[PATCH] docs: Makefile: Add a testdocs target for the documentation unit tests

[Kees Cook <kees@kernel.org>]

tools/unittests/run.py discovers and runs the unit tests there (which
are primarily documentation tools), but nothing in the build calls it,
so the tests are only run by whoever remembers that the script is there.

Give it a target, next to the other checks that need no Sphinx. The name
ends in "docs", so it matches the "%docs" pattern already in
no-dot-config-targets and runs without a configured tree, and it sets
PYTHONPYCACHEPREFIX as the other Python targets here do, to keep
__pycache__ directories out of the source tree.

  $ make testdocs
  ...
  Ran 121 tests

with "make dochelp" listing it between refcheckdocs and cleandocs.

Tested with GNU Make 4.4.1 and Python 3.14.7, on a tree with no .config,
where it ran 121 tests and left no __pycache__ behind.

Assisted-by: LLM
Signed-off-by: Kees Cook <kees@kernel.org>
---
I debated the naming here, since "tools/unittests/" is such a general
directory location, but figured I'd start with a target that made the most
logical sense given what is actually being tested there? I dunno. Maybe
"make testtools"? But that reads weird.
---
 Makefile               | 2 +-
 Documentation/Makefile | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 66654fa71655..88557288163d 100644
--- a/Makefile
+++ b/Makefile
@@ -2002,7 +2002,7 @@ $(help-board-dirs): help-%:
 # ---------------------------------------------------------------------------
 DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
 	       linkcheckdocs dochelp refcheckdocs texinfodocs infodocs mandocs \
-	       htmldocs-redirects
+	       htmldocs-redirects testdocs
 
 PHONY += $(DOC_TARGETS)
 $(DOC_TARGETS):
diff --git a/Documentation/Makefile b/Documentation/Makefile
index 377a449656c8..ee852afe9bb9 100644
--- a/Documentation/Makefile
+++ b/Documentation/Makefile
@@ -74,6 +74,10 @@ htmldocs-redirects: $(srctree)/Documentation/.renames.txt
 refcheckdocs:
 	$(Q)cd $(srctree); tools/docs/documentation-file-ref-check
 
+testdocs:
+	$(Q)PYTHONPYCACHEPREFIX="$(PYTHONPYCACHEPREFIX)" \
+		$(PYTHON3) $(srctree)/tools/unittests/run.py
+
 cleandocs:
 	$(Q)rm -rf $(BUILDDIR)
 
@@ -95,6 +99,7 @@ dochelp:
 	@echo  '                    (will connect to external hosts)'
 	@echo  '  refcheckdocs    - check for references to non-existing files under'
 	@echo  '                    Documentation'
+	@echo  '  testdocs        - run the unit tests of the documentation tools'
 	@echo  '  cleandocs       - clean all generated files'
 	@echo
 	@echo  '  make SPHINXDIRS="s1 s2" [target] Generate only docs of folder s1, s2'
-- 
2.34.1