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::fx::FxHasher;
6 use rustc_hir::def::Res;
7 use rustc_hir::HirIdMap;
9 BinOpKind, Block, BodyId, Expr, ExprField, ExprKind, FnRetTy, GenericArg, GenericArgs, Guard, HirId,
10 InlineAsmOperand, Let, Lifetime, LifetimeName, ParamName, Pat, PatField, PatKind, Path, PathSegment, QPath, Stmt,
11 StmtKind, Ty, TyKind, TypeBinding,
13 use rustc_lexer::{tokenize, TokenKind};
14 use rustc_lint::LateContext;
15 use rustc_middle::ty::TypeckResults;
16 use rustc_span::Symbol;
17 use std::hash::{Hash, Hasher};
19 /// Type used to check whether two ast are the same. This is different from the
21 /// `==` on ast types as this operator would compare true equality with ID and
24 /// Note that some expressions kinds are not considered but could be added.
25 pub struct SpanlessEq<'a, 'tcx> {
26 /// Context used to evaluate constant expressions.
27 cx: &'a LateContext<'tcx>,
28 maybe_typeck_results: Option<&'tcx TypeckResults<'tcx>>,
29 allow_side_effects: bool,
30 expr_fallback: Option<Box<dyn FnMut(&Expr<'_>, &Expr<'_>) -> bool + 'a>>,
33 impl<'a, 'tcx> SpanlessEq<'a, 'tcx> {
34 pub fn new(cx: &'a LateContext<'tcx>) -> Self {
37 maybe_typeck_results: cx.maybe_typeck_results(),
38 allow_side_effects: true,
43 /// Consider expressions containing potential side effects as not equal.
45 pub fn deny_side_effects(self) -> Self {
47 allow_side_effects: false,
53 pub fn expr_fallback(self, expr_fallback: impl FnMut(&Expr<'_>, &Expr<'_>) -> bool + 'a) -> Self {
55 expr_fallback: Some(Box::new(expr_fallback)),
60 /// Use this method to wrap comparisons that may involve inter-expression context.
61 /// See `self.locals`.
62 pub fn inter_expr(&mut self) -> HirEqInterExpr<'_, 'a, 'tcx> {
65 locals: HirIdMap::default(),
70 pub fn eq_block(&mut self, left: &Block<'_>, right: &Block<'_>) -> bool {
71 self.inter_expr().eq_block(left, right)
74 pub fn eq_expr(&mut self, left: &Expr<'_>, right: &Expr<'_>) -> bool {
75 self.inter_expr().eq_expr(left, right)
78 pub fn eq_path_segment(&mut self, left: &PathSegment<'_>, right: &PathSegment<'_>) -> bool {
79 self.inter_expr().eq_path_segment(left, right)
82 pub fn eq_path_segments(&mut self, left: &[PathSegment<'_>], right: &[PathSegment<'_>]) -> bool {
83 self.inter_expr().eq_path_segments(left, right)
87 pub struct HirEqInterExpr<'a, 'b, 'tcx> {
88 inner: &'a mut SpanlessEq<'b, 'tcx>,
90 // When binding are declared, the binding ID in the left expression is mapped to the one on the
91 // right. For example, when comparing `{ let x = 1; x + 2 }` and `{ let y = 1; y + 2 }`,
92 // these blocks are considered equal since `x` is mapped to `y`.
93 locals: HirIdMap<HirId>,
96 impl HirEqInterExpr<'_, '_, '_> {
97 pub fn eq_stmt(&mut self, left: &Stmt<'_>, right: &Stmt<'_>) -> bool {
98 match (&left.kind, &right.kind) {
99 (&StmtKind::Local(l), &StmtKind::Local(r)) => {
100 // This additional check ensures that the type of the locals are equivalent even if the init
101 // expression or type have some inferred parts.
102 if let Some(typeck) = self.inner.maybe_typeck_results {
103 let l_ty = typeck.pat_ty(l.pat);
104 let r_ty = typeck.pat_ty(r.pat);
105 if !rustc_middle::ty::TyS::same_type(l_ty, r_ty) {
110 // eq_pat adds the HirIds to the locals map. We therefor call it last to make sure that
111 // these only get added if the init and type is equal.
112 both(&l.init, &r.init, |l, r| self.eq_expr(l, r))
113 && both(&l.ty, &r.ty, |l, r| self.eq_ty(l, r))
114 && self.eq_pat(l.pat, r.pat)
116 (&StmtKind::Expr(l), &StmtKind::Expr(r)) | (&StmtKind::Semi(l), &StmtKind::Semi(r)) => self.eq_expr(l, r),
121 /// Checks whether two blocks are the same.
