src/librustc_driver/pretty.rs

   1 //! The various pretty-printing routines.
   2
   3 use rustc_ast::ast;
   4 use rustc_ast_pretty::pprust;
   5 use rustc_errors::ErrorReported;
   6 use rustc_hir as hir;
   7 use rustc_hir::def_id::LOCAL_CRATE;
   8 use rustc_hir_pretty as pprust_hir;
   9 use rustc_middle::hir::map as hir_map;
  10 use rustc_middle::ty::{self, TyCtxt};
  11 use rustc_mir::util::{write_mir_graphviz, write_mir_pretty};
  12 use rustc_session::config::{Input, PpMode, PpSourceMode};
  13 use rustc_session::Session;
  14 use rustc_span::symbol::Ident;
  15 use rustc_span::FileName;
  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().krate())
  74         }
  75
  76         PpmIdentified => {
  77             let annotation = IdentifiedAnnotation { sess: tcx.sess, tcx: Some(tcx) };
  78             f(&annotation, tcx.hir().krate())
  79         }
  80         PpmTyped => {
  81             abort_on_err(tcx.analysis(LOCAL_CRATE), tcx.sess);
  82
  83             let annotation = TypedAnnotation { tcx, maybe_typeck_results: Cell::new(None) };
  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(&self) -> &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(&self) -> Option<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(&self) -> &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(&self) -> &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(&self) -> Option<hir_map::Map<'hir>> {
 146         self.tcx.map(|tcx| tcx.hir())
 147     }
 148
 149     fn pp_ann(&self) -> &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() as &dyn hir::intravisit::Map<'_>), 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(&self) -> &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         if let pprust::AnnNode::Expr(_) = node {
 181             s.popen();
 182         }
 183     }
 184     fn post(&self, s: &mut pprust::State<'_>, node: pprust::AnnNode<'_>) {
 185         match node {
 186             pprust::AnnNode::Crate(_) | pprust::AnnNode::Ident(_) | pprust::AnnNode::Name(_) => {}
 187
 188             pprust::AnnNode::Item(item) => {
 189                 s.s.space();
 190                 s.synth_comment(item.id.to_string())
 191             }
 192             pprust::AnnNode::SubItem(id) => {
 193                 s.s.space();
 194                 s.synth_comment(id.to_string())
 195             }
 196             pprust::AnnNode::Block(blk) => {
 197                 s.s.space();
 198                 s.synth_comment(format!("block {}", blk.id))
 199             }
 200             pprust::AnnNode::Expr(expr) => {
 201                 s.s.space();
 202                 s.synth_comment(expr.id.to_string());
 203                 s.pclose()
 204             }
 205             pprust::AnnNode::Pat(pat) => {
 206                 s.s.space();
 207                 s.synth_comment(format!("pat {}", pat.id));
 208             }
 209         }
 210     }
 211 }
 212
 213 impl<'hir> HirPrinterSupport<'hir> for IdentifiedAnnotation<'hir> {
 214     fn sess(&self) -> &Session {
 215         self.sess
 216     }
 217
 218     fn hir_map(&self) -> Option<hir_map::Map<'hir>> {
 219         self.tcx.map(|tcx| tcx.hir())
 220     }
 221
 222     fn pp_ann(&self) -> &dyn pprust_hir::PpAnn {
 223         self
 224     }
 225 }
 226
 227 impl<'hir> pprust_hir::PpAnn for IdentifiedAnnotation<'hir> {
 228     fn nested(&self, state: &mut pprust_hir::State<'_>, nested: pprust_hir::Nested) {
 229         if let Some(ref tcx) = self.tcx {
 230             pprust_hir::PpAnn::nested(&(&tcx.hir() as &dyn hir::intravisit::Map<'_>), state, nested)
 231         }
 232     }
 233     fn pre(&self, s: &mut pprust_hir::State<'_>, node: pprust_hir::AnnNode<'_>) {
 234         if let pprust_hir::AnnNode::Expr(_) = node {
 235             s.popen();
 236         }
 237     }
 238     fn post(&self, s: &mut pprust_hir::State<'_>, node: pprust_hir::AnnNode<'_>) {
 239         match node {
 240             pprust_hir::AnnNode::Name(_) => {}
 241             pprust_hir::AnnNode::Item(item) => {
 242                 s.s.space();
 243                 s.synth_comment(format!("hir_id: {}", item.hir_id));
 244             }
 245             pprust_hir::AnnNode::SubItem(id) => {
 246                 s.s.space();
 247                 s.synth_comment(id.to_string());
 248             }
 249             pprust_hir::AnnNode::Block(blk) => {
 250                 s.s.space();
 251                 s.synth_comment(format!("block hir_id: {}", blk.hir_id));
 252             }
 253             pprust_hir::AnnNode::Expr(expr) => {
 254                 s.s.space();
 255                 s.synth_comment(format!("expr hir_id: {}", expr.hir_id));
 256                 s.pclose();
 257             }
 258             pprust_hir::AnnNode::Pat(pat) => {
 259                 s.s.space();
 260                 s.synth_comment(format!("pat hir_id: {}", pat.hir_id));
