1 use crate::interface::{Compiler, Result};
2 use crate::passes::{self, BoxedResolver, BoxedGlobalCtxt, PluginInfo};
4 use rustc_incremental::DepGraphFuture;
5 use rustc_data_structures::sync::Lrc;
6 use rustc::session::config::{OutputFilenames, OutputType};
7 use rustc::util::common::{time, ErrorReported};
10 use rustc::session::Session;
11 use rustc::lint::LintStore;
12 use rustc::hir::def_id::LOCAL_CRATE;
13 use rustc::ty::steal::Steal;
14 use rustc::ty::ResolverOutputs;
15 use rustc::dep_graph::DepGraph;
16 use std::cell::{Ref, RefMut, RefCell};
20 use syntax::{self, ast};
22 /// Represent the result of a query.
23 /// This result can be stolen with the `take` method and returned with the `give` method.
25 result: RefCell<Option<Result<T>>>,
29 fn compute<F: FnOnce() -> Result<T>>(&self, f: F) -> Result<&Query<T>> {
30 let mut result = self.result.borrow_mut();
34 result.as_ref().unwrap().as_ref().map(|_| self).map_err(|err| *err)
37 /// Takes ownership of the query result. Further attempts to take or peek the query
38 /// result will panic unless it is returned by calling the `give` method.
39 pub fn take(&self) -> T {
43 .expect("missing query result")
47 /// Returns a stolen query result. Panics if there's already a result.
48 pub fn give(&self, value: T) {
49 let mut result = self.result.borrow_mut();
50 assert!(result.is_none(), "a result already exists");
51 *result = Some(Ok(value));
54 /// Borrows the query result using the RefCell. Panics if the result is stolen.
55 pub fn peek(&self) -> Ref<'_, T> {
56 Ref::map(self.result.borrow(), |r| {
57 r.as_ref().unwrap().as_ref().expect("missing query result")
61 /// Mutably borrows the query result using the RefCell. Panics if the result is stolen.
62 pub fn peek_mut(&self) -> RefMut<'_, T> {
63 RefMut::map(self.result.borrow_mut(), |r| {
64 r.as_mut().unwrap().as_mut().expect("missing query result")
69 impl<T> Default for Query<T> {
70 fn default() -> Self {
72 result: RefCell::new(None),
78 pub(crate) struct Queries {
79 dep_graph_future: Query<Option<DepGraphFuture>>,
80 parse: Query<ast::Crate>,
81 crate_name: Query<String>,
82 register_plugins: Query<(ast::Crate, PluginInfo, Lrc<LintStore>)>,
83 expansion: Query<(ast::Crate, Steal<Rc<RefCell<BoxedResolver>>>, Lrc<LintStore>)>,
84 dep_graph: Query<DepGraph>,
85 lower_to_hir: Query<(Steal<hir::map::Forest>, Steal<ResolverOutputs>)>,
86 prepare_outputs: Query<OutputFilenames>,
87 global_ctxt: Query<BoxedGlobalCtxt>,
88 ongoing_codegen: Query<Box<dyn Any>>,
93 pub fn dep_graph_future(&self) -> Result<&Query<Option<DepGraphFuture>>> {
94 self.queries.dep_graph_future.compute(|| {
95 Ok(if self.session().opts.build_dep_graph() {
96 Some(rustc_incremental::load_dep_graph(self.session()))
103 pub fn parse(&self) -> Result<&Query<ast::Crate>> {
104 self.queries.parse.compute(|| {
105 passes::parse(self.session(), &self.input).map_err(
114 pub fn register_plugins(&self) -> Result<&Query<(ast::Crate, PluginInfo, Lrc<LintStore>)>> {
115 self.queries.register_plugins.compute(|| {
116 let crate_name = self.crate_name()?.peek().clone();
117 let krate = self.parse()?.take();
119 let empty: &(dyn Fn(&Session, &mut lint::LintStore) + Sync + Send) = &|_, _| {};
120 let result = passes::register_plugins(
122 &*self.codegen_backend().metadata_loader(),
126 .unwrap_or_else(|| empty),
131 // Compute the dependency graph (in the background). We want to do
132 // this as early as possible, to give the DepGraph maximum time to
133 // load before dep_graph() is called, but it also can't happen
134 // until after rustc_incremental::prepare_session_directory() is
135 // called, which happens within passes::register_plugins().
