src/librustc_interface/queries.rs

   1 use crate::interface::{Compiler, Result};
   2 use crate::passes::{self, BoxedResolver, ExpansionResult, BoxedGlobalCtxt, PluginInfo};
   3
   4 use rustc_incremental::DepGraphFuture;
   5 use rustc_data_structures::sync::Lrc;
   6 use rustc::session::config::{Input, OutputFilenames, OutputType};
   7 use rustc::session::Session;
   8 use rustc::util::common::{time, ErrorReported};
   9 use rustc::util::profiling::ProfileCategory;
  10 use rustc::lint;
  11 use rustc::hir;
  12 use rustc::hir::def_id::LOCAL_CRATE;
  13 use rustc::ty;
  14 use rustc::ty::steal::Steal;
  15 use rustc::dep_graph::DepGraph;
  16 use rustc_passes::hir_stats;
  17 use rustc_plugin::registry::Registry;
  18 use serialize::json;
  19 use std::cell::{Ref, RefMut, RefCell};
  20 use std::ops::Deref;
  21 use std::rc::Rc;
  22 use std::sync::mpsc;
  23 use std::any::Any;
  24 use std::mem;
  25 use syntax::parse::{self, PResult};
  26 use syntax::util::node_count::NodeCounter;
  27 use syntax::{self, ast, attr, diagnostics, visit};
  28 use syntax_pos::hygiene;
  29
  30 /// Represent the result of a query.
  31 /// This result can be stolen with the `take` method and returned with the `give` method.
  32 pub struct Query<T> {
  33     result: RefCell<Option<Result<T>>>,
  34 }
  35
  36 impl<T> Query<T> {
  37     fn compute<F: FnOnce() -> Result<T>>(&self, f: F) -> Result<&Query<T>> {
  38         let mut result = self.result.borrow_mut();
  39         if result.is_none() {
  40             *result = Some(f());
  41         }
  42         result.as_ref().unwrap().as_ref().map(|_| self).map_err(|err| *err)
  43     }
  44
  45     /// Takes ownership of the query result. Further attempts to take or peek the query
  46     /// result will panic unless it is returned by calling the `give` method.
  47     pub fn take(&self) -> T {
  48         self.result
  49             .borrow_mut()
  50             .take()
  51             .expect("missing query result")
  52             .unwrap()
  53     }
  54
  55     /// Returns a stolen query result. Panics if there's already a result.
  56     pub fn give(&self, value: T) {
  57         let mut result = self.result.borrow_mut();
  58         assert!(result.is_none(), "a result already exists");
  59         *result = Some(Ok(value));
  60     }
  61
  62     /// Borrows the query result using the RefCell. Panics if the result is stolen.
  63     pub fn peek(&self) -> Ref<'_, T> {
  64         Ref::map(self.result.borrow(), |r| {
  65             r.as_ref().unwrap().as_ref().expect("missing query result")
  66         })
  67     }
  68
  69     /// Mutably borrows the query result using the RefCell. Panics if the result is stolen.
