Auto merge of #109611 - Zoxc:query-engine-rem, r=cjgillot

Remove `QueryEngine` trait

This removes the `QueryEngine` trait and `Queries` from `rustc_query_impl` and replaced them with function pointers and fields in `QuerySystem`. As a side effect `OnDiskCache` is moved back into `rustc_middle` and the `OnDiskCache` trait is also removed.

This has a couple of benefits.
- `TyCtxt` is used in the query system instead of the removed `QueryCtxt` which is larger.
- Function pointers are more flexible to work with. A variant of https://github.com/rust-lang/rust/pull/107802 is included which avoids the double indirection. For https://github.com/rust-lang/rust/pull/108938 we can name entry point `__rust_end_short_backtrace` to avoid some overhead. For https://github.com/rust-lang/rust/pull/108062 it avoids the duplicate `QueryEngine` structs.
- `QueryContext` now implements `DepContext` which avoids many `dep_context()` calls in `rustc_query_system`.
- The `rustc_driver` size is reduced by 0.33%, hopefully that means some bootstrap improvements.
- This avoids the unsafe code around the `QueryEngine` trait.

r? `@cjgillot`

4 files changed, 7 insertions, 15 deletions

diff --git a/compiler/rustc_interface/src/interface.rs b/compiler/rustc_interface/src/interface.rs
index be7fa9378ca..8e9150ba8ad 100644
--- a/compiler/rustc_interface/src/interface.rs
+++ b/compiler/rustc_interface/src/interface.rs
@@ -12,6 +12,7 @@ use rustc_lint::LintStore;
 use rustc_middle::ty;
 use rustc_parse::maybe_new_parser_from_source_str;
 use rustc_query_impl::QueryCtxt;
+use rustc_query_system::query::print_query_stack;
 use rustc_session::config::{self, CheckCfg, ErrorOutputType, Input, OutputFilenames};
 use rustc_session::lint;
 use rustc_session::parse::{CrateConfig, ParseSess};
@@ -317,7 +318,7 @@ pub fn try_print_query_stack(handler: &Handler, num_frames: Option<usize>) {
     // state if it was responsible for triggering the panic.
     let i = ty::tls::with_context_opt(|icx| {
         if let Some(icx) = icx {
-            QueryCtxt::from_tcx(icx.tcx).try_print_query_stack(icx.query, handler, num_frames)
+            print_query_stack(QueryCtxt { tcx: icx.tcx }, icx.query, handler, num_frames)
         } else {
             0
         }
diff --git a/compiler/rustc_interface/src/passes.rs b/compiler/rustc_interface/src/passes.rs
index 61923db9623..48401eabd1e 100644
--- a/compiler/rustc_interface/src/passes.rs
+++ b/compiler/rustc_interface/src/passes.rs
@@ -23,7 +23,6 @@ use rustc_mir_build as mir_build;
 use rustc_parse::{parse_crate_from_file, parse_crate_from_source_str, validate_attr};
 use rustc_passes::{self, hir_stats, layout_test};
 use rustc_plugin_impl as plugin;
-use rustc_query_impl::{OnDiskCache, Queries as TcxQueries};
 use rustc_resolve::Resolver;
 use rustc_session::config::{CrateType, Input, OutputFilenames, OutputType};
 use rustc_session::cstore::{MetadataLoader, Untracked};
@@ -669,7 +668,6 @@ pub fn create_global_ctxt<'tcx>(
     lint_store: Lrc<LintStore>,
     dep_graph: DepGraph,
     untracked: Untracked,
-    queries: &'tcx OnceCell<TcxQueries<'tcx>>,
     gcx_cell: &'tcx OnceCell<GlobalCtxt<'tcx>>,
     arena: &'tcx WorkerLocal<Arena<'tcx>>,
     hir_arena: &'tcx WorkerLocal<rustc_hir::Arena<'tcx>>,
@@ -693,10 +691,6 @@ pub fn create_global_ctxt<'tcx>(
         callback(sess, &mut local_providers, &mut extern_providers);
     }
 
