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: &QSelf, r: &QSelf) -> bool {
  79     l.position == r.position && eq_ty(&l.ty, &r.ty)
  80 }
  81
  82 pub fn eq_maybe_qself(l: &Option<QSelf>, r: &Option<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         (MethodCall(lc, la, _), MethodCall(rc, ra, _)) => eq_path_seg(lc, rc) && over(la, ra, |l, r| eq_expr(l, r)),
 151         (Binary(lo, ll, lr), Binary(ro, rl, rr)) => lo.node == ro.node && eq_expr(ll, rl) && eq_expr(lr, rr),
 152         (Unary(lo, l), Unary(ro, r)) => mem::discriminant(lo) == mem::discriminant(ro) && eq_expr(l, r),
 153         (Lit(l), Lit(r)) => l.kind == r.kind,
 154         (Cast(l, lt), Cast(r, rt)) | (Type(l, lt), Type(r, rt)) => eq_expr(l, r) && eq_ty(lt, rt),
 155         (Let(lp, le, _), Let(rp, re, _)) => eq_pat(lp, rp) && eq_expr(le, re),
 156         (If(lc, lt, le), If(rc, rt, re)) => eq_expr(lc, rc) && eq_block(lt, rt) && eq_expr_opt(le, re),
 157         (While(lc, lt, ll), While(rc, rt, rl)) => eq_label(ll, rl) && eq_expr(lc, rc) && eq_block(lt, rt),
 158         (ForLoop(lp, li, lt, ll), ForLoop(rp, ri, rt, rl)) => {
 159             eq_label(ll, rl) && eq_pat(lp, rp) && eq_expr(li, ri) && eq_block(lt, rt)
 160         },
 161         (Loop(lt, ll), Loop(rt, rl)) => eq_label(ll, rl) && eq_block(lt, rt),
 162         (Block(lb, ll), Block(rb, rl)) => eq_label(ll, rl) && eq_block(lb, rb),
 163         (TryBlock(l), TryBlock(r)) => eq_block(l, r),
 164         (Yield(l), Yield(r)) | (Ret(l), Ret(r)) => eq_expr_opt(l, r),
 165         (Break(ll, le), Break(rl, re)) => eq_label(ll, rl) && eq_expr_opt(le, re),
 166         (Continue(ll), Continue(rl)) => eq_label(ll, rl),
 167         (Assign(l1, l2, _), Assign(r1, r2, _)) | (Index(l1, l2), Index(r1, r2)) => eq_expr(l1, r1) && eq_expr(l2, r2),
 168         (AssignOp(lo, lp, lv), AssignOp(ro, rp, rv)) => lo.node == ro.node && eq_expr(lp, rp) && eq_expr(lv, rv),
 169         (Field(lp, lf), Field(rp, rf)) => eq_id(*lf, *rf) && eq_expr(lp, rp),
 170         (Match(ls, la), Match(rs, ra)) => eq_expr(ls, rs) && over(la, ra, eq_arm),
 171         (Closure(lc, la, lm, lf, lb, _), Closure(rc, ra, rm, rf, rb, _)) => {
 172             lc == rc && la.is_async() == ra.is_async() && lm == rm && eq_fn_decl(lf, rf) && eq_expr(lb, rb)
 173         },
 174         (Async(lc, _, lb), Async(rc, _, rb)) => lc == rc && eq_block(lb, rb),
 175         (Range(lf, lt, ll), Range(rf, rt, rl)) => ll == rl && eq_expr_opt(lf, rf) && eq_expr_opt(lt, rt),
 176         (AddrOf(lbk, lm, le), AddrOf(rbk, rm, re)) => lbk == rbk && lm == rm && eq_expr(le, re),
 177         (Path(lq, lp), Path(rq, rp)) => both(lq, rq, eq_qself) && eq_path(lp, rp),
 178         (MacCall(l), MacCall(r)) => eq_mac_call(l, r),
 179         (Struct(lse), Struct(rse)) => {
 180             eq_maybe_qself(&lse.qself, &rse.qself)
 181                 && eq_path(&lse.path, &rse.path)
 182                 && eq_struct_rest(&lse.rest, &rse.rest)
 183                 && unordered_over(&lse.fields, &rse.fields, eq_field)
 184         },
 185         _ => false,
 186     }
 187 }
 188
 189 pub fn eq_field(l: &ExprField, r: &ExprField) -> bool {
 190     l.is_placeholder == r.is_placeholder
 191         && eq_id(l.ident, r.ident)
