remove support for the #[start] attribute

77 files changed, 241 insertions, 488 deletions

diff --git a/tests/codegen-units/item-collection/cross-crate-closures.rs b/tests/codegen-units/item-collection/cross-crate-closures.rs
index cb86cf18c0c..75a77cc2671 100644
--- a/tests/codegen-units/item-collection/cross-crate-closures.rs
+++ b/tests/codegen-units/item-collection/cross-crate-closures.rs
@@ -3,14 +3,14 @@
 //@ compile-flags:-Zprint-mono-items=eager -Zinline-mir=no
 
 #![deny(dead_code)]
-#![feature(start)]
+#![no_main]
 
 //@ aux-build:cgu_extern_closures.rs
 extern crate cgu_extern_closures;
 
-//~ MONO_ITEM fn start @@ cross_crate_closures-cgu.0[Internal]
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
+//~ MONO_ITEM fn main @@ cross_crate_closures-cgu.0[External]
+#[no_mangle]
+extern "C" fn main(_: core::ffi::c_int, _: *const *const u8) -> core::ffi::c_int {
     //~ MONO_ITEM fn cgu_extern_closures::inlined_fn @@ cross_crate_closures-cgu.0[Internal]
     //~ MONO_ITEM fn cgu_extern_closures::inlined_fn::{closure#0} @@ cross_crate_closures-cgu.0[Internal]
     let _ = cgu_extern_closures::inlined_fn(1, 2);
diff --git a/tests/codegen-units/item-collection/cross-crate-generic-functions.rs b/tests/codegen-units/item-collection/cross-crate-generic-functions.rs
index d36f7067b32..4382bfdf8d8 100644
--- a/tests/codegen-units/item-collection/cross-crate-generic-functions.rs
+++ b/tests/codegen-units/item-collection/cross-crate-generic-functions.rs
@@ -1,14 +1,14 @@
 //@ compile-flags:-Zprint-mono-items=eager
 
 #![deny(dead_code)]
-#![feature(start)]
+#![crate_type = "lib"]
 
 //@ aux-build:cgu_generic_function.rs
 extern crate cgu_generic_function;
 
 //~ MONO_ITEM fn start
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
+#[no_mangle]
+pub fn start(_: isize, _: *const *const u8) -> isize {
     //~ MONO_ITEM fn cgu_generic_function::bar::<u32>
     //~ MONO_ITEM fn cgu_generic_function::foo::<u32>
     let _ = cgu_generic_function::foo(1u32);
diff --git a/tests/codegen-units/item-collection/cross-crate-trait-method.rs b/tests/codegen-units/item-collection/cross-crate-trait-method.rs
index 99777760315..917354166f5 100644
--- a/tests/codegen-units/item-collection/cross-crate-trait-method.rs
+++ b/tests/codegen-units/item-collection/cross-crate-trait-method.rs
@@ -1,7 +1,7 @@
 //@ compile-flags:-Zprint-mono-items=eager -Zinline-mir=no -Copt-level=0
 
 #![deny(dead_code)]
-#![feature(start)]
+#![crate_type = "lib"]
 
 //@ aux-build:cgu_export_trait_method.rs
 extern crate cgu_export_trait_method;
@@ -9,8 +9,8 @@ extern crate cgu_export_trait_method;
 use cgu_export_trait_method::Trait;
 
 //~ MONO_ITEM fn start
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
+#[no_mangle]
+pub fn start(_: isize, _: *const *const u8) -> isize {
     // The object code of these methods is contained in the external crate, so
     // calling them should *not* introduce codegen items in the current crate.
     let _: (u32, u32) = Trait::without_default_impl(0);
diff --git a/tests/codegen-units/item-collection/drop_in_place_intrinsic.rs b/tests/codegen-units/item-collection/drop_in_place_intrinsic.rs
index d87ad41e70d..e1887b93b93 100644
--- a/tests/codegen-units/item-collection/drop_in_place_intrinsic.rs
+++ b/tests/codegen-units/item-collection/drop_in_place_intrinsic.rs
@@ -3,7 +3,7 @@
 //@ compile-flags:-Zinline-in-all-cgus
 //@ compile-flags:-Zinline-mir=no
 
-#![feature(start)]
+#![crate_type = "lib"]
 
 //~ MONO_ITEM fn std::ptr::drop_in_place::<StructWithDtor> - shim(Some(StructWithDtor)) @@ drop_in_place_intrinsic-cgu.0[Internal]
 struct StructWithDtor(u32);
@@ -14,8 +14,8 @@ impl Drop for StructWithDtor {
 }
 
 //~ MONO_ITEM fn start
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
+#[no_mangle]
+pub fn start(_: isize, _: *const *const u8) -> isize {
     //~ MONO_ITEM fn std::ptr::drop_in_place::<[StructWithDtor; 2]> - shim(Some([StructWithDtor; 2])) @@ drop_in_place_intrinsic-cgu.0[Internal]
     let x = [StructWithDtor(0), StructWithDtor(1)];
 
diff --git a/tests/codegen-units/item-collection/function-as-argument.rs b/tests/codegen-units/item-collection/function-as-argument.rs
index 4be713dc367..146a53bb911 100644
--- a/tests/codegen-units/item-collection/function-as-argument.rs
+++ b/tests/codegen-units/item-collection/function-as-argument.rs
@@ -1,7 +1,7 @@
 //@ compile-flags:-Zprint-mono-items=eager -Zinline-mir=no
 
 #![deny(dead_code)]
-#![feature(start)]
+#![crate_type = "lib"]
 
 fn take_fn_once<T1, T2, F: FnOnce(T1, T2)>(f: F, x: T1, y: T2) {
     (f)(x, y)
@@ -14,8 +14,8 @@ fn take_fn_pointer<T1, T2>(f: fn(T1, T2), x: T1, y: T2) {
 }
 
 //~ MONO_ITEM fn start
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
+#[no_mangle]
+pub fn start(_: isize, _: *const *const u8) -> isize {
     //~ MONO_ITEM fn take_fn_once::<u32, &str, fn(u32, &str) {function::<u32, &str>}>
     //~ MONO_ITEM fn function::<u32, &str>
     //~ MONO_ITEM fn <fn(u32, &str) {function::<u32, &str>} as std::ops::FnOnce<(u32, &str)>>::call_once - shim(fn(u32, &str) {function::<u32, &str>})
diff --git a/tests/codegen-units/item-collection/generic-drop-glue.rs b/tests/codegen-units/item-collection/generic-drop-glue.rs
index d861d269fae..6ecf98a032f 100644
--- a/tests/codegen-units/item-collection/generic-drop-glue.rs
+++ b/tests/codegen-units/item-collection/generic-drop-glue.rs
@@ -3,7 +3,7 @@
 //@ compile-flags:-Zinline-in-all-cgus
 
 #![deny(dead_code)]
-#![feature(start)]
+#![crate_type = "lib"]
 
 struct StructWithDrop<T1, T2> {
     x: T1,
@@ -44,8 +44,8 @@ impl Drop for NonGenericWithDrop {
 }
 
 //~ MONO_ITEM fn start
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
+#[no_mangle]
+pub fn start(_: isize, _: *const *const u8) -> isize {
     //~ MONO_ITEM fn std::ptr::drop_in_place::<StructWithDrop<i8, char>> - shim(Some(StructWithDrop<i8, char>)) @@ generic_drop_glue-cgu.0[Internal]
     //~ MONO_ITEM fn <StructWithDrop<i8, char> as std::ops::Drop>::drop
     let _ = StructWithDrop { x: 0i8, y: 'a' }.x;
diff --git a/tests/codegen-units/item-collection/generic-functions.rs b/tests/codegen-units/item-collection/generic-functions.rs
index 2d7c70c9c4c..4a890790702 100644
--- a/tests/codegen-units/item-collection/generic-functions.rs
+++ b/tests/codegen-units/item-collection/generic-functions.rs
@@ -1,7 +1,7 @@
 //@ compile-flags:-Zprint-mono-items=eager -Zinline-mir=no
 
 #![deny(dead_code)]
-#![feature(start)]
+#![crate_type = "lib"]
 
 fn foo1<T1>(a: T1) -> (T1, u32) {
     (a, 1)
@@ -22,8 +22,8 @@ pub fn lifetime_only<'a>(a: &'a u32) -> &'a u32 {
 }
 
 //~ MONO_ITEM fn start
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
+#[no_mangle]
+pub fn start(_: isize, _: *const *const u8) -> isize {
     //~ MONO_ITEM fn foo1::<i32>
     let _ = foo1(2i32);
     //~ MONO_ITEM fn foo1::<i64>
diff --git a/tests/codegen-units/item-collection/generic-impl.rs b/tests/codegen-units/item-collection/generic-impl.rs
index f6e49f6e6df..5a43bd64b2a 100644
--- a/tests/codegen-units/item-collection/generic-impl.rs
+++ b/tests/codegen-units/item-collection/generic-impl.rs
@@ -1,7 +1,7 @@
 //@ compile-flags:-Zprint-mono-items=eager -Zinline-mir=no
 
 #![deny(dead_code)]
-#![feature(start)]
+#![crate_type = "lib"]
 
 struct Struct<T> {
     x: T,
@@ -38,8 +38,8 @@ impl<'a> LifeTimeOnly<'a> {
 }
 
 //~ MONO_ITEM fn start
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
+#[no_mangle]
+pub fn start(_: isize, _: *const *const u8) -> isize {
     //~ MONO_ITEM fn Struct::<i32>::new
     //~ MONO_ITEM fn id::<i32>
     //~ MONO_ITEM fn Struct::<i32>::get::<i16>
diff --git a/tests/codegen-units/item-collection/impl-in-non-instantiated-generic.rs b/tests/codegen-units/item-collection/impl-in-non-instantiated-generic.rs
index 0b7f30187b5..d916fa6a825 100644
--- a/tests/codegen-units/item-collection/impl-in-non-instantiated-generic.rs
+++ b/tests/codegen-units/item-collection/impl-in-non-instantiated-generic.rs
@@ -1,7 +1,7 @@
 //@ compile-flags:-Zprint-mono-items=eager
 
