From cf34545720986d99712e3b542e8f395360c75095 Mon Sep 17 00:00:00 2001
From: Alan Somers <asomers@gmail.com>
Date: Sun, 27 Oct 2024 11:55:20 -0600
Subject: [PATCH 01/13] CI: build FreeBSD artifacts on FreeBSD 13.4

13.2 is EoL, and 13.3 will be EoL too in about 2 months.  Plus, both
suffer from a bug in LLVM's libunwind.  It causes a segfault inside of
std::backtrace::Backtrace::capture().

Fixes #132185
---
 src/ci/docker/host-x86_64/dist-x86_64-freebsd/Dockerfile | 6 +++---
 src/ci/docker/scripts/freebsd-toolchain.sh               | 6 +++---
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/ci/docker/host-x86_64/dist-x86_64-freebsd/Dockerfile b/src/ci/docker/host-x86_64/dist-x86_64-freebsd/Dockerfile
index f42e6f770ebe8..fd0f5da8c495a 100644
--- a/src/ci/docker/host-x86_64/dist-x86_64-freebsd/Dockerfile
+++ b/src/ci/docker/host-x86_64/dist-x86_64-freebsd/Dockerfile
@@ -29,9 +29,9 @@ COPY scripts/cmake.sh /scripts/
 RUN /scripts/cmake.sh
 
 ENV \
-    AR_x86_64_unknown_freebsd=x86_64-unknown-freebsd12-ar \
-    CC_x86_64_unknown_freebsd=x86_64-unknown-freebsd12-clang \
-    CXX_x86_64_unknown_freebsd=x86_64-unknown-freebsd12-clang++
+    AR_x86_64_unknown_freebsd=x86_64-unknown-freebsd13-ar \
+    CC_x86_64_unknown_freebsd=x86_64-unknown-freebsd13-clang \
+    CXX_x86_64_unknown_freebsd=x86_64-unknown-freebsd13-clang++
 
 ENV HOSTS=x86_64-unknown-freebsd
 
diff --git a/src/ci/docker/scripts/freebsd-toolchain.sh b/src/ci/docker/scripts/freebsd-toolchain.sh
index 0d02636db9196..b927658b4fdc2 100755
--- a/src/ci/docker/scripts/freebsd-toolchain.sh
+++ b/src/ci/docker/scripts/freebsd-toolchain.sh
@@ -5,8 +5,8 @@ set -eux
 
 arch=$1
 binutils_version=2.40
-freebsd_version=12.3
-triple=$arch-unknown-freebsd12
+freebsd_version=13.4
+triple=$arch-unknown-freebsd13
 sysroot=/usr/local/$triple
 
 hide_output() {
@@ -59,7 +59,7 @@ done
 
 # Originally downloaded from:
 # URL=https://download.freebsd.org/ftp/releases/${freebsd_arch}/${freebsd_version}-RELEASE/base.txz
-URL=https://ci-mirrors.rust-lang.org/rustc/2022-05-06-freebsd-${freebsd_version}-${freebsd_arch}-base.txz
+URL=https://ci-mirrors.rust-lang.org/rustc/2024-09-13-freebsd-${freebsd_version}-${freebsd_arch}-base.txz
 curl "$URL" | tar xJf - -C "$sysroot" --wildcards "${files_to_extract[@]}"
 
 # Clang can do cross-builds out of the box, if we give it the right

From 0454d7903b4e5508e5169efdb28e4fa94d2dc64a Mon Sep 17 00:00:00 2001
From: Alan Somers <asomers@gmail.com>
Date: Sun, 12 Jan 2025 14:27:56 -0700
Subject: [PATCH 02/13] Fixup: fix clang command lines in another file

---
 src/ci/docker/host-x86_64/dist-various-2/Dockerfile | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/ci/docker/host-x86_64/dist-various-2/Dockerfile b/src/ci/docker/host-x86_64/dist-various-2/Dockerfile
index ece5f174d06de..8aabfaafbabbc 100644
--- a/src/ci/docker/host-x86_64/dist-various-2/Dockerfile
+++ b/src/ci/docker/host-x86_64/dist-various-2/Dockerfile
@@ -56,9 +56,9 @@ ENV \
     CFLAGS_x86_64_fortanix_unknown_sgx="-D__ELF__ -isystem/usr/include/x86_64-linux-gnu -mlvi-hardening -mllvm -x86-experimental-lvi-inline-asm-hardening" \
     CXX_x86_64_fortanix_unknown_sgx=clang++-11 \
     CXXFLAGS_x86_64_fortanix_unknown_sgx="-D__ELF__ -isystem/usr/include/x86_64-linux-gnu -mlvi-hardening -mllvm -x86-experimental-lvi-inline-asm-hardening" \
-    AR_i686_unknown_freebsd=i686-unknown-freebsd12-ar \
-    CC_i686_unknown_freebsd=i686-unknown-freebsd12-clang \
-    CXX_i686_unknown_freebsd=i686-unknown-freebsd12-clang++ \
+    AR_i686_unknown_freebsd=i686-unknown-freebsd13-ar \
+    CC_i686_unknown_freebsd=i686-unknown-freebsd13-clang \
+    CXX_i686_unknown_freebsd=i686-unknown-freebsd13-clang++ \
     CC_aarch64_unknown_uefi=clang-11 \
     CXX_aarch64_unknown_uefi=clang++-11 \
     CC_i686_unknown_uefi=clang-11 \

From b2b12ae0cb6c7e6dd71092aafa14e06b57a290ec Mon Sep 17 00:00:00 2001
From: Scott McMurray <scottmcm@users.noreply.github.com>
Date: Sun, 19 Jan 2025 16:15:00 -0800
Subject: [PATCH 03/13] Add an example of using `carrying_mul_add` to write
 wider multiplication

Just the basic quadratic version that you wouldn't actually want for a true bigint, but it's nice and short so is useful as an example :)
---
 library/core/src/num/uint_macros.rs | 33 +++++++++++++++++++++++++++--
 1 file changed, 31 insertions(+), 2 deletions(-)

diff --git a/library/core/src/num/uint_macros.rs b/library/core/src/num/uint_macros.rs
index 404e4bcffd379..c8433b3bb168a 100644
--- a/library/core/src/num/uint_macros.rs
+++ b/library/core/src/num/uint_macros.rs
@@ -2663,8 +2663,8 @@ macro_rules! uint_impl {
         ///
         /// Basic usage:
         ///
-        /// Please note that this example is shared between integer types.
-        /// Which explains why `u32` is used here.
+        /// Please note that this example is shared between integer types,
+        /// which explains why `u32` is used here.
         ///
         /// ```
         /// #![feature(bigint_helper_methods)]
@@ -2677,6 +2677,35 @@ macro_rules! uint_impl {
             "(", stringify!($SelfT), "::MAX, ", stringify!($SelfT), "::MAX));"
         )]
         /// ```
+        ///
+        /// This is the core per-digit operation for "grade school" O(n²) multiplication.
+        ///
+        /// Please note that this example is shared between integer types,
+        /// using `u8` for simplicity of the demonstration.
+        ///
+        /// ```
+        /// #![feature(bigint_helper_methods)]
+        ///
+        /// fn quadratic_mul<const N: usize>(a: [u8; N], b: [u8; N]) -> [u8; N] {
+        ///     let mut out = [0; N];
+        ///     for j in 0..N {
+        ///         let mut carry = 0;
+        ///         for i in 0..(N - j) {
+        ///             (out[j + i], carry) = u8::carrying_mul_add(a[i], b[j], out[j + i], carry);
+        ///         }
+        ///     }
+        ///     out
+        /// }
+        ///
+        /// // -1 * -1 == 1
+        /// assert_eq!(quadratic_mul([0xFF; 3], [0xFF; 3]), [1, 0, 0]);
+        ///
+        /// assert_eq!(u32::wrapping_mul(0x9e3779b9, 0x7f4a7c15), 0xCFFC982D);
+        /// assert_eq!(
+        ///     quadratic_mul(u32::to_le_bytes(0x9e3779b9), u32::to_le_bytes(0x7f4a7c15)),
+        ///     u32::to_le_bytes(0xCFFC982D)
+        /// );
+        /// ```
         #[unstable(feature = "bigint_helper_methods", issue = "85532")]
         #[rustc_const_unstable(feature = "bigint_helper_methods", issue = "85532")]
         #[must_use = "this returns the result of the operation, \

From 8dec09f3c5bf8e1f12c6ba6eb6040d710353ca63 Mon Sep 17 00:00:00 2001
From: Folkert de Vries <folkert@folkertdev.nl>
Date: Wed, 15 Jan 2025 21:57:10 +0100
Subject: [PATCH 04/13] support wasm inline assembly in naked functions

---
 .../rustc_codegen_ssa/src/mir/naked_asm.rs    | 140 ++++++++++++-
 tests/assembly/wasm32-naked-fn.rs             | 198 ++++++++++++++++++
 2 files changed, 334 insertions(+), 4 deletions(-)
 create mode 100644 tests/assembly/wasm32-naked-fn.rs

diff --git a/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs b/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs
index 8df270abc8173..35e0ea545258f 100644
--- a/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs
@@ -1,10 +1,12 @@
+use rustc_abi::{BackendRepr, Float, Integer, Primitive, RegKind};
 use rustc_attr_parsing::InstructionSetAttr;
 use rustc_middle::mir::mono::{Linkage, MonoItem, MonoItemData, Visibility};
 use rustc_middle::mir::{Body, InlineAsmOperand};
-use rustc_middle::ty::layout::{HasTyCtxt, HasTypingEnv, LayoutOf};
-use rustc_middle::ty::{Instance, TyCtxt};
+use rustc_middle::ty::layout::{FnAbiOf, HasTyCtxt, HasTypingEnv, LayoutOf};
+use rustc_middle::ty::{Instance, Ty, TyCtxt};
 use rustc_middle::{bug, ty};
 use rustc_span::sym;
+use rustc_target::callconv::{ArgAbi, FnAbi, PassMode};
 
 use crate::common;
 use crate::traits::{AsmCodegenMethods, BuilderMethods, GlobalAsmOperandRef, MiscCodegenMethods};
@@ -32,7 +34,8 @@ pub(crate) fn codegen_naked_asm<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
 
     let item_data = cx.codegen_unit().items().get(&MonoItem::Fn(instance)).unwrap();
     let name = cx.mangled_name(instance);
-    let (begin, end) = prefix_and_suffix(cx.tcx(), instance, &name, item_data);
+    let fn_abi = cx.fn_abi_of_instance(instance, ty::List::empty());
+    let (begin, end) = prefix_and_suffix(cx.tcx(), instance, &name, item_data, fn_abi);
 
     let mut template_vec = Vec::new();
     template_vec.push(rustc_ast::ast::InlineAsmTemplatePiece::String(begin.into()));
@@ -103,6 +106,7 @@ enum AsmBinaryFormat {
     Elf,
     Macho,
     Coff,
+    Wasm,
 }
 
 impl AsmBinaryFormat {
@@ -111,6 +115,8 @@ impl AsmBinaryFormat {
             Self::Coff
         } else if target.is_like_osx {
             Self::Macho
+        } else if target.is_like_wasm {
+            Self::Wasm
         } else {
             Self::Elf
         }
@@ -122,6 +128,7 @@ fn prefix_and_suffix<'tcx>(
     instance: Instance<'tcx>,
     asm_name: &str,
     item_data: &MonoItemData,
+    fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
 ) -> (String, String) {
     use std::fmt::Write;
 
@@ -169,7 +176,7 @@ fn prefix_and_suffix<'tcx>(
             }
             Linkage::LinkOnceAny | Linkage::LinkOnceODR | Linkage::WeakAny | Linkage::WeakODR => {
                 match asm_binary_format {
-                    AsmBinaryFormat::Elf | AsmBinaryFormat::Coff => {
+                    AsmBinaryFormat::Elf | AsmBinaryFormat::Coff | AsmBinaryFormat::Wasm => {
                         writeln!(w, ".weak {asm_name}")?;
                     }
                     AsmBinaryFormat::Macho => {
@@ -264,7 +271,132 @@ fn prefix_and_suffix<'tcx>(
                 writeln!(end, "{}", arch_suffix).unwrap();
             }
         }
+        AsmBinaryFormat::Wasm => {
+            let section = link_section.unwrap_or(format!(".text.{asm_name}"));
+
+            writeln!(begin, ".section {section},\"\",@").unwrap();
+            // wasm functions cannot be aligned, so skip
+            write_linkage(&mut begin).unwrap();
+            if let Visibility::Hidden = item_data.visibility {
+                writeln!(begin, ".hidden {asm_name}").unwrap();
+            }
+            writeln!(begin, ".type {asm_name}, @function").unwrap();
+            if !arch_prefix.is_empty() {
+                writeln!(begin, "{}", arch_prefix).unwrap();
+            }
+            writeln!(begin, "{asm_name}:").unwrap();
+            writeln!(begin, ".functype {asm_name} {}", wasm_functype(tcx, fn_abi)).unwrap();
+
+            writeln!(end).unwrap();
+            // .size is ignored for function symbols, so we can skip it
+            writeln!(end, "end_function").unwrap();
+        }
     }
 
