Rollup of 5 pull requests

compiler/rustc_incremental/src/lib.rs

@@ -10,9 +10,8 @@ mod errors;
 mod persist;
 
 pub use persist::{
-    LoadResult, copy_cgu_workproduct_to_incr_comp_cache_dir, finalize_session_directory,
-    in_incr_comp_dir, in_incr_comp_dir_sess, load_query_result_cache, save_work_product_index,
-    setup_dep_graph,
+    copy_cgu_workproduct_to_incr_comp_cache_dir, finalize_session_directory, in_incr_comp_dir,
+    in_incr_comp_dir_sess, load_query_result_cache, save_work_product_index, setup_dep_graph,
 };
 use rustc_middle::util::Providers;
 

compiler/rustc_incremental/src/persist/fs.rs

@@ -215,9 +215,7 @@ pub(crate) fn prepare_session_directory(
     crate_name: Symbol,
     stable_crate_id: StableCrateId,
 ) {
-    if sess.opts.incremental.is_none() {
-        return;
-    }
+    assert!(sess.opts.incremental.is_some());
 
     let _timer = sess.timer("incr_comp_prepare_session_directory");
 

compiler/rustc_incremental/src/persist/load.rs

@@ -1,75 +1,44 @@
 //! Code to load the dep-graph from files.
 
+use std::io;
 use std::path::PathBuf;
 use std::sync::Arc;
 
 use rustc_data_structures::unord::UnordMap;
 use rustc_hashes::Hash64;
 use rustc_middle::dep_graph::{DepGraph, SerializedDepGraph, WorkProductMap};
 use rustc_middle::query::on_disk_cache::OnDiskCache;
-use rustc_serialize::Decodable;
-use rustc_serialize::opaque::MemDecoder;
+use rustc_serialize::opaque::{FileEncoder, MemDecoder};
+use rustc_serialize::{Decodable, Encodable};
 use rustc_session::config::IncrementalStateAssertion;
 use rustc_session::{Session, StableCrateId};
 use rustc_span::Symbol;
 use tracing::{debug, warn};
 
 use super::data::*;
 use super::fs::*;
-use super::save::build_dep_graph;
 use super::{file_format, work_product};
 use crate::errors;
 use crate::persist::file_format::{OpenFile, OpenFileError};
 
 #[derive(Debug)]
 /// Represents the result of an attempt to load incremental compilation data.
-pub enum LoadResult<T> {
+enum LoadResult {
     /// Loading was successful.
-    Ok {
-        #[allow(missing_docs)]
-        data: T,
-    },
+    Ok { prev_graph: Arc<SerializedDepGraph>, prev_work_products: WorkProductMap },
     /// The file either didn't exist or was produced by an incompatible compiler version.
     DataOutOfDate,
-    /// Loading the dep graph failed.
-    LoadDepGraph(PathBuf, std::io::Error),
-}
-
-impl<T: Default> LoadResult<T> {
-    /// Accesses the data returned in [`LoadResult::Ok`].
-    pub fn open(self, sess: &Session) -> T {
-        // Emit a fatal error if `-Zassert-incr-state` is present and unsatisfied.
-        maybe_assert_incr_state(sess, &self);
-
-        match self {
-            LoadResult::LoadDepGraph(path, err) => {
-                sess.dcx().emit_warn(errors::LoadDepGraph { path, err });
-                Default::default()
-            }
-            LoadResult::DataOutOfDate => {
-                if let Err(err) = delete_all_session_dir_contents(sess) {
-                    sess.dcx()
-                        .emit_err(errors::DeleteIncompatible { path: dep_graph_path(sess), err });
-                }
-                Default::default()
-            }
-            LoadResult::Ok { data } => data,
-        }
-    }
+    /// Loading failed due to an unexpected I/O error.
+    IoError { path: PathBuf, err: io::Error },
 }
 
 fn delete_dirty_work_product(sess: &Session, swp: SerializedWorkProduct) {
     debug!("delete_dirty_work_product({:?})", swp);
     work_product::delete_workproduct_files(sess, &swp.work_product);
 }
 
-fn load_dep_graph(sess: &Session) -> LoadResult<(Arc<SerializedDepGraph>, WorkProductMap)> {
-    let prof = sess.prof.clone();
-
-    if sess.opts.incremental.is_none() {
-        // No incremental compilation.
-        return LoadResult::Ok { data: Default::default() };
-    }
+fn load_dep_graph(sess: &Session) -> LoadResult {
+    assert!(sess.opts.incremental.is_some());
 
     let _timer = sess.prof.generic_activity("incr_comp_prepare_load_dep_graph");
 
@@ -117,11 +86,11 @@ fn load_dep_graph(sess: &Session) -> LoadResult<(Arc<SerializedDepGraph>, WorkPr
         }
     }
 
