src/librustc_driver/pretty.rs

   1 // Copyright 2014 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 //! The various pretty print routines.
  12
  13 pub use self::UserIdentifiedItem::*;
  14 pub use self::PpSourceMode::*;
  15 pub use self::PpMode::*;
  16 use self::NodesMatchingUII::*;
  17
  18 use {abort_on_err, driver};
  19
  20 use rustc::ty::{self, TyCtxt, GlobalArenas, Resolutions};
  21 use rustc::cfg;
  22 use rustc::cfg::graphviz::LabelledCFG;
  23 use rustc::dep_graph::DepGraph;
  24 use rustc::session::Session;
  25 use rustc::session::config::Input;
  26 use rustc_borrowck as borrowck;
  27 use rustc_borrowck::graphviz as borrowck_dot;
  28
  29 use rustc_mir::util::{write_mir_pretty, write_mir_graphviz};
  30
  31 use syntax::ast::{self, BlockCheckMode};
  32 use syntax::fold::{self, Folder};
  33 use syntax::print::{pprust};
  34 use syntax::print::pprust::PrintState;
  35 use syntax::ptr::P;
  36 use syntax::util::small_vector::SmallVector;
  37 use syntax_pos;
  38
  39 use graphviz as dot;
  40
  41 use std::cell::Cell;
  42 use std::fs::File;
  43 use std::io::{self, Write};
  44 use std::option;
  45 use std::path::Path;
  46 use std::str::FromStr;
  47 use std::mem;
  48
  49 use rustc::hir::map as hir_map;
  50 use rustc::hir::map::blocks;
  51 use rustc::hir;
  52 use rustc::hir::print as pprust_hir;
  53
  54 use arena::DroplessArena;
  55
  56 #[derive(Copy, Clone, PartialEq, Debug)]
  57 pub enum PpSourceMode {
  58     PpmNormal,
  59     PpmEveryBodyLoops,
  60     PpmExpanded,
  61     PpmIdentified,
  62     PpmExpandedIdentified,
  63     PpmExpandedHygiene,
  64     PpmTyped,
  65 }
  66
  67 #[derive(Copy, Clone, PartialEq, Debug)]
  68 pub enum PpFlowGraphMode {
  69     Default,
  70     /// Drops the labels from the edges in the flowgraph output. This
  71     /// is mostly for use in the --unpretty flowgraph run-make tests,
  72     /// since the labels are largely uninteresting in those cases and
  73     /// have become a pain to maintain.
  74     UnlabelledEdges,
  75 }
  76 #[derive(Copy, Clone, PartialEq, Debug)]
  77 pub enum PpMode {
  78     PpmSource(PpSourceMode),
  79     PpmHir(PpSourceMode),
  80     PpmFlowGraph(PpFlowGraphMode),
  81     PpmMir,
  82     PpmMirCFG,
  83 }
  84
  85 impl PpMode {
  86     pub fn needs_ast_map(&self, opt_uii: &Option<UserIdentifiedItem>) -> bool {
  87         match *self {
  88             PpmSource(PpmNormal) |
  89             PpmSource(PpmEveryBodyLoops) |
  90             PpmSource(PpmIdentified) => opt_uii.is_some(),
  91
  92             PpmSource(PpmExpanded) |
  93             PpmSource(PpmExpandedIdentified) |
  94             PpmSource(PpmExpandedHygiene) |
  95             PpmHir(_) |
  96             PpmMir |
  97             PpmMirCFG |
  98             PpmFlowGraph(_) => true,
  99             PpmSource(PpmTyped) => panic!("invalid state"),
 100         }
 101     }
 102
 103     pub fn needs_analysis(&self) -> bool {
 104         match *self {
 105             PpmMir | PpmMirCFG | PpmFlowGraph(_) => true,
 106             _ => false,
 107         }
 108     }
 109 }
 110
 111 pub fn parse_pretty(sess: &Session,
 112                     name: &str,
 113                     extended: bool)
 114                     -> (PpMode, Option<UserIdentifiedItem>) {
 115     let mut split = name.splitn(2, '=');
 116     let first = split.next().unwrap();
 117     let opt_second = split.next();
 118     let first = match (first, extended) {
 119         ("normal", _) => PpmSource(PpmNormal),
 120         ("identified", _) => PpmSource(PpmIdentified),
 121         ("everybody_loops", true) => PpmSource(PpmEveryBodyLoops),
 122         ("expanded", _) => PpmSource(PpmExpanded),
 123         ("expanded,identified", _) => PpmSource(PpmExpandedIdentified),
 124         ("expanded,hygiene", _) => PpmSource(PpmExpandedHygiene),
 125         ("hir", true) => PpmHir(PpmNormal),
 126         ("hir,identified", true) => PpmHir(PpmIdentified),
 127         ("hir,typed", true) => PpmHir(PpmTyped),
 128         ("mir", true) => PpmMir,
 129         ("mir-cfg", true) => PpmMirCFG,
 130         ("flowgraph", true) => PpmFlowGraph(PpFlowGraphMode::Default),
 131         ("flowgraph,unlabelled", true) => PpmFlowGraph(PpFlowGraphMode::UnlabelledEdges),
 132         _ => {
 133             if extended {
 134                 sess.fatal(&format!("argument to `unpretty` must be one of `normal`, \
 135                                      `expanded`, `flowgraph[,unlabelled]=<nodeid>`, \
 136                                      `identified`, `expanded,identified`, `everybody_loops`, \
 137                                      `hir`, `hir,identified`, `hir,typed`, or `mir`; got {}",
 138                                     name));
 139             } else {
 140                 sess.fatal(&format!("argument to `pretty` must be one of `normal`, `expanded`, \
 141                                      `identified`, or `expanded,identified`; got {}",
 142                                     name));
