src/tools/rust-analyzer/crates/hir-def/src/body/lower.rs

   1 //! Transforms `ast::Expr` into an equivalent `hir_def::expr::Expr`
   2 //! representation.
   3
   4 use std::{mem, sync::Arc};
   5
   6 use either::Either;
   7 use hir_expand::{
   8     ast_id_map::AstIdMap,
   9     hygiene::Hygiene,
  10     name::{name, AsName, Name},
  11     AstId, ExpandError, HirFileId, InFile,
  12 };
  13 use la_arena::Arena;
  14 use once_cell::unsync::OnceCell;
  15 use profile::Count;
  16 use rustc_hash::FxHashMap;
  17 use syntax::{
  18     ast::{
  19         self, ArrayExprKind, AstChildren, HasArgList, HasLoopBody, HasName, LiteralKind,
  20         SlicePatComponents,
  21     },
  22     AstNode, AstPtr, SyntaxNodePtr,
  23 };
  24
  25 use crate::{
  26     adt::StructKind,
  27     body::{Body, BodySourceMap, Expander, ExprPtr, LabelPtr, LabelSource, PatPtr},
  28     body::{BodyDiagnostic, ExprSource, PatSource},
  29     builtin_type::{BuiltinFloat, BuiltinInt, BuiltinUint},
  30     db::DefDatabase,
  31     expr::{
  32         dummy_expr_id, Array, BindingAnnotation, ClosureKind, Expr, ExprId, FloatTypeWrapper,
  33         Label, LabelId, Literal, MatchArm, Movability, Pat, PatId, RecordFieldPat, RecordLitField,
  34         Statement,
  35     },
  36     intern::Interned,
  37     item_scope::BuiltinShadowMode,
  38     path::{GenericArgs, Path},
  39     type_ref::{Mutability, Rawness, TypeRef},
  40     AdtId, BlockLoc, ModuleDefId, UnresolvedMacro,
  41 };
  42
  43 pub struct LowerCtx<'a> {
  44     pub db: &'a dyn DefDatabase,
  45     hygiene: Hygiene,
  46     ast_id_map: Option<(HirFileId, OnceCell<Arc<AstIdMap>>)>,
  47 }
  48
  49 impl<'a> LowerCtx<'a> {
  50     pub fn new(db: &'a dyn DefDatabase, file_id: HirFileId) -> Self {
  51         LowerCtx {
  52             db,
  53             hygiene: Hygiene::new(db.upcast(), file_id),
  54             ast_id_map: Some((file_id, OnceCell::new())),
  55         }
  56     }
  57
  58     pub fn with_hygiene(db: &'a dyn DefDatabase, hygiene: &Hygiene) -> Self {
  59         LowerCtx { db, hygiene: hygiene.clone(), ast_id_map: None }
  60     }
  61
  62     pub(crate) fn hygiene(&self) -> &Hygiene {
  63         &self.hygiene
  64     }
  65
  66     pub(crate) fn lower_path(&self, ast: ast::Path) -> Option<Path> {
  67         Path::from_src(ast, self)
  68     }
  69
  70     pub(crate) fn ast_id<N: AstNode>(&self, db: &dyn DefDatabase, item: &N) -> Option<AstId<N>> {
  71         let &(file_id, ref ast_id_map) = self.ast_id_map.as_ref()?;
  72         let ast_id_map = ast_id_map.get_or_init(|| db.ast_id_map(file_id));
  73         Some(InFile::new(file_id, ast_id_map.ast_id(item)))
  74     }
  75 }
  76
  77 pub(super) fn lower(
  78     db: &dyn DefDatabase,
  79     expander: Expander,
  80     params: Option<(ast::ParamList, impl Iterator<Item = bool>)>,
  81     body: Option<ast::Expr>,
  82 ) -> (Body, BodySourceMap) {
  83     ExprCollector {
  84         db,
  85         source_map: BodySourceMap::default(),
  86         ast_id_map: db.ast_id_map(expander.current_file_id),
  87         body: Body {
  88             exprs: Arena::default(),
  89             pats: Arena::default(),
  90             labels: Arena::default(),
  91             params: Vec::new(),
  92             body_expr: dummy_expr_id(),
  93             block_scopes: Vec::new(),
  94             _c: Count::new(),
  95             or_pats: Default::default(),
  96         },
  97         expander,
  98         name_to_pat_grouping: Default::default(),
  99         is_lowering_inside_or_pat: false,
 100         is_lowering_assignee_expr: false,
 101         is_lowering_generator: false,
 102     }
 103     .collect(params, body)
 104 }
 105
 106 struct ExprCollector<'a> {
 107     db: &'a dyn DefDatabase,
 108     expander: Expander,
 109     ast_id_map: Arc<AstIdMap>,
 110     body: Body,
 111     source_map: BodySourceMap,
 112     // a poor-mans union-find?
