[ovs-dev] [PATCH v2 4/5] make: Ensure flake8, sphinx run when required

[Stephen Finucane]

If someone makes changes to documentation or Python scripts, they should
validate these changes using the relevant targets. However, said targets
use optional dependencies and are not guaranteed to be enabled. Enforce
running of these checks whenever changes are made to select files,
ensuring the user has installed the changes.

Signed-off-by: Stephen Finucane <stephen at that.guru>
---
 Documentation/automake.mk    | 12 ++++++++----
 Makefile.am                  |  5 ++++-
 build-aux/check-file-changes | 19 +++++++++++++++++++
 3 files changed, 31 insertions(+), 5 deletions(-)
 create mode 100755 build-aux/check-file-changes

diff --git a/Documentation/automake.mk b/Documentation/automake.mk
index 51abd55..aac21d5 100644
--- a/Documentation/automake.mk
+++ b/Documentation/automake.mk
@@ -103,13 +103,17 @@ htmldocs:
 	$(SPHINXBUILD) -b html $(ALLSPHINXOPTS) $(SPHINXBUILDDIR)/html
 ALL_LOCAL += htmldocs
 
-check-docs:
-	$(SPHINXBUILD) -b linkcheck $(ALLSPHINXOPTS) $(SPHINXBUILDDIR)/linkcheck
-
 clean-docs:
 	rm -rf $(SPHINXBUILDDIR)/*
 CLEAN_LOCAL += clean-docs
 endif
 .PHONY: htmldocs
-.PHONY: check-docs
 .PHONY: clean-docs
+
+check-docs:
+if HAVE_SPHINX
+	$(SPHINXBUILD) -b linkcheck $(ALLSPHINXOPTS) $(SPHINXBUILDDIR)/linkcheck
+else
+	$(srcdir)/build-aux/check-file-changes "Documentation/" "sphinx"
+endif
+.PHONY: check-docs
diff --git a/Makefile.am b/Makefile.am
index 74839e1..7969fd1 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -79,6 +79,7 @@ EXTRA_DIST = \
 	build-aux/cccl \
 	build-aux/cksum-schema-check \
 	build-aux/calculate-schema-cksum \
+	build-aux/check-file-changes \
 	build-aux/dist-docs \
 	build-aux/sodepends.pl \
 	build-aux/soexpand.pl \
@@ -319,7 +320,6 @@ manpage-check: $(man_MANS) $(dist_man_MANS) $(noinst_man_MANS)
 CLEANFILES += manpage-check
 endif
 
-if HAVE_FLAKE8
 ALL_LOCAL += flake8-check
 # http://flake8.readthedocs.org/en/latest/warnings.html
 # All warnings explicitly selected or ignored should be listed below.
@@ -343,9 +343,12 @@ ALL_LOCAL += flake8-check
 #   H233 Python 3.x incompatible use of print operator
 #   H238 old style class declaration, use new style (inherit from `object`)
 flake8-check: $(FLAKE8_PYFILES)
+if HAVE_FLAKE8
 	$(AM_V_GEN) if flake8 $^ --select=H231,H232,H233,H238 ${FLAKE8_FLAGS} && \
 		flake8 $^ --ignore=E121,E123,E125,E126,E127,E128,E129,E131,W503,F811,D,H ${FLAKE8_FLAGS}; then \
 		touch $@; else exit 1; fi
+else
+	$(srcdir)/build-aux/check-file-changes "python/" "flake8"
 endif
 CLEANFILES += flake8-check
 
diff --git a/build-aux/check-file-changes b/build-aux/check-file-changes
new file mode 100755
index 0000000..5c0b809
--- /dev/null
+++ b/build-aux/check-file-changes
@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+
+directory="$1"
+dependency="$2"
+
+# ensure git is actually installed
+if ! type "git" > /dev/null; then
+    printf "git is not available - skipping check-file-changes"
+    exit 0
+fi
+
+file_changes=$(git diff --name-only master..HEAD "$directory")
+
+if [ -n "$file_changes" ]; then
+    printf "There are changes in the '$directory' directory, but the "
+    printf "'$dependency' dependency is missing. Install missing dependencies "
+    printf "before continuing.\n"
+    exit 1
+fi
-- 
2.9.3