Preserve the 'accessed' member on macro arguments

Macro arguments get tampered with every time a new call has to be
bundled. Deep down this is done by cloning the underlying object, but
this resets any increase on the 'accessed' member, giving always the
impression that macro arguments are never accessed. Fix this by at least
preserving this member when cloning a macro argument.

Note that this is neither the most elegant solution, and probably not
the most correct. As in, it will probably get into a non-precise count
after some calls. But at least it will be a non-zero value, which is
more than enough to what this is actually used for.

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

5 files changed, 46 insertions, 1 deletions

diff --git a/lib/xixanta/src/object.rs b/lib/xixanta/src/object.rs
index 36b15dc..08f94fd 100644
--- a/lib/xixanta/src/object.rs
+++ b/lib/xixanta/src/object.rs
@@ -343,7 +343,18 @@ impl Context {
                         self.to_human()
                     ));
                 }
-                *sc = object.clone();
+
+                match object.object_type {
+                    // For macro arguments, we still want to preserve the
+                    // 'accessed' member, as arguments are re-created on each
+                    // use and this information might get lost in the process.
+                    ObjectType::Argument => {
+                        let before = sc.accessed;
+                        *sc = object.clone();
+                        sc.accessed = before;
+                    }
+                    _ => *sc = object.clone(),
+                }
             }
             None => {
                 scope.insert(id.value.clone(), object.to_owned());
diff --git a/scripts/test-e2e.sh b/scripts/test-e2e.sh
index 524c75e..9505274 100755
--- a/scripts/test-e2e.sh
+++ b/scripts/test-e2e.sh
@@ -119,6 +119,13 @@ echo "test: custom => unused_definition.nes"
 diff tests/out/unused_definition.txt tests/expected/unused_definition.txt
 exit_code=$((exit_code + $?))
 
+echo "test: custom => unused_macro_arg.nes"
+./target/debug/nasm -c empty -Werror --asan tests/unused_macro_arg.s -o tests/out/unused_macro_arg.nes 2>tests/out/unused_macro_arg.txt
+diff tests/out/unused_macro_arg.txt tests/expected/unused_macro_arg.txt
+exit_code=$((exit_code + $?))
+diff tests/out/unused_macro_arg.nes tests/expected/unused_macro_arg.nes
+exit_code=$((exit_code + $?))
+
 ##
 # code.nes
 
diff --git a/tests/expected/unused_macro_arg.nes b/tests/expected/unused_macro_arg.nes
new file mode 100644
index 0000000..4a14648
--- /dev/null
+++ b/tests/expected/unused_macro_arg.nes
diff --git a/tests/expected/unused_macro_arg.txt b/tests/expected/unused_macro_arg.txt
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/tests/expected/unused_macro_arg.txt
diff --git a/tests/unused_macro_arg.s b/tests/unused_macro_arg.s
new file mode 100644
index 0000000..fe4d7f0
--- /dev/null
+++ b/tests/unused_macro_arg.s
@@ -0,0 +1,27 @@
+.segment "HEADER"
+    .byte 'N', 'E', 'S', $1A
+    .byte $02, $01
+    .byte $00
+    .byte $00
+
+.segment "CODE"
+
+;;; asan:stack full
+
+.macro BCD_ADD ADDR
+    adc ADDR
+    bcc :+
+    nop
+:
+.endmacro
+
+.proc add_to_player_y
+    BCD_ADD additions
+
+    rts
+
+additions:
+    .byte $FF
+.endproc
+
+jsr add_to_player_y