 113     name_to_pat_grouping: FxHashMap<Name, Vec<PatId>>,
 114     is_lowering_inside_or_pat: bool,
 115     is_lowering_assignee_expr: bool,
 116     is_lowering_generator: bool,
 117 }
 118
 119 impl ExprCollector<'_> {
 120     fn collect(
 121         mut self,
 122         param_list: Option<(ast::ParamList, impl Iterator<Item = bool>)>,
 123         body: Option<ast::Expr>,
 124     ) -> (Body, BodySourceMap) {
 125         if let Some((param_list, mut attr_enabled)) = param_list {
 126             if let Some(self_param) =
 127                 param_list.self_param().filter(|_| attr_enabled.next().unwrap_or(false))
 128             {
 129                 let ptr = AstPtr::new(&self_param);
 130                 let param_pat = self.alloc_pat(
 131                     Pat::Bind {
 132                         name: name![self],
 133                         mode: BindingAnnotation::new(
 134                             self_param.mut_token().is_some() && self_param.amp_token().is_none(),
 135                             false,
 136                         ),
 137                         subpat: None,
 138                     },
 139                     Either::Right(ptr),
 140                 );
 141                 self.body.params.push(param_pat);
 142             }
 143
 144             for pat in param_list
 145                 .params()
 146                 .zip(attr_enabled)
 147                 .filter_map(|(param, enabled)| param.pat().filter(|_| enabled))
 148             {
 149                 let param_pat = self.collect_pat(pat);
 150                 self.body.params.push(param_pat);
 151             }
 152         };
 153
 154         self.body.body_expr = self.collect_expr_opt(body);
 155         (self.body, self.source_map)
 156     }
 157
 158     fn ctx(&self) -> LowerCtx<'_> {
 159         LowerCtx::new(self.db, self.expander.current_file_id)
 160     }
 161
 162     fn alloc_expr(&mut self, expr: Expr, ptr: ExprPtr) -> ExprId {
 163         let src = self.expander.to_source(ptr);
 164         let id = self.make_expr(expr, src.clone());
 165         self.source_map.expr_map.insert(src, id);
 166         id
 167     }
 168     // desugared exprs don't have ptr, that's wrong and should be fixed
 169     // somehow.
 170     fn alloc_expr_desugared(&mut self, expr: Expr) -> ExprId {
 171         self.body.exprs.alloc(expr)
 172     }
 173     fn missing_expr(&mut self) -> ExprId {
 174         self.alloc_expr_desugared(Expr::Missing)
 175     }
 176     fn make_expr(&mut self, expr: Expr, src: ExprSource) -> ExprId {
 177         let id = self.body.exprs.alloc(expr);
 178         self.source_map.expr_map_back.insert(id, src);
 179         id
 180     }
 181
 182     fn alloc_pat(&mut self, pat: Pat, ptr: PatPtr) -> PatId {
 183         let src = self.expander.to_source(ptr);
 184         let id = self.make_pat(pat, src.clone());
 185         self.source_map.pat_map.insert(src, id);
 186         id
 187     }
 188     fn missing_pat(&mut self) -> PatId {
 189         self.body.pats.alloc(Pat::Missing)
 190     }
 191     fn make_pat(&mut self, pat: Pat, src: PatSource) -> PatId {
 192         let id = self.body.pats.alloc(pat);
 193         self.source_map.pat_map_back.insert(id, src);
 194         id
 195     }
 196
 197     fn alloc_label(&mut self, label: Label, ptr: LabelPtr) -> LabelId {
 198         let src = self.expander.to_source(ptr);
 199         let id = self.make_label(label, src.clone());
 200         self.source_map.label_map.insert(src, id);
 201         id
 202     }
 203     fn make_label(&mut self, label: Label, src: LabelSource) -> LabelId {
 204         let id = self.body.labels.alloc(label);
 205         self.source_map.label_map_back.insert(id, src);
 206         id
 207     }
 208
 209     fn collect_expr(&mut self, expr: ast::Expr) -> ExprId {
 210         self.maybe_collect_expr(expr).unwrap_or_else(|| self.missing_expr())
 211     }
 212
 213     /// Returns `None` if and only if the expression is `#[cfg]`d out.
 214     fn maybe_collect_expr(&mut self, expr: ast::Expr) -> Option<ExprId> {
 215         let syntax_ptr = AstPtr::new(&expr);
 216         self.check_cfg(&expr)?;
 217
 218         Some(match expr {
 219             ast::Expr::IfExpr(e) => {
 220                 let then_branch = self.collect_block_opt(e.then_branch());
 221
 222                 let else_branch = e.else_branch().map(|b| match b {
 223                     ast::ElseBranch::Block(it) => self.collect_block(it),
 224                     ast::ElseBranch::IfExpr(elif) => {
 225                         let expr: ast::Expr = ast::Expr::cast(elif.syntax().clone()).unwrap();
 226                         self.collect_expr(expr)
 227                     }
 228                 });
 229
 230                 let condition = self.collect_expr_opt(e.condition());
 231
 232                 self.alloc_expr(Expr::If { condition, then_branch, else_branch }, syntax_ptr)
 233             }
 234             ast::Expr::LetExpr(e) => {
 235                 let pat = self.collect_pat_opt(e.pat());
 236                 let expr = self.collect_expr_opt(e.expr());
 237                 self.alloc_expr(Expr::Let { pat, expr }, syntax_ptr)
 238             }
 239             ast::Expr::BlockExpr(e) => match e.modifier() {
 240                 Some(ast::BlockModifier::Try(_)) => {
 241                     let body = self.collect_block(e);
 242                     self.alloc_expr(Expr::TryBlock { body }, syntax_ptr)
 243                 }
 244                 Some(ast::BlockModifier::Unsafe(_)) => {
 245                     let body = self.collect_block(e);
 246                     self.alloc_expr(Expr::Unsafe { body }, syntax_ptr)
 247                 }
 248                 // FIXME: we need to record these effects somewhere...
