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 fn inter_expr(&mut self) -> HirEqInterExpr<'_, 'a, 'tcx> {
64 locals: HirIdMap::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)
85 struct HirEqInterExpr<'a, 'b, 'tcx> {
86 inner: &'a mut SpanlessEq<'b, 'tcx>,
88 // When binding are declared, the binding ID in the left expression is mapped to the one on the
89 // right. For example, when comparing `{ let x = 1; x + 2 }` and `{ let y = 1; y + 2 }`,
90 // these blocks are considered equal since `x` is mapped to `y`.
91 locals: HirIdMap<HirId>,
94 impl HirEqInterExpr<'_, '_, '_> {
95 fn eq_stmt(&mut self, left: &Stmt<'_>, right: &Stmt<'_>) -> bool {
96 match (&left.kind, &right.kind) {
97 (&StmtKind::Local(ref l), &StmtKind::Local(ref r)) => {
98 self.eq_pat(&l.pat, &r.pat)
99 && both(&l.ty, &r.ty, |l, r| self.eq_ty(l, r))
100 && both(&l.init, &r.init, |l, r| self.eq_expr(l, r))
102 (&StmtKind::Expr(ref l), &StmtKind::Expr(ref r)) | (&StmtKind::Semi(ref l), &StmtKind::Semi(ref r)) => {
109 /// Checks whether two blocks are the same.
110 fn eq_block(&mut self, left: &Block<'_>, right: &Block<'_>) -> bool {
111 match (left.stmts, left.expr, right.stmts, right.expr) {
112 ([], None, [], None) => {
113 // For empty blocks, check to see if the tokens are equal. This will catch the case where a macro
114 // expanded to nothing, or the cfg attribute was used.
115 let (left, right) = match (
116 snippet_opt(self.inner.cx, left.span),
117 snippet_opt(self.inner.cx, right.span),
119 (Some(left), Some(right)) => (left, right),
122 let mut left_pos = 0;
123 let left = tokenize(&left)
125 let end = left_pos + t.len;
126 let s = &left[left_pos..end];
133 TokenKind::LineComment { .. } | TokenKind::BlockComment { .. } | TokenKind::Whitespace
137 let mut right_pos = 0;
138 let right = tokenize(&right)
140 let end = right_pos + t.len;
141 let s = &right[right_pos..end];
148 TokenKind::LineComment { .. } | TokenKind::BlockComment { .. } | TokenKind::Whitespace
155 over(&left.stmts, &right.stmts, |l, r| self.eq_stmt(l, r))
156 && both(&left.expr, &right.expr, |l, r| self.eq_expr(l, r))
161 #[allow(clippy::similar_names)]
162 fn eq_expr(&mut self, left: &Expr<'_>, right: &Expr<'_>) -> bool {
163 if !self.inner.allow_side_effects && differing_macro_contexts(left.span, right.span) {
167 if let Some(typeck_results) = self.inner.maybe_typeck_results {
168 if let (Some(l), Some(r)) = (
169 constant_simple(self.inner.cx, typeck_results, left),
170 constant_simple(self.inner.cx, typeck_results, right),
179 &reduce_exprkind(self.inner.cx, &left.kind),
180 &reduce_exprkind(self.inner.cx, &right.kind),
182 (&ExprKind::AddrOf(lb, l_mut, ref le), &ExprKind::AddrOf(rb, r_mut, ref re)) => {
183 lb == rb && l_mut == r_mut && self.eq_expr(le, re)
185 (&ExprKind::Continue(li), &ExprKind::Continue(ri)) => {
186 both(&li.label, &ri.label, |l, r| l.ident.name == r.ident.name)
188 (&ExprKind::Assign(ref ll, ref lr, _), &ExprKind::Assign(ref rl, ref rr, _)) => {
