Rollup merge of #138017 - nnethercote:tighten-assignment-op, r=spastorino

Tighten up assignment operator representations.

This is step 3 of [MCP 831](https://github.com/rust-lang/compiler-team/issues/831).

r? `@spastorino`

13 files changed, 62 insertions, 35 deletions

diff --git a/src/tools/clippy/clippy_lints/src/format_push_string.rs b/src/tools/clippy/clippy_lints/src/format_push_string.rs
index 68cc50f3939..b64d608c0c7 100644
--- a/src/tools/clippy/clippy_lints/src/format_push_string.rs
+++ b/src/tools/clippy/clippy_lints/src/format_push_string.rs
@@ -1,7 +1,7 @@
 use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::higher;
 use clippy_utils::ty::is_type_lang_item;
-use rustc_hir::{BinOpKind, Expr, ExprKind, LangItem, MatchSource};
+use rustc_hir::{AssignOpKind, Expr, ExprKind, LangItem, MatchSource};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::declare_lint_pass;
 use rustc_span::sym;
@@ -77,7 +77,7 @@ impl<'tcx> LateLintPass<'tcx> for FormatPushString {
                     return;
                 }
             },
-            ExprKind::AssignOp(op, left, arg) if op.node == BinOpKind::Add && is_string(cx, left) => arg,
+            ExprKind::AssignOp(op, left, arg) if op.node == AssignOpKind::AddAssign && is_string(cx, left) => arg,
             _ => return,
         };
         if is_format(cx, arg) {
diff --git a/src/tools/clippy/clippy_lints/src/implicit_saturating_add.rs b/src/tools/clippy/clippy_lints/src/implicit_saturating_add.rs
index 41d2b18803d..185fc2aa2d4 100644
--- a/src/tools/clippy/clippy_lints/src/implicit_saturating_add.rs
+++ b/src/tools/clippy/clippy_lints/src/implicit_saturating_add.rs
@@ -5,7 +5,7 @@ use clippy_utils::source::snippet_with_context;
 use rustc_ast::ast::{LitIntType, LitKind};
 use rustc_data_structures::packed::Pu128;
 use rustc_errors::Applicability;
-use rustc_hir::{BinOpKind, Block, Expr, ExprKind, Stmt, StmtKind};
+use rustc_hir::{AssignOpKind, BinOpKind, Block, Expr, ExprKind, Stmt, StmtKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::{IntTy, Ty, UintTy};
 use rustc_session::declare_lint_pass;
@@ -68,7 +68,7 @@ impl<'tcx> LateLintPass<'tcx> for ImplicitSaturatingAdd {
             && ex.span.ctxt() == ctxt
             && expr1.span.ctxt() == ctxt
             && clippy_utils::SpanlessEq::new(cx).eq_expr(l, target)
-            && BinOpKind::Add == op1.node
+            && AssignOpKind::AddAssign == op1.node
             && let ExprKind::Lit(lit) = value.kind
             && let LitKind::Int(Pu128(1), LitIntType::Unsuffixed) = lit.node
             && block.expr.is_none()
diff --git a/src/tools/clippy/clippy_lints/src/implicit_saturating_sub.rs b/src/tools/clippy/clippy_lints/src/implicit_saturating_sub.rs
index cbc3e2ccd5b..5d7d3ae3f24 100644
--- a/src/tools/clippy/clippy_lints/src/implicit_saturating_sub.rs
+++ b/src/tools/clippy/clippy_lints/src/implicit_saturating_sub.rs
@@ -8,7 +8,7 @@ use clippy_utils::{
 use rustc_ast::ast::LitKind;
 use rustc_data_structures::packed::Pu128;
 use rustc_errors::Applicability;
-use rustc_hir::{BinOp, BinOpKind, Expr, ExprKind, QPath};
+use rustc_hir::{AssignOpKind, BinOp, BinOpKind, Expr, ExprKind, QPath};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::impl_lint_pass;