 192         && eq_expr(&l.expr, &r.expr)
 193         && over(&l.attrs, &r.attrs, eq_attr)
 194 }
 195
 196 pub fn eq_arm(l: &Arm, r: &Arm) -> bool {
 197     l.is_placeholder == r.is_placeholder
 198         && eq_pat(&l.pat, &r.pat)
 199         && eq_expr(&l.body, &r.body)
 200         && eq_expr_opt(&l.guard, &r.guard)
 201         && over(&l.attrs, &r.attrs, eq_attr)
 202 }
 203
 204 pub fn eq_label(l: &Option<Label>, r: &Option<Label>) -> bool {
 205     both(l, r, |l, r| eq_id(l.ident, r.ident))
 206 }
 207
 208 pub fn eq_block(l: &Block, r: &Block) -> bool {
 209     l.rules == r.rules && over(&l.stmts, &r.stmts, eq_stmt)
 210 }
 211
 212 pub fn eq_stmt(l: &Stmt, r: &Stmt) -> bool {
 213     use StmtKind::*;
 214     match (&l.kind, &r.kind) {
 215         (Local(l), Local(r)) => {
 216             eq_pat(&l.pat, &r.pat)
 217                 && both(&l.ty, &r.ty, |l, r| eq_ty(l, r))
 218                 && eq_local_kind(&l.kind, &r.kind)
 219                 && over(&l.attrs, &r.attrs, eq_attr)
 220         },
 221         (Item(l), Item(r)) => eq_item(l, r, eq_item_kind),
 222         (Expr(l), Expr(r)) | (Semi(l), Semi(r)) => eq_expr(l, r),
 223         (Empty, Empty) => true,
 224         (MacCall(l), MacCall(r)) => {
 225             l.style == r.style && eq_mac_call(&l.mac, &r.mac) && over(&l.attrs, &r.attrs, eq_attr)
 226         },
 227         _ => false,
 228     }
 229 }
 230
 231 pub fn eq_local_kind(l: &LocalKind, r: &LocalKind) -> bool {
 232     use LocalKind::*;
 233     match (l, r) {
 234         (Decl, Decl) => true,
 235         (Init(l), Init(r)) => eq_expr(l, r),
 236         (InitElse(li, le), InitElse(ri, re)) => eq_expr(li, ri) && eq_block(le, re),
 237         _ => false,
 238     }
 239 }
 240
 241 pub fn eq_item<K>(l: &Item<K>, r: &Item<K>, mut eq_kind: impl FnMut(&K, &K) -> bool) -> bool {
 242     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)
 243 }
 244
 245 #[allow(clippy::too_many_lines)] // Just a big match statement
 246 pub fn eq_item_kind(l: &ItemKind, r: &ItemKind) -> bool {
 247     use ItemKind::*;
 248     match (l, r) {
 249         (ExternCrate(l), ExternCrate(r)) => l == r,
 250         (Use(l), Use(r)) => eq_use_tree(l, r),
 251         (Static(lt, lm, le), Static(rt, rm, re)) => lm == rm && eq_ty(lt, rt) && eq_expr_opt(le, re),
 252         (Const(ld, lt, le), Const(rd, rt, re)) => eq_defaultness(*ld, *rd) && eq_ty(lt, rt) && eq_expr_opt(le, re),
 253         (
 254             Fn(box ast::Fn {
 255                 defaultness: ld,
 256                 sig: lf,
 257                 generics: lg,
 258                 body: lb,
 259             }),
 260             Fn(box ast::Fn {
 261                 defaultness: rd,
 262                 sig: rf,
 263                 generics: rg,
 264                 body: rb,
 265             }),
 266         ) => {
 267             eq_defaultness(*ld, *rd) && eq_fn_sig(lf, rf) && eq_generics(lg, rg) && both(lb, rb, |l, r| eq_block(l, r))
 268         },
 269         (Mod(lu, lmk), Mod(ru, rmk)) => {
 270             lu == ru
 271                 && match (lmk, rmk) {
 272                     (ModKind::Loaded(litems, linline, _), ModKind::Loaded(ritems, rinline, _)) => {
