src/librustc_driver/pretty.rs

   1 //! The various pretty-printing routines.
   2
   3 use rustc::cfg;
   4 use rustc::cfg::graphviz::LabelledCFG;
   5 use rustc::hir;
   6 use rustc::hir::map as hir_map;
   7 use rustc::hir::map::blocks;
   8 use rustc::hir::print as pprust_hir;
   9 use rustc::session::Session;
  10 use rustc::session::config::{Input, OutputFilenames};
  11 use rustc::ty::{self, TyCtxt, Resolutions, AllArenas};
  12 use rustc_borrowck as borrowck;
  13 use rustc_borrowck::graphviz as borrowck_dot;
  14 use rustc_data_structures::thin_vec::ThinVec;
  15 use rustc_metadata::cstore::CStore;
  16 use rustc_mir::util::{write_mir_pretty, write_mir_graphviz};
  17
  18 use syntax::ast::{self, BlockCheckMode};
  19 use syntax::mut_visit::{*, MutVisitor, visit_clobber};
  20 use syntax::print::{pprust};
  21 use syntax::print::pprust::PrintState;
  22 use syntax::ptr::P;
  23 use syntax_pos::{self, FileName};
  24
  25 use graphviz as dot;
  26 use smallvec::SmallVec;
  27
  28 use std::cell::Cell;
  29 use std::fs::File;
  30 use std::io::{self, Write};
  31 use std::ops::DerefMut;
  32 use std::option;
  33 use std::path::Path;
  34 use std::str::FromStr;
  35 use std::mem;
  36
  37 pub use self::UserIdentifiedItem::*;
  38 pub use self::PpSourceMode::*;
  39 pub use self::PpMode::*;
  40 use self::NodesMatchingUII::*;
  41 use {abort_on_err, driver};
  42
  43 #[derive(Copy, Clone, PartialEq, Debug)]
  44 pub enum PpSourceMode {
  45     PpmNormal,
  46     PpmEveryBodyLoops,
  47     PpmExpanded,
  48     PpmIdentified,
  49     PpmExpandedIdentified,
  50     PpmExpandedHygiene,
  51     PpmTyped,
  52 }
  53
  54 #[derive(Copy, Clone, PartialEq, Debug)]
  55 pub enum PpFlowGraphMode {
  56     Default,
  57     /// Drops the labels from the edges in the flowgraph output. This
  58     /// is mostly for use in the -Z unpretty flowgraph run-make tests,
  59     /// since the labels are largely uninteresting in those cases and
  60     /// have become a pain to maintain.
  61     UnlabelledEdges,
  62 }
  63 #[derive(Copy, Clone, PartialEq, Debug)]
  64 pub enum PpMode {
  65     PpmSource(PpSourceMode),
  66     PpmHir(PpSourceMode),
  67     PpmHirTree(PpSourceMode),
  68     PpmFlowGraph(PpFlowGraphMode),
  69     PpmMir,
  70     PpmMirCFG,
  71 }
  72
  73 impl PpMode {
  74     pub fn needs_ast_map(&self, opt_uii: &Option<UserIdentifiedItem>) -> bool {
  75         match *self {
  76             PpmSource(PpmNormal) |
  77             PpmSource(PpmEveryBodyLoops) |
  78             PpmSource(PpmIdentified) => opt_uii.is_some(),
  79
  80             PpmSource(PpmExpanded) |
  81             PpmSource(PpmExpandedIdentified) |
  82             PpmSource(PpmExpandedHygiene) |
  83             PpmHir(_) |
  84             PpmHirTree(_) |
  85             PpmMir |
  86             PpmMirCFG |
  87             PpmFlowGraph(_) => true,
  88             PpmSource(PpmTyped) => panic!("invalid state"),
  89         }
  90     }
  91
  92     pub fn needs_analysis(&self) -> bool {
  93         match *self {
  94             PpmMir | PpmMirCFG | PpmFlowGraph(_) => true,
  95             _ => false,
  96         }
  97     }
  98 }
  99
 100 pub fn parse_pretty(sess: &Session,
 101                     name: &str,
 102                     extended: bool)
 103                     -> (PpMode, Option<UserIdentifiedItem>) {
 104     let mut split = name.splitn(2, '=');
 105     let first = split.next().unwrap();
 106     let opt_second = split.next();
 107     let first = match (first, extended) {
 108         ("normal", _) => PpmSource(PpmNormal),
 109         ("identified", _) => PpmSource(PpmIdentified),
 110         ("everybody_loops", true) => PpmSource(PpmEveryBodyLoops),
 111         ("expanded", _) => PpmSource(PpmExpanded),
 112         ("expanded,identified", _) => PpmSource(PpmExpandedIdentified),
 113         ("expanded,hygiene", _) => PpmSource(PpmExpandedHygiene),
 114         ("hir", true) => PpmHir(PpmNormal),
 115         ("hir,identified", true) => PpmHir(PpmIdentified),
 116         ("hir,typed", true) => PpmHir(PpmTyped),
 117         ("hir-tree", true) => PpmHirTree(PpmNormal),
 118         ("mir", true) => PpmMir,
 119         ("mir-cfg", true) => PpmMirCFG,
 120         ("flowgraph", true) => PpmFlowGraph(PpFlowGraphMode::Default),
 121         ("flowgraph,unlabelled", true) => PpmFlowGraph(PpFlowGraphMode::UnlabelledEdges),
 122         _ => {
 123             if extended {
 124                 sess.fatal(&format!("argument to `unpretty` must be one of `normal`, \
 125                                      `expanded`, `flowgraph[,unlabelled]=<nodeid>`, \
 126                                      `identified`, `expanded,identified`, `everybody_loops`, \
 127                                      `hir`, `hir,identified`, `hir,typed`, `hir-tree`, \
 128                                      `mir` or `mir-cfg`; got {}",
 129                                     name));
 130             } else {
 131                 sess.fatal(&format!("argument to `pretty` must be one of `normal`, `expanded`, \
 132                                      `identified`, or `expanded,identified`; got {}",
 133                                     name));
 134             }
 135         }
 136     };
 137     let opt_second = opt_second.and_then(|s| s.parse::<UserIdentifiedItem>().ok());
 138     (first, opt_second)
 139 }
 140
 141
 142
 143 // This slightly awkward construction is to allow for each PpMode to
 144 // choose whether it needs to do analyses (which can consume the
 145 // Session) and then pass through the session (now attached to the
 146 // analysis results) on to the chosen pretty-printer, along with the
 147 // `&PpAnn` object.
