src/tools/clippy/clippy_utils/src/ast_utils.rs

   1 //! Utilities for manipulating and extracting information from `rustc_ast::ast`.
   2 //!
   3 //! - The `eq_foobar` functions test for semantic equality but ignores `NodeId`s and `Span`s.
   4
   5 #![allow(clippy::similar_names, clippy::wildcard_imports, clippy::enum_glob_use)]
   6
   7 use crate::{both, over};
   8 use rustc_ast::ptr::P;
   9 use rustc_ast::{self as ast, *};
  10 use rustc_span::symbol::Ident;
  11 use std::mem;
  12
  13 pub mod ident_iter;
  14 pub use ident_iter::IdentIter;
  15
  16 pub fn is_useless_with_eq_exprs(kind: BinOpKind) -> bool {
  17     use BinOpKind::*;
  18     matches!(
  19         kind,
  20         Sub | Div | Eq | Lt | Le | Gt | Ge | Ne | And | Or | BitXor | BitAnd | BitOr
  21     )
  22 }
  23
  24 /// Checks if each element in the first slice is contained within the latter as per `eq_fn`.
  25 pub fn unordered_over<X>(left: &[X], right: &[X], mut eq_fn: impl FnMut(&X, &X) -> bool) -> bool {
  26     left.len() == right.len() && left.iter().all(|l| right.iter().any(|r| eq_fn(l, r)))
  27 }
  28
  29 pub fn eq_id(l: Ident, r: Ident) -> bool {
  30     l.name == r.name
  31 }
  32
  33 pub fn eq_pat(l: &Pat, r: &Pat) -> bool {
  34     use PatKind::*;
  35     match (&l.kind, &r.kind) {
  36         (Paren(l), _) => eq_pat(l, r),
  37         (_, Paren(r)) => eq_pat(l, r),
  38         (Wild, Wild) | (Rest, Rest) => true,
  39         (Lit(l), Lit(r)) => eq_expr(l, r),
  40         (Ident(b1, i1, s1), Ident(b2, i2, s2)) => b1 == b2 && eq_id(*i1, *i2) && both(s1, s2, |l, r| eq_pat(l, r)),
  41         (Range(lf, lt, le), Range(rf, rt, re)) => {
  42             eq_expr_opt(lf, rf) && eq_expr_opt(lt, rt) && eq_range_end(&le.node, &re.node)
  43         },
  44         (Box(l), Box(r))
  45         | (Ref(l, Mutability::Not), Ref(r, Mutability::Not))
  46         | (Ref(l, Mutability::Mut), Ref(r, Mutability::Mut)) => eq_pat(l, r),
  47         (Tuple(l), Tuple(r)) | (Slice(l), Slice(r)) => over(l, r, |l, r| eq_pat(l, r)),
  48         (Path(lq, lp), Path(rq, rp)) => both(lq, rq, eq_qself) && eq_path(lp, rp),
  49         (TupleStruct(lqself, lp, lfs), TupleStruct(rqself, rp, rfs)) => {
  50             eq_maybe_qself(lqself, rqself) && eq_path(lp, rp) && over(lfs, rfs, |l, r| eq_pat(l, r))
  51         },
  52         (Struct(lqself, lp, lfs, lr), Struct(rqself, rp, rfs, rr)) => {
  53             lr == rr && eq_maybe_qself(lqself, rqself) && eq_path(lp, rp) && unordered_over(lfs, rfs, eq_field_pat)
  54         },
  55         (Or(ls), Or(rs)) => unordered_over(ls, rs, |l, r| eq_pat(l, r)),
  56         (MacCall(l), MacCall(r)) => eq_mac_call(l, r),
  57         _ => false,
  58     }
  59 }
  60
  61 pub fn eq_range_end(l: &RangeEnd, r: &RangeEnd) -> bool {
  62     match (l, r) {
  63         (RangeEnd::Excluded, RangeEnd::Excluded) => true,
  64         (RangeEnd::Included(l), RangeEnd::Included(r)) => {
  65             matches!(l, RangeSyntax::DotDotEq) == matches!(r, RangeSyntax::DotDotEq)
  66         },
  67         _ => false,
  68     }
  69 }
  70
  71 pub fn eq_field_pat(l: &PatField, r: &PatField) -> bool {
  72     l.is_placeholder == r.is_placeholder
  73         && eq_id(l.ident, r.ident)
  74         && eq_pat(&l.pat, &r.pat)
  75         && over(&l.attrs, &r.attrs, eq_attr)
  76 }
  77
  78 pub fn eq_qself(l: &P<QSelf>, r: &P<QSelf>) -> bool {
