Merge commit '59a81c2ca1edc88ad3ac4b27a8e03977ffb8e73a' into subtree-update_cg_gcc_2025_01_12

19 files changed, 220 insertions, 1211 deletions

diff --git a/compiler/rustc_codegen_gcc/tests/failing-non-lto-tests.txt b/compiler/rustc_codegen_gcc/tests/failing-non-lto-tests.txt
deleted file mode 100644
index 384dfdc26fb..00000000000
--- a/compiler/rustc_codegen_gcc/tests/failing-non-lto-tests.txt
+++ /dev/null
@@ -1,11 +0,0 @@
-tests/ui/issues/issue-44056.rs
-tests/ui/lto/fat-lto.rs
-tests/ui/lto/debuginfo-lto.rs
-tests/ui/lto/lto-many-codegen-units.rs
-tests/ui/lto/issue-100772.rs
-tests/ui/lto/lto-rustc-loads-linker-plugin.rs
-tests/ui/panic-runtime/lto-unwind.rs
-tests/ui/sanitizer/issue-111184-cfi-coroutine-witness.rs
-tests/ui/sepcomp/sepcomp-lib-lto.rs
-tests/ui/lto/lto-opt-level-s.rs
-tests/ui/lto/lto-opt-level-z.rs
diff --git a/compiler/rustc_codegen_gcc/tests/failing-ui-tests.txt b/compiler/rustc_codegen_gcc/tests/failing-ui-tests.txt
index 457072b1a5b..082958bfe1f 100644
--- a/compiler/rustc_codegen_gcc/tests/failing-ui-tests.txt
+++ b/compiler/rustc_codegen_gcc/tests/failing-ui-tests.txt
@@ -69,20 +69,22 @@ tests/ui/mir/mir_heavy_promoted.rs
 tests/ui/consts/const_cmp_type_id.rs
 tests/ui/consts/issue-73976-monomorphic.rs
 tests/ui/consts/issue-94675.rs
-tests/ui/rfcs/rfc-2632-const-trait-impl/const-drop-fail.rs
-tests/ui/rfcs/rfc-2632-const-trait-impl/const-drop.rs
+tests/ui/traits/const-traits/const-drop-fail.rs
+tests/ui/traits/const-traits/const-drop.rs
 tests/ui/runtime/on-broken-pipe/child-processes.rs
-tests/ui/sanitizer/cfi-assoc-ty-lifetime-issue-123053.rs
-tests/ui/sanitizer/cfi-async-closures.rs
-tests/ui/sanitizer/cfi-closures.rs
-tests/ui/sanitizer/cfi-complex-receiver.rs
-tests/ui/sanitizer/cfi-coroutine.rs
-tests/ui/sanitizer/cfi-drop-in-place.rs
-tests/ui/sanitizer/cfi-drop-no-principal.rs
-tests/ui/sanitizer/cfi-fn-ptr.rs
-tests/ui/sanitizer/cfi-self-ref.rs
-tests/ui/sanitizer/cfi-supertraits.rs
-tests/ui/sanitizer/cfi-virtual-auto.rs
+tests/ui/sanitizer/cfi/assoc-ty-lifetime-issue-123053.rs
+tests/ui/sanitizer/cfi/async-closures.rs
+tests/ui/sanitizer/cfi/closures.rs
+tests/ui/sanitizer/cfi/complex-receiver.rs
+tests/ui/sanitizer/cfi/coroutine.rs
+tests/ui/sanitizer/cfi/drop-in-place.rs
+tests/ui/sanitizer/cfi/drop-no-principal.rs
+tests/ui/sanitizer/cfi/fn-ptr.rs
+tests/ui/sanitizer/cfi/self-ref.rs
+tests/ui/sanitizer/cfi/supertraits.rs
+tests/ui/sanitizer/cfi/virtual-auto.rs
+tests/ui/sanitizer/cfi/sized-associated-ty.rs
+tests/ui/sanitizer/cfi/can-reveal-opaques.rs
 tests/ui/sanitizer/kcfi-mangling.rs
 tests/ui/statics/const_generics.rs
 tests/ui/backtrace/dylib-dep.rs
@@ -91,6 +93,7 @@ tests/ui/delegation/fn-header.rs
 tests/ui/consts/zst_no_llvm_alloc.rs
 tests/ui/consts/const-eval/parse_ints.rs
 tests/ui/simd/intrinsic/generic-arithmetic-pass.rs
+tests/ui/simd/intrinsic/generic-as.rs
 tests/ui/backtrace/backtrace.rs
 tests/ui/lifetimes/tail-expr-lock-poisoning.rs
 tests/ui/runtime/rt-explody-panic-payloads.rs
@@ -118,5 +121,4 @@ tests/ui/codegen/equal-pointers-unequal/strict-provenance/print3.rs
 tests/ui/codegen/equal-pointers-unequal/strict-provenance/inline2.rs
 tests/ui/codegen/equal-pointers-unequal/strict-provenance/segfault.rs
 tests/ui/codegen/equal-pointers-unequal/strict-provenance/zero.rs
-tests/ui/sanitizer/cfi-sized-associated-ty.rs
-tests/ui/sanitizer/cfi-can-reveal-opaques.rs
+tests/ui/simd/simd-bitmask-notpow2.rs
diff --git a/compiler/rustc_codegen_gcc/tests/failing-ui-tests12.txt b/compiler/rustc_codegen_gcc/tests/failing-ui-tests12.txt
index 1d9bdaa552c..b10d4bc82aa 100644
--- a/compiler/rustc_codegen_gcc/tests/failing-ui-tests12.txt
+++ b/compiler/rustc_codegen_gcc/tests/failing-ui-tests12.txt
@@ -11,7 +11,6 @@ tests/ui/simd/array-type.rs
 tests/ui/simd/intrinsic/float-minmax-pass.rs
 tests/ui/simd/intrinsic/generic-arithmetic-pass.rs
 tests/ui/simd/intrinsic/generic-arithmetic-saturating-pass.rs
-tests/ui/simd/intrinsic/generic-as.rs
 tests/ui/simd/intrinsic/generic-cast-pass.rs
 tests/ui/simd/intrinsic/generic-cast-pointer-width.rs
 tests/ui/simd/intrinsic/generic-comparison-pass.rs
diff --git a/compiler/rustc_codegen_gcc/tests/hello-world/Cargo.lock b/compiler/rustc_codegen_gcc/tests/hello-world/Cargo.lock
new file mode 100644
index 00000000000..fe252db4425
--- /dev/null
+++ b/compiler/rustc_codegen_gcc/tests/hello-world/Cargo.lock
@@ -0,0 +1,14 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "hello_world"
+version = "0.0.0"
+dependencies = [
+ "mylib",
+]
+
+[[package]]
+name = "mylib"
+version = "0.1.0"
diff --git a/compiler/rustc_codegen_gcc/tests/hello-world/Cargo.toml b/compiler/rustc_codegen_gcc/tests/hello-world/Cargo.toml
index 0b8cdc63fbe..c6e22f642f6 100644
--- a/compiler/rustc_codegen_gcc/tests/hello-world/Cargo.toml
+++ b/compiler/rustc_codegen_gcc/tests/hello-world/Cargo.toml
@@ -1,4 +1,12 @@
 [package]
 name = "hello_world"
+edition = "2024"
 
