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