122 fn eq_block(&mut self, left: &Block<'_>, right: &Block<'_>) -> bool {
123 match (left.stmts, left.expr, right.stmts, right.expr) {
124 ([], None, [], None) => {
125 // For empty blocks, check to see if the tokens are equal. This will catch the case where a macro
126 // expanded to nothing, or the cfg attribute was used.
127 let (left, right) = match (
128 snippet_opt(self.inner.cx, left.span),
129 snippet_opt(self.inner.cx, right.span),
131 (Some(left), Some(right)) => (left, right),
134 let mut left_pos = 0;
135 let left = tokenize(&left)
137 let end = left_pos + t.len;
138 let s = &left[left_pos..end];
145 TokenKind::LineComment { .. } | TokenKind::BlockComment { .. } | TokenKind::Whitespace
149 let mut right_pos = 0;
150 let right = tokenize(&right)
152 let end = right_pos + t.len;
153 let s = &right[right_pos..end];
160 TokenKind::LineComment { .. } | TokenKind::BlockComment { .. } | TokenKind::Whitespace
167 over(left.stmts, right.stmts, |l, r| self.eq_stmt(l, r))
168 && both(&left.expr, &right.expr, |l, r| self.eq_expr(l, r))
173 pub fn eq_body(&mut self, left: BodyId, right: BodyId) -> bool {
174 let cx = self.inner.cx;
175 let eval_const = |body| constant_context(cx, cx.tcx.typeck_body(body)).expr(&cx.tcx.hir().body(body).value);
176 eval_const(left) == eval_const(right)
179 #[allow(clippy::similar_names)]
180 pub fn eq_expr(&mut self, left: &Expr<'_>, right: &Expr<'_>) -> bool {
181 if !self.inner.allow_side_effects && differing_macro_contexts(left.span, right.span) {
185 if let Some(typeck_results) = self.inner.maybe_typeck_results {
186 if let (Some(l), Some(r)) = (
187 constant_simple(self.inner.cx, typeck_results, left),
188 constant_simple(self.inner.cx, typeck_results, right),
197 &reduce_exprkind(self.inner.cx, &left.kind),
198 &reduce_exprkind(self.inner.cx, &right.kind),
200 (&ExprKind::AddrOf(lb, l_mut, le), &ExprKind::AddrOf(rb, r_mut, re)) => {
201 lb == rb && l_mut == r_mut && self.eq_expr(le, re)
203 (&ExprKind::Continue(li), &ExprKind::Continue(ri)) => {
204 both(&li.label, &ri.label, |l, r| l.ident.name == r.ident.name)
206 (&ExprKind::Assign(ll, lr, _), &ExprKind::Assign(rl, rr, _)) => {
207 self.inner.allow_side_effects && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
209 (&ExprKind::AssignOp(ref lo, ll, lr), &ExprKind::AssignOp(ref ro, rl, rr)) => {
210 self.inner.allow_side_effects && lo.node == ro.node && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
212 (&ExprKind::Block(l, _), &ExprKind::Block(r, _)) => self.eq_block(l, r),
213 (&ExprKind::Binary(l_op, ll, lr), &ExprKind::Binary(r_op, rl, rr)) => {
214 l_op.node == r_op.node && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
215 || swap_binop(l_op.node, ll, lr).map_or(false, |(l_op, ll, lr)| {
216 l_op == r_op.node && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
219 (&ExprKind::Break(li, ref le), &ExprKind::Break(ri, ref re)) => {
220 both(&li.label, &ri.label, |l, r| l.ident.name == r.ident.name)
221 && both(le, re, |l, r| self.eq_expr(l, r))
223 (&ExprKind::Box(l), &ExprKind::Box(r)) => self.eq_expr(l, r),
224 (&ExprKind::Call(l_fun, l_args), &ExprKind::Call(r_fun, r_args)) => {
225 self.inner.allow_side_effects && self.eq_expr(l_fun, r_fun) && self.eq_exprs(l_args, r_args)
227 (&ExprKind::Cast(lx, lt), &ExprKind::Cast(rx, rt)) | (&ExprKind::Type(lx, lt), &ExprKind::Type(rx, rt)) => {
228 self.eq_expr(lx, rx) && self.eq_ty(lt, rt)
230 (&ExprKind::Field(l_f_exp, ref l_f_ident), &ExprKind::Field(r_f_exp, ref r_f_ident)) => {
