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 rustc_trans::back::link;
  19
  20 use driver;
  21
  22 use rustc::middle::ty;
  23 use rustc::middle::cfg;
  24 use rustc::middle::cfg::graphviz::LabelledCFG;
  25 use rustc::session::Session;
  26 use rustc::session::config::Input;
  27 use rustc_borrowck as borrowck;
  28 use rustc_borrowck::graphviz as borrowck_dot;
  29 use rustc_resolve as resolve;
  30 use rustc_metadata::cstore::CStore;
  31
  32 use syntax::ast;
  33 use syntax::codemap;
  34 use syntax::fold::{self, Folder};
  35 use syntax::print::{pp, pprust};
  36 use syntax::print::pprust::PrintState;
  37 use syntax::ptr::P;
  38 use syntax::util::small_vector::SmallVector;
  39
  40 use graphviz as dot;
  41
  42 use std::fs::File;
  43 use std::io::{self, Write};
  44 use std::option;
  45 use std::path::PathBuf;
  46 use std::str::FromStr;
  47
  48 use rustc::front::map as hir_map;
  49 use rustc::front::map::{blocks, NodePrinter};
  50 use rustc_front::hir;
  51 use rustc_front::lowering::{lower_crate, LoweringContext};
  52 use rustc_front::print::pprust as pprust_hir;
  53
  54 #[derive(Copy, Clone, PartialEq, Debug)]
  55 pub enum PpSourceMode {
  56     PpmNormal,
  57     PpmEveryBodyLoops,
  58     PpmExpanded,
  59     PpmIdentified,
  60     PpmExpandedIdentified,
  61     PpmExpandedHygiene,
  62     PpmTyped,
  63 }
  64
  65 #[derive(Copy, Clone, PartialEq, Debug)]
  66 pub enum PpFlowGraphMode {
  67     Default,
  68     /// Drops the labels from the edges in the flowgraph output. This
  69     /// is mostly for use in the --unpretty flowgraph run-make tests,
  70     /// since the labels are largely uninteresting in those cases and
  71     /// have become a pain to maintain.
  72     UnlabelledEdges,
  73 }
  74 #[derive(Copy, Clone, PartialEq, Debug)]
  75 pub enum PpMode {
  76     PpmSource(PpSourceMode),
  77     PpmHir(PpSourceMode),
  78     PpmFlowGraph(PpFlowGraphMode),
  79 }
  80
  81 pub fn parse_pretty(sess: &Session,
  82                     name: &str,
  83                     extended: bool)
  84                     -> (PpMode, Option<UserIdentifiedItem>) {
  85     let mut split = name.splitn(2, '=');
  86     let first = split.next().unwrap();
  87     let opt_second = split.next();
  88     let first = match (first, extended) {
  89         ("normal", _) => PpmSource(PpmNormal),
  90         ("identified", _) => PpmSource(PpmIdentified),
  91         ("everybody_loops", true) => PpmSource(PpmEveryBodyLoops),
  92         ("expanded", _) => PpmSource(PpmExpanded),
  93         ("expanded,identified", _) => PpmSource(PpmExpandedIdentified),
  94         ("expanded,hygiene", _) => PpmSource(PpmExpandedHygiene),
  95         ("hir", true) => PpmHir(PpmNormal),
  96         ("hir,identified", true) => PpmHir(PpmIdentified),
  97         ("hir,typed", true) => PpmHir(PpmTyped),
  98         ("flowgraph", true) => PpmFlowGraph(PpFlowGraphMode::Default),
  99         ("flowgraph,unlabelled", true) => PpmFlowGraph(PpFlowGraphMode::UnlabelledEdges),
 100         _ => {
 101             if extended {
 102                 sess.fatal(&format!("argument to `unpretty` must be one of `normal`, \
 103                                      `expanded`, `flowgraph[,unlabelled]=<nodeid>`, \
 104                                      `identified`, `expanded,identified`, `everybody_loops`, \
 105                                      `hir`, `hir,identified`, or `hir,typed`; got {}",
 106                                     name));
 107             } else {
 108                 sess.fatal(&format!("argument to `pretty` must be one of `normal`, `expanded`, \
 109                                      `identified`, or `expanded,identified`; got {}",
 110                                     name));
 111             }
 112         }
 113     };
 114     let opt_second = opt_second.and_then(|s| s.parse::<UserIdentifiedItem>().ok());
 115     (first, opt_second)
 116 }
 117
 118
 119
 120 // This slightly awkward construction is to allow for each PpMode to
 121 // choose whether it needs to do analyses (which can consume the
 122 // Session) and then pass through the session (now attached to the
 123 // analysis results) on to the chosen pretty-printer, along with the
 124 // `&PpAnn` object.
