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_hir as hir;
   9 use rustc_hir::def_id::LOCAL_CRATE;
  10 use rustc_hir::print as pprust_hir;
  11 use rustc_mir::util::{write_mir_graphviz, write_mir_pretty};
  12
  13 use rustc_span::FileName;
  14 use syntax::ast;
  15 use syntax::print::pprust;
  16
  17 use std::cell::Cell;
  18 use std::fs::File;
  19 use std::io::Write;
  20 use std::path::Path;
  21
  22 pub use self::PpMode::*;
  23 pub use self::PpSourceMode::*;
  24 use crate::abort_on_err;
  25
  26 // This slightly awkward construction is to allow for each PpMode to
  27 // choose whether it needs to do analyses (which can consume the
  28 // Session) and then pass through the session (now attached to the
  29 // analysis results) on to the chosen pretty-printer, along with the
  30 // `&PpAnn` object.
  31 //
  32 // Note that since the `&PrinterSupport` is freshly constructed on each
  33 // call, it would not make sense to try to attach the lifetime of `self`
  34 // to the lifetime of the `&PrinterObject`.
  35 //
  36 // (The `use_once_payload` is working around the current lack of once
  37 // functions in the compiler.)
  38
  39 /// Constructs a `PrinterSupport` object and passes it to `f`.
  40 fn call_with_pp_support<'tcx, A, F>(
  41     ppmode: &PpSourceMode,
  42     sess: &'tcx Session,
  43     tcx: Option<TyCtxt<'tcx>>,
  44     f: F,
  45 ) -> A
  46 where
  47     F: FnOnce(&dyn PrinterSupport) -> A,
  48 {
  49     match *ppmode {
  50         PpmNormal | PpmEveryBodyLoops | PpmExpanded => {
  51             let annotation = NoAnn { sess, tcx };
  52             f(&annotation)
  53         }
  54
  55         PpmIdentified | PpmExpandedIdentified => {
  56             let annotation = IdentifiedAnnotation { sess, tcx };
  57             f(&annotation)
  58         }
  59         PpmExpandedHygiene => {
  60             let annotation = HygieneAnnotation { sess };
  61             f(&annotation)
  62         }
  63         _ => panic!("Should use call_with_pp_support_hir"),
  64     }
  65 }
  66 fn call_with_pp_support_hir<A, F>(ppmode: &PpSourceMode, tcx: TyCtxt<'_>, f: F) -> A
  67 where
  68     F: FnOnce(&dyn HirPrinterSupport<'_>, &hir::Crate<'_>) -> A,
  69 {
  70     match *ppmode {
  71         PpmNormal => {
  72             let annotation = NoAnn { sess: tcx.sess, tcx: Some(tcx) };
  73             f(&annotation, tcx.hir().forest.krate())
  74         }
  75
  76         PpmIdentified => {
  77             let annotation = IdentifiedAnnotation { sess: tcx.sess, tcx: Some(tcx) };
  78             f(&annotation, tcx.hir().forest.krate())
  79         }
  80         PpmTyped => {
  81             abort_on_err(tcx.analysis(LOCAL_CRATE), tcx.sess);
  82
  83             let empty_tables = ty::TypeckTables::empty(None);
  84             let annotation = TypedAnnotation { tcx, tables: Cell::new(&empty_tables) };
  85             tcx.dep_graph.with_ignore(|| f(&annotation, tcx.hir().forest.krate()))
  86         }
  87         _ => panic!("Should use call_with_pp_support"),
  88     }
  89 }
  90
  91 trait PrinterSupport: pprust::PpAnn {
  92     /// Provides a uniform interface for re-extracting a reference to a
  93     /// `Session` from a value that now owns it.
  94     fn sess(&self) -> &Session;
  95
  96     /// Produces the pretty-print annotation object.
  97     ///
  98     /// (Rust does not yet support upcasting from a trait object to
  99     /// an object for one of its super-traits.)