 #![deny(dead_code)]
-#![feature(start)]
+#![crate_type = "lib"]
 
 trait SomeTrait {
     fn foo(&self);
@@ -19,8 +19,8 @@ pub fn generic_function<T>(x: T) -> (T, i32) {
 }
 
 //~ MONO_ITEM fn start
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
+#[no_mangle]
+pub fn start(_: isize, _: *const *const u8) -> isize {
     0i64.foo();
 
     0
diff --git a/tests/codegen-units/item-collection/instantiation-through-vtable.rs b/tests/codegen-units/item-collection/instantiation-through-vtable.rs
index 59dd4311a03..9087fc6410a 100644
--- a/tests/codegen-units/item-collection/instantiation-through-vtable.rs
+++ b/tests/codegen-units/item-collection/instantiation-through-vtable.rs
@@ -2,7 +2,7 @@
 //@ compile-flags:-Zprint-mono-items=eager -Zinline-in-all-cgus -Zmir-opt-level=0
 
 #![deny(dead_code)]
-#![feature(start)]
+#![crate_type = "lib"]
 
 trait Trait {
     fn foo(&self) -> u32;
@@ -21,8 +21,8 @@ impl<T> Trait for Struct<T> {
 }
 
 //~ MONO_ITEM fn start
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
+#[no_mangle]
+pub fn start(_: isize, _: *const *const u8) -> isize {
     let s1 = Struct { _a: 0u32 };
 
     //~ MONO_ITEM fn std::ptr::drop_in_place::<Struct<u32>> - shim(None) @@ instantiation_through_vtable-cgu.0[Internal]
diff --git a/tests/codegen-units/item-collection/items-within-generic-items.rs b/tests/codegen-units/item-collection/items-within-generic-items.rs
index 7798d2b46d2..56d21d5895c 100644
--- a/tests/codegen-units/item-collection/items-within-generic-items.rs
+++ b/tests/codegen-units/item-collection/items-within-generic-items.rs
@@ -1,7 +1,7 @@
 //@ compile-flags:-Zprint-mono-items=eager -Copt-level=0
 
 #![deny(dead_code)]
-#![feature(start)]
+#![crate_type = "lib"]
 
 fn generic_fn<T>(a: T) -> (T, i32) {
     //~ MONO_ITEM fn generic_fn::nested_fn
@@ -22,8 +22,8 @@ fn generic_fn<T>(a: T) -> (T, i32) {
 }
 
 //~ MONO_ITEM fn start
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
+#[no_mangle]
+pub fn start(_: isize, _: *const *const u8) -> isize {
     //~ MONO_ITEM fn generic_fn::<i64>
     let _ = generic_fn(0i64);
     //~ MONO_ITEM fn generic_fn::<u16>
diff --git a/tests/codegen-units/item-collection/non-generic-closures.rs b/tests/codegen-units/item-collection/non-generic-closures.rs
index 8847a249b1e..4dbc0b62b97 100644
--- a/tests/codegen-units/item-collection/non-generic-closures.rs
+++ b/tests/codegen-units/item-collection/non-generic-closures.rs
@@ -1,7 +1,7 @@
 //@ compile-flags:-Zprint-mono-items=eager -Zinline-mir=no
 
 #![deny(dead_code)]
-#![feature(start)]
+#![crate_type = "lib"]
 
 //~ MONO_ITEM fn temporary @@ non_generic_closures-cgu.0[Internal]
 fn temporary() {
@@ -40,9 +40,9 @@ fn assigned_to_variable_executed_directly() {
     f(4);
 }
 
-//~ MONO_ITEM fn start @@ non_generic_closures-cgu.0[Internal]
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
+//~ MONO_ITEM fn start @@ non_generic_closures-cgu.0[External]
+#[no_mangle]
+pub fn start(_: isize, _: *const *const u8) -> isize {
     temporary();
     assigned_to_variable_but_not_executed();
     assigned_to_variable_executed_directly();
diff --git a/tests/codegen-units/item-collection/non-generic-drop-glue.rs b/tests/codegen-units/item-collection/non-generic-drop-glue.rs
index f7bb2f3f2f4..c4d7942ba1e 100644
--- a/tests/codegen-units/item-collection/non-generic-drop-glue.rs
+++ b/tests/codegen-units/item-collection/non-generic-drop-glue.rs
@@ -3,7 +3,7 @@
 //@ compile-flags:-Zinline-in-all-cgus
 
 #![deny(dead_code)]
-#![feature(start)]
+#![crate_type = "lib"]
 
 //~ MONO_ITEM fn std::ptr::drop_in_place::<StructWithDrop> - shim(Some(StructWithDrop)) @@ non_generic_drop_glue-cgu.0[Internal]
 struct StructWithDrop {
@@ -34,8 +34,8 @@ enum EnumNoDrop {
 }
 
 //~ MONO_ITEM fn start
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
+#[no_mangle]
+pub fn start(_: isize, _: *const *const u8) -> isize {
     let _ = StructWithDrop { x: 0 }.x;
     let _ = StructNoDrop { x: 0 }.x;
     let _ = match EnumWithDrop::A(0) {
diff --git a/tests/codegen-units/item-collection/non-generic-functions.rs b/tests/codegen-units/item-collection/non-generic-functions.rs
index d4d7d221827..4b86b1088f1 100644
--- a/tests/codegen-units/item-collection/non-generic-functions.rs
+++ b/tests/codegen-units/item-collection/non-generic-functions.rs
@@ -1,7 +1,7 @@
 //@ compile-flags:-Zprint-mono-items=eager
 
 #![deny(dead_code)]
-#![feature(start)]
+#![crate_type = "lib"]
 
 //~ MONO_ITEM fn foo
 fn foo() {
@@ -62,8 +62,8 @@ impl Struct {
 }
 
 //~ MONO_ITEM fn start
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
+#[no_mangle]
+pub fn start(_: isize, _: *const *const u8) -> isize {
     foo();
     bar();
     Struct::foo();
diff --git a/tests/codegen-units/item-collection/static-init.rs b/tests/codegen-units/item-collection/static-init.rs
index 44b80ef73a4..5e3d06790a2 100644
--- a/tests/codegen-units/item-collection/static-init.rs
+++ b/tests/codegen-units/item-collection/static-init.rs
@@ -1,16 +1,16 @@
 //@ compile-flags:-Zprint-mono-items=eager
 
-#![feature(start)]
+#![crate_type = "lib"]
 
-pub static FN: fn() = foo::<i32>;
+static FN: fn() = foo::<i32>;
 
-pub fn foo<T>() {}
+fn foo<T>() {}
 
 //~ MONO_ITEM fn foo::<i32>
 //~ MONO_ITEM static FN
 
 //~ MONO_ITEM fn start
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
+#[no_mangle]
+pub fn start(_: isize, _: *const *const u8) -> isize {
     0
 }
diff --git a/tests/codegen-units/item-collection/statics-and-consts.rs b/tests/codegen-units/item-collection/statics-and-consts.rs
index 1e3782f0c6e..54297a40851 100644
--- a/tests/codegen-units/item-collection/statics-and-consts.rs
+++ b/tests/codegen-units/item-collection/statics-and-consts.rs
@@ -1,7 +1,7 @@
 //@ compile-flags:-Zprint-mono-items=eager
 
 #![deny(dead_code)]
-#![feature(start)]
+#![crate_type = "lib"]
 
 static STATIC1: i64 = {
     const STATIC1_CONST1: i64 = 2;
@@ -38,8 +38,8 @@ fn foo() {
 }
 
 //~ MONO_ITEM fn start
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
+#[no_mangle]
+pub fn start(_: isize, _: *const *const u8) -> isize {
     foo();
     let _ = STATIC1;
 
diff --git a/tests/codegen-units/item-collection/trait-implementations.rs b/tests/codegen-units/item-collection/trait-implementations.rs
index e4c444499e0..3b67d4f22bd 100644
--- a/tests/codegen-units/item-collection/trait-implementations.rs
+++ b/tests/codegen-units/item-collection/trait-implementations.rs
@@ -1,7 +1,7 @@
 //@ compile-flags:-Zprint-mono-items=eager -Zinline-mir=no
 
 #![deny(dead_code)]
-#![feature(start)]
+#![crate_type = "lib"]
 
 pub trait SomeTrait {
     fn foo(&self);
@@ -42,8 +42,8 @@ impl<T> SomeGenericTrait<T> for f32 {
 }
 
 //~ MONO_ITEM fn start
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
+#[no_mangle]
+pub fn start(_: isize, _: *const *const u8) -> isize {
     //~ MONO_ITEM fn <i32 as SomeTrait>::bar::<char>
     0i32.bar('x');
 
diff --git a/tests/codegen-units/item-collection/trait-method-as-argument.rs b/tests/codegen-units/item-collection/trait-method-as-argument.rs
index 10cf2a0e967..d425ea19988 100644
--- a/tests/codegen-units/item-collection/trait-method-as-argument.rs
+++ b/tests/codegen-units/item-collection/trait-method-as-argument.rs
@@ -1,7 +1,7 @@
 //@ compile-flags:-Zprint-mono-items=eager -Zinline-mir=no
 
 #![deny(dead_code)]
-#![feature(start)]
+#![crate_type = "lib"]
 
 trait Trait: Sized {
     fn foo(self) -> Self {
@@ -30,8 +30,8 @@ fn take_foo_mut<T, F: FnMut(T) -> T>(mut f: F, arg: T) -> T {
 }
 
 //~ MONO_ITEM fn start
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
+#[no_mangle]
+pub fn start(_: isize, _: *const *const u8) -> isize {
     //~ MONO_ITEM fn take_foo_once::<u32, fn(u32) -> u32 {<u32 as Trait>::foo}>
     //~ MONO_ITEM fn <u32 as Trait>::foo
     //~ MONO_ITEM fn <fn(u32) -> u32 {<u32 as Trait>::foo} as std::ops::FnOnce<(u32,)>>::call_once - shim(fn(u32) -> u32 {<u32 as Trait>::foo})
diff --git a/tests/codegen-units/item-collection/trait-method-default-impl.rs b/tests/codegen-units/item-collection/trait-method-default-impl.rs
index fd73786a402..cd0a4b89031 100644
--- a/tests/codegen-units/item-collection/trait-method-default-impl.rs
+++ b/tests/codegen-units/item-collection/trait-method-default-impl.rs
@@ -1,7 +1,7 @@
 //@ compile-flags:-Zprint-mono-items=eager -Zinline-mir=no
 
