From 56e17cb31996979b26bb2f25164dfe00365f8aa1 Mon Sep 17 00:00:00 2001
From: sjwang05 <63834813+sjwang05@users.noreply.github.com>
Date: Sun, 9 Aug 2026 21:24:13 -0700
Subject: [PATCH 01/12] equate the assumption's trait ref with the goal's
 directly when considering object bounds

---
 .../src/solve/assembly/mod.rs                 | 41 ++++++++++++++-
 .../src/solve/assembly/structural_traits.rs   |  5 +-
 ...assoc-type-static-lifetime-object-bound.rs | 27 ++++++++++
 ...c-type-static-lifetime-object-bound.stderr | 10 ++++
 .../next-solver/gat-static-in-trait-object.rs | 24 +++++++++
 .../gat-static-in-trait-object.stderr         | 51 +++++++++++++++++++
 ...supertrait-static-lifetime-object-bound.rs | 20 ++++++++
 ...rtrait-static-lifetime-object-bound.stderr | 18 +++++++
 8 files changed, 192 insertions(+), 4 deletions(-)
 create mode 100644 tests/ui/traits/next-solver/assoc-type-static-lifetime-object-bound.rs
 create mode 100644 tests/ui/traits/next-solver/assoc-type-static-lifetime-object-bound.stderr
 create mode 100644 tests/ui/traits/next-solver/gat-static-in-trait-object.rs
 create mode 100644 tests/ui/traits/next-solver/gat-static-in-trait-object.stderr
 create mode 100644 tests/ui/traits/next-solver/supertrait-static-lifetime-object-bound.rs
 create mode 100644 tests/ui/traits/next-solver/supertrait-static-lifetime-object-bound.stderr

diff --git a/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs b/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs
index 040f98de7bcfd..a7a3d5baa50c5 100644
--- a/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs
@@ -85,7 +85,15 @@ where
         goal: Goal<I, Self>,
         assumption: I::Clause,
     ) -> Result<Candidate<I>, NoSolutionOrRerunNonErased> {
-        Self::probe_and_match_goal_against_assumption(ecx, source, goal, assumption, |ecx| {
+        // We inline much of `probe_and_match_goal_against_assumption` and
+        // `TraitPredicate::match_assumption` here, as we never encounter
+        // `Sized` or `MetaSized` goals here, and we need to equate `goal`
+        // and `assumption`'s trait refs directly inside this function in
+        // order to prevent unsoundness (see below).
+
+        Self::fast_reject_assumption(ecx, goal, assumption)?;
+
+        ecx.probe_trait_candidate(source).enter(|ecx| {
             let cx = ecx.cx();
             let ty::Dynamic(bounds, _) = goal.predicate.self_ty().kind() else {
                 panic!("expected object type in `probe_and_consider_object_bound_candidate`");
@@ -106,6 +114,37 @@ where
                 }
             });
 
+            // If we need to prove `dyn for<'x> Trait<'x> + '?temp: Trait<'static>` with
+            //
+            // ```rs
+            // trait Trait<'a>: 'a {}
+            // ```
+            //
+            // we have the goal's trait ref as `Trait<'static>` and a theoretical impl
+            // resembling:
+            //
+            // ```rs
+            // impl<'s, 'hr> Trait<'hr> for dyn for<'x> Trait<'x> + 's
+            // where
+            //     dyn for<'a> Trait<'a> + 's: 'hr
+            // {}
+            // ```
+            //
+            // where 'hr is our bound var. The where-clause elaborates to `'s: 'hr`;
+            // in this case we have 's := '?temp. Instantiating the binder gives us
+            // 'hr := '?infer, and our goal has 'hr := 'static, so we need to equate
+            // the instantiated trait ref to the goal in order to get '?infer := 'static,
+            // since what we want is the constraint `'?temp: 'static`.
+            //
+            // If we instead passed the binder to predicates_for_object_candidate and let
+            // it instantiate the binder itself, we would lose '?infer := 'static, since
+            // predicates_for_object_candidate has no way of equating the trait ref with
+            // the goal. We would simply have 'hr := '?infer, giving us the constraint
+            // `?temp: '?infer`, which is satisfiable for any lifetime, leading to
+            // unsoundness: trait-system-refactor-initiative#295.
+            let trait_ref = ecx.instantiate_binder_with_infer(trait_ref);
+            ecx.eq(goal.param_env, goal.predicate.trait_ref(cx), trait_ref)?;
+
             match structural_traits::predicates_for_object_candidate(
                 ecx,
                 goal.param_env,
diff --git a/compiler/rustc_next_trait_solver/src/solve/assembly/structural_traits.rs b/compiler/rustc_next_trait_solver/src/solve/assembly/structural_traits.rs
index ae78d68865de3..63938c8c60f64 100644
--- a/compiler/rustc_next_trait_solver/src/solve/assembly/structural_traits.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/assembly/structural_traits.rs
@@ -8,7 +8,7 @@ use rustc_type_ir::lang_items::{SolverProjectionLangItem, SolverTraitLangItem};
 use rustc_type_ir::solve::SizedTraitKind;
 use rustc_type_ir::solve::inspect::ProbeKind;
 use rustc_type_ir::{
-    self as ty, Binder, FallibleTypeFolder, Interner, Movability, Mutability, Region, TypeFoldable,
+    self as ty, FallibleTypeFolder, Interner, Movability, Mutability, Region, TypeFoldable,
     TypeSuperFoldable, Unnormalized, Upcast as _, elaborate,
 };
 use rustc_type_ir_macros::{TypeFoldable_Generic, TypeVisitable_Generic};
@@ -889,7 +889,7 @@ pub(in crate::solve) fn const_conditions_for_destruct<I: Interner>(
 pub(in crate::solve) fn predicates_for_object_candidate<D, I>(
     ecx: &mut EvalCtxt<'_, D>,
     param_env: I::ParamEnv,
-    trait_ref: Binder<I, ty::TraitRef<I>>,
+    trait_ref: ty::TraitRef<I>,
     object_bounds: I::BoundExistentialPredicates,
 ) -> Result<Vec<Goal<I, I::Predicate>>, Ambiguous>
 where
@@ -897,7 +897,6 @@ where
     I: Interner,
 {
     let cx = ecx.cx();
-    let trait_ref = ecx.instantiate_binder_with_infer(trait_ref);
     let mut requirements = vec![];
     // Elaborating all supertrait outlives obligations here is not soundness critical,
     // since if we just used the unelaborated set, then the transitive supertraits would
diff --git a/tests/ui/traits/next-solver/assoc-type-static-lifetime-object-bound.rs b/tests/ui/traits/next-solver/assoc-type-static-lifetime-object-bound.rs
new file mode 100644
index 0000000000000..f5ca8c10636a5
--- /dev/null
+++ b/tests/ui/traits/next-solver/assoc-type-static-lifetime-object-bound.rs
@@ -0,0 +1,27 @@
+//! regression test for https://github.com/rust-lang/trait-system-refactor-initiative/issues/295
+
+//@ compile-flags: -Znext-solver
+
+#![forbid(unsafe_code)]
+
+trait Tr<'a> {
+    type A: 'a;
+}
+
+fn f<X: ?Sized + Tr<'static>>(a: <X as Tr<'static>>::A) -> Box<dyn std::any::Any> {
+    Box::new(a)
+}
+
+fn launder<'b>(r: &'b u8) -> &'static u8 {
+    *f::<dyn for<'a> Tr<'a, A = &'b u8>>(r).downcast_ref::<&'static u8>().unwrap()
+    //~^ ERROR lifetime may not live long enough
+}
+
+fn main() {
+    let p;
+    {
+        let x = Box::new(42u8);
+        p = launder(&x);
+    }
+    println!("{}", *p);
+}
diff --git a/tests/ui/traits/next-solver/assoc-type-static-lifetime-object-bound.stderr b/tests/ui/traits/next-solver/assoc-type-static-lifetime-object-bound.stderr
new file mode 100644
index 0000000000000..009091845f85d
--- /dev/null
+++ b/tests/ui/traits/next-solver/assoc-type-static-lifetime-object-bound.stderr
@@ -0,0 +1,10 @@
+error: lifetime may not live long enough
+  --> $DIR/assoc-type-static-lifetime-object-bound.rs:16:6
+   |
+LL | fn launder<'b>(r: &'b u8) -> &'static u8 {
+   |            -- lifetime `'b` defined here
+LL |     *f::<dyn for<'a> Tr<'a, A = &'b u8>>(r).downcast_ref::<&'static u8>().unwrap()
+   |      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ requires that `'b` must outlive `'static`
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/traits/next-solver/gat-static-in-trait-object.rs b/tests/ui/traits/next-solver/gat-static-in-trait-object.rs
new file mode 100644
index 0000000000000..80f3838dc08b6
--- /dev/null
+++ b/tests/ui/traits/next-solver/gat-static-in-trait-object.rs
@@ -0,0 +1,24 @@
+//! regression test from https://github.com/rust-lang/rust/pull/160831/changes#r3852248101
+//! once we allow GATs in object types, we want to make sure this isn't unsound.
+
+//@ compile-flags: -Znext-solver
+
+use std::any::Any;
+
+trait Trait {
+    type Assoc<'a>: 'a;
+}
+
+fn tr<T: Trait>(x: T::Assoc<'static>) -> Box<dyn Any> { Box::new(x) }
+
+fn foo<'s>(x: &'s str) -> Box<dyn Any>
+where
+    dyn for<'hr> Trait<Assoc<'hr> = &'s str>: Trait<Assoc<'static> = &'s str>,
+    //~^ ERROR the trait `Trait` is not dyn compatible
+    //~| ERROR the trait `Trait` is not dyn compatible
+{
+    tr::<dyn for<'hr> Trait<Assoc<'hr> = &'s str>>(x)
+    //~^ ERROR the trait `Trait` is not dyn compatible
+}
+
+fn main() {}
diff --git a/tests/ui/traits/next-solver/gat-static-in-trait-object.stderr b/tests/ui/traits/next-solver/gat-static-in-trait-object.stderr
new file mode 100644
index 0000000000000..ed27a81cc0be5
--- /dev/null
+++ b/tests/ui/traits/next-solver/gat-static-in-trait-object.stderr
@@ -0,0 +1,51 @@
+error[E0038]: the trait `Trait` is not dyn compatible
+  --> $DIR/gat-static-in-trait-object.rs:16:47
+   |
+LL |     dyn for<'hr> Trait<Assoc<'hr> = &'s str>: Trait<Assoc<'static> = &'s str>,
+   |                                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `Trait` is not dyn compatible
+   |
+note: for a trait to be dyn compatible it needs to allow building a vtable
+      for more information, visit <https://doc.rust-lang.org/reference/items/traits.html#dyn-compatibility>
+  --> $DIR/gat-static-in-trait-object.rs:9:10
+   |
+LL | trait Trait {
+   |       ----- this trait is not dyn compatible...
+LL |     type Assoc<'a>: 'a;
+   |          ^^^^^ ...because it contains generic associated type `Assoc`
+   = help: consider moving `Assoc` to another trait
+
+error[E0038]: the trait `Trait` is not dyn compatible
+  --> $DIR/gat-static-in-trait-object.rs:16:53
+   |
+LL |     dyn for<'hr> Trait<Assoc<'hr> = &'s str>: Trait<Assoc<'static> = &'s str>,
+   |                                                     ^^^^^^^^^^^^^^^^^^^^^^^^ `Trait` is not dyn compatible
+   |
+note: for a trait to be dyn compatible it needs to allow building a vtable
+      for more information, visit <https://doc.rust-lang.org/reference/items/traits.html#dyn-compatibility>
+  --> $DIR/gat-static-in-trait-object.rs:9:10
+   |
+LL | trait Trait {
+   |       ----- this trait is not dyn compatible...
+LL |     type Assoc<'a>: 'a;
+   |          ^^^^^ ...because it contains generic associated type `Assoc`
+   = help: consider moving `Assoc` to another trait
+
+error[E0038]: the trait `Trait` is not dyn compatible
+  --> $DIR/gat-static-in-trait-object.rs:20:14
+   |
+LL |     tr::<dyn for<'hr> Trait<Assoc<'hr> = &'s str>>(x)
+   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `Trait` is not dyn compatible
+   |
+note: for a trait to be dyn compatible it needs to allow building a vtable
+      for more information, visit <https://doc.rust-lang.org/reference/items/traits.html#dyn-compatibility>
+  --> $DIR/gat-static-in-trait-object.rs:9:10
+   |
+LL | trait Trait {
+   |       ----- this trait is not dyn compatible...
+LL |     type Assoc<'a>: 'a;
+   |          ^^^^^ ...because it contains generic associated type `Assoc`
+   = help: consider moving `Assoc` to another trait
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0038`.
diff --git a/tests/ui/traits/next-solver/supertrait-static-lifetime-object-bound.rs b/tests/ui/traits/next-solver/supertrait-static-lifetime-object-bound.rs
new file mode 100644
index 0000000000000..b52b1c6cfcbb7
--- /dev/null
+++ b/tests/ui/traits/next-solver/supertrait-static-lifetime-object-bound.rs
@@ -0,0 +1,20 @@
+//! regression test for https://github.com/rust-lang/trait-system-refactor-initiative/issues/295
+
+//@ compile-flags: -Znext-solver
+
+#![forbid(unsafe_code)]
+
+trait Trait<'a>: 'a {}
+
+fn g<'s>(s: &'s String) -> &'static String
+where
+    dyn for<'x> Trait<'x> + 's: Trait<'static>,
+{
+    s
+}
+
+fn main() {
+    let r = g(&String::from("freed"));
+    //~^ ERROR temporary value dropped while borrowed
+    println!("{r}");
+}
diff --git a/tests/ui/traits/next-solver/supertrait-static-lifetime-object-bound.stderr b/tests/ui/traits/next-solver/supertrait-static-lifetime-object-bound.stderr
new file mode 100644
index 0000000000000..9463785a7da15
--- /dev/null
+++ b/tests/ui/traits/next-solver/supertrait-static-lifetime-object-bound.stderr
@@ -0,0 +1,18 @@
+error[E0716]: temporary value dropped while borrowed
+  --> $DIR/supertrait-static-lifetime-object-bound.rs:17:16
+   |
+LL |     let r = g(&String::from("freed"));
+   |             ---^^^^^^^^^^^^^^^^^^^^^-- temporary value is freed at the end of this statement
+   |             |  |
+   |             |  creates a temporary value which is freed while still in use
+   |             argument requires that borrow lasts for `'static`
+   |
+note: requirement that the value outlives `'static` introduced here
+  --> $DIR/supertrait-static-lifetime-object-bound.rs:11:33
+   |
+LL |     dyn for<'x> Trait<'x> + 's: Trait<'static>,
+   |                                 ^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0716`.

