1 use crate::consts::{constant_context, constant_simple};
2 use crate::source::snippet_opt;
3 use rustc_ast::ast::InlineAsmTemplatePiece;
4 use rustc_data_structures::fx::FxHasher;
5 use rustc_hir::def::Res;
6 use rustc_hir::HirIdMap;
8 ArrayLen, BinOpKind, Block, BodyId, Expr, ExprField, ExprKind, FnRetTy, GenericArg, GenericArgs, Guard, HirId,
9 InlineAsmOperand, Let, Lifetime, LifetimeName, ParamName, Pat, PatField, PatKind, Path, PathSegment, QPath, Stmt,
10 StmtKind, Ty, TyKind, TypeBinding,
12 use rustc_lexer::{tokenize, TokenKind};
13 use rustc_lint::LateContext;
14 use rustc_middle::ty::TypeckResults;
15 use rustc_span::Symbol;
16 use std::hash::{Hash, Hasher};
18 /// Type used to check whether two ast are the same. This is different from the
20 /// `==` on ast types as this operator would compare true equality with ID and
23 /// Note that some expressions kinds are not considered but could be added.
24 pub struct SpanlessEq<'a, 'tcx> {
25 /// Context used to evaluate constant expressions.
26 cx: &'a LateContext<'tcx>,
27 maybe_typeck_results: Option<&'tcx TypeckResults<'tcx>>,
28 allow_side_effects: bool,
29 expr_fallback: Option<Box<dyn FnMut(&Expr<'_>, &Expr<'_>) -> bool + 'a>>,
32 impl<'a, 'tcx> SpanlessEq<'a, 'tcx> {
33 pub fn new(cx: &'a LateContext<'tcx>) -> Self {
36 maybe_typeck_results: cx.maybe_typeck_results(),
37 allow_side_effects: true,
42 /// Consider expressions containing potential side effects as not equal.
44 pub fn deny_side_effects(self) -> Self {
46 allow_side_effects: false,
52 pub fn expr_fallback(self, expr_fallback: impl FnMut(&Expr<'_>, &Expr<'_>) -> bool + 'a) -> Self {
54 expr_fallback: Some(Box::new(expr_fallback)),
59 /// Use this method to wrap comparisons that may involve inter-expression context.
60 /// See `self.locals`.
61 pub fn inter_expr(&mut self) -> HirEqInterExpr<'_, 'a, 'tcx> {
64 locals: HirIdMap::default(),
69 pub fn eq_block(&mut self, left: &Block<'_>, right: &Block<'_>) -> bool {
70 self.inter_expr().eq_block(left, right)
73 pub fn eq_expr(&mut self, left: &Expr<'_>, right: &Expr<'_>) -> bool {
74 self.inter_expr().eq_expr(left, right)
77 pub fn eq_path(&mut self, left: &Path<'_>, right: &Path<'_>) -> bool {
78 self.inter_expr().eq_path(left, right)
81 pub fn eq_path_segment(&mut self, left: &PathSegment<'_>, right: &PathSegment<'_>) -> bool {
82 self.inter_expr().eq_path_segment(left, right)
85 pub fn eq_path_segments(&mut self, left: &[PathSegment<'_>], right: &[PathSegment<'_>]) -> bool {
86 self.inter_expr().eq_path_segments(left, right)
90 pub struct HirEqInterExpr<'a, 'b, 'tcx> {
91 inner: &'a mut SpanlessEq<'b, 'tcx>,
93 // When binding are declared, the binding ID in the left expression is mapped to the one on the
94 // right. For example, when comparing `{ let x = 1; x + 2 }` and `{ let y = 1; y + 2 }`,
95 // these blocks are considered equal since `x` is mapped to `y`.
96 locals: HirIdMap<HirId>,
99 impl HirEqInterExpr<'_, '_, '_> {
100 pub fn eq_stmt(&mut self, left: &Stmt<'_>, right: &Stmt<'_>) -> bool {
101 match (&left.kind, &right.kind) {
102 (&StmtKind::Local(l), &StmtKind::Local(r)) => {
103 // This additional check ensures that the type of the locals are equivalent even if the init
104 // expression or type have some inferred parts.
105 if let Some(typeck) = self.inner.maybe_typeck_results {
106 let l_ty = typeck.pat_ty(l.pat);
107 let r_ty = typeck.pat_ty(r.pat);
113 // eq_pat adds the HirIds to the locals map. We therefor call it last to make sure that
114 // these only get added if the init and type is equal.