 148 //
 149 // Note that since the `&PrinterSupport` is freshly constructed on each
 150 // call, it would not make sense to try to attach the lifetime of `self`
 151 // to the lifetime of the `&PrinterObject`.
 152 //
 153 // (The `use_once_payload` is working around the current lack of once
 154 // functions in the compiler.)
 155
 156 impl PpSourceMode {
 157     /// Constructs a `PrinterSupport` object and passes it to `f`.
 158     fn call_with_pp_support<'tcx, A, F>(&self,
 159                                         sess: &'tcx Session,
 160                                         hir_map: Option<&hir_map::Map<'tcx>>,
 161                                         f: F)
 162                                         -> A
 163         where F: FnOnce(&dyn PrinterSupport) -> A
 164     {
 165         match *self {
 166             PpmNormal | PpmEveryBodyLoops | PpmExpanded => {
 167                 let annotation = NoAnn {
 168                     sess,
 169                     hir_map: hir_map.map(|m| m.clone()),
 170                 };
 171                 f(&annotation)
 172             }
 173
 174             PpmIdentified | PpmExpandedIdentified => {
 175                 let annotation = IdentifiedAnnotation {
 176                     sess,
 177                     hir_map: hir_map.map(|m| m.clone()),
 178                 };
 179                 f(&annotation)
 180             }
 181             PpmExpandedHygiene => {
 182                 let annotation = HygieneAnnotation {
 183                     sess,
 184                 };
 185                 f(&annotation)
 186             }
 187             _ => panic!("Should use call_with_pp_support_hir"),
 188         }
 189     }
 190     fn call_with_pp_support_hir<'tcx, A, F>(
 191         &self,
 192         sess: &'tcx Session,
 193         cstore: &'tcx CStore,
 194         hir_map: &hir_map::Map<'tcx>,
 195         resolutions: &Resolutions,
 196         output_filenames: &OutputFilenames,
 197         id: &str,
 198         f: F
 199     ) -> A
 200         where F: FnOnce(&dyn HirPrinterSupport, &hir::Crate) -> A
 201     {
 202         match *self {
 203             PpmNormal => {
 204                 let annotation = NoAnn {
 205                     sess,
 206                     hir_map: Some(hir_map.clone()),
 207                 };
 208                 f(&annotation, hir_map.forest.krate())
 209             }
 210
 211             PpmIdentified => {
 212                 let annotation = IdentifiedAnnotation {
 213                     sess,
 214                     hir_map: Some(hir_map.clone()),
 215                 };
 216                 f(&annotation, hir_map.forest.krate())
 217             }
 218             PpmTyped => {
 219                 let control = &driver::CompileController::basic();
 220                 let codegen_backend = ::get_codegen_backend(sess);
 221                 let mut arenas = AllArenas::new();
 222                 abort_on_err(driver::phase_3_run_analysis_passes(&*codegen_backend,
 223                                                                  control,
 224                                                                  sess,
 225                                                                  cstore,
 226                                                                  hir_map.clone(),
 227                                                                  resolutions.clone(),
 228                                                                  &mut arenas,
 229                                                                  id,
 230                                                                  output_filenames,
 231                                                                  |tcx, _, _| {
 232                     let empty_tables = ty::TypeckTables::empty(None);
 233                     let annotation = TypedAnnotation {
 234                         tcx,
 235                         tables: Cell::new(&empty_tables)
 236                     };
 237                     tcx.dep_graph.with_ignore(|| {
 238                         f(&annotation, hir_map.forest.krate())
 239                     })
 240                 }),
 241                              sess)
 242             }
 243             _ => panic!("Should use call_with_pp_support"),
 244         }
 245     }
 246 }
 247
 248 trait PrinterSupport: pprust::PpAnn {
 249     /// Provides a uniform interface for re-extracting a reference to a
 250     /// `Session` from a value that now owns it.
 251     fn sess<'a>(&'a self) -> &'a Session;
 252
 253     /// Produces the pretty-print annotation object.
 254     ///
 255     /// (Rust does not yet support upcasting from a trait object to
 256     /// an object for one of its super-traits.)
 257     fn pp_ann<'a>(&'a self) -> &'a dyn pprust::PpAnn;
 258 }
 259
 260 trait HirPrinterSupport<'hir>: pprust_hir::PpAnn {
 261     /// Provides a uniform interface for re-extracting a reference to a
 262     /// `Session` from a value that now owns it.
 263     fn sess<'a>(&'a self) -> &'a Session;
 264
 265     /// Provides a uniform interface for re-extracting a reference to an
 266     /// `hir_map::Map` from a value that now owns it.
 267     fn hir_map<'a>(&'a self) -> Option<&'a hir_map::Map<'hir>>;
 268
 269     /// Produces the pretty-print annotation object.
 270     ///
 271     /// (Rust does not yet support upcasting from a trait object to
 272     /// an object for one of its super-traits.)
 273     fn pp_ann<'a>(&'a self) -> &'a dyn pprust_hir::PpAnn;
 274
 275     /// Computes an user-readable representation of a path, if possible.
