remove support for the #[start] attribute

compiler/rustc_codegen_gcc/tests/run/abort1.rs

@@ -3,11 +3,12 @@
 // Run-time:
 //   status: signal
 
-#![feature(auto_traits, lang_items, no_core, start, intrinsics, rustc_attrs)]
+#![feature(auto_traits, lang_items, no_core, intrinsics, rustc_attrs)]
 #![allow(internal_features)]
 
 #![no_std]
 #![no_core]
+#![no_main]
 
 /*
  * Core
@@ -49,7 +50,7 @@ fn test_fail() -> ! {
     unsafe { intrinsics::abort() };
 }
 
-#[start]
-fn main(mut argc: isize, _argv: *const *const u8) -> isize {
+#[no_mangle]
+extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
     test_fail();
 }

compiler/rustc_codegen_gcc/tests/run/abort2.rs

@@ -3,11 +3,12 @@
 // Run-time:
 //   status: signal
 
-#![feature(auto_traits, lang_items, no_core, start, intrinsics, rustc_attrs)]
+#![feature(auto_traits, lang_items, no_core, intrinsics, rustc_attrs)]
 #![allow(internal_features)]
 
 #![no_std]
 #![no_core]
+#![no_main]
 
 /*
  * Core
@@ -50,8 +51,8 @@ fn fail() -> i32 {
     0
 }
 
-#[start]
-fn main(mut argc: isize, _argv: *const *const u8) -> isize {
+#[no_mangle]
+extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
     fail();
     0
 }

compiler/rustc_codegen_gcc/tests/run/array.rs

@@ -7,10 +7,11 @@
 //     5
 //     10
 
-#![feature(no_core, start)]
+#![feature(no_core)]
 
 #![no_std]
 #![no_core]
+#![no_main]
 
 extern crate mini_core;
 
@@ -28,8 +29,8 @@ fn make_array() -> [u8; 3] {
     [42, 10, 5]
 }
 
-#[start]
-fn main(argc: isize, _argv: *const *const u8) -> isize {
+#[no_mangle]
+extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
     let array = [42, 7, 5];
     let array2 = make_array();
     unsafe {

compiler/rustc_codegen_gcc/tests/run/assign.rs

@@ -6,10 +6,11 @@
 //     10
 
 #![allow(internal_features, unused_attributes)]
-#![feature(auto_traits, lang_items, no_core, start, intrinsics, rustc_attrs, track_caller)]
+#![feature(auto_traits, lang_items, no_core, intrinsics, rustc_attrs, track_caller)]
 
 #![no_std]
 #![no_core]
+#![no_main]
 
 /*
  * Core
@@ -142,8 +143,8 @@ fn inc(num: isize) -> isize {
 }
 
 
-#[start]
-fn main(mut argc: isize, _argv: *const *const u8) -> isize {
+#[no_mangle]
+extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
     argc = inc(argc);
     unsafe {
         libc::printf(b"%ld\n\0" as *const u8 as *const i8, argc);

compiler/rustc_codegen_gcc/tests/run/closure.rs

@@ -8,10 +8,11 @@
 //     Int argument: 2
 //     Both args: 11
 
-#![feature(no_core, start)]
+#![feature(no_core)]
 
 #![no_std]
 #![no_core]
+#![no_main]
 
 extern crate mini_core;
 
@@ -22,8 +23,8 @@ mod libc {
     }
 }
 
-#[start]
-fn main(mut argc: isize, _argv: *const *const u8) -> isize {
+#[no_mangle]
+extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
     let string = "Arg: %d\n\0";
     let mut closure = || {
         unsafe {

compiler/rustc_codegen_gcc/tests/run/condition.rs

@@ -5,10 +5,11 @@
 //   stdout: true
 //     1
 
-#![feature(no_core, start)]
+#![feature(no_core)]
 
 #![no_std]
 #![no_core]
+#![no_main]
 
 extern crate mini_core;
 
@@ -19,8 +20,8 @@ mod libc {
     }
 }
 
-#[start]
-fn main(argc: isize, _argv: *const *const u8) -> isize {
+#[no_mangle]
+extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
     unsafe {
         if argc == 1 {
             libc::printf(b"true\n\0" as *const u8 as *const i8);

compiler/rustc_codegen_gcc/tests/run/empty_main.rs

@@ -3,11 +3,12 @@
 // Run-time:
 //   status: 0
 
-#![feature(auto_traits, lang_items, no_core, start)]
+#![feature(auto_traits, lang_items, no_core)]
 #![allow(internal_features)]
 
