compiler/rustc_codegen_cranelift/example/mini_core_hello_world.rs

   1 #![feature(no_core, lang_items, never_type, linkage, extern_types, thread_local)]
   2 #![no_core]
   3 #![allow(dead_code, non_camel_case_types)]
   4
   5 extern crate mini_core;
   6
   7 use mini_core::*;
   8 use mini_core::libc::*;
   9
  10 unsafe extern "C" fn my_puts(s: *const i8) {
  11     puts(s);
  12 }
  13
  14 macro_rules! assert {
  15     ($e:expr) => {
  16         if !$e {
  17             panic(stringify!(! $e));
  18         }
  19     };
  20 }
  21
  22 macro_rules! assert_eq {
  23     ($l:expr, $r: expr) => {
  24         if $l != $r {
  25             panic(stringify!($l != $r));
  26         }
  27     }
  28 }
  29
  30 #[lang = "termination"]
  31 trait Termination {
  32     fn report(self) -> i32;
  33 }
  34
  35 impl Termination for () {
  36     fn report(self) -> i32 {
  37         unsafe {
  38             NUM = 6 * 7 + 1 + (1u8 == 1u8) as u8; // 44
  39             assert_eq!(*NUM_REF as i32, 44);
  40         }
  41         0
  42     }
  43 }
  44
  45 trait SomeTrait {
  46     fn object_safe(&self);
  47 }
  48
  49 impl SomeTrait for &'static str {
  50     fn object_safe(&self) {
  51         unsafe {
  52             puts(*self as *const str as *const i8);
  53         }
  54     }
  55 }
  56
  57 struct NoisyDrop {
  58     text: &'static str,
  59     inner: NoisyDropInner,
  60 }
  61
  62 struct NoisyDropInner;
  63
  64 impl Drop for NoisyDrop {
  65     fn drop(&mut self) {
  66         unsafe {
  67             puts(self.text as *const str as *const i8);
  68         }
  69     }
  70 }
  71
  72 impl Drop for NoisyDropInner {
  73     fn drop(&mut self) {
  74         unsafe {
  75             puts("Inner got dropped!\0" as *const str as *const i8);
  76         }
  77     }
  78 }
  79
  80 impl SomeTrait for NoisyDrop {
  81     fn object_safe(&self) {}
  82 }
  83
  84 enum Ordering {
  85     Less = -1,
  86     Equal = 0,
  87     Greater = 1,
  88 }
  89
  90 #[lang = "start"]
  91 fn start<T: Termination + 'static>(
  92     main: fn() -> T,
  93     argc: isize,
  94     argv: *const *const u8,
  95 ) -> isize {
  96     if argc == 3 {
  97         unsafe { puts(*argv as *const i8); }
  98         unsafe { puts(*((argv as usize + intrinsics::size_of::<*const u8>()) as *const *const i8)); }
  99         unsafe { puts(*((argv as usize + 2 * intrinsics::size_of::<*const u8>()) as *const *const i8)); }
 100     }
 101
 102     main().report() as isize
 103 }
 104
 105 static mut NUM: u8 = 6 * 7;
 106 static NUM_REF: &'static u8 = unsafe { &NUM };
 107
 108 struct Unique<T: ?Sized> {
 109     pointer: *const T,
 110     _marker: PhantomData<T>,
 111 }
 112
 113 impl<T: ?Sized, U: ?Sized> CoerceUnsized<Unique<U>> for Unique<T> where T: Unsize<U> {}
 114
 115 unsafe fn zeroed<T>() -> T {
 116     let mut uninit = MaybeUninit { uninit: () };
 117     intrinsics::write_bytes(&mut uninit.value.value as *mut T, 0, 1);
 118     uninit.value.value
 119 }
 120
 121 fn take_f32(_f: f32) {}
 122 fn take_unique(_u: Unique<()>) {}
 123
 124 fn return_u128_pair() -> (u128, u128) {
 125     (0, 0)
 126 }
 127
 128 fn call_return_u128_pair() {
 129     return_u128_pair();
 130 }
 131
 132 fn main() {
 133     take_unique(Unique {
 134         pointer: 0 as *const (),
 135         _marker: PhantomData,
 136     });
 137     take_f32(0.1);
 138
 139     call_return_u128_pair();
 140
 141     let slice = &[0, 1] as &[i32];
 142     let slice_ptr = slice as *const [i32] as *const i32;
 143
 144     assert_eq!(slice_ptr as usize % 4, 0);
 145
 146     //return;
 147
 148     unsafe {
 149         printf("Hello %s\n\0" as *const str as *const i8, "printf\0" as *const str as *const i8);
 150
 151         let hello: &[u8] = b"Hello\0" as &[u8; 6];
 152         let ptr: *const i8 = hello as *const [u8] as *const i8;
 153         puts(ptr);
 154
 155         let world: Box<&str> = box "World!\0";
 156         puts(*world as *const str as *const i8);
 157         world as Box<dyn SomeTrait>;
 158
 159         assert_eq!(intrinsics::bitreverse(0b10101000u8), 0b00010101u8);
 160
 161         assert_eq!(intrinsics::bswap(0xabu8), 0xabu8);
