macros, vm, bytecode: add #[handler] await-style primop macro

fix-bytecode/src/lib.rs

@@ -152,13 +152,15 @@ pub enum Continuation {
     PAdd,
     PAddErrorContext,
 
-    PAll,
-    PAllCallPred,
-    PAllCheck,
+    PAll0,
+    PAll1,
+    PAll2,
+    PAll3,
 
-    PAny,
-    PAnyCallPred,
-    PAnyCheck,
+    PAny0,
+    PAny1,
+    PAny2,
+    PAny3,
 
     PAppendContext,
     PAppendContextLoop,
@@ -182,9 +184,12 @@ pub enum Continuation {
     PConcatStringsSep,
     PConvertHash,
 
-    PDeepSeq,
-    PDeepSeqPush,
-    PDeepSeqLoop,
+    PDeepSeq0,
+    PDeepSeq1,
+    PDeepSeq2,
+    PDeepSeq3,
+    PDeepSeq4,
+    PDeepSeq5,
 
     PDerivation,
     PDerivationStrict,
@@ -198,19 +203,21 @@ pub enum Continuation {
     PFetchTree,
     PFetchUrl,
 
-    PFilterForceList,
-    PFilterSetupStack,
-    PFilterCallPred,
-    PFilterCheck,
+    PFilter0,
+    PFilter1,
+    PFilter2,
+    PFilter3,
+    PFilter4,
 
     PFilterSource,
     PFindFile,
     PFloor,
-    PFoldlStrict,
-    PFoldlStrictEmpty,
-    PFoldlStrictCall1,
-    PFoldlStrictCall2,
-    PFoldlStrictUpdate,
+    PFoldlStrict0,
+    PFoldlStrict1,
+    PFoldlStrict2,
+    PFoldlStrict3,
+    PFoldlStrict4,
+    PFoldlStrict5,
     PFromJSON,
     PFromTOML,
     PFunctionArgs,
@@ -258,7 +265,8 @@ pub enum Continuation {
     PReadFileType,
     PRemoveAttrs,
     PReplaceStrings,
-    PSeq,
+    PSeq0,
+    PSeq1,
     PSort,
     PSplit,
     PSplitVersion,
@@ -319,8 +327,8 @@ impl Continuation {
             Abort => Self::PAbort,
             Add => Self::PAdd,
             AddErrorContext => Self::PAddErrorContext,
-            All => Self::PAll,
-            Any => Self::PAny,
+            All => Self::PAll0,
+            Any => Self::PAny0,
             AppendContext => Self::PAppendContext,
             AttrNames => Self::PAttrNames,
             AttrValues => Self::PAttrValues,
@@ -336,7 +344,7 @@ impl Continuation {
             ConcatMap => Self::PConcatMap,
             ConcatStringsSep => Self::PConcatStringsSep,
             ConvertHash => Self::PConvertHash,
-            DeepSeq => Self::PDeepSeq,
+            DeepSeq => Self::PDeepSeq0,
             Derivation => Self::PDerivation,
             DerivationStrict => Self::PDerivationStrict,
             DirOf => Self::PDirOf,
@@ -348,11 +356,11 @@ impl Continuation {
             FetchTarball => Self::PFetchTarball,
             FetchTree => Self::PFetchTree,
             FetchUrl => Self::PFetchUrl,
-            Filter => Self::PFilterForceList,
+            Filter => Self::PFilter0,
             FilterSource => Self::PFilterSource,
             FindFile => Self::PFindFile,
             Floor => Self::PFloor,
-            FoldlStrict => Self::PFoldlStrict,
+            FoldlStrict => Self::PFoldlStrict0,
             FromJSON => Self::PFromJSON,
             FromTOML => Self::PFromTOML,
             FunctionArgs => Self::PFunctionArgs,
@@ -396,7 +404,7 @@ impl Continuation {
             RemoveAttrs => Self::PRemoveAttrs,
             ReplaceStrings => Self::PReplaceStrings,
             ScopedImport => Self::PScopedImport,
-            Seq => Self::PSeq,
+            Seq => Self::PSeq0,
             Sort => Self::PSort,
             Split => Self::PSplit,
             SplitVersion => Self::PSplitVersion,

fix-compiler/src/ir/downgrade.rs

@@ -466,7 +466,7 @@ impl<'id: 'ir, 'ir, Ctx: DowngradeContext<'id, 'ir>> Downgrade<'id, 'ir, Ctx> fo
             body: GhostRoIrRef<'id, 'ir>,
         }
 
-        let (ret, thunks) = ctx.with_thunk_scope(|ctx| {
+        let (ret, thunks) = ctx.with_thunk_scope(|ctx| -> Result<Ret> {
             let (param, body) = match raw_param {
                 ast::Param::IdentParam(id) => {
                     let param_sym = ctx.intern_string(id.to_string());
@@ -506,7 +506,7 @@ impl<'id: 'ir, 'ir, Ctx: DowngradeContext<'id, 'ir>> Downgrade<'id, 'ir, Ctx> fo
                 }
             };
 
-            Result::Ok(Ret { param, body })
+            Ok(Ret { param, body })
         });
         let Ret { param, body } = ret?;
 

fix-error/src/lib.rs

@@ -4,7 +4,7 @@ use std::sync::Arc;
 use miette::{Diagnostic, NamedSource, SourceSpan};
 use thiserror::Error;
 
-pub type Result<T> = core::result::Result<T, Box<Error>>;
+pub type Result<T, E = Box<Error>> = core::result::Result<T, E>;
 
 #[derive(Clone, Debug)]
 pub enum SourceType {

fix-macros/Cargo.toml

@@ -9,7 +9,7 @@ proc-macro = true
 [dependencies]
 proc-macro2 = "1.0"
 quote = "1.0"
-syn = { version = "3.0", features = ["full", "visit-mut"] }
+syn = { version = "3.0", features = ["full", "visit", "visit-mut"] }
 
 [lints]
 workspace = true

fix-macros/src/lib.rs

@@ -1,5 +1,15 @@
 extern crate proc_macro;
 
