Rollup merge of #118394 - nnethercote:rm-hir-Ops, r=cjgillot

Remove HIR opkinds

`hir::BinOp`, `hir::BinOpKind`, and `hir::UnOp` are identical to `ast::BinOp`, `ast::BinOpKind`, and `ast::UnOp`, respectively. This seems silly, so this PR removes the HIR ones. (A re-export lets the AST ones be referred to using a `hir::` qualifier, which avoids renaming churn.)

r? `@cjgillot`

12 files changed, 42 insertions, 202 deletions

diff --git a/compiler/rustc_ast/src/ast.rs b/compiler/rustc_ast/src/ast.rs
index 10776f31c07..2b56e9f3a86 100644
--- a/compiler/rustc_ast/src/ast.rs
+++ b/compiler/rustc_ast/src/ast.rs
@@ -817,7 +817,7 @@ pub enum BorrowKind {
     Raw,
 }
 
-#[derive(Clone, PartialEq, Encodable, Decodable, Debug, Copy)]
+#[derive(Clone, Copy, Debug, PartialEq, Encodable, Decodable, HashStable_Generic)]
 pub enum BinOpKind {
     /// The `+` operator (addition)
     Add,
@@ -858,9 +858,9 @@ pub enum BinOpKind {
 }
 
 impl BinOpKind {
-    pub fn to_string(&self) -> &'static str {
+    pub fn as_str(&self) -> &'static str {
         use BinOpKind::*;
-        match *self {
+        match self {
             Add => "+",
             Sub => "-",
             Mul => "*",
@@ -881,19 +881,25 @@ impl BinOpKind {
             Gt => ">",
         }
     }
-    pub fn lazy(&self) -> bool {
+
+    pub fn is_lazy(&self) -> bool {
         matches!(self, BinOpKind::And | BinOpKind::Or)
     }
 
     pub fn is_comparison(&self) -> bool {
         use BinOpKind::*;
-        // Note for developers: please keep this as is;
+        // Note for developers: please keep this match exhaustive;
         // we want compilation to fail if another variant is added.
         match *self {
             Eq | Lt | Le | Ne | Gt | Ge => true,
             And | Or | Add | Sub | Mul | Div | Rem | BitXor | BitAnd | BitOr | Shl | Shr => false,
         }
     }
+
+    /// Returns `true` if the binary operator takes its arguments by value.
+    pub fn is_by_value(self) -> bool {
+        !self.is_comparison()
+    }
 }
 
 pub type BinOp = Spanned<BinOpKind>;
@@ -901,7 +907,7 @@ pub type BinOp = Spanned<BinOpKind>;
 /// Unary operator.
 ///
 /// Note that `&data` is not an operator, it's an `AddrOf` expression.
-#[derive(Clone, Encodable, Decodable, Debug, Copy)]
+#[derive(Clone, Copy, Debug, PartialEq, Encodable, Decodable, HashStable_Generic)]
 pub enum UnOp {
     /// The `*` operator for dereferencing
     Deref,
@@ -912,13 +918,18 @@ pub enum UnOp {
 }
 
 impl UnOp {
-    pub fn to_string(op: UnOp) -> &'static str {
-        match op {
+    pub fn as_str(&self) -> &'static str {
+        match self {
             UnOp::Deref => "*",
             UnOp::Not => "!",
             UnOp::Neg => "-",
         }
     }
+
+    /// Returns `true` if the unary operator takes its argument by value.
+    pub fn is_by_value(self) -> bool {
+        matches!(self, Self::Neg | Self::Not)
+    }
 }
 
 /// A statement
diff --git a/compiler/rustc_ast_lowering/src/expr.rs b/compiler/rustc_ast_lowering/src/expr.rs
index 180459efef9..5de775bef48 100644
--- a/compiler/rustc_ast_lowering/src/expr.rs
+++ b/compiler/rustc_ast_lowering/src/expr.rs
@@ -350,30 +350,8 @@ impl<'hir> LoweringContext<'_, 'hir> {
         }
     }
 
