Paul Eggert wrote: > +/* Specify the number of elements of a function's array parameter, > + as in 'int f (int n, int a[__ARG_NELTS (n)]);'. */ > +#if (defined __STDC_VERSION__ && 199901L <= __STDC_VERSION__ \ > + && !defined __STDC_NO_VLA__) > +# define __ARG_NELTS(n) n > +#else > +# define __ARG_NELTS(n) > +#endif
The documentation of this macro makes it look like it expects an expression as argument. But in the later uses you also often pass the keyword 'static': > + regmatch_t pmatch[__ARG_NELTS (static nmatch)], > + regmatch_t prev_idx_match[__ARG_NELTS (static nmatch)], How about changing the comment to /* Specify the number of elements of a function's array parameter, as in 'int f (int n, int a[__ARG_NELTS (n)]);' or 'int f (int n, int a[__ARG_NELTS (static n)]);' */ By the way, what is the point of adding the 'static' keyword? From [1][2][3] I understand that when one writes 'TYPE a[static n]' it denotes a pointer to an array of at least n objects of type TYPE. But since, for any m ≥ n, a pointer to m objects of type TYPE is also a pointer to n objects of type TYPE, the words "at least" are redundant: 'TYPE a[static n]' denotes a pointer to an array of n objects of type TYPE. So, what does 'TYPE a[n]' denote, then? - the same thing? - or a pointer to one object of type TYPE, just like 'TYPE a[]'? Either way, the syntax 'TYPE a[n]' (without 'static') in function parameter declarations appears redundant. Correct? In that case, shouldn't the comment be changed to /* Specify the number of elements of a function's array parameter, together with the 'static' keyword, as in 'int f (int n, int a[__ARG_NELTS (static n)]);' */ Bruno [1] ISO C 11, § 6.7.6.3.(7) [2] https://en.cppreference.com/w/c/language/array [3] https://stackoverflow.com/questions/17559631/what-are-those-strange-array-sizes-and-static-in-c99
