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 if_chain::if_chain;
   9 use rustc_ast::ptr::P;
  10 use rustc_ast::{self as ast, *};
  11 use rustc_span::symbol::Ident;
  12 use std::mem;
  13
  14 pub mod ident_iter;
  15 pub use ident_iter::IdentIter;
  16
  17 pub fn is_useless_with_eq_exprs(kind: BinOpKind) -> bool {
  18     use BinOpKind::*;
  19     matches!(
  20         kind,
  21         Sub | Div | Eq | Lt | Le | Gt | Ge | Ne | And | Or | BitXor | BitAnd | BitOr
  22     )
  23 }
  24
  25 /// Checks if each element in the first slice is contained within the latter as per `eq_fn`.
  26 pub fn unordered_over<X>(left: &[X], right: &[X], mut eq_fn: impl FnMut(&X, &X) -> bool) -> bool {
  27     left.len() == right.len() && left.iter().all(|l| right.iter().any(|r| eq_fn(l, r)))
  28 }
  29
  30 pub fn eq_id(l: Ident, r: Ident) -> bool {
  31     l.name == r.name
  32 }
  33
  34 pub fn eq_pat(l: &Pat, r: &Pat) -> bool {
  35     use PatKind::*;
  36     match (&l.kind, &r.kind) {
  37         (Paren(l), _) => eq_pat(l, r),
  38         (_, Paren(r)) => eq_pat(l, r),
  39         (Wild, Wild) | (Rest, Rest) => true,
  40         (Lit(l), Lit(r)) => eq_expr(l, r),
  41         (Ident(b1, i1, s1), Ident(b2, i2, s2)) => b1 == b2 && eq_id(*i1, *i2) && both(s1, s2, |l, r| eq_pat(l, r)),
  42         (Range(lf, lt, le), Range(rf, rt, re)) => {
  43             eq_expr_opt(lf, rf) && eq_expr_opt(lt, rt) && eq_range_end(&le.node, &re.node)
  44         },
  45         (Box(l), Box(r))
  46         | (Ref(l, Mutability::Not), Ref(r, Mutability::Not))
  47         | (Ref(l, Mutability::Mut), Ref(r, Mutability::Mut)) => eq_pat(l, r),
  48         (Tuple(l), Tuple(r)) | (Slice(l), Slice(r)) => over(l, r, |l, r| eq_pat(l, r)),
  49         (Path(lq, lp), Path(rq, rp)) => both(lq, rq, |l, r| eq_qself(l, r)) && eq_path(lp, rp),
  50         (TupleStruct(lp, lfs), TupleStruct(rp, rfs)) => eq_path(lp, rp) && over(lfs, rfs, |l, r| eq_pat(l, r)),
  51         (Struct(lp, lfs, lr), Struct(rp, rfs, rr)) => {
  52             lr == rr && eq_path(lp, rp) && unordered_over(lfs, rfs, |lf, rf| eq_field_pat(lf, rf))
  53         },
  54         (Or(ls), Or(rs)) => unordered_over(ls, rs, |l, r| eq_pat(l, r)),
  55         (MacCall(l), MacCall(r)) => eq_mac_call(l, r),
  56         _ => false,
  57     }
  58 }
  59
  60 pub fn eq_range_end(l: &RangeEnd, r: &RangeEnd) -> bool {
  61     match (l, r) {
  62         (RangeEnd::Excluded, RangeEnd::Excluded) => true,
  63         (RangeEnd::Included(l), RangeEnd::Included(r)) => {
  64             matches!(l, RangeSyntax::DotDotEq) == matches!(r, RangeSyntax::DotDotEq)
  65         },
  66         _ => false,
  67     }
  68 }
  69
  70 pub fn eq_field_pat(l: &PatField, r: &PatField) -> bool {
  71     l.is_placeholder == r.is_placeholder
  72         && eq_id(l.ident, r.ident)
  73         && eq_pat(&l.pat, &r.pat)
  74         && over(&l.attrs, &r.attrs, |l, r| eq_attr(l, r))
  75 }
  76
  77 pub fn eq_qself(l: &QSelf, r: &QSelf) -> bool {
  78     l.position == r.position && eq_ty(&l.ty, &r.ty)
  79 }
  80
  81 pub fn eq_path(l: &Path, r: &Path) -> bool {
  82     over(&l.segments, &r.segments, |l, r| eq_path_seg(l, r))
  83 }
  84
  85 pub fn eq_path_seg(l: &PathSegment, r: &PathSegment) -> bool {
  86     eq_id(l.ident, r.ident) && both(&l.args, &r.args, |l, r| eq_generic_args(l, r))
  87 }