+mod handler;
+
+#[proc_macro_attribute]
+pub fn handler(
+    attr: proc_macro::TokenStream,
+    item: proc_macro::TokenStream,
+) -> proc_macro::TokenStream {
+    handler::handler(attr.into(), item.into()).into()
+}
+
 // Adapted from `__unelide_lifetimes` in `gc-arena-derive`.
 // Licensed under the MIT license.
 // See: https://github.com/kyren/gc-arena

fix-runtime/src/lib.rs

@@ -2,6 +2,7 @@ mod boxing;
 mod forced;
 mod host;
 mod machine;
+mod macro_support;
 mod path_util;
 mod resolve;
 mod slot;
@@ -13,6 +14,7 @@ pub use fix_bytecode::{BytecodeReader, OperandData};
 pub use forced::*;
 pub use host::*;
 pub use machine::*;
+pub use macro_support::*;
 pub use path_util::*;
 pub use resolve::*;
 pub use slot::*;

fix-runtime/src/macro_support.rs

@@ -0,0 +1,165 @@
+use std::ops::ControlFlow;
+
+use gc_arena::Mutation;
+
+use crate::{
+    Break, BytecodeReader, Forced, Machine, MachineExt, Slot, SlotContent, Step, StrictValue,
+    Value, ValueVariant,
+};
+
+pub trait UnwrapSlot {
+    type Unwrapped;
+}
+
+impl<T> UnwrapSlot for Slot<T> {
+    type Unwrapped = T;
+}
+
+/// Force-target protocol behind the `#[primop]` `force` form: `Value` only
+/// needs WHNF, `StrictValue` *is* WHNF, and content types are checked through
+/// [`Forced`] on their stored representation.
+pub trait ForceTarget<'gc>: SlotContent<'gc> {
+    /// Type-check the stack slot refined by the previous `force(slot)`; the
+    /// slot is already WHNF when this runs.
+    fn refine_check<M: Machine<'gc>>(
+        m: &mut M,
+        reader: &mut BytecodeReader<'_>,
+        mc: &Mutation<'gc>,
+        depth: usize,
+    ) -> Step;
+
+    /// Pop and convert the previous suspension's result into the annotated
+    /// binding's stored representation.
+    fn conv_force<M: Machine<'gc>>(
+        m: &mut M,
+        reader: &mut BytecodeReader<'_>,
+        mc: &Mutation<'gc>,
+    ) -> ControlFlow<Break, <Self as SlotContent<'gc>>::Ty>;
+}
+
+impl<'gc> ForceTarget<'gc> for Value<'gc> {
+    #[inline(always)]
+    fn refine_check<M: Machine<'gc>>(
+        _m: &mut M,
+        _reader: &mut BytecodeReader<'_>,
+        _mc: &Mutation<'gc>,
+        _depth: usize,
+    ) -> Step {
+        Step::Continue(())
+    }
+
+    #[inline(always)]
+    fn conv_force<M: Machine<'gc>>(
+        m: &mut M,
+        reader: &mut BytecodeReader<'_>,
+        mc: &Mutation<'gc>,
+    ) -> ControlFlow<Break, Value<'gc>> {
+        match m.force_and_retry::<StrictValue<'gc>>(reader, mc) {
+            ControlFlow::Continue(v) => ControlFlow::Continue(v.relax()),
+            ControlFlow::Break(b) => ControlFlow::Break(b),
+        }
+    }
+}
+
+impl<'gc> ForceTarget<'gc> for StrictValue<'gc> {
+    #[inline(always)]
+    fn refine_check<M: Machine<'gc>>(
+        _m: &mut M,
+        _reader: &mut BytecodeReader<'_>,
+        _mc: &Mutation<'gc>,
+        _depth: usize,
+    ) -> Step {
+        Step::Continue(())
+    }
+
+    #[inline(always)]
+    fn conv_force<M: Machine<'gc>>(
+        m: &mut M,
+        reader: &mut BytecodeReader<'_>,
+        mc: &Mutation<'gc>,
+    ) -> ControlFlow<Break, StrictValue<'gc>> {
+        m.force_and_retry::<StrictValue<'gc>>(reader, mc)
+    }
+}
+
+impl<'gc, T> ForceTarget<'gc> for T
+where
+    T: ValueVariant<'gc>,
+    <T as ValueVariant<'gc>>::Ty: Forced<'gc>,
+{
+    #[inline(always)]
+    fn refine_check<M: Machine<'gc>>(
+        m: &mut M,
+        reader: &mut BytecodeReader<'_>,
+        mc: &Mutation<'gc>,
+        depth: usize,
+    ) -> Step {
+        <<T as ValueVariant<'gc>>::Ty as Forced<'gc>>::force_and_check(
+            m,
+            reader,
+            mc,
+            depth,
+            reader.inst_start_pc(),
+        )
+    }
+
+    #[inline(always)]
+    fn conv_force<M: Machine<'gc>>(
+        m: &mut M,
+        reader: &mut BytecodeReader<'_>,
+        mc: &Mutation<'gc>,
+    ) -> ControlFlow<Break, <T as SlotContent<'gc>>::Ty> {
+        m.force_and_retry::<<T as ValueVariant<'gc>>::Ty>(reader, mc)
+    }
+}
+
+/// Callee protocol behind `call(&slot, ..)`: an unforced `Slot<Value>` is
+/// WHNF'd before the call; refined slots already hold strict values.
+pub trait CalleeReady<'gc> {
+    fn callee_ready<M: Machine<'gc>>(
+        &self,
+        m: &mut M,
+        reader: &mut BytecodeReader<'_>,
+        mc: &Mutation<'gc>,
+    ) -> ControlFlow<Break>;
+}
+
+impl<'gc> CalleeReady<'gc> for Slot<Value<'gc>> {
+    #[inline(always)]
+    fn callee_ready<M: Machine<'gc>>(
+        &self,
+        m: &mut M,
+        reader: &mut BytecodeReader<'_>,
+        mc: &Mutation<'gc>,
+    ) -> ControlFlow<Break> {
+        self.force::<StrictValue<'gc>, M>(m, reader, mc)?;
+        ControlFlow::Continue(())
+    }
+}
+
+impl<'gc> CalleeReady<'gc> for Slot<StrictValue<'gc>> {
+    #[inline(always)]
+    fn callee_ready<M: Machine<'gc>>(
+        &self,
+        _m: &mut M,
+        _reader: &mut BytecodeReader<'_>,
+        _mc: &Mutation<'gc>,
+    ) -> ControlFlow<Break> {
+        ControlFlow::Continue(())
+    }
+}
+
+impl<'gc, T> CalleeReady<'gc> for Slot<T>
+where
+    T: ValueVariant<'gc>,
+{
+    #[inline(always)]
+    fn callee_ready<M: Machine<'gc>>(
+        &self,
+        _m: &mut M,
+        _reader: &mut BytecodeReader<'_>,
+        _mc: &Mutation<'gc>,
+    ) -> ControlFlow<Break> {
+        ControlFlow::Continue(())
+    }
+}