231 l_f_ident.name == r_f_ident.name && self.eq_expr(l_f_exp, r_f_exp)
233 (&ExprKind::Index(la, li), &ExprKind::Index(ra, ri)) => self.eq_expr(la, ra) && self.eq_expr(li, ri),
234 (&ExprKind::If(lc, lt, ref le), &ExprKind::If(rc, rt, ref re)) => {
235 self.eq_expr(lc, rc) && self.eq_expr(&**lt, &**rt) && both(le, re, |l, r| self.eq_expr(l, r))
237 (&ExprKind::Let(l), &ExprKind::Let(r)) => {
238 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)
240 (&ExprKind::Lit(ref l), &ExprKind::Lit(ref r)) => l.node == r.node,
241 (&ExprKind::Loop(lb, ref ll, ref lls, _), &ExprKind::Loop(rb, ref rl, ref rls, _)) => {
242 lls == rls && self.eq_block(lb, rb) && both(ll, rl, |l, r| l.ident.name == r.ident.name)
244 (&ExprKind::Match(le, la, ref ls), &ExprKind::Match(re, ra, ref rs)) => {
246 && self.eq_expr(le, re)
247 && over(la, ra, |l, r| {
248 self.eq_pat(l.pat, r.pat)
249 && both(&l.guard, &r.guard, |l, r| self.eq_guard(l, r))
250 && self.eq_expr(l.body, r.body)
253 (&ExprKind::MethodCall(l_path, _, l_args, _), &ExprKind::MethodCall(r_path, _, r_args, _)) => {
254 self.inner.allow_side_effects && self.eq_path_segment(l_path, r_path) && self.eq_exprs(l_args, r_args)
256 (&ExprKind::Repeat(le, ref ll_id), &ExprKind::Repeat(re, ref rl_id)) => {
257 self.eq_expr(le, re) && self.eq_body(ll_id.body, rl_id.body)
259 (&ExprKind::Ret(ref l), &ExprKind::Ret(ref r)) => both(l, r, |l, r| self.eq_expr(l, r)),
260 (&ExprKind::Path(ref l), &ExprKind::Path(ref r)) => self.eq_qpath(l, r),
261 (&ExprKind::Struct(l_path, lf, ref lo), &ExprKind::Struct(r_path, rf, ref ro)) => {
262 self.eq_qpath(l_path, r_path)
263 && both(lo, ro, |l, r| self.eq_expr(l, r))
264 && over(lf, rf, |l, r| self.eq_expr_field(l, r))
266 (&ExprKind::Tup(l_tup), &ExprKind::Tup(r_tup)) => self.eq_exprs(l_tup, r_tup),
267 (&ExprKind::Unary(l_op, le), &ExprKind::Unary(r_op, re)) => l_op == r_op && self.eq_expr(le, re),
268 (&ExprKind::Array(l), &ExprKind::Array(r)) => self.eq_exprs(l, r),
269 (&ExprKind::DropTemps(le), &ExprKind::DropTemps(re)) => self.eq_expr(le, re),
272 is_eq || self.inner.expr_fallback.as_mut().map_or(false, |f| f(left, right))
275 fn eq_exprs(&mut self, left: &[Expr<'_>], right: &[Expr<'_>]) -> bool {
276 over(left, right, |l, r| self.eq_expr(l, r))
279 fn eq_expr_field(&mut self, left: &ExprField<'_>, right: &ExprField<'_>) -> bool {
280 left.ident.name == right.ident.name && self.eq_expr(left.expr, right.expr)
283 fn eq_guard(&mut self, left: &Guard<'_>, right: &Guard<'_>) -> bool {
284 match (left, right) {
285 (Guard::If(l), Guard::If(r)) => self.eq_expr(l, r),
286 (Guard::IfLet(lp, le), Guard::IfLet(rp, re)) => self.eq_pat(lp, rp) && self.eq_expr(le, re),
291 fn eq_generic_arg(&mut self, left: &GenericArg<'_>, right: &GenericArg<'_>) -> bool {
292 match (left, right) {
293 (GenericArg::Const(l), GenericArg::Const(r)) => self.eq_body(l.value.body, r.value.body),
294 (GenericArg::Lifetime(l_lt), GenericArg::Lifetime(r_lt)) => Self::eq_lifetime(l_lt, r_lt),
295 (GenericArg::Type(l_ty), GenericArg::Type(r_ty)) => self.eq_ty(l_ty, r_ty),
296 (GenericArg::Infer(l_inf), GenericArg::Infer(r_inf)) => self.eq_ty(&l_inf.to_ty(), &r_inf.to_ty()),
301 fn eq_lifetime(left: &Lifetime, right: &Lifetime) -> bool {
302 left.name == right.name
305 fn eq_pat_field(&mut self, left: &PatField<'_>, right: &PatField<'_>) -> bool {
306 let (PatField { ident: li, pat: lp, .. }, PatField { ident: ri, pat: rp, .. }) = (&left, &right);
307 li.name == ri.name && self.eq_pat(lp, rp)
310 /// Checks whether two patterns are the same.