  88
  89 pub fn eq_generic_args(l: &GenericArgs, r: &GenericArgs) -> bool {
  90     match (l, r) {
  91         (GenericArgs::AngleBracketed(l), GenericArgs::AngleBracketed(r)) => {
  92             over(&l.args, &r.args, |l, r| eq_angle_arg(l, r))
  93         },
  94         (GenericArgs::Parenthesized(l), GenericArgs::Parenthesized(r)) => {
  95             over(&l.inputs, &r.inputs, |l, r| eq_ty(l, r)) && eq_fn_ret_ty(&l.output, &r.output)
  96         },
  97         _ => false,
  98     }
  99 }
 100
 101 pub fn eq_angle_arg(l: &AngleBracketedArg, r: &AngleBracketedArg) -> bool {
 102     match (l, r) {
 103         (AngleBracketedArg::Arg(l), AngleBracketedArg::Arg(r)) => eq_generic_arg(l, r),
 104         (AngleBracketedArg::Constraint(l), AngleBracketedArg::Constraint(r)) => eq_assoc_constraint(l, r),
 105         _ => false,
 106     }
 107 }
 108
 109 pub fn eq_generic_arg(l: &GenericArg, r: &GenericArg) -> bool {
 110     match (l, r) {
 111         (GenericArg::Lifetime(l), GenericArg::Lifetime(r)) => eq_id(l.ident, r.ident),
 112         (GenericArg::Type(l), GenericArg::Type(r)) => eq_ty(l, r),
 113         (GenericArg::Const(l), GenericArg::Const(r)) => eq_expr(&l.value, &r.value),
 114         _ => false,
 115     }
 116 }
 117
 118 pub fn eq_expr_opt(l: &Option<P<Expr>>, r: &Option<P<Expr>>) -> bool {
 119     both(l, r, |l, r| eq_expr(l, r))
 120 }
 121
 122 pub fn eq_struct_rest(l: &StructRest, r: &StructRest) -> bool {
 123     match (l, r) {
 124         (StructRest::Base(lb), StructRest::Base(rb)) => eq_expr(lb, rb),
 125         (StructRest::Rest(_), StructRest::Rest(_)) | (StructRest::None, StructRest::None) => true,
 126         _ => false,
 127     }
 128 }
 129
 130 pub fn eq_expr(l: &Expr, r: &Expr) -> bool {
 131     use ExprKind::*;
 132     if !over(&l.attrs, &r.attrs, |l, r| eq_attr(l, r)) {
 133         return false;
 134     }
 135     match (&l.kind, &r.kind) {
 136         (Paren(l), _) => eq_expr(l, r),
 137         (_, Paren(r)) => eq_expr(l, r),
 138         (Err, Err) => true,
 139         (Box(l), Box(r)) | (Try(l), Try(r)) | (Await(l), Await(r)) => eq_expr(l, r),
 140         (Array(l), Array(r)) | (Tup(l), Tup(r)) => over(l, r, |l, r| eq_expr(l, r)),
 141         (Repeat(le, ls), Repeat(re, rs)) => eq_expr(le, re) && eq_expr(&ls.value, &rs.value),
 142         (Call(lc, la), Call(rc, ra)) => eq_expr(lc, rc) && over(la, ra, |l, r| eq_expr(l, r)),
 143         (MethodCall(lc, la, _), MethodCall(rc, ra, _)) => eq_path_seg(lc, rc) && over(la, ra, |l, r| eq_expr(l, r)),
 144         (Binary(lo, ll, lr), Binary(ro, rl, rr)) => lo.node == ro.node && eq_expr(ll, rl) && eq_expr(lr, rr),
 145         (Unary(lo, l), Unary(ro, r)) => mem::discriminant(lo) == mem::discriminant(ro) && eq_expr(l, r),
 146         (Lit(l), Lit(r)) => l.kind == r.kind,
 147         (Cast(l, lt), Cast(r, rt)) | (Type(l, lt), Type(r, rt)) => eq_expr(l, r) && eq_ty(lt, rt),
 148         (Let(lp, le), Let(rp, re)) => eq_pat(lp, rp) && eq_expr(le, re),
 149         (If(lc, lt, le), If(rc, rt, re)) => eq_expr(lc, rc) && eq_block(lt, rt) && eq_expr_opt(le, re),
 150         (While(lc, lt, ll), While(rc, rt, rl)) => eq_label(ll, rl) && eq_expr(lc, rc) && eq_block(lt, rt),
 151         (ForLoop(lp, li, lt, ll), ForLoop(rp, ri, rt, rl)) => {
 152             eq_label(ll, rl) && eq_pat(lp, rp) && eq_expr(li, ri) && eq_block(lt, rt)