 276     fn node_path(&self, id: ast::NodeId) -> Option<String> {
 277         self.hir_map().and_then(|map| map.def_path_from_id(id)).map(|path| {
 278             path.data
 279                 .into_iter()
 280                 .map(|elem| elem.data.to_string())
 281                 .collect::<Vec<_>>()
 282                 .join("::")
 283         })
 284     }
 285 }
 286
 287 struct NoAnn<'hir> {
 288     sess: &'hir Session,
 289     hir_map: Option<hir_map::Map<'hir>>,
 290 }
 291
 292 impl<'hir> PrinterSupport for NoAnn<'hir> {
 293     fn sess<'a>(&'a self) -> &'a Session {
 294         self.sess
 295     }
 296
 297     fn pp_ann<'a>(&'a self) -> &'a dyn pprust::PpAnn {
 298         self
 299     }
 300 }
 301
 302 impl<'hir> HirPrinterSupport<'hir> for NoAnn<'hir> {
 303     fn sess<'a>(&'a self) -> &'a Session {
 304         self.sess
 305     }
 306
 307     fn hir_map<'a>(&'a self) -> Option<&'a hir_map::Map<'hir>> {
 308         self.hir_map.as_ref()
 309     }
 310
 311     fn pp_ann<'a>(&'a self) -> &'a dyn pprust_hir::PpAnn {
 312         self
 313     }
 314 }
 315
 316 impl<'hir> pprust::PpAnn for NoAnn<'hir> {}
 317 impl<'hir> pprust_hir::PpAnn for NoAnn<'hir> {
 318     fn nested(&self, state: &mut pprust_hir::State, nested: pprust_hir::Nested)
 319               -> io::Result<()> {
 320         if let Some(ref map) = self.hir_map {
 321             pprust_hir::PpAnn::nested(map, state, nested)
 322         } else {
 323             Ok(())
 324         }
 325     }
 326 }
 327
 328 struct IdentifiedAnnotation<'hir> {
 329     sess: &'hir Session,
 330     hir_map: Option<hir_map::Map<'hir>>,
 331 }
 332
 333 impl<'hir> PrinterSupport for IdentifiedAnnotation<'hir> {
 334     fn sess<'a>(&'a self) -> &'a Session {
 335         self.sess
 336     }
 337
 338     fn pp_ann<'a>(&'a self) -> &'a dyn pprust::PpAnn {
 339         self
 340     }
 341 }
 342
 343 impl<'hir> pprust::PpAnn for IdentifiedAnnotation<'hir> {
 344     fn pre(&self, s: &mut pprust::State, node: pprust::AnnNode) -> io::Result<()> {
 345         match node {
 346             pprust::AnnNode::Expr(_) => s.popen(),
 347             _ => Ok(()),
 348         }
 349     }
 350     fn post(&self, s: &mut pprust::State, node: pprust::AnnNode) -> io::Result<()> {
 351         match node {
 352             pprust::AnnNode::Ident(_) |
 353             pprust::AnnNode::Name(_) => Ok(()),
 354
 355             pprust::AnnNode::Item(item) => {
 356                 s.s.space()?;
 357                 s.synth_comment(item.id.to_string())
 358             }
 359             pprust::AnnNode::SubItem(id) => {
 360                 s.s.space()?;
 361                 s.synth_comment(id.to_string())
 362             }
 363             pprust::AnnNode::Block(blk) => {
 364                 s.s.space()?;
 365                 s.synth_comment(format!("block {}", blk.id))
 366             }
 367             pprust::AnnNode::Expr(expr) => {
 368                 s.s.space()?;
 369                 s.synth_comment(expr.id.to_string())?;
 370                 s.pclose()
 371             }
 372             pprust::AnnNode::Pat(pat) => {
 373                 s.s.space()?;
 374                 s.synth_comment(format!("pat {}", pat.id))
 375             }
 376         }
 377     }
 378 }
 379
 380 impl<'hir> HirPrinterSupport<'hir> for IdentifiedAnnotation<'hir> {
 381     fn sess<'a>(&'a self) -> &'a Session {
 382         self.sess
 383     }
 384
 385     fn hir_map<'a>(&'a self) -> Option<&'a hir_map::Map<'hir>> {
 386         self.hir_map.as_ref()
 387     }
 388
 389     fn pp_ann<'a>(&'a self) -> &'a dyn pprust_hir::PpAnn {
 390         self
 391     }
 392 }
 393
 394 impl<'hir> pprust_hir::PpAnn for IdentifiedAnnotation<'hir> {
 395     fn nested(&self, state: &mut pprust_hir::State, nested: pprust_hir::Nested)
 396               -> io::Result<()> {
 397         if let Some(ref map) = self.hir_map {
 398             pprust_hir::PpAnn::nested(map, state, nested)
 399         } else {
 400             Ok(())
 401         }
 402     }
 403     fn pre(&self, s: &mut pprust_hir::State, node: pprust_hir::AnnNode) -> io::Result<()> {
 404         match node {
 405             pprust_hir::AnnNode::Expr(_) => s.popen(),
 406             _ => Ok(()),
 407         }
 408     }
 409     fn post(&self, s: &mut pprust_hir::State, node: pprust_hir::AnnNode) -> io::Result<()> {
 410         match node {
 411             pprust_hir::AnnNode::Name(_) => Ok(()),
 412             pprust_hir::AnnNode::Item(item) => {
 413                 s.s.space()?;
 414                 s.synth_comment(format!("node_id: {} hir local_id: {}",
 415                                         item.id, item.hir_id.local_id.as_u32()))
 416             }
 417             pprust_hir::AnnNode::SubItem(id) => {
 418                 s.s.space()?;
 419                 s.synth_comment(id.to_string())
 420             }
 421             pprust_hir::AnnNode::Block(blk) => {
 422                 s.s.space()?;
 423                 s.synth_comment(format!("block hir_id: {} hir local_id: {}",
 424                                         blk.hir_id, blk.hir_id.local_id.as_u32()))
 425             }
 426             pprust_hir::AnnNode::Expr(expr) => {
 427                 s.s.space()?;
 428                 s.synth_comment(format!("node_id: {} hir local_id: {}",
 429                                         expr.id, expr.hir_id.local_id.as_u32()))?;
 430                 s.pclose()
 431             }
 432             pprust_hir::AnnNode::Pat(pat) => {
 433                 s.s.space()?;
 434                 s.synth_comment(format!("pat node_id: {} hir local_id: {}",
 435                                         pat.id, pat.hir_id.local_id.as_u32()))
 436             }
 437         }
 438     }
 439 }
 440
 441 struct HygieneAnnotation<'a> {
 442     sess: &'a Session
 443 }
 444
 445 impl<'a> PrinterSupport for HygieneAnnotation<'a> {
 446     fn sess(&self) -> &Session {
 447         self.sess
 448     }
 449
 450     fn pp_ann(&self) -> &dyn pprust::PpAnn {
 451         self
 452     }
 453 }
 454
 455 impl<'a> pprust::PpAnn for HygieneAnnotation<'a> {
 456     fn post(&self, s: &mut pprust::State, node: pprust::AnnNode) -> io::Result<()> {
 457         match node {
 458             pprust::AnnNode::Ident(&ast::Ident { name, span }) => {
