c/9070: Improper warning when casting from pointer to non-const array to const

[Joseph S. Myers]

On Fri, 27 Dec 2002, Matthias Klose wrote:

> gcc generates a warning for the following test program, that I believe
> is inappropriate.  The warning is that it cannot implicitly cast from
> (foo *) to (const foo *).  This occurs when foo is an array type.  The
> sample program compiles without warnings if you remove the "const"
> keyword, or if you remove the [16] making foo an array.

It is an assignment from "pointer to array[16] of char" to "pointer to 
array[16] of const char" rather than to "pointer to const array[16] of 
char", by virtue of the requirement (6.7.3#8 in C99) that a type qualifier 
applied to an array type applies instead to the element type.  Thus the 
case of 6.5.16.1#1 that would be matched in the case of pointers to 
nonarray types adding qualifiers is not matched, thus the warning.

-- 
Joseph S. Myers
jsm28@cam.ac.uk