refactor(TasmObject)!: Move checks to compile time

Add trait `TasmStruct`, moving struct-only capabilities out of
`TasmObject`. This change neither adds nor removes functionality, it
only moves checks from runtime to compile time.

Author: jan-ferdinand

tasm-lib/src/prelude.rs

@@ -12,6 +12,7 @@ pub use crate::library::Library;
 pub use crate::memory::dyn_malloc::DynMalloc;
 pub use crate::memory::memcpy::MemCpy;
 pub use crate::structure::tasm_object::TasmObject;
+pub use crate::structure::tasm_object::TasmStruct;
 pub use crate::traits::basic_snippet::BasicSnippet;
 pub use crate::triton_vm::prelude::Digest;
 pub use crate::triton_vm::prelude::Tip5;

tasm-lib/src/structure/auto_generated_tasm_object_implementations.rs

@@ -6,8 +6,7 @@ use triton_vm::fri::AuthenticationStructure;
 use triton_vm::prelude::*;
 use triton_vm::proof_item::FriResponse;
 
-use crate::library::Library;
-use crate::prelude::TasmObject;
+use crate::prelude::*;
 use crate::twenty_first::prelude::MmrMembershipProof;
 use crate::twenty_first::util_types::mmr::mmr_accumulator::MmrAccumulator;
 use crate::twenty_first::util_types::mmr::mmr_successor_proof::MmrSuccessorProof;
@@ -22,18 +21,6 @@ macro_rules! derive_tasm_object_for {
                 stringify!($actual).to_string()
             }
 
-            fn get_field(field_name: &str) -> Vec<LabelledInstruction> {
-                $fake::get_field(field_name)
-            }
-
-            fn get_field_with_size(field_name: &str) -> Vec<LabelledInstruction> {
-                $fake::get_field_with_size(field_name)
-            }
-
-            fn get_field_start_with_jump_distance(field_name: &str) -> Vec<LabelledInstruction> {
-                $fake::get_field_start_with_jump_distance(field_name)
-            }
-
             fn compute_size_and_assert_valid_size_indicator(
                 library: &mut Library,
             ) -> Vec<LabelledInstruction> {
@@ -47,6 +34,20 @@ macro_rules! derive_tasm_object_for {
                 Ok(Box::new(Self { $($field),* }))
             }
         }
+
+        impl TasmStruct for $actual {
+            fn get_field(field_name: &str) -> Vec<LabelledInstruction> {
+                $fake::get_field(field_name)
+            }
+
+            fn get_field_with_size(field_name: &str) -> Vec<LabelledInstruction> {
+                $fake::get_field_with_size(field_name)
+            }
+
+            fn get_field_start_with_jump_distance(field_name: &str) -> Vec<LabelledInstruction> {
+                $fake::get_field_start_with_jump_distance(field_name)
+            }
+        }
     };
 }
 
@@ -91,18 +92,6 @@ impl TasmObject for MmrAccumulator {
         "MmrAccumulator".to_string()
     }
 
-    fn get_field(field_name: &str) -> Vec<LabelledInstruction> {
-        FakeMmrAccumulator::get_field(field_name)
-    }
-
-    fn get_field_with_size(field_name: &str) -> Vec<LabelledInstruction> {
-        FakeMmrAccumulator::get_field_with_size(field_name)
-    }
-
-    fn get_field_start_with_jump_distance(field_name: &str) -> Vec<LabelledInstruction> {
-        FakeMmrAccumulator::get_field_start_with_jump_distance(field_name)
-    }
-
     fn compute_size_and_assert_valid_size_indicator(
         library: &mut Library,
     ) -> Vec<LabelledInstruction> {
@@ -117,3 +106,17 @@ impl TasmObject for MmrAccumulator {
         Ok(Box::new(Self::init(peaks, leaf_count)))
     }
 }
+
+impl TasmStruct for MmrAccumulator {
+    fn get_field(field_name: &str) -> Vec<LabelledInstruction> {
+        FakeMmrAccumulator::get_field(field_name)
+    }
+
+    fn get_field_with_size(field_name: &str) -> Vec<LabelledInstruction> {
+        FakeMmrAccumulator::get_field_with_size(field_name)
+    }
+
+    fn get_field_start_with_jump_distance(field_name: &str) -> Vec<LabelledInstruction> {
+        FakeMmrAccumulator::get_field_start_with_jump_distance(field_name)
+    }
+}

tasm-lib/src/structure/manual_tasm_object_implementations.rs

@@ -9,24 +9,12 @@ use crate::prelude::*;
 
 impl<const N: usize, T> TasmObject for [T; N]
 where
-    T: BFieldCodec + TasmObject,
+    T: TasmObject,
 {
     fn label_friendly_name() -> String {
         format!("array{}___{}", N, T::label_friendly_name())
     }
 