  79     l.position == r.position && eq_ty(&l.ty, &r.ty)
  80 }
  81
  82 pub fn eq_maybe_qself(l: &Option<P<QSelf>>, r: &Option<P<QSelf>>) -> bool {
  83     match (l, r) {
  84         (Some(l), Some(r)) => eq_qself(l, r),
  85         (None, None) => true,
  86         _ => false,
  87     }
  88 }
  89
  90 pub fn eq_path(l: &Path, r: &Path) -> bool {
  91     over(&l.segments, &r.segments, eq_path_seg)
  92 }
  93
  94 pub fn eq_path_seg(l: &PathSegment, r: &PathSegment) -> bool {
  95     eq_id(l.ident, r.ident) && both(&l.args, &r.args, |l, r| eq_generic_args(l, r))
  96 }
  97
  98 pub fn eq_generic_args(l: &GenericArgs, r: &GenericArgs) -> bool {
  99     match (l, r) {
 100         (GenericArgs::AngleBracketed(l), GenericArgs::AngleBracketed(r)) => over(&l.args, &r.args, eq_angle_arg),
 101         (GenericArgs::Parenthesized(l), GenericArgs::Parenthesized(r)) => {
 102             over(&l.inputs, &r.inputs, |l, r| eq_ty(l, r)) && eq_fn_ret_ty(&l.output, &r.output)
 103         },
 104         _ => false,
 105     }
 106 }
 107
 108 pub fn eq_angle_arg(l: &AngleBracketedArg, r: &AngleBracketedArg) -> bool {
 109     match (l, r) {
 110         (AngleBracketedArg::Arg(l), AngleBracketedArg::Arg(r)) => eq_generic_arg(l, r),
 111         (AngleBracketedArg::Constraint(l), AngleBracketedArg::Constraint(r)) => eq_assoc_constraint(l, r),
 112         _ => false,
 113     }
 114 }
 115
 116 pub fn eq_generic_arg(l: &GenericArg, r: &GenericArg) -> bool {
 117     match (l, r) {
 118         (GenericArg::Lifetime(l), GenericArg::Lifetime(r)) => eq_id(l.ident, r.ident),
 119         (GenericArg::Type(l), GenericArg::Type(r)) => eq_ty(l, r),
 120         (GenericArg::Const(l), GenericArg::Const(r)) => eq_expr(&l.value, &r.value),
 121         _ => false,
 122     }
 123 }
 124
 125 pub fn eq_expr_opt(l: &Option<P<Expr>>, r: &Option<P<Expr>>) -> bool {
 126     both(l, r, |l, r| eq_expr(l, r))
 127 }
 128
 129 pub fn eq_struct_rest(l: &StructRest, r: &StructRest) -> bool {
 130     match (l, r) {
 131         (StructRest::Base(lb), StructRest::Base(rb)) => eq_expr(lb, rb),
 132         (StructRest::Rest(_), StructRest::Rest(_)) | (StructRest::None, StructRest::None) => true,
 133         _ => false,
 134     }
 135 }
 136
 137 pub fn eq_expr(l: &Expr, r: &Expr) -> bool {
 138     use ExprKind::*;
 139     if !over(&l.attrs, &r.attrs, eq_attr) {
 140         return false;
 141     }
 142     match (&l.kind, &r.kind) {
 143         (Paren(l), _) => eq_expr(l, r),
 144         (_, Paren(r)) => eq_expr(l, r),
 145         (Err, Err) => true,
 146         (Try(l), Try(r)) | (Await(l, _), Await(r, _)) => eq_expr(l, r),
 147         (Array(l), Array(r)) => over(l, r, |l, r| eq_expr(l, r)),
 148         (Tup(l), Tup(r)) => over(l, r, |l, r| eq_expr(l, r)),
 149         (Repeat(le, ls), Repeat(re, rs)) => eq_expr(le, re) && eq_expr(&ls.value, &rs.value),
 150         (Call(lc, la), Call(rc, ra)) => eq_expr(lc, rc) && over(la, ra, |l, r| eq_expr(l, r)),
 151         (
 152             MethodCall(box ast::MethodCall {
 153                 seg: ls,
 154                 receiver: lr,
 155                 args: la,
 156                 ..
 157             }),
 158             MethodCall(box ast::MethodCall {
 159                 seg: rs,
 160                 receiver: rr,
 161                 args: ra,
 162                 ..
