Store the gctxt instead of fetching it twice.

Author: oli-obk

compiler/rustc_driver/src/lib.rs

@@ -327,12 +327,14 @@ fn run_compiler(
                 }
             }
 
-            queries.global_ctxt()?;
+            let mut gctxt = queries.global_ctxt()?;
             if callbacks.after_expansion(compiler, queries) == Compilation::Stop {
                 return early_exit();
             }
 
-            queries.global_ctxt()?.enter(|tcx| tcx.output_filenames(()));
+            // Make sure the `output_filenames` query is run for its side
+            // effects of writing the dep-info and reporting errors.
+            gctxt.enter(|tcx| tcx.output_filenames(()));
 
             if sess.opts.output_types.contains_key(&OutputType::DepInfo)
                 && sess.opts.output_types.len() == 1
@@ -344,7 +346,7 @@ fn run_compiler(
                 return early_exit();
             }
 
-            queries.global_ctxt()?.enter(|tcx| {
+            gctxt.enter(|tcx| {
                 let result = tcx.analysis(());
                 if sess.opts.unstable_opts.save_analysis {
                     let crate_name = tcx.crate_name(LOCAL_CRATE);
@@ -361,6 +363,8 @@ fn run_compiler(
                 result
             })?;
 
+            drop(gctxt);
+
             if callbacks.after_analysis(compiler, queries) == Compilation::Stop {
                 return early_exit();
             }

compiler/rustc_interface/src/queries.rs

@@ -65,7 +65,7 @@ impl<'a, T> std::ops::DerefMut for QueryResult<'a, T> {
 }
 
 impl<'a, 'tcx> QueryResult<'a, QueryContext<'tcx>> {
-    pub fn enter<T>(mut self, f: impl FnOnce(TyCtxt<'tcx>) -> T) -> T {
+    pub fn enter<T>(&mut self, f: impl FnOnce(TyCtxt<'tcx>) -> T) -> T {
         (*self.0).get_mut().enter(f)
     }
 }

src/librustdoc/lib.rs

@@ -815,7 +815,7 @@ fn main_args(at_args: &[String]) -> MainResult {
                 sess.fatal("Compilation failed, aborting rustdoc");
             }
 
-            let global_ctxt = abort_on_err(queries.global_ctxt(), sess);
+            let mut global_ctxt = abort_on_err(queries.global_ctxt(), sess);
 
             global_ctxt.enter(|tcx| {
                 let (krate, render_opts, mut cache) = sess.time("run_global_ctxt", || {