 153         },
 154         (Loop(lt, ll), Loop(rt, rl)) => eq_label(ll, rl) && eq_block(lt, rt),
 155         (Block(lb, ll), Block(rb, rl)) => eq_label(ll, rl) && eq_block(lb, rb),
 156         (TryBlock(l), TryBlock(r)) => eq_block(l, r),
 157         (Yield(l), Yield(r)) | (Ret(l), Ret(r)) => eq_expr_opt(l, r),
 158         (Break(ll, le), Break(rl, re)) => eq_label(ll, rl) && eq_expr_opt(le, re),
 159         (Continue(ll), Continue(rl)) => eq_label(ll, rl),
 160         (Assign(l1, l2, _), Assign(r1, r2, _)) | (Index(l1, l2), Index(r1, r2)) => eq_expr(l1, r1) && eq_expr(l2, r2),
 161         (AssignOp(lo, lp, lv), AssignOp(ro, rp, rv)) => lo.node == ro.node && eq_expr(lp, rp) && eq_expr(lv, rv),
 162         (Field(lp, lf), Field(rp, rf)) => eq_id(*lf, *rf) && eq_expr(lp, rp),
 163         (Match(ls, la), Match(rs, ra)) => eq_expr(ls, rs) && over(la, ra, |l, r| eq_arm(l, r)),
 164         (Closure(lc, la, lm, lf, lb, _), Closure(rc, ra, rm, rf, rb, _)) => {
 165             lc == rc && la.is_async() == ra.is_async() && lm == rm && eq_fn_decl(lf, rf) && eq_expr(lb, rb)
 166         },
 167         (Async(lc, _, lb), Async(rc, _, rb)) => lc == rc && eq_block(lb, rb),
 168         (Range(lf, lt, ll), Range(rf, rt, rl)) => ll == rl && eq_expr_opt(lf, rf) && eq_expr_opt(lt, rt),
 169         (AddrOf(lbk, lm, le), AddrOf(rbk, rm, re)) => lbk == rbk && lm == rm && eq_expr(le, re),
 170         (Path(lq, lp), Path(rq, rp)) => both(lq, rq, |l, r| eq_qself(l, r)) && eq_path(lp, rp),
 171         (MacCall(l), MacCall(r)) => eq_mac_call(l, r),
 172         (Struct(lse), Struct(rse)) => {
 173             eq_path(&lse.path, &rse.path)
 174                 && eq_struct_rest(&lse.rest, &rse.rest)
 175                 && unordered_over(&lse.fields, &rse.fields, |l, r| eq_field(l, r))
 176         },
 177         _ => false,
 178     }
 179 }
 180
 181 pub fn eq_field(l: &ExprField, r: &ExprField) -> bool {
 182     l.is_placeholder == r.is_placeholder
 183         && eq_id(l.ident, r.ident)
 184         && eq_expr(&l.expr, &r.expr)
 185         && over(&l.attrs, &r.attrs, |l, r| eq_attr(l, r))
 186 }
 187
 188 pub fn eq_arm(l: &Arm, r: &Arm) -> bool {
 189     l.is_placeholder == r.is_placeholder
 190         && eq_pat(&l.pat, &r.pat)
 191         && eq_expr(&l.body, &r.body)
 192         && eq_expr_opt(&l.guard, &r.guard)
 193         && over(&l.attrs, &r.attrs, |l, r| eq_attr(l, r))
 194 }
 195
 196 pub fn eq_label(l: &Option<Label>, r: &Option<Label>) -> bool {
 197     both(l, r, |l, r| eq_id(l.ident, r.ident))
 198 }
 199
 200 pub fn eq_block(l: &Block, r: &Block) -> bool {
 201     l.rules == r.rules && over(&l.stmts, &r.stmts, |l, r| eq_stmt(l, r))
 202 }
 203
 204 pub fn eq_stmt(l: &Stmt, r: &Stmt) -> bool {
 205     use StmtKind::*;
 206     match (&l.kind, &r.kind) {
 207         (Local(l), Local(r)) => {
 208             eq_pat(&l.pat, &r.pat)
 209                 && both(&l.ty, &r.ty, |l, r| eq_ty(l, r))
 210                 && eq_expr_opt(&l.init, &r.init)
 211                 && over(&l.attrs, &r.attrs, |l, r| eq_attr(l, r))
 212         },
 213         (Item(l), Item(r)) => eq_item(l, r, eq_item_kind),
 214         (Expr(l), Expr(r)) | (Semi(l), Semi(r)) => eq_expr(l, r),
 215         (Empty, Empty) => true,
 216         (MacCall(l), MacCall(r)) => {