 249                 Some(ast::BlockModifier::Label(label)) => {
 250                     let label = self.collect_label(label);
 251                     let res = self.collect_block(e);
 252                     match &mut self.body.exprs[res] {
 253                         Expr::Block { label: block_label, .. } => {
 254                             *block_label = Some(label);
 255                         }
 256                         _ => unreachable!(),
 257                     }
 258                     res
 259                 }
 260                 Some(ast::BlockModifier::Async(_)) => {
 261                     let body = self.collect_block(e);
 262                     self.alloc_expr(Expr::Async { body }, syntax_ptr)
 263                 }
 264                 Some(ast::BlockModifier::Const(_)) => {
 265                     let body = self.collect_block(e);
 266                     self.alloc_expr(Expr::Const { body }, syntax_ptr)
 267                 }
 268                 None => self.collect_block(e),
 269             },
 270             ast::Expr::LoopExpr(e) => {
 271                 let label = e.label().map(|label| self.collect_label(label));
 272                 let body = self.collect_block_opt(e.loop_body());
 273                 self.alloc_expr(Expr::Loop { body, label }, syntax_ptr)
 274             }
 275             ast::Expr::WhileExpr(e) => {
 276                 let label = e.label().map(|label| self.collect_label(label));
 277                 let body = self.collect_block_opt(e.loop_body());
 278
 279                 let condition = self.collect_expr_opt(e.condition());
 280
 281                 self.alloc_expr(Expr::While { condition, body, label }, syntax_ptr)
 282             }
 283             ast::Expr::ForExpr(e) => {
 284                 let label = e.label().map(|label| self.collect_label(label));
 285                 let iterable = self.collect_expr_opt(e.iterable());
 286                 let pat = self.collect_pat_opt(e.pat());
 287                 let body = self.collect_block_opt(e.loop_body());
 288                 self.alloc_expr(Expr::For { iterable, pat, body, label }, syntax_ptr)
 289             }
 290             ast::Expr::CallExpr(e) => {
 291                 let callee = self.collect_expr_opt(e.expr());
 292                 let args = if let Some(arg_list) = e.arg_list() {
 293                     arg_list.args().filter_map(|e| self.maybe_collect_expr(e)).collect()
 294                 } else {
 295                     Box::default()
 296                 };
 297                 self.alloc_expr(
 298                     Expr::Call { callee, args, is_assignee_expr: self.is_lowering_assignee_expr },
 299                     syntax_ptr,
 300                 )
 301             }
 302             ast::Expr::MethodCallExpr(e) => {
 303                 let receiver = self.collect_expr_opt(e.receiver());
 304                 let args = if let Some(arg_list) = e.arg_list() {
 305                     arg_list.args().filter_map(|e| self.maybe_collect_expr(e)).collect()
 306                 } else {
 307                     Box::default()
 308                 };
 309                 let method_name = e.name_ref().map(|nr| nr.as_name()).unwrap_or_else(Name::missing);
 310                 let generic_args = e
 311                     .generic_arg_list()
 312                     .and_then(|it| GenericArgs::from_ast(&self.ctx(), it))
 313                     .map(Box::new);
 314                 self.alloc_expr(
 315                     Expr::MethodCall { receiver, method_name, args, generic_args },
 316                     syntax_ptr,
 317                 )
 318             }
 319             ast::Expr::MatchExpr(e) => {
 320                 let expr = self.collect_expr_opt(e.expr());
 321                 let arms = if let Some(match_arm_list) = e.match_arm_list() {
 322                     match_arm_list
 323                         .arms()
 324                         .filter_map(|arm| {
 325                             self.check_cfg(&arm).map(|()| MatchArm {
 326                                 pat: self.collect_pat_opt(arm.pat()),
 327                                 expr: self.collect_expr_opt(arm.expr()),
 328                                 guard: arm
 329                                     .guard()
 330                                     .map(|guard| self.collect_expr_opt(guard.condition())),
 331                             })
 332                         })
 333                         .collect()
 334                 } else {
 335                     Box::default()
 336                 };
 337                 self.alloc_expr(Expr::Match { expr, arms }, syntax_ptr)
 338             }
 339             ast::Expr::PathExpr(e) => {
 340                 let path = e
 341                     .path()
 342                     .and_then(|path| self.expander.parse_path(self.db, path))
 343                     .map(Expr::Path)
 344                     .unwrap_or(Expr::Missing);
 345                 self.alloc_expr(path, syntax_ptr)
 346             }
 347             ast::Expr::ContinueExpr(e) => self.alloc_expr(
 348                 Expr::Continue { label: e.lifetime().map(|l| Name::new_lifetime(&l)) },
 349                 syntax_ptr,
 350             ),
 351             ast::Expr::BreakExpr(e) => {
 352                 let expr = e.expr().map(|e| self.collect_expr(e));
 353                 self.alloc_expr(
 354                     Expr::Break { expr, label: e.lifetime().map(|l| Name::new_lifetime(&l)) },
 355                     syntax_ptr,
 356                 )
 357             }
 358             ast::Expr::ParenExpr(e) => {
 359                 let inner = self.collect_expr_opt(e.expr());
 360                 // make the paren expr point to the inner expression as well
 361                 let src = self.expander.to_source(syntax_ptr);
 362                 self.source_map.expr_map.insert(src, inner);
 363                 inner
 364             }
 365             ast::Expr::ReturnExpr(e) => {
 366                 let expr = e.expr().map(|e| self.collect_expr(e));
 367                 self.alloc_expr(Expr::Return { expr }, syntax_ptr)
 368             }
 369             ast::Expr::YieldExpr(e) => {
 370                 self.is_lowering_generator = true;
 371                 let expr = e.expr().map(|e| self.collect_expr(e));
 372                 self.alloc_expr(Expr::Yield { expr }, syntax_ptr)
 373             }
 374             ast::Expr::YeetExpr(e) => {
 375                 let expr = e.expr().map(|e| self.collect_expr(e));
 376                 self.alloc_expr(Expr::Yeet { expr }, syntax_ptr)
 377             }
 378             ast::Expr::RecordExpr(e) => {
 379                 let path =
 380                     e.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new);
 381                 let is_assignee_expr = self.is_lowering_assignee_expr;