 162         assert_eq!(intrinsics::bswap(0xddccu16), 0xccddu16);
 163         assert_eq!(intrinsics::bswap(0xffee_ddccu32), 0xccdd_eeffu32);
 164         assert_eq!(intrinsics::bswap(0x1234_5678_ffee_ddccu64), 0xccdd_eeff_7856_3412u64);
 165
 166         assert_eq!(intrinsics::size_of_val(hello) as u8, 6);
 167
 168         let chars = &['C', 'h', 'a', 'r', 's'];
 169         let chars = chars as &[char];
 170         assert_eq!(intrinsics::size_of_val(chars) as u8, 4 * 5);
 171
 172         let a: &dyn SomeTrait = &"abc\0";
 173         a.object_safe();
 174
 175         assert_eq!(intrinsics::size_of_val(a) as u8, 16);
 176         assert_eq!(intrinsics::size_of_val(&0u32) as u8, 4);
 177
 178         assert_eq!(intrinsics::min_align_of::<u16>() as u8, 2);
 179         assert_eq!(intrinsics::min_align_of_val(&a) as u8, intrinsics::min_align_of::<&str>() as u8);
 180
 181         assert!(!intrinsics::needs_drop::<u8>());
 182         assert!(intrinsics::needs_drop::<NoisyDrop>());
 183
 184         Unique {
 185             pointer: 0 as *const &str,
 186             _marker: PhantomData,
 187         } as Unique<dyn SomeTrait>;
 188
 189         struct MyDst<T: ?Sized>(T);
 190
 191         intrinsics::size_of_val(&MyDst([0u8; 4]) as &MyDst<[u8]>);
 192
 193         struct Foo {
 194             x: u8,
 195             y: !,
 196         }
 197
 198         unsafe fn uninitialized<T>() -> T {
 199             MaybeUninit { uninit: () }.value.value
 200         }
 201
 202         zeroed::<(u8, u8)>();
 203         #[allow(unreachable_code)]
 204         {
 205             if false {
 206                 zeroed::<!>();
 207                 zeroed::<Foo>();
 208                 uninitialized::<Foo>();
 209             }
 210         }
 211     }
 212
 213     let _ = box NoisyDrop {
 214         text: "Boxed outer got dropped!\0",
 215         inner: NoisyDropInner,
 216     } as Box<dyn SomeTrait>;
 217
 218     const FUNC_REF: Option<fn()> = Some(main);
 219     match FUNC_REF {
 220         Some(_) => {},
 221         None => assert!(false),
 222     }
 223
 224     match Ordering::Less {
 225         Ordering::Less => {},
 226         _ => assert!(false),
 227     }
 228
 229     [NoisyDropInner, NoisyDropInner];
 230
 231     let x = &[0u32, 42u32] as &[u32];
 232     match x {
 233         [] => assert_eq!(0u32, 1),
 234         [_, ref y @ ..] => assert_eq!(&x[1] as *const u32 as usize, &y[0] as *const u32 as usize),
 235     }
 236
 237     assert_eq!(((|()| 42u8) as fn(()) -> u8)(()), 42);
 238
 239     #[cfg(not(any(jit, windows)))]
 240     {
 241         extern {
 242             #[linkage = "extern_weak"]
 243             static ABC: *const u8;
 244         }
 245
 246         {
 247             extern {
 248                 #[linkage = "extern_weak"]
 249                 static ABC: *const u8;
 250             }
 251         }
 252
 253         unsafe { assert_eq!(ABC as usize, 0); }
 254     }
 255
 256     &mut (|| Some(0 as *const ())) as &mut dyn FnMut() -> Option<*const ()>;
 257
 258     let f = 1000.0;
 259     assert_eq!(f as u8, 255);
 260     let f2 = -1000.0;
 261     assert_eq!(f2 as i8, -128);
 262     assert_eq!(f2 as u8, 0);
 263
 264     let amount = 0;
 265     assert_eq!(1u128 << amount, 1);
 266
 267     static ANOTHER_STATIC: &u8 = &A_STATIC;
 268     assert_eq!(*ANOTHER_STATIC, 42);
 269
 270     check_niche_behavior();
 271
 272     extern "C" {
 273         type ExternType;
 274     }
 275
 276     struct ExternTypeWrapper {
 277         _a: ExternType,
 278     }
 279
 280     let nullptr = 0 as *const ();
 281     let extern_nullptr = nullptr as *const ExternTypeWrapper;
 282     extern_nullptr as *const ();
 283     let slice_ptr = &[] as *const [u8];
 284     slice_ptr as *const u8;
 285
 286     let repeat = [Some(42); 2];
 287     assert_eq!(repeat[0], Some(42));
 288     assert_eq!(repeat[1], Some(42));
 289
 290     from_decimal_string();
 291
 292     #[cfg(not(any(jit, windows)))]
 293     test_tls();
 294
 295     #[cfg(all(not(jit), target_arch = "x86_64", target_os = "linux"))]
 296     unsafe {
 297         global_asm_test();
 298     }
 299
 300     // Both statics have a reference that points to the same anonymous allocation.
