Auto merge of rust-lang#115118 - Zoxc:rustc-query-encode, r=<try>

Extract suitable code from rustc_query_impl into a new crate rustc_query_misc

This extracts code from `rustc_query_impl` into a new crate `rustc_query_misc` in order to reduce the compile time of `rustc_query_impl`. The compile time of the new crate is roughly 60% of the remaining `rustc_query_impl` .

I've picked code which should not impact performance or result in duplicate generic code generation. Encoding and decoding of query results and profiling handling is moved along with some other minor methods which use dynamic dispatch.

r? `@cjgillot`

Cargo.lock

@@ -3959,6 +3959,7 @@ dependencies = [
  "rustc_plugin_impl",
  "rustc_privacy",
  "rustc_query_impl",
+ "rustc_query_misc",
  "rustc_query_system",
  "rustc_resolve",
  "rustc_session",
@@ -4304,7 +4305,6 @@ name = "rustc_query_impl"
 version = "0.0.0"
 dependencies = [
  "field-offset",
- "measureme",
  "memoffset",
  "rustc-rayon-core",
  "rustc_data_structures",
@@ -4313,6 +4313,7 @@ dependencies = [
  "rustc_index",
  "rustc_macros",
  "rustc_middle",
+ "rustc_query_misc",
  "rustc_query_system",
  "rustc_serialize",
  "rustc_session",
@@ -4321,6 +4322,20 @@ dependencies = [
  "tracing",
 ]
 
+[[package]]
+name = "rustc_query_misc"
+version = "0.0.0"
+dependencies = [
+ "measureme",
+ "rustc_data_structures",
+ "rustc_hir",
+ "rustc_index",
+ "rustc_middle",
+ "rustc_query_system",
+ "rustc_serialize",
+ "rustc_span",
+]
+
 [[package]]
 name = "rustc_query_system"
 version = "0.0.0"

compiler/rustc_interface/Cargo.toml

@@ -47,6 +47,7 @@ rustc_plugin_impl = { path = "../rustc_plugin_impl" }
 rustc_privacy = { path = "../rustc_privacy" }
 rustc_query_system = { path = "../rustc_query_system" }
 rustc_query_impl = { path = "../rustc_query_impl" }
+rustc_query_misc = { path = "../rustc_query_misc" }
 rustc_resolve = { path = "../rustc_resolve" }
 rustc_target = { path = "../rustc_target" }
 rustc_trait_selection = { path = "../rustc_trait_selection" }

compiler/rustc_interface/src/queries.rs

@@ -340,7 +340,7 @@ impl Compiler {
             {
                 let _prof_timer =
                     queries.session().prof.generic_activity("self_profile_alloc_query_strings");
-                gcx.enter(rustc_query_impl::alloc_self_profile_query_strings);
+                gcx.enter(rustc_query_misc::alloc_self_profile_query_strings);
             }
 
             self.session()

compiler/rustc_query_impl/Cargo.toml

@@ -8,14 +8,14 @@ edition = "2021"
 
 [dependencies]
 field-offset = "0.3.5"
-measureme = "10.0.0"
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_errors = { path = "../rustc_errors" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_index = { path = "../rustc_index" }
 rustc_macros = { path = "../rustc_macros" }
 rustc_middle = { path = "../rustc_middle" }
 rustc_query_system = { path = "../rustc_query_system" }
+rustc_query_misc = { path = "../rustc_query_misc" }
 rustc-rayon-core = { version = "0.5.0", optional = true }
 rustc_serialize = { path = "../rustc_serialize" }
 rustc_session = { path = "../rustc_session" }

compiler/rustc_query_impl/src/lib.rs

@@ -4,7 +4,6 @@
 // this shouldn't be necessary, but the check for `&mut _` is too naive and denies returning a function pointer that takes a mut ref
 #![feature(const_mut_refs)]
 #![feature(const_refs_to_cell)]
-#![feature(min_specialization)]
 #![feature(never_type)]
 #![feature(rustc_attrs)]
 #![recursion_limit = "256"]
@@ -16,40 +15,35 @@
 #[macro_use]
 extern crate rustc_middle;
 