115 both(&l.init, &r.init, |l, r| self.eq_expr(l, r))
116 && both(&l.ty, &r.ty, |l, r| self.eq_ty(l, r))
117 && self.eq_pat(l.pat, r.pat)
119 (&StmtKind::Expr(l), &StmtKind::Expr(r)) | (&StmtKind::Semi(l), &StmtKind::Semi(r)) => self.eq_expr(l, r),
124 /// Checks whether two blocks are the same.
125 fn eq_block(&mut self, left: &Block<'_>, right: &Block<'_>) -> bool {
126 match (left.stmts, left.expr, right.stmts, right.expr) {
127 ([], None, [], None) => {
128 // For empty blocks, check to see if the tokens are equal. This will catch the case where a macro
129 // expanded to nothing, or the cfg attribute was used.
130 let (left, right) = match (
131 snippet_opt(self.inner.cx, left.span),
132 snippet_opt(self.inner.cx, right.span),
134 (Some(left), Some(right)) => (left, right),
137 let mut left_pos = 0;
138 let left = tokenize(&left)
140 let end = left_pos + t.len;
141 let s = &left[left_pos..end];
148 TokenKind::LineComment { .. } | TokenKind::BlockComment { .. } | TokenKind::Whitespace
152 let mut right_pos = 0;
153 let right = tokenize(&right)
155 let end = right_pos + t.len;
156 let s = &right[right_pos..end];
163 TokenKind::LineComment { .. } | TokenKind::BlockComment { .. } | TokenKind::Whitespace
170 over(left.stmts, right.stmts, |l, r| self.eq_stmt(l, r))
171 && both(&left.expr, &right.expr, |l, r| self.eq_expr(l, r))
176 pub fn eq_array_length(&mut self, left: ArrayLen, right: ArrayLen) -> bool {
177 match (left, right) {
178 (ArrayLen::Infer(..), ArrayLen::Infer(..)) => true,
179 (ArrayLen::Body(l_ct), ArrayLen::Body(r_ct)) => self.eq_body(l_ct.body, r_ct.body),
184 pub fn eq_body(&mut self, left: BodyId, right: BodyId) -> bool {
185 let cx = self.inner.cx;
186 let eval_const = |body| constant_context(cx, cx.tcx.typeck_body(body)).expr(&cx.tcx.hir().body(body).value);
187 eval_const(left) == eval_const(right)
190 #[allow(clippy::similar_names)]
191 pub fn eq_expr(&mut self, left: &Expr<'_>, right: &Expr<'_>) -> bool {
192 if !self.inner.allow_side_effects && left.span.ctxt() != right.span.ctxt() {
196 if let Some(typeck_results) = self.inner.maybe_typeck_results {
197 if let (Some(l), Some(r)) = (
198 constant_simple(self.inner.cx, typeck_results, left),
199 constant_simple(self.inner.cx, typeck_results, right),
208 reduce_exprkind(self.inner.cx, &left.kind),
209 reduce_exprkind(self.inner.cx, &right.kind),
211 (&ExprKind::AddrOf(lb, l_mut, le), &ExprKind::AddrOf(rb, r_mut, re)) => {
212 lb == rb && l_mut == r_mut && self.eq_expr(le, re)
214 (&ExprKind::Continue(li), &ExprKind::Continue(ri)) => {
215 both(&li.label, &ri.label, |l, r| l.ident.name == r.ident.name)
217 (&ExprKind::Assign(ll, lr, _), &ExprKind::Assign(rl, rr, _)) => {
218 self.inner.allow_side_effects && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
220 (&ExprKind::AssignOp(ref lo, ll, lr), &ExprKind::AssignOp(ref ro, rl, rr)) => {
221 self.inner.allow_side_effects && lo.node == ro.node && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
223 (&ExprKind::Block(l, _), &ExprKind::Block(r, _)) => self.eq_block(l, r),
224 (&ExprKind::Binary(l_op, ll, lr), &ExprKind::Binary(r_op, rl, rr)) => {
225 l_op.node == r_op.node && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
226 || swap_binop(l_op.node, ll, lr).map_or(false, |(l_op, ll, lr)| {
227 l_op == r_op.node && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
230 (&ExprKind::Break(li, ref le), &ExprKind::Break(ri, ref re)) => {
231 both(&li.label, &ri.label, |l, r| l.ident.name == r.ident.name)
232 && both(le, re, |l, r| self.eq_expr(l, r))
234 (&ExprKind::Box(l), &ExprKind::Box(r)) => self.eq_expr(l, r),
235 (&ExprKind::Call(l_fun, l_args), &ExprKind::Call(r_fun, r_args)) => {
236 self.inner.allow_side_effects && self.eq_expr(l_fun, r_fun) && self.eq_exprs(l_args, r_args)