-    let _prof_timer = prof.generic_activity("incr_comp_load_dep_graph");
+    let _prof_timer = sess.prof.generic_activity("incr_comp_load_dep_graph");
 
     match file_format::open_incremental_file(sess, &path) {
         Err(OpenFileError::NotFoundOrHeaderMismatch) => LoadResult::DataOutOfDate,
-        Err(OpenFileError::IoError { err }) => LoadResult::LoadDepGraph(path.to_owned(), err),
+        Err(OpenFileError::IoError { err }) => LoadResult::IoError { path: path.to_owned(), err },
         Ok(OpenFile { mmap, start_pos }) => {
             let Ok(mut decoder) = MemDecoder::new(&mmap, start_pos) else {
                 sess.dcx().emit_warn(errors::CorruptFile { path: &path });
@@ -143,9 +112,9 @@ fn load_dep_graph(sess: &Session) -> LoadResult<(Arc<SerializedDepGraph>, WorkPr
                 return LoadResult::DataOutOfDate;
             }
 
-            let dep_graph = SerializedDepGraph::decode(&mut decoder);
+            let prev_graph = SerializedDepGraph::decode(&mut decoder);
 
-            LoadResult::Ok { data: (dep_graph, prev_work_products) }
+            LoadResult::Ok { prev_graph, prev_work_products }
         }
     }
 }
@@ -179,14 +148,14 @@ pub fn load_query_result_cache(sess: &Session) -> Option<OnDiskCache> {
 
 /// Emits a fatal error if the assertion in `-Zassert-incr-state` doesn't match
 /// the outcome of trying to load previous-session state.
-fn maybe_assert_incr_state(sess: &Session, load_result: &LoadResult<impl Sized>) {
+fn maybe_assert_incr_state(sess: &Session, load_result: &LoadResult) {
     // Return immediately if there's nothing to assert.
     let Some(assertion) = sess.opts.unstable_opts.assert_incr_state else { return };
 
     // Match exhaustively to make sure we don't miss any cases.
     let loaded = match load_result {
         LoadResult::Ok { .. } => true,
-        LoadResult::DataOutOfDate | LoadResult::LoadDepGraph(..) => false,
+        LoadResult::DataOutOfDate | LoadResult::IoError { .. } => false,
     };
 
     match assertion {
@@ -203,33 +172,64 @@ fn maybe_assert_incr_state(sess: &Session, load_result: &LoadResult<impl Sized>)
     }
 }
 
-/// Setups the dependency graph by loading an existing graph from disk and set up streaming of a
-/// new graph to an incremental session directory.
+/// Loads the previous session's dependency graph from disk if possible, and
+/// sets up streaming output for the current session's dep graph data into an
+/// incremental session directory.
+///
+/// In non-incremental mode, a dummy dep graph is returned immediately.
 pub fn setup_dep_graph(
     sess: &Session,
     crate_name: Symbol,
     stable_crate_id: StableCrateId,
 ) -> DepGraph {
+    if sess.opts.incremental.is_none() {
+        return DepGraph::new_disabled();
+    }
+
     // `load_dep_graph` can only be called after `prepare_session_directory`.
     prepare_session_directory(sess, crate_name, stable_crate_id);
+    // Try to load the previous session's dep graph and work products.
+    let load_result = load_dep_graph(sess);
+
+    sess.time("incr_comp_garbage_collect_session_directories", || {
+        if let Err(e) = garbage_collect_session_directories(sess) {
+            warn!(
+                "Error while trying to garbage collect incremental compilation \
+                cache directory: {e}",
+            );
+        }
+    });
 
-    let res = sess.opts.build_dep_graph().then(|| load_dep_graph(sess));
+    // Emit a fatal error if `-Zassert-incr-state` is present and unsatisfied.
+    maybe_assert_incr_state(sess, &load_result);
 
-    if sess.opts.incremental.is_some() {
-        sess.time("incr_comp_garbage_collect_session_directories", || {
-            if let Err(e) = garbage_collect_session_directories(sess) {
-                warn!(
-                    "Error while trying to garbage collect incremental \
-                     compilation cache directory: {}",
-                    e
-                );
+    let (prev_graph, prev_work_products) = match load_result {
+        LoadResult::IoError { path, err } => {
+            sess.dcx().emit_warn(errors::LoadDepGraph { path, err });
+            Default::default()
+        }
+        LoadResult::DataOutOfDate => {
+            if let Err(err) = delete_all_session_dir_contents(sess) {
+                sess.dcx().emit_err(errors::DeleteIncompatible { path: dep_graph_path(sess), err });
             }
-        });
-    }
+            Default::default()
+        }
+        LoadResult::Ok { prev_graph, prev_work_products } => (prev_graph, prev_work_products),
+    };
+
+    // 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 = FileEncoder::new(&path_buf).unwrap_or_else(|err| {
+        // We're in incremental mode but couldn't set up streaming output of the dep graph.
+        // Exit immediately instead of continuing in an inconsistent and untested state.
+        sess.dcx().emit_fatal(errors::CreateDepGraph { path: &path_buf, err })
+    });
+
+    file_format::write_file_header(&mut encoder, sess);
+
+    // First encode the commandline arguments hash
+    sess.opts.dep_tracking_hash(false).encode(&mut encoder);
 