 217             l.style == r.style && eq_mac_call(&l.mac, &r.mac) && over(&l.attrs, &r.attrs, |l, r| eq_attr(l, r))
 218         },
 219         _ => false,
 220     }
 221 }
 222
 223 pub fn eq_item<K>(l: &Item<K>, r: &Item<K>, mut eq_kind: impl FnMut(&K, &K) -> bool) -> bool {
 224     eq_id(l.ident, r.ident)
 225         && over(&l.attrs, &r.attrs, |l, r| eq_attr(l, r))
 226         && eq_vis(&l.vis, &r.vis)
 227         && eq_kind(&l.kind, &r.kind)
 228 }
 229
 230 pub fn eq_item_kind(l: &ItemKind, r: &ItemKind) -> bool {
 231     use ItemKind::*;
 232     match (l, r) {
 233         (ExternCrate(l), ExternCrate(r)) => l == r,
 234         (Use(l), Use(r)) => eq_use_tree(l, r),
 235         (Static(lt, lm, le), Static(rt, rm, re)) => lm == rm && eq_ty(lt, rt) && eq_expr_opt(le, re),
 236         (Const(ld, lt, le), Const(rd, rt, re)) => eq_defaultness(*ld, *rd) && eq_ty(lt, rt) && eq_expr_opt(le, re),
 237         (Fn(box FnKind(ld, lf, lg, lb)), Fn(box FnKind(rd, rf, rg, rb))) => {
 238             eq_defaultness(*ld, *rd) && eq_fn_sig(lf, rf) && eq_generics(lg, rg) && both(lb, rb, |l, r| eq_block(l, r))
 239         },
 240         (Mod(lu, lmk), Mod(ru, rmk)) => {
 241             lu == ru
 242                 && match (lmk, rmk) {
 243                     (ModKind::Loaded(litems, linline, _), ModKind::Loaded(ritems, rinline, _)) => {
 244                         linline == rinline && over(litems, ritems, |l, r| eq_item(l, r, eq_item_kind))
 245                     },
 246                     (ModKind::Unloaded, ModKind::Unloaded) => true,
 247                     _ => false,
 248                 }
 249         },
 250         (ForeignMod(l), ForeignMod(r)) => {
 251             both(&l.abi, &r.abi, |l, r| eq_str_lit(l, r))
 252                 && over(&l.items, &r.items, |l, r| eq_item(l, r, eq_foreign_item_kind))
 253         },
 254         (TyAlias(box TyAliasKind(ld, lg, lb, lt)), TyAlias(box TyAliasKind(rd, rg, rb, rt))) => {
 255             eq_defaultness(*ld, *rd)
 256                 && eq_generics(lg, rg)
 257                 && over(lb, rb, |l, r| eq_generic_bound(l, r))
 258                 && both(lt, rt, |l, r| eq_ty(l, r))
 259         },
 260         (Enum(le, lg), Enum(re, rg)) => {
 261             over(&le.variants, &re.variants, |l, r| eq_variant(l, r)) && eq_generics(lg, rg)
 262         },
 263         (Struct(lv, lg), Struct(rv, rg)) | (Union(lv, lg), Union(rv, rg)) => {
 264             eq_variant_data(lv, rv) && eq_generics(lg, rg)
 265         },
 266         (Trait(box TraitKind(la, lu, lg, lb, li)), Trait(box TraitKind(ra, ru, rg, rb, ri))) => {
 267             la == ra
 268                 && matches!(lu, Unsafe::No) == matches!(ru, Unsafe::No)
 269                 && eq_generics(lg, rg)
 270                 && over(lb, rb, |l, r| eq_generic_bound(l, r))
 271                 && over(li, ri, |l, r| eq_item(l, r, eq_assoc_item_kind))
 272         },
 273         (TraitAlias(lg, lb), TraitAlias(rg, rb)) => eq_generics(lg, rg) && over(lb, rb, |l, r| eq_generic_bound(l, r)),
 274         (
 275             Impl(box ImplKind {
 276                 unsafety: lu,
 277                 polarity: lp,
 278                 defaultness: ld,
 279                 constness: lc,
 280                 generics: lg,
 281                 of_trait: lot,
 282                 self_ty: lst,
 283                 items: li,
 284             }),
 285             Impl(box ImplKind {
