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         (Box(l), Box(r)) | (Try(l), Try(r)) | (Await(l), Await(r)) => eq_expr(l, r),
 147         (Array(l), Array(r)) | (Tup(l), Tup(r)) => over(l, r, |l, r| eq_expr(l, r)),
 148         (Repeat(le, ls), Repeat(re, rs)) => eq_expr(le, re) && eq_expr(&ls.value, &rs.value),
 149         (Call(lc, la), Call(rc, ra)) => eq_expr(lc, rc) && over(la, ra, |l, r| eq_expr(l, r)),
 150         (
 151             MethodCall(box ast::MethodCall {
 152                 seg: ls,
 153                 receiver: lr,
 154                 args: la,
 155                 ..
 156             }),
 157             MethodCall(box ast::MethodCall {
 158                 seg: rs,
 159                 receiver: rr,
 160                 args: ra,
 161                 ..
 162             }),
 163         ) => eq_path_seg(ls, rs) && eq_expr(lr, rr) && over(la, ra, |l, r| eq_expr(l, r)),
 164         (Binary(lo, ll, lr), Binary(ro, rl, rr)) => lo.node == ro.node && eq_expr(ll, rl) && eq_expr(lr, rr),
 165         (Unary(lo, l), Unary(ro, r)) => mem::discriminant(lo) == mem::discriminant(ro) && eq_expr(l, r),
 166         (Lit(l), Lit(r)) => l == r,
 167         (Cast(l, lt), Cast(r, rt)) | (Type(l, lt), Type(r, rt)) => eq_expr(l, r) && eq_ty(lt, rt),
 168         (Let(lp, le, _), Let(rp, re, _)) => eq_pat(lp, rp) && eq_expr(le, re),
 169         (If(lc, lt, le), If(rc, rt, re)) => eq_expr(lc, rc) && eq_block(lt, rt) && eq_expr_opt(le, re),
 170         (While(lc, lt, ll), While(rc, rt, rl)) => eq_label(ll, rl) && eq_expr(lc, rc) && eq_block(lt, rt),
 171         (ForLoop(lp, li, lt, ll), ForLoop(rp, ri, rt, rl)) => {
 172             eq_label(ll, rl) && eq_pat(lp, rp) && eq_expr(li, ri) && eq_block(lt, rt)
 173         },
 174         (Loop(lt, ll, _), Loop(rt, rl, _)) => eq_label(ll, rl) && eq_block(lt, rt),
 175         (Block(lb, ll), Block(rb, rl)) => eq_label(ll, rl) && eq_block(lb, rb),
 176         (TryBlock(l), TryBlock(r)) => eq_block(l, r),
 177         (Yield(l), Yield(r)) | (Ret(l), Ret(r)) => eq_expr_opt(l, r),
 178         (Break(ll, le), Break(rl, re)) => eq_label(ll, rl) && eq_expr_opt(le, re),
 179         (Continue(ll), Continue(rl)) => eq_label(ll, rl),
 180         (Assign(l1, l2, _), Assign(r1, r2, _)) | (Index(l1, l2), Index(r1, r2)) => eq_expr(l1, r1) && eq_expr(l2, r2),
 181         (AssignOp(lo, lp, lv), AssignOp(ro, rp, rv)) => lo.node == ro.node && eq_expr(lp, rp) && eq_expr(lv, rv),
 182         (Field(lp, lf), Field(rp, rf)) => eq_id(*lf, *rf) && eq_expr(lp, rp),
 183         (Match(ls, la), Match(rs, ra)) => eq_expr(ls, rs) && over(la, ra, eq_arm),
 184         (
 185             Closure(box ast::Closure {
 186                 binder: lb,
 187                 capture_clause: lc,
 188                 asyncness: la,
 189                 movability: lm,
 190                 fn_decl: lf,
 191                 body: le,
 192                 ..
 193             }),
 194             Closure(box ast::Closure {
 195                 binder: rb,
 196                 capture_clause: rc,
 197                 asyncness: ra,
 198                 movability: rm,
 199                 fn_decl: rf,
 200                 body: re,
 201                 ..
