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::fold::{self, Folder};
  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::option;
  32 use std::path::Path;
  33 use std::str::FromStr;
  34 use std::mem;
  35
  36 pub use self::UserIdentifiedItem::*;
  37 pub use self::PpSourceMode::*;
  38 pub use self::PpMode::*;
  39 use self::NodesMatchingUII::*;
  40 use {abort_on_err, driver};
  41
  42 #[derive(Copy, Clone, PartialEq, Debug)]
  43 pub enum PpSourceMode {
  44     PpmNormal,
  45     PpmEveryBodyLoops,
  46     PpmExpanded,
  47     PpmIdentified,
  48     PpmExpandedIdentified,
  49     PpmExpandedHygiene,
  50     PpmTyped,
  51 }
  52
  53 #[derive(Copy, Clone, PartialEq, Debug)]
  54 pub enum PpFlowGraphMode {
  55     Default,
  56     /// Drops the labels from the edges in the flowgraph output. This
  57     /// is mostly for use in the -Z unpretty flowgraph run-make tests,
  58     /// since the labels are largely uninteresting in those cases and
  59     /// have become a pain to maintain.
  60     UnlabelledEdges,
  61 }
  62 #[derive(Copy, Clone, PartialEq, Debug)]
  63 pub enum PpMode {
  64     PpmSource(PpSourceMode),
  65     PpmHir(PpSourceMode),
  66     PpmHirTree(PpSourceMode),
  67     PpmFlowGraph(PpFlowGraphMode),
  68     PpmMir,
  69     PpmMirCFG,
  70 }
  71
  72 impl PpMode {
  73     pub fn needs_ast_map(&self, opt_uii: &Option<UserIdentifiedItem>) -> bool {
  74         match *self {
  75             PpmSource(PpmNormal) |
  76             PpmSource(PpmEveryBodyLoops) |
  77             PpmSource(PpmIdentified) => opt_uii.is_some(),
  78
  79             PpmSource(PpmExpanded) |
  80             PpmSource(PpmExpandedIdentified) |
  81             PpmSource(PpmExpandedHygiene) |
  82             PpmHir(_) |
  83             PpmHirTree(_) |
  84             PpmMir |
  85             PpmMirCFG |
  86             PpmFlowGraph(_) => true,
  87             PpmSource(PpmTyped) => panic!("invalid state"),
  88         }
  89     }
  90
  91     pub fn needs_analysis(&self) -> bool {
  92         match *self {
  93             PpmMir | PpmMirCFG | PpmFlowGraph(_) => true,
  94             _ => false,
  95         }
  96     }
  97 }
  98
  99 pub fn parse_pretty(sess: &Session,
 100                     name: &str,
 101                     extended: bool)
 102                     -> (PpMode, Option<UserIdentifiedItem>) {
 103     let mut split = name.splitn(2, '=');
 104     let first = split.next().unwrap();
 105     let opt_second = split.next();
 106     let first = match (first, extended) {
 107         ("normal", _) => PpmSource(PpmNormal),
 108         ("identified", _) => PpmSource(PpmIdentified),
 109         ("everybody_loops", true) => PpmSource(PpmEveryBodyLoops),
 110         ("expanded", _) => PpmSource(PpmExpanded),
 111         ("expanded,identified", _) => PpmSource(PpmExpandedIdentified),
 112         ("expanded,hygiene", _) => PpmSource(PpmExpandedHygiene),
 113         ("hir", true) => PpmHir(PpmNormal),
 114         ("hir,identified", true) => PpmHir(PpmIdentified),
 115         ("hir,typed", true) => PpmHir(PpmTyped),
 116         ("hir-tree", true) => PpmHirTree(PpmNormal),
 117         ("mir", true) => PpmMir,
 118         ("mir-cfg", true) => PpmMirCFG,
 119         ("flowgraph", true) => PpmFlowGraph(PpFlowGraphMode::Default),
 120         ("flowgraph,unlabelled", true) => PpmFlowGraph(PpFlowGraphMode::UnlabelledEdges),
 121         _ => {
 122             if extended {
 123                 sess.fatal(&format!("argument to `unpretty` must be one of `normal`, \
 124                                      `expanded`, `flowgraph[,unlabelled]=<nodeid>`, \
 125                                      `identified`, `expanded,identified`, `everybody_loops`, \
 126                                      `hir`, `hir,identified`, `hir,typed`, `hir-tree`, \
 127                                      `mir` or `mir-cfg`; got {}",
 128                                     name));
 129             } else {
 130                 sess.fatal(&format!("argument to `pretty` must be one of `normal`, `expanded`, \
 131                                      `identified`, or `expanded,identified`; got {}",
 132                                     name));
 133             }
 134         }
 135     };
 136     let opt_second = opt_second.and_then(|s| s.parse::<UserIdentifiedItem>().ok());
 137     (first, opt_second)
 138 }
 139
 140
 141
 142 // This slightly awkward construction is to allow for each PpMode to
 143 // choose whether it needs to do analyses (which can consume the
 144 // Session) and then pass through the session (now attached to the
 145 // analysis results) on to the chosen pretty-printer, along with the
 146 // `&PpAnn` object.
 147 //
 148 // Note that since the `&PrinterSupport` is freshly constructed on each
 149 // call, it would not make sense to try to attach the lifetime of `self`
 150 // to the lifetime of the `&PrinterObject`.
 151 //
 152 // (The `use_once_payload` is working around the current lack of once
 153 // functions in the compiler.)
 154
 155 impl PpSourceMode {
 156     /// Constructs a `PrinterSupport` object and passes it to `f`.