 382                 let record_lit = if let Some(nfl) = e.record_expr_field_list() {
 383                     let fields = nfl
 384                         .fields()
 385                         .filter_map(|field| {
 386                             self.check_cfg(&field)?;
 387
 388                             let name = field.field_name()?.as_name();
 389
 390                             let expr = match field.expr() {
 391                                 Some(e) => self.collect_expr(e),
 392                                 None => self.missing_expr(),
 393                             };
 394                             let src = self.expander.to_source(AstPtr::new(&field));
 395                             self.source_map.field_map.insert(src.clone(), expr);
 396                             self.source_map.field_map_back.insert(expr, src);
 397                             Some(RecordLitField { name, expr })
 398                         })
 399                         .collect();
 400                     let spread = nfl.spread().map(|s| self.collect_expr(s));
 401                     let ellipsis = nfl.dotdot_token().is_some();
 402                     Expr::RecordLit { path, fields, spread, ellipsis, is_assignee_expr }
 403                 } else {
 404                     Expr::RecordLit {
 405                         path,
 406                         fields: Box::default(),
 407                         spread: None,
 408                         ellipsis: false,
 409                         is_assignee_expr,
 410                     }
 411                 };
 412
 413                 self.alloc_expr(record_lit, syntax_ptr)
 414             }
 415             ast::Expr::FieldExpr(e) => {
 416                 let expr = self.collect_expr_opt(e.expr());
 417                 let name = match e.field_access() {
 418                     Some(kind) => kind.as_name(),
 419                     _ => Name::missing(),
 420                 };
 421                 self.alloc_expr(Expr::Field { expr, name }, syntax_ptr)
 422             }
 423             ast::Expr::AwaitExpr(e) => {
 424                 let expr = self.collect_expr_opt(e.expr());
 425                 self.alloc_expr(Expr::Await { expr }, syntax_ptr)
 426             }
 427             ast::Expr::TryExpr(e) => {
 428                 let expr = self.collect_expr_opt(e.expr());
 429                 self.alloc_expr(Expr::Try { expr }, syntax_ptr)
 430             }
 431             ast::Expr::CastExpr(e) => {
 432                 let expr = self.collect_expr_opt(e.expr());
 433                 let type_ref = Interned::new(TypeRef::from_ast_opt(&self.ctx(), e.ty()));
 434                 self.alloc_expr(Expr::Cast { expr, type_ref }, syntax_ptr)
 435             }
 436             ast::Expr::RefExpr(e) => {
 437                 let expr = self.collect_expr_opt(e.expr());
 438                 let raw_tok = e.raw_token().is_some();
 439                 let mutability = if raw_tok {
 440                     if e.mut_token().is_some() {
 441                         Mutability::Mut
 442                     } else if e.const_token().is_some() {
 443                         Mutability::Shared
 444                     } else {
 445                         unreachable!("parser only remaps to raw_token() if matching mutability token follows")
 446                     }
 447                 } else {
 448                     Mutability::from_mutable(e.mut_token().is_some())
 449                 };
 450                 let rawness = Rawness::from_raw(raw_tok);
 451                 self.alloc_expr(Expr::Ref { expr, rawness, mutability }, syntax_ptr)
 452             }
 453             ast::Expr::PrefixExpr(e) => {
 454                 let expr = self.collect_expr_opt(e.expr());
 455                 match e.op_kind() {
 456                     Some(op) => self.alloc_expr(Expr::UnaryOp { expr, op }, syntax_ptr),
 457                     None => self.alloc_expr(Expr::Missing, syntax_ptr),
 458                 }
 459             }
 460             ast::Expr::ClosureExpr(e) => {
 461                 let mut args = Vec::new();
 462                 let mut arg_types = Vec::new();
 463                 if let Some(pl) = e.param_list() {
 464                     for param in pl.params() {
 465                         let pat = self.collect_pat_opt(param.pat());
 466                         let type_ref =
 467                             param.ty().map(|it| Interned::new(TypeRef::from_ast(&self.ctx(), it)));
 468                         args.push(pat);
 469                         arg_types.push(type_ref);
 470                     }
 471                 }
 472                 let ret_type = e
 473                     .ret_type()
 474                     .and_then(|r| r.ty())
 475                     .map(|it| Interned::new(TypeRef::from_ast(&self.ctx(), it)));
 476
 477                 let prev_is_lowering_generator = self.is_lowering_generator;
 478                 self.is_lowering_generator = false;
 479
 480                 let body = self.collect_expr_opt(e.body());
 481
 482                 let closure_kind = if self.is_lowering_generator {
 483                     let movability = if e.static_token().is_some() {
 484                         Movability::Static
 485                     } else {
 486                         Movability::Movable
 487                     };
 488                     ClosureKind::Generator(movability)
 489                 } else {
 490                     ClosureKind::Closure
 491                 };
 492                 self.is_lowering_generator = prev_is_lowering_generator;
 493
 494                 self.alloc_expr(
 495                     Expr::Closure {
 496                         args: args.into(),
 497                         arg_types: arg_types.into(),
 498                         ret_type,
 499                         body,
 500                         closure_kind,
 501                     },
 502                     syntax_ptr,
 503                 )
 504             }
 505             ast::Expr::BinExpr(e) => {
 506                 let op = e.op_kind();
 507                 if let Some(ast::BinaryOp::Assignment { op: None }) = op {
 508                     self.is_lowering_assignee_expr = true;
 509                 }
 510                 let lhs = self.collect_expr_opt(e.lhs());
 511                 self.is_lowering_assignee_expr = false;
 512                 let rhs = self.collect_expr_opt(e.rhs());
 513                 self.alloc_expr(Expr::BinaryOp { lhs, rhs, op }, syntax_ptr)
 514             }
 515             ast::Expr::TupleExpr(e) => {
 516                 let exprs = e.fields().map(|expr| self.collect_expr(expr)).collect();
 517                 self.alloc_expr(
 518                     Expr::Tuple { exprs, is_assignee_expr: self.is_lowering_assignee_expr },