 163             }),
 164         ) => eq_path_seg(ls, rs) && eq_expr(lr, rr) && over(la, ra, |l, r| eq_expr(l, r)),
 165         (Binary(lo, ll, lr), Binary(ro, rl, rr)) => lo.node == ro.node && eq_expr(ll, rl) && eq_expr(lr, rr),
 166         (Unary(lo, l), Unary(ro, r)) => mem::discriminant(lo) == mem::discriminant(ro) && eq_expr(l, r),
 167         (Lit(l), Lit(r)) => l == r,
 168         (Cast(l, lt), Cast(r, rt)) | (Type(l, lt), Type(r, rt)) => eq_expr(l, r) && eq_ty(lt, rt),
 169         (Let(lp, le, _, _), Let(rp, re, _, _)) => eq_pat(lp, rp) && eq_expr(le, re),
 170         (If(lc, lt, le), If(rc, rt, re)) => eq_expr(lc, rc) && eq_block(lt, rt) && eq_expr_opt(le, re),
 171         (While(lc, lt, ll), While(rc, rt, rl)) => eq_label(ll, rl) && eq_expr(lc, rc) && eq_block(lt, rt),
 172         (ForLoop(lp, li, lt, ll), ForLoop(rp, ri, rt, rl)) => {
 173             eq_label(ll, rl) && eq_pat(lp, rp) && eq_expr(li, ri) && eq_block(lt, rt)
 174         },
 175         (Loop(lt, ll, _), Loop(rt, rl, _)) => eq_label(ll, rl) && eq_block(lt, rt),
 176         (Block(lb, ll), Block(rb, rl)) => eq_label(ll, rl) && eq_block(lb, rb),
 177         (TryBlock(l), TryBlock(r)) => eq_block(l, r),
 178         (Yield(l), Yield(r)) | (Ret(l), Ret(r)) => eq_expr_opt(l, r),
 179         (Break(ll, le), Break(rl, re)) => eq_label(ll, rl) && eq_expr_opt(le, re),
 180         (Continue(ll), Continue(rl)) => eq_label(ll, rl),
 181         (Assign(l1, l2, _), Assign(r1, r2, _)) | (Index(l1, l2, _), Index(r1, r2, _)) => {
 182             eq_expr(l1, r1) && eq_expr(l2, r2)
 183         },
 184         (AssignOp(lo, lp, lv), AssignOp(ro, rp, rv)) => lo.node == ro.node && eq_expr(lp, rp) && eq_expr(lv, rv),
 185         (Field(lp, lf), Field(rp, rf)) => eq_id(*lf, *rf) && eq_expr(lp, rp),
 186         (Match(ls, la), Match(rs, ra)) => eq_expr(ls, rs) && over(la, ra, eq_arm),
 187         (
 188             Closure(box ast::Closure {
 189                 binder: lb,
 190                 capture_clause: lc,
 191                 asyncness: la,
 192                 movability: lm,
 193                 fn_decl: lf,
 194                 body: le,
 195                 ..
 196             }),
 197             Closure(box ast::Closure {
 198                 binder: rb,
 199                 capture_clause: rc,
 200                 asyncness: ra,
 201                 movability: rm,
 202                 fn_decl: rf,
 203                 body: re,
 204                 ..
 205             }),
 206         ) => {
 207             eq_closure_binder(lb, rb)
 208                 && lc == rc
 209                 && la.is_async() == ra.is_async()
 210                 && lm == rm
 211                 && eq_fn_decl(lf, rf)
 212                 && eq_expr(le, re)
 213         },
 214         (Async(lc, lb), Async(rc, rb)) => lc == rc && eq_block(lb, rb),
 215         (Range(lf, lt, ll), Range(rf, rt, rl)) => ll == rl && eq_expr_opt(lf, rf) && eq_expr_opt(lt, rt),
 216         (AddrOf(lbk, lm, le), AddrOf(rbk, rm, re)) => lbk == rbk && lm == rm && eq_expr(le, re),
 217         (Path(lq, lp), Path(rq, rp)) => both(lq, rq, eq_qself) && eq_path(lp, rp),
 218         (MacCall(l), MacCall(r)) => eq_mac_call(l, r),
 219         (Struct(lse), Struct(rse)) => {
 220             eq_maybe_qself(&lse.qself, &rse.qself)
 221                 && eq_path(&lse.path, &rse.path)
 222                 && eq_struct_rest(&lse.rest, &rse.rest)
 223                 && unordered_over(&lse.fields, &rse.fields, eq_field)
 224         },
 225         _ => false,
 226     }
 227 }
 228
 229 pub fn eq_field(l: &ExprField, r: &ExprField) -> bool {
 230     l.is_placeholder == r.is_placeholder
 231         && eq_id(l.ident, r.ident)
 232         && eq_expr(&l.expr, &r.expr)
 233         && over(&l.attrs, &r.attrs, eq_attr)
 234 }
 235
 236 pub fn eq_arm(l: &Arm, r: &Arm) -> bool {
 237     l.is_placeholder == r.is_placeholder
 238         && eq_pat(&l.pat, &r.pat)
 239         && eq_expr(&l.body, &r.body)
 240         && eq_expr_opt(&l.guard, &r.guard)
 241         && over(&l.attrs, &r.attrs, eq_attr)
 242 }
 243
 244 pub fn eq_label(l: &Option<Label>, r: &Option<Label>) -> bool {
 245     both(l, r, |l, r| eq_id(l.ident, r.ident))
 246 }
 247
 248 pub fn eq_block(l: &Block, r: &Block) -> bool {