-    res.and_then(|result| {
-        let (prev_graph, prev_work_products) = result.open(sess);
-        build_dep_graph(sess, prev_graph, prev_work_products)
-    })
-    .unwrap_or_else(DepGraph::new_disabled)
+    DepGraph::new(sess, prev_graph, prev_work_products, encoder)
 }

compiler/rustc_incremental/src/persist/mod.rs

@@ -11,7 +11,7 @@ mod save;
 mod work_product;
 
 pub use fs::{finalize_session_directory, in_incr_comp_dir, in_incr_comp_dir_sess};
-pub use load::{LoadResult, load_query_result_cache, setup_dep_graph};
+pub use load::{load_query_result_cache, setup_dep_graph};
 pub(crate) use save::save_dep_graph;
 pub use save::save_work_product_index;
 pub use work_product::copy_cgu_workproduct_to_incr_comp_cache_dir;

compiler/rustc_incremental/src/persist/save.rs

@@ -1,11 +1,8 @@
 use std::fs;
-use std::sync::Arc;
 
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::sync::par_join;
-use rustc_middle::dep_graph::{
-    DepGraph, SerializedDepGraph, WorkProduct, WorkProductId, WorkProductMap,
-};
+use rustc_middle::dep_graph::{DepGraph, WorkProduct, WorkProductId};
 use rustc_middle::query::on_disk_cache;
 use rustc_middle::ty::TyCtxt;
 use rustc_serialize::Encodable as RustcEncodable;
@@ -149,38 +146,3 @@ fn encode_work_product_index(
 
     serialized_products.encode(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(crate) fn build_dep_graph(
-    sess: &Session,
-    prev_graph: Arc<SerializedDepGraph>,
-    prev_work_products: WorkProductMap,
-) -> Option<DepGraph> {
-    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.dcx().emit_err(errors::CreateDepGraph { path: &path_buf, err });
-            return None;
-        }
-    };
-
-    file_format::write_file_header(&mut encoder, sess);
-
-    // First encode the commandline arguments hash
-    sess.opts.dep_tracking_hash(false).encode(&mut encoder);
-
-    Some(DepGraph::new(sess, prev_graph, prev_work_products, encoder))
-}

compiler/rustc_middle/src/dep_graph/dep_node.rs

@@ -121,19 +121,7 @@ impl DepNode {
     where
         Key: DepNodeKey<'tcx>,
     {
-        let dep_node = DepNode { kind, key_fingerprint: key.to_fingerprint(tcx).into() };
-
-        #[cfg(debug_assertions)]
-        {
-            if !tcx.key_fingerprint_style(kind).is_maybe_recoverable()
-                && (tcx.sess.opts.unstable_opts.incremental_info
-                    || tcx.sess.opts.unstable_opts.query_dep_graph)
-            {
-                tcx.dep_graph.register_dep_node_debug_str(dep_node, || key.to_debug_str(tcx));
-            }
-        }
-
-        dep_node
+        DepNode { kind, key_fingerprint: key.to_fingerprint(tcx).into() }
     }
 
     /// Construct a DepNode from the given DepKind and DefPathHash. This
@@ -151,24 +139,16 @@ impl DepNode {
 
 impl fmt::Debug for DepNode {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "{:?}(", self.kind)?;
-
         tls::with_opt(|opt_tcx| {
-            if let Some(tcx) = opt_tcx {
-                if let Some(def_id) = self.extract_def_id(tcx) {
-                    write!(f, "{}", tcx.def_path_debug_str(def_id))?;
-                } else if let Some(ref s) = tcx.dep_graph.dep_node_debug_str(*self) {
-                    write!(f, "{s}")?;
-                } else {
-                    write!(f, "{}", self.key_fingerprint)?;
-                }
+            if let Some(tcx) = opt_tcx
+                && let Some(def_id) = self.extract_def_id(tcx)
+            {
+                write!(f, "{:?}({})", self.kind, tcx.def_path_debug_str(def_id))?;
             } else {
-                write!(f, "{}", self.key_fingerprint)?;
+                write!(f, "{:?}({})", self.kind, self.key_fingerprint)?;
             }
             Ok(())
-        })?;
-
-        write!(f, ")")
+        })
     }
 }