238 (&ExprKind::Cast(lx, lt), &ExprKind::Cast(rx, rt)) | (&ExprKind::Type(lx, lt), &ExprKind::Type(rx, rt)) => {
239 self.eq_expr(lx, rx) && self.eq_ty(lt, rt)
241 (&ExprKind::Field(l_f_exp, ref l_f_ident), &ExprKind::Field(r_f_exp, ref r_f_ident)) => {
242 l_f_ident.name == r_f_ident.name && self.eq_expr(l_f_exp, r_f_exp)
244 (&ExprKind::Index(la, li), &ExprKind::Index(ra, ri)) => self.eq_expr(la, ra) && self.eq_expr(li, ri),
245 (&ExprKind::If(lc, lt, ref le), &ExprKind::If(rc, rt, ref re)) => {
246 self.eq_expr(lc, rc) && self.eq_expr(lt, rt) && both(le, re, |l, r| self.eq_expr(l, r))
248 (&ExprKind::Let(l), &ExprKind::Let(r)) => {
249 self.eq_pat(l.pat, r.pat) && both(&l.ty, &r.ty, |l, r| self.eq_ty(l, r)) && self.eq_expr(l.init, r.init)
251 (&ExprKind::Lit(ref l), &ExprKind::Lit(ref r)) => l.node == r.node,
252 (&ExprKind::Loop(lb, ref ll, ref lls, _), &ExprKind::Loop(rb, ref rl, ref rls, _)) => {
253 lls == rls && self.eq_block(lb, rb) && both(ll, rl, |l, r| l.ident.name == r.ident.name)
255 (&ExprKind::Match(le, la, ref ls), &ExprKind::Match(re, ra, ref rs)) => {
257 && self.eq_expr(le, re)
258 && over(la, ra, |l, r| {
259 self.eq_pat(l.pat, r.pat)
260 && both(&l.guard, &r.guard, |l, r| self.eq_guard(l, r))
261 && self.eq_expr(l.body, r.body)
264 (&ExprKind::MethodCall(l_path, l_args, _), &ExprKind::MethodCall(r_path, r_args, _)) => {
265 self.inner.allow_side_effects && self.eq_path_segment(l_path, r_path) && self.eq_exprs(l_args, r_args)
267 (&ExprKind::Repeat(le, ll), &ExprKind::Repeat(re, rl)) => {
268 self.eq_expr(le, re) && self.eq_array_length(ll, rl)
270 (&ExprKind::Ret(ref l), &ExprKind::Ret(ref r)) => both(l, r, |l, r| self.eq_expr(l, r)),
271 (&ExprKind::Path(ref l), &ExprKind::Path(ref r)) => self.eq_qpath(l, r),
272 (&ExprKind::Struct(l_path, lf, ref lo), &ExprKind::Struct(r_path, rf, ref ro)) => {
273 self.eq_qpath(l_path, r_path)
274 && both(lo, ro, |l, r| self.eq_expr(l, r))
275 && over(lf, rf, |l, r| self.eq_expr_field(l, r))
277 (&ExprKind::Tup(l_tup), &ExprKind::Tup(r_tup)) => self.eq_exprs(l_tup, r_tup),
278 (&ExprKind::Unary(l_op, le), &ExprKind::Unary(r_op, re)) => l_op == r_op && self.eq_expr(le, re),
279 (&ExprKind::Array(l), &ExprKind::Array(r)) => self.eq_exprs(l, r),
280 (&ExprKind::DropTemps(le), &ExprKind::DropTemps(re)) => self.eq_expr(le, re),
283 is_eq || self.inner.expr_fallback.as_mut().map_or(false, |f| f(left, right))
286 fn eq_exprs(&mut self, left: &[Expr<'_>], right: &[Expr<'_>]) -> bool {
287 over(left, right, |l, r| self.eq_expr(l, r))
290 fn eq_expr_field(&mut self, left: &ExprField<'_>, right: &ExprField<'_>) -> bool {
291 left.ident.name == right.ident.name && self.eq_expr(left.expr, right.expr)
294 fn eq_guard(&mut self, left: &Guard<'_>, right: &Guard<'_>) -> bool {
295 match (left, right) {
296 (Guard::If(l), Guard::If(r)) => self.eq_expr(l, r),
297 (Guard::IfLet(lp, le), Guard::IfLet(rp, re)) => self.eq_pat(lp, rp) && self.eq_expr(le, re),
302 fn eq_generic_arg(&mut self, left: &GenericArg<'_>, right: &GenericArg<'_>) -> bool {
303 match (left, right) {
304 (GenericArg::Const(l), GenericArg::Const(r)) => self.eq_body(l.value.body, r.value.body),
305 (GenericArg::Lifetime(l_lt), GenericArg::Lifetime(r_lt)) => Self::eq_lifetime(l_lt, r_lt),
306 (GenericArg::Type(l_ty), GenericArg::Type(r_ty)) => self.eq_ty(l_ty, r_ty),
307 (GenericArg::Infer(l_inf), GenericArg::Infer(r_inf)) => self.eq_ty(&l_inf.to_ty(), &r_inf.to_ty()),
312 fn eq_lifetime(left: &Lifetime, right: &Lifetime) -> bool {
313 left.name == right.name
316 fn eq_pat_field(&mut self, left: &PatField<'_>, right: &PatField<'_>) -> bool {
317 let (PatField { ident: li, pat: lp, .. }, PatField { ident: ri, pat: rp, .. }) = (&left, &right);
318 li.name == ri.name && self.eq_pat(lp, rp)
321 /// Checks whether two patterns are the same.