 157     fn call_with_pp_support<'tcx, A, F>(&self,
 158                                         sess: &'tcx Session,
 159                                         hir_map: Option<&hir_map::Map<'tcx>>,
 160                                         f: F)
 161                                         -> A
 162         where F: FnOnce(&dyn PrinterSupport) -> A
 163     {
 164         match *self {
 165             PpmNormal | PpmEveryBodyLoops | PpmExpanded => {
 166                 let annotation = NoAnn {
 167                     sess,
 168                     hir_map: hir_map.map(|m| m.clone()),
 169                 };
 170                 f(&annotation)
 171             }
 172
 173             PpmIdentified | PpmExpandedIdentified => {
 174                 let annotation = IdentifiedAnnotation {
 175                     sess,
 176                     hir_map: hir_map.map(|m| m.clone()),
 177                 };
 178                 f(&annotation)
 179             }
 180             PpmExpandedHygiene => {
 181                 let annotation = HygieneAnnotation {
 182                     sess,
 183                 };
 184                 f(&annotation)
 185             }
 186             _ => panic!("Should use call_with_pp_support_hir"),
 187         }
 188     }
 189     fn call_with_pp_support_hir<'tcx, A, F>(
 190         &self,
 191         sess: &'tcx Session,
 192         cstore: &'tcx CStore,
 193         hir_map: &hir_map::Map<'tcx>,
 194         resolutions: &Resolutions,
 195         output_filenames: &OutputFilenames,
 196         id: &str,
 197         f: F
 198     ) -> A
 199         where F: FnOnce(&dyn HirPrinterSupport, &hir::Crate) -> A
 200     {
 201         match *self {
 202             PpmNormal => {
 203                 let annotation = NoAnn {
 204                     sess,
 205                     hir_map: Some(hir_map.clone()),
 206                 };
 207                 f(&annotation, hir_map.forest.krate())
 208             }
 209
 210             PpmIdentified => {
 211                 let annotation = IdentifiedAnnotation {
 212                     sess,
 213                     hir_map: Some(hir_map.clone()),
 214                 };
 215                 f(&annotation, hir_map.forest.krate())
 216             }
 217             PpmTyped => {
 218                 let control = &driver::CompileController::basic();
 219                 let codegen_backend = ::get_codegen_backend(sess);
 220                 let mut arenas = AllArenas::new();
 221                 abort_on_err(driver::phase_3_run_analysis_passes(&*codegen_backend,
 222                                                                  control,
 223                                                                  sess,
 224                                                                  cstore,
 225                                                                  hir_map.clone(),
 226                                                                  resolutions.clone(),
 227                                                                  &mut arenas,
 228                                                                  id,
 229                                                                  output_filenames,
 230                                                                  |tcx, _, _| {
 231                     let empty_tables = ty::TypeckTables::empty(None);
 232                     let annotation = TypedAnnotation {
 233                         tcx,
 234                         tables: Cell::new(&empty_tables)
 235                     };
 236                     tcx.dep_graph.with_ignore(|| {
 237                         f(&annotation, hir_map.forest.krate())
 238                     })
 239                 }),
 240                              sess)
 241             }
 242             _ => panic!("Should use call_with_pp_support"),
 243         }
 244     }
 245 }
 246
 247 trait PrinterSupport: pprust::PpAnn {
 248     /// Provides a uniform interface for re-extracting a reference to a
 249     /// `Session` from a value that now owns it.
 250     fn sess<'a>(&'a self) -> &'a Session;
 251
 252     /// Produces the pretty-print annotation object.
 253     ///
 254     /// (Rust does not yet support upcasting from a trait object to
 255     /// an object for one of its super-traits.)
 256     fn pp_ann<'a>(&'a self) -> &'a dyn pprust::PpAnn;
 257 }
 258
 259 trait HirPrinterSupport<'hir>: pprust_hir::PpAnn {
 260     /// Provides a uniform interface for re-extracting a reference to a
 261     /// `Session` from a value that now owns it.
 262     fn sess<'a>(&'a self) -> &'a Session;
 263
 264     /// Provides a uniform interface for re-extracting a reference to an
 265     /// `hir_map::Map` from a value that now owns it.
 266     fn hir_map<'a>(&'a self) -> Option<&'a hir_map::Map<'hir>>;
 267
 268     /// Produces the pretty-print annotation object.
 269     ///
 270     /// (Rust does not yet support upcasting from a trait object to
 271     /// an object for one of its super-traits.)
 272     fn pp_ann<'a>(&'a self) -> &'a dyn pprust_hir::PpAnn;
 273
 274     /// Computes an user-readable representation of a path, if possible.
