This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [PATCH]: Fix PR tree-optimization/21407


On May 11, 2005, at 5:25 AM, Kenneth Zadeck wrote:
I wonder, Mike, do you make any distinction between a c program that upcasts on the first field of a record and one that uses the offsetof operator to upcast from the middle of a record?

I don't, but Geoff does as I recall, which is I think what your question was. As I recall, everyone agrees the C standard says the first field is special, you can convert between the pointer to the first field and the structure (I'm only considering struct here, not union):


       [#12]  Within  a structure object, the non-bit-field members
       and the units in which bit-fields reside have addresses that
       increase in the order in which they are declared.  A pointer
       to a structure object, suitably  converted,  points  to  its
       initial  member  (or  if that member is a bit-field, then to
       the unit in which it resides), and vice versa.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]