[VAN-543] unknown input status (#44)

* Add minimized test case
* Add InputStatus resolution for final return data

circom/tests/subcmps/subcmps2.circom

@@ -0,0 +1,43 @@
+pragma circom 2.0.6;
+// REQUIRES: circom
+// RUN: rm -rf %t && mkdir %t && %circom --llvm -o %t %s | sed -n 's/.*Written successfully:.* \(.*\)/\1/p' | xargs cat | FileCheck %s
+
+template Sum(n) {
+    signal input inp[n];
+    signal output outp;
+
+    var s = 0;
+
+    for (var i = 0; i < n; i++) {
+        s += inp[i];
+    }
+
+    outp <== s;
+}
+
+function nop(i) {
+    return i;
+}
+
+template Caller() {
+    signal input inp[4];
+    signal output outp;
+
+    component s = Sum(4);
+
+    for (var i = 0; i < 4; i++) {
+        s.inp[i] <== nop(inp[i]);
+    }
+
+    outp <== s.outp;
+}
+
+component main = Caller();
+
+//CHECK-LABEL: define void @Caller_{{[0-9]+}}_run
+//CHECK-SAME: ([0 x i256]* %0)
+//CHECK: %[[CALL_VAL:call\.nop_[0-3]]] = call i256 @nop_{{[0-3]}}(i256* %6)
+//CHECK: %[[SUBCMP_PTR:.*]] = getelementptr [1 x { [0 x i256]*, i32 }], [1 x { [0 x i256]*, i32 }]* %subcmps, i32 0, i32 0, i32 {{[0-3]}}
+//CHECK: %[[SUBCMP:.*]] = load [0 x i256]*, [0 x i256]** %[[SUBCMP_PTR]]
+//CHECK: %[[SUBCMP_INP:.*]] = getelementptr [0 x i256], [0 x i256]* %[[SUBCMP]], i32 0, i32 {{[1-4]}}
+//CHECK: store i256 %[[CALL_VAL]], i256* %[[SUBCMP_INP]]

circuit_passes/src/passes/deterministic_subcomponent_invocation.rs

@@ -22,38 +22,42 @@ impl DeterministicSubCmpInvokePass {
             replacements: Default::default(),
         }
     }
-}
-
-impl InterpreterObserver for DeterministicSubCmpInvokePass {
-    fn on_value_bucket(&self, _bucket: &ValueBucket, _env: &Env) -> bool {
-        true
-    }
-
-    fn on_load_bucket(&self, _bucket: &LoadBucket, _env: &Env) -> bool {
-        true
-    }
 
-    fn on_store_bucket(&self, bucket: &StoreBucket, env: &Env) -> bool {
-        let env = env.clone();
-        let mem = self.memory.borrow();
-        let interpreter = mem.build_interpreter(self);
-        // If the address of the subcomponent input information is unk, then
-        // If executing this store bucket would result in calling the subcomponent we replace it with Last
+    pub fn try_resolve_input_status(&self, address_type: &AddressType, env: &Env) {
+        // If the address of the subcomponent input information is unknown, then
+        // If executing this instruction would result in calling the subcomponent we replace it with Last
         //    Will result in calling if the counter is at one because after the execution it will be 0
         // If not replace with NoLast
         if let AddressType::SubcmpSignal {
             input_information: InputInformation::Input { status: StatusInput::Unknown },
             cmp_address,
             ..
-        } = &bucket.dest_address_type
+        } = address_type
         {
+            let env = env.clone();
+            let mem = self.memory.borrow();
+            let interpreter = mem.build_interpreter(self);
             let (addr, env) = interpreter.execute_instruction(cmp_address, env, false);
             let addr = addr
-                .expect("cmp_address instruction in StoreBucket SubcmpSignal must produce a value!")
+                .expect("cmp_address instruction in SubcmpSignal must produce a value!")
                 .get_u32();
             let new_status = if env.subcmp_counter_equal_to(addr, 1) { Last } else { NoLast };
-            self.replacements.borrow_mut().insert(bucket.dest_address_type.clone(), new_status);
+            self.replacements.borrow_mut().insert(address_type.clone(), new_status);
         }
+    }
+}
+
+impl InterpreterObserver for DeterministicSubCmpInvokePass {
+    fn on_value_bucket(&self, _bucket: &ValueBucket, _env: &Env) -> bool {
+        true
+    }
+
+    fn on_load_bucket(&self, _bucket: &LoadBucket, _env: &Env) -> bool {
+        true
+    }
+
+    fn on_store_bucket(&self, bucket: &StoreBucket, env: &Env) -> bool {
+        self.try_resolve_input_status(&bucket.dest_address_type, env);
         true
     }
 
@@ -89,8 +93,14 @@ impl InterpreterObserver for DeterministicSubCmpInvokePass {
         true
     }
 
-    fn on_call_bucket(&self, _bucket: &CallBucket, _env: &Env) -> bool {
-        true
+    fn on_call_bucket(&self, bucket: &CallBucket, env: &Env) -> bool {
+        match &bucket.return_info {
+            ReturnType::Intermediate {..} => true,
+            ReturnType::Final(data) => {
+                self.try_resolve_input_status(&data.dest_address_type, env);
+                true
+            },
+        }
     }
 
     fn on_branch_bucket(&self, _bucket: &BranchBucket, _env: &Env) -> bool {

compiler/src/intermediate_representation/store_bucket.rs

@@ -189,7 +189,7 @@ impl StoreBucket{
                 match status {
                     StatusInput::Last => {
                         let run_fn = run_fn_name(sub_cmp_name.expect("Could not get the name of the subcomponent"));
-                        // If we reach this point gep is the address of the subcomponent so we ca just reuse it
+                        // If we reach this point gep is the address of the subcomponent so we can just reuse it
                         let addr = cmp_address.produce_llvm_ir(producer).expect("The address of a subcomponent must yield a value!");
                         let subcmp = producer.template_ctx().load_subcmp_addr(producer, addr);
                         create_call(producer, run_fn.as_str(), &[subcmp.into()]);