 #![no_std]
 #![no_core]
+#![no_main]
 
 /*
  * Core
@@ -34,7 +35,7 @@ pub(crate) unsafe auto trait Freeze {}
  * Code
  */
 
-#[start]
-fn main(_argc: isize, _argv: *const *const u8) -> isize {
+#[no_mangle]
+extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
     0
 }

compiler/rustc_codegen_gcc/tests/run/exit.rs

@@ -3,11 +3,12 @@
 // Run-time:
 //   status: 2
 
-#![feature(auto_traits, lang_items, no_core, start, intrinsics)]
+#![feature(auto_traits, lang_items, no_core, intrinsics)]
 #![allow(internal_features)]
 
 #![no_std]
 #![no_core]
+#![no_main]
 
 mod libc {
     #[link(name = "c")]
@@ -41,8 +42,8 @@ pub(crate) unsafe auto trait Freeze {}
  * Code
  */
 
-#[start]
-fn main(mut argc: isize, _argv: *const *const u8) -> isize {
+#[no_mangle]
+extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
     unsafe {
         libc::exit(2);
     }

compiler/rustc_codegen_gcc/tests/run/exit_code.rs

@@ -3,11 +3,12 @@
 // Run-time:
 //   status: 1
 
-#![feature(auto_traits, lang_items, no_core, start)]
+#![feature(auto_traits, lang_items, no_core)]
 #![allow(internal_features)]
 
 #![no_std]
 #![no_core]
+#![no_main]
 
 /*
  * Core
@@ -34,7 +35,7 @@ pub(crate) unsafe auto trait Freeze {}
  * Code
  */
 
-#[start]
-fn main(mut argc: isize, _argv: *const *const u8) -> isize {
+#[no_mangle]
+extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
     1
 }

compiler/rustc_codegen_gcc/tests/run/fun_ptr.rs

@@ -4,10 +4,11 @@
 //   status: 0
 //   stdout: 1
 
-#![feature(no_core, start)]
+#![feature(no_core)]
 
 #![no_std]
 #![no_core]
+#![no_main]
 
 extern crate mini_core;
 
@@ -26,8 +27,8 @@ fn call_func(func: fn(i16) -> i8, param: i16) -> i8 {
     func(param)
 }
 
-#[start]
-fn main(argc: isize, _argv: *const *const u8) -> isize {
+#[no_mangle]
+extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
     unsafe {
         let result = call_func(i16_as_i8, argc as i16) as isize;
         libc::printf(b"%ld\n\0" as *const u8 as *const i8, result);

compiler/rustc_codegen_gcc/tests/run/mut_ref.rs

@@ -8,10 +8,11 @@
 //     11
 
 #![allow(internal_features, unused_attributes)]
-#![feature(auto_traits, lang_items, no_core, start, intrinsics, rustc_attrs, track_caller)]
+#![feature(auto_traits, lang_items, no_core, intrinsics, rustc_attrs, track_caller)]
 
 #![no_std]
 #![no_core]
+#![no_main]
 
 /*
  * Core
@@ -148,8 +149,8 @@ fn update_num(num: &mut isize) {
     *num = *num + 5;
 }
 
-#[start]
-fn main(mut argc: isize, _argv: *const *const u8) -> isize {
+#[no_mangle]
+extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
     let mut test = test(argc);
     unsafe {
         libc::printf(b"%ld\n\0" as *const u8 as *const i8, test.field);

compiler/rustc_codegen_gcc/tests/run/operations.rs

@@ -6,10 +6,11 @@
 //     10
 
 #![allow(internal_features, unused_attributes)]
-#![feature(auto_traits, lang_items, no_core, start, intrinsics, arbitrary_self_types, rustc_attrs)]
+#![feature(auto_traits, lang_items, no_core, intrinsics, arbitrary_self_types, rustc_attrs)]
 
 #![no_std]
 #![no_core]
+#![no_main]
 
 /*
  * Core
@@ -231,8 +232,8 @@ pub fn panic_const_mul_overflow() -> ! {
  * Code
  */
 
-#[start]
-fn main(mut argc: isize, _argv: *const *const u8) -> isize {
+#[no_mangle]
+extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
     unsafe {
         libc::printf(b"%ld\n\0" as *const u8 as *const i8, 40 + argc);
         libc::printf(b"%ld\n\0" as *const u8 as *const i8, 40 - argc);

compiler/rustc_codegen_gcc/tests/run/ptr_cast.rs

@@ -4,10 +4,11 @@
 //   status: 0
 //   stdout: 1
 
-#![feature(no_core, start)]
+#![feature(no_core)]
 
