]> git.lizzy.rs Git - rust.git/blobdiff - clippy_lints/src/assign_ops.rs
Use span_suggestion_with_applicability instead of span_suggestion
[rust.git] / clippy_lints / src / assign_ops.rs
index a3d9d5cbba8621a6675fc9bacba52b45606fbaa2..5cf714bed86a08cc897baf18befa4315edc5fd4d 100644 (file)
@@ -1,27 +1,12 @@
-use rustc::hir;
-use rustc::hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
-use rustc::lint::*;
-use syntax::ast;
-use utils::{get_trait_def_id, implements_trait, snippet_opt, span_lint_and_then, SpanlessEq};
-use utils::{higher, sugg};
-
-/// **What it does:** Checks for compound assignment operations (`+=` and
-/// similar).
-///
-/// **Why is this bad?** Projects with many developers from languages without
-/// those operations may find them unreadable and not worth their weight.
-///
-/// **Known problems:** Types implementing `OpAssign` don't necessarily
-/// implement `Op`.
-///
-/// **Example:**
-/// ```rust
-/// a += 1;
-/// ```
-declare_restriction_lint! {
-    pub ASSIGN_OPS,
-    "any compound assignment operation"
-}
+use crate::utils::{get_trait_def_id, implements_trait, snippet_opt, span_lint_and_then, SpanlessEq};
+use crate::utils::{higher, sugg};
+use crate::rustc::hir;
+use crate::rustc::hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
+use crate::rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
+use crate::rustc::{declare_tool_lint, lint_array};
+use if_chain::if_chain;
+use crate::syntax::ast;
+use crate::rustc_errors::Applicability;
 
 /// **What it does:** Checks for `a = a op b` or `a = b commutative_op a`
 /// patterns.
@@ -37,9 +22,9 @@
 /// ...
 /// a = a + b;
 /// ```
-declare_lint! {
+declare_clippy_lint! {
     pub ASSIGN_OP_PATTERN,
-    Warn,
+    style,
     "assigning the result of an operation on a variable to that same variable"
 }
 
 /// **Why is this bad?** Most likely these are bugs where one meant to write `a
 /// op= b`.
 ///
-/// **Known problems:** Someone might actually mean `a op= a op b`, but that
-/// should rather be written as `a = (2 * a) op b` where applicable.
+/// **Known problems:** Clippy cannot know for sure if `a op= a op b` should have
+/// been `a = a op a op b` or `a = a op b`/`a op= b`. Therefore it suggests both.
+/// If `a op= a op b` is really the correct behaviour it should be
+/// written as `a = a op a op b` as it's less confusing.
 ///
 /// **Example:**
 /// ```rust
@@ -57,9 +44,9 @@
 /// ...
 /// a += a + b;
 /// ```
-declare_lint! {
+declare_clippy_lint! {
     pub MISREFACTORED_ASSIGN_OP,
-    Warn,
+    complexity,
     "having a variable on both sides of an assign op"
 }
 
