-use rustc::hir;
-use rustc::lint::*;
-use syntax::ast;
-use utils::{span_lint_and_then, snippet_opt, SpanlessEq, get_trait_def_id, implements_trait};
-use utils::{higher, sugg};
+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 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"
-}
-
-/// **What it does:** Checks for `a = a op b` or `a = b commutative_op a` patterns.
+/// **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`.
///
/// ...
/// 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"
}
/// **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`.
+/// **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
/// ...
/// 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: &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.span)) {
- db.span_suggestion(expr.span,
- "replace it with",
- format!("{} {}= {}",
- snip_a,
- op.node.as_str(),
- snip_r));
- });
+ 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::Unspecified,
+ );
+ db.span_suggestion_with_applicability(
+ expr.span,
+ "or",
+ long,
+ Applicability::Unspecified,
+ );
+ }
+ },
+ );
};
// lhs op= l op r
if SpanlessEq::new(cx).ignore_fn().eq_expr(lhs, l) {
}
}
},
- 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);
$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
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
- if_let_chain!{[
- parent_impl != ast::CRATE_NODE_ID,
- let hir::map::Node::NodeItem(item) = cx.tcx.hir.get(parent_impl),
- let hir::Item_::ItemImpl(_, _, _, _, Some(ref trait_ref), _, _) = item.node,
- trait_ref.path.def.def_id() == trait_id
- ], { return; }}
+ 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(ref trait_ref), _, _) =
+ item.node;
+ if trait_ref.path.def.def_id() == trait_id;
+ then { return; }
+ }
implements_trait($cx, $ty, trait_id, &[$rty])
},)*
_ => false,
}
}
}
- if ops!(op.node,
+ if ops!(
+ op.node,
+ cx,
+ ty,
+ rty.into(),
+ Add,
+ Sub,
+ Mul,
+ Div,
+ Rem,
+ And,
+ Or,
+ BitAnd,
+ BitOr,
+ BitXor,
+ Shr,
+ Shl
+ ) {
+ span_lint_and_then(
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) {
- 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));
- });
+ 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_with_applicability(
+ expr.span,
+ "replace it with",
+ format!("{} {}= {}", snip_a, op.node.as_str(), snip_r),
+ Applicability::Unspecified,
+ );
+ }
+ },
+ );
}
};
- // a = a op b
- if SpanlessEq::new(cx).ignore_fn().eq_expr(assignee, l) {
- lint(assignee, r);
- }
- // 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 => {
- lint(assignee, l);
- },
- _ => {},
+
+ let mut visitor = ExprVisitor {
+ assignee,
+ counter: 0,
+ cx,
+ };
+
+ walk_expr(&mut visitor, e);
+
+ if visitor.counter == 1 {
+ // a = a op b
+ if SpanlessEq::new(cx).ignore_fn().eq_expr(assignee, l) {
+ lint(assignee, r);
+ }
+ // a = b commutative_op a
+ if SpanlessEq::new(cx).ignore_fn().eq_expr(assignee, r) {
+ match op.node {
+ hir::BinOpKind::Add
+ | hir::BinOpKind::Mul
+ | hir::BinOpKind::And
+ | hir::BinOpKind::Or
+ | hir::BinOpKind::BitXor
+ | hir::BinOpKind::BitAnd
+ | hir::BinOpKind::BitOr => {
+ lint(assignee, l);
+ },
+ _ => {},
+ }
}
}
}
}
}
-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,
+ }
+}
+
+struct ExprVisitor<'a, 'tcx: 'a> {
+ assignee: &'a hir::Expr,
+ 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) {
+ 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> {
+ NestedVisitorMap::None
}
}
projects / rust.git / blobdiff