 202             }),
 203         ) => {
 204             eq_closure_binder(lb, rb)
 205                 && lc == rc
 206                 && la.is_async() == ra.is_async()
 207                 && lm == rm
 208                 && eq_fn_decl(lf, rf)
 209                 && eq_expr(le, re)
 210         },
 211         (Async(lc, _, lb), Async(rc, _, rb)) => lc == rc && eq_block(lb, rb),
 212         (Range(lf, lt, ll), Range(rf, rt, rl)) => ll == rl && eq_expr_opt(lf, rf) && eq_expr_opt(lt, rt),
 213         (AddrOf(lbk, lm, le), AddrOf(rbk, rm, re)) => lbk == rbk && lm == rm && eq_expr(le, re),
 214         (Path(lq, lp), Path(rq, rp)) => both(lq, rq, eq_qself) && eq_path(lp, rp),
 215         (MacCall(l), MacCall(r)) => eq_mac_call(l, r),
 216         (Struct(lse), Struct(rse)) => {
 217             eq_maybe_qself(&lse.qself, &rse.qself)
 218                 && eq_path(&lse.path, &rse.path)
 219                 && eq_struct_rest(&lse.rest, &rse.rest)
 220                 && unordered_over(&lse.fields, &rse.fields, eq_field)
 221         },
 222         _ => false,
 223     }
 224 }
 225
 226 pub fn eq_field(l: &ExprField, r: &ExprField) -> bool {
 227     l.is_placeholder == r.is_placeholder
 228         && eq_id(l.ident, r.ident)
 229         && eq_expr(&l.expr, &r.expr)
 230         && over(&l.attrs, &r.attrs, eq_attr)
 231 }
 232
 233 pub fn eq_arm(l: &Arm, r: &Arm) -> bool {
 234     l.is_placeholder == r.is_placeholder
 235         && eq_pat(&l.pat, &r.pat)
 236         && eq_expr(&l.body, &r.body)
 237         && eq_expr_opt(&l.guard, &r.guard)
 238         && over(&l.attrs, &r.attrs, eq_attr)
 239 }
 240
 241 pub fn eq_label(l: &Option<Label>, r: &Option<Label>) -> bool {
 242     both(l, r, |l, r| eq_id(l.ident, r.ident))
 243 }
 244
 245 pub fn eq_block(l: &Block, r: &Block) -> bool {
 246     l.rules == r.rules && over(&l.stmts, &r.stmts, eq_stmt)
 247 }
 248
 249 pub fn eq_stmt(l: &Stmt, r: &Stmt) -> bool {
 250     use StmtKind::*;
 251     match (&l.kind, &r.kind) {
 252         (Local(l), Local(r)) => {
 253             eq_pat(&l.pat, &r.pat)
 254                 && both(&l.ty, &r.ty, |l, r| eq_ty(l, r))
 255                 && eq_local_kind(&l.kind, &r.kind)
 256                 && over(&l.attrs, &r.attrs, eq_attr)
 257         },
 258         (Item(l), Item(r)) => eq_item(l, r, eq_item_kind),
 259         (Expr(l), Expr(r)) | (Semi(l), Semi(r)) => eq_expr(l, r),
 260         (Empty, Empty) => true,
 261         (MacCall(l), MacCall(r)) => {
 262             l.style == r.style && eq_mac_call(&l.mac, &r.mac) && over(&l.attrs, &r.attrs, eq_attr)
 263         },
 264         _ => false,
 265     }
 266 }
 267
 268 pub fn eq_local_kind(l: &LocalKind, r: &LocalKind) -> bool {
 269     use LocalKind::*;
 270     match (l, r) {
 271         (Decl, Decl) => true,
 272         (Init(l), Init(r)) => eq_expr(l, r),
 273         (InitElse(li, le), InitElse(ri, re)) => eq_expr(li, ri) && eq_block(le, re),
 274         _ => false,
 275     }
 276 }
 277
 278 pub fn eq_item<K>(l: &Item<K>, r: &Item<K>, mut eq_kind: impl FnMut(&K, &K) -> bool) -> bool {
 279     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)
 280 }
 281
 282 #[expect(clippy::too_many_lines)] // Just a big match statement
 283 pub fn eq_item_kind(l: &ItemKind, r: &ItemKind) -> bool {
 284     use ItemKind::*;
 285     match (l, r) {
 286         (ExternCrate(l), ExternCrate(r)) => l == r,
 287         (Use(l), Use(r)) => eq_use_tree(l, r),
 288         (Static(lt, lm, le), Static(rt, rm, re)) => lm == rm && eq_ty(lt, rt) && eq_expr_opt(le, re),
 289         (Const(ld, lt, le), Const(rd, rt, re)) => eq_defaultness(*ld, *rd) && eq_ty(lt, rt) && eq_expr_opt(le, re),
 290         (