 #![deny(dead_code)]
-#![feature(start)]
+#![crate_type = "lib"]
 
 trait SomeTrait {
     fn foo(&self) {}
@@ -39,8 +39,8 @@ impl<T1> SomeGenericTrait<T1> for u32 {
 }
 
 //~ MONO_ITEM fn start
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
+#[no_mangle]
+pub fn start(_: isize, _: *const *const u8) -> isize {
     //~ MONO_ITEM fn <i8 as SomeTrait>::bar::<char>
     let _ = 1i8.bar('c');
 
diff --git a/tests/codegen-units/item-collection/transitive-drop-glue.rs b/tests/codegen-units/item-collection/transitive-drop-glue.rs
index 7c879dee1a1..18954fab86f 100644
--- a/tests/codegen-units/item-collection/transitive-drop-glue.rs
+++ b/tests/codegen-units/item-collection/transitive-drop-glue.rs
@@ -3,7 +3,7 @@
 //@ compile-flags:-Zinline-in-all-cgus
 
 #![deny(dead_code)]
-#![feature(start)]
+#![crate_type = "lib"]
 
 //~ MONO_ITEM fn std::ptr::drop_in_place::<Root> - shim(Some(Root)) @@ transitive_drop_glue-cgu.0[Internal]
 struct Root(#[allow(dead_code)] Intermediate);
@@ -26,8 +26,8 @@ impl<T> Drop for LeafGen<T> {
 }
 
 //~ MONO_ITEM fn start
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
+#[no_mangle]
+pub fn start(_: isize, _: *const *const u8) -> isize {
     let _ = Root(Intermediate(Leaf));
 
     //~ MONO_ITEM fn std::ptr::drop_in_place::<RootGen<u32>> - shim(Some(RootGen<u32>)) @@ transitive_drop_glue-cgu.0[Internal]
diff --git a/tests/codegen-units/item-collection/tuple-drop-glue.rs b/tests/codegen-units/item-collection/tuple-drop-glue.rs
index 9d8b0cdd384..2e70d0151eb 100644
--- a/tests/codegen-units/item-collection/tuple-drop-glue.rs
+++ b/tests/codegen-units/item-collection/tuple-drop-glue.rs
@@ -3,7 +3,7 @@
 //@ compile-flags:-Zinline-in-all-cgus
 
 #![deny(dead_code)]
-#![feature(start)]
+#![crate_type = "lib"]
 
 //~ MONO_ITEM fn std::ptr::drop_in_place::<Dropped> - shim(Some(Dropped)) @@ tuple_drop_glue-cgu.0[Internal]
 struct Dropped;
@@ -14,8 +14,8 @@ impl Drop for Dropped {
 }
 
 //~ MONO_ITEM fn start
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
+#[no_mangle]
+pub fn start(_: isize, _: *const *const u8) -> isize {
     //~ MONO_ITEM fn std::ptr::drop_in_place::<(u32, Dropped)> - shim(Some((u32, Dropped))) @@ tuple_drop_glue-cgu.0[Internal]
     let x = (0u32, Dropped);
 
diff --git a/tests/codegen-units/item-collection/unsizing.rs b/tests/codegen-units/item-collection/unsizing.rs
index 5ea8b47962a..23e6003dc19 100644
--- a/tests/codegen-units/item-collection/unsizing.rs
+++ b/tests/codegen-units/item-collection/unsizing.rs
@@ -5,7 +5,7 @@
 #![deny(dead_code)]
 #![feature(coerce_unsized)]
 #![feature(unsize)]
-#![feature(start)]
+#![crate_type = "lib"]
 
 use std::marker::Unsize;
 use std::ops::CoerceUnsized;
@@ -45,8 +45,8 @@ struct Wrapper<T: ?Sized>(#[allow(dead_code)] *const T);
 impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<Wrapper<U>> for Wrapper<T> {}
 
 //~ MONO_ITEM fn start
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
+#[no_mangle]
+pub fn start(_: isize, _: *const *const u8) -> isize {
     // simple case
     let bool_sized = &true;
     //~ MONO_ITEM fn std::ptr::drop_in_place::<bool> - shim(None) @@ unsizing-cgu.0[Internal]
diff --git a/tests/codegen-units/partitioning/methods-are-with-self-type.rs b/tests/codegen-units/partitioning/methods-are-with-self-type.rs
index 7c9045e8f1a..94d06829c6c 100644
--- a/tests/codegen-units/partitioning/methods-are-with-self-type.rs
+++ b/tests/codegen-units/partitioning/methods-are-with-self-type.rs
@@ -46,6 +46,7 @@ mod type2 {
 }
 
 //~ MONO_ITEM fn start @@ methods_are_with_self_type[External]
+#[no_mangle]
 pub fn start() {
     //~ MONO_ITEM fn mod1::<impl SomeGenericType<u32, u64>>::method @@ methods_are_with_self_type.volatile[External]
     SomeGenericType(0u32, 0u64).method();
diff --git a/tests/codegen-units/partitioning/vtable-through-const.rs b/tests/codegen-units/partitioning/vtable-through-const.rs
index a9186cea9c8..3880bba6f6b 100644
--- a/tests/codegen-units/partitioning/vtable-through-const.rs
+++ b/tests/codegen-units/partitioning/vtable-through-const.rs
@@ -2,11 +2,13 @@
 //@ incremental
 //@ compile-flags:-Zprint-mono-items=lazy
 //@ compile-flags:-Zinline-in-all-cgus
+// Need to disable optimizations to ensure consistent output across all CI runners.
+//@ compile-flags:-Copt-level=0
 
 // This test case makes sure, that references made through constants are
 // recorded properly in the InliningMap.
 
-#![feature(start)]
+#![crate_type = "lib"]
 
 mod mod1 {
     struct NeedsDrop;
@@ -51,8 +53,8 @@ mod mod1 {
         fn do_something_else(&self) {}
     }
 
-    //~ MONO_ITEM fn <mod1::NeedsDrop as mod1::Trait2>::do_something @@ vtable_through_const-mod1.volatile[Internal]
-    //~ MONO_ITEM fn <mod1::NeedsDrop as mod1::Trait2>::do_something_else @@ vtable_through_const-mod1.volatile[Internal]
+    //~ MONO_ITEM fn <mod1::NeedsDrop as mod1::Trait2>::do_something @@ vtable_through_const-mod1.volatile[External]
+    //~ MONO_ITEM fn <mod1::NeedsDrop as mod1::Trait2>::do_something_else @@ vtable_through_const-mod1.volatile[External]
     impl Trait2 for NeedsDrop {}
 
     pub trait Trait2Gen<T> {
@@ -76,9 +78,9 @@ mod mod1 {
 }
 
 //~ MONO_ITEM fn start
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
-    //~ MONO_ITEM fn <mod1::NeedsDrop as std::ops::Drop>::drop @@ vtable_through_const-fallback.cgu[Internal]
+#[no_mangle]
+pub fn start(_: isize, _: *const *const u8) -> isize {
+    //~ MONO_ITEM fn <mod1::NeedsDrop as std::ops::Drop>::drop @@ vtable_through_const-fallback.cgu[External]
     //~ MONO_ITEM fn std::ptr::drop_in_place::<mod1::NeedsDrop> - shim(Some(mod1::NeedsDrop)) @@ vtable_through_const-fallback.cgu[External]
 
     // Since Trait1::do_something() is instantiated via its default implementation,
@@ -95,8 +97,8 @@ fn start(_: isize, _: *const *const u8) -> isize {
     // Same as above
     //~ MONO_ITEM fn <mod1::NeedsDrop as mod1::Trait1Gen<u8>>::do_something @@ vtable_through_const-mod1.volatile[External]
     //~ MONO_ITEM fn <mod1::NeedsDrop as mod1::Trait1Gen<u8>>::do_something_else @@ vtable_through_const-mod1.volatile[External]
-    //~ MONO_ITEM fn <mod1::NeedsDrop as mod1::Trait2Gen<u8>>::do_something @@ vtable_through_const-mod1.volatile[Internal]
-    //~ MONO_ITEM fn <mod1::NeedsDrop as mod1::Trait2Gen<u8>>::do_something_else @@ vtable_through_const-mod1.volatile[Internal]
+    //~ MONO_ITEM fn <mod1::NeedsDrop as mod1::Trait2Gen<u8>>::do_something @@ vtable_through_const-mod1.volatile[External]
+    //~ MONO_ITEM fn <mod1::NeedsDrop as mod1::Trait2Gen<u8>>::do_something_else @@ vtable_through_const-mod1.volatile[External]
     mod1::TRAIT1_GEN_REF.do_something(0u8);
 
     //~ MONO_ITEM fn mod1::id::<char> @@ vtable_through_const-mod1.volatile[External]
diff --git a/tests/codegen/gdb_debug_script_load.rs b/tests/codegen/gdb_debug_script_load.rs
index 30d518c0bcb..3e92eba10b1 100644
--- a/tests/codegen/gdb_debug_script_load.rs
+++ b/tests/codegen/gdb_debug_script_load.rs
@@ -4,14 +4,34 @@
 //@ ignore-wasm
 //@ ignore-emscripten
 
-//@ compile-flags: -g -C no-prepopulate-passes
+//@ compile-flags: -g -C no-prepopulate-passes -Cpanic=abort
 
-#![feature(start)]
+#![feature(lang_items)]
+#![no_std]
 