 use rustc_span::Span;
@@ -366,7 +366,7 @@ fn subtracts_one<'a>(cx: &LateContext<'_>, expr: &'a Expr<'a>) -> Option<&'a Exp
     match peel_blocks_with_stmt(expr).kind {
         ExprKind::AssignOp(ref op1, target, value) => {
             // Check if literal being subtracted is one
-            (BinOpKind::Sub == op1.node && is_integer_literal(value, 1)).then_some(target)
+            (AssignOpKind::SubAssign == op1.node && is_integer_literal(value, 1)).then_some(target)
         },
         ExprKind::Assign(target, value, _) => {
             if let ExprKind::Binary(ref op1, left1, right1) = value.kind
diff --git a/src/tools/clippy/clippy_lints/src/loops/utils.rs b/src/tools/clippy/clippy_lints/src/loops/utils.rs
index a5185d38e7c..3c6fbef2bda 100644
--- a/src/tools/clippy/clippy_lints/src/loops/utils.rs
+++ b/src/tools/clippy/clippy_lints/src/loops/utils.rs
@@ -3,7 +3,9 @@ use clippy_utils::{get_parent_expr, is_integer_const, path_to_local, path_to_loc
 use rustc_ast::ast::{LitIntType, LitKind};
 use rustc_errors::Applicability;
 use rustc_hir::intravisit::{Visitor, walk_expr, walk_local};
-use rustc_hir::{BinOpKind, BorrowKind, Expr, ExprKind, HirId, HirIdMap, LetStmt, Mutability, PatKind};
+use rustc_hir::{
+    AssignOpKind, BorrowKind, Expr, ExprKind, HirId, HirIdMap, LetStmt, Mutability, PatKind
+};
 use rustc_lint::LateContext;
 use rustc_middle::hir::nested_filter;
 use rustc_middle::ty::{self, Ty};
@@ -58,7 +60,7 @@ impl<'tcx> Visitor<'tcx> for IncrementVisitor<'_, 'tcx> {
                 match parent.kind {
                     ExprKind::AssignOp(op, lhs, rhs) => {
                         if lhs.hir_id == expr.hir_id {
-                            *state = if op.node == BinOpKind::Add
+                            *state = if op.node == AssignOpKind::AddAssign
                                 && is_integer_const(self.cx, rhs, 1)
                                 && *state == IncrementVisitorVarState::Initial
                                 && self.depth == 0
diff --git a/src/tools/clippy/clippy_lints/src/missing_asserts_for_indexing.rs b/src/tools/clippy/clippy_lints/src/missing_asserts_for_indexing.rs
index d78299fe08b..cdd6f4e5b03 100644
--- a/src/tools/clippy/clippy_lints/src/missing_asserts_for_indexing.rs
+++ b/src/tools/clippy/clippy_lints/src/missing_asserts_for_indexing.rs
@@ -10,7 +10,7 @@ use rustc_ast::{LitKind, RangeLimits};
 use rustc_data_structures::packed::Pu128;
 use rustc_data_structures::unhash::UnindexMap;
 use rustc_errors::{Applicability, Diag};
-use rustc_hir::{BinOp, Block, Body, Expr, ExprKind, UnOp};
+use rustc_hir::{BinOpKind, Block, Body, Expr, ExprKind, UnOp};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::declare_lint_pass;
 use rustc_span::source_map::Spanned;
@@ -97,7 +97,7 @@ enum LengthComparison {
 ///
 /// E.g. for `v.len() > 5` this returns `Some((LengthComparison::IntLessThanLength, 5, v.len()))`
 fn len_comparison<'hir>(
-    bin_op: BinOp,
+    bin_op: BinOpKind,
     left: &'hir Expr<'hir>,
     right: &'hir Expr<'hir>,
 ) -> Option<(LengthComparison, usize, &'hir Expr<'hir>)> {
@@ -112,7 +112,7 @@ fn len_comparison<'hir>(
 
