From: Cursor Agent <cursoragent@cursor.com>
Date: Mon, 20 Oct 2025 10:15:38 +0000
Subject: doc: enable parallel Sphinx builds; silence edit_on_github

Mark the custom edit_on_github extension as safe for parallel
reading/writing and forward GNU make's -j to sphinx-build. This removes
the Sphinx warning and allows true parallel docs builds.

Changes
- doc/source/_ext/edit_on_github.py: setup() now returns
  parallel_read_safe=True and parallel_write_safe=True (plus version).
- doc/Makefile: if SPHINXOPTS lacks -j, propagate -jN from MAKEFLAGS to
  sphinx-build. Bare "-j" maps to "-j auto". Respects explicit -j in
  SPHINXOPTS.

Fixes: https://github.com/rsyslog/rsyslog/issues/6254

Co-authored-by: alorbach <alorbach@adiscon.com>
(cherry picked from commit 81eabd3cb3e358bffcb2e648fcd0102e62660547)
---
 doc/Makefile                      | 13 ++++++++++++-
 doc/source/_ext/edit_on_github.py |  8 ++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/doc/Makefile b/doc/Makefile
index 9c8d292..4164bfd 100644
--- a/doc/Makefile
+++ b/doc/Makefile
@@ -1,32 +1,43 @@
 # Makefile for rsyslog-doc
 #
 # You can set these variables from the command line.
-SPHINXOPTS ?=
+SPHINXOPTS := $(SPHINXOPTS)
 SPHINXBUILD ?= sphinx-build
 SOURCEDIR = source
 BUILDDIR = build
 
+# Function to add parallel jobs from MAKEFLAGS to SPHINXOPTS
+define add_parallel_jobs
+	$(eval SPHINXOPTS += $(if $(filter -j%,$(SPHINXOPTS)),,$(filter -j%,$(MAKEFLAGS))))
+endef
+
 .PHONY: help clean html singlehtml json alljson
 
 help:
+	@$(call add_parallel_jobs)
 	@$(SPHINXBUILD) -M help "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
 
 clean:
 	rm -rf "$(BUILDDIR)"
 
 html:
+	@$(call add_parallel_jobs)
 	@$(SPHINXBUILD) -M html "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
 
 singlehtml:  # -t minimal_build triggers stripped-down config in conf.py
+	@$(call add_parallel_jobs)
 	@$(SPHINXBUILD) -M singlehtml "$(SOURCEDIR)" "$(BUILDDIR)" -t minimal_build $(SPHINXOPTS) -D rst_epilog='' $(O)
 	@echo
 	@echo "Build finished. The minimal single page HTML is in $(BUILDDIR)/singlehtml."
 
 json:
+	@$(call add_parallel_jobs)
 	@$(SPHINXBUILD) -b json "$(SOURCEDIR)" "$(BUILDDIR)/json" $(SPHINXOPTS) $(O)
 
 alljson: json
+	@$(call add_parallel_jobs)
 	@$(SPHINXBUILD) -b json "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
 
 %:
+	@$(call add_parallel_jobs)
 	@$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
diff --git a/doc/source/_ext/edit_on_github.py b/doc/source/_ext/edit_on_github.py
index a8d22c1..0c86dff 100644
--- a/doc/source/_ext/edit_on_github.py
+++ b/doc/source/_ext/edit_on_github.py
@@ -40,4 +40,12 @@ def setup(app):
     app.add_config_value('edit_on_github_project', '', True)
     app.add_config_value('edit_on_github_branch', 'master', True)
     app.connect('html-page-context', html_page_context)
+    # Declare the extension as safe for Sphinx parallel reading/writing.
+    # This extension does not maintain global mutable state and only
+    # augments per-page rendering context, so it is safe.
+    return {
+        'version': '1.0',
+        'parallel_read_safe': True,
+        'parallel_write_safe': True,
+    }