+#[panic_handler]
+fn panic_handler(_: &core::panic::PanicInfo) -> ! {
+    loop {}
+}
+
+#[no_mangle]
+extern "C" fn rust_eh_personality() {
+    loop {}
+}
+
+// Needs rustc to generate `main` as that's where the magic load is inserted.
+// IOW, we cannot write this test with `#![no_main]`.
 // CHECK-LABEL: @main
 // CHECK: load volatile i8, {{.+}} @__rustc_debug_gdb_scripts_section__
 
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
+#[lang = "start"]
+fn lang_start<T: 'static>(
+    _main: fn() -> T,
+    _argc: isize,
+    _argv: *const *const u8,
+    _sigpipe: u8,
+) -> isize {
     return 0;
 }
+
+fn main() {}
diff --git a/tests/codegen/mainsubprogramstart.rs b/tests/codegen/mainsubprogramstart.rs
deleted file mode 100644
index 0bcb311644d..00000000000
--- a/tests/codegen/mainsubprogramstart.rs
+++ /dev/null
@@ -1,14 +0,0 @@
-//@ ignore-apple
-//@ ignore-wasi wasi codegens the main symbol differently
-
-//@ compile-flags: -g -C no-prepopulate-passes
-
-#![feature(start)]
-
-// CHECK-LABEL: @main
-// CHECK: {{.*}}DISubprogram{{.*}}name: "start",{{.*}}DI{{(SP)?}}FlagMainSubprogram{{.*}}
-
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
-    return 0;
-}
diff --git a/tests/run-make/crate-circular-deps-link/c.rs b/tests/run-make/crate-circular-deps-link/c.rs
index 9d72657aa59..cfe00a2a347 100644
--- a/tests/run-make/crate-circular-deps-link/c.rs
+++ b/tests/run-make/crate-circular-deps-link/c.rs
@@ -1,5 +1,5 @@
 #![crate_type = "bin"]
-#![feature(start)]
+#![no_main]
 #![no_std]
 
 extern crate a;
@@ -24,8 +24,8 @@ unsafe impl GlobalAlloc for Allocator {
 #[global_allocator]
 static ALLOCATOR: Allocator = Allocator;
 
-#[start]
-fn main(argc: isize, _argv: *const *const u8) -> isize {
+#[no_mangle]
+extern "C" fn main(argc: core::ffi::c_int, _argv: *const *const u8) -> core::ffi::c_int {
     let mut v = Vec::new();
     for i in 0..argc {
         v.push(i);
diff --git a/tests/run-make/fmt-write-bloat/main.rs b/tests/run-make/fmt-write-bloat/main.rs
index 6f206d6515a..b50461c0a02 100644
--- a/tests/run-make/fmt-write-bloat/main.rs
+++ b/tests/run-make/fmt-write-bloat/main.rs
@@ -1,5 +1,5 @@
 #![feature(lang_items)]
-#![feature(start)]
+#![no_main]
 #![no_std]
 
 use core::fmt;
@@ -17,8 +17,8 @@ impl fmt::Write for Dummy {
     }
 }
 
-#[start]
-fn main(_: isize, _: *const *const u8) -> isize {
+#[no_mangle]
+extern "C" fn main(_argc: core::ffi::c_int, _argv: *const *const u8) -> core::ffi::c_int {
     let _ = writeln!(Dummy, "Hello World");
     0
 }
diff --git a/tests/run-make/no-alloc-shim/foo.rs b/tests/run-make/no-alloc-shim/foo.rs
index a3daec3db39..42606961f8b 100644
--- a/tests/run-make/no-alloc-shim/foo.rs
+++ b/tests/run-make/no-alloc-shim/foo.rs
@@ -35,7 +35,7 @@ unsafe impl GlobalAlloc for Alloc {
 static __rust_no_alloc_shim_is_unstable: u8 = 0;
 
 #[no_mangle]
-extern "C" fn main(_argc: usize, _argv: *const *const i8) -> i32 {
+extern "C" fn main(_argc: core::ffi::c_int, _argv: *const *const i8) -> i32 {
     unsafe {
         assert_eq!(alloc::alloc::alloc(Layout::new::<()>()), core::ptr::null_mut());
     }
diff --git a/tests/run-make/sepcomp-inlining/foo.rs b/tests/run-make/sepcomp-inlining/foo.rs
index 2fe5f9cb726..9101ee691a4 100644
--- a/tests/run-make/sepcomp-inlining/foo.rs
+++ b/tests/run-make/sepcomp-inlining/foo.rs
@@ -1,4 +1,4 @@
-#![feature(start)]
+#![crate_type = "lib"]
 
 #[inline]
 fn inlined() -> u32 {
@@ -21,8 +21,7 @@ mod b {
     }
 }
 
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
+pub fn start(_: isize, _: *const *const u8) -> isize {
     a::f();
     b::f();
 
diff --git a/tests/ui/array-slice-vec/vec-macro-no-std.rs b/tests/ui/array-slice-vec/vec-macro-no-std.rs
index 1b5ab536dcb..ea0df0bea71 100644
--- a/tests/ui/array-slice-vec/vec-macro-no-std.rs
+++ b/tests/ui/array-slice-vec/vec-macro-no-std.rs
@@ -1,21 +1,21 @@
 //@ run-pass
-
 //@ ignore-emscripten no no_std executables
+//@ ignore-wasm different `main` convention
 
-#![feature(lang_items, start, rustc_private)]
 #![no_std]
+#![no_main]
 
+// Import global allocator and panic handler.
 extern crate std as other;
 
-#[macro_use]
-extern crate alloc;
+#[macro_use] extern crate alloc;
 
 use alloc::vec::Vec;
 
 // Issue #16806
 
-#[start]
-fn start(_argc: isize, _argv: *const *const u8) -> isize {
+#[no_mangle]
+extern "C" fn main(_argc: core::ffi::c_int, _argv: *const *const u8) -> core::ffi::c_int {
     let x: Vec<u8> = vec![0, 1, 2];
     match x.last() {
         Some(&2) => (),
diff --git a/tests/ui/async-await/issue-68523-start.rs b/tests/ui/async-await/issue-68523-start.rs
deleted file mode 100644
index ee3baf4990c..00000000000
--- a/tests/ui/async-await/issue-68523-start.rs
+++ /dev/null
@@ -1,9 +0,0 @@
-//@ edition:2018
-
-#![feature(start)]
-
-#[start]
-pub async fn start(_: isize, _: *const *const u8) -> isize {
-//~^ ERROR `#[start]` function is not allowed to be `async`
-    0
-}
diff --git a/tests/ui/async-await/issue-68523-start.stderr b/tests/ui/async-await/issue-68523-start.stderr
deleted file mode 100644
index 5b76ab56e24..00000000000
--- a/tests/ui/async-await/issue-68523-start.stderr
+++ /dev/null
@@ -1,9 +0,0 @@
-error[E0752]: `#[start]` function is not allowed to be `async`
-  --> $DIR/issue-68523-start.rs:6:1
-   |
-LL | pub async fn start(_: isize, _: *const *const u8) -> isize {
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `#[start]` is not allowed to be `async`
-
-error: aborting due to 1 previous error
-
-For more information about this error, try `rustc --explain E0752`.
diff --git a/tests/ui/attr-start.rs b/tests/ui/attr-start.rs
deleted file mode 100644
index 232f50955b2..00000000000
--- a/tests/ui/attr-start.rs
+++ /dev/null
@@ -1,8 +0,0 @@
-//@ run-pass
-
-#![feature(start)]
-
-#[start]
-fn start(_argc: isize, _argv: *const *const u8) -> isize {
-    return 0;
-}
diff --git a/tests/ui/duplicate/dupe-symbols-7.stderr b/tests/ui/duplicate/dupe-symbols-7.stderr
index ab9167e005a..aa6213af2e4 100644
--- a/tests/ui/duplicate/dupe-symbols-7.stderr
+++ b/tests/ui/duplicate/dupe-symbols-7.stderr
@@ -4,7 +4,7 @@ error: entry symbol `main` declared multiple times
 LL | fn main(){}
    | ^^^^^^^^^
    |
-   = help: did you use `#[no_mangle]` on `fn main`? Use `#[start]` instead
+   = help: did you use `#[no_mangle]` on `fn main`? Use `#![no_main]` to suppress the usual Rust-generated entry point
 
 error: aborting due to 1 previous error
 
diff --git a/tests/ui/duplicate/dupe-symbols-8.stderr b/tests/ui/duplicate/dupe-symbols-8.stderr
index d7d419c9aa4..0f47d3683b5 100644
--- a/tests/ui/duplicate/dupe-symbols-8.stderr
+++ b/tests/ui/duplicate/dupe-symbols-8.stderr
@@ -4,7 +4,7 @@ error: entry symbol `main` declared multiple times
 LL | fn main() {
    | ^^^^^^^^^
    |
-   = help: did you use `#[no_mangle]` on `fn main`? Use `#[start]` instead
+   = help: did you use `#[no_mangle]` on `fn main`? Use `#![no_main]` to suppress the usual Rust-generated entry point
 
