src/librustc_driver/pretty.rs

   1 //! The various pretty-printing routines.
   2
   3 use rustc::hir::map as hir_map;
   4 use rustc::session::config::{Input, PpMode, PpSourceMode};
   5 use rustc::session::Session;
   6 use rustc::ty::{self, TyCtxt};
   7 use rustc::util::common::ErrorReported;
   8 use rustc_ast_pretty::pprust;
   9 use rustc_hir as hir;
  10 use rustc_hir::def_id::LOCAL_CRATE;
  11 use rustc_hir::print as pprust_hir;
  12 use rustc_mir::util::{write_mir_graphviz, write_mir_pretty};
  13 use rustc_span::FileName;
  14 use syntax::ast;
  15
  16 use std::cell::Cell;
  17 use std::fs::File;
  18 use std::io::Write;
  19 use std::path::Path;
  20
  21 pub use self::PpMode::*;
  22 pub use self::PpSourceMode::*;
  23 use crate::abort_on_err;
  24
  25 // This slightly awkward construction is to allow for each PpMode to
  26 // choose whether it needs to do analyses (which can consume the
  27 // Session) and then pass through the session (now attached to the
  28 // analysis results) on to the chosen pretty-printer, along with the
  29 // `&PpAnn` object.
  30 //
  31 // Note that since the `&PrinterSupport` is freshly constructed on each
  32 // call, it would not make sense to try to attach the lifetime of `self`
  33 // to the lifetime of the `&PrinterObject`.
  34 //
  35 // (The `use_once_payload` is working around the current lack of once
  36 // functions in the compiler.)
  37
  38 /// Constructs a `PrinterSupport` object and passes it to `f`.
  39 fn call_with_pp_support<'tcx, A, F>(
  40     ppmode: &PpSourceMode,
  41     sess: &'tcx Session,
  42     tcx: Option<TyCtxt<'tcx>>,
  43     f: F,
  44 ) -> A
  45 where
  46     F: FnOnce(&dyn PrinterSupport) -> A,
  47 {
  48     match *ppmode {
  49         PpmNormal | PpmEveryBodyLoops | PpmExpanded => {
  50             let annotation = NoAnn { sess, tcx };
  51             f(&annotation)
  52         }
  53
  54         PpmIdentified | PpmExpandedIdentified => {
  55             let annotation = IdentifiedAnnotation { sess, tcx };
  56             f(&annotation)
  57         }
  58         PpmExpandedHygiene => {
  59             let annotation = HygieneAnnotation { sess };
  60             f(&annotation)
  61         }
  62         _ => panic!("Should use call_with_pp_support_hir"),
  63     }
  64 }
  65 fn call_with_pp_support_hir<A, F>(ppmode: &PpSourceMode, tcx: TyCtxt<'_>, f: F) -> A
  66 where
  67     F: FnOnce(&dyn HirPrinterSupport<'_>, &hir::Crate<'_>) -> A,
  68 {
  69     match *ppmode {
  70         PpmNormal => {
  71             let annotation = NoAnn { sess: tcx.sess, tcx: Some(tcx) };
  72             f(&annotation, tcx.hir().krate())
  73         }
  74
  75         PpmIdentified => {
  76             let annotation = IdentifiedAnnotation { sess: tcx.sess, tcx: Some(tcx) };
  77             f(&annotation, tcx.hir().krate())
  78         }
  79         PpmTyped => {
  80             abort_on_err(tcx.analysis(LOCAL_CRATE), tcx.sess);
  81
  82             let empty_tables = ty::TypeckTables::empty(None);
  83             let annotation = TypedAnnotation { tcx, tables: Cell::new(&empty_tables) };
  84             tcx.dep_graph.with_ignore(|| f(&annotation, tcx.hir().krate()))
  85         }
  86         _ => panic!("Should use call_with_pp_support"),
  87     }
  88 }
  89
  90 trait PrinterSupport: pprust::PpAnn {
  91     /// Provides a uniform interface for re-extracting a reference to a
  92     /// `Session` from a value that now owns it.