-    fn lower_binop(&mut self, b: BinOp) -> hir::BinOp {
-        Spanned {
-            node: match b.node {
-                BinOpKind::Add => hir::BinOpKind::Add,
-                BinOpKind::Sub => hir::BinOpKind::Sub,
-                BinOpKind::Mul => hir::BinOpKind::Mul,
-                BinOpKind::Div => hir::BinOpKind::Div,
-                BinOpKind::Rem => hir::BinOpKind::Rem,
-                BinOpKind::And => hir::BinOpKind::And,
-                BinOpKind::Or => hir::BinOpKind::Or,
-                BinOpKind::BitXor => hir::BinOpKind::BitXor,
-                BinOpKind::BitAnd => hir::BinOpKind::BitAnd,
-                BinOpKind::BitOr => hir::BinOpKind::BitOr,
-                BinOpKind::Shl => hir::BinOpKind::Shl,
-                BinOpKind::Shr => hir::BinOpKind::Shr,
-                BinOpKind::Eq => hir::BinOpKind::Eq,
-                BinOpKind::Lt => hir::BinOpKind::Lt,
-                BinOpKind::Le => hir::BinOpKind::Le,
-                BinOpKind::Ne => hir::BinOpKind::Ne,
-                BinOpKind::Ge => hir::BinOpKind::Ge,
-                BinOpKind::Gt => hir::BinOpKind::Gt,
-            },
-            span: self.lower_span(b.span),
-        }
+    fn lower_binop(&mut self, b: BinOp) -> BinOp {
+        Spanned { node: b.node, span: self.lower_span(b.span) }
     }
 
     fn lower_legacy_const_generics(
diff --git a/compiler/rustc_ast_pretty/src/pprust/state/expr.rs b/compiler/rustc_ast_pretty/src/pprust/state/expr.rs
index ed9b68a1d5a..45a55e20ca7 100644
--- a/compiler/rustc_ast_pretty/src/pprust/state/expr.rs
+++ b/compiler/rustc_ast_pretty/src/pprust/state/expr.rs
@@ -255,12 +255,12 @@ impl<'a> State<'a> {
 
         self.print_expr_maybe_paren(lhs, left_prec);
         self.space();
-        self.word_space(op.node.to_string());
+        self.word_space(op.node.as_str());
         self.print_expr_maybe_paren(rhs, right_prec)
     }
 
     fn print_expr_unary(&mut self, op: ast::UnOp, expr: &ast::Expr) {
-        self.word(ast::UnOp::to_string(op));
+        self.word(op.as_str());
         self.print_expr_maybe_paren(expr, parser::PREC_PREFIX)
     }
 
@@ -470,7 +470,7 @@ impl<'a> State<'a> {
                 let prec = AssocOp::Assign.precedence() as i8;
                 self.print_expr_maybe_paren(lhs, prec + 1);
                 self.space();
-                self.word(op.node.to_string());
+                self.word(op.node.as_str());
                 self.word_space("=");
                 self.print_expr_maybe_paren(rhs, prec);
             }
diff --git a/compiler/rustc_hir/src/hir.rs b/compiler/rustc_hir/src/hir.rs
index d2b83d0eb00..bd6eba37547 100644
--- a/compiler/rustc_hir/src/hir.rs
+++ b/compiler/rustc_hir/src/hir.rs
@@ -7,8 +7,8 @@ use crate::LangItem;
 use rustc_ast as ast;
 use rustc_ast::util::parser::ExprPrecedence;
 use rustc_ast::{Attribute, FloatTy, IntTy, Label, LitKind, TraitObjectSyntax, UintTy};
-pub use rustc_ast::{BindingAnnotation, BorrowKind, ByRef, ImplPolarity, IsAuto};
-pub use rustc_ast::{CaptureBy, Movability, Mutability};
+pub use rustc_ast::{BinOp, BinOpKind, BindingAnnotation, BorrowKind, ByRef, CaptureBy};
+pub use rustc_ast::{ImplPolarity, IsAuto, Movability, Mutability, UnOp};
 use rustc_ast::{InlineAsmOptions, InlineAsmTemplatePiece};
 use rustc_data_structures::fingerprint::Fingerprint;
 use rustc_data_structures::fx::FxHashMap;
@@ -1174,155 +1174,6 @@ pub enum PatKind<'hir> {
     Slice(&'hir [Pat<'hir>], Option<&'hir Pat<'hir>>, &'hir [Pat<'hir>]),
 }
 
