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::FxHashMap;
6 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
7 use rustc_hir::def::Res;
9 BinOpKind, Block, BlockCheckMode, BodyId, BorrowKind, CaptureBy, Expr, ExprKind, Field, FieldPat, FnRetTy,
10 GenericArg, GenericArgs, Guard, HirId, InlineAsmOperand, Lifetime, LifetimeName, ParamName, Pat, 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 fn inter_expr(&mut self) -> HirEqInterExpr<'_, 'a, 'tcx> {
64 locals: FxHashMap::default(),
68 pub fn eq_block(&mut self, left: &Block<'_>, right: &Block<'_>) -> bool {
69 self.inter_expr().eq_block(left, right)
72 pub fn eq_expr(&mut self, left: &Expr<'_>, right: &Expr<'_>) -> bool {
73 self.inter_expr().eq_expr(left, right)
76 pub fn eq_path_segment(&mut self, left: &PathSegment<'_>, right: &PathSegment<'_>) -> bool {
77 self.inter_expr().eq_path_segment(left, right)
80 pub fn eq_path_segments(&mut self, left: &[PathSegment<'_>], right: &[PathSegment<'_>]) -> bool {
81 self.inter_expr().eq_path_segments(left, right)
84 pub fn eq_ty_kind(&mut self, left: &TyKind<'_>, right: &TyKind<'_>) -> bool {
85 self.inter_expr().eq_ty_kind(left, right)
89 struct HirEqInterExpr<'a, 'b, 'tcx> {
90 inner: &'a mut SpanlessEq<'b, 'tcx>,
92 // When binding are declared, the binding ID in the left expression is mapped to the one on the
93 // right. For example, when comparing `{ let x = 1; x + 2 }` and `{ let y = 1; y + 2 }`,
94 // these blocks are considered equal since `x` is mapped to `y`.
95 locals: FxHashMap<HirId, HirId>,
98 impl HirEqInterExpr<'_, '_, '_> {
99 fn eq_stmt(&mut self, left: &Stmt<'_>, right: &Stmt<'_>) -> bool {
100 match (&left.kind, &right.kind) {
101 (&StmtKind::Local(ref l), &StmtKind::Local(ref r)) => {
102 self.eq_pat(&l.pat, &r.pat)
103 && both(&l.ty, &r.ty, |l, r| self.eq_ty(l, r))
104 && both(&l.init, &r.init, |l, r| self.eq_expr(l, r))
106 (&StmtKind::Expr(ref l), &StmtKind::Expr(ref r)) | (&StmtKind::Semi(ref l), &StmtKind::Semi(ref r)) => {
113 /// Checks whether two blocks are the same.
114 fn eq_block(&mut self, left: &Block<'_>, right: &Block<'_>) -> bool {
115 match (left.stmts, left.expr, right.stmts, right.expr) {
116 ([], None, [], None) => {
117 // For empty blocks, check to see if the tokens are equal. This will catch the case where a macro
118 // expanded to nothing, or the cfg attribute was used.
