In the past, we’ve seen how structure instance representation can be changed by editing the structure in the Structures window. In IDA 8.4, a new unified view was introduced for Local Types and the same operations can (and should) be done in that window. Instead of comments, additional custom attributes are printed now:
In addition to the shortcuts (H, A and so on) and “Field type” submenu actions, you can also use the C syntax editor to add or edit these attributes:
Some may be obvious but what options are there? As of IDA 8.4, the following formatting attributes are supported:
__bin unsigned binary number __oct unsigned octal number __hex unsigned hexadecimal number __dec signed decimal number __sbin signed binary number __soct signed octal number __shex signed hexadecimal number __udec unsigned decimal number __float floating point __char character __segm segment name __enum() enumeration member (symbolic constant) __off offset expression (a simpler version of __offset) __offset() offset expression __strlit() string __stroff() structure offset __custom() custom data type and format __invsign inverted sign __invbits inverted bitwise __lzero add leading zeroes __tabform() tabular form (formatted array)
(see the link at the bottom of the post for details)
The new attributes offer possibilities that were not available before; for example, signed fields were not supported explicitly but either always positive or always negated values.
See also:
