Initial fixed-length list implementation

crates/c/src/lib.rs

@@ -1825,6 +1825,16 @@ impl<'a> wit_bindgen_core::AnonymousTypeGenerator<'a> for InterfaceGenerator<'a>
     fn anonymous_type_type(&mut self, _id: TypeId, _ty: &Type, _docs: &Docs) {
         todo!("print_anonymous_type for type");
     }
+
+    fn anonymous_type_fixed_length_list(
+        &mut self,
+        _id: TypeId,
+        _ty: &Type,
+        _size: u32,
+        _docs: &Docs,
+    ) {
+        todo!("print_anonymous_type for fixed length list");
+    }
 }
 
 pub enum CTypeNameInfo<'a> {

crates/core/src/abi.rs

@@ -309,6 +309,39 @@ def_instruction! {
             ty: TypeId,
         } : [2] => [1],
 
+        /// Pops all fields for a fixed list off the stack and then composes them
+        /// into an array.
+        FixedLengthListLift {
+            element: &'a Type,
+            size: u32,
+            id: TypeId,
+        } : [*size as usize] => [1],
+
+        /// Pops an array off the stack, decomposes the elements and then pushes them onto the stack.
+        FixedLengthListLower {
+            element: &'a Type,
+            size: u32,
+            id: TypeId,
+        } : [1] => [*size as usize],
+
+        /// Pops an array and an address off the stack, passes each element to a block storing it
+        FixedLengthListLowerToMemory {
+            element: &'a Type,
+            size: u32,
+            id: TypeId,
+        } : [2] => [0],
+
+        /// Pops base address, pushes an array
+        ///
+        /// This will also pop a block from the block stack which is how to
+        /// read each individual element from the list.
+        FixedLengthListLiftFromMemory {
+            element: &'a Type,
+            size: u32,
+            id: TypeId,
+        } : [1] => [1],
+
+
         /// Pushes an operand onto the stack representing the list item from
         /// each iteration of the list.
         ///
@@ -840,7 +873,7 @@ fn needs_deallocate(resolve: &Resolve, ty: &Type, what: Deallocate) -> bool {
             TypeDefKind::Flags(_) | TypeDefKind::Enum(_) => false,
             TypeDefKind::Future(_) | TypeDefKind::Stream(_) => what.handles(),
             TypeDefKind::Unknown => unreachable!(),
-            TypeDefKind::FixedSizeList(..) => todo!(),
+            TypeDefKind::FixedSizeList(t, _) => needs_deallocate(resolve, t, what),
             TypeDefKind::Map(..) => todo!(),
         },
 
@@ -1564,7 +1597,21 @@ impl<'a, B: Bindgen> Generator<'a, B> {
                     });
                 }
                 TypeDefKind::Unknown => unreachable!(),
-                TypeDefKind::FixedSizeList(..) => todo!(),
+                TypeDefKind::FixedSizeList(ty, size) => {
+                    self.emit(&FixedLengthListLower {
+                        element: ty,
+                        size: *size,
+                        id,
+                    });
+                    let mut values = self
+                        .stack
+                        .drain(self.stack.len() - (*size as usize)..)
+                        .collect::<Vec<_>>();
+                    for value in values.drain(..) {
+                        self.stack.push(value);
+                        self.lower(ty);
+                    }
+                }
                 TypeDefKind::Map(..) => todo!(),
             },
         }
@@ -1748,7 +1795,24 @@ impl<'a, B: Bindgen> Generator<'a, B> {
                     });
                 }
                 TypeDefKind::Unknown => unreachable!(),
-                TypeDefKind::FixedSizeList(..) => todo!(),
+                TypeDefKind::FixedSizeList(ty, size) => {
+                    let temp = flat_types(self.resolve, ty, None).unwrap();
+                    let flat_per_elem = temp.to_vec().len();
+                    let flatsize = flat_per_elem * (*size as usize);
+                    let mut lowered_args = self
+                        .stack
+                        .drain(self.stack.len() - flatsize..)
+                        .collect::<Vec<_>>();
+                    for _ in 0..*size {
+                        self.stack.extend(lowered_args.drain(..flat_per_elem));
+                        self.lift(ty);
+                    }
+                    self.emit(&FixedLengthListLift {
+                        element: ty,
+                        size: *size,
+                        id,
+                    });
+                }
                 TypeDefKind::Map(..) => todo!(),
             },
         }
@@ -1931,7 +1995,21 @@ impl<'a, B: Bindgen> Generator<'a, B> {
                 }
 