 error: aborting due to 1 previous error
 
diff --git a/tests/ui/error-codes/E0132.rs b/tests/ui/error-codes/E0132.rs
deleted file mode 100644
index fb5e5d7b95a..00000000000
--- a/tests/ui/error-codes/E0132.rs
+++ /dev/null
@@ -1,7 +0,0 @@
-#![feature(start)]
-
-#[start]
-fn f< T >() {} //~ ERROR E0132
-
-fn main() {
-}
diff --git a/tests/ui/error-codes/E0132.stderr b/tests/ui/error-codes/E0132.stderr
deleted file mode 100644
index b1990afa3ae..00000000000
--- a/tests/ui/error-codes/E0132.stderr
+++ /dev/null
@@ -1,9 +0,0 @@
-error[E0132]: `#[start]` function is not allowed to have type parameters
-  --> $DIR/E0132.rs:4:5
-   |
-LL | fn f< T >() {}
-   |     ^^^^^ `#[start]` function cannot have type parameters
-
-error: aborting due to 1 previous error
-
-For more information about this error, try `rustc --explain E0132`.
diff --git a/tests/ui/error-codes/E0138.rs b/tests/ui/error-codes/E0138.rs
deleted file mode 100644
index 6f3c36282e8..00000000000
--- a/tests/ui/error-codes/E0138.rs
+++ /dev/null
@@ -1,8 +0,0 @@
-#![feature(start)]
-
-#[start]
-fn foo(argc: isize, argv: *const *const u8) -> isize { 0 }
-
-#[start]
-fn f(argc: isize, argv: *const *const u8) -> isize { 0 }
-//~^ ERROR E0138
diff --git a/tests/ui/error-codes/E0138.stderr b/tests/ui/error-codes/E0138.stderr
deleted file mode 100644
index 04877ab4082..00000000000
--- a/tests/ui/error-codes/E0138.stderr
+++ /dev/null
@@ -1,12 +0,0 @@
-error[E0138]: multiple `start` functions
-  --> $DIR/E0138.rs:7:1
-   |
-LL | fn foo(argc: isize, argv: *const *const u8) -> isize { 0 }
-   | ---------------------------------------------------- previous `#[start]` function here
-...
-LL | fn f(argc: isize, argv: *const *const u8) -> isize { 0 }
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ multiple `start` functions
-
-error: aborting due to 1 previous error
-
-For more information about this error, try `rustc --explain E0138`.
diff --git a/tests/ui/error-codes/E0647.rs b/tests/ui/error-codes/E0647.rs
deleted file mode 100644
index fc085511cbc..00000000000
--- a/tests/ui/error-codes/E0647.rs
+++ /dev/null
@@ -1,9 +0,0 @@
-#![no_std]
-#![feature(start)]
-
-extern crate std;
-
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize where (): Copy { //~ ERROR [E0647]
-    0
-}
diff --git a/tests/ui/error-codes/E0647.stderr b/tests/ui/error-codes/E0647.stderr
deleted file mode 100644
index 4b444e5a397..00000000000
--- a/tests/ui/error-codes/E0647.stderr
+++ /dev/null
@@ -1,9 +0,0 @@
-error[E0647]: `#[start]` function is not allowed to have a `where` clause
-  --> $DIR/E0647.rs:7:50
-   |
-LL | fn start(_: isize, _: *const *const u8) -> isize where (): Copy {
-   |                                                  ^^^^^^^^^^^^^^ `#[start]` function cannot have a `where` clause
-
-error: aborting due to 1 previous error
-
-For more information about this error, try `rustc --explain E0647`.
diff --git a/tests/ui/extern/extern-prelude-core.rs b/tests/ui/extern/extern-prelude-core.rs
index ced1e5c3915..5108c02517c 100644
--- a/tests/ui/extern/extern-prelude-core.rs
+++ b/tests/ui/extern/extern-prelude-core.rs
@@ -1,5 +1,5 @@
 //@ run-pass
-#![feature(lang_items, start)]
+#![feature(lang_items)]
 #![no_std]
 
 extern crate std as other;
@@ -11,8 +11,6 @@ mod foo {
     }
 }
 
-#[start]
-fn start(_argc: isize, _argv: *const *const u8) -> isize {
+fn main() {
     foo::test();
-    0
 }
diff --git a/tests/ui/feature-gates/feature-gate-start.rs b/tests/ui/feature-gates/feature-gate-start.rs
deleted file mode 100644
index e617f1c4759..00000000000
--- a/tests/ui/feature-gates/feature-gate-start.rs
+++ /dev/null
@@ -1,3 +0,0 @@
-#[start]
-fn foo(_: isize, _: *const *const u8) -> isize { 0 }
-//~^ ERROR `#[start]` functions are experimental
diff --git a/tests/ui/feature-gates/feature-gate-start.stderr b/tests/ui/feature-gates/feature-gate-start.stderr
deleted file mode 100644
index b1859c43718..00000000000
--- a/tests/ui/feature-gates/feature-gate-start.stderr
+++ /dev/null
@@ -1,13 +0,0 @@
-error[E0658]: `#[start]` functions are experimental and their signature may change over time
-  --> $DIR/feature-gate-start.rs:2:1
-   |
-LL | fn foo(_: isize, _: *const *const u8) -> isize { 0 }
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: see issue #29633 <https://github.com/rust-lang/rust/issues/29633> for more information
-   = help: add `#![feature(start)]` to the crate attributes to enable
-   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
-
-error: aborting due to 1 previous error
-
-For more information about this error, try `rustc --explain E0658`.
diff --git a/tests/ui/feature-gates/issue-43106-gating-of-builtin-attrs-error.rs b/tests/ui/feature-gates/issue-43106-gating-of-builtin-attrs-error.rs
index afffb3b1443..02a56c7e6aa 100644
--- a/tests/ui/feature-gates/issue-43106-gating-of-builtin-attrs-error.rs
+++ b/tests/ui/feature-gates/issue-43106-gating-of-builtin-attrs-error.rs
@@ -14,8 +14,6 @@
 #![rustc_main] //~ ERROR: the `#[rustc_main]` attribute is used internally to specify
 //~^ ERROR: `rustc_main` attribute cannot be used at crate level
 //~| NOTE: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
-#![start]
-//~^ ERROR: `start` attribute cannot be used at crate level
 #![repr()]
 //~^ ERROR: `repr` attribute cannot be used at crate level
 #![path = "3800"]
@@ -38,7 +36,6 @@ mod inline {
     //~| NOTE the inner attribute doesn't annotate this module
     //~| NOTE the inner attribute doesn't annotate this module
     //~| NOTE the inner attribute doesn't annotate this module
-    //~| NOTE the inner attribute doesn't annotate this module
 
     mod inner { #![inline] }
     //~^ ERROR attribute should be applied to function or closure
@@ -123,24 +120,6 @@ mod export_name {
     }
 }
 
-#[start]
-//~^ ERROR: `start` attribute can only be used on functions
-mod start {
-    mod inner { #![start] }
-    //~^ ERROR: `start` attribute can only be used on functions
-
-    // for `fn f()` case, see feature-gate-start.rs
-
-    #[start] struct S;
-    //~^ ERROR: `start` attribute can only be used on functions
-
-    #[start] type T = S;
-    //~^ ERROR: `start` attribute can only be used on functions
-
-    #[start] impl S { }
-    //~^ ERROR: `start` attribute can only be used on functions
-}
-
 #[repr(C)]
 //~^ ERROR: attribute should be applied to a struct, enum, or union
 mod repr {
diff --git a/tests/ui/feature-gates/issue-43106-gating-of-builtin-attrs-error.stderr b/tests/ui/feature-gates/issue-43106-gating-of-builtin-attrs-error.stderr
index db8c5295a2d..648bafe6460 100644
--- a/tests/ui/feature-gates/issue-43106-gating-of-builtin-attrs-error.stderr
+++ b/tests/ui/feature-gates/issue-43106-gating-of-builtin-attrs-error.stderr
@@ -8,7 +8,7 @@ LL | #![rustc_main]
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
 error: valid forms for the attribute are `#[inline]` and `#[inline(always|never)]`
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:47:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:44:5
    |
 LL |     #[inline = "2100"] fn f() { }
    |     ^^^^^^^^^^^^^^^^^^
@@ -17,38 +17,8 @@ LL |     #[inline = "2100"] fn f() { }
    = note: for more information, see issue #57571 <https://github.com/rust-lang/rust/issues/57571>
    = note: `#[deny(ill_formed_attribute_input)]` on by default
 
-error: `start` attribute can only be used on functions
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:126:1
-   |
-LL | #[start]
-   | ^^^^^^^^
-
-error: `start` attribute can only be used on functions
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:129:17
-   |
-LL |     mod inner { #![start] }
-   |                 ^^^^^^^^^
-
-error: `start` attribute can only be used on functions
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:134:5
-   |
-LL |     #[start] struct S;
-   |     ^^^^^^^^
-
-error: `start` attribute can only be used on functions
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:137:5
-   |
-LL |     #[start] type T = S;
-   |     ^^^^^^^^
-
-error: `start` attribute can only be used on functions
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:140:5
-   |
-LL |     #[start] impl S { }
-   |     ^^^^^^^^
-
 error[E0518]: attribute should be applied to function or closure
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:32:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:30:1
    |
 LL |   #[inline]
    |   ^^^^^^^^^
@@ -59,7 +29,7 @@ LL | | }
    | |_- not a function or closure
 
 error: attribute should be applied to an `extern crate` item
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:66:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:63:1
    |
 LL |   #[no_link]
    |   ^^^^^^^^^^
@@ -73,7 +43,7 @@ LL | | }
    | |_- not an `extern crate` item
 
 error: attribute should be applied to a free function, impl method or static
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:92:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:89:1
    |
 LL |   #[export_name = "2200"]
    |   ^^^^^^^^^^^^^^^^^^^^^^^
@@ -87,7 +57,7 @@ LL | | }
    | |_- not a free function, impl method or static
 
 error[E0517]: attribute should be applied to a struct, enum, or union
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:144:8
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:123:8
    |
 LL |   #[repr(C)]
    |          ^
@@ -100,7 +70,7 @@ LL | | }
    | |_- not a struct, enum, or union
 
 error[E0517]: attribute should be applied to a struct, enum, or union
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:168:8
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:147:8
    |
 LL |   #[repr(Rust)]
    |          ^^^^
@@ -113,19 +83,19 @@ LL | | }
    | |_- not a struct, enum, or union
 
 error: attribute should be applied to an `extern crate` item
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:26:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:24:1
    |
 LL | #![no_link]
    | ^^^^^^^^^^^ not an `extern crate` item
 
 error: attribute should be applied to a free function, impl method or static
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:28:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:26:1
    |
 LL | #![export_name = "2200"]
    | ^^^^^^^^^^^^^^^^^^^^^^^^ not a free function, impl method or static
 
 error[E0518]: attribute should be applied to function or closure
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:30:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:28:1
    |
 LL | #![inline]
    | ^^^^^^^^^^ not a function or closure
@@ -160,23 +130,8 @@ LL - #![rustc_main]
 LL + #[rustc_main]
    |
 