 100     fn pp_ann<'a>(&'a self) -> &'a dyn pprust::PpAnn;
 101 }
 102
 103 trait HirPrinterSupport<'hir>: pprust_hir::PpAnn {
 104     /// Provides a uniform interface for re-extracting a reference to a
 105     /// `Session` from a value that now owns it.
 106     fn sess(&self) -> &Session;
 107
 108     /// Provides a uniform interface for re-extracting a reference to an
 109     /// `hir_map::Map` from a value that now owns it.
 110     fn hir_map<'a>(&'a self) -> Option<&'a hir_map::Map<'hir>>;
 111
 112     /// Produces the pretty-print annotation object.
 113     ///
 114     /// (Rust does not yet support upcasting from a trait object to
 115     /// an object for one of its super-traits.)
 116     fn pp_ann<'a>(&'a self) -> &'a dyn pprust_hir::PpAnn;
 117
 118     /// Computes an user-readable representation of a path, if possible.
 119     fn node_path(&self, id: hir::HirId) -> Option<String> {
 120         self.hir_map().and_then(|map| map.def_path_from_hir_id(id)).map(|path| {
 121             path.data.into_iter().map(|elem| elem.data.to_string()).collect::<Vec<_>>().join("::")
 122         })
 123     }
 124 }
 125
 126 struct NoAnn<'hir> {
 127     sess: &'hir Session,
 128     tcx: Option<TyCtxt<'hir>>,
 129 }
 130
 131 impl<'hir> PrinterSupport for NoAnn<'hir> {
 132     fn sess(&self) -> &Session {
 133         self.sess
 134     }
 135
 136     fn pp_ann<'a>(&'a self) -> &'a dyn pprust::PpAnn {
 137         self
 138     }
 139 }
 140
 141 impl<'hir> HirPrinterSupport<'hir> for NoAnn<'hir> {
 142     fn sess(&self) -> &Session {
 143         self.sess
 144     }
 145
 146     fn hir_map<'a>(&'a self) -> Option<&'a hir_map::Map<'hir>> {
 147         self.tcx.map(|tcx| tcx.hir())
 148     }
 149
 150     fn pp_ann<'a>(&'a self) -> &'a dyn pprust_hir::PpAnn {
 151         self
 152     }
 153 }
 154
 155 impl<'hir> pprust::PpAnn for NoAnn<'hir> {}
 156 impl<'hir> pprust_hir::PpAnn for NoAnn<'hir> {
 157     fn nested(&self, state: &mut pprust_hir::State<'_>, nested: pprust_hir::Nested) {
 158         if let Some(tcx) = self.tcx {
 159             pprust_hir::PpAnn::nested(tcx.hir(), state, nested)
 160         }
 161     }
 162 }
 163
 164 struct IdentifiedAnnotation<'hir> {
 165     sess: &'hir Session,
 166     tcx: Option<TyCtxt<'hir>>,
 167 }
 168
 169 impl<'hir> PrinterSupport for IdentifiedAnnotation<'hir> {
 170     fn sess(&self) -> &Session {
 171         self.sess
 172     }
 173
 174     fn pp_ann<'a>(&'a self) -> &'a dyn pprust::PpAnn {
 175         self
 176     }
 177 }
 178
 179 impl<'hir> pprust::PpAnn for IdentifiedAnnotation<'hir> {
 180     fn pre(&self, s: &mut pprust::State<'_>, node: pprust::AnnNode<'_>) {
 181         match node {
 182             pprust::AnnNode::Expr(_) => s.popen(),
 183             _ => {}
 184         }
 185     }
 186     fn post(&self, s: &mut pprust::State<'_>, node: pprust::AnnNode<'_>) {
 187         match node {
 188             pprust::AnnNode::Crate(_) | pprust::AnnNode::Ident(_) | pprust::AnnNode::Name(_) => {}
 189
 190             pprust::AnnNode::Item(item) => {
 191                 s.s.space();
 192                 s.synth_comment(item.id.to_string())
 193             }
 194             pprust::AnnNode::SubItem(id) => {
 195                 s.s.space();
 196                 s.synth_comment(id.to_string())
 197             }
 198             pprust::AnnNode::Block(blk) => {