 519                     syntax_ptr,
 520                 )
 521             }
 522             ast::Expr::BoxExpr(e) => {
 523                 let expr = self.collect_expr_opt(e.expr());
 524                 self.alloc_expr(Expr::Box { expr }, syntax_ptr)
 525             }
 526
 527             ast::Expr::ArrayExpr(e) => {
 528                 let kind = e.kind();
 529
 530                 match kind {
 531                     ArrayExprKind::ElementList(e) => {
 532                         let elements = e.map(|expr| self.collect_expr(expr)).collect();
 533                         self.alloc_expr(
 534                             Expr::Array(Array::ElementList {
 535                                 elements,
 536                                 is_assignee_expr: self.is_lowering_assignee_expr,
 537                             }),
 538                             syntax_ptr,
 539                         )
 540                     }
 541                     ArrayExprKind::Repeat { initializer, repeat } => {
 542                         let initializer = self.collect_expr_opt(initializer);
 543                         let repeat = self.collect_expr_opt(repeat);
 544                         self.alloc_expr(
 545                             Expr::Array(Array::Repeat { initializer, repeat }),
 546                             syntax_ptr,
 547                         )
 548                     }
 549                 }
 550             }
 551
 552             ast::Expr::Literal(e) => self.alloc_expr(Expr::Literal(e.kind().into()), syntax_ptr),
 553             ast::Expr::IndexExpr(e) => {
 554                 let base = self.collect_expr_opt(e.base());
 555                 let index = self.collect_expr_opt(e.index());
 556                 self.alloc_expr(Expr::Index { base, index }, syntax_ptr)
 557             }
 558             ast::Expr::RangeExpr(e) => {
 559                 let lhs = e.start().map(|lhs| self.collect_expr(lhs));
 560                 let rhs = e.end().map(|rhs| self.collect_expr(rhs));
 561                 match e.op_kind() {
 562                     Some(range_type) => {
 563                         self.alloc_expr(Expr::Range { lhs, rhs, range_type }, syntax_ptr)
 564                     }
 565                     None => self.alloc_expr(Expr::Missing, syntax_ptr),
 566                 }
 567             }
 568             ast::Expr::MacroExpr(e) => {
 569                 let e = e.macro_call()?;
 570                 let macro_ptr = AstPtr::new(&e);
 571                 let id = self.collect_macro_call(e, macro_ptr, true, |this, expansion| {
 572                     expansion.map(|it| this.collect_expr(it))
 573                 });
 574                 match id {
 575                     Some(id) => {
 576                         // Make the macro-call point to its expanded expression so we can query
 577                         // semantics on syntax pointers to the macro
 578                         let src = self.expander.to_source(syntax_ptr);
 579                         self.source_map.expr_map.insert(src, id);
 580                         id
 581                     }
 582                     None => self.alloc_expr(Expr::Missing, syntax_ptr),
 583                 }
 584             }
 585             ast::Expr::UnderscoreExpr(_) => self.alloc_expr(Expr::Underscore, syntax_ptr),
 586         })
 587     }
 588
 589     fn collect_macro_call<F, T, U>(
 590         &mut self,
 591         mcall: ast::MacroCall,
 592         syntax_ptr: AstPtr<ast::MacroCall>,
 593         record_diagnostics: bool,
 594         collector: F,
 595     ) -> U
 596     where
 597         F: FnOnce(&mut Self, Option<T>) -> U,
 598         T: ast::AstNode,
 599     {
 600         // File containing the macro call. Expansion errors will be attached here.
 601         let outer_file = self.expander.current_file_id;
 602
 603         let macro_call_ptr = self.expander.to_source(AstPtr::new(&mcall));
 604         let res = self.expander.enter_expand(self.db, mcall);
 605
 606         let res = match res {
 607             Ok(res) => res,
 608             Err(UnresolvedMacro { path }) => {
 609                 if record_diagnostics {
 610                     self.source_map.diagnostics.push(BodyDiagnostic::UnresolvedMacroCall {
 611                         node: InFile::new(outer_file, syntax_ptr),
 612                         path,
 613                     });
 614                 }
 615                 return collector(self, None);
 616             }
 617         };
 618
 619         if record_diagnostics {
 620             match &res.err {
 621                 Some(ExpandError::UnresolvedProcMacro(krate)) => {
 622                     self.source_map.diagnostics.push(BodyDiagnostic::UnresolvedProcMacro {
 623                         node: InFile::new(outer_file, syntax_ptr),
 624                         krate: *krate,
 625                     });
 626                 }
 627                 Some(err) => {
 628                     self.source_map.diagnostics.push(BodyDiagnostic::MacroError {
 629                         node: InFile::new(outer_file, syntax_ptr),
 630                         message: err.to_string(),
 631                     });
 632                 }
 633                 None => {}
 634             }
 635         }
 636
 637         match res.value {
 638             Some((mark, expansion)) => {
 639                 self.source_map.expansions.insert(macro_call_ptr, self.expander.current_file_id);
 640                 let prev_ast_id_map = mem::replace(
 641                     &mut self.ast_id_map,
 642                     self.db.ast_id_map(self.expander.current_file_id),
 643                 );
 644
 645                 let id = collector(self, Some(expansion));
 646                 self.ast_id_map = prev_ast_id_map;
 647                 self.expander.exit(self.db, mark);
 648                 id
 649             }
 650             None => collector(self, None),
 651         }
 652     }
 653
 654     fn collect_expr_opt(&mut self, expr: Option<ast::Expr>) -> ExprId {
 655         match expr {
 656             Some(expr) => self.collect_expr(expr),
 657             None => self.missing_expr(),
 658         }
 659     }
 660
 661     fn collect_macro_as_stmt(
 662         &mut self,
 663         statements: &mut Vec<Statement>,
 664         mac: ast::MacroExpr,
 665     ) -> Option<ExprId> {
 666         let mac_call = mac.macro_call()?;
 667         let syntax_ptr = AstPtr::new(&ast::Expr::from(mac));
 668         let macro_ptr = AstPtr::new(&mac_call);
 669         let expansion = self.collect_macro_call(
 670             mac_call,
 671             macro_ptr,
 672             false,
 673             |this, expansion: Option<ast::MacroStmts>| match expansion {
 674                 Some(expansion) => {