 459                 s.s.space()?;
 460                 // FIXME #16420: this doesn't display the connections
 461                 // between syntax contexts
 462                 s.synth_comment(format!("{}{:?}", name.as_u32(), span.ctxt()))
 463             }
 464             pprust::AnnNode::Name(&name) => {
 465                 s.s.space()?;
 466                 s.synth_comment(name.as_u32().to_string())
 467             }
 468             _ => Ok(()),
 469         }
 470     }
 471 }
 472
 473
 474 struct TypedAnnotation<'a, 'tcx: 'a> {
 475     tcx: TyCtxt<'a, 'tcx, 'tcx>,
 476     tables: Cell<&'a ty::TypeckTables<'tcx>>,
 477 }
 478
 479 impl<'b, 'tcx> HirPrinterSupport<'tcx> for TypedAnnotation<'b, 'tcx> {
 480     fn sess<'a>(&'a self) -> &'a Session {
 481         &self.tcx.sess
 482     }
 483
 484     fn hir_map<'a>(&'a self) -> Option<&'a hir_map::Map<'tcx>> {
 485         Some(&self.tcx.hir())
 486     }
 487
 488     fn pp_ann<'a>(&'a self) -> &'a dyn pprust_hir::PpAnn {
 489         self
 490     }
 491
 492     fn node_path(&self, id: ast::NodeId) -> Option<String> {
 493         Some(self.tcx.node_path_str(id))
 494     }
 495 }
 496
 497 impl<'a, 'tcx> pprust_hir::PpAnn for TypedAnnotation<'a, 'tcx> {
 498     fn nested(&self, state: &mut pprust_hir::State, nested: pprust_hir::Nested)
 499               -> io::Result<()> {
 500         let old_tables = self.tables.get();
 501         if let pprust_hir::Nested::Body(id) = nested {
 502             self.tables.set(self.tcx.body_tables(id));
 503         }
 504         pprust_hir::PpAnn::nested(self.tcx.hir(), state, nested)?;
 505         self.tables.set(old_tables);
 506         Ok(())
 507     }
 508     fn pre(&self, s: &mut pprust_hir::State, node: pprust_hir::AnnNode) -> io::Result<()> {
 509         match node {
 510             pprust_hir::AnnNode::Expr(_) => s.popen(),
 511             _ => Ok(()),
 512         }
 513     }
 514     fn post(&self, s: &mut pprust_hir::State, node: pprust_hir::AnnNode) -> io::Result<()> {
 515         match node {
 516             pprust_hir::AnnNode::Expr(expr) => {
 517                 s.s.space()?;
 518                 s.s.word("as")?;
 519                 s.s.space()?;
 520                 s.s.word(self.tables.get().expr_ty(expr).to_string())?;
 521                 s.pclose()
 522             }
 523             _ => Ok(()),
 524         }
 525     }
 526 }
 527
 528 fn gather_flowgraph_variants(sess: &Session) -> Vec<borrowck_dot::Variant> {
 529     let print_loans = sess.opts.debugging_opts.flowgraph_print_loans;
 530     let print_moves = sess.opts.debugging_opts.flowgraph_print_moves;
 531     let print_assigns = sess.opts.debugging_opts.flowgraph_print_assigns;
 532     let print_all = sess.opts.debugging_opts.flowgraph_print_all;
 533     let mut variants = Vec::new();
 534     if print_all || print_loans {
 535         variants.push(borrowck_dot::Loans);
 536     }
 537     if print_all || print_moves {
 538         variants.push(borrowck_dot::Moves);
 539     }
 540     if print_all || print_assigns {
 541         variants.push(borrowck_dot::Assigns);
 542     }
 543     variants
 544 }
 545
 546 #[derive(Clone, Debug)]
 547 pub enum UserIdentifiedItem {
 548     ItemViaNode(ast::NodeId),
 549     ItemViaPath(Vec<String>),
 550 }
 551
 552 impl FromStr for UserIdentifiedItem {
 553     type Err = ();
 554     fn from_str(s: &str) -> Result<UserIdentifiedItem, ()> {
 555         Ok(s.parse()
 556             .map(ast::NodeId::from_u32)
 557             .map(ItemViaNode)
 558             .unwrap_or_else(|_| ItemViaPath(s.split("::").map(|s| s.to_string()).collect())))
 559     }
 560 }
 561
 562 enum NodesMatchingUII<'a, 'hir: 'a> {
 563     NodesMatchingDirect(option::IntoIter<ast::NodeId>),
 564     NodesMatchingSuffix(hir_map::NodesMatchingSuffix<'a, 'hir>),
 565 }
 566
 567 impl<'a, 'hir> Iterator for NodesMatchingUII<'a, 'hir> {
 568     type Item = ast::NodeId;
 569
 570     fn next(&mut self) -> Option<ast::NodeId> {
 571         match self {
 572             &mut NodesMatchingDirect(ref mut iter) => iter.next(),
 573             &mut NodesMatchingSuffix(ref mut iter) => iter.next(),
 574         }
 575     }
 576
 577     fn size_hint(&self) -> (usize, Option<usize>) {
 578         match self {
 579             &NodesMatchingDirect(ref iter) => iter.size_hint(),
 580             &NodesMatchingSuffix(ref iter) => iter.size_hint(),
 581         }
 582     }
 583 }
 584
 585 impl UserIdentifiedItem {
 586     fn reconstructed_input(&self) -> String {
 587         match *self {
 588             ItemViaNode(node_id) => node_id.to_string(),
 589             ItemViaPath(ref parts) => parts.join("::"),
 590         }
 591     }
 592
 593     fn all_matching_node_ids<'a, 'hir>(&'a self,
 594                                        map: &'a hir_map::Map<'hir>)
 595                                        -> NodesMatchingUII<'a, 'hir> {
 596         match *self {
 597             ItemViaNode(node_id) => NodesMatchingDirect(Some(node_id).into_iter()),
 598             ItemViaPath(ref parts) => NodesMatchingSuffix(map.nodes_matching_suffix(&parts)),
 599         }
 600     }
 601
 602     fn to_one_node_id(self, user_option: &str, sess: &Session, map: &hir_map::Map) -> ast::NodeId {
 603         let fail_because = |is_wrong_because| -> ast::NodeId {
 604             let message = format!("{} needs NodeId (int) or unique path suffix (b::c::d); got \
 605                                    {}, which {}",
 606                                   user_option,
 607                                   self.reconstructed_input(),
 608                                   is_wrong_because);
 609             sess.fatal(&message)
 610         };
 611
 612         let mut saw_node = ast::DUMMY_NODE_ID;
 613         let mut seen = 0;
 614         for node in self.all_matching_node_ids(map) {
 615             saw_node = node;
 616             seen += 1;
 617             if seen > 1 {
 618                 fail_because("does not resolve uniquely");
 619             }
 620         }
 621         if seen == 0 {
 622             fail_because("does not resolve to any item");
 623         }
 624
 625         assert!(seen == 1);
 626         return saw_node;
 627     }
 628 }
 629
 630 // Note: Also used by librustdoc, see PR #43348. Consider moving this struct elsewhere.
