1 use crate::interface::{Compiler, Result};
2 use crate::passes::{self, BoxedResolver, ExpansionResult, 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::dep_graph::DepGraph;
15 use std::cell::{Ref, RefMut, RefCell};
19 use syntax::{self, ast};
21 /// Represent the result of a query.
22 /// This result can be stolen with the `take` method and returned with the `give` method.
24 result: RefCell<Option<Result<T>>>,
28 fn compute<F: FnOnce() -> Result<T>>(&self, f: F) -> Result<&Query<T>> {
29 let mut result = self.result.borrow_mut();
33 result.as_ref().unwrap().as_ref().map(|_| self).map_err(|err| *err)
36 /// Takes ownership of the query result. Further attempts to take or peek the query
37 /// result will panic unless it is returned by calling the `give` method.
38 pub fn take(&self) -> T {
42 .expect("missing query result")
46 /// Returns a stolen query result. Panics if there's already a result.
47 pub fn give(&self, value: T) {
48 let mut result = self.result.borrow_mut();
49 assert!(result.is_none(), "a result already exists");
50 *result = Some(Ok(value));
53 /// Borrows the query result using the RefCell. Panics if the result is stolen.
54 pub fn peek(&self) -> Ref<'_, T> {
55 Ref::map(self.result.borrow(), |r| {
56 r.as_ref().unwrap().as_ref().expect("missing query result")
60 /// Mutably borrows the query result using the RefCell. Panics if the result is stolen.
61 pub fn peek_mut(&self) -> RefMut<'_, T> {
62 RefMut::map(self.result.borrow_mut(), |r| {
63 r.as_mut().unwrap().as_mut().expect("missing query result")
68 impl<T> Default for Query<T> {
69 fn default() -> Self {
71 result: RefCell::new(None),
77 pub(crate) struct Queries {
78 dep_graph_future: Query<Option<DepGraphFuture>>,
79 parse: Query<ast::Crate>,
80 crate_name: Query<String>,
81 register_plugins: Query<(ast::Crate, PluginInfo, Lrc<LintStore>)>,
82 expansion: Query<(ast::Crate, Steal<Rc<RefCell<BoxedResolver>>>, Lrc<LintStore>)>,
83 dep_graph: Query<DepGraph>,
84 lower_to_hir: Query<(Steal<hir::map::Forest>, ExpansionResult)>,
85 prepare_outputs: Query<OutputFilenames>,
86 global_ctxt: Query<BoxedGlobalCtxt>,
87 ongoing_codegen: Query<Box<dyn Any>>,
92 pub fn dep_graph_future(&self) -> Result<&Query<Option<DepGraphFuture>>> {
93 self.queries.dep_graph_future.compute(|| {
94 Ok(if self.session().opts.build_dep_graph() {
95 Some(rustc_incremental::load_dep_graph(self.session()))
102 pub fn parse(&self) -> Result<&Query<ast::Crate>> {
103 self.queries.parse.compute(|| {
104 passes::parse(self.session(), &self.input).map_err(
113 pub fn register_plugins(&self) -> Result<&Query<(ast::Crate, PluginInfo, Lrc<LintStore>)>> {
114 self.queries.register_plugins.compute(|| {
115 let crate_name = self.crate_name()?.peek().clone();
116 let krate = self.parse()?.take();
118 let empty: &(dyn Fn(&Session, &mut lint::LintStore) + Sync + Send) = &|_, _| {};
119 let result = passes::register_plugins(
121 &*self.codegen_backend().metadata_loader(),
125 .unwrap_or_else(|| empty),
130 // Compute the dependency graph (in the background). We want to do
131 // this as early as possible, to give the DepGraph maximum time to
132 // load before dep_graph() is called, but it also can't happen
133 // until after rustc_incremental::prepare_session_directory() is
134 // called, which happens within passes::register_plugins().
