[OE-core][RFC] classes/native: Propagate dependencies to outhash

[Joshua Watt <jpewhacker@gmail.com>]

Native task outputs are directly run on the target (host) system after
being built. Even if the output of a native recipe doesn't change, a
change in one of its dependencies may cause a change in the output it
generates (e.g. rpm output depends on the output of its dependent zstd
library).

This can cause poor interactions with hash equivalence, since this
recipes output-changing dependency is "hidden" and downstream task only
see that this recipe has the same outhash and therefore is equivalent.
This can result in different output in different cases.

To resolve this, unhide the output-changing dependency by adding it's
unihash to this tasks outhash calculation. Unfortunately, don't know
specifically know which dependencies are output-changing, so we have to
add all of them.

[YOCTO #14685]

Signed-off-by: Joshua Watt <JPEWhacker@gmail.com>
---
 meta/classes/native.bbclass | 31 +++++++++++++++++++++++++++++++
 meta/lib/oe/sstatesig.py    | 10 +++++++---
 2 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/meta/classes/native.bbclass b/meta/classes/native.bbclass
index 76a599bc15..fc7422c5d7 100644
--- a/meta/classes/native.bbclass
+++ b/meta/classes/native.bbclass
@@ -195,3 +195,34 @@ USE_NLS = "no"
 
 RECIPERDEPTASK = "do_populate_sysroot"
 do_populate_sysroot[rdeptask] = "${RECIPERDEPTASK}"
+
+#
+# Native task outputs are directly run on the target (host) system after being
+# built. Even if the output of this recipe doesn't change, a change in one of
+# its dependencies may cause a change in the output it generates (e.g. rpm
+# output depends on the output of its dependent zstd library).
+#
+# This can cause poor interactions with hash equivalence, since this recipes
+# output-changing dependency is "hidden" and downstream task only see that this
+# recipe has the same outhash and therefore is equivalent. This can result in
+# different output in different cases.
+#
+# To resolve this, unhide the output-changing dependency by adding its unihash
+# to this tasks outhash calculation. Unfortunately, don't know specifically
+# know which dependencies are output-changing, so we have to add all of them.
+#
+python native_add_do_populate_sysroot_deps () {
+    current_task = "do_" + d.getVar("BB_CURRENTTASK")
+    if current_task != "do_populate_sysroot":
+        return
+
+    taskdepdata = d.getVar("BB_TASKDEPDATA", False)
+    pn = d.getVar("PN")
+    deps = {
+        dep[0]:dep[6] for dep in taskdepdata.values() if
+            dep[1] == current_task and dep[0] != pn
+    }
+
+    d.setVar("HASHEQUIV_EXTRA_SIGDATA", "\n".join("%s: %s" % (k, deps[k]) for k in sorted(deps.keys())))
+}
+SSTATECREATEFUNCS += "native_add_do_populate_sysroot_deps"
diff --git a/meta/lib/oe/sstatesig.py b/meta/lib/oe/sstatesig.py
index 038404e377..abcd96231e 100644
--- a/meta/lib/oe/sstatesig.py
+++ b/meta/lib/oe/sstatesig.py
@@ -491,7 +491,8 @@ def OEOuthashBasic(path, sigfile, task, d):
     if task == "package":
         include_timestamps = True
         include_root = False
-    extra_content = d.getVar('HASHEQUIV_HASH_VERSION')
+    hash_version = d.getVar('HASHEQUIV_HASH_VERSION')
+    extra_sigdata = d.getVar("HASHEQUIV_EXTRA_SIGDATA")
 
     filemaps = {}
     for m in (d.getVar('SSTATE_HASHEQUIV_FILEMAP') or '').split():
@@ -506,8 +507,11 @@ def OEOuthashBasic(path, sigfile, task, d):
         basepath = os.path.normpath(path)
 
         update_hash("OEOuthashBasic\n")
-        if extra_content:
-            update_hash(extra_content + "\n")
+        if hash_version:
+            update_hash(hash_version + "\n")
+
+        if extra_sigdata:
+            update_hash(extra_sigdata + "\n")
 
         # It is only currently useful to get equivalent hashes for things that
         # can be restored from sstate. Since the sstate object is named using
-- 
2.33.0