1 use crate::consts::{constant_context, constant_simple};
2 use crate::differing_macro_contexts;
3 use crate::source::snippet_opt;
4 use rustc_ast::ast::InlineAsmTemplatePiece;
5 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
6 use rustc_hir::def::Res;
7 use rustc_hir::HirIdMap;
9 BinOpKind, Block, BlockCheckMode, BodyId, BorrowKind, CaptureBy, Expr, ExprField, ExprKind, FnRetTy, GenericArg,
10 GenericArgs, Guard, HirId, InlineAsmOperand, Lifetime, LifetimeName, ParamName, Pat, PatField, PatKind, Path,
11 PathSegment, QPath, Stmt, StmtKind, Ty, TyKind, TypeBinding,
13 use rustc_lexer::{tokenize, TokenKind};
14 use rustc_lint::LateContext;
15 use rustc_middle::ich::StableHashingContextProvider;
16 use rustc_middle::ty::TypeckResults;
17 use rustc_span::Symbol;
20 /// Type used to check whether two ast are the same. This is different from the
22 /// `==` on ast types as this operator would compare true equality with ID and
25 /// Note that some expressions kinds are not considered but could be added.
26 pub struct SpanlessEq<'a, 'tcx> {
27 /// Context used to evaluate constant expressions.
28 cx: &'a LateContext<'tcx>,
29 maybe_typeck_results: Option<&'tcx TypeckResults<'tcx>>,
30 allow_side_effects: bool,
31 expr_fallback: Option<Box<dyn FnMut(&Expr<'_>, &Expr<'_>) -> bool + 'a>>,
34 impl<'a, 'tcx> SpanlessEq<'a, 'tcx> {
35 pub fn new(cx: &'a LateContext<'tcx>) -> Self {
38 maybe_typeck_results: cx.maybe_typeck_results(),
39 allow_side_effects: true,
44 /// Consider expressions containing potential side effects as not equal.
45 pub fn deny_side_effects(self) -> Self {
47 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_segment(&mut self, left: &PathSegment<'_>, right: &PathSegment<'_>) -> bool {
78 self.inter_expr().eq_path_segment(left, right)
81 pub fn eq_path_segments(&mut self, left: &[PathSegment<'_>], right: &[PathSegment<'_>]) -> bool {
82 self.inter_expr().eq_path_segments(left, right)
86 pub struct HirEqInterExpr<'a, 'b, 'tcx> {
87 inner: &'a mut SpanlessEq<'b, 'tcx>,
89 // When binding are declared, the binding ID in the left expression is mapped to the one on the
90 // right. For example, when comparing `{ let x = 1; x + 2 }` and `{ let y = 1; y + 2 }`,
91 // these blocks are considered equal since `x` is mapped to `y`.
92 locals: HirIdMap<HirId>,
95 impl HirEqInterExpr<'_, '_, '_> {
96 pub fn eq_stmt(&mut self, left: &Stmt<'_>, right: &Stmt<'_>) -> bool {
97 match (&left.kind, &right.kind) {
98 (&StmtKind::Local(l), &StmtKind::Local(r)) => {
99 // This additional check ensures that the type of the locals are equivalent even if the init
100 // expression or type have some inferred parts.
101 if let Some(typeck) = self.inner.maybe_typeck_results {
102 let l_ty = typeck.pat_ty(l.pat);
103 let r_ty = typeck.pat_ty(r.pat);
104 if !rustc_middle::ty::TyS::same_type(l_ty, r_ty) {
109 // eq_pat adds the HirIds to the locals map. We therefor call it last to make sure that
110 // these only get added if the init and type is equal.
111 both(&l.init, &r.init, |l, r| self.eq_expr(l, r))
112 && both(&l.ty, &r.ty, |l, r| self.eq_ty(l, r))
113 && self.eq_pat(l.pat, r.pat)
115 (&StmtKind::Expr(l), &StmtKind::Expr(r)) | (&StmtKind::Semi(l), &StmtKind::Semi(r)) => self.eq_expr(l, r),
120 /// Checks whether two blocks are the same.
121 fn eq_block(&mut self, left: &Block<'_>, right: &Block<'_>) -> bool {
122 match (left.stmts, left.expr, right.stmts, right.expr) {
123 ([], None, [], None) => {
124 // For empty blocks, check to see if the tokens are equal. This will catch the case where a macro
125 // expanded to nothing, or the cfg attribute was used.
