[cfe-dev] Nasty problem in sizeof evaluation?

[Abramo Bagnara]

$ cat p.c
#define HUGE (1LL<<61)
typedef char a[HUGE];
typedef char b[(long long)sizeof(a)-1];

$ clang -m64 p.c
p.c:3:16: error: array size is negative
typedef char b[(long long)sizeof(a)-1];
               ^~~~~~~~~~~~~~~~~~~~~~
1 error generated.

I believe this is due to the fact that type size is evaluated in bits
unit with 64 bits of precision and then it is divided by 8.

This lead to the observed problem.