 301     static REF1: &u8 = &42;
 302     static REF2: &u8 = REF1;
 303     assert_eq!(*REF1, *REF2);
 304 }
 305
 306 #[cfg(all(not(jit), target_arch = "x86_64", target_os = "linux"))]
 307 extern "C" {
 308     fn global_asm_test();
 309 }
 310
 311 #[cfg(all(not(jit), target_arch = "x86_64", target_os = "linux"))]
 312 global_asm! {
 313     "
 314     .global global_asm_test
 315     global_asm_test:
 316     // comment that would normally be removed by LLVM
 317     ret
 318     "
 319 }
 320
 321 #[repr(C)]
 322 enum c_void {
 323     _1,
 324     _2,
 325 }
 326
 327 type c_int = i32;
 328 type c_ulong = u64;
 329
 330 type pthread_t = c_ulong;
 331
 332 #[repr(C)]
 333 struct pthread_attr_t {
 334     __size: [u64; 7],
 335 }
 336
 337 #[link(name = "pthread")]
 338 extern "C" {
 339     fn pthread_attr_init(attr: *mut pthread_attr_t) -> c_int;
 340
 341     fn pthread_create(
 342         native: *mut pthread_t,
 343         attr: *const pthread_attr_t,
 344         f: extern "C" fn(_: *mut c_void) -> *mut c_void,
 345         value: *mut c_void
 346     ) -> c_int;
 347
 348     fn pthread_join(
 349         native: pthread_t,
 350         value: *mut *mut c_void
 351     ) -> c_int;
 352 }
 353
 354 #[thread_local]
 355 #[cfg(not(jit))]
 356 static mut TLS: u8 = 42;
 357
 358 #[cfg(not(jit))]
 359 extern "C" fn mutate_tls(_: *mut c_void) -> *mut c_void {
 360     unsafe { TLS = 0; }
 361     0 as *mut c_void
 362 }
 363
 364 #[cfg(not(jit))]
 365 fn test_tls() {
 366     unsafe {
 367         let mut attr: pthread_attr_t = zeroed();
 368         let mut thread: pthread_t = 0;
 369
 370         assert_eq!(TLS, 42);
 371
 372         if pthread_attr_init(&mut attr) != 0 {
 373             assert!(false);
 374         }
 375
 376         if pthread_create(&mut thread, &attr, mutate_tls, 0 as *mut c_void) != 0 {
 377             assert!(false);
 378         }
 379
 380         let mut res = 0 as *mut c_void;
 381         pthread_join(thread, &mut res);
 382
 383         // TLS of main thread must not have been changed by the other thread.
 384         assert_eq!(TLS, 42);
 385
 386         puts("TLS works!\n\0" as *const str as *const i8);
 387     }
 388 }
 389
 390 // Copied ui/issues/issue-61696.rs
 391
 392 pub enum Infallible {}
 393
 394 // The check that the `bool` field of `V1` is encoding a "niche variant"
 395 // (i.e. not `V1`, so `V3` or `V4`) used to be mathematically incorrect,
 396 // causing valid `V1` values to be interpreted as other variants.
 397 pub enum E1 {
 398     V1 { f: bool },
 399     V2 { f: Infallible },
 400     V3,
 401     V4,
 402 }
 403
 404 // Computing the discriminant used to be done using the niche type (here `u8`,
 405 // from the `bool` field of `V1`), overflowing for variants with large enough
 406 // indices (`V3` and `V4`), causing them to be interpreted as other variants.