 273                         linline == rinline && over(litems, ritems, |l, r| eq_item(l, r, eq_item_kind))
 274                     },
 275                     (ModKind::Unloaded, ModKind::Unloaded) => true,
 276                     _ => false,
 277                 }
 278         },
 279         (ForeignMod(l), ForeignMod(r)) => {
 280             both(&l.abi, &r.abi, eq_str_lit) && over(&l.items, &r.items, |l, r| eq_item(l, r, eq_foreign_item_kind))
 281         },
 282         (
 283             TyAlias(box ast::TyAlias {
 284                 defaultness: ld,
 285                 generics: lg,
 286                 bounds: lb,
 287                 ty: lt,
 288             }),
 289             TyAlias(box ast::TyAlias {
 290                 defaultness: rd,
 291                 generics: rg,
 292                 bounds: rb,
 293                 ty: rt,
 294             }),
 295         ) => {
 296             eq_defaultness(*ld, *rd)
 297                 && eq_generics(lg, rg)
 298                 && over(lb, rb, eq_generic_bound)
 299                 && both(lt, rt, |l, r| eq_ty(l, r))
 300         },
 301         (Enum(le, lg), Enum(re, rg)) => over(&le.variants, &re.variants, eq_variant) && eq_generics(lg, rg),
 302         (Struct(lv, lg), Struct(rv, rg)) | (Union(lv, lg), Union(rv, rg)) => {
 303             eq_variant_data(lv, rv) && eq_generics(lg, rg)
 304         },
 305         (
 306             Trait(box ast::Trait {
 307                 is_auto: la,
 308                 unsafety: lu,
 309                 generics: lg,
 310                 bounds: lb,
 311                 items: li,
 312             }),
 313             Trait(box ast::Trait {
 314                 is_auto: ra,
 315                 unsafety: ru,
 316                 generics: rg,
 317                 bounds: rb,
 318                 items: ri,
 319             }),
 320         ) => {
 321             la == ra
 322                 && matches!(lu, Unsafe::No) == matches!(ru, Unsafe::No)
 323                 && eq_generics(lg, rg)
 324                 && over(lb, rb, eq_generic_bound)
 325                 && over(li, ri, |l, r| eq_item(l, r, eq_assoc_item_kind))
 326         },
 327         (TraitAlias(lg, lb), TraitAlias(rg, rb)) => eq_generics(lg, rg) && over(lb, rb, eq_generic_bound),
 328         (
 329             Impl(box ast::Impl {
 330                 unsafety: lu,
 331                 polarity: lp,
 332                 defaultness: ld,
 333                 constness: lc,
 334                 generics: lg,
 335                 of_trait: lot,
 336                 self_ty: lst,
 337                 items: li,
 338             }),
 339             Impl(box ast::Impl {
 340                 unsafety: ru,
 341                 polarity: rp,
 342                 defaultness: rd,
 343                 constness: rc,
 344                 generics: rg,
 345                 of_trait: rot,
 346                 self_ty: rst,
 347                 items: ri,
 348             }),
 349         ) => {
 350             matches!(lu, Unsafe::No) == matches!(ru, Unsafe::No)
 351                 && matches!(lp, ImplPolarity::Positive) == matches!(rp, ImplPolarity::Positive)
 352                 && eq_defaultness(*ld, *rd)
 353                 && matches!(lc, ast::Const::No) == matches!(rc, ast::Const::No)