     (begin, end)
 }
+
+/// The webassembly type signature for the given function.
+///
+/// Used by the `.functype` directive on wasm targets.
+fn wasm_functype<'tcx>(tcx: TyCtxt<'tcx>, fn_abi: &FnAbi<'tcx, Ty<'tcx>>) -> String {
+    let mut signature = String::with_capacity(64);
+
+    let ptr_type = match tcx.data_layout.pointer_size.bits() {
+        32 => "i32",
+        64 => "i64",
+        other => bug!("wasm pointer size cannot be {other} bits"),
+    };
+
+    let hidden_return =
+        matches!(fn_abi.ret.mode, PassMode::Indirect { .. } | PassMode::Pair { .. });
+
+    signature.push('(');
+
+    if hidden_return {
+        signature.push_str(ptr_type);
+        if !fn_abi.args.is_empty() {
+            signature.push_str(", ");
+        }
+    }
+
+    let mut it = fn_abi.args.iter().peekable();
+    while let Some(arg_abi) = it.next() {
+        wasm_type(&mut signature, arg_abi, ptr_type);
+        if it.peek().is_some() {
+            signature.push_str(", ");
+        }
+    }
+
+    signature.push_str(") -> (");
+
+    if !hidden_return {
+        wasm_type(&mut signature, &fn_abi.ret, ptr_type);
+    }
+
+    signature.push(')');
+
+    signature
+}
+
+fn wasm_type<'tcx>(signature: &mut String, arg_abi: &ArgAbi<'_, Ty<'tcx>>, ptr_type: &'static str) {
+    match arg_abi.mode {
+        PassMode::Ignore => { /* do nothing */ }
+        PassMode::Direct(_) => {
+            let direct_type = match arg_abi.layout.backend_repr {
+                BackendRepr::Scalar(scalar) => wasm_primitive(scalar.primitive(), ptr_type),
+                BackendRepr::Vector { .. } => "v128",
+                other => unreachable!("unexpected BackendRepr: {:?}", other),
+            };
+
+            signature.push_str(direct_type);
+        }
+        PassMode::Pair(_, _) => match arg_abi.layout.backend_repr {
+            BackendRepr::ScalarPair(a, b) => {
+                signature.push_str(wasm_primitive(a.primitive(), ptr_type));
+                signature.push_str(", ");
+                signature.push_str(wasm_primitive(b.primitive(), ptr_type));
+            }
+            other => unreachable!("{other:?}"),
+        },
+        PassMode::Cast { pad_i32, ref cast } => {
+            // For wasm, Cast is used for single-field primitive wrappers like `struct Wrapper(i64);`
+            assert!(!pad_i32, "not currently used by wasm calling convention");
+            assert!(cast.prefix[0].is_none(), "no prefix");
+            assert_eq!(cast.rest.total, arg_abi.layout.size, "single item");
+
+            let wrapped_wasm_type = match cast.rest.unit.kind {
+                RegKind::Integer => match cast.rest.unit.size.bytes() {
+                    ..=4 => "i32",
+                    ..=8 => "i64",
+                    _ => ptr_type,
+                },
+                RegKind::Float => match cast.rest.unit.size.bytes() {
+                    ..=4 => "f32",
+                    ..=8 => "f64",
+                    _ => ptr_type,
+                },
+                RegKind::Vector => "v128",
+            };
+
+            signature.push_str(wrapped_wasm_type);
+        }
+        PassMode::Indirect { .. } => signature.push_str(ptr_type),
+    }
+}
+
+fn wasm_primitive(primitive: Primitive, ptr_type: &'static str) -> &'static str {
+    match primitive {
+        Primitive::Int(integer, _) => match integer {
+            Integer::I8 | Integer::I16 | Integer::I32 => "i32",
+            Integer::I64 => "i64",
+            Integer::I128 => "i64, i64",
+        },
+        Primitive::Float(float) => match float {
+            Float::F16 | Float::F32 => "f32",
+            Float::F64 => "f64",
+            Float::F128 => "i64, i64",
+        },
+        Primitive::Pointer(_) => ptr_type,
+    }
+}
diff --git a/tests/assembly/wasm32-naked-fn.rs b/tests/assembly/wasm32-naked-fn.rs
new file mode 100644
index 0000000000000..8e98b0847298f
--- /dev/null
+++ b/tests/assembly/wasm32-naked-fn.rs
@@ -0,0 +1,198 @@
+//@ revisions: wasm32-unknown wasm64-unknown wasm32-wasip1
+//@ add-core-stubs
+//@ assembly-output: emit-asm
+//@ [wasm32-unknown] compile-flags: --target wasm32-unknown-unknown
+//@ [wasm64-unknown] compile-flags: --target wasm64-unknown-unknown
+//@ [wasm32-wasip1] compile-flags: --target wasm32-wasip1
+//@ [wasm32-unknown] needs-llvm-components: webassembly
+//@ [wasm64-unknown] needs-llvm-components: webassembly
+//@ [wasm32-wasip1] needs-llvm-components: webassembly
+
+#![crate_type = "lib"]
+#![feature(no_core, naked_functions, asm_experimental_arch, f128, linkage, fn_align)]
+#![no_core]
+
+extern crate minicore;
+use minicore::*;
+
+// CHECK: .section  .text.nop,"",@
+// CHECK: .globl nop
+// CHECK-LABEL: nop:
+// CHECK: .functype nop () -> ()
+// CHECK-NOT: .size
+// CHECK: end_function
+#[no_mangle]
+#[naked]
+unsafe extern "C" fn nop() {
+    naked_asm!("nop")
+}
+
+// CHECK: .section  .text.weak_aligned_nop,"",@
+// CHECK: .weak weak_aligned_nop
+// CHECK-LABEL: nop:
+// CHECK: .functype weak_aligned_nop () -> ()
+// CHECK-NOT: .size
+// CHECK: end_function
+#[no_mangle]
+#[naked]
+#[linkage = "weak"]
+// wasm functions cannot be aligned, so this has no effect
+#[repr(align(32))]
+unsafe extern "C" fn weak_aligned_nop() {
+    naked_asm!("nop")
+}
+
+// CHECK-LABEL: fn_i8_i8:
+// CHECK-NEXT: .functype fn_i8_i8 (i32) -> (i32)
+//
+// CHECK-NEXT: local.get 0
+// CHECK-NEXT: local.get 0
+// CHECK-NEXT: i32.mul
+//
+// CHECK-NEXT: end_function
+#[no_mangle]
+#[naked]
+unsafe extern "C" fn fn_i8_i8(num: i8) -> i8 {
+    naked_asm!("local.get 0", "local.get 0", "i32.mul")
+}
+
+// CHECK-LABEL: fn_i8_i8_i8:
+// CHECK: .functype fn_i8_i8_i8 (i32, i32) -> (i32)
+#[no_mangle]
+#[naked]
+unsafe extern "C" fn fn_i8_i8_i8(a: i8, b: i8) -> i8 {
+    naked_asm!("local.get 1", "local.get 0", "i32.mul")
+}
+
+// CHECK-LABEL: fn_unit_i8:
+// CHECK: .functype fn_unit_i8 () -> (i32)
+#[no_mangle]
+#[naked]
+unsafe extern "C" fn fn_unit_i8() -> i8 {
+    naked_asm!("i32.const 42")
+}
+
+// CHECK-LABEL: fn_i8_unit:
+// CHECK: .functype fn_i8_unit (i32) -> ()
+#[no_mangle]
+#[naked]
+unsafe extern "C" fn fn_i8_unit(_: i8) {
+    naked_asm!("nop")
+}
+
+// CHECK-LABEL: fn_i32_i32:
+// CHECK: .functype fn_i32_i32 (i32) -> (i32)
+#[no_mangle]
+#[naked]
+unsafe extern "C" fn fn_i32_i32(num: i32) -> i32 {
+    naked_asm!("local.get 0", "local.get 0", "i32.mul")
+}
+
+// CHECK-LABEL: fn_i64_i64:
+// CHECK: .functype fn_i64_i64 (i64) -> (i64)
+#[no_mangle]
+#[naked]
+unsafe extern "C" fn fn_i64_i64(num: i64) -> i64 {
+    naked_asm!("local.get 0", "local.get 0", "i64.mul")
+}
+
+// CHECK-LABEL: fn_i128_i128:
+// wasm32-unknown,wasm32-wasip1: .functype fn_i128_i128 (i32, i64, i64) -> ()
+// wasm64-unknown: .functype fn_i128_i128 (i64, i64, i64) -> ()
+#[allow(improper_ctypes_definitions)]
+#[no_mangle]
+#[naked]
+unsafe extern "C" fn fn_i128_i128(num: i128) -> i128 {
+    naked_asm!(
+        "local.get       0",
+        "local.get       2",
+        "i64.store       8",
+        "local.get       0",
+        "local.get       1",
+        "i64.store       0",
+    )
+}
+
+// CHECK-LABEL: fn_f128_f128:
+// wasm32-unknown,wasm32-wasip1: .functype fn_f128_f128 (i32, i64, i64) -> ()
+// wasm64-unknown: .functype fn_f128_f128 (i64, i64, i64) -> ()
+#[no_mangle]
+#[naked]
+unsafe extern "C" fn fn_f128_f128(num: f128) -> f128 {
+    naked_asm!(
+        "local.get       0",
+        "local.get       2",
+        "i64.store       8",
+        "local.get       0",
+        "local.get       1",
+        "i64.store       0",
+    )
+}
+
+#[repr(C)]
+struct Compound {
+    a: u16,
+    b: i64,
+}
+
+// CHECK-LABEL: fn_compound_compound:
+// wasm32-wasip1: .functype fn_compound_compound (i32, i32) -> ()
+// wasm32-unknown: .functype fn_compound_compound (i32, i32, i64) -> ()
+// wasm64-unknown: .functype fn_compound_compound (i64, i64) -> ()
+#[no_mangle]
+#[naked]
+unsafe extern "C" fn fn_compound_compound(_: Compound) -> Compound {
+    // this is the wasm32-unknown-unknown assembly
+    naked_asm!(
+        "local.get       0",
+        "local.get       2",
+        "i64.store       8",
+        "local.get       0",
+        "local.get       1",
+        "i32.store16     0",
+    )
+}
+
+#[repr(C)]
+struct WrapperI32(i32);
+
+// CHECK-LABEL: fn_wrapperi32_wrapperi32:
+// CHECK: .functype fn_wrapperi32_wrapperi32 (i32) -> (i32)
+#[no_mangle]
+#[naked]
+unsafe extern "C" fn fn_wrapperi32_wrapperi32(_: WrapperI32) -> WrapperI32 {
+    naked_asm!("local.get       0")
+}
+
+#[repr(C)]
+struct WrapperI64(i64);
+
+// CHECK-LABEL: fn_wrapperi64_wrapperi64:
+// CHECK: .functype fn_wrapperi64_wrapperi64 (i64) -> (i64)
+#[no_mangle]
+#[naked]
+unsafe extern "C" fn fn_wrapperi64_wrapperi64(_: WrapperI64) -> WrapperI64 {
+    naked_asm!("local.get       0")
+}
+
+#[repr(C)]
+struct WrapperF32(f32);
+
+// CHECK-LABEL: fn_wrapperf32_wrapperf32:
+// CHECK: .functype fn_wrapperf32_wrapperf32 (f32) -> (f32)
+#[no_mangle]
+#[naked]
+unsafe extern "C" fn fn_wrapperf32_wrapperf32(_: WrapperF32) -> WrapperF32 {
+    naked_asm!("local.get       0")
+}
+
+#[repr(C)]
+struct WrapperF64(f64);
+
+// CHECK-LABEL: fn_wrapperf64_wrapperf64:
+// CHECK: .functype fn_wrapperf64_wrapperf64 (f64) -> (f64)
+#[no_mangle]
+#[naked]
+unsafe extern "C" fn fn_wrapperf64_wrapperf64(_: WrapperF64) -> WrapperF64 {
+    naked_asm!("local.get       0")
+}

From bcf478b7a6915a8ce14009934f2893ddcce8052c Mon Sep 17 00:00:00 2001
From: Folkert de Vries <folkert@folkertdev.nl>
Date: Fri, 17 Jan 2025 22:34:26 +0100
Subject: [PATCH 05/13] work around the `wasm32-unknown-unknown` ABI being
 broken