 407 pub enum E2<X> {
 408     V1 { f: bool },
 409
 410     /*_00*/ _01(X), _02(X), _03(X), _04(X), _05(X), _06(X), _07(X),
 411     _08(X), _09(X), _0A(X), _0B(X), _0C(X), _0D(X), _0E(X), _0F(X),
 412     _10(X), _11(X), _12(X), _13(X), _14(X), _15(X), _16(X), _17(X),
 413     _18(X), _19(X), _1A(X), _1B(X), _1C(X), _1D(X), _1E(X), _1F(X),
 414     _20(X), _21(X), _22(X), _23(X), _24(X), _25(X), _26(X), _27(X),
 415     _28(X), _29(X), _2A(X), _2B(X), _2C(X), _2D(X), _2E(X), _2F(X),
 416     _30(X), _31(X), _32(X), _33(X), _34(X), _35(X), _36(X), _37(X),
 417     _38(X), _39(X), _3A(X), _3B(X), _3C(X), _3D(X), _3E(X), _3F(X),
 418     _40(X), _41(X), _42(X), _43(X), _44(X), _45(X), _46(X), _47(X),
 419     _48(X), _49(X), _4A(X), _4B(X), _4C(X), _4D(X), _4E(X), _4F(X),
 420     _50(X), _51(X), _52(X), _53(X), _54(X), _55(X), _56(X), _57(X),
 421     _58(X), _59(X), _5A(X), _5B(X), _5C(X), _5D(X), _5E(X), _5F(X),
 422     _60(X), _61(X), _62(X), _63(X), _64(X), _65(X), _66(X), _67(X),
 423     _68(X), _69(X), _6A(X), _6B(X), _6C(X), _6D(X), _6E(X), _6F(X),
 424     _70(X), _71(X), _72(X), _73(X), _74(X), _75(X), _76(X), _77(X),
 425     _78(X), _79(X), _7A(X), _7B(X), _7C(X), _7D(X), _7E(X), _7F(X),
 426     _80(X), _81(X), _82(X), _83(X), _84(X), _85(X), _86(X), _87(X),
 427     _88(X), _89(X), _8A(X), _8B(X), _8C(X), _8D(X), _8E(X), _8F(X),
 428     _90(X), _91(X), _92(X), _93(X), _94(X), _95(X), _96(X), _97(X),
 429     _98(X), _99(X), _9A(X), _9B(X), _9C(X), _9D(X), _9E(X), _9F(X),
 430     _A0(X), _A1(X), _A2(X), _A3(X), _A4(X), _A5(X), _A6(X), _A7(X),
 431     _A8(X), _A9(X), _AA(X), _AB(X), _AC(X), _AD(X), _AE(X), _AF(X),
 432     _B0(X), _B1(X), _B2(X), _B3(X), _B4(X), _B5(X), _B6(X), _B7(X),
 433     _B8(X), _B9(X), _BA(X), _BB(X), _BC(X), _BD(X), _BE(X), _BF(X),
 434     _C0(X), _C1(X), _C2(X), _C3(X), _C4(X), _C5(X), _C6(X), _C7(X),
 435     _C8(X), _C9(X), _CA(X), _CB(X), _CC(X), _CD(X), _CE(X), _CF(X),
 436     _D0(X), _D1(X), _D2(X), _D3(X), _D4(X), _D5(X), _D6(X), _D7(X),
 437     _D8(X), _D9(X), _DA(X), _DB(X), _DC(X), _DD(X), _DE(X), _DF(X),
 438     _E0(X), _E1(X), _E2(X), _E3(X), _E4(X), _E5(X), _E6(X), _E7(X),
 439     _E8(X), _E9(X), _EA(X), _EB(X), _EC(X), _ED(X), _EE(X), _EF(X),
 440     _F0(X), _F1(X), _F2(X), _F3(X), _F4(X), _F5(X), _F6(X), _F7(X),
 441     _F8(X), _F9(X), _FA(X), _FB(X), _FC(X), _FD(X), _FE(X), _FF(X),
 442
 443     V3,
 444     V4,
 445 }
 446
 447 fn check_niche_behavior () {
 448     if let E1::V2 { .. } = (E1::V1 { f: true }) {
 449         intrinsics::abort();
 450     }
 451
 452     if let E2::V1 { .. } = E2::V3::<Infallible> {
 453         intrinsics::abort();
 454     }
 455 }
 456
 457 fn from_decimal_string() {
 458     loop {
 459         let multiplier = 1;
 460
 461         take_multiplier_ref(&multiplier);
 462
 463         if multiplier == 1 {
 464             break;
 465         }
 466
 467         unreachable();
 468     }
 469 }
 470
 471 fn take_multiplier_ref(_multiplier: &u128) {}
 472
 473 fn unreachable() -> ! {
 474     panic("unreachable")
 475 }