  93     fn sess(&self) -> &Session;
  94
  95     /// Produces the pretty-print annotation object.
  96     ///
  97     /// (Rust does not yet support upcasting from a trait object to
  98     /// an object for one of its super-traits.)
  99     fn pp_ann<'a>(&'a self) -> &'a dyn pprust::PpAnn;
 100 }
 101
 102 trait HirPrinterSupport<'hir>: pprust_hir::PpAnn {
 103     /// Provides a uniform interface for re-extracting a reference to a
 104     /// `Session` from a value that now owns it.
 105     fn sess(&self) -> &Session;
 106
 107     /// Provides a uniform interface for re-extracting a reference to an
 108     /// `hir_map::Map` from a value that now owns it.
 109     fn hir_map<'a>(&'a self) -> Option<&'a hir_map::Map<'hir>>;
 110
 111     /// Produces the pretty-print annotation object.
 112     ///
 113     /// (Rust does not yet support upcasting from a trait object to
 114     /// an object for one of its super-traits.)
 115     fn pp_ann<'a>(&'a self) -> &'a dyn pprust_hir::PpAnn;
 116
 117     /// Computes an user-readable representation of a path, if possible.
 118     fn node_path(&self, id: hir::HirId) -> Option<String> {
 119         self.hir_map().and_then(|map| map.def_path_from_hir_id(id)).map(|path| {
 120             path.data.into_iter().map(|elem| elem.data.to_string()).collect::<Vec<_>>().join("::")
 121         })
 122     }
 123 }
 124
 125 struct NoAnn<'hir> {
 126     sess: &'hir Session,
 127     tcx: Option<TyCtxt<'hir>>,
 128 }
 129
 130 impl<'hir> PrinterSupport for NoAnn<'hir> {
 131     fn sess(&self) -> &Session {
 132         self.sess
 133     }
 134
 135     fn pp_ann<'a>(&'a self) -> &'a dyn pprust::PpAnn {
 136         self
 137     }
 138 }
 139
 140 impl<'hir> HirPrinterSupport<'hir> for NoAnn<'hir> {
 141     fn sess(&self) -> &Session {
 142         self.sess
 143     }
 144
 145     fn hir_map<'a>(&'a self) -> Option<&'a hir_map::Map<'hir>> {
 146         self.tcx.map(|tcx| *tcx.hir())
 147     }
 148
 149     fn pp_ann<'a>(&'a self) -> &'a dyn pprust_hir::PpAnn {
 150         self
 151     }
 152 }
 153
 154 impl<'hir> pprust::PpAnn for NoAnn<'hir> {}
 155 impl<'hir> pprust_hir::PpAnn for NoAnn<'hir> {
 156     fn nested(&self, state: &mut pprust_hir::State<'_>, nested: pprust_hir::Nested) {
 157         if let Some(tcx) = self.tcx {
 158             pprust_hir::PpAnn::nested(*tcx.hir(), state, nested)
 159         }
 160     }
 161 }
 162
 163 struct IdentifiedAnnotation<'hir> {
 164     sess: &'hir Session,
 165     tcx: Option<TyCtxt<'hir>>,
 166 }
 167
 168 impl<'hir> PrinterSupport for IdentifiedAnnotation<'hir> {
 169     fn sess(&self) -> &Session {
 170         self.sess
 171     }
 172
 173     fn pp_ann<'a>(&'a self) -> &'a dyn pprust::PpAnn {
 174         self
 175     }
 176 }
 177
 178 impl<'hir> pprust::PpAnn for IdentifiedAnnotation<'hir> {
 179     fn pre(&self, s: &mut pprust::State<'_>, node: pprust::AnnNode<'_>) {
 180         match node {
 181             pprust::AnnNode::Expr(_) => s.popen(),
 182             _ => {}
 183         }
 184     }
 185     fn post(&self, s: &mut pprust::State<'_>, node: pprust::AnnNode<'_>) {
 186         match node {
 187             pprust::AnnNode::Crate(_) | pprust::AnnNode::Ident(_) | pprust::AnnNode::Name(_) => {}
 188
 189             pprust::AnnNode::Item(item) => {
 190                 s.s.space();
 191                 s.synth_comment(item.id.to_string())
 192             }
 193             pprust::AnnNode::SubItem(id) => {