 286                 unsafety: ru,
 287                 polarity: rp,
 288                 defaultness: rd,
 289                 constness: rc,
 290                 generics: rg,
 291                 of_trait: rot,
 292                 self_ty: rst,
 293                 items: ri,
 294             }),
 295         ) => {
 296             matches!(lu, Unsafe::No) == matches!(ru, Unsafe::No)
 297                 && matches!(lp, ImplPolarity::Positive) == matches!(rp, ImplPolarity::Positive)
 298                 && eq_defaultness(*ld, *rd)
 299                 && matches!(lc, ast::Const::No) == matches!(rc, ast::Const::No)
 300                 && eq_generics(lg, rg)
 301                 && both(lot, rot, |l, r| eq_path(&l.path, &r.path))
 302                 && eq_ty(lst, rst)
 303                 && over(li, ri, |l, r| eq_item(l, r, eq_assoc_item_kind))
 304         },
 305         (MacCall(l), MacCall(r)) => eq_mac_call(l, r),
 306         (MacroDef(l), MacroDef(r)) => l.macro_rules == r.macro_rules && eq_mac_args(&l.body, &r.body),
 307         _ => false,
 308     }
 309 }
 310
 311 pub fn eq_foreign_item_kind(l: &ForeignItemKind, r: &ForeignItemKind) -> bool {
 312     use ForeignItemKind::*;
 313     match (l, r) {
 314         (Static(lt, lm, le), Static(rt, rm, re)) => lm == rm && eq_ty(lt, rt) && eq_expr_opt(le, re),
 315         (Fn(box FnKind(ld, lf, lg, lb)), Fn(box FnKind(rd, rf, rg, rb))) => {
 316             eq_defaultness(*ld, *rd) && eq_fn_sig(lf, rf) && eq_generics(lg, rg) && both(lb, rb, |l, r| eq_block(l, r))
 317         },
 318         (TyAlias(box TyAliasKind(ld, lg, lb, lt)), TyAlias(box TyAliasKind(rd, rg, rb, rt))) => {
 319             eq_defaultness(*ld, *rd)
 320                 && eq_generics(lg, rg)
 321                 && over(lb, rb, |l, r| eq_generic_bound(l, r))
 322                 && both(lt, rt, |l, r| eq_ty(l, r))
 323         },
 324         (MacCall(l), MacCall(r)) => eq_mac_call(l, r),
 325         _ => false,
 326     }
 327 }
 328
 329 pub fn eq_assoc_item_kind(l: &AssocItemKind, r: &AssocItemKind) -> bool {
 330     use AssocItemKind::*;
 331     match (l, r) {
 332         (Const(ld, lt, le), Const(rd, rt, re)) => eq_defaultness(*ld, *rd) && eq_ty(lt, rt) && eq_expr_opt(le, re),
 333         (Fn(box FnKind(ld, lf, lg, lb)), Fn(box FnKind(rd, rf, rg, rb))) => {
 334             eq_defaultness(*ld, *rd) && eq_fn_sig(lf, rf) && eq_generics(lg, rg) && both(lb, rb, |l, r| eq_block(l, r))
 335         },
 336         (TyAlias(box TyAliasKind(ld, lg, lb, lt)), TyAlias(box TyAliasKind(rd, rg, rb, rt))) => {
 337             eq_defaultness(*ld, *rd)
 338                 && eq_generics(lg, rg)
 339                 && over(lb, rb, |l, r| eq_generic_bound(l, r))
 340                 && both(lt, rt, |l, r| eq_ty(l, r))
 341         },
 342         (MacCall(l), MacCall(r)) => eq_mac_call(l, r),
 343         _ => false,
 344     }
 345 }
 346
 347 pub fn eq_variant(l: &Variant, r: &Variant) -> bool {
 348     l.is_placeholder == r.is_placeholder
 349         && over(&l.attrs, &r.attrs, |l, r| eq_attr(l, r))
 350         && eq_vis(&l.vis, &r.vis)
 351         && eq_id(l.ident, r.ident)
 352         && eq_variant_data(&l.data, &r.data)
 353         && both(&l.disr_expr, &r.disr_expr, |l, r| eq_expr(&l.value, &r.value))
 354 }
 355
 356 pub fn eq_variant_data(l: &VariantData, r: &VariantData) -> bool {