189 self.inner.allow_side_effects && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
191 (&ExprKind::AssignOp(ref lo, ref ll, ref lr), &ExprKind::AssignOp(ref ro, ref rl, ref rr)) => {
192 self.inner.allow_side_effects && lo.node == ro.node && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
194 (&ExprKind::Block(ref l, _), &ExprKind::Block(ref r, _)) => self.eq_block(l, r),
195 (&ExprKind::Binary(l_op, ref ll, ref lr), &ExprKind::Binary(r_op, ref rl, ref rr)) => {
196 l_op.node == r_op.node && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
197 || swap_binop(l_op.node, ll, lr).map_or(false, |(l_op, ll, lr)| {
198 l_op == r_op.node && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
201 (&ExprKind::Break(li, ref le), &ExprKind::Break(ri, ref re)) => {
202 both(&li.label, &ri.label, |l, r| l.ident.name == r.ident.name)
203 && both(le, re, |l, r| self.eq_expr(l, r))
205 (&ExprKind::Box(ref l), &ExprKind::Box(ref r)) => self.eq_expr(l, r),
206 (&ExprKind::Call(l_fun, l_args), &ExprKind::Call(r_fun, r_args)) => {
207 self.inner.allow_side_effects && self.eq_expr(l_fun, r_fun) && self.eq_exprs(l_args, r_args)
209 (&ExprKind::Cast(ref lx, ref lt), &ExprKind::Cast(ref rx, ref rt))
210 | (&ExprKind::Type(ref lx, ref lt), &ExprKind::Type(ref rx, ref rt)) => {
211 self.eq_expr(lx, rx) && self.eq_ty(lt, rt)
213 (&ExprKind::Field(ref l_f_exp, ref l_f_ident), &ExprKind::Field(ref r_f_exp, ref r_f_ident)) => {
214 l_f_ident.name == r_f_ident.name && self.eq_expr(l_f_exp, r_f_exp)
216 (&ExprKind::Index(ref la, ref li), &ExprKind::Index(ref ra, ref ri)) => {
217 self.eq_expr(la, ra) && self.eq_expr(li, ri)
219 (&ExprKind::If(ref lc, ref lt, ref le), &ExprKind::If(ref rc, ref rt, ref re)) => {
220 self.eq_expr(lc, rc) && self.eq_expr(&**lt, &**rt) && both(le, re, |l, r| self.eq_expr(l, r))
222 (&ExprKind::Lit(ref l), &ExprKind::Lit(ref r)) => l.node == r.node,
223 (&ExprKind::Loop(ref lb, ref ll, ref lls, _), &ExprKind::Loop(ref rb, ref rl, ref rls, _)) => {
224 lls == rls && self.eq_block(lb, rb) && both(ll, rl, |l, r| l.ident.name == r.ident.name)
226 (&ExprKind::Match(ref le, ref la, ref ls), &ExprKind::Match(ref re, ref ra, ref rs)) => {
228 && self.eq_expr(le, re)
229 && over(la, ra, |l, r| {
230 self.eq_pat(&l.pat, &r.pat)
231 && both(&l.guard, &r.guard, |l, r| self.eq_guard(l, r))
232 && self.eq_expr(&l.body, &r.body)
235 (&ExprKind::MethodCall(l_path, _, l_args, _), &ExprKind::MethodCall(r_path, _, r_args, _)) => {
236 self.inner.allow_side_effects && self.eq_path_segment(l_path, r_path) && self.eq_exprs(l_args, r_args)
238 (&ExprKind::Repeat(ref le, ref ll_id), &ExprKind::Repeat(ref re, ref rl_id)) => {
239 let mut celcx = constant_context(self.inner.cx, self.inner.cx.tcx.typeck_body(ll_id.body));
240 let ll = celcx.expr(&self.inner.cx.tcx.hir().body(ll_id.body).value);
241 let mut celcx = constant_context(self.inner.cx, self.inner.cx.tcx.typeck_body(rl_id.body));