 143             }
 144         }
 145     };
 146     let opt_second = opt_second.and_then(|s| s.parse::<UserIdentifiedItem>().ok());
 147     (first, opt_second)
 148 }
 149
 150
 151
 152 // This slightly awkward construction is to allow for each PpMode to
 153 // choose whether it needs to do analyses (which can consume the
 154 // Session) and then pass through the session (now attached to the
 155 // analysis results) on to the chosen pretty-printer, along with the
 156 // `&PpAnn` object.
 157 //
 158 // Note that since the `&PrinterSupport` is freshly constructed on each
 159 // call, it would not make sense to try to attach the lifetime of `self`
 160 // to the lifetime of the `&PrinterObject`.
 161 //
 162 // (The `use_once_payload` is working around the current lack of once
 163 // functions in the compiler.)
 164
 165 impl PpSourceMode {
 166     /// Constructs a `PrinterSupport` object and passes it to `f`.
 167     fn call_with_pp_support<'tcx, A, F>(&self,
 168                                            sess: &'tcx Session,
 169                                            hir_map: Option<&hir_map::Map<'tcx>>,
 170                                            f: F)
 171                                            -> A
 172         where F: FnOnce(&PrinterSupport) -> A
 173     {
 174         match *self {
 175             PpmNormal | PpmEveryBodyLoops | PpmExpanded => {
 176                 let annotation = NoAnn {
 177                     sess,
 178                     hir_map: hir_map.map(|m| m.clone()),
 179                 };
 180                 f(&annotation)
 181             }
 182
 183             PpmIdentified | PpmExpandedIdentified => {
 184                 let annotation = IdentifiedAnnotation {
 185                     sess,
 186                     hir_map: hir_map.map(|m| m.clone()),
 187                 };
 188                 f(&annotation)
 189             }
 190             PpmExpandedHygiene => {
 191                 let annotation = HygieneAnnotation {
 192                     sess,
 193                 };
 194                 f(&annotation)
 195             }
 196             _ => panic!("Should use call_with_pp_support_hir"),
 197         }
 198     }
 199     fn call_with_pp_support_hir<'tcx, A, F>(&self,
 200                                                sess: &'tcx Session,
 201                                                hir_map: &hir_map::Map<'tcx>,
 202                                                analysis: &ty::CrateAnalysis,
 203                                                resolutions: &Resolutions,
 204                                                arena: &'tcx DroplessArena,
 205                                                arenas: &'tcx GlobalArenas<'tcx>,
 206                                                id: &str,
 207                                                f: F)
 208                                                -> A
 209         where F: FnOnce(&HirPrinterSupport, &hir::Crate) -> A
 210     {
 211         match *self {
 212             PpmNormal => {
 213                 let annotation = NoAnn {
 214                     sess,
 215                     hir_map: Some(hir_map.clone()),
 216                 };
 217                 f(&annotation, hir_map.forest.krate())
 218             }
 219
 220             PpmIdentified => {
 221                 let annotation = IdentifiedAnnotation {
 222                     sess,
 223                     hir_map: Some(hir_map.clone()),
 224                 };
 225                 f(&annotation, hir_map.forest.krate())
 226             }
 227             PpmTyped => {
 228                 abort_on_err(driver::phase_3_run_analysis_passes(sess,
 229                                                                  hir_map.clone(),
 230                                                                  analysis.clone(),
 231                                                                  resolutions.clone(),
 232                                                                  arena,
 233                                                                  arenas,
 234                                                                  id,
 235                                                                  |tcx, _, _, _| {
 236                     let empty_tables = ty::TypeckTables::empty(None);
 237                     let annotation = TypedAnnotation {
 238                         tcx,
 239                         tables: Cell::new(&empty_tables)
 240                     };
 241                     let _ignore = tcx.dep_graph.in_ignore();
 242                     f(&annotation, hir_map.forest.krate())
 243                 }),
 244                              sess)
 245             }
 246             _ => panic!("Should use call_with_pp_support"),
 247         }
 248     }
 249 }
 250
 251 trait PrinterSupport: pprust::PpAnn {
 252     /// Provides a uniform interface for re-extracting a reference to a
 253     /// `Session` from a value that now owns it.