119 let (left, right) = match (
120 snippet_opt(self.inner.cx, left.span),
121 snippet_opt(self.inner.cx, right.span),
123 (Some(left), Some(right)) => (left, right),
126 let mut left_pos = 0;
127 let left = tokenize(&left)
129 let end = left_pos + t.len;
130 let s = &left[left_pos..end];
137 TokenKind::LineComment { .. } | TokenKind::BlockComment { .. } | TokenKind::Whitespace
141 let mut right_pos = 0;
142 let right = tokenize(&right)
144 let end = right_pos + t.len;
145 let s = &right[right_pos..end];
152 TokenKind::LineComment { .. } | TokenKind::BlockComment { .. } | TokenKind::Whitespace
159 over(&left.stmts, &right.stmts, |l, r| self.eq_stmt(l, r))
160 && both(&left.expr, &right.expr, |l, r| self.eq_expr(l, r))
165 #[allow(clippy::similar_names)]
166 fn eq_expr(&mut self, left: &Expr<'_>, right: &Expr<'_>) -> bool {
167 if !self.inner.allow_side_effects && differing_macro_contexts(left.span, right.span) {
171 if let Some(typeck_results) = self.inner.maybe_typeck_results {
172 if let (Some(l), Some(r)) = (
173 constant_simple(self.inner.cx, typeck_results, left),
174 constant_simple(self.inner.cx, typeck_results, right),
183 &reduce_exprkind(self.inner.cx, &left.kind),
184 &reduce_exprkind(self.inner.cx, &right.kind),
186 (&ExprKind::AddrOf(lb, l_mut, ref le), &ExprKind::AddrOf(rb, r_mut, ref re)) => {
187 lb == rb && l_mut == r_mut && self.eq_expr(le, re)
189 (&ExprKind::Continue(li), &ExprKind::Continue(ri)) => {
190 both(&li.label, &ri.label, |l, r| l.ident.name == r.ident.name)
192 (&ExprKind::Assign(ref ll, ref lr, _), &ExprKind::Assign(ref rl, ref rr, _)) => {
193 self.inner.allow_side_effects && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
195 (&ExprKind::AssignOp(ref lo, ref ll, ref lr), &ExprKind::AssignOp(ref ro, ref rl, ref rr)) => {
196 self.inner.allow_side_effects && lo.node == ro.node && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
198 (&ExprKind::Block(ref l, _), &ExprKind::Block(ref r, _)) => self.eq_block(l, r),
199 (&ExprKind::Binary(l_op, ref ll, ref lr), &ExprKind::Binary(r_op, ref rl, ref rr)) => {
200 l_op.node == r_op.node && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
201 || swap_binop(l_op.node, ll, lr).map_or(false, |(l_op, ll, lr)| {
202 l_op == r_op.node && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
205 (&ExprKind::Break(li, ref le), &ExprKind::Break(ri, ref re)) => {
206 both(&li.label, &ri.label, |l, r| l.ident.name == r.ident.name)
207 && both(le, re, |l, r| self.eq_expr(l, r))
209 (&ExprKind::Box(ref l), &ExprKind::Box(ref r)) => self.eq_expr(l, r),
210 (&ExprKind::Call(l_fun, l_args), &ExprKind::Call(r_fun, r_args)) => {
211 self.inner.allow_side_effects && self.eq_expr(l_fun, r_fun) && self.eq_exprs(l_args, r_args)
213 (&ExprKind::Cast(ref lx, ref lt), &ExprKind::Cast(ref rx, ref rt))
214 | (&ExprKind::Type(ref lx, ref lt), &ExprKind::Type(ref rx, ref rt)) => {
215 self.eq_expr(lx, rx) && self.eq_ty(lt, rt)
217 (&ExprKind::Field(ref l_f_exp, ref l_f_ident), &ExprKind::Field(ref r_f_exp, ref r_f_ident)) => {
218 l_f_ident.name == r_f_ident.name && self.eq_expr(l_f_exp, r_f_exp)
220 (&ExprKind::Index(ref la, ref li), &ExprKind::Index(ref ra, ref ri)) => {
221 self.eq_expr(la, ra) && self.eq_expr(li, ri)
223 (&ExprKind::If(ref lc, ref lt, ref le), &ExprKind::If(ref rc, ref rt, ref re)) => {