-use crate::plumbing::{__rust_begin_short_backtrace, encode_all_query_results, try_mark_green};
+use crate::plumbing::{__rust_begin_short_backtrace, try_mark_green};
 use field_offset::offset_of;
 use rustc_data_structures::stable_hasher::HashStable;
 use rustc_data_structures::sync::AtomicU64;
 use rustc_middle::arena::Arena;
 use rustc_middle::dep_graph::DepNodeIndex;
 use rustc_middle::dep_graph::{self, DepKind, DepKindStruct};
 use rustc_middle::query::erase::{erase, restore, Erase};
-use rustc_middle::query::on_disk_cache::{CacheEncoder, EncodedDepNodeIndex, OnDiskCache};
-use rustc_middle::query::plumbing::{
-    DynamicQuery, QueryKeyStringCache, QuerySystem, QuerySystemFns,
-};
+use rustc_middle::query::on_disk_cache::OnDiskCache;
+use rustc_middle::query::plumbing::{DynamicQuery, QuerySystem, QuerySystemFns};
 use rustc_middle::query::AsLocalKey;
 use rustc_middle::query::{
     queries, DynamicQueries, ExternProviders, Providers, QueryCaches, QueryEngine, QueryStates,
 };
 use rustc_middle::ty::TyCtxt;
+use rustc_query_misc::{encode_all_query_results, query_utils};
 use rustc_query_system::dep_graph::SerializedDepNodeIndex;
 use rustc_query_system::ich::StableHashingContext;
 use rustc_query_system::query::{
     get_query_incr, get_query_non_incr, HashResult, QueryCache, QueryConfig, QueryInfo, QueryMap,
     QueryMode, QueryState,
 };
 use rustc_query_system::HandleCycleError;
-use rustc_query_system::Value;
 use rustc_span::{ErrorGuaranteed, Span};
 
 #[macro_use]
 mod plumbing;
 pub use crate::plumbing::QueryCtxt;
 
-mod profiling_support;
-pub use self::profiling_support::alloc_self_profile_query_strings;
-
 struct DynamicConfig<
     'tcx,
     C: QueryCache,

compiler/rustc_query_impl/src/plumbing.rs

@@ -2,32 +2,24 @@
 //! generate the actual methods on tcx which find and execute the provider,
 //! manage the caches, and so forth.
 
-use crate::rustc_middle::dep_graph::DepContext;
-use crate::rustc_middle::ty::TyEncoder;
 use crate::QueryConfigRestored;
 use rustc_data_structures::stable_hasher::{Hash64, HashStable, StableHasher};
 use rustc_data_structures::sync::Lock;
 use rustc_errors::Diagnostic;
 
-use rustc_index::Idx;
 use rustc_middle::dep_graph::dep_kinds;
 use rustc_middle::dep_graph::{
     self, DepKind, DepKindStruct, DepNode, DepNodeIndex, SerializedDepNodeIndex,
 };
-use rustc_middle::query::on_disk_cache::AbsoluteBytePos;
-use rustc_middle::query::on_disk_cache::{CacheDecoder, CacheEncoder, EncodedDepNodeIndex};
 use rustc_middle::query::Key;
 use rustc_middle::ty::tls::{self, ImplicitCtxt};
 use rustc_middle::ty::{self, print::with_no_queries, TyCtxt};
 use rustc_query_system::dep_graph::{DepNodeParams, HasDepContext};
 use rustc_query_system::ich::StableHashingContext;
 use rustc_query_system::query::{
-    force_query, QueryCache, QueryConfig, QueryContext, QueryJobId, QueryMap, QuerySideEffects,
-    QueryStackFrame,
+    force_query, QueryConfig, QueryContext, QueryJobId, QueryMap, QuerySideEffects, QueryStackFrame,
 };
 use rustc_query_system::{LayoutOfDepth, QueryOverflow};
-use rustc_serialize::Decodable;
-use rustc_serialize::Encodable;
 use rustc_session::Limit;
 use rustc_span::def_id::LOCAL_CRATE;
 use std::num::NonZeroU64;
@@ -180,16 +172,6 @@ pub(super) fn try_mark_green<'tcx>(tcx: TyCtxt<'tcx>, dep_node: &dep_graph::DepN
     tcx.dep_graph.try_mark_green(QueryCtxt::new(tcx), dep_node).is_some()
 }
 