                 TypeDefKind::Unknown => unreachable!(),
-                TypeDefKind::FixedSizeList(..) => todo!(),
+                TypeDefKind::FixedSizeList(element, size) => {
+                    // resembles write_list_to_memory
+                    self.push_block();
+                    self.emit(&IterElem { element });
+                    self.emit(&IterBasePointer);
+                    let elem_addr = self.stack.pop().unwrap();
+                    self.write_to_memory(element, elem_addr, offset);
+                    self.finish_block(0);
+                    self.stack.push(addr);
+                    self.emit(&FixedLengthListLowerToMemory {
+                        element,
+                        size: *size,
+                        id,
+                    });
+                }
                 TypeDefKind::Map(..) => todo!(),
             },
         }
@@ -2119,7 +2197,19 @@ impl<'a, B: Bindgen> Generator<'a, B> {
                 }
 
                 TypeDefKind::Unknown => unreachable!(),
-                TypeDefKind::FixedSizeList(..) => todo!(),
+                TypeDefKind::FixedSizeList(ty, size) => {
+                    self.push_block();
+                    self.emit(&IterBasePointer);
+                    let elemaddr = self.stack.pop().unwrap();
+                    self.read_from_memory(ty, elemaddr, offset);
+                    self.finish_block(1);
+                    self.stack.push(addr.clone());
+                    self.emit(&FixedLengthListLiftFromMemory {
+                        element: ty,
+                        size: *size,
+                        id,
+                    });
+                }
                 TypeDefKind::Map(..) => todo!(),
             },
         }
@@ -2430,7 +2520,7 @@ impl<'a, B: Bindgen> Generator<'a, B> {
                 TypeDefKind::Future(_) => unreachable!(),
                 TypeDefKind::Stream(_) => unreachable!(),
                 TypeDefKind::Unknown => unreachable!(),
-                TypeDefKind::FixedSizeList(..) => todo!(),
+                TypeDefKind::FixedSizeList(_, _) => {}
                 TypeDefKind::Map(..) => todo!(),
             },
         }

crates/core/src/lib.rs

@@ -196,6 +196,7 @@ pub trait AnonymousTypeGenerator<'a> {
     fn anonymous_type_option(&mut self, id: TypeId, ty: &Type, docs: &Docs);
     fn anonymous_type_result(&mut self, id: TypeId, ty: &Result_, docs: &Docs);
     fn anonymous_type_list(&mut self, id: TypeId, ty: &Type, docs: &Docs);
+    fn anonymous_type_fixed_length_list(&mut self, id: TypeId, ty: &Type, size: u32, docs: &Docs);
     fn anonymous_type_future(&mut self, id: TypeId, ty: &Option<Type>, docs: &Docs);
     fn anonymous_type_stream(&mut self, id: TypeId, ty: &Option<Type>, docs: &Docs);
     fn anonymous_type_type(&mut self, id: TypeId, ty: &Type, docs: &Docs);
@@ -218,7 +219,9 @@ pub trait AnonymousTypeGenerator<'a> {
             TypeDefKind::Future(f) => self.anonymous_type_future(id, f, &ty.docs),
             TypeDefKind::Stream(s) => self.anonymous_type_stream(id, s, &ty.docs),
             TypeDefKind::Handle(handle) => self.anonymous_type_handle(id, handle, &ty.docs),
-            TypeDefKind::FixedSizeList(..) => todo!(),
+            TypeDefKind::FixedSizeList(t, size) => {
+                self.anonymous_type_fixed_length_list(id, t, *size, &ty.docs)
+            }
             TypeDefKind::Map(..) => todo!(),
             TypeDefKind::Unknown => unreachable!(),
         }