 249     l.rules == r.rules && over(&l.stmts, &r.stmts, eq_stmt)
 250 }
 251
 252 pub fn eq_stmt(l: &Stmt, r: &Stmt) -> bool {
 253     use StmtKind::*;
 254     match (&l.kind, &r.kind) {
 255         (Local(l), Local(r)) => {
 256             eq_pat(&l.pat, &r.pat)
 257                 && both(&l.ty, &r.ty, |l, r| eq_ty(l, r))
 258                 && eq_local_kind(&l.kind, &r.kind)
 259                 && over(&l.attrs, &r.attrs, eq_attr)
 260         },
 261         (Item(l), Item(r)) => eq_item(l, r, eq_item_kind),
 262         (Expr(l), Expr(r)) | (Semi(l), Semi(r)) => eq_expr(l, r),
 263         (Empty, Empty) => true,
 264         (MacCall(l), MacCall(r)) => {
 265             l.style == r.style && eq_mac_call(&l.mac, &r.mac) && over(&l.attrs, &r.attrs, eq_attr)
 266         },
 267         _ => false,
 268     }
 269 }
 270
 271 pub fn eq_local_kind(l: &LocalKind, r: &LocalKind) -> bool {
 272     use LocalKind::*;
 273     match (l, r) {
 274         (Decl, Decl) => true,
 275         (Init(l), Init(r)) => eq_expr(l, r),
 276         (InitElse(li, le), InitElse(ri, re)) => eq_expr(li, ri) && eq_block(le, re),
 277         _ => false,
 278     }
 279 }
 280
 281 pub fn eq_item<K>(l: &Item<K>, r: &Item<K>, mut eq_kind: impl FnMut(&K, &K) -> bool) -> bool {
 282     eq_id(l.ident, r.ident) && over(&l.attrs, &r.attrs, eq_attr) && eq_vis(&l.vis, &r.vis) && eq_kind(&l.kind, &r.kind)
 283 }
 284
 285 #[expect(clippy::too_many_lines)] // Just a big match statement
 286 pub fn eq_item_kind(l: &ItemKind, r: &ItemKind) -> bool {
 287     use ItemKind::*;
 288     match (l, r) {
 289         (ExternCrate(l), ExternCrate(r)) => l == r,
 290         (Use(l), Use(r)) => eq_use_tree(l, r),
 291         (
 292             Static(box ast::StaticItem {
 293                 ty: lt,
 294                 mutability: lm,
 295                 expr: le,
 296             }),
 297             Static(box ast::StaticItem {
 298                 ty: rt,
 299                 mutability: rm,
 300                 expr: re,
 301             }),
 302         ) => lm == rm && eq_ty(lt, rt) && eq_expr_opt(le, re),
 303         (
 304             Const(box ast::ConstItem {
 305                 defaultness: ld,
 306                 generics: lg,
 307                 ty: lt,
 308                 expr: le,
 309             }),
 310             Const(box ast::ConstItem {
 311                 defaultness: rd,
 312                 generics: rg,
 313                 ty: rt,
 314                 expr: re,
 315             }),
 316         ) => eq_defaultness(*ld, *rd) && eq_generics(lg, rg) && eq_ty(lt, rt) && eq_expr_opt(le, re),
 317         (
 318             Fn(box ast::Fn {
 319                 defaultness: ld,
 320                 sig: lf,
 321                 generics: lg,
 322                 body: lb,
 323             }),
 324             Fn(box ast::Fn {
 325                 defaultness: rd,
 326                 sig: rf,
 327                 generics: rg,
 328                 body: rb,
 329             }),
 330         ) => {
 331             eq_defaultness(*ld, *rd) && eq_fn_sig(lf, rf) && eq_generics(lg, rg) && both(lb, rb, |l, r| eq_block(l, r))
 332         },
 333         (Mod(lu, lmk), Mod(ru, rmk)) => {
 334             lu == ru
 335                 && match (lmk, rmk) {
 336                     (ModKind::Loaded(litems, linline, _), ModKind::Loaded(ritems, rinline, _)) => {
 337                         linline == rinline && over(litems, ritems, |l, r| eq_item(l, r, eq_item_kind))
 338                     },
 339                     (ModKind::Unloaded, ModKind::Unloaded) => true,
 340                     _ => false,
 341                 }
 342         },
 343         (ForeignMod(l), ForeignMod(r)) => {
 344             both(&l.abi, &r.abi, eq_str_lit) && over(&l.items, &r.items, |l, r| eq_item(l, r, eq_foreign_item_kind))
 345         },
 346         (
 347             TyAlias(box ast::TyAlias {
 348                 defaultness: ld,
 349                 generics: lg,
 350                 bounds: lb,
 351                 ty: lt,
 352                 ..
 353             }),
 354             TyAlias(box ast::TyAlias {
 355                 defaultness: rd,
 356                 generics: rg,
 357                 bounds: rb,
 358                 ty: rt,
 359                 ..
