Add __NASM__ protection on the --prelude output

The __fallthrough__ macro can only be done when using ca65, not nasm, as
that's a protected identifier. Hence, wrap the __fallthrough__ macro
definition via an .ifndef __NASM__.

Signed-off-by: Miquel Sabaté Solà <mssola@mssola.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/crates/nasm/src/main.rs b/crates/nasm/src/main.rs
index 923f89e..e6c0042 100644
--- a/crates/nasm/src/main.rs
+++ b/crates/nasm/src/main.rs
@@ -51,9 +51,11 @@ fn print_prelude() {
     println!(
         r#";; The __fallthrough__ special statement allows developers to explicitly tell
 ;; the assembler that a "fall through" situation does not happen by mistake.
-.macro __fallthrough__ arg
-  ;; NOTE: nothing to do :)
-.endmacro"#
+.ifndef __NASM__
+  .macro __fallthrough__ arg
+    ;; NOTE: nothing to do :)
+  .endmacro
+.endif"#
     );
 
     std::process::exit(0);