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(ref l), &StmtKind::Local(ref r)) => {
99 // eq_pat adds the HirIds to the locals map. We therefor call it last to make sure that
100 // these only get added if the init and type is equal.
101 both(&l.init, &r.init, |l, r| self.eq_expr(l, r))
102 && both(&l.ty, &r.ty, |l, r| self.eq_ty(l, r))
103 && self.eq_pat(&l.pat, &r.pat)
105 (&StmtKind::Expr(ref l), &StmtKind::Expr(ref r)) | (&StmtKind::Semi(ref l), &StmtKind::Semi(ref r)) => {
112 /// Checks whether two blocks are the same.
113 fn eq_block(&mut self, left: &Block<'_>, right: &Block<'_>) -> bool {
114 match (left.stmts, left.expr, right.stmts, right.expr) {
115 ([], None, [], None) => {
116 // For empty blocks, check to see if the tokens are equal. This will catch the case where a macro
117 // expanded to nothing, or the cfg attribute was used.
118 let (left, right) = match (
119 snippet_opt(self.inner.cx, left.span),
120 snippet_opt(self.inner.cx, right.span),
122 (Some(left), Some(right)) => (left, right),
125 let mut left_pos = 0;
126 let left = tokenize(&left)
128 let end = left_pos + t.len;
129 let s = &left[left_pos..end];
136 TokenKind::LineComment { .. } | TokenKind::BlockComment { .. } | TokenKind::Whitespace
140 let mut right_pos = 0;
141 let right = tokenize(&right)
143 let end = right_pos + t.len;
144 let s = &right[right_pos..end];
151 TokenKind::LineComment { .. } | TokenKind::BlockComment { .. } | TokenKind::Whitespace
158 over(&left.stmts, &right.stmts, |l, r| self.eq_stmt(l, r))
159 && both(&left.expr, &right.expr, |l, r| self.eq_expr(l, r))
164 #[allow(clippy::similar_names)]
165 pub fn eq_expr(&mut self, left: &Expr<'_>, right: &Expr<'_>) -> bool {
166 if !self.inner.allow_side_effects && differing_macro_contexts(left.span, right.span) {
170 if let Some(typeck_results) = self.inner.maybe_typeck_results {
171 if let (Some(l), Some(r)) = (
172 constant_simple(self.inner.cx, typeck_results, left),
173 constant_simple(self.inner.cx, typeck_results, right),
182 &reduce_exprkind(self.inner.cx, &left.kind),
183 &reduce_exprkind(self.inner.cx, &right.kind),
185 (&ExprKind::AddrOf(lb, l_mut, ref le), &ExprKind::AddrOf(rb, r_mut, ref re)) => {
186 lb == rb && l_mut == r_mut && self.eq_expr(le, re)
188 (&ExprKind::Continue(li), &ExprKind::Continue(ri)) => {
189 both(&li.label, &ri.label, |l, r| l.ident.name == r.ident.name)
191 (&ExprKind::Assign(ref ll, ref lr, _), &ExprKind::Assign(ref rl, ref rr, _)) => {
192 self.inner.allow_side_effects && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
194 (&ExprKind::AssignOp(ref lo, ref ll, ref lr), &ExprKind::AssignOp(ref ro, ref rl, ref rr)) => {
195 self.inner.allow_side_effects && lo.node == ro.node && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
197 (&ExprKind::Block(ref l, _), &ExprKind::Block(ref r, _)) => self.eq_block(l, r),
198 (&ExprKind::Binary(l_op, ref ll, ref lr), &ExprKind::Binary(r_op, ref rl, ref rr)) => {
