gtkdoc: Add `ignore_headers` positional argument

Not all headers are public, or contain public types. GTK-Doc allows
adding headers to be ignored during the "scan" phase, by passing the
`--ignore-headers` command line argument to gtkdoc-scan.

Currently, you can do something like:

  ignored_headers = [ 'foo-private.h', 'bar-private.h', ]

  gnome.gtkdoc(...
               scan_args: [
                 '--ignore-headers=' + ' '.join(ignored_headers),
               ],
               ...)

But it does not guarantee escaping rules and it's definitely not nice.

We can add a simpler version of that mechanism through a new positional
argument, `ignore_headers`, which behaves like `content_files` or
`html_assets`, and takes an array of header files to ignore:

  gnome.gtkdoc(...
               ignore_headers: ignored_headers,
               ...)

1 files changed, 1 insertions, 0 deletions

diff --git a/mesonbuild/modules/gnome.py b/mesonbuild/modules/gnome.py
index 4ce8a4a..89d41c5 100644
--- a/mesonbuild/modules/gnome.py
+++ b/mesonbuild/modules/gnome.py
@@ -568,6 +568,7 @@ class GnomeModule:
         args += self.unpack_args('--fixxrefargs=', 'fixxref_args', kwargs)
         args += self.unpack_args('--html-assets=', 'html_assets', kwargs, state)
         args += self.unpack_args('--content-files=', 'content_files', kwargs, state)
+        args += self.unpack_args('--ignore-headers=', 'ignore_headers', kwargs)
         args += self.unpack_args('--installdir=', 'install_dir', kwargs, state)
         args += self.get_build_args(kwargs, state)
         res = [build.RunTarget(targetname, command[0], command[1:] + args, [], state.subdir)]