Merge branch 'maint'

Author: kvakvs

system/doc/top/Makefile

@@ -81,9 +81,11 @@ man_index.md: src/otp_man_index.beam $(wildcard $(ERL_TOP)/erts/ebin/*.beam) $(w
 
 core/erts.md: Makefile | core
 	$(gen_verbose)echo "# erts" > $@
+
+MISSING_APP_DISCLAIMER="The documentation for this application was not generated because the application was skipped during the source build."
 %.md: Makefile | core database oam interfaces tools testing documentation
 	$(gen_verbose)APP=$(basename $(notdir $@)) && \
-		echo "# $${APP}" > $@
+		echo "# $${APP}\n\n$(MISSING_APP_DISCLAIMER)\n" > $@
 
 HTML_DEPS=README.md man_index.md ../guides $(REDIRECTS)
 EPUB=false

system/doc/top/docs.exs

@@ -25,10 +25,26 @@ system_guides =
     line |> String.split(":") |> Enum.at(0)
   end)
 
+# Root /configure creates artifact /lib/SKIP-APPLICATIONS containing all apps
+# not built for various reasons. We can't build documentation for them either.
+skipped_apps_from_file =
+  with erl_top when is_binary(erl_top) <- System.get_env("ERL_TOP"),
+       skip_path <- Path.join([erl_top, "lib", "SKIP-APPLICATIONS"]),
+       true <- File.exists?(skip_path),
+       {:ok, content} <- File.read(skip_path) do
+    content
+    |> String.split(~r/\s+/, trim: true)
+    |> Enum.map(&String.downcase/1)
+    |> MapSet.new()
+  else
+    _ -> MapSet.new()
+  end
+
 apps =
   Path.wildcard("{core,database,oam,interfaces,tools,testing,documentation}/*.md")
   |> Enum.map(&Path.basename/1)
   |> Enum.map(&Path.rootname/1)
+  |> Enum.reject(fn app -> skipped_apps_from_file |> MapSet.member?(app) end)
 
 redirects =
   Enum.map(apps, fn