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 operator
11 /// `==` on ast types as this operator would compare true equality with ID and span.
13 /// Note that some expressions kinds are not considered but could be added.
14 pub struct SpanlessEq<'a, 'tcx: 'a> {
15 /// Context used to evaluate constant expressions.
16 cx: &'a LateContext<'a, 'tcx>,
17 /// If is true, never consider as equal expressions containing function calls.
21 impl<'a, 'tcx: 'a> SpanlessEq<'a, 'tcx> {
22 pub fn new(cx: &'a LateContext<'a, 'tcx>) -> Self {
29 pub fn ignore_fn(self) -> Self {
36 /// Check whether two statements are the same.
37 pub fn eq_stmt(&self, left: &Stmt, right: &Stmt) -> bool {
38 match (&left.node, &right.node) {
39 (&StmtDecl(ref l, _), &StmtDecl(ref r, _)) => {
40 if let (&DeclLocal(ref l), &DeclLocal(ref r)) = (&l.node, &r.node) {
41 both(&l.ty, &r.ty, |l, r| self.eq_ty(l, r)) && both(&l.init, &r.init, |l, r| self.eq_expr(l, r))
46 (&StmtExpr(ref l, _), &StmtExpr(ref r, _)) |
47 (&StmtSemi(ref l, _), &StmtSemi(ref r, _)) => self.eq_expr(l, r),
52 /// Check whether two blocks are the same.
53 pub fn eq_block(&self, left: &Block, right: &Block) -> bool {
54 over(&left.stmts, &right.stmts, |l, r| self.eq_stmt(l, r)) &&
55 both(&left.expr, &right.expr, |l, r| self.eq_expr(l, r))
58 pub fn eq_expr(&self, left: &Expr, right: &Expr) -> bool {
59 if self.ignore_fn && differing_macro_contexts(left.span, right.span) {
63 if let (Some(l), Some(r)) = (constant(self.cx, left), constant(self.cx, right)) {
69 match (&left.node, &right.node) {
70 (&ExprAddrOf(l_mut, ref le), &ExprAddrOf(r_mut, ref re)) => l_mut == r_mut && self.eq_expr(le, re),
71 (&ExprAgain(li), &ExprAgain(ri)) => {
72 both(&li.ident, &ri.ident, |l, r| l.node.name.as_str() == r.node.name.as_str())
74 (&ExprAssign(ref ll, ref lr), &ExprAssign(ref rl, ref rr)) => self.eq_expr(ll, rl) && self.eq_expr(lr, rr),
75 (&ExprAssignOp(ref lo, ref ll, ref lr), &ExprAssignOp(ref ro, ref rl, ref rr)) => {
76 lo.node == ro.node && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
78 (&ExprBlock(ref l), &ExprBlock(ref r)) => self.eq_block(l, r),
79 (&ExprBinary(l_op, ref ll, ref lr), &ExprBinary(r_op, ref rl, ref rr)) => {
80 l_op.node == r_op.node && self.eq_expr(ll, rl) && self.eq_expr(lr, rr) ||
81 swap_binop(l_op.node, ll, lr).map_or(false, |(l_op, ll, lr)| {
82 l_op == r_op.node && self.eq_expr(ll, rl) && self.eq_expr(lr, rr)
85 (&ExprBreak(li, ref le), &ExprBreak(ri, ref re)) => {
86 both(&li.ident, &ri.ident, |l, r| l.node.name.as_str() == r.node.name.as_str()) &&
87 both(le, re, |l, r| self.eq_expr(l, r))
89 (&ExprBox(ref l), &ExprBox(ref r)) => self.eq_expr(l, r),
90 (&ExprCall(ref l_fun, ref l_args), &ExprCall(ref r_fun, ref r_args)) => {
91 !self.ignore_fn && self.eq_expr(l_fun, r_fun) && self.eq_exprs(l_args, r_args)
93 (&ExprCast(ref lx, ref lt), &ExprCast(ref rx, ref rt)) |
