use rustc_data_structures::fx::FxHashMap; use rustc_data_structures::sync::join; use rustc_middle::dep_graph::{DepGraph, SerializedDepGraph, WorkProduct, WorkProductId}; use rustc_middle::ty::TyCtxt; use rustc_serialize::opaque::{FileEncodeResult, FileEncoder}; use rustc_serialize::Encodable as RustcEncodable; use rustc_session::Session; use std::fs; use super::data::*; use super::dirty_clean; use super::file_format; use super::fs::*; use super::work_product; /// Saves and writes the [`DepGraph`] to the file system. /// /// This function saves both the dep-graph and the query result cache, /// and drops the result cache. /// /// This function should only run after all queries have completed. /// Trying to execute a query afterwards would attempt to read the result cache we just dropped. pub fn save_dep_graph(tcx: TyCtxt<'_>) { debug!("save_dep_graph()"); tcx.dep_graph.with_ignore(|| { let sess = tcx.sess; if sess.opts.incremental.is_none() { return; } // This is going to be deleted in finalize_session_directory, so let's not create it if sess.has_errors_or_delayed_span_bugs() { return; } let query_cache_path = query_cache_path(sess); let dep_graph_path = dep_graph_path(sess); let staging_dep_graph_path = staging_dep_graph_path(sess); sess.time("assert_dep_graph", || crate::assert_dep_graph(tcx)); sess.time("check_dirty_clean", || dirty_clean::check_dirty_clean_annotations(tcx)); if sess.opts.unstable_opts.incremental_info { tcx.dep_graph.print_incremental_info() } join( move || { sess.time("incr_comp_persist_result_cache", || { // Drop the memory map so that we can remove the file and write to it. if let Some(odc) = &tcx.on_disk_cache { odc.drop_serialized_data(tcx); } file_format::save_in(sess, query_cache_path, "query cache", |e| { encode_query_cache(tcx, e) }); }); }, move || { sess.time("incr_comp_persist_dep_graph", || { if let Err(err) = tcx.dep_graph.encode(&tcx.sess.prof) { sess.err(&format!( "failed to write dependency graph to `{}`: {}", staging_dep_graph_path.display(), err )); } if let Err(err) = fs::rename(&staging_dep_graph_path, &dep_graph_path) { sess.err(&format!( "failed to move dependency graph from `{}` to `{}`: {}", staging_dep_graph_path.display(), dep_graph_path.display(), err )); } }); }, ); }) } /// Saves the work product index. pub fn save_work_product_index( sess: &Session, dep_graph: &DepGraph, new_work_products: FxHashMap, ) { if sess.opts.incremental.is_none() { return; } // This is going to be deleted in finalize_session_directory, so let's not create it if sess.has_errors_or_delayed_span_bugs() { return; } debug!("save_work_product_index()"); dep_graph.assert_ignored(); let path = work_products_path(sess); file_format::save_in(sess, path, "work product index", |mut e| { encode_work_product_index(&new_work_products, &mut e); e.finish() }); // We also need to clean out old work-products, as not all of them are // deleted during invalidation. Some object files don't change their // content, they are just not needed anymore. let previous_work_products = dep_graph.previous_work_products(); for (id, wp) in previous_work_products.iter() { if !new_work_products.contains_key(id) { work_product::delete_workproduct_files(sess, wp); debug_assert!( !wp.saved_files.iter().all(|(_, path)| in_incr_comp_dir_sess(sess, path).exists()) ); } } // Check that we did not delete one of the current work-products: debug_assert!({ new_work_products.iter().all(|(_, wp)| { wp.saved_files.iter().all(|(_, path)| in_incr_comp_dir_sess(sess, path).exists()) }) }); } fn encode_work_product_index( work_products: &FxHashMap, encoder: &mut FileEncoder, ) { let serialized_products: Vec<_> = work_products .iter() .map(|(id, work_product)| SerializedWorkProduct { id: *id, work_product: work_product.clone(), }) .collect(); serialized_products.encode(encoder) } fn encode_query_cache(tcx: TyCtxt<'_>, encoder: FileEncoder) -> FileEncodeResult { tcx.sess.time("incr_comp_serialize_result_cache", || tcx.serialize_query_result_cache(encoder)) } /// Builds the dependency graph. /// /// This function creates the *staging dep-graph*. When the dep-graph is modified by a query /// execution, the new dependency information is not kept in memory but directly /// output to this file. `save_dep_graph` then finalizes the staging dep-graph /// and moves it to the permanent dep-graph path pub fn build_dep_graph( sess: &Session, prev_graph: SerializedDepGraph, prev_work_products: FxHashMap, ) -> Option { if sess.opts.incremental.is_none() { // No incremental compilation. return None; } // Stream the dep-graph to an alternate file, to avoid overwriting anything in case of errors. let path_buf = staging_dep_graph_path(sess); let mut encoder = match FileEncoder::new(&path_buf) { Ok(encoder) => encoder, Err(err) => { sess.err(&format!( "failed to create dependency graph at `{}`: {}", path_buf.display(), err )); return None; } }; file_format::write_file_header(&mut encoder, sess.is_nightly_build()); // First encode the commandline arguments hash sess.opts.dep_tracking_hash(false).encode(&mut encoder); Some(DepGraph::new( &sess.prof, prev_graph, prev_work_products, encoder, sess.opts.unstable_opts.query_dep_graph, sess.opts.unstable_opts.incremental_info, )) }