 675                     expansion.statements().for_each(|stmt| this.collect_stmt(statements, stmt));
 676                     expansion.expr().and_then(|expr| match expr {
 677                         ast::Expr::MacroExpr(mac) => this.collect_macro_as_stmt(statements, mac),
 678                         expr => Some(this.collect_expr(expr)),
 679                     })
 680                 }
 681                 None => None,
 682             },
 683         );
 684         match expansion {
 685             Some(tail) => {
 686                 // Make the macro-call point to its expanded expression so we can query
 687                 // semantics on syntax pointers to the macro
 688                 let src = self.expander.to_source(syntax_ptr);
 689                 self.source_map.expr_map.insert(src, tail);
 690                 Some(tail)
 691             }
 692             None => None,
 693         }
 694     }
 695
 696     fn collect_stmt(&mut self, statements: &mut Vec<Statement>, s: ast::Stmt) {
 697         match s {
 698             ast::Stmt::LetStmt(stmt) => {
 699                 if self.check_cfg(&stmt).is_none() {
 700                     return;
 701                 }
 702                 let pat = self.collect_pat_opt(stmt.pat());
 703                 let type_ref =
 704                     stmt.ty().map(|it| Interned::new(TypeRef::from_ast(&self.ctx(), it)));
 705                 let initializer = stmt.initializer().map(|e| self.collect_expr(e));
 706                 let else_branch = stmt
 707                     .let_else()
 708                     .and_then(|let_else| let_else.block_expr())
 709                     .map(|block| self.collect_block(block));
 710                 statements.push(Statement::Let { pat, type_ref, initializer, else_branch });
 711             }
 712             ast::Stmt::ExprStmt(stmt) => {
 713                 let expr = stmt.expr();
 714                 match &expr {
 715                     Some(expr) if self.check_cfg(expr).is_none() => return,
 716                     _ => (),
 717                 }
 718                 let has_semi = stmt.semicolon_token().is_some();
 719                 // Note that macro could be expanded to multiple statements
 720                 if let Some(ast::Expr::MacroExpr(mac)) = expr {
 721                     if let Some(expr) = self.collect_macro_as_stmt(statements, mac) {
 722                         statements.push(Statement::Expr { expr, has_semi })
 723                     }
 724                 } else {
 725                     let expr = self.collect_expr_opt(expr);
 726                     statements.push(Statement::Expr { expr, has_semi });
 727                 }
 728             }
 729             ast::Stmt::Item(_item) => (),
 730         }
 731     }
 732
 733     fn collect_block(&mut self, block: ast::BlockExpr) -> ExprId {
 734         let file_local_id = self.ast_id_map.ast_id(&block);
 735         let ast_id = AstId::new(self.expander.current_file_id, file_local_id);
 736         let block_loc =
 737             BlockLoc { ast_id, module: self.expander.def_map.module_id(self.expander.module) };
 738         let block_id = self.db.intern_block(block_loc);
 739
 740         let (module, def_map) = match self.db.block_def_map(block_id) {
 741             Some(def_map) => {
 742                 self.body.block_scopes.push(block_id);
 743                 (def_map.root(), def_map)
 744             }
 745             None => (self.expander.module, self.expander.def_map.clone()),
 746         };
 747         let prev_def_map = mem::replace(&mut self.expander.def_map, def_map);
 748         let prev_local_module = mem::replace(&mut self.expander.module, module);
 749
 750         let mut statements = Vec::new();
 751         block.statements().for_each(|s| self.collect_stmt(&mut statements, s));
 752         let tail = block.tail_expr().and_then(|e| match e {
 753             ast::Expr::MacroExpr(mac) => self.collect_macro_as_stmt(&mut statements, mac),
 754             expr => self.maybe_collect_expr(expr),
 755         });
 756         let tail = tail.or_else(|| {
 757             let stmt = statements.pop()?;
 758             if let Statement::Expr { expr, has_semi: false } = stmt {
 759                 return Some(expr);
 760             }
 761             statements.push(stmt);
 762             None
 763         });
 764
 765         let syntax_node_ptr = AstPtr::new(&block.into());
 766         let expr_id = self.alloc_expr(
 767             Expr::Block {
 768                 id: block_id,
 769                 statements: statements.into_boxed_slice(),
 770                 tail,
 771                 label: None,
 772             },
 773             syntax_node_ptr,
 774         );
 775
 776         self.expander.def_map = prev_def_map;
 777         self.expander.module = prev_local_module;
 778         expr_id
 779     }
 780
 781     fn collect_block_opt(&mut self, expr: Option<ast::BlockExpr>) -> ExprId {
 782         match expr {
 783             Some(block) => self.collect_block(block),
 784             None => self.missing_expr(),
 785         }
 786     }
 787
 788     fn collect_label(&mut self, ast_label: ast::Label) -> LabelId {
 789         let label = Label {
 790             name: ast_label.lifetime().as_ref().map_or_else(Name::missing, Name::new_lifetime),
 791         };
 792         self.alloc_label(label, AstPtr::new(&ast_label))
 793     }
 794
 795     fn collect_pat(&mut self, pat: ast::Pat) -> PatId {
 796         let pat_id = self.collect_pat_(pat);
 797         for (_, pats) in self.name_to_pat_grouping.drain() {
 798             let pats = Arc::<[_]>::from(pats);
 799             self.body.or_pats.extend(pats.iter().map(|&pat| (pat, pats.clone())));
 800         }
 801         self.is_lowering_inside_or_pat = false;
 802         pat_id
 803     }
 804
 805     fn collect_pat_opt(&mut self, pat: Option<ast::Pat>) -> PatId {
 806         match pat {
 807             Some(pat) => self.collect_pat(pat),
 808             None => self.missing_pat(),
 809         }
 810     }
 811
 812     fn collect_pat_(&mut self, pat: ast::Pat) -> PatId {
 813         let pattern = match &pat {
 814             ast::Pat::IdentPat(bp) => {
 815                 let name = bp.name().map(|nr| nr.as_name()).unwrap_or_else(Name::missing);
 816
 817                 let key = self.is_lowering_inside_or_pat.then(|| name.clone());
 818                 let annotation =
 819                     BindingAnnotation::new(bp.mut_token().is_some(), bp.ref_token().is_some());
 820                 let subpat = bp.pat().map(|subpat| self.collect_pat_(subpat));
 821                 let pattern = if annotation == BindingAnnotation::Unannotated && subpat.is_none() {
 822                     // This could also be a single-segment path pattern. To
 823                     // decide that, we need to try resolving the name.