 [dependencies]
+mylib = { path = "mylib" }
+
+[profile.dev]
+lto = "thin"
+
+[profile.release]
+lto = "fat"
diff --git a/compiler/rustc_codegen_gcc/tests/hello-world/mylib/Cargo.lock b/compiler/rustc_codegen_gcc/tests/hello-world/mylib/Cargo.lock
new file mode 100644
index 00000000000..c8a0bfc6354
--- /dev/null
+++ b/compiler/rustc_codegen_gcc/tests/hello-world/mylib/Cargo.lock
@@ -0,0 +1,5 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+[[package]]
+name = "mylib"
+version = "0.1.0"
diff --git a/compiler/rustc_codegen_gcc/tests/hello-world/mylib/Cargo.toml b/compiler/rustc_codegen_gcc/tests/hello-world/mylib/Cargo.toml
new file mode 100644
index 00000000000..d15f62bfb6d
--- /dev/null
+++ b/compiler/rustc_codegen_gcc/tests/hello-world/mylib/Cargo.toml
@@ -0,0 +1,9 @@
+[package]
+name = "mylib"
+version = "0.1.0"
+authors = ["Antoni Boucher <bouanto@zoho.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/compiler/rustc_codegen_gcc/tests/hello-world/mylib/src/lib.rs b/compiler/rustc_codegen_gcc/tests/hello-world/mylib/src/lib.rs
new file mode 100644
index 00000000000..8d3d111bd19
--- /dev/null
+++ b/compiler/rustc_codegen_gcc/tests/hello-world/mylib/src/lib.rs
@@ -0,0 +1,7 @@
+pub fn my_func(a: i32, b: i32) -> i32 {
+    let mut res = a;
+    for i in a..b {
+        res += i;
+    }
+    res
+}
diff --git a/compiler/rustc_codegen_gcc/tests/hello-world/src/main.rs b/compiler/rustc_codegen_gcc/tests/hello-world/src/main.rs
index e7a11a969c0..71c78d364ac 100644
--- a/compiler/rustc_codegen_gcc/tests/hello-world/src/main.rs
+++ b/compiler/rustc_codegen_gcc/tests/hello-world/src/main.rs
@@ -1,3 +1,5 @@
+use mylib::my_func;
+
 fn main() {
-    println!("Hello, world!");
+    println!("{}", my_func(5, 10));
 }
diff --git a/compiler/rustc_codegen_gcc/tests/lang_tests_common.rs b/compiler/rustc_codegen_gcc/tests/lang_tests_common.rs
index aecea37ab5a..fafb7be55ce 100644
--- a/compiler/rustc_codegen_gcc/tests/lang_tests_common.rs
+++ b/compiler/rustc_codegen_gcc/tests/lang_tests_common.rs
@@ -22,14 +22,20 @@ pub fn main_inner(profile: Profile) {
     let tempdir = TempDir::new().expect("temp dir");
     let current_dir = current_dir().expect("current dir");
     let current_dir = current_dir.to_str().expect("current dir").to_string();
-    let toml = Toml::parse(include_str!("../config.toml")).expect("Failed to parse `config.toml`");
-    let gcc_path = if let Ok(gcc_path) = toml.get_string("gcc-path") {
-        PathBuf::from(gcc_path.to_string())
-    } else {
-        // then we try to retrieve it from the `target` folder.
-        let commit = include_str!("../libgccjit.version").trim();
-        Path::new("build/libgccjit").join(commit)
-    };
+
+    let manifest_dir = Path::new(env!("CARGO_MANIFEST_DIR"));
+
+    let gcc_path = std::fs::read_to_string(manifest_dir.join("config.toml"))
+        .ok()
+        .and_then(|v| {
+            let toml = Toml::parse(&v).expect("Failed to parse `config.toml`");
+            toml.get_string("gcc-path").map(PathBuf::from).ok()
+        })
+        .unwrap_or_else(|| {
+            // then we try to retrieve it from the `target` folder.
+            let commit = include_str!("../libgccjit.version").trim();
+            Path::new("build/libgccjit").join(commit)
+        });
 
     let gcc_path = Path::new(&gcc_path)
         .canonicalize()
@@ -83,6 +89,8 @@ pub fn main_inner(profile: Profile) {
                 &format!("{}/build/build_sysroot/sysroot/", current_dir),
                 "-C",
                 "link-arg=-lc",
+                "--extern",
+                "mini_core=target/out/libmini_core.rlib",
                 "-o",
                 exe.to_str().expect("to_str"),
                 path.to_str().expect("to_str"),
diff --git a/compiler/rustc_codegen_gcc/tests/run/array.rs b/compiler/rustc_codegen_gcc/tests/run/array.rs
index d8de9f28d4c..c3c08c29c6d 100644
--- a/compiler/rustc_codegen_gcc/tests/run/array.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/array.rs
@@ -7,38 +7,12 @@
 //     5
 //     10
 
