcx, def_id, &OPTION_NONE);
+ if let Res::Def(DefKind::Ctor(def::CtorOf::Variant, def::CtorKind::Const), def_id) =
+ cx.tables.qpath_res(qp, expression.hir_id)
+ {
+ return match_def_path(cx, def_id, &OPTION_NONE);
}
false
}
}
- fn return_expression(block: &Block) -> Option<P<Expr>> {
+ fn return_expression<'tcx>(block: &Block<'tcx>) -> Option<&'tcx Expr<'tcx>> {
// Check if last expression is a return statement. Then, return the expression
if_chain! {
if block.stmts.len() == 1;
if let Some(expr) = block.stmts.iter().last();
- if let StmtKind::Semi(ref expr) = expr.node;
- if let ExprKind::Ret(ref ret_expr) = expr.node;
- if let &Some(ref ret_expr) = ret_expr;
+ if let StmtKind::Semi(ref expr) = expr.kind;
+ if let ExprKind::Ret(ret_expr) = expr.kind;
+ if let Some(ret_expr) = ret_expr;
then {
- return Some(ret_expr.clone());
+ return Some(ret_expr);
}
}
// Check for `return` without a semicolon.
if_chain! {
- if block.stmts.len() == 0;
- if let Some(ExprKind::Ret(Some(ret_expr))) = block.expr.as_ref().map(|e| &e.node);
+ if block.stmts.is_empty();
+ if let Some(ExprKind::Ret(Some(ret_expr))) = block.expr.as_ref().map(|e| &e.kind);
then {
- return Some(ret_expr.clone());
+ return Some(ret_expr);
}
}
}
}
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
- fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for QuestionMark {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
Self::check_is_none_and_early_return_none(cx, expr);
}
}
projects / rust.git / blobdiff