 275     fn node_path(&self, id: ast::NodeId) -> Option<String> {
 276         self.hir_map().and_then(|map| map.def_path_from_id(id)).map(|path| {
 277             path.data
 278                 .into_iter()
 279                 .map(|elem| elem.data.to_string())
 280                 .collect::<Vec<_>>()
 281                 .join("::")
 282         })
 283     }
 284 }
 285
 286 struct NoAnn<'hir> {
 287     sess: &'hir Session,
 288     hir_map: Option<hir_map::Map<'hir>>,
 289 }
 290
 291 impl<'hir> PrinterSupport for NoAnn<'hir> {
 292     fn sess<'a>(&'a self) -> &'a Session {
 293         self.sess
 294     }
 295
 296     fn pp_ann<'a>(&'a self) -> &'a dyn pprust::PpAnn {
 297         self
 298     }
 299 }
 300
 301 impl<'hir> HirPrinterSupport<'hir> for NoAnn<'hir> {
 302     fn sess<'a>(&'a self) -> &'a Session {
 303         self.sess
 304     }
 305
 306     fn hir_map<'a>(&'a self) -> Option<&'a hir_map::Map<'hir>> {
 307         self.hir_map.as_ref()
 308     }
 309
 310     fn pp_ann<'a>(&'a self) -> &'a dyn pprust_hir::PpAnn {
 311         self
 312     }
 313 }
 314
 315 impl<'hir> pprust::PpAnn for NoAnn<'hir> {}
 316 impl<'hir> pprust_hir::PpAnn for NoAnn<'hir> {
 317     fn nested(&self, state: &mut pprust_hir::State, nested: pprust_hir::Nested)
 318               -> io::Result<()> {
 319         if let Some(ref map) = self.hir_map {
 320             pprust_hir::PpAnn::nested(map, state, nested)
 321         } else {
 322             Ok(())
 323         }
 324     }
 325 }
 326
 327 struct IdentifiedAnnotation<'hir> {
 328     sess: &'hir Session,
 329     hir_map: Option<hir_map::Map<'hir>>,
 330 }
 331
 332 impl<'hir> PrinterSupport for IdentifiedAnnotation<'hir> {
 333     fn sess<'a>(&'a self) -> &'a Session {
 334         self.sess
 335     }
 336
 337     fn pp_ann<'a>(&'a self) -> &'a dyn pprust::PpAnn {
 338         self
 339     }
 340 }
 341
 342 impl<'hir> pprust::PpAnn for IdentifiedAnnotation<'hir> {
 343     fn pre(&self, s: &mut pprust::State, node: pprust::AnnNode) -> io::Result<()> {
 344         match node {
 345             pprust::AnnNode::Expr(_) => s.popen(),
 346             _ => Ok(()),
 347         }
 348     }
 349     fn post(&self, s: &mut pprust::State, node: pprust::AnnNode) -> io::Result<()> {
 350         match node {
 351             pprust::AnnNode::Ident(_) |
 352             pprust::AnnNode::Name(_) => Ok(()),
 353
 354             pprust::AnnNode::Item(item) => {
 355                 s.s.space()?;
 356                 s.synth_comment(item.id.to_string())
 357             }
 358             pprust::AnnNode::SubItem(id) => {
 359                 s.s.space()?;
 360                 s.synth_comment(id.to_string())
 361             }
 362             pprust::AnnNode::Block(blk) => {
 363                 s.s.space()?;
 364                 s.synth_comment(format!("block {}", blk.id))
 365             }
 366             pprust::AnnNode::Expr(expr) => {
 367                 s.s.space()?;
 368                 s.synth_comment(expr.id.to_string())?;
 369                 s.pclose()
 370             }
 371             pprust::AnnNode::Pat(pat) => {
 372                 s.s.space()?;
 373                 s.synth_comment(format!("pat {}", pat.id))
 374             }
 375         }
 376     }
 377 }
 378
 379 impl<'hir> HirPrinterSupport<'hir> for IdentifiedAnnotation<'hir> {
 380     fn sess<'a>(&'a self) -> &'a Session {
 381         self.sess
 382     }
 383
 384     fn hir_map<'a>(&'a self) -> Option<&'a hir_map::Map<'hir>> {
 385         self.hir_map.as_ref()
 386     }
 387
 388     fn pp_ann<'a>(&'a self) -> &'a dyn pprust_hir::PpAnn {
 389         self
 390     }
 391 }
 392
 393 impl<'hir> pprust_hir::PpAnn for IdentifiedAnnotation<'hir> {
 394     fn nested(&self, state: &mut pprust_hir::State, nested: pprust_hir::Nested)
 395               -> io::Result<()> {
 396         if let Some(ref map) = self.hir_map {
 397             pprust_hir::PpAnn::nested(map, state, nested)
 398         } else {
 399             Ok(())
 400         }
 401     }
 402     fn pre(&self, s: &mut pprust_hir::State, node: pprust_hir::AnnNode) -> io::Result<()> {
 403         match node {
 404             pprust_hir::AnnNode::Expr(_) => s.popen(),
 405             _ => Ok(()),
 406         }
 407     }
 408     fn post(&self, s: &mut pprust_hir::State, node: pprust_hir::AnnNode) -> io::Result<()> {
 409         match node {
 410             pprust_hir::AnnNode::Name(_) => Ok(()),
 411             pprust_hir::AnnNode::Item(item) => {
 412                 s.s.space()?;
 413                 s.synth_comment(format!("node_id: {} hir local_id: {}",
 414                                         item.id, item.hir_id.local_id.as_u32()))
 415             }
 416             pprust_hir::AnnNode::SubItem(id) => {
 417                 s.s.space()?;
 418                 s.synth_comment(id.to_string())
 419             }
 420             pprust_hir::AnnNode::Block(blk) => {
 421                 s.s.space()?;
 422                 s.synth_comment(format!("block node_id: {} hir local_id: {}",
 423                                         blk.id, blk.hir_id.local_id.as_u32()))
 424             }
 425             pprust_hir::AnnNode::Expr(expr) => {
 426                 s.s.space()?;
 427                 s.synth_comment(format!("node_id: {} hir local_id: {}",
 428                                         expr.id, expr.hir_id.local_id.as_u32()))?;
 429                 s.pclose()
 430             }
 431             pprust_hir::AnnNode::Pat(pat) => {
 432                 s.s.space()?;
 433                 s.synth_comment(format!("pat node_id: {} hir local_id: {}",
 434                                         pat.id, pat.hir_id.local_id.as_u32()))
 435             }
 436         }
 437     }
 438 }
 439
 440 struct HygieneAnnotation<'a> {
 441     sess: &'a Session
 442 }
 443
 444 impl<'a> PrinterSupport for HygieneAnnotation<'a> {
 445     fn sess(&self) -> &Session {
 446         self.sess
 447     }
 448
 449     fn pp_ann(&self) -> &dyn pprust::PpAnn {
 450         self
 451     }
 452 }
 453
 454 impl<'a> pprust::PpAnn for HygieneAnnotation<'a> {
 455     fn post(&self, s: &mut pprust::State, node: pprust::AnnNode) -> io::Result<()> {
 456         match node {
 457             pprust::AnnNode::Ident(&ast::Ident { name, span }) => {