224 self.eq_expr(lc, rc) && self.eq_expr(&**lt, &**rt) && both(le, re, |l, r| self.eq_expr(l, r))
226 (&ExprKind::Lit(ref l), &ExprKind::Lit(ref r)) => l.node == r.node,
227 (&ExprKind::Loop(ref lb, ref ll, ref lls, _), &ExprKind::Loop(ref rb, ref rl, ref rls, _)) => {
228 lls == rls && self.eq_block(lb, rb) && both(ll, rl, |l, r| l.ident.name == r.ident.name)
230 (&ExprKind::Match(ref le, ref la, ref ls), &ExprKind::Match(ref re, ref ra, ref rs)) => {
232 && self.eq_expr(le, re)
233 && over(la, ra, |l, r| {
234 self.eq_pat(&l.pat, &r.pat)
235 && both(&l.guard, &r.guard, |l, r| self.eq_guard(l, r))
236 && self.eq_expr(&l.body, &r.body)
239 (&ExprKind::MethodCall(l_path, _, l_args, _), &ExprKind::MethodCall(r_path, _, r_args, _)) => {
240 self.inner.allow_side_effects && self.eq_path_segment(l_path, r_path) && self.eq_exprs(l_args, r_args)
242 (&ExprKind::Repeat(ref le, ref ll_id), &ExprKind::Repeat(ref re, ref rl_id)) => {
243 let mut celcx = constant_context(self.inner.cx, self.inner.cx.tcx.typeck_body(ll_id.body));
244 let ll = celcx.expr(&self.inner.cx.tcx.hir().body(ll_id.body).value);
245 let mut celcx = constant_context(self.inner.cx, self.inner.cx.tcx.typeck_body(rl_id.body));
246 let rl = celcx.expr(&self.inner.cx.tcx.hir().body(rl_id.body).value);
248 self.eq_expr(le, re) && ll == rl
250 (&ExprKind::Ret(ref l), &ExprKind::Ret(ref r)) => both(l, r, |l, r| self.eq_expr(l, r)),
251 (&ExprKind::Path(ref l), &ExprKind::Path(ref r)) => self.eq_qpath(l, r),
252 (&ExprKind::Struct(ref l_path, ref lf, ref lo), &ExprKind::Struct(ref r_path, ref rf, ref ro)) => {
253 self.eq_qpath(l_path, r_path)
254 && both(lo, ro, |l, r| self.eq_expr(l, r))
255 && over(lf, rf, |l, r| self.eq_field(l, r))
257 (&ExprKind::Tup(l_tup), &ExprKind::Tup(r_tup)) => self.eq_exprs(l_tup, r_tup),
258 (&ExprKind::Unary(l_op, ref le), &ExprKind::Unary(r_op, ref re)) => l_op == r_op && self.eq_expr(le, re),
259 (&ExprKind::Array(l), &ExprKind::Array(r)) => self.eq_exprs(l, r),
260 (&ExprKind::DropTemps(ref le), &ExprKind::DropTemps(ref re)) => self.eq_expr(le, re),
263 is_eq || self.inner.expr_fallback.as_mut().map_or(false, |f| f(left, right))
266 fn eq_exprs(&mut self, left: &[Expr<'_>], right: &[Expr<'_>]) -> bool {
267 over(left, right, |l, r| self.eq_expr(l, r))
270 fn eq_field(&mut self, left: &Field<'_>, right: &Field<'_>) -> bool {
271 left.ident.name == right.ident.name && self.eq_expr(&left.expr, &right.expr)
274 fn eq_guard(&mut self, left: &Guard<'_>, right: &Guard<'_>) -> bool {
275 match (left, right) {
276 (Guard::If(l), Guard::If(r)) => self.eq_expr(l, r),
277 (Guard::IfLet(lp, le), Guard::IfLet(rp, re)) => self.eq_pat(lp, rp) && self.eq_expr(le, re),
282 fn eq_generic_arg(&mut self, left: &GenericArg<'_>, right: &GenericArg<'_>) -> bool {
283 match (left, right) {
284 (GenericArg::Lifetime(l_lt), GenericArg::Lifetime(r_lt)) => Self::eq_lifetime(l_lt, r_lt),
285 (GenericArg::Type(l_ty), GenericArg::Type(r_ty)) => self.eq_ty(l_ty, r_ty),
290 fn eq_lifetime(left: &Lifetime, right: &Lifetime) -> bool {
291 left.name == right.name
294 fn eq_fieldpat(&mut self, left: &FieldPat<'_>, right: &FieldPat<'_>) -> bool {
295 let (FieldPat { ident: li, pat: lp, .. }, FieldPat { ident: ri, pat: rp, .. }) = (&left, &right);
296 li.name == ri.name && self.eq_pat(lp, rp)
299 /// Checks whether two patterns are the same.