  70     pub fn peek_mut(&self) -> RefMut<'_, T> {
  71         RefMut::map(self.result.borrow_mut(), |r| {
  72             r.as_mut().unwrap().as_mut().expect("missing query result")
  73         })
  74     }
  75 }
  76
  77 impl<T> Default for Query<T> {
  78     fn default() -> Self {
  79         Query {
  80             result: RefCell::new(None),
  81         }
  82     }
  83 }
  84
  85 #[derive(Default)]
  86 pub(crate) struct Queries {
  87     dep_graph_future: Query<Option<DepGraphFuture>>,
  88     parse: Query<ast::Crate>,
  89     crate_name: Query<String>,
  90     register_plugins: Query<(ast::Crate, PluginInfo)>,
  91     expansion: Query<(ast::Crate, Rc<Option<RefCell<BoxedResolver>>>)>,
  92     dep_graph: Query<DepGraph>,
  93     lower_to_hir: Query<(Steal<hir::map::Forest>, ExpansionResult)>,
  94     prepare_outputs: Query<OutputFilenames>,
  95     codegen_channel: Query<(Steal<mpsc::Sender<Box<dyn Any + Send>>>,
  96                             Steal<mpsc::Receiver<Box<dyn Any + Send>>>)>,
  97     global_ctxt: Query<BoxedGlobalCtxt>,
  98     ongoing_codegen: Query<Box<dyn Any>>,
  99     link: Query<()>,
 100 }
 101
 102 impl Compiler {
 103     pub fn dep_graph_future(&self) -> Result<&Query<Option<DepGraphFuture>>> {
 104         self.queries.dep_graph_future.compute(|| {
 105             Ok(if self.session().opts.build_dep_graph() {
 106                 Some(rustc_incremental::load_dep_graph(self.session()))
 107             } else {
 108                 None
 109             })
 110         })
 111     }
 112
 113     pub fn parse(&self) -> Result<&Query<ast::Crate>> {
 114         self.queries.parse.compute(|| {
 115             passes::parse(self.session(), &self.input).map_err(
 116                 |mut parse_error| {
 117                     parse_error.emit();
 118                     ErrorReported
 119                 },
 120             )
 121         })
 122     }
 123
 124     pub fn register_plugins(&self) -> Result<&Query<(ast::Crate, PluginInfo)>> {
 125         self.queries.register_plugins.compute(|| {
 126             let crate_name = self.crate_name()?.peek().clone();
 127             let krate = self.parse()?.take();
 128
 129             passes::register_plugins(
 130                 self,
 131                 self.session(),
 132                 self.cstore(),
 133                 krate,
 134                 &crate_name,
 135             )
 136         })
 137     }
 138
 139     pub fn crate_name(&self) -> Result<&Query<String>> {
 140         self.queries.crate_name.compute(|| {
 141             let parse_result = self.parse()?;
 142             let krate = parse_result.peek();
 143             let result = match self.crate_name {
 144                 Some(ref crate_name) => crate_name.clone(),
 145                 None => rustc_codegen_utils::link::find_crate_name(
 146                     Some(self.session()),
 147                     &krate.attrs,
 148                     &self.input
 149                 ),
 150             };
 151             Ok(result)
 152         })
 153     }
 154
 155     pub fn expansion(
 156         &self
 157     ) -> Result<&Query<(ast::Crate, Rc<Option<RefCell<BoxedResolver>>>)>> {
 158         self.queries.expansion.compute(|| {
 159             let crate_name = self.crate_name()?.peek().clone();
 160             let (krate, plugin_info) = self.register_plugins()?.take();
 161             passes::configure_and_expand(
 162                 self.sess.clone(),
 163                 self.cstore().clone(),
 164                 krate,
 165                 &crate_name,
 166                 plugin_info,
 167             ).map(|(krate, resolver)| (krate, Rc::new(Some(RefCell::new(resolver)))))
 168         })
 169     }
 170
 171     pub fn dep_graph(&self) -> Result<&Query<DepGraph>> {
 172         self.queries.dep_graph.compute(|| {
 173             Ok(match self.dep_graph_future()?.take() {
 174                 None => DepGraph::new_disabled(),
 175                 Some(future) => {
 176                     let (prev_graph, prev_work_products) =
 177                         time(self.session(), "blocked while dep-graph loading finishes", || {
 178                             future.open().unwrap_or_else(|e| rustc_incremental::LoadResult::Error {
 179                                 message: format!("could not decode incremental cache: {:?}", e),
 180                             }).open(self.session())
 181                         });
 182                     DepGraph::new(prev_graph, prev_work_products)
 183                 }
 184             })
 185         })