199 l_op.node == r_op.node && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
200 || swap_binop(l_op.node, ll, lr).map_or(false, |(l_op, ll, lr)| {
201 l_op == r_op.node && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
204 (&ExprKind::Break(li, ref le), &ExprKind::Break(ri, ref re)) => {
205 both(&li.label, &ri.label, |l, r| l.ident.name == r.ident.name)
206 && both(le, re, |l, r| self.eq_expr(l, r))
208 (&ExprKind::Box(ref l), &ExprKind::Box(ref r)) => self.eq_expr(l, r),
209 (&ExprKind::Call(l_fun, l_args), &ExprKind::Call(r_fun, r_args)) => {
210 self.inner.allow_side_effects && self.eq_expr(l_fun, r_fun) && self.eq_exprs(l_args, r_args)
212 (&ExprKind::Cast(ref lx, ref lt), &ExprKind::Cast(ref rx, ref rt))
213 | (&ExprKind::Type(ref lx, ref lt), &ExprKind::Type(ref rx, ref rt)) => {
214 self.eq_expr(lx, rx) && self.eq_ty(lt, rt)
216 (&ExprKind::Field(ref l_f_exp, ref l_f_ident), &ExprKind::Field(ref r_f_exp, ref r_f_ident)) => {
217 l_f_ident.name == r_f_ident.name && self.eq_expr(l_f_exp, r_f_exp)
219 (&ExprKind::Index(ref la, ref li), &ExprKind::Index(ref ra, ref ri)) => {
220 self.eq_expr(la, ra) && self.eq_expr(li, ri)
222 (&ExprKind::If(ref lc, ref lt, ref le), &ExprKind::If(ref rc, ref rt, ref re)) => {
223 self.eq_expr(lc, rc) && self.eq_expr(&**lt, &**rt) && both(le, re, |l, r| self.eq_expr(l, r))
225 (&ExprKind::Lit(ref l), &ExprKind::Lit(ref r)) => l.node == r.node,
226 (&ExprKind::Loop(ref lb, ref ll, ref lls, _), &ExprKind::Loop(ref rb, ref rl, ref rls, _)) => {
227 lls == rls && self.eq_block(lb, rb) && both(ll, rl, |l, r| l.ident.name == r.ident.name)
229 (&ExprKind::Match(ref le, ref la, ref ls), &ExprKind::Match(ref re, ref ra, ref rs)) => {
231 && self.eq_expr(le, re)
232 && over(la, ra, |l, r| {
233 self.eq_pat(&l.pat, &r.pat)
234 && both(&l.guard, &r.guard, |l, r| self.eq_guard(l, r))
235 && self.eq_expr(&l.body, &r.body)
238 (&ExprKind::MethodCall(l_path, _, l_args, _), &ExprKind::MethodCall(r_path, _, r_args, _)) => {
239 self.inner.allow_side_effects && self.eq_path_segment(l_path, r_path) && self.eq_exprs(l_args, r_args)
241 (&ExprKind::Repeat(ref le, ref ll_id), &ExprKind::Repeat(ref re, ref rl_id)) => {
242 let mut celcx = constant_context(self.inner.cx, self.inner.cx.tcx.typeck_body(ll_id.body));
243 let ll = celcx.expr(&self.inner.cx.tcx.hir().body(ll_id.body).value);
244 let mut celcx = constant_context(self.inner.cx, self.inner.cx.tcx.typeck_body(rl_id.body));
245 let rl = celcx.expr(&self.inner.cx.tcx.hir().body(rl_id.body).value);
247 self.eq_expr(le, re) && ll == rl
249 (&ExprKind::Ret(ref l), &ExprKind::Ret(ref r)) => both(l, r, |l, r| self.eq_expr(l, r)),
250 (&ExprKind::Path(ref l), &ExprKind::Path(ref r)) => self.eq_qpath(l, r),
251 (&ExprKind::Struct(ref l_path, ref lf, ref lo), &ExprKind::Struct(ref r_path, ref rf, ref ro)) => {
252 self.eq_qpath(l_path, r_path)
253 && both(lo, ro, |l, r| self.eq_expr(l, r))