300 fn eq_pat(&mut self, left: &Pat<'_>, right: &Pat<'_>) -> bool {
301 match (&left.kind, &right.kind) {
302 (&PatKind::Box(ref l), &PatKind::Box(ref r)) => self.eq_pat(l, r),
303 (&PatKind::Struct(ref lp, ref la, ..), &PatKind::Struct(ref rp, ref ra, ..)) => {
304 self.eq_qpath(lp, rp) && over(la, ra, |l, r| self.eq_fieldpat(l, r))
306 (&PatKind::TupleStruct(ref lp, ref la, ls), &PatKind::TupleStruct(ref rp, ref ra, rs)) => {
307 self.eq_qpath(lp, rp) && over(la, ra, |l, r| self.eq_pat(l, r)) && ls == rs
309 (&PatKind::Binding(lb, li, _, ref lp), &PatKind::Binding(rb, ri, _, ref rp)) => {
310 let eq = lb == rb && both(lp, rp, |l, r| self.eq_pat(l, r));
312 self.locals.insert(li, ri);
316 (&PatKind::Path(ref l), &PatKind::Path(ref r)) => self.eq_qpath(l, r),
317 (&PatKind::Lit(ref l), &PatKind::Lit(ref r)) => self.eq_expr(l, r),
318 (&PatKind::Tuple(ref l, ls), &PatKind::Tuple(ref r, rs)) => {
319 ls == rs && over(l, r, |l, r| self.eq_pat(l, r))
321 (&PatKind::Range(ref ls, ref le, li), &PatKind::Range(ref rs, ref re, ri)) => {
322 both(ls, rs, |a, b| self.eq_expr(a, b)) && both(le, re, |a, b| self.eq_expr(a, b)) && (li == ri)
324 (&PatKind::Ref(ref le, ref lm), &PatKind::Ref(ref re, ref rm)) => lm == rm && self.eq_pat(le, re),
325 (&PatKind::Slice(ref ls, ref li, ref le), &PatKind::Slice(ref rs, ref ri, ref re)) => {
326 over(ls, rs, |l, r| self.eq_pat(l, r))
327 && over(le, re, |l, r| self.eq_pat(l, r))
328 && both(li, ri, |l, r| self.eq_pat(l, r))
330 (&PatKind::Wild, &PatKind::Wild) => true,
335 #[allow(clippy::similar_names)]
336 fn eq_qpath(&mut self, left: &QPath<'_>, right: &QPath<'_>) -> bool {
337 match (left, right) {
338 (&QPath::Resolved(ref lty, ref lpath), &QPath::Resolved(ref rty, ref rpath)) => {
339 both(lty, rty, |l, r| self.eq_ty(l, r)) && self.eq_path(lpath, rpath)
341 (&QPath::TypeRelative(ref lty, ref lseg), &QPath::TypeRelative(ref rty, ref rseg)) => {
342 self.eq_ty(lty, rty) && self.eq_path_segment(lseg, rseg)
344 (&QPath::LangItem(llang_item, _), &QPath::LangItem(rlang_item, _)) => llang_item == rlang_item,
349 fn eq_path(&mut self, left: &Path<'_>, right: &Path<'_>) -> bool {
350 match (left.res, right.res) {
351 (Res::Local(l), Res::Local(r)) => l == r || self.locals.get(&l) == Some(&r),
352 (Res::Local(_), _) | (_, Res::Local(_)) => false,
353 _ => over(&left.segments, &right.segments, |l, r| self.eq_path_segment(l, r)),
357 fn eq_path_parameters(&mut self, left: &GenericArgs<'_>, right: &GenericArgs<'_>) -> bool {
358 if !(left.parenthesized || right.parenthesized) {
359 over(&left.args, &right.args, |l, r| self.eq_generic_arg(l, r)) // FIXME(flip1995): may not work
360 && over(&left.bindings, &right.bindings, |l, r| self.eq_type_binding(l, r))
361 } else if left.parenthesized && right.parenthesized {
362 over(left.inputs(), right.inputs(), |l, r| self.eq_ty(l, r))
363 && both(&Some(&left.bindings[0].ty()), &Some(&right.bindings[0].ty()), |l, r| {
371 pub fn eq_path_segments(&mut self, left: &[PathSegment<'_>], right: &[PathSegment<'_>]) -> bool {
372 left.len() == right.len() && left.iter().zip(right).all(|(l, r)| self.eq_path_segment(l, r))
375 pub fn eq_path_segment(&mut self, left: &PathSegment<'_>, right: &PathSegment<'_>) -> bool {
376 // The == of idents doesn't work with different contexts,
377 // we have to be explicit about hygiene