 125 //
 126 // Note that since the `&PrinterSupport` is freshly constructed on each
 127 // call, it would not make sense to try to attach the lifetime of `self`
 128 // to the lifetime of the `&PrinterObject`.
 129 //
 130 // (The `use_once_payload` is working around the current lack of once
 131 // functions in the compiler.)
 132
 133 impl PpSourceMode {
 134     /// Constructs a `PrinterSupport` object and passes it to `f`.
 135     fn call_with_pp_support<'tcx, A, B, F>(&self,
 136                                            sess: &'tcx Session,
 137                                            ast_map: Option<hir_map::Map<'tcx>>,
 138                                            payload: B,
 139                                            f: F)
 140                                            -> A
 141         where F: FnOnce(&PrinterSupport, B) -> A
 142     {
 143         match *self {
 144             PpmNormal | PpmEveryBodyLoops | PpmExpanded => {
 145                 let annotation = NoAnn {
 146                     sess: sess,
 147                     ast_map: ast_map,
 148                 };
 149                 f(&annotation, payload)
 150             }
 151
 152             PpmIdentified | PpmExpandedIdentified => {
 153                 let annotation = IdentifiedAnnotation {
 154                     sess: sess,
 155                     ast_map: ast_map,
 156                 };
 157                 f(&annotation, payload)
 158             }
 159             PpmExpandedHygiene => {
 160                 let annotation = HygieneAnnotation {
 161                     sess: sess,
 162                     ast_map: ast_map,
 163                 };
 164                 f(&annotation, payload)
 165             }
 166             _ => panic!("Should use call_with_pp_support_hir"),
 167         }
 168     }
 169     fn call_with_pp_support_hir<'tcx, A, B, F>(&self,
 170                                                sess: &'tcx Session,
 171                                                cstore: &CStore,
 172                                                ast_map: &hir_map::Map<'tcx>,
 173                                                arenas: &'tcx ty::CtxtArenas<'tcx>,
 174                                                id: &str,
 175                                                payload: B,
 176                                                f: F)
 177                                                -> A
 178         where F: FnOnce(&HirPrinterSupport, B, &hir::Crate) -> A
 179     {
 180         match *self {
 181             PpmNormal => {
 182                 let annotation = NoAnn {
 183                     sess: sess,
 184                     ast_map: Some(ast_map.clone()),
 185                 };
 186                 f(&annotation, payload, &ast_map.forest.krate)
 187             }
 188
 189             PpmIdentified => {
 190                 let annotation = IdentifiedAnnotation {
 191                     sess: sess,
 192                     ast_map: Some(ast_map.clone()),
 193                 };
 194                 f(&annotation, payload, &ast_map.forest.krate)
 195             }
 196             PpmTyped => {
 197                 driver::phase_3_run_analysis_passes(sess,
 198                                                     cstore,
 199                                                     ast_map.clone(),
 200                                                     arenas,
 201                                                     id,
 202                                                     resolve::MakeGlobMap::No,
 203                                                     |tcx, _, _| {
 204                                                         let annotation = TypedAnnotation {
 205                                                             tcx: tcx,
 206                                                         };
 207                                                         f(&annotation,
 208                                                           payload,
 209                                                           &ast_map.forest.krate)
 210                                                     })
 211             }
 212             _ => panic!("Should use call_with_pp_support"),
 213         }
 214     }
 215 }
 216
 217 trait PrinterSupport<'ast>: pprust::PpAnn {
 218     /// Provides a uniform interface for re-extracting a reference to a
 219     /// `Session` from a value that now owns it.
 220     fn sess<'a>(&'a self) -> &'a Session;
 221
 222     /// Provides a uniform interface for re-extracting a reference to an
 223     /// `hir_map::Map` from a value that now owns it.
 224     fn ast_map<'a>(&'a self) -> Option<&'a hir_map::Map<'ast>>;
 225
 226     /// Produces the pretty-print annotation object.
 227     ///
 228     /// (Rust does not yet support upcasting from a trait object to
 229     /// an object for one of its super-traits.)
 230     fn pp_ann<'a>(&'a self) -> &'a pprust::PpAnn;
 231 }
 232
 233 trait HirPrinterSupport<'ast>: pprust_hir::PpAnn {
 234     /// Provides a uniform interface for re-extracting a reference to a
 235     /// `Session` from a value that now owns it.