fix-runtime/src/slot.rs

@@ -6,6 +6,11 @@ use gc_arena::Mutation;
 
 use crate::{Break, Forced, Machine, NixType, Step, StrictValue, Value, ValueVariant};
 
+pub struct TypeError {
+    pub expected: NixType,
+    pub got: NixType,
+}
+
 pub trait SlotContent<'gc> {
     type Ty: Into<Value<'gc>> + TryFrom<Value<'gc>> + 'gc;
 }
@@ -50,12 +55,6 @@ where
         T::Ty::try_from(m.peek(self.depth as usize)).expect("slot held a value of the wrong type")
     }
 
-    #[inline(always)]
-    pub fn read_checked<M: Machine<'gc>>(&self, m: &M) -> Result<T::Ty, NixType> {
-        let val = m.peek(self.depth as usize);
-        T::Ty::try_from(val).map_err(|_err| val.ty())
-    }
-
     #[inline(always)]
     pub fn write<M: Machine<'gc>>(&self, m: &mut M, val: T::Ty) {
         m.replace(self.depth as usize, T::Ty::into(val));

fix-vm/src/instructions/calls.rs

@@ -165,7 +165,7 @@ pub(crate) fn op_return<'gc, M: Machine<'gc>>(
                     depth: None,
                 });
                 m.inc_call_depth();
-                reader.set_pc(Continuation::PDeepSeq.ip() as usize);
+                reader.set_pc(Continuation::PDeepSeq0.ip() as usize);
                 return Step::Continue(());
             }
         }

fix-vm/src/lib.rs

@@ -20,8 +20,12 @@ use smallvec::SmallVec;
 #[cfg(feature = "tailcall")]
 mod dispatch_tailcall;
 pub use fix_runtime::*;
+#[doc(hidden)]
+#[path = "macro_support.rs"]
+pub mod __macro_support;
 mod instructions;
 mod primops;
+extern crate self as fix_vm;
 
 type VmResult<T> = std::result::Result<T, VmError>;
 

fix-vm/src/macro_support.rs

@@ -0,0 +1,36 @@
+//! Single macro-facing path for the `#[primop]` support surface: the traits
+//! generated code type-checks through (defined in `fix_runtime`, where the
+//! impl sets are coherent) and the stub trio that keeps un-expanded primop
+//! sources resolving in tooling.
+
+use std::future::Future;
+
+pub use fix_runtime::{CalleeReady, ForceTarget, UnwrapSlot};
+use fix_runtime::{Slot, Value};
+
+macro_rules! type_hint {
+    () => {
+        if false {
+            return async {
+                unreachable!();
+            };
+        }
+    };
+}
+
+#[expect(clippy::panic, reason = "deliberately panic when the stub is called")]
+pub fn force<T>(_: Slot<Value<'_>>) -> impl Future<Output = Slot<T>> {
+    type_hint!();
+    panic!("stub `force` called at runtime")
+}
+
+#[expect(clippy::panic, reason = "deliberately panic when the stub is called")]
+pub fn call<T, A, R>(_: &T, _: A) -> impl Future<Output = R> {
+    type_hint!();
+    panic!("stub `call` called at runtime")
+}
+
+#[expect(clippy::panic, reason = "deliberately panic when the stub is called")]
+pub fn spill<T>(_: T) -> Slot<T> {
+    panic!("stub `spill` called at runtime")
+}

fix-vm/src/primops/control.rs

@@ -1,22 +1,89 @@
 use fix_bytecode::Continuation;
-use fix_error::Error;
+use fix_error::{Error, Result};
+use fix_macros::handler;
 use fix_runtime::{
-    AttrSet, BytecodeReader, Closure, Env, List, Machine, MachineExt, Step, StrictValue, Value,
-    VmRuntimeCtx, VmRuntimeCtxExt,
+    AttrSet, BytecodeReader, Closure, Env, List, Machine, MachineExt, Slot, Step, StrictValue,
+    Value, VmRuntimeCtx, VmRuntimeCtxExt,
 };
 use gc_arena::{Gc, Mutation, RefLock};
 use smallvec::SmallVec;
 