378 left.ident.name == right.ident.name && both(&left.args, &right.args, |l, r| self.eq_path_parameters(l, r))
381 fn eq_ty(&mut self, left: &Ty<'_>, right: &Ty<'_>) -> bool {
382 self.eq_ty_kind(&left.kind, &right.kind)
385 #[allow(clippy::similar_names)]
386 fn eq_ty_kind(&mut self, left: &TyKind<'_>, right: &TyKind<'_>) -> bool {
387 match (left, right) {
388 (&TyKind::Slice(ref l_vec), &TyKind::Slice(ref r_vec)) => self.eq_ty(l_vec, r_vec),
389 (&TyKind::Array(ref lt, ref ll_id), &TyKind::Array(ref rt, ref rl_id)) => {
390 let cx = self.inner.cx;
392 |body| constant_context(cx, cx.tcx.typeck_body(body)).expr(&cx.tcx.hir().body(body).value);
393 self.eq_ty(lt, rt) && eval_const(ll_id.body) == eval_const(rl_id.body)
395 (&TyKind::Ptr(ref l_mut), &TyKind::Ptr(ref r_mut)) => {
396 l_mut.mutbl == r_mut.mutbl && self.eq_ty(&*l_mut.ty, &*r_mut.ty)
398 (&TyKind::Rptr(_, ref l_rmut), &TyKind::Rptr(_, ref r_rmut)) => {
399 l_rmut.mutbl == r_rmut.mutbl && self.eq_ty(&*l_rmut.ty, &*r_rmut.ty)
401 (&TyKind::Path(ref l), &TyKind::Path(ref r)) => self.eq_qpath(l, r),
402 (&TyKind::Tup(ref l), &TyKind::Tup(ref r)) => over(l, r, |l, r| self.eq_ty(l, r)),
403 (&TyKind::Infer, &TyKind::Infer) => true,
408 fn eq_type_binding(&mut self, left: &TypeBinding<'_>, right: &TypeBinding<'_>) -> bool {
409 left.ident.name == right.ident.name && self.eq_ty(&left.ty(), &right.ty())
413 /// Some simple reductions like `{ return }` => `return`
414 fn reduce_exprkind<'hir>(cx: &LateContext<'_>, kind: &'hir ExprKind<'hir>) -> &'hir ExprKind<'hir> {
415 if let ExprKind::Block(block, _) = kind {
416 match (block.stmts, block.expr) {
417 // From an `if let` expression without an `else` block. The arm for the implicit wild pattern is an empty
418 // block with an empty span.
419 ([], None) if block.span.is_empty() => &ExprKind::Tup(&[]),
421 ([], None) => match snippet_opt(cx, block.span) {
422 // Don't reduce if there are any tokens contained in the braces
429 TokenKind::LineComment { .. } | TokenKind::BlockComment { .. } | TokenKind::Whitespace
432 .ne([TokenKind::OpenBrace, TokenKind::CloseBrace].iter().cloned()) =>
436 _ => &ExprKind::Tup(&[]),
438 ([], Some(expr)) => match expr.kind {
439 // `{ return .. }` => `return ..`
440 ExprKind::Ret(..) => &expr.kind,
443 ([stmt], None) => match stmt.kind {
444 StmtKind::Expr(expr) | StmtKind::Semi(expr) => match expr.kind {
445 // `{ return ..; }` => `return ..`
446 ExprKind::Ret(..) => &expr.kind,
462 ) -> Option<(BinOpKind, &'a Expr<'a>, &'a Expr<'a>)> {
464 BinOpKind::Add | BinOpKind::Eq | BinOpKind::Ne | BinOpKind::BitAnd | BinOpKind::BitXor | BinOpKind::BitOr => {
465 Some((binop, rhs, lhs))
467 BinOpKind::Lt => Some((BinOpKind::Gt, rhs, lhs)),
468 BinOpKind::Le => Some((BinOpKind::Ge, rhs, lhs)),
469 BinOpKind::Ge => Some((BinOpKind::Le, rhs, lhs)),
470 BinOpKind::Gt => Some((BinOpKind::Lt, rhs, lhs)),
471 BinOpKind::Mul // Not always commutative, e.g. with matrices. See issue #5698
478 | BinOpKind::Or => None,
482 /// Checks if the two `Option`s are both `None` or some equal values as per
484 pub fn both<X>(l: &Option<X>, r: &Option<X>, mut eq_fn: impl FnMut(&X, &X) -> bool) -> bool {
486 .map_or_else(|| r.is_none(), |x| r.as_ref().map_or(false, |y| eq_fn(x, y)))
489 /// Checks if two slices are equal as per `eq_fn`.