311 fn eq_pat(&mut self, left: &Pat<'_>, right: &Pat<'_>) -> bool {
312 match (&left.kind, &right.kind) {
313 (&PatKind::Box(l), &PatKind::Box(r)) => self.eq_pat(l, r),
314 (&PatKind::Struct(ref lp, la, ..), &PatKind::Struct(ref rp, ra, ..)) => {
315 self.eq_qpath(lp, rp) && over(la, ra, |l, r| self.eq_pat_field(l, r))
317 (&PatKind::TupleStruct(ref lp, la, ls), &PatKind::TupleStruct(ref rp, ra, rs)) => {
318 self.eq_qpath(lp, rp) && over(la, ra, |l, r| self.eq_pat(l, r)) && ls == rs
320 (&PatKind::Binding(lb, li, _, ref lp), &PatKind::Binding(rb, ri, _, ref rp)) => {
321 let eq = lb == rb && both(lp, rp, |l, r| self.eq_pat(l, r));
323 self.locals.insert(li, ri);
327 (&PatKind::Path(ref l), &PatKind::Path(ref r)) => self.eq_qpath(l, r),
328 (&PatKind::Lit(l), &PatKind::Lit(r)) => self.eq_expr(l, r),
329 (&PatKind::Tuple(l, ls), &PatKind::Tuple(r, rs)) => ls == rs && over(l, r, |l, r| self.eq_pat(l, r)),
330 (&PatKind::Range(ref ls, ref le, li), &PatKind::Range(ref rs, ref re, ri)) => {
331 both(ls, rs, |a, b| self.eq_expr(a, b)) && both(le, re, |a, b| self.eq_expr(a, b)) && (li == ri)
333 (&PatKind::Ref(le, ref lm), &PatKind::Ref(re, ref rm)) => lm == rm && self.eq_pat(le, re),
334 (&PatKind::Slice(ls, ref li, le), &PatKind::Slice(rs, ref ri, re)) => {
335 over(ls, rs, |l, r| self.eq_pat(l, r))
336 && over(le, re, |l, r| self.eq_pat(l, r))
337 && both(li, ri, |l, r| self.eq_pat(l, r))
339 (&PatKind::Wild, &PatKind::Wild) => true,
344 #[allow(clippy::similar_names)]
345 fn eq_qpath(&mut self, left: &QPath<'_>, right: &QPath<'_>) -> bool {
346 match (left, right) {
347 (&QPath::Resolved(ref lty, lpath), &QPath::Resolved(ref rty, rpath)) => {
348 both(lty, rty, |l, r| self.eq_ty(l, r)) && self.eq_path(lpath, rpath)
350 (&QPath::TypeRelative(lty, lseg), &QPath::TypeRelative(rty, rseg)) => {
351 self.eq_ty(lty, rty) && self.eq_path_segment(lseg, rseg)
353 (&QPath::LangItem(llang_item, ..), &QPath::LangItem(rlang_item, ..)) => llang_item == rlang_item,
358 fn eq_path(&mut self, left: &Path<'_>, right: &Path<'_>) -> bool {
359 match (left.res, right.res) {
360 (Res::Local(l), Res::Local(r)) => l == r || self.locals.get(&l) == Some(&r),
361 (Res::Local(_), _) | (_, Res::Local(_)) => false,
362 _ => over(left.segments, right.segments, |l, r| self.eq_path_segment(l, r)),
366 fn eq_path_parameters(&mut self, left: &GenericArgs<'_>, right: &GenericArgs<'_>) -> bool {
367 if !(left.parenthesized || right.parenthesized) {
368 over(left.args, right.args, |l, r| self.eq_generic_arg(l, r)) // FIXME(flip1995): may not work
369 && over(left.bindings, right.bindings, |l, r| self.eq_type_binding(l, r))
370 } else if left.parenthesized && right.parenthesized {
371 over(left.inputs(), right.inputs(), |l, r| self.eq_ty(l, r))
372 && both(&Some(&left.bindings[0].ty()), &Some(&right.bindings[0].ty()), |l, r| {
380 pub fn eq_path_segments(&mut self, left: &[PathSegment<'_>], right: &[PathSegment<'_>]) -> bool {
381 left.len() == right.len() && left.iter().zip(right).all(|(l, r)| self.eq_path_segment(l, r))
384 pub fn eq_path_segment(&mut self, left: &PathSegment<'_>, right: &PathSegment<'_>) -> bool {