126 let (left, right) = match (
127 snippet_opt(self.inner.cx, left.span),
128 snippet_opt(self.inner.cx, right.span),
130 (Some(left), Some(right)) => (left, right),
133 let mut left_pos = 0;
134 let left = tokenize(&left)
136 let end = left_pos + t.len;
137 let s = &left[left_pos..end];
144 TokenKind::LineComment { .. } | TokenKind::BlockComment { .. } | TokenKind::Whitespace
148 let mut right_pos = 0;
149 let right = tokenize(&right)
151 let end = right_pos + t.len;
152 let s = &right[right_pos..end];
159 TokenKind::LineComment { .. } | TokenKind::BlockComment { .. } | TokenKind::Whitespace
166 over(left.stmts, right.stmts, |l, r| self.eq_stmt(l, r))
167 && both(&left.expr, &right.expr, |l, r| self.eq_expr(l, r))
172 #[allow(clippy::similar_names)]
173 pub fn eq_expr(&mut self, left: &Expr<'_>, right: &Expr<'_>) -> bool {
174 if !self.inner.allow_side_effects && differing_macro_contexts(left.span, right.span) {
178 if let Some(typeck_results) = self.inner.maybe_typeck_results {
179 if let (Some(l), Some(r)) = (
180 constant_simple(self.inner.cx, typeck_results, left),
181 constant_simple(self.inner.cx, typeck_results, right),
190 &reduce_exprkind(self.inner.cx, &left.kind),
191 &reduce_exprkind(self.inner.cx, &right.kind),
193 (&ExprKind::AddrOf(lb, l_mut, le), &ExprKind::AddrOf(rb, r_mut, re)) => {
194 lb == rb && l_mut == r_mut && self.eq_expr(le, re)
196 (&ExprKind::Continue(li), &ExprKind::Continue(ri)) => {
197 both(&li.label, &ri.label, |l, r| l.ident.name == r.ident.name)
199 (&ExprKind::Assign(ll, lr, _), &ExprKind::Assign(rl, rr, _)) => {
200 self.inner.allow_side_effects && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
202 (&ExprKind::AssignOp(ref lo, ll, lr), &ExprKind::AssignOp(ref ro, rl, rr)) => {
203 self.inner.allow_side_effects && lo.node == ro.node && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
205 (&ExprKind::Block(l, _), &ExprKind::Block(r, _)) => self.eq_block(l, r),
206 (&ExprKind::Binary(l_op, ll, lr), &ExprKind::Binary(r_op, rl, rr)) => {
207 l_op.node == r_op.node && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
208 || swap_binop(l_op.node, ll, lr).map_or(false, |(l_op, ll, lr)| {
209 l_op == r_op.node && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
212 (&ExprKind::Break(li, ref le), &ExprKind::Break(ri, ref re)) => {
213 both(&li.label, &ri.label, |l, r| l.ident.name == r.ident.name)
214 && both(le, re, |l, r| self.eq_expr(l, r))
216 (&ExprKind::Box(l), &ExprKind::Box(r)) => self.eq_expr(l, r),
217 (&ExprKind::Call(l_fun, l_args), &ExprKind::Call(r_fun, r_args)) => {
218 self.inner.allow_side_effects && self.eq_expr(l_fun, r_fun) && self.eq_exprs(l_args, r_args)
220 (&ExprKind::Cast(lx, lt), &ExprKind::Cast(rx, rt)) | (&ExprKind::Type(lx, lt), &ExprKind::Type(rx, rt)) => {
221 self.eq_expr(lx, rx) && self.eq_ty(lt, rt)
223 (&ExprKind::Field(l_f_exp, ref l_f_ident), &ExprKind::Field(r_f_exp, ref r_f_ident)) => {
224 l_f_ident.name == r_f_ident.name && self.eq_expr(l_f_exp, r_f_exp)
226 (&ExprKind::Index(la, li), &ExprKind::Index(ra, ri)) => self.eq_expr(la, ra) && self.eq_expr(li, ri),
227 (&ExprKind::If(lc, lt, ref le), &ExprKind::If(rc, rt, ref re)) => {
228 self.eq_expr(lc, rc) && self.eq_expr(&**lt, &**rt) && both(le, re, |l, r| self.eq_expr(l, r))