---
 .../rustc_codegen_ssa/src/mir/naked_asm.rs    | 47 +++++++++++++++----
 tests/assembly/wasm32-naked-fn.rs             | 17 +++----
 2 files changed, 48 insertions(+), 16 deletions(-)

diff --git a/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs b/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs
index 35e0ea545258f..dc406809874d5 100644
--- a/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs
@@ -1,12 +1,14 @@
 use rustc_abi::{BackendRepr, Float, Integer, Primitive, RegKind};
 use rustc_attr_parsing::InstructionSetAttr;
+use rustc_hir::def_id::DefId;
 use rustc_middle::mir::mono::{Linkage, MonoItem, MonoItemData, Visibility};
 use rustc_middle::mir::{Body, InlineAsmOperand};
 use rustc_middle::ty::layout::{FnAbiOf, HasTyCtxt, HasTypingEnv, LayoutOf};
 use rustc_middle::ty::{Instance, Ty, TyCtxt};
-use rustc_middle::{bug, ty};
+use rustc_middle::{bug, span_bug, ty};
 use rustc_span::sym;
 use rustc_target::callconv::{ArgAbi, FnAbi, PassMode};
+use rustc_target::spec::WasmCAbi;
 
 use crate::common;
 use crate::traits::{AsmCodegenMethods, BuilderMethods, GlobalAsmOperandRef, MiscCodegenMethods};
@@ -285,7 +287,12 @@ fn prefix_and_suffix<'tcx>(
                 writeln!(begin, "{}", arch_prefix).unwrap();
             }
             writeln!(begin, "{asm_name}:").unwrap();
-            writeln!(begin, ".functype {asm_name} {}", wasm_functype(tcx, fn_abi)).unwrap();
+            writeln!(
+                begin,
+                ".functype {asm_name} {}",
+                wasm_functype(tcx, fn_abi, instance.def_id())
+            )
+            .unwrap();
 
             writeln!(end).unwrap();
             // .size is ignored for function symbols, so we can skip it
@@ -299,7 +306,7 @@ fn prefix_and_suffix<'tcx>(
 /// The webassembly type signature for the given function.
 ///
 /// Used by the `.functype` directive on wasm targets.
-fn wasm_functype<'tcx>(tcx: TyCtxt<'tcx>, fn_abi: &FnAbi<'tcx, Ty<'tcx>>) -> String {
+fn wasm_functype<'tcx>(tcx: TyCtxt<'tcx>, fn_abi: &FnAbi<'tcx, Ty<'tcx>>, def_id: DefId) -> String {
     let mut signature = String::with_capacity(64);
 
     let ptr_type = match tcx.data_layout.pointer_size.bits() {
@@ -308,8 +315,18 @@ fn wasm_functype<'tcx>(tcx: TyCtxt<'tcx>, fn_abi: &FnAbi<'tcx, Ty<'tcx>>) -> Str
         other => bug!("wasm pointer size cannot be {other} bits"),
     };
 
-    let hidden_return =
-        matches!(fn_abi.ret.mode, PassMode::Indirect { .. } | PassMode::Pair { .. });
+    // FIXME: remove this once the wasm32-unknown-unknown ABI is fixed
+    // please also add `wasm32-unknown-unknown` back in `tests/assembly/wasm32-naked-fn.rs`
+    // basically the commit introducing this comment should be reverted
+    if let PassMode::Pair { .. } = fn_abi.ret.mode {
+        let _ = WasmCAbi::Legacy;
+        span_bug!(
+            tcx.def_span(def_id),
+            "cannot return a pair (the wasm32-unknown-unknown ABI is broken, see https://github.com/rust-lang/rust/issues/115666"
+        );
+    }
+
+    let hidden_return = matches!(fn_abi.ret.mode, PassMode::Indirect { .. });
 
     signature.push('(');
 
@@ -322,7 +339,7 @@ fn wasm_functype<'tcx>(tcx: TyCtxt<'tcx>, fn_abi: &FnAbi<'tcx, Ty<'tcx>>) -> Str
 
     let mut it = fn_abi.args.iter().peekable();
     while let Some(arg_abi) = it.next() {
-        wasm_type(&mut signature, arg_abi, ptr_type);
+        wasm_type(tcx, &mut signature, arg_abi, ptr_type, def_id);
         if it.peek().is_some() {
             signature.push_str(", ");
         }
@@ -331,7 +348,7 @@ fn wasm_functype<'tcx>(tcx: TyCtxt<'tcx>, fn_abi: &FnAbi<'tcx, Ty<'tcx>>) -> Str
     signature.push_str(") -> (");
 
     if !hidden_return {
-        wasm_type(&mut signature, &fn_abi.ret, ptr_type);
+        wasm_type(tcx, &mut signature, &fn_abi.ret, ptr_type, def_id);
     }
 
     signature.push(')');
@@ -339,13 +356,27 @@ fn wasm_functype<'tcx>(tcx: TyCtxt<'tcx>, fn_abi: &FnAbi<'tcx, Ty<'tcx>>) -> Str
     signature
 }
 
-fn wasm_type<'tcx>(signature: &mut String, arg_abi: &ArgAbi<'_, Ty<'tcx>>, ptr_type: &'static str) {
+fn wasm_type<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    signature: &mut String,
+    arg_abi: &ArgAbi<'_, Ty<'tcx>>,
+    ptr_type: &'static str,
+    def_id: DefId,
+) {
     match arg_abi.mode {
         PassMode::Ignore => { /* do nothing */ }
         PassMode::Direct(_) => {
             let direct_type = match arg_abi.layout.backend_repr {
                 BackendRepr::Scalar(scalar) => wasm_primitive(scalar.primitive(), ptr_type),
                 BackendRepr::Vector { .. } => "v128",
+                BackendRepr::Memory { .. } => {
+                    // FIXME: remove this branch once the wasm32-unknown-unknown ABI is fixed
+                    let _ = WasmCAbi::Legacy;
+                    span_bug!(
+                        tcx.def_span(def_id),
+                        "cannot use memory args (the wasm32-unknown-unknown ABI is broken, see https://github.com/rust-lang/rust/issues/115666"
+                    );
+                }
                 other => unreachable!("unexpected BackendRepr: {:?}", other),
             };
 
diff --git a/tests/assembly/wasm32-naked-fn.rs b/tests/assembly/wasm32-naked-fn.rs
index 8e98b0847298f..4911a6bd08f68 100644
--- a/tests/assembly/wasm32-naked-fn.rs
+++ b/tests/assembly/wasm32-naked-fn.rs
@@ -1,10 +1,10 @@
-//@ revisions: wasm32-unknown wasm64-unknown wasm32-wasip1
+// FIXME: add wasm32-unknown when the wasm32-unknown-unknown ABI is fixed
+// see https://github.com/rust-lang/rust/issues/115666
+//@ revisions: wasm64-unknown wasm32-wasip1
 //@ add-core-stubs
 //@ assembly-output: emit-asm
-//@ [wasm32-unknown] compile-flags: --target wasm32-unknown-unknown
 //@ [wasm64-unknown] compile-flags: --target wasm64-unknown-unknown
 //@ [wasm32-wasip1] compile-flags: --target wasm32-wasip1
-//@ [wasm32-unknown] needs-llvm-components: webassembly
 //@ [wasm64-unknown] needs-llvm-components: webassembly
 //@ [wasm32-wasip1] needs-llvm-components: webassembly
 
@@ -97,7 +97,7 @@ unsafe extern "C" fn fn_i64_i64(num: i64) -> i64 {
 }
 
 // CHECK-LABEL: fn_i128_i128:
-// wasm32-unknown,wasm32-wasip1: .functype fn_i128_i128 (i32, i64, i64) -> ()
+// wasm32-wasip1: .functype fn_i128_i128 (i32, i64, i64) -> ()
 // wasm64-unknown: .functype fn_i128_i128 (i64, i64, i64) -> ()
 #[allow(improper_ctypes_definitions)]
 #[no_mangle]
@@ -114,7 +114,7 @@ unsafe extern "C" fn fn_i128_i128(num: i128) -> i128 {
 }
 
 // CHECK-LABEL: fn_f128_f128:
-// wasm32-unknown,wasm32-wasip1: .functype fn_f128_f128 (i32, i64, i64) -> ()
+// wasm32-wasip1: .functype fn_f128_f128 (i32, i64, i64) -> ()
 // wasm64-unknown: .functype fn_f128_f128 (i64, i64, i64) -> ()
 #[no_mangle]
 #[naked]
@@ -137,18 +137,19 @@ struct Compound {
 
 // CHECK-LABEL: fn_compound_compound:
 // wasm32-wasip1: .functype fn_compound_compound (i32, i32) -> ()
-// wasm32-unknown: .functype fn_compound_compound (i32, i32, i64) -> ()
 // wasm64-unknown: .functype fn_compound_compound (i64, i64) -> ()
 #[no_mangle]
 #[naked]
 unsafe extern "C" fn fn_compound_compound(_: Compound) -> Compound {
-    // this is the wasm32-unknown-unknown assembly
+    // this is the wasm32-wasip1 assembly
     naked_asm!(
         "local.get       0",
-        "local.get       2",
+        "local.get       1",
+        "i64.load        8",
         "i64.store       8",
         "local.get       0",
         "local.get       1",
+        "i32.load16_u    0",
         "i32.store16     0",
     )
 }

From a175e8d90312a113869d366ba7dde0742df7f5e2 Mon Sep 17 00:00:00 2001
From: MarcoIeni <11428655+MarcoIeni@users.noreply.github.com>
Date: Mon, 20 Jan 2025 17:38:17 +0100
Subject: [PATCH 06/13] CI: free disk on linux arm runner

---
 src/ci/github-actions/jobs.yml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/ci/github-actions/jobs.yml b/src/ci/github-actions/jobs.yml
index 799ea3e9ad2df..ecd8642d76674 100644
--- a/src/ci/github-actions/jobs.yml
+++ b/src/ci/github-actions/jobs.yml
@@ -44,6 +44,8 @@ runners:
     <<: *base-job
 
   - &job-aarch64-linux
+    # Free some disk space to avoid running out of space during the build.
+    free_disk: true
     os: ubuntu-22.04-arm
 
 envs:

From 9d6a1c980e7de879d6eb64c281aac3cdfdefce3f Mon Sep 17 00:00:00 2001
From: jyn <github@jyn.dev>
Date: Sat, 18 Jan 2025 16:55:31 -0500
Subject: [PATCH 07/13] Shorten linker output even more when `--verbose` is not
 present

- Don't show environment variables. Seeing PATH is almost never useful, and it can be extremely long.
- For .rlibs in the sysroot, replace crate hashes with a `"-*"` string. This will expand to the full crate name when pasted into the shell.
- Move `.rlib` to outside the glob.
- Abbreviate the sysroot path to `<sysroot>` wherever it appears in the arguments.

This also adds an example of the linker output as a run-make test. Currently it only runs on x86_64-unknown-linux-gnu, because each platform has its own linker arguments. So that it's stable across machines, pass BUILD_ROOT as an argument through compiletest through to run-make tests.
---
 Cargo.lock                                    |  1 +
 compiler/rustc_codegen_ssa/Cargo.toml         |  1 +
 .../rustc_codegen_ssa/src/back/command.rs     | 17 ++++-
 compiler/rustc_codegen_ssa/src/back/link.rs   |  1 +
 compiler/rustc_codegen_ssa/src/errors.rs      | 62 ++++++++++++++-----
 src/tools/compiletest/src/runtest/run_make.rs |  2 +
 src/tools/run-make-support/src/lib.rs         |  2 +-
 .../run-make-support/src/path_helpers.rs      |  6 ++
 src/tools/tidy/src/deps.rs                    |  1 +
 tests/run-make/linker-warning/rmake.rs        | 41 ++++++++----
 tests/run-make/linker-warning/short-error.txt |  9 +++
 11 files changed, 115 insertions(+), 28 deletions(-)
 create mode 100644 tests/run-make/linker-warning/short-error.txt

diff --git a/Cargo.lock b/Cargo.lock
index a08d43a014c06..2917b9ef5d91a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3536,6 +3536,7 @@ dependencies = [
  "ar_archive_writer",
  "arrayvec",
  "bitflags",
+ "bstr",
  "cc",
  "either",
  "itertools",
diff --git a/compiler/rustc_codegen_ssa/Cargo.toml b/compiler/rustc_codegen_ssa/Cargo.toml
index 3254b5d38e7a4..904297b987268 100644
--- a/compiler/rustc_codegen_ssa/Cargo.toml
+++ b/compiler/rustc_codegen_ssa/Cargo.toml
@@ -8,6 +8,7 @@ edition = "2021"
 ar_archive_writer = "0.4.2"
 arrayvec = { version = "0.7", default-features = false }
 bitflags = "2.4.1"
+bstr = "1.11.3"
 # Pinned so `cargo update` bumps don't cause breakage. Please also update the
 # `cc` in `rustc_llvm` if you update the `cc` here.
 cc = "=1.2.7"
diff --git a/compiler/rustc_codegen_ssa/src/back/command.rs b/compiler/rustc_codegen_ssa/src/back/command.rs
index b3c5b86ccf430..63023fdba20fc 100644
--- a/compiler/rustc_codegen_ssa/src/back/command.rs
+++ b/compiler/rustc_codegen_ssa/src/back/command.rs
@@ -13,6 +13,7 @@ pub(crate) struct Command {
     args: Vec<OsString>,
     env: Vec<(OsString, OsString)>,
     env_remove: Vec<OsString>,
+    env_clear: bool,
 }
 