 199                 s.s.space();
 200                 s.synth_comment(format!("block {}", blk.id))
 201             }
 202             pprust::AnnNode::Expr(expr) => {
 203                 s.s.space();
 204                 s.synth_comment(expr.id.to_string());
 205                 s.pclose()
 206             }
 207             pprust::AnnNode::Pat(pat) => {
 208                 s.s.space();
 209                 s.synth_comment(format!("pat {}", pat.id));
 210             }
 211         }
 212     }
 213 }
 214
 215 impl<'hir> HirPrinterSupport<'hir> for IdentifiedAnnotation<'hir> {
 216     fn sess(&self) -> &Session {
 217         self.sess
 218     }
 219
 220     fn hir_map<'a>(&'a self) -> Option<&'a hir_map::Map<'hir>> {
 221         self.tcx.map(|tcx| tcx.hir())
 222     }
 223
 224     fn pp_ann<'a>(&'a self) -> &'a dyn pprust_hir::PpAnn {
 225         self
 226     }
 227 }
 228
 229 impl<'hir> pprust_hir::PpAnn for IdentifiedAnnotation<'hir> {
 230     fn nested(&self, state: &mut pprust_hir::State<'_>, nested: pprust_hir::Nested) {
 231         if let Some(ref tcx) = self.tcx {
 232             pprust_hir::PpAnn::nested(tcx.hir(), state, nested)
 233         }
 234     }
 235     fn pre(&self, s: &mut pprust_hir::State<'_>, node: pprust_hir::AnnNode<'_>) {
 236         match node {
 237             pprust_hir::AnnNode::Expr(_) => s.popen(),
 238             _ => {}
 239         }
 240     }
 241     fn post(&self, s: &mut pprust_hir::State<'_>, node: pprust_hir::AnnNode<'_>) {
 242         match node {
 243             pprust_hir::AnnNode::Name(_) => {}
 244             pprust_hir::AnnNode::Item(item) => {
 245                 s.s.space();
 246                 s.synth_comment(format!("hir_id: {}", item.hir_id));
 247             }
 248             pprust_hir::AnnNode::SubItem(id) => {
 249                 s.s.space();
 250                 s.synth_comment(id.to_string());
 251             }
 252             pprust_hir::AnnNode::Block(blk) => {
 253                 s.s.space();
 254                 s.synth_comment(format!("block hir_id: {}", blk.hir_id));
 255             }
 256             pprust_hir::AnnNode::Expr(expr) => {
 257                 s.s.space();
 258                 s.synth_comment(format!("expr hir_id: {}", expr.hir_id));
 259                 s.pclose();
 260             }
 261             pprust_hir::AnnNode::Pat(pat) => {
 262                 s.s.space();
 263                 s.synth_comment(format!("pat hir_id: {}", pat.hir_id));
 264             }
 265             pprust_hir::AnnNode::Arm(arm) => {
 266                 s.s.space();
 267                 s.synth_comment(format!("arm hir_id: {}", arm.hir_id));
 268             }
 269         }
 270     }
 271 }
 272
 273 struct HygieneAnnotation<'a> {
 274     sess: &'a Session,
 275 }
 276
 277 impl<'a> PrinterSupport for HygieneAnnotation<'a> {
 278     fn sess(&self) -> &Session {
 279         self.sess
 280     }
 281
 282     fn pp_ann(&self) -> &dyn pprust::PpAnn {
 283         self
 284     }
 285 }
 286
 287 impl<'a> pprust::PpAnn for HygieneAnnotation<'a> {
 288     fn post(&self, s: &mut pprust::State<'_>, node: pprust::AnnNode<'_>) {
 289         match node {
 290             pprust::AnnNode::Ident(&ast::Ident { name, span }) => {
 291                 s.s.space();
 292                 s.synth_comment(format!("{}{:?}", name.as_u32(), span.ctxt()))