230 (&ExprKind::Lit(ref l), &ExprKind::Lit(ref r)) => l.node == r.node,
231 (&ExprKind::Loop(lb, ref ll, ref lls, _), &ExprKind::Loop(rb, ref rl, ref rls, _)) => {
232 lls == rls && self.eq_block(lb, rb) && both(ll, rl, |l, r| l.ident.name == r.ident.name)
234 (&ExprKind::Match(le, la, ref ls), &ExprKind::Match(re, ra, ref rs)) => {
236 && self.eq_expr(le, re)
237 && over(la, ra, |l, r| {
238 self.eq_pat(l.pat, r.pat)
239 && both(&l.guard, &r.guard, |l, r| self.eq_guard(l, r))
240 && self.eq_expr(l.body, r.body)
243 (&ExprKind::MethodCall(l_path, _, l_args, _), &ExprKind::MethodCall(r_path, _, r_args, _)) => {
244 self.inner.allow_side_effects && self.eq_path_segment(l_path, r_path) && self.eq_exprs(l_args, r_args)
246 (&ExprKind::Repeat(le, ref ll_id), &ExprKind::Repeat(re, ref rl_id)) => {
247 let mut celcx = constant_context(self.inner.cx, self.inner.cx.tcx.typeck_body(ll_id.body));
248 let ll = celcx.expr(&self.inner.cx.tcx.hir().body(ll_id.body).value);
249 let mut celcx = constant_context(self.inner.cx, self.inner.cx.tcx.typeck_body(rl_id.body));
250 let rl = celcx.expr(&self.inner.cx.tcx.hir().body(rl_id.body).value);
252 self.eq_expr(le, re) && ll == rl
254 (&ExprKind::Ret(ref l), &ExprKind::Ret(ref r)) => both(l, r, |l, r| self.eq_expr(l, r)),
255 (&ExprKind::Path(ref l), &ExprKind::Path(ref r)) => self.eq_qpath(l, r),
256 (&ExprKind::Struct(l_path, lf, ref lo), &ExprKind::Struct(r_path, rf, ref ro)) => {
257 self.eq_qpath(l_path, r_path)
258 && both(lo, ro, |l, r| self.eq_expr(l, r))
259 && over(lf, rf, |l, r| self.eq_expr_field(l, r))
261 (&ExprKind::Tup(l_tup), &ExprKind::Tup(r_tup)) => self.eq_exprs(l_tup, r_tup),
262 (&ExprKind::Unary(l_op, le), &ExprKind::Unary(r_op, re)) => l_op == r_op && self.eq_expr(le, re),
263 (&ExprKind::Array(l), &ExprKind::Array(r)) => self.eq_exprs(l, r),
264 (&ExprKind::DropTemps(le), &ExprKind::DropTemps(re)) => self.eq_expr(le, re),
267 is_eq || self.inner.expr_fallback.as_mut().map_or(false, |f| f(left, right))
270 fn eq_exprs(&mut self, left: &[Expr<'_>], right: &[Expr<'_>]) -> bool {
271 over(left, right, |l, r| self.eq_expr(l, r))
274 fn eq_expr_field(&mut self, left: &ExprField<'_>, right: &ExprField<'_>) -> bool {
275 left.ident.name == right.ident.name && self.eq_expr(left.expr, right.expr)
278 fn eq_guard(&mut self, left: &Guard<'_>, right: &Guard<'_>) -> bool {
279 match (left, right) {
280 (Guard::If(l), Guard::If(r)) => self.eq_expr(l, r),
281 (Guard::IfLet(lp, le), Guard::IfLet(rp, re)) => self.eq_pat(lp, rp) && self.eq_expr(le, re),
286 fn eq_generic_arg(&mut self, left: &GenericArg<'_>, right: &GenericArg<'_>) -> bool {
287 match (left, right) {
288 (GenericArg::Lifetime(l_lt), GenericArg::Lifetime(r_lt)) => Self::eq_lifetime(l_lt, r_lt),
289 (GenericArg::Type(l_ty), GenericArg::Type(r_ty)) => self.eq_ty(l_ty, r_ty),
294 fn eq_lifetime(left: &Lifetime, right: &Lifetime) -> bool {
295 left.name == right.name
298 fn eq_pat_field(&mut self, left: &PatField<'_>, right: &PatField<'_>) -> bool {
299 let (PatField { ident: li, pat: lp, .. }, PatField { ident: ri, pat: rp, .. }) = (&left, &right);
300 li.name == ri.name && self.eq_pat(lp, rp)
303 /// Checks whether two patterns are the same.