     // normalize comparison, `v.len() > 4` becomes `4 < v.len()`
     // this simplifies the logic a bit
-    let (op, left, right) = normalize_comparison(bin_op.node, left, right)?;
+    let (op, left, right) = normalize_comparison(bin_op, left, right)?;
     match (op, left.kind, right.kind) {
         (Rel::Lt, int_lit_pat!(left), _) => Some((LengthComparison::IntLessThanLength, left as usize, right)),
         (Rel::Lt, _, int_lit_pat!(right)) => Some((LengthComparison::LengthLessThanInt, right as usize, left)),
@@ -138,7 +138,7 @@ fn assert_len_expr<'hir>(
         && let ExprKind::Unary(UnOp::Not, condition) = &cond.kind
         && let ExprKind::Binary(bin_op, left, right) = &condition.kind
 
-        && let Some((cmp, asserted_len, slice_len)) = len_comparison(*bin_op, left, right)
+        && let Some((cmp, asserted_len, slice_len)) = len_comparison(bin_op.node, left, right)
         && let ExprKind::MethodCall(method, recv, [], _) = &slice_len.kind
         && cx.typeck_results().expr_ty_adjusted(recv).peel_refs().is_slice()
         && method.ident.name == sym::len
diff --git a/src/tools/clippy/clippy_lints/src/mixed_read_write_in_expression.rs b/src/tools/clippy/clippy_lints/src/mixed_read_write_in_expression.rs
index be728e6c8b7..fbd287f5285 100644
--- a/src/tools/clippy/clippy_lints/src/mixed_read_write_in_expression.rs
+++ b/src/tools/clippy/clippy_lints/src/mixed_read_write_in_expression.rs
@@ -261,10 +261,11 @@ fn check_expr<'tcx>(vis: &mut ReadVisitor<'_, 'tcx>, expr: &'tcx Expr<'_>) -> St
         | ExprKind::Assign(..)
         | ExprKind::Index(..)
         | ExprKind::Repeat(_, _)
-        | ExprKind::Struct(_, _, _) => {
+        | ExprKind::Struct(_, _, _)
+        | ExprKind::AssignOp(_, _, _) => {
             walk_expr(vis, expr);
         },
-        ExprKind::Binary(op, _, _) | ExprKind::AssignOp(op, _, _) => {
+        ExprKind::Binary(op, _, _) => {
             if op.node == BinOpKind::And || op.node == BinOpKind::Or {
                 // x && y and x || y always evaluate x first, so these are
                 // strictly sequenced.
diff --git a/src/tools/clippy/clippy_lints/src/operators/arithmetic_side_effects.rs b/src/tools/clippy/clippy_lints/src/operators/arithmetic_side_effects.rs
index 08fcd17e555..a78a342d4fe 100644
--- a/src/tools/clippy/clippy_lints/src/operators/arithmetic_side_effects.rs
+++ b/src/tools/clippy/clippy_lints/src/operators/arithmetic_side_effects.rs
@@ -335,9 +335,12 @@ impl<'tcx> LateLintPass<'tcx> for ArithmeticSideEffects {
             return;
         }
         match &expr.kind {
-            hir::ExprKind::AssignOp(op, lhs, rhs) | hir::ExprKind::Binary(op, lhs, rhs) => {
+            hir::ExprKind::Binary(op, lhs, rhs) => {
                 self.manage_bin_ops(cx, expr, op.node, lhs, rhs);
             },
+            hir::ExprKind::AssignOp(op, lhs, rhs) => {
+                self.manage_bin_ops(cx, expr, op.node.into(), lhs, rhs);
+            },
             hir::ExprKind::MethodCall(ps, receiver, args, _) => {
                 self.manage_method_call(args, cx, expr, ps, receiver);
             },
diff --git a/src/tools/clippy/clippy_lints/src/operators/mod.rs b/src/tools/clippy/clippy_lints/src/operators/mod.rs
index f758d08d366..d32c062cf56 100644
--- a/src/tools/clippy/clippy_lints/src/operators/mod.rs
+++ b/src/tools/clippy/clippy_lints/src/operators/mod.rs
@@ -913,9 +913,10 @@ impl<'tcx> LateLintPass<'tcx> for Operators {
                 );
             },
             ExprKind::AssignOp(op, lhs, rhs) => {
-                self.arithmetic_context.check_binary(cx, e, op.node, lhs, rhs);
-                misrefactored_assign_op::check(cx, e, op.node, lhs, rhs);
-                modulo_arithmetic::check(cx, e, op.node, lhs, rhs, false);
+                let bin_op = op.node.into();
+                self.arithmetic_context.check_binary(cx, e, bin_op, lhs, rhs);
+                misrefactored_assign_op::check(cx, e, bin_op, lhs, rhs);
+                modulo_arithmetic::check(cx, e, bin_op, lhs, rhs, false);
             },
             ExprKind::Assign(lhs, rhs, _) => {
                 assign_op_pattern::check(cx, e, lhs, rhs);
diff --git a/src/tools/clippy/clippy_lints/src/suspicious_trait_impl.rs b/src/tools/clippy/clippy_lints/src/suspicious_trait_impl.rs
index fb426e91bf0..56bd8fefdb4 100644
--- a/src/tools/clippy/clippy_lints/src/suspicious_trait_impl.rs
+++ b/src/tools/clippy/clippy_lints/src/suspicious_trait_impl.rs
@@ -5,6 +5,7 @@ use core::ops::ControlFlow;
 use rustc_hir as hir;
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::declare_lint_pass;
+use rustc_span::Span;
 