-pub fn seq<'gc, M: Machine<'gc>>(
-    m: &mut M,
-    reader: &mut BytecodeReader<'_>,
+use crate::primops::stubs::*;
+
+#[handler(name = PSeq)]
+fn seq<'gc>(mc: &Mutation<'gc>, e1: Slot<Value<'gc>>, e2: Slot<Value<'gc>>) -> Result<Value<'gc>> {
+    let _e1: Slot<StrictValue<'gc>> = force(e1).await?;
+    Ok(e2.get())
+}
+
+#[handler(name = PDeepSeq)]
+fn deep_seq<'gc>(
     mc: &Mutation<'gc>,
-) -> Step {
-    // stack: [e1, e2] - force e1, return e2
-    m.force_slot(1, reader, mc)?;
-    let e2 = m.pop();
-    m.drop_n(1);
-    m.return_from_primop(e2, reader)
+    e1: Slot<Value<'gc>>,
+    e2: Slot<Value<'gc>>,
+) -> Result<Value<'gc>> {
+    let e1: Slot<StrictValue<'gc>> = force(e1).await?;
+    if collect_children(e1.get()).is_empty() {
+        return Ok(e2.get());
+    }
+    let seen: Slot<List<'gc>> = spill(Gc::new(mc, List::default()));
+    let worklist: Slot<List<'gc>> = spill(List::new(mc, collect_children(e1.get())));
+    let count: Slot<i32> = spill(worklist.get().inner.borrow().len() as i32);
+    loop {
+        if count.get() == 0 {
+            return Ok(e2.get());
+        }
+        let item = worklist
+            .get()
+            .unlock(mc)
+            .borrow_mut()
+            .pop()
+            .expect("worklist is non-empty while count > 0");
+        count.set(count.get() - 1);
+        let item: Slot<StrictValue<'gc>> = force(item).await?;
+        let added = push_children(mc, seen.get(), worklist.get(), item);
+        count.set(count.get() + added);
+    }
+}
+
+fn collect_children<'gc>(val: StrictValue<'gc>) -> SmallVec<[Value<'gc>; 4]> {
+    if let Some(attrs) = val.downcast::<AttrSet<'gc>>() {
+        attrs.entries.iter().map(|&(_, v)| v).collect()
+    } else if let Some(list) = val.downcast::<List<'gc>>() {
+        list.inner.borrow().iter().copied().collect()
+    } else {
+        SmallVec::new()
+    }
+}
+
+fn push_children<'gc>(
+    mc: &Mutation<'gc>,
+    seen: Gc<'gc, List<'gc>>,
+    worklist: Gc<'gc, List<'gc>>,
+    item: StrictValue<'gc>,
+) -> i32 {
+    let mut added = 0i32;
+    if let Some(attrs) = item.downcast::<AttrSet<'gc>>()
+        && !is_value_in_seen(seen, item.relax())
+    {
+        add_value_to_seen(seen, mc, item.relax());
+        let mut wl = worklist.unlock(mc).borrow_mut();
+        for &(_, v) in attrs.entries.iter() {
+            wl.push(v);
+        }
+        added = attrs.entries.len() as i32;
+    } else if let Some(list) = item.downcast::<List<'gc>>()
+        && !is_value_in_seen(seen, item.relax())
+    {
+        add_value_to_seen(seen, mc, item.relax());
+        let inner = list.inner.borrow();
+        let mut wl = worklist.unlock(mc).borrow_mut();
+        for &v in inner.iter() {
+            wl.push(v);
+        }
+        added = inner.len() as i32;
+    }
+    added
 }
 
 pub fn abort<'gc, M: Machine<'gc>>(
@@ -34,148 +101,6 @@ pub fn abort<'gc, M: Machine<'gc>>(
     )))
 }
 
-pub fn deep_seq_force_top<'gc, M: Machine<'gc>>(
-    m: &mut M,
-    reader: &mut BytecodeReader<'_>,
-    mc: &Mutation<'gc>,
-) -> Step {
-    // stack: [e1, e2] - force e1, return e2
-    m.force_slot(1, reader, mc)?;
-
-    let e1 = m.peek_forced(1);
-
-    let children: SmallVec<_> = if let Some(attrs) = e1.downcast::<AttrSet>() {
-        let attrs = &attrs.entries;
-        if attrs.is_empty() {
-            SmallVec::new()
-        } else {
-            attrs.iter().map(|&(_, v)| v).collect()
-        }
-    } else if let Some(list) = e1.downcast::<List>() {
-        let inner = list.inner.borrow();
-        if inner.is_empty() {
-            SmallVec::new()
-        } else {
-            inner.iter().copied().collect()
-        }
-    } else {
-        SmallVec::new()
-    };
-
-    if children.is_empty() {
-        let e2 = m.pop();
-        m.drop_n(1);
-        return m.return_from_primop(e2, reader);
-    }
-
-    let count = children.len() as i32;
-    let seen = Gc::new(mc, List::default());
-    let worklist = List::new(mc, children);
-
-    let e2 = m.pop();
-    m.drop_n(1);
-    m.push(e2);
-    m.push(Value::new(seen));
-    m.push(Value::new(worklist));
-    m.push(Value::new(count));
-    reader.set_pc(Continuation::PDeepSeqPush.ip() as usize);
-    Step::Continue(())
-}
-
-pub fn deep_seq_push<'gc, M: Machine<'gc>>(
-    m: &mut M,
-    reader: &mut BytecodeReader<'_>,
-    mc: &Mutation<'gc>,
-) -> Step {
-    // stack: [e2, seen, worklist, counter]
-    let counter = m
-        .peek(0)
-        .downcast::<i32>()
-        .expect("stack slot must be an integer");
-    if counter == 0 {
-        m.drop_n(3);
-        let val = m.pop();
-        return m.return_from_primop(val, reader);
-    }
-
-    let worklist = m
-        .peek_forced(1)
-        .downcast::<List>()
-        .expect("stack slot must be a list");
-    let item = worklist
-        .unlock(mc)
-        .borrow_mut()
-        .pop()
-        .expect("worklist is non-empty while counter > 0");
-    m.replace(0, Value::new(counter - 1));
-    m.push(item);
-
-    // force item at TOS, resume at DeepSeqLoop after force
-    m.force_slot_to_pc(0, reader, mc, Continuation::PDeepSeqLoop.ip() as usize)?;
-    reader.set_pc(Continuation::PDeepSeqLoop.ip() as usize);
-    Step::Continue(())
-}
-
-pub fn deep_seq_loop<'gc, M: Machine<'gc>>(
-    m: &mut M,
-    reader: &mut BytecodeReader<'_>,
-    mc: &Mutation<'gc>,
-) -> Step {
-    // stack after pop: [e2, seen, worklist, counter]
-    let item = m.pop();
-    let counter = m
-        .peek(0)
-        .downcast::<i32>()
-        .expect("stack slot must be an integer");
-
-    let mut added: usize = 0;
-    if let Some(attrs) = item.downcast::<AttrSet>() {
-        let attrs = &attrs.entries;
-        let seen = m
-            .peek_forced(2)
-            .downcast::<List>()
-            .expect("stack slot must be a list");
-        if !is_value_in_seen(seen, item) {
-            add_value_to_seen(seen, mc, item);
-            let worklist = m
-                .peek_forced(1)
-                .downcast::<List>()
-                .expect("stack slot must be a list");
-            {
-                let mut wl = worklist.unlock(mc).borrow_mut();
-                for &(_, v) in attrs.iter() {
-                    wl.push(v);
-                }
-                added = attrs.len();
-            }
-        }
-    } else if let Some(list) = item.downcast::<List>() {
-        let seen = m
-            .peek_forced(2)
-            .downcast::<List>()
-            .expect("stack slot must be a list");
-        if !is_value_in_seen(seen, item) {
-            add_value_to_seen(seen, mc, item);
-            let worklist = m
-                .peek_forced(1)
-                .downcast::<List>()
-                .expect("stack slot must be a list");
-            {
-                let inner = list.inner.borrow();
-                let mut wl = worklist.unlock(mc).borrow_mut();
-                for &v in inner.iter() {
-                    wl.push(v);
-                }
-                added = inner.len();
-            }
-        }
-    }
-
-    m.replace(0, Value::new(counter + added as i32));
-    reader.set_pc(Continuation::PDeepSeqPush.ip() as usize);
-    Step::Continue(())
-}
-
 pub fn force_result_shallow<'gc, M: Machine<'gc>>(
     m: &mut M,
     ctx: &mut impl VmRuntimeCtx,