 #[derive(Clone)]
@@ -36,7 +37,13 @@ impl Command {
     }
 
     fn _new(program: Program) -> Command {
-        Command { program, args: Vec::new(), env: Vec::new(), env_remove: Vec::new() }
+        Command {
+            program,
+            args: Vec::new(),
+            env: Vec::new(),
+            env_remove: Vec::new(),
+            env_clear: false,
+        }
     }
 
     pub(crate) fn arg<P: AsRef<OsStr>>(&mut self, arg: P) -> &mut Command {
@@ -79,6 +86,11 @@ impl Command {
         self
     }
 
+    pub(crate) fn env_clear(&mut self) -> &mut Command {
+        self.env_clear = true;
+        self
+    }
+
     fn _env_remove(&mut self, key: &OsStr) {
         self.env_remove.push(key.to_owned());
     }
@@ -106,6 +118,9 @@ impl Command {
         for k in &self.env_remove {
             ret.env_remove(k);
         }
+        if self.env_clear {
+            ret.env_clear();
+        }
         ret
     }
 
diff --git a/compiler/rustc_codegen_ssa/src/back/link.rs b/compiler/rustc_codegen_ssa/src/back/link.rs
index df35b5e8426f1..ba59bd1266af7 100644
--- a/compiler/rustc_codegen_ssa/src/back/link.rs
+++ b/compiler/rustc_codegen_ssa/src/back/link.rs
@@ -991,6 +991,7 @@ fn link_natively(
                     command: cmd,
                     escaped_output,
                     verbose: sess.opts.verbose,
+                    sysroot_dir: sess.sysroot.clone(),
                 };
                 sess.dcx().emit_err(err);
                 // If MSVC's `link.exe` was expected but the return code
diff --git a/compiler/rustc_codegen_ssa/src/errors.rs b/compiler/rustc_codegen_ssa/src/errors.rs
index c7213bbc801f9..5e684632fb247 100644
--- a/compiler/rustc_codegen_ssa/src/errors.rs
+++ b/compiler/rustc_codegen_ssa/src/errors.rs
@@ -351,6 +351,7 @@ pub(crate) struct LinkingFailed<'a> {
     pub command: Command,
     pub escaped_output: String,
     pub verbose: bool,
+    pub sysroot_dir: PathBuf,
 }
 
 impl<G: EmissionGuarantee> Diagnostic<'_, G> for LinkingFailed<'_> {
@@ -364,6 +365,8 @@ impl<G: EmissionGuarantee> Diagnostic<'_, G> for LinkingFailed<'_> {
         if self.verbose {
             diag.note(format!("{:?}", self.command));
         } else {
+            self.command.env_clear();
+
             enum ArgGroup {
                 Regular(OsString),
                 Objects(usize),
@@ -398,26 +401,55 @@ impl<G: EmissionGuarantee> Diagnostic<'_, G> for LinkingFailed<'_> {
                     args.push(ArgGroup::Regular(arg));
                 }
             }
-            self.command.args(args.into_iter().map(|arg_group| match arg_group {
-                ArgGroup::Regular(arg) => arg,
-                ArgGroup::Objects(n) => OsString::from(format!("<{n} object files omitted>")),
-                ArgGroup::Rlibs(dir, rlibs) => {
-                    let mut arg = dir.into_os_string();
-                    arg.push("/{");
-                    let mut first = true;
-                    for rlib in rlibs {
-                        if !first {
-                            arg.push(",");
+            let crate_hash = regex::bytes::Regex::new(r"-[0-9a-f]+\.rlib$").unwrap();
+            self.command.args(args.into_iter().map(|arg_group| {
+                match arg_group {
+                    // SAFETY: we are only matching on ASCII, not any surrogate pairs, so any replacements we do will still be valid.
+                    ArgGroup::Regular(arg) => unsafe {
+                        use bstr::ByteSlice;
+                        OsString::from_encoded_bytes_unchecked(
+                            arg.as_encoded_bytes().replace(
+                                self.sysroot_dir.as_os_str().as_encoded_bytes(),
+                                b"<sysroot>",
+                            ),
+                        )
+                    },
+                    ArgGroup::Objects(n) => OsString::from(format!("<{n} object files omitted>")),
+                    ArgGroup::Rlibs(mut dir, rlibs) => {
+                        let is_sysroot_dir = match dir.strip_prefix(&self.sysroot_dir) {
+                            Ok(short) => {
+                                dir = Path::new("<sysroot>").join(short);
+                                true
+                            }
+                            Err(_) => false,
+                        };
+                        let mut arg = dir.into_os_string();
+                        arg.push("/{");
+                        let mut first = true;
+                        for mut rlib in rlibs {
+                            if !first {
+                                arg.push(",");
+                            }
+                            first = false;
+                            if is_sysroot_dir {
+                                // SAFETY: Regex works one byte at a type, and our regex will not match surrogate pairs (because it only matches ascii).
+                                rlib = unsafe {
+                                    OsString::from_encoded_bytes_unchecked(
+                                        crate_hash
+                                            .replace(rlib.as_encoded_bytes(), b"-*")
+                                            .into_owned(),
+                                    )
+                                };
+                            }
+                            arg.push(rlib);
                         }
-                        first = false;
-                        arg.push(rlib);
+                        arg.push("}.rlib");
+                        arg
                     }
-                    arg.push("}");
-                    arg
                 }
             }));
 
-            diag.note(format!("{:?}", self.command));
+            diag.note(format!("{:?}", self.command).trim_start_matches("env -i").to_owned());
             diag.note("some arguments are omitted. use `--verbose` to show all linker arguments");
         }
 
diff --git a/src/tools/compiletest/src/runtest/run_make.rs b/src/tools/compiletest/src/runtest/run_make.rs
index 8a49d63053521..7ef16e4a9667b 100644
--- a/src/tools/compiletest/src/runtest/run_make.rs
+++ b/src/tools/compiletest/src/runtest/run_make.rs
@@ -414,6 +414,8 @@ impl TestCx<'_> {
             // Provide path to checkout root. This is the top-level directory containing
             // rust-lang/rust checkout.
             .env("SOURCE_ROOT", &source_root)
+            // Path to the build directory. This is usually the same as `source_root.join("build").join("host")`.
+            .env("BUILD_ROOT", &build_root)
             // Provide path to stage-corresponding rustc.
             .env("RUSTC", &self.config.rustc_path)
             // Provide the directory to libraries that are needed to run the *compiler*. This is not
diff --git a/src/tools/run-make-support/src/lib.rs b/src/tools/run-make-support/src/lib.rs
index ffd4ca22a0086..7316244b3841d 100644
--- a/src/tools/run-make-support/src/lib.rs
+++ b/src/tools/run-make-support/src/lib.rs
@@ -90,7 +90,7 @@ pub use artifact_names::{
 /// Path-related helpers.
 pub use path_helpers::{
     cwd, filename_contains, filename_not_in_denylist, has_extension, has_prefix, has_suffix,
-    not_contains, path, shallow_find_files, source_root,
+    not_contains, path, shallow_find_files, build_root, source_root,
 };
 
 /// Helpers for scoped test execution where certain properties are attempted to be maintained.
diff --git a/src/tools/run-make-support/src/path_helpers.rs b/src/tools/run-make-support/src/path_helpers.rs
index 87901793a921e..1c59f2feea4c7 100644
--- a/src/tools/run-make-support/src/path_helpers.rs
+++ b/src/tools/run-make-support/src/path_helpers.rs
@@ -34,6 +34,12 @@ pub fn source_root() -> PathBuf {
     env_var("SOURCE_ROOT").into()
 }
 
+/// Path to the build directory root.
+#[must_use]
+pub fn build_root() -> PathBuf {
+    env_var("BUILD_ROOT").into()
+}
+
 /// Browse the directory `path` non-recursively and return all files which respect the parameters
 /// outlined by `closure`.
 #[track_caller]
diff --git a/src/tools/tidy/src/deps.rs b/src/tools/tidy/src/deps.rs
index d4cbc37f6d2b3..e9e2deb240f5f 100644
--- a/src/tools/tidy/src/deps.rs
+++ b/src/tools/tidy/src/deps.rs
@@ -253,6 +253,7 @@ const PERMITTED_RUSTC_DEPENDENCIES: &[&str] = &[
     "bitflags",
     "blake3",
     "block-buffer",
+    "bstr",
     "byteorder", // via ruzstd in object in thorin-dwp
     "cc",
     "cfg-if",
diff --git a/tests/run-make/linker-warning/rmake.rs b/tests/run-make/linker-warning/rmake.rs
index 4d21c5ea5690a..88e467e6cce3f 100644
--- a/tests/run-make/linker-warning/rmake.rs
+++ b/tests/run-make/linker-warning/rmake.rs
@@ -1,8 +1,16 @@
-use run_make_support::{Rustc, rustc};
+use run_make_support::{Rustc, diff, regex, rustc};
 
 fn run_rustc() -> Rustc {
     let mut rustc = rustc();
-    rustc.arg("main.rs").output("main").linker("./fake-linker");
+    rustc
+        .arg("main.rs")
+        // NOTE: `link-self-contained` can vary depending on config.toml.
+        // Make sure we use a consistent value.
+        .arg("-Clink-self-contained=-linker")
+        .arg("-Clinker-flavor=gnu-cc")
+        .arg("-Zunstable-options")
+        .output("main")
+        .linker("./fake-linker");
     rustc
 }
 
@@ -11,18 +19,29 @@ fn main() {
     rustc().arg("fake-linker.rs").output("fake-linker").run();
 
     // Make sure we don't show the linker args unless `--verbose` is passed
-    run_rustc()
-        .link_arg("run_make_error")
-        .verbose()
-        .run_fail()
-        .assert_stderr_contains_regex("fake-linker.*run_make_error")
+    let out = run_rustc().link_arg("run_make_error").verbose().run_fail();
+    out.assert_stderr_contains_regex("fake-linker.*run_make_error")
         .assert_stderr_not_contains("object files omitted")
+        .assert_stderr_contains("PATH=\"")
         .assert_stderr_contains_regex(r"lib(/|\\\\)libstd");
-    run_rustc()
-        .link_arg("run_make_error")
-        .run_fail()
-        .assert_stderr_contains("fake-linker")
+
+    let out = run_rustc().link_arg("run_make_error").run_fail();
+    out.assert_stderr_contains("fake-linker")
         .assert_stderr_contains("object files omitted")
         .assert_stderr_contains_regex(r"\{")
+        .assert_stderr_not_contains("PATH=\"")
         .assert_stderr_not_contains_regex(r"lib(/|\\\\)libstd");
+
+    // FIXME: we should have a version of this for mac and windows
+    if run_make_support::target() == "x86_64-unknown-linux-gnu" {
+        diff()
+            .expected_file("short-error.txt")
+            .actual_text("(linker error)", out.stderr())
+            .normalize(r#"/rustc[^/]*/"#, "/rustc/")
+            .normalize(
+                regex::escape(run_make_support::build_root().to_str().unwrap()),
+                "/build-root",
+            )
+            .run();
+    }
 }
diff --git a/tests/run-make/linker-warning/short-error.txt b/tests/run-make/linker-warning/short-error.txt
new file mode 100644
index 0000000000000..dd3b742bbfd56
--- /dev/null
+++ b/tests/run-make/linker-warning/short-error.txt
@@ -0,0 +1,9 @@
+error: linking with `./fake-linker` failed: exit status: 1
+  |
+  = note:  "./fake-linker" "-m64" "/tmp/rustc/symbols.o" "<2 object files omitted>" "-Wl,--as-needed" "-Wl,-Bstatic" "<sysroot>/lib/rustlib/x86_64-unknown-linux-gnu/lib/{libstd-*,libpanic_unwind-*,libobject-*,libmemchr-*,libaddr2line-*,libgimli-*,librustc_demangle-*,libstd_detect-*,libhashbrown-*,librustc_std_workspace_alloc-*,libminiz_oxide-*,libadler2-*,libunwind-*,libcfg_if-*,liblibc-*,liballoc-*,librustc_std_workspace_core-*,libcore-*,libcompiler_builtins-*}.rlib" "-Wl,-Bdynamic" "-lgcc_s" "-lutil" "-lrt" "-lpthread" "-lm" "-ldl" "-lc" "-Wl,--eh-frame-hdr" "-Wl,-z,noexecstack" "-L" "/build-root/test/run-make/linker-warning/rmake_out" "-L" "<sysroot>/lib/rustlib/x86_64-unknown-linux-gnu/lib" "-o" "main" "-Wl,--gc-sections" "-pie" "-Wl,-z,relro,-z,now" "-nodefaultlibs" "run_make_error"
+  = note: some arguments are omitted. use `--verbose` to show all linker arguments
+  = note: error: baz
+          
+
+error: aborting due to 1 previous error
+

From 9d88b82b99cdd43c79e5fb5d031e522347863db2 Mon Sep 17 00:00:00 2001
From: jyn <github@jyn.dev>
Date: Mon, 20 Jan 2025 16:08:08 -0500
Subject: [PATCH 08/13] Ignore `mermaid.min.js`

It is very long and tends to match a lot of search queries. It's not useful to show with ripgrep.