From 2c09a80e4fdf2ed01b3c64126b585f1fb542e76a Mon Sep 17 00:00:00 2001
From: bjorn3 <17426603+bjorn3@users.noreply.github.com>
Date: Tue, 8 Sep 2026 13:30:06 +0200
Subject: [PATCH 02/12] Merge commit 'db693f7dbcfab9af2a89b703096f692417e2f756'
 into sync_cg_clif-2026-09-08

---
 .github/workflows/freebsd.yml                 |  3 -
 Cargo.lock                                    | 77 +++++++++---------
 Cargo.toml                                    | 24 +++---
 Readme.md                                     |  3 +-
 build_system/build_sysroot.rs                 |  1 -
 example/mini_core_hello_world.rs              |  1 -
 ...0027-stdlib-128bit-atomic-operations.patch | 81 ++++++-------------
 rust-toolchain.toml                           |  2 +-
 scripts/test_rustc_tests.sh                   |  3 +
 src/constant.rs                               | 44 +---------
 src/debuginfo/unwind.rs                       |  2 +-
 src/lib.rs                                    |  2 +
 12 files changed, 85 insertions(+), 158 deletions(-)

diff --git a/.github/workflows/freebsd.yml b/.github/workflows/freebsd.yml
index f344113aa7fdf..e0b2bd34631f9 100644
--- a/.github/workflows/freebsd.yml
+++ b/.github/workflows/freebsd.yml
@@ -34,8 +34,5 @@ jobs:
             # Disabling incr comp reduces cache size and incr comp doesn't save
             # as much on CI anyway.
             export CARGO_BUILD_INCREMENTAL=false
-            # FIXME(rust-lang/rust#134863) necessary to avoid error when
-            # dlopening proc macros during compilation of cg_clif.
-            export LD_STATIC_TLS_EXTRA=4096
             # Skip rand as it fails on FreeBSD due to rust-random/rand#1355
             ./y.sh test --skip-test test.rust-random/rand
diff --git a/Cargo.lock b/Cargo.lock
index 88ea75a6b0299..80bbbfe4e9bc1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -43,27 +43,27 @@ checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
 
 [[package]]
 name = "cranelift-assembler-x64"
-version = "0.134.0"
+version = "0.135.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a25c5b1bb1d86ae68dca1826a1b668b9951056c42e0eef89e35942c7001eb481"
+checksum = "a4a59ddc4abd9c5560f4742864b2cd8c19e73c7263f0c866b2c45c2d31587adc"
 dependencies = [
  "cranelift-assembler-x64-meta",
 ]
 
 [[package]]
 name = "cranelift-assembler-x64-meta"
-version = "0.134.0"
+version = "0.135.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c1b052a1fd94b4565697c56f9d358723c7c354feef42a6569081225c1bed6e86"
+checksum = "8a8c361cd22fd0fdd8e61af6bfd86ad9c0c62f78b2b1caa2b9e4e97cd8f605fe"
 dependencies = [
  "cranelift-srcgen",
 ]
 
 [[package]]
 name = "cranelift-bforest"
-version = "0.134.0"
+version = "0.135.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a599e8ffa6a1a118d2dce4809073ad2f2534b1ae1c6d55697b6b8a324446c971"
+checksum = "b86c34ae183cf2410318f899648fe1ef6ab9148486e7b938d7b4d814e61dafc9"
 dependencies = [
  "cranelift-entity",
  "wasmtime-internal-core",
@@ -71,18 +71,18 @@ dependencies = [
 
 [[package]]
 name = "cranelift-bitset"
-version = "0.134.0"
+version = "0.135.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1e1ae13182fadc731b1387287b4c6d257b9191fbb7c980ebb2d74c2db74b743e"
+checksum = "415f1a12668869e16ac3b66a729fb8cce8bbe6e50e68d1fa0142acd0c9c05f0c"
 dependencies = [
  "wasmtime-internal-core",
 ]
 
 [[package]]
 name = "cranelift-codegen"
-version = "0.134.0"
+version = "0.135.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dce9c62e5e11d12f4a8f5f939f29899f32002d38193b47491e2539705a1d447e"
+checksum = "73eecedc85ffca4f34dbe197c6545c8ade6579a61352457936f53c3bffa6353b"
 dependencies = [
  "bumpalo",
  "cranelift-assembler-x64",
@@ -107,9 +107,9 @@ dependencies = [
 
 [[package]]
 name = "cranelift-codegen-meta"
-version = "0.134.0"
+version = "0.135.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3c29d6b53cfd758dc1a269310fc92199056db03943b9b774b4911cd615e02ad7"
+checksum = "66834005198c3e9e3d89cd69cf1541419402ab75250afbeaa3128db6d5254025"
 dependencies = [
  "cranelift-assembler-x64-meta",
  "cranelift-codegen-shared",
@@ -119,24 +119,24 @@ dependencies = [
 
 [[package]]
 name = "cranelift-codegen-shared"
-version = "0.134.0"
+version = "0.135.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8cd8cfe23f3349bfa62e06a450cd94cf5f84fbe78556f4df3276534c4b93d834"
+checksum = "7e6efaf74077091a2ff41317cc8eb2779264dae4b8a16d955835f3fcda338f52"
 
 [[package]]
 name = "cranelift-control"
-version = "0.134.0"
+version = "0.135.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f991b4712f21d9502758f7e6cb11746ca2e6186b06c42995eaf31b1e50a9c498"
+checksum = "a4258d4ed6ad4e698fe1fec4277b1fcbea6f2a17cb5ec3f04bddfb38ca83d93e"
 dependencies = [
  "arbitrary",
 ]
 
 [[package]]
 name = "cranelift-entity"
-version = "0.134.0"
+version = "0.135.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5e24f9c233a43730e22cf42ab0c03f41265e147eca97b3362be01e0da359d7a5"
+checksum = "4f016b6f87b1a46a3f5df59b82d88bb352bf2fa6d7868875dfc4d6b65de5242d"
 dependencies = [
  "cranelift-bitset",
  "wasmtime-internal-core",
@@ -144,9 +144,9 @@ dependencies = [
 
 [[package]]
 name = "cranelift-frontend"
-version = "0.134.0"
+version = "0.135.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "61325401051d35ddbf8e2b5d5b5dec8dd54688c9054046b62e76146e61c88a99"
+checksum = "b16f2b149dae6ea3886bee931445196d86d8e71b66f7c3b21abe434f77189be8"
 dependencies = [
  "cranelift-codegen",
  "hashbrown 0.17.0",
@@ -157,15 +157,15 @@ dependencies = [
 
 [[package]]
 name = "cranelift-isle"
-version = "0.134.0"
+version = "0.135.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "62f71d642812aa70284750719efbd2cc5ad7e7c5e6c43c026b5b0686ce8a6052"
+checksum = "f00258ff3d37f52ed731df679205e66175c728846dbde186ee20e93973d12ee7"
 
 [[package]]
 name = "cranelift-jit"
-version = "0.134.0"
+version = "0.135.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "92a0f9300c8a5738553a440fe4f25b85f574d5c41b946880dabd47c809f87997"
+checksum = "fa063cc98af51fb9090cd40b674503e21bdfa705d2bff75ebf98b79ffc0f598d"
 dependencies = [
  "anyhow",
  "cranelift-codegen",
@@ -184,9 +184,9 @@ dependencies = [
 
 [[package]]
 name = "cranelift-module"
-version = "0.134.0"
+version = "0.135.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5f723983af35e690c4e2fc160df5d8895bb4a419a54d693367163d781bd830cc"
+checksum = "bff0025f1ff6a0470cbd2a61b125f8501311ea9e6c46ed5bb2110ee6710c6a76"
 dependencies = [
  "anyhow",
  "cranelift-codegen",
@@ -195,9 +195,9 @@ dependencies = [
 
 [[package]]
 name = "cranelift-native"
-version = "0.134.0"
+version = "0.135.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b5c50cffac70c30cc5d0b1d8d287e7712dc76b1181c43697de63d27f38236ddd"
+checksum = "4f31eb7e08f31e5bc9c167c35718b0325efa3d4e234e2e9342316e01b18a4b51"
 dependencies = [
  "cranelift-codegen",
  "libc",
@@ -206,9 +206,9 @@ dependencies = [
 
 [[package]]
 name = "cranelift-object"
-version = "0.134.0"
+version = "0.135.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "430e18f4886ba98f6a7dbb82c86df19f28f27cac417611e5dcc427a7a8decac9"
+checksum = "7ca0d86955529d5b9041c4c07745f6ffa42c32326e9f467a834e2b7bd9a9d156"
 dependencies = [
  "anyhow",
  "cranelift-codegen",
@@ -221,9 +221,9 @@ dependencies = [
 
 [[package]]
 name = "cranelift-srcgen"
-version = "0.134.0"
+version = "0.135.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bc5972dc0a5df7ba6f11e8e1654287c40ea1704ca6ce3b76ef54fa58445ee4ad"
+checksum = "2e0b67d313f510520f40c1496c3446af0d6b30219d1ba9a4c09c77ec288a561b"
 