-#[derive(Copy, Clone, PartialEq, Debug, HashStable_Generic)]
-pub enum BinOpKind {
-    /// The `+` operator (addition).
-    Add,
-    /// The `-` operator (subtraction).
-    Sub,
-    /// The `*` operator (multiplication).
-    Mul,
-    /// The `/` operator (division).
-    Div,
-    /// The `%` operator (modulus).
-    Rem,
-    /// The `&&` operator (logical and).
-    And,
-    /// The `||` operator (logical or).
-    Or,
-    /// The `^` operator (bitwise xor).
-    BitXor,
-    /// The `&` operator (bitwise and).
-    BitAnd,
-    /// The `|` operator (bitwise or).
-    BitOr,
-    /// The `<<` operator (shift left).
-    Shl,
-    /// The `>>` operator (shift right).
-    Shr,
-    /// The `==` operator (equality).
-    Eq,
-    /// The `<` operator (less than).
-    Lt,
-    /// The `<=` operator (less than or equal to).
-    Le,
-    /// The `!=` operator (not equal to).
-    Ne,
-    /// The `>=` operator (greater than or equal to).
-    Ge,
-    /// The `>` operator (greater than).
-    Gt,
-}
-
-impl BinOpKind {
-    pub fn as_str(self) -> &'static str {
-        match self {
-            BinOpKind::Add => "+",
-            BinOpKind::Sub => "-",
-            BinOpKind::Mul => "*",
-            BinOpKind::Div => "/",
-            BinOpKind::Rem => "%",
-            BinOpKind::And => "&&",
-            BinOpKind::Or => "||",
-            BinOpKind::BitXor => "^",
-            BinOpKind::BitAnd => "&",
-            BinOpKind::BitOr => "|",
-            BinOpKind::Shl => "<<",
-            BinOpKind::Shr => ">>",
-            BinOpKind::Eq => "==",
-            BinOpKind::Lt => "<",
-            BinOpKind::Le => "<=",
-            BinOpKind::Ne => "!=",
-            BinOpKind::Ge => ">=",
-            BinOpKind::Gt => ">",
-        }
-    }
-
-    pub fn is_lazy(self) -> bool {
-        matches!(self, BinOpKind::And | BinOpKind::Or)
-    }
-
-    pub fn is_comparison(self) -> bool {
-        match self {
-            BinOpKind::Eq
-            | BinOpKind::Lt
-            | BinOpKind::Le
-            | BinOpKind::Ne
-            | BinOpKind::Gt
-            | BinOpKind::Ge => true,
-            BinOpKind::And
-            | BinOpKind::Or
-            | BinOpKind::Add
-            | BinOpKind::Sub
-            | BinOpKind::Mul
-            | BinOpKind::Div
-            | BinOpKind::Rem
-            | BinOpKind::BitXor
-            | BinOpKind::BitAnd
-            | BinOpKind::BitOr
-            | BinOpKind::Shl
-            | BinOpKind::Shr => false,
-        }
-    }
-
-    /// Returns `true` if the binary operator takes its arguments by value.
-    pub fn is_by_value(self) -> bool {
-        !self.is_comparison()
-    }
-}
-
-impl Into<ast::BinOpKind> for BinOpKind {
-    fn into(self) -> ast::BinOpKind {
-        match self {
-            BinOpKind::Add => ast::BinOpKind::Add,
-            BinOpKind::Sub => ast::BinOpKind::Sub,
-            BinOpKind::Mul => ast::BinOpKind::Mul,
-            BinOpKind::Div => ast::BinOpKind::Div,
-            BinOpKind::Rem => ast::BinOpKind::Rem,
-            BinOpKind::And => ast::BinOpKind::And,
-            BinOpKind::Or => ast::BinOpKind::Or,
-            BinOpKind::BitXor => ast::BinOpKind::BitXor,
-            BinOpKind::BitAnd => ast::BinOpKind::BitAnd,
-            BinOpKind::BitOr => ast::BinOpKind::BitOr,
-            BinOpKind::Shl => ast::BinOpKind::Shl,
-            BinOpKind::Shr => ast::BinOpKind::Shr,
-            BinOpKind::Eq => ast::BinOpKind::Eq,
-            BinOpKind::Lt => ast::BinOpKind::Lt,
-            BinOpKind::Le => ast::BinOpKind::Le,
-            BinOpKind::Ne => ast::BinOpKind::Ne,
-            BinOpKind::Ge => ast::BinOpKind::Ge,
-            BinOpKind::Gt => ast::BinOpKind::Gt,
-        }
-    }
-}
-
-pub type BinOp = Spanned<BinOpKind>;
-
-#[derive(Copy, Clone, PartialEq, Debug, HashStable_Generic)]
-pub enum UnOp {
-    /// The `*` operator (dereferencing).
-    Deref,
-    /// The `!` operator (logical negation).
-    Not,
-    /// The `-` operator (negation).
-    Neg,
-}
-
-impl UnOp {
-    pub fn as_str(self) -> &'static str {
-        match self {
-            Self::Deref => "*",
-            Self::Not => "!",
-            Self::Neg => "-",
-        }
-    }
-
-    /// Returns `true` if the unary operator takes its argument by value.
-    pub fn is_by_value(self) -> bool {
-        matches!(self, Self::Neg | Self::Not)
-    }
-}
-
 /// A statement.
 #[derive(Debug, Clone, Copy, HashStable_Generic)]
 pub struct Stmt<'hir> {
diff --git a/compiler/rustc_lint/src/unused.rs b/compiler/rustc_lint/src/unused.rs
index b4535c72d6c..a7a4709e887 100644
--- a/compiler/rustc_lint/src/unused.rs
+++ b/compiler/rustc_lint/src/unused.rs
@@ -656,7 +656,7 @@ trait UnusedDelimLint {
     ) -> bool {
         if followed_by_else {
             match inner.kind {
-                ast::ExprKind::Binary(op, ..) if op.node.lazy() => return true,
+                ast::ExprKind::Binary(op, ..) if op.node.is_lazy() => return true,
                 _ if classify::expr_trailing_brace(inner).is_some() => return true,
                 _ => {}
             }
@@ -1016,7 +1016,7 @@ impl UnusedDelimLint for UnusedParens {
                                 rustc_span::source_map::Spanned { node, .. },
                                 _,
                                 _,
-                            ) if node.lazy()))
+                            ) if node.is_lazy()))
                 {
                     self.emit_unused_delims_expr(cx, value, ctx, left_pos, right_pos, is_kw)
                 }
diff --git a/compiler/rustc_parse/src/parser/stmt.rs b/compiler/rustc_parse/src/parser/stmt.rs
index 620ba4a3cb3..1ee5a96d5dc 100644
--- a/compiler/rustc_parse/src/parser/stmt.rs
+++ b/compiler/rustc_parse/src/parser/stmt.rs
@@ -384,10 +384,10 @@ impl<'a> Parser<'a> {
 
