Re: hash: provide hash_xinitialize

[Bruno Haible]

Hi Akim,

>     * modules/hash (Depends-on): Add xalloc.
>     * lib/hash.h, lib/hash.c (hash_xinitialize): New.

This patch produces gnulib-tool warnings:

$ ./gnulib-tool --test hash
gnulib-tool: warning: module hash depends on a module with an incompatible 
license: error
gnulib-tool: warning: module hash depends on a module with an incompatible 
license: getprogname
gnulib-tool: warning: module hash depends on a module with an incompatible 
license: xalloc
gnulib-tool: warning: module hash depends on a module with an incompatible 
license: xalloc-die
...

What gnulib-tool is telling you is that the module 'hash' has a license
that makes it suitable for use in libraries. Adding a dependency to 'xalloc'
to it can't be done in this module, because library code should never
call xalloc_die().

The fix is to create a new module, with prefix 'x', that adds the
function. You can leave it declared in hash.h; this is not a problem.
But it needs to be defined in a different compilation unit.

For a model of this idiom, look at the modules 'concat-filename'
and 'xconcat-filename'.

Bruno