1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 // rsbegin.o and rsend.o are the so called "compiler runtime startup objects".
12 // They contain code needed to correctly initialize the compiler runtime.
14 // When an executable or dylib image is linked, all user code and libraries are
15 // "sandwiched" between these two object files, so code or data from rsbegin.o
16 // become first in the respective sections of the image, whereas code and data
17 // from rsend.o become the last ones. This effect can be used to place symbols
18 // at the beginning or at the end of a section, as well as to insert any required
19 // headers or footers.
21 // Note that the actual module entry point is located in the C runtime startup
22 // object (usually called `crtX.o), which then invokes initialization callbacks
23 // of other runtime components (registered via yet another special image section).
25 #![feature(no_core, lang_items, optin_builtin_traits)]
26 #![crate_type = "rlib"]
28 #![allow(non_camel_case_types)]
39 #[lang = "drop_in_place"]
41 #[allow(unconditional_recursion)]
42 pub unsafe fn drop_in_place<T: ?Sized>(to_drop: *mut T) {
43 drop_in_place(to_drop);
46 #[cfg(all(target_os = "windows", target_arch = "x86", target_env = "gnu"))]
49 #[link_section = ".eh_frame"]
50 // Marks beginning of the stack frame unwind info section
51 pub static __EH_FRAME_BEGIN__: [u8; 0] = [];
53 // Scratch space for unwinder's internal book-keeping.
54 // This is defined as `struct object` in $GCC/libgcc/unwind-dw2-fde.h.
55 static mut OBJ: [isize; 6] = [0; 6];
57 macro_rules! impl_copy {
66 usize u8 u16 u32 u64 u128
67 isize i8 i16 i32 i64 i128
72 // Unwind info registration/deregistration routines.
73 // See the docs of `unwind` module in libstd.
75 fn rust_eh_register_frames(eh_frame_begin: *const u8, object: *mut u8);
76 fn rust_eh_unregister_frames(eh_frame_begin: *const u8, object: *mut u8);
80 // register unwind info on module startup
81 rust_eh_register_frames(
82 &__EH_FRAME_BEGIN__ as *const u8,
83 &mut OBJ as *mut _ as *mut u8,
88 // unregister on shutdown
89 rust_eh_unregister_frames(
90 &__EH_FRAME_BEGIN__ as *const u8,
91 &mut OBJ as *mut _ as *mut u8,
95 // MSVC-specific init/uninit routine registration
97 // .CRT$X?? sections are roughly analogous to ELF's .init_array and .fini_array,
98 // except that they exploit the fact that linker will sort them alphabitically,
99 // so e.g. sections with names between .CRT$XIA and .CRT$XIZ are guaranteed to be
100 // placed between those two, without requiring any ordering of objects on the linker
102 // Note that ordering of same-named sections from different objects is not guaranteed.
103 // Since .CRT$XIA contains init array's header symbol, which must always come first,
104 // we place our initialization callback into .CRT$XIB.
106 #[link_section = ".CRT$XIB"] // .CRT$XI? : C initialization callbacks
107 pub static P_INIT: unsafe fn() = super::init;
109 #[link_section = ".CRT$XTY"] // .CRT$XT? : C termination callbacks
110 pub static P_UNINIT: unsafe fn() = super::uninit;