 194                 s.s.space();
 195                 s.synth_comment(id.to_string())
 196             }
 197             pprust::AnnNode::Block(blk) => {
 198                 s.s.space();
 199                 s.synth_comment(format!("block {}", blk.id))
 200             }
 201             pprust::AnnNode::Expr(expr) => {
 202                 s.s.space();
 203                 s.synth_comment(expr.id.to_string());
 204                 s.pclose()
 205             }
 206             pprust::AnnNode::Pat(pat) => {
 207                 s.s.space();
 208                 s.synth_comment(format!("pat {}", pat.id));
 209             }
 210         }
 211     }
 212 }
 213
 214 impl<'hir> HirPrinterSupport<'hir> for IdentifiedAnnotation<'hir> {
 215     fn sess(&self) -> &Session {
 216         self.sess
 217     }
 218
 219     fn hir_map<'a>(&'a self) -> Option<&'a hir_map::Map<'hir>> {
 220         self.tcx.map(|tcx| *tcx.hir())
 221     }
 222
 223     fn pp_ann<'a>(&'a self) -> &'a dyn pprust_hir::PpAnn {
 224         self
 225     }
 226 }
 227
 228 impl<'hir> pprust_hir::PpAnn for IdentifiedAnnotation<'hir> {
 229     fn nested(&self, state: &mut pprust_hir::State<'_>, nested: pprust_hir::Nested) {
 230         if let Some(ref tcx) = self.tcx {
 231             pprust_hir::PpAnn::nested(*tcx.hir(), state, nested)
 232         }
 233     }
 234     fn pre(&self, s: &mut pprust_hir::State<'_>, node: pprust_hir::AnnNode<'_>) {
 235         match node {
 236             pprust_hir::AnnNode::Expr(_) => s.popen(),
 237             _ => {}
 238         }
 239     }
 240     fn post(&self, s: &mut pprust_hir::State<'_>, node: pprust_hir::AnnNode<'_>) {
 241         match node {
 242             pprust_hir::AnnNode::Name(_) => {}
 243             pprust_hir::AnnNode::Item(item) => {
 244                 s.s.space();
 245                 s.synth_comment(format!("hir_id: {}", item.hir_id));
 246             }
 247             pprust_hir::AnnNode::SubItem(id) => {
 248                 s.s.space();
 249                 s.synth_comment(id.to_string());
 250             }
 251             pprust_hir::AnnNode::Block(blk) => {
 252                 s.s.space();
 253                 s.synth_comment(format!("block hir_id: {}", blk.hir_id));
 254             }
 255             pprust_hir::AnnNode::Expr(expr) => {
 256                 s.s.space();
 257                 s.synth_comment(format!("expr hir_id: {}", expr.hir_id));
 258                 s.pclose();
 259             }
 260             pprust_hir::AnnNode::Pat(pat) => {
 261                 s.s.space();
 262                 s.synth_comment(format!("pat hir_id: {}", pat.hir_id));
 263             }
 264             pprust_hir::AnnNode::Arm(arm) => {
 265                 s.s.space();
 266                 s.synth_comment(format!("arm hir_id: {}", arm.hir_id));
 267             }
 268         }
 269     }
 270 }
 271
 272 struct HygieneAnnotation<'a> {
 273     sess: &'a Session,
 274 }
 275
 276 impl<'a> PrinterSupport for HygieneAnnotation<'a> {
 277     fn sess(&self) -> &Session {
 278         self.sess
 279     }
 280
 281     fn pp_ann(&self) -> &dyn pprust::PpAnn {
 282         self
 283     }
 284 }
 285
 286 impl<'a> pprust::PpAnn for HygieneAnnotation<'a> {
 287     fn post(&self, s: &mut pprust::State<'_>, node: pprust::AnnNode<'_>) {
 288         match node {
 289             pprust::AnnNode::Ident(&ast::Ident { name, span }) => {
 290                 s.s.space();