 [[package]]
 name = "crc32fast"
@@ -379,9 +379,9 @@ dependencies = [
 
 [[package]]
 name = "regalloc2"
-version = "0.15.1"
+version = "0.15.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "de2c52737737f8609e94f975dee22854a2d5c125772d4b1cf292120f4d45c186"
+checksum = "757712e8e61590d6d4f5d563483755538b5aa13467837a3b41cd9832509a7f85"
 dependencies = [
  "allocator-api2",
  "bumpalo",
@@ -493,9 +493,9 @@ checksum = "9312f7c4f6ff9069b165498234ce8be658059c6728633667c526e27dc2cf1df5"
 
 [[package]]
 name = "wasmtime-internal-core"
-version = "47.0.0"
+version = "48.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "852f3326264aea590131a422e3ecb33fae3b6695fd67e2e202e2799cd8d27629"
+checksum = "2c01c81d781512e17b38c3a76ca9aa2564bc3f9fd8ff6ffc77ba3e1c290d488a"
 dependencies = [
  "hashbrown 0.17.0",
  "libm",
@@ -503,11 +503,10 @@ dependencies = [
 
 [[package]]
 name = "wasmtime-internal-jit-icache-coherence"
-version = "47.0.0"
+version = "48.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e537f59b5ab127ca2d421ecbd8728d70bd6cdc9891cec193fb1f594c3309836c"
+checksum = "2a09abde04346919af1136a28f344e200685509e28815aef4c39dc08977cc1d8"
 dependencies = [
- "cfg-if",
  "libc",
  "wasmtime-internal-core",
  "windows-sys 0.61.2",
diff --git a/Cargo.toml b/Cargo.toml
index cb595332bac61..ca03be20cd100 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,12 +8,12 @@ crate-type = ["dylib"]
 
 [dependencies]
 # These have to be in sync with each other
-cranelift-codegen = { version = "0.134.0", default-features = false, features = ["std", "timing", "unwind", "all-native-arch"] }
-cranelift-frontend = { version = "0.134.0" }
-cranelift-module = { version = "0.134.0" }
-cranelift-native = { version = "0.134.0" }
-cranelift-jit = { version = "0.134.0", optional = true }
-cranelift-object = { version = "0.134.0", default-features = false }
+cranelift-codegen = { version = "0.135.0", default-features = false, features = ["std", "timing", "unwind", "all-native-arch"] }
+cranelift-frontend = { version = "0.135.0" }
+cranelift-module = { version = "0.135.0" }
+cranelift-native = { version = "0.135.0" }
+cranelift-jit = { version = "0.135.0", optional = true }
+cranelift-object = { version = "0.135.0", default-features = false }
 target-lexicon = "0.13"
 gimli = { version = "0.33", default-features = false, features = ["write"] }
 object = { version = "0.39.1", default-features = false, features = ["std", "read_core", "write", "archive", "coff", "elf", "macho", "pe"] }
@@ -24,12 +24,12 @@ smallvec = "1.8.1"
 
 # Uncomment to use an unreleased version of cranelift
 #[patch.crates-io]
-#cranelift-codegen = { git = "https://github.com/bytecodealliance/wasmtime.git", branch = "release-47.0.0" }
-#cranelift-frontend = { git = "https://github.com/bytecodealliance/wasmtime.git", branch = "release-47.0.0" }
-#cranelift-module = { git = "https://github.com/bytecodealliance/wasmtime.git", branch = "release-47.0.0" }
-#cranelift-native = { git = "https://github.com/bytecodealliance/wasmtime.git", branch = "release-47.0.0" }
-#cranelift-jit = { git = "https://github.com/bytecodealliance/wasmtime.git", branch = "release-47.0.0" }
-#cranelift-object = { git = "https://github.com/bytecodealliance/wasmtime.git", branch = "release-47.0.0" }
+#cranelift-codegen = { git = "https://github.com/bytecodealliance/wasmtime.git", branch = "release-48.0.0" }
+#cranelift-frontend = { git = "https://github.com/bytecodealliance/wasmtime.git", branch = "release-48.0.0" }
+#cranelift-module = { git = "https://github.com/bytecodealliance/wasmtime.git", branch = "release-48.0.0" }
+#cranelift-native = { git = "https://github.com/bytecodealliance/wasmtime.git", branch = "release-48.0.0" }
+#cranelift-jit = { git = "https://github.com/bytecodealliance/wasmtime.git", branch = "release-48.0.0" }
+#cranelift-object = { git = "https://github.com/bytecodealliance/wasmtime.git", branch = "release-48.0.0" }
 
 # Uncomment to use local checkout of cranelift
 #cranelift-codegen = { path = "../wasmtime/cranelift/codegen" }
diff --git a/Readme.md b/Readme.md
index c5436cf67c80a..48003ad270e6f 100644
--- a/Readme.md
+++ b/Readme.md
@@ -66,7 +66,7 @@ For more docs on how to build and test see [build_system/usage.txt](build_system
 |OS \ architecture|x86\_64|AArch64|Riscv64|s390x (System-Z)|
 |---|---|---|---|---|
 |Linux|✅|✅|✅[^no-rustup]|✅[^no-rustup]|
-|FreeBSD|✅[^no-rustup][^tls]|❓|❓|❓|
+|FreeBSD|✅[^no-rustup]|❓|❓|❓|
 |AIX|❌[^xcoff]|N/A|N/A|❌[^xcoff]|
 |Other unixes|❓|❓|❓|❓|
 |macOS|✅|✅|N/A|N/A|
@@ -80,7 +80,6 @@ Not all targets are available as rustup component for nightly. See notes in the
 
 [^xcoff]: XCOFF object file format is not supported.
 [^no-rustup]: Not available as [rustup component for nightly](https://rust-lang.github.io/rustup-components-history/). You can build it yourself.
-[^tls]: FreeBSD requires setting `LD_STATIC_TLS_EXTRA=4096` to build cg_clif. In addition you need at least FreeBSD 14.
 
 ## Usage
 
diff --git a/build_system/build_sysroot.rs b/build_system/build_sysroot.rs
index 71c0523615ff1..3ac7724f8f318 100644
--- a/build_system/build_sysroot.rs
+++ b/build_system/build_sysroot.rs
@@ -252,7 +252,6 @@ fn build_clif_sysroot_for_target(
     build_cmd.arg("--features").arg("backtrace panic-unwind");
     build_cmd.arg(format!("-Zroot-dir={}", STDLIB_SRC.to_path(dirs).display()));
     build_cmd.arg("-Zembed-metadata=no");
-    build_cmd.arg("-Zbuild-dir-new-layout");
     build_cmd.env("CARGO_PROFILE_RELEASE_DEBUG", "true");
     build_cmd.env("__CARGO_DEFAULT_LIB_METADATA", "cg_clif");
     if compiler.target.contains("apple") {
diff --git a/example/mini_core_hello_world.rs b/example/mini_core_hello_world.rs
index 5e986201b385c..9a710caae9cd1 100644
--- a/example/mini_core_hello_world.rs
+++ b/example/mini_core_hello_world.rs
@@ -1,7 +1,6 @@
 #![feature(
     no_core,
     lang_items,
-    never_type,
     extern_types,
     thread_local,
     repr_simd,
diff --git a/patches/0027-stdlib-128bit-atomic-operations.patch b/patches/0027-stdlib-128bit-atomic-operations.patch
index 2268ff9cb266e..f821099e68f88 100644
--- a/patches/0027-stdlib-128bit-atomic-operations.patch
+++ b/patches/0027-stdlib-128bit-atomic-operations.patch
@@ -5,83 +5,54 @@ Subject: [PATCH] Disable 128bit atomic operations
 
 Cranelift doesn't support them yet
 ---
- library/core/src/panic/unwind_safe.rs |  6 -----
- library/core/src/sync/atomic.rs       | 38 ---------------------------
- 2 files changed, 44 deletions(-)
+ library/core/src/panic/unwind_safe.rs | 4 ++--
+ library/core/src/sync/atomic.rs       | 4 ++--
+ 2 files changed, 4 insertions(+), 4 deletions(-)
 
 diff --git a/library/core/src/panic/unwind_safe.rs b/library/core/src/panic/unwind_safe.rs
-index a60f0799c0e..af056fbf41f 100644
+index bf2e61d..cb82b07 100644
 --- a/library/core/src/panic/unwind_safe.rs
 +++ b/library/core/src/panic/unwind_safe.rs
-@@ -216,9 +216,6 @@ impl RefUnwindSafe for crate::sync::atomic::AtomicI32 {}
+@@ -217,7 +217,7 @@ impl RefUnwindSafe for crate::sync::atomic::AtomicI32 {}
  #[cfg(target_has_atomic_load_store = "64")]
  #[stable(feature = "integer_atomics_stable", since = "1.34.0")]
  impl RefUnwindSafe for crate::sync::atomic::AtomicI64 {}
 -#[cfg(target_has_atomic_load_store = "128")]
--#[unstable(feature = "integer_atomics", issue = "99069")]
--impl RefUnwindSafe for crate::sync::atomic::AtomicI128 {}
++#[cfg(false)]
+ #[unstable(feature = "integer_atomics", issue = "99069")]
+ impl RefUnwindSafe for crate::sync::atomic::AtomicI128 {}
  
- #[cfg(target_has_atomic_load_store = "ptr")]
- #[stable(feature = "unwind_safe_atomic_refs", since = "1.14.0")]
-@@ -235,9 +232,6 @@ impl RefUnwindSafe for crate::sync::atomic::AtomicU32 {}
+@@ -236,7 +236,7 @@ impl RefUnwindSafe for crate::sync::atomic::AtomicU32 {}
  #[cfg(target_has_atomic_load_store = "64")]
  #[stable(feature = "integer_atomics_stable", since = "1.34.0")]
  impl RefUnwindSafe for crate::sync::atomic::AtomicU64 {}
 -#[cfg(target_has_atomic_load_store = "128")]
--#[unstable(feature = "integer_atomics", issue = "99069")]
--impl RefUnwindSafe for crate::sync::atomic::AtomicU128 {}
++#[cfg(false)]
+ #[unstable(feature = "integer_atomics", issue = "99069")]
+ impl RefUnwindSafe for crate::sync::atomic::AtomicU128 {}
  
- #[cfg(target_has_atomic_load_store = "8")]
- #[stable(feature = "unwind_safe_atomic_refs", since = "1.14.0")]
 diff --git a/library/core/src/sync/atomic.rs b/library/core/src/sync/atomic.rs
-index 8a9a0b5..92ed9a6 100644
+index e676a38..b6a9a3c 100644
 --- a/library/core/src/sync/atomic.rs
 +++ b/library/core/src/sync/atomic.rs
-@@ -3762,44 +3757,6 @@ atomic_int! {
+@@ -3850,7 +3850,7 @@ atomic_int! {
      8,
      u64 AtomicU64
  }
 -#[cfg(any(target_has_atomic_load_store = "128", doc))]
--atomic_int! {
--    target_has_atomic_load_store = "128",
--    target_has_atomic = "128",
--    target_has_atomic_primitive_alignment = "128",
--    unstable(feature = "integer_atomics", issue = "99069"),
--    unstable(feature = "integer_atomics", issue = "99069"),
--    unstable(feature = "integer_atomics", issue = "99069"),
--    unstable(feature = "integer_atomics", issue = "99069"),
--    unstable(feature = "integer_atomics", issue = "99069"),
--    unstable(feature = "integer_atomics", issue = "99069"),
--    rustc_const_unstable(feature = "integer_atomics", issue = "99069"),
--    rustc_const_unstable(feature = "integer_atomics", issue = "99069"),
--    "i128",
--    "#![feature(integer_atomics)]\n\n",
--    atomic_min, atomic_max,
--    16,
--    i128 AtomicI128
--}
++#[cfg(false)]
+ atomic_int! {
+     target_has_atomic_load_store = "128",
+     target_has_atomic = "128",
+@@ -3869,7 +3869,7 @@ atomic_int! {
+     16,
+     i128 AtomicI128
+ }
 -#[cfg(any(target_has_atomic_load_store = "128", doc))]
--atomic_int! {
--    target_has_atomic_load_store = "128",
--    target_has_atomic = "128",
--    target_has_atomic_primitive_alignment = "128",
--    unstable(feature = "integer_atomics", issue = "99069"),
--    unstable(feature = "integer_atomics", issue = "99069"),
--    unstable(feature = "integer_atomics", issue = "99069"),
--    unstable(feature = "integer_atomics", issue = "99069"),
--    unstable(feature = "integer_atomics", issue = "99069"),
--    unstable(feature = "integer_atomics", issue = "99069"),
--    rustc_const_unstable(feature = "integer_atomics", issue = "99069"),
--    rustc_const_unstable(feature = "integer_atomics", issue = "99069"),
--    "u128",
--    "#![feature(integer_atomics)]\n\n",
--    atomic_umin, atomic_umax,
--    16,
--    u128 AtomicU128
--}
- 
- #[cfg(target_has_atomic_load_store = "ptr")]
- macro_rules! atomic_int_ptr_sized {
++#[cfg(false)]
+ atomic_int! {
+     target_has_atomic_load_store = "128",
+     target_has_atomic = "128",
 -- 
 2.48.1
 
diff --git a/rust-toolchain.toml b/rust-toolchain.toml
index ea4ff67c93c89..bc8bfacba1923 100644
--- a/rust-toolchain.toml
+++ b/rust-toolchain.toml
@@ -1,4 +1,4 @@
 [toolchain]
-channel = "nightly-2026-08-19"
+channel = "nightly-2026-09-08"
 components = ["rust-src", "rustc-dev", "llvm-tools", "rustfmt"]
 profile = "minimal"
diff --git a/scripts/test_rustc_tests.sh b/scripts/test_rustc_tests.sh
index 3885561e94a1e..5a1374fe56e09 100755
--- a/scripts/test_rustc_tests.sh
+++ b/scripts/test_rustc_tests.sh
@@ -138,6 +138,7 @@ rm -r tests/run-make/panic-impl-transitive
 rm tests/ui/debuginfo/debuginfo-emit-llvm-ir-and-split-debuginfo.rs
 rm tests/ui/statics/issue-91050-1.rs
 rm tests/ui/statics/issue-91050-2.rs
+rm -r tests/run-make/locate-panic-runtime
 
 # giving different but possibly correct results
 # =============================================
@@ -157,6 +158,7 @@ rm -r tests/run-make/strip # same
 rm -r tests/run-make-cargo/compiler-builtins # Expects lib/rustlib/src/rust to contains the standard library source
 rm -r tests/run-make-cargo/panic-immediate-abort-works # same
 rm -r tests/run-make-cargo/panic-immediate-abort-codegen # same
+rm -r tests/run-make-cargo/panic-strategies # same
 rm -r tests/run-make/missing-unstable-trait-bound # This disables support for unstable features, but running cg_clif needs some unstable features
 rm -r tests/run-make/const-trait-stable-toolchain # same
 rm -r tests/run-make/print-request-help-stable-unstable # same
@@ -174,6 +176,7 @@ rm tests/ui/process/println-with-broken-pipe.rs # same
 rm -r tests/run-make/extern-fn-explicit-align # argument alignment not yet supported
 rm -r tests/run-make/panic-abort-eh_frame # .eh_frame emitted with panic=abort
 rm -r tests/run-make/used-proc-macro # doesn't work on arm64 for some reason
+rm tests/ui/async-await/async-drop/async-drop-async-gen-return-pending.rs # rustc side fnsig issue
 
 # bugs in the test suite
 # ======================
diff --git a/src/constant.rs b/src/constant.rs
index b1cb5f30cbdfe..e2b0035361733 100644
--- a/src/constant.rs
+++ b/src/constant.rs
@@ -415,49 +415,7 @@ fn define_all_allocs(tcx: TyCtxt<'_>, module: &mut dyn Module, cx: &mut Constant
         data.set_align(alloc.align.bytes());
 
         if let Some(section_name) = section_name {
-            let (segment_name, section_name) = if tcx.sess.target.is_like_darwin {
-                // See https://github.com/llvm/llvm-project/blob/main/llvm/lib/MC/MCSectionMachO.cpp
-                let mut parts = section_name.as_str().split(',');
-                let Some(segment_name) = parts.next() else {
-                    tcx.dcx().fatal(format!(
-                        "#[link_section = \"{}\"] is not valid for macos target: must be segment and section separated by comma",
-                        section_name
-                    ));
-                };
-                let Some(section_name) = parts.next() else {
-                    tcx.dcx().fatal(format!(
-                        "#[link_section = \"{}\"] is not valid for macos target: must be segment and section separated by comma",
-                        section_name
-                    ));
-                };
-                if section_name.len() > 16 {
-                    tcx.dcx().fatal(format!(
-                        "#[link_section = \"{}\"] is not valid for macos target: section name bigger than 16 bytes",
-                        section_name
-                    ));
-                }
-                let section_type = parts.next().unwrap_or("regular");
-                if section_type != "regular" && section_type != "cstring_literals" {
-                    tcx.dcx().fatal(format!(
-                        "#[link_section = \"{}\"] is not supported: unsupported section type {}",
-                        section_name, section_type,
-                    ));
-                }
-                let _attrs = parts.next();
-                if parts.next().is_some() {
-                    tcx.dcx().fatal(format!(
-                        "#[link_section = \"{}\"] is not valid for macos target: too many components",
-                        section_name
-                    ));
-                }
-                // FIXME(bytecodealliance/wasmtime#8901) set S_CSTRING_LITERALS section type when
-                // cstring_literals is specified
-                (segment_name, section_name)
-            } else {
-                ("", section_name.as_str())
-            };
-            // FIXME pass correct section flags on Mach-O
-            data.set_segment_section(segment_name, section_name, 0);
+            data.set_custom_section(section_name.as_str());
         }
 
         let bytes = alloc.inspect_with_uninit_and_ptr_outside_interpreter(0..alloc.len()).to_vec();
diff --git a/src/debuginfo/unwind.rs b/src/debuginfo/unwind.rs
index 4b0260a8abc74..ad0a15bf7f6e5 100644
--- a/src/debuginfo/unwind.rs
+++ b/src/debuginfo/unwind.rs
@@ -204,7 +204,7 @@ impl UnwindContext {
 
                     let mut data = DataDescription::new();
                     data.define(gcc_except_table.writer.into_vec().into_boxed_slice());
-                    data.set_segment_section("", ".gcc_except_table", 0);
+                    data.set_custom_section(".gcc_except_table");
 
                     for reloc in &gcc_except_table.relocs {
                         match reloc.name {
diff --git a/src/lib.rs b/src/lib.rs
index 71fce9e28f120..6d2a353745235 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -23,6 +23,8 @@ extern crate rustc_index;
 extern crate rustc_log;
 extern crate rustc_session;
 extern crate rustc_span;
+#[cfg(feature = "jit")]
+extern crate rustc_structures;
 extern crate rustc_symbol_mangling;
 extern crate rustc_target;
 

From 26800a4dda0c2cefea63d656bafcc4084e7ee532 Mon Sep 17 00:00:00 2001
From: bjorn3 <17426603+bjorn3@users.noreply.github.com>
Date: Wed, 9 Sep 2026 12:47:02 +0200
Subject: [PATCH 03/12] Pass -Zforce-unstable-if-unmarked to cg_clif tests

This makes their test environment consistent between runs inside the
cg_clif and rust repos.
---
 build_system/tests.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/build_system/tests.rs b/build_system/tests.rs
index c7b61f519d247..5ae76dc1e591e 100644
--- a/build_system/tests.rs
+++ b/build_system/tests.rs
@@ -478,6 +478,8 @@ impl<'a> TestRunner<'a> {
         cmd.arg("--check-cfg=cfg(jit)");
         cmd.arg("--check-cfg=cfg(target_has_reliable_f128)");
         cmd.arg("--edition=2024");
+        // implicitly passed when building inside the rust repo
+        cmd.arg("-Zforce-unstable-if-unmarked");
         cmd.args(args);
         cmd
     }

From 54b751d55a2e2748171c0ba761ae9006552cbe88 Mon Sep 17 00:00:00 2001
From: bjorn3 <17426603+bjorn3@users.noreply.github.com>
Date: Mon, 17 Aug 2026 17:15:59 +0200
Subject: [PATCH 04/12] Remove emit_almost_fatal

A fatal error that doesn't actually abort is indistinguishable from a
regular error. And the only places where emit_almost_fatal is called,
the produced FatalError is ignored.
---
 compiler/rustc_codegen_llvm/src/intrinsic.rs | 10 ++---
 compiler/rustc_errors/src/diagnostic.rs      |  7 ---
 compiler/rustc_errors/src/lib.rs             | 46 +++++++-------------
 3 files changed, 20 insertions(+), 43 deletions(-)

diff --git a/compiler/rustc_codegen_llvm/src/intrinsic.rs b/compiler/rustc_codegen_llvm/src/intrinsic.rs
index 1844a8e5c0bca..743145a0e5baf 100644
--- a/compiler/rustc_codegen_llvm/src/intrinsic.rs
+++ b/compiler/rustc_codegen_llvm/src/intrinsic.rs
@@ -231,11 +231,11 @@ impl<'ll, 'tcx> IntrinsicCallBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> {
             }
             sym::offload => {
                 if tcx.sess.opts.unstable_opts.offload.is_empty() {
-                    let _ = tcx.dcx().emit_almost_fatal(OffloadWithoutEnable);
+                    let _ = tcx.dcx().emit_err(OffloadWithoutEnable);
                 }
 
                 if tcx.sess.lto() != rustc_session::config::Lto::Fat {
-                    let _ = tcx.dcx().emit_almost_fatal(OffloadWithoutFatLTO);
+                    let _ = tcx.dcx().emit_err(OffloadWithoutFatLTO);
                 }
 
                 codegen_offload(self, tcx, instance, args);
@@ -1752,18 +1752,18 @@ fn codegen_autodiff<'ll, 'tcx>(
 ) -> IntrinsicResult<'tcx, &'ll Value> {
     let tcx = bx.tcx;
     if !tcx.sess.opts.unstable_opts.autodiff.contains(&rustc_session::config::AutoDiff::Enable) {
-        let _ = tcx.dcx().emit_almost_fatal(AutoDiffWithoutEnable);
+        let _ = tcx.dcx().emit_err(AutoDiffWithoutEnable);
     }
 
     let ct = tcx.crate_types();
     let lto = tcx.sess.lto();
     if ct.len() == 1 && ct.contains(&CrateType::Executable) {
         if lto != rustc_session::config::Lto::Fat {
-            let _ = tcx.dcx().emit_almost_fatal(AutoDiffWithoutLto);
+            let _ = tcx.dcx().emit_err(AutoDiffWithoutLto);
         }
     } else {
         if lto != rustc_session::config::Lto::Fat && !tcx.sess.opts.cg.linker_plugin_lto.enabled() {
-            let _ = tcx.dcx().emit_almost_fatal(AutoDiffWithoutLto);
+            let _ = tcx.dcx().emit_err(AutoDiffWithoutLto);
         }
     }
 
diff --git a/compiler/rustc_errors/src/diagnostic.rs b/compiler/rustc_errors/src/diagnostic.rs
index d1dc3ab6e9525..caba9e55edcc3 100644
--- a/compiler/rustc_errors/src/diagnostic.rs
+++ b/compiler/rustc_errors/src/diagnostic.rs
@@ -73,13 +73,6 @@ impl EmissionGuarantee for FatalAbort {
     }
 }
 
-impl EmissionGuarantee for rustc_span::fatal_error::FatalError {
-    fn emit_producing_guarantee(diag: Diag<'_, Self>) -> Self::EmitResult {
-        diag.emit_producing_nothing();
-        rustc_span::fatal_error::FatalError
-    }
-}
-
 /// Trait implemented by error types. This is rarely implemented manually. Instead, use
 /// `#[derive(Diagnostic)]` -- see [rustc_macros::Diagnostic].
 ///
diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
index f868b11ea6fd2..146eef4096f17 100644
--- a/compiler/rustc_errors/src/lib.rs
+++ b/compiler/rustc_errors/src/lib.rs
@@ -1026,19 +1026,6 @@ impl<'a> DiagCtxtHandle<'a> {
         self.create_fatal(fatal).emit()
     }
 
-    #[track_caller]
-    pub fn create_almost_fatal(
-        self,
-        fatal: impl Diagnostic<'a, FatalError>,
-    ) -> Diag<'a, FatalError> {
-        fatal.into_diag(self, Fatal)
-    }
-
-    #[track_caller]
-    pub fn emit_almost_fatal(self, fatal: impl Diagnostic<'a, FatalError>) -> FatalError {
-        self.create_almost_fatal(fatal).emit()
-    }
-
     // FIXME: This method should be removed (every error should have an associated error code).
     #[track_caller]
     pub fn struct_err(self, msg: impl Into<DiagMessage>) -> Diag<'a> {
@@ -1582,24 +1569,21 @@ impl DelayedDiagInner {
     }
 }
 
-/// | Level        | is_error | EmissionGuarantee            | Top-level | Sub | Used in lints?
-/// | -----        | -------- | -----------------            | --------- | --- | --------------
-/// | Bug          | yes      | BugAbort                     | yes       | -   | -
-/// | Fatal        | yes      | FatalAbort/FatalError[^star] | yes       | -   | -
-/// | Error        | yes      | ErrorGuaranteed              | yes       | -   | yes
-/// | DelayedBug   | yes      | ErrorGuaranteed              | yes       | -   | -
-/// | ForceWarning | -        | ()                           | yes       | -   | lint-only
-/// | Warning      | -        | ()                           | yes       | yes | yes
-/// | Note         | -        | ()                           | rare      | yes | -
-/// | OnceNote     | -        | ()                           | -         | yes | lint-only
-/// | Help         | -        | ()                           | rare      | yes | -
-/// | OnceHelp     | -        | ()                           | -         | yes | lint-only
-/// | FailureNote  | -        | ()                           | rare      | -   | -
-/// | Allow        | -        | ()                           | yes       | -   | lint-only
-/// | Expect       | -        | ()                           | yes       | -   | lint-only
-///
-/// [^star]: `FatalAbort` normally, `FatalError` in the non-aborting "almost fatal" case that is
-///     occasionally used.
+/// | Level        | is_error | EmissionGuarantee | Top-level | Sub | Used in lints?
+/// | -----        | -------- | ----------------- | --------- | --- | --------------
+/// | Bug          | yes      | BugAbort          | yes       | -   | -
+/// | Fatal        | yes      | FatalAbort        | yes       | -   | -
+/// | Error        | yes      | ErrorGuaranteed   | yes       | -   | yes
+/// | DelayedBug   | yes      | ErrorGuaranteed   | yes       | -   | -
+/// | ForceWarning | -        | ()                | yes       | -   | lint-only
+/// | Warning      | -        | ()                | yes       | yes | yes
+/// | Note         | -        | ()                | rare      | yes | -
+/// | OnceNote     | -        | ()                | -         | yes | lint-only
+/// | Help         | -        | ()                | rare      | yes | -
+/// | OnceHelp     | -        | ()                | -         | yes | lint-only
+/// | FailureNote  | -        | ()                | rare      | -   | -
+/// | Allow        | -        | ()                | yes       | -   | lint-only
+/// | Expect       | -        | ()                | yes       | -   | lint-only
 ///
 #[derive(Copy, PartialEq, Eq, Clone, Hash, Debug, Encodable, Decodable)]
 pub enum Level {

From 8b71848ed47f0f4f9e041bff45e4ca0aeb11c4a5 Mon Sep 17 00:00:00 2001
From: bjorn3 <17426603+bjorn3@users.noreply.github.com>
Date: Mon, 17 Aug 2026 17:47:40 +0200
Subject: [PATCH 05/12] Avoid fatal errors in raw-dylib handling

---
 compiler/rustc_metadata/src/native_libs.rs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/compiler/rustc_metadata/src/native_libs.rs b/compiler/rustc_metadata/src/native_libs.rs
index 87e0902b1f7f8..eff464bcfc526 100644
--- a/compiler/rustc_metadata/src/native_libs.rs
+++ b/compiler/rustc_metadata/src/native_libs.rs
@@ -274,7 +274,8 @@ impl<'tcx> Collector<'tcx> {
                     DllCallingConvention::Vectorcall(self.i686_arg_list_size(item))
                 }
                 _ => {
-                    self.tcx.dcx().emit_fatal(diagnostics::RawDylibUnsupportedAbi { span });
+                    self.tcx.dcx().emit_err(diagnostics::RawDylibUnsupportedAbi { span });
+                    return None;
                 }
             }
         } else {
@@ -283,7 +284,8 @@ impl<'tcx> Collector<'tcx> {
                     DllCallingConvention::C
                 }
                 _ => {
-                    self.tcx.dcx().emit_fatal(diagnostics::RawDylibUnsupportedAbi { span });
+                    self.tcx.dcx().emit_err(diagnostics::RawDylibUnsupportedAbi { span });
+                    return None;
                 }
             }
         };

From d9e75ad87ca8e084700e2b83fa7ec7f69d0b9f43 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mateusz=20Miku=C5=82a?= <oss@mateuszmikula.dev>
Date: Wed, 9 Sep 2026 13:29:37 +0200
Subject: [PATCH 06/12] Fix run-make/prune-link-args to work with MinGW

The explanation provided was wrong. Libc doesn't exist on Windows, so
naturally this failed on missing lib. I have no idea what shenanigans
link.exe does to make this pass, but surely it doesn't actually link
libc.
---
 tests/run-make/prune-link-args/rmake.rs | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/tests/run-make/prune-link-args/rmake.rs b/tests/run-make/prune-link-args/rmake.rs
index ea4ffa732bf3f..6702984d2e85a 100644
--- a/tests/run-make/prune-link-args/rmake.rs
+++ b/tests/run-make/prune-link-args/rmake.rs
@@ -6,12 +6,10 @@
 // See https://github.com/rust-lang/rust/pull/10749
 
 //@ ignore-cross-compile
-//@ ignore-windows-gnu
-// Reason: The space is parsed as an empty linker argument on windows-gnu.
 
 use run_make_support::rustc;
 
 fn main() {
-    // Notice the space at the end of -lc, which emulates the output of pkg-config.
-    rustc().arg("-Clink-args=-lc ").input("empty.rs").run();
+    // Notice the space at the end of -lm, which emulates the output of pkg-config.
+    rustc().arg("-Clink-args=-lm ").input("empty.rs").run();
 }

From 910f84c5c78003cef02e3b2ce9634472249ee9f0 Mon Sep 17 00:00:00 2001
From: Jonathan Brouwer <jonathantbrouwer@gmail.com>
Date: Wed, 9 Sep 2026 22:37:11 +0200
Subject: [PATCH 07/12] Attemped fix for home dir problem

---
 src/ci/scripts/disable-git-crlf-conversion.sh | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/ci/scripts/disable-git-crlf-conversion.sh b/src/ci/scripts/disable-git-crlf-conversion.sh
index 6de080a9fde00..856c2fa03700e 100755
--- a/src/ci/scripts/disable-git-crlf-conversion.sh
+++ b/src/ci/scripts/disable-git-crlf-conversion.sh
@@ -10,4 +10,8 @@
 set -euo pipefail
 IFS=$'\n\t'
 
+# Workaround for issue where the home dir of `msys64` sometimes doesn't exist on github runners
+echo $HOME
+mkdir -p $HOME
+
 git config --replace-all --global core.autocrlf false

From 88db34ad12223f211786050877bb6005cfcaa1e6 Mon Sep 17 00:00:00 2001
From: Jonas Berlin <xkr47@xkr47-nitor-lap3.local>
Date: Thu, 10 Sep 2026 08:49:25 +0300
Subject: [PATCH 08/12] doc: Fix external mention of signum() return value
 regarding NaNs

---
 library/core/src/num/f128.rs | 4 ++--
 library/core/src/num/f16.rs  | 4 ++--
 library/core/src/num/f32.rs  | 4 ++--
 library/core/src/num/f64.rs  | 4 ++--
 4 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/library/core/src/num/f128.rs b/library/core/src/num/f128.rs
index 93dd52198f488..db05d7fdc5087 100644
--- a/library/core/src/num/f128.rs
+++ b/library/core/src/num/f128.rs
@@ -594,7 +594,7 @@ impl f128 {
     /// conserved over arithmetic operations, the result of `is_sign_positive` on
     /// a NaN might produce an unexpected or non-portable result. See the [specification
     /// of NaN bit patterns](f32#nan-bit-patterns) for more info. Use `self.signum() == 1.0`
-    /// if you need fully portable behavior (will return `false` for all NaNs).
+    /// if you need fully portable behavior (will return NaN for all NaNs).
     ///
     /// ```
     /// #![feature(f128)]
@@ -620,7 +620,7 @@ impl f128 {
     /// conserved over arithmetic operations, the result of `is_sign_negative` on
     /// a NaN might produce an unexpected or non-portable result. See the [specification
     /// of NaN bit patterns](f32#nan-bit-patterns) for more info. Use `self.signum() == -1.0`
-    /// if you need fully portable behavior (will return `false` for all NaNs).
+    /// if you need fully portable behavior (will return NaN for all NaNs).
     ///
     /// ```
     /// #![feature(f128)]
diff --git a/library/core/src/num/f16.rs b/library/core/src/num/f16.rs
index cb79c0736c608..273ef3688ca5f 100644
--- a/library/core/src/num/f16.rs
+++ b/library/core/src/num/f16.rs
@@ -588,7 +588,7 @@ impl f16 {
     /// conserved over arithmetic operations, the result of `is_sign_positive` on
     /// a NaN might produce an unexpected or non-portable result. See the [specification
     /// of NaN bit patterns](f32#nan-bit-patterns) for more info. Use `self.signum() == 1.0`
-    /// if you need fully portable behavior (will return `false` for all NaNs).
+    /// if you need fully portable behavior (will return NaN for all NaNs).
     ///
     /// ```
     /// #![feature(f16)]
@@ -616,7 +616,7 @@ impl f16 {
     /// conserved over arithmetic operations, the result of `is_sign_negative` on
     /// a NaN might produce an unexpected or non-portable result. See the [specification
     /// of NaN bit patterns](f32#nan-bit-patterns) for more info. Use `self.signum() == -1.0`
-    /// if you need fully portable behavior (will return `false` for all NaNs).
+    /// if you need fully portable behavior (will return NaN for all NaNs).
     ///
     /// ```
     /// #![feature(f16)]
diff --git a/library/core/src/num/f32.rs b/library/core/src/num/f32.rs
index 8a02aa7517474..d3dea38dc2fcf 100644
--- a/library/core/src/num/f32.rs
+++ b/library/core/src/num/f32.rs
@@ -811,7 +811,7 @@ impl f32 {
     /// conserved over arithmetic operations, the result of `is_sign_positive` on
     /// a NaN might produce an unexpected or non-portable result. See the [specification
     /// of NaN bit patterns](f32#nan-bit-patterns) for more info. Use `self.signum() == 1.0`
-    /// if you need fully portable behavior (will return `false` for all NaNs).
+    /// if you need fully portable behavior (will return NaN for all NaNs).
     ///
     /// ```
     /// let f = 7.0_f32;
@@ -836,7 +836,7 @@ impl f32 {
     /// conserved over arithmetic operations, the result of `is_sign_negative` on
     /// a NaN might produce an unexpected or non-portable result. See the [specification
     /// of NaN bit patterns](f32#nan-bit-patterns) for more info. Use `self.signum() == -1.0`
-    /// if you need fully portable behavior (will return `false` for all NaNs).
+    /// if you need fully portable behavior (will return NaN for all NaNs).
     ///
     /// ```
     /// let f = 7.0f32;
diff --git a/library/core/src/num/f64.rs b/library/core/src/num/f64.rs
index e0bb0e35415b6..7c5082749cd11 100644
--- a/library/core/src/num/f64.rs
+++ b/library/core/src/num/f64.rs
@@ -810,7 +810,7 @@ impl f64 {
     /// conserved over arithmetic operations, the result of `is_sign_positive` on
     /// a NaN might produce an unexpected or non-portable result. See the [specification
     /// of NaN bit patterns](f32#nan-bit-patterns) for more info. Use `self.signum() == 1.0`
-    /// if you need fully portable behavior (will return `false` for all NaNs).
+    /// if you need fully portable behavior (will return NaN for all NaNs).
     ///
     /// ```
     /// let f = 7.0_f64;
@@ -835,7 +835,7 @@ impl f64 {
     /// conserved over arithmetic operations, the result of `is_sign_negative` on
     /// a NaN might produce an unexpected or non-portable result. See the [specification
     /// of NaN bit patterns](f32#nan-bit-patterns) for more info. Use `self.signum() == -1.0`
-    /// if you need fully portable behavior (will return `false` for all NaNs).
+    /// if you need fully portable behavior (will return NaN for all NaNs).
     ///
     /// ```
     /// let f = 7.0_f64;