 458                 s.s.space()?;
 459                 // FIXME #16420: this doesn't display the connections
 460                 // between syntax contexts
 461                 s.synth_comment(format!("{}{:?}", name.as_u32(), span.ctxt()))
 462             }
 463             pprust::AnnNode::Name(&name) => {
 464                 s.s.space()?;
 465                 s.synth_comment(name.as_u32().to_string())
 466             }
 467             _ => Ok(()),
 468         }
 469     }
 470 }
 471
 472
 473 struct TypedAnnotation<'a, 'tcx: 'a> {
 474     tcx: TyCtxt<'a, 'tcx, 'tcx>,
 475     tables: Cell<&'a ty::TypeckTables<'tcx>>,
 476 }
 477
 478 impl<'b, 'tcx> HirPrinterSupport<'tcx> for TypedAnnotation<'b, 'tcx> {
 479     fn sess<'a>(&'a self) -> &'a Session {
 480         &self.tcx.sess
 481     }
 482
 483     fn hir_map<'a>(&'a self) -> Option<&'a hir_map::Map<'tcx>> {
 484         Some(&self.tcx.hir())
 485     }
 486
 487     fn pp_ann<'a>(&'a self) -> &'a dyn pprust_hir::PpAnn {
 488         self
 489     }
 490
 491     fn node_path(&self, id: ast::NodeId) -> Option<String> {
 492         Some(self.tcx.node_path_str(id))
 493     }
 494 }
 495
 496 impl<'a, 'tcx> pprust_hir::PpAnn for TypedAnnotation<'a, 'tcx> {
 497     fn nested(&self, state: &mut pprust_hir::State, nested: pprust_hir::Nested)
 498               -> io::Result<()> {
 499         let old_tables = self.tables.get();
 500         if let pprust_hir::Nested::Body(id) = nested {
 501             self.tables.set(self.tcx.body_tables(id));
 502         }
 503         pprust_hir::PpAnn::nested(self.tcx.hir(), state, nested)?;
 504         self.tables.set(old_tables);
 505         Ok(())
 506     }
 507     fn pre(&self, s: &mut pprust_hir::State, node: pprust_hir::AnnNode) -> io::Result<()> {
 508         match node {
 509             pprust_hir::AnnNode::Expr(_) => s.popen(),
 510             _ => Ok(()),
 511         }
 512     }
 513     fn post(&self, s: &mut pprust_hir::State, node: pprust_hir::AnnNode) -> io::Result<()> {
 514         match node {
 515             pprust_hir::AnnNode::Expr(expr) => {
 516                 s.s.space()?;
 517                 s.s.word("as")?;
 518                 s.s.space()?;
 519                 s.s.word(self.tables.get().expr_ty(expr).to_string())?;
 520                 s.pclose()
 521             }
 522             _ => Ok(()),
 523         }
 524     }
 525 }
 526
 527 fn gather_flowgraph_variants(sess: &Session) -> Vec<borrowck_dot::Variant> {
 528     let print_loans = sess.opts.debugging_opts.flowgraph_print_loans;
 529     let print_moves = sess.opts.debugging_opts.flowgraph_print_moves;
 530     let print_assigns = sess.opts.debugging_opts.flowgraph_print_assigns;
 531     let print_all = sess.opts.debugging_opts.flowgraph_print_all;
 532     let mut variants = Vec::new();
 533     if print_all || print_loans {
 534         variants.push(borrowck_dot::Loans);
 535     }
 536     if print_all || print_moves {
 537         variants.push(borrowck_dot::Moves);
 538     }
 539     if print_all || print_assigns {
 540         variants.push(borrowck_dot::Assigns);
 541     }
 542     variants
 543 }
 544
 545 #[derive(Clone, Debug)]
 546 pub enum UserIdentifiedItem {
 547     ItemViaNode(ast::NodeId),
 548     ItemViaPath(Vec<String>),
 549 }
 550
 551 impl FromStr for UserIdentifiedItem {
 552     type Err = ();
 553     fn from_str(s: &str) -> Result<UserIdentifiedItem, ()> {
 554         Ok(s.parse()
 555             .map(ast::NodeId::from_u32)
 556             .map(ItemViaNode)
 557             .unwrap_or_else(|_| ItemViaPath(s.split("::").map(|s| s.to_string()).collect())))
 558     }
 559 }
 560
 561 enum NodesMatchingUII<'a, 'hir: 'a> {
 562     NodesMatchingDirect(option::IntoIter<ast::NodeId>),
 563     NodesMatchingSuffix(hir_map::NodesMatchingSuffix<'a, 'hir>),
 564 }
 565
 566 impl<'a, 'hir> Iterator for NodesMatchingUII<'a, 'hir> {
 567     type Item = ast::NodeId;
 568
 569     fn next(&mut self) -> Option<ast::NodeId> {
 570         match self {
 571             &mut NodesMatchingDirect(ref mut iter) => iter.next(),
 572             &mut NodesMatchingSuffix(ref mut iter) => iter.next(),
 573         }
 574     }
 575
 576     fn size_hint(&self) -> (usize, Option<usize>) {
 577         match self {
 578             &NodesMatchingDirect(ref iter) => iter.size_hint(),
 579             &NodesMatchingSuffix(ref iter) => iter.size_hint(),
 580         }
 581     }
 582 }
 583
 584 impl UserIdentifiedItem {
 585     fn reconstructed_input(&self) -> String {
 586         match *self {
 587             ItemViaNode(node_id) => node_id.to_string(),
 588             ItemViaPath(ref parts) => parts.join("::"),
 589         }
 590     }
 591
 592     fn all_matching_node_ids<'a, 'hir>(&'a self,
 593                                        map: &'a hir_map::Map<'hir>)
 594                                        -> NodesMatchingUII<'a, 'hir> {
 595         match *self {
 596             ItemViaNode(node_id) => NodesMatchingDirect(Some(node_id).into_iter()),
 597             ItemViaPath(ref parts) => NodesMatchingSuffix(map.nodes_matching_suffix(&parts)),
 598         }
 599     }
 600
 601     fn to_one_node_id(self, user_option: &str, sess: &Session, map: &hir_map::Map) -> ast::NodeId {
 602         let fail_because = |is_wrong_because| -> ast::NodeId {
 603             let message = format!("{} needs NodeId (int) or unique path suffix (b::c::d); got \
 604                                    {}, which {}",
 605                                   user_option,
 606                                   self.reconstructed_input(),
 607                                   is_wrong_because);
 608             sess.fatal(&message)
 609         };
 610
 611         let mut saw_node = ast::DUMMY_NODE_ID;
 612         let mut seen = 0;
 613         for node in self.all_matching_node_ids(map) {
 614             saw_node = node;
 615             seen += 1;
 616             if seen > 1 {
 617                 fail_because("does not resolve uniquely");
 618             }
 619         }
 620         if seen == 0 {
 621             fail_because("does not resolve to any item");
 622         }
 623
 624         assert!(seen == 1);
 625         return saw_node;
 626     }
 627 }
 628
 629 // Note: Also used by librustdoc, see PR #43348. Consider moving this struct elsewhere.