 
 impl LintPass for AssignOps {
     fn get_lints(&self) -> LintArray {
-        lint_array!(ASSIGN_OPS, ASSIGN_OP_PATTERN, MISREFACTORED_ASSIGN_OP)
+        lint_array!(ASSIGN_OP_PATTERN, MISREFACTORED_ASSIGN_OP)
     }
 }
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for AssignOps {
     fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr) {
         match expr.node {
-            hir::ExprAssignOp(op, ref lhs, ref rhs) => {
-                span_lint_and_then(cx, ASSIGN_OPS, expr.span, "assign operation detected", |db| {
-                    let lhs = &sugg::Sugg::hir(cx, lhs, "..");
-                    let rhs = &sugg::Sugg::hir(cx, rhs, "..");
-
-                    db.span_suggestion(
-                        expr.span,
-                        "replace it with",
-                        format!("{} = {}", lhs, sugg::make_binop(higher::binop(op.node), lhs, rhs)),
-                    );
-                });
-                if let hir::ExprBinary(binop, ref l, ref r) = rhs.node {
+            hir::ExprKind::AssignOp(op, ref lhs, ref rhs) => {
+                if let hir::ExprKind::Binary(binop, ref l, ref r) = rhs.node {
                     if op.node == binop.node {
                         let lint = |assignee: &hir::Expr, rhs_other: &hir::Expr| {
                             span_lint_and_then(
@@ -94,24 +71,34 @@ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr) {
                                 MISREFACTORED_ASSIGN_OP,
                                 expr.span,
                                 "variable appears on both sides of an assignment operation",
-                                |db| if let (Some(snip_a), Some(snip_r)) =
-                                    (snippet_opt(cx, assignee.span), snippet_opt(cx, rhs_other.span))
-                                {
-                                    let a = &sugg::Sugg::hir(cx, assignee, "..");
-                                    let r = &sugg::Sugg::hir(cx, rhs, "..");
-                                    let long = format!("{} = {}", snip_a, sugg::make_binop(higher::binop(op.node), a, r));
-                                    db.span_suggestion(
-                                        expr.span,
-                                        &format!("Did you mean {} = {} {} {} or {}? Consider replacing it with",
-                                                 snip_a, snip_a, op.node.as_str(), snip_r,
-                                                 long),
-                                        format!("{} {}= {}", snip_a, op.node.as_str(), snip_r)
-                                    );
-                                    db.span_suggestion(
-                                        expr.span,
-                                        "or",
-                                        long
-                                    );
+                                |db| {
+                                    if let (Some(snip_a), Some(snip_r)) =
+                                        (snippet_opt(cx, assignee.span), snippet_opt(cx, rhs_other.span))
+                                    {
+                                        let a = &sugg::Sugg::hir(cx, assignee, "..");
+                                        let r = &sugg::Sugg::hir(cx, rhs, "..");
+                                        let long =
+                                            format!("{} = {}", snip_a, sugg::make_binop(higher::binop(op.node), a, r));
+                                        db.span_suggestion_with_applicability(
+                                            expr.span,
+                                            &format!(
+                                                "Did you mean {} = {} {} {} or {}? Consider replacing it with",
+                                                snip_a,
+                                                snip_a,
+                                                op.node.as_str(),
+                                                snip_r,
+                                                long
+                                            ),
+                                            format!("{} {}= {}", snip_a, op.node.as_str(), snip_r),
+                                            Applicability::Unspecified,
+                                        );
+                                        db.span_suggestion_with_applicability(
+                                            expr.span, 
+                                            "or", 
+                                            long,
+                                            Applicability::Unspecified,
+                                            );
+                                    }
                                 },
                             );
                         };
@@ -126,9 +113,9 @@ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr) {
                     }
                 }
             },
-            hir::ExprAssign(ref assignee, ref e) => {
-                if let hir::ExprBinary(op, ref l, ref r) = e.node {
-                    #[allow(cyclomatic_complexity)]
+            hir::ExprKind::Assign(ref assignee, ref e) => {
+                if let hir::ExprKind::Binary(op, ref l, ref r) = e.node {
+                    #[allow(clippy::cyclomatic_complexity)]
                     let lint = |assignee: &hir::Expr, rhs: &hir::Expr| {
                         let ty = cx.tables.expr_ty(assignee);
                         let rty = cx.tables.expr_ty(rhs);
@@ -137,10 +124,10 @@ macro_rules! ops {
                              $cx:expr,
                              $ty:expr,
                              $rty:expr,
-                             $($trait_name:ident:$full_trait_name:ident),+) => {
+                             $($trait_name:ident),+) => {
                                 match $op {
-                                    $(hir::$full_trait_name => {
-                                        let [krate, module] = ::utils::paths::OPS_MODULE;
+                                    $(hir::BinOpKind::$trait_name => {
+                                        let [krate, module] = crate::utils::paths::OPS_MODULE;
                                         let path = [krate, module, concat!(stringify!($trait_name), "Assign")];
                                         let trait_id = if let Some(trait_id) = get_trait_def_id($cx, &path) {
                                             trait_id
@@ -153,8 +140,8 @@ macro_rules! ops {
                                         // the crate node is the only one that is not in the map
                                         if_chain! {
                                             if parent_impl != ast::CRATE_NODE_ID;
-                                            if let hir::map::Node::NodeItem(item) = cx.tcx.hir.get(parent_impl);
-                                            if let hir::Item_::ItemImpl(_, _, _, _, Some(ref trait_ref), _, _) =
+                                            if let hir::Node::Item(item) = cx.tcx.hir.get(parent_impl);
+                                            if let hir::ItemKind::Impl(_, _, _, _, Some(ref trait_ref), _, _) =
                                                 item.node;
                                             if trait_ref.path.def.def_id() == trait_id;
                                             then { return; }
@@ -169,33 +156,36 @@ macro_rules! ops {
                             op.node,
                             cx,
                             ty,
-                            rty,
-                            Add: BiAdd,
-                            Sub: BiSub,
-                            Mul: BiMul,
-                            Div: BiDiv,
-                            Rem: BiRem,
-                            And: BiAnd,
-                            Or: BiOr,
-                            BitAnd: BiBitAnd,
-                            BitOr: BiBitOr,
-                            BitXor: BiBitXor,
-                            Shr: BiShr,
-                            Shl: BiShl
+                            rty.into(),
+                            Add,
+                            Sub,
+                            Mul,
+                            Div,
+                            Rem,
+                            And,
+                            Or,
+                            BitAnd,
+                            BitOr,
+                            BitXor,
+                            Shr,
+                            Shl
                         ) {
                             span_lint_and_then(
                                 cx,
                                 ASSIGN_OP_PATTERN,
                                 expr.span,
                                 "manual implementation of an assign operation",
-                                |db| if let (Some(snip_a), Some(snip_r)) =
-                                    (snippet_opt(cx, assignee.span), snippet_opt(cx, rhs.span))
-                                {
-                                    db.span_suggestion(
-                                        expr.span,
-                                        "replace it with",
-                                        format!("{} {}= {}", snip_a, op.node.as_str(), snip_r),
-                                    );
+                                |db| {
+                                    if let (Some(snip_a), Some(snip_r)) =
+                                        (snippet_opt(cx, assignee.span), snippet_opt(cx, rhs.span))
+                                    {
+                                        db.span_suggestion_with_applicability(
+                                            expr.span,
+                                            "replace it with",
+                                            format!("{} {}= {}", snip_a, op.node.as_str(), snip_r),
+                                            Applicability::Unspecified,
+                                        );
+                                    }
                                 },
                             );
                         }
@@ -204,7 +194,7 @@ macro_rules! ops {
                     let mut visitor = ExprVisitor {
                         assignee,
                         counter: 0,
-                        cx
+                        cx,
                     };
 