 631 //
 632 // FIXME: Currently the `everybody_loops` transformation is not applied to:
 633 //  * `const fn`, due to issue #43636 that `loop` is not supported for const evaluation. We are
 634 //    waiting for miri to fix that.
 635 //  * `impl Trait`, due to issue #43869 that functions returning impl Trait cannot be diverging.
 636 //    Solving this may require `!` to implement every trait, which relies on the an even more
 637 //    ambitious form of the closed RFC #1637. See also [#34511].
 638 //
 639 // [#34511]: https://github.com/rust-lang/rust/issues/34511#issuecomment-322340401
 640 pub struct ReplaceBodyWithLoop<'a> {
 641     within_static_or_const: bool,
 642     nested_blocks: Option<Vec<ast::Block>>,
 643     sess: &'a Session,
 644 }
 645
 646 impl<'a> ReplaceBodyWithLoop<'a> {
 647     pub fn new(sess: &'a Session) -> ReplaceBodyWithLoop<'a> {
 648         ReplaceBodyWithLoop {
 649             within_static_or_const: false,
 650             nested_blocks: None,
 651             sess
 652         }
 653     }
 654
 655     fn run<R, F: FnOnce(&mut Self) -> R>(&mut self, is_const: bool, action: F) -> R {
 656         let old_const = mem::replace(&mut self.within_static_or_const, is_const);
 657         let old_blocks = self.nested_blocks.take();
 658         let ret = action(self);
 659         self.within_static_or_const = old_const;
 660         self.nested_blocks = old_blocks;
 661         ret
 662     }
 663
 664     fn should_ignore_fn(ret_ty: &ast::FnDecl) -> bool {
 665         if let ast::FunctionRetTy::Ty(ref ty) = ret_ty.output {
 666             fn involves_impl_trait(ty: &ast::Ty) -> bool {
 667                 match ty.node {
 668                     ast::TyKind::ImplTrait(..) => true,
 669                     ast::TyKind::Slice(ref subty) |
 670                     ast::TyKind::Array(ref subty, _) |
 671                     ast::TyKind::Ptr(ast::MutTy { ty: ref subty, .. }) |
 672                     ast::TyKind::Rptr(_, ast::MutTy { ty: ref subty, .. }) |
 673                     ast::TyKind::Paren(ref subty) => involves_impl_trait(subty),
 674                     ast::TyKind::Tup(ref tys) => any_involves_impl_trait(tys.iter()),
 675                     ast::TyKind::Path(_, ref path) => path.segments.iter().any(|seg| {
 676                         match seg.args.as_ref().map(|generic_arg| &**generic_arg) {
 677                             None => false,
 678                             Some(&ast::GenericArgs::AngleBracketed(ref data)) => {
 679                                 let types = data.args.iter().filter_map(|arg| match arg {
 680                                     ast::GenericArg::Type(ty) => Some(ty),
 681                                     _ => None,
 682                                 });
 683                                 any_involves_impl_trait(types.into_iter()) ||
 684                                 any_involves_impl_trait(data.bindings.iter().map(|b| &b.ty))
 685                             },
 686                             Some(&ast::GenericArgs::Parenthesized(ref data)) => {
 687                                 any_involves_impl_trait(data.inputs.iter()) ||
 688                                 any_involves_impl_trait(data.output.iter())
 689                             }
 690                         }
 691                     }),
 692                     _ => false,
 693                 }
 694             }
 695
 696             fn any_involves_impl_trait<'a, I: Iterator<Item = &'a P<ast::Ty>>>(mut it: I) -> bool {
 697                 it.any(|subty| involves_impl_trait(subty))
 698             }
 699
 700             involves_impl_trait(ty)
 701         } else {
 702             false
 703         }
 704     }
 705 }
 706
 707 impl<'a> MutVisitor for ReplaceBodyWithLoop<'a> {
 708     fn visit_item_kind(&mut self, i: &mut ast::ItemKind) {
 709         let is_const = match i {
 710             ast::ItemKind::Static(..) | ast::ItemKind::Const(..) => true,
 711             ast::ItemKind::Fn(ref decl, ref header, _, _) =>
 712                 header.constness.node == ast::Constness::Const || Self::should_ignore_fn(decl),
 713             _ => false,
 714         };
 715         self.run(is_const, |s| noop_visit_item_kind(i, s))
 716     }
 717
 718     fn flat_map_trait_item(&mut self, i: ast::TraitItem) -> SmallVec<[ast::TraitItem; 1]> {
 719         let is_const = match i.node {
 720             ast::TraitItemKind::Const(..) => true,
 721             ast::TraitItemKind::Method(ast::MethodSig { ref decl, ref header, .. }, _) =>
 722                 header.constness.node == ast::Constness::Const || Self::should_ignore_fn(decl),
 723             _ => false,
 724         };
 725         self.run(is_const, |s| noop_flat_map_trait_item(i, s))