 declare_clippy_lint! {
     /// ### What it does
@@ -56,8 +57,27 @@ declare_lint_pass!(SuspiciousImpl => [SUSPICIOUS_ARITHMETIC_IMPL, SUSPICIOUS_OP_
 
 impl<'tcx> LateLintPass<'tcx> for SuspiciousImpl {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) {
-        if let hir::ExprKind::Binary(binop, _, _) | hir::ExprKind::AssignOp(binop, ..) = expr.kind
-            && let Some((binop_trait_lang, op_assign_trait_lang)) = binop_traits(binop.node)
+        match expr.kind {
+            hir::ExprKind::Binary(op, _, _) => {
+                self.check_expr_inner(cx, expr, op.node, op.span);
+            }
+            hir::ExprKind::AssignOp(op, _, _) => {
+                self.check_expr_inner(cx, expr, op.node.into(), op.span);
+            }
+            _ => {}
+        }
+    }
+}
+
+impl<'tcx> SuspiciousImpl {
+    fn check_expr_inner(
+        &mut self,
+        cx: &LateContext<'tcx>,
+        expr: &'tcx hir::Expr<'_>,
+        binop: hir::BinOpKind,
+        span: Span,
+    ) {
+        if let Some((binop_trait_lang, op_assign_trait_lang)) = binop_traits(binop)
             && let Some(binop_trait_id) = cx.tcx.lang_items().get(binop_trait_lang)
             && let Some(op_assign_trait_id) = cx.tcx.lang_items().get(op_assign_trait_lang)
 
@@ -82,10 +102,10 @@ impl<'tcx> LateLintPass<'tcx> for SuspiciousImpl {
             span_lint(
                 cx,
                 lint,
-                binop.span,
+                span,
                 format!(
                     "suspicious use of `{}` in `{}` impl",
-                    binop.node.as_str(),
+                    binop.as_str(),
                     cx.tcx.item_name(trait_id)
                 ),
             );
diff --git a/src/tools/clippy/clippy_lints/src/swap.rs b/src/tools/clippy/clippy_lints/src/swap.rs
index 7176d533b61..0337b74b4b1 100644
--- a/src/tools/clippy/clippy_lints/src/swap.rs
+++ b/src/tools/clippy/clippy_lints/src/swap.rs
@@ -10,7 +10,7 @@ use rustc_data_structures::fx::FxIndexSet;
 use rustc_hir::intravisit::{Visitor, walk_expr};
 
