Re: [PATCH] warnings: check -Wfoo rather than -Wno-foo

[Paul Eggert]

Eric Blake wrote:

> -  gl_AS_VAR_APPEND(m4_defn([gl_Flags]), [" $gl_unknown_warnings_are_errors 
> $1"])
> +  gl_AS_VAR_APPEND(m4_defn([gl_Flags]),
> +    [" $gl_unknown_warnings_are_errors ]m4_bpatsubst([$1], [^-Wno-], 
> [-W])["])

This assumes that gl_COMPILER_OPTION_IF's argument is
a constant, so won't it have trouble with the following
common idiom (this example taken from coreutils/configure.ac)?
 
  gl_MANYWARN_ALL_GCC([ws])
  gl_MANYWARN_COMPLEMENT([ws], [$ws], [$nw])
  for w in $ws; do
    gl_WARN_ADD([$w])
  done

gl_WARN_ADD calls gl_COMPILER_OPTION_IF.