]> git.lizzy.rs Git - rust.git/blobdiff - clippy_lints/src/matches.rs
Merge pull request #3465 from flip1995/rustfmt
[rust.git] / clippy_lints / src / matches.rs
index 3ecf5d3b5b854818c111f2714240c1648eb2ccff..dedf9a16b356d215c5cf0b2f452468ce70be8318 100644 (file)
@@ -1,17 +1,29 @@
-use rustc::hir::*;
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass, in_external_macro, LintContext};
-use rustc::{declare_tool_lint, lint_array};
+// Copyright 2014-2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use crate::consts::{constant, Constant};
+use crate::rustc::hir::*;
+use crate::rustc::lint::{in_external_macro, LateContext, LateLintPass, LintArray, LintContext, LintPass};
+use crate::rustc::ty::{self, Ty};
+use crate::rustc::{declare_tool_lint, lint_array};
+use crate::rustc_errors::Applicability;
+use crate::syntax::ast::LitKind;
+use crate::syntax::source_map::Span;
+use crate::utils::paths;
+use crate::utils::sugg::Sugg;
+use crate::utils::{
+    expr_block, in_macro, is_allowed, is_expn_of, match_qpath, match_type, multispan_sugg, remove_blocks, snippet,
+    snippet_with_applicability, span_lint_and_sugg, span_lint_and_then, span_note_and_lint, walk_ptrs_ty,
+};
 use if_chain::if_chain;
-use rustc::ty::{self, Ty};
 use std::cmp::Ordering;
 use std::collections::Bound;
-use syntax::ast::LitKind;
-use syntax::source_map::Span;
-use crate::utils::paths;
-use crate::utils::{expr_block, is_allowed, is_expn_of, match_qpath, match_type, multispan_sugg,
-            remove_blocks, snippet, span_lint_and_sugg, span_lint_and_then, span_note_and_lint, walk_ptrs_ty};
-use crate::utils::sugg::Sugg;
-use crate::consts::{constant, Constant};
 
 /// **What it does:** Checks for matches with a single arm where an `if let`
 /// will usually suffice.
 /// ```rust
 /// match x {
 ///     Some(ref foo) => bar(foo),
-///     _ => ()
+///     _ => (),
 /// }
 /// ```
 declare_clippy_lint! {
     pub SINGLE_MATCH,
     style,
-    "a match statement with a single nontrivial arm (i.e. where the other arm \
-     is `_ => {}`) instead of `if let`"
+    "a match statement with a single nontrivial arm (i.e. where the other arm is `_ => {}`) instead of `if let`"
 }
 
 /// **What it does:** Checks for matches with a two arms where an `if let` will
@@ -51,8 +62,7 @@
 declare_clippy_lint! {
     pub SINGLE_MATCH_ELSE,
     pedantic,
-    "a match statement with a two arms where the second arm's pattern is a wildcard \
-     instead of `if let`"
+    "a match statement with a two arms where the second arm's pattern is a wildcard instead of `if let`"
 }
 
 /// **What it does:** Checks for matches where all arms match a reference,
 /// ```rust
 /// let x = 5;
 /// match x {
-///     1 ... 10 => println!("1 ... 10"),
-///     5 ... 15 => println!("5 ... 15"),
+///     1...10 => println!("1 ... 10"),
+///     5...15 => println!("5 ... 15"),
 ///     _ => (),
 /// }
 /// ```
 ///
 /// **Example:**
 /// ```rust
-/// let x : Result(i32, &str) = Ok(3);
+/// let x: Result(i32, &str) = Ok(3);
 /// match x {
 ///     Ok(_) => println!("ok"),
 ///     Err(_) => panic!("err"),
 /// ```rust
 /// let x: Option<()> = None;
 /// let r: Option<&()> = match x {
-///   None => None,
-///   Some(ref v) => Some(v),
+///     None => None,
+///     Some(ref v) => Some(v),
 /// };
 /// ```
 declare_clippy_lint! {
@@ -231,19 +241,29 @@ fn check_single_match(cx: &LateContext<'_, '_>, ex: &Expr, arms: &[Arm], expr: &
     }
 }
 
-fn check_single_match_single_pattern(cx: &LateContext<'_, '_>, ex: &Expr, arms: &[Arm], expr: &Expr, els: Option<&Expr>) {
+fn check_single_match_single_pattern(
+    cx: &LateContext<'_, '_>,
+    ex: &Expr,
+    arms: &[Arm],
+    expr: &Expr,
+    els: Option<&Expr>,
+) {
     if is_wild(&arms[1].pats[0]) {
         report_single_match_single_pattern(cx, ex, arms, expr, els);
     }
 }
 