254 && over(lf, rf, |l, r| self.eq_expr_field(l, r))
256 (&ExprKind::Tup(l_tup), &ExprKind::Tup(r_tup)) => self.eq_exprs(l_tup, r_tup),
257 (&ExprKind::Unary(l_op, ref le), &ExprKind::Unary(r_op, ref re)) => l_op == r_op && self.eq_expr(le, re),
258 (&ExprKind::Array(l), &ExprKind::Array(r)) => self.eq_exprs(l, r),
259 (&ExprKind::DropTemps(ref le), &ExprKind::DropTemps(ref re)) => self.eq_expr(le, re),
262 is_eq || self.inner.expr_fallback.as_mut().map_or(false, |f| f(left, right))
265 fn eq_exprs(&mut self, left: &[Expr<'_>], right: &[Expr<'_>]) -> bool {
266 over(left, right, |l, r| self.eq_expr(l, r))
269 fn eq_expr_field(&mut self, left: &ExprField<'_>, right: &ExprField<'_>) -> bool {
270 left.ident.name == right.ident.name && self.eq_expr(&left.expr, &right.expr)
273 fn eq_guard(&mut self, left: &Guard<'_>, right: &Guard<'_>) -> bool {
274 match (left, right) {
275 (Guard::If(l), Guard::If(r)) => self.eq_expr(l, r),
276 (Guard::IfLet(lp, le), Guard::IfLet(rp, re)) => self.eq_pat(lp, rp) && self.eq_expr(le, re),
281 fn eq_generic_arg(&mut self, left: &GenericArg<'_>, right: &GenericArg<'_>) -> bool {
282 match (left, right) {
283 (GenericArg::Lifetime(l_lt), GenericArg::Lifetime(r_lt)) => Self::eq_lifetime(l_lt, r_lt),
284 (GenericArg::Type(l_ty), GenericArg::Type(r_ty)) => self.eq_ty(l_ty, r_ty),
289 fn eq_lifetime(left: &Lifetime, right: &Lifetime) -> bool {
290 left.name == right.name
293 fn eq_pat_field(&mut self, left: &PatField<'_>, right: &PatField<'_>) -> bool {
294 let (PatField { ident: li, pat: lp, .. }, PatField { ident: ri, pat: rp, .. }) = (&left, &right);
295 li.name == ri.name && self.eq_pat(lp, rp)
298 /// Checks whether two patterns are the same.
299 fn eq_pat(&mut self, left: &Pat<'_>, right: &Pat<'_>) -> bool {
300 match (&left.kind, &right.kind) {
301 (&PatKind::Box(ref l), &PatKind::Box(ref r)) => self.eq_pat(l, r),
302 (&PatKind::Struct(ref lp, ref la, ..), &PatKind::Struct(ref rp, ref ra, ..)) => {
303 self.eq_qpath(lp, rp) && over(la, ra, |l, r| self.eq_pat_field(l, r))
305 (&PatKind::TupleStruct(ref lp, ref la, ls), &PatKind::TupleStruct(ref rp, ref ra, rs)) => {
306 self.eq_qpath(lp, rp) && over(la, ra, |l, r| self.eq_pat(l, r)) && ls == rs
308 (&PatKind::Binding(lb, li, _, ref lp), &PatKind::Binding(rb, ri, _, ref rp)) => {
309 let eq = lb == rb && both(lp, rp, |l, r| self.eq_pat(l, r));
311 self.locals.insert(li, ri);
315 (&PatKind::Path(ref l), &PatKind::Path(ref r)) => self.eq_qpath(l, r),
316 (&PatKind::Lit(ref l), &PatKind::Lit(ref r)) => self.eq_expr(l, r),
317 (&PatKind::Tuple(ref l, ls), &PatKind::Tuple(ref r, rs)) => {
318 ls == rs && over(l, r, |l, r| self.eq_pat(l, r))
320 (&PatKind::Range(ref ls, ref le, li), &PatKind::Range(ref rs, ref re, ri)) => {
321 both(ls, rs, |a, b| self.eq_expr(a, b)) && both(le, re, |a, b| self.eq_expr(a, b)) && (li == ri)
323 (&PatKind::Ref(ref le, ref lm), &PatKind::Ref(ref re, ref rm)) => lm == rm && self.eq_pat(le, re),
