Auto merge of #105603 - oli-obk:non_repeatable_queries, r=petrochenkov

Harden the pre-tyctxt query system against accidental recomputation

While the current compiler has no issues where we `take` and then compute the query again, in https://github.com/rust-lang/rust/pull/105462 I accidentally introduced such a case.

I also took the opportunity to remove `peek_mut`, which is only ever used for `global_tcx` to then invoke `enter`. I added an `enter` method directly on the query.

3 files changed, 6 insertions, 9 deletions

diff --git a/src/librustdoc/doctest.rs b/src/librustdoc/doctest.rs
index 81d9c46447a..5f8c777f32a 100644
--- a/src/librustdoc/doctest.rs
+++ b/src/librustdoc/doctest.rs
@@ -115,9 +115,7 @@ pub(crate) fn run(options: RustdocOptions) -> Result<(), ErrorGuaranteed> {
     let (tests, unused_extern_reports, compiling_test_count) =
         interface::run_compiler(config, |compiler| {
             compiler.enter(|queries| {
-                let mut global_ctxt = queries.global_ctxt()?.take();
-
-                let collector = global_ctxt.enter(|tcx| {
+                let collector = queries.global_ctxt()?.enter(|tcx| {
                     let crate_attrs = tcx.hir().attrs(CRATE_HIR_ID);
 
                     let opts = scrape_test_config(crate_attrs);
@@ -156,9 +154,7 @@ pub(crate) fn run(options: RustdocOptions) -> Result<(), ErrorGuaranteed> {
 
                 let unused_extern_reports = collector.unused_extern_reports.clone();
                 let compiling_test_count = collector.compiling_test_count.load(Ordering::SeqCst);
-                let ret: Result<_, ErrorGuaranteed> =
-                    Ok((collector.tests, unused_extern_reports, compiling_test_count));
-                ret
+                Ok((collector.tests, unused_extern_reports, compiling_test_count))
             })
         })?;
 
diff --git a/src/librustdoc/lib.rs b/src/librustdoc/lib.rs
index ef1d7da5a34..ed77de200a9 100644
--- a/src/librustdoc/lib.rs
+++ b/src/librustdoc/lib.rs
@@ -800,7 +800,8 @@ fn main_args(at_args: &[String]) -> MainResult {
             // FIXME(#83761): Resolver cloning can lead to inconsistencies between data in the
             // two copies because one of the copies can be modified after `TyCtxt` construction.
             let (resolver, resolver_caches) = {
-                let (krate, resolver, _) = &*abort_on_err(queries.expansion(), sess).peek();
+                let expansion = abort_on_err(queries.expansion(), sess);
+                let (krate, resolver, _) = &*expansion.borrow();
                 let resolver_caches = resolver.borrow_mut().access(|resolver| {
                     collect_intra_doc_links::early_resolve_intra_doc_links(
                         resolver,
@@ -817,7 +818,7 @@ fn main_args(at_args: &[String]) -> MainResult {
                 sess.fatal("Compilation failed, aborting rustdoc");
             }
 
-            let mut global_ctxt = abort_on_err(queries.global_ctxt(), sess).peek_mut();
+            let global_ctxt = abort_on_err(queries.global_ctxt(), sess);
 
             global_ctxt.enter(|tcx| {
                 let (krate, render_opts, mut cache) = sess.time("run_global_ctxt", || {
diff --git a/src/tools/miri/src/bin/miri.rs b/src/tools/miri/src/bin/miri.rs
index 8c01748613c..6a147de3be2 100644
--- a/src/tools/miri/src/bin/miri.rs
+++ b/src/tools/miri/src/bin/miri.rs
@@ -61,7 +61,7 @@ impl rustc_driver::Callbacks for MiriCompilerCalls {
     ) -> Compilation {
         compiler.session().abort_if_errors();
 
-        queries.global_ctxt().unwrap().peek_mut().enter(|tcx| {
+        queries.global_ctxt().unwrap().enter(|tcx| {
             init_late_loggers(tcx);
             if !tcx.sess.crate_types().contains(&CrateType::Executable) {
                 tcx.sess.fatal("miri only makes sense on bin crates");