 354                 && eq_generics(lg, rg)
 355                 && both(lot, rot, |l, r| eq_path(&l.path, &r.path))
 356                 && eq_ty(lst, rst)
 357                 && over(li, ri, |l, r| eq_item(l, r, eq_assoc_item_kind))
 358         },
 359         (MacCall(l), MacCall(r)) => eq_mac_call(l, r),
 360         (MacroDef(l), MacroDef(r)) => l.macro_rules == r.macro_rules && eq_mac_args(&l.body, &r.body),
 361         _ => false,
 362     }
 363 }
 364
 365 pub fn eq_foreign_item_kind(l: &ForeignItemKind, r: &ForeignItemKind) -> bool {
 366     use ForeignItemKind::*;
 367     match (l, r) {
 368         (Static(lt, lm, le), Static(rt, rm, re)) => lm == rm && eq_ty(lt, rt) && eq_expr_opt(le, re),
 369         (
 370             Fn(box ast::Fn {
 371                 defaultness: ld,
 372                 sig: lf,
 373                 generics: lg,
 374                 body: lb,
 375             }),
 376             Fn(box ast::Fn {
 377                 defaultness: rd,
 378                 sig: rf,
 379                 generics: rg,
 380                 body: rb,
 381             }),
 382         ) => {
 383             eq_defaultness(*ld, *rd) && eq_fn_sig(lf, rf) && eq_generics(lg, rg) && both(lb, rb, |l, r| eq_block(l, r))
 384         },
 385         (
 386             TyAlias(box ast::TyAlias {
 387                 defaultness: ld,
 388                 generics: lg,
 389                 bounds: lb,
 390                 ty: lt,
 391             }),
 392             TyAlias(box ast::TyAlias {
 393                 defaultness: rd,
 394                 generics: rg,
 395                 bounds: rb,
 396                 ty: rt,
 397             }),
 398         ) => {
 399             eq_defaultness(*ld, *rd)
 400                 && eq_generics(lg, rg)
 401                 && over(lb, rb, eq_generic_bound)
 402                 && both(lt, rt, |l, r| eq_ty(l, r))
 403         },
 404         (MacCall(l), MacCall(r)) => eq_mac_call(l, r),
 405         _ => false,
 406     }
 407 }
 408
 409 pub fn eq_assoc_item_kind(l: &AssocItemKind, r: &AssocItemKind) -> bool {
 410     use AssocItemKind::*;
 411     match (l, r) {
 412         (Const(ld, lt, le), Const(rd, rt, re)) => eq_defaultness(*ld, *rd) && eq_ty(lt, rt) && eq_expr_opt(le, re),
 413         (
 414             Fn(box ast::Fn {
 415                 defaultness: ld,
 416                 sig: lf,
 417                 generics: lg,
 418                 body: lb,
 419             }),
 420             Fn(box ast::Fn {
 421                 defaultness: rd,
 422                 sig: rf,
 423                 generics: rg,
 424                 body: rb,
 425             }),
 426         ) => {
 427             eq_defaultness(*ld, *rd) && eq_fn_sig(lf, rf) && eq_generics(lg, rg) && both(lb, rb, |l, r| eq_block(l, r))
 428         },
 429         (
 430             TyAlias(box ast::TyAlias {
 431                 defaultness: ld,
 432                 generics: lg,
 433                 bounds: lb,
 434                 ty: lt,
 435             }),
 436             TyAlias(box ast::TyAlias {
 437                 defaultness: rd,
 438                 generics: rg,
 439                 bounds: rb,
 440                 ty: rt,
 441             }),
 442         ) => {