-    let queries = queries.get_or_init(|| {
-        TcxQueries::new(local_providers, extern_providers, query_result_on_disk_cache)
-    });
-
     sess.time("setup_global_ctxt", || {
         gcx_cell.get_or_init(move || {
             TyCtxt::create_global_ctxt(
@@ -706,9 +700,9 @@ pub fn create_global_ctxt<'tcx>(
                 hir_arena,
                 untracked,
                 dep_graph,
-                queries.on_disk_cache.as_ref().map(OnDiskCache::as_dyn),
-                queries.as_dyn(),
+                query_result_on_disk_cache,
                 rustc_query_impl::query_callbacks(arena),
+                rustc_query_impl::query_system_fns(local_providers, extern_providers),
             )
         })
     })
diff --git a/compiler/rustc_interface/src/queries.rs b/compiler/rustc_interface/src/queries.rs
index 818f450a58c..77fbbf64a0a 100644
--- a/compiler/rustc_interface/src/queries.rs
+++ b/compiler/rustc_interface/src/queries.rs
@@ -16,7 +16,6 @@ use rustc_metadata::creader::CStore;
 use rustc_middle::arena::Arena;
 use rustc_middle::dep_graph::DepGraph;
 use rustc_middle::ty::{GlobalCtxt, TyCtxt};
-use rustc_query_impl::Queries as TcxQueries;
 use rustc_session::config::{self, OutputFilenames, OutputType};
 use rustc_session::cstore::Untracked;
 use rustc_session::{output::find_crate_name, Session};
@@ -81,7 +80,6 @@ impl<T> Default for Query<T> {
 pub struct Queries<'tcx> {
     compiler: &'tcx Compiler,
     gcx_cell: OnceCell<GlobalCtxt<'tcx>>,
-    queries: OnceCell<TcxQueries<'tcx>>,
 
     arena: WorkerLocal<Arena<'tcx>>,
     hir_arena: WorkerLocal<rustc_hir::Arena<'tcx>>,
@@ -102,7 +100,6 @@ impl<'tcx> Queries<'tcx> {
         Queries {
             compiler,
             gcx_cell: OnceCell::new(),
-            queries: OnceCell::new(),
             arena: WorkerLocal::new(|_| Arena::default()),
             hir_arena: WorkerLocal::new(|_| rustc_hir::Arena::default()),
             dep_graph_future: Default::default(),
@@ -225,7 +222,6 @@ impl<'tcx> Queries<'tcx> {
                 lint_store,
                 self.dep_graph()?.steal(),
                 untracked,
-                &self.queries,
                 &self.gcx_cell,
                 &self.arena,
                 &self.hir_arena,
diff --git a/compiler/rustc_interface/src/util.rs b/compiler/rustc_interface/src/util.rs
index a27a1e2978a..8d37b1053d8 100644
--- a/compiler/rustc_interface/src/util.rs
+++ b/compiler/rustc_interface/src/util.rs
@@ -170,7 +170,8 @@ pub(crate) fn run_in_thread_pool_with_globals<F: FnOnce() -> R + Send, R: Send>(
 ) -> R {
     use rustc_data_structures::jobserver;
     use rustc_middle::ty::tls;
-    use rustc_query_impl::{deadlock, QueryContext, QueryCtxt};
+    use rustc_query_impl::QueryCtxt;
+    use rustc_query_system::query::{deadlock, QueryContext};
 
     let registry = sync::Registry::new(threads);
     let mut builder = rayon::ThreadPoolBuilder::new()
@@ -182,7 +183,7 @@ pub(crate) fn run_in_thread_pool_with_globals<F: FnOnce() -> R + Send, R: Send>(
             // On deadlock, creates a new thread and forwards information in thread
             // locals to it. The new thread runs the deadlock handler.
             let query_map = tls::with(|tcx| {
-                QueryCtxt::from_tcx(tcx)
+                QueryCtxt::new(tcx)
                     .try_collect_active_jobs()
                     .expect("active jobs shouldn't be locked in deadlock handler")
             });