-pub(super) fn encode_all_query_results<'tcx>(
-    tcx: TyCtxt<'tcx>,
-    encoder: &mut CacheEncoder<'_, 'tcx>,
-    query_result_index: &mut EncodedDepNodeIndex,
-) {
-    for encode in super::ENCODE_QUERY_RESULTS.iter().copied().flatten() {
-        encode(tcx, encoder, query_result_index);
-    }
-}
-
 macro_rules! handle_cycle_error {
     ([]) => {{
         rustc_query_system::HandleCycleError::Error
@@ -254,10 +236,10 @@ macro_rules! feedable {
 }
 
 macro_rules! hash_result {
-    ([][$V:ty]) => {{
-        Some(|hcx, result| dep_graph::hash_result(hcx, &restore::<$V>(*result)))
+    ([][$f:path]) => {{
+        Some($f)
     }};
-    ([(no_hash) $($rest:tt)*][$V:ty]) => {{
+    ([(no_hash) $($rest:tt)*]$args:tt) => {{
         None
     }};
     ([$other:tt $($modifiers:tt)*][$($args:tt)*]) => {
@@ -341,33 +323,6 @@ pub(crate) fn create_query_frame<
     QueryStackFrame::new(description, span, def_id, def_kind, kind, ty_adt_id, hash)
 }
 
-pub(crate) fn encode_query_results<'a, 'tcx, Q>(
-    query: Q::Config,
-    qcx: QueryCtxt<'tcx>,
-    encoder: &mut CacheEncoder<'a, 'tcx>,
-    query_result_index: &mut EncodedDepNodeIndex,
-) where
-    Q: super::QueryConfigRestored<'tcx>,
-    Q::RestoredValue: Encodable<CacheEncoder<'a, 'tcx>>,
-{
-    let _timer = qcx.profiler().generic_activity_with_arg("encode_query_results_for", query.name());
-
-    assert!(query.query_state(qcx).all_inactive());
-    let cache = query.query_cache(qcx);
-    cache.iter(&mut |key, value, dep_node| {
-        if query.cache_on_disk(qcx.tcx, &key) {
-            let dep_node = SerializedDepNodeIndex::new(dep_node.index());
-
-            // Record position of the cache entry.
-            query_result_index.push((dep_node, AbsoluteBytePos::new(encoder.position())));
-
-            // Encode the type check tables with the `SerializedDepNodeIndex`
-            // as tag.
-            encoder.encode_tagged(dep_node, &Q::restore(*value));
-        }
-    });
-}
-
 fn try_load_from_on_disk_cache<'tcx, Q>(query: Q, tcx: TyCtxt<'tcx>, dep_node: DepNode)
 where
     Q: QueryConfig<QueryCtxt<'tcx>>,
@@ -382,38 +337,6 @@ where
     }
 }
 
-pub(crate) fn loadable_from_disk<'tcx>(tcx: TyCtxt<'tcx>, id: SerializedDepNodeIndex) -> bool {
-    if let Some(cache) = tcx.query_system.on_disk_cache.as_ref() {
-        cache.loadable_from_disk(id)
-    } else {
-        false
-    }
-}
-
-pub(crate) fn try_load_from_disk<'tcx, V>(
-    tcx: TyCtxt<'tcx>,
-    prev_index: SerializedDepNodeIndex,
-    index: DepNodeIndex,
-) -> Option<V>
-where
-    V: for<'a> Decodable<CacheDecoder<'a, 'tcx>>,
-{
-    let on_disk_cache = tcx.query_system.on_disk_cache.as_ref()?;
-
-    let prof_timer = tcx.prof.incr_cache_loading();
-
-    // The call to `with_query_deserialization` enforces that no new `DepNodes`
-    // are created during deserialization. See the docs of that method for more
-    // details.
-    let value = tcx
-        .dep_graph
-        .with_query_deserialization(|| on_disk_cache.try_load_query_result(tcx, prev_index));
-
-    prof_timer.finish_with_query_invocation_id(index.into());
-
-    value
-}
-
 fn force_from_dep_node<'tcx, Q>(query: Q, tcx: TyCtxt<'tcx>, dep_node: DepNode) -> bool
 where
     Q: QueryConfig<QueryCtxt<'tcx>>,
@@ -477,28 +400,6 @@ where
     }
 }
 