 291             Fn(box ast::Fn {
 292                 defaultness: ld,
 293                 sig: lf,
 294                 generics: lg,
 295                 body: lb,
 296             }),
 297             Fn(box ast::Fn {
 298                 defaultness: rd,
 299                 sig: rf,
 300                 generics: rg,
 301                 body: rb,
 302             }),
 303         ) => {
 304             eq_defaultness(*ld, *rd) && eq_fn_sig(lf, rf) && eq_generics(lg, rg) && both(lb, rb, |l, r| eq_block(l, r))
 305         },
 306         (Mod(lu, lmk), Mod(ru, rmk)) => {
 307             lu == ru
 308                 && match (lmk, rmk) {
 309                     (ModKind::Loaded(litems, linline, _), ModKind::Loaded(ritems, rinline, _)) => {
 310                         linline == rinline && over(litems, ritems, |l, r| eq_item(l, r, eq_item_kind))
 311                     },
 312                     (ModKind::Unloaded, ModKind::Unloaded) => true,
 313                     _ => false,
 314                 }
 315         },
 316         (ForeignMod(l), ForeignMod(r)) => {
 317             both(&l.abi, &r.abi, eq_str_lit) && over(&l.items, &r.items, |l, r| eq_item(l, r, eq_foreign_item_kind))
 318         },
 319         (
 320             TyAlias(box ast::TyAlias {
 321                 defaultness: ld,
 322                 generics: lg,
 323                 bounds: lb,
 324                 ty: lt,
 325                 ..
 326             }),
 327             TyAlias(box ast::TyAlias {
 328                 defaultness: rd,
 329                 generics: rg,
 330                 bounds: rb,
 331                 ty: rt,
 332                 ..
 333             }),
 334         ) => {
 335             eq_defaultness(*ld, *rd)
 336                 && eq_generics(lg, rg)
 337                 && over(lb, rb, eq_generic_bound)
 338                 && both(lt, rt, |l, r| eq_ty(l, r))
 339         },
 340         (Enum(le, lg), Enum(re, rg)) => over(&le.variants, &re.variants, eq_variant) && eq_generics(lg, rg),
 341         (Struct(lv, lg), Struct(rv, rg)) | (Union(lv, lg), Union(rv, rg)) => {
 342             eq_variant_data(lv, rv) && eq_generics(lg, rg)
 343         },
 344         (
 345             Trait(box ast::Trait {
 346                 is_auto: la,
 347                 unsafety: lu,
 348                 generics: lg,
 349                 bounds: lb,
 350                 items: li,
 351             }),
 352             Trait(box ast::Trait {
 353                 is_auto: ra,
 354                 unsafety: ru,
 355                 generics: rg,
 356                 bounds: rb,
 357                 items: ri,
 358             }),
 359         ) => {
 360             la == ra
 361                 && matches!(lu, Unsafe::No) == matches!(ru, Unsafe::No)
 362                 && eq_generics(lg, rg)
 363                 && over(lb, rb, eq_generic_bound)
 364                 && over(li, ri, |l, r| eq_item(l, r, eq_assoc_item_kind))
 365         },
 366         (TraitAlias(lg, lb), TraitAlias(rg, rb)) => eq_generics(lg, rg) && over(lb, rb, eq_generic_bound),
 367         (
 368             Impl(box ast::Impl {
 369                 unsafety: lu,
 370                 polarity: lp,
 371                 defaultness: ld,
 372                 constness: lc,
 373                 generics: lg,
 374                 of_trait: lot,
 375                 self_ty: lst,
 376                 items: li,
 377             }),
 378             Impl(box ast::Impl {
 379                 unsafety: ru,
 380                 polarity: rp,
 381                 defaultness: rd,
 382                 constness: rc,
 383                 generics: rg,
 384                 of_trait: rot,