324 (&PatKind::Slice(ref ls, ref li, ref le), &PatKind::Slice(ref rs, ref ri, ref re)) => {
325 over(ls, rs, |l, r| self.eq_pat(l, r))
326 && over(le, re, |l, r| self.eq_pat(l, r))
327 && both(li, ri, |l, r| self.eq_pat(l, r))
329 (&PatKind::Wild, &PatKind::Wild) => true,
334 #[allow(clippy::similar_names)]
335 fn eq_qpath(&mut self, left: &QPath<'_>, right: &QPath<'_>) -> bool {
336 match (left, right) {
337 (&QPath::Resolved(ref lty, ref lpath), &QPath::Resolved(ref rty, ref rpath)) => {
338 both(lty, rty, |l, r| self.eq_ty(l, r)) && self.eq_path(lpath, rpath)
340 (&QPath::TypeRelative(ref lty, ref lseg), &QPath::TypeRelative(ref rty, ref rseg)) => {
341 self.eq_ty(lty, rty) && self.eq_path_segment(lseg, rseg)
343 (&QPath::LangItem(llang_item, _), &QPath::LangItem(rlang_item, _)) => llang_item == rlang_item,
348 fn eq_path(&mut self, left: &Path<'_>, right: &Path<'_>) -> bool {
349 match (left.res, right.res) {
350 (Res::Local(l), Res::Local(r)) => l == r || self.locals.get(&l) == Some(&r),
351 (Res::Local(_), _) | (_, Res::Local(_)) => false,
352 _ => over(&left.segments, &right.segments, |l, r| self.eq_path_segment(l, r)),
356 fn eq_path_parameters(&mut self, left: &GenericArgs<'_>, right: &GenericArgs<'_>) -> bool {
357 if !(left.parenthesized || right.parenthesized) {
358 over(&left.args, &right.args, |l, r| self.eq_generic_arg(l, r)) // FIXME(flip1995): may not work
359 && over(&left.bindings, &right.bindings, |l, r| self.eq_type_binding(l, r))
360 } else if left.parenthesized && right.parenthesized {
361 over(left.inputs(), right.inputs(), |l, r| self.eq_ty(l, r))
362 && both(&Some(&left.bindings[0].ty()), &Some(&right.bindings[0].ty()), |l, r| {
370 pub fn eq_path_segments(&mut self, left: &[PathSegment<'_>], right: &[PathSegment<'_>]) -> bool {
371 left.len() == right.len() && left.iter().zip(right).all(|(l, r)| self.eq_path_segment(l, r))
374 pub fn eq_path_segment(&mut self, left: &PathSegment<'_>, right: &PathSegment<'_>) -> bool {
375 // The == of idents doesn't work with different contexts,
376 // we have to be explicit about hygiene
377 left.ident.name == right.ident.name && both(&left.args, &right.args, |l, r| self.eq_path_parameters(l, r))
380 #[allow(clippy::similar_names)]
381 fn eq_ty(&mut self, left: &Ty<'_>, right: &Ty<'_>) -> bool {
382 match (&left.kind, &right.kind) {
383 (&TyKind::Slice(ref l_vec), &TyKind::Slice(ref r_vec)) => self.eq_ty(l_vec, r_vec),
384 (&TyKind::Array(ref lt, ref ll_id), &TyKind::Array(ref rt, ref rl_id)) => {
385 let cx = self.inner.cx;
387 |body| constant_context(cx, cx.tcx.typeck_body(body)).expr(&cx.tcx.hir().body(body).value);
388 self.eq_ty(lt, rt) && eval_const(ll_id.body) == eval_const(rl_id.body)
390 (&TyKind::Ptr(ref l_mut), &TyKind::Ptr(ref r_mut)) => {
391 l_mut.mutbl == r_mut.mutbl && self.eq_ty(&*l_mut.ty, &*r_mut.ty)
393 (&TyKind::Rptr(_, ref l_rmut), &TyKind::Rptr(_, ref r_rmut)) => {
