propagate embed call in reducer

changelogs/unreleased/1313-schaeff

@@ -0,0 +1 @@
+Propagate embed call

zokrates_analysis/src/propagation.rs

@@ -55,7 +55,7 @@ impl fmt::Display for Error {
 pub struct Propagator<'ast, T> {
     // constants keeps track of constant expressions
     // we currently do not support partially constant expressions: `field [x, 1][1]` is not considered constant, `field [0, 1][1]` is
-    constants: Constants<'ast, T>,
+    pub constants: Constants<'ast, T>,
 }
 
 impl<'ast, T: Field> Propagator<'ast, T> {

zokrates_analysis/src/reducer/mod.rs

@@ -213,6 +213,8 @@ impl<'ast, 'a, T: Field> ResultFolder<'ast, T> for Reducer<'ast, 'a, T> {
 
                 let return_value = self.fold_expression(return_value)?;
 
+                let return_value = self.propagator.fold_expression(return_value)?;
+
                 Ok(FunctionCallOrExpression::Expression(
                     E::from(return_value).into_inner(),
                 ))
@@ -226,22 +228,28 @@ impl<'ast, 'a, T: Field> ResultFolder<'ast, T> for Reducer<'ast, 'a, T> {
                 FunctionCallExpression::<_, E>::new(e.function_key, generics, arguments)
             ))),
             Err(InlineError::Flat(embed, generics, output_type)) => {
-                let identifier = self.ssa.issue_next_identifier(CoreIdentifier::Call(0));
+                let identifier = self.ssa.issue_next_identifier(CoreIdentifier::Call);
 
                 let var = Variable::new(identifier.clone(), output_type);
 
                 let v: TypedAssignee<'ast, T> = var.clone().into();
 
-                self.statement_buffer.push(
-                    TypedStatement::embed_call_definition(
-                        v,
-                        EmbedCall::new(embed, generics, arguments),
-                    )
-                    .span(span),
-                );
-                Ok(FunctionCallOrExpression::Expression(
-                    E::identifier(identifier).span(span),
-                ))
+                let definition = TypedStatement::embed_call_definition(
+                    v,
+                    EmbedCall::new(embed, generics, arguments),
+                )
+                .span(span);
+
+                let definition = self.propagator.fold_statement(definition)?;
+
+                self.statement_buffer.extend(definition);
+
+                let e = match self.propagator.constants.get(&identifier) {
+                    Some(v) => E::try_from(v.clone()).unwrap().into_inner(),
+                    None => E::identifier(identifier),
+                };
+
+                Ok(FunctionCallOrExpression::Expression(e.span(span)))
             }
         };
 

zokrates_ast/src/typed/identifier.rs

@@ -8,7 +8,7 @@ pub type SourceIdentifier<'ast> = std::borrow::Cow<'ast, str>;
 pub enum CoreIdentifier<'ast> {
     #[serde(borrow)]
     Source(ShadowedIdentifier<'ast>),
-    Call(usize),
+    Call,
     Constant(CanonicalConstantIdentifier<'ast>),
     Condition(usize),
 }
@@ -17,7 +17,7 @@ impl<'ast> fmt::Display for CoreIdentifier<'ast> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match self {
             CoreIdentifier::Source(s) => write!(f, "{}", s),
-            CoreIdentifier::Call(i) => write!(f, "#CALL_RETURN_AT_INDEX_{}", i),
+            CoreIdentifier::Call => write!(f, "#CALL_RETURN"),
             CoreIdentifier::Constant(c) => write!(f, "{}/{}", c.module.display(), c.id),
             CoreIdentifier::Condition(i) => write!(f, "#CONDITION_{}", i),
         }

zokrates_core_test/tests/tests/constants/propagate_embed.json

@@ -0,0 +1,5 @@
+{
+  "entry_point": "./tests/tests/constants/propagate_embed.zok",
+  "max_constraint_count": 2,
+  "tests": []
+}

zokrates_core_test/tests/tests/constants/propagate_embed.zok

@@ -0,0 +1,16 @@
+import "utils/casts/field_to_u32";
+from "EMBED" import unpack;
+
+def foo<N>() -> field {
+    return 1;
+}
+
+def main() -> field {
+    u32 N = field_to_u32(1);
+    for u32 i in 0..N {
+        log("{}", i);
+    }
+    bool[1] B = unpack(1);
+    u32 P = B[0] ? 1 : 0;
+    return foo::<N>() + foo::<P>();
+}