Implement provenance. (#1109)

Co-authored-by: porcuquine <porcuquine@users.noreply.github.com>

src/circuit/gadgets/macros.rs

@@ -1,5 +1,12 @@
 #![allow(unused_macros)]
 
+/// Simplify creating a namespace.
+macro_rules! ns {
+    ($cs:ident, $e:expr) => {
+        &mut $cs.namespace(|| $e)
+    };
+}
+
 // Enforces constraint that a implies b.
 macro_rules! if_then {
     ($cs:ident, $a:expr, $b:expr) => {

src/coprocessor/gadgets.rs

@@ -125,7 +125,7 @@ pub(crate) fn construct_list<F: LurkField, CS: ConstraintSystem<F>>(
     cs: &mut CS,
     g: &GlobalAllocator<F>,
     store: &Store<F>,
-    elts: &[&AllocatedPtr<F>],
+    elts: &[AllocatedPtr<F>],
     last: Option<AllocatedPtr<F>>,
 ) -> Result<AllocatedPtr<F>, SynthesisError> {
     let init = match last {
@@ -173,11 +173,36 @@ pub(crate) fn construct_env<F: LurkField, CS: ConstraintSystem<F>>(
     Ok(AllocatedPtr::from_parts(tag, hash))
 }
 
+#[inline]
+pub(crate) fn construct_provenance<F: LurkField, CS: ConstraintSystem<F>>(
+    cs: &mut CS,
+    g: &GlobalAllocator<F>,
+    store: &Store<F>,
+    query_hash: &AllocatedNum<F>,
+    result: &AllocatedPtr<F>,
+    deps: &AllocatedNum<F>,
+) -> Result<AllocatedPtr<F>, SynthesisError> {
+    // TODO: should there be a provenance tag?
+    let tag = g.alloc_tag_cloned(cs, &ExprTag::Env);
+
+    let hash = hash_poseidon(
+        cs,
+        vec![
+            query_hash.clone(),
+            result.tag().clone(),
+            result.hash().clone(),
+            deps.clone(),
+        ],
+        store.poseidon_cache.constants.c4(),
+    )?;
+
+    Ok(AllocatedPtr::from_parts(tag, hash))
+}
+
 /// Deconstructs `env`, assumed to be a composition of a symbol hash, a value `Ptr`, and a next `Env` hash.
 ///
 /// # Panics
 /// Panics if the store can't deconstruct the env hash.
-#[allow(dead_code)]
 pub(crate) fn deconstruct_env<F: LurkField, CS: ConstraintSystem<F>>(
     cs: &mut CS,
     s: &Store<F>,
@@ -226,6 +251,65 @@ pub(crate) fn deconstruct_env<F: LurkField, CS: ConstraintSystem<F>>(
     Ok((key_sym_hash, val, new_env_hash))
 }
 
+#[allow(dead_code)]
+pub(crate) fn deconstruct_provenance<F: LurkField, CS: ConstraintSystem<F>>(
+    cs: &mut CS,
+    s: &Store<F>,
+    not_dummy: &Boolean,
+    provenance: &AllocatedNum<F>,
+) -> Result<(AllocatedNum<F>, AllocatedPtr<F>, AllocatedNum<F>), SynthesisError> {
+    let prov_zptr = ZPtr::from_parts(
+        tag::Tag::Expr(ExprTag::Env),
+        provenance.get_value().unwrap(),
+    );
+    let prov_ptr = s.to_ptr(&prov_zptr);
+
+    let (a, b, c, d) = {
+        if let Some([q, res, deps]) = s.pop_provenance(prov_ptr) {
+            let q_zptr = s.hash_ptr(&q);
+            let res_zptr = s.hash_ptr(&res);
+            let deps_zptr = s.hash_ptr(&deps);
+            (
+                *q_zptr.value(),
+                res_zptr.tag().to_field::<F>(),
+                *res_zptr.value(),
+                *deps_zptr.value(),
+            )
+        } else {
+            (F::ZERO, F::ZERO, F::ZERO, F::ZERO)
+        }
+    };
+
+    let query_cons_hash =
+        AllocatedNum::alloc_infallible(&mut cs.namespace(|| "query_cons_hash"), || a);
+    let res_tag = AllocatedNum::alloc_infallible(&mut cs.namespace(|| "res_tag"), || b);
+    let res_hash = AllocatedNum::alloc_infallible(&mut cs.namespace(|| "res_hash"), || c);
+    let deps_tuple_hash =
+        AllocatedNum::alloc_infallible(&mut cs.namespace(|| "deps_tuple_hash"), || d);
+
+    let hash = hash_poseidon(
+        &mut cs.namespace(|| "hash"),
+        vec![
+            query_cons_hash.clone(),
+            res_tag.clone(),
+            res_hash.clone(),
+            deps_tuple_hash.clone(),
+        ],
+        s.poseidon_cache.constants.c4(),
+    )?;
+
+    let res = AllocatedPtr::from_parts(res_tag, res_hash);
+
+    implies_equal(
+        &mut cs.namespace(|| "hash equality"),
+        not_dummy,
+        provenance,
+        &hash,
+    );
+
+    Ok((query_cons_hash, res, deps_tuple_hash))
+}
+
 /// Retrieves the `Ptr` that corresponds to `a_ptr` by using the `Store` as the
 /// hint provider
 #[allow(dead_code)]
@@ -688,13 +772,20 @@ mod test {
         let a_one = g.alloc_ptr(&mut cs, &one, &store);
 
         // proper list
-        let a_list = construct_list(&mut cs, &g, &store, &[&a_one, &a_one], None).unwrap();
+        let a_list =
+            construct_list(&mut cs, &g, &store, &[a_one.clone(), a_one.clone()], None).unwrap();
         let z_list = store.hash_ptr(&store.list(vec![one, one]));
         assert_eq!(a_ptr_as_z_ptr(&a_list), Some(z_list));
 
         // improper list
-        let a_list =
-            construct_list(&mut cs, &g, &store, &[&a_one, &a_one], Some(a_one.clone())).unwrap();
+        let a_list = construct_list(
+            &mut cs,
+            &g,
+            &store,
+            &[a_one.clone(), a_one.clone()],
+            Some(a_one.clone()),
+        )
+        .unwrap();
         let z_list = store.hash_ptr(&store.improper_list(vec![one, one], one));
         assert_eq!(a_ptr_as_z_ptr(&a_list), Some(z_list));
     }

src/coroutine/memoset/demo.rs

@@ -6,6 +6,7 @@ use super::{
 };
 use crate::circuit::gadgets::constraints::alloc_is_zero;
 use crate::circuit::gadgets::pointer::AllocatedPtr;
+use crate::coprocessor::gadgets::construct_cons;
 use crate::field::LurkField;
 use crate::lem::circuit::GlobalAllocator;
 use crate::lem::{pointers::Ptr, store::Store};
@@ -27,7 +28,7 @@ pub(crate) enum DemoCircuitQuery<F: LurkField> {
 impl<F: LurkField> Query<F> for DemoQuery<F> {
     type CQ = DemoCircuitQuery<F>;
 
-    fn eval(&self, s: &Store<F>, scope: &mut Scope<Self, LogMemo<F>>) -> Ptr {
+    fn eval(&self, s: &Store<F>, scope: &mut Scope<Self, LogMemo<F>, F>) -> Ptr {
         match self {
             Self::Factorial(n) => {
                 let n_zptr = s.hash_ptr(n);
@@ -117,15 +118,11 @@ impl<F: LurkField> RecursiveQuery<F> for DemoCircuitQuery<F> {
         match self {
             Self::Factorial(n) => {
                 let result_f = n.hash().mul(
-                    &mut cs.namespace(|| "incremental multiplication"),
+                    ns!(cs, "incremental multiplication"),
                     subquery_result.hash(),
                 )?;
 
-                AllocatedPtr::alloc_tag(
-                    &mut cs.namespace(|| "result"),
-                    ExprTag::Num.to_field(),
-                    result_f,
-                )
+                AllocatedPtr::alloc_tag(ns!(cs, "result"), ExprTag::Num.to_field(), result_f)
             }
         }
     }
@@ -140,20 +137,27 @@ impl<F: LurkField> CircuitQuery<F> for DemoCircuitQuery<F> {
         scope: &mut CircuitScope<F, LogMemoCircuit<F>>,
         acc: &AllocatedPtr<F>,
         transcript: &CircuitTranscript<F>,
-    ) -> Result<(AllocatedPtr<F>, AllocatedPtr<F>, CircuitTranscript<F>), SynthesisError> {
+    ) -> Result<
+        (
+            (AllocatedPtr<F>, AllocatedPtr<F>),
+            AllocatedPtr<F>,
+            CircuitTranscript<F>,
+        ),
+        SynthesisError,
+    > {
         match self {
             Self::Factorial(n) => {
                 // FIXME: Check n tag or decide not to.
                 let base_case_f = g.alloc_const(cs, F::ONE);
                 let base_case = AllocatedPtr::alloc_tag(
-                    &mut cs.namespace(|| "base_case"),
+                    ns!(cs, "base_case"),
                     ExprTag::Num.to_field(),
                     base_case_f.clone(),
                 )?;
 
-                let n_is_zero = alloc_is_zero(&mut cs.namespace(|| "n_is_zero"), n.hash())?;
+                let n_is_zero = alloc_is_zero(ns!(cs, "n_is_zero"), n.hash())?;
 
-                let new_n = AllocatedNum::alloc(&mut cs.namespace(|| "new_n"), || {
+                let new_n = AllocatedNum::alloc(ns!(cs, "new_n"), || {
                     n.hash()
                         .get_value()
                         .map(|n| n - F::ONE)
@@ -168,17 +172,19 @@ impl<F: LurkField> CircuitQuery<F> for DemoCircuitQuery<F> {
                     |lc| lc + n.hash().get_variable() - CS::one(),
                 );
 
-                let new_num = AllocatedPtr::alloc_tag(
-                    &mut cs.namespace(|| "new_num"),
-                    ExprTag::Num.to_field(),
-                    new_n,
-                )?;
+                let new_num =
+                    AllocatedPtr::alloc_tag(ns!(cs, "new_num"), ExprTag::Num.to_field(), new_n)?;
+
+                let symbol = g.alloc_ptr(ns!(cs, "symbol_"), &self.symbol_ptr(store), store);
+
+                let query = construct_cons(ns!(cs, "query"), g, store, &symbol, n)?;
 
                 self.recurse(
                     cs,
                     g,
                     store,
                     scope,
+                    &query,
                     &new_num,
                     &n_is_zero.not(),
                     (&base_case, acc, transcript),
@@ -212,7 +218,7 @@ mod test {
     #[test]
     fn test_factorial() {
         let s = Store::default();
-        let mut scope: Scope<DemoQuery<F>, LogMemo<F>> = Scope::default();
+        let mut scope: Scope<DemoQuery<F>, LogMemo<F>, F> = Scope::default();
         let zero = s.num(F::ZERO);
         let one = s.num(F::ONE);
         let two = s.num(F::from_u64(2));