394 l_rmut.mutbl == r_rmut.mutbl && self.eq_ty(&*l_rmut.ty, &*r_rmut.ty)
396 (&TyKind::Path(ref l), &TyKind::Path(ref r)) => self.eq_qpath(l, r),
397 (&TyKind::Tup(ref l), &TyKind::Tup(ref r)) => over(l, r, |l, r| self.eq_ty(l, r)),
398 (&TyKind::Infer, &TyKind::Infer) => true,
403 fn eq_type_binding(&mut self, left: &TypeBinding<'_>, right: &TypeBinding<'_>) -> bool {
404 left.ident.name == right.ident.name && self.eq_ty(&left.ty(), &right.ty())
408 /// Some simple reductions like `{ return }` => `return`
409 fn reduce_exprkind<'hir>(cx: &LateContext<'_>, kind: &'hir ExprKind<'hir>) -> &'hir ExprKind<'hir> {
410 if let ExprKind::Block(block, _) = kind {
411 match (block.stmts, block.expr) {
412 // From an `if let` expression without an `else` block. The arm for the implicit wild pattern is an empty
413 // block with an empty span.
414 ([], None) if block.span.is_empty() => &ExprKind::Tup(&[]),
416 ([], None) => match snippet_opt(cx, block.span) {
417 // Don't reduce if there are any tokens contained in the braces
424 TokenKind::LineComment { .. } | TokenKind::BlockComment { .. } | TokenKind::Whitespace
427 .ne([TokenKind::OpenBrace, TokenKind::CloseBrace].iter().cloned()) =>
431 _ => &ExprKind::Tup(&[]),
433 ([], Some(expr)) => match expr.kind {
434 // `{ return .. }` => `return ..`
435 ExprKind::Ret(..) => &expr.kind,
438 ([stmt], None) => match stmt.kind {
439 StmtKind::Expr(expr) | StmtKind::Semi(expr) => match expr.kind {
440 // `{ return ..; }` => `return ..`
441 ExprKind::Ret(..) => &expr.kind,
457 ) -> Option<(BinOpKind, &'a Expr<'a>, &'a Expr<'a>)> {
459 BinOpKind::Add | BinOpKind::Eq | BinOpKind::Ne | BinOpKind::BitAnd | BinOpKind::BitXor | BinOpKind::BitOr => {
460 Some((binop, rhs, lhs))
462 BinOpKind::Lt => Some((BinOpKind::Gt, rhs, lhs)),
463 BinOpKind::Le => Some((BinOpKind::Ge, rhs, lhs)),
464 BinOpKind::Ge => Some((BinOpKind::Le, rhs, lhs)),
465 BinOpKind::Gt => Some((BinOpKind::Lt, rhs, lhs)),
466 BinOpKind::Mul // Not always commutative, e.g. with matrices. See issue #5698
473 | BinOpKind::Or => None,
477 /// Checks if the two `Option`s are both `None` or some equal values as per
479 pub fn both<X>(l: &Option<X>, r: &Option<X>, mut eq_fn: impl FnMut(&X, &X) -> bool) -> bool {
481 .map_or_else(|| r.is_none(), |x| r.as_ref().map_or(false, |y| eq_fn(x, y)))
484 /// Checks if two slices are equal as per `eq_fn`.
485 pub fn over<X>(left: &[X], right: &[X], mut eq_fn: impl FnMut(&X, &X) -> bool) -> bool {
486 left.len() == right.len() && left.iter().zip(right).all(|(x, y)| eq_fn(x, y))
489 /// Counts how many elements of the slices are equal as per `eq_fn`.
490 pub fn count_eq<X: Sized>(
491 left: &mut dyn Iterator<Item = X>,
492 right: &mut dyn Iterator<Item = X>,
493 mut eq_fn: impl FnMut(&X, &X) -> bool,
495 left.zip(right).take_while(|(l, r)| eq_fn(l, r)).count()
498 /// Checks if two expressions evaluate to the same value, and don't contain any side effects.