 186     }
 187
 188     pub fn lower_to_hir(&self) -> Result<&Query<(Steal<hir::map::Forest>, ExpansionResult)>> {
 189         self.queries.lower_to_hir.compute(|| {
 190             let expansion_result = self.expansion()?;
 191             let (krate, resolver) = expansion_result.take();
 192             let resolver_ref = &*resolver;
 193             let hir = Steal::new(resolver_ref.as_ref().unwrap().borrow_mut().access(|resolver| {
 194                 passes::lower_to_hir(
 195                     self.session(),
 196                     self.cstore(),
 197                     resolver,
 198                     &*self.dep_graph()?.peek(),
 199                     &krate
 200                 )
 201             })?);
 202             expansion_result.give((krate, Rc::new(None)));
 203             Ok((hir, BoxedResolver::to_expansion_result(resolver)))
 204         })
 205     }
 206
 207     pub fn prepare_outputs(&self) -> Result<&Query<OutputFilenames>> {
 208         self.queries.prepare_outputs.compute(|| {
 209             self.lower_to_hir()?;
 210             let krate = self.expansion()?;
 211             let krate = krate.peek();
 212             let crate_name = self.crate_name()?;
 213             let crate_name = crate_name.peek();
 214             passes::prepare_outputs(self.session(), self, &krate.0, &*crate_name)
 215         })
 216     }
 217
 218     pub fn codegen_channel(&self) -> Result<&Query<(Steal<mpsc::Sender<Box<dyn Any + Send>>>,
 219                                                     Steal<mpsc::Receiver<Box<dyn Any + Send>>>)>> {
 220         self.queries.codegen_channel.compute(|| {
 221             let (tx, rx) = mpsc::channel();
 222             Ok((Steal::new(tx), Steal::new(rx)))
 223         })
 224     }
 225
 226     pub fn global_ctxt(&self) -> Result<&Query<BoxedGlobalCtxt>> {
 227         self.queries.global_ctxt.compute(|| {
 228             let crate_name = self.crate_name()?.peek().clone();
 229             let outputs = self.prepare_outputs()?.peek().clone();
 230             let hir = self.lower_to_hir()?;
 231             let hir = hir.peek();
 232             let (ref hir_forest, ref expansion) = *hir;
 233             let tx = self.codegen_channel()?.peek().0.steal();
 234             Ok(passes::create_global_ctxt(
 235                 self,
 236                 hir_forest.steal(),
 237                 expansion.defs.steal(),
 238                 expansion.resolutions.steal(),
 239                 outputs,
 240                 tx,
 241                 &crate_name))
 242         })
 243     }
 244
 245     pub fn ongoing_codegen(&self) -> Result<&Query<Box<dyn Any>>> {
 246         self.queries.ongoing_codegen.compute(|| {
 247             let rx = self.codegen_channel()?.peek().1.steal();
 248             let outputs = self.prepare_outputs()?;
 249             self.global_ctxt()?.peek_mut().enter(|tcx| {
 250                 tcx.analysis(LOCAL_CRATE).ok();
 251
 252                 // Don't do code generation if there were any errors
 253                 self.session().compile_status()?;
 254
 255                 Ok(passes::start_codegen(
 256                     &***self.codegen_backend(),
 257                     tcx,
 258                     rx,
 259                     &*outputs.peek()
 260                 ))
 261             })
 262         })
 263     }
 264
 265     pub fn link(&self) -> Result<&Query<()>> {
 266         self.queries.link.compute(|| {
 267             let sess = self.session();
 268
 269             let ongoing_codegen = self.ongoing_codegen()?.take();
 270
 271             self.codegen_backend().join_codegen_and_link(
 272                 ongoing_codegen,
 273                 sess,
 274                 &*self.dep_graph()?.peek(),
 275                 &*self.prepare_outputs()?.peek(),
 276             ).map_err(|_| ErrorReported)?;
 277
 278             Ok(())
 279         })
 280     }
 281
 282     pub fn compile(&self) -> Result<()> {
 283         self.prepare_outputs()?;
 284
 285         if self.session().opts.output_types.contains_key(&OutputType::DepInfo)
 286             && self.session().opts.output_types.len() == 1
 287         {
 288             return Ok(())
 289         }
 290
 291         self.global_ctxt()?;
 292
 293         // Drop AST after creating GlobalCtxt to free memory
 294         mem::drop(self.expansion()?.take());
 295
 296         self.ongoing_codegen()?;
 297
 298         // Drop GlobalCtxt after starting codegen to free memory
 299         mem::drop(self.global_ctxt()?.take());
 300
 301         self.link().map(|_| ())
 302     }
 303 }