]> git.lizzy.rs Git - rust.git/blobdiff - clippy_lints/src/eq_op.rs
Auto merge of #3946 - rchaser53:issue-3920, r=flip1995
[rust.git] / clippy_lints / src / eq_op.rs
index ca441aa9a93c91401171d10ce075bb41a4f88609..1f42a06fbcd3dc768c3781a74abe3aa94a2d64c8 100644 (file)
@@ -1,41 +1,46 @@
+use crate::utils::{
+    implements_trait, in_macro, is_copy, multispan_sugg, snippet, span_lint, span_lint_and_then, SpanlessEq,
+};
 use rustc::hir::*;
-use rustc::lint::*;
-use utils::{in_macro, implements_trait, is_copy, multispan_sugg, snippet, span_lint, span_lint_and_then, SpanlessEq};
+use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
+use rustc::{declare_tool_lint, lint_array};
+use rustc_errors::Applicability;
 
-/// **What it does:** Checks for equal operands to comparison, logical and
-/// bitwise, difference and division binary operators (`==`, `>`, etc., `&&`,
-/// `||`, `&`, `|`, `^`, `-` and `/`).
-///
-/// **Why is this bad?** This is usually just a typo or a copy and paste error.
-///
-/// **Known problems:** False negatives: We had some false positives regarding
-/// calls (notably [racer](https://github.com/phildawes/racer) had one instance
-/// of `x.pop() && x.pop()`), so we removed matching any function or method
-/// calls. We may introduce a whitelist of known pure functions in the future.
-///
-/// **Example:**
-/// ```rust
-/// x + 1 == x + 1
-/// ```
 declare_clippy_lint! {
+    /// **What it does:** Checks for equal operands to comparison, logical and
+    /// bitwise, difference and division binary operators (`==`, `>`, etc., `&&`,
+    /// `||`, `&`, `|`, `^`, `-` and `/`).
+    ///
+    /// **Why is this bad?** This is usually just a typo or a copy and paste error.
+    ///
+    /// **Known problems:** False negatives: We had some false positives regarding
+    /// calls (notably [racer](https://github.com/phildawes/racer) had one instance
+    /// of `x.pop() && x.pop()`), so we removed matching any function or method
+    /// calls. We may introduce a whitelist of known pure functions in the future.
+    ///
+    /// **Example:**
+    /// ```rust
+    /// # let x = 1;
+    /// if x + 1 == x + 1 {}
+    /// ```
     pub EQ_OP,
     correctness,
-    "equal operands on both sides of a comparison or bitwise combination (e.g. `x == x`)"
+    "equal operands on both sides of a comparison or bitwise combination (e.g., `x == x`)"
 }
 
-/// **What it does:** Checks for arguments to `==` which have their address
-/// taken to satisfy a bound
-/// and suggests to dereference the other argument instead
-///
-/// **Why is this bad?** It is more idiomatic to dereference the other argument.
-///
-/// **Known problems:** None
-///
-/// **Example:**
-/// ```rust
-/// &x == y
-/// ```
 declare_clippy_lint! {
+    /// **What it does:** Checks for arguments to `==` which have their address
+    /// taken to satisfy a bound
+    /// and suggests to dereference the other argument instead
+    ///
+    /// **Why is this bad?** It is more idiomatic to dereference the other argument.
