Remove trampoline, pass ret and unwind when handling intrinsics

src/libpanic_unwind/lib.rs

@@ -39,9 +39,6 @@
     if #[cfg(miri)] {
         #[path = "miri.rs"]
         mod imp;
-        // Export this at the root of the crate so that Miri
-        // has a stable palce to look it up
-        pub use imp::miri_panic_trampoline;
     } else if #[cfg(target_os = "emscripten")] {
         #[path = "emcc.rs"]
         mod imp;

src/libpanic_unwind/miri.rs

@@ -21,8 +21,3 @@ pub unsafe fn cleanup(ptr: *mut u8) -> Box<dyn Any + Send> {
 fn rust_eh_personality() {
     unsafe { core::intrinsics::abort() }
 }
-
-// A dummy helper function for Miri.
-// Used to push an empty stack frame when we start unwinding
-#[cfg(miri)]
-pub fn miri_panic_trampoline() {}

src/librustc_mir/const_eval.rs

@@ -376,6 +376,8 @@ fn call_intrinsic(
         instance: ty::Instance<'tcx>,
         args: &[OpTy<'tcx>],
         dest: Option<PlaceTy<'tcx>>,
+        _ret: Option<mir::BasicBlock>,
+        _unwind: Option<mir::BasicBlock>
     ) -> InterpResult<'tcx> {
         if ecx.emulate_intrinsic(span, instance, args, dest)? {
             return Ok(());

src/librustc_mir/interpret/eval_context.rs

@@ -585,21 +585,17 @@ pub(super) fn pop_stack_frame(
             "tried to pop a stack frame, but there were none",
         );
         let stack_pop_info = M::stack_pop(self, frame.extra, unwinding)?;
-        match (unwinding, stack_pop_info) {
-            (true, StackPopInfo::StartUnwinding) =>
-                bug!("Attempted to start unwinding while already unwinding!"),
-            (false, StackPopInfo::StopUnwinding) =>
-                bug!("Attempted to stop unwinding while there is no unwinding!"),
-            _ => {}
+        if let (false, StackPopInfo::StopUnwinding) = (unwinding, stack_pop_info) {
+            bug!("Attempted to stop unwinding while there is no unwinding!");
         }
 
         // Now where do we jump next?
 
         // Determine if we leave this function normally or via unwinding.
-        let cur_unwinding = match stack_pop_info {
-            StackPopInfo::StartUnwinding => true,
-            StackPopInfo::StopUnwinding => false,
-            _ => unwinding
+        let cur_unwinding = if let StackPopInfo::StopUnwinding = stack_pop_info {
+            false
+        } else {
+            unwinding
         };
 
         // Usually we want to clean up (deallocate locals), but in a few rare cases we don't.

src/librustc_mir/interpret/machine.rs

@@ -20,10 +20,6 @@
 /// to provide further control over the popping of the stack frame
 #[derive(Eq, PartialEq, Debug, Copy, Clone)]
 pub enum StackPopInfo {
-    /// Indicates that we have just started unwinding
-    /// as the result of panic
-    StartUnwinding,
-
     /// Indicates that no special handling should be
     /// done - we'll either return normally or unwind
     /// based on the terminator for the function
@@ -177,6 +173,8 @@ fn call_intrinsic(
         instance: ty::Instance<'tcx>,
         args: &[OpTy<'tcx, Self::PointerTag>],
         dest: Option<PlaceTy<'tcx, Self::PointerTag>>,
+        ret: Option<mir::BasicBlock>,
+        unwind: Option<mir::BasicBlock>,
     ) -> InterpResult<'tcx>;
 
     /// Called for read access to a foreign static item.

src/librustc_mir/interpret/terminator.rs

@@ -265,7 +265,7 @@ fn eval_fn_call(
         match instance.def {
             ty::InstanceDef::Intrinsic(..) => {
                 let old_stack = self.cur_frame();
-                M::call_intrinsic(self, span, instance, args, dest)?;
+                M::call_intrinsic(self, span, instance, args, dest, ret, unwind)?;
                 // No stack frame gets pushed, the main loop will just act as if the
                 // call completed.
                 if ret.is_some() {

src/librustc_mir/transform/const_prop.rs

@@ -164,6 +164,8 @@ fn call_intrinsic(
         _instance: ty::Instance<'tcx>,
         _args: &[OpTy<'tcx>],
         _dest: Option<PlaceTy<'tcx>>,
+        _ret: Option<BasicBlock>,
+        _unwind: Option<BasicBlock>
     ) -> InterpResult<'tcx> {
         throw_unsup_format!("calling intrinsics isn't supported in ConstProp");
     }