 254     fn sess<'a>(&'a self) -> &'a Session;
 255
 256     /// Produces the pretty-print annotation object.
 257     ///
 258     /// (Rust does not yet support upcasting from a trait object to
 259     /// an object for one of its super-traits.)
 260     fn pp_ann<'a>(&'a self) -> &'a pprust::PpAnn;
 261 }
 262
 263 trait HirPrinterSupport<'hir>: pprust_hir::PpAnn {
 264     /// Provides a uniform interface for re-extracting a reference to a
 265     /// `Session` from a value that now owns it.
 266     fn sess<'a>(&'a self) -> &'a Session;
 267
 268     /// Provides a uniform interface for re-extracting a reference to an
 269     /// `hir_map::Map` from a value that now owns it.
 270     fn hir_map<'a>(&'a self) -> Option<&'a hir_map::Map<'hir>>;
 271
 272     /// Produces the pretty-print annotation object.
 273     ///
 274     /// (Rust does not yet support upcasting from a trait object to
 275     /// an object for one of its super-traits.)
 276     fn pp_ann<'a>(&'a self) -> &'a pprust_hir::PpAnn;
 277
 278     /// Computes an user-readable representation of a path, if possible.
 279     fn node_path(&self, id: ast::NodeId) -> Option<String> {
 280         self.hir_map().and_then(|map| map.def_path_from_id(id)).map(|path| {
 281             path.data
 282                 .into_iter()
 283                 .map(|elem| elem.data.to_string())
 284                 .collect::<Vec<_>>()
 285                 .join("::")
 286         })
 287     }
 288 }
 289
 290 struct NoAnn<'hir> {
 291     sess: &'hir Session,
 292     hir_map: Option<hir_map::Map<'hir>>,
 293 }
 294
 295 impl<'hir> PrinterSupport for NoAnn<'hir> {
 296     fn sess<'a>(&'a self) -> &'a Session {
 297         self.sess
 298     }
 299
 300     fn pp_ann<'a>(&'a self) -> &'a pprust::PpAnn {
 301         self
 302     }
 303 }
 304
 305 impl<'hir> HirPrinterSupport<'hir> for NoAnn<'hir> {
 306     fn sess<'a>(&'a self) -> &'a Session {
 307         self.sess
 308     }
 309
 310     fn hir_map<'a>(&'a self) -> Option<&'a hir_map::Map<'hir>> {
 311         self.hir_map.as_ref()
 312     }
 313
 314     fn pp_ann<'a>(&'a self) -> &'a pprust_hir::PpAnn {
 315         self
 316     }
 317 }
 318
 319 impl<'hir> pprust::PpAnn for NoAnn<'hir> {}
 320 impl<'hir> pprust_hir::PpAnn for NoAnn<'hir> {
 321     fn nested(&self, state: &mut pprust_hir::State, nested: pprust_hir::Nested)
 322               -> io::Result<()> {
 323         if let Some(ref map) = self.hir_map {
 324             pprust_hir::PpAnn::nested(map, state, nested)
 325         } else {
 326             Ok(())
 327         }
 328     }
 329 }
 330
 331 struct IdentifiedAnnotation<'hir> {
 332     sess: &'hir Session,
 333     hir_map: Option<hir_map::Map<'hir>>,
 334 }
 335
 336 impl<'hir> PrinterSupport for IdentifiedAnnotation<'hir> {
 337     fn sess<'a>(&'a self) -> &'a Session {
 338         self.sess
 339     }
 340
 341     fn pp_ann<'a>(&'a self) -> &'a pprust::PpAnn {
 342         self
 343     }
 344 }
 345
 346 impl<'hir> pprust::PpAnn for IdentifiedAnnotation<'hir> {
 347     fn pre(&self, s: &mut pprust::State, node: pprust::AnnNode) -> io::Result<()> {
 348         match node {
 349             pprust::NodeExpr(_) => s.popen(),
 350             _ => Ok(()),
 351         }
 352     }
 353     fn post(&self, s: &mut pprust::State, node: pprust::AnnNode) -> io::Result<()> {
 354         match node {
 355             pprust::NodeIdent(_) |
 356             pprust::NodeName(_) => Ok(()),
 357
 358             pprust::NodeItem(item) => {
 359                 s.s.space()?;
 360                 s.synth_comment(item.id.to_string())
 361             }
 362             pprust::NodeSubItem(id) => {
 363                 s.s.space()?;
 364                 s.synth_comment(id.to_string())
 365             }
 366             pprust::NodeBlock(blk) => {
 367                 s.s.space()?;
 368                 s.synth_comment(format!("block {}", blk.id))
 369             }
 370             pprust::NodeExpr(expr) => {
 371                 s.s.space()?;
 372                 s.synth_comment(expr.id.to_string())?;
 373                 s.pclose()
 374             }
 375             pprust::NodePat(pat) => {
 376                 s.s.space()?;
 377                 s.synth_comment(format!("pat {}", pat.id))
 378             }
 379         }
 380     }
 381 }
 382
 383 impl<'hir> HirPrinterSupport<'hir> for IdentifiedAnnotation<'hir> {
