function attribute const

[Jan Hubicka]

> The gcc info page says
> 
>      Note that a function that has pointer arguments and examines the
>      data pointed to must _not_ be declared `const'.
> 
> If the programmer knows that the data structures which a function
> examines will not change from one invocation of the function to
> another, why can't the function be declared const?

Compiler may want to move the function call around and may get it before
the structure is initialized.

Honza
> 
> Tony.