 385                 self_ty: rst,
 386                 items: ri,
 387             }),
 388         ) => {
 389             matches!(lu, Unsafe::No) == matches!(ru, Unsafe::No)
 390                 && matches!(lp, ImplPolarity::Positive) == matches!(rp, ImplPolarity::Positive)
 391                 && eq_defaultness(*ld, *rd)
 392                 && matches!(lc, ast::Const::No) == matches!(rc, ast::Const::No)
 393                 && eq_generics(lg, rg)
 394                 && both(lot, rot, |l, r| eq_path(&l.path, &r.path))
 395                 && eq_ty(lst, rst)
 396                 && over(li, ri, |l, r| eq_item(l, r, eq_assoc_item_kind))
 397         },
 398         (MacCall(l), MacCall(r)) => eq_mac_call(l, r),
 399         (MacroDef(l), MacroDef(r)) => l.macro_rules == r.macro_rules && eq_delim_args(&l.body, &r.body),
 400         _ => false,
 401     }
 402 }
 403
 404 pub fn eq_foreign_item_kind(l: &ForeignItemKind, r: &ForeignItemKind) -> bool {
 405     use ForeignItemKind::*;
 406     match (l, r) {
 407         (Static(lt, lm, le), Static(rt, rm, re)) => lm == rm && eq_ty(lt, rt) && eq_expr_opt(le, re),
 408         (
 409             Fn(box ast::Fn {
 410                 defaultness: ld,
 411                 sig: lf,
 412                 generics: lg,
 413                 body: lb,
 414             }),
 415             Fn(box ast::Fn {
 416                 defaultness: rd,
 417                 sig: rf,
 418                 generics: rg,
 419                 body: rb,
 420             }),
 421         ) => {
 422             eq_defaultness(*ld, *rd) && eq_fn_sig(lf, rf) && eq_generics(lg, rg) && both(lb, rb, |l, r| eq_block(l, r))
 423         },
 424         (
 425             TyAlias(box ast::TyAlias {
 426                 defaultness: ld,
 427                 generics: lg,
 428                 bounds: lb,
 429                 ty: lt,
 430                 ..
 431             }),
 432             TyAlias(box ast::TyAlias {
 433                 defaultness: rd,
 434                 generics: rg,
 435                 bounds: rb,
 436                 ty: rt,
 437                 ..
 438             }),
 439         ) => {
 440             eq_defaultness(*ld, *rd)
 441                 && eq_generics(lg, rg)
 442                 && over(lb, rb, eq_generic_bound)
 443                 && both(lt, rt, |l, r| eq_ty(l, r))
 444         },
 445         (MacCall(l), MacCall(r)) => eq_mac_call(l, r),
 446         _ => false,
 447     }
 448 }
 449
 450 pub fn eq_assoc_item_kind(l: &AssocItemKind, r: &AssocItemKind) -> bool {
 451     use AssocItemKind::*;
 452     match (l, r) {
 453         (Const(ld, lt, le), Const(rd, rt, re)) => eq_defaultness(*ld, *rd) && eq_ty(lt, rt) && eq_expr_opt(le, re),
 454         (
 455             Fn(box ast::Fn {
 456                 defaultness: ld,
 457                 sig: lf,
 458                 generics: lg,
 459                 body: lb,
 460             }),
 461             Fn(box ast::Fn {
 462                 defaultness: rd,
 463                 sig: rf,
 464                 generics: rg,
 465                 body: rb,
 466             }),
 467         ) => {
 468             eq_defaultness(*ld, *rd) && eq_fn_sig(lf, rf) && eq_generics(lg, rg) && both(lb, rb, |l, r| eq_block(l, r))
 469         },
 470         (
 471             Type(box ast::TyAlias {
 472                 defaultness: ld,
 473                 generics: lg,
 474                 bounds: lb,
 475                 ty: lt,
 476                 ..
 477             }),
 478             Type(box ast::TyAlias {
 479                 defaultness: rd,
 480                 generics: rg,
 481                 bounds: rb,
 482                 ty: rt,
 483                 ..
