-use crate::utils::{get_trait_def_id, implements_trait, snippet_opt, span_lint_and_then, SpanlessEq};
+use crate::utils::{
+ get_trait_def_id, implements_trait, snippet_opt, span_lint_and_then, trait_ref_of_method, SpanlessEq,
+};
use crate::utils::{higher, sugg};
use if_chain::if_chain;
-use rustc::hir;
-use rustc::hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::{declare_tool_lint, lint_array};
+use rustc::hir::map::Map;
use rustc_errors::Applicability;
-use syntax::ast;
+use rustc_hir as hir;
+use rustc_hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
-/// **What it does:** Checks for `a = a op b` or `a = b commutative_op a`
-/// patterns.
-///
-/// **Why is this bad?** These can be written as the shorter `a op= b`.
-///
-/// **Known problems:** While forbidden by the spec, `OpAssign` traits may have
-/// implementations that differ from the regular `Op` impl.
-///
-/// **Example:**
-/// ```rust
-/// let mut a = 5;
-/// ...
-/// a = a + b;
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Checks for `a = a op b` or `a = b commutative_op a`
+ /// patterns.
+ ///
+ /// **Why is this bad?** These can be written as the shorter `a op= b`.
+ ///
+ /// **Known problems:** While forbidden by the spec, `OpAssign` traits may have
+ /// implementations that differ from the regular `Op` impl.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// let mut a = 5;
+ /// let b = 0;
+ /// // ...
+ /// a = a + b;
+ /// ```
pub ASSIGN_OP_PATTERN,
style,
"assigning the result of an operation on a variable to that same variable"
}
-/// **What it does:** Checks for `a op= a op b` or `a op= b op a` patterns.
-///
-/// **Why is this bad?** Most likely these are bugs where one meant to write `a
-/// op= b`.
-///
-/// **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
-/// let mut a = 5;
-/// ...
-/// a += a + b;
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Checks for `a op= a op b` or `a op= b op a` patterns.
+ ///
+ /// **Why is this bad?** Most likely these are bugs where one meant to write `a
+ /// op= b`.
+ ///
+ /// **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
+ /// let mut a = 5;
+ /// let b = 2;
+ /// // ...
+ /// a += a + b;
+ /// ```
pub MISREFACTORED_ASSIGN_OP,
complexity,
"having a variable on both sides of an assign op"
}
-#[derive(Copy, Clone, Default)]
-pub struct AssignOps;
-
-impl LintPass for AssignOps {
- fn get_lints(&self) -> LintArray {
- lint_array!(ASSIGN_OP_PATTERN, MISREFACTORED_ASSIGN_OP)
- }
-}
+declare_lint_pass!(AssignOps => [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 {
+ #[allow(clippy::too_many_lines)]
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr<'_>) {
+ match &expr.kind {
hir::ExprKind::AssignOp(op, lhs, rhs) => {
- if let hir::ExprKind::Binary(binop, l, r) = &rhs.node {
- if op.node == binop.node {
- let lint = |assignee: &hir::Expr, rhs_other: &hir::Expr| {
- span_lint_and_then(
- cx,
- 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_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::MachineApplicable,
- );
- db.span_suggestion_with_applicability(
- expr.span,
- "or",
- long,
- Applicability::MachineApplicable, // snippet
- );
- }
- },
- );
- };
- // lhs op= l op r
- if SpanlessEq::new(cx).ignore_fn().eq_expr(lhs, l) {
- lint(lhs, r);
- }
- // lhs op= l commutative_op r
- if is_commutative(op.node) && SpanlessEq::new(cx).ignore_fn().eq_expr(lhs, r) {
- lint(lhs, l);
- }
+ if let hir::ExprKind::Binary(binop, l, r) = &rhs.kind {
+ if op.node != binop.node {
+ return;
+ }
+ // lhs op= l op r
+ if SpanlessEq::new(cx).ignore_fn().eq_expr(lhs, l) {
