compiler/rustc_driver/src/pretty.rs

   1 //! The various pretty-printing routines.
   2
   3 use rustc_ast as 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::path::Path;
  19
  20 pub use self::PpMode::*;
  21 pub use self::PpSourceMode::*;
  22 use crate::abort_on_err;
  23
  24 // This slightly awkward construction is to allow for each PpMode to
  25 // choose whether it needs to do analyses (which can consume the
  26 // Session) and then pass through the session (now attached to the
  27 // analysis results) on to the chosen pretty-printer, along with the
  28 // `&PpAnn` object.
  29 //
  30 // Note that since the `&PrinterSupport` is freshly constructed on each
  31 // call, it would not make sense to try to attach the lifetime of `self`
  32 // to the lifetime of the `&PrinterObject`.
  33
  34 /// Constructs a `PrinterSupport` object and passes it to `f`.
  35 fn call_with_pp_support<'tcx, A, F>(
  36     ppmode: &PpSourceMode,
  37     sess: &'tcx Session,
  38     tcx: Option<TyCtxt<'tcx>>,
  39     f: F,
  40 ) -> A
  41 where
  42     F: FnOnce(&dyn PrinterSupport) -> A,
  43 {
  44     match *ppmode {
  45         PpmNormal | PpmEveryBodyLoops | PpmExpanded => {
  46             let annotation = NoAnn { sess, tcx };
  47             f(&annotation)
  48         }
  49
  50         PpmIdentified | PpmExpandedIdentified => {
  51             let annotation = IdentifiedAnnotation { sess, tcx };
  52             f(&annotation)
  53         }
  54         PpmExpandedHygiene => {
  55             let annotation = HygieneAnnotation { sess };
  56             f(&annotation)
  57         }
  58         _ => panic!("Should use call_with_pp_support_hir"),
  59     }
  60 }
  61 fn call_with_pp_support_hir<A, F>(ppmode: &PpSourceMode, tcx: TyCtxt<'_>, f: F) -> A
  62 where
  63     F: FnOnce(&dyn HirPrinterSupport<'_>, &hir::Crate<'_>) -> A,
  64 {
  65     match *ppmode {
  66         PpmNormal => {
  67             let annotation = NoAnn { sess: tcx.sess, tcx: Some(tcx) };
  68             f(&annotation, tcx.hir().krate())
  69         }
  70
  71         PpmIdentified => {
  72             let annotation = IdentifiedAnnotation { sess: tcx.sess, tcx: Some(tcx) };
  73             f(&annotation, tcx.hir().krate())
  74         }
  75         PpmTyped => {
  76             abort_on_err(tcx.analysis(LOCAL_CRATE), tcx.sess);
  77
  78             let annotation = TypedAnnotation { tcx, maybe_typeck_results: Cell::new(None) };
  79             tcx.dep_graph.with_ignore(|| f(&annotation, tcx.hir().krate()))
  80         }
  81         _ => panic!("Should use call_with_pp_support"),
  82     }
  83 }
  84
  85 trait PrinterSupport: pprust::PpAnn {
  86     /// Provides a uniform interface for re-extracting a reference to a
  87     /// `Session` from a value that now owns it.
  88     fn sess(&self) -> &Session;
  89
  90     /// Produces the pretty-print annotation object.
  91     ///
  92     /// (Rust does not yet support upcasting from a trait object to
  93     /// an object for one of its super-traits.)
  94     fn pp_ann(&self) -> &dyn pprust::PpAnn;
  95 }
  96
  97 trait HirPrinterSupport<'hir>: pprust_hir::PpAnn {
  98     /// Provides a uniform interface for re-extracting a reference to a
  99     /// `Session` from a value that now owns it.
 100     fn sess(&self) -> &Session;
 101
 102     /// Provides a uniform interface for re-extracting a reference to an
 103     /// `hir_map::Map` from a value that now owns it.
