refactor(memory): simplify and rename TypeLayout trait

crates/mun_memory/src/gc.rs

@@ -2,7 +2,7 @@ mod mark_sweep;
 mod ptr;
 mod root_ptr;
 
-use crate::TypeLayout;
+use crate::TypeMemory;
 use std::marker::PhantomData;
 
 pub use mark_sweep::MarkSweep;
@@ -24,7 +24,7 @@ pub trait TypeTrace: Send + Sync {
 }
 
 /// An object that can be used to allocate and collect memory.
-pub trait GcRuntime<T: TypeLayout + TypeTrace>: Send + Sync {
+pub trait GcRuntime<T: TypeMemory + TypeTrace>: Send + Sync {
     /// Allocates an object of the given type returning a GcPtr
     fn alloc(&self, ty: T) -> GcPtr;
 

crates/mun_memory/src/gc/mark_sweep.rs

@@ -2,7 +2,7 @@ use crate::{
     cast,
     gc::{Event, GcPtr, GcRuntime, Observer, RawGcPtr, Stats, TypeTrace},
     mapping::{self, FieldMapping, MemoryMapper},
-    TypeDesc, TypeLayout,
+    TypeDesc, TypeMemory,
 };
 use mapping::{Conversion, Mapping};
 use parking_lot::RwLock;
@@ -18,7 +18,7 @@ use std::{
 #[derive(Debug)]
 pub struct MarkSweep<T, O>
 where
-    T: TypeLayout + TypeTrace + Clone,
+    T: TypeMemory + TypeTrace + Clone,
     O: Observer<Event = Event>,
 {
     objects: RwLock<HashMap<GcPtr, Pin<Box<ObjectInfo<T>>>>>,
@@ -28,7 +28,7 @@ where
 
 impl<T, O> Default for MarkSweep<T, O>
 where
-    T: TypeLayout + TypeTrace + Clone,
+    T: TypeMemory + TypeTrace + Clone,
     O: Observer<Event = Event> + Default,
 {
     fn default() -> Self {
@@ -42,7 +42,7 @@ where
 
 impl<T, O> MarkSweep<T, O>
 where
-    T: TypeLayout + TypeTrace + Clone,
+    T: TypeMemory + TypeTrace + Clone,
     O: Observer<Event = Event>,
 {
     /// Creates a `MarkSweep` memory collector with the specified `Observer`.
@@ -70,7 +70,7 @@ where
     }
 }
 
-fn alloc_obj<T: Clone + TypeLayout + TypeTrace>(ty: T) -> Pin<Box<ObjectInfo<T>>> {
+fn alloc_obj<T: Clone + TypeMemory + TypeTrace>(ty: T) -> Pin<Box<ObjectInfo<T>>> {
     let ptr = unsafe { std::alloc::alloc(ty.layout()) };
     Box::pin(ObjectInfo {
         ptr,
@@ -82,7 +82,7 @@ fn alloc_obj<T: Clone + TypeLayout + TypeTrace>(ty: T) -> Pin<Box<ObjectInfo<T>>
 
 impl<T, O> GcRuntime<T> for MarkSweep<T, O>
 where
-    T: TypeLayout + TypeTrace + Clone,
+    T: TypeMemory + TypeTrace + Clone,
     O: Observer<Event = Event>,
 {
     fn alloc(&self, ty: T) -> GcPtr {
@@ -135,7 +135,7 @@ where
 
 impl<T, O> MarkSweep<T, O>
 where
-    T: TypeLayout + TypeTrace + Clone,
+    T: TypeMemory + TypeTrace + Clone,
     O: Observer<Event = Event>,
 {
     /// Collects all memory that is no longer referenced by rooted objects. Returns `true` if memory
@@ -207,7 +207,7 @@ where
 
 impl<T, O> MemoryMapper<T> for MarkSweep<T, O>
 where
-    T: TypeDesc + TypeLayout + TypeTrace + Clone + Eq + Hash,
+    T: TypeDesc + TypeMemory + TypeTrace + Clone + Eq + Hash,
     O: Observer<Event = Event>,
 {
     fn map_memory(&self, mapping: Mapping<T, T>) -> Vec<GcPtr> {
@@ -292,7 +292,7 @@ where
             src: NonNull<u8>,
             dest: NonNull<u8>,
         ) where
-            T: TypeDesc + TypeLayout + TypeTrace + Clone + Eq + Hash,
+            T: TypeDesc + TypeMemory + TypeTrace + Clone + Eq + Hash,
             O: Observer<Event = Event>,
         {
             for FieldMapping {
@@ -315,10 +315,8 @@ where
                             src as *mut u8
                         };
 