322 fn eq_pat(&mut self, left: &Pat<'_>, right: &Pat<'_>) -> bool {
323 match (&left.kind, &right.kind) {
324 (&PatKind::Box(l), &PatKind::Box(r)) => self.eq_pat(l, r),
325 (&PatKind::Struct(ref lp, la, ..), &PatKind::Struct(ref rp, ra, ..)) => {
326 self.eq_qpath(lp, rp) && over(la, ra, |l, r| self.eq_pat_field(l, r))
328 (&PatKind::TupleStruct(ref lp, la, ls), &PatKind::TupleStruct(ref rp, ra, rs)) => {
329 self.eq_qpath(lp, rp) && over(la, ra, |l, r| self.eq_pat(l, r)) && ls == rs
331 (&PatKind::Binding(lb, li, _, ref lp), &PatKind::Binding(rb, ri, _, ref rp)) => {
332 let eq = lb == rb && both(lp, rp, |l, r| self.eq_pat(l, r));
334 self.locals.insert(li, ri);
338 (&PatKind::Path(ref l), &PatKind::Path(ref r)) => self.eq_qpath(l, r),
339 (&PatKind::Lit(l), &PatKind::Lit(r)) => self.eq_expr(l, r),
340 (&PatKind::Tuple(l, ls), &PatKind::Tuple(r, rs)) => ls == rs && over(l, r, |l, r| self.eq_pat(l, r)),
341 (&PatKind::Range(ref ls, ref le, li), &PatKind::Range(ref rs, ref re, ri)) => {
342 both(ls, rs, |a, b| self.eq_expr(a, b)) && both(le, re, |a, b| self.eq_expr(a, b)) && (li == ri)
344 (&PatKind::Ref(le, ref lm), &PatKind::Ref(re, ref rm)) => lm == rm && self.eq_pat(le, re),
345 (&PatKind::Slice(ls, ref li, le), &PatKind::Slice(rs, ref ri, re)) => {
346 over(ls, rs, |l, r| self.eq_pat(l, r))
347 && over(le, re, |l, r| self.eq_pat(l, r))
348 && both(li, ri, |l, r| self.eq_pat(l, r))
350 (&PatKind::Wild, &PatKind::Wild) => true,
355 #[allow(clippy::similar_names)]
356 fn eq_qpath(&mut self, left: &QPath<'_>, right: &QPath<'_>) -> bool {
357 match (left, right) {
358 (&QPath::Resolved(ref lty, lpath), &QPath::Resolved(ref rty, rpath)) => {
359 both(lty, rty, |l, r| self.eq_ty(l, r)) && self.eq_path(lpath, rpath)
361 (&QPath::TypeRelative(lty, lseg), &QPath::TypeRelative(rty, rseg)) => {
362 self.eq_ty(lty, rty) && self.eq_path_segment(lseg, rseg)
364 (&QPath::LangItem(llang_item, ..), &QPath::LangItem(rlang_item, ..)) => llang_item == rlang_item,
369 pub fn eq_path(&mut self, left: &Path<'_>, right: &Path<'_>) -> bool {
370 match (left.res, right.res) {
371 (Res::Local(l), Res::Local(r)) => l == r || self.locals.get(&l) == Some(&r),
372 (Res::Local(_), _) | (_, Res::Local(_)) => false,
373 _ => over(left.segments, right.segments, |l, r| self.eq_path_segment(l, r)),
377 fn eq_path_parameters(&mut self, left: &GenericArgs<'_>, right: &GenericArgs<'_>) -> bool {
378 if !(left.parenthesized || right.parenthesized) {
379 over(left.args, right.args, |l, r| self.eq_generic_arg(l, r)) // FIXME(flip1995): may not work
380 && over(left.bindings, right.bindings, |l, r| self.eq_type_binding(l, r))
381 } else if left.parenthesized && right.parenthesized {
382 over(left.inputs(), right.inputs(), |l, r| self.eq_ty(l, r))
383 && both(&Some(&left.bindings[0].ty()), &Some(&right.bindings[0].ty()), |l, r| {
391 pub fn eq_path_segments(&mut self, left: &[PathSegment<'_>], right: &[PathSegment<'_>]) -> bool {
392 left.len() == right.len() && left.iter().zip(right).all(|(l, r)| self.eq_path_segment(l, r))
395 pub fn eq_path_segment(&mut self, left: &PathSegment<'_>, right: &PathSegment<'_>) -> bool {