304 fn eq_pat(&mut self, left: &Pat<'_>, right: &Pat<'_>) -> bool {
305 match (&left.kind, &right.kind) {
306 (&PatKind::Box(l), &PatKind::Box(r)) => self.eq_pat(l, r),
307 (&PatKind::Struct(ref lp, la, ..), &PatKind::Struct(ref rp, ra, ..)) => {
308 self.eq_qpath(lp, rp) && over(la, ra, |l, r| self.eq_pat_field(l, r))
310 (&PatKind::TupleStruct(ref lp, la, ls), &PatKind::TupleStruct(ref rp, ra, rs)) => {
311 self.eq_qpath(lp, rp) && over(la, ra, |l, r| self.eq_pat(l, r)) && ls == rs
313 (&PatKind::Binding(lb, li, _, ref lp), &PatKind::Binding(rb, ri, _, ref rp)) => {
314 let eq = lb == rb && both(lp, rp, |l, r| self.eq_pat(l, r));
316 self.locals.insert(li, ri);
320 (&PatKind::Path(ref l), &PatKind::Path(ref r)) => self.eq_qpath(l, r),
321 (&PatKind::Lit(l), &PatKind::Lit(r)) => self.eq_expr(l, r),
322 (&PatKind::Tuple(l, ls), &PatKind::Tuple(r, rs)) => ls == rs && over(l, r, |l, r| self.eq_pat(l, r)),
323 (&PatKind::Range(ref ls, ref le, li), &PatKind::Range(ref rs, ref re, ri)) => {
324 both(ls, rs, |a, b| self.eq_expr(a, b)) && both(le, re, |a, b| self.eq_expr(a, b)) && (li == ri)
326 (&PatKind::Ref(le, ref lm), &PatKind::Ref(re, ref rm)) => lm == rm && self.eq_pat(le, re),
327 (&PatKind::Slice(ls, ref li, le), &PatKind::Slice(rs, ref ri, re)) => {
328 over(ls, rs, |l, r| self.eq_pat(l, r))
329 && over(le, re, |l, r| self.eq_pat(l, r))
330 && both(li, ri, |l, r| self.eq_pat(l, r))
332 (&PatKind::Wild, &PatKind::Wild) => true,
337 #[allow(clippy::similar_names)]
338 fn eq_qpath(&mut self, left: &QPath<'_>, right: &QPath<'_>) -> bool {
339 match (left, right) {
340 (&QPath::Resolved(ref lty, lpath), &QPath::Resolved(ref rty, rpath)) => {
341 both(lty, rty, |l, r| self.eq_ty(l, r)) && self.eq_path(lpath, rpath)
343 (&QPath::TypeRelative(lty, lseg), &QPath::TypeRelative(rty, rseg)) => {
344 self.eq_ty(lty, rty) && self.eq_path_segment(lseg, rseg)
346 (&QPath::LangItem(llang_item, _), &QPath::LangItem(rlang_item, _)) => llang_item == rlang_item,
351 fn eq_path(&mut self, left: &Path<'_>, right: &Path<'_>) -> bool {
352 match (left.res, right.res) {
353 (Res::Local(l), Res::Local(r)) => l == r || self.locals.get(&l) == Some(&r),
354 (Res::Local(_), _) | (_, Res::Local(_)) => false,
355 _ => over(left.segments, right.segments, |l, r| self.eq_path_segment(l, r)),
359 fn eq_path_parameters(&mut self, left: &GenericArgs<'_>, right: &GenericArgs<'_>) -> bool {
360 if !(left.parenthesized || right.parenthesized) {
361 over(left.args, right.args, |l, r| self.eq_generic_arg(l, r)) // FIXME(flip1995): may not work
362 && over(left.bindings, right.bindings, |l, r| self.eq_type_binding(l, r))
363 } else if left.parenthesized && right.parenthesized {
364 over(left.inputs(), right.inputs(), |l, r| self.eq_ty(l, r))
365 && both(&Some(&left.bindings[0].ty()), &Some(&right.bindings[0].ty()), |l, r| {
373 pub fn eq_path_segments(&mut self, left: &[PathSegment<'_>], right: &[PathSegment<'_>]) -> bool {
374 left.len() == right.len() && left.iter().zip(right).all(|(l, r)| self.eq_path_segment(l, r))
377 pub fn eq_path_segment(&mut self, left: &PathSegment<'_>, right: &PathSegment<'_>) -> bool {
378 // The == of idents doesn't work with different contexts,