 261             }
 262             pprust_hir::AnnNode::Arm(arm) => {
 263                 s.s.space();
 264                 s.synth_comment(format!("arm hir_id: {}", arm.hir_id));
 265             }
 266         }
 267     }
 268 }
 269
 270 struct HygieneAnnotation<'a> {
 271     sess: &'a Session,
 272 }
 273
 274 impl<'a> PrinterSupport for HygieneAnnotation<'a> {
 275     fn sess(&self) -> &Session {
 276         self.sess
 277     }
 278
 279     fn pp_ann(&self) -> &dyn pprust::PpAnn {
 280         self
 281     }
 282 }
 283
 284 impl<'a> pprust::PpAnn for HygieneAnnotation<'a> {
 285     fn post(&self, s: &mut pprust::State<'_>, node: pprust::AnnNode<'_>) {
 286         match node {
 287             pprust::AnnNode::Ident(&Ident { name, span }) => {
 288                 s.s.space();
 289                 s.synth_comment(format!("{}{:?}", name.as_u32(), span.ctxt()))
 290             }
 291             pprust::AnnNode::Name(&name) => {
 292                 s.s.space();
 293                 s.synth_comment(name.as_u32().to_string())
 294             }
 295             pprust::AnnNode::Crate(_) => {
 296                 s.s.hardbreak();
 297                 let verbose = self.sess.verbose();
 298                 s.synth_comment(rustc_span::hygiene::debug_hygiene_data(verbose));
 299                 s.s.hardbreak_if_not_bol();
 300             }
 301             _ => {}
 302         }
 303     }
 304 }
 305
 306 struct TypedAnnotation<'tcx> {
 307     tcx: TyCtxt<'tcx>,
 308     maybe_typeck_results: Cell<Option<&'tcx ty::TypeckResults<'tcx>>>,
 309 }
 310
 311 impl<'tcx> TypedAnnotation<'tcx> {
 312     /// Gets the type-checking results for the current body.
 313     /// As this will ICE if called outside bodies, only call when working with
 314     /// `Expr` or `Pat` nodes (they are guaranteed to be found only in bodies).
 315     #[track_caller]
 316     fn typeck_results(&self) -> &'tcx ty::TypeckResults<'tcx> {
 317         self.maybe_typeck_results
 318             .get()
 319             .expect("`TypedAnnotation::typeck_results` called outside of body")
 320     }
 321 }
 322
 323 impl<'tcx> HirPrinterSupport<'tcx> for TypedAnnotation<'tcx> {
 324     fn sess(&self) -> &Session {
 325         &self.tcx.sess
 326     }
 327
 328     fn hir_map(&self) -> Option<hir_map::Map<'tcx>> {
 329         Some(self.tcx.hir())
 330     }
 331
 332     fn pp_ann(&self) -> &dyn pprust_hir::PpAnn {
 333         self
 334     }
 335
 336     fn node_path(&self, id: hir::HirId) -> Option<String> {
 337         Some(self.tcx.def_path_str(self.tcx.hir().local_def_id(id).to_def_id()))
 338     }
 339 }
 340
 341 impl<'tcx> pprust_hir::PpAnn for TypedAnnotation<'tcx> {
 342     fn nested(&self, state: &mut pprust_hir::State<'_>, nested: pprust_hir::Nested) {
 343         let old_maybe_typeck_results = self.maybe_typeck_results.get();
 344         if let pprust_hir::Nested::Body(id) = nested {
 345             self.maybe_typeck_results.set(Some(self.tcx.typeck_body(id)));
 346         }
 347         let pp_ann = &(&self.tcx.hir() as &dyn hir::intravisit::Map<'_>);
 348         pprust_hir::PpAnn::nested(pp_ann, state, nested);
 349         self.maybe_typeck_results.set(old_maybe_typeck_results);
 350     }
 351     fn pre(&self, s: &mut pprust_hir::State<'_>, node: pprust_hir::AnnNode<'_>) {
 352         if let pprust_hir::AnnNode::Expr(_) = node {
 353             s.popen();
 354         }
 355     }
 356     fn post(&self, s: &mut pprust_hir::State<'_>, node: pprust_hir::AnnNode<'_>) {
 357         if let pprust_hir::AnnNode::Expr(expr) = node {
 358             s.s.space();
 359             s.s.word("as");
 360             s.s.space();
 361             s.s.word(self.typeck_results().expr_ty(expr).to_string());
 362             s.pclose();
 363         }
 364     }
 365 }
 366
 367 fn get_source(input: &Input, sess: &Session) -> (String, FileName) {
 368     let src_name = input.source_name();
 369     let src =
 370         String::clone(&sess.source_map().get_source_file(&src_name).unwrap().src.as_ref().unwrap());
 371     (src, src_name)
 372 }
 373
 374 fn write_output(out: Vec<u8>, ofile: Option<&Path>) {
 375     match ofile {
 376         None => print!("{}", String::from_utf8(out).unwrap()),
 377         Some(p) => match File::create(p) {
 378             Ok(mut w) => w.write_all(&out).unwrap(),
 379             Err(e) => panic!("print-print failed to open {} due to {}", p.display(), e),
 380         },
 381     }
 382 }
 383
 384 pub fn print_after_parsing(
 385     sess: &Session,
 386     input: &Input,
 387     krate: &ast::Crate,
 388     ppm: PpMode,
 389     ofile: Option<&Path>,
 390 ) {
 391     let (src, src_name) = get_source(input, sess);
 392
 393     let mut out = String::new();
 394
 395     if let PpmSource(s) = ppm {
 396         // Silently ignores an identified node.