 360             }),
 361         ) => {
 362             eq_defaultness(*ld, *rd)
 363                 && eq_generics(lg, rg)
 364                 && over(lb, rb, eq_generic_bound)
 365                 && both(lt, rt, |l, r| eq_ty(l, r))
 366         },
 367         (Enum(le, lg), Enum(re, rg)) => over(&le.variants, &re.variants, eq_variant) && eq_generics(lg, rg),
 368         (Struct(lv, lg), Struct(rv, rg)) | (Union(lv, lg), Union(rv, rg)) => {
 369             eq_variant_data(lv, rv) && eq_generics(lg, rg)
 370         },
 371         (
 372             Trait(box ast::Trait {
 373                 is_auto: la,
 374                 unsafety: lu,
 375                 generics: lg,
 376                 bounds: lb,
 377                 items: li,
 378             }),
 379             Trait(box ast::Trait {
 380                 is_auto: ra,
 381                 unsafety: ru,
 382                 generics: rg,
 383                 bounds: rb,
 384                 items: ri,
 385             }),
 386         ) => {
 387             la == ra
 388                 && matches!(lu, Unsafe::No) == matches!(ru, Unsafe::No)
 389                 && eq_generics(lg, rg)
 390                 && over(lb, rb, eq_generic_bound)
 391                 && over(li, ri, |l, r| eq_item(l, r, eq_assoc_item_kind))
 392         },
 393         (TraitAlias(lg, lb), TraitAlias(rg, rb)) => eq_generics(lg, rg) && over(lb, rb, eq_generic_bound),
 394         (
 395             Impl(box ast::Impl {
 396                 unsafety: lu,
 397                 polarity: lp,
 398                 defaultness: ld,
 399                 constness: lc,
 400                 generics: lg,
 401                 of_trait: lot,
 402                 self_ty: lst,
 403                 items: li,
 404             }),
 405             Impl(box ast::Impl {
 406                 unsafety: ru,
 407                 polarity: rp,
 408                 defaultness: rd,
 409                 constness: rc,
 410                 generics: rg,
 411                 of_trait: rot,
 412                 self_ty: rst,
 413                 items: ri,
 414             }),
 415         ) => {
 416             matches!(lu, Unsafe::No) == matches!(ru, Unsafe::No)
 417                 && matches!(lp, ImplPolarity::Positive) == matches!(rp, ImplPolarity::Positive)
 418                 && eq_defaultness(*ld, *rd)
 419                 && matches!(lc, ast::Const::No) == matches!(rc, ast::Const::No)
 420                 && eq_generics(lg, rg)
 421                 && both(lot, rot, |l, r| eq_path(&l.path, &r.path))
 422                 && eq_ty(lst, rst)
 423                 && over(li, ri, |l, r| eq_item(l, r, eq_assoc_item_kind))
 424         },
 425         (MacCall(l), MacCall(r)) => eq_mac_call(l, r),
 426         (MacroDef(l), MacroDef(r)) => l.macro_rules == r.macro_rules && eq_delim_args(&l.body, &r.body),
 427         _ => false,
 428     }
 429 }
 430
 431 pub fn eq_foreign_item_kind(l: &ForeignItemKind, r: &ForeignItemKind) -> bool {
 432     use ForeignItemKind::*;
 433     match (l, r) {
 434         (Static(lt, lm, le), Static(rt, rm, re)) => lm == rm && eq_ty(lt, rt) && eq_expr_opt(le, re),
 435         (
 436             Fn(box ast::Fn {
 437                 defaultness: ld,
 438                 sig: lf,
 439                 generics: lg,
 440                 body: lb,
 441             }),
 442             Fn(box ast::Fn {
 443                 defaultness: rd,
 444                 sig: rf,
 445                 generics: rg,
 446                 body: rb,
 447             }),
 448         ) => {
 449             eq_defaultness(*ld, *rd) && eq_fn_sig(lf, rf) && eq_generics(lg, rg) && both(lb, rb, |l, r| eq_block(l, r))
 450         },
 451         (
 452             TyAlias(box ast::TyAlias {
 453                 defaultness: ld,
 454                 generics: lg,
 455                 bounds: lb,
 456                 ty: lt,
 457                 ..
 458             }),
 459             TyAlias(box ast::TyAlias {
 460                 defaultness: rd,
 461                 generics: rg,
 462                 bounds: rb,
 463                 ty: rt,
 464                 ..