 484             }),
 485         ) => {
 486             eq_defaultness(*ld, *rd)
 487                 && eq_generics(lg, rg)
 488                 && over(lb, rb, eq_generic_bound)
 489                 && both(lt, rt, |l, r| eq_ty(l, r))
 490         },
 491         (MacCall(l), MacCall(r)) => eq_mac_call(l, r),
 492         _ => false,
 493     }
 494 }
 495
 496 pub fn eq_variant(l: &Variant, r: &Variant) -> bool {
 497     l.is_placeholder == r.is_placeholder
 498         && over(&l.attrs, &r.attrs, eq_attr)
 499         && eq_vis(&l.vis, &r.vis)
 500         && eq_id(l.ident, r.ident)
 501         && eq_variant_data(&l.data, &r.data)
 502         && both(&l.disr_expr, &r.disr_expr, |l, r| eq_expr(&l.value, &r.value))
 503 }
 504
 505 pub fn eq_variant_data(l: &VariantData, r: &VariantData) -> bool {
 506     use VariantData::*;
 507     match (l, r) {
 508         (Unit(_), Unit(_)) => true,
 509         (Struct(l, _), Struct(r, _)) | (Tuple(l, _), Tuple(r, _)) => over(l, r, eq_struct_field),
 510         _ => false,
 511     }
 512 }
 513
 514 pub fn eq_struct_field(l: &FieldDef, r: &FieldDef) -> bool {
 515     l.is_placeholder == r.is_placeholder
 516         && over(&l.attrs, &r.attrs, eq_attr)
 517         && eq_vis(&l.vis, &r.vis)
 518         && both(&l.ident, &r.ident, |l, r| eq_id(*l, *r))
 519         && eq_ty(&l.ty, &r.ty)
 520 }
 521
 522 pub fn eq_fn_sig(l: &FnSig, r: &FnSig) -> bool {
 523     eq_fn_decl(&l.decl, &r.decl) && eq_fn_header(&l.header, &r.header)
 524 }
 525
 526 pub fn eq_fn_header(l: &FnHeader, r: &FnHeader) -> bool {
 527     matches!(l.unsafety, Unsafe::No) == matches!(r.unsafety, Unsafe::No)
 528         && l.asyncness.is_async() == r.asyncness.is_async()
 529         && matches!(l.constness, Const::No) == matches!(r.constness, Const::No)
 530         && eq_ext(&l.ext, &r.ext)
 531 }
 532
 533 pub fn eq_generics(l: &Generics, r: &Generics) -> bool {
 534     over(&l.params, &r.params, eq_generic_param)
 535         && over(&l.where_clause.predicates, &r.where_clause.predicates, |l, r| {
 536             eq_where_predicate(l, r)
 537         })
 538 }
 539
 540 pub fn eq_where_predicate(l: &WherePredicate, r: &WherePredicate) -> bool {
 541     use WherePredicate::*;
 542     match (l, r) {
 543         (BoundPredicate(l), BoundPredicate(r)) => {
 544             over(&l.bound_generic_params, &r.bound_generic_params, |l, r| {
 545                 eq_generic_param(l, r)
 546             }) && eq_ty(&l.bounded_ty, &r.bounded_ty)
 547                 && over(&l.bounds, &r.bounds, eq_generic_bound)
 548         },
 549         (RegionPredicate(l), RegionPredicate(r)) => {
 550             eq_id(l.lifetime.ident, r.lifetime.ident) && over(&l.bounds, &r.bounds, eq_generic_bound)
 551         },
 552         (EqPredicate(l), EqPredicate(r)) => eq_ty(&l.lhs_ty, &r.lhs_ty) && eq_ty(&l.rhs_ty, &r.rhs_ty),
 553         _ => false,
 554     }
 555 }
 556
 557 pub fn eq_use_tree(l: &UseTree, r: &UseTree) -> bool {
 558     eq_path(&l.prefix, &r.prefix) && eq_use_tree_kind(&l.kind, &r.kind)
 559 }
 560
 561 pub fn eq_anon_const(l: &AnonConst, r: &AnonConst) -> bool {
 562     eq_expr(&l.value, &r.value)
 563 }
 564
 565 pub fn eq_use_tree_kind(l: &UseTreeKind, r: &UseTreeKind) -> bool {
 566     use UseTreeKind::*;
 567     match (l, r) {
 568         (Glob, Glob) => true,
 569         (Simple(l), Simple(r)) => both(l, r, |l, r| eq_id(*l, *r)),
 570         (Nested(l), Nested(r)) => over(l, r, |(l, _), (r, _)| eq_use_tree(l, r)),