From 052ee70292daaccd4fa5b383a4784ee730f9cc6e Mon Sep 17 00:00:00 2001
From: bjorn3 <17426603+bjorn3@users.noreply.github.com>
Date: Mon, 31 Aug 2026 12:56:40 +0200
Subject: [PATCH 09/12] Don't rely on codegen emitting fn_abi_of_* errors in
 abi checks

This avoids a delayed bug if compilation is aborted between checking
function ABIs and codegening all functions.
---
 .../rustc_codegen_cranelift/src/common.rs     | 21 ++------
 compiler/rustc_codegen_gcc/src/context.rs     | 23 ++------
 compiler/rustc_codegen_llvm/src/context.rs    | 22 ++------
 compiler/rustc_middle/src/ty/layout.rs        | 26 ++++++++-
 .../src/mono_checks/abi_check.rs              | 53 ++++++++++++++-----
 tests/crashes/152204.rs                       |  9 ----
 tests/ui/abi/no_delayed_bug.rs                | 15 ++++++
 tests/ui/abi/no_delayed_bug.stderr            | 11 ++++
 tests/ui/limits/issue-17913.32bit.stderr      |  5 +-
 tests/ui/limits/issue-17913.64bit.stderr      |  5 +-
 tests/ui/limits/issue-17913.rs                |  1 +
 11 files changed, 111 insertions(+), 80 deletions(-)
 delete mode 100644 tests/crashes/152204.rs
 create mode 100644 tests/ui/abi/no_delayed_bug.rs
 create mode 100644 tests/ui/abi/no_delayed_bug.stderr

diff --git a/compiler/rustc_codegen_cranelift/src/common.rs b/compiler/rustc_codegen_cranelift/src/common.rs
index 1bdb3efefa1aa..d31c8fc810b2c 100644
--- a/compiler/rustc_codegen_cranelift/src/common.rs
+++ b/compiler/rustc_codegen_cranelift/src/common.rs
@@ -5,8 +5,9 @@ use rustc_index::IndexVec;
 use rustc_middle::ty::TypeFoldable;
 use rustc_middle::ty::layout::{
     self, FnAbiError, FnAbiOfHelpers, FnAbiRequest, LayoutError, LayoutOfHelpers,
+    codegen_handle_fn_abi_err,
 };
-use rustc_span::{Spanned, Symbol};
+use rustc_span::Symbol;
 use rustc_target::callconv::FnAbi;
 use rustc_target::spec::{Arch, HasTargetSpec, Target};
 
@@ -453,23 +454,7 @@ impl<'tcx> FnAbiOfHelpers<'tcx> for FullyMonomorphizedLayoutCx<'tcx> {
         span: Span,
         fn_abi_request: FnAbiRequest<'tcx>,
     ) -> ! {
-        if let FnAbiError::Layout(LayoutError::SizeOverflow(_) | LayoutError::InvalidSimd { .. }) =
-            err
-        {
-            self.0.sess.dcx().emit_fatal(Spanned { span, node: err })
-        } else {
-            match fn_abi_request {
-                FnAbiRequest::OfFnPtr { sig, extra_args } => {
-                    span_bug!(span, "`fn_abi_of_fn_ptr({sig}, {extra_args:?})` failed: {err:?}");
-                }
-                FnAbiRequest::OfInstance { instance, extra_args } => {
-                    span_bug!(
-                        span,
-                        "`fn_abi_of_instance({instance}, {extra_args:?})` failed: {err:?}"
-                    );
-                }
-            }
-        }
+        codegen_handle_fn_abi_err(self.0, err, span, fn_abi_request).raise_fatal()
     }
 }
 
diff --git a/compiler/rustc_codegen_gcc/src/context.rs b/compiler/rustc_codegen_gcc/src/context.rs
index 19fbe37c27b9e..64f9982ac7de6 100644
--- a/compiler/rustc_codegen_gcc/src/context.rs
+++ b/compiler/rustc_codegen_gcc/src/context.rs
@@ -10,16 +10,15 @@ use rustc_data_structures::base_n::{ALPHANUMERIC_ONLY, ToBaseN};
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_middle::mir::interpret::Allocation;
 use rustc_middle::mono::CodegenUnit;
-use rustc_middle::span_bug;
 use rustc_middle::ty::layout::{
     FnAbiError, FnAbiOf, FnAbiOfHelpers, FnAbiRequest, HasTyCtxt, HasTypingEnv, LayoutError,
-    LayoutOfHelpers,
+    LayoutOfHelpers, codegen_handle_fn_abi_err,
 };
 use rustc_middle::ty::{self, ExistentialTraitRef, Instance, Ty, TyCtxt};
 #[cfg(feature = "master")]
 use rustc_session::config::DebugInfo;
 use rustc_session::{PointerAuthSchema, Session};
-use rustc_span::{DUMMY_SP, Span, Symbol, respan};
+use rustc_span::{DUMMY_SP, Span, Symbol};
 use rustc_target::spec::{HasTargetSpec, HasX86AbiOpt, Target, TlsModel, X86Abi};
 
 #[cfg(feature = "master")]
@@ -562,23 +561,7 @@ impl<'gcc, 'tcx> FnAbiOfHelpers<'tcx> for CodegenCx<'gcc, 'tcx> {
         span: Span,
         fn_abi_request: FnAbiRequest<'tcx>,
     ) -> ! {
-        if let FnAbiError::Layout(LayoutError::SizeOverflow(_) | LayoutError::InvalidSimd { .. }) =
-            err
-        {
-            self.tcx.dcx().emit_fatal(respan(span, err))
-        } else {
-            match fn_abi_request {
-                FnAbiRequest::OfFnPtr { sig, extra_args } => {
-                    span_bug!(span, "`fn_abi_of_fn_ptr({sig}, {extra_args:?})` failed: {err:?}");
-                }
-                FnAbiRequest::OfInstance { instance, extra_args } => {
-                    span_bug!(
-                        span,
-                        "`fn_abi_of_instance({instance}, {extra_args:?})` failed: {err:?}"
-                    );
-                }
-            }
-        }
+        codegen_handle_fn_abi_err(self.tcx, err, span, fn_abi_request).raise_fatal()
     }
 }
 
diff --git a/compiler/rustc_codegen_llvm/src/context.rs b/compiler/rustc_codegen_llvm/src/context.rs
index 9e127edbd2ff9..3b58a7f00146b 100644
--- a/compiler/rustc_codegen_llvm/src/context.rs
+++ b/compiler/rustc_codegen_llvm/src/context.rs
@@ -14,18 +14,19 @@ use rustc_data_structures::base_n::{ALPHANUMERIC_ONLY, ToBaseN};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::small_c_str::SmallCStr;
 use rustc_hir::def_id::DefId;
+use rustc_middle::bug;
 use rustc_middle::mono::CodegenUnit;
 use rustc_middle::ty::layout::{
     FnAbiError, FnAbiOfHelpers, FnAbiRequest, HasTypingEnv, LayoutError, LayoutOfHelpers,
+    codegen_handle_fn_abi_err,
 };
 use rustc_middle::ty::{self, Instance, Ty, TyCtxt};
-use rustc_middle::{bug, span_bug};
 use rustc_sanitizers::ignorelist::{SanitizerIgnoreList, typename_for_ignore_list};
 use rustc_session::config::{
     BranchProtection, CFGuard, CFProtection, DebugInfo, FunctionReturn, PAuthKey, PacRet,
 };
 use rustc_session::{PointerAuthSchema, Session};
-use rustc_span::{DUMMY_SP, Span, Spanned, Symbol, sym};
+use rustc_span::{DUMMY_SP, Span, Symbol, sym};
 use rustc_structures::CrateType;
 use rustc_target::spec::{
     Arch, CfgAbi, Env, FramePointer, HasTargetSpec, Os, RelocModel, SmallDataThresholdSupport,
@@ -1316,21 +1317,6 @@ impl<'tcx> FnAbiOfHelpers<'tcx> for CodegenCx<'_, 'tcx> {
         span: Span,
         fn_abi_request: FnAbiRequest<'tcx>,
     ) -> ! {
-        match err {
-            FnAbiError::Layout(LayoutError::SizeOverflow(_) | LayoutError::InvalidSimd { .. }) => {
-                self.tcx.dcx().emit_fatal(Spanned { span, node: err });
-            }
-            _ => match fn_abi_request {
-                FnAbiRequest::OfFnPtr { sig, extra_args } => {
-                    span_bug!(span, "`fn_abi_of_fn_ptr({sig}, {extra_args:?})` failed: {err:?}",);
-                }
-                FnAbiRequest::OfInstance { instance, extra_args } => {
-                    span_bug!(
-                        span,
-                        "`fn_abi_of_instance({instance}, {extra_args:?})` failed: {err:?}",
-                    );
-                }
-            },
-        }
+        codegen_handle_fn_abi_err(self.tcx, err, span, fn_abi_request).raise_fatal()
     }
 }
diff --git a/compiler/rustc_middle/src/ty/layout.rs b/compiler/rustc_middle/src/ty/layout.rs
index c18bf81121377..85e1df8b057a0 100644
--- a/compiler/rustc_middle/src/ty/layout.rs
+++ b/compiler/rustc_middle/src/ty/layout.rs
@@ -14,7 +14,7 @@ use rustc_hir::attrs::lang_items::LangItem;
 use rustc_hir::def_id::DefId;
 use rustc_macros::{StableHash, TyDecodable, TyEncodable, extension};
 use rustc_session::config::OptLevel;
-use rustc_span::{DUMMY_SP, ErrorGuaranteed, Span, Symbol, sym};
+use rustc_span::{DUMMY_SP, ErrorGuaranteed, Span, Spanned, Symbol, sym};
 use rustc_structures::Limit;
 use rustc_target::callconv::FnAbi;
 use rustc_target::spec::{HasTargetSpec, HasX86AbiOpt, Target, X86Abi};
@@ -1374,6 +1374,8 @@ pub trait FnAbiOfHelpers<'tcx>: LayoutOfHelpers<'tcx> {
     /// but this hook allows e.g. codegen to return only `&FnAbi` from its
     /// `cx.fn_abi_of_*(...)`, without any `Result<...>` around it to deal with
     /// (and any `FnAbiError`s are turned into fatal errors or ICEs).
+    ///
+    /// Codegen backends should use [`codegen_handle_fn_abi_err`] as implementation.
     fn handle_fn_abi_err(
         &self,
         err: FnAbiError<'tcx>,
@@ -1382,6 +1384,28 @@ pub trait FnAbiOfHelpers<'tcx>: LayoutOfHelpers<'tcx> {
     ) -> <Self::FnAbiOfResult as MaybeResult<&'tcx FnAbi<'tcx, Ty<'tcx>>>>::Error;
 }
 