 384     fn sess<'a>(&'a self) -> &'a Session {
 385         self.sess
 386     }
 387
 388     fn hir_map<'a>(&'a self) -> Option<&'a hir_map::Map<'hir>> {
 389         self.hir_map.as_ref()
 390     }
 391
 392     fn pp_ann<'a>(&'a self) -> &'a pprust_hir::PpAnn {
 393         self
 394     }
 395 }
 396
 397 impl<'hir> pprust_hir::PpAnn for IdentifiedAnnotation<'hir> {
 398     fn nested(&self, state: &mut pprust_hir::State, nested: pprust_hir::Nested)
 399               -> io::Result<()> {
 400         if let Some(ref map) = self.hir_map {
 401             pprust_hir::PpAnn::nested(map, state, nested)
 402         } else {
 403             Ok(())
 404         }
 405     }
 406     fn pre(&self, s: &mut pprust_hir::State, node: pprust_hir::AnnNode) -> io::Result<()> {
 407         match node {
 408             pprust_hir::NodeExpr(_) => s.popen(),
 409             _ => Ok(()),
 410         }
 411     }
 412     fn post(&self, s: &mut pprust_hir::State, node: pprust_hir::AnnNode) -> io::Result<()> {
 413         match node {
 414             pprust_hir::NodeName(_) => Ok(()),
 415             pprust_hir::NodeItem(item) => {
 416                 s.s.space()?;
 417                 s.synth_comment(item.id.to_string())
 418             }
 419             pprust_hir::NodeSubItem(id) => {
 420                 s.s.space()?;
 421                 s.synth_comment(id.to_string())
 422             }
 423             pprust_hir::NodeBlock(blk) => {
 424                 s.s.space()?;
 425                 s.synth_comment(format!("block {}", blk.id))
 426             }
 427             pprust_hir::NodeExpr(expr) => {
 428                 s.s.space()?;
 429                 s.synth_comment(expr.id.to_string())?;
 430                 s.pclose()
 431             }
 432             pprust_hir::NodePat(pat) => {
 433                 s.s.space()?;
 434                 s.synth_comment(format!("pat {}", pat.id))
 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) -> &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::NodeIdent(&ast::Ident { name, ctxt }) => {
 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(), ctxt))
 462             }
 463             pprust::NodeName(&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 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::NodeExpr(_) => 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::NodeExpr(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::new)
 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
 577 impl UserIdentifiedItem {
 578     fn reconstructed_input(&self) -> String {
 579         match *self {
 580             ItemViaNode(node_id) => node_id.to_string(),
 581             ItemViaPath(ref parts) => parts.join("::"),
 582         }
 583     }
 584
 585     fn all_matching_node_ids<'a, 'hir>(&'a self,
 586                                        map: &'a hir_map::Map<'hir>)
 587                                        -> NodesMatchingUII<'a, 'hir> {
 588         match *self {
 589             ItemViaNode(node_id) => NodesMatchingDirect(Some(node_id).into_iter()),
 590             ItemViaPath(ref parts) => NodesMatchingSuffix(map.nodes_matching_suffix(&parts)),
 591         }
 592     }
 593
 594     fn to_one_node_id(self, user_option: &str, sess: &Session, map: &hir_map::Map) -> ast::NodeId {
 595         let fail_because = |is_wrong_because| -> ast::NodeId {
 596             let message = format!("{} needs NodeId (int) or unique path suffix (b::c::d); got \
 597                                    {}, which {}",
 598                                   user_option,
 599                                   self.reconstructed_input(),
 600                                   is_wrong_because);
 601             sess.fatal(&message)
 602         };
 603
 604         let mut saw_node = ast::DUMMY_NODE_ID;
 605         let mut seen = 0;
 606         for node in self.all_matching_node_ids(map) {
 607             saw_node = node;
 608             seen += 1;
 609             if seen > 1 {
 610                 fail_because("does not resolve uniquely");
 611             }
 612         }
 613         if seen == 0 {
 614             fail_because("does not resolve to any item");
 615         }
 616
 617         assert!(seen == 1);
 618         return saw_node;
 619     }
 620 }
 621
 622 // Note: Also used by librustdoc, see PR #43348. Consider moving this struct elsewhere.