-                        if let Some(old_memory_kind) = old_ty.memory_kind() {
-                            let new_memory_kind = new_ty.memory_kind().expect(
-                                    "We are dealing with a struct and we do not directly compare fundamental types and struct type, so its counterpart must also be a struct.",
-                                );
+                        if old_ty.group().is_struct() {
+                            debug_assert!(new_ty.group().is_struct());
 
                             // When the name is the same, we are dealing with the same struct,
                             // but different internals
@@ -327,8 +325,8 @@ where
                             // If the same struct changed, there must also be a conversion
                             let conversion = conversions.get(old_ty);
 
-                            if old_memory_kind == abi::StructMemoryKind::Value {
-                                if new_memory_kind == abi::StructMemoryKind::Value {
+                            if old_ty.is_stack_allocated() {
+                                if new_ty.is_stack_allocated() {
                                     // struct(value) -> struct(value)
                                     if is_same_struct {
                                         // Map in-memory struct to in-memory struct
@@ -378,7 +376,7 @@ where
 
                                     new_allocations.push(object);
                                 }
-                            } else if new_memory_kind == abi::StructMemoryKind::GC {
+                            } else if !new_ty.is_stack_allocated() {
                                 // struct(gc) -> struct(gc)
                                 let field_src = field_src.cast::<GcPtr>();
                                 let field_dest = field_dest.cast::<GcPtr>();
@@ -472,7 +470,7 @@ where
                         };
                     }
                     mapping::Action::Insert => {
-                        if let Some(abi::StructMemoryKind::GC) = new_ty.memory_kind() {
+                        if !new_ty.is_stack_allocated() {
                             let object = alloc_obj(new_ty.clone());
 
                             // We want to return a pointer to the `ObjectInfo`, to be used as
@@ -516,36 +514,36 @@ enum Color {
 /// meta information.
 #[derive(Debug)]
 #[repr(C)]
-struct ObjectInfo<T: TypeLayout + TypeTrace + Clone> {
+struct ObjectInfo<T: TypeMemory + TypeTrace + Clone> {
     pub ptr: *mut u8,
     pub roots: u32,
     pub color: Color,
     pub ty: T,
 }
 
 /// An `ObjectInfo` is thread-safe.
-unsafe impl<T: TypeLayout + TypeTrace + Clone> Send for ObjectInfo<T> {}
-unsafe impl<T: TypeLayout + TypeTrace + Clone> Sync for ObjectInfo<T> {}
+unsafe impl<T: TypeMemory + TypeTrace + Clone> Send for ObjectInfo<T> {}
+unsafe impl<T: TypeMemory + TypeTrace + Clone> Sync for ObjectInfo<T> {}
 
-impl<T: TypeLayout + TypeTrace + Clone> Into<*const ObjectInfo<T>> for GcPtr {
+impl<T: TypeMemory + TypeTrace + Clone> Into<*const ObjectInfo<T>> for GcPtr {
     fn into(self) -> *const ObjectInfo<T> {
         self.as_ptr() as *const ObjectInfo<T>
     }
 }
 
-impl<T: TypeLayout + TypeTrace + Clone> Into<*mut ObjectInfo<T>> for GcPtr {
+impl<T: TypeMemory + TypeTrace + Clone> Into<*mut ObjectInfo<T>> for GcPtr {
     fn into(self) -> *mut ObjectInfo<T> {
         self.as_ptr() as *mut ObjectInfo<T>
     }
 }
 
-impl<T: TypeLayout + TypeTrace + Clone> Into<GcPtr> for *const ObjectInfo<T> {
+impl<T: TypeMemory + TypeTrace + Clone> Into<GcPtr> for *const ObjectInfo<T> {
     fn into(self) -> GcPtr {
         (self as RawGcPtr).into()
     }
 }
 
-impl<T: TypeLayout + TypeTrace + Clone> Into<GcPtr> for *mut ObjectInfo<T> {
+impl<T: TypeMemory + TypeTrace + Clone> Into<GcPtr> for *mut ObjectInfo<T> {
     fn into(self) -> GcPtr {
         (self as RawGcPtr).into()
     }

crates/mun_memory/src/gc/root_ptr.rs

@@ -1,18 +1,18 @@
 use crate::{
     gc::{GcPtr, GcRuntime, HasIndirectionPtr, TypeTrace},
-    TypeLayout,
+    TypeMemory,
 };
 use std::marker::PhantomData;
 use std::sync::{Arc, Weak};
 