+    ///
+    /// **Known problems:** None
+    ///
+    /// **Example:**
+    /// ```ignore
+    /// &x == y
+    /// ```
     pub OP_REF,
     style,
     "taking a reference to satisfy the type constraints on `==`"
@@ -48,12 +53,20 @@ impl LintPass for EqOp {
     fn get_lints(&self) -> LintArray {
         lint_array!(EQ_OP, OP_REF)
     }
+
+    fn name(&self) -> &'static str {
+        "EqOp"
+    }
 }
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for EqOp {
+    #[allow(clippy::similar_names, clippy::too_many_lines)]
     fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr) {
-        if let ExprBinary(ref op, ref left, ref right) = e.node {
-            if is_valid_operator(op) && SpanlessEq::new(cx).ignore_fn().eq_expr(left, right) && !in_macro(e.span) {
+        if let ExprKind::Binary(op, ref left, ref right) = e.node {
+            if in_macro(e.span) {
+                return;
+            }
+            if is_valid_operator(op) && SpanlessEq::new(cx).ignore_fn().eq_expr(left, right) {
                 span_lint(
                     cx,
                     EQ_OP,
@@ -63,28 +76,30 @@ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr) {
                 return;
             }
             let (trait_id, requires_ref) = match op.node {
-                BiAdd => (cx.tcx.lang_items().add_trait(), false),
-                BiSub => (cx.tcx.lang_items().sub_trait(), false),
-                BiMul => (cx.tcx.lang_items().mul_trait(), false),
-                BiDiv => (cx.tcx.lang_items().div_trait(), false),
-                BiRem => (cx.tcx.lang_items().rem_trait(), false),
+                BinOpKind::Add => (cx.tcx.lang_items().add_trait(), false),
+                BinOpKind::Sub => (cx.tcx.lang_items().sub_trait(), false),
+                BinOpKind::Mul => (cx.tcx.lang_items().mul_trait(), false),
+                BinOpKind::Div => (cx.tcx.lang_items().div_trait(), false),
+                BinOpKind::Rem => (cx.tcx.lang_items().rem_trait(), false),
                 // don't lint short circuiting ops
-                BiAnd | BiOr => return,
-                BiBitXor => (cx.tcx.lang_items().bitxor_trait(), false),
-                BiBitAnd => (cx.tcx.lang_items().bitand_trait(), false),
-                BiBitOr => (cx.tcx.lang_items().bitor_trait(), false),
-                BiShl => (cx.tcx.lang_items().shl_trait(), false),
-                BiShr => (cx.tcx.lang_items().shr_trait(), false),
-                BiNe | BiEq => (cx.tcx.lang_items().eq_trait(), true),
-                BiLt | BiLe | BiGe | BiGt => (cx.tcx.lang_items().ord_trait(), true),
+                BinOpKind::And | BinOpKind::Or => return,
+                BinOpKind::BitXor => (cx.tcx.lang_items().bitxor_trait(), false),
+                BinOpKind::BitAnd => (cx.tcx.lang_items().bitand_trait(), false),
+                BinOpKind::BitOr => (cx.tcx.lang_items().bitor_trait(), false),
+                BinOpKind::Shl => (cx.tcx.lang_items().shl_trait(), false),
+                BinOpKind::Shr => (cx.tcx.lang_items().shr_trait(), false),
+                BinOpKind::Ne | BinOpKind::Eq => (cx.tcx.lang_items().eq_trait(), true),
+                BinOpKind::Lt | BinOpKind::Le | BinOpKind::Ge | BinOpKind::Gt => {
+                    (cx.tcx.lang_items().ord_trait(), true)
+                },
             };
             if let Some(trait_id) = trait_id {
-                #[allow(match_same_arms)]
+                #[allow(clippy::match_same_arms)]
                 match (&left.node, &right.node) {
                     // do not suggest to dereference literals
-                    (&ExprLit(..), _) | (_, &ExprLit(..)) => {},
+                    (&ExprKind::Lit(..), _) | (_, &ExprKind::Lit(..)) => {},
                     // &foo == &bar
-                    (&ExprAddrOf(_, ref l), &ExprAddrOf(_, ref r)) => {
+                    (&ExprKind::AddrOf(_, ref l), &ExprKind::AddrOf(_, ref r)) => {
                         let lty = cx.tables.expr_ty(l);
                         let rty = cx.tables.expr_ty(r);
                         let lcpy = is_copy(cx, lty);
@@ -106,12 +121,23 @@ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr) {
                                     );
                                 },
                             )
-                        } else if lcpy && !rcpy && implements_trait(cx, lty, trait_id, &[cx.tables.expr_ty(right).into()]) {
+                        } else if lcpy
+                            && !rcpy
+                            && implements_trait(cx, lty, trait_id, &[cx.tables.expr_ty(right).into()])
+                        {
                             span_lint_and_then(cx, OP_REF, e.span, "needlessly taken reference of left operand", |db| {
                                 let lsnip = snippet(cx, l.span, "...").to_string();
-                                db.span_suggestion(left.span, "use the left value directly", lsnip);
+                                db.span_suggestion(
+                                    left.span,
+                                    "use the left value directly",
+                                    lsnip,
+                                    Applicability::MachineApplicable, // snippet
+                                );
                             })
-                        } else if !lcpy && rcpy && implements_trait(cx, cx.tables.expr_ty(left), trait_id, &[rty.into()]) {
+                        } else if !lcpy
+                            && rcpy
+                            && implements_trait(cx, cx.tables.expr_ty(left), trait_id, &[rty.into()])
+                        {
                             span_lint_and_then(
                                 cx,
                                 OP_REF,
@@ -119,30 +145,49 @@ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr) {
                                 "needlessly taken reference of right operand",
                                 |db| {
                                     let rsnip = snippet(cx, r.span, "...").to_string();
-                                    db.span_suggestion(right.span, "use the right value directly", rsnip);
+                                    db.span_suggestion(
+                                        right.span,
+                                        "use the right value directly",
+                                        rsnip,
+                                        Applicability::MachineApplicable, // snippet
+                                    );
                                 },
                             )
                         }
                     },
                     // &foo == bar
-                    (&ExprAddrOf(_, ref l), _) => {
+                    (&ExprKind::AddrOf(_, ref l), _) => {
                         let lty = cx.tables.expr_ty(l);
                         let lcpy = is_copy(cx, lty);
-                        if (requires_ref || lcpy) && implements_trait(cx, lty, trait_id, &[cx.tables.expr_ty(right).into()]) {
+                        if (requires_ref || lcpy)
+                            && implements_trait(cx, lty, trait_id, &[cx.tables.expr_ty(right).into()])
+                        {
                             span_lint_and_then(cx, OP_REF, e.span, "needlessly taken reference of left operand", |db| {
                                 let lsnip = snippet(cx, l.span, "...").to_string();
-                                db.span_suggestion(left.span, "use the left value directly", lsnip);
+                                db.span_suggestion(
+                                    left.span,
+                                    "use the left value directly",
+                                    lsnip,
+                                    Applicability::MachineApplicable, // snippet
+                                );
                             })
                         }
                     },
                     // foo == &bar
-                    (_, &ExprAddrOf(_, ref r)) => {
+                    (_, &ExprKind::AddrOf(_, ref r)) => {
                         let rty = cx.tables.expr_ty(r);
                         let rcpy = is_copy(cx, rty);
-                        if (requires_ref || rcpy) && implements_trait(cx, cx.tables.expr_ty(left), trait_id, &[rty.into()]) {
+                        if (requires_ref || rcpy)
+                            && implements_trait(cx, cx.tables.expr_ty(left), trait_id, &[rty.into()])
+                        {
                             span_lint_and_then(cx, OP_REF, e.span, "taken reference of right operand", |db| {
                                 let rsnip = snippet(cx, r.span, "...").to_string();
-                                db.span_suggestion(right.span, "use the right value directly", rsnip);
+                                db.span_suggestion(
+                                    right.span,
+                                    "use the right value directly",
+                                    rsnip,
+                                    Applicability::MachineApplicable, // snippet
+                                );
                             })
                         }
                     },
@@ -153,10 +198,21 @@ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr) {
     }
 }
 
-
-fn is_valid_operator(op: &BinOp) -> bool {
+fn is_valid_operator(op: BinOp) -> bool {
     match op.node {
-        BiSub | BiDiv | BiEq | BiLt | BiLe | BiGt | BiGe | BiNe | BiAnd | BiOr | BiBitXor | BiBitAnd | BiBitOr => true,
+        BinOpKind::Sub
+        | BinOpKind::Div
+        | BinOpKind::Eq
+        | BinOpKind::Lt
+        | BinOpKind::Le
+        | BinOpKind::Gt
+        | BinOpKind::Ge
+        | BinOpKind::Ne
+        | BinOpKind::And
+        | BinOpKind::Or
+        | BinOpKind::BitXor
+        | BinOpKind::BitAnd
+        | BinOpKind::BitOr => true,
         _ => false,
     }
 }