 104     fn hir_map(&self) -> Option<hir_map::Map<'hir>>;
 105
 106     /// Produces the pretty-print annotation object.
 107     ///
 108     /// (Rust does not yet support upcasting from a trait object to
 109     /// an object for one of its super-traits.)
 110     fn pp_ann(&self) -> &dyn pprust_hir::PpAnn;
 111
 112     /// Computes an user-readable representation of a path, if possible.
 113     fn node_path(&self, id: hir::HirId) -> Option<String> {
 114         self.hir_map().and_then(|map| map.def_path_from_hir_id(id)).map(|path| {
 115             path.data.into_iter().map(|elem| elem.data.to_string()).collect::<Vec<_>>().join("::")
 116         })
 117     }
 118 }
 119
 120 struct NoAnn<'hir> {
 121     sess: &'hir Session,
 122     tcx: Option<TyCtxt<'hir>>,
 123 }
 124
 125 impl<'hir> PrinterSupport for NoAnn<'hir> {
 126     fn sess(&self) -> &Session {
 127         self.sess
 128     }
 129
 130     fn pp_ann(&self) -> &dyn pprust::PpAnn {
 131         self
 132     }
 133 }
 134
 135 impl<'hir> HirPrinterSupport<'hir> for NoAnn<'hir> {
 136     fn sess(&self) -> &Session {
 137         self.sess
 138     }
 139
 140     fn hir_map(&self) -> Option<hir_map::Map<'hir>> {
 141         self.tcx.map(|tcx| tcx.hir())
 142     }
 143
 144     fn pp_ann(&self) -> &dyn pprust_hir::PpAnn {
 145         self
 146     }
 147 }
 148
 149 impl<'hir> pprust::PpAnn for NoAnn<'hir> {}
 150 impl<'hir> pprust_hir::PpAnn for NoAnn<'hir> {
 151     fn nested(&self, state: &mut pprust_hir::State<'_>, nested: pprust_hir::Nested) {
 152         if let Some(tcx) = self.tcx {
 153             pprust_hir::PpAnn::nested(&(&tcx.hir() as &dyn hir::intravisit::Map<'_>), state, nested)
 154         }
 155     }
 156 }
 157
 158 struct IdentifiedAnnotation<'hir> {
 159     sess: &'hir Session,
 160     tcx: Option<TyCtxt<'hir>>,
 161 }
 162
 163 impl<'hir> PrinterSupport for IdentifiedAnnotation<'hir> {
 164     fn sess(&self) -> &Session {
 165         self.sess
 166     }
 167
 168     fn pp_ann(&self) -> &dyn pprust::PpAnn {
 169         self
 170     }
 171 }
 172
 173 impl<'hir> pprust::PpAnn for IdentifiedAnnotation<'hir> {
 174     fn pre(&self, s: &mut pprust::State<'_>, node: pprust::AnnNode<'_>) {
 175         if let pprust::AnnNode::Expr(_) = node {
 176             s.popen();
 177         }
 178     }
 179     fn post(&self, s: &mut pprust::State<'_>, node: pprust::AnnNode<'_>) {
 180         match node {
 181             pprust::AnnNode::Crate(_) | pprust::AnnNode::Ident(_) | pprust::AnnNode::Name(_) => {}
 182
 183             pprust::AnnNode::Item(item) => {
 184                 s.s.space();
 185                 s.synth_comment(item.id.to_string())
 186             }
 187             pprust::AnnNode::SubItem(id) => {
 188                 s.s.space();
 189                 s.synth_comment(id.to_string())
 190             }
 191             pprust::AnnNode::Block(blk) => {
 192                 s.s.space();
 193                 s.synth_comment(format!("block {}", blk.id))
 194             }
 195             pprust::AnnNode::Expr(expr) => {
 196                 s.s.space();
 197                 s.synth_comment(expr.id.to_string());
 198                 s.pclose()
 199             }
 200             pprust::AnnNode::Pat(pat) => {
 201                 s.s.space();
 202                 s.synth_comment(format!("pat {}", pat.id));
 203             }
 204         }
 205     }
 206 }
 207
 208 impl<'hir> HirPrinterSupport<'hir> for IdentifiedAnnotation<'hir> {
 209     fn sess(&self) -> &Session {
