4 use std::hash::{Hash, Hasher};
5 use std::collections::hash_map::DefaultHasher;
8 use utils::differing_macro_contexts;
10 /// Type used to check whether two ast are the same. This is different from the
12 /// `==` on ast types as this operator would compare true equality with ID and
15 /// Note that some expressions kinds are not considered but could be added.
16 pub struct SpanlessEq<'a, 'tcx: 'a> {
17 /// Context used to evaluate constant expressions.
18 cx: &'a LateContext<'a, 'tcx>,
19 /// If is true, never consider as equal expressions containing function
24 impl<'a, 'tcx: 'a> SpanlessEq<'a, 'tcx> {
25 pub fn new(cx: &'a LateContext<'a, 'tcx>) -> Self {
32 pub fn ignore_fn(self) -> Self {
39 /// Check whether two statements are the same.
40 pub fn eq_stmt(&self, left: &Stmt, right: &Stmt) -> bool {
41 match (&left.node, &right.node) {
42 (&StmtDecl(ref l, _), &StmtDecl(ref r, _)) => {
43 if let (&DeclLocal(ref l), &DeclLocal(ref r)) = (&l.node, &r.node) {
44 both(&l.ty, &r.ty, |l, r| self.eq_ty(l, r)) && both(&l.init, &r.init, |l, r| self.eq_expr(l, r))
49 (&StmtExpr(ref l, _), &StmtExpr(ref r, _)) |
50 (&StmtSemi(ref l, _), &StmtSemi(ref r, _)) => self.eq_expr(l, r),
55 /// Check whether two blocks are the same.
56 pub fn eq_block(&self, left: &Block, right: &Block) -> bool {
57 over(&left.stmts, &right.stmts, |l, r| self.eq_stmt(l, r)) &&
58 both(&left.expr, &right.expr, |l, r| self.eq_expr(l, r))
61 pub fn eq_expr(&self, left: &Expr, right: &Expr) -> bool {
62 if self.ignore_fn && differing_macro_contexts(left.span, right.span) {
66 if let (Some(l), Some(r)) = (constant(self.cx, left), constant(self.cx, right)) {
72 match (&left.node, &right.node) {
73 (&ExprAddrOf(l_mut, ref le), &ExprAddrOf(r_mut, ref re)) => l_mut == r_mut && self.eq_expr(le, re),
74 (&ExprAgain(li), &ExprAgain(ri)) => {
75 both(&li.ident, &ri.ident, |l, r| l.node.name.as_str() == r.node.name.as_str())
77 (&ExprAssign(ref ll, ref lr), &ExprAssign(ref rl, ref rr)) => self.eq_expr(ll, rl) && self.eq_expr(lr, rr),
78 (&ExprAssignOp(ref lo, ref ll, ref lr), &ExprAssignOp(ref ro, ref rl, ref rr)) => {
79 lo.node == ro.node && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
81 (&ExprBlock(ref l), &ExprBlock(ref r)) => self.eq_block(l, r),
82 (&ExprBinary(l_op, ref ll, ref lr), &ExprBinary(r_op, ref rl, ref rr)) => {
83 l_op.node == r_op.node && self.eq_expr(ll, rl) && self.eq_expr(lr, rr) ||
84 swap_binop(l_op.node, ll, lr).map_or(false, |(l_op, ll, lr)| {
85 l_op == r_op.node && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
88 (&ExprBreak(li, ref le), &ExprBreak(ri, ref re)) => {
89 both(&li.ident, &ri.ident, |l, r| l.node.name.as_str() == r.node.name.as_str()) &&
90 both(le, re, |l, r| self.eq_expr(l, r))
92 (&ExprBox(ref l), &ExprBox(ref r)) => self.eq_expr(l, r),
93 (&ExprCall(ref l_fun, ref l_args), &ExprCall(ref r_fun, ref r_args)) => {
