add addressing to evaluate_operand

twasm/asm/main.asm

@@ -773,13 +773,27 @@ evaluate_operand:
   pop rdi      ; rdi -> first byte of operand
   mov rsi, rax ; rsi = size of operand w/o trailing whitespace
 
-  cmp [rdi + 1], '['
+  cmp rsi, 0       ; case: 0 length
+  je .unrecognised ; unrecognised
+
+  cmp byte [rdi], '[' ; case: memory addressing
   je .address
 
-  jmp .register
+  jmp .register ; otherwise: register
 
   .address:
-    jmp halt
+    cmp byte [rdi + rsi - 1], ']' ; check if address is closed correctly
+    jne .unrecognised             ; if not, fail
+    inc rdi    ; rdi -> enclosed operand
+    sub rsi, 2 ; rsi = length of enclosed operand
+    call evaluate_operand
+    ; rax = binary data
+    ; dl = return code
+    cmp dl, 0x10     ; make sure return code isn't another memory reference
+    je .unrecognised ; if it is, fail
+
+    or dl, 0x10 ; flip bit for address return
+    ret
 
   .register:
     cmp rsi, 4
@@ -799,10 +813,6 @@ evaluate_operand:
     je .register1
   .register1:
     and edi, 0xFF
-    push rsi
-    mov rsi, .msg
-    call print.debug
-    pop rsi
   .register2:
     and edi, 0xFFFF
   .register3:
@@ -822,6 +832,7 @@ evaluate_operand:
   .unrecognised:
     mov dl, 0xFF
     ret
+
   .msg db "evaluate_operand", 0x0A, 0x00
 
 ; ------------------------------------------------------------------------------
@@ -1549,6 +1560,6 @@ program:
   db "xor eax, eax", 0x0A
   db "inc rax ; inline comment", 0x0A
   db "; one line comment", 0x0A
-  db "mov [ rax ], rdx", 0x0A
+  db "mov [rax], rdx", 0x0A
   db "hlt", 0x00 ; for the sake of being able to print it, I made it a string
   .size db $ - program

twasm/asm/tests.asm

@@ -535,6 +535,14 @@ test_evaluate_operand:
   cmp ax, 0x0003
   jne .fail
 
+  mov rdi, .case3
+  mov rsi, 5
+  call evaluate_operand
+  cmp dl, 0x10
+  jne .fail
+  cmp ax, 0x0003
+  jne .fail
+
   .pass:
     mov rsi, msg_pass
     call print
@@ -546,6 +554,7 @@ test_evaluate_operand:
   .case0 db "rax"
   .case1: ; intentionally blank
   .case2 db "rdx"
+  .case3 db "[rdx]"
   .msg db "test_evaluate_operand...", 0x00
 
 msg_pass: