structure offset to structure name conversion.

structure offset to structure name conversion.

[James Courtier-Dutton]

Hi,

If I have a structure e.g.
struct test_s {
    int32_t var1;
    int32_t var2;
    uint64_t var3;
    int var4;
} test;

If I have an offset value of 8, I wish to do a lookup and get to:
test.var3

Is there some part of gcc that I could use to parse .h files and
produce a table for me of offset against each variable in the
structure to permit this sort of lookup?

Kind Regards

James

Re: structure offset to structure name conversion.

[Ian Lance Taylor]

James Courtier-Dutton <james.dutton@gmail.com> writes:

> If I have a structure e.g.
> struct test_s {
>     int32_t var1;
>     int32_t var2;
>     uint64_t var3;
>     int var4;
> } test;
>
> If I have an offset value of 8, I wish to do a lookup and get to:
> test.var3
>
> Is there some part of gcc that I could use to parse .h files and
> produce a table for me of offset against each variable in the
> structure to permit this sort of lookup?

This message would be more appropriate on the mailing list
gcc-help@gcc.gnu.org.  Please take any followups to gcc-help.  Thanks.

I'm not aware of anything quite like that, no.  I think the closest you
could get easily would be to examine the debugging information.  E.g.,
you could compile with -gstabs and run objdump -g.  You would still have
to parse the objdump -g output, but at least the offset is there.

Ian

RE: structure offset to structure name conversion.

[Paul_Koning]

> If I have a structure e.g.
> struct test_s {
>     int32_t var1;
>     int32_t var2;
>     uint64_t var3;
>     int var4;
> } test;
>
> If I have an offset value of 8, I wish to do a lookup and get to:
> test.var3
>
> Is there some part of gcc that I could use to parse .h files and 
> produce a table for me of offset against each variable in the 
> structure to permit this sort of lookup?

GDB can do this, of course.  There is also a utility "pahole" that reads debug data from an object file or executable file and produces that information.  See your favorite search engine.

	paul