Auto merge of #3033 - rust-lang:rustup-2023-08-21, r=RalfJung

Automatic sync from rustc

Author: bors

rust-version

@@ -1 +1 @@
-656ee47db32e882fb02913f6204e09cc7a41a50e
+c40cfcf0494ff7506e753e750adb00eeea839f9c

src/machine.rs

@@ -971,9 +971,22 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for MiriMachine<'mir, 'tcx> {
         ecx.assert_panic(msg, unwind)
     }
 
-    #[inline(always)]
-    fn abort(_ecx: &mut MiriInterpCx<'mir, 'tcx>, msg: String) -> InterpResult<'tcx, !> {
-        throw_machine_stop!(TerminationInfo::Abort(msg))
+    fn panic_nounwind(ecx: &mut InterpCx<'mir, 'tcx, Self>, msg: &str) -> InterpResult<'tcx> {
+        ecx.start_panic_nounwind(msg)
+    }
+
+    fn unwind_terminate(ecx: &mut InterpCx<'mir, 'tcx, Self>) -> InterpResult<'tcx> {
+        // Call the lang item.
+        let panic = ecx.tcx.lang_items().panic_cannot_unwind().unwrap();
+        let panic = ty::Instance::mono(ecx.tcx.tcx, panic);
+        ecx.call_function(
+            panic,
+            Abi::Rust,
+            &[],
+            None,
+            StackPopCleanup::Goto { ret: None, unwind: mir::UnwindAction::Unreachable },
+        )?;
+        Ok(())
     }
 
     #[inline(always)]

src/shims/intrinsics/mod.rs

@@ -34,10 +34,20 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         if this.emulate_intrinsic(instance, args, dest, ret)? {
             return Ok(());
         }
-
-        // All remaining supported intrinsics have a return place.
         let intrinsic_name = this.tcx.item_name(instance.def_id());
         let intrinsic_name = intrinsic_name.as_str();
+
+        // Handle intrinsics without return place.
+        match intrinsic_name {
+            "abort" => {
+                throw_machine_stop!(TerminationInfo::Abort(
+                    "the program aborted execution".to_owned()
+                ))
+            }
+            _ => {}
+        }
+
+        // All remaining supported intrinsics have a return place.
         let ret = match ret {
             None => throw_unsup_format!("unimplemented (diverging) intrinsic: `{intrinsic_name}`"),
             Some(p) => p,
@@ -393,7 +403,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
             "breakpoint" => {
                 let [] = check_arg_count(args)?;
                 // normally this would raise a SIGTRAP, which aborts if no debugger is connected
-                throw_machine_stop!(TerminationInfo::Abort(format!("Trace/breakpoint trap")))
+                throw_machine_stop!(TerminationInfo::Abort(format!("trace/breakpoint trap")))
             }
 
             name => throw_unsup_format!("unimplemented intrinsic: `{name}`"),

src/shims/panic.rs

@@ -188,6 +188,25 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         )
     }
 
+    /// Start a non-unwinding panic in the interpreter with the given message as payload.
+    fn start_panic_nounwind(&mut self, msg: &str) -> InterpResult<'tcx> {
+        let this = self.eval_context_mut();
+
+        // First arg: message.
+        let msg = this.allocate_str(msg, MiriMemoryKind::Machine.into(), Mutability::Not)?;
+
+        // Call the lang item.
+        let panic = this.tcx.lang_items().panic_nounwind().unwrap();
+        let panic = ty::Instance::mono(this.tcx.tcx, panic);
+        this.call_function(
+            panic,
+            Abi::Rust,
+            &[msg.to_ref(this)],
+            None,
+            StackPopCleanup::Goto { ret: None, unwind: mir::UnwindAction::Unreachable },
+        )
+    }
+
     fn assert_panic(
         &mut self,
         msg: &mir::AssertMessage<'tcx>,

tests/fail/breakpoint.rs

@@ -2,6 +2,6 @@
 
 fn main() {
     unsafe {
-        core::intrinsics::breakpoint() //~ ERROR: Trace/breakpoint trap
+        core::intrinsics::breakpoint() //~ ERROR: trace/breakpoint trap
     };
 }

tests/fail/breakpoint.stderr

@@ -1,8 +1,8 @@
-error: abnormal termination: Trace/breakpoint trap
+error: abnormal termination: trace/breakpoint trap
   --> $DIR/breakpoint.rs:LL:CC
    |
 LL |         core::intrinsics::breakpoint()
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Trace/breakpoint trap
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ trace/breakpoint trap
    |
    = note: inside `main` at $DIR/breakpoint.rs:LL:CC
 

tests/fail/function_calls/arg_inplace_mutate.rs

@@ -8,13 +8,13 @@ pub struct S(i32);
 #[custom_mir(dialect = "runtime", phase = "optimized")]
 fn main() {
     mir! {
-        let unit: ();
+        let _unit: ();
         {
             let non_copy = S(42);
             let ptr = std::ptr::addr_of_mut!(non_copy);
             // Inside `callee`, the first argument and `*ptr` are basically
             // aliasing places!
-            Call(unit, after_call, callee(Move(*ptr), ptr))
+            Call(_unit = callee(Move(*ptr), ptr), after_call)
         }
         after_call = {
             Return()

tests/fail/function_calls/arg_inplace_mutate.stack.stderr

@@ -10,7 +10,7 @@ help: <TAG> was created by a SharedReadWrite retag at offsets [0x0..0x4]
   --> $DIR/arg_inplace_mutate.rs:LL:CC
    |
 LL | /     mir! {
-LL | |         let unit: ();
+LL | |         let _unit: ();
 LL | |         {
 LL | |             let non_copy = S(42);
 ...  |
@@ -27,8 +27,8 @@ LL |     unsafe { ptr.write(S(0)) };
 note: inside `main`
   --> $DIR/arg_inplace_mutate.rs:LL:CC
    |
-LL |             Call(unit, after_call, callee(Move(*ptr), ptr))
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL |             Call(_unit = callee(Move(*ptr), ptr), after_call)
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: this error originates in the macro `::core::intrinsics::mir::__internal_remove_let` which comes from the expansion of the macro `mir` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace

tests/fail/function_calls/arg_inplace_mutate.tree.stderr

@@ -12,7 +12,7 @@ help: the accessed tag <TAG> was created here
   --> $DIR/arg_inplace_mutate.rs:LL:CC
    |
 LL | /     mir! {
-LL | |         let unit: ();
+LL | |         let _unit: ();
 LL | |         {
 LL | |             let non_copy = S(42);
 ...  |
@@ -29,8 +29,8 @@ LL |     unsafe { ptr.write(S(0)) };
 note: inside `main`
   --> $DIR/arg_inplace_mutate.rs:LL:CC
    |
-LL |             Call(unit, after_call, callee(Move(*ptr), ptr))
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL |             Call(_unit = callee(Move(*ptr), ptr), after_call)
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: this error originates in the macro `::core::intrinsics::mir::__internal_remove_let` which comes from the expansion of the macro `mir` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace

tests/fail/function_calls/arg_inplace_observe_after.rs

@@ -6,12 +6,12 @@ pub struct S(i32);
 #[custom_mir(dialect = "runtime", phase = "optimized")]
 fn main() {
     mir! {
-        let unit: ();
+        let _unit: ();
         let _observe: i32;
         {
             let non_copy = S(42);
             // This could change `non_copy` in-place
-            Call(unit, after_call, change_arg(Move(non_copy)))
+            Call(_unit = change_arg(Move(non_copy)), after_call)
         }
         after_call = {
             // So now we must not be allowed to observe non-copy again.