-#![feature(arbitrary_self_types, auto_traits, lang_items, no_core, start, intrinsics, rustc_attrs)]
-#![allow(internal_features)]
+#![feature(no_core, start)]
 
 #![no_std]
 #![no_core]
 
-/*
- * Core
- */
-
-// Because we don't have core yet.
-#[lang = "sized"]
-pub trait Sized {}
-
-#[lang = "copy"]
-trait Copy {
-}
-
-impl Copy for isize {}
-impl Copy for usize {}
-impl Copy for i32 {}
-impl Copy for u8 {}
-impl Copy for i8 {}
-impl Copy for i16 {}
-impl<T: ?Sized> Copy for *mut T {}
-
-#[lang = "receiver"]
-trait Receiver {
-}
-
-#[lang = "freeze"]
-pub(crate) unsafe auto trait Freeze {}
+extern crate mini_core;
 
 mod libc {
     #[link(name = "c")]
@@ -48,182 +22,6 @@ mod libc {
     }
 }
 
-#[lang = "index"]
-pub trait Index<Idx: ?Sized> {
-    type Output: ?Sized;
-    fn index(&self, index: Idx) -> &Self::Output;
-}
-
-impl<T> Index<usize> for [T; 3] {
-    type Output = T;
-
-    fn index(&self, index: usize) -> &Self::Output {
-        &self[index]
-    }
-}
-
-impl<T> Index<usize> for [T] {
-    type Output = T;
-
-    fn index(&self, index: usize) -> &Self::Output {
-        &self[index]
-    }
-}
-
-#[lang = "drop_in_place"]
-#[allow(unconditional_recursion)]
-pub unsafe fn drop_in_place<T: ?Sized>(to_drop: *mut T) {
-    // Code here does not matter - this is replaced by the
-    // real drop glue by the compiler.
-    drop_in_place(to_drop);
-}
-
-#[lang = "panic"]
-#[track_caller]
-#[no_mangle]
-pub fn panic(_msg: &'static str) -> ! {
-    unsafe {
-        libc::puts("Panicking\0" as *const str as *const u8);
-        intrinsics::abort();
-    }
-}
-
-#[lang = "panic_location"]
-struct PanicLocation {
-    file: &'static str,
-    line: u32,
-    column: u32,
-}
-
-#[lang = "panic_bounds_check"]
-#[track_caller]
-#[no_mangle]
-fn panic_bounds_check(index: usize, len: usize) -> ! {
-    unsafe {
-        libc::printf("index out of bounds: the len is %d but the index is %d\n\0" as *const str as *const i8, len, index);
-        intrinsics::abort();
-    }
-}
-
-mod intrinsics {
-    #[rustc_nounwind]
-    #[rustc_intrinsic]
-    #[rustc_intrinsic_must_be_overridden]
-    pub fn abort() -> ! {
-        loop {}
-    }
-}
-
-#[lang = "add"]
-trait Add<RHS = Self> {
-    type Output;
-
-    fn add(self, rhs: RHS) -> Self::Output;
-}
-
-impl Add for u8 {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for i8 {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for i32 {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for usize {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for isize {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-#[lang = "sub"]
-pub trait Sub<RHS = Self> {
-    type Output;
-
-    fn sub(self, rhs: RHS) -> Self::Output;
-}
-
-impl Sub for usize {
-    type Output = Self;
-
-    fn sub(self, rhs: Self) -> Self {
-        self - rhs
-    }
-}
-
-impl Sub for isize {
-    type Output = Self;
-
-    fn sub(self, rhs: Self) -> Self {
-        self - rhs
-    }
-}
-
-impl Sub for u8 {
-    type Output = Self;
-
-    fn sub(self, rhs: Self) -> Self {
-        self - rhs
-    }
-}
-
-impl Sub for i8 {
-    type Output = Self;
-
-    fn sub(self, rhs: Self) -> Self {
-        self - rhs
-    }
-}
-
-impl Sub for i16 {
-    type Output = Self;
-
-    fn sub(self, rhs: Self) -> Self {
-        self - rhs
-    }
-}
-
-#[track_caller]
-#[lang = "panic_const_add_overflow"]
-pub fn panic_const_add_overflow() -> ! {
-    panic("attempt to add with overflow");
-}
-
-#[track_caller]
-#[lang = "panic_const_sub_overflow"]
-pub fn panic_const_sub_overflow() -> ! {
-    panic("attempt to subtract with overflow");
-}
-
-/*
- * Code
- */
-
 static mut ONE: usize = 1;
 
 fn make_array() -> [u8; 3] {
diff --git a/compiler/rustc_codegen_gcc/tests/run/closure.rs b/compiler/rustc_codegen_gcc/tests/run/closure.rs
index b0d0ca4ee8d..46c47bc54ed 100644
--- a/compiler/rustc_codegen_gcc/tests/run/closure.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/closure.rs
@@ -8,200 +8,20 @@
 //     Int argument: 2
 //     Both args: 11
 
-#![feature(arbitrary_self_types, auto_traits, lang_items, no_core, start, intrinsics,
-    unboxed_closures, rustc_attrs)]
-#![allow(internal_features)]
+#![feature(no_core, start)]
 
 #![no_std]
 #![no_core]
 
-/*
- * Core
- */
-
-// Because we don't have core yet.
-#[lang = "sized"]
-pub trait Sized {}
-
-#[lang = "copy"]
-trait Copy {
-}
-
-impl Copy for isize {}
-impl Copy for usize {}
-impl Copy for i32 {}
-impl Copy for u32 {}
-impl Copy for u8 {}
-impl Copy for i8 {}
-impl<T: ?Sized> Copy for *mut T {}
-
-#[lang = "receiver"]
-trait Receiver {
-}
-
-#[lang = "freeze"]
-pub(crate) unsafe auto trait Freeze {}
+extern crate mini_core;
 
 mod libc {
     #[link(name = "c")]
     extern "C" {
-        pub fn puts(s: *const u8) -> i32;
         pub fn printf(format: *const i8, ...) -> i32;
     }
 }
 