242 let rl = celcx.expr(&self.inner.cx.tcx.hir().body(rl_id.body).value);
244 self.eq_expr(le, re) && ll == rl
246 (&ExprKind::Ret(ref l), &ExprKind::Ret(ref r)) => both(l, r, |l, r| self.eq_expr(l, r)),
247 (&ExprKind::Path(ref l), &ExprKind::Path(ref r)) => self.eq_qpath(l, r),
248 (&ExprKind::Struct(ref l_path, ref lf, ref lo), &ExprKind::Struct(ref r_path, ref rf, ref ro)) => {
249 self.eq_qpath(l_path, r_path)
250 && both(lo, ro, |l, r| self.eq_expr(l, r))
251 && over(lf, rf, |l, r| self.eq_expr_field(l, r))
253 (&ExprKind::Tup(l_tup), &ExprKind::Tup(r_tup)) => self.eq_exprs(l_tup, r_tup),
254 (&ExprKind::Unary(l_op, ref le), &ExprKind::Unary(r_op, ref re)) => l_op == r_op && self.eq_expr(le, re),
255 (&ExprKind::Array(l), &ExprKind::Array(r)) => self.eq_exprs(l, r),
256 (&ExprKind::DropTemps(ref le), &ExprKind::DropTemps(ref re)) => self.eq_expr(le, re),
259 is_eq || self.inner.expr_fallback.as_mut().map_or(false, |f| f(left, right))
262 fn eq_exprs(&mut self, left: &[Expr<'_>], right: &[Expr<'_>]) -> bool {
263 over(left, right, |l, r| self.eq_expr(l, r))
266 fn eq_expr_field(&mut self, left: &ExprField<'_>, right: &ExprField<'_>) -> bool {
267 left.ident.name == right.ident.name && self.eq_expr(&left.expr, &right.expr)
270 fn eq_guard(&mut self, left: &Guard<'_>, right: &Guard<'_>) -> bool {
271 match (left, right) {
272 (Guard::If(l), Guard::If(r)) => self.eq_expr(l, r),
273 (Guard::IfLet(lp, le), Guard::IfLet(rp, re)) => self.eq_pat(lp, rp) && self.eq_expr(le, re),
278 fn eq_generic_arg(&mut self, left: &GenericArg<'_>, right: &GenericArg<'_>) -> bool {
279 match (left, right) {
280 (GenericArg::Lifetime(l_lt), GenericArg::Lifetime(r_lt)) => Self::eq_lifetime(l_lt, r_lt),
281 (GenericArg::Type(l_ty), GenericArg::Type(r_ty)) => self.eq_ty(l_ty, r_ty),
286 fn eq_lifetime(left: &Lifetime, right: &Lifetime) -> bool {
287 left.name == right.name
290 fn eq_pat_field(&mut self, left: &PatField<'_>, right: &PatField<'_>) -> bool {
291 let (PatField { ident: li, pat: lp, .. }, PatField { ident: ri, pat: rp, .. }) = (&left, &right);
292 li.name == ri.name && self.eq_pat(lp, rp)
295 /// Checks whether two patterns are the same.
296 fn eq_pat(&mut self, left: &Pat<'_>, right: &Pat<'_>) -> bool {
297 match (&left.kind, &right.kind) {
298 (&PatKind::Box(ref l), &PatKind::Box(ref r)) => self.eq_pat(l, r),
299 (&PatKind::Struct(ref lp, ref la, ..), &PatKind::Struct(ref rp, ref ra, ..)) => {
300 self.eq_qpath(lp, rp) && over(la, ra, |l, r| self.eq_pat_field(l, r))
302 (&PatKind::TupleStruct(ref lp, ref la, ls), &PatKind::TupleStruct(ref rp, ref ra, rs)) => {
303 self.eq_qpath(lp, rp) && over(la, ra, |l, r| self.eq_pat(l, r)) && ls == rs
305 (&PatKind::Binding(lb, li, _, ref lp), &PatKind::Binding(rb, ri, _, ref rp)) => {
306 let eq = lb == rb && both(lp, rp, |l, r| self.eq_pat(l, r));
308 self.locals.insert(li, ri);
312 (&PatKind::Path(ref l), &PatKind::Path(ref r)) => self.eq_qpath(l, r),
313 (&PatKind::Lit(ref l), &PatKind::Lit(ref r)) => self.eq_expr(l, r),