 397         let out = &mut out;
 398         call_with_pp_support(&s, sess, None, move |annotation| {
 399             debug!("pretty printing source code {:?}", s);
 400             let sess = annotation.sess();
 401             let parse = &sess.parse_sess;
 402             *out = pprust::print_crate(
 403                 sess.source_map(),
 404                 krate,
 405                 src_name,
 406                 src,
 407                 annotation.pp_ann(),
 408                 false,
 409                 parse.edition,
 410                 parse.injected_crate_name.get().is_some(),
 411             )
 412         })
 413     } else {
 414         unreachable!();
 415     };
 416
 417     write_output(out.into_bytes(), ofile);
 418 }
 419
 420 pub fn print_after_hir_lowering<'tcx>(
 421     tcx: TyCtxt<'tcx>,
 422     input: &Input,
 423     krate: &ast::Crate,
 424     ppm: PpMode,
 425     ofile: Option<&Path>,
 426 ) {
 427     if ppm.needs_analysis() {
 428         abort_on_err(print_with_analysis(tcx, ppm, ofile), tcx.sess);
 429         return;
 430     }
 431
 432     let (src, src_name) = get_source(input, tcx.sess);
 433
 434     let mut out = String::new();
 435
 436     match ppm {
 437         PpmSource(s) => {
 438             // Silently ignores an identified node.
 439             let out = &mut out;
 440             call_with_pp_support(&s, tcx.sess, Some(tcx), move |annotation| {
 441                 debug!("pretty printing source code {:?}", s);
 442                 let sess = annotation.sess();
 443                 let parse = &sess.parse_sess;
 444                 *out = pprust::print_crate(
 445                     sess.source_map(),
 446                     krate,
 447                     src_name,
 448                     src,
 449                     annotation.pp_ann(),
 450                     true,
 451                     parse.edition,
 452                     parse.injected_crate_name.get().is_some(),
 453                 )
 454             })
 455         }
 456
 457         PpmHir(s) => {
 458             let out = &mut out;
 459             call_with_pp_support_hir(&s, tcx, move |annotation, krate| {
 460                 debug!("pretty printing source code {:?}", s);
 461                 let sess = annotation.sess();
 462                 let sm = sess.source_map();
 463                 *out = pprust_hir::print_crate(sm, krate, src_name, src, annotation.pp_ann())
 464             })
 465         }
 466
 467         PpmHirTree(s) => {
 468             let out = &mut out;
 469             call_with_pp_support_hir(&s, tcx, move |_annotation, krate| {
 470                 debug!("pretty printing source code {:?}", s);
 471                 *out = format!("{:#?}", krate);
 472             });
 473         }
 474
 475         _ => unreachable!(),
 476     }
 477
 478     write_output(out.into_bytes(), ofile);
 479 }
 480
 481 // In an ideal world, this would be a public function called by the driver after
 482 // analysis is performed. However, we want to call `phase_3_run_analysis_passes`
 483 // with a different callback than the standard driver, so that isn't easy.
 484 // Instead, we call that function ourselves.
 485 fn print_with_analysis(
 486     tcx: TyCtxt<'_>,
 487     ppm: PpMode,
 488     ofile: Option<&Path>,
 489 ) -> Result<(), ErrorReported> {
 490     let mut out = Vec::new();
 491
 492     tcx.analysis(LOCAL_CRATE)?;
 493
 494     match ppm {
 495         PpmMir | PpmMirCFG => match ppm {
 496             PpmMir => write_mir_pretty(tcx, None, &mut out),
 497             PpmMirCFG => write_mir_graphviz(tcx, None, &mut out),
 498             _ => unreachable!(),
 499         },
 500         _ => unreachable!(),
 501     }
 502     .unwrap();
 503
 504     write_output(out, ofile);
 505
 506     Ok(())
 507 }