fix-vm/src/primops/list.rs

@@ -1,396 +1,116 @@
-use fix_bytecode::Continuation;
-use fix_runtime::{
-    BytecodeReader, List, Machine, MachineExt, NixType, Slot, Step, StrictValue, Value,
-};
+use fix_error::Result;
+use fix_macros::handler;
+use fix_runtime::{List, Slot, StrictValue, Value};
 use gc_arena::Mutation;
 
-use crate::slots;
+use crate::primops::stubs::*;
 
-pub mod filter {
-    use super::*;
-
-    #[expect(
-        clippy::unreachable,
-        reason = "dispatch_cont routes only the PFilter* continuations to this function, so the fallback arm is unreachable"
-    )]
-    pub fn dispatch<'gc, M: Machine<'gc>>(
-        m: &mut M,
-        reader: &mut BytecodeReader<'_>,
-        mc: &Mutation<'gc>,
-        cont: Continuation,
-    ) -> Step {
-        use Continuation::*;
-
-        match cont {
-            PFilterForceList => force_list(m, reader, mc),
-            PFilterSetupStack => setup_stack(m, reader, mc),
-            PFilterCallPred => call_pred(m, reader, mc),
-            PFilterCheck => check(m, reader, mc),
-            _ => unreachable!(),
+#[handler(name = PFilter)]
+fn filter<'gc>(
+    mc: &Mutation<'gc>,
+    pred: Slot<Value<'gc>>,
+    list: Slot<Value<'gc>>,
+) -> Result<Value<'gc>> {
+    let list: Slot<List<'gc>> = force(list).await?;
+    if list.get().inner.borrow().is_empty() {
+        return Ok(Value::new(list.get()));
+    }
+    let idx: Slot<i32> = spill(0i32);
+    let acc: Slot<List<'gc>> = spill(List::new_gc(mc));
+    loop {
+        #[expect(
+            clippy::indexing_slicing,
+            reason = "idx is a non-negative loop counter in 0..list.len(), so it indexes the list in bounds"
+        )]
+        let keep: bool = call(&pred, list.get().inner.borrow()[idx.get() as usize]).await?;
+        if keep {
+            #[expect(
+                clippy::indexing_slicing,
+                reason = "idx is a non-negative loop counter in 0..list.len(), so it indexes the list in bounds"
+            )]
+            let elem = list.get().inner.borrow()[idx.get() as usize];
+            acc.get().unlock(mc).borrow_mut().push(elem);
         }
-    }
-
-    fn force_list<'gc, M: Machine<'gc>>(
-        m: &mut M,
-        reader: &mut BytecodeReader<'_>,
-        mc: &Mutation<'gc>,
-    ) -> Step {
-        slots! {
-            list: Value;
-            _pred: Value;
-        };
-        list.force_to_pc(m, reader, mc, Continuation::PFilterSetupStack.ip() as usize)?;
-        setup_stack(m, reader, mc)
-    }
-
-    fn setup_stack<'gc, M: Machine<'gc>>(
-        m: &mut M,
-        reader: &mut BytecodeReader<'_>,
-        mc: &Mutation<'gc>,
-    ) -> Step {
-        slots! {
-            list: List;
-            _pred: Value;
-        };
-        let list = match list.read_checked(m) {
-            Ok(list) => list,
-            Err(got) => return m.finish_type_err(NixType::List, got),
-        };
-        if list.inner.borrow().is_empty() {
-            let val = m.pop();
-            let _pred = m.pop();
-            return m.return_from_primop(val, reader);
+        if idx.get() as usize == list.get().inner.borrow().len() - 1 {
+            return Ok(Value::new(acc.get()));
         }
-        // prepare stack layout: [ pred list idx acc ]
-        m.push(Value::new(0));
-        m.push(Value::new(List::new_gc(mc)));
-        reader.set_pc(Continuation::PFilterCallPred.ip() as usize);
-        Step::Continue(())
+        idx.set(idx.get() + 1);
     }
+}
 