-#[lang = "index"]
-pub trait Index<Idx: ?Sized> {
-    type Output: ?Sized;
-    fn index(&self, index: Idx) -> &Self::Output;
-}
-
-impl<T> Index<usize> for [T; 3] {
-    type Output = T;
-
-    fn index(&self, index: usize) -> &Self::Output {
-        &self[index]
-    }
-}
-
-impl<T> Index<usize> for [T] {
-    type Output = T;
-
-    fn index(&self, index: usize) -> &Self::Output {
-        &self[index]
-    }
-}
-
-#[lang = "drop_in_place"]
-#[allow(unconditional_recursion)]
-pub unsafe fn drop_in_place<T: ?Sized>(to_drop: *mut T) {
-    // Code here does not matter - this is replaced by the
-    // real drop glue by the compiler.
-    drop_in_place(to_drop);
-}
-
-#[lang = "panic_location"]
-struct PanicLocation {
-    file: &'static str,
-    line: u32,
-    column: u32,
-}
-
-#[lang = "panic_bounds_check"]
-#[track_caller]
-#[no_mangle]
-fn panic_bounds_check(index: usize, len: usize) -> ! {
-    unsafe {
-        libc::printf("index out of bounds: the len is %d but the index is %d\n\0" as *const str as *const i8, len, index);
-        intrinsics::abort();
-    }
-}
-
-mod intrinsics {
-    #[rustc_nounwind]
-    #[rustc_intrinsic]
-    #[rustc_intrinsic_must_be_overridden]
-    pub fn abort() -> ! {
-        loop {}
-    }
-}
-
-#[lang = "tuple_trait"]
-pub trait Tuple {}
-
-#[lang = "unsize"]
-pub trait Unsize<T: ?Sized> {}
-
-#[lang = "coerce_unsized"]
-pub trait CoerceUnsized<T> {}
-
-impl<'a, 'b: 'a, T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<&'a U> for &'b T {}
-impl<'a, T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<&'a mut U> for &'a mut T {}
-impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<*const U> for *const T {}
-impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<*mut U> for *mut T {}
-
-#[lang = "fn_once"]
-#[rustc_paren_sugar]
-pub trait FnOnce<Args: Tuple> {
-    #[lang = "fn_once_output"]
-    type Output;
-
-    extern "rust-call" fn call_once(self, args: Args) -> Self::Output;
-}
-
-#[lang = "fn_mut"]
-#[rustc_paren_sugar]
-pub trait FnMut<Args: Tuple>: FnOnce<Args> {
-    extern "rust-call" fn call_mut(&mut self, args: Args) -> Self::Output;
-}
-
-#[lang = "add"]
-trait Add<RHS = Self> {
-    type Output;
-
-    fn add(self, rhs: RHS) -> Self::Output;
-}
-
-impl Add for u8 {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for i8 {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for i32 {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for usize {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for isize {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-#[lang = "panic"]
-#[track_caller]
-#[no_mangle]
-pub fn panic(_msg: &'static str) -> ! {
-    unsafe {
-        libc::puts("Panicking\0" as *const str as *const u8);
-        intrinsics::abort();
-    }
-}
-
-#[track_caller]
-#[lang = "panic_const_add_overflow"]
-pub fn panic_const_add_overflow() -> ! {
-    panic("attempt to add with overflow");
-}
-
-/*
- * Code
- */
-
 #[start]
 fn main(mut argc: isize, _argv: *const *const u8) -> isize {
     let string = "Arg: %d\n\0";
diff --git a/compiler/rustc_codegen_gcc/tests/run/condition.rs b/compiler/rustc_codegen_gcc/tests/run/condition.rs
index 770b18a89e3..039ef94eaa7 100644
--- a/compiler/rustc_codegen_gcc/tests/run/condition.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/condition.rs
@@ -5,304 +5,20 @@
 //   stdout: true
 //     1
 
-#![feature(arbitrary_self_types, auto_traits, lang_items, no_core, start, intrinsics, rustc_attrs)]
-#![allow(internal_features)]
+#![feature(no_core, start)]
 
 #![no_std]
 #![no_core]
 
-/*
- * Core
- */
-
-// Because we don't have core yet.
-#[lang = "sized"]
-pub trait Sized {}
-
-#[lang = "copy"]
-trait Copy {
-}
-
-impl Copy for isize {}
-impl Copy for usize {}
-impl Copy for u64 {}
-impl Copy for i32 {}
-impl Copy for u32 {}
-impl Copy for bool {}
-impl Copy for u16 {}
-impl Copy for i16 {}
-impl Copy for char {}
-impl Copy for i8 {}
-impl Copy for u8 {}
-impl<T: ?Sized> Copy for *mut T {}
-
-#[lang = "receiver"]
-trait Receiver {
-}
-
-#[lang = "freeze"]
-pub(crate) unsafe auto trait Freeze {}
+extern crate mini_core;
 