 357     use VariantData::*;
 358     match (l, r) {
 359         (Unit(_), Unit(_)) => true,
 360         (Struct(l, _), Struct(r, _)) | (Tuple(l, _), Tuple(r, _)) => over(l, r, |l, r| eq_struct_field(l, r)),
 361         _ => false,
 362     }
 363 }
 364
 365 pub fn eq_struct_field(l: &FieldDef, r: &FieldDef) -> bool {
 366     l.is_placeholder == r.is_placeholder
 367         && over(&l.attrs, &r.attrs, |l, r| eq_attr(l, r))
 368         && eq_vis(&l.vis, &r.vis)
 369         && both(&l.ident, &r.ident, |l, r| eq_id(*l, *r))
 370         && eq_ty(&l.ty, &r.ty)
 371 }
 372
 373 pub fn eq_fn_sig(l: &FnSig, r: &FnSig) -> bool {
 374     eq_fn_decl(&l.decl, &r.decl) && eq_fn_header(&l.header, &r.header)
 375 }
 376
 377 pub fn eq_fn_header(l: &FnHeader, r: &FnHeader) -> bool {
 378     matches!(l.unsafety, Unsafe::No) == matches!(r.unsafety, Unsafe::No)
 379         && l.asyncness.is_async() == r.asyncness.is_async()
 380         && matches!(l.constness, Const::No) == matches!(r.constness, Const::No)
 381         && eq_ext(&l.ext, &r.ext)
 382 }
 383
 384 pub fn eq_generics(l: &Generics, r: &Generics) -> bool {
 385     over(&l.params, &r.params, |l, r| eq_generic_param(l, r))
 386         && over(&l.where_clause.predicates, &r.where_clause.predicates, |l, r| {
 387             eq_where_predicate(l, r)
 388         })
 389 }
 390
 391 pub fn eq_where_predicate(l: &WherePredicate, r: &WherePredicate) -> bool {
 392     use WherePredicate::*;
 393     match (l, r) {
 394         (BoundPredicate(l), BoundPredicate(r)) => {
 395             over(&l.bound_generic_params, &r.bound_generic_params, |l, r| {
 396                 eq_generic_param(l, r)
 397             }) && eq_ty(&l.bounded_ty, &r.bounded_ty)
 398                 && over(&l.bounds, &r.bounds, |l, r| eq_generic_bound(l, r))
 399         },
 400         (RegionPredicate(l), RegionPredicate(r)) => {
 401             eq_id(l.lifetime.ident, r.lifetime.ident) && over(&l.bounds, &r.bounds, |l, r| eq_generic_bound(l, r))
 402         },
 403         (EqPredicate(l), EqPredicate(r)) => eq_ty(&l.lhs_ty, &r.lhs_ty) && eq_ty(&l.rhs_ty, &r.rhs_ty),
 404         _ => false,
 405     }
 406 }
 407
 408 pub fn eq_use_tree(l: &UseTree, r: &UseTree) -> bool {
 409     eq_path(&l.prefix, &r.prefix) && eq_use_tree_kind(&l.kind, &r.kind)
 410 }
 411
 412 pub fn eq_anon_const(l: &AnonConst, r: &AnonConst) -> bool {
 413     eq_expr(&l.value, &r.value)
 414 }
 415
 416 pub fn eq_use_tree_kind(l: &UseTreeKind, r: &UseTreeKind) -> bool {
 417     use UseTreeKind::*;
 418     match (l, r) {
 419         (Glob, Glob) => true,
 420         (Simple(l, _, _), Simple(r, _, _)) => both(l, r, |l, r| eq_id(*l, *r)),
 421         (Nested(l), Nested(r)) => over(l, r, |(l, _), (r, _)| eq_use_tree(l, r)),
 422         _ => false,
 423     }
 424 }
 425
 426 pub fn eq_defaultness(l: Defaultness, r: Defaultness) -> bool {
 427     matches!(
 428         (l, r),
 429         (Defaultness::Final, Defaultness::Final) | (Defaultness::Default(_), Defaultness::Default(_))
 430     )
 431 }
 432
 433 pub fn eq_vis(l: &Visibility, r: &Visibility) -> bool {
 434     use VisibilityKind::*;
 435     match (&l.kind, &r.kind) {
 436         (Public, Public) | (Inherited, Inherited) | (Crate(_), Crate(_)) => true,
 437         (Restricted { path: l, .. }, Restricted { path: r, .. }) => eq_path(l, r),