 291                 s.synth_comment(format!("{}{:?}", name.as_u32(), span.ctxt()))
 292             }
 293             pprust::AnnNode::Name(&name) => {
 294                 s.s.space();
 295                 s.synth_comment(name.as_u32().to_string())
 296             }
 297             pprust::AnnNode::Crate(_) => {
 298                 s.s.hardbreak();
 299                 let verbose = self.sess.verbose();
 300                 s.synth_comment(rustc_span::hygiene::debug_hygiene_data(verbose));
 301                 s.s.hardbreak_if_not_bol();
 302             }
 303             _ => {}
 304         }
 305     }
 306 }
 307
 308 struct TypedAnnotation<'a, 'tcx> {
 309     tcx: TyCtxt<'tcx>,
 310     tables: Cell<&'a ty::TypeckTables<'tcx>>,
 311 }
 312
 313 impl<'b, 'tcx> HirPrinterSupport<'tcx> for TypedAnnotation<'b, 'tcx> {
 314     fn sess(&self) -> &Session {
 315         &self.tcx.sess
 316     }
 317
 318     fn hir_map<'a>(&'a self) -> Option<&'a hir_map::Map<'tcx>> {
 319         Some(&self.tcx.hir())
 320     }
 321
 322     fn pp_ann<'a>(&'a self) -> &'a dyn pprust_hir::PpAnn {
 323         self
 324     }
 325
 326     fn node_path(&self, id: hir::HirId) -> Option<String> {
 327         Some(self.tcx.def_path_str(self.tcx.hir().local_def_id(id)))
 328     }
 329 }
 330
 331 impl<'a, 'tcx> pprust_hir::PpAnn for TypedAnnotation<'a, 'tcx> {
 332     fn nested(&self, state: &mut pprust_hir::State<'_>, nested: pprust_hir::Nested) {
 333         let old_tables = self.tables.get();
 334         if let pprust_hir::Nested::Body(id) = nested {
 335             self.tables.set(self.tcx.body_tables(id));
 336         }
 337         pprust_hir::PpAnn::nested(*self.tcx.hir(), state, nested);
 338         self.tables.set(old_tables);
 339     }
 340     fn pre(&self, s: &mut pprust_hir::State<'_>, node: pprust_hir::AnnNode<'_>) {
 341         match node {
 342             pprust_hir::AnnNode::Expr(_) => s.popen(),
 343             _ => {}
 344         }
 345     }
 346     fn post(&self, s: &mut pprust_hir::State<'_>, node: pprust_hir::AnnNode<'_>) {
 347         match node {
 348             pprust_hir::AnnNode::Expr(expr) => {
 349                 s.s.space();
 350                 s.s.word("as");
 351                 s.s.space();
 352                 s.s.word(self.tables.get().expr_ty(expr).to_string());
 353                 s.pclose();
 354             }
 355             _ => {}
 356         }
 357     }
 358 }
 359
 360 fn get_source(input: &Input, sess: &Session) -> (String, FileName) {
 361     let src_name = input.source_name();
 362     let src =
 363         String::clone(&sess.source_map().get_source_file(&src_name).unwrap().src.as_ref().unwrap());
 364     (src, src_name)
 365 }
 366
 367 fn write_output(out: Vec<u8>, ofile: Option<&Path>) {
 368     match ofile {
 369         None => print!("{}", String::from_utf8(out).unwrap()),
 370         Some(p) => match File::create(p) {
 371             Ok(mut w) => w.write_all(&out).unwrap(),
 372             Err(e) => panic!("print-print failed to open {} due to {}", p.display(), e),
 373         },
 374     }
 375 }
 376
 377 pub fn print_after_parsing(
 378     sess: &Session,
 379     input: &Input,
 380     krate: &ast::Crate,
 381     ppm: PpMode,
 382     ofile: Option<&Path>,
 383 ) {
 384     let (src, src_name) = get_source(input, sess);
 385
 386     let mut out = String::new();
 387
 388     if let PpmSource(s) = ppm {
 389         // Silently ignores an identified node.