490 pub fn over<X>(left: &[X], right: &[X], mut eq_fn: impl FnMut(&X, &X) -> bool) -> bool {
491 left.len() == right.len() && left.iter().zip(right).all(|(x, y)| eq_fn(x, y))
494 /// Checks if two expressions evaluate to the same value, and don't contain any side effects.
495 pub fn eq_expr_value(cx: &LateContext<'_>, left: &Expr<'_>, right: &Expr<'_>) -> bool {
496 SpanlessEq::new(cx).deny_side_effects().eq_expr(left, right)
499 /// Type used to hash an ast element. This is different from the `Hash` trait
500 /// on ast types as this
501 /// trait would consider IDs and spans.
503 /// All expressions kind are hashed, but some might have a weaker hash.
504 pub struct SpanlessHash<'a, 'tcx> {
505 /// Context used to evaluate constant expressions.
506 cx: &'a LateContext<'tcx>,
507 maybe_typeck_results: Option<&'tcx TypeckResults<'tcx>>,
511 impl<'a, 'tcx> SpanlessHash<'a, 'tcx> {
512 pub fn new(cx: &'a LateContext<'tcx>) -> Self {
515 maybe_typeck_results: cx.maybe_typeck_results(),
516 s: StableHasher::new(),
520 pub fn finish(self) -> u64 {
524 pub fn hash_block(&mut self, b: &Block<'_>) {
529 if let Some(ref e) = b.expr {
534 BlockCheckMode::DefaultBlock => 0,
535 BlockCheckMode::UnsafeBlock(_) => 1,
536 BlockCheckMode::PushUnsafeBlock(_) => 2,
537 BlockCheckMode::PopUnsafeBlock(_) => 3,
542 #[allow(clippy::many_single_char_names, clippy::too_many_lines)]
543 pub fn hash_expr(&mut self, e: &Expr<'_>) {
544 let simple_const = self
545 .maybe_typeck_results
546 .and_then(|typeck_results| constant_simple(self.cx, typeck_results, e));
548 // const hashing may result in the same hash as some unrelated node, so add a sort of
549 // discriminant depending on which path we're choosing next
550 simple_const.is_some().hash(&mut self.s);
552 if let Some(e) = simple_const {
553 return e.hash(&mut self.s);
556 std::mem::discriminant(&e.kind).hash(&mut self.s);
559 ExprKind::AddrOf(kind, m, ref e) => {
561 BorrowKind::Ref => 0,
562 BorrowKind::Raw => 1,
568 ExprKind::Continue(i) => {
569 if let Some(i) = i.label {
570 self.hash_name(i.ident.name);
573 ExprKind::Assign(ref l, ref r, _) => {
577 ExprKind::AssignOp(ref o, ref l, ref r) => {
579 .hash_stable(&mut self.cx.tcx.get_stable_hashing_context(), &mut self.s);
583 ExprKind::Block(ref b, _) => {
586 ExprKind::Binary(op, ref l, ref r) => {
588 .hash_stable(&mut self.cx.tcx.get_stable_hashing_context(), &mut self.s);
592 ExprKind::Break(i, ref j) => {
593 if let Some(i) = i.label {
594 self.hash_name(i.ident.name);
596 if let Some(ref j) = *j {
600 ExprKind::Box(ref e) | ExprKind::DropTemps(ref e) | ExprKind::Yield(ref e, _) => {
603 ExprKind::Call(ref fun, args) => {
605 self.hash_exprs(args);
607 ExprKind::Cast(ref e, ref ty) | ExprKind::Type(ref e, ref ty) => {
611 ExprKind::Closure(cap, _, eid, _, _) => {
613 CaptureBy::Value => 0,
617 // closures inherit TypeckResults
618 self.hash_expr(&self.cx.tcx.hir().body(eid).value);
620 ExprKind::Field(ref e, ref f) => {