 mod libc {
     #[link(name = "c")]
     extern "C" {
         pub fn printf(format: *const i8, ...) -> i32;
-        pub fn puts(s: *const u8) -> i32;
-    }
-}
-
-#[lang = "index"]
-pub trait Index<Idx: ?Sized> {
-    type Output: ?Sized;
-    fn index(&self, index: Idx) -> &Self::Output;
-}
-
-impl<T> Index<usize> for [T; 3] {
-    type Output = T;
-
-    fn index(&self, index: usize) -> &Self::Output {
-        &self[index]
-    }
-}
-
-impl<T> Index<usize> for [T] {
-    type Output = T;
-
-    fn index(&self, index: usize) -> &Self::Output {
-        &self[index]
-    }
-}
-
-#[lang = "drop_in_place"]
-#[allow(unconditional_recursion)]
-pub unsafe fn drop_in_place<T: ?Sized>(to_drop: *mut T) {
-    // Code here does not matter - this is replaced by the
-    // real drop glue by the compiler.
-    drop_in_place(to_drop);
-}
-
-#[lang = "panic"]
-#[track_caller]
-#[no_mangle]
-pub fn panic(_msg: &'static str) -> ! {
-    unsafe {
-        libc::puts("Panicking\0" as *const str as *const u8);
-        intrinsics::abort();
-    }
-}
-
-#[lang = "panic_location"]
-struct PanicLocation {
-    file: &'static str,
-    line: u32,
-    column: u32,
-}
-
-#[lang = "panic_bounds_check"]
-#[track_caller]
-#[no_mangle]
-fn panic_bounds_check(index: usize, len: usize) -> ! {
-    unsafe {
-        libc::printf("index out of bounds: the len is %d but the index is %d\n\0" as *const str as *const i8, len, index);
-        intrinsics::abort();
-    }
-}
-
-mod intrinsics {
-    #[rustc_nounwind]
-    #[rustc_intrinsic]
-    #[rustc_intrinsic_must_be_overridden]
-    pub fn abort() -> ! {
-        loop {}
-    }
-}
-
-#[lang = "add"]
-trait Add<RHS = Self> {
-    type Output;
-
-    fn add(self, rhs: RHS) -> Self::Output;
-}
-
-impl Add for u8 {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for i8 {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for i32 {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for usize {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for isize {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-#[lang = "sub"]
-pub trait Sub<RHS = Self> {
-    type Output;
-
-    fn sub(self, rhs: RHS) -> Self::Output;
-}
-
-impl Sub for usize {
-    type Output = Self;
-
-    fn sub(self, rhs: Self) -> Self {
-        self - rhs
-    }
-}
-
-impl Sub for isize {
-    type Output = Self;
-
-    fn sub(self, rhs: Self) -> Self {
-        self - rhs
-    }
-}
-
-impl Sub for u8 {
-    type Output = Self;
-
-    fn sub(self, rhs: Self) -> Self {
-        self - rhs
-    }
-}
-
-impl Sub for i8 {
-    type Output = Self;
-
-    fn sub(self, rhs: Self) -> Self {
-        self - rhs
     }
 }
 
-impl Sub for i16 {
-    type Output = Self;
-
-    fn sub(self, rhs: Self) -> Self {
-        self - rhs
-    }
-}
-
-#[lang = "eq"]
-pub trait PartialEq<Rhs: ?Sized = Self> {
-    fn eq(&self, other: &Rhs) -> bool;
-    fn ne(&self, other: &Rhs) -> bool;
-}
-
-impl PartialEq for u8 {
-    fn eq(&self, other: &u8) -> bool {
-        (*self) == (*other)
-    }
-    fn ne(&self, other: &u8) -> bool {
-        (*self) != (*other)
-    }
-}
-
-impl PartialEq for u16 {
-    fn eq(&self, other: &u16) -> bool {
-        (*self) == (*other)
-    }
-    fn ne(&self, other: &u16) -> bool {
-        (*self) != (*other)
-    }
-}
-
-impl PartialEq for u32 {
-    fn eq(&self, other: &u32) -> bool {
-        (*self) == (*other)
-    }
-    fn ne(&self, other: &u32) -> bool {
-        (*self) != (*other)
-    }
-}
-
-
-impl PartialEq for u64 {
-    fn eq(&self, other: &u64) -> bool {
-        (*self) == (*other)
-    }
-    fn ne(&self, other: &u64) -> bool {
-        (*self) != (*other)
-    }
-}
-
-impl PartialEq for usize {
-    fn eq(&self, other: &usize) -> bool {
-        (*self) == (*other)
-    }
-    fn ne(&self, other: &usize) -> bool {
-        (*self) != (*other)
-    }
-}
-
-impl PartialEq for i8 {
-    fn eq(&self, other: &i8) -> bool {
-        (*self) == (*other)
-    }
-    fn ne(&self, other: &i8) -> bool {
-        (*self) != (*other)
-    }
-}
-
-impl PartialEq for i32 {
-    fn eq(&self, other: &i32) -> bool {
-        (*self) == (*other)
-    }
-    fn ne(&self, other: &i32) -> bool {
-        (*self) != (*other)
-    }
-}
-
-impl PartialEq for isize {
-    fn eq(&self, other: &isize) -> bool {
-        (*self) == (*other)
-    }
-    fn ne(&self, other: &isize) -> bool {
-        (*self) != (*other)
-    }
-}
-
-impl PartialEq for char {
-    fn eq(&self, other: &char) -> bool {
-        (*self) == (*other)
-    }
-    fn ne(&self, other: &char) -> bool {
-        (*self) != (*other)
-    }
-}
-
-/*
- * Code
- */
-
 #[start]
 fn main(argc: isize, _argv: *const *const u8) -> isize {
     unsafe {
diff --git a/compiler/rustc_codegen_gcc/tests/run/fun_ptr.rs b/compiler/rustc_codegen_gcc/tests/run/fun_ptr.rs
index 523544ee6bb..ed1bf72bb27 100644
--- a/compiler/rustc_codegen_gcc/tests/run/fun_ptr.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/fun_ptr.rs
@@ -4,212 +4,20 @@
 //   status: 0
 //   stdout: 1
 
-#![feature(arbitrary_self_types, auto_traits, lang_items, no_core, start, intrinsics, rustc_attrs)]
-#![allow(internal_features)]
+#![feature(no_core, start)]
 
 #![no_std]
 #![no_core]
 
-/*
- * Core
- */
-
-// Because we don't have core yet.
-#[lang = "sized"]
-pub trait Sized {}
-
-#[lang = "copy"]
-trait Copy {
-}
-
-impl Copy for isize {}
-impl Copy for usize {}
-impl Copy for i32 {}
-impl Copy for u8 {}
-impl Copy for i8 {}
-impl Copy for i16 {}
-impl<T: ?Sized> Copy for *mut T {}
-
-#[lang = "receiver"]
-trait Receiver {
-}
-
-#[lang = "freeze"]
-pub(crate) unsafe auto trait Freeze {}
+extern crate mini_core;
 