Note that this does not actually untrack the file; changes can still be committed (although I suspect it may not have been intentional to commit originally?). This just changes how it interacts with tools that use `.gitignore` as a default filter.
---
 .gitignore | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.gitignore b/.gitignore
index f84a3704ca900..ddc8dad95e809 100644
--- a/.gitignore
+++ b/.gitignore
@@ -83,6 +83,7 @@ __pycache__/
 node_modules
 package-lock.json
 package.json
+/src/doc/rustc-dev-guide/mermaid.min.js
 
 ## Rustdoc GUI tests
 tests/rustdoc-gui/src/**.lock

From 51af4d6d228490bb97cc53f9eea50647e0443513 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jakub=20Ber=C3=A1nek?= <berykubik@gmail.com>
Date: Tue, 21 Jan 2025 10:23:14 +0100
Subject: [PATCH 09/13] Add Kobzol on vacation

---
 triagebot.toml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/triagebot.toml b/triagebot.toml
index 5ee52bbf435c9..4a09fe116a572 100644
--- a/triagebot.toml
+++ b/triagebot.toml
@@ -1025,6 +1025,7 @@ users_on_vacation = [
     "nnethercote",
     "spastorino",
     "workingjubilee",
+    "kobzol"
 ]
 
 [[assign.warn_non_default_branch.exceptions]]

From 00381ead1af39db9e5ce24a8da4dda59b714dbf7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jakub=20Ber=C3=A1nek?= <jakub.beranek@vsb.cz>
Date: Thu, 2 Jan 2025 18:02:57 +0100
Subject: [PATCH 10/13] Make it possible to build GCC on CI

This is the first step to enable download of precompiled GCC
---
 src/bootstrap/src/core/build_steps/gcc.rs     | 54 +++++++++++++++++--
 .../host-x86_64/dist-x86_64-linux/Dockerfile  |  1 +
 src/ci/docker/scripts/build-zstd.sh           |  6 +++
 3 files changed, 57 insertions(+), 4 deletions(-)

diff --git a/src/bootstrap/src/core/build_steps/gcc.rs b/src/bootstrap/src/core/build_steps/gcc.rs
index 563b715fa6400..98b8635132b0d 100644
--- a/src/bootstrap/src/core/build_steps/gcc.rs
+++ b/src/bootstrap/src/core/build_steps/gcc.rs
@@ -12,6 +12,8 @@ use std::fs;
 use std::path::PathBuf;
 use std::sync::OnceLock;
 
+use build_helper::ci::CiEnv;
+
 use crate::Kind;
 use crate::core::builder::{Builder, RunConfig, ShouldRun, Step};
 use crate::core::config::TargetSelection;
@@ -112,16 +114,60 @@ impl Step for Gcc {
             return true;
         }
 
-        command(root.join("contrib/download_prerequisites")).current_dir(&root).run(builder);
-        command(root.join("configure"))
+        // GCC creates files (e.g. symlinks to the downloaded dependencies)
+        // in the source directory, which does not work with our CI setup, where we mount
+        // source directories as read-only on Linux.
+        // Therefore, as a part of the build in CI, we first copy the whole source directory
+        // to the build directory, and perform the build from there.
+        let src_dir = if CiEnv::is_ci() {
+            let src_dir = builder.gcc_out(target).join("src");
+            if src_dir.exists() {
+                builder.remove_dir(&src_dir);
+            }
+            builder.create_dir(&src_dir);
+            builder.cp_link_r(&root, &src_dir);
+            src_dir
+        } else {
+            root
+        };
+
+        command(src_dir.join("contrib/download_prerequisites")).current_dir(&src_dir).run(builder);
+        let mut configure_cmd = command(src_dir.join("configure"));
+        configure_cmd
             .current_dir(&out_dir)
+            // On CI, we compile GCC with Clang.
+            // The -Wno-everything flag is needed to make GCC compile with Clang 19.
+            // `-g -O2` are the default flags that are otherwise used by Make.
+            // FIXME(kobzol): change the flags once we have [gcc] configuration in config.toml.
+            .env("CXXFLAGS", "-Wno-everything -g -O2")
+            .env("CFLAGS", "-Wno-everything -g -O2")
             .arg("--enable-host-shared")
             .arg("--enable-languages=jit")
             .arg("--enable-checking=release")
             .arg("--disable-bootstrap")
             .arg("--disable-multilib")
-            .arg(format!("--prefix={}", install_dir.display()))
-            .run(builder);
+            .arg(format!("--prefix={}", install_dir.display()));
+        let cc = builder.build.cc(target).display().to_string();
+        let cc = builder
+            .build
+            .config
+            .ccache
+            .as_ref()
+            .map_or_else(|| cc.clone(), |ccache| format!("{ccache} {cc}"));
+        configure_cmd.env("CC", cc);
+
+        if let Ok(ref cxx) = builder.build.cxx(target) {
+            let cxx = cxx.display().to_string();
+            let cxx = builder
+                .build
+                .config
+                .ccache
+                .as_ref()
+                .map_or_else(|| cxx.clone(), |ccache| format!("{ccache} {cxx}"));
+            configure_cmd.env("CXX", cxx);
+        }
+        configure_cmd.run(builder);
+
         command("make").current_dir(&out_dir).arg(format!("-j{}", builder.jobs())).run(builder);
         command("make").current_dir(&out_dir).arg("install").run(builder);
 
diff --git a/src/ci/docker/host-x86_64/dist-x86_64-linux/Dockerfile b/src/ci/docker/host-x86_64/dist-x86_64-linux/Dockerfile
index dde6fe7f6d0f3..3a39623058255 100644
--- a/src/ci/docker/host-x86_64/dist-x86_64-linux/Dockerfile
+++ b/src/ci/docker/host-x86_64/dist-x86_64-linux/Dockerfile
@@ -34,6 +34,7 @@ RUN yum upgrade -y && \
       python3 \
       unzip \
       wget \
+      flex \
       xz \
       zlib-devel.i686 \
       zlib-devel.x86_64 \
diff --git a/src/ci/docker/scripts/build-zstd.sh b/src/ci/docker/scripts/build-zstd.sh
index a3d37ccc31120..cffa7151e3864 100755
--- a/src/ci/docker/scripts/build-zstd.sh
+++ b/src/ci/docker/scripts/build-zstd.sh
@@ -25,5 +25,11 @@ cd zstd-$ZSTD
 CFLAGS=-fPIC hide_output make -j$(nproc) VERBOSE=1
 hide_output make install
 
+# It doesn't seem to be possible to move destination directory
+# of the `make install` above. We thus copy the built artifacts
+# manually to our custom rustroot, so that it can be found through
+# LD_LIBRARY_PATH.
+cp /usr/local/lib/libzstd* /rustroot/lib64
+
 cd ..
 rm -rf zstd-$ZSTD

From bac4db378b5108d973f17c2010adbfede83d8f2a Mon Sep 17 00:00:00 2001
From: Boxy <rust@boxyuwu.dev>
Date: Tue, 21 Jan 2025 11:10:02 +0000
Subject: [PATCH 11/13] Use `structurally_normalize` instead of manual
 `normalizes-to` goals

---
 .../rustc_next_trait_solver/src/solve/mod.rs  | 42 +++++------
 .../traits/fulfillment_errors.rs              | 21 +++---
 .../src/traits/engine.rs                      | 11 +++
 .../src/traits/structural_normalize.rs        | 71 +++++++------------
 ...not-fn.stderr => is-not-fn.current.stderr} |  8 +--
 .../async-closures/is-not-fn.next.stderr      | 19 +++++
 .../async-await/async-closures/is-not-fn.rs   |  5 +-
 ...stituting-in-region-112823.current.stderr} |  6 +-
 ...nsubstituting-in-region-112823.next.stderr | 29 ++++++++
 ...-type-whensubstituting-in-region-112823.rs |  8 ++-
 ...3941.stderr => issue-33941.current.stderr} |  6 +-
 tests/ui/issues/issue-33941.next.stderr       | 25 +++++++
 tests/ui/issues/issue-33941.rs                |  6 +-
 ...rg-type-mismatch-issue-45727.current.fixed | 12 ++++
 ...-type-mismatch-issue-45727.current.stderr} |  4 +-
 ...losure-arg-type-mismatch-issue-45727.fixed |  5 --
 ...-arg-type-mismatch-issue-45727.next.stderr | 24 +++++++
 .../closure-arg-type-mismatch-issue-45727.rs  | 13 +++-
 ...elate_error_uses_structurally_normalize.rs | 28 ++++++++
 19 files changed, 236 insertions(+), 107 deletions(-)
 rename tests/ui/async-await/async-closures/{is-not-fn.stderr => is-not-fn.current.stderr} (77%)
 create mode 100644 tests/ui/async-await/async-closures/is-not-fn.next.stderr
 rename tests/ui/impl-trait/{ice-unexpected-param-type-whensubstituting-in-region-112823.stderr => ice-unexpected-param-type-whensubstituting-in-region-112823.current.stderr} (96%)
 create mode 100644 tests/ui/impl-trait/ice-unexpected-param-type-whensubstituting-in-region-112823.next.stderr
 rename tests/ui/issues/{issue-33941.stderr => issue-33941.current.stderr} (93%)
 create mode 100644 tests/ui/issues/issue-33941.next.stderr
 create mode 100644 tests/ui/mismatched_types/closure-arg-type-mismatch-issue-45727.current.fixed
 rename tests/ui/mismatched_types/{closure-arg-type-mismatch-issue-45727.stderr => closure-arg-type-mismatch-issue-45727.current.stderr} (92%)
 delete mode 100644 tests/ui/mismatched_types/closure-arg-type-mismatch-issue-45727.fixed
 create mode 100644 tests/ui/mismatched_types/closure-arg-type-mismatch-issue-45727.next.stderr
 create mode 100644 tests/ui/traits/next-solver/diagnostics/alias_relate_error_uses_structurally_normalize.rs

diff --git a/compiler/rustc_next_trait_solver/src/solve/mod.rs b/compiler/rustc_next_trait_solver/src/solve/mod.rs
index 37678bfd8805f..8d1194ee53980 100644
--- a/compiler/rustc_next_trait_solver/src/solve/mod.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/mod.rs
@@ -277,23 +277,7 @@ where
         param_env: I::ParamEnv,
         ty: I::Ty,
     ) -> Result<I::Ty, NoSolution> {
-        if let ty::Alias(..) = ty.kind() {
-            let normalized_ty = self.next_ty_infer();
-            let alias_relate_goal = Goal::new(
-                self.cx(),
-                param_env,
-                ty::PredicateKind::AliasRelate(
-                    ty.into(),
-                    normalized_ty.into(),
-                    ty::AliasRelationDirection::Equate,
-                ),
-            );
-            self.add_goal(GoalSource::Misc, alias_relate_goal);
-            self.try_evaluate_added_goals()?;
-            Ok(self.resolve_vars_if_possible(normalized_ty))
-        } else {
-            Ok(ty)
-        }
+        self.structurally_normalize_term(param_env, ty.into()).map(|term| term.expect_ty())
     }
 
     /// Normalize a const for when it is structurally matched on, or more likely
@@ -308,22 +292,34 @@ where
         param_env: I::ParamEnv,
         ct: I::Const,
     ) -> Result<I::Const, NoSolution> {
-        if let ty::ConstKind::Unevaluated(..) = ct.kind() {
-            let normalized_ct = self.next_const_infer();
+        self.structurally_normalize_term(param_env, ct.into()).map(|term| term.expect_const())
+    }
+
+    /// Normalize a term for when it is structurally matched on.
+    ///
+    /// This function is necessary in nearly all cases before matching on a ty/const.
+    /// Not doing so is likely to be incomplete and therefore unsound during coherence.
+    fn structurally_normalize_term(
+        &mut self,
+        param_env: I::ParamEnv,
+        term: I::Term,
+    ) -> Result<I::Term, NoSolution> {
+        if let Some(_) = term.to_alias_term() {
+            let normalized_term = self.next_term_infer_of_kind(term);
             let alias_relate_goal = Goal::new(
                 self.cx(),
                 param_env,
                 ty::PredicateKind::AliasRelate(
-                    ct.into(),
-                    normalized_ct.into(),
+                    term,
+                    normalized_term,
                     ty::AliasRelationDirection::Equate,
                 ),
             );
             self.add_goal(GoalSource::Misc, alias_relate_goal);
             self.try_evaluate_added_goals()?;
-            Ok(self.resolve_vars_if_possible(normalized_ct))
+            Ok(self.resolve_vars_if_possible(normalized_term))
         } else {
-            Ok(ct)
+            Ok(term)
         }
     }
 
diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs
index c40ba33084569..bcd3b0109b709 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs
@@ -1338,20 +1338,15 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
                     let derive_better_type_error =
                         |alias_term: ty::AliasTerm<'tcx>, expected_term: ty::Term<'tcx>| {
                             let ocx = ObligationCtxt::new(self);
-                            let normalized_term = match expected_term.unpack() {
-                                ty::TermKind::Ty(_) => self.next_ty_var(DUMMY_SP).into(),
-                                ty::TermKind::Const(_) => self.next_const_var(DUMMY_SP).into(),
-                            };
-                            ocx.register_obligation(Obligation::new(
-                                self.tcx,
-                                ObligationCause::dummy(),
+
+                            let Ok(normalized_term) = ocx.structurally_normalize_term(
+                                &ObligationCause::dummy(),
                                 obligation.param_env,
-                                ty::PredicateKind::NormalizesTo(ty::NormalizesTo {
-                                    alias: alias_term,
-                                    term: normalized_term,
-                                }),
-                            ));
-                            let _ = ocx.select_where_possible();
+                                alias_term.to_term(self.tcx),
+                            ) else {
+                                return None;
+                            };
+
                             if let Err(terr) = ocx.eq(
                                 &ObligationCause::dummy(),
                                 obligation.param_env,
diff --git a/compiler/rustc_trait_selection/src/traits/engine.rs b/compiler/rustc_trait_selection/src/traits/engine.rs
index 5e270b62b0081..48b26ee19d4dc 100644
--- a/compiler/rustc_trait_selection/src/traits/engine.rs
+++ b/compiler/rustc_trait_selection/src/traits/engine.rs
@@ -340,4 +340,15 @@ where
             .at(cause, param_env)
             .structurally_normalize_const(value, &mut **self.engine.borrow_mut())
     }
+
+    pub fn structurally_normalize_term(
+        &self,
+        cause: &ObligationCause<'tcx>,
+        param_env: ty::ParamEnv<'tcx>,
+        value: ty::Term<'tcx>,
+    ) -> Result<ty::Term<'tcx>, Vec<E>> {
+        self.infcx
+            .at(cause, param_env)
+            .structurally_normalize_term(value, &mut **self.engine.borrow_mut())
+    }
 }
diff --git a/compiler/rustc_trait_selection/src/traits/structural_normalize.rs b/compiler/rustc_trait_selection/src/traits/structural_normalize.rs
index f8e8f2176c182..458791df66fd6 100644
--- a/compiler/rustc_trait_selection/src/traits/structural_normalize.rs
+++ b/compiler/rustc_trait_selection/src/traits/structural_normalize.rs
@@ -12,39 +12,7 @@ impl<'tcx> At<'_, 'tcx> {
         ty: Ty<'tcx>,
         fulfill_cx: &mut dyn TraitEngine<'tcx, E>,
     ) -> Result<Ty<'tcx>, Vec<E>> {
-        assert!(!ty.is_ty_var(), "should have resolved vars before calling");
-
-        if self.infcx.next_trait_solver() {
-            let ty::Alias(..) = *ty.kind() else {
-                return Ok(ty);
-            };
-
-            let new_infer_ty = self.infcx.next_ty_var(self.cause.span);
-
-            // We simply emit an `alias-eq` goal here, since that will take care of
-            // normalizing the LHS of the projection until it is a rigid projection
-            // (or a not-yet-defined opaque in scope).
-            let obligation = Obligation::new(
-                self.infcx.tcx,
-                self.cause.clone(),
-                self.param_env,
-                ty::PredicateKind::AliasRelate(
-                    ty.into(),
-                    new_infer_ty.into(),
-                    ty::AliasRelationDirection::Equate,
-                ),
-            );
-
-            fulfill_cx.register_predicate_obligation(self.infcx, obligation);
-            let errors = fulfill_cx.select_where_possible(self.infcx);
-            if !errors.is_empty() {
-                return Err(errors);
-            }
-
-            Ok(self.infcx.resolve_vars_if_possible(new_infer_ty))
-        } else {
-            Ok(self.normalize(ty).into_value_registering_obligations(self.infcx, fulfill_cx))
-        }
+        self.structurally_normalize_term(ty.into(), fulfill_cx).map(|term| term.expect_type())
     }
 
     fn structurally_normalize_const<E: 'tcx>(
@@ -52,14 +20,29 @@ impl<'tcx> At<'_, 'tcx> {
         ct: ty::Const<'tcx>,
         fulfill_cx: &mut dyn TraitEngine<'tcx, E>,
     ) -> Result<ty::Const<'tcx>, Vec<E>> {
-        assert!(!ct.is_ct_infer(), "should have resolved vars before calling");
+        if self.infcx.tcx.features().generic_const_exprs() {
+            return Ok(super::evaluate_const(&self.infcx, ct, self.param_env));
+        }
+
+        self.structurally_normalize_term(ct.into(), fulfill_cx).map(|term| term.expect_const())
+    }
+
+    fn structurally_normalize_term<E: 'tcx>(
+        &self,
+        term: ty::Term<'tcx>,
+        fulfill_cx: &mut dyn TraitEngine<'tcx, E>,
+    ) -> Result<ty::Term<'tcx>, Vec<E>> {
+        assert!(!term.is_infer(), "should have resolved vars before calling");
 
         if self.infcx.next_trait_solver() {
-            let ty::ConstKind::Unevaluated(..) = ct.kind() else {
-                return Ok(ct);
-            };
+            if let None = term.to_alias_term() {
+                return Ok(term);
+            }
 
-            let new_infer_ct = self.infcx.next_const_var(self.cause.span);
+            let new_infer = match term.unpack() {
+                ty::TermKind::Ty(_) => self.infcx.next_ty_var(self.cause.span).into(),
+                ty::TermKind::Const(_) => self.infcx.next_const_var(self.cause.span).into(),
+            };
 
             // We simply emit an `alias-eq` goal here, since that will take care of
             // normalizing the LHS of the projection until it is a rigid projection
@@ -68,11 +51,7 @@ impl<'tcx> At<'_, 'tcx> {
                 self.infcx.tcx,
                 self.cause.clone(),
                 self.param_env,
-                ty::PredicateKind::AliasRelate(
-                    ct.into(),
-                    new_infer_ct.into(),
-                    ty::AliasRelationDirection::Equate,
-                ),
+                ty::PredicateKind::AliasRelate(term, new_infer, ty::AliasRelationDirection::Equate),
             );
 
             fulfill_cx.register_predicate_obligation(self.infcx, obligation);
@@ -81,11 +60,9 @@ impl<'tcx> At<'_, 'tcx> {
                 return Err(errors);
             }
 
-            Ok(self.infcx.resolve_vars_if_possible(new_infer_ct))
-        } else if self.infcx.tcx.features().generic_const_exprs() {
-            Ok(super::evaluate_const(&self.infcx, ct, self.param_env))
+            Ok(self.infcx.resolve_vars_if_possible(new_infer))
         } else {
-            Ok(self.normalize(ct).into_value_registering_obligations(self.infcx, fulfill_cx))
+            Ok(self.normalize(term).into_value_registering_obligations(self.infcx, fulfill_cx))
         }
     }
 }
diff --git a/tests/ui/async-await/async-closures/is-not-fn.stderr b/tests/ui/async-await/async-closures/is-not-fn.current.stderr
similarity index 77%
rename from tests/ui/async-await/async-closures/is-not-fn.stderr
rename to tests/ui/async-await/async-closures/is-not-fn.current.stderr
index bc1d5e6e9d112..e7be1d5b10efe 100644
--- a/tests/ui/async-await/async-closures/is-not-fn.stderr
+++ b/tests/ui/async-await/async-closures/is-not-fn.current.stderr
@@ -1,5 +1,5 @@
-error[E0271]: expected `{async closure@is-not-fn.rs:5:14}` to be a closure that returns `()`, but it returns `{async closure body@$DIR/is-not-fn.rs:5:23: 5:25}`
-  --> $DIR/is-not-fn.rs:5:14
+error[E0271]: expected `{async closure@is-not-fn.rs:8:14}` to be a closure that returns `()`, but it returns `{async closure body@$DIR/is-not-fn.rs:8:23: 8:25}`
+  --> $DIR/is-not-fn.rs:8:14
    |
 LL |     needs_fn(async || {});
    |     -------- ^^^^^^^^^^^ expected `()`, found `async` closure body
@@ -7,9 +7,9 @@ LL |     needs_fn(async || {});
    |     required by a bound introduced by this call
    |
    = note:         expected unit type `()`
-           found `async` closure body `{async closure body@$DIR/is-not-fn.rs:5:23: 5:25}`
+           found `async` closure body `{async closure body@$DIR/is-not-fn.rs:8:23: 8:25}`
 note: required by a bound in `needs_fn`
-  --> $DIR/is-not-fn.rs:4:25
+  --> $DIR/is-not-fn.rs:7:25
    |
 LL |     fn needs_fn(x: impl FnOnce()) {}
    |                         ^^^^^^^^ required by this bound in `needs_fn`
diff --git a/tests/ui/async-await/async-closures/is-not-fn.next.stderr b/tests/ui/async-await/async-closures/is-not-fn.next.stderr
new file mode 100644
index 0000000000000..e7be1d5b10efe
--- /dev/null
+++ b/tests/ui/async-await/async-closures/is-not-fn.next.stderr
@@ -0,0 +1,19 @@
+error[E0271]: expected `{async closure@is-not-fn.rs:8:14}` to be a closure that returns `()`, but it returns `{async closure body@$DIR/is-not-fn.rs:8:23: 8:25}`
+  --> $DIR/is-not-fn.rs:8:14
+   |
+LL |     needs_fn(async || {});
+   |     -------- ^^^^^^^^^^^ expected `()`, found `async` closure body
+   |     |
+   |     required by a bound introduced by this call
+   |
+   = note:         expected unit type `()`
+           found `async` closure body `{async closure body@$DIR/is-not-fn.rs:8:23: 8:25}`
+note: required by a bound in `needs_fn`
+  --> $DIR/is-not-fn.rs:7:25
+   |
+LL |     fn needs_fn(x: impl FnOnce()) {}
+   |                         ^^^^^^^^ required by this bound in `needs_fn`
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0271`.
diff --git a/tests/ui/async-await/async-closures/is-not-fn.rs b/tests/ui/async-await/async-closures/is-not-fn.rs
index 4acaa5d9809a1..eacd07b7cdd86 100644
--- a/tests/ui/async-await/async-closures/is-not-fn.rs
+++ b/tests/ui/async-await/async-closures/is-not-fn.rs
@@ -1,7 +1,10 @@
 //@ edition:2021
+//@ revisions: current next
+//@ ignore-compare-mode-next-solver (explicit revisions)
+//@[next] compile-flags: -Znext-solver
 
 fn main() {
     fn needs_fn(x: impl FnOnce()) {}
     needs_fn(async || {});
-    //~^ ERROR expected `{async closure@is-not-fn.rs:5:14}` to be a closure that returns `()`
+    //~^ ERROR expected `{async closure@is-not-fn.rs:8:14}` to be a closure that returns `()`
 }
diff --git a/tests/ui/impl-trait/ice-unexpected-param-type-whensubstituting-in-region-112823.stderr b/tests/ui/impl-trait/ice-unexpected-param-type-whensubstituting-in-region-112823.current.stderr
similarity index 96%
rename from tests/ui/impl-trait/ice-unexpected-param-type-whensubstituting-in-region-112823.stderr
rename to tests/ui/impl-trait/ice-unexpected-param-type-whensubstituting-in-region-112823.current.stderr
index 28a0f7461e2d5..146a3d21068cd 100644
--- a/tests/ui/impl-trait/ice-unexpected-param-type-whensubstituting-in-region-112823.stderr
+++ b/tests/ui/impl-trait/ice-unexpected-param-type-whensubstituting-in-region-112823.current.stderr
@@ -1,11 +1,11 @@
 error[E0407]: method `line_stream` is not a member of trait `X`
-  --> $DIR/ice-unexpected-param-type-whensubstituting-in-region-112823.rs:25:5
+  --> $DIR/ice-unexpected-param-type-whensubstituting-in-region-112823.rs:28:5
    |
 LL |     fn line_stream<'a, Repr>(&'a self) -> Self::LineStreamFut<'a, Repr> {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not a member of trait `X`
 
 error[E0049]: type `LineStream` has 0 type parameters but its trait declaration has 1 type parameter
-  --> $DIR/ice-unexpected-param-type-whensubstituting-in-region-112823.rs:22:21
+  --> $DIR/ice-unexpected-param-type-whensubstituting-in-region-112823.rs:25:21
    |
 LL |     type LineStream<'a, Repr>
    |                     --  ----
@@ -18,7 +18,7 @@ LL |     type LineStream<'c, 'd> = impl Stream;
    |                     found 0 type parameters
 
