From fd150521a480c04ff64f84e3c1a2faf1e8394516 Mon Sep 17 00:00:00 2001
From: Tom French <15848336+TomAFrench@users.noreply.github.com>
Date: Wed, 7 Feb 2024 16:09:55 +0000
Subject: [PATCH] fix: simplify constant assert messages into
 `ConstrainError::Static` (#4287)

# Description

## Problem\*

Resolves <!-- Link to GitHub Issue -->

## Summary\*

This PR removes the unnecessary foreign call we're performing for static
error messages.

## Additional Context



## Documentation\*

Check one:
- [x] No documentation needed.
- [ ] Documentation included in this PR.
- [ ] **[Exceptional Case]** Documentation to be submitted in a separate
PR.

# PR Checklist\*

- [x] I have tested the changes locally.
- [x] I have formatted the changes with [Prettier](https://prettier.io/)
and/or `cargo fmt` on default settings.
---
 compiler/noirc_evaluator/src/ssa/ssa_gen/mod.rs   |  6 ++++++
 .../noirc_frontend/src/hir/resolution/resolver.rs | 15 +++++++++------
 tooling/debugger/src/context.rs                   |  4 ++--
 3 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/compiler/noirc_evaluator/src/ssa/ssa_gen/mod.rs b/compiler/noirc_evaluator/src/ssa/ssa_gen/mod.rs
index 76fefae9864..3780477cf71 100644
--- a/compiler/noirc_evaluator/src/ssa/ssa_gen/mod.rs
+++ b/compiler/noirc_evaluator/src/ssa/ssa_gen/mod.rs
@@ -688,6 +688,12 @@ impl<'a> FunctionContext<'a> {
             return Ok(None)
         };
 
+        if let ast::Expression::Literal(ast::Literal::Str(assert_message)) =
+            assert_message_expr.as_ref()
+        {
+            return Ok(Some(Box::new(ConstrainError::Static(assert_message.to_string()))));
+        }
+
         let ast::Expression::Call(call) = assert_message_expr.as_ref() else {
             return Err(InternalError::Unexpected {
                 expected: "Expected a call expression".to_owned(),
diff --git a/compiler/noirc_frontend/src/hir/resolution/resolver.rs b/compiler/noirc_frontend/src/hir/resolution/resolver.rs
index b899a5a325a..347bf9451f6 100644
--- a/compiler/noirc_frontend/src/hir/resolution/resolver.rs
+++ b/compiler/noirc_frontend/src/hir/resolution/resolver.rs
@@ -1211,12 +1211,14 @@ impl<'a> Resolver<'a> {
         span: Span,
         condition: Expression,
     ) -> Option<ExprId> {
-        let mut assert_msg_call_args = if let Some(assert_message_expr) = assert_message_expr {
-            vec![assert_message_expr.clone()]
-        } else {
-            return None;
-        };
-        assert_msg_call_args.push(condition);
+        let assert_message_expr = assert_message_expr?;
+
+        if matches!(
+            assert_message_expr,
+            Expression { kind: ExpressionKind::Literal(Literal::Str(..)), .. }
+        ) {
+            return Some(self.resolve_expression(assert_message_expr));
+        }
 
         let is_in_stdlib = self.path_resolver.module_id().krate.is_stdlib();
         let assert_msg_call_path = if is_in_stdlib {
@@ -1232,6 +1234,7 @@ impl<'a> Resolver<'a> {
                 span,
             })
         };
+        let assert_msg_call_args = vec![assert_message_expr.clone(), condition];
         let assert_msg_call_expr = Expression::call(
             Expression { kind: assert_msg_call_path, span },
             assert_msg_call_args,
diff --git a/tooling/debugger/src/context.rs b/tooling/debugger/src/context.rs
index 3cababe7605..618f00b5ce1 100644
--- a/tooling/debugger/src/context.rs
+++ b/tooling/debugger/src/context.rs
@@ -530,7 +530,7 @@ mod tests {
         let initial_witness = BTreeMap::from([(Witness(1), fe_1)]).into();
 
         let foreign_call_executor =
-            Box::new(DefaultDebugForeignCallExecutor::from_artifact(true, &debug_artifact));
+            Box::new(DefaultDebugForeignCallExecutor::from_artifact(true, debug_artifact));
         let mut context = DebugContext::new(
             &StubbedBlackBoxSolver,
             circuit,
@@ -624,7 +624,7 @@ mod tests {
         let initial_witness = BTreeMap::from([(Witness(1), fe_1), (Witness(2), fe_1)]).into();
 
         let foreign_call_executor =
-            Box::new(DefaultDebugForeignCallExecutor::from_artifact(true, &debug_artifact));
+            Box::new(DefaultDebugForeignCallExecutor::from_artifact(true, debug_artifact));
         let mut context = DebugContext::new(
             &StubbedBlackBoxSolver,
             circuit,