 438         _ => false,
 439     }
 440 }
 441
 442 pub fn eq_fn_decl(l: &FnDecl, r: &FnDecl) -> bool {
 443     eq_fn_ret_ty(&l.output, &r.output)
 444         && over(&l.inputs, &r.inputs, |l, r| {
 445             l.is_placeholder == r.is_placeholder
 446                 && eq_pat(&l.pat, &r.pat)
 447                 && eq_ty(&l.ty, &r.ty)
 448                 && over(&l.attrs, &r.attrs, |l, r| eq_attr(l, r))
 449         })
 450 }
 451
 452 pub fn eq_fn_ret_ty(l: &FnRetTy, r: &FnRetTy) -> bool {
 453     match (l, r) {
 454         (FnRetTy::Default(_), FnRetTy::Default(_)) => true,
 455         (FnRetTy::Ty(l), FnRetTy::Ty(r)) => eq_ty(l, r),
 456         _ => false,
 457     }
 458 }
 459
 460 pub fn eq_ty(l: &Ty, r: &Ty) -> bool {
 461     use TyKind::*;
 462     match (&l.kind, &r.kind) {
 463         (Paren(l), _) => eq_ty(l, r),
 464         (_, Paren(r)) => eq_ty(l, r),
 465         (Never, Never) | (Infer, Infer) | (ImplicitSelf, ImplicitSelf) | (Err, Err) | (CVarArgs, CVarArgs) => true,
 466         (Slice(l), Slice(r)) => eq_ty(l, r),
 467         (Array(le, ls), Array(re, rs)) => eq_ty(le, re) && eq_expr(&ls.value, &rs.value),
 468         (Ptr(l), Ptr(r)) => l.mutbl == r.mutbl && eq_ty(&l.ty, &r.ty),
 469         (Rptr(ll, l), Rptr(rl, r)) => {
 470             both(ll, rl, |l, r| eq_id(l.ident, r.ident)) && l.mutbl == r.mutbl && eq_ty(&l.ty, &r.ty)
 471         },
 472         (BareFn(l), BareFn(r)) => {
 473             l.unsafety == r.unsafety
 474                 && eq_ext(&l.ext, &r.ext)
 475                 && over(&l.generic_params, &r.generic_params, |l, r| eq_generic_param(l, r))
 476                 && eq_fn_decl(&l.decl, &r.decl)
 477         },
 478         (Tup(l), Tup(r)) => over(l, r, |l, r| eq_ty(l, r)),
 479         (Path(lq, lp), Path(rq, rp)) => both(lq, rq, |l, r| eq_qself(l, r)) && eq_path(lp, rp),
 480         (TraitObject(lg, ls), TraitObject(rg, rs)) => ls == rs && over(lg, rg, |l, r| eq_generic_bound(l, r)),
 481         (ImplTrait(_, lg), ImplTrait(_, rg)) => over(lg, rg, |l, r| eq_generic_bound(l, r)),
 482         (Typeof(l), Typeof(r)) => eq_expr(&l.value, &r.value),
 483         (MacCall(l), MacCall(r)) => eq_mac_call(l, r),
 484         _ => false,
 485     }
 486 }
 487
 488 pub fn eq_ext(l: &Extern, r: &Extern) -> bool {
 489     use Extern::*;
 490     match (l, r) {
 491         (None, None) | (Implicit, Implicit) => true,
 492         (Explicit(l), Explicit(r)) => eq_str_lit(l, r),
 493         _ => false,
 494     }
 495 }
 496
 497 pub fn eq_str_lit(l: &StrLit, r: &StrLit) -> bool {
 498     l.style == r.style && l.symbol == r.symbol && l.suffix == r.suffix
 499 }
 500
 501 pub fn eq_poly_ref_trait(l: &PolyTraitRef, r: &PolyTraitRef) -> bool {
 502     eq_path(&l.trait_ref.path, &r.trait_ref.path)
 503         && over(&l.bound_generic_params, &r.bound_generic_params, |l, r| {
 504             eq_generic_param(l, r)
 505         })
 506 }
 507
 508 pub fn eq_generic_param(l: &GenericParam, r: &GenericParam) -> bool {
 509     use GenericParamKind::*;
 510     l.is_placeholder == r.is_placeholder
 511         && eq_id(l.ident, r.ident)
 512         && over(&l.bounds, &r.bounds, |l, r| eq_generic_bound(l, r))
 513         && match (&l.kind, &r.kind) {
 514             (Lifetime, Lifetime) => true,
 515             (Type { default: l }, Type { default: r }) => both(l, r, |l, r| eq_ty(l, r)),
