Add more values to the ast to facilitate encoding

- Add a instruction value that contains the encoding, the address and a
  flag to indicate if this instruction contains label references
- Add label value that contains an address
- Add reference value that contains offset, an absolute address and an
  operand size

src/ast.h

@@ -75,7 +75,7 @@ typedef struct register_ {
 } register_t;
 
 typedef struct opcode_encoding {
-    uint8_t encoding[32];
+    uint8_t buffer[32];
     size_t len;
 } opcode_encoding_t;
 
@@ -89,7 +89,19 @@ struct ast_node {
     union {
         register_t reg;
         number_t number;
+        struct {
+            bool has_reference;
             opcode_encoding_t encoding;
+            int64_t address;
+        } instruction;
+        struct {
+            int64_t offset;
+            int64_t address;
+            operand_size_t size;
+        } reference;
+        struct {
+            int64_t address;
+        } label;
     } value;
 };
 

src/encoder/encoder.c

@@ -481,7 +481,7 @@ error_t *encoder_encode_instruction(encoder_t *encoder,
         return err;
 
     // produce the actual encoding output in the NODE_INSTRUCTION value
-    uint8_t *output = instruction->value.encoding.encoding;
+    uint8_t *output = instruction->value.instruction.encoding.buffer;
     size_t output_len = 0;
 
     // Handle prefixes
@@ -500,7 +500,7 @@ error_t *encoder_encode_instruction(encoder_t *encoder,
     memcpy(output + output_len, encoding->buffer, encoding->len);
     output_len += encoding->len;
 
-    instruction->value.encoding.len = output_len;
+    instruction->value.instruction.encoding.len = output_len;
 
     return nullptr;
 }

src/main.c

@@ -88,7 +88,8 @@ error_t *print_encoding(tokenlist_t *list) {
         if (node->id != NODE_INSTRUCTION)
             continue;
 
-        print_hex(node->value.encoding.len, node->value.encoding.encoding);
+        print_hex(node->value.instruction.encoding.len,
+                  node->value.instruction.encoding.buffer);
     }
 
     encoder_free(encoder);