Auto merge of #124890 - matthiaskrgr:rollup-25iq88h, r=matthiaskrgr

Rollup of 3 pull requests

Successful merges:

 - #124548 (Handle normalization failure in `struct_tail_erasing_lifetimes`)
 - #124761 (Fix insufficient logic when searching for the underlying allocation)
 - #124864 (rustdoc: use stability, instead of features, to decide what to show)

r? `@ghost`
`@rustbot` modify labels: rollup

9 files changed, 94 insertions, 36 deletions

diff --git a/compiler/rustc_lint/src/reference_casting.rs b/compiler/rustc_lint/src/reference_casting.rs
index 9fed91f7262..63d55a73a98 100644
--- a/compiler/rustc_lint/src/reference_casting.rs
+++ b/compiler/rustc_lint/src/reference_casting.rs
@@ -199,6 +199,13 @@ fn is_cast_to_bigger_memory_layout<'tcx>(
     let e_alloc = cx.expr_or_init(e);
     let e_alloc =
         if let ExprKind::AddrOf(_, _, inner_expr) = e_alloc.kind { inner_expr } else { e_alloc };
+
+    // if the current expr looks like this `&mut expr[index]` then just looking
+    // at `expr[index]` won't give us the underlying allocation, so we just skip it
+    if let ExprKind::Index(..) = e_alloc.kind {
+        return None;
+    }
+
     let alloc_ty = cx.typeck_results().node_type(e_alloc.hir_id);
 
     // if we do not find it we bail out, as this may not be UB
diff --git a/compiler/rustc_middle/src/ty/layout.rs b/compiler/rustc_middle/src/ty/layout.rs
index f8490e5e15f..f17413af777 100644
--- a/compiler/rustc_middle/src/ty/layout.rs
+++ b/compiler/rustc_middle/src/ty/layout.rs
@@ -333,7 +333,22 @@ impl<'tcx> SizeSkeleton<'tcx> {
         match *ty.kind() {
             ty::Ref(_, pointee, _) | ty::RawPtr(pointee, _) => {
                 let non_zero = !ty.is_unsafe_ptr();
-                let tail = tcx.struct_tail_erasing_lifetimes(pointee, param_env);
+
+                let tail = tcx.struct_tail_with_normalize(
+                    pointee,
+                    |ty| match tcx.try_normalize_erasing_regions(param_env, ty) {
+                        Ok(ty) => ty,
+                        Err(_e) => {
+                            if let Some(guar) = tcx.dcx().has_errors() {
+                                Ty::new_error(tcx, guar)
+                            } else {
+                                bug!("normalization failed, but no errors reported");
+                            }
+                        }
+                    },
+                    || {},
+                );
+
                 match tail.kind() {
                     ty::Param(_) | ty::Alias(ty::Projection | ty::Inherent, _) => {
                         debug_assert!(tail.has_non_region_param());
diff --git a/src/librustdoc/clean/inline.rs b/src/librustdoc/clean/inline.rs
index 4d506edc47b..7d8b6f34cbb 100644
--- a/src/librustdoc/clean/inline.rs
+++ b/src/librustdoc/clean/inline.rs
@@ -14,6 +14,7 @@ use rustc_hir::Mutability;
 use rustc_metadata::creader::{CStore, LoadedMacro};
 use rustc_middle::ty::fast_reject::SimplifiedType;
 use rustc_middle::ty::{self, TyCtxt};
+use rustc_span::def_id::LOCAL_CRATE;
 use rustc_span::hygiene::MacroKind;
 use rustc_span::symbol::{kw, sym, Symbol};
 
@@ -444,24 +445,24 @@ pub(crate) fn build_impl(
 
     let associated_trait = tcx.impl_trait_ref(did).map(ty::EarlyBinder::skip_binder);
 
+    // Do not inline compiler-internal items unless we're a compiler-internal crate.
+    let is_compiler_internal = |did| {
+        tcx.lookup_stability(did)
+            .is_some_and(|stab| stab.is_unstable() && stab.feature == sym::rustc_private)
+    };
+    let document_compiler_internal = is_compiler_internal(LOCAL_CRATE.as_def_id());
+    let is_directly_public = |cx: &mut DocContext<'_>, did| {
+        cx.cache.effective_visibilities.is_directly_public(tcx, did)
+            && (document_compiler_internal || !is_compiler_internal(did))
+    };
+
     // Only inline impl if the implemented trait is
     // reachable in rustdoc generated documentation
     if !did.is_local()
         && let Some(traitref) = associated_trait
+        && !is_directly_public(cx, traitref.def_id)
     {
-        let did = traitref.def_id;
-        if !cx.cache.effective_visibilities.is_directly_public(tcx, did) {
-            return;
-        }
-
-        if !tcx.features().rustc_private && !cx.render_options.force_unstable_if_unmarked {
-            if let Some(stab) = tcx.lookup_stability(did)
-                && stab.is_unstable()
-                && stab.feature == sym::rustc_private
-            {
-                return;
-            }
-        }
+        return;
     }
 
     let impl_item = match did.as_local() {
@@ -484,21 +485,11 @@ pub(crate) fn build_impl(
 
     // Only inline impl if the implementing type is
     // reachable in rustdoc generated documentation
-    if !did.is_local() {
-        if let Some(did) = for_.def_id(&cx.cache) {
-            if !cx.cache.effective_visibilities.is_directly_public(tcx, did) {
-                return;
-            }
-
-            if !tcx.features().rustc_private && !cx.render_options.force_unstable_if_unmarked {
-                if let Some(stab) = tcx.lookup_stability(did)
-                    && stab.is_unstable()
-                    && stab.feature == sym::rustc_private
-                {
-                    return;
-                }
-            }
-        }
+    if !did.is_local()
+        && let Some(did) = for_.def_id(&cx.cache)
+        && !is_directly_public(cx, did)
+    {
+        return;
     }
 
     let document_hidden = cx.render_options.document_hidden;
diff --git a/src/librustdoc/config.rs b/src/librustdoc/config.rs
index 465f969435d..d4468fecba4 100644
--- a/src/librustdoc/config.rs
+++ b/src/librustdoc/config.rs
@@ -285,8 +285,6 @@ pub(crate) struct RenderOptions {
     pub(crate) no_emit_shared: bool,
     /// If `true`, HTML source code pages won't be generated.
     pub(crate) html_no_source: bool,
-    /// Whether `-Zforce-unstable-if-unmarked` unstable option is set
-    pub(crate) force_unstable_if_unmarked: bool,
 }
 
 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
@@ -353,7 +351,6 @@ impl Options {
 
         let codegen_options = CodegenOptions::build(early_dcx, matches);
         let unstable_opts = UnstableOptions::build(early_dcx, matches);
-        let force_unstable_if_unmarked = unstable_opts.force_unstable_if_unmarked;
 
         let dcx = new_dcx(error_format, None, diagnostic_width, &unstable_opts);
 
@@ -790,7 +787,6 @@ impl Options {
             call_locations,
             no_emit_shared: false,
             html_no_source,
-            force_unstable_if_unmarked,
         };
         Some((options, render_options))
     }
diff --git a/tests/rustdoc/inline_cross/issue-76736-2.rs b/tests/rustdoc/inline_cross/issue-76736-2.rs
index 83529dd1887..d4e6a697fc8 100644
--- a/tests/rustdoc/inline_cross/issue-76736-2.rs
+++ b/tests/rustdoc/inline_cross/issue-76736-2.rs
@@ -1,6 +1,8 @@
 //@ aux-build:issue-76736-1.rs
 //@ aux-build:issue-76736-2.rs
 
+// https://github.com/rust-lang/rust/issues/124635
+
 #![crate_name = "foo"]
 #![feature(rustc_private)]
 
@@ -8,9 +10,9 @@ extern crate issue_76736_1;
 extern crate issue_76736_2;
 
 // @has foo/struct.Foo.html
-// @has - '//*[@class="impl"]//h3[@class="code-header"]' 'MaybeResult'
+// @!has - '//*[@class="impl"]//h3[@class="code-header"]' 'MaybeResult'
 pub struct Foo;
 