 210         self.sess
 211     }
 212
 213     fn hir_map(&self) -> Option<hir_map::Map<'hir>> {
 214         self.tcx.map(|tcx| tcx.hir())
 215     }
 216
 217     fn pp_ann(&self) -> &dyn pprust_hir::PpAnn {
 218         self
 219     }
 220 }
 221
 222 impl<'hir> pprust_hir::PpAnn for IdentifiedAnnotation<'hir> {
 223     fn nested(&self, state: &mut pprust_hir::State<'_>, nested: pprust_hir::Nested) {
 224         if let Some(ref tcx) = self.tcx {
 225             pprust_hir::PpAnn::nested(&(&tcx.hir() as &dyn hir::intravisit::Map<'_>), state, nested)
 226         }
 227     }
 228     fn pre(&self, s: &mut pprust_hir::State<'_>, node: pprust_hir::AnnNode<'_>) {
 229         if let pprust_hir::AnnNode::Expr(_) = node {
 230             s.popen();
 231         }
 232     }
 233     fn post(&self, s: &mut pprust_hir::State<'_>, node: pprust_hir::AnnNode<'_>) {
 234         match node {
 235             pprust_hir::AnnNode::Name(_) => {}
 236             pprust_hir::AnnNode::Item(item) => {
 237                 s.s.space();
 238                 s.synth_comment(format!("hir_id: {}", item.hir_id()));
 239             }
 240             pprust_hir::AnnNode::SubItem(id) => {
 241                 s.s.space();
 242                 s.synth_comment(id.to_string());
 243             }
 244             pprust_hir::AnnNode::Block(blk) => {
 245                 s.s.space();
 246                 s.synth_comment(format!("block hir_id: {}", blk.hir_id));
 247             }
 248             pprust_hir::AnnNode::Expr(expr) => {
 249                 s.s.space();
 250                 s.synth_comment(format!("expr hir_id: {}", expr.hir_id));
 251                 s.pclose();
 252             }
 253             pprust_hir::AnnNode::Pat(pat) => {
 254                 s.s.space();
 255                 s.synth_comment(format!("pat hir_id: {}", pat.hir_id));
 256             }
 257             pprust_hir::AnnNode::Arm(arm) => {
 258                 s.s.space();
 259                 s.synth_comment(format!("arm hir_id: {}", arm.hir_id));
 260             }
 261         }
 262     }
 263 }
 264
 265 struct HygieneAnnotation<'a> {
 266     sess: &'a Session,
 267 }
 268
 269 impl<'a> PrinterSupport for HygieneAnnotation<'a> {
 270     fn sess(&self) -> &Session {
 271         self.sess
 272     }
 273
 274     fn pp_ann(&self) -> &dyn pprust::PpAnn {
 275         self
 276     }
 277 }
 278
 279 impl<'a> pprust::PpAnn for HygieneAnnotation<'a> {
 280     fn post(&self, s: &mut pprust::State<'_>, node: pprust::AnnNode<'_>) {
 281         match node {
 282             pprust::AnnNode::Ident(&Ident { name, span }) => {
 283                 s.s.space();
 284                 s.synth_comment(format!("{}{:?}", name.as_u32(), span.ctxt()))
 285             }
 286             pprust::AnnNode::Name(&name) => {
 287                 s.s.space();
 288                 s.synth_comment(name.as_u32().to_string())
 289             }
 290             pprust::AnnNode::Crate(_) => {
 291                 s.s.hardbreak();
 292                 let verbose = self.sess.verbose();
 293                 s.synth_comment(rustc_span::hygiene::debug_hygiene_data(verbose));
 294                 s.s.hardbreak_if_not_bol();
 295             }
 296             _ => {}
 297         }
 298     }
 299 }
 300
 301 struct TypedAnnotation<'tcx> {
 302     tcx: TyCtxt<'tcx>,
 303     maybe_typeck_results: Cell<Option<&'tcx ty::TypeckResults<'tcx>>>,
 304 }
 305
 306 impl<'tcx> TypedAnnotation<'tcx> {
 307     /// Gets the type-checking results for the current body.