-    fn get_field(_field_name: &str) -> Vec<LabelledInstruction> {
-        todo!()
-    }
-
-    fn get_field_with_size(_field_name: &str) -> Vec<LabelledInstruction> {
-        todo!()
-    }
-
-    fn get_field_start_with_jump_distance(_field_name: &str) -> Vec<LabelledInstruction> {
-        todo!()
-    }
-
     fn compute_size_and_assert_valid_size_indicator(_: &mut Library) -> Vec<LabelledInstruction> {
         if let Some(static_size) = T::static_length() {
             let own_size = static_size * N;
@@ -49,24 +37,12 @@ where
 
 impl<T> TasmObject for Vec<T>
 where
-    T: BFieldCodec + TasmObject,
+    T: TasmObject,
 {
     fn label_friendly_name() -> String {
         format!("vec___{}", T::label_friendly_name())
     }
 
-    fn get_field(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!("`Vec` does not have fields; cannot access them")
-    }
-
-    fn get_field_with_size(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!("`Vec` does not have fields; cannot access them")
-    }
-
-    fn get_field_start_with_jump_distance(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!("`Vec` does not have fields; cannot access them")
-    }
-
     fn compute_size_and_assert_valid_size_indicator(
         library: &mut Library,
     ) -> Vec<LabelledInstruction> {
@@ -209,18 +185,6 @@ impl TasmObject for BFieldElement {
         DataType::Bfe.label_friendly_name()
     }
 
-    fn get_field(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!()
-    }
-
-    fn get_field_with_size(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!()
-    }
-
-    fn get_field_start_with_jump_distance(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!()
-    }
-
     fn compute_size_and_assert_valid_size_indicator(_: &mut Library) -> Vec<LabelledInstruction> {
         panic!("Size is known statically for BFieldElement encoding")
     }
@@ -236,18 +200,6 @@ impl TasmObject for XFieldElement {
         DataType::Xfe.label_friendly_name()
     }
 
-    fn get_field(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!()
-    }
-
-    fn get_field_with_size(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!()
-    }
-
-    fn get_field_start_with_jump_distance(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!()
-    }
-
     fn compute_size_and_assert_valid_size_indicator(_: &mut Library) -> Vec<LabelledInstruction> {
         panic!("Size is known statically for XFieldElement encoding")
     }
@@ -266,18 +218,6 @@ impl TasmObject for Digest {
         DataType::Digest.label_friendly_name()
     }
 
-    fn get_field(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!()
-    }
-
-    fn get_field_with_size(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!()
-    }
-
-    fn get_field_start_with_jump_distance(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!()
-    }
-
     fn compute_size_and_assert_valid_size_indicator(_: &mut Library) -> Vec<LabelledInstruction> {
         panic!("Size is known statically for Digest encoding")
     }
@@ -296,18 +236,6 @@ impl TasmObject for bool {
         DataType::Bool.label_friendly_name()
     }
 
-    fn get_field(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!()
-    }
-
-    fn get_field_with_size(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!()
-    }
-
-    fn get_field_start_with_jump_distance(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!()
-    }
-
     fn compute_size_and_assert_valid_size_indicator(_: &mut Library) -> Vec<LabelledInstruction> {
         panic!("Size is known statically for bool encoding")
     }
@@ -327,18 +255,6 @@ impl TasmObject for u32 {
         DataType::U32.label_friendly_name()
     }
 
-    fn get_field(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!()
-    }
-
-    fn get_field_with_size(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!()
-    }
-
-    fn get_field_start_with_jump_distance(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!()
-    }
-
     fn compute_size_and_assert_valid_size_indicator(_: &mut Library) -> Vec<LabelledInstruction> {
         panic!("Size is known statically for u32 encoding")
     }
@@ -359,18 +275,6 @@ impl TasmObject for u64 {
         DataType::U64.label_friendly_name()
     }
 
