From 698f8c2f01ea549d77d7dc3338a12e04c11057b9 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Wed, 17 Apr 2024 14:02:58 +0200
Subject: Adding upstream version 1.64.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 library/rtstartup/rsbegin.rs | 97 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 97 insertions(+)
 create mode 100644 library/rtstartup/rsbegin.rs

(limited to 'library/rtstartup/rsbegin.rs')

diff --git a/library/rtstartup/rsbegin.rs b/library/rtstartup/rsbegin.rs
new file mode 100644
index 000000000..c6a4548ec
--- /dev/null
+++ b/library/rtstartup/rsbegin.rs
@@ -0,0 +1,97 @@
+// rsbegin.o and rsend.o are the so called "compiler runtime startup objects".
+// They contain code needed to correctly initialize the compiler runtime.
+//
+// When an executable or dylib image is linked, all user code and libraries are
+// "sandwiched" between these two object files, so code or data from rsbegin.o
+// become first in the respective sections of the image, whereas code and data
+// from rsend.o become the last ones. This effect can be used to place symbols
+// at the beginning or at the end of a section, as well as to insert any required
+// headers or footers.
+//
+// Note that the actual module entry point is located in the C runtime startup
+// object (usually called `crtX.o`), which then invokes initialization callbacks
+// of other runtime components (registered via yet another special image section).
+
+#![feature(no_core)]
+#![feature(lang_items)]
+#![feature(auto_traits)]
+#![crate_type = "rlib"]
+#![no_core]
+#![allow(non_camel_case_types)]
+
+#[lang = "sized"]
+trait Sized {}
+#[lang = "sync"]
+auto trait Sync {}
+#[lang = "copy"]
+trait Copy {}
+#[lang = "freeze"]
+auto trait Freeze {}
+
+#[lang = "drop_in_place"]
+#[inline]
+#[allow(unconditional_recursion)]
+pub unsafe fn drop_in_place<T: ?Sized>(to_drop: *mut T) {
+    drop_in_place(to_drop);
+}
+
+#[cfg(all(target_os = "windows", target_arch = "x86", target_env = "gnu"))]
+pub mod eh_frames {
+    #[no_mangle]
+    #[link_section = ".eh_frame"]
+    // Marks beginning of the stack frame unwind info section
+    pub static __EH_FRAME_BEGIN__: [u8; 0] = [];
+
+    // Scratch space for unwinder's internal book-keeping.
+    // This is defined as `struct object` in $GCC/libgcc/unwind-dw2-fde.h.
+    static mut OBJ: [isize; 6] = [0; 6];
+
+    macro_rules! impl_copy {
+        ($($t:ty)*) => {
+            $(
+                impl ::Copy for $t {}
+            )*
+        }
+    }
+
+    impl_copy! {
+        usize u8 u16 u32 u64 u128
+        isize i8 i16 i32 i64 i128
+        f32 f64
+        bool char
+    }
+
+    // Unwind info registration/deregistration routines.
+    // See the docs of libpanic_unwind.
+    extern "C" {
+        fn rust_eh_register_frames(eh_frame_begin: *const u8, object: *mut u8);
+        fn rust_eh_unregister_frames(eh_frame_begin: *const u8, object: *mut u8);
+    }
+
+    unsafe extern "C" fn init() {
+        // register unwind info on module startup
+        rust_eh_register_frames(&__EH_FRAME_BEGIN__ as *const u8, &mut OBJ as *mut _ as *mut u8);
+    }
+
+    unsafe extern "C" fn uninit() {
+        // unregister on shutdown
+        rust_eh_unregister_frames(&__EH_FRAME_BEGIN__ as *const u8, &mut OBJ as *mut _ as *mut u8);
+    }
+
+    // MinGW-specific init/uninit routine registration
+    pub mod mingw_init {
+        // MinGW's startup objects (crt0.o / dllcrt0.o) will invoke global constructors in the
+        // .ctors and .dtors sections on startup and exit. In the case of DLLs, this is done when
+        // the DLL is loaded and unloaded.
+        //
+        // The linker will sort the sections, which ensures that our callbacks are located at the
+        // end of the list. Since constructors are run in reverse order, this ensures that our
+        // callbacks are the first and last ones executed.
+
+        #[link_section = ".ctors.65535"] // .ctors.* : C initialization callbacks
+        pub static P_INIT: unsafe extern "C" fn() = super::init;
+
+        #[link_section = ".dtors.65535"] // .dtors.* : C termination callbacks
+        pub static P_UNINIT: unsafe extern "C" fn() = super::uninit;
+    }
+}
-- 
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