 726     }
 727
 728     fn flat_map_impl_item(&mut self, i: ast::ImplItem) -> SmallVec<[ast::ImplItem; 1]> {
 729         let is_const = match i.node {
 730             ast::ImplItemKind::Const(..) => true,
 731             ast::ImplItemKind::Method(ast::MethodSig { ref decl, ref header, .. }, _) =>
 732                 header.constness.node == ast::Constness::Const || Self::should_ignore_fn(decl),
 733             _ => false,
 734         };
 735         self.run(is_const, |s| noop_flat_map_impl_item(i, s))
 736     }
 737
 738     fn visit_anon_const(&mut self, c: &mut ast::AnonConst) {
 739         self.run(true, |s| noop_visit_anon_const(c, s))
 740     }
 741
 742     fn visit_block(&mut self, b: &mut P<ast::Block>) {
 743         fn stmt_to_block(rules: ast::BlockCheckMode,
 744                          s: Option<ast::Stmt>,
 745                          sess: &Session) -> ast::Block {
 746             ast::Block {
 747                 stmts: s.into_iter().collect(),
 748                 rules,
 749                 id: sess.next_node_id(),
 750                 span: syntax_pos::DUMMY_SP,
 751             }
 752         }
 753
 754         fn block_to_stmt(b: ast::Block, sess: &Session) -> ast::Stmt {
 755             let expr = P(ast::Expr {
 756                 id: sess.next_node_id(),
 757                 node: ast::ExprKind::Block(P(b), None),
 758                 span: syntax_pos::DUMMY_SP,
 759                 attrs: ThinVec::new(),
 760             });
 761
 762             ast::Stmt {
 763                 id: sess.next_node_id(),
 764                 node: ast::StmtKind::Expr(expr),
 765                 span: syntax_pos::DUMMY_SP,
 766             }
 767         }
 768
 769         let empty_block = stmt_to_block(BlockCheckMode::Default, None, self.sess);
 770         let loop_expr = P(ast::Expr {
 771             node: ast::ExprKind::Loop(P(empty_block), None),
 772             id: self.sess.next_node_id(),
 773             span: syntax_pos::DUMMY_SP,
 774                 attrs: ThinVec::new(),
 775         });
 776
 777         let loop_stmt = ast::Stmt {
 778             id: self.sess.next_node_id(),
 779             span: syntax_pos::DUMMY_SP,
 780             node: ast::StmtKind::Expr(loop_expr),
 781         };
 782
 783         if self.within_static_or_const {
 784             noop_visit_block(b, self)
 785         } else {
 786             visit_clobber(b.deref_mut(), |b| {
 787                 let mut stmts = vec![];
 788                 for s in b.stmts {
 789                     let old_blocks = self.nested_blocks.replace(vec![]);
 790
 791                     stmts.extend(self.flat_map_stmt(s).into_iter().filter(|s| s.is_item()));
 792
 793                     // we put a Some in there earlier with that replace(), so this is valid
 794                     let new_blocks = self.nested_blocks.take().unwrap();
 795                     self.nested_blocks = old_blocks;
 796                     stmts.extend(new_blocks.into_iter().map(|b| block_to_stmt(b, &self.sess)));
 797                 }
 798
 799                 let mut new_block = ast::Block {
 800                     stmts,
 801                     ..b
 802                 };
 803
 804                 if let Some(old_blocks) = self.nested_blocks.as_mut() {
 805                     //push our fresh block onto the cache and yield an empty block with `loop {}`
 806                     if !new_block.stmts.is_empty() {
 807                         old_blocks.push(new_block);
 808                     }
 809
 810                     stmt_to_block(b.rules, Some(loop_stmt), self.sess)
 811                 } else {
 812                     //push `loop {}` onto the end of our fresh block and yield that
 813                     new_block.stmts.push(loop_stmt);
 814
 815                     new_block
 816                 }
 817             })
 818         }
 819     }
 820
 821     // in general the pretty printer processes unexpanded code, so
 822     // we override the default `visit_mac` method which panics.
 823     fn visit_mac(&mut self, mac: &mut ast::Mac) {
 824         noop_visit_mac(mac, self)
 825     }
 826 }
 827
 828 fn print_flowgraph<'a, 'tcx, W: Write>(variants: Vec<borrowck_dot::Variant>,
 829                                        tcx: TyCtxt<'a, 'tcx, 'tcx>,
 830                                        code: blocks::Code<'tcx>,
 831                                        mode: PpFlowGraphMode,
 832                                        mut out: W)
 833                                        -> io::Result<()> {
 834     let body_id = match code {
 835         blocks::Code::Expr(expr) => {
 836             // Find the function this expression is from.
