I was reading DWARFv4 spec and came across attribute DW_AT_endianity.
Correct me if my understanding is wrong.
As per spec, Two of the tag values TAG_variable and TAG_base_type both can have that attribute.
But as far as, i understand when you create a TAG_variable you have to pass the "Type", which can be of TAG_base_type(others are also possible). So my question is if we are setting DW_AT_endianity on TAG_variable, why TAG_base_type also supports that attribute.
In other words every variable is of some type and can have that attribute, so why need attribute support for both type and variable?
The DW_AT_endianity attribute was the response to a proposed C compiler extension allowing the "creation of data in both big and little endian formats". It appears that the attribute was intended for base types (like this example) or structs/unions (like this one). Using the same attribute for both a simple variable and its underlying base type would, as you say, be redundant — note that the attribute is optional (see DWARF 4, sections 4.1.12 and 5.1).