 236     fn sess<'a>(&'a self) -> &'a Session;
 237
 238     /// Provides a uniform interface for re-extracting a reference to an
 239     /// `hir_map::Map` from a value that now owns it.
 240     fn ast_map<'a>(&'a self) -> Option<&'a hir_map::Map<'ast>>;
 241
 242     /// Produces the pretty-print annotation object.
 243     ///
 244     /// (Rust does not yet support upcasting from a trait object to
 245     /// an object for one of its super-traits.)
 246     fn pp_ann<'a>(&'a self) -> &'a pprust_hir::PpAnn;
 247 }
 248
 249 struct NoAnn<'ast> {
 250     sess: &'ast Session,
 251     ast_map: Option<hir_map::Map<'ast>>,
 252 }
 253
 254 impl<'ast> PrinterSupport<'ast> for NoAnn<'ast> {
 255     fn sess<'a>(&'a self) -> &'a Session {
 256         self.sess
 257     }
 258
 259     fn ast_map<'a>(&'a self) -> Option<&'a hir_map::Map<'ast>> {
 260         self.ast_map.as_ref()
 261     }
 262
 263     fn pp_ann<'a>(&'a self) -> &'a pprust::PpAnn {
 264         self
 265     }
 266 }
 267
 268 impl<'ast> HirPrinterSupport<'ast> for NoAnn<'ast> {
 269     fn sess<'a>(&'a self) -> &'a Session {
 270         self.sess
 271     }
 272
 273     fn ast_map<'a>(&'a self) -> Option<&'a hir_map::Map<'ast>> {
 274         self.ast_map.as_ref()
 275     }
 276
 277     fn pp_ann<'a>(&'a self) -> &'a pprust_hir::PpAnn {
 278         self
 279     }
 280 }
 281
 282 impl<'ast> pprust::PpAnn for NoAnn<'ast> {}
 283 impl<'ast> pprust_hir::PpAnn for NoAnn<'ast> {}
 284
 285 struct IdentifiedAnnotation<'ast> {
 286     sess: &'ast Session,
 287     ast_map: Option<hir_map::Map<'ast>>,
 288 }
 289
 290 impl<'ast> PrinterSupport<'ast> for IdentifiedAnnotation<'ast> {
 291     fn sess<'a>(&'a self) -> &'a Session {
 292         self.sess
 293     }
 294
 295     fn ast_map<'a>(&'a self) -> Option<&'a hir_map::Map<'ast>> {
 296         self.ast_map.as_ref()
 297     }
 298
 299     fn pp_ann<'a>(&'a self) -> &'a pprust::PpAnn {
 300         self
 301     }
 302 }
 303
 304 impl<'ast> pprust::PpAnn for IdentifiedAnnotation<'ast> {
 305     fn pre(&self, s: &mut pprust::State, node: pprust::AnnNode) -> io::Result<()> {
 306         match node {
 307             pprust::NodeExpr(_) => s.popen(),
 308             _ => Ok(()),
 309         }
 310     }
 311     fn post(&self, s: &mut pprust::State, node: pprust::AnnNode) -> io::Result<()> {
 312         match node {
 313             pprust::NodeIdent(_) | pprust::NodeName(_) => Ok(()),
 314
 315             pprust::NodeItem(item) => {
 316                 try!(pp::space(&mut s.s));
 317                 s.synth_comment(item.id.to_string())
 318             }
 319             pprust::NodeSubItem(id) => {
 320                 try!(pp::space(&mut s.s));
 321                 s.synth_comment(id.to_string())
 322             }
 323             pprust::NodeBlock(blk) => {
 324                 try!(pp::space(&mut s.s));
 325                 s.synth_comment(format!("block {}", blk.id))
 326             }
 327             pprust::NodeExpr(expr) => {
 328                 try!(pp::space(&mut s.s));
 329                 try!(s.synth_comment(expr.id.to_string()));
 330                 s.pclose()
 331             }
 332             pprust::NodePat(pat) => {
 333                 try!(pp::space(&mut s.s));
 334                 s.synth_comment(format!("pat {}", pat.id))
 335             }
 336         }
 337     }
 338 }
 339
 340 impl<'ast> HirPrinterSupport<'ast> for IdentifiedAnnotation<'ast> {
 341     fn sess<'a>(&'a self) -> &'a Session {
 342         self.sess
 343     }
 344
 345     fn ast_map<'a>(&'a self) -> Option<&'a hir_map::Map<'ast>> {
