Re: meson documentation build open issues

On 09.11.23 01:59, Andres Freund wrote:
>> I think we could build doc/src/sgml/postgres-full.xml by default.  That
>> takes less than 0.5 seconds here and it's an intermediate target for html
>> and man.
> That does require the docbook dtd to be installed, afaict. I think we would
> need a configure test for that to be present if we want to build it by
> default, otherwise we'll cause errors on plenty systems that don't get them
> today.  The docbook dts aren't a huge dependency, but still. Some OSs might
> not have a particularly install source for them, e.g. windows.

I was thinking we would do it only if the required tools are found. 
Basically like

  postgres_full_xml = custom_target('postgres-full.xml',
    input: 'postgres.sgml',
    output: 'postgres-full.xml',
    depfile: 'postgres-full.xml.d',
    command: [xmllint, '--nonet', '--noent', '--valid',
              '--path', '@OUTDIR@', '-o', '@OUTPUT@', '@INPUT@'],
    depends: doc_generated,
-  build_by_default: false,
+  build_by_default: xmllint_bin.found(),
  )

Besides giving you a quick validity check of the XML, this also builds 
the doc_generated, which draw from non-doc source files, so this would 
also serve to check that those are sound and didn't mess up the docs.

> I don't think that'd detect the missing ids?

Right, it wouldn't do that.