     fn check_let_else_init_bool_expr(&self, init: &ast::Expr) {
         if let ast::ExprKind::Binary(op, ..) = init.kind {
-            if op.node.lazy() {
+            if op.node.is_lazy() {
                 self.sess.emit_err(errors::InvalidExpressionInLetElse {
                     span: init.span,
-                    operator: op.node.to_string(),
+                    operator: op.node.as_str(),
                     sugg: errors::WrapExpressionInParentheses {
                         left: init.span.shrink_to_lo(),
                         right: init.span.shrink_to_hi(),
diff --git a/src/tools/clippy/clippy_lints/src/formatting.rs b/src/tools/clippy/clippy_lints/src/formatting.rs
index 70892ce608f..2ab04682f1d 100644
--- a/src/tools/clippy/clippy_lints/src/formatting.rs
+++ b/src/tools/clippy/clippy_lints/src/formatting.rs
@@ -1,7 +1,7 @@
 use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_note};
 use clippy_utils::is_span_if;
 use clippy_utils::source::snippet_opt;
-use rustc_ast::ast::{BinOpKind, Block, Expr, ExprKind, StmtKind, UnOp};
+use rustc_ast::ast::{BinOpKind, Block, Expr, ExprKind, StmtKind};
 use rustc_lint::{EarlyContext, EarlyLintPass, LintContext};
 use rustc_middle::lint::in_external_macro;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
@@ -144,7 +144,7 @@ fn check_assign(cx: &EarlyContext<'_>, expr: &Expr) {
             let eq_span = lhs.span.between(rhs.span);
             if let ExprKind::Unary(op, ref sub_rhs) = rhs.kind {
                 if let Some(eq_snippet) = snippet_opt(cx, eq_span) {
-                    let op = UnOp::to_string(op);
+                    let op = op.as_str();
                     let eqop_span = lhs.span.between(sub_rhs.span);
                     if eq_snippet.ends_with('=') {
                         span_lint_and_note(
@@ -177,11 +177,11 @@ fn check_unop(cx: &EarlyContext<'_>, expr: &Expr) {
         && let unop_operand_span = rhs.span.until(un_rhs.span)
         && let Some(binop_snippet) = snippet_opt(cx, binop_span)
         && let Some(unop_operand_snippet) = snippet_opt(cx, unop_operand_span)
-        && let binop_str = BinOpKind::to_string(&binop.node)
+        && let binop_str = binop.node.as_str()
         // no space after BinOp operator and space after UnOp operator
         && binop_snippet.ends_with(binop_str) && unop_operand_snippet.ends_with(' ')
     {
-        let unop_str = UnOp::to_string(op);
+        let unop_str = op.as_str();
         let eqop_span = lhs.span.between(un_rhs.span);
         span_lint_and_help(
             cx,
diff --git a/src/tools/clippy/clippy_lints/src/precedence.rs b/src/tools/clippy/clippy_lints/src/precedence.rs
index b638e83997a..52cec437378 100644
--- a/src/tools/clippy/clippy_lints/src/precedence.rs
+++ b/src/tools/clippy/clippy_lints/src/precedence.rs
@@ -78,7 +78,7 @@ impl EarlyLintPass for Precedence {
                     let sugg = format!(
                         "({}) {} ({})",
                         snippet_with_applicability(cx, left.span, "..", &mut applicability),
-                        op.to_string(),
+                        op.as_str(),
                         snippet_with_applicability(cx, right.span, "..", &mut applicability)
                     );
                     span_sugg(expr, sugg, applicability);
@@ -87,7 +87,7 @@ impl EarlyLintPass for Precedence {
                     let sugg = format!(
                         "({}) {} {}",
                         snippet_with_applicability(cx, left.span, "..", &mut applicability),
-                        op.to_string(),
+                        op.as_str(),
                         snippet_with_applicability(cx, right.span, "..", &mut applicability)
                     );
                     span_sugg(expr, sugg, applicability);
@@ -96,7 +96,7 @@ impl EarlyLintPass for Precedence {
                     let sugg = format!(
                         "{} {} ({})",
                         snippet_with_applicability(cx, left.span, "..", &mut applicability),
-                        op.to_string(),
+                        op.as_str(),
                         snippet_with_applicability(cx, right.span, "..", &mut applicability)
                     );
                     span_sugg(expr, sugg, applicability);
diff --git a/src/tools/clippy/clippy_lints/src/suspicious_operation_groupings.rs b/src/tools/clippy/clippy_lints/src/suspicious_operation_groupings.rs
index 92de7917871..b332309a552 100644
--- a/src/tools/clippy/clippy_lints/src/suspicious_operation_groupings.rs
+++ b/src/tools/clippy/clippy_lints/src/suspicious_operation_groupings.rs
@@ -298,7 +298,7 @@ fn replace_left_sugg(
 ) -> String {
     format!(
         "{left_suggestion} {} {}",
-        binop.op.to_string(),
+        binop.op.as_str(),
         snippet_with_applicability(cx, binop.right.span, "..", applicability),
     )
 }
@@ -312,7 +312,7 @@ fn replace_right_sugg(
     format!(
         "{} {} {right_suggestion}",
         snippet_with_applicability(cx, binop.left.span, "..", applicability),
-        binop.op.to_string(),
+        binop.op.as_str(),
     )
 }
 