-error: `start` attribute cannot be used at crate level
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:17:1
-   |
-LL | #![start]
-   | ^^^^^^^^^
-...
-LL | mod inline {
-   |     ------ the inner attribute doesn't annotate this module
-   |
-help: perhaps you meant to use an outer attribute
-   |
-LL - #![start]
-LL + #[start]
-   |
-
 error: `repr` attribute cannot be used at crate level
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:19:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:17:1
    |
 LL | #![repr()]
    | ^^^^^^^^^^
@@ -191,7 +146,7 @@ LL + #[repr()]
    |
 
 error: `path` attribute cannot be used at crate level
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:21:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:19:1
    |
 LL | #![path = "3800"]
    | ^^^^^^^^^^^^^^^^^
@@ -206,7 +161,7 @@ LL + #[path = "3800"]
    |
 
 error: `automatically_derived` attribute cannot be used at crate level
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:23:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:21:1
    |
 LL | #![automatically_derived]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -221,144 +176,144 @@ LL + #[automatically_derived]
    |
 
 error[E0518]: attribute should be applied to function or closure
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:43:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:40:17
    |
 LL |     mod inner { #![inline] }
    |     ------------^^^^^^^^^^-- not a function or closure
 
 error[E0518]: attribute should be applied to function or closure
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:53:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:50:5
    |
 LL |     #[inline] struct S;
    |     ^^^^^^^^^ --------- not a function or closure
 
 error[E0518]: attribute should be applied to function or closure
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:57:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:54:5
    |
 LL |     #[inline] type T = S;
    |     ^^^^^^^^^ ----------- not a function or closure
 
 error[E0518]: attribute should be applied to function or closure
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:61:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:58:5
    |
 LL |     #[inline] impl S { }
    |     ^^^^^^^^^ ---------- not a function or closure
 
 error: attribute should be applied to an `extern crate` item
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:71:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:68:17
    |
 LL |     mod inner { #![no_link] }
    |     ------------^^^^^^^^^^^-- not an `extern crate` item
 
 error: attribute should be applied to an `extern crate` item
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:75:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:72:5
    |
 LL |     #[no_link] fn f() { }
    |     ^^^^^^^^^^ ---------- not an `extern crate` item
 
 error: attribute should be applied to an `extern crate` item
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:79:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:76:5
    |
 LL |     #[no_link] struct S;
    |     ^^^^^^^^^^ --------- not an `extern crate` item
 
 error: attribute should be applied to an `extern crate` item
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:83:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:80:5
    |
 LL |     #[no_link]type T = S;
    |     ^^^^^^^^^^----------- not an `extern crate` item
 
 error: attribute should be applied to an `extern crate` item
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:87:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:84:5
    |
 LL |     #[no_link] impl S { }
    |     ^^^^^^^^^^ ---------- not an `extern crate` item
 
 error: attribute should be applied to a free function, impl method or static
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:97:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:94:17
    |
 LL |     mod inner { #![export_name="2200"] }
    |     ------------^^^^^^^^^^^^^^^^^^^^^^-- not a free function, impl method or static
 
 error: attribute should be applied to a free function, impl method or static
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:103:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:100:5
    |
 LL |     #[export_name = "2200"] struct S;
    |     ^^^^^^^^^^^^^^^^^^^^^^^ --------- not a free function, impl method or static
 
 error: attribute should be applied to a free function, impl method or static
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:107:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:104:5
    |
 LL |     #[export_name = "2200"] type T = S;
    |     ^^^^^^^^^^^^^^^^^^^^^^^ ----------- not a free function, impl method or static
 
 error: attribute should be applied to a free function, impl method or static
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:111:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:108:5
    |
 LL |     #[export_name = "2200"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^ ---------- not a free function, impl method or static
 
 error: attribute should be applied to a free function, impl method or static
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:116:9
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:113:9
    |
 LL |         #[export_name = "2200"] fn foo();
    |         ^^^^^^^^^^^^^^^^^^^^^^^ --------- not a free function, impl method or static
 
 error: attribute should be applied to a free function, impl method or static
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:120:9
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:117:9
    |
 LL |         #[export_name = "2200"] fn bar() {}
    |         ^^^^^^^^^^^^^^^^^^^^^^^ ----------- not a free function, impl method or static
 
 error[E0517]: attribute should be applied to a struct, enum, or union
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:148:25
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:127:25
    |
 LL |     mod inner { #![repr(C)] }
    |     --------------------^---- not a struct, enum, or union
 
 error[E0517]: attribute should be applied to a struct, enum, or union
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:152:12
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:131:12
    |
 LL |     #[repr(C)] fn f() { }
    |            ^   ---------- not a struct, enum, or union
 
 error[E0517]: attribute should be applied to a struct, enum, or union
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:158:12
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:137:12
    |
 LL |     #[repr(C)] type T = S;
    |            ^   ----------- not a struct, enum, or union
 
 error[E0517]: attribute should be applied to a struct, enum, or union
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:162:12
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:141:12
    |
 LL |     #[repr(C)] impl S { }
    |            ^   ---------- not a struct, enum, or union
 
 error[E0517]: attribute should be applied to a struct, enum, or union
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:172:25
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:151:25
    |
 LL |     mod inner { #![repr(Rust)] }
    |     --------------------^^^^---- not a struct, enum, or union
 
 error[E0517]: attribute should be applied to a struct, enum, or union
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:176:12
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:155:12
    |
 LL |     #[repr(Rust)] fn f() { }
    |            ^^^^   ---------- not a struct, enum, or union
 
 error[E0517]: attribute should be applied to a struct, enum, or union
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:182:12
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:161:12
    |
 LL |     #[repr(Rust)] type T = S;
    |            ^^^^   ----------- not a struct, enum, or union
 
 error[E0517]: attribute should be applied to a struct, enum, or union
-  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:186:12
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:165:12
    |
 LL |     #[repr(Rust)] impl S { }
    |            ^^^^   ---------- not a struct, enum, or union
 
-error: aborting due to 44 previous errors
+error: aborting due to 38 previous errors
 
 Some errors have detailed explanations: E0517, E0518, E0658.
 For more information about an error, try `rustc --explain E0517`.
diff --git a/tests/ui/for-loop-while/for-loop-no-std.rs b/tests/ui/for-loop-while/for-loop-no-std.rs
index 4511146dc75..8255d7b4200 100644
--- a/tests/ui/for-loop-while/for-loop-no-std.rs
+++ b/tests/ui/for-loop-while/for-loop-no-std.rs
@@ -1,14 +1,19 @@
 //@ run-pass
+//@ ignore-emscripten no no_std executables
+//@ ignore-wasm different `main` convention
 #![allow(unused_imports)]
-#![feature(lang_items, start)]
 #![no_std]
+#![no_main]
 
+// Import global allocator and panic handler.
 extern crate std as other;
 
 #[macro_use] extern crate alloc;
 
-#[start]
-fn start(_argc: isize, _argv: *const *const u8) -> isize {
+use alloc::string::ToString;
+
+#[no_mangle]
+extern "C" fn main(_argc: core::ffi::c_int, _argv: *const *const u8) -> core::ffi::c_int {
     for _ in [1,2,3].iter() { }
     0
 }
diff --git a/tests/ui/format-no-std.rs b/tests/ui/format-no-std.rs
index 27c31f48a00..657b210a9a0 100644
--- a/tests/ui/format-no-std.rs
+++ b/tests/ui/format-no-std.rs
@@ -1,17 +1,20 @@
 //@ run-pass
 //@ ignore-emscripten no no_std executables
+//@ ignore-wasm different `main` convention
 
-#![feature(lang_items, start)]
+#![feature(lang_items)]
 #![no_std]
+#![no_main]
 
+// Import global allocator and panic handler.
 extern crate std as other;
 
 #[macro_use] extern crate alloc;
 
 use alloc::string::ToString;
 
-#[start]
-fn start(_argc: isize, _argv: *const *const u8) -> isize {
+#[no_mangle]
+extern "C" fn main(_argc: core::ffi::c_int, _argv: *const *const u8) -> core::ffi::c_int {
     let s = format!("{}", 1_isize);
     assert_eq!(s, "1".to_string());
 
diff --git a/tests/ui/issues/issue-50714-1.rs b/tests/ui/issues/issue-50714-1.rs
deleted file mode 100644
index a25940ce1cb..00000000000
--- a/tests/ui/issues/issue-50714-1.rs
+++ /dev/null
@@ -1,11 +0,0 @@
-// Regression test for issue 50714, make sure that this isn't a linker error.
-
-#![no_std]
-#![feature(start)]
-
-extern crate std;
-
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize where fn(&()): Eq { //~ ERROR [E0647]
-    0
-}
diff --git a/tests/ui/issues/issue-50714-1.stderr b/tests/ui/issues/issue-50714-1.stderr
deleted file mode 100644
index 7593ac38346..00000000000
--- a/tests/ui/issues/issue-50714-1.stderr
+++ /dev/null
@@ -1,9 +0,0 @@
-error[E0647]: `#[start]` function is not allowed to have a `where` clause
-  --> $DIR/issue-50714-1.rs:9:50
-   |
-LL | fn start(_: isize, _: *const *const u8) -> isize where fn(&()): Eq {
-   |                                                  ^^^^^^^^^^^^^^^^^ `#[start]` function cannot have a `where` clause
-
-error: aborting due to 1 previous error
-
-For more information about this error, try `rustc --explain E0647`.
diff --git a/tests/ui/issues/issue-9575.rs b/tests/ui/issues/issue-9575.rs
deleted file mode 100644
index 06b252990b6..00000000000
--- a/tests/ui/issues/issue-9575.rs
+++ /dev/null
@@ -1,7 +0,0 @@
-#![feature(start)]
-
-#[start]
-fn start(argc: isize, argv: *const *const u8, crate_map: *const u8) -> isize {
-    //~^ `#[start]` function has wrong type
-   0
-}
diff --git a/tests/ui/issues/issue-9575.stderr b/tests/ui/issues/issue-9575.stderr
deleted file mode 100644
index 2f6e2687d24..00000000000
--- a/tests/ui/issues/issue-9575.stderr
+++ /dev/null
@@ -1,12 +0,0 @@
-error[E0308]: `#[start]` function has wrong type
-  --> $DIR/issue-9575.rs:4:1
-   |
-LL | fn start(argc: isize, argv: *const *const u8, crate_map: *const u8) -> isize {
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ incorrect number of function parameters
-   |
-   = note: expected signature `fn(isize, *const *const u8) -> _`
-              found signature `fn(isize, *const *const u8, *const u8) -> _`
-
-error: aborting due to 1 previous error
-
-For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/lang-items/issue-19660.rs b/tests/ui/lang-items/issue-19660.rs
deleted file mode 100644
index aff57df7ece..00000000000
--- a/tests/ui/lang-items/issue-19660.rs
+++ /dev/null
@@ -1,15 +0,0 @@
-//@ error-pattern: requires `copy` lang_item
-
-#![feature(lang_items, start, no_core)]
-#![no_core]
-
-#[lang = "sized"]
-trait Sized { }
-
-struct S;
-
-#[start]
-fn main(_: isize, _: *const *const u8) -> isize {
-    let _ = S;
-    0
-}
diff --git a/tests/ui/lang-items/issue-19660.stderr b/tests/ui/lang-items/issue-19660.stderr
deleted file mode 100644
index e5a8a143d03..00000000000
--- a/tests/ui/lang-items/issue-19660.stderr
+++ /dev/null
@@ -1,4 +0,0 @@
-error: requires `copy` lang_item
-
-error: aborting due to 1 previous error
-
diff --git a/tests/ui/lang-items/lang-item-missing.rs b/tests/ui/lang-items/lang-item-missing.rs
index 8762594202a..5b832a5bb8f 100644
--- a/tests/ui/lang-items/lang-item-missing.rs
+++ b/tests/ui/lang-items/lang-item-missing.rs
@@ -3,10 +3,11 @@
 