379 // we have to be explicit about hygiene
380 left.ident.name == right.ident.name && both(&left.args, &right.args, |l, r| self.eq_path_parameters(l, r))
383 #[allow(clippy::similar_names)]
384 fn eq_ty(&mut self, left: &Ty<'_>, right: &Ty<'_>) -> bool {
385 match (&left.kind, &right.kind) {
386 (&TyKind::Slice(l_vec), &TyKind::Slice(r_vec)) => self.eq_ty(l_vec, r_vec),
387 (&TyKind::Array(lt, ref ll_id), &TyKind::Array(rt, ref rl_id)) => {
388 let cx = self.inner.cx;
390 |body| constant_context(cx, cx.tcx.typeck_body(body)).expr(&cx.tcx.hir().body(body).value);
391 self.eq_ty(lt, rt) && eval_const(ll_id.body) == eval_const(rl_id.body)
393 (&TyKind::Ptr(ref l_mut), &TyKind::Ptr(ref r_mut)) => {
394 l_mut.mutbl == r_mut.mutbl && self.eq_ty(&*l_mut.ty, &*r_mut.ty)
396 (&TyKind::Rptr(_, ref l_rmut), &TyKind::Rptr(_, ref r_rmut)) => {
397 l_rmut.mutbl == r_rmut.mutbl && self.eq_ty(&*l_rmut.ty, &*r_rmut.ty)
399 (&TyKind::Path(ref l), &TyKind::Path(ref r)) => self.eq_qpath(l, r),
400 (&TyKind::Tup(l), &TyKind::Tup(r)) => over(l, r, |l, r| self.eq_ty(l, r)),
401 (&TyKind::Infer, &TyKind::Infer) => true,
406 fn eq_type_binding(&mut self, left: &TypeBinding<'_>, right: &TypeBinding<'_>) -> bool {
407 left.ident.name == right.ident.name && self.eq_ty(left.ty(), right.ty())
411 /// Some simple reductions like `{ return }` => `return`
412 fn reduce_exprkind<'hir>(cx: &LateContext<'_>, kind: &'hir ExprKind<'hir>) -> &'hir ExprKind<'hir> {
413 if let ExprKind::Block(block, _) = kind {
414 match (block.stmts, block.expr) {
415 // From an `if let` expression without an `else` block. The arm for the implicit wild pattern is an empty
416 // block with an empty span.
417 ([], None) if block.span.is_empty() => &ExprKind::Tup(&[]),
419 ([], None) => match snippet_opt(cx, block.span) {
420 // Don't reduce if there are any tokens contained in the braces
427 TokenKind::LineComment { .. } | TokenKind::BlockComment { .. } | TokenKind::Whitespace
430 .ne([TokenKind::OpenBrace, TokenKind::CloseBrace].iter().copied()) =>
434 _ => &ExprKind::Tup(&[]),
436 ([], Some(expr)) => match expr.kind {
437 // `{ return .. }` => `return ..`
438 ExprKind::Ret(..) => &expr.kind,
441 ([stmt], None) => match stmt.kind {
442 StmtKind::Expr(expr) | StmtKind::Semi(expr) => match expr.kind {
443 // `{ return ..; }` => `return ..`
444 ExprKind::Ret(..) => &expr.kind,
460 ) -> Option<(BinOpKind, &'a Expr<'a>, &'a Expr<'a>)> {
462 BinOpKind::Add | BinOpKind::Eq | BinOpKind::Ne | BinOpKind::BitAnd | BinOpKind::BitXor | BinOpKind::BitOr => {
463 Some((binop, rhs, lhs))
465 BinOpKind::Lt => Some((BinOpKind::Gt, rhs, lhs)),
466 BinOpKind::Le => Some((BinOpKind::Ge, rhs, lhs)),
467 BinOpKind::Ge => Some((BinOpKind::Le, rhs, lhs)),
468 BinOpKind::Gt => Some((BinOpKind::Lt, rhs, lhs)),
469 BinOpKind::Mul // Not always commutative, e.g. with matrices. See issue #5698
476 | BinOpKind::Or => None,
480 /// Checks if the two `Option`s are both `None` or some equal values as per
482 pub fn both<X>(l: &Option<X>, r: &Option<X>, mut eq_fn: impl FnMut(&X, &X) -> bool) -> bool {
484 .map_or_else(|| r.is_none(), |x| r.as_ref().map_or(false, |y| eq_fn(x, y)))
487 /// Checks if two slices are equal as per `eq_fn`.
