1 // rsbegin.o and rsend.o are the so called "compiler runtime startup objects".
2 // They contain code needed to correctly initialize the compiler runtime.
4 // When an executable or dylib image is linked, all user code and libraries are
5 // "sandwiched" between these two object files, so code or data from rsbegin.o
6 // become first in the respective sections of the image, whereas code and data
7 // from rsend.o become the last ones. This effect can be used to place symbols
8 // at the beginning or at the end of a section, as well as to insert any required
11 // Note that the actual module entry point is located in the C runtime startup
12 // object (usually called `crtX.o), which then invokes initialization callbacks
13 // of other runtime components (registered via yet another special image section).
15 #![feature(no_core, lang_items, optin_builtin_traits)]
16 #![crate_type = "rlib"]
18 #![allow(non_camel_case_types)]
29 #[lang = "drop_in_place"]
31 #[allow(unconditional_recursion)]
32 pub unsafe fn drop_in_place<T: ?Sized>(to_drop: *mut T) {
33 drop_in_place(to_drop);
36 #[cfg(all(target_os = "windows", target_arch = "x86", target_env = "gnu"))]
39 #[link_section = ".eh_frame"]
40 // Marks beginning of the stack frame unwind info section
41 pub static __EH_FRAME_BEGIN__: [u8; 0] = [];
43 // Scratch space for unwinder's internal book-keeping.
44 // This is defined as `struct object` in $GCC/libgcc/unwind-dw2-fde.h.
45 static mut OBJ: [isize; 6] = [0; 6];
47 macro_rules! impl_copy {
56 usize u8 u16 u32 u64 u128
57 isize i8 i16 i32 i64 i128
62 // Unwind info registration/deregistration routines.
63 // See the docs of `unwind` module in libstd.
65 fn rust_eh_register_frames(eh_frame_begin: *const u8, object: *mut u8);
66 fn rust_eh_unregister_frames(eh_frame_begin: *const u8, object: *mut u8);
70 // register unwind info on module startup
71 rust_eh_register_frames(
72 &__EH_FRAME_BEGIN__ as *const u8,
73 &mut OBJ as *mut _ as *mut u8,
78 // unregister on shutdown
79 rust_eh_unregister_frames(
80 &__EH_FRAME_BEGIN__ as *const u8,
81 &mut OBJ as *mut _ as *mut u8,
85 // MSVC-specific init/uninit routine registration
87 // .CRT$X?? sections are roughly analogous to ELF's .init_array and .fini_array,
88 // except that they exploit the fact that linker will sort them alphabitically,
89 // so e.g., sections with names between .CRT$XIA and .CRT$XIZ are guaranteed to be
90 // placed between those two, without requiring any ordering of objects on the linker
92 // Note that ordering of same-named sections from different objects is not guaranteed.
93 // Since .CRT$XIA contains init array's header symbol, which must always come first,
94 // we place our initialization callback into .CRT$XIB.
96 #[link_section = ".CRT$XIB"] // .CRT$XI? : C initialization callbacks
97 pub static P_INIT: unsafe fn() = super::init;
99 #[link_section = ".CRT$XTY"] // .CRT$XT? : C termination callbacks
100 pub static P_UNINIT: unsafe fn() = super::uninit;