 390         let out = &mut out;
 391         call_with_pp_support(&s, sess, None, move |annotation| {
 392             debug!("pretty printing source code {:?}", s);
 393             let sess = annotation.sess();
 394             let parse = &sess.parse_sess;
 395             *out = pprust::print_crate(
 396                 sess.source_map(),
 397                 krate,
 398                 src_name,
 399                 src,
 400                 annotation.pp_ann(),
 401                 false,
 402                 parse.edition,
 403                 parse.injected_crate_name.try_get().is_some(),
 404             )
 405         })
 406     } else {
 407         unreachable!();
 408     };
 409
 410     write_output(out.into_bytes(), ofile);
 411 }
 412
 413 pub fn print_after_hir_lowering<'tcx>(
 414     tcx: TyCtxt<'tcx>,
 415     input: &Input,
 416     krate: &ast::Crate,
 417     ppm: PpMode,
 418     ofile: Option<&Path>,
 419 ) {
 420     if ppm.needs_analysis() {
 421         abort_on_err(print_with_analysis(tcx, ppm, ofile), tcx.sess);
 422         return;
 423     }
 424
 425     let (src, src_name) = get_source(input, tcx.sess);
 426
 427     let mut out = String::new();
 428
 429     match ppm {
 430         PpmSource(s) => {
 431             // Silently ignores an identified node.
 432             let out = &mut out;
 433             call_with_pp_support(&s, tcx.sess, Some(tcx), move |annotation| {
 434                 debug!("pretty printing source code {:?}", s);
 435                 let sess = annotation.sess();
 436                 let parse = &sess.parse_sess;
 437                 *out = pprust::print_crate(
 438                     sess.source_map(),
 439                     krate,
 440                     src_name,
 441                     src,
 442                     annotation.pp_ann(),
 443                     true,
 444                     parse.edition,
 445                     parse.injected_crate_name.try_get().is_some(),
 446                 )
 447             })
 448         }
 449
 450         PpmHir(s) => {
 451             let out = &mut out;
 452             call_with_pp_support_hir(&s, tcx, move |annotation, krate| {
 453                 debug!("pretty printing source code {:?}", s);
 454                 let sess = annotation.sess();
 455                 let cm = sess.source_map();
 456                 *out = pprust_hir::print_crate(cm, krate, src_name, src, annotation.pp_ann())
 457             })
 458         }
 459
 460         PpmHirTree(s) => {
 461             let out = &mut out;
 462             call_with_pp_support_hir(&s, tcx, move |_annotation, krate| {
 463                 debug!("pretty printing source code {:?}", s);
 464                 *out = format!("{:#?}", krate);
 465             });
 466         }
 467
 468         _ => unreachable!(),
 469     }
 470
 471     write_output(out.into_bytes(), ofile);
 472 }
 473
 474 // In an ideal world, this would be a public function called by the driver after
 475 // analysis is performed. However, we want to call `phase_3_run_analysis_passes`
 476 // with a different callback than the standard driver, so that isn't easy.
 477 // Instead, we call that function ourselves.
 478 fn print_with_analysis(
 479     tcx: TyCtxt<'_>,
 480     ppm: PpMode,
 481     ofile: Option<&Path>,
 482 ) -> Result<(), ErrorReported> {
 483     let mut out = Vec::new();
 484
 485     tcx.analysis(LOCAL_CRATE)?;
 486
 487     match ppm {
 488         PpmMir | PpmMirCFG => match ppm {
 489             PpmMir => write_mir_pretty(tcx, None, &mut out),
 490             PpmMirCFG => write_mir_graphviz(tcx, None, &mut out),
 491             _ => unreachable!(),
 492         },
 493         _ => unreachable!(),
 494     }
 495     .unwrap();
 496
 497     write_output(out, ofile);
 498
 499     Ok(())
 500 }