-fn report_single_match_single_pattern(cx: &LateContext<'_, '_>, ex: &Expr, arms: &[Arm], expr: &Expr, els: Option<&Expr>) {
-    let lint = if els.is_some() {
-        SINGLE_MATCH_ELSE
-    } else {
-        SINGLE_MATCH
-    };
-    let els_str = els.map_or(String::new(), |els| format!(" else {}", expr_block(cx, els, None, "..")));
+fn report_single_match_single_pattern(
+    cx: &LateContext<'_, '_>,
+    ex: &Expr,
+    arms: &[Arm],
+    expr: &Expr,
+    els: Option<&Expr>,
+) {
+    let lint = if els.is_some() { SINGLE_MATCH_ELSE } else { SINGLE_MATCH };
+    let els_str = els.map_or(String::new(), |els| {
+        format!(" else {}", expr_block(cx, els, None, ".."))
+    });
     span_lint_and_sugg(
         cx,
         lint,
@@ -256,12 +276,20 @@ fn report_single_match_single_pattern(cx: &LateContext<'_, '_>, ex: &Expr, arms:
             snippet(cx, arms[0].pats[0].span, ".."),
             snippet(cx, ex.span, ".."),
             expr_block(cx, &arms[0].body, None, ".."),
-            els_str
+            els_str,
         ),
+        Applicability::HasPlaceholders,
     );
 }
 
-fn check_single_match_opt_like(cx: &LateContext<'_, '_>, ex: &Expr, arms: &[Arm], expr: &Expr, ty: Ty<'_>, els: Option<&Expr>) {
+fn check_single_match_opt_like(
+    cx: &LateContext<'_, '_>,
+    ex: &Expr,
+    arms: &[Arm],
+    expr: &Expr,
+    ty: Ty<'_>,
+    els: Option<&Expr>,
+) {
     // list of candidate Enums we know will never get any more members
     let candidates = &[
         (&paths::COW, "Borrowed"),
@@ -339,7 +367,12 @@ fn check_match_bool(cx: &LateContext<'_, '_>, ex: &Expr, arms: &[Arm], expr: &Ex
                         };
 
                         if let Some(sugg) = sugg {
-                            db.span_suggestion(expr.span, "consider using an if/else expression", sugg);
+                            db.span_suggestion_with_applicability(
+                                expr.span,
+                                "consider using an if/else expression",
+                                sugg,
+                                Applicability::HasPlaceholders,
+                            );
                         }
                     }
                 }
@@ -440,15 +473,20 @@ fn check_match_ref_pats(cx: &LateContext<'_, '_>, ex: &Expr, arms: &[Arm], expr:
         }));
 
         span_lint_and_then(cx, MATCH_REF_PATS, expr.span, title, |db| {
-            multispan_sugg(db, msg.to_owned(), suggs);
+            if !in_macro(expr.span) {
+                multispan_sugg(db, msg.to_owned(), suggs);
+            }
         });
     }
 }
 
 fn check_match_as_ref(cx: &LateContext<'_, '_>, ex: &Expr, arms: &[Arm], expr: &Expr) {
-    if arms.len() == 2 &&
-        arms[0].pats.len() == 1 && arms[0].guard.is_none() &&
-        arms[1].pats.len() == 1 && arms[1].guard.is_none() {
+    if arms.len() == 2
+        && arms[0].pats.len() == 1
+        && arms[0].guard.is_none()
+        && arms[1].pats.len() == 1
+        && arms[1].guard.is_none()
+    {
         let arm_ref: Option<BindingAnnotation> = if is_none_arm(&arms[0]) {
             is_ref_some_arm(&arms[1])
         } else if is_none_arm(&arms[1]) {
@@ -457,36 +495,42 @@ fn check_match_as_ref(cx: &LateContext<'_, '_>, ex: &Expr, arms: &[Arm], expr: &
             None
         };
         if let Some(rb) = arm_ref {
-            let suggestion = if rb == BindingAnnotation::Ref { "as_ref" } else { "as_mut" };
+            let suggestion = if rb == BindingAnnotation::Ref {
+                "as_ref"
+            } else {
+                "as_mut"
+            };
+            let mut applicability = Applicability::MachineApplicable;
             span_lint_and_sugg(
                 cx,
                 MATCH_AS_REF,
                 expr.span,
                 &format!("use {}() instead", suggestion),
                 "try this",
-                format!("{}.{}()", snippet(cx, ex.span, "_"), suggestion)
+                format!(
+                    "{}.{}()",
+                    snippet_with_applicability(cx, ex.span, "_", &mut applicability),
+                    suggestion
+                ),
+                applicability,
             )
         }
     }
 }
 