 mod libc {
     #[link(name = "c")]
     extern "C" {
         pub fn printf(format: *const i8, ...) -> i32;
-        pub fn puts(s: *const u8) -> i32;
-    }
-}
-
-#[lang = "index"]
-pub trait Index<Idx: ?Sized> {
-    type Output: ?Sized;
-    fn index(&self, index: Idx) -> &Self::Output;
-}
-
-impl<T> Index<usize> for [T; 3] {
-    type Output = T;
-
-    fn index(&self, index: usize) -> &Self::Output {
-        &self[index]
-    }
-}
-
-impl<T> Index<usize> for [T] {
-    type Output = T;
-
-    fn index(&self, index: usize) -> &Self::Output {
-        &self[index]
-    }
-}
-
-#[lang = "drop_in_place"]
-#[allow(unconditional_recursion)]
-pub unsafe fn drop_in_place<T: ?Sized>(to_drop: *mut T) {
-    // Code here does not matter - this is replaced by the
-    // real drop glue by the compiler.
-    drop_in_place(to_drop);
-}
-
-#[lang = "panic"]
-#[track_caller]
-#[no_mangle]
-pub fn panic(_msg: &'static str) -> ! {
-    unsafe {
-        libc::puts("Panicking\0" as *const str as *const u8);
-        intrinsics::abort();
-    }
-}
-
-#[lang = "panic_location"]
-struct PanicLocation {
-    file: &'static str,
-    line: u32,
-    column: u32,
-}
-
-#[lang = "panic_bounds_check"]
-#[track_caller]
-#[no_mangle]
-fn panic_bounds_check(index: usize, len: usize) -> ! {
-    unsafe {
-        libc::printf("index out of bounds: the len is %d but the index is %d\n\0" as *const str as *const i8, len, index);
-        intrinsics::abort();
-    }
-}
-
-mod intrinsics {
-    #[rustc_nounwind]
-    #[rustc_intrinsic]
-    #[rustc_intrinsic_must_be_overridden]
-    pub fn abort() -> ! {
-        loop {}
-    }
-}
-
-#[lang = "add"]
-trait Add<RHS = Self> {
-    type Output;
-
-    fn add(self, rhs: RHS) -> Self::Output;
-}
-
-impl Add for u8 {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for i8 {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for i32 {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for usize {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for isize {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-#[lang = "sub"]
-pub trait Sub<RHS = Self> {
-    type Output;
-
-    fn sub(self, rhs: RHS) -> Self::Output;
-}
-
-impl Sub for usize {
-    type Output = Self;
-
-    fn sub(self, rhs: Self) -> Self {
-        self - rhs
-    }
-}
-
-impl Sub for isize {
-    type Output = Self;
-
-    fn sub(self, rhs: Self) -> Self {
-        self - rhs
-    }
-}
-
-impl Sub for u8 {
-    type Output = Self;
-
-    fn sub(self, rhs: Self) -> Self {
-        self - rhs
     }
 }
 
-impl Sub for i8 {
-    type Output = Self;
-
-    fn sub(self, rhs: Self) -> Self {
-        self - rhs
-    }
-}
-
-impl Sub for i16 {
-    type Output = Self;
-
-    fn sub(self, rhs: Self) -> Self {
-        self - rhs
-    }
-}
-
-
-/*
- * Code
- */
-
 fn i16_as_i8(a: i16) -> i8 {
     a as i8
 }
diff --git a/compiler/rustc_codegen_gcc/tests/run/operations.rs b/compiler/rustc_codegen_gcc/tests/run/operations.rs
index 2e3c021d5f7..0e44fc580b8 100644
--- a/compiler/rustc_codegen_gcc/tests/run/operations.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/operations.rs
@@ -38,8 +38,8 @@ pub trait Deref {
     fn deref(&self) -> &Self::Target;
 }
 
-#[lang = "receiver"]
-trait Receiver {
+#[lang = "legacy_receiver"]
+trait LegacyReceiver {
 }
 
 #[lang = "freeze"]
diff --git a/compiler/rustc_codegen_gcc/tests/run/ptr_cast.rs b/compiler/rustc_codegen_gcc/tests/run/ptr_cast.rs
index c7510d16449..2b8812ad51c 100644
--- a/compiler/rustc_codegen_gcc/tests/run/ptr_cast.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/ptr_cast.rs
@@ -4,212 +4,20 @@
 //   status: 0
 //   stdout: 1
 
-#![feature(arbitrary_self_types, auto_traits, lang_items, no_core, start, intrinsics, rustc_attrs)]
-#![allow(internal_features)]
+#![feature(no_core, start)]
 
 #![no_std]
 #![no_core]
 
-/*
- * Core
- */
-
-// Because we don't have core yet.
-#[lang = "sized"]
-pub trait Sized {}
-
-#[lang = "copy"]
-trait Copy {
-}
-
-impl Copy for isize {}
-impl Copy for usize {}
-impl Copy for i32 {}
-impl Copy for u8 {}
-impl Copy for i8 {}
-impl Copy for i16 {}
-impl<T: ?Sized> Copy for *mut T {}
-
-#[lang = "receiver"]
-trait Receiver {
-}
-
-#[lang = "freeze"]
-pub(crate) unsafe auto trait Freeze {}
+extern crate mini_core;
 