396 // The == of idents doesn't work with different contexts,
397 // we have to be explicit about hygiene
398 left.ident.name == right.ident.name && both(&left.args, &right.args, |l, r| self.eq_path_parameters(l, r))
401 #[allow(clippy::similar_names)]
402 pub fn eq_ty(&mut self, left: &Ty<'_>, right: &Ty<'_>) -> bool {
403 match (&left.kind, &right.kind) {
404 (&TyKind::Slice(l_vec), &TyKind::Slice(r_vec)) => self.eq_ty(l_vec, r_vec),
405 (&TyKind::Array(lt, ll), &TyKind::Array(rt, rl)) => self.eq_ty(lt, rt) && self.eq_array_length(ll, rl),
406 (&TyKind::Ptr(ref l_mut), &TyKind::Ptr(ref r_mut)) => {
407 l_mut.mutbl == r_mut.mutbl && self.eq_ty(&*l_mut.ty, &*r_mut.ty)
409 (&TyKind::Rptr(_, ref l_rmut), &TyKind::Rptr(_, ref r_rmut)) => {
410 l_rmut.mutbl == r_rmut.mutbl && self.eq_ty(&*l_rmut.ty, &*r_rmut.ty)
412 (&TyKind::Path(ref l), &TyKind::Path(ref r)) => self.eq_qpath(l, r),
413 (&TyKind::Tup(l), &TyKind::Tup(r)) => over(l, r, |l, r| self.eq_ty(l, r)),
414 (&TyKind::Infer, &TyKind::Infer) => true,
419 fn eq_type_binding(&mut self, left: &TypeBinding<'_>, right: &TypeBinding<'_>) -> bool {
420 left.ident.name == right.ident.name && self.eq_ty(left.ty(), right.ty())
424 /// Some simple reductions like `{ return }` => `return`
425 fn reduce_exprkind<'hir>(cx: &LateContext<'_>, kind: &'hir ExprKind<'hir>) -> &'hir ExprKind<'hir> {
426 if let ExprKind::Block(block, _) = kind {
427 match (block.stmts, block.expr) {
428 // From an `if let` expression without an `else` block. The arm for the implicit wild pattern is an empty
429 // block with an empty span.
430 ([], None) if block.span.is_empty() => &ExprKind::Tup(&[]),
432 ([], None) => match snippet_opt(cx, block.span) {
433 // Don't reduce if there are any tokens contained in the braces
440 TokenKind::LineComment { .. } | TokenKind::BlockComment { .. } | TokenKind::Whitespace
443 .ne([TokenKind::OpenBrace, TokenKind::CloseBrace].iter().copied()) =>
447 _ => &ExprKind::Tup(&[]),
449 ([], Some(expr)) => match expr.kind {
450 // `{ return .. }` => `return ..`
451 ExprKind::Ret(..) => &expr.kind,
454 ([stmt], None) => match stmt.kind {
455 StmtKind::Expr(expr) | StmtKind::Semi(expr) => match expr.kind {
456 // `{ return ..; }` => `return ..`
457 ExprKind::Ret(..) => &expr.kind,
473 ) -> Option<(BinOpKind, &'a Expr<'a>, &'a Expr<'a>)> {
475 BinOpKind::Add | BinOpKind::Eq | BinOpKind::Ne | BinOpKind::BitAnd | BinOpKind::BitXor | BinOpKind::BitOr => {
476 Some((binop, rhs, lhs))
478 BinOpKind::Lt => Some((BinOpKind::Gt, rhs, lhs)),
479 BinOpKind::Le => Some((BinOpKind::Ge, rhs, lhs)),
480 BinOpKind::Ge => Some((BinOpKind::Le, rhs, lhs)),
481 BinOpKind::Gt => Some((BinOpKind::Lt, rhs, lhs)),
482 BinOpKind::Mul // Not always commutative, e.g. with matrices. See issue #5698
489 | BinOpKind::Or => None,
493 /// Checks if the two `Option`s are both `None` or some equal values as per
495 pub fn both<X>(l: &Option<X>, r: &Option<X>, mut eq_fn: impl FnMut(&X, &X) -> bool) -> bool {
497 .map_or_else(|| r.is_none(), |x| r.as_ref().map_or(false, |y| eq_fn(x, y)))
500 /// Checks if two slices are equal as per `eq_fn`.