 use rustc_errors::Applicability;
-use rustc_hir::{BinOpKind, Block, Expr, ExprKind, LetStmt, PatKind, QPath, Stmt, StmtKind};
+use rustc_hir::{AssignOpKind, Block, Expr, ExprKind, LetStmt, PatKind, QPath, Stmt, StmtKind};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::ty;
 use rustc_session::declare_lint_pass;
@@ -307,7 +307,7 @@ fn extract_sides_of_xor_assign<'a, 'hir>(
     if let StmtKind::Semi(expr) = stmt.kind
         && let ExprKind::AssignOp(
             Spanned {
-                node: BinOpKind::BitXor,
+                node: AssignOpKind::BitXorAssign,
                 ..
             },
             lhs,
diff --git a/src/tools/clippy/clippy_utils/src/consts.rs b/src/tools/clippy/clippy_utils/src/consts.rs
index dd149c4a29b..17751e824c0 100644
--- a/src/tools/clippy/clippy_utils/src/consts.rs
+++ b/src/tools/clippy/clippy_utils/src/consts.rs
@@ -15,7 +15,7 @@ use rustc_apfloat::ieee::{Half, Quad};
 use rustc_ast::ast::{self, LitFloatType, LitKind};
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::{
-    BinOp, BinOpKind, Block, ConstBlock, Expr, ExprKind, HirId, Item, ItemKind, Node, PatExpr, PatExprKind, QPath, UnOp,
+    BinOpKind, Block, ConstBlock, Expr, ExprKind, HirId, Item, ItemKind, Node, PatExpr, PatExprKind, QPath, UnOp,
 };
 use rustc_lexer::tokenize;
 use rustc_lint::LateContext;
@@ -506,7 +506,7 @@ impl<'tcx> ConstEvalCtxt<'tcx> {
                 UnOp::Deref => Some(if let Constant::Ref(r) = o { *r } else { o }),
             }),
             ExprKind::If(cond, then, ref otherwise) => self.ifthenelse(cond, then, *otherwise),
-            ExprKind::Binary(op, left, right) => self.binop(op, left, right),
+            ExprKind::Binary(op, left, right) => self.binop(op.node, left, right),
             ExprKind::Call(callee, []) => {
                 // We only handle a few const functions for now.
                 if let ExprKind::Path(qpath) = &callee.kind
@@ -744,7 +744,7 @@ impl<'tcx> ConstEvalCtxt<'tcx> {
         }
     }
 
-    fn binop(&self, op: BinOp, left: &Expr<'_>, right: &Expr<'_>) -> Option<Constant<'tcx>> {
+    fn binop(&self, op: BinOpKind, left: &Expr<'_>, right: &Expr<'_>) -> Option<Constant<'tcx>> {
         let l = self.expr(left)?;
         let r = self.expr(right);
         match (l, r) {
@@ -757,7 +757,7 @@ impl<'tcx> ConstEvalCtxt<'tcx> {
 
                     // Using / or %, where the left-hand argument is the smallest integer of a signed integer type and
                     // the right-hand argument is -1 always panics, even with overflow-checks disabled
-                    if let BinOpKind::Div | BinOpKind::Rem = op.node
+                    if let BinOpKind::Div | BinOpKind::Rem = op
                         && l == ty_min_value
                         && r == -1
                     {
@@ -765,7 +765,7 @@ impl<'tcx> ConstEvalCtxt<'tcx> {
                     }
 
                     let zext = |n: i128| Constant::Int(unsext(self.tcx, n, ity));
-                    match op.node {
+                    match op {
                         // When +, * or binary - create a value greater than the maximum value, or less than
                         // the minimum value that can be stored, it panics.
                         BinOpKind::Add => l.checked_add(r).and_then(|n| ity.ensure_fits(n)).map(zext),
@@ -792,7 +792,7 @@ impl<'tcx> ConstEvalCtxt<'tcx> {
                 ty::Uint(ity) => {
                     let bits = ity.bits();
 