 837             let mut node_id = expr.id;
 838             loop {
 839                 let node = tcx.hir().get(node_id);
 840                 if let Some(n) = hir::map::blocks::FnLikeNode::from_node(node) {
 841                     break n.body();
 842                 }
 843                 let parent = tcx.hir().get_parent_node(node_id);
 844                 assert_ne!(node_id, parent);
 845                 node_id = parent;
 846             }
 847         }
 848         blocks::Code::FnLike(fn_like) => fn_like.body(),
 849     };
 850     let body = tcx.hir().body(body_id);
 851     let cfg = cfg::CFG::new(tcx, &body);
 852     let labelled_edges = mode != PpFlowGraphMode::UnlabelledEdges;
 853     let lcfg = LabelledCFG {
 854         tcx,
 855         cfg: &cfg,
 856         name: format!("node_{}", code.id()),
 857         labelled_edges,
 858     };
 859
 860     match code {
 861         _ if variants.is_empty() => {
 862             let r = dot::render(&lcfg, &mut out);
 863             return expand_err_details(r);
 864         }
 865         blocks::Code::Expr(_) => {
 866             tcx.sess.err("--pretty flowgraph with -Z flowgraph-print annotations requires \
 867                           fn-like node id.");
 868             return Ok(());
 869         }
 870         blocks::Code::FnLike(fn_like) => {
 871             let (bccx, analysis_data) =
 872                 borrowck::build_borrowck_dataflow_data_for_fn(tcx, fn_like.body(), &cfg);
 873
 874             let lcfg = borrowck_dot::DataflowLabeller {
 875                 inner: lcfg,
 876                 variants,
 877                 borrowck_ctxt: &bccx,
 878                 analysis_data: &analysis_data,
 879             };
 880             let r = dot::render(&lcfg, &mut out);
 881             return expand_err_details(r);
 882         }
 883     }
 884
 885     fn expand_err_details(r: io::Result<()>) -> io::Result<()> {
 886         r.map_err(|ioerr| {
 887             io::Error::new(io::ErrorKind::Other,
 888                            format!("graphviz::render failed: {}", ioerr))
 889         })
 890     }
 891 }
 892
 893 pub fn visit_crate(sess: &Session, krate: &mut ast::Crate, ppm: PpMode) {
 894     if let PpmSource(PpmEveryBodyLoops) = ppm {
 895         ReplaceBodyWithLoop::new(sess).visit_crate(krate);
 896     }
 897 }
 898
 899 fn get_source(input: &Input, sess: &Session) -> (Vec<u8>, FileName) {
 900     let src_name = driver::source_name(input);
 901     let src = sess.source_map()
 902         .get_source_file(&src_name)
 903         .unwrap()
 904         .src
 905         .as_ref()
 906         .unwrap()
 907         .as_bytes()
 908         .to_vec();
 909     (src, src_name)
 910 }
 911
 912 fn write_output(out: Vec<u8>, ofile: Option<&Path>) {
 913     match ofile {
 914         None => print!("{}", String::from_utf8(out).unwrap()),
 915         Some(p) => {
 916             match File::create(p) {
 917                 Ok(mut w) => w.write_all(&out).unwrap(),
 918                 Err(e) => panic!("print-print failed to open {} due to {}", p.display(), e),
 919             }
 920         }
 921     }
 922 }
 923
 924 pub fn print_after_parsing(sess: &Session,
 925                            input: &Input,
 926                            krate: &ast::Crate,
 927                            ppm: PpMode,
 928                            ofile: Option<&Path>) {
 929     let (src, src_name) = get_source(input, sess);
 930
 931     let mut rdr = &*src;
 932     let mut out = Vec::new();
 933
 934     if let PpmSource(s) = ppm {
 935         // Silently ignores an identified node.
 936         let out: &mut dyn Write = &mut out;
 937         s.call_with_pp_support(sess, None, move |annotation| {
 938             debug!("pretty printing source code {:?}", s);
 939             let sess = annotation.sess();
 940             pprust::print_crate(sess.source_map(),
 941                                 &sess.parse_sess,
 942                                 krate,
 943                                 src_name,
 944                                 &mut rdr,
 945                                 box out,
 946                                 annotation.pp_ann(),
 947                                 false)
 948         }).unwrap()
 949     } else {
 950         unreachable!();
 951     };
 952
 953     write_output(out, ofile);
 954 }
 955
 956 pub fn print_after_hir_lowering<'tcx, 'a: 'tcx>(sess: &'a Session,
 957                                                 cstore: &'tcx CStore,
 958                                                 hir_map: &hir_map::Map<'tcx>,
 959                                                 resolutions: &Resolutions,
 960                                                 input: &Input,
 961                                                 krate: &ast::Crate,
 962                                                 crate_name: &str,
 963                                                 ppm: PpMode,
 964                                                 output_filenames: &OutputFilenames,
 965                                                 opt_uii: Option<UserIdentifiedItem>,
 966                                                 ofile: Option<&Path>) {
 967     if ppm.needs_analysis() {
 968         print_with_analysis(sess,
 969                             cstore,
 970                             hir_map,
 971                             resolutions,
 972                             crate_name,
 973                             output_filenames,
 974                             ppm,
 975                             opt_uii,
 976                             ofile);
 977         return;
 978     }
 979
 980     let (src, src_name) = get_source(input, sess);
 981
 982     let mut rdr = &src[..];
 983     let mut out = Vec::new();
 984
 985     match (ppm, opt_uii) {
 986             (PpmSource(s), _) => {
 987                 // Silently ignores an identified node.
