check-variable-fonts.py: add a helper to display instructions

Use lib docstring to output the comments via --help/-h. With
that, update the default instructions to recomment it instead
of asking the user to read the source code.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Message-ID: <577162cf4e07de74c4a783f16e3404f0040e5e0a.1758196090.git.mchehab+huawei@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

1 files changed, 9 insertions, 4 deletions

diff --git a/tools/docs/lib/latex_fonts.py b/tools/docs/lib/latex_fonts.py
index 81358a70f320..29317f8006ea 100755
--- a/tools/docs/lib/latex_fonts.py
+++ b/tools/docs/lib/latex_fonts.py
@@ -105,14 +105,18 @@ class LatexFontChecker:
     translations.
     """
 
-    def __init__(self):
-        deny_vf = os.environ.get('FONTS_CONF_DENY_VF', "~/deny-vf")
+    def __init__(self, deny_vf=None):
+        if not deny_vf:
+            deny_vf = os.environ.get('FONTS_CONF_DENY_VF', "~/deny-vf")
 
         self.environ = os.environ.copy()
         self.environ['XDG_CONFIG_HOME'] = os.path.expanduser(deny_vf)
 
         self.re_cjk = re.compile(r"([^:]+):\s*Noto\s+(Sans|Sans Mono|Serif) CJK")
 
+    def description(self):
+        return __doc__
+
     def get_noto_cjk_vf_fonts(self):
         """Get Noto CJK fonts"""
 
@@ -154,8 +158,9 @@ class LatexFontChecker:
                 For CJK pages in PDF, they need to be hidden from XeTeX by denylisting.
                 Or, CJK pages can be skipped by uninstalling texlive-xecjk.
 
-                For more info on denylisting, other options, and variable font, see header
-                comments of {rel_file}.
+                For more info on denylisting, other options, and variable font, run:
+
+                    tools/docs/check-variable-fonts.py -h
             """)
         msg += "=" * 77