Raise error if an instruction name is redefined

1 files changed, 3 insertions, 0 deletions

diff --git a/src/stages/semantic_tokens.rs b/src/stages/semantic_tokens.rs
index fc454be..c735828 100644
--- a/src/stages/semantic_tokens.rs
+++ b/src/stages/semantic_tokens.rs
@@ -49,6 +49,7 @@ pub enum SemanticToken {
 
 pub enum SemanticError {
     InvocationBeforeDefinition,
+    ReservedIdentifier(String),
 }
 
 
@@ -64,6 +65,8 @@ fn report_semantic_error(error: &Tracked<SemanticError>, source_code: &str) {
     let message = match &error.value {
         SemanticError::InvocationBeforeDefinition =>
             "Macro cannot be invoked before it has been defined",
+        SemanticError::ReservedIdentifier(name) =>
+            &format!("Identifier '{name}' is reserved for a built-in instruction"),
     };
     report_source_issue(LogLevel::Error, &context, message);
 }