 mod libc {
     #[link(name = "c")]
     extern "C" {
         pub fn printf(format: *const i8, ...) -> i32;
-        pub fn puts(s: *const u8) -> i32;
-    }
-}
-
-#[lang = "index"]
-pub trait Index<Idx: ?Sized> {
-    type Output: ?Sized;
-    fn index(&self, index: Idx) -> &Self::Output;
-}
-
-impl<T> Index<usize> for [T; 3] {
-    type Output = T;
-
-    fn index(&self, index: usize) -> &Self::Output {
-        &self[index]
-    }
-}
-
-impl<T> Index<usize> for [T] {
-    type Output = T;
-
-    fn index(&self, index: usize) -> &Self::Output {
-        &self[index]
-    }
-}
-
-#[lang = "drop_in_place"]
-#[allow(unconditional_recursion)]
-pub unsafe fn drop_in_place<T: ?Sized>(to_drop: *mut T) {
-    // Code here does not matter - this is replaced by the
-    // real drop glue by the compiler.
-    drop_in_place(to_drop);
-}
-
-#[lang = "panic"]
-#[track_caller]
-#[no_mangle]
-pub fn panic(_msg: &'static str) -> ! {
-    unsafe {
-        libc::puts("Panicking\0" as *const str as *const u8);
-        intrinsics::abort();
-    }
-}
-
-#[lang = "panic_location"]
-struct PanicLocation {
-    file: &'static str,
-    line: u32,
-    column: u32,
-}
-
-#[lang = "panic_bounds_check"]
-#[track_caller]
-#[no_mangle]
-fn panic_bounds_check(index: usize, len: usize) -> ! {
-    unsafe {
-        libc::printf("index out of bounds: the len is %d but the index is %d\n\0" as *const str as *const i8, len, index);
-        intrinsics::abort();
-    }
-}
-
-mod intrinsics {
-    #[rustc_nounwind]
-    #[rustc_intrinsic]
-    #[rustc_intrinsic_must_be_overridden]
-    pub fn abort() -> ! {
-        loop {}
-    }
-}
-
-#[lang = "add"]
-trait Add<RHS = Self> {
-    type Output;
-
-    fn add(self, rhs: RHS) -> Self::Output;
-}
-
-impl Add for u8 {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for i8 {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for i32 {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for usize {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for isize {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-#[lang = "sub"]
-pub trait Sub<RHS = Self> {
-    type Output;
-
-    fn sub(self, rhs: RHS) -> Self::Output;
-}
-
-impl Sub for usize {
-    type Output = Self;
-
-    fn sub(self, rhs: Self) -> Self {
-        self - rhs
-    }
-}
-
-impl Sub for isize {
-    type Output = Self;
-
-    fn sub(self, rhs: Self) -> Self {
-        self - rhs
-    }
-}
-
-impl Sub for u8 {
-    type Output = Self;
-
-    fn sub(self, rhs: Self) -> Self {
-        self - rhs
     }
 }
 
-impl Sub for i8 {
-    type Output = Self;
-
-    fn sub(self, rhs: Self) -> Self {
-        self - rhs
-    }
-}
-
-impl Sub for i16 {
-    type Output = Self;
-
-    fn sub(self, rhs: Self) -> Self {
-        self - rhs
-    }
-}
-
-
-/*
- * Code
- */
-
 static mut ONE: usize = 1;
 
 fn make_array() -> [u8; 3] {
diff --git a/compiler/rustc_codegen_gcc/tests/run/return-tuple.rs b/compiler/rustc_codegen_gcc/tests/run/return-tuple.rs
index 8d40deb8c85..f2a5a2e4384 100644
--- a/compiler/rustc_codegen_gcc/tests/run/return-tuple.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/return-tuple.rs
@@ -15,18 +15,18 @@
 #[lang = "copy"]
 pub unsafe trait Copy {}
 
-unsafe impl Copy for bool {}
-unsafe impl Copy for u8 {}
-unsafe impl Copy for u16 {}
-unsafe impl Copy for u32 {}
-unsafe impl Copy for u64 {}
-unsafe impl Copy for usize {}
-unsafe impl Copy for i8 {}
-unsafe impl Copy for i16 {}
-unsafe impl Copy for i32 {}
-unsafe impl Copy for isize {}
-unsafe impl Copy for f32 {}
-unsafe impl Copy for char {}
+impl Copy for bool {}
+impl Copy for u8 {}
+impl Copy for u16 {}
+impl Copy for u32 {}
+impl Copy for u64 {}
+impl Copy for usize {}
+impl Copy for i8 {}
+impl Copy for i16 {}
+impl Copy for i32 {}
+impl Copy for isize {}
+impl Copy for f32 {}
+impl Copy for char {}
 
 mod libc {
     #[link(name = "c")]
@@ -43,8 +43,8 @@ mod libc {
 #[lang = "sized"]
 pub trait Sized {}
 
-#[lang = "receiver"]
-trait Receiver {
+#[lang = "legacy_receiver"]
+trait LegacyReceiver {
 }
 
 #[lang = "freeze"]
diff --git a/compiler/rustc_codegen_gcc/tests/run/slice.rs b/compiler/rustc_codegen_gcc/tests/run/slice.rs
index 35ad594ecde..fba93fc1554 100644
--- a/compiler/rustc_codegen_gcc/tests/run/slice.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/slice.rs
@@ -4,36 +4,12 @@
 //   status: 0
 //   stdout: 5
 
-#![feature(arbitrary_self_types, auto_traits, lang_items, no_core, start, intrinsics, rustc_attrs)]
-#![allow(internal_features)]
+#![feature(no_core, start)]
 
 #![no_std]
 #![no_core]
 
-/*
- * Core
- */
-
-// Because we don't have core yet.
-#[lang = "sized"]
-pub trait Sized {}
-
-#[lang = "copy"]
-trait Copy {
-}
-
-impl Copy for isize {}
-impl Copy for usize {}
-impl Copy for i32 {}
-impl Copy for u32 {}
-impl<T: ?Sized> Copy for *mut T {}
-
-#[lang = "receiver"]
-trait Receiver {
-}
-
-#[lang = "freeze"]
-pub(crate) unsafe auto trait Freeze {}
+extern crate mini_core;
 
