Rollup merge of #73418 - doctorn:variants-intrinsic, r=kennytm

[rust.git] / src / libpanic_unwind / lib.rs

diff --git a/src/libpanic_unwind/lib.rs b/src/libpanic_unwind/lib.rs
index 6383ae39fb6dba0c6795de05873964bc528341bb..f361354da2ac2ff59081a778e10b4fcfb67edec6 100644 (file)
--- a/src/libpanic_unwind/lib.rs
+++ b/src/libpanic_unwind/lib.rs
@@ -22,42 +22,53 @@
 #![feature(libc)]
 #![feature(nll)]
 #![feature(panic_unwind)]
-#![feature(raw)]
 #![feature(staged_api)]
 #![feature(std_internals)]
 #![feature(unwind_attributes)]
 #![feature(abi_thiscall)]
+#![feature(rustc_attrs)]
+#![feature(raw)]
 #![panic_runtime]
 #![feature(panic_runtime)]
+// `real_imp` is unused with Miri, so silence warnings.
+#![cfg_attr(miri, allow(dead_code))]
 
 use alloc::boxed::Box;
-use core::intrinsics;
-use core::mem;
+use core::any::Any;
 use core::panic::BoxMeUp;
-use core::raw;
 
 cfg_if::cfg_if! {
     if #[cfg(target_os = "emscripten")] {
         #[path = "emcc.rs"]
-        mod imp;
+        mod real_imp;
     } else if #[cfg(target_arch = "wasm32")] {
         #[path = "dummy.rs"]
-        mod imp;
+        mod real_imp;
     } else if #[cfg(target_os = "hermit")] {
         #[path = "hermit.rs"]
-        mod imp;
-    } else if #[cfg(all(target_env = "msvc", target_arch = "aarch64"))] {
-        #[path = "dummy.rs"]
-        mod imp;
+        mod real_imp;
     } else if #[cfg(target_env = "msvc")] {
         #[path = "seh.rs"]
-        mod imp;
+        mod real_imp;
     } else {
         // Rust runtime's startup objects depend on these symbols, so make them public.
         #[cfg(all(target_os="windows", target_arch = "x86", target_env="gnu"))]
-        pub use imp::eh_frame_registry::*;
+        pub use real_imp::eh_frame_registry::*;
         #[path = "gcc.rs"]
+        mod real_imp;
+    }
+}
+
+cfg_if::cfg_if! {
+    if #[cfg(miri)] {
+        // Use the Miri runtime.
+        // We still need to also load the normal runtime above, as rustc expects certain lang
+        // items from there to be defined.
+        #[path = "miri.rs"]
         mod imp;
+    } else {
+        // Use the real runtime.
+        use real_imp as imp;
     }
 }
 
@@ -69,44 +80,19 @@
 
 mod dwarf;
 
-// Entry point for catching an exception, implemented using the `try` intrinsic
-// in the compiler.
-//
-// The interaction between the `payload` function and the compiler is pretty
-// hairy and tightly coupled, for more information see the compiler's
-// implementation of this.
-#[no_mangle]
-pub unsafe extern "C" fn __rust_maybe_catch_panic(
-    f: fn(*mut u8),
-    data: *mut u8,
-    data_ptr: *mut usize,
-    vtable_ptr: *mut usize,
-) -> u32 {
-    let mut payload = imp::payload();
-    if intrinsics::r#try(f, data, &mut payload as *mut _ as *mut _) == 0 {
-        0
-    } else {
-        let obj = mem::transmute::<_, raw::TraitObject>(imp::cleanup(payload));
-        *data_ptr = obj.data as usize;
-        *vtable_ptr = obj.vtable as usize;
-        1
-    }
+#[rustc_std_internal_symbol]
+#[cfg_attr(not(bootstrap), allow(improper_ctypes_definitions))]
+pub unsafe extern "C" fn __rust_panic_cleanup(payload: *mut u8) -> *mut (dyn Any + Send + 'static) {
+    Box::into_raw(imp::cleanup(payload))
 }
 
 // Entry point for raising an exception, just delegates to the platform-specific
 // implementation.
-#[no_mangle]
+#[rustc_std_internal_symbol]
 #[unwind(allowed)]
 pub unsafe extern "C" fn __rust_start_panic(payload: usize) -> u32 {
     let payload = payload as *mut &mut dyn BoxMeUp;
     let payload = (*payload).take_box();
 
-    // Miri panic support: cfg'd out of normal builds just to be sure.
-    // When going through normal codegen, `miri_start_panic` is a NOP, so the
-    // Miri-enabled sysroot still supports normal unwinding. But when executed in
-    // Miri, this line initiates unwinding.
-    #[cfg(miri)]
-    core::intrinsics::miri_start_panic(payload);
-
     imp::panic(Box::from_raw(payload))
 }