 //@ error-pattern: requires `sized` lang_item
 
-#![feature(start, no_core)]
+#![feature(lang_items, no_core)]
 #![no_core]
+#![no_main]
 
-#[start]
-fn start(argc: isize, argv: *const *const u8) -> isize {
-    0
+#[no_mangle]
+extern "C" fn main(_argc: i32, _argv: *const *const u8) -> i32 {
+    loop {}
 }
diff --git a/tests/ui/lang-items/missing-copy-lang-item-issue-19660.rs b/tests/ui/lang-items/missing-copy-lang-item-issue-19660.rs
new file mode 100644
index 00000000000..9b634ee8ee3
--- /dev/null
+++ b/tests/ui/lang-items/missing-copy-lang-item-issue-19660.rs
@@ -0,0 +1,15 @@
+//@ error-pattern: requires `copy` lang_item
+
+#![feature(lang_items, no_core)]
+#![no_core]
+#![no_main]
+
+#[lang = "sized"]
+trait Sized { }
+
+struct S;
+
+#[no_mangle]
+extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
+    argc
+}
diff --git a/tests/ui/lang-items/missing-copy-lang-item-issue-19660.stderr b/tests/ui/lang-items/missing-copy-lang-item-issue-19660.stderr
new file mode 100644
index 00000000000..3dc7716ecd2
--- /dev/null
+++ b/tests/ui/lang-items/missing-copy-lang-item-issue-19660.stderr
@@ -0,0 +1,8 @@
+error: requires `copy` lang_item
+  --> $DIR/missing-copy-lang-item-issue-19660.rs:14:5
+   |
+LL |     argc
+   |     ^^^^
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/lint/dead-code/lint-dead-code-2.rs b/tests/ui/lint/dead-code/lint-dead-code-2.rs
index 6bfa4d96f71..c82088ec54b 100644
--- a/tests/ui/lint/dead-code/lint-dead-code-2.rs
+++ b/tests/ui/lint/dead-code/lint-dead-code-2.rs
@@ -1,6 +1,6 @@
 #![allow(unused_variables)]
 #![deny(dead_code)]
-#![feature(rustc_attrs, start)]
+#![feature(rustc_attrs)]
 
 struct Foo;
 
@@ -21,21 +21,16 @@ fn live_fn() {}
 
 fn dead_fn() {} //~ ERROR: function `dead_fn` is never used
 
-#[rustc_main]
-fn dead_fn2() {} //~ ERROR: function `dead_fn2` is never used
-
 fn used_fn() {}
 
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
+#[rustc_main]
+fn actual_main() {
     used_fn();
     let foo = Foo;
     foo.bar2();
-    0
 }
 
 // this is not main
 fn main() { //~ ERROR: function `main` is never used
     dead_fn();
-    dead_fn2();
 }
diff --git a/tests/ui/lint/dead-code/lint-dead-code-2.stderr b/tests/ui/lint/dead-code/lint-dead-code-2.stderr
index 85af553c986..4a5f3b8a687 100644
--- a/tests/ui/lint/dead-code/lint-dead-code-2.stderr
+++ b/tests/ui/lint/dead-code/lint-dead-code-2.stderr
@@ -10,17 +10,11 @@ note: the lint level is defined here
 LL | #![deny(dead_code)]
    |         ^^^^^^^^^
 
-error: function `dead_fn2` is never used
-  --> $DIR/lint-dead-code-2.rs:25:4
-   |
-LL | fn dead_fn2() {}
-   |    ^^^^^^^^
-
 error: function `main` is never used
-  --> $DIR/lint-dead-code-2.rs:38:4
+  --> $DIR/lint-dead-code-2.rs:34:4
    |
 LL | fn main() {
    |    ^^^^
 
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors
 
diff --git a/tests/ui/print_type_sizes/anonymous.rs b/tests/ui/print_type_sizes/anonymous.rs
index a3a32228088..7819e5ea767 100644
--- a/tests/ui/print_type_sizes/anonymous.rs
+++ b/tests/ui/print_type_sizes/anonymous.rs
@@ -1,14 +1,13 @@
-//@ compile-flags: -Z print-type-sizes
+//@ compile-flags: -Z print-type-sizes --crate-type=lib
 //@ build-pass
 
 // All of the types that occur in this function are uninteresting, in
 // that one cannot control the sizes of these types with the same sort
 // of enum-variant manipulation tricks.
 
-#![feature(start)]
+#![no_std]
 
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize {
+pub fn main() -> isize {
     let _byte: u8 = 0;
     let _word: usize = 0;
     let _tuple: (u8, usize)= (0, 0);
diff --git a/tests/ui/privacy/privacy1.rs b/tests/ui/privacy/privacy1.rs
index 31f39601003..9436441ecc6 100644
--- a/tests/ui/privacy/privacy1.rs
+++ b/tests/ui/privacy/privacy1.rs
@@ -1,4 +1,4 @@
-#![feature(lang_items, start, no_core)]
+#![feature(lang_items, no_core)]
 #![no_core] // makes debugging this test *a lot* easier (during resolve)
 
 #[lang="sized"]
@@ -173,4 +173,4 @@ pub mod mytest {
     }
 }
 
-#[start] fn main(_: isize, _: *const *const u8) -> isize { 3 }
+fn main() {}
diff --git a/tests/ui/privacy/privacy2.rs b/tests/ui/privacy/privacy2.rs
index 33292a65c5d..ab6d805544e 100644
--- a/tests/ui/privacy/privacy2.rs
+++ b/tests/ui/privacy/privacy2.rs
@@ -1,6 +1,6 @@
 //@ compile-flags: -Zdeduplicate-diagnostics=yes
 
-#![feature(start, no_core)]
+#![feature(no_core)]
 #![no_core] // makes debugging this test *a lot* easier (during resolve)
 
 // Test to make sure that globs don't leak in regular `use` statements.
@@ -26,4 +26,4 @@ fn test2() {
     //~^ ERROR `foo` is private
 }
 
-#[start] fn main(_: isize, _: *const *const u8) -> isize { 3 }
+fn main() {}
diff --git a/tests/ui/privacy/privacy3.rs b/tests/ui/privacy/privacy3.rs
index fb1f432410d..6298a6bc8cf 100644
--- a/tests/ui/privacy/privacy3.rs
+++ b/tests/ui/privacy/privacy3.rs
@@ -1,6 +1,6 @@
 //@ compile-flags: -Zdeduplicate-diagnostics=yes
 
-#![feature(start, no_core)]
+#![feature( no_core)]
 #![no_core] // makes debugging this test *a lot* easier (during resolve)
 
 // Test to make sure that private items imported through globs remain private
@@ -26,4 +26,4 @@ fn test1() {
     gpriv();
 }
 
-#[start] fn main(_: isize, _: *const *const u8) -> isize { 3 }
+fn main() {}
diff --git a/tests/ui/privacy/privacy4.rs b/tests/ui/privacy/privacy4.rs
index fa257b80039..7341c7752bb 100644
--- a/tests/ui/privacy/privacy4.rs
+++ b/tests/ui/privacy/privacy4.rs
@@ -1,4 +1,4 @@
-#![feature(lang_items, start, no_core)]
+#![feature(lang_items, no_core)]
 #![no_core] // makes debugging this test *a lot* easier (during resolve)
 
 #[lang = "sized"] pub trait Sized {}
@@ -22,4 +22,4 @@ fn test2() {
     gpriv();
 }
 
