From be392d4001f360be482dfe6730b2eae756f2b9f1 Mon Sep 17 00:00:00 2001
From: Patrick LaFontaine <32135464+Pat-Lafon@users.noreply.github.com>
Date: Sat, 9 Sep 2023 11:47:35 -0400
Subject: [PATCH] Move main typecheck to typechecking rather than runtime

---
 brilirs/src/check.rs  | 7 +++++++
 brilirs/src/interp.rs | 5 -----
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/brilirs/src/check.rs b/brilirs/src/check.rs
index f14a56e12..09075d705 100644
--- a/brilirs/src/check.rs
+++ b/brilirs/src/check.rs
@@ -508,6 +508,13 @@ fn type_check_instruction<'a>(
 }
 
 fn type_check_func(bbfunc: &BBFunction, bbprog: &BBProgram) -> Result<(), PositionalInterpError> {
+  if bbfunc.name == "main" {
+    if bbfunc.return_type.is_some() {
+      return Err(InterpError::NonEmptyRetForFunc(bbfunc.name.clone()))
+        .map_err(|e| e.add_pos(bbfunc.pos.clone()));
+    }
+  }
+
   let mut env: FxHashMap<&str, &Type> =
     FxHashMap::with_capacity_and_hasher(20, fxhash::FxBuildHasher::default());
   bbfunc.args.iter().for_each(|a| {
diff --git a/brilirs/src/interp.rs b/brilirs/src/interp.rs
index 17c5a5596..de8d5fdab 100644
--- a/brilirs/src/interp.rs
+++ b/brilirs/src/interp.rs
@@ -796,11 +796,6 @@ pub fn execute_main<T: std::io::Write, U: std::io::Write>(
     .map(|i| prog.get(i).unwrap())
     .ok_or(InterpError::NoMainFunction)?;
 
-  if main_func.return_type.is_some() {
-    return Err(InterpError::NonEmptyRetForFunc(main_func.name.clone()))
-      .map_err(|e| e.add_pos(main_func.pos.clone()));
-  }
-
   let mut env = Environment::new(main_func.num_of_vars);
   let heap = Heap::default();