 630 //
 631 // FIXME: Currently the `everybody_loops` transformation is not applied to:
 632 //  * `const fn`, due to issue #43636 that `loop` is not supported for const evaluation. We are
 633 //    waiting for miri to fix that.
 634 //  * `impl Trait`, due to issue #43869 that functions returning impl Trait cannot be diverging.
 635 //    Solving this may require `!` to implement every trait, which relies on the an even more
 636 //    ambitious form of the closed RFC #1637. See also [#34511].
 637 //
 638 // [#34511]: https://github.com/rust-lang/rust/issues/34511#issuecomment-322340401
 639 pub struct ReplaceBodyWithLoop<'a> {
 640     within_static_or_const: bool,
 641     nested_blocks: Option<Vec<ast::Block>>,
 642     sess: &'a Session,
 643 }
 644
 645 impl<'a> ReplaceBodyWithLoop<'a> {
 646     pub fn new(sess: &'a Session) -> ReplaceBodyWithLoop<'a> {
 647         ReplaceBodyWithLoop {
 648             within_static_or_const: false,
 649             nested_blocks: None,
 650             sess
 651         }
 652     }
 653
 654     fn run<R, F: FnOnce(&mut Self) -> R>(&mut self, is_const: bool, action: F) -> R {
 655         let old_const = mem::replace(&mut self.within_static_or_const, is_const);
 656         let old_blocks = self.nested_blocks.take();
 657         let ret = action(self);
 658         self.within_static_or_const = old_const;
 659         self.nested_blocks = old_blocks;
 660         ret
 661     }
 662
 663     fn should_ignore_fn(ret_ty: &ast::FnDecl) -> bool {
 664         if let ast::FunctionRetTy::Ty(ref ty) = ret_ty.output {
 665             fn involves_impl_trait(ty: &ast::Ty) -> bool {
 666                 match ty.node {
 667                     ast::TyKind::ImplTrait(..) => true,
 668                     ast::TyKind::Slice(ref subty) |
 669                     ast::TyKind::Array(ref subty, _) |
 670                     ast::TyKind::Ptr(ast::MutTy { ty: ref subty, .. }) |
 671                     ast::TyKind::Rptr(_, ast::MutTy { ty: ref subty, .. }) |
 672                     ast::TyKind::Paren(ref subty) => involves_impl_trait(subty),
 673                     ast::TyKind::Tup(ref tys) => any_involves_impl_trait(tys.iter()),
 674                     ast::TyKind::Path(_, ref path) => path.segments.iter().any(|seg| {
 675                         match seg.args.as_ref().map(|generic_arg| &**generic_arg) {
 676                             None => false,
 677                             Some(&ast::GenericArgs::AngleBracketed(ref data)) => {
 678                                 let types = data.args.iter().filter_map(|arg| match arg {
 679                                     ast::GenericArg::Type(ty) => Some(ty),
 680                                     _ => None,
 681                                 });
 682                                 any_involves_impl_trait(types.into_iter()) ||
 683                                 any_involves_impl_trait(data.bindings.iter().map(|b| &b.ty))
 684                             },
 685                             Some(&ast::GenericArgs::Parenthesized(ref data)) => {
 686                                 any_involves_impl_trait(data.inputs.iter()) ||
 687                                 any_involves_impl_trait(data.output.iter())
 688                             }
 689                         }
 690                     }),
 691                     _ => false,
 692                 }
 693             }
 694
 695             fn any_involves_impl_trait<'a, I: Iterator<Item = &'a P<ast::Ty>>>(mut it: I) -> bool {
 696                 it.any(|subty| involves_impl_trait(subty))
 697             }
 698
 699             involves_impl_trait(ty)
 700         } else {
 701             false
 702         }
 703     }
 704 }
 705
 706 impl<'a> fold::Folder for ReplaceBodyWithLoop<'a> {
 707     fn fold_item_kind(&mut self, i: ast::ItemKind) -> ast::ItemKind {
 708         let is_const = match i {
 709             ast::ItemKind::Static(..) | ast::ItemKind::Const(..) => true,
 710             ast::ItemKind::Fn(ref decl, ref header, _, _) =>
 711                 header.constness.node == ast::Constness::Const || Self::should_ignore_fn(decl),
 712             _ => false,
 713         };
 714         self.run(is_const, |s| fold::noop_fold_item_kind(i, s))
 715     }
 716
 717     fn fold_trait_item(&mut self, i: ast::TraitItem) -> SmallVec<[ast::TraitItem; 1]> {
 718         let is_const = match i.node {
 719             ast::TraitItemKind::Const(..) => true,
 720             ast::TraitItemKind::Method(ast::MethodSig { ref decl, ref header, .. }, _) =>
 721                 header.constness.node == ast::Constness::Const || Self::should_ignore_fn(decl),
 722             _ => false,
 723         };
 724         self.run(is_const, |s| fold::noop_fold_trait_item(i, s))