 // @has foo/struct.Bar.html
-// @has - '//*[@class="impl"]//h3[@class="code-header"]' 'MaybeResult'
+// @!has - '//*[@class="impl"]//h3[@class="code-header"]' 'MaybeResult'
 pub use issue_76736_2::Bar;
diff --git a/tests/rustdoc/inline_cross/issue-76736-4.rs b/tests/rustdoc/inline_cross/issue-76736-4.rs
new file mode 100644
index 00000000000..297657ef9de
--- /dev/null
+++ b/tests/rustdoc/inline_cross/issue-76736-4.rs
@@ -0,0 +1,19 @@
+//@ aux-build:issue-76736-1.rs
+//@ aux-build:issue-76736-2.rs
+
+// https://github.com/rust-lang/rust/issues/124635
+
+#![crate_name = "foo"]
+#![feature(rustc_private, staged_api)]
+#![unstable(feature = "rustc_private", issue = "none")]
+
+extern crate issue_76736_1;
+extern crate issue_76736_2;
+
+// @has foo/struct.Foo.html
+// @has - '//*[@class="impl"]//h3[@class="code-header"]' 'MaybeResult'
+pub struct Foo;
+
+// @has foo/struct.Bar.html
+// @has - '//*[@class="impl"]//h3[@class="code-header"]' 'MaybeResult'
+pub use issue_76736_2::Bar;
diff --git a/tests/ui/lint/reference_casting.rs b/tests/ui/lint/reference_casting.rs
index d6897ab7b14..3d0c36ca118 100644
--- a/tests/ui/lint/reference_casting.rs
+++ b/tests/ui/lint/reference_casting.rs
@@ -247,6 +247,14 @@ unsafe fn bigger_layout() {
     unsafe fn from_ref(this: &i32) -> &i64 {
         &*(this as *const i32 as *const i64)
     }
+
+    // https://github.com/rust-lang/rust/issues/124685
+    unsafe fn slice_index(array: &mut [u8], offset: usize) {
+        let a1 = &mut array[offset];
+        let a2 = a1 as *mut u8;
+        let a3 = a2 as *mut u64;
+        unsafe { *a3 = 3 };
+    }
 }
 
 const RAW_PTR: *mut u8 = 1 as *mut u8;
diff --git a/tests/crashes/113272.rs b/tests/ui/structs/ice-struct-tail-normalization-113272.rs
index d161575c657..85d3d1b4886 100644
--- a/tests/crashes/113272.rs
+++ b/tests/ui/structs/ice-struct-tail-normalization-113272.rs
@@ -1,9 +1,10 @@
-//@ known-bug: #113272
 trait Trait {
     type RefTarget;
 }
 
 impl Trait for () where Missing: Trait {}
+//~^ ERROR cannot find type `Missing` in this scope
+//~| ERROR not all trait items implemented, missing: `RefTarget`
 
 struct Other {
     data: <() as Trait>::RefTarget,
diff --git a/tests/ui/structs/ice-struct-tail-normalization-113272.stderr b/tests/ui/structs/ice-struct-tail-normalization-113272.stderr
new file mode 100644
index 00000000000..a205eb80f5c
--- /dev/null
+++ b/tests/ui/structs/ice-struct-tail-normalization-113272.stderr
@@ -0,0 +1,19 @@
+error[E0412]: cannot find type `Missing` in this scope
+  --> $DIR/ice-struct-tail-normalization-113272.rs:5:25
+   |
+LL | impl Trait for () where Missing: Trait {}
+   |                         ^^^^^^^ not found in this scope
+
+error[E0046]: not all trait items implemented, missing: `RefTarget`
+  --> $DIR/ice-struct-tail-normalization-113272.rs:5:1
+   |
+LL |     type RefTarget;
+   |     -------------- `RefTarget` from trait
+...
+LL | impl Trait for () where Missing: Trait {}
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ missing `RefTarget` in implementation
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0046, E0412.
+For more information about an error, try `rustc --explain E0046`.