diff --git a/src/tools/clippy/clippy_utils/src/sugg.rs b/src/tools/clippy/clippy_utils/src/sugg.rs
index db79dd78801..f143163152e 100644
--- a/src/tools/clippy/clippy_utils/src/sugg.rs
+++ b/src/tools/clippy/clippy_utils/src/sugg.rs
@@ -382,7 +382,7 @@ fn binop_to_string(op: AssocOp, lhs: &str, rhs: &str) -> String {
         | AssocOp::GreaterEqual => {
             format!(
                 "{lhs} {} {rhs}",
-                op.to_ast_binop().expect("Those are AST ops").to_string()
+                op.to_ast_binop().expect("Those are AST ops").as_str()
             )
         },
         AssocOp::Assign => format!("{lhs} = {rhs}"),
diff --git a/src/tools/rustfmt/src/expr.rs b/src/tools/rustfmt/src/expr.rs
index fa941e6146a..60e0e007b1d 100644
--- a/src/tools/rustfmt/src/expr.rs
+++ b/src/tools/rustfmt/src/expr.rs
@@ -1933,7 +1933,7 @@ fn rewrite_unary_op(
     shape: Shape,
 ) -> Option<String> {
     // For some reason, an UnOp is not spanned like BinOp!
-    rewrite_unary_prefix(context, ast::UnOp::to_string(op), expr, shape)
+    rewrite_unary_prefix(context, op.as_str(), expr, shape)
 }
 
 pub(crate) enum RhsAssignKind<'ast> {
diff --git a/src/tools/rustfmt/src/pairs.rs b/src/tools/rustfmt/src/pairs.rs
index 07c05193739..bfc2ffed383 100644
--- a/src/tools/rustfmt/src/pairs.rs
+++ b/src/tools/rustfmt/src/pairs.rs
@@ -339,7 +339,7 @@ impl FlattenPair for ast::Expr {
                     if let Some(pop) = stack.pop() {
                         match pop.kind {
                             ast::ExprKind::Binary(op, _, ref rhs) => {
-                                separators.push(op.node.to_string());
+                                separators.push(op.node.as_str());
                                 node = rhs;
                             }
                             _ => unreachable!(),