staging: Remove uninstalled dependencies from sysroots

Currently, if something is added to a sysroot, its hash remains unchanged,
and it continues to be buildable, it doesn't get removed from the sysroot.

This patch handles the case where something is removed from DEPENDS or
[depends].

It does introduce its own issue where something could get removed even
though some other task in parallel may have the same requirement. This
case should be extrememly rare and fixing the more common DEPENDS removal
is likely the bigger win though.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 28 insertions, 0 deletions

diff --git a/meta/classes/staging.bbclass b/meta/classes/staging.bbclass
index 6dd21e8ec4..27fcd1efa9 100644
--- a/meta/classes/staging.bbclass
+++ b/meta/classes/staging.bbclass
@@ -469,6 +469,8 @@ python extend_recipe_sysroot() {
     multilibs = {}
     manifests = {}
 
+    installed = []
+
     for f in os.listdir(depdir):
         if not f.endswith(".complete"):
             continue
@@ -487,6 +489,9 @@ python extend_recipe_sysroot() {
         if mytaskname in ["do_sdk_depends", "do_populate_sdk_ext"] and c.endswith("-initial"):
             bb.note("Skipping initial setscene dependency %s for installation into the sysroot" % c)
             continue
+
+        installed.append(c)
+
         if os.path.exists(depdir + "/" + c):
             lnk = os.readlink(depdir + "/" + c)
             if lnk == c + "." + taskhash and os.path.exists(depdir + "/" + c + ".complete"):
@@ -601,6 +606,29 @@ python extend_recipe_sysroot() {
         c = setscenedeps[dep][0]
         os.symlink(manifests[dep], depdir + "/" + c + ".complete")
 
+    # We want to remove anything which this task previously installed but is no longer a dependency
+    # This could potentially race against another task which also installed it but still requires it
+    # but the alternative is not doing anything at all and that race window should be small enough
+    # to be insignificant
+    taskindex = depdir + "/" + "index." + mytaskname
+    if os.path.exists(taskindex):
+        with open(taskindex, "r") as f:
+            for l in f:
+                l = l.strip()
+                if l not in installed:
+                    l = depdir + "/" + l
+                    if not os.path.exists(l):
+                        # Was likely already uninstalled
+                        continue
+                    bb.note("Task %s no longer depends on %s, removing from sysroot" % (mytaskname, l))
+                    lnk = os.readlink(l)
+                    sstate_clean_manifest(depdir + "/" + lnk, d, workdir)
+                    os.unlink(l)
+                    os.unlink(l + ".complete")
+    with open(taskindex, "w") as f:
+        for l in sorted(installed):
+            f.write(l + "\n")
+
     bb.utils.unlockfile(lock)
 }
 extend_recipe_sysroot[vardepsexclude] += "MACHINE_ARCH PACKAGE_EXTRA_ARCHS SDK_ARCH BUILD_ARCH SDK_OS BB_TASKDEPDATA"