poky.yaml: introduce DISTRO_LATEST_TAG

Introduce the DISTRO_LATEST_TAG macro, which should always point to the
latest existing tag in the documentation, unlike DISTRO which may point
to A.B.999 to represent the tip of a branch.

This variable is needed to fix dead links in the documentation that
currently use the DISTRO macro.

Also, make DISTRO_REL_TAG use the DISTRO macro directly, to avoid
repetition, and add a DISTRO_REL_LATEST_TAG macro that has the same role
as DISTRO_LATEST_TAG but with "yocto-" prepended to it.

In set_versions.py, run the "git describe --abbrev=0 --tags
--match='yocto-*'" command to get the latest existing tag on the
currently checked out commit. Fallback to ourversion in case we didn't
find any.

(From yocto-docs rev: 9fabb08405601646fd9b00326442e03d43f68804)

Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
(cherry picked from commit a85b0e500c94921f77fa7b7dbb877e4945f96d1e)
Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

2 files changed, 23 insertions, 2 deletions

diff --git a/documentation/poky.yaml.in b/documentation/poky.yaml.in
index 7a71007f93..de880af514 100644
--- a/documentation/poky.yaml.in
+++ b/documentation/poky.yaml.in
@@ -2,13 +2,22 @@
 # Macros used in the documentation
 #
 
+# The DISTRO variable represents the current docs version. It should be used
+# when referring to the current docs version. See also DISTRO_LATEST_TAG.
 DISTRO : "4.0"
+# The DISTRO_LATEST_TAG represents the latest tag on the current branch. It
+# should be used in HTTP link referring to the current docs version. In these
+# cases, the DISTRO may point to A.B.999 which does not exist (just used to
+# represent the latest HEAD revision on the branch). DISTRO_LATEST_TAG should
+# always point to an existing tag.
+DISTRO_LATEST_TAG : "4.0"
 DISTRO_NAME_NO_CAP : "kirkstone"
 DISTRO_NAME : "Kirkstone"
 DISTRO_NAME_NO_CAP_MINUS_ONE : "honister"
 DISTRO_NAME_NO_CAP_LTS : "dunfell"
 YOCTO_DOC_VERSION : "4.0"
-DISTRO_REL_TAG : "yocto-4.0"
+DISTRO_REL_TAG : "yocto-$DISTRO;"
+DISTRO_REL_LATEST_TAG : "yocto-&DISTRO_LATEST_TAG;"
 DOCCONF_VERSION : "dev"
 BITBAKE_SERIES : ""
 YOCTO_DL_URL : "https://downloads.yoctoproject.org"
diff --git a/documentation/set_versions.py b/documentation/set_versions.py
index 33d9da55ea..3ae7a07f4f 100755
--- a/documentation/set_versions.py
+++ b/documentation/set_versions.py
@@ -152,17 +152,29 @@ series = [k for k in release_series]
 previousseries = series[series.index(ourseries)+1:] or [""]
 lastlts = [k for k in previousseries if k in ltsseries] or "dunfell"
 
+latestreltag = subprocess.run(["git", "describe", "--abbrev=0", "--tags", "--match", "yocto-*"], capture_output=True, text=True).stdout
+latestreltag = latestreltag.strip()
+if latestreltag:
+    if latestreltag.startswith("yocto-"):
+        latesttag = latestreltag[6:]
+else:
+    # fallback on the calculated version
+    print("Did not find a tag with 'git describe', falling back to %s" % ourversion)
+    latestreltag = "yocto-" + ourversion
+    latesttag = ourversion
+
 print("Version calculated to be %s" % ourversion)
+print("Latest release tag found is %s" % latestreltag)
 print("Release series calculated to be %s" % ourseries)
 
 replacements = {
     "DISTRO" : ourversion,
+    "DISTRO_LATEST_TAG": latesttag,
     "DISTRO_NAME_NO_CAP" : ourseries,
     "DISTRO_NAME" : ourseries.capitalize(),
     "DISTRO_NAME_NO_CAP_MINUS_ONE" : previousseries[0],
     "DISTRO_NAME_NO_CAP_LTS" : lastlts[0],
     "YOCTO_DOC_VERSION" : ourversion,
-    "DISTRO_REL_TAG" : "yocto-" + ourversion,
     "DOCCONF_VERSION" : docconfver,
     "BITBAKE_SERIES" : bitbakeversion,
 }