 465             }),
 466         ) => {
 467             eq_defaultness(*ld, *rd)
 468                 && eq_generics(lg, rg)
 469                 && over(lb, rb, eq_generic_bound)
 470                 && both(lt, rt, |l, r| eq_ty(l, r))
 471         },
 472         (MacCall(l), MacCall(r)) => eq_mac_call(l, r),
 473         _ => false,
 474     }
 475 }
 476
 477 pub fn eq_assoc_item_kind(l: &AssocItemKind, r: &AssocItemKind) -> bool {
 478     use AssocItemKind::*;
 479     match (l, r) {
 480         (
 481             Const(box ast::ConstItem {
 482                 defaultness: ld,
 483                 generics: lg,
 484                 ty: lt,
 485                 expr: le,
 486             }),
 487             Const(box ast::ConstItem {
 488                 defaultness: rd,
 489                 generics: rg,
 490                 ty: rt,
 491                 expr: re,
 492             }),
 493         ) => eq_defaultness(*ld, *rd) && eq_generics(lg, rg) && eq_ty(lt, rt) && eq_expr_opt(le, re),
 494         (
 495             Fn(box ast::Fn {
 496                 defaultness: ld,
 497                 sig: lf,
 498                 generics: lg,
 499                 body: lb,
 500             }),
 501             Fn(box ast::Fn {
 502                 defaultness: rd,
 503                 sig: rf,
 504                 generics: rg,
 505                 body: rb,
 506             }),
 507         ) => {
 508             eq_defaultness(*ld, *rd) && eq_fn_sig(lf, rf) && eq_generics(lg, rg) && both(lb, rb, |l, r| eq_block(l, r))
 509         },
 510         (
 511             Type(box ast::TyAlias {
 512                 defaultness: ld,
 513                 generics: lg,
 514                 bounds: lb,
 515                 ty: lt,
 516                 ..
 517             }),
 518             Type(box ast::TyAlias {
 519                 defaultness: rd,
 520                 generics: rg,
 521                 bounds: rb,
 522                 ty: rt,
 523                 ..
 524             }),
 525         ) => {
 526             eq_defaultness(*ld, *rd)
 527                 && eq_generics(lg, rg)
 528                 && over(lb, rb, eq_generic_bound)
 529                 && both(lt, rt, |l, r| eq_ty(l, r))
 530         },
 531         (MacCall(l), MacCall(r)) => eq_mac_call(l, r),
 532         _ => false,
 533     }
 534 }
 535
 536 pub fn eq_variant(l: &Variant, r: &Variant) -> bool {
 537     l.is_placeholder == r.is_placeholder
 538         && over(&l.attrs, &r.attrs, eq_attr)
 539         && eq_vis(&l.vis, &r.vis)
 540         && eq_id(l.ident, r.ident)
 541         && eq_variant_data(&l.data, &r.data)
 542         && both(&l.disr_expr, &r.disr_expr, |l, r| eq_expr(&l.value, &r.value))
 543 }
 544
 545 pub fn eq_variant_data(l: &VariantData, r: &VariantData) -> bool {
 546     use VariantData::*;
 547     match (l, r) {
 548         (Unit(_), Unit(_)) => true,
 549         (Struct(l, _), Struct(r, _)) | (Tuple(l, _), Tuple(r, _)) => over(l, r, eq_struct_field),
 550         _ => false,
 551     }
 552 }
 553
 554 pub fn eq_struct_field(l: &FieldDef, r: &FieldDef) -> bool {
 555     l.is_placeholder == r.is_placeholder
 556         && over(&l.attrs, &r.attrs, eq_attr)
 557         && eq_vis(&l.vis, &r.vis)
 558         && both(&l.ident, &r.ident, |l, r| eq_id(*l, *r))
 559         && eq_ty(&l.ty, &r.ty)
 560 }
 561
 562 pub fn eq_fn_sig(l: &FnSig, r: &FnSig) -> bool {
 563     eq_fn_decl(&l.decl, &r.decl) && eq_fn_header(&l.header, &r.header)
 564 }
 565
 566 pub fn eq_fn_header(l: &FnHeader, r: &FnHeader) -> bool {
 567     matches!(l.unsafety, Unsafe::No) == matches!(r.unsafety, Unsafe::No)
 568         && l.asyncness.is_async() == r.asyncness.is_async()
 569         && matches!(l.constness, Const::No) == matches!(r.constness, Const::No)
 570         && eq_ext(&l.ext, &r.ext)
 571 }
 572
 573 pub fn eq_generics(l: &Generics, r: &Generics) -> bool {
 574     over(&l.params, &r.params, eq_generic_param)
 575         && over(&l.where_clause.predicates, &r.where_clause.predicates, |l, r| {
 576             eq_where_predicate(l, r)
 577         })
 578 }
 579
 580 pub fn eq_where_predicate(l: &WherePredicate, r: &WherePredicate) -> bool {