 346         self.ast_map.as_ref()
 347     }
 348
 349     fn pp_ann<'a>(&'a self) -> &'a pprust_hir::PpAnn {
 350         self
 351     }
 352 }
 353
 354 impl<'ast> pprust_hir::PpAnn for IdentifiedAnnotation<'ast> {
 355     fn pre(&self, s: &mut pprust_hir::State, node: pprust_hir::AnnNode) -> io::Result<()> {
 356         match node {
 357             pprust_hir::NodeExpr(_) => s.popen(),
 358             _ => Ok(()),
 359         }
 360     }
 361     fn post(&self, s: &mut pprust_hir::State, node: pprust_hir::AnnNode) -> io::Result<()> {
 362         match node {
 363             pprust_hir::NodeName(_) => Ok(()),
 364             pprust_hir::NodeItem(item) => {
 365                 try!(pp::space(&mut s.s));
 366                 s.synth_comment(item.id.to_string())
 367             }
 368             pprust_hir::NodeSubItem(id) => {
 369                 try!(pp::space(&mut s.s));
 370                 s.synth_comment(id.to_string())
 371             }
 372             pprust_hir::NodeBlock(blk) => {
 373                 try!(pp::space(&mut s.s));
 374                 s.synth_comment(format!("block {}", blk.id))
 375             }
 376             pprust_hir::NodeExpr(expr) => {
 377                 try!(pp::space(&mut s.s));
 378                 try!(s.synth_comment(expr.id.to_string()));
 379                 s.pclose()
 380             }
 381             pprust_hir::NodePat(pat) => {
 382                 try!(pp::space(&mut s.s));
 383                 s.synth_comment(format!("pat {}", pat.id))
 384             }
 385         }
 386     }
 387 }
 388
 389 struct HygieneAnnotation<'ast> {
 390     sess: &'ast Session,
 391     ast_map: Option<hir_map::Map<'ast>>,
 392 }
 393
 394 impl<'ast> PrinterSupport<'ast> for HygieneAnnotation<'ast> {
 395     fn sess<'a>(&'a self) -> &'a Session {
 396         self.sess
 397     }
 398
 399     fn ast_map<'a>(&'a self) -> Option<&'a hir_map::Map<'ast>> {
 400         self.ast_map.as_ref()
 401     }
 402
 403     fn pp_ann<'a>(&'a self) -> &'a pprust::PpAnn {
 404         self
 405     }
 406 }
 407
 408 impl<'ast> pprust::PpAnn for HygieneAnnotation<'ast> {
 409     fn post(&self, s: &mut pprust::State, node: pprust::AnnNode) -> io::Result<()> {
 410         match node {
 411             pprust::NodeIdent(&ast::Ident { name: ast::Name(nm), ctxt }) => {
 412                 try!(pp::space(&mut s.s));
 413                 // FIXME #16420: this doesn't display the connections
 414                 // between syntax contexts
 415                 s.synth_comment(format!("{}#{}", nm, ctxt.0))
 416             }
 417             pprust::NodeName(&ast::Name(nm)) => {
 418                 try!(pp::space(&mut s.s));
 419                 s.synth_comment(nm.to_string())
 420             }
 421             _ => Ok(()),
 422         }
 423     }
 424 }
 425
 426
 427 struct TypedAnnotation<'a, 'tcx: 'a> {
 428     tcx: &'a ty::ctxt<'tcx>,
 429 }
 430
 431 impl<'b, 'tcx> HirPrinterSupport<'tcx> for TypedAnnotation<'b, 'tcx> {
 432     fn sess<'a>(&'a self) -> &'a Session {
 433         &self.tcx.sess
 434     }
 435
 436     fn ast_map<'a>(&'a self) -> Option<&'a hir_map::Map<'tcx>> {
 437         Some(&self.tcx.map)
 438     }
 439
 440     fn pp_ann<'a>(&'a self) -> &'a pprust_hir::PpAnn {
 441         self
 442     }
 443 }
 444
 445 impl<'a, 'tcx> pprust_hir::PpAnn for TypedAnnotation<'a, 'tcx> {
 446     fn pre(&self, s: &mut pprust_hir::State, node: pprust_hir::AnnNode) -> io::Result<()> {
 447         match node {
 448             pprust_hir::NodeExpr(_) => s.popen(),