 443             eq_defaultness(*ld, *rd)
 444                 && eq_generics(lg, rg)
 445                 && over(lb, rb, eq_generic_bound)
 446                 && both(lt, rt, |l, r| eq_ty(l, r))
 447         },
 448         (MacCall(l), MacCall(r)) => eq_mac_call(l, r),
 449         _ => false,
 450     }
 451 }
 452
 453 pub fn eq_variant(l: &Variant, r: &Variant) -> bool {
 454     l.is_placeholder == r.is_placeholder
 455         && over(&l.attrs, &r.attrs, eq_attr)
 456         && eq_vis(&l.vis, &r.vis)
 457         && eq_id(l.ident, r.ident)
 458         && eq_variant_data(&l.data, &r.data)
 459         && both(&l.disr_expr, &r.disr_expr, |l, r| eq_expr(&l.value, &r.value))
 460 }
 461
 462 pub fn eq_variant_data(l: &VariantData, r: &VariantData) -> bool {
 463     use VariantData::*;
 464     match (l, r) {
 465         (Unit(_), Unit(_)) => true,
 466         (Struct(l, _), Struct(r, _)) | (Tuple(l, _), Tuple(r, _)) => over(l, r, eq_struct_field),
 467         _ => false,
 468     }
 469 }
 470
 471 pub fn eq_struct_field(l: &FieldDef, r: &FieldDef) -> bool {
 472     l.is_placeholder == r.is_placeholder
 473         && over(&l.attrs, &r.attrs, eq_attr)
 474         && eq_vis(&l.vis, &r.vis)
 475         && both(&l.ident, &r.ident, |l, r| eq_id(*l, *r))
 476         && eq_ty(&l.ty, &r.ty)
 477 }
 478
 479 pub fn eq_fn_sig(l: &FnSig, r: &FnSig) -> bool {
 480     eq_fn_decl(&l.decl, &r.decl) && eq_fn_header(&l.header, &r.header)
 481 }
 482
 483 pub fn eq_fn_header(l: &FnHeader, r: &FnHeader) -> bool {
 484     matches!(l.unsafety, Unsafe::No) == matches!(r.unsafety, Unsafe::No)
 485         && l.asyncness.is_async() == r.asyncness.is_async()
 486         && matches!(l.constness, Const::No) == matches!(r.constness, Const::No)
 487         && eq_ext(&l.ext, &r.ext)
 488 }
 489
 490 pub fn eq_generics(l: &Generics, r: &Generics) -> bool {
 491     over(&l.params, &r.params, eq_generic_param)
 492         && over(&l.where_clause.predicates, &r.where_clause.predicates, |l, r| {
 493             eq_where_predicate(l, r)
 494         })
 495 }
 496
 497 pub fn eq_where_predicate(l: &WherePredicate, r: &WherePredicate) -> bool {
 498     use WherePredicate::*;
 499     match (l, r) {
 500         (BoundPredicate(l), BoundPredicate(r)) => {
 501             over(&l.bound_generic_params, &r.bound_generic_params, |l, r| {
 502                 eq_generic_param(l, r)
 503             }) && eq_ty(&l.bounded_ty, &r.bounded_ty)
 504                 && over(&l.bounds, &r.bounds, eq_generic_bound)
 505         },
 506         (RegionPredicate(l), RegionPredicate(r)) => {
 507             eq_id(l.lifetime.ident, r.lifetime.ident) && over(&l.bounds, &r.bounds, eq_generic_bound)
 508         },
 509         (EqPredicate(l), EqPredicate(r)) => eq_ty(&l.lhs_ty, &r.lhs_ty) && eq_ty(&l.rhs_ty, &r.rhs_ty),
 510         _ => false,
 511     }
 512 }
 513
 514 pub fn eq_use_tree(l: &UseTree, r: &UseTree) -> bool {
 515     eq_path(&l.prefix, &r.prefix) && eq_use_tree_kind(&l.kind, &r.kind)
 516 }
 517
 518 pub fn eq_anon_const(l: &AnonConst, r: &AnonConst) -> bool {
 519     eq_expr(&l.value, &r.value)
 520 }
 521
 522 pub fn eq_use_tree_kind(l: &UseTreeKind, r: &UseTreeKind) -> bool {
 523     use UseTreeKind::*;
 524     match (l, r) {
