Array indexing/offset inline asm ambiguity

[David Nadlinger]

Hi all,

Another installment in the »What does the following function 
return« series:

---
int[2] foo() {
   int[2] regs;
   asm {
     mov regs[1], 0xdeadbeef;
   }
   return regs;
}
---

If you answered [0, 0xdeadbeef], then congratulations: You fell 
into exactly the same trap as Martin Nowak and I did in 
https://github.com/D-Programming-Language/druntime/pull/426, 
without any of the other reviewers noticing either.

The issue is that in an inline asm block, regs[1] is actually 
equivalent to 1[regs] or [regs + 1] and evaluates to an address 
one *byte* after the start of regs, not one element as it does 
everywhere else.

In my opinion, this is completely counterintuitive and a source 
of bugs that could easily be prevented by the language. But 
Walter seems to think this issue not worth addressing: 
http://d.puremagic.com/issues/show_bug.cgi?id=9738

What do you think?

Thanks,
David