 mod libc {
     #[link(name = "c")]
@@ -42,79 +18,6 @@ mod libc {
     }
 }
 
-#[lang = "index"]
-pub trait Index<Idx: ?Sized> {
-    type Output: ?Sized;
-    fn index(&self, index: Idx) -> &Self::Output;
-}
-
-impl<T> Index<usize> for [T; 3] {
-    type Output = T;
-
-    fn index(&self, index: usize) -> &Self::Output {
-        &self[index]
-    }
-}
-
-impl<T> Index<usize> for [T] {
-    type Output = T;
-
-    fn index(&self, index: usize) -> &Self::Output {
-        &self[index]
-    }
-}
-
-#[lang = "unsize"]
-pub trait Unsize<T: ?Sized> {}
-
-#[lang = "coerce_unsized"]
-pub trait CoerceUnsized<T> {}
-
-impl<'a, 'b: 'a, T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<&'a U> for &'b T {}
-impl<'a, T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<&'a mut U> for &'a mut T {}
-impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<*const U> for *const T {}
-impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<*mut U> for *mut T {}
-
-#[lang = "drop_in_place"]
-#[allow(unconditional_recursion)]
-pub unsafe fn drop_in_place<T: ?Sized>(to_drop: *mut T) {
-    // Code here does not matter - this is replaced by the
-    // real drop glue by the compiler.
-    drop_in_place(to_drop);
-}
-
-#[lang = "panic_location"]
-struct PanicLocation {
-    file: &'static str,
-    line: u32,
-    column: u32,
-}
-
-#[lang = "panic_bounds_check"]
-#[track_caller]
-#[no_mangle]
-fn panic_bounds_check(index: usize, len: usize) -> ! {
-    unsafe {
-        libc::printf("index out of bounds: the len is %d but the index is %d\n\0" as *const str as *const i8, len, index);
-        intrinsics::abort();
-    }
-}
-
-mod intrinsics {
-    use super::Sized;
-
-    #[rustc_nounwind]
-    #[rustc_intrinsic]
-    #[rustc_intrinsic_must_be_overridden]
-    pub fn abort() -> ! {
-        loop {}
-    }
-}
-
-/*
- * Code
- */
-
 static mut TWO: usize = 2;
 
 fn index_slice(s: &[u32]) -> u32 {
diff --git a/compiler/rustc_codegen_gcc/tests/run/volatile2.rs b/compiler/rustc_codegen_gcc/tests/run/volatile2.rs
new file mode 100644
index 00000000000..a177b817ab3
--- /dev/null
+++ b/compiler/rustc_codegen_gcc/tests/run/volatile2.rs
@@ -0,0 +1,113 @@
+// Compiler:
+//
+// Run-time:
+//   status: 0
+
+mod libc {
+    #[link(name = "c")]
+    extern "C" {
+        pub fn puts(s: *const u8) -> i32;
+
+        pub fn sigaction(signum: i32, act: *const sigaction, oldact: *mut sigaction) -> i32;
+        pub fn mmap(addr: *mut (), len: usize, prot: i32, flags: i32, fd: i32, offset: i64) -> *mut ();
+        pub fn mprotect(addr: *mut (), len: usize, prot: i32) -> i32;
+    }
+
+    pub const PROT_READ: i32 = 1;
+    pub const PROT_WRITE: i32 = 2;
+    pub const MAP_PRIVATE: i32 = 0x0002;
+    pub const MAP_ANONYMOUS: i32 = 0x0020;
+    pub const MAP_FAILED: *mut u8 = !0 as *mut u8;
+
+    /// glibc sigaction
+    #[repr(C)]
+    pub struct sigaction {
+        pub sa_sigaction: Option<unsafe extern "C" fn(i32, *mut (), *mut ())>,
+        pub sa_mask: [u32; 32],
+        pub sa_flags: i32,
+        pub sa_restorer: Option<unsafe extern "C" fn()>,
+    }
+
+    pub const SA_SIGINFO: i32 = 0x00000004;
+    pub const SIGSEGV: i32 = 11;
+}
+
+static mut COUNT: u32 = 0;
+static mut STORAGE: *mut u8 = core::ptr::null_mut();
+const PAGE_SIZE: usize = 1 << 15;
+
+fn main() {
+    unsafe {
+        // Register a segfault handler
+        libc::sigaction(
+            libc::SIGSEGV,
+            &libc::sigaction {
+                sa_sigaction: Some(segv_handler),
+                sa_flags: libc::SA_SIGINFO,
+                ..core::mem::zeroed()
+            },
+            core::ptr::null_mut(),
+        );
+
+        STORAGE = libc::mmap(
+            core::ptr::null_mut(),
+            PAGE_SIZE * 2,
+            0,
+            libc::MAP_PRIVATE | libc::MAP_ANONYMOUS,
+            -1,
+            0,
+        ).cast();
+        if STORAGE == libc::MAP_FAILED {
+            panic!("error: mmap failed");
+        }
+
+        let p_count = (&mut COUNT) as *mut u32;
+        p_count.write_volatile(0);
+
+        // Trigger segfaults
+        STORAGE.add(0).write_volatile(1);
+        STORAGE.add(PAGE_SIZE).write_volatile(1);
+        STORAGE.add(0).write_volatile(1);
+        STORAGE.add(PAGE_SIZE).write_volatile(1);
+        STORAGE.add(0).write_volatile(1);
+        STORAGE.add(PAGE_SIZE).write_volatile(1);
+        STORAGE.add(0).read_volatile();
+        STORAGE.add(PAGE_SIZE).read_volatile();
+        STORAGE.add(0).read_volatile();
+        STORAGE.add(PAGE_SIZE).read_volatile();
+        STORAGE.add(0).read_volatile();
+        STORAGE.add(PAGE_SIZE).read_volatile();
+        STORAGE.add(0).write_volatile(1);
+        STORAGE.add(PAGE_SIZE).write_volatile(1);
+
+        // The segfault handler should have been called for every `write_volatile` and
+        // `read_volatile` in `STORAGE`. If the compiler ignores volatility, some of these writes
+        // will be combined, causing a different number of segfaults.
+        //
+        // This `p_count` read is done by a volatile read. If the compiler
+        // ignores volatility, the compiler will speculate that `*p_count` is
+        // unchanged and remove this check, failing the test.
+        if p_count.read_volatile() != 14 {
+            panic!("error: segfault count mismatch: {}", p_count.read_volatile());
+        }
+    }
+}
+
+unsafe extern "C" fn segv_handler(_: i32, _: *mut (), _: *mut ()) {
+    let p_count = (&mut COUNT) as *mut u32;
+    p_count.write_volatile(p_count.read_volatile() + 1);
+    let count = p_count.read_volatile();
+
+    // Toggle the protected page so that the handler will be called for
+    // each `write_volatile`
+    libc::mprotect(
+        STORAGE.cast(),
+        PAGE_SIZE,
+        if count % 2 == 1 { libc::PROT_READ | libc::PROT_WRITE } else { 0 },
+    );
+    libc::mprotect(
+        STORAGE.add(PAGE_SIZE).cast(),
+        PAGE_SIZE,
+        if count % 2 == 0 { libc::PROT_READ | libc::PROT_WRITE } else { 0 },
+    );
+}