+ lint_misrefactored_assign_op(cx, expr, *op, rhs, lhs, r);
+ }
+ // lhs op= l commutative_op r
+ if is_commutative(op.node) && SpanlessEq::new(cx).ignore_fn().eq_expr(lhs, r) {
+ lint_misrefactored_assign_op(cx, expr, *op, rhs, lhs, l);
}
}
},
- hir::ExprKind::Assign(assignee, e) => {
- if let hir::ExprKind::Binary(op, l, r) = &e.node {
- #[allow(clippy::cyclomatic_complexity)]
- let lint = |assignee: &hir::Expr, rhs: &hir::Expr| {
+ hir::ExprKind::Assign(assignee, e, _) => {
+ if let hir::ExprKind::Binary(op, l, r) = &e.kind {
+ #[allow(clippy::cognitive_complexity)]
+ let lint = |assignee: &hir::Expr<'_>, rhs: &hir::Expr<'_>| {
let ty = cx.tables.expr_ty(assignee);
let rty = cx.tables.expr_ty(rhs);
macro_rules! ops {
match $op {
$(hir::BinOpKind::$trait_name => {
let [krate, module] = crate::utils::paths::OPS_MODULE;
- let path = [krate, module, concat!(stringify!($trait_name), "Assign")];
+ let path: [&str; 3] = [krate, module, concat!(stringify!($trait_name), "Assign")];
let trait_id = if let Some(trait_id) = get_trait_def_id($cx, &path) {
trait_id
} else {
return; // useless if the trait doesn't exist
};
// check that we are not inside an `impl AssignOp` of this exact operation
- let parent_fn = cx.tcx.hir().get_parent(e.id);
- let parent_impl = cx.tcx.hir().get_parent(parent_fn);
- // the crate node is the only one that is not in the map
+ let parent_fn = cx.tcx.hir().get_parent_item(e.hir_id);
if_chain! {
- if parent_impl != ast::CRATE_NODE_ID;
- if let hir::Node::Item(item) = cx.tcx.hir().get(parent_impl);
- if let hir::ItemKind::Impl(_, _, _, _, Some(trait_ref), _, _) =
- &item.node;
- if trait_ref.path.def.def_id() == trait_id;
+ if let Some(trait_ref) = trait_ref_of_method(cx, parent_fn);
+ if trait_ref.path.res.def_id() == trait_id;
then { return; }
}
implements_trait($cx, $ty, trait_id, &[$rty])
if let (Some(snip_a), Some(snip_r)) =
(snippet_opt(cx, assignee.span), snippet_opt(cx, rhs.span))
{
- db.span_suggestion_with_applicability(
+ db.span_suggestion(
expr.span,
"replace it with",
format!("{} {}= {}", snip_a, op.node.as_str(), snip_r),
}
}
+fn lint_misrefactored_assign_op(
+ cx: &LateContext<'_, '_>,
+ expr: &hir::Expr<'_>,
+ op: hir::BinOp,
+ rhs: &hir::Expr<'_>,
+ assignee: &hir::Expr<'_>,
+ rhs_other: &hir::Expr<'_>,
+) {
+ span_lint_and_then(
+ cx,
+ 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),
+ Applicability::MaybeIncorrect,
+ );
+ db.span_suggestion(
+ expr.span,
+ "or",
+ long,
+ Applicability::MaybeIncorrect, // snippet
+ );
+ }
+ },
+ );
+}
+
+#[must_use]
fn is_commutative(op: hir::BinOpKind) -> bool {
- use rustc::hir::BinOpKind::*;
+ use rustc_hir::BinOpKind::{
+ Add, And, BitAnd, BitOr, BitXor, Div, Eq, Ge, Gt, Le, Lt, Mul, Ne, Or, Rem, Shl, Shr, Sub,
+ };
match op {
Add | Mul | And | Or | BitXor | BitAnd | BitOr | Eq | Ne => true,
Sub | Div | Rem | Shl | Shr | Lt | Le | Ge | Gt => false,
}
}
-struct ExprVisitor<'a, 'tcx: 'a> {
- assignee: &'a hir::Expr,
+struct ExprVisitor<'a, 'tcx> {
+ assignee: &'a hir::Expr<'a>,
counter: u8,
cx: &'a LateContext<'a, 'tcx>,
}
-impl<'a, 'tcx: 'a> Visitor<'tcx> for ExprVisitor<'a, 'tcx> {
- fn visit_expr(&mut self, expr: &'tcx hir::Expr) {
+impl<'a, 'tcx> Visitor<'tcx> for ExprVisitor<'a, 'tcx> {
+ type Map = Map<'tcx>;
+
+ fn visit_expr(&mut self, expr: &'tcx hir::Expr<'_>) {
if SpanlessEq::new(self.cx).ignore_fn().eq_expr(self.assignee, expr) {
self.counter += 1;
}
walk_expr(self, expr);
}
- fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
+ fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
NestedVisitorMap::None
}
}
projects / rust.git / blobdiff