314 (&PatKind::Tuple(ref l, ls), &PatKind::Tuple(ref r, rs)) => {
315 ls == rs && over(l, r, |l, r| self.eq_pat(l, r))
317 (&PatKind::Range(ref ls, ref le, li), &PatKind::Range(ref rs, ref re, ri)) => {
318 both(ls, rs, |a, b| self.eq_expr(a, b)) && both(le, re, |a, b| self.eq_expr(a, b)) && (li == ri)
320 (&PatKind::Ref(ref le, ref lm), &PatKind::Ref(ref re, ref rm)) => lm == rm && self.eq_pat(le, re),
321 (&PatKind::Slice(ref ls, ref li, ref le), &PatKind::Slice(ref rs, ref ri, ref re)) => {
322 over(ls, rs, |l, r| self.eq_pat(l, r))
323 && over(le, re, |l, r| self.eq_pat(l, r))
324 && both(li, ri, |l, r| self.eq_pat(l, r))
326 (&PatKind::Wild, &PatKind::Wild) => true,
331 #[allow(clippy::similar_names)]
332 fn eq_qpath(&mut self, left: &QPath<'_>, right: &QPath<'_>) -> bool {
333 match (left, right) {
334 (&QPath::Resolved(ref lty, ref lpath), &QPath::Resolved(ref rty, ref rpath)) => {
335 both(lty, rty, |l, r| self.eq_ty(l, r)) && self.eq_path(lpath, rpath)
337 (&QPath::TypeRelative(ref lty, ref lseg), &QPath::TypeRelative(ref rty, ref rseg)) => {
338 self.eq_ty(lty, rty) && self.eq_path_segment(lseg, rseg)
340 (&QPath::LangItem(llang_item, _), &QPath::LangItem(rlang_item, _)) => llang_item == rlang_item,
345 fn eq_path(&mut self, left: &Path<'_>, right: &Path<'_>) -> bool {
346 match (left.res, right.res) {
347 (Res::Local(l), Res::Local(r)) => l == r || self.locals.get(&l) == Some(&r),
348 (Res::Local(_), _) | (_, Res::Local(_)) => false,
349 _ => over(&left.segments, &right.segments, |l, r| self.eq_path_segment(l, r)),
353 fn eq_path_parameters(&mut self, left: &GenericArgs<'_>, right: &GenericArgs<'_>) -> bool {
354 if !(left.parenthesized || right.parenthesized) {
355 over(&left.args, &right.args, |l, r| self.eq_generic_arg(l, r)) // FIXME(flip1995): may not work
356 && over(&left.bindings, &right.bindings, |l, r| self.eq_type_binding(l, r))
357 } else if left.parenthesized && right.parenthesized {
358 over(left.inputs(), right.inputs(), |l, r| self.eq_ty(l, r))
359 && both(&Some(&left.bindings[0].ty()), &Some(&right.bindings[0].ty()), |l, r| {
367 pub fn eq_path_segments(&mut self, left: &[PathSegment<'_>], right: &[PathSegment<'_>]) -> bool {
368 left.len() == right.len() && left.iter().zip(right).all(|(l, r)| self.eq_path_segment(l, r))
371 pub fn eq_path_segment(&mut self, left: &PathSegment<'_>, right: &PathSegment<'_>) -> bool {
372 // The == of idents doesn't work with different contexts,
373 // we have to be explicit about hygiene
374 left.ident.name == right.ident.name && both(&left.args, &right.args, |l, r| self.eq_path_parameters(l, r))
377 #[allow(clippy::similar_names)]
378 fn eq_ty(&mut self, left: &Ty<'_>, right: &Ty<'_>) -> bool {
379 match (&left.kind, &right.kind) {
380 (&TyKind::Slice(ref l_vec), &TyKind::Slice(ref r_vec)) => self.eq_ty(l_vec, r_vec),
381 (&TyKind::Array(ref lt, ref ll_id), &TyKind::Array(ref rt, ref rl_id)) => {
382 let cx = self.inner.cx;