 308     /// As this will ICE if called outside bodies, only call when working with
 309     /// `Expr` or `Pat` nodes (they are guaranteed to be found only in bodies).
 310     #[track_caller]
 311     fn typeck_results(&self) -> &'tcx ty::TypeckResults<'tcx> {
 312         self.maybe_typeck_results
 313             .get()
 314             .expect("`TypedAnnotation::typeck_results` called outside of body")
 315     }
 316 }
 317
 318 impl<'tcx> HirPrinterSupport<'tcx> for TypedAnnotation<'tcx> {
 319     fn sess(&self) -> &Session {
 320         &self.tcx.sess
 321     }
 322
 323     fn hir_map(&self) -> Option<hir_map::Map<'tcx>> {
 324         Some(self.tcx.hir())
 325     }
 326
 327     fn pp_ann(&self) -> &dyn pprust_hir::PpAnn {
 328         self
 329     }
 330
 331     fn node_path(&self, id: hir::HirId) -> Option<String> {
 332         Some(self.tcx.def_path_str(self.tcx.hir().local_def_id(id).to_def_id()))
 333     }
 334 }
 335
 336 impl<'tcx> pprust_hir::PpAnn for TypedAnnotation<'tcx> {
 337     fn nested(&self, state: &mut pprust_hir::State<'_>, nested: pprust_hir::Nested) {
 338         let old_maybe_typeck_results = self.maybe_typeck_results.get();
 339         if let pprust_hir::Nested::Body(id) = nested {
 340             self.maybe_typeck_results.set(Some(self.tcx.typeck_body(id)));
 341         }
 342         let pp_ann = &(&self.tcx.hir() as &dyn hir::intravisit::Map<'_>);
 343         pprust_hir::PpAnn::nested(pp_ann, state, nested);
 344         self.maybe_typeck_results.set(old_maybe_typeck_results);
 345     }
 346     fn pre(&self, s: &mut pprust_hir::State<'_>, node: pprust_hir::AnnNode<'_>) {
 347         if let pprust_hir::AnnNode::Expr(_) = node {
 348             s.popen();
 349         }
 350     }
 351     fn post(&self, s: &mut pprust_hir::State<'_>, node: pprust_hir::AnnNode<'_>) {
 352         if let pprust_hir::AnnNode::Expr(expr) = node {
 353             s.s.space();
 354             s.s.word("as");
 355             s.s.space();
 356             s.s.word(self.typeck_results().expr_ty(expr).to_string());
 357             s.pclose();
 358         }
 359     }
 360 }
 361
 362 fn get_source(input: &Input, sess: &Session) -> (String, FileName) {
 363     let src_name = input.source_name();
 364     let src = String::clone(
 365         &sess
 366             .source_map()
 367             .get_source_file(&src_name)
 368             .expect("get_source_file")
 369             .src
 370             .as_ref()
 371             .expect("src"),
 372     );
 373     (src, src_name)
 374 }
 375
 376 fn write_or_print(out: &str, ofile: Option<&Path>) {
 377     match ofile {
 378         None => print!("{}", out),
 379         Some(p) => {
 380             if let Err(e) = std::fs::write(p, out) {
 381                 panic!("print-print failed to write {} due to {}", p.display(), e);
 382             }
 383         }
 384     }
 385 }
 386
 387 pub fn print_after_parsing(
 388     sess: &Session,
 389     input: &Input,
 390     krate: &ast::Crate,
 391     ppm: PpMode,
 392     ofile: Option<&Path>,
 393 ) {
 394     let (src, src_name) = get_source(input, sess);
 395
 396     let mut out = String::new();
 397
 398     if let PpmSource(s) = ppm {
 399         // Silently ignores an identified node.