-    fn get_field(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!()
-    }
-
-    fn get_field_with_size(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!()
-    }
-
-    fn get_field_start_with_jump_distance(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!()
-    }
-
     fn compute_size_and_assert_valid_size_indicator(_: &mut Library) -> Vec<LabelledInstruction> {
         panic!("Size is known statically for u64 encoding")
     }
@@ -393,18 +297,6 @@ impl TasmObject for u128 {
         DataType::U128.label_friendly_name()
     }
 
-    fn get_field(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!()
-    }
-
-    fn get_field_with_size(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!()
-    }
-
-    fn get_field_start_with_jump_distance(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!()
-    }
-
     fn compute_size_and_assert_valid_size_indicator(_: &mut Library) -> Vec<LabelledInstruction> {
         panic!("Size is known statically for u128 encoding")
     }
@@ -426,8 +318,8 @@ impl TasmObject for u128 {
 
 impl<T, S> TasmObject for (T, S)
 where
-    T: TasmObject + BFieldCodec,
-    S: TasmObject + BFieldCodec,
+    T: TasmObject,
+    S: TasmObject,
 {
     fn label_friendly_name() -> String {
         format!(
@@ -437,18 +329,6 @@ where
         )
     }
 
-    fn get_field(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!()
-    }
-
-    fn get_field_with_size(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!()
-    }
-
-    fn get_field_start_with_jump_distance(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!()
-    }
-
     fn compute_size_and_assert_valid_size_indicator(
         library: &mut Library,
     ) -> Vec<LabelledInstruction> {
@@ -558,18 +438,6 @@ impl TasmObject for Polynomial<'_, XFieldElement> {
         "polynomial_xfe".to_owned()
     }
 
-    fn get_field(_field_name: &str) -> Vec<LabelledInstruction> {
-        todo!()
-    }
-
-    fn get_field_with_size(_field_name: &str) -> Vec<LabelledInstruction> {
-        todo!()
-    }
-
-    fn get_field_start_with_jump_distance(_field_name: &str) -> Vec<LabelledInstruction> {
-        todo!()
-    }
-
     fn compute_size_and_assert_valid_size_indicator(_: &mut Library) -> Vec<LabelledInstruction> {
         triton_asm!(
             // _ *field_size
@@ -613,18 +481,6 @@ impl TasmObject for Proof {
         "tvm_proof".to_owned()
     }
 
-    fn get_field(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!()
-    }
-
-    fn get_field_with_size(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!()
-    }
-
-    fn get_field_start_with_jump_distance(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!()
-    }
-
     fn compute_size_and_assert_valid_size_indicator(_: &mut Library) -> Vec<LabelledInstruction> {
         // Proofs are special, as the fields of a proof is only accessed through
         // the [`DequeueNextAs`](crate::verifier::vm_proof_iter::dequeue_next_as)
@@ -653,24 +509,12 @@ impl TasmObject for Proof {
 
 impl<T> TasmObject for Option<T>
 where
-    T: TasmObject + BFieldCodec,
+    T: TasmObject,
 {
     fn label_friendly_name() -> String {
         format!("option_L_{}_R", T::label_friendly_name())
     }
 
-    fn get_field(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!("cannot get field of an option type");
-    }
-
-    fn get_field_with_size(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!("cannot get field with size of an option type");
-    }
-
-    fn get_field_start_with_jump_distance(_field_name: &str) -> Vec<LabelledInstruction> {
-        panic!("cannot get field start with jump distance of an option type");
-    }
-
     fn compute_size_and_assert_valid_size_indicator(
         library: &mut Library,
     ) -> Vec<LabelledInstruction> {
@@ -777,7 +621,7 @@ mod tests {
     use super::*;
     use crate::memory::encode_to_memory;
 
-    fn decode_iter_prop<T: TasmObject + BFieldCodec + Eq + Debug>(obj_written: T) {
+    fn decode_iter_prop<T: TasmObject + Eq + Debug>(obj_written: T) {
         let mut memory = HashMap::default();
         let address = random();
         encode_to_memory(&mut memory, address, &obj_written);