crates/core/src/types.rs

@@ -203,7 +203,9 @@ impl Types {
                 // should use the same ownership semantics as `own<T>`
                 info.has_own_handle = true;
             }
-            TypeDefKind::FixedSizeList(..) => todo!(),
+            TypeDefKind::FixedSizeList(ty, _) => {
+                info = self.type_info(resolve, ty);
+            }
             TypeDefKind::Map(..) => todo!(),
             TypeDefKind::Unknown => unreachable!(),
         }

crates/cpp/src/lib.rs

@@ -74,6 +74,7 @@ struct Includes {
     // needs wit types
     needs_wit: bool,
     needs_memory: bool,
+    needs_array: bool,
 }
 
 #[derive(Default)]
@@ -428,6 +429,9 @@ impl Cpp {
         if self.dependencies.needs_memory {
             self.include("<memory>");
         }
+        if self.dependencies.needs_array {
+            self.include("<array>");
+        }
         if self.dependencies.needs_bit {
             self.include("<bit>");
         }
@@ -1698,7 +1702,13 @@ impl CppInterfaceGenerator<'_> {
                 TypeDefKind::Future(_) => todo!(),
                 TypeDefKind::Stream(_) => todo!(),
                 TypeDefKind::Type(ty) => self.type_name(ty, from_namespace, flavor),
-                TypeDefKind::FixedSizeList(_, _) => todo!(),
+                TypeDefKind::FixedSizeList(ty, size) => {
+                    self.r#gen.dependencies.needs_array = true;
+                    format!(
+                        "std::array<{}, {size}>",
+                        self.type_name(ty, from_namespace, flavor)
+                    )
+                }
                 TypeDefKind::Map(_, _) => todo!(),
                 TypeDefKind::Unknown => todo!(),
             },
@@ -2532,7 +2542,7 @@ impl<'a, 'b> Bindgen for FunctionBindgen<'a, 'b> {
                     "auto base = {ptr} + i * {size};\n",
                     size = size.format(POINTER_SIZE_EXPRESSION)
                 ));
-                self.push_str(&format!("auto&& IterElem = {val}[i];\n"));
+                self.push_str(&format!("auto&& iter_elem = {val}[i];\n"));
                 self.push_str(&format!("{}\n", body.0));
                 self.push_str("}\n");
                 if realloc.is_none() {
@@ -2648,7 +2658,94 @@ impl<'a, 'b> Bindgen for FunctionBindgen<'a, 'b> {
                     results.push(move_if_necessary(&result));
                 }
             }
-            abi::Instruction::IterElem { .. } => results.push("IterElem".to_string()),
+            abi::Instruction::FixedLengthListLift {
+                element,
+                size,
+                id: _,
+            } => {
+                let tmp = self.tmp();
+                let result = format!("result{tmp}");
+                let typename = self
+                    .r#gen
+                    .type_name(element, &self.namespace, Flavor::InStruct);
+                self.push_str(&format!("std::array<{typename}, {size}> {result} = {{",));
+                for a in operands.drain(0..(*size as usize)) {
+                    self.push_str(&a);
+                    self.push_str(", ");
+                }
+                self.push_str("};\n");
+                results.push(result);
+            }
+            abi::Instruction::FixedLengthListLiftFromMemory {
+                element,
+                size: elemsize,
+                id: _,
+            } => {
+                let body = self.blocks.pop().unwrap();
+                let tmp = self.tmp();
+                let vec = format!("array{tmp}");
+                let source = operands[0].clone();
+                let size = self.r#gen.sizes.size(element);
+                let size_str = size.format(POINTER_SIZE_EXPRESSION);
+                let typename = self
+                    .r#gen
+                    .type_name(element, &self.namespace, Flavor::InStruct);
+                let ptr_type = self.r#gen.r#gen.opts.ptr_type();
+                self.push_str(&format!("std::array<{typename}, {elemsize}> {vec};\n"));
+                self.push_str(&format!(
+                    "{{
+                    {ptr_type} outer_base = {source};\n"
+                ));
+                let source: String = "outer_base".into();
