1 use crate::interface::{Compiler, Result};
2 use crate::passes::{self, BoxedResolver, ExpansionResult, BoxedGlobalCtxt, PluginInfo};
4 use rustc_incremental::DepGraphFuture;
5 use rustc::session::config::{OutputFilenames, OutputType};
6 use rustc::util::common::{time, ErrorReported};
8 use rustc::hir::def_id::LOCAL_CRATE;
9 use rustc::ty::steal::Steal;
10 use rustc::dep_graph::DepGraph;
11 use std::cell::{Ref, RefMut, RefCell};
15 use syntax::{self, ast};
17 /// Represent the result of a query.
18 /// This result can be stolen with the `take` method and returned with the `give` method.
20 result: RefCell<Option<Result<T>>>,
24 fn compute<F: FnOnce() -> Result<T>>(&self, f: F) -> Result<&Query<T>> {
25 let mut result = self.result.borrow_mut();
29 result.as_ref().unwrap().as_ref().map(|_| self).map_err(|err| *err)
32 /// Takes ownership of the query result. Further attempts to take or peek the query
33 /// result will panic unless it is returned by calling the `give` method.
34 pub fn take(&self) -> T {
38 .expect("missing query result")
42 /// Returns a stolen query result. Panics if there's already a result.
43 pub fn give(&self, value: T) {
44 let mut result = self.result.borrow_mut();
45 assert!(result.is_none(), "a result already exists");
46 *result = Some(Ok(value));
49 /// Borrows the query result using the RefCell. Panics if the result is stolen.
50 pub fn peek(&self) -> Ref<'_, T> {
51 Ref::map(self.result.borrow(), |r| {
52 r.as_ref().unwrap().as_ref().expect("missing query result")
56 /// Mutably borrows the query result using the RefCell. Panics if the result is stolen.
57 pub fn peek_mut(&self) -> RefMut<'_, T> {
58 RefMut::map(self.result.borrow_mut(), |r| {
59 r.as_mut().unwrap().as_mut().expect("missing query result")
64 impl<T> Default for Query<T> {
65 fn default() -> Self {
67 result: RefCell::new(None),
73 pub(crate) struct Queries {
74 dep_graph_future: Query<Option<DepGraphFuture>>,
75 parse: Query<ast::Crate>,
76 crate_name: Query<String>,
77 register_plugins: Query<(ast::Crate, PluginInfo)>,
78 expansion: Query<(ast::Crate, Steal<Rc<RefCell<BoxedResolver>>>)>,
79 dep_graph: Query<DepGraph>,
80 lower_to_hir: Query<(Steal<hir::map::Forest>, ExpansionResult)>,
81 prepare_outputs: Query<OutputFilenames>,
82 global_ctxt: Query<BoxedGlobalCtxt>,
83 ongoing_codegen: Query<Box<dyn Any>>,
88 pub fn dep_graph_future(&self) -> Result<&Query<Option<DepGraphFuture>>> {
89 self.queries.dep_graph_future.compute(|| {
90 Ok(if self.session().opts.build_dep_graph() {
91 Some(rustc_incremental::load_dep_graph(self.session()))
98 pub fn parse(&self) -> Result<&Query<ast::Crate>> {
99 self.queries.parse.compute(|| {
100 passes::parse(self.session(), &self.input).map_err(
109 pub fn register_plugins(&self) -> Result<&Query<(ast::Crate, PluginInfo)>> {
110 self.queries.register_plugins.compute(|| {
111 let crate_name = self.crate_name()?.peek().clone();
112 let krate = self.parse()?.take();
114 let result = passes::register_plugins(
121 // Compute the dependency graph (in the background). We want to do
122 // this as early as possible, to give the DepGraph maximum time to
123 // load before dep_graph() is called, but it also can't happen
124 // until after rustc_incremental::prepare_session_directory() is
125 // called, which happens within passes::register_plugins().
