interpret: rename StackPopCleanup

Author: RalfJung

compiler/rustc_const_eval/src/const_eval/eval_queries.rs

@@ -19,7 +19,7 @@ use super::{CanAccessMutGlobal, CompileTimeInterpCx, CompileTimeMachine};
 use crate::const_eval::CheckAlignment;
 use crate::interpret::{
     CtfeValidationMode, GlobalId, Immediate, InternKind, InternResult, InterpCx, InterpErrorKind,
-    InterpResult, MPlaceTy, MemoryKind, OpTy, RefTracking, StackPopCleanup, create_static_alloc,
+    InterpResult, MPlaceTy, MemoryKind, OpTy, RefTracking, ReturnContinuation, create_static_alloc,
     intern_const_alloc_recursive, interp_ok, throw_exhaust,
 };
 use crate::{CTRL_C_RECEIVED, errors};
@@ -76,7 +76,7 @@ fn eval_body_using_ecx<'tcx, R: InterpretationResult<'tcx>>(
         cid.instance,
         body,
         &ret.clone().into(),
-        StackPopCleanup::Root { cleanup: false },
+        ReturnContinuation::Stop { cleanup: false },
     )?;
     ecx.storage_live_for_always_live_locals()?;
 

compiler/rustc_const_eval/src/interpret/call.rs

@@ -15,7 +15,7 @@ use tracing::{info, instrument, trace};
 
 use super::{
     CtfeProvenance, FnVal, ImmTy, InterpCx, InterpResult, MPlaceTy, Machine, OpTy, PlaceTy,
-    Projectable, Provenance, ReturnAction, Scalar, StackPopCleanup, StackPopInfo, interp_ok,
+    Projectable, Provenance, ReturnAction, ReturnContinuation, Scalar, StackPopInfo, interp_ok,
     throw_ub, throw_ub_custom, throw_unsup_format,
 };
 use crate::fluent_generated as fluent;
@@ -340,7 +340,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         args: &[FnArg<'tcx, M::Provenance>],
         with_caller_location: bool,
         destination: &PlaceTy<'tcx, M::Provenance>,
-        mut stack_pop: StackPopCleanup,
+        mut cont: ReturnContinuation,
     ) -> InterpResult<'tcx> {
         // Compute callee information.
         // FIXME: for variadic support, do we have to somehow determine callee's extra_args?
@@ -365,15 +365,15 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
 
         if !callee_fn_abi.can_unwind {
             // The callee cannot unwind, so force the `Unreachable` unwind handling.
-            match &mut stack_pop {
-                StackPopCleanup::Root { .. } => {}
-                StackPopCleanup::Goto { unwind, .. } => {
+            match &mut cont {
+                ReturnContinuation::Stop { .. } => {}
+                ReturnContinuation::Goto { unwind, .. } => {
                     *unwind = mir::UnwindAction::Unreachable;
                 }
             }
         }
 
-        self.push_stack_frame_raw(instance, body, destination, stack_pop)?;
+        self.push_stack_frame_raw(instance, body, destination, cont)?;
 
         // If an error is raised here, pop the frame again to get an accurate backtrace.
         // To this end, we wrap it all in a `try` block.
@@ -617,7 +617,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                     &args,
                     with_caller_location,
                     destination,
-                    StackPopCleanup::Goto { ret: target, unwind },
+                    ReturnContinuation::Goto { ret: target, unwind },
                 )
             }
             // `InstanceKind::Virtual` does not have callable MIR. Calls to `Virtual` instances must be
@@ -755,16 +755,16 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         // Note that we are using `pop_stack_frame_raw` and not `return_from_current_stack_frame`,
         // as the latter "executes" the goto to the return block, but we don't want to,
         // only the tail called function should return to the current return block.
-        let StackPopInfo { return_action, return_to_block, return_place } = self
-            .pop_stack_frame_raw(false, |_this, _return_place| {
+        let StackPopInfo { return_action, return_cont, return_place } =
+            self.pop_stack_frame_raw(false, |_this, _return_place| {
                 // This function's return value is just discarded, the tail-callee will fill in the return place instead.
                 interp_ok(())
             })?;
 
         assert_eq!(return_action, ReturnAction::Normal);
 
         // Take the "stack pop cleanup" info, and use that to initiate the next call.
-        let StackPopCleanup::Goto { ret, unwind } = return_to_block else {
+        let ReturnContinuation::Goto { ret, unwind } = return_cont else {
             bug!("can't tailcall as root");
         };
 
@@ -896,23 +896,23 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         // Normal return, figure out where to jump.
         if unwinding {
             // Follow the unwind edge.
-            match stack_pop_info.return_to_block {
-                StackPopCleanup::Goto { unwind, .. } => {
+            match stack_pop_info.return_cont {
+                ReturnContinuation::Goto { unwind, .. } => {
                     // This must be the very last thing that happens, since it can in fact push a new stack frame.
                     self.unwind_to_block(unwind)
                 }
-                StackPopCleanup::Root { .. } => {
-                    panic!("encountered StackPopCleanup::Root when unwinding!")
+                ReturnContinuation::Stop { .. } => {
+                    panic!("encountered ReturnContinuation::Stop when unwinding!")
                 }
             }
         } else {
             // Follow the normal return edge.
-            match stack_pop_info.return_to_block {
-                StackPopCleanup::Goto { ret, .. } => self.return_to_block(ret),
-                StackPopCleanup::Root { .. } => {
+            match stack_pop_info.return_cont {
+                ReturnContinuation::Goto { ret, .. } => self.return_to_block(ret),
+                ReturnContinuation::Stop { .. } => {
                     assert!(
                         self.stack().is_empty(),
-                        "only the bottommost frame can have StackPopCleanup::Root"
+                        "only the bottommost frame can have ReturnContinuation::Stop"
                     );
                     interp_ok(())
                 }

compiler/rustc_const_eval/src/interpret/mod.rs

@@ -36,7 +36,7 @@ pub use self::operand::{ImmTy, Immediate, OpTy};
 pub use self::place::{MPlaceTy, MemPlaceMeta, PlaceTy, Writeable};
 use self::place::{MemPlace, Place};
 pub use self::projection::{OffsetMode, Projectable};
-pub use self::stack::{Frame, FrameInfo, LocalState, StackPopCleanup, StackPopInfo};
+pub use self::stack::{Frame, FrameInfo, LocalState, ReturnContinuation, StackPopInfo};
 pub(crate) use self::util::create_static_alloc;
 pub use self::validity::{CtfeValidationMode, RangeSet, RefTracking};
 pub use self::visitor::ValueVisitor;

compiler/rustc_const_eval/src/interpret/stack.rs

@@ -72,8 +72,8 @@ pub struct Frame<'tcx, Prov: Provenance = CtfeProvenance, Extra = ()> {
     ////////////////////////////////////////////////////////////////////////////////
     // Return place and locals
     ////////////////////////////////////////////////////////////////////////////////
-    /// Work to perform when returning from this function.
-    return_to_block: StackPopCleanup,
+    /// Where to continue when returning from this function.
+    return_cont: ReturnContinuation,
 
     /// The location where the result of the current stack frame should be written to,
     /// and its layout in the caller. This place is to be interpreted relative to the
@@ -106,19 +106,19 @@ pub struct Frame<'tcx, Prov: Provenance = CtfeProvenance, Extra = ()> {
     pub(super) loc: Either<mir::Location, Span>,
 }
 
+/// Where and how to continue when returning/unwinding from the current function.
 #[derive(Clone, Copy, Eq, PartialEq, Debug)] // Miri debug-prints these
-pub enum StackPopCleanup {
+pub enum ReturnContinuation {
     /// Jump to the next block in the caller, or cause UB if None (that's a function
-    /// that may never return). Also store layout of return place so
-    /// we can validate it at that layout.
+    /// that may never return).
     /// `ret` stores the block we jump to on a normal return, while `unwind`
     /// stores the block used for cleanup during unwinding.
     Goto { ret: Option<mir::BasicBlock>, unwind: mir::UnwindAction },
-    /// The root frame of the stack: nowhere else to jump to.
+    /// The root frame of the stack: nowhere else to jump to, so we stop.
     /// `cleanup` says whether locals are deallocated. Static computation
     /// wants them leaked to intern what they need (and just throw away
     /// the entire `ecx` when it is done).
-    Root { cleanup: bool },
+    Stop { cleanup: bool },
 }
 
 /// Return type of [`InterpCx::pop_stack_frame_raw`].
@@ -127,8 +127,8 @@ pub struct StackPopInfo<'tcx, Prov: Provenance> {
     /// stack frame.
     pub return_action: ReturnAction,
 
-    /// [`return_to_block`](Frame::return_to_block) of the popped stack frame.
-    pub return_to_block: StackPopCleanup,
+    /// [`return_cont`](Frame::return_cont) of the popped stack frame.
+    pub return_cont: ReturnContinuation,
 
     /// [`return_place`](Frame::return_place) of the popped stack frame.
     pub return_place: PlaceTy<'tcx, Prov>,
@@ -255,7 +255,7 @@ impl<'tcx, Prov: Provenance> Frame<'tcx, Prov> {
         Frame {
             body: self.body,
             instance: self.instance,
-            return_to_block: self.return_to_block,
+            return_cont: self.return_cont,
             return_place: self.return_place,
             locals: self.locals,
             loc: self.loc,
@@ -350,20 +350,20 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
     /// the arguments or local variables.
     ///
     /// The high-level version of this is `init_stack_frame`.
-    #[instrument(skip(self, body, return_place, return_to_block), level = "debug")]
+    #[instrument(skip(self, body, return_place, return_cont), level = "debug")]
     pub(crate) fn push_stack_frame_raw(
         &mut self,
         instance: ty::Instance<'tcx>,
         body: &'tcx mir::Body<'tcx>,
         return_place: &PlaceTy<'tcx, M::Provenance>,
-        return_to_block: StackPopCleanup,
+        return_cont: ReturnContinuation,
     ) -> InterpResult<'tcx> {
         trace!("body: {:#?}", body);
 
         // We can push a `Root` frame if and only if the stack is empty.
         debug_assert_eq!(
             self.stack().is_empty(),
-            matches!(return_to_block, StackPopCleanup::Root { .. })
+            matches!(return_cont, ReturnContinuation::Stop { .. })
         );
 
         // First push a stack frame so we have access to `instantiate_from_current_frame` and other
@@ -373,7 +373,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         let pre_frame = Frame {
             body,
             loc: Right(body.span), // Span used for errors caused during preamble.
-            return_to_block,
+            return_cont,
             return_place: return_place.clone(),
             locals,
             instance,
@@ -429,15 +429,15 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
             copy_ret_val(self, &frame.return_place)?;
         }
 
-        let return_to_block = frame.return_to_block;
+        let return_cont = frame.return_cont;
         let return_place = frame.return_place.clone();
 
         // Cleanup: deallocate locals.
         // Usually we want to clean up (deallocate locals), but in a few rare cases we don't.
         // We do this while the frame is still on the stack, so errors point to the callee.
-        let cleanup = match return_to_block {
-            StackPopCleanup::Goto { .. } => true,
-            StackPopCleanup::Root { cleanup, .. } => cleanup,
+        let cleanup = match return_cont {
+            ReturnContinuation::Goto { .. } => true,
+            ReturnContinuation::Stop { cleanup, .. } => cleanup,
         };
 
         let return_action = if cleanup {
@@ -455,7 +455,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
             ReturnAction::NoCleanup
         };
 
-        interp_ok(StackPopInfo { return_action, return_to_block, return_place })
+        interp_ok(StackPopInfo { return_action, return_cont, return_place })
     }
 
     /// In the current stack frame, mark all locals as live that are not arguments and don't have

src/tools/miri/src/concurrency/thread.rs

@@ -894,7 +894,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
             start_abi,
             &[func_arg],
             Some(&ret_place),
-            StackPopCleanup::Root { cleanup: true },
+            ReturnContinuation::Stop { cleanup: true },
         )?;
 
         // Restore the old active thread frame.

src/tools/miri/src/eval.rs

@@ -436,7 +436,7 @@ pub fn create_ecx<'tcx>(
                     ImmTy::from_uint(sigpipe, ecx.machine.layouts.u8),
                 ],
                 Some(&ret_place),
-                StackPopCleanup::Root { cleanup: true },
+                ReturnContinuation::Stop { cleanup: true },
             )?;
         }
         MiriEntryFnType::MiriStart => {
@@ -445,7 +445,7 @@ pub fn create_ecx<'tcx>(
                 ExternAbi::Rust,
                 &[argc, argv],
                 Some(&ret_place),
-                StackPopCleanup::Root { cleanup: true },
+                ReturnContinuation::Stop { cleanup: true },
             )?;
         }
     }

src/tools/miri/src/helpers.rs

@@ -444,7 +444,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         caller_abi: ExternAbi,
         args: &[ImmTy<'tcx>],
         dest: Option<&MPlaceTy<'tcx>>,
-        stack_pop: StackPopCleanup,
+        cont: ReturnContinuation,
     ) -> InterpResult<'tcx> {
         let this = self.eval_context_mut();
 
@@ -472,7 +472,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
             &args.iter().map(|a| FnArg::Copy(a.clone().into())).collect::<Vec<_>>(),
             /*with_caller_location*/ false,
             &dest.into(),
-            stack_pop,
+            cont,
         )
     }
 

src/tools/miri/src/machine.rs

@@ -1199,7 +1199,7 @@ impl<'tcx> Machine<'tcx> for MiriMachine<'tcx> {
             ExternAbi::Rust,
             &[],
             None,
-            StackPopCleanup::Goto { ret: None, unwind: mir::UnwindAction::Unreachable },
+            ReturnContinuation::Goto { ret: None, unwind: mir::UnwindAction::Unreachable },
         )?;
         interp_ok(())
     }

src/tools/miri/src/shims/panic.rs

@@ -92,7 +92,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
             &[data.clone()],
             None,
             // Directly return to caller.
-            StackPopCleanup::Goto { ret, unwind: mir::UnwindAction::Continue },
+            ReturnContinuation::Goto { ret, unwind: mir::UnwindAction::Continue },
         )?;
 
         // We ourselves will return `0`, eventually (will be overwritten if we catch a panic).
@@ -143,7 +143,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                 &[catch_unwind.data, payload],
                 None,
                 // Directly return to caller of `catch_unwind`.
-                StackPopCleanup::Goto {
+                ReturnContinuation::Goto {
                     ret: catch_unwind.ret,
                     // `catch_fn` must not unwind.
                     unwind: mir::UnwindAction::Unreachable,
@@ -172,7 +172,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
             ExternAbi::Rust,
             &[this.mplace_to_ref(&msg)?],
             None,
-            StackPopCleanup::Goto { ret: None, unwind },
+            ReturnContinuation::Goto { ret: None, unwind },
         )
     }
 
@@ -191,7 +191,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
             ExternAbi::Rust,
             &[this.mplace_to_ref(&msg)?],
             None,
-            StackPopCleanup::Goto { ret: None, unwind: mir::UnwindAction::Unreachable },
+            ReturnContinuation::Goto { ret: None, unwind: mir::UnwindAction::Unreachable },
         )
     }
 
@@ -220,7 +220,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                     ExternAbi::Rust,
                     &[index, len],
                     None,
-                    StackPopCleanup::Goto { ret: None, unwind },
+                    ReturnContinuation::Goto { ret: None, unwind },
                 )?;
             }
             MisalignedPointerDereference { required, found } => {
@@ -241,7 +241,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                     ExternAbi::Rust,
                     &[required, found],
                     None,
-                    StackPopCleanup::Goto { ret: None, unwind },
+                    ReturnContinuation::Goto { ret: None, unwind },
                 )?;
             }
 
@@ -254,7 +254,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                     ExternAbi::Rust,
                     &[],
                     None,
-                    StackPopCleanup::Goto { ret: None, unwind },
+                    ReturnContinuation::Goto { ret: None, unwind },
                 )?;
             }
         }

src/tools/miri/src/shims/tls.rs

@@ -325,7 +325,7 @@ trait EvalContextPrivExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
             ExternAbi::System { unwind: false },
             &[null_ptr.clone(), ImmTy::from_scalar(reason, this.machine.layouts.u32), null_ptr],
             None,
-            StackPopCleanup::Root { cleanup: true },
+            ReturnContinuation::Stop { cleanup: true },
         )?;
         interp_ok(())
     }
@@ -346,7 +346,7 @@ trait EvalContextPrivExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                 ExternAbi::C { unwind: false },
                 &[ImmTy::from_scalar(data, this.machine.layouts.mut_raw_ptr)],
                 None,
-                StackPopCleanup::Root { cleanup: true },
+                ReturnContinuation::Stop { cleanup: true },
             )?;
 
             return interp_ok(Poll::Pending);
@@ -383,7 +383,7 @@ trait EvalContextPrivExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                 ExternAbi::C { unwind: false },
                 &[ImmTy::from_scalar(ptr, this.machine.layouts.mut_raw_ptr)],
                 None,
-                StackPopCleanup::Root { cleanup: true },
+                ReturnContinuation::Stop { cleanup: true },
             )?;
 
             return interp_ok(Poll::Pending);