 525         (Glob, Glob) => true,
 526         (Simple(l, _, _), Simple(r, _, _)) => both(l, r, |l, r| eq_id(*l, *r)),
 527         (Nested(l), Nested(r)) => over(l, r, |(l, _), (r, _)| eq_use_tree(l, r)),
 528         _ => false,
 529     }
 530 }
 531
 532 pub fn eq_defaultness(l: Defaultness, r: Defaultness) -> bool {
 533     matches!(
 534         (l, r),
 535         (Defaultness::Final, Defaultness::Final) | (Defaultness::Default(_), Defaultness::Default(_))
 536     )
 537 }
 538
 539 pub fn eq_vis(l: &Visibility, r: &Visibility) -> bool {
 540     use VisibilityKind::*;
 541     match (&l.kind, &r.kind) {
 542         (Public, Public) | (Inherited, Inherited) | (Crate(_), Crate(_)) => true,
 543         (Restricted { path: l, .. }, Restricted { path: r, .. }) => eq_path(l, r),
 544         _ => false,
 545     }
 546 }
 547
 548 pub fn eq_fn_decl(l: &FnDecl, r: &FnDecl) -> bool {
 549     eq_fn_ret_ty(&l.output, &r.output)
 550         && over(&l.inputs, &r.inputs, |l, r| {
 551             l.is_placeholder == r.is_placeholder
 552                 && eq_pat(&l.pat, &r.pat)
 553                 && eq_ty(&l.ty, &r.ty)
 554                 && over(&l.attrs, &r.attrs, eq_attr)
 555         })
 556 }
 557
 558 pub fn eq_fn_ret_ty(l: &FnRetTy, r: &FnRetTy) -> bool {
 559     match (l, r) {
 560         (FnRetTy::Default(_), FnRetTy::Default(_)) => true,
 561         (FnRetTy::Ty(l), FnRetTy::Ty(r)) => eq_ty(l, r),
 562         _ => false,
 563     }
 564 }
 565
 566 pub fn eq_ty(l: &Ty, r: &Ty) -> bool {
 567     use TyKind::*;
 568     match (&l.kind, &r.kind) {
 569         (Paren(l), _) => eq_ty(l, r),
 570         (_, Paren(r)) => eq_ty(l, r),
 571         (Never, Never) | (Infer, Infer) | (ImplicitSelf, ImplicitSelf) | (Err, Err) | (CVarArgs, CVarArgs) => true,
 572         (Slice(l), Slice(r)) => eq_ty(l, r),
 573         (Array(le, ls), Array(re, rs)) => eq_ty(le, re) && eq_expr(&ls.value, &rs.value),
 574         (Ptr(l), Ptr(r)) => l.mutbl == r.mutbl && eq_ty(&l.ty, &r.ty),
 575         (Rptr(ll, l), Rptr(rl, r)) => {
 576             both(ll, rl, |l, r| eq_id(l.ident, r.ident)) && l.mutbl == r.mutbl && eq_ty(&l.ty, &r.ty)
 577         },
 578         (BareFn(l), BareFn(r)) => {
 579             l.unsafety == r.unsafety
 580                 && eq_ext(&l.ext, &r.ext)
 581                 && over(&l.generic_params, &r.generic_params, eq_generic_param)
 582                 && eq_fn_decl(&l.decl, &r.decl)
 583         },
 584         (Tup(l), Tup(r)) => over(l, r, |l, r| eq_ty(l, r)),
 585         (Path(lq, lp), Path(rq, rp)) => both(lq, rq, eq_qself) && eq_path(lp, rp),
 586         (TraitObject(lg, ls), TraitObject(rg, rs)) => ls == rs && over(lg, rg, eq_generic_bound),
 587         (ImplTrait(_, lg), ImplTrait(_, rg)) => over(lg, rg, eq_generic_bound),
 588         (Typeof(l), Typeof(r)) => eq_expr(&l.value, &r.value),
 589         (MacCall(l), MacCall(r)) => eq_mac_call(l, r),
 590         _ => false,
 591     }
 592 }
 593
 594 pub fn eq_ext(l: &Extern, r: &Extern) -> bool {
 595     use Extern::*;
 596     match (l, r) {
 597         (None, None) | (Implicit, Implicit) => true,
 598         (Explicit(l), Explicit(r)) => eq_str_lit(l, r),
 599         _ => false,
 600     }
 601 }
 602
