src/libstd/rt.rs

   1 //! Runtime services
   2 //!
   3 //! The `rt` module provides a narrow set of runtime services,
   4 //! including the global heap (exported in `heap`) and unwinding and
   5 //! backtrace support. The APIs in this module are highly unstable,
   6 //! and should be considered as private implementation details for the
   7 //! time being.
   8
   9 #![unstable(feature = "rt",
  10             reason = "this public module should not exist and is highly likely \
  11                       to disappear",
  12             issue = "0")]
  13 #![doc(hidden)]
  14
  15
  16 // Re-export some of our utilities which are expected by other crates.
  17 pub use crate::panicking::{begin_panic, begin_panic_fmt, update_panic_count};
  18
  19 // To reduce the generated code of the new `lang_start`, this function is doing
  20 // the real work.
  21 #[cfg(not(test))]
  22 fn lang_start_internal(main: &(dyn Fn() -> i32 + Sync + crate::panic::RefUnwindSafe),
  23                        argc: isize, argv: *const *const u8) -> isize {
  24     use crate::panic;
  25     use crate::sys;
  26     use crate::sys_common;
  27     use crate::sys_common::thread_info;
  28     use crate::thread::Thread;
  29
  30     sys::init();
  31
  32     unsafe {
  33         let main_guard = sys::thread::guard::init();
  34         sys::stack_overflow::init();
  35
  36         // Next, set up the current Thread with the guard information we just
  37         // created. Note that this isn't necessary in general for new threads,
  38         // but we just do this to name the main thread and to give it correct
  39         // info about the stack bounds.
  40         let thread = Thread::new(Some("main".to_owned()));
  41         thread_info::set(main_guard, thread);
  42
  43         // Store our args if necessary in a squirreled away location
  44         sys::args::init(argc, argv);
  45
  46         // Let's run some code!
  47         let exit_code = panic::catch_unwind(|| {
  48             sys_common::backtrace::__rust_begin_short_backtrace(move || main())
  49         });
  50
  51         sys_common::cleanup();
  52         exit_code.unwrap_or(101) as isize
  53     }
  54 }
  55
  56 #[cfg(not(test))]
  57 #[lang = "start"]
  58 fn lang_start<T: crate::process::Termination + 'static>
  59     (main: fn() -> T, argc: isize, argv: *const *const u8) -> isize
  60 {
  61     lang_start_internal(&move || main().report(), argc, argv)
  62 }