94 !self.ignore_fn && self.eq_expr(l_fun, r_fun) && self.eq_exprs(l_args, r_args)
96 (&ExprCast(ref lx, ref lt), &ExprCast(ref rx, ref rt)) |
97 (&ExprType(ref lx, ref lt), &ExprType(ref rx, ref rt)) => self.eq_expr(lx, rx) && self.eq_ty(lt, rt),
98 (&ExprField(ref l_f_exp, ref l_f_ident), &ExprField(ref r_f_exp, ref r_f_ident)) => {
99 l_f_ident.node == r_f_ident.node && self.eq_expr(l_f_exp, r_f_exp)
101 (&ExprIndex(ref la, ref li), &ExprIndex(ref ra, ref ri)) => self.eq_expr(la, ra) && self.eq_expr(li, ri),
102 (&ExprIf(ref lc, ref lt, ref le), &ExprIf(ref rc, ref rt, ref re)) => {
103 self.eq_expr(lc, rc) && self.eq_expr(&**lt, &**rt) && both(le, re, |l, r| self.eq_expr(l, r))
105 (&ExprLit(ref l), &ExprLit(ref r)) => l.node == r.node,
106 (&ExprLoop(ref lb, ref ll, ref lls), &ExprLoop(ref rb, ref rl, ref rls)) => {
107 lls == rls && self.eq_block(lb, rb) && both(ll, rl, |l, r| l.node.as_str() == r.node.as_str())
109 (&ExprMatch(ref le, ref la, ref ls), &ExprMatch(ref re, ref ra, ref rs)) => {
110 ls == rs && self.eq_expr(le, re) &&
111 over(la, ra, |l, r| {
112 self.eq_expr(&l.body, &r.body) && both(&l.guard, &r.guard, |l, r| self.eq_expr(l, r)) &&
113 over(&l.pats, &r.pats, |l, r| self.eq_pat(l, r))
116 (&ExprMethodCall(ref l_path, _, ref l_args), &ExprMethodCall(ref r_path, _, ref r_args)) => {
117 !self.ignore_fn && l_path == r_path && self.eq_exprs(l_args, r_args)
119 (&ExprRepeat(ref le, ll_id), &ExprRepeat(ref re, rl_id)) => {
120 self.eq_expr(le, re) &&
121 self.eq_expr(&self.cx.tcx.hir.body(ll_id).value, &self.cx.tcx.hir.body(rl_id).value)
123 (&ExprRet(ref l), &ExprRet(ref r)) => both(l, r, |l, r| self.eq_expr(l, r)),
124 (&ExprPath(ref l), &ExprPath(ref r)) => self.eq_qpath(l, r),
125 (&ExprStruct(ref l_path, ref lf, ref lo), &ExprStruct(ref r_path, ref rf, ref ro)) => {
126 self.eq_qpath(l_path, r_path) && both(lo, ro, |l, r| self.eq_expr(l, r)) &&
127 over(lf, rf, |l, r| self.eq_field(l, r))
129 (&ExprTup(ref l_tup), &ExprTup(ref r_tup)) => self.eq_exprs(l_tup, r_tup),
130 (&ExprTupField(ref le, li), &ExprTupField(ref re, ri)) => li.node == ri.node && self.eq_expr(le, re),
131 (&ExprUnary(l_op, ref le), &ExprUnary(r_op, ref re)) => l_op == r_op && self.eq_expr(le, re),
132 (&ExprArray(ref l), &ExprArray(ref r)) => self.eq_exprs(l, r),
133 (&ExprWhile(ref lc, ref lb, ref ll), &ExprWhile(ref rc, ref rb, ref rl)) => {
134 self.eq_expr(lc, rc) && self.eq_block(lb, rb) && both(ll, rl, |l, r| l.node.as_str() == r.node.as_str())
140 fn eq_exprs(&self, left: &P<[Expr]>, right: &P<[Expr]>) -> bool {
141 over(left, right, |l, r| self.eq_expr(l, r))
144 fn eq_field(&self, left: &Field, right: &Field) -> bool {
145 left.name.node == right.name.node && self.eq_expr(&left.expr, &right.expr)
148 fn eq_lifetime(&self, left: &Lifetime, right: &Lifetime) -> bool {
149 left.name == right.name
152 /// Check whether two patterns are the same.