 /// A `GcPtr` that automatically roots and unroots its internal `GcPtr`.
-pub struct GcRootPtr<T: TypeLayout + TypeTrace, G: GcRuntime<T>> {
+pub struct GcRootPtr<T: TypeMemory + TypeTrace, G: GcRuntime<T>> {
     handle: GcPtr,
     runtime: Weak<G>,
     ty: PhantomData<T>,
 }
 
-impl<T: TypeLayout + TypeTrace, G: GcRuntime<T>> Clone for GcRootPtr<T, G> {
+impl<T: TypeMemory + TypeTrace, G: GcRuntime<T>> Clone for GcRootPtr<T, G> {
     fn clone(&self) -> Self {
         if let Some(runtime) = self.runtime.upgrade() {
             runtime.root(self.handle)
@@ -25,7 +25,7 @@ impl<T: TypeLayout + TypeTrace, G: GcRuntime<T>> Clone for GcRootPtr<T, G> {
     }
 }
 
-impl<T: TypeLayout + TypeTrace, G: GcRuntime<T>> GcRootPtr<T, G> {
+impl<T: TypeMemory + TypeTrace, G: GcRuntime<T>> GcRootPtr<T, G> {
     /// Constructs a new GCRootHandle from a runtime and a handle
     pub fn new(runtime: &Arc<G>, handle: GcPtr) -> Self {
         runtime.root(handle);
@@ -47,21 +47,21 @@ impl<T: TypeLayout + TypeTrace, G: GcRuntime<T>> GcRootPtr<T, G> {
     }
 }
 
-impl<T: TypeLayout + TypeTrace, G: GcRuntime<T>> Into<GcPtr> for GcRootPtr<T, G> {
+impl<T: TypeMemory + TypeTrace, G: GcRuntime<T>> Into<GcPtr> for GcRootPtr<T, G> {
     fn into(self) -> GcPtr {
         self.handle
     }
 }
 
-impl<T: TypeLayout + TypeTrace, G: GcRuntime<T>> Drop for GcRootPtr<T, G> {
+impl<T: TypeMemory + TypeTrace, G: GcRuntime<T>> Drop for GcRootPtr<T, G> {
     fn drop(&mut self) {
         if let Some(runtime) = self.runtime.upgrade() {
             runtime.unroot(self.handle)
         }
     }
 }
 
-impl<T: TypeLayout + TypeTrace, G: GcRuntime<T>> HasIndirectionPtr for GcRootPtr<T, G> {
+impl<T: TypeMemory + TypeTrace, G: GcRuntime<T>> HasIndirectionPtr for GcRootPtr<T, G> {
     unsafe fn deref<R: Sized>(&self) -> *const R {
         self.handle.deref()
     }

crates/mun_memory/src/lib.rs

@@ -20,12 +20,12 @@ pub trait TypeDesc: Send + Sync {
     fn group(&self) -> abi::TypeGroup;
 }
 
-/// A trait used to obtain a type's memory layout.
-pub trait TypeLayout: Send + Sync {
+/// A trait used to obtain a type's memory description.
+pub trait TypeMemory: Send + Sync {
     /// Returns the memory layout of this type.
     fn layout(&self) -> Layout;
-    /// Returns the memory kind of this type, if it is a struct.
-    fn memory_kind(&self) -> Option<abi::StructMemoryKind>;
+    /// Returns whether the memory is stack-allocated.
+    fn is_stack_allocated(&self) -> bool;
 }
 
 /// A trait used to obtain a type's fields.

crates/mun_memory/src/mapping.rs

@@ -1,43 +1,43 @@
 use crate::{
     diff::{diff, Diff, FieldDiff, FieldEditKind},
     gc::GcPtr,
-    TypeDesc, TypeFields, TypeLayout,
+    TypeDesc, TypeFields, TypeMemory,
 };
 use std::{
     collections::{HashMap, HashSet},
     hash::Hash,
 };
 
-pub struct Mapping<T: Eq + Hash, U: TypeDesc + TypeLayout> {
+pub struct Mapping<T: Eq + Hash, U: TypeDesc + TypeMemory> {
     pub deletions: HashSet<T>,
     pub conversions: HashMap<T, Conversion<U>>,
     pub identical: Vec<(T, T)>,
 }
 
-pub struct Conversion<T: TypeDesc + TypeLayout> {
+pub struct Conversion<T: TypeDesc + TypeMemory> {
     pub field_mapping: Vec<FieldMapping<T>>,
     pub new_ty: T,
 }
 