 581     use WherePredicate::*;
 582     match (l, r) {
 583         (BoundPredicate(l), BoundPredicate(r)) => {
 584             over(&l.bound_generic_params, &r.bound_generic_params, |l, r| {
 585                 eq_generic_param(l, r)
 586             }) && eq_ty(&l.bounded_ty, &r.bounded_ty)
 587                 && over(&l.bounds, &r.bounds, eq_generic_bound)
 588         },
 589         (RegionPredicate(l), RegionPredicate(r)) => {
 590             eq_id(l.lifetime.ident, r.lifetime.ident) && over(&l.bounds, &r.bounds, eq_generic_bound)
 591         },
 592         (EqPredicate(l), EqPredicate(r)) => eq_ty(&l.lhs_ty, &r.lhs_ty) && eq_ty(&l.rhs_ty, &r.rhs_ty),
 593         _ => false,
 594     }
 595 }
 596
 597 pub fn eq_use_tree(l: &UseTree, r: &UseTree) -> bool {
 598     eq_path(&l.prefix, &r.prefix) && eq_use_tree_kind(&l.kind, &r.kind)
 599 }
 600
 601 pub fn eq_anon_const(l: &AnonConst, r: &AnonConst) -> bool {
 602     eq_expr(&l.value, &r.value)
 603 }
 604
 605 pub fn eq_use_tree_kind(l: &UseTreeKind, r: &UseTreeKind) -> bool {
 606     use UseTreeKind::*;
 607     match (l, r) {
 608         (Glob, Glob) => true,
 609         (Simple(l), Simple(r)) => both(l, r, |l, r| eq_id(*l, *r)),
 610         (Nested(l), Nested(r)) => over(l, r, |(l, _), (r, _)| eq_use_tree(l, r)),
 611         _ => false,
 612     }
 613 }
 614
 615 pub fn eq_defaultness(l: Defaultness, r: Defaultness) -> bool {
 616     matches!(
 617         (l, r),
 618         (Defaultness::Final, Defaultness::Final) | (Defaultness::Default(_), Defaultness::Default(_))
 619     )
 620 }
 621
 622 pub fn eq_vis(l: &Visibility, r: &Visibility) -> bool {
 623     use VisibilityKind::*;
 624     match (&l.kind, &r.kind) {
 625         (Public, Public) | (Inherited, Inherited) => true,
 626         (Restricted { path: l, .. }, Restricted { path: r, .. }) => eq_path(l, r),
 627         _ => false,
 628     }
 629 }
 630
 631 pub fn eq_fn_decl(l: &FnDecl, r: &FnDecl) -> bool {
 632     eq_fn_ret_ty(&l.output, &r.output)
 633         && over(&l.inputs, &r.inputs, |l, r| {
 634             l.is_placeholder == r.is_placeholder
 635                 && eq_pat(&l.pat, &r.pat)
 636                 && eq_ty(&l.ty, &r.ty)
 637                 && over(&l.attrs, &r.attrs, eq_attr)
 638         })
 639 }
 640
 641 pub fn eq_closure_binder(l: &ClosureBinder, r: &ClosureBinder) -> bool {
 642     match (l, r) {
 643         (ClosureBinder::NotPresent, ClosureBinder::NotPresent) => true,
 644         (ClosureBinder::For { generic_params: lp, .. }, ClosureBinder::For { generic_params: rp, .. }) => {
 645             lp.len() == rp.len() && std::iter::zip(lp.iter(), rp.iter()).all(|(l, r)| eq_generic_param(l, r))
 646         },
 647         _ => false,
 648     }
 649 }
 650
 651 pub fn eq_fn_ret_ty(l: &FnRetTy, r: &FnRetTy) -> bool {
 652     match (l, r) {
 653         (FnRetTy::Default(_), FnRetTy::Default(_)) => true,
 654         (FnRetTy::Ty(l), FnRetTy::Ty(r)) => eq_ty(l, r),
 655         _ => false,
 656     }
 657 }
 658
 659 pub fn eq_ty(l: &Ty, r: &Ty) -> bool {
 660     use TyKind::*;
 661     match (&l.kind, &r.kind) {
 662         (Paren(l), _) => eq_ty(l, r),
 663         (_, Paren(r)) => eq_ty(l, r),
 664         (Never, Never) | (Infer, Infer) | (ImplicitSelf, ImplicitSelf) | (Err, Err) | (CVarArgs, CVarArgs) => true,
 665         (Slice(l), Slice(r)) => eq_ty(l, r),
 666         (Array(le, ls), Array(re, rs)) => eq_ty(le, re) && eq_expr(&ls.value, &rs.value),
 667         (Ptr(l), Ptr(r)) => l.mutbl == r.mutbl && eq_ty(&l.ty, &r.ty),
 668         (Ref(ll, l), Ref(rl, r)) => {
 669             both(ll, rl, |l, r| eq_id(l.ident, r.ident)) && l.mutbl == r.mutbl && eq_ty(&l.ty, &r.ty)
 670         },
 671         (BareFn(l), BareFn(r)) => {
 672             l.unsafety == r.unsafety
 673                 && eq_ext(&l.ext, &r.ext)
 674                 && over(&l.generic_params, &r.generic_params, eq_generic_param)
 675                 && eq_fn_decl(&l.decl, &r.decl)
 676         },
 677         (Tup(l), Tup(r)) => over(l, r, |l, r| eq_ty(l, r)),
 678         (Path(lq, lp), Path(rq, rp)) => both(lq, rq, eq_qself) && eq_path(lp, rp),