94 (&ExprType(ref lx, ref lt), &ExprType(ref rx, ref rt)) => self.eq_expr(lx, rx) && self.eq_ty(lt, rt),
95 (&ExprField(ref l_f_exp, ref l_f_ident), &ExprField(ref r_f_exp, ref r_f_ident)) => {
96 l_f_ident.node == r_f_ident.node && self.eq_expr(l_f_exp, r_f_exp)
98 (&ExprIndex(ref la, ref li), &ExprIndex(ref ra, ref ri)) => self.eq_expr(la, ra) && self.eq_expr(li, ri),
99 (&ExprIf(ref lc, ref lt, ref le), &ExprIf(ref rc, ref rt, ref re)) => {
100 self.eq_expr(lc, rc) && self.eq_expr(&**lt, &**rt) && both(le, re, |l, r| self.eq_expr(l, r))
102 (&ExprLit(ref l), &ExprLit(ref r)) => l.node == r.node,
103 (&ExprLoop(ref lb, ref ll, ref lls), &ExprLoop(ref rb, ref rl, ref rls)) => {
104 lls == rls && self.eq_block(lb, rb) && both(ll, rl, |l, r| l.node.as_str() == r.node.as_str())
106 (&ExprMatch(ref le, ref la, ref ls), &ExprMatch(ref re, ref ra, ref rs)) => {
107 ls == rs && self.eq_expr(le, re) &&
108 over(la, ra, |l, r| {
109 self.eq_expr(&l.body, &r.body) && both(&l.guard, &r.guard, |l, r| self.eq_expr(l, r)) &&
110 over(&l.pats, &r.pats, |l, r| self.eq_pat(l, r))
113 (&ExprMethodCall(ref l_name, ref l_tys, ref l_args),
114 &ExprMethodCall(ref r_name, ref r_tys, ref r_args)) => {
115 !self.ignore_fn && l_name.node == r_name.node && over(l_tys, r_tys, |l, r| self.eq_ty(l, r)) &&
116 self.eq_exprs(l_args, r_args)
118 (&ExprRepeat(ref le, ll_id), &ExprRepeat(ref re, rl_id)) => {
119 self.eq_expr(le, re) &&
120 self.eq_expr(&self.cx.tcx.hir.body(ll_id).value, &self.cx.tcx.hir.body(rl_id).value)
122 (&ExprRet(ref l), &ExprRet(ref r)) => both(l, r, |l, r| self.eq_expr(l, r)),
123 (&ExprPath(ref l), &ExprPath(ref r)) => self.eq_qpath(l, r),
124 (&ExprStruct(ref l_path, ref lf, ref lo), &ExprStruct(ref r_path, ref rf, ref ro)) => {
125 self.eq_qpath(l_path, r_path) && both(lo, ro, |l, r| self.eq_expr(l, r)) &&
126 over(lf, rf, |l, r| self.eq_field(l, r))
128 (&ExprTup(ref l_tup), &ExprTup(ref r_tup)) => self.eq_exprs(l_tup, r_tup),
129 (&ExprTupField(ref le, li), &ExprTupField(ref re, ri)) => li.node == ri.node && self.eq_expr(le, re),
130 (&ExprUnary(l_op, ref le), &ExprUnary(r_op, ref re)) => l_op == r_op && self.eq_expr(le, re),
131 (&ExprArray(ref l), &ExprArray(ref r)) => self.eq_exprs(l, r),
132 (&ExprWhile(ref lc, ref lb, ref ll), &ExprWhile(ref rc, ref rb, ref rl)) => {
133 self.eq_expr(lc, rc) && self.eq_block(lb, rb) && both(ll, rl, |l, r| l.node.as_str() == r.node.as_str())
139 fn eq_exprs(&self, left: &P<[Expr]>, right: &P<[Expr]>) -> bool {
140 over(left, right, |l, r| self.eq_expr(l, r))
143 fn eq_field(&self, left: &Field, right: &Field) -> bool {
144 left.name.node == right.name.node && self.eq_expr(&left.expr, &right.expr)
147 fn eq_lifetime(&self, left: &Lifetime, right: &Lifetime) -> bool {
148 left.name == right.name
151 /// Check whether two patterns are the same.