-                    match op.node {
+                    match op {
                         BinOpKind::Add => l.checked_add(r).and_then(|n| ity.ensure_fits(n)).map(Constant::Int),
                         BinOpKind::Sub => l.checked_sub(r).and_then(|n| ity.ensure_fits(n)).map(Constant::Int),
                         BinOpKind::Mul => l.checked_mul(r).and_then(|n| ity.ensure_fits(n)).map(Constant::Int),
@@ -815,7 +815,7 @@ impl<'tcx> ConstEvalCtxt<'tcx> {
                 _ => None,
             },
             // FIXME(f16_f128): add these types when binary operations are available on all platforms
-            (Constant::F32(l), Some(Constant::F32(r))) => match op.node {
+            (Constant::F32(l), Some(Constant::F32(r))) => match op {
                 BinOpKind::Add => Some(Constant::F32(l + r)),
                 BinOpKind::Sub => Some(Constant::F32(l - r)),
                 BinOpKind::Mul => Some(Constant::F32(l * r)),
@@ -829,7 +829,7 @@ impl<'tcx> ConstEvalCtxt<'tcx> {
                 BinOpKind::Gt => Some(Constant::Bool(l > r)),
                 _ => None,
             },
-            (Constant::F64(l), Some(Constant::F64(r))) => match op.node {
+            (Constant::F64(l), Some(Constant::F64(r))) => match op {
                 BinOpKind::Add => Some(Constant::F64(l + r)),
                 BinOpKind::Sub => Some(Constant::F64(l - r)),
                 BinOpKind::Mul => Some(Constant::F64(l * r)),
@@ -843,7 +843,7 @@ impl<'tcx> ConstEvalCtxt<'tcx> {
                 BinOpKind::Gt => Some(Constant::Bool(l > r)),
                 _ => None,
             },
-            (l, r) => match (op.node, l, r) {
+            (l, r) => match (op, l, r) {
                 (BinOpKind::And, Constant::Bool(false), _) => Some(Constant::Bool(false)),
                 (BinOpKind::Or, Constant::Bool(true), _) => Some(Constant::Bool(true)),
                 (BinOpKind::And, Constant::Bool(true), Some(r)) | (BinOpKind::Or, Constant::Bool(false), Some(r)) => {
diff --git a/src/tools/clippy/clippy_utils/src/sugg.rs b/src/tools/clippy/clippy_utils/src/sugg.rs
index 065d48119a2..e92c0c79b25 100644
--- a/src/tools/clippy/clippy_utils/src/sugg.rs
+++ b/src/tools/clippy/clippy_utils/src/sugg.rs
@@ -357,7 +357,7 @@ fn binop_to_string(op: AssocOp, lhs: &str, rhs: &str) -> String {
     match op {
         AssocOp::Binary(op) => format!("{lhs} {} {rhs}", op.as_str()),
         AssocOp::Assign => format!("{lhs} = {rhs}"),
-        AssocOp::AssignOp(op) => format!("{lhs} {}= {rhs}", op.as_str()),
+        AssocOp::AssignOp(op) => format!("{lhs} {} {rhs}", op.as_str()),
         AssocOp::Cast => format!("{lhs} as {rhs}"),
         AssocOp::Range(limits) => format!("{lhs}{}{rhs}", limits.as_str()),
     }
diff --git a/src/tools/rustfmt/src/expr.rs b/src/tools/rustfmt/src/expr.rs
index 65120770edd..be6b483bfff 100644
--- a/src/tools/rustfmt/src/expr.rs
+++ b/src/tools/rustfmt/src/expr.rs
@@ -2058,7 +2058,7 @@ fn rewrite_assignment(
     context: &RewriteContext<'_>,
     lhs: &ast::Expr,
     rhs: &ast::Expr,
-    op: Option<&ast::BinOp>,
+    op: Option<&ast::AssignOp>,
     shape: Shape,
 ) -> RewriteResult {
     let operator_str = match op {