 725     }
 726
 727     fn fold_impl_item(&mut self, i: ast::ImplItem) -> SmallVec<[ast::ImplItem; 1]> {
 728         let is_const = match i.node {
 729             ast::ImplItemKind::Const(..) => true,
 730             ast::ImplItemKind::Method(ast::MethodSig { ref decl, ref header, .. }, _) =>
 731                 header.constness.node == ast::Constness::Const || Self::should_ignore_fn(decl),
 732             _ => false,
 733         };
 734         self.run(is_const, |s| fold::noop_fold_impl_item(i, s))
 735     }
 736
 737     fn fold_anon_const(&mut self, c: ast::AnonConst) -> ast::AnonConst {
 738         self.run(true, |s| fold::noop_fold_anon_const(c, s))
 739     }
 740
 741     fn fold_block(&mut self, b: P<ast::Block>) -> P<ast::Block> {
 742         fn stmt_to_block(rules: ast::BlockCheckMode,
 743                          s: Option<ast::Stmt>,
 744                          sess: &Session) -> ast::Block {
 745             ast::Block {
 746                 stmts: s.into_iter().collect(),
 747                 rules,
 748                 id: sess.next_node_id(),
 749                 span: syntax_pos::DUMMY_SP,
 750             }
 751         }
 752
 753         fn block_to_stmt(b: ast::Block, sess: &Session) -> ast::Stmt {
 754             let expr = P(ast::Expr {
 755                 id: sess.next_node_id(),
 756                 node: ast::ExprKind::Block(P(b), None),
 757                 span: syntax_pos::DUMMY_SP,
 758                 attrs: ThinVec::new(),
 759             });
 760
 761             ast::Stmt {
 762                 id: sess.next_node_id(),
 763                 node: ast::StmtKind::Expr(expr),
 764                 span: syntax_pos::DUMMY_SP,
 765             }
 766         }
 767
 768         let empty_block = stmt_to_block(BlockCheckMode::Default, None, self.sess);
 769         let loop_expr = P(ast::Expr {
 770             node: ast::ExprKind::Loop(P(empty_block), None),
 771             id: self.sess.next_node_id(),
 772             span: syntax_pos::DUMMY_SP,
 773                 attrs: ThinVec::new(),
 774         });
 775
 776         let loop_stmt = ast::Stmt {
 777             id: self.sess.next_node_id(),
 778             span: syntax_pos::DUMMY_SP,
 779             node: ast::StmtKind::Expr(loop_expr),
 780         };
 781
 782         if self.within_static_or_const {
 783             fold::noop_fold_block(b, self)
 784         } else {
 785             b.map(|b| {
 786                 let mut stmts = vec![];
 787                 for s in b.stmts {
 788                     let old_blocks = self.nested_blocks.replace(vec![]);
 789
 790                     stmts.extend(self.fold_stmt(s).into_iter().filter(|s| s.is_item()));
 791
 792                     // we put a Some in there earlier with that replace(), so this is valid
 793                     let new_blocks = self.nested_blocks.take().unwrap();
 794                     self.nested_blocks = old_blocks;
 795                     stmts.extend(new_blocks.into_iter().map(|b| block_to_stmt(b, &self.sess)));
 796                 }
 797
 798                 let mut new_block = ast::Block {
 799                     stmts,
 800                     ..b
 801                 };
 802
 803                 if let Some(old_blocks) = self.nested_blocks.as_mut() {
 804                     //push our fresh block onto the cache and yield an empty block with `loop {}`
 805                     if !new_block.stmts.is_empty() {
 806                         old_blocks.push(new_block);
 807                     }
 808
 809                     stmt_to_block(b.rules, Some(loop_stmt), self.sess)
 810                 } else {
 811                     //push `loop {}` onto the end of our fresh block and yield that
 812                     new_block.stmts.push(loop_stmt);
 813
 814                     new_block
 815                 }
 816             })
 817         }
 818     }
 819
 820     // in general the pretty printer processes unexpanded code, so
 821     // we override the default `fold_mac` method which panics.
 822     fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
 823         fold::noop_fold_mac(mac, self)
 824     }
 825 }
 826
 827 fn print_flowgraph<'a, 'tcx, W: Write>(variants: Vec<borrowck_dot::Variant>,
 828                                        tcx: TyCtxt<'a, 'tcx, 'tcx>,
 829                                        code: blocks::Code<'tcx>,
 830                                        mode: PpFlowGraphMode,
 831                                        mut out: W)
 832                                        -> io::Result<()> {
 833     let body_id = match code {
 834         blocks::Code::Expr(expr) => {
 835             // Find the function this expression is from.