+/// Implementation of [`FnAbiOfHelpers::handle_fn_abi_err`] for codegen backends.
+pub fn codegen_handle_fn_abi_err<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    err: FnAbiError<'tcx>,
+    span: Span,
+    fn_abi_request: FnAbiRequest<'tcx>,
+) -> ErrorGuaranteed {
+    match err {
+        FnAbiError::Layout(LayoutError::SizeOverflow(_) | LayoutError::InvalidSimd { .. }) => {
+            tcx.dcx().emit_err(Spanned { span, node: err })
+        }
+        _ => match fn_abi_request {
+            FnAbiRequest::OfFnPtr { sig, extra_args } => {
+                span_bug!(span, "`fn_abi_of_fn_ptr({sig}, {extra_args:?})` failed: {err:?}",);
+            }
+            FnAbiRequest::OfInstance { instance, extra_args } => {
+                span_bug!(span, "`fn_abi_of_instance({instance}, {extra_args:?})` failed: {err:?}",);
+            }
+        },
+    }
+}
+
 /// Blanket extension trait for contexts that can compute `FnAbi`s.
 pub trait FnAbiOf<'tcx>: FnAbiOfHelpers<'tcx> {
     /// Compute a `FnAbi` suitable for indirect calls, i.e. to `fn` pointers.
diff --git a/compiler/rustc_monomorphize/src/mono_checks/abi_check.rs b/compiler/rustc_monomorphize/src/mono_checks/abi_check.rs
index 885ad6071d91c..1ba48e6829070 100644
--- a/compiler/rustc_monomorphize/src/mono_checks/abi_check.rs
+++ b/compiler/rustc_monomorphize/src/mono_checks/abi_check.rs
@@ -3,6 +3,7 @@
 use rustc_abi::{BackendRepr, CanonAbi, ExternAbi, RegKind, X86Call};
 use rustc_hir::{CRATE_HIR_ID, HirId};
 use rustc_middle::mir::{self, Location, traversal};
+use rustc_middle::ty::layout::{FnAbiRequest, codegen_handle_fn_abi_err};
 use rustc_middle::ty::{self, Instance, InstanceKind, Ty, TyCtxt};
 use rustc_span::def_id::DefId;
 use rustc_span::{DUMMY_SP, Span, Symbol, sym};
@@ -173,12 +174,19 @@ fn check_instance_abi<'tcx>(tcx: TyCtxt<'tcx>, instance: Instance<'tcx>) {
         // LLVM intrinsics
         return;
     }
-    let Ok(abi) = tcx.fn_abi_of_instance(typing_env.as_query_input((instance, ty::List::empty())))
-    else {
-        // An error will be reported during codegen if we cannot determine the ABI of this
-        // function.
-        tcx.dcx().delayed_bug("ABI computation failure should lead to compilation failure");
-        return;
+    let abi = match tcx.fn_abi_of_instance(typing_env.as_query_input((instance, ty::List::empty())))
+    {
+        Ok(abi) => abi,
+        Err(err) => {
+            codegen_handle_fn_abi_err(
+                tcx,
+                *err,
+                tcx.def_span(instance.def_id()),
+                FnAbiRequest::OfInstance { instance, extra_args: ty::List::empty() },
+            );
+            // ABI failed to compute; this will not get through codegen.
+            return;
+        }
     };
     // Unlike the call-site check, we do also check "Rust" ABI functions here. This can actually
     // trigger due to scalable vectors being require for the "Rust" ABI for some types.
@@ -214,7 +222,20 @@ fn check_call_site_abi<'tcx>(
     let typing_env = ty::TypingEnv::fully_monomorphized();
     let callee_abi = match *callee.kind() {
         ty::FnPtr(..) => {
-            tcx.fn_abi_of_fn_ptr(typing_env.as_query_input((callee.fn_sig(tcx), ty::List::empty())))
+            let sig = callee.fn_sig(tcx);
+            match tcx.fn_abi_of_fn_ptr(typing_env.as_query_input((sig, ty::List::empty()))) {
+                Ok(callee_abi) => callee_abi,
+                Err(err) => {
+                    codegen_handle_fn_abi_err(
+                        tcx,
+                        *err,
+                        loc().0,
+                        FnAbiRequest::OfFnPtr { sig, extra_args: ty::List::empty() },
+                    );
+                    // ABI failed to compute; this will not get through codegen.
+                    return;
+                }
+            }
         }
         ty::FnDef(def_id, args) => {
             // Intrinsics are handled separately by the compiler.
@@ -232,17 +253,25 @@ fn check_call_site_abi<'tcx>(
                 // LLVM intrinsics don't have an ABI, so there is nothing to check.
                 return;
             }
-            tcx.fn_abi_of_instance(typing_env.as_query_input((instance, ty::List::empty())))
+            match tcx.fn_abi_of_instance(typing_env.as_query_input((instance, ty::List::empty()))) {
+                Ok(callee_abi) => callee_abi,
+                Err(err) => {
+                    codegen_handle_fn_abi_err(
+                        tcx,
+                        *err,
+                        loc().0,
+                        FnAbiRequest::OfInstance { instance, extra_args: ty::List::empty() },
+                    );
+                    // ABI failed to compute; this will not get through codegen.
+                    return;
+                }
+            }
         }
         _ => {
             panic!("Invalid function call");
         }
     };
 
-    let Ok(callee_abi) = callee_abi else {
-        // ABI failed to compute; this will not get through codegen.
-        return;
-    };
     do_check_unsized_params(tcx, callee_abi, /*is_call*/ true, loc);
     do_check_simd_vector_abi(tcx, callee_abi, caller.def_id(), /*is_call*/ true, loc);
 }
diff --git a/tests/crashes/152204.rs b/tests/crashes/152204.rs
deleted file mode 100644
index 8c9be213d9ea5..0000000000000
--- a/tests/crashes/152204.rs
+++ /dev/null
@@ -1,9 +0,0 @@
-//@ known-bug: #152204
-//@ compile-flags: -Copt-level=0
-#![feature(portable_simd)]
-
-fn main() {
-    if false {
-        let _ = core::simd::Simd::<u8, 256>::splat(0);
-    }
-}
diff --git a/tests/ui/abi/no_delayed_bug.rs b/tests/ui/abi/no_delayed_bug.rs
new file mode 100644
index 0000000000000..9b378ba9d25a7
--- /dev/null
+++ b/tests/ui/abi/no_delayed_bug.rs
@@ -0,0 +1,15 @@
+// Used to ICE due to the ABI checker emitting a delayed bug when failing to get
+// the FnAbi due to a const assert, while codegen skipped the call due to being
+// unreachable.
+//@ compile-flags: -Copt-level=0
+//@ build-fail
+
+//~? ERROR the SIMD type `Simd<u8, 256>` has more elements than the limit 64
+
+#![feature(portable_simd)]
+
+fn main() {
+    if false {
+        let _ = core::simd::Simd::<u8, 256>::splat(0);
+    }
+}
diff --git a/tests/ui/abi/no_delayed_bug.stderr b/tests/ui/abi/no_delayed_bug.stderr
new file mode 100644
index 0000000000000..c21256b86a6c4
--- /dev/null
+++ b/tests/ui/abi/no_delayed_bug.stderr
@@ -0,0 +1,11 @@
+error: the SIMD type `Simd<u8, 256>` has more elements than the limit 64
+  --> $SRC_DIR/core/src/../../portable-simd/crates/core_simd/src/vector.rs:LL:COL
+
+note: the above error was encountered while instantiating `fn Simd::<u8, 256>::splat`
+  --> $DIR/no_delayed_bug.rs:13:17
+   |
+LL |         let _ = core::simd::Simd::<u8, 256>::splat(0);
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/limits/issue-17913.32bit.stderr b/tests/ui/limits/issue-17913.32bit.stderr
index 1e3e3a9f32295..6ddde4b891836 100644
--- a/tests/ui/limits/issue-17913.32bit.stderr
+++ b/tests/ui/limits/issue-17913.32bit.stderr
@@ -1,3 +1,6 @@
+error: values of the type `[&usize; usize::MAX]` are too big for the target architecture
+  --> $SRC_DIR/alloc/src/boxed.rs:LL:COL
+
 error[E0080]: values of the type `[&usize; usize::MAX]` are too big for the target architecture
   --> $SRC_DIR/core/src/mem/mod.rs:LL:COL
    |
@@ -9,6 +12,6 @@ note: the above error was encountered while instantiating `fn Box::<[&usize; usi
 LL |     let a: Box<_> = Box::new([&n; SIZE]);
    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 1 previous error
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0080`.
diff --git a/tests/ui/limits/issue-17913.64bit.stderr b/tests/ui/limits/issue-17913.64bit.stderr
index 5e92c70a764c4..d35d697d5f3f3 100644
--- a/tests/ui/limits/issue-17913.64bit.stderr
+++ b/tests/ui/limits/issue-17913.64bit.stderr
@@ -1,3 +1,6 @@
+error: values of the type `[&usize; usize::MAX]` are too big for the target architecture
+  --> $SRC_DIR/alloc/src/boxed.rs:LL:COL
+
 error[E0080]: values of the type `[&usize; usize::MAX]` are too big for the target architecture
   --> $SRC_DIR/core/src/mem/mod.rs:LL:COL
    |
@@ -9,6 +12,6 @@ note: the above error was encountered while instantiating `fn Box::<[&usize; usi
 LL |     let a: Box<_> = Box::new([&n; SIZE]);
    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 1 previous error
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0080`.
diff --git a/tests/ui/limits/issue-17913.rs b/tests/ui/limits/issue-17913.rs
index 9448358edba00..d804b64ab330e 100644
--- a/tests/ui/limits/issue-17913.rs
+++ b/tests/ui/limits/issue-17913.rs
@@ -18,3 +18,4 @@ fn main() {
 }
 
 //~? ERROR are too big for the target architecture
+//~? ERROR are too big for the target architecture

From e525d70b9faee49982f1e5cf6bc5ad87e147ed02 Mon Sep 17 00:00:00 2001
From: bjorn3 <17426603+bjorn3@users.noreply.github.com>
Date: Mon, 31 Aug 2026 13:12:15 +0200
Subject: [PATCH 10/12] Avoid panic when metadata encoder is called with errors

And remove the encoded metadata if there are any errors or delayed bugs
after encoding.
---
 compiler/rustc_interface/src/passes.rs       |  5 ++++-
 compiler/rustc_metadata/src/fs.rs            |  9 +++++++--
 compiler/rustc_metadata/src/rmeta/encoder.rs | 15 +++++++++++++--
 3 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/compiler/rustc_interface/src/passes.rs b/compiler/rustc_interface/src/passes.rs
index 68af061769437..12f3140a8c7b3 100644
--- a/compiler/rustc_interface/src/passes.rs
+++ b/compiler/rustc_interface/src/passes.rs
@@ -1302,7 +1302,10 @@ pub(crate) fn start_codegen<'tcx>(
 
     info!("Pre-codegen\n{:?}", tcx.debug_stats());
 