385 // The == of idents doesn't work with different contexts,
386 // we have to be explicit about hygiene
387 left.ident.name == right.ident.name && both(&left.args, &right.args, |l, r| self.eq_path_parameters(l, r))
390 #[allow(clippy::similar_names)]
391 pub fn eq_ty(&mut self, left: &Ty<'_>, right: &Ty<'_>) -> bool {
392 match (&left.kind, &right.kind) {
393 (&TyKind::Slice(l_vec), &TyKind::Slice(r_vec)) => self.eq_ty(l_vec, r_vec),
394 (&TyKind::Array(lt, ref ll_id), &TyKind::Array(rt, ref rl_id)) => {
395 self.eq_ty(lt, rt) && self.eq_body(ll_id.body, rl_id.body)
397 (&TyKind::Ptr(ref l_mut), &TyKind::Ptr(ref r_mut)) => {
398 l_mut.mutbl == r_mut.mutbl && self.eq_ty(&*l_mut.ty, &*r_mut.ty)
400 (&TyKind::Rptr(_, ref l_rmut), &TyKind::Rptr(_, ref r_rmut)) => {
401 l_rmut.mutbl == r_rmut.mutbl && self.eq_ty(&*l_rmut.ty, &*r_rmut.ty)
403 (&TyKind::Path(ref l), &TyKind::Path(ref r)) => self.eq_qpath(l, r),
404 (&TyKind::Tup(l), &TyKind::Tup(r)) => over(l, r, |l, r| self.eq_ty(l, r)),
405 (&TyKind::Infer, &TyKind::Infer) => true,
410 fn eq_type_binding(&mut self, left: &TypeBinding<'_>, right: &TypeBinding<'_>) -> bool {
411 left.ident.name == right.ident.name && self.eq_ty(left.ty(), right.ty())
415 /// Some simple reductions like `{ return }` => `return`
416 fn reduce_exprkind<'hir>(cx: &LateContext<'_>, kind: &'hir ExprKind<'hir>) -> &'hir ExprKind<'hir> {
417 if let ExprKind::Block(block, _) = kind {
418 match (block.stmts, block.expr) {
419 // From an `if let` expression without an `else` block. The arm for the implicit wild pattern is an empty
420 // block with an empty span.
421 ([], None) if block.span.is_empty() => &ExprKind::Tup(&[]),
423 ([], None) => match snippet_opt(cx, block.span) {
424 // Don't reduce if there are any tokens contained in the braces
431 TokenKind::LineComment { .. } | TokenKind::BlockComment { .. } | TokenKind::Whitespace
434 .ne([TokenKind::OpenBrace, TokenKind::CloseBrace].iter().copied()) =>
438 _ => &ExprKind::Tup(&[]),
440 ([], Some(expr)) => match expr.kind {
441 // `{ return .. }` => `return ..`
442 ExprKind::Ret(..) => &expr.kind,
445 ([stmt], None) => match stmt.kind {
446 StmtKind::Expr(expr) | StmtKind::Semi(expr) => match expr.kind {
447 // `{ return ..; }` => `return ..`
448 ExprKind::Ret(..) => &expr.kind,
464 ) -> Option<(BinOpKind, &'a Expr<'a>, &'a Expr<'a>)> {
466 BinOpKind::Add | BinOpKind::Eq | BinOpKind::Ne | BinOpKind::BitAnd | BinOpKind::BitXor | BinOpKind::BitOr => {
467 Some((binop, rhs, lhs))
469 BinOpKind::Lt => Some((BinOpKind::Gt, rhs, lhs)),
470 BinOpKind::Le => Some((BinOpKind::Ge, rhs, lhs)),
471 BinOpKind::Ge => Some((BinOpKind::Le, rhs, lhs)),
472 BinOpKind::Gt => Some((BinOpKind::Lt, rhs, lhs)),
473 BinOpKind::Mul // Not always commutative, e.g. with matrices. See issue #5698
480 | BinOpKind::Or => None,
484 /// Checks if the two `Option`s are both `None` or some equal values as per
486 pub fn both<X>(l: &Option<X>, r: &Option<X>, mut eq_fn: impl FnMut(&X, &X) -> bool) -> bool {
488 .map_or_else(|| r.is_none(), |x| r.as_ref().map_or(false, |y| eq_fn(x, y)))
491 /// Checks if two slices are equal as per `eq_fn`.
