Rollup merge of #57570 - Xanewok:querify-some, r=Zoxc

Querify local `plugin_registrar_fn` and `proc_macro_decls_static`

Instead of calculating them as part of the `Session`, we do that in the query system.
It's also nice that these queries are already defined for external crates - here, we provide the queries for the local crate.

r? @nikomatsakis

8 files changed, 66 insertions, 41 deletions

diff --git a/src/librustc/session/mod.rs b/src/librustc/session/mod.rs
index fa0dfc4b38c..7363b8b3a78 100644
--- a/src/librustc/session/mod.rs
+++ b/src/librustc/session/mod.rs
@@ -69,8 +69,6 @@ pub struct Session {
     pub parse_sess: ParseSess,
     /// For a library crate, this is always none
     pub entry_fn: Once<Option<(NodeId, Span, config::EntryFnType)>>,
-    pub plugin_registrar_fn: Once<Option<ast::NodeId>>,
-    pub proc_macro_decls_static: Once<Option<ast::NodeId>>,
     pub sysroot: PathBuf,
     /// The name of the root source file of the crate, in the local file system.
     /// `None` means that there is no source file.
@@ -1177,8 +1175,6 @@ pub fn build_session_(
         parse_sess: p_s,
         // For a library crate, this is always none
         entry_fn: Once::new(),
-        plugin_registrar_fn: Once::new(),
-        proc_macro_decls_static: Once::new(),
         sysroot,
         local_crate_source_file,
         working_dir,
diff --git a/src/librustc_codegen_ssa/back/symbol_export.rs b/src/librustc_codegen_ssa/back/symbol_export.rs
index 928e171fe0f..bf69089a254 100644
--- a/src/librustc_codegen_ssa/back/symbol_export.rs
+++ b/src/librustc_codegen_ssa/back/symbol_export.rs
@@ -147,14 +147,12 @@ fn reachable_non_generics_provider<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
         })
         .collect();
 
-    if let Some(id) = *tcx.sess.proc_macro_decls_static.get() {
-        let def_id = tcx.hir().local_def_id(id);
-        reachable_non_generics.insert(def_id, SymbolExportLevel::C);
+    if let Some(id) = tcx.proc_macro_decls_static(LOCAL_CRATE) {
+        reachable_non_generics.insert(id, SymbolExportLevel::C);
     }
 
-    if let Some(id) = *tcx.sess.plugin_registrar_fn.get() {
-        let def_id = tcx.hir().local_def_id(id);
-        reachable_non_generics.insert(def_id, SymbolExportLevel::C);
+    if let Some(id) = tcx.plugin_registrar_fn(LOCAL_CRATE) {
+        reachable_non_generics.insert(id, SymbolExportLevel::C);
     }
 
     Lrc::new(reachable_non_generics)
diff --git a/src/librustc_codegen_utils/symbol_names.rs b/src/librustc_codegen_utils/symbol_names.rs
index 5a5d1b20b21..9267f14f242 100644
--- a/src/librustc_codegen_utils/symbol_names.rs
+++ b/src/librustc_codegen_utils/symbol_names.rs
@@ -242,12 +242,12 @@ fn compute_symbol_name<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, instance: Instance
 
     let node_id = tcx.hir().as_local_node_id(def_id);
 
-    if let Some(id) = node_id {
-        if *tcx.sess.plugin_registrar_fn.get() == Some(id) {
+    if def_id.is_local() {
+        if tcx.plugin_registrar_fn(LOCAL_CRATE) == Some(def_id) {
             let disambiguator = tcx.sess.local_crate_disambiguator();
             return tcx.sess.generate_plugin_registrar_symbol(disambiguator);
         }
-        if *tcx.sess.proc_macro_decls_static.get() == Some(id) {
+        if tcx.proc_macro_decls_static(LOCAL_CRATE) == Some(def_id) {
             let disambiguator = tcx.sess.local_crate_disambiguator();
             return tcx.sess.generate_proc_macro_decls_symbol(disambiguator);
         }
diff --git a/src/librustc_driver/driver.rs b/src/librustc_driver/driver.rs
index 380f9afd68d..3b7de37ae4b 100644
--- a/src/librustc_driver/driver.rs
+++ b/src/librustc_driver/driver.rs
@@ -1158,6 +1158,8 @@ where
 }
 
 pub fn default_provide(providers: &mut ty::query::Providers) {
+    proc_macro_decls::provide(providers);
+    plugin::build::provide(providers);
     hir::provide(providers);
     borrowck::provide(providers);
     mir::provide(providers);
@@ -1212,13 +1214,6 @@ where
         middle::entry::find_entry_point(sess, &hir_map, name)
     });
 