-macro_rules! item_if_cached {
-    ([] $tokens:tt) => {};
-    ([(cache) $($rest:tt)*] { $($tokens:tt)* }) => {
-        $($tokens)*
-    };
-    ([$other:tt $($modifiers:tt)*] $tokens:tt) => {
-        item_if_cached! { [$($modifiers)*] $tokens }
-    };
-}
-
-macro_rules! expand_if_cached {
-    ([], $tokens:expr) => {{
-        None
-    }};
-    ([(cache) $($rest:tt)*], $tokens:expr) => {{
-        Some($tokens)
-    }};
-    ([$other:tt $($modifiers:tt)*], $tokens:expr) => {
-        expand_if_cached!([$($modifiers)*], $tokens)
-    };
-}
-
 /// Don't show the backtrace for query system by default
 /// use `RUST_BACKTRACE=full` to show all the backtraces
 #[inline(never)]
@@ -590,38 +491,11 @@ macro_rules! define_queries {
                         )
                     },
                     can_load_from_disk: should_ever_cache_on_disk!([$($modifiers)*] true false),
-                    try_load_from_disk: should_ever_cache_on_disk!([$($modifiers)*] {
-                        |tcx, key, prev_index, index| {
-                            if ::rustc_middle::query::cached::$name(tcx, key) {
-                                let value = $crate::plumbing::try_load_from_disk::<
-                                    queries::$name::ProvidedValue<'tcx>
-                                >(
-                                    tcx,
-                                    prev_index,
-                                    index,
-                                );
-                                value.map(|value| queries::$name::provided_to_erased(tcx, value))
-                            } else {
-                                None
-                            }
-                        }
-                    } {
-                        |_tcx, _key, _prev_index, _index| None
-                    }),
-                    value_from_cycle_error: |tcx, cycle, guar| {
-                        let result: queries::$name::Value<'tcx> = Value::from_cycle_error(tcx, cycle, guar);
-                        erase(result)
-                    },
-                    loadable_from_disk: |_tcx, _key, _index| {
-                        should_ever_cache_on_disk!([$($modifiers)*] {
-                            ::rustc_middle::query::cached::$name(_tcx, _key) &&
-                                $crate::plumbing::loadable_from_disk(_tcx, _index)
-                        } {
-                            false
-                        })
-                    },
-                    hash_result: hash_result!([$($modifiers)*][queries::$name::Value<'tcx>]),
-                    format_value: |value| format!("{:?}", restore::<queries::$name::Value<'tcx>>(*value)),
+                    try_load_from_disk: query_utils::$name::try_load_from_disk,
+                    loadable_from_disk: query_utils::$name::loadable_from_disk,
+                    value_from_cycle_error: query_utils::$name::value_from_cycle_error,
+                    hash_result: hash_result!([$($modifiers)*][query_utils::$name::hash_result]),
+                    format_value: query_utils::$name::format_value,
                 }
             }
 
@@ -667,30 +541,6 @@ macro_rules! define_queries {
                     qmap,
                 ).unwrap();
             }
-
-            pub fn alloc_self_profile_query_strings<'tcx>(tcx: TyCtxt<'tcx>, string_cache: &mut QueryKeyStringCache) {
-                $crate::profiling_support::alloc_self_profile_query_strings_for_query_cache(
-                    tcx,
-                    stringify!($name),
-                    &tcx.query_system.caches.$name,
-                    string_cache,
-                )
-            }
-
-            item_if_cached! { [$($modifiers)*] {
-                pub fn encode_query_results<'tcx>(
-                    tcx: TyCtxt<'tcx>,
-                    encoder: &mut CacheEncoder<'_, 'tcx>,
-                    query_result_index: &mut EncodedDepNodeIndex
-                ) {
-                    $crate::plumbing::encode_query_results::<query_impl::$name::QueryType<'tcx>>(
-                        query_impl::$name::QueryType::config(tcx),
-                        QueryCtxt::new(tcx),
-                        encoder,
-                        query_result_index,
-                    )
-                }
-            }}
         })*}
 
         pub(crate) fn engine(incremental: bool) -> QueryEngine {
@@ -713,23 +563,11 @@ macro_rules! define_queries {
             }
         }
 
-        // These arrays are used for iteration and can't be indexed by `DepKind`.
+        // This array is used for iteration and can't be indexed by `DepKind`.
 
         const TRY_COLLECT_ACTIVE_JOBS: &[for<'tcx> fn(TyCtxt<'tcx>, &mut QueryMap)] =
             &[$(query_impl::$name::try_collect_active_jobs),*];
 
-        const ALLOC_SELF_PROFILE_QUERY_STRINGS: &[
-            for<'tcx> fn(TyCtxt<'tcx>, &mut QueryKeyStringCache)
-        ] = &[$(query_impl::$name::alloc_self_profile_query_strings),*];
-
-        const ENCODE_QUERY_RESULTS: &[
-            Option<for<'tcx> fn(
-                TyCtxt<'tcx>,
-                &mut CacheEncoder<'_, 'tcx>,
-                &mut EncodedDepNodeIndex)
-            >
-        ] = &[$(expand_if_cached!([$($modifiers)*], query_impl::$name::encode_query_results)),*];
-
         #[allow(nonstandard_style)]
         mod query_callbacks {
             use super::*;