492 pub fn over<X>(left: &[X], right: &[X], mut eq_fn: impl FnMut(&X, &X) -> bool) -> bool {
493 left.len() == right.len() && left.iter().zip(right).all(|(x, y)| eq_fn(x, y))
496 /// Counts how many elements of the slices are equal as per `eq_fn`.
497 pub fn count_eq<X: Sized>(
498 left: &mut dyn Iterator<Item = X>,
499 right: &mut dyn Iterator<Item = X>,
500 mut eq_fn: impl FnMut(&X, &X) -> bool,
502 left.zip(right).take_while(|(l, r)| eq_fn(l, r)).count()
505 /// Checks if two expressions evaluate to the same value, and don't contain any side effects.
506 pub fn eq_expr_value(cx: &LateContext<'_>, left: &Expr<'_>, right: &Expr<'_>) -> bool {
507 SpanlessEq::new(cx).deny_side_effects().eq_expr(left, right)
510 /// Type used to hash an ast element. This is different from the `Hash` trait
511 /// on ast types as this
512 /// trait would consider IDs and spans.
514 /// All expressions kind are hashed, but some might have a weaker hash.
515 pub struct SpanlessHash<'a, 'tcx> {
516 /// Context used to evaluate constant expressions.
517 cx: &'a LateContext<'tcx>,
518 maybe_typeck_results: Option<&'tcx TypeckResults<'tcx>>,
522 impl<'a, 'tcx> SpanlessHash<'a, 'tcx> {
523 pub fn new(cx: &'a LateContext<'tcx>) -> Self {
526 maybe_typeck_results: cx.maybe_typeck_results(),
527 s: FxHasher::default(),
531 pub fn finish(self) -> u64 {
535 pub fn hash_block(&mut self, b: &Block<'_>) {
540 if let Some(e) = b.expr {
544 std::mem::discriminant(&b.rules).hash(&mut self.s);
547 #[allow(clippy::too_many_lines)]
548 pub fn hash_expr(&mut self, e: &Expr<'_>) {
549 let simple_const = self
550 .maybe_typeck_results
551 .and_then(|typeck_results| constant_simple(self.cx, typeck_results, e));
553 // const hashing may result in the same hash as some unrelated node, so add a sort of
554 // discriminant depending on which path we're choosing next
555 simple_const.hash(&mut self.s);
556 if simple_const.is_some() {
560 std::mem::discriminant(&e.kind).hash(&mut self.s);
563 ExprKind::AddrOf(kind, m, e) => {
564 std::mem::discriminant(&kind).hash(&mut self.s);
568 ExprKind::Continue(i) => {
569 if let Some(i) = i.label {
570 self.hash_name(i.ident.name);
573 ExprKind::Assign(l, r, _) => {
577 ExprKind::AssignOp(ref o, l, r) => {
578 std::mem::discriminant(&o.node).hash(&mut self.s);
582 ExprKind::Block(b, _) => {
585 ExprKind::Binary(op, l, r) => {
586 std::mem::discriminant(&op.node).hash(&mut self.s);
590 ExprKind::Break(i, ref j) => {
591 if let Some(i) = i.label {
592 self.hash_name(i.ident.name);
594 if let Some(j) = *j {
598 ExprKind::Box(e) | ExprKind::DropTemps(e) | ExprKind::Yield(e, _) => {
601 ExprKind::Call(fun, args) => {
603 self.hash_exprs(args);
605 ExprKind::Cast(e, ty) | ExprKind::Type(e, ty) => {
609 ExprKind::Closure(cap, _, eid, _, _) => {
610 std::mem::discriminant(&cap).hash(&mut self.s);
611 // closures inherit TypeckResults
612 self.hash_expr(&self.cx.tcx.hir().body(eid).value);
614 ExprKind::Field(e, ref f) => {
616 self.hash_name(f.name);
618 ExprKind::Index(a, i) => {
622 ExprKind::InlineAsm(asm) => {
623 for piece in asm.template {
625 InlineAsmTemplatePiece::String(s) => s.hash(&mut self.s),
626 InlineAsmTemplatePiece::Placeholder {
631 operand_idx.hash(&mut self.s);
632 modifier.hash(&mut self.s);
636 asm.options.hash(&mut self.s);
637 for (op, _op_sp) in asm.operands {
639 InlineAsmOperand::In { reg, expr } => {
640 reg.hash(&mut self.s);
641 self.hash_expr(expr);
643 InlineAsmOperand::Out { reg, late, expr } => {
644 reg.hash(&mut self.s);