 824                     let (resolved, _) = self.expander.def_map.resolve_path(
 825                         self.db,
 826                         self.expander.module,
 827                         &name.clone().into(),
 828                         BuiltinShadowMode::Other,
 829                     );
 830                     match resolved.take_values() {
 831                         Some(ModuleDefId::ConstId(_)) => Pat::Path(name.into()),
 832                         Some(ModuleDefId::EnumVariantId(_)) => {
 833                             // this is only really valid for unit variants, but
 834                             // shadowing other enum variants with a pattern is
 835                             // an error anyway
 836                             Pat::Path(name.into())
 837                         }
 838                         Some(ModuleDefId::AdtId(AdtId::StructId(s)))
 839                             if self.db.struct_data(s).variant_data.kind() != StructKind::Record =>
 840                         {
 841                             // Funnily enough, record structs *can* be shadowed
 842                             // by pattern bindings (but unit or tuple structs
 843                             // can't).
 844                             Pat::Path(name.into())
 845                         }
 846                         // shadowing statics is an error as well, so we just ignore that case here
 847                         _ => Pat::Bind { name, mode: annotation, subpat },
 848                     }
 849                 } else {
 850                     Pat::Bind { name, mode: annotation, subpat }
 851                 };
 852
 853                 let ptr = AstPtr::new(&pat);
 854                 let pat = self.alloc_pat(pattern, Either::Left(ptr));
 855                 if let Some(key) = key {
 856                     self.name_to_pat_grouping.entry(key).or_default().push(pat);
 857                 }
 858                 return pat;
 859             }
 860             ast::Pat::TupleStructPat(p) => {
 861                 let path =
 862                     p.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new);
 863                 let (args, ellipsis) = self.collect_tuple_pat(p.fields());
 864                 Pat::TupleStruct { path, args, ellipsis }
 865             }
 866             ast::Pat::RefPat(p) => {
 867                 let pat = self.collect_pat_opt(p.pat());
 868                 let mutability = Mutability::from_mutable(p.mut_token().is_some());
 869                 Pat::Ref { pat, mutability }
 870             }
 871             ast::Pat::PathPat(p) => {
 872                 let path =
 873                     p.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new);
 874                 path.map(Pat::Path).unwrap_or(Pat::Missing)
 875             }
 876             ast::Pat::OrPat(p) => {
 877                 self.is_lowering_inside_or_pat = true;
 878                 let pats = p.pats().map(|p| self.collect_pat_(p)).collect();
 879                 Pat::Or(pats)
 880             }
 881             ast::Pat::ParenPat(p) => return self.collect_pat_opt_(p.pat()),
 882             ast::Pat::TuplePat(p) => {
 883                 let (args, ellipsis) = self.collect_tuple_pat(p.fields());
 884                 Pat::Tuple { args, ellipsis }
 885             }
 886             ast::Pat::WildcardPat(_) => Pat::Wild,
 887             ast::Pat::RecordPat(p) => {
 888                 let path =
 889                     p.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new);
 890                 let args = p
 891                     .record_pat_field_list()
 892                     .expect("every struct should have a field list")
 893                     .fields()
 894                     .filter_map(|f| {
 895                         let ast_pat = f.pat()?;
 896                         let pat = self.collect_pat_(ast_pat);
 897                         let name = f.field_name()?.as_name();
 898                         Some(RecordFieldPat { name, pat })
 899                     })
 900                     .collect();
 901
 902                 let ellipsis = p
 903                     .record_pat_field_list()
 904                     .expect("every struct should have a field list")
 905                     .rest_pat()
 906                     .is_some();
 907
 908                 Pat::Record { path, args, ellipsis }
 909             }
 910             ast::Pat::SlicePat(p) => {
 911                 let SlicePatComponents { prefix, slice, suffix } = p.components();
 912
 913                 // FIXME properly handle `RestPat`
 914                 Pat::Slice {
 915                     prefix: prefix.into_iter().map(|p| self.collect_pat_(p)).collect(),
 916                     slice: slice.map(|p| self.collect_pat_(p)),
 917                     suffix: suffix.into_iter().map(|p| self.collect_pat_(p)).collect(),
 918                 }
 919             }
 920             ast::Pat::LiteralPat(lit) => {
 921                 if let Some(ast_lit) = lit.literal() {
 922                     let expr = Expr::Literal(ast_lit.kind().into());
 923                     let expr_ptr = AstPtr::new(&ast::Expr::Literal(ast_lit));
 924                     let expr_id = self.alloc_expr(expr, expr_ptr);
 925                     Pat::Lit(expr_id)
 926                 } else {
 927                     Pat::Missing
 928                 }
 929             }
 930             ast::Pat::RestPat(_) => {
 931                 // `RestPat` requires special handling and should not be mapped
 932                 // to a Pat. Here we are using `Pat::Missing` as a fallback for
 933                 // when `RestPat` is mapped to `Pat`, which can easily happen
 934                 // when the source code being analyzed has a malformed pattern
 935                 // which includes `..` in a place where it isn't valid.