153 pub fn eq_pat(&self, left: &Pat, right: &Pat) -> bool {
154 match (&left.node, &right.node) {
155 (&PatKind::Box(ref l), &PatKind::Box(ref r)) => self.eq_pat(l, r),
156 (&PatKind::TupleStruct(ref lp, ref la, ls), &PatKind::TupleStruct(ref rp, ref ra, rs)) => {
157 self.eq_qpath(lp, rp) && over(la, ra, |l, r| self.eq_pat(l, r)) && ls == rs
159 (&PatKind::Binding(ref lb, _, ref li, ref lp), &PatKind::Binding(ref rb, _, ref ri, ref rp)) => {
160 lb == rb && li.node.as_str() == ri.node.as_str() && both(lp, rp, |l, r| self.eq_pat(l, r))
162 (&PatKind::Path(ref l), &PatKind::Path(ref r)) => self.eq_qpath(l, r),
163 (&PatKind::Lit(ref l), &PatKind::Lit(ref r)) => self.eq_expr(l, r),
164 (&PatKind::Tuple(ref l, ls), &PatKind::Tuple(ref r, rs)) => {
165 ls == rs && over(l, r, |l, r| self.eq_pat(l, r))
167 (&PatKind::Range(ref ls, ref le, ref li), &PatKind::Range(ref rs, ref re, ref ri)) => {
168 self.eq_expr(ls, rs) && self.eq_expr(le, re) && (*li == *ri)
170 (&PatKind::Ref(ref le, ref lm), &PatKind::Ref(ref re, ref rm)) => lm == rm && self.eq_pat(le, re),
171 (&PatKind::Slice(ref ls, ref li, ref le), &PatKind::Slice(ref rs, ref ri, ref re)) => {
172 over(ls, rs, |l, r| self.eq_pat(l, r)) && over(le, re, |l, r| self.eq_pat(l, r)) &&
173 both(li, ri, |l, r| self.eq_pat(l, r))
175 (&PatKind::Wild, &PatKind::Wild) => true,
180 fn eq_qpath(&self, left: &QPath, right: &QPath) -> bool {
181 match (left, right) {
182 (&QPath::Resolved(ref lty, ref lpath), &QPath::Resolved(ref rty, ref rpath)) => {
183 both(lty, rty, |l, r| self.eq_ty(l, r)) && self.eq_path(lpath, rpath)
185 (&QPath::TypeRelative(ref lty, ref lseg), &QPath::TypeRelative(ref rty, ref rseg)) => {
186 self.eq_ty(lty, rty) && self.eq_path_segment(lseg, rseg)
192 fn eq_path(&self, left: &Path, right: &Path) -> bool {
193 left.is_global() == right.is_global() &&
194 over(&left.segments, &right.segments, |l, r| self.eq_path_segment(l, r))
197 fn eq_path_parameters(&self, left: &PathParameters, right: &PathParameters) -> bool {
198 if !(left.parenthesized || right.parenthesized) {
199 over(&left.lifetimes, &right.lifetimes, |l, r| self.eq_lifetime(l, r)) &&
200 over(&left.types, &right.types, |l, r| self.eq_ty(l, r)) &&
201 over(&left.bindings, &right.bindings, |l, r| self.eq_type_binding(l, r))
202 } else if left.parenthesized && right.parenthesized {
203 over(left.inputs(), right.inputs(), |l, r| self.eq_ty(l, r)) &&
204 both(&Some(&left.bindings[0].ty), &Some(&right.bindings[0].ty), |l, r| self.eq_ty(l, r))
210 fn eq_path_segment(&self, left: &PathSegment, right: &PathSegment) -> bool {
211 // The == of idents doesn't work with different contexts,
212 // we have to be explicit about hygiene
213 left.name.as_str() == right.name.as_str() && self.eq_path_parameters(&left.parameters, &right.parameters)
216 fn eq_ty(&self, left: &Ty, right: &Ty) -> bool {
217 match (&left.node, &right.node) {
218 (&TySlice(ref l_vec), &TySlice(ref r_vec)) => self.eq_ty(l_vec, r_vec),
219 (&TyArray(ref lt, ll_id), &TyArray(ref rt, rl_id)) => {
220 self.eq_ty(lt, rt) &&