136 self.dep_graph_future().ok();
142 pub fn crate_name(&self) -> Result<&Query<String>> {
143 self.queries.crate_name.compute(|| {
144 Ok(match self.crate_name {
145 Some(ref crate_name) => crate_name.clone(),
147 let parse_result = self.parse()?;
148 let krate = parse_result.peek();
149 rustc_codegen_utils::link::find_crate_name(
150 Some(self.session()),
161 ) -> Result<&Query<(ast::Crate, Steal<Rc<RefCell<BoxedResolver>>>, Lrc<LintStore>)>> {
162 self.queries.expansion.compute(|| {
163 let crate_name = self.crate_name()?.peek().clone();
164 let (krate, plugin_info, lint_store) = self.register_plugins()?.take();
165 passes::configure_and_expand(
168 self.codegen_backend().metadata_loader(),
172 ).map(|(krate, resolver)| {
173 (krate, Steal::new(Rc::new(RefCell::new(resolver))), lint_store)
178 pub fn dep_graph(&self) -> Result<&Query<DepGraph>> {
179 self.queries.dep_graph.compute(|| {
180 Ok(match self.dep_graph_future()?.take() {
181 None => DepGraph::new_disabled(),
183 let (prev_graph, prev_work_products) =
184 time(self.session(), "blocked while dep-graph loading finishes", || {
185 future.open().unwrap_or_else(|e| rustc_incremental::LoadResult::Error {
186 message: format!("could not decode incremental cache: {:?}", e),
187 }).open(self.session())
189 DepGraph::new(prev_graph, prev_work_products)
197 ) -> Result<&Query<(Steal<hir::map::Forest>, Steal<ResolverOutputs>)>> {
198 self.queries.lower_to_hir.compute(|| {
199 let expansion_result = self.expansion()?;
200 let peeked = expansion_result.peek();
201 let krate = &peeked.0;
202 let resolver = peeked.1.steal();
203 let lint_store = &peeked.2;
204 let hir = Steal::new(resolver.borrow_mut().access(|resolver| {
205 passes::lower_to_hir(
209 &*self.dep_graph()?.peek(),
213 Ok((hir, Steal::new(BoxedResolver::to_resolver_outputs(resolver))))
217 pub fn prepare_outputs(&self) -> Result<&Query<OutputFilenames>> {
218 self.queries.prepare_outputs.compute(|| {
219 let expansion_result = self.expansion()?;
220 let (krate, boxed_resolver, _) = &*expansion_result.peek();
221 let crate_name = self.crate_name()?;
222 let crate_name = crate_name.peek();
223 passes::prepare_outputs(self.session(), self, &krate, &boxed_resolver, &crate_name)
227 pub fn global_ctxt(&self) -> Result<&Query<BoxedGlobalCtxt>> {
228 self.queries.global_ctxt.compute(|| {
229 let crate_name = self.crate_name()?.peek().clone();
230 let outputs = self.prepare_outputs()?.peek().clone();
231 let lint_store = self.expansion()?.peek().2.clone();
232 let hir = self.lower_to_hir()?;
233 let hir = hir.peek();
234 let (hir_forest, resolver_outputs) = &*hir;
235 Ok(passes::create_global_ctxt(
239 resolver_outputs.steal(),
245 pub fn ongoing_codegen(&self) -> Result<&Query<Box<dyn Any>>> {
246 self.queries.ongoing_codegen.compute(|| {
247 let outputs = self.prepare_outputs()?;
248 self.global_ctxt()?.peek_mut().enter(|tcx| {
249 tcx.analysis(LOCAL_CRATE).ok();
251 // Don't do code generation if there were any errors
252 self.session().compile_status()?;
254 Ok(passes::start_codegen(
255 &***self.codegen_backend(),
263 pub fn link(&self) -> Result<&Query<()>> {
264 self.queries.link.compute(|| {
265 let sess = self.session();
267 let ongoing_codegen = self.ongoing_codegen()?.take();
269 self.codegen_backend().join_codegen_and_link(
272 &*self.dep_graph()?.peek(),
273 &*self.prepare_outputs()?.peek(),
274 ).map_err(|_| ErrorReported)?;
280 // This method is different to all the other methods in `Compiler` because
281 // it lacks a `Queries` entry. It's also not currently used. It does serve
282 // as an example of how `Compiler` can be used, with additional steps added
283 // between some passes. And see `rustc_driver::run_compiler` for a more
285 pub fn compile(&self) -> Result<()> {
286 self.prepare_outputs()?;
288 if self.session().opts.output_types.contains_key(&OutputType::DepInfo)
289 && self.session().opts.output_types.len() == 1
296 // Drop AST after creating GlobalCtxt to free memory.
297 mem::drop(self.expansion()?.take());
299 self.ongoing_codegen()?;
301 // Drop GlobalCtxt after starting codegen to free memory.
302 mem::drop(self.global_ctxt()?.take());
304 self.link().map(|_| ())