 571         _ => false,
 572     }
 573 }
 574
 575 pub fn eq_defaultness(l: Defaultness, r: Defaultness) -> bool {
 576     matches!(
 577         (l, r),
 578         (Defaultness::Final, Defaultness::Final) | (Defaultness::Default(_), Defaultness::Default(_))
 579     )
 580 }
 581
 582 pub fn eq_vis(l: &Visibility, r: &Visibility) -> bool {
 583     use VisibilityKind::*;
 584     match (&l.kind, &r.kind) {
 585         (Public, Public) | (Inherited, Inherited) => true,
 586         (Restricted { path: l, .. }, Restricted { path: r, .. }) => eq_path(l, r),
 587         _ => false,
 588     }
 589 }
 590
 591 pub fn eq_fn_decl(l: &FnDecl, r: &FnDecl) -> bool {
 592     eq_fn_ret_ty(&l.output, &r.output)
 593         && over(&l.inputs, &r.inputs, |l, r| {
 594             l.is_placeholder == r.is_placeholder
 595                 && eq_pat(&l.pat, &r.pat)
 596                 && eq_ty(&l.ty, &r.ty)
 597                 && over(&l.attrs, &r.attrs, eq_attr)
 598         })
 599 }
 600
 601 pub fn eq_closure_binder(l: &ClosureBinder, r: &ClosureBinder) -> bool {
 602     match (l, r) {
 603         (ClosureBinder::NotPresent, ClosureBinder::NotPresent) => true,
 604         (ClosureBinder::For { generic_params: lp, .. }, ClosureBinder::For { generic_params: rp, .. }) => {
 605             lp.len() == rp.len() && std::iter::zip(lp.iter(), rp.iter()).all(|(l, r)| eq_generic_param(l, r))
 606         },
 607         _ => false,
 608     }
 609 }
 610
 611 pub fn eq_fn_ret_ty(l: &FnRetTy, r: &FnRetTy) -> bool {
 612     match (l, r) {
 613         (FnRetTy::Default(_), FnRetTy::Default(_)) => true,
 614         (FnRetTy::Ty(l), FnRetTy::Ty(r)) => eq_ty(l, r),
 615         _ => false,
 616     }
 617 }
 618
 619 pub fn eq_ty(l: &Ty, r: &Ty) -> bool {
 620     use TyKind::*;
 621     match (&l.kind, &r.kind) {
 622         (Paren(l), _) => eq_ty(l, r),
 623         (_, Paren(r)) => eq_ty(l, r),
 624         (Never, Never) | (Infer, Infer) | (ImplicitSelf, ImplicitSelf) | (Err, Err) | (CVarArgs, CVarArgs) => true,
 625         (Slice(l), Slice(r)) => eq_ty(l, r),
 626         (Array(le, ls), Array(re, rs)) => eq_ty(le, re) && eq_expr(&ls.value, &rs.value),
 627         (Ptr(l), Ptr(r)) => l.mutbl == r.mutbl && eq_ty(&l.ty, &r.ty),
 628         (Ref(ll, l), Ref(rl, r)) => {
 629             both(ll, rl, |l, r| eq_id(l.ident, r.ident)) && l.mutbl == r.mutbl && eq_ty(&l.ty, &r.ty)
 630         },
 631         (BareFn(l), BareFn(r)) => {
 632             l.unsafety == r.unsafety
 633                 && eq_ext(&l.ext, &r.ext)
 634                 && over(&l.generic_params, &r.generic_params, eq_generic_param)
 635                 && eq_fn_decl(&l.decl, &r.decl)
 636         },
 637         (Tup(l), Tup(r)) => over(l, r, |l, r| eq_ty(l, r)),
 638         (Path(lq, lp), Path(rq, rp)) => both(lq, rq, eq_qself) && eq_path(lp, rp),
 639         (TraitObject(lg, ls), TraitObject(rg, rs)) => ls == rs && over(lg, rg, eq_generic_bound),
 640         (ImplTrait(_, lg), ImplTrait(_, rg)) => over(lg, rg, eq_generic_bound),
 641         (Typeof(l), Typeof(r)) => eq_expr(&l.value, &r.value),
 642         (MacCall(l), MacCall(r)) => eq_mac_call(l, r),
 643         _ => false,
 644     }
 645 }
 646
 647 pub fn eq_ext(l: &Extern, r: &Extern) -> bool {
 648     use Extern::*;
 649     match (l, r) {
 650         (None, None) | (Implicit(_), Implicit(_)) => true,
 651         (Explicit(l, _), Explicit(r, _)) => eq_str_lit(l, r),
 652         _ => false,
 653     }
 654 }
 655