 679         (TraitObject(lg, ls), TraitObject(rg, rs)) => ls == rs && over(lg, rg, eq_generic_bound),
 680         (ImplTrait(_, lg), ImplTrait(_, rg)) => over(lg, rg, eq_generic_bound),
 681         (Typeof(l), Typeof(r)) => eq_expr(&l.value, &r.value),
 682         (MacCall(l), MacCall(r)) => eq_mac_call(l, r),
 683         _ => false,
 684     }
 685 }
 686
 687 pub fn eq_ext(l: &Extern, r: &Extern) -> bool {
 688     use Extern::*;
 689     match (l, r) {
 690         (None, None) | (Implicit(_), Implicit(_)) => true,
 691         (Explicit(l, _), Explicit(r, _)) => eq_str_lit(l, r),
 692         _ => false,
 693     }
 694 }
 695
 696 pub fn eq_str_lit(l: &StrLit, r: &StrLit) -> bool {
 697     l.style == r.style && l.symbol == r.symbol && l.suffix == r.suffix
 698 }
 699
 700 pub fn eq_poly_ref_trait(l: &PolyTraitRef, r: &PolyTraitRef) -> bool {
 701     eq_path(&l.trait_ref.path, &r.trait_ref.path)
 702         && over(&l.bound_generic_params, &r.bound_generic_params, |l, r| {
 703             eq_generic_param(l, r)
 704         })
 705 }
 706
 707 pub fn eq_generic_param(l: &GenericParam, r: &GenericParam) -> bool {
 708     use GenericParamKind::*;
 709     l.is_placeholder == r.is_placeholder
 710         && eq_id(l.ident, r.ident)
 711         && over(&l.bounds, &r.bounds, eq_generic_bound)
 712         && match (&l.kind, &r.kind) {
 713             (Lifetime, Lifetime) => true,
 714             (Type { default: l }, Type { default: r }) => both(l, r, |l, r| eq_ty(l, r)),
 715             (
 716                 Const {
 717                     ty: lt,
 718                     kw_span: _,
 719                     default: ld,
 720                 },
 721                 Const {
 722                     ty: rt,
 723                     kw_span: _,
 724                     default: rd,
 725                 },
 726             ) => eq_ty(lt, rt) && both(ld, rd, eq_anon_const),
 727             _ => false,
 728         }
 729         && over(&l.attrs, &r.attrs, eq_attr)
 730 }
 731
 732 pub fn eq_generic_bound(l: &GenericBound, r: &GenericBound) -> bool {
 733     use GenericBound::*;
 734     match (l, r) {
 735         (Trait(ptr1, tbm1), Trait(ptr2, tbm2)) => tbm1 == tbm2 && eq_poly_ref_trait(ptr1, ptr2),
 736         (Outlives(l), Outlives(r)) => eq_id(l.ident, r.ident),
 737         _ => false,
 738     }
 739 }
 740
 741 fn eq_term(l: &Term, r: &Term) -> bool {
 742     match (l, r) {
 743         (Term::Ty(l), Term::Ty(r)) => eq_ty(l, r),
 744         (Term::Const(l), Term::Const(r)) => eq_anon_const(l, r),
 745         _ => false,
 746     }
 747 }
 748
 749 pub fn eq_assoc_constraint(l: &AssocConstraint, r: &AssocConstraint) -> bool {
 750     use AssocConstraintKind::*;
 751     eq_id(l.ident, r.ident)
 752         && match (&l.kind, &r.kind) {
 753             (Equality { term: l }, Equality { term: r }) => eq_term(l, r),
 754             (Bound { bounds: l }, Bound { bounds: r }) => over(l, r, eq_generic_bound),
 755             _ => false,
 756         }
 757 }
 758
 759 pub fn eq_mac_call(l: &MacCall, r: &MacCall) -> bool {
 760     eq_path(&l.path, &r.path) && eq_delim_args(&l.args, &r.args)
 761 }
 762
 763 pub fn eq_attr(l: &Attribute, r: &Attribute) -> bool {
 764     use AttrKind::*;
 765     l.style == r.style
 766         && match (&l.kind, &r.kind) {
 767             (DocComment(l1, l2), DocComment(r1, r2)) => l1 == r1 && l2 == r2,
 768             (Normal(l), Normal(r)) => eq_path(&l.item.path, &r.item.path) && eq_attr_args(&l.item.args, &r.item.args),
 769             _ => false,
 770         }
 771 }
 772
 773 pub fn eq_attr_args(l: &AttrArgs, r: &AttrArgs) -> bool {
 774     use AttrArgs::*;
 775     match (l, r) {
 776         (Empty, Empty) => true,
 777         (Delimited(la), Delimited(ra)) => eq_delim_args(la, ra),
 778         (Eq(_, AttrArgsEq::Ast(le)), Eq(_, AttrArgsEq::Ast(re))) => eq_expr(le, re),
 779         (Eq(_, AttrArgsEq::Hir(ll)), Eq(_, AttrArgsEq::Hir(rl))) => ll.kind == rl.kind,
 780         _ => false,
 781     }
 782 }
 783
 784 pub fn eq_delim_args(l: &DelimArgs, r: &DelimArgs) -> bool {
 785     l.delim == r.delim && l.tokens.eq_unspanned(&r.tokens)
 786 }