 623 //
 624 // FIXME: Currently the `everybody_loops` transformation is not applied to:
 625 //  * `const fn`, due to issue #43636 that `loop` is not supported for const evaluation. We are
 626 //    waiting for miri to fix that.
 627 //  * `impl Trait`, due to issue #43869 that functions returning impl Trait cannot be diverging.
 628 //    Solving this may require `!` to implement every trait, which relies on the an even more
 629 //    ambitious form of the closed RFC #1637. See also [#34511].
 630 //
 631 // [#34511]: https://github.com/rust-lang/rust/issues/34511#issuecomment-322340401
 632 pub struct ReplaceBodyWithLoop {
 633     within_static_or_const: bool,
 634 }
 635
 636 impl ReplaceBodyWithLoop {
 637     pub fn new() -> ReplaceBodyWithLoop {
 638         ReplaceBodyWithLoop { within_static_or_const: false }
 639     }
 640
 641     fn run<R, F: FnOnce(&mut Self) -> R>(&mut self, is_const: bool, action: F) -> R {
 642         let old_const = mem::replace(&mut self.within_static_or_const, is_const);
 643         let ret = action(self);
 644         self.within_static_or_const = old_const;
 645         ret
 646     }
 647
 648     fn should_ignore_fn(ret_ty: &ast::FnDecl) -> bool {
 649         if let ast::FunctionRetTy::Ty(ref ty) = ret_ty.output {
 650             fn involves_impl_trait(ty: &ast::Ty) -> bool {
 651                 match ty.node {
 652                     ast::TyKind::ImplTrait(_) => true,
 653                     ast::TyKind::Slice(ref subty) |
 654                     ast::TyKind::Array(ref subty, _) |
 655                     ast::TyKind::Ptr(ast::MutTy { ty: ref subty, .. }) |
 656                     ast::TyKind::Rptr(_, ast::MutTy { ty: ref subty, .. }) |
 657                     ast::TyKind::Paren(ref subty) => involves_impl_trait(subty),
 658                     ast::TyKind::Tup(ref tys) => tys.iter().any(|subty| involves_impl_trait(subty)),
 659                     _ => false,
 660                 }
 661             }
 662             involves_impl_trait(ty)
 663         } else {
 664             false
 665         }
 666     }
 667 }
 668
 669 impl fold::Folder for ReplaceBodyWithLoop {
 670     fn fold_item_kind(&mut self, i: ast::ItemKind) -> ast::ItemKind {
 671         let is_const = match i {
 672             ast::ItemKind::Static(..) | ast::ItemKind::Const(..) => true,
 673             ast::ItemKind::Fn(ref decl, _, ref constness, _, _, _) =>
 674                 constness.node == ast::Constness::Const || Self::should_ignore_fn(decl),
 675             _ => false,
 676         };
 677         self.run(is_const, |s| fold::noop_fold_item_kind(i, s))
 678     }
 679
 680     fn fold_trait_item(&mut self, i: ast::TraitItem) -> SmallVector<ast::TraitItem> {
 681         let is_const = match i.node {
 682             ast::TraitItemKind::Const(..) => true,
 683             ast::TraitItemKind::Method(ast::MethodSig { ref decl, ref constness, .. }, _) =>
 684                 constness.node == ast::Constness::Const || Self::should_ignore_fn(decl),
 685             _ => false,
 686         };
 687         self.run(is_const, |s| fold::noop_fold_trait_item(i, s))
 688     }
 689
 690     fn fold_impl_item(&mut self, i: ast::ImplItem) -> SmallVector<ast::ImplItem> {
 691         let is_const = match i.node {
 692             ast::ImplItemKind::Const(..) => true,
 693             ast::ImplItemKind::Method(ast::MethodSig { ref decl, ref constness, .. }, _) =>
 694                 constness.node == ast::Constness::Const || Self::should_ignore_fn(decl),
 695             _ => false,
 696         };
 697         self.run(is_const, |s| fold::noop_fold_impl_item(i, s))
 698     }
 699
 700     fn fold_block(&mut self, b: P<ast::Block>) -> P<ast::Block> {
 701         fn expr_to_block(rules: ast::BlockCheckMode, e: Option<P<ast::Expr>>) -> P<ast::Block> {
 702             P(ast::Block {
 703                 stmts: e.map(|e| {
 704                         ast::Stmt {
 705                             id: ast::DUMMY_NODE_ID,
 706                             span: e.span,
 707                             node: ast::StmtKind::Expr(e),
 708                         }
 709                     })
 710                     .into_iter()
 711                     .collect(),
 712                 rules,
 713                 id: ast::DUMMY_NODE_ID,
 714                 span: syntax_pos::DUMMY_SP,
 715             })
 716         }
 717
 718         if !self.within_static_or_const {
 719
 720             let empty_block = expr_to_block(BlockCheckMode::Default, None);
 721             let loop_expr = P(ast::Expr {
 722                 node: ast::ExprKind::Loop(empty_block, None),
 723                 id: ast::DUMMY_NODE_ID,
 724                 span: syntax_pos::DUMMY_SP,
 725                 attrs: ast::ThinVec::new(),
 726             });
 727
 728             expr_to_block(b.rules, Some(loop_expr))
 729
 730         } else {
 731             fold::noop_fold_block(b, self)
 732         }
 733     }
 734
 735     // in general the pretty printer processes unexpanded code, so
 736     // we override the default `fold_mac` method which panics.