 293             }
 294             pprust::AnnNode::Name(&name) => {
 295                 s.s.space();
 296                 s.synth_comment(name.as_u32().to_string())
 297             }
 298             pprust::AnnNode::Crate(_) => {
 299                 s.s.hardbreak();
 300                 let verbose = self.sess.verbose();
 301                 s.synth_comment(rustc_span::hygiene::debug_hygiene_data(verbose));
 302                 s.s.hardbreak_if_not_bol();
 303             }
 304             _ => {}
 305         }
 306     }
 307 }
 308
 309 struct TypedAnnotation<'a, 'tcx> {
 310     tcx: TyCtxt<'tcx>,
 311     tables: Cell<&'a ty::TypeckTables<'tcx>>,
 312 }
 313
 314 impl<'b, 'tcx> HirPrinterSupport<'tcx> for TypedAnnotation<'b, 'tcx> {
 315     fn sess(&self) -> &Session {
 316         &self.tcx.sess
 317     }
 318
 319     fn hir_map<'a>(&'a self) -> Option<&'a hir_map::Map<'tcx>> {
 320         Some(&self.tcx.hir())
 321     }
 322
 323     fn pp_ann<'a>(&'a self) -> &'a dyn pprust_hir::PpAnn {
 324         self
 325     }
 326
 327     fn node_path(&self, id: hir::HirId) -> Option<String> {
 328         Some(self.tcx.def_path_str(self.tcx.hir().local_def_id(id)))
 329     }
 330 }
 331
 332 impl<'a, 'tcx> pprust_hir::PpAnn for TypedAnnotation<'a, 'tcx> {
 333     fn nested(&self, state: &mut pprust_hir::State<'_>, nested: pprust_hir::Nested) {
 334         let old_tables = self.tables.get();
 335         if let pprust_hir::Nested::Body(id) = nested {
 336             self.tables.set(self.tcx.body_tables(id));
 337         }
 338         pprust_hir::PpAnn::nested(self.tcx.hir(), state, nested);
 339         self.tables.set(old_tables);
 340     }
 341     fn pre(&self, s: &mut pprust_hir::State<'_>, node: pprust_hir::AnnNode<'_>) {
 342         match node {
 343             pprust_hir::AnnNode::Expr(_) => s.popen(),
 344             _ => {}
 345         }
 346     }
 347     fn post(&self, s: &mut pprust_hir::State<'_>, node: pprust_hir::AnnNode<'_>) {
 348         match node {
 349             pprust_hir::AnnNode::Expr(expr) => {
 350                 s.s.space();
 351                 s.s.word("as");
 352                 s.s.space();
 353                 s.s.word(self.tables.get().expr_ty(expr).to_string());
 354                 s.pclose();
 355             }
 356             _ => {}
 357         }
 358     }
 359 }
 360
 361 fn get_source(input: &Input, sess: &Session) -> (String, FileName) {
 362     let src_name = input.source_name();
 363     let src =
 364         String::clone(&sess.source_map().get_source_file(&src_name).unwrap().src.as_ref().unwrap());
 365     (src, src_name)
 366 }
 367
 368 fn write_output(out: Vec<u8>, ofile: Option<&Path>) {
 369     match ofile {
 370         None => print!("{}", String::from_utf8(out).unwrap()),
 371         Some(p) => match File::create(p) {
 372             Ok(mut w) => w.write_all(&out).unwrap(),
 373             Err(e) => panic!("print-print failed to open {} due to {}", p.display(), e),
 374         },
 375     }
 376 }
 377
 378 pub fn print_after_parsing(
 379     sess: &Session,
 380     input: &Input,
 381     krate: &ast::Crate,
 382     ppm: PpMode,
 383     ofile: Option<&Path>,
 384 ) {
 385     let (src, src_name) = get_source(input, sess);
 386
 387     let mut out = String::new();
 388
 389     if let PpmSource(s) = ppm {
 390         // Silently ignores an identified node.