 449             _ => Ok(()),
 450         }
 451     }
 452     fn post(&self, s: &mut pprust_hir::State, node: pprust_hir::AnnNode) -> io::Result<()> {
 453         match node {
 454             pprust_hir::NodeExpr(expr) => {
 455                 try!(pp::space(&mut s.s));
 456                 try!(pp::word(&mut s.s, "as"));
 457                 try!(pp::space(&mut s.s));
 458                 try!(pp::word(&mut s.s, &self.tcx.expr_ty(expr).to_string()));
 459                 s.pclose()
 460             }
 461             _ => Ok(()),
 462         }
 463     }
 464 }
 465
 466 fn gather_flowgraph_variants(sess: &Session) -> Vec<borrowck_dot::Variant> {
 467     let print_loans = sess.opts.debugging_opts.flowgraph_print_loans;
 468     let print_moves = sess.opts.debugging_opts.flowgraph_print_moves;
 469     let print_assigns = sess.opts.debugging_opts.flowgraph_print_assigns;
 470     let print_all = sess.opts.debugging_opts.flowgraph_print_all;
 471     let mut variants = Vec::new();
 472     if print_all || print_loans {
 473         variants.push(borrowck_dot::Loans);
 474     }
 475     if print_all || print_moves {
 476         variants.push(borrowck_dot::Moves);
 477     }
 478     if print_all || print_assigns {
 479         variants.push(borrowck_dot::Assigns);
 480     }
 481     variants
 482 }
 483
 484 #[derive(Clone, Debug)]
 485 pub enum UserIdentifiedItem {
 486     ItemViaNode(ast::NodeId),
 487     ItemViaPath(Vec<String>),
 488 }
 489
 490 impl FromStr for UserIdentifiedItem {
 491     type Err = ();
 492     fn from_str(s: &str) -> Result<UserIdentifiedItem, ()> {
 493         Ok(s.parse()
 494             .map(ItemViaNode)
 495             .unwrap_or_else(|_| ItemViaPath(s.split("::").map(|s| s.to_string()).collect())))
 496     }
 497 }
 498
 499 enum NodesMatchingUII<'a, 'ast: 'a> {
 500     NodesMatchingDirect(option::IntoIter<ast::NodeId>),
 501     NodesMatchingSuffix(hir_map::NodesMatchingSuffix<'a, 'ast>),
 502 }
 503
 504 impl<'a, 'ast> Iterator for NodesMatchingUII<'a, 'ast> {
 505     type Item = ast::NodeId;
 506
 507     fn next(&mut self) -> Option<ast::NodeId> {
 508         match self {
 509             &mut NodesMatchingDirect(ref mut iter) => iter.next(),
 510             &mut NodesMatchingSuffix(ref mut iter) => iter.next(),
 511         }
 512     }
 513 }
 514
 515 impl UserIdentifiedItem {
 516     fn reconstructed_input(&self) -> String {
 517         match *self {
 518             ItemViaNode(node_id) => node_id.to_string(),
 519             ItemViaPath(ref parts) => parts.join("::"),
 520         }
 521     }
 522
 523     fn all_matching_node_ids<'a, 'ast>(&'a self,
 524                                        map: &'a hir_map::Map<'ast>)
 525                                        -> NodesMatchingUII<'a, 'ast> {
 526         match *self {
 527             ItemViaNode(node_id) => NodesMatchingDirect(Some(node_id).into_iter()),
 528             ItemViaPath(ref parts) => NodesMatchingSuffix(map.nodes_matching_suffix(&parts[..])),
 529         }
 530     }
 531
 532     fn to_one_node_id(self, user_option: &str, sess: &Session, map: &hir_map::Map) -> ast::NodeId {
 533         let fail_because = |is_wrong_because| -> ast::NodeId {
 534             let message = format!("{} needs NodeId (int) or unique path suffix (b::c::d); got \
 535                                    {}, which {}",
 536                                   user_option,
 537                                   self.reconstructed_input(),
 538                                   is_wrong_because);
 539             sess.fatal(&message[..])