-    #[expect(
-        clippy::indexing_slicing,
-        clippy::cast_sign_loss,
-        reason = "idx is a non-negative loop counter in 0..list.len(), so it indexes the list in bounds"
-    )]
-    fn call_pred<'gc, M: Machine<'gc>>(
-        m: &mut M,
-        reader: &mut BytecodeReader<'_>,
-        mc: &Mutation<'gc>,
-    ) -> Step {
-        slots! {
-            _acc: List;
-            idx: i32;
-            list: List;
-            pred: Value;
-        };
-
-        let pred: Slot<StrictValue> = pred.force(m, reader, mc)?;
-        let elem = list.read(m).inner.borrow()[idx.read(m) as usize];
-        m.push(pred.read(m).relax());
-        m.call(reader, mc, elem, Continuation::PFilterCheck.ip() as usize)
+#[handler(name = PAll)]
+fn all<'gc>(
+    mc: &Mutation<'gc>,
+    pred: Slot<Value<'gc>>,
+    list: Slot<Value<'gc>>,
+) -> Result<Value<'gc>> {
+    let list: Slot<List<'gc>> = force(list).await?;
+    if list.get().inner.borrow().is_empty() {
+        return Ok(Value::new(true));
     }
-
-    #[expect(
-        clippy::indexing_slicing,
-        clippy::cast_sign_loss,
-        reason = "idx is a non-negative loop counter in 0..list.len(), so it indexes the list in bounds"
-    )]
-    pub fn check<'gc, M: Machine<'gc>>(
-        m: &mut M,
-        reader: &mut BytecodeReader<'_>,
-        mc: &Mutation<'gc>,
-    ) -> Step {
-        slots! {
-            acc: List;
-            idx: i32;
-            list: List;
-            _pred: StrictValue;
-        };
-
-        let ret = m.force_and_retry::<bool>(reader, mc)?;
-        let list = list.read(m).as_ref().inner.borrow();
-        let acc = acc.read(m);
-        let old_idx = idx.read(m);
-        if ret {
-            let mut acc = acc.unlock(mc).borrow_mut();
-            acc.push(list[old_idx as usize]);
+    let idx: Slot<i32> = spill(0i32);
+    loop {
+        #[expect(
+            clippy::indexing_slicing,
+            reason = "idx is a non-negative loop counter in 0..list.len(), so it indexes the list in bounds"
+        )]
+        let keep: bool = call(&pred, list.get().inner.borrow()[idx.get() as usize]).await?;
+        if !keep || idx.get() as usize + 1 == list.get().inner.borrow().len() {
+            return Ok(Value::new(keep));
         }
-        if old_idx as usize == list.len() - 1 {
-            let acc = m.pop();
-            m.drop_n(3);
-            return m.return_from_primop(acc, reader);
+        idx.set(idx.get() + 1);
+    }
+}
+
+#[handler(name = PAny)]
+fn any<'gc>(
+    mc: &Mutation<'gc>,
+    pred: Slot<Value<'gc>>,
+    list: Slot<Value<'gc>>,
+) -> Result<Value<'gc>> {
+    let list: Slot<List<'gc>> = force(list).await?;
+    if list.get().inner.borrow().is_empty() {
+        return Ok(Value::new(false));
+    }
+    let idx: Slot<i32> = spill(0i32);
+    loop {
+        #[expect(
+            clippy::indexing_slicing,
+            reason = "idx is a non-negative loop counter in 0..list.len(), so it indexes the list in bounds"
+        )]
+        let keep: bool = call(&pred, list.get().inner.borrow()[idx.get() as usize]).await?;
+        if keep || idx.get() as usize + 1 == list.get().inner.borrow().len() {
+            return Ok(Value::new(keep));
         }
-        idx.write(m, old_idx + 1);
-        reader.set_pc(Continuation::PFilterCallPred.ip() as usize);
-        Step::Continue(())
+        idx.set(idx.get() + 1);
     }
 }
 