499 pub fn eq_expr_value(cx: &LateContext<'_>, left: &Expr<'_>, right: &Expr<'_>) -> bool {
500 SpanlessEq::new(cx).deny_side_effects().eq_expr(left, right)
503 /// Type used to hash an ast element. This is different from the `Hash` trait
504 /// on ast types as this
505 /// trait would consider IDs and spans.
507 /// All expressions kind are hashed, but some might have a weaker hash.
508 pub struct SpanlessHash<'a, 'tcx> {
509 /// Context used to evaluate constant expressions.
510 cx: &'a LateContext<'tcx>,
511 maybe_typeck_results: Option<&'tcx TypeckResults<'tcx>>,
515 impl<'a, 'tcx> SpanlessHash<'a, 'tcx> {
516 pub fn new(cx: &'a LateContext<'tcx>) -> Self {
519 maybe_typeck_results: cx.maybe_typeck_results(),
520 s: StableHasher::new(),
524 pub fn finish(self) -> u64 {
528 pub fn hash_block(&mut self, b: &Block<'_>) {
533 if let Some(ref e) = b.expr {
538 BlockCheckMode::DefaultBlock => 0,
539 BlockCheckMode::UnsafeBlock(_) => 1,
540 BlockCheckMode::PushUnsafeBlock(_) => 2,
541 BlockCheckMode::PopUnsafeBlock(_) => 3,
546 #[allow(clippy::many_single_char_names, clippy::too_many_lines)]
547 pub fn hash_expr(&mut self, e: &Expr<'_>) {
548 let simple_const = self
549 .maybe_typeck_results
550 .and_then(|typeck_results| constant_simple(self.cx, typeck_results, e));
552 // const hashing may result in the same hash as some unrelated node, so add a sort of
553 // discriminant depending on which path we're choosing next
554 simple_const.is_some().hash(&mut self.s);
556 if let Some(e) = simple_const {
557 return e.hash(&mut self.s);
560 std::mem::discriminant(&e.kind).hash(&mut self.s);
563 ExprKind::AddrOf(kind, m, ref e) => {
565 BorrowKind::Ref => 0,
566 BorrowKind::Raw => 1,
572 ExprKind::Continue(i) => {
573 if let Some(i) = i.label {
574 self.hash_name(i.ident.name);
577 ExprKind::Assign(ref l, ref r, _) => {
581 ExprKind::AssignOp(ref o, ref l, ref r) => {
583 .hash_stable(&mut self.cx.tcx.get_stable_hashing_context(), &mut self.s);
587 ExprKind::Block(ref b, _) => {
590 ExprKind::Binary(op, ref l, ref r) => {
592 .hash_stable(&mut self.cx.tcx.get_stable_hashing_context(), &mut self.s);
596 ExprKind::Break(i, ref j) => {
597 if let Some(i) = i.label {
598 self.hash_name(i.ident.name);
600 if let Some(ref j) = *j {
604 ExprKind::Box(ref e) | ExprKind::DropTemps(ref e) | ExprKind::Yield(ref e, _) => {
607 ExprKind::Call(ref fun, args) => {
609 self.hash_exprs(args);
611 ExprKind::Cast(ref e, ref ty) | ExprKind::Type(ref e, ref ty) => {
615 ExprKind::Closure(cap, _, eid, _, _) => {
617 CaptureBy::Value => 0,
621 // closures inherit TypeckResults
622 self.hash_expr(&self.cx.tcx.hir().body(eid).value);
624 ExprKind::Field(ref e, ref f) => {
626 self.hash_name(f.name);
628 ExprKind::Index(ref a, ref i) => {
632 ExprKind::InlineAsm(ref asm) => {
633 for piece in asm.template {
635 InlineAsmTemplatePiece::String(s) => s.hash(&mut self.s),
636 InlineAsmTemplatePiece::Placeholder {
641 operand_idx.hash(&mut self.s);
642 modifier.hash(&mut self.s);
646 asm.options.hash(&mut self.s);
647 for (op, _op_sp) in asm.operands {
649 InlineAsmOperand::In { reg, expr } => {
650 reg.hash(&mut self.s);
651 self.hash_expr(expr);
653 InlineAsmOperand::Out { reg, late, expr } => {
654 reg.hash(&mut self.s);
655 late.hash(&mut self.s);
656 if let Some(expr) = expr {
657 self.hash_expr(expr);
660 InlineAsmOperand::InOut { reg, late, expr } => {
661 reg.hash(&mut self.s);
662 late.hash(&mut self.s);
663 self.hash_expr(expr);
665 InlineAsmOperand::SplitInOut {
671 reg.hash(&mut self.s);
672 late.hash(&mut self.s);
673 self.hash_expr(in_expr);
674 if let Some(out_expr) = out_expr {
675 self.hash_expr(out_expr);
678 InlineAsmOperand::Const { anon_const } => self.hash_body(anon_const.body),
679 InlineAsmOperand::Sym { expr } => self.hash_expr(expr),
683 ExprKind::LlvmInlineAsm(..) | ExprKind::Err => {},
684 ExprKind::Lit(ref l) => {
685 l.node.hash(&mut self.s);
687 ExprKind::Loop(ref b, ref i, ..) => {
689 if let Some(i) = *i {
690 self.hash_name(i.ident.name);
693 ExprKind::If(ref cond, ref then, ref else_opt) => {
694 let c: fn(_, _, _) -> _ = ExprKind::If;
696 self.hash_expr(cond);
697 self.hash_expr(&**then);
698 if let Some(ref e) = *else_opt {
702 ExprKind::Match(ref e, arms, ref s) => {
707 if let Some(ref e) = arm.guard {
710 self.hash_expr(&arm.body);
715 ExprKind::MethodCall(ref path, ref _tys, args, ref _fn_span) => {
716 self.hash_name(path.ident.name);
717 self.hash_exprs(args);
719 ExprKind::ConstBlock(ref l_id) => {
720 self.hash_body(l_id.body);
722 ExprKind::Repeat(ref e, ref l_id) => {
724 self.hash_body(l_id.body);
726 ExprKind::Ret(ref e) => {
727 if let Some(ref e) = *e {
731 ExprKind::Path(ref qpath) => {
732 self.hash_qpath(qpath);
734 ExprKind::Struct(ref path, fields, ref expr) => {
735 self.hash_qpath(path);
738 self.hash_name(f.ident.name);
739 self.hash_expr(&f.expr);
742 if let Some(ref e) = *expr {
746 ExprKind::Tup(tup) => {
747 self.hash_exprs(tup);
749 ExprKind::Array(v) => {
752 ExprKind::Unary(lop, ref le) => {
753 lop.hash_stable(&mut self.cx.tcx.get_stable_hashing_context(), &mut self.s);
759 pub fn hash_exprs(&mut self, e: &[Expr<'_>]) {
765 pub fn hash_name(&mut self, n: Symbol) {
766 n.as_str().hash(&mut self.s);
769 pub fn hash_qpath(&mut self, p: &QPath<'_>) {
771 QPath::Resolved(_, ref path) => {
772 self.hash_path(path);
774 QPath::TypeRelative(_, ref path) => {
775 self.hash_name(path.ident.name);
777 QPath::LangItem(lang_item, ..) => {
778 lang_item.hash_stable(&mut self.cx.tcx.get_stable_hashing_context(), &mut self.s);
781 // self.maybe_typeck_results.unwrap().qpath_res(p, id).hash(&mut self.s);
784 pub fn hash_path(&mut self, path: &Path<'_>) {
786 // constant hash since equality is dependant on inter-expression context
787 Res::Local(_) => 1_usize.hash(&mut self.s),
789 for seg in path.segments {
790 self.hash_name(seg.ident.name);
796 pub fn hash_stmt(&mut self, b: &Stmt<'_>) {