645 late.hash(&mut self.s);
646 if let Some(expr) = expr {
647 self.hash_expr(expr);
650 InlineAsmOperand::InOut { reg, late, expr } => {
651 reg.hash(&mut self.s);
652 late.hash(&mut self.s);
653 self.hash_expr(expr);
655 InlineAsmOperand::SplitInOut {
661 reg.hash(&mut self.s);
662 late.hash(&mut self.s);
663 self.hash_expr(in_expr);
664 if let Some(out_expr) = out_expr {
665 self.hash_expr(out_expr);
668 InlineAsmOperand::Const { anon_const } => self.hash_body(anon_const.body),
669 InlineAsmOperand::Sym { expr } => self.hash_expr(expr),
673 ExprKind::Let(Let { pat, init, ty, .. }) => {
674 self.hash_expr(init);
675 if let Some(ty) = ty {
680 ExprKind::LlvmInlineAsm(..) | ExprKind::Err => {},
681 ExprKind::Lit(ref l) => {
682 l.node.hash(&mut self.s);
684 ExprKind::Loop(b, ref i, ..) => {
686 if let Some(i) = *i {
687 self.hash_name(i.ident.name);
690 ExprKind::If(cond, then, ref else_opt) => {
691 self.hash_expr(cond);
692 self.hash_expr(then);
693 if let Some(e) = *else_opt {
697 ExprKind::Match(e, arms, ref s) => {
701 self.hash_pat(arm.pat);
702 if let Some(ref e) = arm.guard {
705 self.hash_expr(arm.body);
710 ExprKind::MethodCall(path, ref _tys, args, ref _fn_span) => {
711 self.hash_name(path.ident.name);
712 self.hash_exprs(args);
714 ExprKind::ConstBlock(ref l_id) => {
715 self.hash_body(l_id.body);
717 ExprKind::Repeat(e, ref l_id) => {
719 self.hash_body(l_id.body);
721 ExprKind::Ret(ref e) => {
722 if let Some(e) = *e {
726 ExprKind::Path(ref qpath) => {
727 self.hash_qpath(qpath);
729 ExprKind::Struct(path, fields, ref expr) => {
730 self.hash_qpath(path);
733 self.hash_name(f.ident.name);
734 self.hash_expr(f.expr);
737 if let Some(e) = *expr {
741 ExprKind::Tup(tup) => {
742 self.hash_exprs(tup);
744 ExprKind::Array(v) => {
747 ExprKind::Unary(lop, le) => {
748 std::mem::discriminant(&lop).hash(&mut self.s);
754 pub fn hash_exprs(&mut self, e: &[Expr<'_>]) {
760 pub fn hash_name(&mut self, n: Symbol) {
764 pub fn hash_qpath(&mut self, p: &QPath<'_>) {
766 QPath::Resolved(_, path) => {
767 self.hash_path(path);
769 QPath::TypeRelative(_, path) => {
770 self.hash_name(path.ident.name);
772 QPath::LangItem(lang_item, ..) => {
773 std::mem::discriminant(&lang_item).hash(&mut self.s);
776 // self.maybe_typeck_results.unwrap().qpath_res(p, id).hash(&mut self.s);
779 pub fn hash_pat(&mut self, pat: &Pat<'_>) {
780 std::mem::discriminant(&pat.kind).hash(&mut self.s);
782 PatKind::Binding(ann, _, _, pat) => {
783 std::mem::discriminant(&ann).hash(&mut self.s);
784 if let Some(pat) = pat {
788 PatKind::Box(pat) => self.hash_pat(pat),
789 PatKind::Lit(expr) => self.hash_expr(expr),
790 PatKind::Or(pats) => {
795 PatKind::Path(ref qpath) => self.hash_qpath(qpath),
796 PatKind::Range(s, e, i) => {
803 std::mem::discriminant(&i).hash(&mut self.s);
805 PatKind::Ref(pat, mu) => {
807 std::mem::discriminant(&mu).hash(&mut self.s);
809 PatKind::Slice(l, m, r) => {
813 if let Some(pat) = m {
820 PatKind::Struct(ref qpath, fields, e) => {
821 self.hash_qpath(qpath);
823 self.hash_name(f.ident.name);
824 self.hash_pat(f.pat);
828 PatKind::Tuple(pats, e) => {
834 PatKind::TupleStruct(ref qpath, pats, e) => {
835 self.hash_qpath(qpath);
845 pub fn hash_path(&mut self, path: &Path<'_>) {
847 // constant hash since equality is dependant on inter-expression context
848 // e.g. The expressions `if let Some(x) = foo() {}` and `if let Some(y) = foo() {}` are considered equal
849 // even though the binding names are different and they have different `HirId`s.