 836             let mut node_id = expr.id;
 837             loop {
 838                 let node = tcx.hir().get(node_id);
 839                 if let Some(n) = hir::map::blocks::FnLikeNode::from_node(node) {
 840                     break n.body();
 841                 }
 842                 let parent = tcx.hir().get_parent_node(node_id);
 843                 assert_ne!(node_id, parent);
 844                 node_id = parent;
 845             }
 846         }
 847         blocks::Code::FnLike(fn_like) => fn_like.body(),
 848     };
 849     let body = tcx.hir().body(body_id);
 850     let cfg = cfg::CFG::new(tcx, &body);
 851     let labelled_edges = mode != PpFlowGraphMode::UnlabelledEdges;
 852     let lcfg = LabelledCFG {
 853         tcx,
 854         cfg: &cfg,
 855         name: format!("node_{}", code.id()),
 856         labelled_edges,
 857     };
 858
 859     match code {
 860         _ if variants.is_empty() => {
 861             let r = dot::render(&lcfg, &mut out);
 862             return expand_err_details(r);
 863         }
 864         blocks::Code::Expr(_) => {
 865             tcx.sess.err("--pretty flowgraph with -Z flowgraph-print annotations requires \
 866                           fn-like node id.");
 867             return Ok(());
 868         }
 869         blocks::Code::FnLike(fn_like) => {
 870             let (bccx, analysis_data) =
 871                 borrowck::build_borrowck_dataflow_data_for_fn(tcx, fn_like.body(), &cfg);
 872
 873             let lcfg = borrowck_dot::DataflowLabeller {
 874                 inner: lcfg,
 875                 variants,
 876                 borrowck_ctxt: &bccx,
 877                 analysis_data: &analysis_data,
 878             };
 879             let r = dot::render(&lcfg, &mut out);
 880             return expand_err_details(r);
 881         }
 882     }
 883
 884     fn expand_err_details(r: io::Result<()>) -> io::Result<()> {
 885         r.map_err(|ioerr| {
 886             io::Error::new(io::ErrorKind::Other,
 887                            format!("graphviz::render failed: {}", ioerr))
 888         })
 889     }
 890 }
 891
 892 pub fn fold_crate(sess: &Session, krate: ast::Crate, ppm: PpMode) -> ast::Crate {
 893     if let PpmSource(PpmEveryBodyLoops) = ppm {
 894         let mut fold = ReplaceBodyWithLoop::new(sess);
 895         fold.fold_crate(krate)
 896     } else {
 897         krate
 898     }
 899 }
 900
 901 fn get_source(input: &Input, sess: &Session) -> (Vec<u8>, FileName) {
 902     let src_name = driver::source_name(input);
 903     let src = sess.source_map()
 904         .get_source_file(&src_name)
 905         .unwrap()
 906         .src
 907         .as_ref()
 908         .unwrap()
 909         .as_bytes()
 910         .to_vec();
 911     (src, src_name)
 912 }
 913
 914 fn write_output(out: Vec<u8>, ofile: Option<&Path>) {
 915     match ofile {
 916         None => print!("{}", String::from_utf8(out).unwrap()),
 917         Some(p) => {
 918             match File::create(p) {
 919                 Ok(mut w) => w.write_all(&out).unwrap(),
 920                 Err(e) => panic!("print-print failed to open {} due to {}", p.display(), e),
 921             }
 922         }
 923     }
 924 }
 925
 926 pub fn print_after_parsing(sess: &Session,
 927                            input: &Input,
 928                            krate: &ast::Crate,
 929                            ppm: PpMode,
 930                            ofile: Option<&Path>) {
 931     let (src, src_name) = get_source(input, sess);
 932
 933     let mut rdr = &*src;
 934     let mut out = Vec::new();
 935
 936     if let PpmSource(s) = ppm {
 937         // Silently ignores an identified node.
 938         let out: &mut dyn Write = &mut out;
 939         s.call_with_pp_support(sess, None, move |annotation| {
 940             debug!("pretty printing source code {:?}", s);
 941             let sess = annotation.sess();
 942             pprust::print_crate(sess.source_map(),
 943                                 &sess.parse_sess,
 944                                 krate,
 945                                 src_name,
 946                                 &mut rdr,
 947                                 box out,
 948                                 annotation.pp_ann(),
 949                                 false)
 950         }).unwrap()
 951     } else {
 952         unreachable!();
 953     };
 954
 955     write_output(out, ofile);
 956 }
 957
 958 pub fn print_after_hir_lowering<'tcx, 'a: 'tcx>(sess: &'a Session,
 959                                                 cstore: &'tcx CStore,
 960                                                 hir_map: &hir_map::Map<'tcx>,
 961                                                 resolutions: &Resolutions,
 962                                                 input: &Input,
 963                                                 krate: &ast::Crate,
 964                                                 crate_name: &str,
 965                                                 ppm: PpMode,
 966                                                 output_filenames: &OutputFilenames,
 967                                                 opt_uii: Option<UserIdentifiedItem>,
 968                                                 ofile: Option<&Path>) {
 969     if ppm.needs_analysis() {
 970         print_with_analysis(sess,
 971                             cstore,
 972                             hir_map,
 973                             resolutions,
 974                             crate_name,
 975                             output_filenames,
 976                             ppm,
 977                             opt_uii,
 978                             ofile);
 979         return;
 980     }
 981
 982     let (src, src_name) = get_source(input, sess);
 983
 984     let mut rdr = &src[..];
 985     let mut out = Vec::new();
 986
 987     match (ppm, opt_uii) {
 988             (PpmSource(s), _) => {
 989                 // Silently ignores an identified node.
