[OE-core][PATCH v2] sstatesig: Include all dependencies in SPDX task signatures

[Joshua Watt <jpewhacker@gmail.com>]

SDPX generation involves looking through BB_TASKDEPDATA for
dependencies, then linking to the generated documents for those
dependencies. These document links use a checksum to validate the
document, which means that if a upstream document changes, all
downstream documents must be regenerated to get the new checksum,
otherwise the compendium of documents produced by the build will have
broken links; therefore all dependent task should be included in the
signature (even from "ABI safe" recipes).

Signed-off-by: Joshua Watt <JPEWhacker@gmail.com>
---
 meta/lib/oe/sstatesig.py | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/meta/lib/oe/sstatesig.py b/meta/lib/oe/sstatesig.py
index 7150bd0929..de65244932 100644
--- a/meta/lib/oe/sstatesig.py
+++ b/meta/lib/oe/sstatesig.py
@@ -24,10 +24,19 @@ def sstate_rundepfilter(siggen, fn, recipename, task, dep, depname, dataCaches):
         return "/allarch.bbclass" in inherits
     def isImage(mc, fn):
         return "/image.bbclass" in " ".join(dataCaches[mc].inherits[fn])
+    def isSPDXTask(task):
+        return task in ("do_create_spdx", "do_create_runtime_spdx")
 
     depmc, _, deptaskname, depmcfn = bb.runqueue.split_tid_mcfn(dep)
     mc, _ = bb.runqueue.split_mc(fn)
 
+    # Keep all dependencies between SPDX tasks in the signature. SPDX documents
+    # are linked together by hashes, which means if a dependent document changes,
+    # all downstream documents must be re-written (even if they are "safe"
+    # dependencies).
+    if isSPDXTask(task) and isSPDXTask(deptaskname):
+        return True
+
     # (Almost) always include our own inter-task dependencies (unless it comes
     # from a mcdepends). The exception is the special
     # do_kernel_configme->do_unpack_and_patch dependency from archiver.bbclass.
-- 
2.33.0