850 Res::Local(_) => 1_usize.hash(&mut self.s),
852 for seg in path.segments {
853 self.hash_name(seg.ident.name);
854 self.hash_generic_args(seg.args().args);
860 pub fn hash_stmt(&mut self, b: &Stmt<'_>) {
861 std::mem::discriminant(&b.kind).hash(&mut self.s);
864 StmtKind::Local(local) => {
865 self.hash_pat(local.pat);
866 if let Some(init) = local.init {
867 self.hash_expr(init);
870 StmtKind::Item(..) => {},
871 StmtKind::Expr(expr) | StmtKind::Semi(expr) => {
872 self.hash_expr(expr);
877 pub fn hash_guard(&mut self, g: &Guard<'_>) {
879 Guard::If(expr) | Guard::IfLet(_, expr) => {
880 self.hash_expr(expr);
885 pub fn hash_lifetime(&mut self, lifetime: Lifetime) {
886 std::mem::discriminant(&lifetime.name).hash(&mut self.s);
887 if let LifetimeName::Param(ref name) = lifetime.name {
888 std::mem::discriminant(name).hash(&mut self.s);
890 ParamName::Plain(ref ident) => {
891 ident.name.hash(&mut self.s);
893 ParamName::Fresh(ref size) => {
894 size.hash(&mut self.s);
896 ParamName::Error => {},
901 pub fn hash_ty(&mut self, ty: &Ty<'_>) {
902 std::mem::discriminant(&ty.kind).hash(&mut self.s);
903 self.hash_tykind(&ty.kind);
906 pub fn hash_tykind(&mut self, ty: &TyKind<'_>) {
908 TyKind::Slice(ty) => {
911 TyKind::Array(ty, anon_const) => {
913 self.hash_body(anon_const.body);
915 TyKind::Ptr(ref mut_ty) => {
916 self.hash_ty(mut_ty.ty);
917 mut_ty.mutbl.hash(&mut self.s);
919 TyKind::Rptr(lifetime, ref mut_ty) => {
920 self.hash_lifetime(*lifetime);
921 self.hash_ty(mut_ty.ty);
922 mut_ty.mutbl.hash(&mut self.s);
924 TyKind::BareFn(bfn) => {
925 bfn.unsafety.hash(&mut self.s);
926 bfn.abi.hash(&mut self.s);
927 for arg in bfn.decl.inputs {
930 std::mem::discriminant(&bfn.decl.output).hash(&mut self.s);
931 match bfn.decl.output {
932 FnRetTy::DefaultReturn(_) => {},
933 FnRetTy::Return(ty) => {
937 bfn.decl.c_variadic.hash(&mut self.s);
939 TyKind::Tup(ty_list) => {
944 TyKind::Path(ref qpath) => self.hash_qpath(qpath),
945 TyKind::OpaqueDef(_, arg_list) => {
946 self.hash_generic_args(arg_list);
948 TyKind::TraitObject(_, lifetime, _) => {
949 self.hash_lifetime(*lifetime);
951 TyKind::Typeof(anon_const) => {
952 self.hash_body(anon_const.body);
954 TyKind::Err | TyKind::Infer | TyKind::Never => {},
958 pub fn hash_body(&mut self, body_id: BodyId) {
959 // swap out TypeckResults when hashing a body
960 let old_maybe_typeck_results = self.maybe_typeck_results.replace(self.cx.tcx.typeck_body(body_id));
961 self.hash_expr(&self.cx.tcx.hir().body(body_id).value);
962 self.maybe_typeck_results = old_maybe_typeck_results;
965 fn hash_generic_args(&mut self, arg_list: &[GenericArg<'_>]) {
966 for arg in arg_list {
968 GenericArg::Lifetime(l) => self.hash_lifetime(l),
969 GenericArg::Type(ref ty) => self.hash_ty(ty),
970 GenericArg::Const(ref ca) => self.hash_body(ca.value.body),
971 GenericArg::Infer(ref inf) => self.hash_ty(&inf.to_ty()),