488 pub fn over<X>(left: &[X], right: &[X], mut eq_fn: impl FnMut(&X, &X) -> bool) -> bool {
489 left.len() == right.len() && left.iter().zip(right).all(|(x, y)| eq_fn(x, y))
492 /// Counts how many elements of the slices are equal as per `eq_fn`.
493 pub fn count_eq<X: Sized>(
494 left: &mut dyn Iterator<Item = X>,
495 right: &mut dyn Iterator<Item = X>,
496 mut eq_fn: impl FnMut(&X, &X) -> bool,
498 left.zip(right).take_while(|(l, r)| eq_fn(l, r)).count()
501 /// Checks if two expressions evaluate to the same value, and don't contain any side effects.
502 pub fn eq_expr_value(cx: &LateContext<'_>, left: &Expr<'_>, right: &Expr<'_>) -> bool {
503 SpanlessEq::new(cx).deny_side_effects().eq_expr(left, right)
506 /// Type used to hash an ast element. This is different from the `Hash` trait
507 /// on ast types as this
508 /// trait would consider IDs and spans.
510 /// All expressions kind are hashed, but some might have a weaker hash.
511 pub struct SpanlessHash<'a, 'tcx> {
512 /// Context used to evaluate constant expressions.
513 cx: &'a LateContext<'tcx>,
514 maybe_typeck_results: Option<&'tcx TypeckResults<'tcx>>,
518 impl<'a, 'tcx> SpanlessHash<'a, 'tcx> {
519 pub fn new(cx: &'a LateContext<'tcx>) -> Self {
522 maybe_typeck_results: cx.maybe_typeck_results(),
523 s: StableHasher::new(),
527 pub fn finish(self) -> u64 {
531 pub fn hash_block(&mut self, b: &Block<'_>) {
536 if let Some(e) = b.expr {
541 BlockCheckMode::DefaultBlock => 0,
542 BlockCheckMode::UnsafeBlock(_) => 1,
543 BlockCheckMode::PushUnsafeBlock(_) => 2,
544 BlockCheckMode::PopUnsafeBlock(_) => 3,
549 #[allow(clippy::many_single_char_names, clippy::too_many_lines)]
550 pub fn hash_expr(&mut self, e: &Expr<'_>) {
551 let simple_const = self
552 .maybe_typeck_results
553 .and_then(|typeck_results| constant_simple(self.cx, typeck_results, e));
555 // const hashing may result in the same hash as some unrelated node, so add a sort of
556 // discriminant depending on which path we're choosing next
557 simple_const.is_some().hash(&mut self.s);
559 if let Some(e) = simple_const {
560 return e.hash(&mut self.s);
563 std::mem::discriminant(&e.kind).hash(&mut self.s);
566 ExprKind::AddrOf(kind, m, e) => {
568 BorrowKind::Ref => 0,
569 BorrowKind::Raw => 1,
575 ExprKind::Continue(i) => {
576 if let Some(i) = i.label {
577 self.hash_name(i.ident.name);
580 ExprKind::Assign(l, r, _) => {
584 ExprKind::AssignOp(ref o, l, r) => {
586 .hash_stable(&mut self.cx.tcx.get_stable_hashing_context(), &mut self.s);
590 ExprKind::Block(b, _) => {
593 ExprKind::Binary(op, l, r) => {
595 .hash_stable(&mut self.cx.tcx.get_stable_hashing_context(), &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, _, _) => {
620 CaptureBy::Value => 0,
624 // closures inherit TypeckResults
625 self.hash_expr(&self.cx.tcx.hir().body(eid).value);
627 ExprKind::Field(e, ref f) => {
629 self.hash_name(f.name);
631 ExprKind::Index(a, i) => {
635 ExprKind::InlineAsm(asm) => {
636 for piece in asm.template {
638 InlineAsmTemplatePiece::String(s) => s.hash(&mut self.s),
639 InlineAsmTemplatePiece::Placeholder {
644 operand_idx.hash(&mut self.s);
645 modifier.hash(&mut self.s);
649 asm.options.hash(&mut self.s);
650 for (op, _op_sp) in asm.operands {
652 InlineAsmOperand::In { reg, expr } => {