501 pub fn over<X>(left: &[X], right: &[X], mut eq_fn: impl FnMut(&X, &X) -> bool) -> bool {
502 left.len() == right.len() && left.iter().zip(right).all(|(x, y)| eq_fn(x, y))
505 /// Counts how many elements of the slices are equal as per `eq_fn`.
506 pub fn count_eq<X: Sized>(
507 left: &mut dyn Iterator<Item = X>,
508 right: &mut dyn Iterator<Item = X>,
509 mut eq_fn: impl FnMut(&X, &X) -> bool,
511 left.zip(right).take_while(|(l, r)| eq_fn(l, r)).count()
514 /// Checks if two expressions evaluate to the same value, and don't contain any side effects.
515 pub fn eq_expr_value(cx: &LateContext<'_>, left: &Expr<'_>, right: &Expr<'_>) -> bool {
516 SpanlessEq::new(cx).deny_side_effects().eq_expr(left, right)
519 /// Type used to hash an ast element. This is different from the `Hash` trait
520 /// on ast types as this
521 /// trait would consider IDs and spans.
523 /// All expressions kind are hashed, but some might have a weaker hash.
524 pub struct SpanlessHash<'a, 'tcx> {
525 /// Context used to evaluate constant expressions.
526 cx: &'a LateContext<'tcx>,
527 maybe_typeck_results: Option<&'tcx TypeckResults<'tcx>>,
531 impl<'a, 'tcx> SpanlessHash<'a, 'tcx> {
532 pub fn new(cx: &'a LateContext<'tcx>) -> Self {
535 maybe_typeck_results: cx.maybe_typeck_results(),
536 s: FxHasher::default(),
540 pub fn finish(self) -> u64 {
544 pub fn hash_block(&mut self, b: &Block<'_>) {
549 if let Some(e) = b.expr {
553 std::mem::discriminant(&b.rules).hash(&mut self.s);
556 #[allow(clippy::too_many_lines)]
557 pub fn hash_expr(&mut self, e: &Expr<'_>) {
558 let simple_const = self
559 .maybe_typeck_results
560 .and_then(|typeck_results| constant_simple(self.cx, typeck_results, e));
562 // const hashing may result in the same hash as some unrelated node, so add a sort of
563 // discriminant depending on which path we're choosing next
564 simple_const.hash(&mut self.s);
565 if simple_const.is_some() {
569 std::mem::discriminant(&e.kind).hash(&mut self.s);
572 ExprKind::AddrOf(kind, m, e) => {
573 std::mem::discriminant(&kind).hash(&mut self.s);
577 ExprKind::Continue(i) => {
578 if let Some(i) = i.label {
579 self.hash_name(i.ident.name);
582 ExprKind::Assign(l, r, _) => {
586 ExprKind::AssignOp(ref o, l, r) => {
587 std::mem::discriminant(&o.node).hash(&mut self.s);
591 ExprKind::Block(b, _) => {
594 ExprKind::Binary(op, l, r) => {
595 std::mem::discriminant(&op.node).hash(&mut self.s);
599 ExprKind::Break(i, ref j) => {
600 if let Some(i) = i.label {
601 self.hash_name(i.ident.name);
603 if let Some(j) = *j {
607 ExprKind::Box(e) | ExprKind::DropTemps(e) | ExprKind::Yield(e, _) => {
610 ExprKind::Call(fun, args) => {
612 self.hash_exprs(args);
614 ExprKind::Cast(e, ty) | ExprKind::Type(e, ty) => {
618 ExprKind::Closure(cap, _, eid, _, _) => {
619 std::mem::discriminant(&cap).hash(&mut self.s);
620 // closures inherit TypeckResults
621 self.hash_expr(&self.cx.tcx.hir().body(eid).value);
623 ExprKind::Field(e, ref f) => {
625 self.hash_name(f.name);
627 ExprKind::Index(a, i) => {
631 ExprKind::InlineAsm(asm) => {
632 for piece in asm.template {
634 InlineAsmTemplatePiece::String(s) => s.hash(&mut self.s),
635 InlineAsmTemplatePiece::Placeholder {
640 operand_idx.hash(&mut self.s);
641 modifier.hash(&mut self.s);
645 asm.options.hash(&mut self.s);
646 for (op, _op_sp) in asm.operands {
648 InlineAsmOperand::In { reg, expr } => {
649 reg.hash(&mut self.s);
650 self.hash_expr(expr);
652 InlineAsmOperand::Out { reg, late, expr } => {
