gcc4 generates lots of warnings like:

cairo_wideint.h:159: warning: type qualifiers ignored on function return type


Researching this for a similar bug on another project found:

  In ISO C, type qualifiers on the return type of a function are
  generally allowed but have no effect since the value returned by a
  function is not an lvalue (and can't be accessed after the next
  sequence point, so restrict qualifiers don't come into play).  Since
  such qualifiers won't have whatever effect a programmer might have
  intended, this patch adds a warning for them at -W (except for the
  "volatile void" GNU extension, which gets warned about at -pedantic).

Ref: http://gcc.gnu.org/ml/gcc-patches/2000-10/msg00814.html


I'll followup with patches to cairo_wideint.[ch] to remove the offending "const"
qualifiers.