 656 pub fn eq_str_lit(l: &StrLit, r: &StrLit) -> bool {
 657     l.style == r.style && l.symbol == r.symbol && l.suffix == r.suffix
 658 }
 659
 660 pub fn eq_poly_ref_trait(l: &PolyTraitRef, r: &PolyTraitRef) -> bool {
 661     eq_path(&l.trait_ref.path, &r.trait_ref.path)
 662         && over(&l.bound_generic_params, &r.bound_generic_params, |l, r| {
 663             eq_generic_param(l, r)
 664         })
 665 }
 666
 667 pub fn eq_generic_param(l: &GenericParam, r: &GenericParam) -> bool {
 668     use GenericParamKind::*;
 669     l.is_placeholder == r.is_placeholder
 670         && eq_id(l.ident, r.ident)
 671         && over(&l.bounds, &r.bounds, eq_generic_bound)
 672         && match (&l.kind, &r.kind) {
 673             (Lifetime, Lifetime) => true,
 674             (Type { default: l }, Type { default: r }) => both(l, r, |l, r| eq_ty(l, r)),
 675             (
 676                 Const {
 677                     ty: lt,
 678                     kw_span: _,
 679                     default: ld,
 680                 },
 681                 Const {
 682                     ty: rt,
 683                     kw_span: _,
 684                     default: rd,
 685                 },
 686             ) => eq_ty(lt, rt) && both(ld, rd, eq_anon_const),
 687             _ => false,
 688         }
 689         && over(&l.attrs, &r.attrs, eq_attr)
 690 }
 691
 692 pub fn eq_generic_bound(l: &GenericBound, r: &GenericBound) -> bool {
 693     use GenericBound::*;
 694     match (l, r) {
 695         (Trait(ptr1, tbm1), Trait(ptr2, tbm2)) => tbm1 == tbm2 && eq_poly_ref_trait(ptr1, ptr2),
 696         (Outlives(l), Outlives(r)) => eq_id(l.ident, r.ident),
 697         _ => false,
 698     }
 699 }
 700
 701 fn eq_term(l: &Term, r: &Term) -> bool {
 702     match (l, r) {
 703         (Term::Ty(l), Term::Ty(r)) => eq_ty(l, r),
 704         (Term::Const(l), Term::Const(r)) => eq_anon_const(l, r),
 705         _ => false,
 706     }
 707 }
 708
 709 pub fn eq_assoc_constraint(l: &AssocConstraint, r: &AssocConstraint) -> bool {
 710     use AssocConstraintKind::*;
 711     eq_id(l.ident, r.ident)
 712         && match (&l.kind, &r.kind) {
 713             (Equality { term: l }, Equality { term: r }) => eq_term(l, r),
 714             (Bound { bounds: l }, Bound { bounds: r }) => over(l, r, eq_generic_bound),
 715             _ => false,
 716         }
 717 }
 718
 719 pub fn eq_mac_call(l: &MacCall, r: &MacCall) -> bool {
 720     eq_path(&l.path, &r.path) && eq_delim_args(&l.args, &r.args)
 721 }
 722
 723 pub fn eq_attr(l: &Attribute, r: &Attribute) -> bool {
 724     use AttrKind::*;
 725     l.style == r.style
 726         && match (&l.kind, &r.kind) {
 727             (DocComment(l1, l2), DocComment(r1, r2)) => l1 == r1 && l2 == r2,
 728             (Normal(l), Normal(r)) => eq_path(&l.item.path, &r.item.path) && eq_attr_args(&l.item.args, &r.item.args),
 729             _ => false,
 730         }
 731 }
 732
 733 pub fn eq_attr_args(l: &AttrArgs, r: &AttrArgs) -> bool {
 734     use AttrArgs::*;
 735     match (l, r) {
 736         (Empty, Empty) => true,
 737         (Delimited(la), Delimited(ra)) => eq_delim_args(la, ra),
 738         (Eq(_, AttrArgsEq::Ast(le)), Eq(_, AttrArgsEq::Ast(re))) => eq_expr(le, re),
 739         (Eq(_, AttrArgsEq::Hir(ll)), Eq(_, AttrArgsEq::Hir(rl))) => ll.kind == rl.kind,
 740         _ => false,
 741     }
 742 }
 743
 744 pub fn eq_delim_args(l: &DelimArgs, r: &DelimArgs) -> bool {
 745     l.delim == r.delim && l.tokens.eq_unspanned(&r.tokens)
 746 }