 737     fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
 738         fold::noop_fold_mac(mac, self)
 739     }
 740 }
 741
 742 fn print_flowgraph<'a, 'tcx, W: Write>(variants: Vec<borrowck_dot::Variant>,
 743                                        tcx: TyCtxt<'a, 'tcx, 'tcx>,
 744                                        code: blocks::Code<'tcx>,
 745                                        mode: PpFlowGraphMode,
 746                                        mut out: W)
 747                                        -> io::Result<()> {
 748     let body_id = match code {
 749         blocks::Code::Expr(expr) => {
 750             // Find the function this expression is from.
 751             let mut node_id = expr.id;
 752             loop {
 753                 let node = tcx.hir.get(node_id);
 754                 if let Some(n) = hir::map::blocks::FnLikeNode::from_node(node) {
 755                     break n.body();
 756                 }
 757                 let parent = tcx.hir.get_parent_node(node_id);
 758                 assert!(node_id != parent);
 759                 node_id = parent;
 760             }
 761         }
 762         blocks::Code::FnLike(fn_like) => fn_like.body(),
 763     };
 764     let body = tcx.hir.body(body_id);
 765     let cfg = cfg::CFG::new(tcx, &body);
 766     let labelled_edges = mode != PpFlowGraphMode::UnlabelledEdges;
 767     let lcfg = LabelledCFG {
 768         hir_map: &tcx.hir,
 769         cfg: &cfg,
 770         name: format!("node_{}", code.id()),
 771         labelled_edges,
 772     };
 773
 774     match code {
 775         _ if variants.is_empty() => {
 776             let r = dot::render(&lcfg, &mut out);
 777             return expand_err_details(r);
 778         }
 779         blocks::Code::Expr(_) => {
 780             tcx.sess.err("--pretty flowgraph with -Z flowgraph-print annotations requires \
 781                           fn-like node id.");
 782             return Ok(());
 783         }
 784         blocks::Code::FnLike(fn_like) => {
 785             let (bccx, analysis_data) =
 786                 borrowck::build_borrowck_dataflow_data_for_fn(tcx, fn_like.body(), &cfg);
 787
 788             let lcfg = borrowck_dot::DataflowLabeller {
 789                 inner: lcfg,
 790                 variants,
 791                 borrowck_ctxt: &bccx,
 792                 analysis_data: &analysis_data,
 793             };
 794             let r = dot::render(&lcfg, &mut out);
 795             return expand_err_details(r);
 796         }
 797     }
 798
 799     fn expand_err_details(r: io::Result<()>) -> io::Result<()> {
 800         r.map_err(|ioerr| {
 801             io::Error::new(io::ErrorKind::Other,
 802                            format!("graphviz::render failed: {}", ioerr))
 803         })
 804     }
 805 }
 806
 807 pub fn fold_crate(krate: ast::Crate, ppm: PpMode) -> ast::Crate {
 808     if let PpmSource(PpmEveryBodyLoops) = ppm {
 809         let mut fold = ReplaceBodyWithLoop::new();
 810         fold.fold_crate(krate)
 811     } else {
 812         krate
 813     }
 814 }
 815
 816 fn get_source(input: &Input, sess: &Session) -> (Vec<u8>, String) {
 817     let src_name = driver::source_name(input);
 818     let src = sess.codemap()
 819         .get_filemap(&src_name)
 820         .unwrap()
 821         .src
 822         .as_ref()
 823         .unwrap()
 824         .as_bytes()
 825         .to_vec();
 826     (src, src_name)
 827 }
 828
 829 fn write_output(out: Vec<u8>, ofile: Option<&Path>) {
 830     match ofile {
 831         None => print!("{}", String::from_utf8(out).unwrap()),
 832         Some(p) => {
 833             match File::create(p) {
 834                 Ok(mut w) => w.write_all(&out).unwrap(),
 835                 Err(e) => panic!("print-print failed to open {} due to {}", p.display(), e),
 836             }
 837         }
 838     }
 839 }
 840
 841 pub fn print_after_parsing(sess: &Session,
 842                            input: &Input,
 843                            krate: &ast::Crate,
 844                            ppm: PpMode,
 845                            ofile: Option<&Path>) {
 846     let dep_graph = DepGraph::new(false);
 847     let _ignore = dep_graph.in_ignore();
 848
 849     let (src, src_name) = get_source(input, sess);
 850
 851     let mut rdr = &*src;
 852     let mut out = Vec::new();
 853
 854     if let PpmSource(s) = ppm {
 855         // Silently ignores an identified node.