 540         };
 541
 542         let mut saw_node = ast::DUMMY_NODE_ID;
 543         let mut seen = 0;
 544         for node in self.all_matching_node_ids(map) {
 545             saw_node = node;
 546             seen += 1;
 547             if seen > 1 {
 548                 fail_because("does not resolve uniquely");
 549             }
 550         }
 551         if seen == 0 {
 552             fail_because("does not resolve to any item");
 553         }
 554
 555         assert!(seen == 1);
 556         return saw_node;
 557     }
 558 }
 559
 560 fn needs_ast_map(ppm: &PpMode, opt_uii: &Option<UserIdentifiedItem>) -> bool {
 561     match *ppm {
 562         PpmSource(PpmNormal) |
 563         PpmSource(PpmEveryBodyLoops) |
 564         PpmSource(PpmIdentified) => opt_uii.is_some(),
 565
 566         PpmSource(PpmExpanded) |
 567         PpmSource(PpmExpandedIdentified) |
 568         PpmSource(PpmExpandedHygiene) |
 569         PpmHir(_) |
 570         PpmFlowGraph(_) => true,
 571         PpmSource(PpmTyped) => panic!("invalid state"),
 572     }
 573 }
 574
 575 fn needs_expansion(ppm: &PpMode) -> bool {
 576     match *ppm {
 577         PpmSource(PpmNormal) |
 578         PpmSource(PpmEveryBodyLoops) |
 579         PpmSource(PpmIdentified) => false,
 580
 581         PpmSource(PpmExpanded) |
 582         PpmSource(PpmExpandedIdentified) |
 583         PpmSource(PpmExpandedHygiene) |
 584         PpmHir(_) |
 585         PpmFlowGraph(_) => true,
 586         PpmSource(PpmTyped) => panic!("invalid state"),
 587     }
 588 }
 589
 590 struct ReplaceBodyWithLoop {
 591     within_static_or_const: bool,
 592 }
 593
 594 impl ReplaceBodyWithLoop {
 595     fn new() -> ReplaceBodyWithLoop {
 596         ReplaceBodyWithLoop { within_static_or_const: false }
 597     }
 598 }
 599
 600 impl fold::Folder for ReplaceBodyWithLoop {
 601     fn fold_item_underscore(&mut self, i: ast::Item_) -> ast::Item_ {
 602         match i {
 603             ast::ItemStatic(..) | ast::ItemConst(..) => {
 604                 self.within_static_or_const = true;
 605                 let ret = fold::noop_fold_item_underscore(i, self);
 606                 self.within_static_or_const = false;
 607                 return ret;
 608             }
 609             _ => {
 610                 fold::noop_fold_item_underscore(i, self)
 611             }
 612         }
 613     }
 614
 615     fn fold_trait_item(&mut self, i: P<ast::TraitItem>) -> SmallVector<P<ast::TraitItem>> {
 616         match i.node {
 617             ast::ConstTraitItem(..) => {
 618                 self.within_static_or_const = true;
 619                 let ret = fold::noop_fold_trait_item(i, self);
 620                 self.within_static_or_const = false;
 621                 return ret;
 622             }
 623             _ => fold::noop_fold_trait_item(i, self),
 624         }
 625     }
 626
 627     fn fold_impl_item(&mut self, i: P<ast::ImplItem>) -> SmallVector<P<ast::ImplItem>> {
 628         match i.node {
 629             ast::ImplItemKind::Const(..) => {
 630                 self.within_static_or_const = true;
 631                 let ret = fold::noop_fold_impl_item(i, self);
 632                 self.within_static_or_const = false;
 633                 return ret;
 634             }
 635             _ => fold::noop_fold_impl_item(i, self),
 636         }
 637     }
 638
 639     fn fold_block(&mut self, b: P<ast::Block>) -> P<ast::Block> {
 640         fn expr_to_block(rules: ast::BlockCheckMode, e: Option<P<ast::Expr>>) -> P<ast::Block> {
 641             P(ast::Block {
 642                 expr: e,
 643                 stmts: vec![],
 644                 rules: rules,
 645                 id: ast::DUMMY_NODE_ID,
 646                 span: codemap::DUMMY_SP,
 647             })
 648         }
 649
 650         if !self.within_static_or_const {
 651
 652             let empty_block = expr_to_block(ast::DefaultBlock, None);
 653             let loop_expr = P(ast::Expr {
 654                 node: ast::ExprLoop(empty_block, None),
 655                 id: ast::DUMMY_NODE_ID,
 656                 span: codemap::DUMMY_SP,
 657             });
 658
 659             expr_to_block(b.rules, Some(loop_expr))
 660
 661         } else {
 662             fold::noop_fold_block(b, self)
 663         }
 664     }
 665
 666     // in general the pretty printer processes unexpanded code, so
 667     // we override the default `fold_mac` method which panics.