-    sess.plugin_registrar_fn
-        .set(time(sess, "looking for plugin registrar", || {
-            plugin::build::find_plugin_registrar(sess.diagnostic(), &hir_map)
-        }));
-    sess.proc_macro_decls_static
-        .set(proc_macro_decls::find(&hir_map));
-
     let mut local_providers = ty::query::Providers::default();
     default_provide(&mut local_providers);
     codegen_backend.provide(&mut local_providers);
@@ -1248,6 +1243,14 @@ where
             // tcx available.
             time(sess, "dep graph tcx init", || rustc_incremental::dep_graph_tcx_init(tcx));
 
+            time(sess, "looking for plugin registrar", || {
+                plugin::build::find_plugin_registrar(tcx)
+            });
+
+            time(sess, "looking for derive registrar", || {
+                proc_macro_decls::find(tcx)
+            });
+
             time(sess, "loop checking", || loops::check_crate(tcx));
 
             time(sess, "attribute checking", || {
diff --git a/src/librustc_driver/proc_macro_decls.rs b/src/librustc_driver/proc_macro_decls.rs
index bb2ea6c2a97..093d15b7e3c 100644
--- a/src/librustc_driver/proc_macro_decls.rs
+++ b/src/librustc_driver/proc_macro_decls.rs
@@ -1,15 +1,25 @@
 use rustc::hir::itemlikevisit::ItemLikeVisitor;
-use rustc::hir::map::Map;
+use rustc::hir::def_id::{CrateNum, DefId, LOCAL_CRATE};
 use rustc::hir;
+use rustc::ty::TyCtxt;
+use rustc::ty::query::Providers;
 use syntax::ast;
 use syntax::attr;
 
-pub fn find(hir_map: &Map) -> Option<ast::NodeId> {
-    let krate = hir_map.krate();
+pub fn find<'tcx>(tcx: TyCtxt<'_, 'tcx, 'tcx>) -> Option<DefId> {
+    tcx.proc_macro_decls_static(LOCAL_CRATE)
+}
+
+fn proc_macro_decls_static<'tcx>(
+    tcx: TyCtxt<'_, 'tcx, 'tcx>,
+    cnum: CrateNum,
+) -> Option<DefId> {
+    assert_eq!(cnum, LOCAL_CRATE);
 
     let mut finder = Finder { decls: None };
-    krate.visit_all_item_likes(&mut finder);
-    finder.decls
+    tcx.hir().krate().visit_all_item_likes(&mut finder);
+
+    finder.decls.map(|id| tcx.hir().local_def_id(id))
 }
 
 struct Finder {
@@ -30,3 +40,9 @@ impl<'v> ItemLikeVisitor<'v> for Finder {
     }
 }
 
+pub(crate) fn provide(providers: &mut Providers<'_>) {
+    *providers = Providers {
+        proc_macro_decls_static,
+        ..*providers
+    };
+}
diff --git a/src/librustc_lint/builtin.rs b/src/librustc_lint/builtin.rs
index 5678f30dabc..72bcf8edfdd 100644
--- a/src/librustc_lint/builtin.rs
+++ b/src/librustc_lint/builtin.rs
@@ -19,7 +19,7 @@
 //! a `pub fn new()`.
 
