Avoiding struct member padding in C

Question

Hello,
The following is a very simple structure, the hand calculated size of which is 6.
On solaris we know that members are padded to word, byte boundaries for better performance.
Hence the sizeof(phone) is 8.
struct phone
unsigned int telno;
unsigned short int code;
In gcc I found a compiler flag called -fpack-struct that avoids the padding bytes in the compiler itself. Is there any such thing with the solaris C compilers.
Using 'pragma pack' is not feasible as the actual intent is to use in a bigger program, that has many such structs and manually going to each struct and changing them is not feasible.
Any compilation facility would be very helpful.
Any pointers that you feel relevant can make a big difference.
Thanking in advance for the help

Answer 1

A couple of things. Unless your structures are unique enough so that different packing is required for each structure, you can use the pack pragma since it holds for the entire file. In other words, a single pack pragma at the beginning of a file effects all the structures from that point on. So, you don't necessarily have to put a different pragma on each structure definition.
Second, you can use the -xmemalign compiler option to alert you when a mis-aligned load or store takes place. So, placing a single pack pragma in each file and compiling with -xmemalign will allow you to track down structures that might need special handling.
You can read about the -xmemalign option here
http://docs.sun.com/source/816-2454/cc_ops.app.html#32726
There does not appear to be a direct replacement for the gcc -fpack-struct compiler flag.