653 reg.hash(&mut self.s);
654 late.hash(&mut self.s);
655 if let Some(expr) = expr {
656 self.hash_expr(expr);
659 InlineAsmOperand::InOut { reg, late, expr } => {
660 reg.hash(&mut self.s);
661 late.hash(&mut self.s);
662 self.hash_expr(expr);
664 InlineAsmOperand::SplitInOut {
670 reg.hash(&mut self.s);
671 late.hash(&mut self.s);
672 self.hash_expr(in_expr);
673 if let Some(out_expr) = out_expr {
674 self.hash_expr(out_expr);
677 InlineAsmOperand::Const { anon_const } => self.hash_body(anon_const.body),
678 InlineAsmOperand::Sym { expr } => self.hash_expr(expr),
682 ExprKind::Let(Let { pat, init, ty, .. }) => {
683 self.hash_expr(init);
684 if let Some(ty) = ty {
690 ExprKind::Lit(ref l) => {
691 l.node.hash(&mut self.s);
693 ExprKind::Loop(b, ref i, ..) => {
695 if let Some(i) = *i {
696 self.hash_name(i.ident.name);
699 ExprKind::If(cond, then, ref else_opt) => {
700 self.hash_expr(cond);
701 self.hash_expr(then);
702 if let Some(e) = *else_opt {
706 ExprKind::Match(e, arms, ref s) => {
710 self.hash_pat(arm.pat);
711 if let Some(ref e) = arm.guard {
714 self.hash_expr(arm.body);
719 ExprKind::MethodCall(path, args, ref _fn_span) => {
720 self.hash_name(path.ident.name);
721 self.hash_exprs(args);
723 ExprKind::ConstBlock(ref l_id) => {
724 self.hash_body(l_id.body);
726 ExprKind::Repeat(e, len) => {
728 self.hash_array_length(len);
730 ExprKind::Ret(ref e) => {
731 if let Some(e) = *e {
735 ExprKind::Path(ref qpath) => {
736 self.hash_qpath(qpath);
738 ExprKind::Struct(path, fields, ref expr) => {
739 self.hash_qpath(path);
742 self.hash_name(f.ident.name);
743 self.hash_expr(f.expr);
746 if let Some(e) = *expr {
750 ExprKind::Tup(tup) => {
751 self.hash_exprs(tup);
753 ExprKind::Array(v) => {
756 ExprKind::Unary(lop, le) => {
757 std::mem::discriminant(&lop).hash(&mut self.s);
763 pub fn hash_exprs(&mut self, e: &[Expr<'_>]) {
769 pub fn hash_name(&mut self, n: Symbol) {
773 pub fn hash_qpath(&mut self, p: &QPath<'_>) {
775 QPath::Resolved(_, path) => {
776 self.hash_path(path);
778 QPath::TypeRelative(_, path) => {
779 self.hash_name(path.ident.name);
781 QPath::LangItem(lang_item, ..) => {
782 std::mem::discriminant(&lang_item).hash(&mut self.s);
785 // self.maybe_typeck_results.unwrap().qpath_res(p, id).hash(&mut self.s);
788 pub fn hash_pat(&mut self, pat: &Pat<'_>) {
789 std::mem::discriminant(&pat.kind).hash(&mut self.s);
791 PatKind::Binding(ann, _, _, pat) => {
792 std::mem::discriminant(&ann).hash(&mut self.s);
793 if let Some(pat) = pat {
797 PatKind::Box(pat) => self.hash_pat(pat),
798 PatKind::Lit(expr) => self.hash_expr(expr),
799 PatKind::Or(pats) => {
804 PatKind::Path(ref qpath) => self.hash_qpath(qpath),
805 PatKind::Range(s, e, i) => {
812 std::mem::discriminant(&i).hash(&mut self.s);
814 PatKind::Ref(pat, mu) => {
816 std::mem::discriminant(&mu).hash(&mut self.s);
818 PatKind::Slice(l, m, r) => {
822 if let Some(pat) = m {
829 PatKind::Struct(ref qpath, fields, e) => {
830 self.hash_qpath(qpath);
832 self.hash_name(f.ident.name);
833 self.hash_pat(f.pat);
837 PatKind::Tuple(pats, e) => {
843 PatKind::TupleStruct(ref qpath, pats, e) => {
844 self.hash_qpath(qpath);
854 pub fn hash_path(&mut self, path: &Path<'_>) {
856 // constant hash since equality is dependant on inter-expression context
857 // e.g. The expressions `if let Some(x) = foo() {}` and `if let Some(y) = foo() {}` are considered equal
858 // even though the binding names are different and they have different `HirId`s.