-#[start] fn main(_: isize, _: *const *const u8) -> isize { 3 }
+fn main() {}
diff --git a/tests/ui/rfcs/rfc-2091-track-caller/error-with-start.rs b/tests/ui/rfcs/rfc-2091-track-caller/error-with-start.rs
deleted file mode 100644
index f0e111b578f..00000000000
--- a/tests/ui/rfcs/rfc-2091-track-caller/error-with-start.rs
+++ /dev/null
@@ -1,7 +0,0 @@
-#![feature(start)]
-
-#[start]
-#[track_caller] //~ ERROR `#[start]` function is not allowed to be `#[track_caller]`
-fn start(_argc: isize, _argv: *const *const u8) -> isize {
-    panic!("{}: oh no", std::panic::Location::caller());
-}
diff --git a/tests/ui/rfcs/rfc-2091-track-caller/error-with-start.stderr b/tests/ui/rfcs/rfc-2091-track-caller/error-with-start.stderr
deleted file mode 100644
index 2738444f21f..00000000000
--- a/tests/ui/rfcs/rfc-2091-track-caller/error-with-start.stderr
+++ /dev/null
@@ -1,10 +0,0 @@
-error: `#[start]` function is not allowed to be `#[track_caller]`
-  --> $DIR/error-with-start.rs:4:1
-   |
-LL | #[track_caller]
-   | ^^^^^^^^^^^^^^^
-LL | fn start(_argc: isize, _argv: *const *const u8) -> isize {
-   | -------------------------------------------------------- `#[start]` function is not allowed to be `#[track_caller]`
-
-error: aborting due to 1 previous error
-
diff --git a/tests/ui/rfcs/rfc-2396-target_feature-11/issue-108645-target-feature-on-start.rs b/tests/ui/rfcs/rfc-2396-target_feature-11/issue-108645-target-feature-on-start.rs
deleted file mode 100644
index 6aa8f6fd821..00000000000
--- a/tests/ui/rfcs/rfc-2396-target_feature-11/issue-108645-target-feature-on-start.rs
+++ /dev/null
@@ -1,9 +0,0 @@
-//@ only-x86_64
-
-#![feature(start)]
-#![feature(target_feature_11)]
-
-#[start]
-#[target_feature(enable = "avx2")]
-//~^ ERROR `#[start]` function is not allowed to have `#[target_feature]`
-fn start(_argc: isize, _argv: *const *const u8) -> isize { 0 }
diff --git a/tests/ui/rfcs/rfc-2396-target_feature-11/issue-108645-target-feature-on-start.stderr b/tests/ui/rfcs/rfc-2396-target_feature-11/issue-108645-target-feature-on-start.stderr
deleted file mode 100644
index d0a67c4f6a8..00000000000
--- a/tests/ui/rfcs/rfc-2396-target_feature-11/issue-108645-target-feature-on-start.stderr
+++ /dev/null
@@ -1,11 +0,0 @@
-error: `#[start]` function is not allowed to have `#[target_feature]`
-  --> $DIR/issue-108645-target-feature-on-start.rs:7:1
-   |
-LL | #[target_feature(enable = "avx2")]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-LL |
-LL | fn start(_argc: isize, _argv: *const *const u8) -> isize { 0 }
-   | -------------------------------------------------------- `#[start]` function is not allowed to have `#[target_feature]`
-
-error: aborting due to 1 previous error
-
diff --git a/tests/ui/runtime/native-print-no-runtime.rs b/tests/ui/runtime/native-print-no-runtime.rs
deleted file mode 100644
index f0ed7d97b2c..00000000000
--- a/tests/ui/runtime/native-print-no-runtime.rs
+++ /dev/null
@@ -1,9 +0,0 @@
-//@ run-pass
-
-#![feature(start)]
-
-#[start]
-pub fn main(_: isize, _: *const *const u8) -> isize {
-    println!("hello");
-    0
-}
diff --git a/tests/ui/runtime/on-broken-pipe/auxiliary/assert-sigpipe-disposition.rs b/tests/ui/runtime/on-broken-pipe/auxiliary/assert-sigpipe-disposition.rs
index 229408fb724..f3f9ce0bd87 100644
--- a/tests/ui/runtime/on-broken-pipe/auxiliary/assert-sigpipe-disposition.rs
+++ b/tests/ui/runtime/on-broken-pipe/auxiliary/assert-sigpipe-disposition.rs
@@ -4,15 +4,16 @@
 //@ compile-flags: -Cpanic=abort
 //@ no-prefer-dynamic so panic=abort works
 
-#![feature(start, rustc_private)]
+#![feature(rustc_private)]
+#![no_main]
 
 extern crate libc;
 
-// Use #[start] so we don't have a runtime that messes with SIGPIPE.
-#[start]
-fn start(argc: isize, argv: *const *const u8) -> isize {
+// Use no_main so we don't have a runtime that messes with SIGPIPE.
+#[no_mangle]
+extern "C" fn main(argc: core::ffi::c_int, argv: *const *const u8) -> core::ffi::c_int {
     assert_eq!(argc, 2, "Must pass SIG_IGN or SIG_DFL as first arg");
-    let arg1 = unsafe { std::ffi::CStr::from_ptr(*argv.offset(1) as *const libc::c_char) }
+    let arg1 = unsafe { core::ffi::CStr::from_ptr(*argv.offset(1) as *const libc::c_char) }
         .to_str()
         .unwrap();
 
@@ -23,8 +24,8 @@ fn start(argc: isize, argv: *const *const u8) -> isize {
     };
 
     let actual = unsafe {
-        let mut actual: libc::sigaction = std::mem::zeroed();
-        libc::sigaction(libc::SIGPIPE, std::ptr::null(), &mut actual);
+        let mut actual: libc::sigaction = core::mem::zeroed();
+        libc::sigaction(libc::SIGPIPE, core::ptr::null(), &mut actual);
         #[cfg(not(target_os = "aix"))]
         {
             actual.sa_sigaction
diff --git a/tests/ui/runtime/running-with-no-runtime.rs b/tests/ui/runtime/running-with-no-runtime.rs
index 695025b3859..5c219b6feda 100644
--- a/tests/ui/runtime/running-with-no-runtime.rs
+++ b/tests/ui/runtime/running-with-no-runtime.rs
@@ -2,15 +2,15 @@
 //@ ignore-wasm32 spawning processes is not supported
 //@ ignore-sgx no processes
 
-#![feature(start)]
+#![no_main]
 
 use std::ffi::CStr;
 use std::process::{Command, Output};
 use std::panic;
 use std::str;
 
-#[start]
-fn start(argc: isize, argv: *const *const u8) -> isize {
+#[no_mangle]
+extern "C" fn main(argc: core::ffi::c_int, argv: *const *const u8) -> core::ffi::c_int {
     if argc > 1 {
         unsafe {
             match **argv.offset(1) as char {
diff --git a/tests/ui/sanitizer/memory-eager.rs b/tests/ui/sanitizer/memory-eager.rs
index 9e7889fa1bc..532d7b308f6 100644
--- a/tests/ui/sanitizer/memory-eager.rs
+++ b/tests/ui/sanitizer/memory-eager.rs
@@ -15,7 +15,7 @@
 // since it will be linked with an uninstrumented version of it.
 
 #![feature(core_intrinsics)]
-#![feature(start)]
+#![no_main]
 
 use std::hint::black_box;
 use std::mem::MaybeUninit;
@@ -29,8 +29,8 @@ fn random() -> char {
     black_box(r)
 }
 
-#[start]
-fn main(_: isize, _: *const *const u8) -> isize {
+#[no_mangle]
+extern "C" fn main(_argc: std::ffi::c_int, _argv: *const *const u8) -> std::ffi::c_int {
     random();
     0
 }
diff --git a/tests/ui/sanitizer/memory-passing.rs b/tests/ui/sanitizer/memory-passing.rs
index c8ab64bfaf8..96a4cd909c7 100644
--- a/tests/ui/sanitizer/memory-passing.rs
+++ b/tests/ui/sanitizer/memory-passing.rs
@@ -12,8 +12,8 @@
 // since it will be linked with an uninstrumented version of it.
 
 #![feature(core_intrinsics)]
-#![feature(start)]
 #![allow(invalid_value)]
+#![no_main]
 
 use std::hint::black_box;
 
@@ -25,8 +25,8 @@ fn calling_black_box_on_zst_ok() {
     black_box(zst);
 }
 
-#[start]
-fn main(_: isize, _: *const *const u8) -> isize {
+#[no_mangle]
+extern "C" fn main(_argc: std::ffi::c_int, _argv: *const *const u8) -> std::ffi::c_int {
     calling_black_box_on_zst_ok();
     0
 }
diff --git a/tests/ui/sanitizer/memory.rs b/tests/ui/sanitizer/memory.rs
index bd2d6771749..a91fefe4d16 100644
--- a/tests/ui/sanitizer/memory.rs
+++ b/tests/ui/sanitizer/memory.rs
@@ -15,8 +15,8 @@
 // since it will be linked with an uninstrumented version of it.
 
 #![feature(core_intrinsics)]
-#![feature(start)]
 #![allow(invalid_value)]
+#![no_main]
 
 use std::hint::black_box;
 use std::mem::MaybeUninit;
@@ -39,8 +39,8 @@ fn xor(a: &[isize]) -> isize {
     s
 }
 
-#[start]
-fn main(_: isize, _: *const *const u8) -> isize {
+#[no_mangle]
+extern "C" fn main(_argc: std::ffi::c_int, _argv: *const *const u8) -> std::ffi::c_int {
     let r = black_box(random as fn() -> [isize; 32])();
-    xor(&r)
+    xor(&r) as std::ffi::c_int
 }
diff --git a/tests/ui/test-attrs/test-runner-hides-start.rs b/tests/ui/test-attrs/test-runner-hides-start.rs
deleted file mode 100644
index 444ac237cfa..00000000000
--- a/tests/ui/test-attrs/test-runner-hides-start.rs
+++ /dev/null
@@ -1,7 +0,0 @@
-//@ run-pass
-//@ compile-flags: --test
-
-#![feature(start)]
-
-#[start]
-fn start(_: isize, _: *const *const u8) -> isize { panic!(); }
diff --git a/tests/ui/use/use.rs b/tests/ui/use/use.rs
index db031500a4a..25b8e529c43 100644
--- a/tests/ui/use/use.rs
+++ b/tests/ui/use/use.rs
@@ -3,7 +3,7 @@
 #![allow(stable_features)]
 
 #![allow(unused_imports)]
-#![feature(start, no_core, core)]
+#![feature(no_core, core)]
 #![no_core]
 
 extern crate std;
@@ -18,5 +18,4 @@ mod baz {
     pub use std::str as x;
 }
 
-#[start]
-pub fn start(_: isize, _: *const *const u8) -> isize { 0 }
+fn main() {}