 400         let out = &mut out;
 401         call_with_pp_support(&s, sess, None, move |annotation| {
 402             debug!("pretty printing source code {:?}", s);
 403             let sess = annotation.sess();
 404             let parse = &sess.parse_sess;
 405             *out = pprust::print_crate(
 406                 sess.source_map(),
 407                 krate,
 408                 src_name,
 409                 src,
 410                 annotation.pp_ann(),
 411                 false,
 412                 parse.edition,
 413             )
 414         })
 415     } else {
 416         unreachable!();
 417     };
 418
 419     write_or_print(&out, ofile);
 420 }
 421
 422 pub fn print_after_hir_lowering<'tcx>(
 423     tcx: TyCtxt<'tcx>,
 424     input: &Input,
 425     krate: &ast::Crate,
 426     ppm: PpMode,
 427     ofile: Option<&Path>,
 428 ) {
 429     if ppm.needs_analysis() {
 430         abort_on_err(print_with_analysis(tcx, ppm, ofile), tcx.sess);
 431         return;
 432     }
 433
 434     let (src, src_name) = get_source(input, tcx.sess);
 435
 436     let mut out = String::new();
 437
 438     match ppm {
 439         PpmSource(s) => {
 440             // Silently ignores an identified node.
 441             let out = &mut out;
 442             call_with_pp_support(&s, tcx.sess, Some(tcx), move |annotation| {
 443                 debug!("pretty printing source code {:?}", s);
 444                 let sess = annotation.sess();
 445                 let parse = &sess.parse_sess;
 446                 *out = pprust::print_crate(
 447                     sess.source_map(),
 448                     krate,
 449                     src_name,
 450                     src,
 451                     annotation.pp_ann(),
 452                     true,
 453                     parse.edition,
 454                 )
 455             })
 456         }
 457
 458         PpmHir(s) => {
 459             let out = &mut out;
 460             call_with_pp_support_hir(&s, tcx, move |annotation, krate| {
 461                 debug!("pretty printing source code {:?}", s);
 462                 let sess = annotation.sess();
 463                 let sm = sess.source_map();
 464                 *out = pprust_hir::print_crate(sm, krate, src_name, src, annotation.pp_ann())
 465             })
 466         }
 467
 468         PpmHirTree(s) => {
 469             let out = &mut out;
 470             call_with_pp_support_hir(&s, tcx, move |_annotation, krate| {
 471                 debug!("pretty printing source code {:?}", s);
 472                 *out = format!("{:#?}", krate);
 473             });
 474         }
 475
 476         _ => unreachable!(),
 477     }
 478
 479     write_or_print(&out, ofile);
 480 }
 481
 482 // In an ideal world, this would be a public function called by the driver after
 483 // analysis is performed. However, we want to call `phase_3_run_analysis_passes`
 484 // with a different callback than the standard driver, so that isn't easy.
 485 // Instead, we call that function ourselves.
 486 fn print_with_analysis(
 487     tcx: TyCtxt<'_>,
 488     ppm: PpMode,
 489     ofile: Option<&Path>,
 490 ) -> Result<(), ErrorReported> {
 491     let mut out = Vec::new();
 492
 493     tcx.analysis(LOCAL_CRATE)?;
 494
 495     match ppm {
 496         PpmMir | PpmMirCFG => match ppm {
 497             PpmMir => write_mir_pretty(tcx, None, &mut out),
 498             PpmMirCFG => write_mir_graphviz(tcx, None, &mut out),
 499             _ => unreachable!(),
 500         },
 501         _ => unreachable!(),
 502     }
 503     .unwrap();
 504
 505     let out = std::str::from_utf8(&out).unwrap();
 506     write_or_print(out, ofile);
 507
 508     Ok(())
 509 }