LLVM. How to access to struct fields based on their names?

Question

I have little example code in C++:

struct RecordTest
{
    int value1;
    int value2;
};

void test()
{
    RecordTest rt;
    rt.value1 = 15;
    rt.value2         


        

Answer 1

You cannot access the fields of the struct by name, only by index. This information is just normally not there when you compile with Clang.

There is one exception to this, and this is if you compiled with debug information. In that case, you'll have ample data about the type; specifically, you'll get the order of the fields, along with a metadata entry for each field which contains its name (and other useful stuff, such as its offset from the beginning of the type).

Read more about this on the Source Level Debugging guide - and particularly, see this section about struct encoding, with its very nice example.

Take a look at DebugInfo.h for classes to help on querying debug info, though I think you're going to have to do some manually digging anyway.