 668     fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
 669         fold::noop_fold_mac(mac, self)
 670     }
 671 }
 672
 673 pub fn pretty_print_input(sess: Session,
 674                           cstore: &CStore,
 675                           cfg: ast::CrateConfig,
 676                           input: &Input,
 677                           ppm: PpMode,
 678                           opt_uii: Option<UserIdentifiedItem>,
 679                           ofile: Option<PathBuf>) {
 680     let krate = driver::phase_1_parse_input(&sess, cfg, input);
 681
 682     let krate = if let PpmSource(PpmEveryBodyLoops) = ppm {
 683         let mut fold = ReplaceBodyWithLoop::new();
 684         fold.fold_crate(krate)
 685     } else {
 686         krate
 687     };
 688
 689     let id = link::find_crate_name(Some(&sess), &krate.attrs, input);
 690
 691     let is_expanded = needs_expansion(&ppm);
 692     let compute_ast_map = needs_ast_map(&ppm, &opt_uii);
 693     let krate = if compute_ast_map {
 694         match driver::phase_2_configure_and_expand(&sess, &cstore, krate, &id[..], None) {
 695             None => return,
 696             Some(k) => driver::assign_node_ids(&sess, k),
 697         }
 698     } else {
 699         krate
 700     };
 701
 702     // There is some twisted, god-forsaken tangle of lifetimes here which makes
 703     // the ordering of stuff super-finicky.
 704     let mut hir_forest;
 705     let lcx = LoweringContext::new(&sess, Some(&krate));
 706     let arenas = ty::CtxtArenas::new();
 707     let ast_map = if compute_ast_map {
 708         hir_forest = hir_map::Forest::new(lower_crate(&lcx, &krate));
 709         let map = driver::make_map(&sess, &mut hir_forest);
 710         Some(map)
 711     } else {
 712         None
 713     };
 714
 715     let src_name = driver::source_name(input);
 716     let src = sess.codemap()
 717                   .get_filemap(&src_name[..])
 718                   .src
 719                   .as_ref()
 720                   .unwrap()
 721                   .as_bytes()
 722                   .to_vec();
 723     let mut rdr = &src[..];
 724
 725     let mut out = Vec::new();
 726
 727     match (ppm, opt_uii) {
 728         (PpmSource(s), _) => {
 729             // Silently ignores an identified node.
 730             let out: &mut Write = &mut out;
 731             s.call_with_pp_support(&sess, ast_map, box out, |annotation, out| {
 732                 debug!("pretty printing source code {:?}", s);
 733                 let sess = annotation.sess();
 734                 pprust::print_crate(sess.codemap(),
 735                                     sess.diagnostic(),
 736                                     &krate,
 737                                     src_name.to_string(),
 738                                     &mut rdr,
 739                                     out,
 740                                     annotation.pp_ann(),
 741                                     is_expanded)
 742             })
 743         }
 744
 745         (PpmHir(s), None) => {
 746             let out: &mut Write = &mut out;
 747             s.call_with_pp_support_hir(&sess,
 748                                        cstore,
 749                                        &ast_map.unwrap(),
 750                                        &arenas,
 751                                        &id,
 752                                        box out,
 753                                        |annotation, out, krate| {
 754                                            debug!("pretty printing source code {:?}", s);
 755                                            let sess = annotation.sess();
 756                                            pprust_hir::print_crate(sess.codemap(),
 757                                                                    sess.diagnostic(),
 758                                                                    krate,
 759                                                                    src_name.to_string(),
 760                                                                    &mut rdr,
 761                                                                    out,
 762                                                                    annotation.pp_ann(),
 763                                                                    is_expanded)
 764                                        })
 765         }
 766
 767         (PpmHir(s), Some(uii)) => {
 768             let out: &mut Write = &mut out;
 769             s.call_with_pp_support_hir(&sess,
 770                                        cstore,
 771                                        &ast_map.unwrap(),
 772                                        &arenas,
 773                                        &id,
 774                                        (out,uii),
 775                                        |annotation, (out,uii), _| {
 776                 debug!("pretty printing source code {:?}", s);
 777                 let sess = annotation.sess();
 778                 let ast_map = annotation.ast_map().expect("--pretty missing ast_map");
 779                 let mut pp_state =
 780                     pprust_hir::State::new_from_input(sess.codemap(),
 781                                                       sess.diagnostic(),
 782                                                       src_name.to_string(),
 783                                                       &mut rdr,
 784                                                       box out,
 785                                                       annotation.pp_ann(),
 786                                                       true,
 787                                                       Some(ast_map.krate()));