 #![no_std]
 #![no_core]
+#![no_main]
 
 extern crate mini_core;
 
@@ -24,8 +25,8 @@ fn make_array() -> [u8; 3] {
     [42, 10, 5]
 }
 
-#[start]
-fn main(argc: isize, _argv: *const *const u8) -> isize {
+#[no_mangle]
+extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
     unsafe {
         let ptr = ONE as *mut usize;
         let value = ptr as usize;

compiler/rustc_codegen_gcc/tests/run/return-tuple.rs

@@ -6,11 +6,12 @@
 //     10
 //     42
 
-#![feature(auto_traits, lang_items, no_core, start, intrinsics)]
+#![feature(auto_traits, lang_items, no_core, intrinsics)]
 #![allow(internal_features)]
 
 #![no_std]
 #![no_core]
+#![no_main]
 
 #[lang = "copy"]
 pub unsafe trait Copy {}
@@ -61,8 +62,8 @@ fn int_cast(a: u16, b: i16) -> (u8, u16, u32, usize, i8, i16, i32, isize, u8, u3
     )
 }
 
-#[start]
-fn main(argc: isize, _argv: *const *const u8) -> isize {
+#[no_mangle]
+extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
     let (a, b, c, d, e, f, g, h, i, j) = int_cast(10, 42);
     unsafe {
         libc::printf(b"%d\n\0" as *const u8 as *const i8, c);

compiler/rustc_codegen_gcc/tests/run/slice.rs

@@ -4,10 +4,11 @@
 //   status: 0
 //   stdout: 5
 
-#![feature(no_core, start)]
+#![feature(no_core)]
 
 #![no_std]
 #![no_core]
+#![no_main]
 
 extern crate mini_core;
 
@@ -26,8 +27,8 @@ fn index_slice(s: &[u32]) -> u32 {
     }
 }
 
-#[start]
-fn main(mut argc: isize, _argv: *const *const u8) -> isize {
+#[no_mangle]
+extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
     let array = [42, 7, 5];
     unsafe {
         libc::printf(b"%ld\n\0" as *const u8 as *const i8, index_slice(&array));

compiler/rustc_codegen_gcc/tests/run/static.rs

@@ -9,11 +9,12 @@
 //      12
 //      1
 
-#![feature(auto_traits, lang_items, no_core, start, intrinsics, rustc_attrs)]
+#![feature(auto_traits, lang_items, no_core, intrinsics, rustc_attrs)]
 #![allow(internal_features)]
 
 #![no_std]
 #![no_core]
+#![no_main]
 
 /*
  * Core
@@ -98,8 +99,8 @@ static mut WITH_REF: WithRef = WithRef {
     refe: unsafe { &TEST },
 };
 
-#[start]
-fn main(mut argc: isize, _argv: *const *const u8) -> isize {
+#[no_mangle]
+extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
     unsafe {
         libc::printf(b"%ld\n\0" as *const u8 as *const i8, CONSTANT);
         libc::printf(b"%ld\n\0" as *const u8 as *const i8, TEST2.field);

compiler/rustc_codegen_gcc/tests/run/structs.rs

@@ -5,11 +5,12 @@
 //   stdout: 1
 //     2
 
-#![feature(auto_traits, lang_items, no_core, start, intrinsics)]
+#![feature(auto_traits, lang_items, no_core, intrinsics)]
 #![allow(internal_features)]
 
 #![no_std]
 #![no_core]
+#![no_main]
 
 /*
  * Core
@@ -55,8 +56,8 @@ fn one() -> isize {
     1
 }
 
-#[start]
-fn main(mut argc: isize, _argv: *const *const u8) -> isize {
+#[no_mangle]
+extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
     let test = Test {
         field: one(),
     };

compiler/rustc_codegen_gcc/tests/run/tuple.rs

@@ -4,11 +4,12 @@
 //   status: 0
 //   stdout: 3
 
-#![feature(auto_traits, lang_items, no_core, start, intrinsics)]
+#![feature(auto_traits, lang_items, no_core, intrinsics)]
 #![allow(internal_features)]
 
 #![no_std]
 #![no_core]
+#![no_main]
 
 /*
  * Core
@@ -42,8 +43,8 @@ mod libc {
  * Code
  */
 
-#[start]
-fn main(mut argc: isize, _argv: *const *const u8) -> isize {
+#[no_mangle]
+extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
     let test: (isize, isize, isize) = (3, 1, 4);
     unsafe {
         libc::printf(b"%ld\n\0" as *const u8 as *const i8, test.0);