 936
 937                 Pat::Missing
 938             }
 939             ast::Pat::BoxPat(boxpat) => {
 940                 let inner = self.collect_pat_opt_(boxpat.pat());
 941                 Pat::Box { inner }
 942             }
 943             ast::Pat::ConstBlockPat(const_block_pat) => {
 944                 if let Some(expr) = const_block_pat.block_expr() {
 945                     let expr_id = self.collect_block(expr);
 946                     Pat::ConstBlock(expr_id)
 947                 } else {
 948                     Pat::Missing
 949                 }
 950             }
 951             ast::Pat::MacroPat(mac) => match mac.macro_call() {
 952                 Some(call) => {
 953                     let macro_ptr = AstPtr::new(&call);
 954                     let src = self.expander.to_source(Either::Left(AstPtr::new(&pat)));
 955                     let pat =
 956                         self.collect_macro_call(call, macro_ptr, true, |this, expanded_pat| {
 957                             this.collect_pat_opt_(expanded_pat)
 958                         });
 959                     self.source_map.pat_map.insert(src, pat);
 960                     return pat;
 961                 }
 962                 None => Pat::Missing,
 963             },
 964             // FIXME: implement
 965             ast::Pat::RangePat(_) => Pat::Missing,
 966         };
 967         let ptr = AstPtr::new(&pat);
 968         self.alloc_pat(pattern, Either::Left(ptr))
 969     }
 970
 971     fn collect_pat_opt_(&mut self, pat: Option<ast::Pat>) -> PatId {
 972         match pat {
 973             Some(pat) => self.collect_pat_(pat),
 974             None => self.missing_pat(),
 975         }
 976     }
 977
 978     fn collect_tuple_pat(&mut self, args: AstChildren<ast::Pat>) -> (Box<[PatId]>, Option<usize>) {
 979         // Find the location of the `..`, if there is one. Note that we do not
 980         // consider the possibility of there being multiple `..` here.
 981         let ellipsis = args.clone().position(|p| matches!(p, ast::Pat::RestPat(_)));
 982         // We want to skip the `..` pattern here, since we account for it above.
 983         let args = args
 984             .filter(|p| !matches!(p, ast::Pat::RestPat(_)))
 985             .map(|p| self.collect_pat_(p))
 986             .collect();
 987
 988         (args, ellipsis)
 989     }
 990
 991     /// Returns `None` (and emits diagnostics) when `owner` if `#[cfg]`d out, and `Some(())` when
 992     /// not.
 993     fn check_cfg(&mut self, owner: &dyn ast::HasAttrs) -> Option<()> {
 994         match self.expander.parse_attrs(self.db, owner).cfg() {
 995             Some(cfg) => {
 996                 if self.expander.cfg_options().check(&cfg) != Some(false) {
 997                     return Some(());
 998                 }
 999
1000                 self.source_map.diagnostics.push(BodyDiagnostic::InactiveCode {
1001                     node: InFile::new(
1002                         self.expander.current_file_id,
1003                         SyntaxNodePtr::new(owner.syntax()),
1004                     ),
1005                     cfg,
1006                     opts: self.expander.cfg_options().clone(),
1007                 });
1008
1009                 None
1010             }
1011             None => Some(()),
1012         }
1013     }
1014 }
1015
1016 impl From<ast::LiteralKind> for Literal {
1017     fn from(ast_lit_kind: ast::LiteralKind) -> Self {
1018         match ast_lit_kind {
1019             // FIXME: these should have actual values filled in, but unsure on perf impact
1020             LiteralKind::IntNumber(lit) => {
1021                 if let builtin @ Some(_) = lit.suffix().and_then(BuiltinFloat::from_suffix) {
1022                     Literal::Float(
1023                         FloatTypeWrapper::new(lit.float_value().unwrap_or(Default::default())),
1024                         builtin,
1025                     )
1026                 } else if let builtin @ Some(_) = lit.suffix().and_then(BuiltinInt::from_suffix) {
1027                     Literal::Int(lit.value().unwrap_or(0) as i128, builtin)
1028                 } else {
1029                     let builtin = lit.suffix().and_then(BuiltinUint::from_suffix);
1030                     Literal::Uint(lit.value().unwrap_or(0), builtin)
1031                 }
1032             }
1033             LiteralKind::FloatNumber(lit) => {
1034                 let ty = lit.suffix().and_then(BuiltinFloat::from_suffix);
1035                 Literal::Float(FloatTypeWrapper::new(lit.value().unwrap_or(Default::default())), ty)
1036             }
1037             LiteralKind::ByteString(bs) => {
1038                 let text = bs.value().map(Box::from).unwrap_or_else(Default::default);
1039                 Literal::ByteString(text)
1040             }
1041             LiteralKind::String(s) => {
1042                 let text = s.value().map(Box::from).unwrap_or_else(Default::default);
1043                 Literal::String(text)
1044             }
1045             LiteralKind::Byte(b) => {
1046                 Literal::Uint(b.value().unwrap_or_default() as u128, Some(BuiltinUint::U8))
1047             }
1048             LiteralKind::Char(c) => Literal::Char(c.value().unwrap_or_default()),
1049             LiteralKind::Bool(val) => Literal::Bool(val),
1050         }
1051     }
1052 }