 603 pub fn eq_str_lit(l: &StrLit, r: &StrLit) -> bool {
 604     l.style == r.style && l.symbol == r.symbol && l.suffix == r.suffix
 605 }
 606
 607 pub fn eq_poly_ref_trait(l: &PolyTraitRef, r: &PolyTraitRef) -> bool {
 608     eq_path(&l.trait_ref.path, &r.trait_ref.path)
 609         && over(&l.bound_generic_params, &r.bound_generic_params, |l, r| {
 610             eq_generic_param(l, r)
 611         })
 612 }
 613
 614 pub fn eq_generic_param(l: &GenericParam, r: &GenericParam) -> bool {
 615     use GenericParamKind::*;
 616     l.is_placeholder == r.is_placeholder
 617         && eq_id(l.ident, r.ident)
 618         && over(&l.bounds, &r.bounds, eq_generic_bound)
 619         && match (&l.kind, &r.kind) {
 620             (Lifetime, Lifetime) => true,
 621             (Type { default: l }, Type { default: r }) => both(l, r, |l, r| eq_ty(l, r)),
 622             (
 623                 Const {
 624                     ty: lt,
 625                     kw_span: _,
 626                     default: ld,
 627                 },
 628                 Const {
 629                     ty: rt,
 630                     kw_span: _,
 631                     default: rd,
 632                 },
 633             ) => eq_ty(lt, rt) && both(ld, rd, eq_anon_const),
 634             _ => false,
 635         }
 636         && over(&l.attrs, &r.attrs, eq_attr)
 637 }
 638
 639 pub fn eq_generic_bound(l: &GenericBound, r: &GenericBound) -> bool {
 640     use GenericBound::*;
 641     match (l, r) {
 642         (Trait(ptr1, tbm1), Trait(ptr2, tbm2)) => tbm1 == tbm2 && eq_poly_ref_trait(ptr1, ptr2),
 643         (Outlives(l), Outlives(r)) => eq_id(l.ident, r.ident),
 644         _ => false,
 645     }
 646 }
 647
 648 fn eq_term(l: &Term, r: &Term) -> bool {
 649     match (l, r) {
 650         (Term::Ty(l), Term::Ty(r)) => eq_ty(l, r),
 651         (Term::Const(l), Term::Const(r)) => eq_anon_const(l, r),
 652         _ => false,
 653     }
 654 }
 655
 656 pub fn eq_assoc_constraint(l: &AssocConstraint, r: &AssocConstraint) -> bool {
 657     use AssocConstraintKind::*;
 658     eq_id(l.ident, r.ident)
 659         && match (&l.kind, &r.kind) {
 660             (Equality { term: l }, Equality { term: r }) => eq_term(l, r),
 661             (Bound { bounds: l }, Bound { bounds: r }) => over(l, r, eq_generic_bound),
 662             _ => false,
 663         }
 664 }
 665
 666 pub fn eq_mac_call(l: &MacCall, r: &MacCall) -> bool {
 667     eq_path(&l.path, &r.path) && eq_mac_args(&l.args, &r.args)
 668 }
 669
 670 pub fn eq_attr(l: &Attribute, r: &Attribute) -> bool {
 671     use AttrKind::*;
 672     l.style == r.style
 673         && match (&l.kind, &r.kind) {
 674             (DocComment(l1, l2), DocComment(r1, r2)) => l1 == r1 && l2 == r2,
 675             (Normal(l, _), Normal(r, _)) => eq_path(&l.path, &r.path) && eq_mac_args(&l.args, &r.args),
 676             _ => false,
 677         }
 678 }
 679
 680 pub fn eq_mac_args(l: &MacArgs, r: &MacArgs) -> bool {
 681     use MacArgs::*;
 682     match (l, r) {
 683         (Empty, Empty) => true,
 684         (Delimited(_, ld, lts), Delimited(_, rd, rts)) => ld == rd && lts.eq_unspanned(rts),
 685         (Eq(_, lt), Eq(_, rt)) => lt.kind == rt.kind,
 686         _ => false,
 687     }
 688 }