Auto merge of #88597 - cjgillot:lower-global, r=petrochenkov

Move global analyses from lowering to resolution

Split off https://github.com/rust-lang/rust/pull/87234

r? `@petrochenkov`

3 files changed, 49 insertions, 4 deletions

diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
index 5c7b4b02822..7b65ab2acf6 100644
--- a/compiler/rustc_resolve/src/late.rs
+++ b/compiler/rustc_resolve/src/late.rs
@@ -952,6 +952,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
         match item.kind {
             ItemKind::TyAlias(box TyAliasKind(_, ref generics, _, _))
             | ItemKind::Fn(box FnKind(_, _, ref generics, _)) => {
+                self.compute_num_lifetime_params(item.id, generics);
                 self.with_generic_param_rib(generics, ItemRibKind(HasGenericParams::Yes), |this| {
                     visit::walk_item(this, item)
                 });
@@ -960,6 +961,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
             ItemKind::Enum(_, ref generics)
             | ItemKind::Struct(_, ref generics)
             | ItemKind::Union(_, ref generics) => {
+                self.compute_num_lifetime_params(item.id, generics);
                 self.resolve_adt(item, generics);
             }
 
@@ -970,10 +972,12 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
                 items: ref impl_items,
                 ..
             }) => {
+                self.compute_num_lifetime_params(item.id, generics);
                 self.resolve_implementation(generics, of_trait, &self_ty, item.id, impl_items);
             }
 
             ItemKind::Trait(box TraitKind(.., ref generics, ref bounds, ref trait_items)) => {
+                self.compute_num_lifetime_params(item.id, generics);
                 // Create a new rib for the trait-wide type parameters.
                 self.with_generic_param_rib(generics, ItemRibKind(HasGenericParams::Yes), |this| {
                     let local_def_id = this.r.local_def_id(item.id).to_def_id();
@@ -1025,6 +1029,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
             }
 
             ItemKind::TraitAlias(ref generics, ref bounds) => {
+                self.compute_num_lifetime_params(item.id, generics);
                 // Create a new rib for the trait-wide type parameters.
                 self.with_generic_param_rib(generics, ItemRibKind(HasGenericParams::Yes), |this| {
                     let local_def_id = this.r.local_def_id(item.id).to_def_id();
@@ -1276,7 +1281,14 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
             this.with_self_rib(Res::SelfTy(None, None), |this| {
                 // Resolve the trait reference, if necessary.
                 this.with_optional_trait_ref(opt_trait_reference.as_ref(), |this, trait_id| {
-                    let item_def_id = this.r.local_def_id(item_id).to_def_id();
+                    let item_def_id = this.r.local_def_id(item_id);
+
+                    // Register the trait definitions from here.
+                    if let Some(trait_id) = trait_id {
+                        this.r.trait_impls.entry(trait_id).or_default().push(item_def_id);
+                    }
+
+                    let item_def_id = item_def_id.to_def_id();
                     this.with_self_rib(Res::SelfTy(trait_id, Some((item_def_id, false))), |this| {
                         if let Some(trait_ref) = opt_trait_reference.as_ref() {
                             // Resolve type arguments in the trait path.
@@ -2463,6 +2475,16 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
             Some((ident.name, ns)),
         )
     }
+
+    fn compute_num_lifetime_params(&mut self, id: NodeId, generics: &Generics) {
+        let def_id = self.r.local_def_id(id);
+        let count = generics
+            .params
+            .iter()
+            .filter(|param| matches!(param.kind, ast::GenericParamKind::Lifetime { .. }))
+            .count();
+        self.r.item_generics_num_lifetimes.insert(def_id, count);
+    }
 }
 
 impl<'a> Resolver<'a> {
diff --git a/compiler/rustc_resolve/src/lib.rs b/compiler/rustc_resolve/src/lib.rs
index da3beac0819..152d34fd635 100644
--- a/compiler/rustc_resolve/src/lib.rs
+++ b/compiler/rustc_resolve/src/lib.rs
@@ -60,7 +60,7 @@ use rustc_span::{Span, DUMMY_SP};
 