 988                 let out: &mut dyn Write = &mut out;
 989                 s.call_with_pp_support(sess, Some(hir_map), move |annotation| {
 990                     debug!("pretty printing source code {:?}", s);
 991                     let sess = annotation.sess();
 992                     pprust::print_crate(sess.source_map(),
 993                                         &sess.parse_sess,
 994                                         krate,
 995                                         src_name,
 996                                         &mut rdr,
 997                                         box out,
 998                                         annotation.pp_ann(),
 999                                         true)
1000                 })
1001             }
1002
1003             (PpmHir(s), None) => {
1004                 let out: &mut dyn Write = &mut out;
1005                 s.call_with_pp_support_hir(sess,
1006                                            cstore,
1007                                            hir_map,
1008                                            resolutions,
1009                                            output_filenames,
1010                                            crate_name,
1011                                            move |annotation, krate| {
1012                     debug!("pretty printing source code {:?}", s);
1013                     let sess = annotation.sess();
1014                     pprust_hir::print_crate(sess.source_map(),
1015                                             &sess.parse_sess,
1016                                             krate,
1017                                             src_name,
1018                                             &mut rdr,
1019                                             box out,
1020                                             annotation.pp_ann(),
1021                                             true)
1022                 })
1023             }
1024
1025             (PpmHirTree(s), None) => {
1026                 let out: &mut dyn Write = &mut out;
1027                 s.call_with_pp_support_hir(sess,
1028                                            cstore,
1029                                            hir_map,
1030                                            resolutions,
1031                                            output_filenames,
1032                                            crate_name,
1033                                            move |_annotation, krate| {
1034                     debug!("pretty printing source code {:?}", s);
1035                     write!(out, "{:#?}", krate)
1036                 })
1037             }
1038
1039             (PpmHir(s), Some(uii)) => {
1040                 let out: &mut dyn Write = &mut out;
1041                 s.call_with_pp_support_hir(sess,
1042                                            cstore,
1043                                            hir_map,
1044                                            resolutions,
1045                                            output_filenames,
1046                                            crate_name,
1047                                            move |annotation, _| {
1048                     debug!("pretty printing source code {:?}", s);
1049                     let sess = annotation.sess();
1050                     let hir_map = annotation.hir_map().expect("-Z unpretty missing HIR map");
1051                     let mut pp_state = pprust_hir::State::new_from_input(sess.source_map(),
1052                                                                          &sess.parse_sess,
1053                                                                          src_name,
1054                                                                          &mut rdr,
1055                                                                          box out,
1056                                                                          annotation.pp_ann(),
1057                                                                          true);
1058                     for node_id in uii.all_matching_node_ids(hir_map) {
1059                         let node = hir_map.get(node_id);
1060                         pp_state.print_node(node)?;
1061                         pp_state.s.space()?;
1062                         let path = annotation.node_path(node_id)
1063                             .expect("-Z unpretty missing node paths");
1064                         pp_state.synth_comment(path)?;
1065                         pp_state.s.hardbreak()?;
1066                     }
1067                     pp_state.s.eof()
1068                 })
1069             }
1070
1071             (PpmHirTree(s), Some(uii)) => {
1072                 let out: &mut dyn Write = &mut out;
1073                 s.call_with_pp_support_hir(sess,
1074                                            cstore,
1075                                            hir_map,
1076                                            resolutions,
1077                                            output_filenames,
1078                                            crate_name,
1079                                            move |_annotation, _krate| {
1080                     debug!("pretty printing source code {:?}", s);
1081                     for node_id in uii.all_matching_node_ids(hir_map) {
1082                         let node = hir_map.get(node_id);
1083                         write!(out, "{:#?}", node)?;
1084                     }
1085                     Ok(())
1086                 })
1087             }
1088
1089             _ => unreachable!(),
1090         }
1091         .unwrap();
1092
1093     write_output(out, ofile);
1094 }
1095
1096 // In an ideal world, this would be a public function called by the driver after
1097 // analysis is performed. However, we want to call `phase_3_run_analysis_passes`
1098 // with a different callback than the standard driver, so that isn't easy.
1099 // Instead, we call that function ourselves.
1100 fn print_with_analysis<'tcx, 'a: 'tcx>(sess: &'a Session,
1101                                        cstore: &'a CStore,
1102                                        hir_map: &hir_map::Map<'tcx>,
1103                                        resolutions: &Resolutions,
1104                                        crate_name: &str,
1105                                        output_filenames: &OutputFilenames,
1106                                        ppm: PpMode,
1107                                        uii: Option<UserIdentifiedItem>,
1108                                        ofile: Option<&Path>) {
1109     let nodeid = if let Some(uii) = uii {
1110         debug!("pretty printing for {:?}", uii);
1111         Some(uii.to_one_node_id("-Z unpretty", sess, &hir_map))
1112     } else {
1113         debug!("pretty printing for whole crate");
1114         None
1115     };
1116
1117     let mut out = Vec::new();
1118
1119     let control = &driver::CompileController::basic();
1120     let codegen_backend = ::get_codegen_backend(sess);
1121     let mut arenas = AllArenas::new();
1122     abort_on_err(driver::phase_3_run_analysis_passes(&*codegen_backend,
1123                                                      control,
1124                                                      sess,
1125                                                      cstore,
1126                                                      hir_map.clone(),
1127                                                      resolutions.clone(),
1128                                                      &mut arenas,
1129                                                      crate_name,
1130                                                      output_filenames,
1131                                                      |tcx, _, _| {
1132         match ppm {
1133             PpmMir | PpmMirCFG => {
1134                 if let Some(nodeid) = nodeid {
1135                     let def_id = tcx.hir().local_def_id(nodeid);
1136                     match ppm {
1137                         PpmMir => write_mir_pretty(tcx, Some(def_id), &mut out),
1138                         PpmMirCFG => write_mir_graphviz(tcx, Some(def_id), &mut out),
1139                         _ => unreachable!(),
1140                     }?;
1141                 } else {
1142                     match ppm {
1143                         PpmMir => write_mir_pretty(tcx, None, &mut out),
1144                         PpmMirCFG => write_mir_graphviz(tcx, None, &mut out),
1145                         _ => unreachable!(),
1146                     }?;
1147                 }
1148                 Ok(())
1149             }
1150             PpmFlowGraph(mode) => {
1151                 let nodeid =
1152                     nodeid.expect("`pretty flowgraph=..` needs NodeId (int) or unique path \
1153                                    suffix (b::c::d)");
1154                 let node = tcx.hir().find(nodeid).unwrap_or_else(|| {
1155                     tcx.sess.fatal(&format!("--pretty flowgraph couldn't find id: {}", nodeid))
1156                 });
1157
1158                 match blocks::Code::from_node(&tcx.hir(), nodeid) {
1159                     Some(code) => {
1160                         let variants = gather_flowgraph_variants(tcx.sess);
1161
1162                         let out: &mut dyn Write = &mut out;
1163
1164                         print_flowgraph(variants, tcx, code, mode, out)
1165                     }
1166                     None => {
1167                         let message = format!("--pretty=flowgraph needs block, fn, or method; \
1168                                                got {:?}",
1169                                               node);
1170
1171                         tcx.sess.span_fatal(tcx.hir().span(nodeid), &message)
1172                     }
1173                 }
1174             }
1175             _ => unreachable!(),
1176         }
1177     }),
1178                  sess)
1179         .unwrap();
1180
1181     write_output(out, ofile);
1182 }