-    let metadata = rustc_metadata::fs::encode_and_write_metadata(tcx);
+    let metadata = match rustc_metadata::fs::encode_and_write_metadata(tcx) {
+        Ok(metadata) => metadata,
+        Err(guar) => guar.raise_fatal(),
+    };
 
     let is_host_metadata = tcx
         .sess
diff --git a/compiler/rustc_metadata/src/fs.rs b/compiler/rustc_metadata/src/fs.rs
index 535197b3dc51a..ed177708facc0 100644
--- a/compiler/rustc_metadata/src/fs.rs
+++ b/compiler/rustc_metadata/src/fs.rs
@@ -7,6 +7,7 @@ use rustc_middle::ty::TyCtxt;
 use rustc_session::Session;
 use rustc_session::config::{OutFileName, OutputType};
 use rustc_session::output::filename_for_metadata;
+use rustc_span::ErrorGuaranteed;
 use rustc_structures::CrateType;
 
 use crate::diagnostics::{
@@ -34,7 +35,7 @@ pub fn emit_wrapper_file(sess: &Session, data: &[u8], tmpdir: &Path, name: &str)
     out_filename
 }
 
-pub fn encode_and_write_metadata(tcx: TyCtxt<'_>) -> EncodedMetadata {
+pub fn encode_and_write_metadata(tcx: TyCtxt<'_>) -> Result<EncodedMetadata, ErrorGuaranteed> {
     let out_filename = filename_for_metadata(tcx.sess, tcx.output_filenames(()));
     // To avoid races with another rustc process scanning the output directory,
     // we need to write the file somewhere else and atomically move it to its
@@ -70,6 +71,10 @@ pub fn encode_and_write_metadata(tcx: TyCtxt<'_>) -> EncodedMetadata {
         }
     }
 
+    if let Some(guar) = tcx.sess.dcx().has_errors_or_delayed_bugs() {
+        return Err(guar);
+    }
+
     let _prof_timer = tcx.sess.prof.generic_activity("write_crate_metadata");
 
     // If the user requests metadata as output, rename `metadata_filename`
@@ -109,7 +114,7 @@ pub fn encode_and_write_metadata(tcx: TyCtxt<'_>) -> EncodedMetadata {
                 tcx.dcx().emit_fatal(FailedCreateEncodedMetadata { err });
             });
 
-    metadata
+    Ok(metadata)
 }
 
 #[cfg(not(target_os = "linux"))]
diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs
index 713671c3a5b47..dc4a41ace6b88 100644
--- a/compiler/rustc_metadata/src/rmeta/encoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/encoder.rs
@@ -1571,8 +1571,19 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             }
             if let DefKind::Static { .. } = def_kind {
                 if !self.tcx.is_foreign_item(def_id) {
-                    let data = self.tcx.eval_static_initializer(def_id).unwrap();
-                    record!(self.tables.eval_static_initializer[def_id] <- data);
+                    match self.tcx.eval_static_initializer(def_id) {
+                        Ok(data) => record!(self.tables.eval_static_initializer[def_id] <- data),
+                        Err(err) => match err {
+                            interpret::ErrorHandled::Reported(_, _) => {
+                                self.tcx.dcx().delayed_bug(format!(
+                                    "eval_static_initializer returned an error in metadata emission"
+                                ));
+                            }
+                            interpret::ErrorHandled::TooGeneric(span) => {
+                                span_bug!(span, "generic static???");
+                            }
+                        },
+                    };
                 }
             }
             if let DefKind::Enum | DefKind::Struct | DefKind::Union = def_kind {

From 5e120485964f4857f1ad70f7d661fd244d087668 Mon Sep 17 00:00:00 2001
From: bjorn3 <17426603+bjorn3@users.noreply.github.com>
Date: Thu, 10 Sep 2026 10:13:46 +0200
Subject: [PATCH 11/12] Rustup to rustc 1.100.0-nightly (a36d05efa 2026-09-09)

---
 example/mini_core.rs | 1 +
 rust-toolchain.toml  | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/example/mini_core.rs b/example/mini_core.rs
index 40ce0bf30d144..08adec96a079b 100644
--- a/example/mini_core.rs
+++ b/example/mini_core.rs
@@ -6,6 +6,7 @@
     extern_types,
     decl_macro,
     rustc_attrs,
+    rustc_private,
     transparent_unions,
     pattern_types,
     auto_traits,
diff --git a/rust-toolchain.toml b/rust-toolchain.toml
index bc8bfacba1923..b83354ee49fb9 100644
--- a/rust-toolchain.toml
+++ b/rust-toolchain.toml
@@ -1,4 +1,4 @@
 [toolchain]
-channel = "nightly-2026-09-08"
+channel = "nightly-2026-09-10"
 components = ["rust-src", "rustc-dev", "llvm-tools", "rustfmt"]
 profile = "minimal"

From 21b046d7dc696715a327415fc70a24d180618ea4 Mon Sep 17 00:00:00 2001
From: Jiaxiang Zhang <nuclefpv@nuclefpv.com>
Date: Thu, 10 Sep 2026 09:21:12 +0000
Subject: [PATCH 12/12] fix(traits): Remove expression references from index
 suggestions

* fix(traits): Remove expression references from index suggestions
* Use expression spans for index reference removal suggestions
* refactor(trait-selection): Simplify dereference suggestion guard
---
 .../src/error_reporting/traits/suggestions.rs | 32 +++++++++
 .../suggest-remove-reference-index.fixed      | 10 +++
 .../suggest-remove-reference-index.rs         | 10 +++
 .../suggest-remove-reference-index.stderr     | 66 +++++++++++++++++++
 4 files changed, 118 insertions(+)
 create mode 100644 tests/ui/suggestions/suggest-remove-reference-index.fixed
 create mode 100644 tests/ui/suggestions/suggest-remove-reference-index.rs
 create mode 100644 tests/ui/suggestions/suggest-remove-reference-index.stderr

diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs
index 65e589d336500..51527991b073b 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs
@@ -5147,6 +5147,38 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
             && let ty::Ref(_, inner_ty, _) = trait_pred.skip_binder().self_ty().kind()
             && let ty::Uint(ty::UintTy::Usize) = inner_ty.kind()
         {
+            // If the index is written as `&i`, suggest removing the borrow instead of
+            // dereferencing it, i.e. `v[&i]` -> `v[i]` rather than `v[*&i]`.
+            let span = obligation.cause.span;
+            if !span.from_expansion()
+                && let Some(body) = self.tcx.hir_maybe_body_owned_by(obligation.cause.body_def_id)
+                && let Some(expr) = {
+                    let mut finder = FindExprBySpan::new(span, self.tcx);
+                    finder.visit_expr(body.value);
+                    finder.result
+                }
+                && let hir::ExprKind::AddrOf(hir::BorrowKind::Ref, hir::Mutability::Not, borrowed) =
+                    expr.kind
+                && let Some(amp_span) = borrowed
+                    .span
+                    .find_ancestor_inside_same_ctxt(expr.span)
+                    .map(|borrowed_span| expr.span.until(borrowed_span))
+                && self
+                    .tcx
+                    .sess
+                    .source_map()
+                    .span_to_snippet(amp_span)
+                    .is_ok_and(|snippet| snippet.starts_with('&'))
+            {
+                err.span_suggestion_verbose(
+                    amp_span,
+                    "remove this reference",
+                    "",
+                    Applicability::MachineApplicable,
+                );
+                return;
+            }
+
             err.span_suggestion_verbose(
                 obligation.cause.span.shrink_to_lo(),
                 "dereference this index",
diff --git a/tests/ui/suggestions/suggest-remove-reference-index.fixed b/tests/ui/suggestions/suggest-remove-reference-index.fixed
new file mode 100644
index 0000000000000..646c650de4584
--- /dev/null
+++ b/tests/ui/suggestions/suggest-remove-reference-index.fixed
@@ -0,0 +1,10 @@
+//@ run-rustfix
+
+fn main() {
+    let arr = [false];
+    let i = 0usize;
+
+    println!("{}", arr[i]); //~ ERROR the type `[bool]` cannot be indexed by `&usize`
+    println!("{}", arr[(i + 0)]); //~ ERROR the type `[bool]` cannot be indexed by `&usize`
+    println!("{}", arr[i]); //~ ERROR the type `[bool]` cannot be indexed by `&usize`
+}
diff --git a/tests/ui/suggestions/suggest-remove-reference-index.rs b/tests/ui/suggestions/suggest-remove-reference-index.rs
new file mode 100644
index 0000000000000..db0a33a89eff3
--- /dev/null
+++ b/tests/ui/suggestions/suggest-remove-reference-index.rs
@@ -0,0 +1,10 @@
+//@ run-rustfix
+
+fn main() {
+    let arr = [false];
+    let i = 0usize;
+
+    println!("{}", arr[&i]); //~ ERROR the type `[bool]` cannot be indexed by `&usize`
+    println!("{}", arr[&(i + 0)]); //~ ERROR the type `[bool]` cannot be indexed by `&usize`
+    println!("{}", arr[& i]); //~ ERROR the type `[bool]` cannot be indexed by `&usize`
+}
diff --git a/tests/ui/suggestions/suggest-remove-reference-index.stderr b/tests/ui/suggestions/suggest-remove-reference-index.stderr
new file mode 100644
index 0000000000000..4f396fe529508
--- /dev/null
+++ b/tests/ui/suggestions/suggest-remove-reference-index.stderr
@@ -0,0 +1,66 @@
+error[E0277]: the type `[bool]` cannot be indexed by `&usize`
+  --> $DIR/suggest-remove-reference-index.rs:7:24
+   |
+LL |     println!("{}", arr[&i]);
+   |                        ^^ slice indices are of type `usize` or ranges of `usize`
+   |
+   = help: the trait `SliceIndex<[bool]>` is not implemented for `&usize`
+help: `usize` implements trait `SliceIndex<T>`
+  --> $SRC_DIR/core/src/slice/index.rs:LL:COL
+   |
+   = note: `SliceIndex<[T]>`
+  --> $SRC_DIR/core/src/bstr/traits.rs:LL:COL
+   |
+   = note: `SliceIndex<ByteStr>`
+   = note: required for `[bool]` to implement `Index<&usize>`
+help: remove this reference
+   |
+LL -     println!("{}", arr[&i]);
+LL +     println!("{}", arr[i]);
+   |
+
+error[E0277]: the type `[bool]` cannot be indexed by `&usize`
+  --> $DIR/suggest-remove-reference-index.rs:8:24
+   |
+LL |     println!("{}", arr[&(i + 0)]);
+   |                        ^^^^^^^^ slice indices are of type `usize` or ranges of `usize`
+   |
+   = help: the trait `SliceIndex<[bool]>` is not implemented for `&usize`
+help: `usize` implements trait `SliceIndex<T>`
+  --> $SRC_DIR/core/src/slice/index.rs:LL:COL
+   |
+   = note: `SliceIndex<[T]>`
+  --> $SRC_DIR/core/src/bstr/traits.rs:LL:COL
+   |
+   = note: `SliceIndex<ByteStr>`
+   = note: required for `[bool]` to implement `Index<&usize>`
+help: remove this reference
+   |
+LL -     println!("{}", arr[&(i + 0)]);
+LL +     println!("{}", arr[(i + 0)]);
+   |
+
+error[E0277]: the type `[bool]` cannot be indexed by `&usize`
+  --> $DIR/suggest-remove-reference-index.rs:9:24
+   |
+LL |     println!("{}", arr[& i]);
+   |                        ^^^ slice indices are of type `usize` or ranges of `usize`
+   |
+   = help: the trait `SliceIndex<[bool]>` is not implemented for `&usize`
+help: `usize` implements trait `SliceIndex<T>`
+  --> $SRC_DIR/core/src/slice/index.rs:LL:COL
+   |
+   = note: `SliceIndex<[T]>`
+  --> $SRC_DIR/core/src/bstr/traits.rs:LL:COL
+   |
+   = note: `SliceIndex<ByteStr>`
+   = note: required for `[bool]` to implement `Index<&usize>`
+help: remove this reference
+   |
+LL -     println!("{}", arr[& i]);
+LL +     println!("{}", arr[i]);
+   |
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0277`.