 /// Description of the mapping of a single field. When stored together with the new index, this
 /// provides all information necessary for a mapping function.
-pub struct FieldMapping<T: TypeDesc + TypeLayout> {
+pub struct FieldMapping<T: TypeDesc + TypeMemory> {
     pub new_ty: T,
     pub new_offset: usize,
     pub action: Action<T>,
 }
 
 /// The `Action` to take when mapping memory from A to B.
 #[derive(Eq, PartialEq)]
-pub enum Action<T: TypeDesc + TypeLayout> {
+pub enum Action<T: TypeDesc + TypeMemory> {
     Cast { old_offset: usize, old_ty: T },
     Copy { old_offset: usize },
     Insert,
 }
 
 impl<T> Mapping<T, T>
 where
-    T: TypeDesc + TypeFields<T> + TypeLayout + Copy + Eq + Hash,
+    T: TypeDesc + TypeFields<T> + TypeMemory + Copy + Eq + Hash,
 {
     ///
     pub fn new(old: &[T], new: &[T]) -> Self {
@@ -83,7 +83,7 @@ where
         let mut new_candidates: HashSet<T> = new
             .iter()
             // Filter non-struct types
-            .filter(|ty| ty.memory_kind().is_some())
+            .filter(|ty| ty.group().is_struct())
             // Filter inserted structs
             .filter(|ty| !insertions.contains(*ty))
             .cloned()
@@ -92,7 +92,7 @@ where
         let mut old_candidates: HashSet<T> = old
             .iter()
             // Filter non-struct types
-            .filter(|ty| ty.memory_kind().is_some())
+            .filter(|ty| ty.group().is_struct())
             // Filter deleted structs
             .filter(|ty| !deletions.contains(*ty))
             // Filter edited types
@@ -139,7 +139,7 @@ where
 /// # Safety
 ///
 /// Expects the `diff` to be based on `old_ty` and `new_ty`. If not, it causes undefined behavior.
-pub unsafe fn field_mapping<T: Clone + TypeDesc + TypeFields<T> + TypeLayout>(
+pub unsafe fn field_mapping<T: Clone + TypeDesc + TypeFields<T> + TypeMemory>(
     old_ty: T,
     new_ty: T,
     diff: &[FieldDiff],
@@ -265,7 +265,7 @@ pub unsafe fn field_mapping<T: Clone + TypeDesc + TypeFields<T> + TypeLayout>(
 }
 
 /// A trait used to map allocated memory using type differences.
-pub trait MemoryMapper<T: Eq + Hash + TypeDesc + TypeLayout> {
+pub trait MemoryMapper<T: Eq + Hash + TypeDesc + TypeMemory> {
     /// Maps its allocated memory using the provided `mapping`.
     ///
     /// A `Vec<GcPtr>` is returned containing all objects of types that were deleted. The

crates/mun_memory/tests/diff/util.rs

@@ -1,7 +1,7 @@
 #![allow(dead_code)]
 use mun_memory::{
     diff::{myers, Diff, FieldDiff, FieldEditKind},
-    TypeDesc, TypeFields, TypeLayout,
+    TypeDesc, TypeFields, TypeMemory,
 };
 use std::alloc::Layout;
 
@@ -106,14 +106,14 @@ impl TypeDesc for &TypeInfo {
     }
 }
 
-impl TypeLayout for &TypeInfo {
+impl TypeMemory for &TypeInfo {
     fn layout(&self) -> Layout {
         self.layout
     }
 
-    fn memory_kind(&self) -> Option<abi::StructMemoryKind> {
+    fn is_stack_allocated(&self) -> bool {
         // NOTE: This contrived test does not support structs
-        None
+        true
     }
 }
 

crates/mun_memory/tests/gc/util.rs

@@ -72,15 +72,15 @@ macro_rules! impl_struct_ty {
 
 impl_primitive_types!(i8, i16, i32, i64, u8, u16, u32, u64, f32, f64, bool);
 
-impl mun_memory::TypeLayout for &'static TypeInfo {
+impl mun_memory::TypeMemory for &'static TypeInfo {
     fn layout(&self) -> Layout {
         Layout::from_size_align(self.size as usize, self.alignment as usize)
             .expect("invalid layout specified by TypeInfo")
     }
 
-    fn memory_kind(&self) -> Option<abi::StructMemoryKind> {
+    fn is_stack_allocated(&self) -> bool {
         // NOTE: This contrived test does not support structs
-        None
+        true
     }
 }