More grammar

src/parser/parser.c

@@ -12,6 +12,90 @@ parse_result_t parse_number(tokenlist_entry_t *current) {
     return parse_any(current, parsers);
 }
 
+parse_result_t parse_plus_or_minus(tokenlist_entry_t *current) {
+    parser_t parsers[] = {parse_plus, parse_minus, nullptr};
+    return parse_any(current, parsers);
+}
+
+parse_result_t parse_register_index(tokenlist_entry_t *current) {
+    parser_t parsers[] = {parse_plus, parse_register, parse_asterisk,
+                          parse_number, nullptr};
+    return parse_consecutive(current, NODE_LABEL, parsers);
+}
+
+parse_result_t parse_register_offset(tokenlist_entry_t *current) {
+    parser_t parsers[] = {parse_plus_or_minus, parse_number, nullptr};
+    return parse_consecutive(current, NODE_LABEL, parsers);
+}
+
+parse_result_t parse_register_expression(tokenlist_entry_t *current) {
+    parse_result_t result;
+
+    ast_node_t *expr;
+    error_t *err = ast_node_alloc(&expr);
+    if (err)
+        return parse_error(err);
+
+    // <register>
+    result = parse_register(current);
+    if (result.err) {
+        ast_node_free(expr);
+        return result;
+    }
+    err = ast_node_add_child(expr, result.node);
+    if (err) {
+        ast_node_free(result.node);
+        ast_node_free(expr);
+        return parse_error(err);
+    }
+    current = result.next;
+
+    // <register_index>?
+    result = parse_register_index(current);
+    if (result.err) {
+        error_free(result.err);
+    } else {
+        err = ast_node_add_child(expr, result.node);
+        if (err) {
+            ast_node_free(result.node);
+            ast_node_free(expr);
+            return parse_error(err);
+        }
+        current = result.next;
+    }
+
+    // <register_offset>?
+    result = parse_register_offset(current);
+    if (result.err) {
+        error_free(result.err);
+    } else {
+        err = ast_node_add_child(expr, result.node);
+        if (err) {
+            ast_node_free(result.node);
+            ast_node_free(expr);
+            return parse_error(err);
+        }
+        current = result.next;
+    }
+    return parse_success(expr, current);
+}
+
+parse_result_t parse_immediate(tokenlist_entry_t *current) {
+    parser_t parsers[] = {parse_number, parse_identifier, nullptr};
+    return parse_any(current, parsers);
+}
+
+parse_result_t parse_memory_expression(tokenlist_entry_t *current) {
+    parser_t parsers[] = {parse_register_expression, parse_identifier, nullptr};
+    return parse_any(current, parsers);
+}
+
+parse_result_t parse_memory(tokenlist_entry_t *current) {
+    parser_t parsers[] = {parse_lbracket, parse_memory_expression,
+                          parse_rbracket, nullptr};
+    return parse_consecutive(current, NODE_LABEL, parsers);
+}
+
 parse_result_t parse_operand(tokenlist_entry_t *current) {
     // FIXME: not the correct set of parsers
     parser_t parsers[] = {parse_register, parse_number, nullptr};