-// foldl' op nul list
-//
-// Stack layouts across phases:
-//   Entry:  [op, nul, list]
-//   Empty:  [op, nul]
-//   Call1:  [op, list, idx, acc]
-//   Call2:  [op, list, idx, acc, intermediate]
-//   Update: [op, list, idx, acc, result]
-pub fn foldl_strict_entry<'gc, M: Machine<'gc>>(
-    m: &mut M,
-    reader: &mut BytecodeReader<'_>,
+#[handler(name = PFoldlStrict)]
+fn foldl_strict<'gc>(
     mc: &Mutation<'gc>,
-) -> Step {
-    m.force_slot(0, reader, mc)?;
-    let list_val = m.peek_forced(0);
-    let Some(list) = list_val.downcast::<List>() else {
-        return m.finish_type_err(NixType::List, list_val.ty());
-    };
-    if list.inner.borrow().is_empty() {
-        m.drop_n(1);
-        reader.set_pc(Continuation::PFoldlStrictEmpty.ip() as usize);
-        return Step::Continue(());
+    op: Slot<Value<'gc>>,
+    nul: Slot<Value<'gc>>,
+    list: Slot<Value<'gc>>,
+) -> Result<Value<'gc>> {
+    let list: Slot<List<'gc>> = force(list).await?;
+    if list.get().inner.borrow().is_empty() {
+        return Ok(nul.get());
     }
-    let list_val = m.pop();
-    let nul_val = m.pop();
-    m.push(list_val);
-    m.push(Value::new(0i32));
-    m.push(nul_val);
-    reader.set_pc(Continuation::PFoldlStrictCall1.ip() as usize);
-    Step::Continue(())
-}
-
-pub fn foldl_strict_empty<'gc, M: Machine<'gc>>(
-    m: &mut M,
-    reader: &mut BytecodeReader<'_>,
-    mc: &Mutation<'gc>,
-) -> Step {
-    let nul = m.force_and_retry::<StrictValue>(reader, mc)?;
-    m.drop_n(1);
-    m.return_from_primop(nul.relax(), reader)
-}
-
-pub fn foldl_strict_call1<'gc, M: Machine<'gc>>(
-    m: &mut M,
-    reader: &mut BytecodeReader<'_>,
-    mc: &Mutation<'gc>,
-) -> Step {
-    m.force_slot(3, reader, mc)?;
-    let op = m.peek_forced(3);
-    let acc = m.peek(0);
-    m.push(op.relax());
-    m.call(
-        reader,
-        mc,
-        acc,
-        Continuation::PFoldlStrictCall2.ip() as usize,
-    )
-}
-
-#[expect(
-    clippy::indexing_slicing,
-    clippy::cast_sign_loss,
-    reason = "idx is a non-negative loop counter in 0..list.len(), so it indexes the list in bounds"
-)]
-pub fn foldl_strict_call2<'gc, M: Machine<'gc>>(
-    m: &mut M,
-    reader: &mut BytecodeReader<'_>,
-    mc: &Mutation<'gc>,
-) -> Step {
-    let idx = m
-        .peek(2)
-        .downcast::<i32>()
-        .expect("stack slot must be an integer");
-    let list = m
-        .peek_forced(3)
-        .downcast::<List>()
-        .expect("stack slot must be a list");
-    let elem = list.inner.borrow()[idx as usize];
-    m.call(
-        reader,
-        mc,
-        elem,
-        Continuation::PFoldlStrictUpdate.ip() as usize,
-    )
-}
-
-#[expect(
-    clippy::cast_sign_loss,
-    reason = "idx is a non-negative loop counter in 0..list.len()"
-)]
-pub fn foldl_strict_update<'gc, M: Machine<'gc>>(
-    m: &mut M,
-    reader: &mut BytecodeReader<'_>,
-    _mc: &Mutation<'gc>,
-) -> Step {
-    let result = m.pop();
-    m.replace(0, result);
-    let idx = m
-        .peek(1)
-        .downcast::<i32>()
-        .expect("stack slot must be an integer");
-    let list = m
-        .peek_forced(2)
-        .downcast::<List>()
-        .expect("stack slot must be a list");
-    let len = list.inner.borrow().len();
-    if (idx as usize) + 1 == len {
-        let acc = m.pop();
-        m.drop_n(3);
-        return m.return_from_primop(acc, reader);
+    let idx: Slot<i32> = spill(0i32);
+    let acc = spill(nul.get());
+    loop {
+        let f = call(&op, acc.get()).await?;
+        #[expect(
+            clippy::indexing_slicing,
+            reason = "idx is a non-negative loop counter in 0..list.len(), so it indexes the list in bounds"
+        )]
+        let new_acc: StrictValue<'gc> =
+            call(&f, list.get().inner.borrow()[idx.get() as usize]).await?;
+        acc.set(new_acc.relax());
+        if idx.get() as usize + 1 == list.get().inner.borrow().len() {
+            return Ok(acc.get());
+        }
+        idx.set(idx.get() + 1);
     }
-    m.replace(1, Value::new(idx + 1));
-    reader.set_pc(Continuation::PFoldlStrictCall1.ip() as usize);
-    Step::Continue(())
-}
-
-pub fn all_entry<'gc, M: Machine<'gc>>(
-    m: &mut M,
-    reader: &mut BytecodeReader<'_>,
-    mc: &Mutation<'gc>,
-) -> Step {
-    m.force_slot(0, reader, mc)?;
-    let list = match m.peek_forced(0).expect::<List>() {
-        Ok(list) => list,
-        Err(got) => return m.finish_type_err(NixType::List, got),
-    };
-    // FIXME: force callable
-    m.force_slot(1, reader, mc)?;
-    if list.inner.borrow().is_empty() {
-        let _list = m.pop();
-        let _pred = m.pop();
-        return m.return_from_primop(Value::new(true), reader);
-    }
-    // prepare stack layout: [ pred list idx ]
-    m.push(Value::new(0));
-    reader.set_pc(Continuation::PAllCallPred.ip() as usize);
-    Step::Continue(())
-}
-
-#[expect(
-    clippy::indexing_slicing,
-    clippy::cast_sign_loss,
-    reason = "idx is a non-negative loop counter in 0..list.len(), so it indexes the list in bounds"
-)]
-pub fn all_call_pred<'gc, M: Machine<'gc>>(
-    m: &mut M,
-    reader: &mut BytecodeReader<'_>,
-    mc: &Mutation<'gc>,
-) -> Step {
-    let pred = m.peek_forced(2);
-    let idx = m
-        .peek(0)
-        .downcast::<i32>()
-        .expect("stack slot must be an integer");
-    let elem = m
-        .peek_forced(1)
-        .downcast::<List>()
-        .expect("stack slot must be a list")
-        .inner
-        .borrow()[idx as usize];
-    m.push(pred.relax());
-    m.call(reader, mc, elem, Continuation::PAllCheck.ip() as usize)
-}
-
-#[expect(
-    clippy::cast_sign_loss,
-    reason = "idx is a non-negative loop counter in 0..list.len()"
-)]
-pub fn all_check<'gc, M: Machine<'gc>>(
-    m: &mut M,
-    reader: &mut BytecodeReader<'_>,
-    mc: &Mutation<'gc>,
-) -> Step {
-    let ret = m.force_and_retry::<bool>(reader, mc)?;
-    let idx = m
-        .peek(0)
-        .downcast::<i32>()
-        .expect("stack slot must be an integer");
-    let list = m
-        .peek_forced(1)
-        .downcast::<List>()
-        .expect("stack slot must be a list");
-    let list = list.inner.borrow();
-    if idx as usize == list.len() - 1 || !ret {
-        m.drop_n(3);
-        return m.return_from_primop(Value::new(ret), reader);
-    }
-    m.replace(0, Value::new(idx + 1));
-    reader.set_pc(Continuation::PAllCallPred.ip() as usize);
-    Step::Continue(())
-}
-
-pub fn any_entry<'gc, M: Machine<'gc>>(
-    m: &mut M,
-    reader: &mut BytecodeReader<'_>,
-    mc: &Mutation<'gc>,
-) -> Step {
-    m.force_slot(0, reader, mc)?;
-    let list = match m.peek_forced(0).expect::<List>() {
-        Ok(list) => list,
-        Err(got) => return m.finish_type_err(NixType::List, got),
-    };
-    // FIXME: force callable
-    m.force_slot(1, reader, mc)?;
-    if list.inner.borrow().is_empty() {
-        let _list = m.pop();
-        let _pred = m.pop();
-        return m.return_from_primop(Value::new(false), reader);
-    }
-    // prepare stack layout: [ pred list idx ]
-    m.push(Value::new(0));
-    reader.set_pc(Continuation::PAnyCallPred.ip() as usize);
-    Step::Continue(())
-}
-
-#[expect(
-    clippy::indexing_slicing,
-    clippy::cast_sign_loss,
-    reason = "idx is a non-negative loop counter in 0..list.len(), so it indexes the list in bounds"
-)]
-pub fn any_call_pred<'gc, M: Machine<'gc>>(
-    m: &mut M,
-    reader: &mut BytecodeReader<'_>,
-    mc: &Mutation<'gc>,
-) -> Step {
-    let pred = m.peek_forced(2);
-    let idx = m
-        .peek(0)
-        .downcast::<i32>()
-        .expect("stack slot must be an integer");
-    let elem = m
-        .peek_forced(1)
-        .downcast::<List>()
-        .expect("stack slot must be a list")
-        .inner
-        .borrow()[idx as usize];
-    m.push(pred.relax());
-    m.call(reader, mc, elem, Continuation::PAnyCheck.ip() as usize)
-}
-
-#[expect(
-    clippy::cast_sign_loss,
-    reason = "idx is a non-negative loop counter in 0..list.len()"
-)]
-pub fn any_check<'gc, M: Machine<'gc>>(
-    m: &mut M,
-    reader: &mut BytecodeReader<'_>,
-    mc: &Mutation<'gc>,
-) -> Step {
-    let ret = m.force_and_retry::<bool>(reader, mc)?;
-    let idx = m
-        .peek(0)
-        .downcast::<i32>()
-        .expect("stack slot must be an integer");
-    let list = m
-        .peek_forced(1)
-        .downcast::<List>()
-        .expect("stack slot must be a list");
-    let list = list.inner.borrow();
-    if idx as usize == list.len() - 1 || ret {
-        m.drop_n(3);
-        return m.return_from_primop(Value::new(ret), reader);
-    }
-    m.replace(0, Value::new(idx + 1));
-    reader.set_pc(Continuation::PAnyCallPred.ip() as usize);
-    Step::Continue(())
 }

