[dune] [doc] Support for building the reference manual with Dune.

This is a reduced version of #8503 as to provide a way to build the
reference manual with Dune.

Dune 1.6 supports (experimentally) directories as targets, thus we
introduce a rule that will call `sphinx` to build the manual.

This only provides build, however generation of `.install` rules is
not done, it will be hopefully addressed in #8503.

Note that we set `expire: 1 month` for all the artifacts we build with
Dune. IMHO this makes most sense as not to abuse Gitlab's hosting,
however of course we could consider a different deployment strategy if
wanted.

1 files changed, 24 insertions, 0 deletions

diff --git a/doc/dune b/doc/dune
new file mode 100644
index 0000000000..54ffa87205
--- /dev/null
+++ b/doc/dune
@@ -0,0 +1,24 @@
+(rule
+ (targets sphinx_build)
+ (deps
+  ; We could use finer dependencies here so the build is faster:
+  ;
+  ; - vo files: generated by sphinx after parsing the doc, promoted,
+  ; - Static files:
+  ;   + %{bin:coqdoc} etc...
+  ;   + config/coq_config.py
+  ;   + tools/coqdoc/coqdoc.css
+  (package coq)
+  (source_tree sphinx)
+  (source_tree tools))
+ (action (run sphinx-build -j4 -b html -d sphinx_build/doctrees sphinx sphinx_build/html)))
+
+(alias
+ (name refman-html)
+ (deps sphinx_build))
+
+; The install target still needs more work.
+; (install
+;  (section doc)
+;  (package coq-refman)
+;  (files sphinx_build))