Auto merge of #4093 - rust-lang:rustup, r=oli-obk

[rust.git] / clippy_lints / src / question_mark.rs

diff --git a/clippy_lints/src/question_mark.rs b/clippy_lints/src/question_mark.rs
index 762401098e6c3a065ecfc08f654b2a129b70e968..1949101def9e9a793a5b4aee141c9d42b6ebaea2 100644 (file)
--- a/clippy_lints/src/question_mark.rs
+++ b/clippy_lints/src/question_mark.rs
@@ -1,19 +1,20 @@
-use crate::utils::sugg::Sugg;
 use if_chain::if_chain;
-use rustc::hir::def::Def;
+use rustc::hir::def::{DefKind, Res};
 use rustc::hir::*;
 use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::{declare_tool_lint, lint_array};
+use rustc::{declare_lint_pass, declare_tool_lint};
+use rustc_errors::Applicability;
 use syntax::ptr::P;
 
 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::sym;
+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
     ///
@@ -34,21 +35,10 @@
     "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() {
@@ -59,9 +49,9 @@ impl Pass {
     /// 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) {
         if_chain! {
-            if let ExprKind::If(if_expr, body, else_) = &expr.node;
+            if let Some((if_expr, body, else_)) = higher::if_block(&expr);
             if let ExprKind::MethodCall(segment, _, args) = &if_expr.node;
-            if segment.ident.name == "is_none";
+            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);
@@ -114,7 +104,7 @@ fn moves_by_default(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)
+        match_type(cx, expr_ty, &*OPTION)
     }
 
     fn expression_returns_none(cx: &LateContext<'_, '_>, expression: &Expr) -> bool {
@@ -128,8 +118,10 @@ fn expression_returns_none(cx: &LateContext<'_, '_>, expression: &Expr) -> bool
             },
             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
@@ -165,7 +157,7 @@ fn return_expression(block: &Block) -> Option<P<Expr>> {
     }
 }
 
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
+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);
     }