 /// Get all arms that are unbounded `PatRange`s.
-fn all_ranges<'a, 'tcx>(
-    cx: &LateContext<'a, 'tcx>,
-    arms: &'tcx [Arm],
-) -> Vec<SpannedRange<Constant>> {
+fn all_ranges<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, arms: &'tcx [Arm]) -> Vec<SpannedRange<Constant>> {
     arms.iter()
         .flat_map(|arm| {
             if let Arm {
-                ref pats,
-                guard: None,
-                ..
+                ref pats, guard: None, ..
             } = *arm
             {
                 pats.iter()
             } else {
                 [].iter()
-            }.filter_map(|pat| {
+            }
+            .filter_map(|pat| {
                 if let PatKind::Range(ref lhs, ref rhs, ref range_end) = pat.node {
                     let lhs = constant(cx, cx.tables, lhs)?.0;
                     let rhs = constant(cx, cx.tables, rhs)?.0;
@@ -494,12 +538,18 @@ fn all_ranges<'a, 'tcx>(
                         RangeEnd::Included => Bound::Included(rhs),
                         RangeEnd::Excluded => Bound::Excluded(rhs),
                     };
-                    return Some(SpannedRange { span: pat.span, node: (lhs, rhs) });
+                    return Some(SpannedRange {
+                        span: pat.span,
+                        node: (lhs, rhs),
+                    });
                 }
 
                 if let PatKind::Lit(ref value) = pat.node {
                     let value = constant(cx, cx.tables, value)?.0;
-                    return Some(SpannedRange { span: pat.span, node: (value.clone(), Bound::Included(value)) });
+                    return Some(SpannedRange {
+                        span: pat.span,
+                        node: (value.clone(), Bound::Included(value)),
+                    });
                 }
 
                 None
@@ -523,24 +573,15 @@ fn type_ranges(ranges: &[SpannedRange<Constant>]) -> TypedRanges {
     ranges
         .iter()
         .filter_map(|range| match range.node {
-            (
-                Constant::Int(start),
-                Bound::Included(Constant::Int(end)),
-            ) => Some(SpannedRange {
+            (Constant::Int(start), Bound::Included(Constant::Int(end))) => Some(SpannedRange {
                 span: range.span,
                 node: (start, Bound::Included(end)),
             }),
-            (
-                Constant::Int(start),
-                Bound::Excluded(Constant::Int(end)),
-            ) => Some(SpannedRange {
+            (Constant::Int(start), Bound::Excluded(Constant::Int(end))) => Some(SpannedRange {
                 span: range.span,
                 node: (start, Bound::Excluded(end)),
             }),
-            (
-                Constant::Int(start),
-                Bound::Unbounded,
-            ) => Some(SpannedRange {
+            (Constant::Int(start), Bound::Unbounded) => Some(SpannedRange {
                 span: range.span,
                 node: (start, Bound::Unbounded),
             }),
@@ -586,7 +627,8 @@ fn is_ref_some_arm(arm: &Arm) -> Option<BindingAnnotation> {
 }
 
 fn has_only_ref_pats(arms: &[Arm]) -> bool {
-    let mapped = arms.iter()
+    let mapped = arms
+        .iter()
         .flat_map(|a| &a.pats)
         .map(|p| {
             match p.node {
@@ -660,8 +702,10 @@ fn cmp(&self, other: &Self) -> Ordering {
 
     for (a, b) in values.iter().zip(values.iter().skip(1)) {
         match (a, b) {
-            (&Kind::Start(_, ra), &Kind::End(_, rb)) => if ra.node != rb.node {
-                return Some((ra, rb));
+            (&Kind::Start(_, ra), &Kind::End(_, rb)) => {
+                if ra.node != rb.node {
+                    return Some((ra, rb));
+                }
             },
             (&Kind::End(a, _), &Kind::Start(b, _)) if a != Bound::Included(b) => (),
             _ => return Some((a.range(), b.range())),