221 self.eq_expr(&self.cx.tcx.hir.body(ll_id).value, &self.cx.tcx.hir.body(rl_id).value)
223 (&TyPtr(ref l_mut), &TyPtr(ref r_mut)) => l_mut.mutbl == r_mut.mutbl && self.eq_ty(&*l_mut.ty, &*r_mut.ty),
224 (&TyRptr(_, ref l_rmut), &TyRptr(_, ref r_rmut)) => {
225 l_rmut.mutbl == r_rmut.mutbl && self.eq_ty(&*l_rmut.ty, &*r_rmut.ty)
227 (&TyPath(ref l), &TyPath(ref r)) => self.eq_qpath(l, r),
228 (&TyTup(ref l), &TyTup(ref r)) => over(l, r, |l, r| self.eq_ty(l, r)),
229 (&TyInfer, &TyInfer) => true,
234 fn eq_type_binding(&self, left: &TypeBinding, right: &TypeBinding) -> bool {
235 left.name == right.name && self.eq_ty(&left.ty, &right.ty)
239 fn swap_binop<'a>(binop: BinOp_, lhs: &'a Expr, rhs: &'a Expr) -> Option<(BinOp_, &'a Expr, &'a Expr)> {
241 BiAdd | BiMul | BiBitXor | BiBitAnd | BiEq | BiNe | BiBitOr => Some((binop, rhs, lhs)),
242 BiLt => Some((BiGt, rhs, lhs)),
243 BiLe => Some((BiGe, rhs, lhs)),
244 BiGe => Some((BiLe, rhs, lhs)),
245 BiGt => Some((BiLt, rhs, lhs)),
246 BiShl | BiShr | BiRem | BiSub | BiDiv | BiAnd | BiOr => None,
250 /// Check if the two `Option`s are both `None` or some equal values as per
252 fn both<X, F>(l: &Option<X>, r: &Option<X>, mut eq_fn: F) -> bool
254 F: FnMut(&X, &X) -> bool,
256 l.as_ref().map_or_else(|| r.is_none(), |x| {
257 r.as_ref().map_or(false, |y| eq_fn(x, y))
261 /// Check if two slices are equal as per `eq_fn`.
262 fn over<X, F>(left: &[X], right: &[X], mut eq_fn: F) -> bool
264 F: FnMut(&X, &X) -> bool,
266 left.len() == right.len() && left.iter().zip(right).all(|(x, y)| eq_fn(x, y))
270 /// Type used to hash an ast element. This is different from the `Hash` trait
271 /// on ast types as this
272 /// trait would consider IDs and spans.
274 /// All expressions kind are hashed, but some might have a weaker hash.
275 pub struct SpanlessHash<'a, 'tcx: 'a> {
276 /// Context used to evaluate constant expressions.
277 cx: &'a LateContext<'a, 'tcx>,
281 impl<'a, 'tcx: 'a> SpanlessHash<'a, 'tcx> {
282 pub fn new(cx: &'a LateContext<'a, 'tcx>) -> Self {
285 s: DefaultHasher::new(),
289 pub fn finish(&self) -> u64 {
293 pub fn hash_block(&mut self, b: &Block) {
298 if let Some(ref e) = b.expr {
302 b.rules.hash(&mut self.s);
305 pub fn hash_expr(&mut self, e: &Expr) {
306 if let Some(e) = constant(self.cx, e) {
307 return e.hash(&mut self.s);
311 ExprAddrOf(m, ref e) => {
312 let c: fn(_, _) -> _ = ExprAddrOf;
318 let c: fn(_) -> _ = ExprAgain;
320 if let Some(i) = i.ident {
321 self.hash_name(&i.node.name);
324 ExprAssign(ref l, ref r) => {
325 let c: fn(_, _) -> _ = ExprAssign;
330 ExprAssignOp(ref o, ref l, ref r) => {
331 let c: fn(_, _, _) -> _ = ExprAssignOp;
337 ExprBlock(ref b) => {
338 let c: fn(_) -> _ = ExprBlock;
342 ExprBinary(op, ref l, ref r) => {
343 let c: fn(_, _, _) -> _ = ExprBinary;
345 op.node.hash(&mut self.s);
349 ExprBreak(i, ref j) => {
350 let c: fn(_, _) -> _ = ExprBreak;
352 if let Some(i) = i.ident {
353 self.hash_name(&i.node.name);
355 if let Some(ref j) = *j {
360 let c: fn(_) -> _ = ExprBox;
364 ExprCall(ref fun, ref args) => {
365 let c: fn(_, _) -> _ = ExprCall;
368 self.hash_exprs(args);