653 reg.hash(&mut self.s);
654 self.hash_expr(expr);
656 InlineAsmOperand::Out { reg, late, expr } => {
657 reg.hash(&mut self.s);
658 late.hash(&mut self.s);
659 if let Some(expr) = expr {
660 self.hash_expr(expr);
663 InlineAsmOperand::InOut { reg, late, expr } => {
664 reg.hash(&mut self.s);
665 late.hash(&mut self.s);
666 self.hash_expr(expr);
668 InlineAsmOperand::SplitInOut {
674 reg.hash(&mut self.s);
675 late.hash(&mut self.s);
676 self.hash_expr(in_expr);
677 if let Some(out_expr) = out_expr {
678 self.hash_expr(out_expr);
681 InlineAsmOperand::Const { anon_const } => self.hash_body(anon_const.body),
682 InlineAsmOperand::Sym { expr } => self.hash_expr(expr),
686 ExprKind::LlvmInlineAsm(..) | ExprKind::Err => {},
687 ExprKind::Lit(ref l) => {
688 l.node.hash(&mut self.s);
690 ExprKind::Loop(b, ref i, ..) => {
692 if let Some(i) = *i {
693 self.hash_name(i.ident.name);
696 ExprKind::If(cond, then, ref else_opt) => {
697 let c: fn(_, _, _) -> _ = ExprKind::If;
699 self.hash_expr(cond);
700 self.hash_expr(then);
701 if let Some(e) = *else_opt {
705 ExprKind::Match(e, arms, ref s) => {
709 self.hash_pat(arm.pat);
710 if let Some(ref e) = arm.guard {
713 self.hash_expr(arm.body);
718 ExprKind::MethodCall(path, ref _tys, args, ref _fn_span) => {
719 self.hash_name(path.ident.name);
720 self.hash_exprs(args);
722 ExprKind::ConstBlock(ref l_id) => {
723 self.hash_body(l_id.body);
725 ExprKind::Repeat(e, ref l_id) => {
727 self.hash_body(l_id.body);
729 ExprKind::Ret(ref e) => {
730 if let Some(e) = *e {
734 ExprKind::Path(ref qpath) => {
735 self.hash_qpath(qpath);
737 ExprKind::Struct(path, fields, ref expr) => {
738 self.hash_qpath(path);
741 self.hash_name(f.ident.name);
742 self.hash_expr(f.expr);
745 if let Some(e) = *expr {
749 ExprKind::Tup(tup) => {
750 self.hash_exprs(tup);
752 ExprKind::Array(v) => {
755 ExprKind::Unary(lop, le) => {
756 lop.hash_stable(&mut self.cx.tcx.get_stable_hashing_context(), &mut self.s);
762 pub fn hash_exprs(&mut self, e: &[Expr<'_>]) {
768 pub fn hash_name(&mut self, n: Symbol) {
769 n.as_str().hash(&mut self.s);
772 pub fn hash_qpath(&mut self, p: &QPath<'_>) {
774 QPath::Resolved(_, path) => {
775 self.hash_path(path);
777 QPath::TypeRelative(_, path) => {
778 self.hash_name(path.ident.name);
780 QPath::LangItem(lang_item, ..) => {
781 lang_item.hash_stable(&mut self.cx.tcx.get_stable_hashing_context(), &mut self.s);
784 // self.maybe_typeck_results.unwrap().qpath_res(p, id).hash(&mut self.s);
787 pub fn hash_pat(&mut self, pat: &Pat<'_>) {
788 std::mem::discriminant(&pat.kind).hash(&mut self.s);
790 PatKind::Binding(ann, _, _, pat) => {
791 ann.hash_stable(&mut self.cx.tcx.get_stable_hashing_context(), &mut self.s);
792 if let Some(pat) = pat {
796 PatKind::Box(pat) => self.hash_pat(pat),
797 PatKind::Lit(expr) => self.hash_expr(expr),
798 PatKind::Or(pats) => {
803 PatKind::Path(ref qpath) => self.hash_qpath(qpath),
804 PatKind::Range(s, e, i) => {
811 i.hash_stable(&mut self.cx.tcx.get_stable_hashing_context(), &mut self.s);
813 PatKind::Ref(pat, m) => {
817 PatKind::Slice(l, m, r) => {
821 if let Some(pat) = m {
828 PatKind::Struct(ref qpath, fields, e) => {
829 self.hash_qpath(qpath);
831 self.hash_name(f.ident.name);
832 self.hash_pat(f.pat);