384 |body| constant_context(cx, cx.tcx.typeck_body(body)).expr(&cx.tcx.hir().body(body).value);
385 self.eq_ty(lt, rt) && eval_const(ll_id.body) == eval_const(rl_id.body)
387 (&TyKind::Ptr(ref l_mut), &TyKind::Ptr(ref r_mut)) => {
388 l_mut.mutbl == r_mut.mutbl && self.eq_ty(&*l_mut.ty, &*r_mut.ty)
390 (&TyKind::Rptr(_, ref l_rmut), &TyKind::Rptr(_, ref r_rmut)) => {
391 l_rmut.mutbl == r_rmut.mutbl && self.eq_ty(&*l_rmut.ty, &*r_rmut.ty)
393 (&TyKind::Path(ref l), &TyKind::Path(ref r)) => self.eq_qpath(l, r),
394 (&TyKind::Tup(ref l), &TyKind::Tup(ref r)) => over(l, r, |l, r| self.eq_ty(l, r)),
395 (&TyKind::Infer, &TyKind::Infer) => true,
400 fn eq_type_binding(&mut self, left: &TypeBinding<'_>, right: &TypeBinding<'_>) -> bool {
401 left.ident.name == right.ident.name && self.eq_ty(&left.ty(), &right.ty())
405 /// Some simple reductions like `{ return }` => `return`
406 fn reduce_exprkind<'hir>(cx: &LateContext<'_>, kind: &'hir ExprKind<'hir>) -> &'hir ExprKind<'hir> {
407 if let ExprKind::Block(block, _) = kind {
408 match (block.stmts, block.expr) {
409 // From an `if let` expression without an `else` block. The arm for the implicit wild pattern is an empty
410 // block with an empty span.
411 ([], None) if block.span.is_empty() => &ExprKind::Tup(&[]),
413 ([], None) => match snippet_opt(cx, block.span) {
414 // Don't reduce if there are any tokens contained in the braces
421 TokenKind::LineComment { .. } | TokenKind::BlockComment { .. } | TokenKind::Whitespace
424 .ne([TokenKind::OpenBrace, TokenKind::CloseBrace].iter().cloned()) =>
428 _ => &ExprKind::Tup(&[]),
430 ([], Some(expr)) => match expr.kind {
431 // `{ return .. }` => `return ..`
432 ExprKind::Ret(..) => &expr.kind,
435 ([stmt], None) => match stmt.kind {
436 StmtKind::Expr(expr) | StmtKind::Semi(expr) => match expr.kind {
437 // `{ return ..; }` => `return ..`
438 ExprKind::Ret(..) => &expr.kind,
454 ) -> Option<(BinOpKind, &'a Expr<'a>, &'a Expr<'a>)> {
456 BinOpKind::Add | BinOpKind::Eq | BinOpKind::Ne | BinOpKind::BitAnd | BinOpKind::BitXor | BinOpKind::BitOr => {
457 Some((binop, rhs, lhs))
459 BinOpKind::Lt => Some((BinOpKind::Gt, rhs, lhs)),
460 BinOpKind::Le => Some((BinOpKind::Ge, rhs, lhs)),
461 BinOpKind::Ge => Some((BinOpKind::Le, rhs, lhs)),
462 BinOpKind::Gt => Some((BinOpKind::Lt, rhs, lhs)),
463 BinOpKind::Mul // Not always commutative, e.g. with matrices. See issue #5698
470 | BinOpKind::Or => None,
474 /// Checks if the two `Option`s are both `None` or some equal values as per
476 pub fn both<X>(l: &Option<X>, r: &Option<X>, mut eq_fn: impl FnMut(&X, &X) -> bool) -> bool {
478 .map_or_else(|| r.is_none(), |x| r.as_ref().map_or(false, |y| eq_fn(x, y)))
481 /// Checks if two slices are equal as per `eq_fn`.
482 pub fn over<X>(left: &[X], right: &[X], mut eq_fn: impl FnMut(&X, &X) -> bool) -> bool {
483 left.len() == right.len() && left.iter().zip(right).all(|(x, y)| eq_fn(x, y))
486 /// Counts how many elements of the slices are equal as per `eq_fn`.