859 Res::Local(_) => 1_usize.hash(&mut self.s),
861 for seg in path.segments {
862 self.hash_name(seg.ident.name);
863 self.hash_generic_args(seg.args().args);
869 pub fn hash_stmt(&mut self, b: &Stmt<'_>) {
870 std::mem::discriminant(&b.kind).hash(&mut self.s);
873 StmtKind::Local(local) => {
874 self.hash_pat(local.pat);
875 if let Some(init) = local.init {
876 self.hash_expr(init);
879 StmtKind::Item(..) => {},
880 StmtKind::Expr(expr) | StmtKind::Semi(expr) => {
881 self.hash_expr(expr);
886 pub fn hash_guard(&mut self, g: &Guard<'_>) {
888 Guard::If(expr) | Guard::IfLet(_, expr) => {
889 self.hash_expr(expr);
894 pub fn hash_lifetime(&mut self, lifetime: Lifetime) {
895 std::mem::discriminant(&lifetime.name).hash(&mut self.s);
896 if let LifetimeName::Param(ref name) = lifetime.name {
897 std::mem::discriminant(name).hash(&mut self.s);
899 ParamName::Plain(ref ident) => {
900 ident.name.hash(&mut self.s);
902 ParamName::Fresh(ref size) => {
903 size.hash(&mut self.s);
905 ParamName::Error => {},
910 pub fn hash_ty(&mut self, ty: &Ty<'_>) {
911 std::mem::discriminant(&ty.kind).hash(&mut self.s);
912 self.hash_tykind(&ty.kind);
915 pub fn hash_tykind(&mut self, ty: &TyKind<'_>) {
917 TyKind::Slice(ty) => {
920 &TyKind::Array(ty, len) => {
922 self.hash_array_length(len);
924 TyKind::Ptr(ref mut_ty) => {
925 self.hash_ty(mut_ty.ty);
926 mut_ty.mutbl.hash(&mut self.s);
928 TyKind::Rptr(lifetime, ref mut_ty) => {
929 self.hash_lifetime(*lifetime);
930 self.hash_ty(mut_ty.ty);
931 mut_ty.mutbl.hash(&mut self.s);
933 TyKind::BareFn(bfn) => {
934 bfn.unsafety.hash(&mut self.s);
935 bfn.abi.hash(&mut self.s);
936 for arg in bfn.decl.inputs {
939 std::mem::discriminant(&bfn.decl.output).hash(&mut self.s);
940 match bfn.decl.output {
941 FnRetTy::DefaultReturn(_) => {},
942 FnRetTy::Return(ty) => {
946 bfn.decl.c_variadic.hash(&mut self.s);
948 TyKind::Tup(ty_list) => {
953 TyKind::Path(ref qpath) => self.hash_qpath(qpath),
954 TyKind::OpaqueDef(_, arg_list) => {
955 self.hash_generic_args(arg_list);
957 TyKind::TraitObject(_, lifetime, _) => {
958 self.hash_lifetime(*lifetime);
960 TyKind::Typeof(anon_const) => {
961 self.hash_body(anon_const.body);
963 TyKind::Err | TyKind::Infer | TyKind::Never => {},
967 pub fn hash_array_length(&mut self, length: ArrayLen) {
969 ArrayLen::Infer(..) => {},
970 ArrayLen::Body(anon_const) => self.hash_body(anon_const.body),
974 pub fn hash_body(&mut self, body_id: BodyId) {
975 // swap out TypeckResults when hashing a body
976 let old_maybe_typeck_results = self.maybe_typeck_results.replace(self.cx.tcx.typeck_body(body_id));
977 self.hash_expr(&self.cx.tcx.hir().body(body_id).value);
978 self.maybe_typeck_results = old_maybe_typeck_results;
981 fn hash_generic_args(&mut self, arg_list: &[GenericArg<'_>]) {
982 for arg in arg_list {
984 GenericArg::Lifetime(l) => self.hash_lifetime(l),
985 GenericArg::Type(ref ty) => self.hash_ty(ty),
986 GenericArg::Const(ref ca) => self.hash_body(ca.value.body),
987 GenericArg::Infer(ref inf) => self.hash_ty(&inf.to_ty()),