 use smallvec::{smallvec, SmallVec};
 use std::cell::{Cell, RefCell};
-use std::collections::BTreeSet;
+use std::collections::{BTreeMap, BTreeSet};
 use std::ops::ControlFlow;
 use std::{cmp, fmt, iter, ptr};
 use tracing::debug;
@@ -1030,8 +1030,14 @@ pub struct Resolver<'a> {
     trait_impl_items: FxHashSet<LocalDefId>,
 
     legacy_const_generic_args: FxHashMap<DefId, Option<Vec<usize>>>,
+    /// Amount of lifetime parameters for each item in the crate.
+    item_generics_num_lifetimes: FxHashMap<LocalDefId, usize>,
 
     main_def: Option<MainDefinition>,
+    trait_impls: BTreeMap<DefId, Vec<LocalDefId>>,
+    /// A list of proc macro LocalDefIds, written out in the order in which
+    /// they are declared in the static array generated by proc_macro_harness.
+    proc_macros: Vec<NodeId>,
 }
 
 /// Nothing really interesting here; it just provides memory for the rest of the crate.
@@ -1109,8 +1115,12 @@ impl ResolverAstLowering for Resolver<'_> {
         }
     }
 
-    fn item_generics_num_lifetimes(&self, def_id: DefId, sess: &Session) -> usize {
-        self.cstore().item_generics_num_lifetimes(def_id, sess)
+    fn item_generics_num_lifetimes(&self, def_id: DefId) -> usize {
+        if let Some(def_id) = def_id.as_local() {
+            self.item_generics_num_lifetimes[&def_id]
+        } else {
+            self.cstore().item_generics_num_lifetimes(def_id, self.session)
+        }
     }
 
     fn legacy_const_generic_args(&mut self, expr: &Expr) -> Option<Vec<usize>> {
@@ -1390,7 +1400,10 @@ impl<'a> Resolver<'a> {
             next_disambiguator: Default::default(),
             trait_impl_items: Default::default(),
             legacy_const_generic_args: Default::default(),
+            item_generics_num_lifetimes: Default::default(),
             main_def: Default::default(),
+            trait_impls: Default::default(),
+            proc_macros: Default::default(),
         };
 
         let root_parent_scope = ParentScope::module(graph_root, &resolver);
@@ -1425,6 +1438,7 @@ impl<'a> Resolver<'a> {
     }
 
     pub fn into_outputs(self) -> ResolverOutputs {
+        let proc_macros = self.proc_macros.iter().map(|id| self.local_def_id(*id)).collect();
         let definitions = self.definitions;
         let visibilities = self.visibilities;
         let extern_crate_map = self.extern_crate_map;
@@ -1448,10 +1462,13 @@ impl<'a> Resolver<'a> {
                 .map(|(ident, entry)| (ident.name, entry.introduced_by_item))
                 .collect(),
             main_def,
+            trait_impls: self.trait_impls,
+            proc_macros,
         }
     }
 
     pub fn clone_outputs(&self) -> ResolverOutputs {
+        let proc_macros = self.proc_macros.iter().map(|id| self.local_def_id(*id)).collect();
         ResolverOutputs {
             definitions: self.definitions.clone(),
             cstore: Box::new(self.cstore().clone()),
@@ -1467,6 +1484,8 @@ impl<'a> Resolver<'a> {
                 .map(|(ident, entry)| (ident.name, entry.introduced_by_item))
                 .collect(),
             main_def: self.main_def.clone(),
+            trait_impls: self.trait_impls.clone(),
+            proc_macros,
         }
     }
 
diff --git a/compiler/rustc_resolve/src/macros.rs b/compiler/rustc_resolve/src/macros.rs
index 7f86f891c44..6dc3aa0888a 100644
--- a/compiler/rustc_resolve/src/macros.rs
+++ b/compiler/rustc_resolve/src/macros.rs
@@ -466,6 +466,10 @@ impl<'a> ResolverExpand for Resolver<'a> {
     fn get_proc_macro_quoted_span(&self, krate: CrateNum, id: usize) -> Span {
         self.crate_loader.cstore().get_proc_macro_quoted_span_untracked(krate, id, self.session)
     }
+
+    fn declare_proc_macro(&mut self, id: NodeId) {
+        self.proc_macros.push(id)
+    }
 }
 
 impl<'a> Resolver<'a> {