487 pub fn count_eq<X: Sized>(
488 left: &mut dyn Iterator<Item = X>,
489 right: &mut dyn Iterator<Item = X>,
490 mut eq_fn: impl FnMut(&X, &X) -> bool,
492 left.zip(right).take_while(|(l, r)| eq_fn(l, r)).count()
495 /// Checks if two expressions evaluate to the same value, and don't contain any side effects.
496 pub fn eq_expr_value(cx: &LateContext<'_>, left: &Expr<'_>, right: &Expr<'_>) -> bool {
497 SpanlessEq::new(cx).deny_side_effects().eq_expr(left, right)
500 /// Type used to hash an ast element. This is different from the `Hash` trait
501 /// on ast types as this
502 /// trait would consider IDs and spans.
504 /// All expressions kind are hashed, but some might have a weaker hash.
505 pub struct SpanlessHash<'a, 'tcx> {
506 /// Context used to evaluate constant expressions.
507 cx: &'a LateContext<'tcx>,
508 maybe_typeck_results: Option<&'tcx TypeckResults<'tcx>>,
512 impl<'a, 'tcx> SpanlessHash<'a, 'tcx> {
513 pub fn new(cx: &'a LateContext<'tcx>) -> Self {
516 maybe_typeck_results: cx.maybe_typeck_results(),
517 s: StableHasher::new(),
521 pub fn finish(self) -> u64 {
525 pub fn hash_block(&mut self, b: &Block<'_>) {
530 if let Some(ref e) = b.expr {
535 BlockCheckMode::DefaultBlock => 0,
536 BlockCheckMode::UnsafeBlock(_) => 1,
537 BlockCheckMode::PushUnsafeBlock(_) => 2,
538 BlockCheckMode::PopUnsafeBlock(_) => 3,
543 #[allow(clippy::many_single_char_names, clippy::too_many_lines)]
544 pub fn hash_expr(&mut self, e: &Expr<'_>) {
545 let simple_const = self
546 .maybe_typeck_results
547 .and_then(|typeck_results| constant_simple(self.cx, typeck_results, e));
549 // const hashing may result in the same hash as some unrelated node, so add a sort of
550 // discriminant depending on which path we're choosing next
551 simple_const.is_some().hash(&mut self.s);
553 if let Some(e) = simple_const {
554 return e.hash(&mut self.s);
557 std::mem::discriminant(&e.kind).hash(&mut self.s);
560 ExprKind::AddrOf(kind, m, ref e) => {
562 BorrowKind::Ref => 0,
563 BorrowKind::Raw => 1,
569 ExprKind::Continue(i) => {
570 if let Some(i) = i.label {
571 self.hash_name(i.ident.name);
574 ExprKind::Assign(ref l, ref r, _) => {
578 ExprKind::AssignOp(ref o, ref l, ref r) => {
580 .hash_stable(&mut self.cx.tcx.get_stable_hashing_context(), &mut self.s);
584 ExprKind::Block(ref b, _) => {
587 ExprKind::Binary(op, ref l, ref r) => {
589 .hash_stable(&mut self.cx.tcx.get_stable_hashing_context(), &mut self.s);
593 ExprKind::Break(i, ref j) => {
594 if let Some(i) = i.label {
595 self.hash_name(i.ident.name);
597 if let Some(ref j) = *j {
601 ExprKind::Box(ref e) | ExprKind::DropTemps(ref e) | ExprKind::Yield(ref e, _) => {
604 ExprKind::Call(ref fun, args) => {
606 self.hash_exprs(args);
608 ExprKind::Cast(ref e, ref ty) | ExprKind::Type(ref e, ref ty) => {
612 ExprKind::Closure(cap, _, eid, _, _) => {
614 CaptureBy::Value => 0,
618 // closures inherit TypeckResults
619 self.hash_expr(&self.cx.tcx.hir().body(eid).value);
621 ExprKind::Field(ref e, ref f) => {
623 self.hash_name(f.name);