622 self.hash_name(f.name);
624 ExprKind::Index(ref a, ref i) => {
628 ExprKind::InlineAsm(ref asm) => {
629 for piece in asm.template {
631 InlineAsmTemplatePiece::String(s) => s.hash(&mut self.s),
632 InlineAsmTemplatePiece::Placeholder {
637 operand_idx.hash(&mut self.s);
638 modifier.hash(&mut self.s);
642 asm.options.hash(&mut self.s);
643 for (op, _op_sp) in asm.operands {
645 InlineAsmOperand::In { reg, expr } => {
646 reg.hash(&mut self.s);
647 self.hash_expr(expr);
649 InlineAsmOperand::Out { reg, late, expr } => {
650 reg.hash(&mut self.s);
651 late.hash(&mut self.s);
652 if let Some(expr) = expr {
653 self.hash_expr(expr);
656 InlineAsmOperand::InOut { reg, late, expr } => {
657 reg.hash(&mut self.s);
658 late.hash(&mut self.s);
659 self.hash_expr(expr);
661 InlineAsmOperand::SplitInOut {
667 reg.hash(&mut self.s);
668 late.hash(&mut self.s);
669 self.hash_expr(in_expr);
670 if let Some(out_expr) = out_expr {
671 self.hash_expr(out_expr);
674 InlineAsmOperand::Const { expr } | InlineAsmOperand::Sym { expr } => self.hash_expr(expr),
678 ExprKind::LlvmInlineAsm(..) | ExprKind::Err => {},
679 ExprKind::Lit(ref l) => {
680 l.node.hash(&mut self.s);
682 ExprKind::Loop(ref b, ref i, ..) => {
684 if let Some(i) = *i {
685 self.hash_name(i.ident.name);
688 ExprKind::If(ref cond, ref then, ref else_opt) => {
689 let c: fn(_, _, _) -> _ = ExprKind::If;
691 self.hash_expr(cond);
692 self.hash_expr(&**then);
693 if let Some(ref e) = *else_opt {
697 ExprKind::Match(ref e, arms, ref s) => {
702 if let Some(ref e) = arm.guard {
705 self.hash_expr(&arm.body);
710 ExprKind::MethodCall(ref 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(ref e, ref l_id) => {
719 self.hash_body(l_id.body);
721 ExprKind::Ret(ref e) => {
722 if let Some(ref e) = *e {
726 ExprKind::Path(ref qpath) => {
727 self.hash_qpath(qpath);
729 ExprKind::Struct(ref 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(ref e) = *expr {
741 ExprKind::Tup(tup) => {
742 self.hash_exprs(tup);
744 ExprKind::Array(v) => {
747 ExprKind::Unary(lop, ref le) => {
748 lop.hash_stable(&mut self.cx.tcx.get_stable_hashing_context(), &mut self.s);
754 pub fn hash_exprs(&mut self, e: &[Expr<'_>]) {
760 pub fn hash_name(&mut self, n: Symbol) {
761 n.as_str().hash(&mut self.s);
764 pub fn hash_qpath(&mut self, p: &QPath<'_>) {
766 QPath::Resolved(_, ref path) => {
767 self.hash_path(path);
769 QPath::TypeRelative(_, ref path) => {
770 self.hash_name(path.ident.name);
772 QPath::LangItem(lang_item, ..) => {
773 lang_item.hash_stable(&mut self.cx.tcx.get_stable_hashing_context(), &mut self.s);
776 // self.maybe_typeck_results.unwrap().qpath_res(p, id).hash(&mut self.s);
779 pub fn hash_path(&mut self, path: &Path<'_>) {
781 // constant hash since equality is dependant on inter-expression context
782 Res::Local(_) => 1_usize.hash(&mut self.s),
784 for seg in path.segments {
785 self.hash_name(seg.ident.name);