+                // let vec: String = "outer_vec".into();
+                self.push_str(&format!("for (unsigned i = 0; i<{elemsize}; ++i) {{\n",));
+                self.push_str(&format!("{ptr_type} base = {source} + i * {size_str};\n"));
+                self.push_str(&body.0);
+                self.push_str(&format!("{vec}[i] = {};", body.1[0]));
+                self.push_str("\n}\n}\n");
+                results.push(vec);
+            }
+            abi::Instruction::FixedLengthListLower {
+                element: _,
+                size,
+                id: _,
+            } => {
+                for i in 0..(*size as usize) {
+                    results.push(format!("{}[{i}]", operands[0]));
+                }
+            }
+            abi::Instruction::FixedLengthListLowerToMemory {
+                element,
+                size: elemsize,
+                id: _,
+            } => {
+                let body = self.blocks.pop().unwrap();
+                let vec = operands[0].clone();
+                let target = operands[1].clone();
+                let size = self.r#gen.sizes.size(element);
+                let size_str = size.format(POINTER_SIZE_EXPRESSION);
+                let typename = self
+                    .r#gen
+                    .type_name(element, &self.namespace, Flavor::InStruct);
+                let ptr_type = self.r#gen.r#gen.opts.ptr_type();
+                self.push_str(&format!(
+                    "{{
+                    {ptr_type} outer_base = {target};\n"
+                ));
+                let target: String = "outer_base".into();
+                self.push_str(&format!(
+                    "std::array<{typename}, {elemsize}>& outer_vec = {vec};\n"
+                ));
+                let vec: String = "outer_vec".into();
+                self.push_str(&format!("for (unsigned i = 0; i<{vec}.size(); ++i) {{\n",));
+                self.push_str(&format!(
+                    "{ptr_type} base = {target} + i * {size_str};
+                     {typename}& iter_elem = {vec}[i];\n"
+                ));
+                self.push_str(&body.0);
+                self.push_str("\n}\n}\n");
+            }
+            abi::Instruction::IterElem { .. } => results.push("iter_elem".to_string()),
             abi::Instruction::IterBasePointer => results.push("base".to_string()),
             abi::Instruction::RecordLower { record, .. } => {
                 let op = &operands[0];
@@ -3254,7 +3351,7 @@ impl<'a, 'b> Bindgen for FunctionBindgen<'a, 'b> {
                             self.src.push_str(">(");
                         }
                         if *amt == 1 {
-                            if operands[0].starts_with("std::move(") {
+                            if operands[0].starts_with("std::move(") && !operands[0].contains('.') {
                                 // remove the std::move due to return value optimization (and complex rules about when std::move harms)
                                 self.src.push_str(&operands[0][9..]);
                             } else {

crates/csharp/src/function.rs

@@ -1445,6 +1445,10 @@ impl Bindgen for FunctionBindgen<'_, '_> {
             | Instruction::ErrorContextLower { .. }
             | Instruction::ErrorContextLift { .. }
             | Instruction::DropHandle { .. }
+            | Instruction::FixedLengthListLift { .. }
+            | Instruction::FixedLengthListLower { .. }
+            | Instruction::FixedLengthListLowerToMemory { .. }
+            | Instruction::FixedLengthListLiftFromMemory { .. }
             => {
                 dbg!(inst);
                 todo!()

crates/moonbit/src/lib.rs

@@ -2696,6 +2696,10 @@ impl Bindgen for FunctionBindgen<'_, '_> {
             Instruction::ErrorContextLower { .. }
             | Instruction::ErrorContextLift { .. }
             | Instruction::DropHandle { .. } => todo!(),
+            Instruction::FixedLengthListLift { .. } => todo!(),
+            Instruction::FixedLengthListLower { .. } => todo!(),
+            Instruction::FixedLengthListLowerToMemory { .. } => todo!(),
+            Instruction::FixedLengthListLiftFromMemory { .. } => todo!(),
         }
     }