Auto merge of #85093 - camelid:remove-fake-expect_local, r=GuillaumeGomez

Remove `FakeDefId::expect_local()`

This function returned a fake `DefIndex`, with no indication that it was
fake, when it was provided with a `FakeDefId::Fake`. Every use of the
function uses the returned `DefIndex` in a call to
`tcx.local_def_id_to_hir_id()`, which I'm pretty sure would panic if it
were given a fake `DefIndex`.

I removed the function and replaced all calls to it with a call to
`expect_real()` followed by `DefId::expect_local()` (that's a function
on the *real* `DefId`).

4 files changed, 17 insertions, 20 deletions

diff --git a/src/librustdoc/clean/types.rs b/src/librustdoc/clean/types.rs
index 9861e838e33..33aa42b137a 100644
--- a/src/librustdoc/clean/types.rs
+++ b/src/librustdoc/clean/types.rs
@@ -18,7 +18,7 @@ use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::thin_vec::ThinVec;
 use rustc_hir as hir;
 use rustc_hir::def::{CtorKind, DefKind, Res};
-use rustc_hir::def_id::{CrateNum, DefId, DefIndex, LocalDefId, CRATE_DEF_INDEX, LOCAL_CRATE};
+use rustc_hir::def_id::{CrateNum, DefId, DefIndex, CRATE_DEF_INDEX, LOCAL_CRATE};
 use rustc_hir::lang_items::LangItem;
 use rustc_hir::{BodyId, Mutability};
 use rustc_index::vec::IndexVec;
@@ -86,22 +86,7 @@ impl FakeDefId {
     }
 
     #[inline]
-    crate fn as_local(self) -> Option<LocalDefId> {
-        match self {
-            FakeDefId::Real(id) => id.as_local(),
-            FakeDefId::Fake(idx, krate) => {
-                (krate == LOCAL_CRATE).then(|| LocalDefId { local_def_index: idx })
-            }
-        }
-    }
-
-    #[inline]
-    crate fn expect_local(self) -> LocalDefId {
-        self.as_local()
-            .unwrap_or_else(|| panic!("FakeDefId::expect_local: `{:?}` isn't local", self))
-    }
-
-    #[inline]
+    #[track_caller]
     crate fn expect_real(self) -> rustc_hir::def_id::DefId {
         self.as_real().unwrap_or_else(|| panic!("FakeDefId::expect_real: `{:?}` isn't real", self))
     }
diff --git a/src/librustdoc/passes/calculate_doc_coverage.rs b/src/librustdoc/passes/calculate_doc_coverage.rs
index c8b82fb1563..e65fcf057f1 100644
--- a/src/librustdoc/passes/calculate_doc_coverage.rs
+++ b/src/librustdoc/passes/calculate_doc_coverage.rs
@@ -213,7 +213,13 @@ impl<'a, 'b> fold::DocFolder for CoverageCalculator<'a, 'b> {
 
                 let filename = i.span(self.ctx.tcx).filename(self.ctx.sess());
                 let has_doc_example = tests.found_tests != 0;
-                let hir_id = self.ctx.tcx.hir().local_def_id_to_hir_id(i.def_id.expect_local());
+                // The `expect_real()` should be okay because `local_def_id_to_hir_id`
+                // would presumably panic if a fake `DefIndex` were passed.
+                let hir_id = self
+                    .ctx
+                    .tcx
+                    .hir()
+                    .local_def_id_to_hir_id(i.def_id.expect_real().expect_local());
                 let (level, source) = self.ctx.tcx.lint_level_at_node(MISSING_DOCS, hir_id);
                 // `missing_docs` is allow-by-default, so don't treat this as ignoring the item
                 // unless the user had an explicit `allow`
diff --git a/src/librustdoc/passes/collect_intra_doc_links.rs b/src/librustdoc/passes/collect_intra_doc_links.rs
index 4317b974735..8838dc57d5a 100644
--- a/src/librustdoc/passes/collect_intra_doc_links.rs
+++ b/src/librustdoc/passes/collect_intra_doc_links.rs
@@ -1207,7 +1207,11 @@ impl LinkCollector<'_, '_> {
             // item can be non-local e.g. when using #[doc(primitive = "pointer")]
             if let Some((src_id, dst_id)) = id
                 .as_local()
-                .and_then(|dst_id| item.def_id.as_local().map(|src_id| (src_id, dst_id)))
+                // The `expect_real()` should be okay because `local_def_id_to_hir_id`
+                // would presumably panic if a fake `DefIndex` were passed.
+                .and_then(|dst_id| {
+                    item.def_id.expect_real().as_local().map(|src_id| (src_id, dst_id))
+                })
             {
                 use rustc_hir::def_id::LOCAL_CRATE;
 
diff --git a/src/librustdoc/passes/doc_test_lints.rs b/src/librustdoc/passes/doc_test_lints.rs
index 7362cfcb71b..ba698474f16 100644
--- a/src/librustdoc/passes/doc_test_lints.rs
+++ b/src/librustdoc/passes/doc_test_lints.rs
@@ -71,7 +71,9 @@ crate fn should_have_doc_example(cx: &DocContext<'_>, item: &clean::Item) -> boo
     {
         return false;
     }
-    let hir_id = cx.tcx.hir().local_def_id_to_hir_id(item.def_id.expect_local());
+    // The `expect_real()` should be okay because `local_def_id_to_hir_id`
+    // would presumably panic if a fake `DefIndex` were passed.
+    let hir_id = cx.tcx.hir().local_def_id_to_hir_id(item.def_id.expect_real().expect_local());
     if cx.tcx.hir().attrs(hir_id).lists(sym::doc).has_word(sym::hidden)
         || inherits_doc_hidden(cx.tcx, hir_id)
     {