 516             (
 517                 Const {
 518                     ty: lt,
 519                     kw_span: _,
 520                     default: ld,
 521                 },
 522                 Const {
 523                     ty: rt,
 524                     kw_span: _,
 525                     default: rd,
 526                 },
 527             ) => eq_ty(lt, rt) && both(ld, rd, |ld, rd| eq_anon_const(ld, rd)),
 528             _ => false,
 529         }
 530         && over(&l.attrs, &r.attrs, |l, r| eq_attr(l, r))
 531 }
 532
 533 pub fn eq_generic_bound(l: &GenericBound, r: &GenericBound) -> bool {
 534     use GenericBound::*;
 535     match (l, r) {
 536         (Trait(ptr1, tbm1), Trait(ptr2, tbm2)) => tbm1 == tbm2 && eq_poly_ref_trait(ptr1, ptr2),
 537         (Outlives(l), Outlives(r)) => eq_id(l.ident, r.ident),
 538         _ => false,
 539     }
 540 }
 541
 542 pub fn eq_assoc_constraint(l: &AssocTyConstraint, r: &AssocTyConstraint) -> bool {
 543     use AssocTyConstraintKind::*;
 544     eq_id(l.ident, r.ident)
 545         && match (&l.kind, &r.kind) {
 546             (Equality { ty: l }, Equality { ty: r }) => eq_ty(l, r),
 547             (Bound { bounds: l }, Bound { bounds: r }) => over(l, r, |l, r| eq_generic_bound(l, r)),
 548             _ => false,
 549         }
 550 }
 551
 552 pub fn eq_mac_call(l: &MacCall, r: &MacCall) -> bool {
 553     eq_path(&l.path, &r.path) && eq_mac_args(&l.args, &r.args)
 554 }
 555
 556 pub fn eq_attr(l: &Attribute, r: &Attribute) -> bool {
 557     use AttrKind::*;
 558     l.style == r.style
 559         && match (&l.kind, &r.kind) {
 560             (DocComment(l1, l2), DocComment(r1, r2)) => l1 == r1 && l2 == r2,
 561             (Normal(l, _), Normal(r, _)) => eq_path(&l.path, &r.path) && eq_mac_args(&l.args, &r.args),
 562             _ => false,
 563         }
 564 }
 565
 566 pub fn eq_mac_args(l: &MacArgs, r: &MacArgs) -> bool {
 567     use MacArgs::*;
 568     match (l, r) {
 569         (Empty, Empty) => true,
 570         (Delimited(_, ld, lts), Delimited(_, rd, rts)) => ld == rd && lts.eq_unspanned(rts),
 571         (Eq(_, lt), Eq(_, rt)) => lt.kind == rt.kind,
 572         _ => false,
 573     }
 574 }
 575
 576 /// Extract args from an assert-like macro.
 577 ///
 578 /// Currently working with:
 579 /// - `assert_eq!` and `assert_ne!`
 580 /// - `debug_assert_eq!` and `debug_assert_ne!`
 581 ///
 582 /// For example:
 583 ///
 584 /// `debug_assert_eq!(a, b)` will return Some([a, b])
 585 pub fn extract_assert_macro_args(mut expr: &Expr) -> Option<[&Expr; 2]> {
 586     if_chain! {
 587         if let ExprKind::If(_, ref block, _) = expr.kind;
 588         if let StmtKind::Semi(ref e) = block.stmts.get(0)?.kind;
 589         then {
 590             expr = e;
 591         }
 592     }
 593     if_chain! {
 594         if let ExprKind::Block(ref block, _) = expr.kind;
 595         if let StmtKind::Expr(ref expr) = block.stmts.get(0)?.kind;
 596         if let ExprKind::Match(ref match_expr, _) = expr.kind;
 597         if let ExprKind::Tup(ref tup) = match_expr.kind;
 598         if let [a, b, ..] = tup.as_slice();
 599         if let (&ExprKind::AddrOf(_, _, ref a), &ExprKind::AddrOf(_, _, ref b)) = (&a.kind, &b.kind);
 600         then {
 601             return Some([&*a, &*b]);
 602         }
 603     }
 604     None
 605 }