Report unused label definitions

When the assembler successfully assembles a program, it will now report
the names of all label definitions for which there are no label references.
This is to aid the user in finding dead code within their programs.

1 files changed, 11 insertions, 0 deletions

diff --git a/src/main.rs b/src/main.rs
index ead1268..159b725 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -15,6 +15,17 @@ fn main() {
     for token in &tokens {
         if token.print_error(&source_code) { is_error = true };
     }
+    if !is_error {
+        for token in &tokens {
+            if let SemanticTokenType::LabelDefinition(def) = &token.r#type {
+                if def.references.is_empty() {
+                    eprintln!("Unused label definition: {}", def.name);
+                }
+            }
+        }
+        eprintln!();
+    }
+
     eprintln!("Assembled program in {} bytes.", bytecode.len());
 
     if is_error {