791 pub fn hash_stmt(&mut self, b: &Stmt<'_>) {
792 std::mem::discriminant(&b.kind).hash(&mut self.s);
795 StmtKind::Local(local) => {
796 if let Some(ref init) = local.init {
797 self.hash_expr(init);
800 StmtKind::Item(..) => {},
801 StmtKind::Expr(expr) | StmtKind::Semi(expr) => {
802 self.hash_expr(expr);
807 pub fn hash_guard(&mut self, g: &Guard<'_>) {
809 Guard::If(ref expr) | Guard::IfLet(_, ref expr) => {
810 self.hash_expr(expr);
815 pub fn hash_lifetime(&mut self, lifetime: &Lifetime) {
816 std::mem::discriminant(&lifetime.name).hash(&mut self.s);
817 if let LifetimeName::Param(ref name) = lifetime.name {
818 std::mem::discriminant(name).hash(&mut self.s);
820 ParamName::Plain(ref ident) => {
821 ident.name.hash(&mut self.s);
823 ParamName::Fresh(ref size) => {
824 size.hash(&mut self.s);
826 ParamName::Error => {},
831 pub fn hash_ty(&mut self, ty: &Ty<'_>) {
832 self.hash_tykind(&ty.kind);
835 pub fn hash_tykind(&mut self, ty: &TyKind<'_>) {
836 std::mem::discriminant(ty).hash(&mut self.s);
838 TyKind::Slice(ty) => {
841 TyKind::Array(ty, anon_const) => {
843 self.hash_body(anon_const.body);
845 TyKind::Ptr(mut_ty) => {
846 self.hash_ty(&mut_ty.ty);
847 mut_ty.mutbl.hash(&mut self.s);
849 TyKind::Rptr(lifetime, mut_ty) => {
850 self.hash_lifetime(lifetime);
851 self.hash_ty(&mut_ty.ty);
852 mut_ty.mutbl.hash(&mut self.s);
854 TyKind::BareFn(bfn) => {
855 bfn.unsafety.hash(&mut self.s);
856 bfn.abi.hash(&mut self.s);
857 for arg in bfn.decl.inputs {
860 match bfn.decl.output {
861 FnRetTy::DefaultReturn(_) => {
862 ().hash(&mut self.s);
864 FnRetTy::Return(ref ty) => {
868 bfn.decl.c_variadic.hash(&mut self.s);
870 TyKind::Tup(ty_list) => {
875 TyKind::Path(qpath) => match qpath {
876 QPath::Resolved(ref maybe_ty, ref path) => {
877 if let Some(ref ty) = maybe_ty {
880 for segment in path.segments {
881 segment.ident.name.hash(&mut self.s);
882 self.hash_generic_args(segment.args().args);
885 QPath::TypeRelative(ref ty, ref segment) => {
887 segment.ident.name.hash(&mut self.s);
889 QPath::LangItem(lang_item, ..) => {
890 lang_item.hash(&mut self.s);
893 TyKind::OpaqueDef(_, arg_list) => {
894 self.hash_generic_args(arg_list);
896 TyKind::TraitObject(_, lifetime) => {
897 self.hash_lifetime(lifetime);
899 TyKind::Typeof(anon_const) => {
900 self.hash_body(anon_const.body);
902 TyKind::Err | TyKind::Infer | TyKind::Never => {},
906 pub fn hash_body(&mut self, body_id: BodyId) {
907 // swap out TypeckResults when hashing a body
908 let old_maybe_typeck_results = self.maybe_typeck_results.replace(self.cx.tcx.typeck_body(body_id));
909 self.hash_expr(&self.cx.tcx.hir().body(body_id).value);
910 self.maybe_typeck_results = old_maybe_typeck_results;
913 fn hash_generic_args(&mut self, arg_list: &[GenericArg<'_>]) {
914 for arg in arg_list {
916 GenericArg::Lifetime(ref l) => self.hash_lifetime(l),
917 GenericArg::Type(ref ty) => self.hash_ty(&ty),
918 GenericArg::Const(ref ca) => self.hash_body(ca.value.body),