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