126 self.dep_graph_future().ok();
132 pub fn crate_name(&self) -> Result<&Query<String>> {
133 self.queries.crate_name.compute(|| {
134 Ok(match self.crate_name {
135 Some(ref crate_name) => crate_name.clone(),
137 let parse_result = self.parse()?;
138 let krate = parse_result.peek();
139 rustc_codegen_utils::link::find_crate_name(
140 Some(self.session()),
151 ) -> Result<&Query<(ast::Crate, Steal<Rc<RefCell<BoxedResolver>>>)>> {
152 self.queries.expansion.compute(|| {
153 let crate_name = self.crate_name()?.peek().clone();
154 let (krate, plugin_info) = self.register_plugins()?.take();
155 passes::configure_and_expand(
157 self.cstore().clone(),
161 ).map(|(krate, resolver)| (krate, Steal::new(Rc::new(RefCell::new(resolver)))))
165 pub fn dep_graph(&self) -> Result<&Query<DepGraph>> {
166 self.queries.dep_graph.compute(|| {
167 Ok(match self.dep_graph_future()?.take() {
168 None => DepGraph::new_disabled(),
170 let (prev_graph, prev_work_products) =
171 time(self.session(), "blocked while dep-graph loading finishes", || {
172 future.open().unwrap_or_else(|e| rustc_incremental::LoadResult::Error {
173 message: format!("could not decode incremental cache: {:?}", e),
174 }).open(self.session())
176 DepGraph::new(prev_graph, prev_work_products)
182 pub fn lower_to_hir(&self) -> Result<&Query<(Steal<hir::map::Forest>, ExpansionResult)>> {
183 self.queries.lower_to_hir.compute(|| {
184 let expansion_result = self.expansion()?;
185 let peeked = expansion_result.peek();
186 let krate = &peeked.0;
187 let resolver = peeked.1.steal();
188 let hir = Steal::new(resolver.borrow_mut().access(|resolver| {
189 passes::lower_to_hir(
193 &*self.dep_graph()?.peek(),
197 Ok((hir, BoxedResolver::to_expansion_result(resolver)))
201 pub fn prepare_outputs(&self) -> Result<&Query<OutputFilenames>> {
202 self.queries.prepare_outputs.compute(|| {
203 let krate = self.expansion()?;
204 let krate = krate.peek();
205 let crate_name = self.crate_name()?;
206 let crate_name = crate_name.peek();
207 passes::prepare_outputs(self.session(), self, &krate.0, &*crate_name)
211 pub fn global_ctxt(&self) -> Result<&Query<BoxedGlobalCtxt>> {
212 self.queries.global_ctxt.compute(|| {
213 let crate_name = self.crate_name()?.peek().clone();
214 let outputs = self.prepare_outputs()?.peek().clone();
215 let hir = self.lower_to_hir()?;
216 let hir = hir.peek();
217 let (ref hir_forest, ref expansion) = *hir;
218 Ok(passes::create_global_ctxt(
221 expansion.defs.steal(),
222 expansion.resolutions.steal(),
228 pub fn ongoing_codegen(&self) -> Result<&Query<Box<dyn Any>>> {
229 self.queries.ongoing_codegen.compute(|| {
230 let outputs = self.prepare_outputs()?;
231 self.global_ctxt()?.peek_mut().enter(|tcx| {
232 tcx.analysis(LOCAL_CRATE).ok();
234 // Don't do code generation if there were any errors
235 self.session().compile_status()?;
237 Ok(passes::start_codegen(
238 &***self.codegen_backend(),
246 pub fn link(&self) -> Result<&Query<()>> {
247 self.queries.link.compute(|| {
248 let sess = self.session();
250 let ongoing_codegen = self.ongoing_codegen()?.take();
252 self.codegen_backend().join_codegen_and_link(
255 &*self.dep_graph()?.peek(),
256 &*self.prepare_outputs()?.peek(),
257 ).map_err(|_| ErrorReported)?;
263 // This method is different to all the other methods in `Compiler` because
264 // it lacks a `Queries` entry. It's also not currently used. It does serve
265 // as an example of how `Compiler` can be used, with additional steps added
266 // between some passes. And see `rustc_driver::run_compiler` for a more
268 pub fn compile(&self) -> Result<()> {
269 self.prepare_outputs()?;
271 if self.session().opts.output_types.contains_key(&OutputType::DepInfo)
272 && self.session().opts.output_types.len() == 1
279 // Drop AST after creating GlobalCtxt to free memory.
280 mem::drop(self.expansion()?.take());
282 self.ongoing_codegen()?;
284 // Drop GlobalCtxt after starting codegen to free memory.
285 mem::drop(self.global_ctxt()?.take());
287 self.link().map(|_| ())