 error[E0277]: `()` is not a future
-  --> $DIR/ice-unexpected-param-type-whensubstituting-in-region-112823.rs:25:43
+  --> $DIR/ice-unexpected-param-type-whensubstituting-in-region-112823.rs:28:43
    |
 LL |     fn line_stream<'a, Repr>(&'a self) -> Self::LineStreamFut<'a, Repr> {}
    |                                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `()` is not a future
diff --git a/tests/ui/impl-trait/ice-unexpected-param-type-whensubstituting-in-region-112823.next.stderr b/tests/ui/impl-trait/ice-unexpected-param-type-whensubstituting-in-region-112823.next.stderr
new file mode 100644
index 0000000000000..3c24eb9adbee7
--- /dev/null
+++ b/tests/ui/impl-trait/ice-unexpected-param-type-whensubstituting-in-region-112823.next.stderr
@@ -0,0 +1,29 @@
+error[E0407]: method `line_stream` is not a member of trait `X`
+  --> $DIR/ice-unexpected-param-type-whensubstituting-in-region-112823.rs:28:5
+   |
+LL |     fn line_stream<'a, Repr>(&'a self) -> Self::LineStreamFut<'a, Repr> {}
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not a member of trait `X`
+
+error[E0049]: type `LineStream` has 0 type parameters but its trait declaration has 1 type parameter
+  --> $DIR/ice-unexpected-param-type-whensubstituting-in-region-112823.rs:25:21
+   |
+LL |     type LineStream<'a, Repr>
+   |                     --  ----
+   |                     |
+   |                     expected 1 type parameter
+...
+LL |     type LineStream<'c, 'd> = impl Stream;
+   |                     ^^  ^^
+   |                     |
+   |                     found 0 type parameters
+
+error[E0271]: type mismatch resolving `<Y as X>::LineStreamFut<'a, Repr> == ()`
+  --> $DIR/ice-unexpected-param-type-whensubstituting-in-region-112823.rs:28:43
+   |
+LL |     fn line_stream<'a, Repr>(&'a self) -> Self::LineStreamFut<'a, Repr> {}
+   |                                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ types differ
+
+error: aborting due to 3 previous errors
+
+Some errors have detailed explanations: E0049, E0271, E0407.
+For more information about an error, try `rustc --explain E0049`.
diff --git a/tests/ui/impl-trait/ice-unexpected-param-type-whensubstituting-in-region-112823.rs b/tests/ui/impl-trait/ice-unexpected-param-type-whensubstituting-in-region-112823.rs
index d6fa56663a3f0..c97bd1799436f 100644
--- a/tests/ui/impl-trait/ice-unexpected-param-type-whensubstituting-in-region-112823.rs
+++ b/tests/ui/impl-trait/ice-unexpected-param-type-whensubstituting-in-region-112823.rs
@@ -1,3 +1,6 @@
+//@ revisions: current next
+//@ ignore-compare-mode-next-solver (explicit revisions)
+//@[next] compile-flags: -Znext-solver
 // test for ICE #112823
 // Unexpected parameter Type(Repr) when substituting in region
 
@@ -23,8 +26,9 @@ impl X for Y {
     //~^ ERROR type `LineStream` has 0 type parameters but its trait declaration has 1 type parameter
     type LineStreamFut<'a, Repr> = impl Future<Output = Self::LineStream<'a, Repr>>;
     fn line_stream<'a, Repr>(&'a self) -> Self::LineStreamFut<'a, Repr> {}
-    //~^ ERROR `()` is not a future
-    //~^^ method `line_stream` is not a member of trait `X`
+    //[current]~^ ERROR `()` is not a future
+    //[next]~^^ ERROR type mismatch resolving `<Y as X>::LineStreamFut<'a, Repr> == ()`
+    //~^^^ method `line_stream` is not a member of trait `X`
 }
 
 pub fn main() {}
diff --git a/tests/ui/issues/issue-33941.stderr b/tests/ui/issues/issue-33941.current.stderr
similarity index 93%
rename from tests/ui/issues/issue-33941.stderr
rename to tests/ui/issues/issue-33941.current.stderr
index 9535ea57430d0..d653bbd327427 100644
--- a/tests/ui/issues/issue-33941.stderr
+++ b/tests/ui/issues/issue-33941.current.stderr
@@ -1,5 +1,5 @@
 error[E0271]: expected `Iter<'_, _, _>` to be an iterator that yields `&_`, but it yields `(&_, &_)`
-  --> $DIR/issue-33941.rs:6:36
+  --> $DIR/issue-33941.rs:9:36
    |
 LL |     for _ in HashMap::new().iter().cloned() {}
    |                                    ^^^^^^ expected `&_`, found `(&_, &_)`
@@ -7,7 +7,7 @@ LL |     for _ in HashMap::new().iter().cloned() {}
    = note: expected reference `&_`
                   found tuple `(&_, &_)`
 note: the method call chain might not have had the expected associated types
-  --> $DIR/issue-33941.rs:6:29
+  --> $DIR/issue-33941.rs:9:29
    |
 LL |     for _ in HashMap::new().iter().cloned() {}
    |              -------------- ^^^^^^ `Iterator::Item` is `(&_, &_)` here
@@ -17,7 +17,7 @@ note: required by a bound in `cloned`
   --> $SRC_DIR/core/src/iter/traits/iterator.rs:LL:COL
 
 error[E0271]: expected `Iter<'_, _, _>` to be an iterator that yields `&_`, but it yields `(&_, &_)`
-  --> $DIR/issue-33941.rs:6:14
+  --> $DIR/issue-33941.rs:9:14
    |
 LL |     for _ in HashMap::new().iter().cloned() {}
    |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `&_`, found `(&_, &_)`
diff --git a/tests/ui/issues/issue-33941.next.stderr b/tests/ui/issues/issue-33941.next.stderr
new file mode 100644
index 0000000000000..a5a6e51545a58
--- /dev/null
+++ b/tests/ui/issues/issue-33941.next.stderr
@@ -0,0 +1,25 @@
+error[E0271]: expected `Iter<'_, _, _>` to be an iterator that yields `&_`, but it yields `(&_, &_)`
+  --> $DIR/issue-33941.rs:9:36
+   |
+LL |     for _ in HashMap::new().iter().cloned() {}
+   |                                    ^^^^^^ expected `&_`, found `(&_, &_)`
+   |
+   = note: expected reference `&_`
+                  found tuple `(&_, &_)`
+note: required by a bound in `cloned`
+  --> $SRC_DIR/core/src/iter/traits/iterator.rs:LL:COL
+
+error[E0271]: expected `Iter<'_, _, _>` to be an iterator that yields `&_`, but it yields `(&_, &_)`
+  --> $DIR/issue-33941.rs:9:14
+   |
+LL |     for _ in HashMap::new().iter().cloned() {}
+   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `&_`, found `(&_, &_)`
+   |
+   = note: expected reference `&_`
+                  found tuple `(&_, &_)`
+   = note: required for `Cloned<std::collections::hash_map::Iter<'_, _, _>>` to implement `Iterator`
+   = note: required for `Cloned<std::collections::hash_map::Iter<'_, _, _>>` to implement `IntoIterator`
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0271`.
diff --git a/tests/ui/issues/issue-33941.rs b/tests/ui/issues/issue-33941.rs
index 7b5be30834b9d..b0736204a0811 100644
--- a/tests/ui/issues/issue-33941.rs
+++ b/tests/ui/issues/issue-33941.rs
@@ -1,8 +1,12 @@
+//@ revisions: current next
+//@ ignore-compare-mode-next-solver (explicit revisions)
+//@[next] compile-flags: -Znext-solver
 //@ compile-flags: -Zdeduplicate-diagnostics=yes
 
 use std::collections::HashMap;
 
 fn main() {
-    for _ in HashMap::new().iter().cloned() {} //~ ERROR expected `Iter<'_, _, _>` to be an iterator that yields `&_`, but it yields `(&_, &_)`
+    for _ in HashMap::new().iter().cloned() {}
     //~^ ERROR expected `Iter<'_, _, _>` to be an iterator that yields `&_`, but it yields `(&_, &_)`
+    //~| ERROR expected `Iter<'_, _, _>` to be an iterator that yields `&_`, but it yields `(&_, &_)`
 }
diff --git a/tests/ui/mismatched_types/closure-arg-type-mismatch-issue-45727.current.fixed b/tests/ui/mismatched_types/closure-arg-type-mismatch-issue-45727.current.fixed
new file mode 100644
index 0000000000000..7383ab177dc31
--- /dev/null
+++ b/tests/ui/mismatched_types/closure-arg-type-mismatch-issue-45727.current.fixed
@@ -0,0 +1,12 @@
+//@ revisions: current next
+//@ ignore-compare-mode-next-solver (explicit revisions)
+//@[next] compile-flags: -Znext-solver
+//@[current] run-rustfix
+fn main() {
+    let _ = (-10..=10).find(|x: &i32| x.signum() == 0);
+    //[current]~^ ERROR type mismatch in closure arguments
+    //[next]~^^ ERROR expected a `FnMut(&<RangeInclusive<{integer}> as Iterator>::Item)` closure, found
+    let _ = (-10..=10).find(|x: &i32| x.signum() == 0);
+    //[current]~^ ERROR type mismatch in closure arguments
+    //[next]~^^ ERROR expected `RangeInclusive<{integer}>` to be an iterator that yields `&&i32`, but it yields `{integer}`
+}
diff --git a/tests/ui/mismatched_types/closure-arg-type-mismatch-issue-45727.stderr b/tests/ui/mismatched_types/closure-arg-type-mismatch-issue-45727.current.stderr
similarity index 92%
rename from tests/ui/mismatched_types/closure-arg-type-mismatch-issue-45727.stderr
rename to tests/ui/mismatched_types/closure-arg-type-mismatch-issue-45727.current.stderr
index e52e095e9f729..c35d70a635cbd 100644
--- a/tests/ui/mismatched_types/closure-arg-type-mismatch-issue-45727.stderr
+++ b/tests/ui/mismatched_types/closure-arg-type-mismatch-issue-45727.current.stderr
@@ -1,5 +1,5 @@
 error[E0631]: type mismatch in closure arguments
-  --> $DIR/closure-arg-type-mismatch-issue-45727.rs:3:24
+  --> $DIR/closure-arg-type-mismatch-issue-45727.rs:6:24
    |
 LL |     let _ = (-10..=10).find(|x: i32| x.signum() == 0);
    |                        ^^^^ -------- found signature defined here
@@ -16,7 +16,7 @@ LL |     let _ = (-10..=10).find(|x: &i32| x.signum() == 0);
    |                                 +
 
 error[E0631]: type mismatch in closure arguments
-  --> $DIR/closure-arg-type-mismatch-issue-45727.rs:4:24
+  --> $DIR/closure-arg-type-mismatch-issue-45727.rs:9:24
    |
 LL |     let _ = (-10..=10).find(|x: &&&i32| x.signum() == 0);
    |                        ^^^^ ----------- found signature defined here
diff --git a/tests/ui/mismatched_types/closure-arg-type-mismatch-issue-45727.fixed b/tests/ui/mismatched_types/closure-arg-type-mismatch-issue-45727.fixed
deleted file mode 100644
index e6e3e1551e959..0000000000000
--- a/tests/ui/mismatched_types/closure-arg-type-mismatch-issue-45727.fixed
+++ /dev/null
@@ -1,5 +0,0 @@
-//@ run-rustfix
-fn main() {
-    let _ = (-10..=10).find(|x: &i32| x.signum() == 0); //~ ERROR type mismatch in closure arguments
-    let _ = (-10..=10).find(|x: &i32| x.signum() == 0); //~ ERROR type mismatch in closure arguments
-}
diff --git a/tests/ui/mismatched_types/closure-arg-type-mismatch-issue-45727.next.stderr b/tests/ui/mismatched_types/closure-arg-type-mismatch-issue-45727.next.stderr
new file mode 100644
index 0000000000000..6104a08933737
--- /dev/null
+++ b/tests/ui/mismatched_types/closure-arg-type-mismatch-issue-45727.next.stderr
@@ -0,0 +1,24 @@
+error[E0277]: expected a `FnMut(&<RangeInclusive<{integer}> as Iterator>::Item)` closure, found `{closure@$DIR/closure-arg-type-mismatch-issue-45727.rs:6:29: 6:37}`
+  --> $DIR/closure-arg-type-mismatch-issue-45727.rs:6:29
+   |
+LL |     let _ = (-10..=10).find(|x: i32| x.signum() == 0);
+   |                        ---- ^^^^^^^^^^^^^^^^^^^^^^^^ expected an `FnMut(&<RangeInclusive<{integer}> as Iterator>::Item)` closure, found `{closure@$DIR/closure-arg-type-mismatch-issue-45727.rs:6:29: 6:37}`
+   |                        |
+   |                        required by a bound introduced by this call
+   |
+   = help: the trait `for<'a> FnMut(&'a <RangeInclusive<{integer}> as Iterator>::Item)` is not implemented for closure `{closure@$DIR/closure-arg-type-mismatch-issue-45727.rs:6:29: 6:37}`
+   = note: expected a closure with arguments `(i32,)`
+              found a closure with arguments `(&<RangeInclusive<{integer}> as Iterator>::Item,)`
+note: required by a bound in `find`
+  --> $SRC_DIR/core/src/iter/traits/iterator.rs:LL:COL
+
+error[E0271]: expected `RangeInclusive<{integer}>` to be an iterator that yields `&&i32`, but it yields `{integer}`
+  --> $DIR/closure-arg-type-mismatch-issue-45727.rs:9:33
+   |
+LL |     let _ = (-10..=10).find(|x: &&&i32| x.signum() == 0);
+   |                                 ^^^^^^ expected `&&i32`, found integer
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0271, E0277.
+For more information about an error, try `rustc --explain E0271`.
diff --git a/tests/ui/mismatched_types/closure-arg-type-mismatch-issue-45727.rs b/tests/ui/mismatched_types/closure-arg-type-mismatch-issue-45727.rs
index 64e815606d427..668a1a7a29c6f 100644
--- a/tests/ui/mismatched_types/closure-arg-type-mismatch-issue-45727.rs
+++ b/tests/ui/mismatched_types/closure-arg-type-mismatch-issue-45727.rs
@@ -1,5 +1,12 @@
-//@ run-rustfix
+//@ revisions: current next
+//@ ignore-compare-mode-next-solver (explicit revisions)
+//@[next] compile-flags: -Znext-solver
+//@[current] run-rustfix
 fn main() {
-    let _ = (-10..=10).find(|x: i32| x.signum() == 0); //~ ERROR type mismatch in closure arguments
-    let _ = (-10..=10).find(|x: &&&i32| x.signum() == 0); //~ ERROR type mismatch in closure arguments
+    let _ = (-10..=10).find(|x: i32| x.signum() == 0);
+    //[current]~^ ERROR type mismatch in closure arguments
+    //[next]~^^ ERROR expected a `FnMut(&<RangeInclusive<{integer}> as Iterator>::Item)` closure, found
+    let _ = (-10..=10).find(|x: &&&i32| x.signum() == 0);
+    //[current]~^ ERROR type mismatch in closure arguments
+    //[next]~^^ ERROR expected `RangeInclusive<{integer}>` to be an iterator that yields `&&i32`, but it yields `{integer}`
 }
diff --git a/tests/ui/traits/next-solver/diagnostics/alias_relate_error_uses_structurally_normalize.rs b/tests/ui/traits/next-solver/diagnostics/alias_relate_error_uses_structurally_normalize.rs
new file mode 100644
index 0000000000000..5cea9bb74d793
--- /dev/null
+++ b/tests/ui/traits/next-solver/diagnostics/alias_relate_error_uses_structurally_normalize.rs
@@ -0,0 +1,28 @@
+//@ compile-flags: -Znext-solver
+
+// When encountering a fulfillment error from an `alias-relate` goal failing, we
+// would previously manually construct a `normalizes-to` goal involving the alias
+// and an infer var. This would then ICE as normalization would return a nested
+// goal (the `T: Sized` from the `Trait` impl for `Foo<T>` below) from the root goal
+// which is not supported.
+
+struct Foo<T>(T);
+
+trait Trait {
+    type Assoc;
+}
+
+// `T: Sized` being explicit is not required, but the bound being present *is*.
+impl<T: Sized> Trait for Foo<T> {
+    type Assoc = u64;
+}
+
+fn bar<T: Trait<Assoc = u32>>(_: T) {}
+
+fn main() {
+    let foo = Foo(Default::default());
+    bar(foo);
+    //~^ ERROR: type mismatch resolving `<Foo<_> as Trait>::Assoc == u32`
+    // Here diagnostics would manually construct a `<Foo<?y> as Trait>::Assoc normalizes-to ?x` goal
+    // which would return a nested goal of `?y: Sized` from the impl.
+}

From dbf4040b66eff160bd48c9c04aa8ceb026c19d42 Mon Sep 17 00:00:00 2001
From: Boxy <rust@boxyuwu.dev>
Date: Tue, 21 Jan 2025 11:22:30 +0000
Subject: [PATCH 12/13] Rename `structurally_normalize` to
 `structurally_normalize_ty`

---
 compiler/rustc_borrowck/src/type_check/canonical.rs       | 4 ++--
 compiler/rustc_hir_analysis/src/autoderef.rs              | 8 ++++----
 compiler/rustc_hir_analysis/src/coherence/orphan.rs       | 2 +-
 compiler/rustc_hir_typeck/src/coercion.rs                 | 2 +-
 compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs            | 2 +-
 compiler/rustc_trait_selection/src/traits/coherence.rs    | 2 +-
 compiler/rustc_trait_selection/src/traits/engine.rs       | 4 ++--
 .../src/traits/structural_normalize.rs                    | 2 +-
 8 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/compiler/rustc_borrowck/src/type_check/canonical.rs b/compiler/rustc_borrowck/src/type_check/canonical.rs
index 3903c45fda529..bffd9f383343d 100644
--- a/compiler/rustc_borrowck/src/type_check/canonical.rs
+++ b/compiler/rustc_borrowck/src/type_check/canonical.rs
@@ -185,7 +185,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 CustomTypeOp::new(
                     |ocx| {
                         let structurally_normalize = |ty| {
-                            ocx.structurally_normalize(
+                            ocx.structurally_normalize_ty(
                                 &ObligationCause::misc(
                                     location.to_locations().span(body),
                                     body.source.def_id().expect_local(),
@@ -230,7 +230,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 ConstraintCategory::Boring,
                 CustomTypeOp::new(
                     |ocx| {
-                        ocx.structurally_normalize(
+                        ocx.structurally_normalize_ty(
                             &ObligationCause::misc(
                                 location.to_locations().span(body),
                                 body.source.def_id().expect_local(),
diff --git a/compiler/rustc_hir_analysis/src/autoderef.rs b/compiler/rustc_hir_analysis/src/autoderef.rs
index d8e9227a87c86..b3eade8c8ae47 100644
--- a/compiler/rustc_hir_analysis/src/autoderef.rs
+++ b/compiler/rustc_hir_analysis/src/autoderef.rs
@@ -86,7 +86,7 @@ impl<'a, 'tcx> Iterator for Autoderef<'a, 'tcx> {
                 if self.infcx.next_trait_solver()
                     && let ty::Alias(..) = ty.kind()
                 {
-                    let (normalized_ty, obligations) = self.structurally_normalize(ty)?;
+                    let (normalized_ty, obligations) = self.structurally_normalize_ty(ty)?;
                     self.state.obligations.extend(obligations);
                     (AutoderefKind::Builtin, normalized_ty)
                 } else {
@@ -166,7 +166,7 @@ impl<'a, 'tcx> Autoderef<'a, 'tcx> {
         }
 
         let (normalized_ty, obligations) =
-            self.structurally_normalize(Ty::new_projection(tcx, trait_target_def_id, [ty]))?;
+            self.structurally_normalize_ty(Ty::new_projection(tcx, trait_target_def_id, [ty]))?;
         debug!("overloaded_deref_ty({:?}) = ({:?}, {:?})", ty, normalized_ty, obligations);
         self.state.obligations.extend(obligations);
 
@@ -174,12 +174,12 @@ impl<'a, 'tcx> Autoderef<'a, 'tcx> {
     }
 
     #[instrument(level = "debug", skip(self), ret)]
-    pub fn structurally_normalize(
+    pub fn structurally_normalize_ty(
         &self,
         ty: Ty<'tcx>,
     ) -> Option<(Ty<'tcx>, PredicateObligations<'tcx>)> {
         let ocx = ObligationCtxt::new(self.infcx);
-        let Ok(normalized_ty) = ocx.structurally_normalize(
+        let Ok(normalized_ty) = ocx.structurally_normalize_ty(
             &traits::ObligationCause::misc(self.span, self.body_id),
             self.param_env,
             ty,
diff --git a/compiler/rustc_hir_analysis/src/coherence/orphan.rs b/compiler/rustc_hir_analysis/src/coherence/orphan.rs
index 7d651155781a1..d17ee86ba667c 100644
--- a/compiler/rustc_hir_analysis/src/coherence/orphan.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/orphan.rs
@@ -320,7 +320,7 @@ fn orphan_check<'tcx>(
         }
 
         let ty = if infcx.next_trait_solver() {
-            ocx.structurally_normalize(
+            ocx.structurally_normalize_ty(
                 &cause,
                 ty::ParamEnv::empty(),
                 infcx.resolve_vars_if_possible(ty),
diff --git a/compiler/rustc_hir_typeck/src/coercion.rs b/compiler/rustc_hir_typeck/src/coercion.rs
index 6945dbc321697..3c25f4a8b7cc2 100644
--- a/compiler/rustc_hir_typeck/src/coercion.rs
+++ b/compiler/rustc_hir_typeck/src/coercion.rs
@@ -1124,7 +1124,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 if self.next_trait_solver()
                     && let ty::Alias(..) = ty.kind()
                 {
-                    ocx.structurally_normalize(&cause, self.param_env, ty)
+                    ocx.structurally_normalize_ty(&cause, self.param_env, ty)
                 } else {
                     Ok(ty)
                 }
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
index be6d9570e35b4..e26c09e3601cb 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
@@ -1433,7 +1433,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // in a reentrant borrow, causing an ICE.
             let result = self
                 .at(&self.misc(sp), self.param_env)
-                .structurally_normalize(ty, &mut **self.fulfillment_cx.borrow_mut());
+                .structurally_normalize_ty(ty, &mut **self.fulfillment_cx.borrow_mut());
             match result {
                 Ok(normalized_ty) => normalized_ty,
                 Err(errors) => {
diff --git a/compiler/rustc_trait_selection/src/traits/coherence.rs b/compiler/rustc_trait_selection/src/traits/coherence.rs
index e27143f139641..50d47d20e1a4e 100644
--- a/compiler/rustc_trait_selection/src/traits/coherence.rs
+++ b/compiler/rustc_trait_selection/src/traits/coherence.rs
@@ -709,7 +709,7 @@ impl<'a, 'tcx> ProofTreeVisitor<'tcx> for AmbiguityCausesVisitor<'a, 'tcx> {
             if matches!(ty.kind(), ty::Alias(..)) {
                 let ocx = ObligationCtxt::new(infcx);
                 ty = ocx
-                    .structurally_normalize(&ObligationCause::dummy(), param_env, ty)
+                    .structurally_normalize_ty(&ObligationCause::dummy(), param_env, ty)
                     .map_err(|_| ())?;
                 if !ocx.select_where_possible().is_empty() {
                     return Err(());
diff --git a/compiler/rustc_trait_selection/src/traits/engine.rs b/compiler/rustc_trait_selection/src/traits/engine.rs
index 48b26ee19d4dc..4a3983fca31ce 100644
--- a/compiler/rustc_trait_selection/src/traits/engine.rs
+++ b/compiler/rustc_trait_selection/src/traits/engine.rs
@@ -319,7 +319,7 @@ where
         self.infcx.at(cause, param_env).deeply_normalize(value, &mut **self.engine.borrow_mut())
     }
 
-    pub fn structurally_normalize(
+    pub fn structurally_normalize_ty(
         &self,
         cause: &ObligationCause<'tcx>,
         param_env: ty::ParamEnv<'tcx>,
@@ -327,7 +327,7 @@ where
     ) -> Result<Ty<'tcx>, Vec<E>> {
         self.infcx
             .at(cause, param_env)
-            .structurally_normalize(value, &mut **self.engine.borrow_mut())
+            .structurally_normalize_ty(value, &mut **self.engine.borrow_mut())
     }
 
     pub fn structurally_normalize_const(
diff --git a/compiler/rustc_trait_selection/src/traits/structural_normalize.rs b/compiler/rustc_trait_selection/src/traits/structural_normalize.rs
index 458791df66fd6..e6d5d336b8d55 100644
--- a/compiler/rustc_trait_selection/src/traits/structural_normalize.rs
+++ b/compiler/rustc_trait_selection/src/traits/structural_normalize.rs
@@ -7,7 +7,7 @@ use crate::traits::{NormalizeExt, Obligation};
 
 #[extension(pub trait StructurallyNormalizeExt<'tcx>)]
 impl<'tcx> At<'_, 'tcx> {
-    fn structurally_normalize<E: 'tcx>(
+    fn structurally_normalize_ty<E: 'tcx>(
         &self,
         ty: Ty<'tcx>,
         fulfill_cx: &mut dyn TraitEngine<'tcx, E>,

From 587b9c64d02c5ccf35eeef74d635dc3596bdf74a Mon Sep 17 00:00:00 2001
From: Caio <c410.f3r@gmail.com>
Date: Tue, 21 Jan 2025 08:45:33 -0300
Subject: [PATCH 13/13] [cfg_match] Document the use of expressions

---
 library/core/src/macros/mod.rs | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/library/core/src/macros/mod.rs b/library/core/src/macros/mod.rs
index 5c04e5a40df09..6b93b44226d76 100644
--- a/library/core/src/macros/mod.rs
+++ b/library/core/src/macros/mod.rs
@@ -313,6 +313,17 @@ pub macro cfg_match {
 ///     }
 /// }
 /// ```
+///
+/// If desired, it is possible to return expressions through the use of surrounding braces:
+///
+/// ```
+/// #![feature(cfg_match)]
+///
+/// let _some_string = cfg_match! {{
+///     unix => { "With great power comes great electricity bills" },
+///     _ => { "Behind every successful diet is an unwatched pizza" },
+/// }};
+/// ```
 #[cfg(not(bootstrap))]
 #[unstable(feature = "cfg_match", issue = "115585")]
 #[rustc_diagnostic_item = "cfg_match"]