fix-vm/src/primops/mod.rs

@@ -5,6 +5,7 @@ mod eq;
 mod io;
 mod list;
 mod path;
+mod stubs;
 
 pub use context::*;
 pub use control::*;
@@ -18,27 +19,6 @@ pub use io::*;
 pub use list::*;
 pub use path::*;
 
-#[macro_export]
-macro_rules! slots {
-    { $($ident:ident : $ty:ty);* $(;)? } => {
-        slots! { @acc [ 0 ] $($ident : $ty;)* }
-    };
-    /* { $($ident:ident : $ty:ty);* $(;)? } => {
-        slots! { @reverse [ $($ident : $ty;)* ] [] }
-    };
-    { @reverse [ $ident:ident : $ty:ty; $($remain:tt)* ] [ $($acc:tt)* ] } => {
-        slots! { @reverse [ $($remain)* ] [ $ident : $ty; $($acc)* ] }
-    };
-    { @reverse [] [ $($rev_id:ident : $rev_ty:ty;)* ] } => {
-        slots! { @acc [ 0 ] $($rev_id : $rev_ty;)* }
-    }; */
-    { @acc [ $($acc:tt)* ] $ident:ident : $ty:ty; $($remain:tt)* } => {
-        let $ident : Slot<$ty> = Slot::new($($acc)*);
-        slots! { @acc [ $($acc)* + 1 ] $($remain)* }
-    };
-    { @acc [ $($acc:tt)* ] } => {};
-}
-
 pub fn dispatch_cont<'gc, M: Machine<'gc>>(
     m: &mut M,
     ctx: &mut impl VmRuntimeCtx,
@@ -53,28 +33,18 @@ pub fn dispatch_cont<'gc, M: Machine<'gc>>(
     match cont {
         PAbort => abort(m, ctx, reader, mc),
 
-        PAll => all_entry(m, reader, mc),
-        PAllCallPred => all_call_pred(m, reader, mc),
-        PAllCheck => all_check(m, reader, mc),
-
-        PAny => any_entry(m, reader, mc),
-        PAnyCallPred => any_call_pred(m, reader, mc),
-        PAnyCheck => any_check(m, reader, mc),
-
-        PDeepSeq => deep_seq_force_top(m, reader, mc),
-        PDeepSeqPush => deep_seq_push(m, reader, mc),
-        PDeepSeqLoop => deep_seq_loop(m, reader, mc),
-        PSeq => seq(m, reader, mc),
-
-        PFilterForceList | PFilterSetupStack | PFilterCallPred | PFilterCheck => {
-            filter::dispatch(m, reader, mc, cont)
+        PAll0 | PAll1 | PAll2 | PAll3 => all(m, reader, mc, cont),
+        PAny0 | PAny1 | PAny2 | PAny3 => any(m, reader, mc, cont),
+        PDeepSeq0 | PDeepSeq1 | PDeepSeq2 | PDeepSeq3 | PDeepSeq4 | PDeepSeq5 => {
+            deep_seq(m, reader, mc, cont)
         }
+        PSeq0 | PSeq1 => seq(m, reader, mc, cont),
 
-        PFoldlStrict => foldl_strict_entry(m, reader, mc),
-        PFoldlStrictEmpty => foldl_strict_empty(m, reader, mc),
-        PFoldlStrictCall1 => foldl_strict_call1(m, reader, mc),
-        PFoldlStrictCall2 => foldl_strict_call2(m, reader, mc),
-        PFoldlStrictUpdate => foldl_strict_update(m, reader, mc),
+        PFilter0 | PFilter1 | PFilter2 | PFilter3 | PFilter4 => filter(m, reader, mc, cont),
+
+        PFoldlStrict0 | PFoldlStrict1 | PFoldlStrict2 | PFoldlStrict3 | PFoldlStrict4 | PFoldlStrict5 => {
+            foldl_strict(m, reader, mc, cont)
+        }
 
         ForceResultShallow => force_result_shallow(m, ctx, reader, mc),
         ForceResultShallowPush => force_result_shallow_push(m, ctx, reader, mc),

fix-vm/src/primops/stubs.rs

@@ -0,0 +1,9 @@
+//! Fallback definitions for the `#[primop]` surface syntax.
+//!
+//! `force`, `call`, and `spill` are recognized and rewritten by the
+//! `#[primop]` proc macro, so compiled code never calls them. They exist only
+//! so the un-expanded source name-resolves in tooling that does not run the
+//! macro (e.g. rust-analyzer while the macro crate is being rebuilt). Calling
+//! one for real is impossible: they never return.
+
+pub use crate::__macro_support::{call, force, spill};