152 pub fn eq_pat(&self, left: &Pat, right: &Pat) -> bool {
153 match (&left.node, &right.node) {
154 (&PatKind::Box(ref l), &PatKind::Box(ref r)) => self.eq_pat(l, r),
155 (&PatKind::TupleStruct(ref lp, ref la, ls), &PatKind::TupleStruct(ref rp, ref ra, rs)) => {
156 self.eq_qpath(lp, rp) && over(la, ra, |l, r| self.eq_pat(l, r)) && ls == rs
158 (&PatKind::Binding(ref lb, _, ref li, ref lp), &PatKind::Binding(ref rb, _, ref ri, ref rp)) => {
159 lb == rb && li.node.as_str() == ri.node.as_str() && both(lp, rp, |l, r| self.eq_pat(l, r))
161 (&PatKind::Path(ref l), &PatKind::Path(ref r)) => self.eq_qpath(l, r),
162 (&PatKind::Lit(ref l), &PatKind::Lit(ref r)) => self.eq_expr(l, r),
163 (&PatKind::Tuple(ref l, ls), &PatKind::Tuple(ref r, rs)) => {
164 ls == rs && over(l, r, |l, r| self.eq_pat(l, r))
166 (&PatKind::Range(ref ls, ref le, ref li), &PatKind::Range(ref rs, ref re, ref ri)) => {
167 self.eq_expr(ls, rs) && self.eq_expr(le, re) && (*li == *ri)
169 (&PatKind::Ref(ref le, ref lm), &PatKind::Ref(ref re, ref rm)) => lm == rm && self.eq_pat(le, re),
170 (&PatKind::Slice(ref ls, ref li, ref le), &PatKind::Slice(ref rs, ref ri, ref re)) => {
171 over(ls, rs, |l, r| self.eq_pat(l, r)) && over(le, re, |l, r| self.eq_pat(l, r)) &&
172 both(li, ri, |l, r| self.eq_pat(l, r))
174 (&PatKind::Wild, &PatKind::Wild) => true,
179 fn eq_qpath(&self, left: &QPath, right: &QPath) -> bool {
180 match (left, right) {
181 (&QPath::Resolved(ref lty, ref lpath), &QPath::Resolved(ref rty, ref rpath)) => {
182 both(lty, rty, |l, r| self.eq_ty(l, r)) && self.eq_path(lpath, rpath)
184 (&QPath::TypeRelative(ref lty, ref lseg), &QPath::TypeRelative(ref rty, ref rseg)) => {
185 self.eq_ty(lty, rty) && self.eq_path_segment(lseg, rseg)
191 fn eq_path(&self, left: &Path, right: &Path) -> bool {
192 left.is_global() == right.is_global() &&
193 over(&left.segments, &right.segments, |l, r| self.eq_path_segment(l, r))
196 fn eq_path_parameters(&self, left: &PathParameters, right: &PathParameters) -> bool {
197 match (left, right) {
198 (&AngleBracketedParameters(ref left), &AngleBracketedParameters(ref right)) => {
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))
203 (&ParenthesizedParameters(ref left), &ParenthesizedParameters(ref right)) => {
204 over(&left.inputs, &right.inputs, |l, r| self.eq_ty(l, r)) &&
205 both(&left.output, &right.output, |l, r| self.eq_ty(l, r))
207 (&AngleBracketedParameters(_), &ParenthesizedParameters(_)) |
208 (&ParenthesizedParameters(_), &AngleBracketedParameters(_)) => false,
212 fn eq_path_segment(&self, left: &PathSegment, right: &PathSegment) -> bool {
213 // The == of idents doesn't work with different contexts,
214 // we have to be explicit about hygiene
215 left.name.as_str() == right.name.as_str() && self.eq_path_parameters(&left.parameters, &right.parameters)
218 fn eq_ty(&self, left: &Ty, right: &Ty) -> bool {
219 match (&left.node, &right.node) {
220 (&TySlice(ref l_vec), &TySlice(ref r_vec)) => self.eq_ty(l_vec, r_vec),
221 (&TyArray(ref lt, ll_id), &TyArray(ref rt, rl_id)) => {
222 self.eq_ty(lt, rt) &&