370 ExprCast(ref e, ref _ty) => {
371 let c: fn(_, _) -> _ = ExprCast;
376 ExprClosure(cap, _, eid, _) => {
377 let c: fn(_, _, _, _) -> _ = ExprClosure;
379 cap.hash(&mut self.s);
380 self.hash_expr(&self.cx.tcx.hir.body(eid).value);
382 ExprField(ref e, ref f) => {
383 let c: fn(_, _) -> _ = ExprField;
386 self.hash_name(&f.node);
388 ExprIndex(ref a, ref i) => {
389 let c: fn(_, _) -> _ = ExprIndex;
394 ExprInlineAsm(..) => {
395 let c: fn(_, _, _) -> _ = ExprInlineAsm;
398 ExprIf(ref cond, ref t, ref e) => {
399 let c: fn(_, _, _) -> _ = ExprIf;
401 self.hash_expr(cond);
402 self.hash_expr(&**t);
403 if let Some(ref e) = *e {
408 let c: fn(_) -> _ = ExprLit;
412 ExprLoop(ref b, ref i, _) => {
413 let c: fn(_, _, _) -> _ = ExprLoop;
416 if let Some(i) = *i {
417 self.hash_name(&i.node);
420 ExprMatch(ref e, ref arms, ref s) => {
421 let c: fn(_, _, _) -> _ = ExprMatch;
427 if let Some(ref e) = arm.guard {
430 self.hash_expr(&arm.body);
435 ExprMethodCall(ref path, ref _tys, ref args) => {
436 let c: fn(_, _, _) -> _ = ExprMethodCall;
438 self.hash_name(&path.name);
439 self.hash_exprs(args);
441 ExprRepeat(ref e, l_id) => {
442 let c: fn(_, _) -> _ = ExprRepeat;
445 self.hash_expr(&self.cx.tcx.hir.body(l_id).value);
448 let c: fn(_) -> _ = ExprRet;
450 if let Some(ref e) = *e {
454 ExprPath(ref qpath) => {
455 let c: fn(_) -> _ = ExprPath;
457 self.hash_qpath(qpath);
459 ExprStruct(ref path, ref fields, ref expr) => {
460 let c: fn(_, _, _) -> _ = ExprStruct;
463 self.hash_qpath(path);
466 self.hash_name(&f.name.node);
467 self.hash_expr(&f.expr);
470 if let Some(ref e) = *expr {
474 ExprTup(ref tup) => {
475 let c: fn(_) -> _ = ExprTup;
477 self.hash_exprs(tup);
479 ExprTupField(ref le, li) => {
480 let c: fn(_, _) -> _ = ExprTupField;
484 li.node.hash(&mut self.s);
486 ExprType(ref e, ref _ty) => {
487 let c: fn(_, _) -> _ = ExprType;
492 ExprUnary(lop, ref le) => {
493 let c: fn(_, _) -> _ = ExprUnary;
496 lop.hash(&mut self.s);
499 ExprArray(ref v) => {
500 let c: fn(_) -> _ = ExprArray;
505 ExprWhile(ref cond, ref b, l) => {
506 let c: fn(_, _, _) -> _ = ExprWhile;
509 self.hash_expr(cond);
512 self.hash_name(&l.node);
518 pub fn hash_exprs(&mut self, e: &P<[Expr]>) {
524 pub fn hash_name(&mut self, n: &Name) {
525 n.as_str().hash(&mut self.s);
528 pub fn hash_qpath(&mut self, p: &QPath) {
530 QPath::Resolved(_, ref path) => {
531 self.hash_path(path);
533 QPath::TypeRelative(_, ref path) => {
534 self.hash_name(&path.name);
537 // self.cx.tables.qpath_def(p, id).hash(&mut self.s);
540 pub fn hash_path(&mut self, p: &Path) {
541 p.is_global().hash(&mut self.s);
542 for p in &p.segments {
543 self.hash_name(&p.name);
547 pub fn hash_stmt(&mut self, b: &Stmt) {
549 StmtDecl(ref decl, _) => {
550 let c: fn(_, _) -> _ = StmtDecl;
553 if let DeclLocal(ref local) = decl.node {
554 if let Some(ref init) = local.init {
555 self.hash_expr(init);
559 StmtExpr(ref expr, _) => {
560 let c: fn(_, _) -> _ = StmtExpr;
562 self.hash_expr(expr);
564 StmtSemi(ref expr, _) => {
565 let c: fn(_, _) -> _ = StmtSemi;
567 self.hash_expr(expr);