compiler/rustc_codegen_cranelift/example/alloc_example.rs

   1 #![feature(start, box_syntax, alloc_system, core_intrinsics, alloc_prelude, alloc_error_handler)]
   2 #![no_std]
   3
   4 extern crate alloc;
   5 extern crate alloc_system;
   6
   7 use alloc::prelude::v1::*;
   8
   9 use alloc_system::System;
  10
  11 #[global_allocator]
  12 static ALLOC: System = System;
  13
  14 #[cfg_attr(unix, link(name = "c"))]
  15 #[cfg_attr(target_env = "msvc", link(name = "msvcrt"))]
  16 extern "C" {
  17     fn puts(s: *const u8) -> i32;
  18 }
  19
  20 #[panic_handler]
  21 fn panic_handler(_: &core::panic::PanicInfo) -> ! {
  22     core::intrinsics::abort();
  23 }
  24
  25 #[alloc_error_handler]
  26 fn alloc_error_handler(_: alloc::alloc::Layout) -> ! {
  27     core::intrinsics::abort();
  28 }
  29
  30 #[start]
  31 fn main(_argc: isize, _argv: *const *const u8) -> isize {
  32     let world: Box<&str> = box "Hello World!\0";
  33     unsafe {
  34         puts(*world as *const str as *const u8);
  35     }
  36
  37     0
  38 }