135 self.dep_graph_future().ok();
141 pub fn crate_name(&self) -> Result<&Query<String>> {
142 self.queries.crate_name.compute(|| {
143 Ok(match self.crate_name {
144 Some(ref crate_name) => crate_name.clone(),
146 let parse_result = self.parse()?;
147 let krate = parse_result.peek();
148 rustc_codegen_utils::link::find_crate_name(
149 Some(self.session()),
160 ) -> Result<&Query<(ast::Crate, Steal<Rc<RefCell<BoxedResolver>>>, Lrc<LintStore>)>> {
161 self.queries.expansion.compute(|| {
162 let crate_name = self.crate_name()?.peek().clone();
163 let (krate, plugin_info, lint_store) = self.register_plugins()?.take();
164 passes::configure_and_expand(
167 self.cstore().clone(),
171 ).map(|(krate, resolver)| {
172 (krate, Steal::new(Rc::new(RefCell::new(resolver))), lint_store)
177 pub fn dep_graph(&self) -> Result<&Query<DepGraph>> {
178 self.queries.dep_graph.compute(|| {
179 Ok(match self.dep_graph_future()?.take() {
180 None => DepGraph::new_disabled(),
182 let (prev_graph, prev_work_products) =
183 time(self.session(), "blocked while dep-graph loading finishes", || {
184 future.open().unwrap_or_else(|e| rustc_incremental::LoadResult::Error {
185 message: format!("could not decode incremental cache: {:?}", e),
186 }).open(self.session())
188 DepGraph::new(prev_graph, prev_work_products)
194 pub fn lower_to_hir(&self) -> Result<&Query<(Steal<hir::map::Forest>, ExpansionResult)>> {
195 self.queries.lower_to_hir.compute(|| {
196 let expansion_result = self.expansion()?;
197 let peeked = expansion_result.peek();
198 let krate = &peeked.0;
199 let resolver = peeked.1.steal();
200 let lint_store = &peeked.2;
201 let hir = Steal::new(resolver.borrow_mut().access(|resolver| {
202 passes::lower_to_hir(
207 &*self.dep_graph()?.peek(),
211 Ok((hir, BoxedResolver::to_expansion_result(resolver)))
215 pub fn prepare_outputs(&self) -> Result<&Query<OutputFilenames>> {
216 self.queries.prepare_outputs.compute(|| {
217 let krate = self.expansion()?;
218 let krate = krate.peek();
219 let crate_name = self.crate_name()?;
220 let crate_name = crate_name.peek();
221 passes::prepare_outputs(self.session(), self, &krate.0, &*crate_name)
225 pub fn global_ctxt(&self) -> Result<&Query<BoxedGlobalCtxt>> {
226 self.queries.global_ctxt.compute(|| {
227 let crate_name = self.crate_name()?.peek().clone();
228 let outputs = self.prepare_outputs()?.peek().clone();
229 let lint_store = self.expansion()?.peek().2.clone();
230 let hir = self.lower_to_hir()?;
231 let hir = hir.peek();
232 let (ref hir_forest, ref expansion) = *hir;
233 Ok(passes::create_global_ctxt(
237 expansion.defs.steal(),
238 expansion.resolutions.steal(),
244 pub fn ongoing_codegen(&self) -> Result<&Query<Box<dyn Any>>> {
245 self.queries.ongoing_codegen.compute(|| {
246 let outputs = self.prepare_outputs()?;
247 self.global_ctxt()?.peek_mut().enter(|tcx| {
248 tcx.analysis(LOCAL_CRATE).ok();
250 // Don't do code generation if there were any errors
251 self.session().compile_status()?;
253 Ok(passes::start_codegen(
254 &***self.codegen_backend(),
262 pub fn link(&self) -> Result<&Query<()>> {
263 self.queries.link.compute(|| {
264 let sess = self.session();
266 let ongoing_codegen = self.ongoing_codegen()?.take();
268 self.codegen_backend().join_codegen_and_link(
271 &*self.dep_graph()?.peek(),
272 &*self.prepare_outputs()?.peek(),
273 ).map_err(|_| ErrorReported)?;
279 // This method is different to all the other methods in `Compiler` because
280 // it lacks a `Queries` entry. It's also not currently used. It does serve
281 // as an example of how `Compiler` can be used, with additional steps added
282 // between some passes. And see `rustc_driver::run_compiler` for a more
284 pub fn compile(&self) -> Result<()> {
285 self.prepare_outputs()?;
287 if self.session().opts.output_types.contains_key(&OutputType::DepInfo)
288 && self.session().opts.output_types.len() == 1
295 // Drop AST after creating GlobalCtxt to free memory.
296 mem::drop(self.expansion()?.take());
298 self.ongoing_codegen()?;
300 // Drop GlobalCtxt after starting codegen to free memory.
301 mem::drop(self.global_ctxt()?.take());
303 self.link().map(|_| ())