 use rustc::hir::def::Def;
-use rustc::hir::def_id::DefId;
+use rustc::hir::def_id::{DefId, LOCAL_CRATE};
 use rustc::ty::{self, Ty};
 use hir::Node;
 use util::nodemap::NodeSet;
@@ -860,7 +860,7 @@ impl LintPass for PluginAsLibrary {
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for PluginAsLibrary {
     fn check_item(&mut self, cx: &LateContext, it: &hir::Item) {
-        if cx.sess().plugin_registrar_fn.get().is_some() {
+        if cx.tcx.plugin_registrar_fn(LOCAL_CRATE).is_some() {
             // We're compiling a plugin; it's fine to link other plugins.
             return;
         }
diff --git a/src/librustc_metadata/encoder.rs b/src/librustc_metadata/encoder.rs
index 032a4656efc..2de1637fb0d 100644
--- a/src/librustc_metadata/encoder.rs
+++ b/src/librustc_metadata/encoder.rs
@@ -482,13 +482,10 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             has_global_allocator: has_global_allocator,
             has_panic_handler: has_panic_handler,
             has_default_lib_allocator: has_default_lib_allocator,
-            plugin_registrar_fn: tcx.sess
-                .plugin_registrar_fn
-                .get()
-                .map(|id| tcx.hir().local_def_id(id).index),
+            plugin_registrar_fn: tcx.plugin_registrar_fn(LOCAL_CRATE).map(|id| id.index),
             proc_macro_decls_static: if is_proc_macro {
-                let id = tcx.sess.proc_macro_decls_static.get().unwrap();
-                Some(tcx.hir().local_def_id(id).index)
+                let id = tcx.proc_macro_decls_static(LOCAL_CRATE).unwrap();
+                Some(id.index)
             } else {
                 None
             },
diff --git a/src/librustc_plugin/build.rs b/src/librustc_plugin/build.rs
index eca2736ee52..46c452668c3 100644
--- a/src/librustc_plugin/build.rs
+++ b/src/librustc_plugin/build.rs
@@ -2,11 +2,12 @@
 
 use syntax::ast;
 use syntax::attr;
-use errors;
 use syntax_pos::Span;
-use rustc::hir::map::Map;
 use rustc::hir::itemlikevisit::ItemLikeVisitor;
 use rustc::hir;
+use rustc::hir::def_id::{CrateNum, DefId, LOCAL_CRATE};
+use rustc::ty::TyCtxt;
+use rustc::ty::query::Providers;
 
 struct RegistrarFinder {
     registrars: Vec<(ast::NodeId, Span)> ,
@@ -30,21 +31,27 @@ impl<'v> ItemLikeVisitor<'v> for RegistrarFinder {
 }
 
 /// Find the function marked with `#[plugin_registrar]`, if any.
-pub fn find_plugin_registrar(diagnostic: &errors::Handler,
-                             hir_map: &Map)
-                             -> Option<ast::NodeId> {
-    let krate = hir_map.krate();
+pub fn find_plugin_registrar<'tcx>(tcx: TyCtxt<'_, 'tcx, 'tcx>) -> Option<DefId> {
+    tcx.plugin_registrar_fn(LOCAL_CRATE)
+}
+
+fn plugin_registrar_fn<'tcx>(
+    tcx: TyCtxt<'_, 'tcx, 'tcx>,
+    cnum: CrateNum,
+) -> Option<DefId> {
+    assert_eq!(cnum, LOCAL_CRATE);
 
     let mut finder = RegistrarFinder { registrars: Vec::new() };
-    krate.visit_all_item_likes(&mut finder);
+    tcx.hir().krate().visit_all_item_likes(&mut finder);
 
     match finder.registrars.len() {
         0 => None,
         1 => {
             let (node_id, _) = finder.registrars.pop().unwrap();
-            Some(node_id)
+            Some(tcx.hir().local_def_id(node_id))
         },
         _ => {
+            let diagnostic = tcx.sess.diagnostic();
             let mut e = diagnostic.struct_err("multiple plugin registration functions found");
             for &(_, span) in &finder.registrars {
                 e.span_note(span, "one is here");
@@ -55,3 +62,11 @@ pub fn find_plugin_registrar(diagnostic: &errors::Handler,
         }
     }
 }
+
+
+pub fn provide(providers: &mut Providers<'_>) {
+    *providers = Providers {
+        plugin_registrar_fn,
+        ..*providers
+    };
+}