 990                 let out: &mut dyn Write = &mut out;
 991                 s.call_with_pp_support(sess, Some(hir_map), move |annotation| {
 992                     debug!("pretty printing source code {:?}", s);
 993                     let sess = annotation.sess();
 994                     pprust::print_crate(sess.source_map(),
 995                                         &sess.parse_sess,
 996                                         krate,
 997                                         src_name,
 998                                         &mut rdr,
 999                                         box out,
1000                                         annotation.pp_ann(),
1001                                         true)
1002                 })
1003             }
1004
1005             (PpmHir(s), None) => {
1006                 let out: &mut dyn Write = &mut out;
1007                 s.call_with_pp_support_hir(sess,
1008                                            cstore,
1009                                            hir_map,
1010                                            resolutions,
1011                                            output_filenames,
1012                                            crate_name,
1013                                            move |annotation, krate| {
1014                     debug!("pretty printing source code {:?}", s);
1015                     let sess = annotation.sess();
1016                     pprust_hir::print_crate(sess.source_map(),
1017                                             &sess.parse_sess,
1018                                             krate,
1019                                             src_name,
1020                                             &mut rdr,
1021                                             box out,
1022                                             annotation.pp_ann(),
1023                                             true)
1024                 })
1025             }
1026
1027             (PpmHirTree(s), None) => {
1028                 let out: &mut dyn Write = &mut out;
1029                 s.call_with_pp_support_hir(sess,
1030                                            cstore,
1031                                            hir_map,
1032                                            resolutions,
1033                                            output_filenames,
1034                                            crate_name,
1035                                            move |_annotation, krate| {
1036                     debug!("pretty printing source code {:?}", s);
1037                     write!(out, "{:#?}", krate)
1038                 })
1039             }
1040
1041             (PpmHir(s), Some(uii)) => {
1042                 let out: &mut dyn Write = &mut out;
1043                 s.call_with_pp_support_hir(sess,
1044                                            cstore,
1045                                            hir_map,
1046                                            resolutions,
1047                                            output_filenames,
1048                                            crate_name,
1049                                            move |annotation, _| {
1050                     debug!("pretty printing source code {:?}", s);
1051                     let sess = annotation.sess();
1052                     let hir_map = annotation.hir_map().expect("-Z unpretty missing HIR map");
1053                     let mut pp_state = pprust_hir::State::new_from_input(sess.source_map(),
1054                                                                          &sess.parse_sess,
1055                                                                          src_name,
1056                                                                          &mut rdr,
1057                                                                          box out,
1058                                                                          annotation.pp_ann(),
1059                                                                          true);
1060                     for node_id in uii.all_matching_node_ids(hir_map) {
1061                         let node = hir_map.get(node_id);
1062                         pp_state.print_node(node)?;
1063                         pp_state.s.space()?;
1064                         let path = annotation.node_path(node_id)
1065                             .expect("-Z unpretty missing node paths");
1066                         pp_state.synth_comment(path)?;
1067                         pp_state.s.hardbreak()?;
1068                     }
1069                     pp_state.s.eof()
1070                 })
1071             }
1072
1073             (PpmHirTree(s), Some(uii)) => {
1074                 let out: &mut dyn Write = &mut out;
1075                 s.call_with_pp_support_hir(sess,
1076                                            cstore,
1077                                            hir_map,
1078                                            resolutions,
1079                                            output_filenames,
1080                                            crate_name,
1081                                            move |_annotation, _krate| {
1082                     debug!("pretty printing source code {:?}", s);
1083                     for node_id in uii.all_matching_node_ids(hir_map) {
1084                         let node = hir_map.get(node_id);
1085                         write!(out, "{:#?}", node)?;
1086                     }
1087                     Ok(())
1088                 })
1089             }
1090
1091             _ => unreachable!(),
1092         }
1093         .unwrap();
1094
1095     write_output(out, ofile);
1096 }
1097
1098 // In an ideal world, this would be a public function called by the driver after
1099 // analysis is performed. However, we want to call `phase_3_run_analysis_passes`
1100 // with a different callback than the standard driver, so that isn't easy.
1101 // Instead, we call that function ourselves.
1102 fn print_with_analysis<'tcx, 'a: 'tcx>(sess: &'a Session,
1103                                        cstore: &'a CStore,
1104                                        hir_map: &hir_map::Map<'tcx>,
1105                                        resolutions: &Resolutions,
1106                                        crate_name: &str,
1107                                        output_filenames: &OutputFilenames,
1108                                        ppm: PpMode,
1109                                        uii: Option<UserIdentifiedItem>,
1110                                        ofile: Option<&Path>) {
1111     let nodeid = if let Some(uii) = uii {
1112         debug!("pretty printing for {:?}", uii);
1113         Some(uii.to_one_node_id("-Z unpretty", sess, &hir_map))
1114     } else {
1115         debug!("pretty printing for whole crate");
1116         None
1117     };
1118
1119     let mut out = Vec::new();
1120
1121     let control = &driver::CompileController::basic();
1122     let codegen_backend = ::get_codegen_backend(sess);
1123     let mut arenas = AllArenas::new();
1124     abort_on_err(driver::phase_3_run_analysis_passes(&*codegen_backend,
1125                                                      control,
1126                                                      sess,
1127                                                      cstore,
1128                                                      hir_map.clone(),
1129                                                      resolutions.clone(),
1130                                                      &mut arenas,
1131                                                      crate_name,
1132                                                      output_filenames,
1133                                                      |tcx, _, _| {
1134         match ppm {
1135             PpmMir | PpmMirCFG => {
1136                 if let Some(nodeid) = nodeid {
1137                     let def_id = tcx.hir().local_def_id(nodeid);
1138                     match ppm {
1139                         PpmMir => write_mir_pretty(tcx, Some(def_id), &mut out),
1140                         PpmMirCFG => write_mir_graphviz(tcx, Some(def_id), &mut out),
1141                         _ => unreachable!(),
1142                     }?;
1143                 } else {
1144                     match ppm {
1145                         PpmMir => write_mir_pretty(tcx, None, &mut out),
1146                         PpmMirCFG => write_mir_graphviz(tcx, None, &mut out),
1147                         _ => unreachable!(),
1148                     }?;
1149                 }
1150                 Ok(())
1151             }
1152             PpmFlowGraph(mode) => {
1153                 let nodeid =
1154                     nodeid.expect("`pretty flowgraph=..` needs NodeId (int) or unique path \
1155                                    suffix (b::c::d)");
1156                 let node = tcx.hir().find(nodeid).unwrap_or_else(|| {
1157                     tcx.sess.fatal(&format!("--pretty flowgraph couldn't find id: {}", nodeid))
1158                 });
1159
1160                 match blocks::Code::from_node(&tcx.hir(), nodeid) {
1161                     Some(code) => {
1162                         let variants = gather_flowgraph_variants(tcx.sess);
1163
1164                         let out: &mut dyn Write = &mut out;
1165
1166                         print_flowgraph(variants, tcx, code, mode, out)
1167                     }
1168                     None => {
1169                         let message = format!("--pretty=flowgraph needs block, fn, or method; \
1170                                                got {:?}",
1171                                               node);
1172
1173                         tcx.sess.span_fatal(tcx.hir().span(nodeid), &message)
1174                     }
1175                 }
1176             }
1177             _ => unreachable!(),
1178         }
1179     }),
1180                  sess)
1181         .unwrap();
1182
1183     write_output(out, ofile);
1184 }