625 ExprKind::Index(ref a, ref i) => {
629 ExprKind::InlineAsm(ref asm) => {
630 for piece in asm.template {
632 InlineAsmTemplatePiece::String(s) => s.hash(&mut self.s),
633 InlineAsmTemplatePiece::Placeholder {
638 operand_idx.hash(&mut self.s);
639 modifier.hash(&mut self.s);
643 asm.options.hash(&mut self.s);
644 for (op, _op_sp) in asm.operands {
646 InlineAsmOperand::In { reg, expr } => {
647 reg.hash(&mut self.s);
648 self.hash_expr(expr);
650 InlineAsmOperand::Out { reg, late, expr } => {
651 reg.hash(&mut self.s);
652 late.hash(&mut self.s);
653 if let Some(expr) = expr {
654 self.hash_expr(expr);
657 InlineAsmOperand::InOut { reg, late, expr } => {
658 reg.hash(&mut self.s);
659 late.hash(&mut self.s);
660 self.hash_expr(expr);
662 InlineAsmOperand::SplitInOut {
668 reg.hash(&mut self.s);
669 late.hash(&mut self.s);
670 self.hash_expr(in_expr);
671 if let Some(out_expr) = out_expr {
672 self.hash_expr(out_expr);
675 InlineAsmOperand::Const { expr } | InlineAsmOperand::Sym { expr } => self.hash_expr(expr),
679 ExprKind::LlvmInlineAsm(..) | ExprKind::Err => {},
680 ExprKind::Lit(ref l) => {
681 l.node.hash(&mut self.s);
683 ExprKind::Loop(ref b, ref i, ..) => {
685 if let Some(i) = *i {
686 self.hash_name(i.ident.name);
689 ExprKind::If(ref cond, ref then, ref else_opt) => {
690 let c: fn(_, _, _) -> _ = ExprKind::If;
692 self.hash_expr(cond);
693 self.hash_expr(&**then);
694 if let Some(ref e) = *else_opt {
698 ExprKind::Match(ref e, arms, ref s) => {
703 if let Some(ref e) = arm.guard {
706 self.hash_expr(&arm.body);
711 ExprKind::MethodCall(ref path, ref _tys, args, ref _fn_span) => {
712 self.hash_name(path.ident.name);
713 self.hash_exprs(args);
715 ExprKind::ConstBlock(ref l_id) => {
716 self.hash_body(l_id.body);
718 ExprKind::Repeat(ref e, ref l_id) => {
720 self.hash_body(l_id.body);
722 ExprKind::Ret(ref e) => {
723 if let Some(ref e) = *e {
727 ExprKind::Path(ref qpath) => {
728 self.hash_qpath(qpath);
730 ExprKind::Struct(ref path, fields, ref expr) => {
731 self.hash_qpath(path);
734 self.hash_name(f.ident.name);
735 self.hash_expr(&f.expr);
738 if let Some(ref e) = *expr {
742 ExprKind::Tup(tup) => {
743 self.hash_exprs(tup);
745 ExprKind::Array(v) => {
748 ExprKind::Unary(lop, ref le) => {
749 lop.hash_stable(&mut self.cx.tcx.get_stable_hashing_context(), &mut self.s);
755 pub fn hash_exprs(&mut self, e: &[Expr<'_>]) {
761 pub fn hash_name(&mut self, n: Symbol) {
762 n.as_str().hash(&mut self.s);
765 pub fn hash_qpath(&mut self, p: &QPath<'_>) {
767 QPath::Resolved(_, ref path) => {
768 self.hash_path(path);
770 QPath::TypeRelative(_, ref path) => {
771 self.hash_name(path.ident.name);
773 QPath::LangItem(lang_item, ..) => {
774 lang_item.hash_stable(&mut self.cx.tcx.get_stable_hashing_context(), &mut self.s);
777 // self.maybe_typeck_results.unwrap().qpath_res(p, id).hash(&mut self.s);
780 pub fn hash_path(&mut self, path: &Path<'_>) {
782 // constant hash since equality is dependant on inter-expression context
783 Res::Local(_) => 1_usize.hash(&mut self.s),
