asan: don't complain on arithmetic with addresses

This was already the case for plain addresses, but it was not being
considered in the case of an arithmetic operation.

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

3 files changed, 20 insertions, 6 deletions

diff --git a/lib/xixanta/src/assembler.rs b/lib/xixanta/src/assembler.rs
index 96fdd01..507f5e1 100644
--- a/lib/xixanta/src/assembler.rs
+++ b/lib/xixanta/src/assembler.rs
@@ -2948,13 +2948,26 @@ impl<'a> Assembler<'a> {
             }
             NodeType::Operation(OperationType::Add) | NodeType::Operation(OperationType::Sub) => {
                 // Get the name of the variable involved.
-                let left_name = &node.left.as_ref().unwrap().value.value;
-                let right_name = &node.left.as_ref().unwrap().value.value;
-                let name = if is_asan_friendly_name(left_name) {
+                let left_name = &node.left.as_ref().unwrap().value;
+                let right_name = &node.left.as_ref().unwrap().value;
+                let name = if is_asan_friendly_name(&left_name.value) {
                     node.left.as_ref().unwrap()
-                } else if is_asan_friendly_name(right_name) {
+                } else if is_asan_friendly_name(&right_name.value) {
                     node.right.as_ref().unwrap()
                 } else {
+                    // If everything failed but because it was an address
+                    // (e.g. 'lda palettes + 1, x'), then return early.
+                    if let Ok(var) = self.context.get_variable(left_name, &self.mappings) {
+                        if matches!(var.object_type, ObjectType::Address) {
+                            return Ok(());
+                        }
+                    }
+                    if let Ok(var) = self.context.get_variable(right_name, &self.mappings) {
+                        if matches!(var.object_type, ObjectType::Address) {
+                            return Ok(());
+                        }
+                    }
+
                     self.warnings.push(Error {
                         line: node.value.line,
                         message: "accessing a memory region without a proper name".to_string(),
diff --git a/tests/bare_accesses.s b/tests/bare_accesses.s
index 61ae7c6..cebdc10 100644
--- a/tests/bare_accesses.s
+++ b/tests/bare_accesses.s
@@ -32,9 +32,10 @@ lda zp_used - 1
 
 ldx #0
 lda palettes, x
+lda palettes + 1, x
 
 palettes:
-    .byte $0F
+    .byte $0F, $FF
 
 lda $200                        ; asan:ignore
 lda $200
diff --git a/tests/expected/bare_accesses.txt b/tests/expected/bare_accesses.txt
index 0eab60f..676723f 100644
--- a/tests/expected/bare_accesses.txt
+++ b/tests/expected/bare_accesses.txt
@@ -1,5 +1,5 @@
 warning: accessing a memory region without using a variable (bare_accesses.s: line 22)
 warning: accessing a memory region without a proper name ('whatever') (bare_accesses.s: line 23)
-warning: accessing a memory region without using a variable (bare_accesses.s: line 40)
+warning: accessing a memory region without using a variable (bare_accesses.s: line 41)
 error: out of bounds memory access for 'zp_used' ($00-$01) (bare_accesses.s: line 27)
 error: out of bounds memory access for 'zp_used' ($00-$01) (bare_accesses.s: line 28)