🚀 go-pugleaf

In article <1996Mar5.114346.1790@ittpub>
wil@ittpub.nl (Wil Evers) writes:
<snip>
WE: 1. Is there any technical reason why the memory layouts of CUSTOMER_TYPE  
WE: and PROPER_CUSTOMER_TYPE would be different? It seems to me that wrapping  
WE: an array into a structure is something relevant at compile-time, not at  
WE: run time. IMHO the generated code for accessing the fields in a  
WE: CUSTOMER_TYPE could be exactly the same as the code for accessing the  
WE: fields in a PROPER_CUSTOMER_TYPE.

Because the easiest implementations need the representation of all
struct types to be identical, maybe your compiler is trying to enforce
their alignment as identical too? Why? You don't seem to be on a
machine where the generation of an unaligned pointer (rather than its
dereference) will create a hardware fault. 

But, in any case, wrapping an array in a struct may introduce padding
at the end.

WE:  
WE: 2. Assuming there is no technical reason for this difference, shouldn't  
WE: the C standard require that the layouts of these two types be the same?  
WE: [Please don't ask me for an exact phrasing - I'll happily leave that to  
WE: the experts.]

The C standards committee has been very unwilling to put absolutely
any limits on the implementation decision to introduce padding. I do
believe that a quality implementation should provide a pragma
(yecchhh)/compiler switch to pack structs: but that has little to do
with comp.std.c

Cheers
Tanmoy
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