                     walk_expr(&mut visitor, e);
@@ -217,13 +207,13 @@ macro_rules! ops {
                         // a = b commutative_op a
                         if SpanlessEq::new(cx).ignore_fn().eq_expr(assignee, r) {
                             match op.node {
-                                hir::BiAdd |
-                                hir::BiMul |
-                                hir::BiAnd |
-                                hir::BiOr |
-                                hir::BiBitXor |
-                                hir::BiBitAnd |
-                                hir::BiBitOr => {
+                                hir::BinOpKind::Add
+                                | hir::BinOpKind::Mul
+                                | hir::BinOpKind::And
+                                | hir::BinOpKind::Or
+                                | hir::BinOpKind::BitXor
+                                | hir::BinOpKind::BitAnd
+                                | hir::BinOpKind::BitOr => {
                                     lint(assignee, l);
                                 },
                                 _ => {},
@@ -237,11 +227,11 @@ macro_rules! ops {
     }
 }
 
-fn is_commutative(op: hir::BinOp_) -> bool {
-    use rustc::hir::BinOp_::*;
+fn is_commutative(op: hir::BinOpKind) -> bool {
+    use crate::rustc::hir::BinOpKind::*;
     match op {
-        BiAdd | BiMul | BiAnd | BiOr | BiBitXor | BiBitAnd | BiBitOr | BiEq | BiNe => true,
-        BiSub | BiDiv | BiRem | BiShl | BiShr | BiLt | BiLe | BiGe | BiGt => false,
+        Add | Mul | And | Or | BitXor | BitAnd | BitOr | Eq | Ne => true,
+        Sub | Div | Rem | Shl | Shr | Lt | Le | Ge | Gt => false,
     }
 }