797 std::mem::discriminant(&b.kind).hash(&mut self.s);
800 StmtKind::Local(local) => {
801 if let Some(ref init) = local.init {
802 self.hash_expr(init);
805 StmtKind::Item(..) => {},
806 StmtKind::Expr(expr) | StmtKind::Semi(expr) => {
807 self.hash_expr(expr);
812 pub fn hash_guard(&mut self, g: &Guard<'_>) {
814 Guard::If(ref expr) | Guard::IfLet(_, ref expr) => {
815 self.hash_expr(expr);
820 pub fn hash_lifetime(&mut self, lifetime: &Lifetime) {
821 std::mem::discriminant(&lifetime.name).hash(&mut self.s);
822 if let LifetimeName::Param(ref name) = lifetime.name {
823 std::mem::discriminant(name).hash(&mut self.s);
825 ParamName::Plain(ref ident) => {
826 ident.name.hash(&mut self.s);
828 ParamName::Fresh(ref size) => {
829 size.hash(&mut self.s);
831 ParamName::Error => {},
836 pub fn hash_ty(&mut self, ty: &Ty<'_>) {
837 self.hash_tykind(&ty.kind);
840 pub fn hash_tykind(&mut self, ty: &TyKind<'_>) {
841 std::mem::discriminant(ty).hash(&mut self.s);
843 TyKind::Slice(ty) => {
846 TyKind::Array(ty, anon_const) => {
848 self.hash_body(anon_const.body);
850 TyKind::Ptr(mut_ty) => {
851 self.hash_ty(&mut_ty.ty);
852 mut_ty.mutbl.hash(&mut self.s);
854 TyKind::Rptr(lifetime, mut_ty) => {
855 self.hash_lifetime(lifetime);
856 self.hash_ty(&mut_ty.ty);
857 mut_ty.mutbl.hash(&mut self.s);
859 TyKind::BareFn(bfn) => {
860 bfn.unsafety.hash(&mut self.s);
861 bfn.abi.hash(&mut self.s);
862 for arg in bfn.decl.inputs {
865 match bfn.decl.output {
866 FnRetTy::DefaultReturn(_) => {
867 ().hash(&mut self.s);
869 FnRetTy::Return(ref ty) => {
873 bfn.decl.c_variadic.hash(&mut self.s);
875 TyKind::Tup(ty_list) => {
880 TyKind::Path(qpath) => match qpath {
881 QPath::Resolved(ref maybe_ty, ref path) => {
882 if let Some(ref ty) = maybe_ty {
885 for segment in path.segments {
886 segment.ident.name.hash(&mut self.s);
887 self.hash_generic_args(segment.args().args);
890 QPath::TypeRelative(ref ty, ref segment) => {
892 segment.ident.name.hash(&mut self.s);
894 QPath::LangItem(lang_item, ..) => {
895 lang_item.hash(&mut self.s);
898 TyKind::OpaqueDef(_, arg_list) => {
899 self.hash_generic_args(arg_list);
901 TyKind::TraitObject(_, lifetime, _) => {
902 self.hash_lifetime(lifetime);
904 TyKind::Typeof(anon_const) => {
905 self.hash_body(anon_const.body);
907 TyKind::Err | TyKind::Infer | TyKind::Never => {},
911 pub fn hash_body(&mut self, body_id: BodyId) {
912 // swap out TypeckResults when hashing a body
913 let old_maybe_typeck_results = self.maybe_typeck_results.replace(self.cx.tcx.typeck_body(body_id));
914 self.hash_expr(&self.cx.tcx.hir().body(body_id).value);
915 self.maybe_typeck_results = old_maybe_typeck_results;
918 fn hash_generic_args(&mut self, arg_list: &[GenericArg<'_>]) {
919 for arg in arg_list {
921 GenericArg::Lifetime(ref l) => self.hash_lifetime(l),
922 GenericArg::Type(ref ty) => self.hash_ty(&ty),
923 GenericArg::Const(ref ca) => self.hash_body(ca.value.body),