785 for seg in path.segments {
786 self.hash_name(seg.ident.name);
792 pub fn hash_stmt(&mut self, b: &Stmt<'_>) {
793 std::mem::discriminant(&b.kind).hash(&mut self.s);
796 StmtKind::Local(local) => {
797 if let Some(ref init) = local.init {
798 self.hash_expr(init);
801 StmtKind::Item(..) => {},
802 StmtKind::Expr(expr) | StmtKind::Semi(expr) => {
803 self.hash_expr(expr);
808 pub fn hash_guard(&mut self, g: &Guard<'_>) {
810 Guard::If(ref expr) | Guard::IfLet(_, ref expr) => {
811 self.hash_expr(expr);
816 pub fn hash_lifetime(&mut self, lifetime: &Lifetime) {
817 std::mem::discriminant(&lifetime.name).hash(&mut self.s);
818 if let LifetimeName::Param(ref name) = lifetime.name {
819 std::mem::discriminant(name).hash(&mut self.s);
821 ParamName::Plain(ref ident) => {
822 ident.name.hash(&mut self.s);
824 ParamName::Fresh(ref size) => {
825 size.hash(&mut self.s);
827 ParamName::Error => {},
832 pub fn hash_ty(&mut self, ty: &Ty<'_>) {
833 self.hash_tykind(&ty.kind);
836 pub fn hash_tykind(&mut self, ty: &TyKind<'_>) {
837 std::mem::discriminant(ty).hash(&mut self.s);
839 TyKind::Slice(ty) => {
842 TyKind::Array(ty, anon_const) => {
844 self.hash_body(anon_const.body);
846 TyKind::Ptr(mut_ty) => {
847 self.hash_ty(&mut_ty.ty);
848 mut_ty.mutbl.hash(&mut self.s);
850 TyKind::Rptr(lifetime, mut_ty) => {
851 self.hash_lifetime(lifetime);
852 self.hash_ty(&mut_ty.ty);
853 mut_ty.mutbl.hash(&mut self.s);
855 TyKind::BareFn(bfn) => {
856 bfn.unsafety.hash(&mut self.s);
857 bfn.abi.hash(&mut self.s);
858 for arg in bfn.decl.inputs {
861 match bfn.decl.output {
862 FnRetTy::DefaultReturn(_) => {
863 ().hash(&mut self.s);
865 FnRetTy::Return(ref ty) => {
869 bfn.decl.c_variadic.hash(&mut self.s);
871 TyKind::Tup(ty_list) => {
876 TyKind::Path(qpath) => match qpath {
877 QPath::Resolved(ref maybe_ty, ref path) => {
878 if let Some(ref ty) = maybe_ty {
881 for segment in path.segments {
882 segment.ident.name.hash(&mut self.s);
883 self.hash_generic_args(segment.args().args);
886 QPath::TypeRelative(ref ty, ref segment) => {
888 segment.ident.name.hash(&mut self.s);
890 QPath::LangItem(lang_item, ..) => {
891 lang_item.hash(&mut self.s);
894 TyKind::OpaqueDef(_, arg_list) => {
895 self.hash_generic_args(arg_list);
897 TyKind::TraitObject(_, lifetime, _) => {
898 self.hash_lifetime(lifetime);
900 TyKind::Typeof(anon_const) => {
901 self.hash_body(anon_const.body);
903 TyKind::Err | TyKind::Infer | TyKind::Never => {},
907 pub fn hash_body(&mut self, body_id: BodyId) {
908 // swap out TypeckResults when hashing a body
909 let old_maybe_typeck_results = self.maybe_typeck_results.replace(self.cx.tcx.typeck_body(body_id));
910 self.hash_expr(&self.cx.tcx.hir().body(body_id).value);
911 self.maybe_typeck_results = old_maybe_typeck_results;
914 fn hash_generic_args(&mut self, arg_list: &[GenericArg<'_>]) {
915 for arg in arg_list {
917 GenericArg::Lifetime(ref l) => self.hash_lifetime(l),
918 GenericArg::Type(ref ty) => self.hash_ty(&ty),
919 GenericArg::Const(ref ca) => self.hash_body(ca.value.body),