 391         let out = &mut out;
 392         call_with_pp_support(&s, sess, None, move |annotation| {
 393             debug!("pretty printing source code {:?}", s);
 394             let sess = annotation.sess();
 395             *out = pprust::print_crate(
 396                 sess.source_map(),
 397                 &sess.parse_sess,
 398                 krate,
 399                 src_name,
 400                 src,
 401                 annotation.pp_ann(),
 402                 false,
 403             )
 404         })
 405     } else {
 406         unreachable!();
 407     };
 408
 409     write_output(out.into_bytes(), ofile);
 410 }
 411
 412 pub fn print_after_hir_lowering<'tcx>(
 413     tcx: TyCtxt<'tcx>,
 414     input: &Input,
 415     krate: &ast::Crate,
 416     ppm: PpMode,
 417     ofile: Option<&Path>,
 418 ) {
 419     if ppm.needs_analysis() {
 420         abort_on_err(print_with_analysis(tcx, ppm, ofile), tcx.sess);
 421         return;
 422     }
 423
 424     let (src, src_name) = get_source(input, tcx.sess);
 425
 426     let mut out = String::new();
 427
 428     match ppm {
 429         PpmSource(s) => {
 430             // Silently ignores an identified node.
 431             let out = &mut out;
 432             call_with_pp_support(&s, tcx.sess, Some(tcx), move |annotation| {
 433                 debug!("pretty printing source code {:?}", s);
 434                 let sess = annotation.sess();
 435                 *out = pprust::print_crate(
 436                     sess.source_map(),
 437                     &sess.parse_sess,
 438                     krate,
 439                     src_name,
 440                     src,
 441                     annotation.pp_ann(),
 442                     true,
 443                 )
 444             })
 445         }
 446
 447         PpmHir(s) => {
 448             let out = &mut out;
 449             call_with_pp_support_hir(&s, tcx, move |annotation, krate| {
 450                 debug!("pretty printing source code {:?}", s);
 451                 let sess = annotation.sess();
 452                 *out = pprust_hir::print_crate(
 453                     sess.source_map(),
 454                     &sess.parse_sess,
 455                     krate,
 456                     src_name,
 457                     src,
 458                     annotation.pp_ann(),
 459                 )
 460             })
 461         }
 462
 463         PpmHirTree(s) => {
 464             let out = &mut out;
 465             call_with_pp_support_hir(&s, tcx, move |_annotation, krate| {
 466                 debug!("pretty printing source code {:?}", s);
 467                 *out = format!("{:#?}", krate);
 468             });
 469         }
 470
 471         _ => unreachable!(),
 472     }
 473
 474     write_output(out.into_bytes(), ofile);
 475 }
 476
 477 // In an ideal world, this would be a public function called by the driver after
 478 // analysis is performed. However, we want to call `phase_3_run_analysis_passes`
 479 // with a different callback than the standard driver, so that isn't easy.
 480 // Instead, we call that function ourselves.
 481 fn print_with_analysis(
 482     tcx: TyCtxt<'_>,
 483     ppm: PpMode,
 484     ofile: Option<&Path>,
 485 ) -> Result<(), ErrorReported> {
 486     let mut out = Vec::new();
 487
 488     tcx.analysis(LOCAL_CRATE)?;
 489
 490     match ppm {
 491         PpmMir | PpmMirCFG => match ppm {
 492             PpmMir => write_mir_pretty(tcx, None, &mut out),
 493             PpmMirCFG => write_mir_graphviz(tcx, None, &mut out),
 494             _ => unreachable!(),
 495         },
 496         _ => unreachable!(),
 497     }
 498     .unwrap();
 499
 500     write_output(out, ofile);
 501
 502     Ok(())
 503 }