836 PatKind::Tuple(pats, e) => {
842 PatKind::TupleStruct(ref qpath, pats, e) => {
843 self.hash_qpath(qpath);
853 pub fn hash_path(&mut self, path: &Path<'_>) {
855 // constant hash since equality is dependant on inter-expression context
856 Res::Local(_) => 1_usize.hash(&mut self.s),
858 for seg in path.segments {
859 self.hash_name(seg.ident.name);
865 pub fn hash_stmt(&mut self, b: &Stmt<'_>) {
866 std::mem::discriminant(&b.kind).hash(&mut self.s);
869 StmtKind::Local(local) => {
870 self.hash_pat(local.pat);
871 if let Some(init) = local.init {
872 self.hash_expr(init);
875 StmtKind::Item(..) => {},
876 StmtKind::Expr(expr) | StmtKind::Semi(expr) => {
877 self.hash_expr(expr);
882 pub fn hash_guard(&mut self, g: &Guard<'_>) {
884 Guard::If(expr) | Guard::IfLet(_, expr) => {
885 self.hash_expr(expr);
890 pub fn hash_lifetime(&mut self, lifetime: Lifetime) {
891 std::mem::discriminant(&lifetime.name).hash(&mut self.s);
892 if let LifetimeName::Param(ref name) = lifetime.name {
893 std::mem::discriminant(name).hash(&mut self.s);
895 ParamName::Plain(ref ident) => {
896 ident.name.hash(&mut self.s);
898 ParamName::Fresh(ref size) => {
899 size.hash(&mut self.s);
901 ParamName::Error => {},
906 pub fn hash_ty(&mut self, ty: &Ty<'_>) {
907 std::mem::discriminant(&ty.kind).hash(&mut self.s);
909 TyKind::Slice(ty) => {
912 TyKind::Array(ty, anon_const) => {
914 self.hash_body(anon_const.body);
916 TyKind::Ptr(ref mut_ty) => {
917 self.hash_ty(mut_ty.ty);
918 mut_ty.mutbl.hash(&mut self.s);
920 TyKind::Rptr(lifetime, ref mut_ty) => {
921 self.hash_lifetime(lifetime);
922 self.hash_ty(mut_ty.ty);
923 mut_ty.mutbl.hash(&mut self.s);
925 TyKind::BareFn(bfn) => {
926 bfn.unsafety.hash(&mut self.s);
927 bfn.abi.hash(&mut self.s);
928 for arg in bfn.decl.inputs {
931 match bfn.decl.output {
932 FnRetTy::DefaultReturn(_) => {
933 ().hash(&mut self.s);
935 FnRetTy::Return(ty) => {
939 bfn.decl.c_variadic.hash(&mut self.s);
941 TyKind::Tup(ty_list) => {
946 TyKind::Path(ref qpath) => match qpath {
947 QPath::Resolved(ref maybe_ty, path) => {
948 if let Some(ty) = maybe_ty {
951 for segment in path.segments {
952 segment.ident.name.hash(&mut self.s);
953 self.hash_generic_args(segment.args().args);
956 QPath::TypeRelative(ty, segment) => {
958 segment.ident.name.hash(&mut self.s);
960 QPath::LangItem(lang_item, ..) => {
961 lang_item.hash(&mut self.s);
964 TyKind::OpaqueDef(_, arg_list) => {
965 self.hash_generic_args(arg_list);
967 TyKind::TraitObject(_, lifetime, _) => {
968 self.hash_lifetime(lifetime);
970 TyKind::Typeof(anon_const) => {
971 self.hash_body(anon_const.body);
973 TyKind::Err | TyKind::Infer | TyKind::Never => {},
977 pub fn hash_body(&mut self, body_id: BodyId) {
978 // swap out TypeckResults when hashing a body
979 let old_maybe_typeck_results = self.maybe_typeck_results.replace(self.cx.tcx.typeck_body(body_id));
980 self.hash_expr(&self.cx.tcx.hir().body(body_id).value);
981 self.maybe_typeck_results = old_maybe_typeck_results;
984 fn hash_generic_args(&mut self, arg_list: &[GenericArg<'_>]) {
985 for arg in arg_list {
987 GenericArg::Lifetime(l) => self.hash_lifetime(l),
988 GenericArg::Type(ref ty) => self.hash_ty(ty),
989 GenericArg::Const(ref ca) => self.hash_body(ca.value.body),