[cfe-dev] Compound Literal semantic analysis...

[Chris Lattner]

>> C99 6.5.2.5p6 says the following:
>>
>> The value of the compound literal is that of an unnamed object
>> initialized by the
>> initializer list. If the compound literal occurs outside the body  
>> of a
>> function, the object
>> has static storage duration; otherwise, it has automatic storage
>> duration associated with
>> the enclosing block.
>>
>> This seems pretty clear to me...GCC is right and EDG is wrong.
>>
>> Anyone disagree?
>
> I'm curious about your reasoning.  My front end, which is pretty
> good about most things but a tad weak on compuond literals emits:
>
> neil at duron:~/src/c$ ../cfe/cfe /tmp/bug.c
> "/tmp/bug.c", line 3: error: expression must be a constant
> static int *t = &tmp;        // Both GCC and EDG issue an error
>                ^
> "/tmp/bug.c", line 4: warning: declaration hides function "a" declared
> at line 1
> static int *a = (int[]){1}; // GCC issues an error diagnostic for this
>            ^
> "/tmp/bug.c", line 3: warning: variable "t" declared but not used
> static int *t = &tmp;        // Both GCC and EDG issue an error
>            ^
> "/tmp/bug.c", line 4: warning: variable "a" declared but not used
> static int *a = (int[]){1}; // GCC issues an error diagnostic for this
>            ^
>
> 1 error found compiling "/tmp/bug.c".
>
> Which agrees with GCC and seems pretty reasonable to me :)

Compatibility with GCC isn't as important as compatibility with the  
spec (i.e. we should accept this, but as an explicit extension).  The  
spec says:

"If the compound literal occurs outside the body of a
function, the object
has static storage duration; otherwise, it has automatic storage
duration associated with
the enclosing block."

Doesn't that preclude this example from being accepted, or does  
"automatic storage" still mean it can be a constant somehow?

-Chris