 856         let out: &mut Write = &mut out;
 857         s.call_with_pp_support(sess, None, move |annotation| {
 858                 debug!("pretty printing source code {:?}", s);
 859                 let sess = annotation.sess();
 860                 pprust::print_crate(sess.codemap(),
 861                                     &sess.parse_sess,
 862                                     krate,
 863                                     src_name.to_string(),
 864                                     &mut rdr,
 865                                     box out,
 866                                     annotation.pp_ann(),
 867                                     false)
 868             })
 869             .unwrap()
 870     } else {
 871         unreachable!();
 872     };
 873
 874     write_output(out, ofile);
 875 }
 876
 877 pub fn print_after_hir_lowering<'tcx, 'a: 'tcx>(sess: &'a Session,
 878                                                 hir_map: &hir_map::Map<'tcx>,
 879                                                 analysis: &ty::CrateAnalysis,
 880                                                 resolutions: &Resolutions,
 881                                                 input: &Input,
 882                                                 krate: &ast::Crate,
 883                                                 crate_name: &str,
 884                                                 ppm: PpMode,
 885                                                 arena: &'tcx DroplessArena,
 886                                                 arenas: &'tcx GlobalArenas<'tcx>,
 887                                                 opt_uii: Option<UserIdentifiedItem>,
 888                                                 ofile: Option<&Path>) {
 889     let dep_graph = DepGraph::new(false);
 890     let _ignore = dep_graph.in_ignore();
 891
 892     if ppm.needs_analysis() {
 893         print_with_analysis(sess,
 894                             hir_map,
 895                             analysis,
 896                             resolutions,
 897                             crate_name,
 898                             arena,
 899                             arenas,
 900                             ppm,
 901                             opt_uii,
 902                             ofile);
 903         return;
 904     }
 905
 906     let (src, src_name) = get_source(input, sess);
 907
 908     let mut rdr = &src[..];
 909     let mut out = Vec::new();
 910
 911     match (ppm, opt_uii) {
 912             (PpmSource(s), _) => {
 913                 // Silently ignores an identified node.
 914                 let out: &mut Write = &mut out;
 915                 s.call_with_pp_support(sess, Some(hir_map), move |annotation| {
 916                     debug!("pretty printing source code {:?}", s);
 917                     let sess = annotation.sess();
 918                     pprust::print_crate(sess.codemap(),
 919                                         &sess.parse_sess,
 920                                         krate,
 921                                         src_name.to_string(),
 922                                         &mut rdr,
 923                                         box out,
 924                                         annotation.pp_ann(),
 925                                         true)
 926                 })
 927             }
 928
 929             (PpmHir(s), None) => {
 930                 let out: &mut Write = &mut out;
 931                 s.call_with_pp_support_hir(sess,
 932                                            hir_map,
 933                                            analysis,
 934                                            resolutions,
 935                                            arena,
 936                                            arenas,
 937                                            crate_name,
 938                                            move |annotation, krate| {
 939                     debug!("pretty printing source code {:?}", s);
 940                     let sess = annotation.sess();
 941                     pprust_hir::print_crate(sess.codemap(),
 942                                             &sess.parse_sess,
 943                                             krate,
 944                                             src_name.to_string(),
 945                                             &mut rdr,
 946                                             box out,
 947                                             annotation.pp_ann(),
 948                                             true)
 949                 })
 950             }
 951
 952             (PpmHir(s), Some(uii)) => {
 953                 let out: &mut Write = &mut out;
 954                 s.call_with_pp_support_hir(sess,
 955                                            hir_map,
 956                                            analysis,
 957                                            resolutions,
 958                                            arena,
 959                                            arenas,
 960                                            crate_name,
 961                                            move |annotation, _| {
 962                     debug!("pretty printing source code {:?}", s);
 963                     let sess = annotation.sess();
 964                     let hir_map = annotation.hir_map().expect("--unpretty missing HIR map");
 965                     let mut pp_state = pprust_hir::State::new_from_input(sess.codemap(),
 966                                                                          &sess.parse_sess,
 967                                                                          src_name.to_string(),
 968                                                                          &mut rdr,
 969                                                                          box out,
 970                                                                          annotation.pp_ann(),
 971                                                                          true);
 972                     for node_id in uii.all_matching_node_ids(hir_map) {
 973                         let node = hir_map.get(node_id);
 974                         pp_state.print_node(node)?;
 975                         pp_state.s.space()?;
 976                         let path = annotation.node_path(node_id)
 977                             .expect("--unpretty missing node paths");
 978                         pp_state.synth_comment(path)?;
 979                         pp_state.s.hardbreak()?;
 980                     }
 981                     pp_state.s.eof()
 982                 })
 983             }
 984             _ => unreachable!(),
 985         }
 986         .unwrap();
 987
 988     write_output(out, ofile);
 989 }
 990
 991 // In an ideal world, this would be a public function called by the driver after
 992 // analsysis is performed. However, we want to call `phase_3_run_analysis_passes`
 993 // with a different callback than the standard driver, so that isn't easy.
 994 // Instead, we call that function ourselves.
 995 fn print_with_analysis<'tcx, 'a: 'tcx>(sess: &'a Session,
 996                                        hir_map: &hir_map::Map<'tcx>,
 997                                        analysis: &ty::CrateAnalysis,
 998                                        resolutions: &Resolutions,
 999                                        crate_name: &str,
1000                                        arena: &'tcx DroplessArena,
1001                                        arenas: &'tcx GlobalArenas<'tcx>,
1002                                        ppm: PpMode,
1003                                        uii: Option<UserIdentifiedItem>,
1004                                        ofile: Option<&Path>) {
1005     let nodeid = if let Some(uii) = uii {
1006         debug!("pretty printing for {:?}", uii);
1007         Some(uii.to_one_node_id("--unpretty", sess, &hir_map))
1008     } else {
1009         debug!("pretty printing for whole crate");
1010         None
1011     };
1012
1013     let mut out = Vec::new();
1014
1015     abort_on_err(driver::phase_3_run_analysis_passes(sess,
1016                                                      hir_map.clone(),
1017                                                      analysis.clone(),
1018                                                      resolutions.clone(),
1019                                                      arena,
1020                                                      arenas,
1021                                                      crate_name,
1022                                                      |tcx, _, _, _| {
1023         match ppm {
1024             PpmMir | PpmMirCFG => {
1025                 if let Some(nodeid) = nodeid {
1026                     let def_id = tcx.hir.local_def_id(nodeid);
1027                     match ppm {
1028                         PpmMir => write_mir_pretty(tcx, Some(def_id), &mut out),
1029                         PpmMirCFG => write_mir_graphviz(tcx, Some(def_id), &mut out),
1030                         _ => unreachable!(),
1031                     }?;
1032                 } else {
1033                     match ppm {
1034                         PpmMir => write_mir_pretty(tcx, None, &mut out),
1035                         PpmMirCFG => write_mir_graphviz(tcx, None, &mut out),
1036                         _ => unreachable!(),
1037                     }?;
1038                 }
1039                 Ok(())
1040             }
1041             PpmFlowGraph(mode) => {
1042                 let nodeid =
1043                     nodeid.expect("`pretty flowgraph=..` needs NodeId (int) or unique path \
1044                                    suffix (b::c::d)");
1045                 let node = tcx.hir.find(nodeid).unwrap_or_else(|| {
1046                     tcx.sess.fatal(&format!("--pretty flowgraph couldn't find id: {}", nodeid))
1047                 });
1048
1049                 match blocks::Code::from_node(&tcx.hir, nodeid) {
1050                     Some(code) => {
1051                         let variants = gather_flowgraph_variants(tcx.sess);
1052
1053                         let out: &mut Write = &mut out;
1054
1055                         print_flowgraph(variants, tcx, code, mode, out)
1056                     }
1057                     None => {
1058                         let message = format!("--pretty=flowgraph needs block, fn, or method; \
1059                                                got {:?}",
1060                                               node);
1061
1062                         tcx.sess.span_fatal(tcx.hir.span(nodeid), &message)
1063                     }
1064                 }
1065             }
1066             _ => unreachable!(),
1067         }
1068     }),
1069                  sess)
1070         .unwrap();
1071
1072     write_output(out, ofile);
1073 }