223 self.eq_expr(&self.cx.tcx.hir.body(ll_id).value, &self.cx.tcx.hir.body(rl_id).value)
225 (&TyPtr(ref l_mut), &TyPtr(ref r_mut)) => l_mut.mutbl == r_mut.mutbl && self.eq_ty(&*l_mut.ty, &*r_mut.ty),
226 (&TyRptr(_, ref l_rmut), &TyRptr(_, ref r_rmut)) => {
227 l_rmut.mutbl == r_rmut.mutbl && self.eq_ty(&*l_rmut.ty, &*r_rmut.ty)
229 (&TyPath(ref l), &TyPath(ref r)) => self.eq_qpath(l, r),
230 (&TyTup(ref l), &TyTup(ref r)) => over(l, r, |l, r| self.eq_ty(l, r)),
231 (&TyInfer, &TyInfer) => true,
236 fn eq_type_binding(&self, left: &TypeBinding, right: &TypeBinding) -> bool {
237 left.name == right.name && self.eq_ty(&left.ty, &right.ty)
241 fn swap_binop<'a>(binop: BinOp_, lhs: &'a Expr, rhs: &'a Expr) -> Option<(BinOp_, &'a Expr, &'a Expr)> {
243 BiAdd | BiMul | BiBitXor | BiBitAnd | BiEq | BiNe | BiBitOr => Some((binop, rhs, lhs)),
244 BiLt => Some((BiGt, rhs, lhs)),
245 BiLe => Some((BiGe, rhs, lhs)),
246 BiGe => Some((BiLe, rhs, lhs)),
247 BiGt => Some((BiLt, rhs, lhs)),
248 BiShl | BiShr | BiRem | BiSub | BiDiv | BiAnd | BiOr => None,
252 /// Check if the two `Option`s are both `None` or some equal values as per `eq_fn`.
253 fn both<X, F>(l: &Option<X>, r: &Option<X>, mut eq_fn: F) -> bool
254 where F: FnMut(&X, &X) -> bool
256 l.as_ref().map_or_else(|| r.is_none(), |x| r.as_ref().map_or(false, |y| eq_fn(x, y)))
259 /// Check if two slices are equal as per `eq_fn`.
260 fn over<X, F>(left: &[X], right: &[X], mut eq_fn: F) -> bool
261 where F: FnMut(&X, &X) -> bool
263 left.len() == right.len() && left.iter().zip(right).all(|(x, y)| eq_fn(x, y))
267 /// Type used to hash an ast element. This is different from the `Hash` trait on ast types as this
268 /// trait would consider IDs and spans.
270 /// All expressions kind are hashed, but some might have a weaker hash.
271 pub struct SpanlessHash<'a, 'tcx: 'a> {
272 /// Context used to evaluate constant expressions.
273 cx: &'a LateContext<'a, 'tcx>,
277 impl<'a, 'tcx: 'a> SpanlessHash<'a, 'tcx> {
278 pub fn new(cx: &'a LateContext<'a, 'tcx>) -> Self {
281 s: DefaultHasher::new(),
285 pub fn finish(&self) -> u64 {
289 pub fn hash_block(&mut self, b: &Block) {
294 if let Some(ref e) = b.expr {
298 b.rules.hash(&mut self.s);
301 pub fn hash_expr(&mut self, e: &Expr) {
302 if let Some(e) = constant(self.cx, e) {
303 return e.hash(&mut self.s);
307 ExprAddrOf(m, ref e) => {
308 let c: fn(_, _) -> _ = ExprAddrOf;
314 let c: fn(_) -> _ = ExprAgain;
316 if let Some(i) = i.ident {
317 self.hash_name(&i.node.name);
320 ExprAssign(ref l, ref r) => {
321 let c: fn(_, _) -> _ = ExprAssign;
326 ExprAssignOp(ref o, ref l, ref r) => {
327 let c: fn(_, _, _) -> _ = ExprAssignOp;
333 ExprBlock(ref b) => {
334 let c: fn(_) -> _ = ExprBlock;
338 ExprBinary(op, ref l, ref r) => {
339 let c: fn(_, _, _) -> _ = ExprBinary;
341 op.node.hash(&mut self.s);
345 ExprBreak(i, ref j) => {
346 let c: fn(_, _) -> _ = ExprBreak;
348 if let Some(i) = i.ident {
349 self.hash_name(&i.node.name);
351 if let Some(ref j) = *j {
356 let c: fn(_) -> _ = ExprBox;
360 ExprCall(ref fun, ref args) => {
361 let c: fn(_, _) -> _ = ExprCall;
364 self.hash_exprs(args);