 788                 for node_id in uii.all_matching_node_ids(ast_map) {
 789                     let node = ast_map.get(node_id);
 790                     try!(pp_state.print_node(&node));
 791                     try!(pp::space(&mut pp_state.s));
 792                     try!(pp_state.synth_comment(ast_map.path_to_string(node_id)));
 793                     try!(pp::hardbreak(&mut pp_state.s));
 794                 }
 795                 pp::eof(&mut pp_state.s)
 796             })
 797         }
 798
 799         (PpmFlowGraph(mode), opt_uii) => {
 800             debug!("pretty printing flow graph for {:?}", opt_uii);
 801             let uii = opt_uii.unwrap_or_else(|| {
 802                 sess.fatal(&format!("`pretty flowgraph=..` needs NodeId (int) or
 803                                      \
 804                                      unique path suffix (b::c::d)"))
 805
 806             });
 807             let ast_map = ast_map.expect("--pretty flowgraph missing ast_map");
 808             let nodeid = uii.to_one_node_id("--pretty", &sess, &ast_map);
 809
 810             let node = ast_map.find(nodeid).unwrap_or_else(|| {
 811                 sess.fatal(&format!("--pretty flowgraph couldn't find id: {}", nodeid))
 812             });
 813
 814             let code = blocks::Code::from_node(node);
 815             let out: &mut Write = &mut out;
 816             match code {
 817                 Some(code) => {
 818                     let variants = gather_flowgraph_variants(&sess);
 819                     driver::phase_3_run_analysis_passes(&sess,
 820                                                         &cstore,
 821                                                         ast_map,
 822                                                         &arenas,
 823                                                         &id,
 824                                                         resolve::MakeGlobMap::No,
 825                                                         |tcx, _, _| {
 826                                                             print_flowgraph(variants,
 827                                                                             tcx,
 828                                                                             code,
 829                                                                             mode,
 830                                                                             out)
 831                                                         })
 832                 }
 833                 None => {
 834                     let message = format!("--pretty=flowgraph needs block, fn, or method; got \
 835                                            {:?}",
 836                                           node);
 837
 838                     // point to what was found, if there's an
 839                     // accessible span.
 840                     match ast_map.opt_span(nodeid) {
 841                         Some(sp) => sess.span_fatal(sp, &message[..]),
 842                         None => sess.fatal(&message[..]),
 843                     }
 844                 }
 845             }
 846         }
 847     }
 848     .unwrap();
 849
 850     match ofile {
 851         None => print!("{}", String::from_utf8(out).unwrap()),
 852         Some(p) => {
 853             match File::create(&p) {
 854                 Ok(mut w) => w.write_all(&out).unwrap(),
 855                 Err(e) => panic!("print-print failed to open {} due to {}", p.display(), e),
 856             }
 857         }
 858     }
 859 }
 860
 861 fn print_flowgraph<W: Write>(variants: Vec<borrowck_dot::Variant>,
 862                              tcx: &ty::ctxt,
 863                              code: blocks::Code,
 864                              mode: PpFlowGraphMode,
 865                              mut out: W)
 866                              -> io::Result<()> {
 867     let cfg = match code {
 868         blocks::BlockCode(block) => cfg::CFG::new(tcx, &*block),
 869         blocks::FnLikeCode(fn_like) => cfg::CFG::new(tcx, &*fn_like.body()),
 870     };
 871     let labelled_edges = mode != PpFlowGraphMode::UnlabelledEdges;
 872     let lcfg = LabelledCFG {
 873         ast_map: &tcx.map,
 874         cfg: &cfg,
 875         name: format!("node_{}", code.id()),
 876         labelled_edges: labelled_edges,
 877     };
 878
 879     match code {
 880         _ if variants.is_empty() => {
 881             let r = dot::render(&lcfg, &mut out);
 882             return expand_err_details(r);
 883         }
 884         blocks::BlockCode(_) => {
 885             tcx.sess.err("--pretty flowgraph with -Z flowgraph-print annotations requires \
 886                           fn-like node id.");
 887             return Ok(());
 888         }
 889         blocks::FnLikeCode(fn_like) => {
 890             let fn_parts = borrowck::FnPartsWithCFG::from_fn_like(&fn_like, &cfg);
 891             let (bccx, analysis_data) = borrowck::build_borrowck_dataflow_data_for_fn(tcx,
 892                                                                                       fn_parts);
 893
 894             let lcfg = borrowck_dot::DataflowLabeller {
 895                 inner: lcfg,
 896                 variants: variants,
 897                 borrowck_ctxt: &bccx,
 898                 analysis_data: &analysis_data,
 899             };
 900             let r = dot::render(&lcfg, &mut out);
 901             return expand_err_details(r);
 902         }
 903     }
 904
 905     fn expand_err_details(r: io::Result<()>) -> io::Result<()> {
 906         r.map_err(|ioerr| {
 907             io::Error::new(io::ErrorKind::Other,
 908                            &format!("graphviz::render failed: {}", ioerr)[..])
 909         })
 910     }
 911 }