366 ExprCast(ref e, ref _ty) => {
367 let c: fn(_, _) -> _ = ExprCast;
372 ExprClosure(cap, _, eid, _) => {
373 let c: fn(_, _, _, _) -> _ = ExprClosure;
375 cap.hash(&mut self.s);
376 self.hash_expr(&self.cx.tcx.hir.body(eid).value);
378 ExprField(ref e, ref f) => {
379 let c: fn(_, _) -> _ = ExprField;
382 self.hash_name(&f.node);
384 ExprIndex(ref a, ref i) => {
385 let c: fn(_, _) -> _ = ExprIndex;
390 ExprInlineAsm(..) => {
391 let c: fn(_, _, _) -> _ = ExprInlineAsm;
394 ExprIf(ref cond, ref t, ref e) => {
395 let c: fn(_, _, _) -> _ = ExprIf;
397 self.hash_expr(cond);
398 self.hash_expr(&**t);
399 if let Some(ref e) = *e {
404 let c: fn(_) -> _ = ExprLit;
408 ExprLoop(ref b, ref i, _) => {
409 let c: fn(_, _, _) -> _ = ExprLoop;
412 if let Some(i) = *i {
413 self.hash_name(&i.node);
416 ExprMatch(ref e, ref arms, ref s) => {
417 let c: fn(_, _, _) -> _ = ExprMatch;
423 if let Some(ref e) = arm.guard {
426 self.hash_expr(&arm.body);
431 ExprMethodCall(ref name, ref _tys, ref args) => {
432 let c: fn(_, _, _) -> _ = ExprMethodCall;
434 self.hash_name(&name.node);
435 self.hash_exprs(args);
437 ExprRepeat(ref e, l_id) => {
438 let c: fn(_, _) -> _ = ExprRepeat;
441 self.hash_expr(&self.cx.tcx.hir.body(l_id).value);
444 let c: fn(_) -> _ = ExprRet;
446 if let Some(ref e) = *e {
450 ExprPath(ref qpath) => {
451 let c: fn(_) -> _ = ExprPath;
453 self.hash_qpath(qpath);
455 ExprStruct(ref path, ref fields, ref expr) => {
456 let c: fn(_, _, _) -> _ = ExprStruct;
459 self.hash_qpath(path);
462 self.hash_name(&f.name.node);
463 self.hash_expr(&f.expr);
466 if let Some(ref e) = *expr {
470 ExprTup(ref tup) => {
471 let c: fn(_) -> _ = ExprTup;
473 self.hash_exprs(tup);
475 ExprTupField(ref le, li) => {
476 let c: fn(_, _) -> _ = ExprTupField;
480 li.node.hash(&mut self.s);
482 ExprType(ref e, ref _ty) => {
483 let c: fn(_, _) -> _ = ExprType;
488 ExprUnary(lop, ref le) => {
489 let c: fn(_, _) -> _ = ExprUnary;
492 lop.hash(&mut self.s);
495 ExprArray(ref v) => {
496 let c: fn(_) -> _ = ExprArray;
501 ExprWhile(ref cond, ref b, l) => {
502 let c: fn(_, _, _) -> _ = ExprWhile;
505 self.hash_expr(cond);
508 self.hash_name(&l.node);
514 pub fn hash_exprs(&mut self, e: &P<[Expr]>) {
520 pub fn hash_name(&mut self, n: &Name) {
521 n.as_str().hash(&mut self.s);
524 pub fn hash_qpath(&mut self, p: &QPath) {
526 QPath::Resolved(_, ref path) => {
527 self.hash_path(path);
529 QPath::TypeRelative(_, ref path) => {
530 self.hash_name(&path.name);
533 // self.cx.tables.qpath_def(p, id).hash(&mut self.s);
536 pub fn hash_path(&mut self, p: &Path) {
537 p.is_global().hash(&mut self.s);
538 for p in &p.segments {
539 self.hash_name(&p.name);
543 pub fn hash_stmt(&mut self, b: &Stmt) {
545 StmtDecl(ref decl, _) => {
546 let c: fn(_, _) -> _ = StmtDecl;
549 if let DeclLocal(ref local) = decl.node {
550 if let Some(ref init) = local.init {
551 self.hash_expr(init);
555 StmtExpr(ref expr, _) => {
556 let c: fn(_, _) -> _ = StmtExpr;
558 self.hash_expr(expr);
560 StmtSemi(ref expr, _) => {
561 let c: fn(_, _) -> _ = StmtSemi;
563 self.hash_expr(expr);