lib: Fix dependencies on SPDX code

The SPDX library code was being ignored from taskhash calculations due
to accidentally being omitted from BBIMPORTS. This meant that changes in
the code or dependent variables would not cause the task to rebuild
correctly.

In order to add spdx_common, convert the `Dep` object from a named tuple
to a frozen dataclass. These function more or less equivalently, but the
bitbake code parser cannot handle named tuples.

Finally, the vardepsexclude that used to be present on the recipe tasks
needs to be moved to the python code in order for the variables to be
correctly ignored. Several unused exclusions were removed

(From OE-Core rev: eb597bf61cbcb0a4d43149404c93eec0894fb4c7)

Signed-off-by: Joshua Watt <JPEWhacker@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/create-spdx-3.0.bbclass

@@ -134,7 +134,6 @@ python do_create_spdx() {
     import oe.spdx30_tasks
     oe.spdx30_tasks.create_spdx(d)
 }
-do_create_spdx[vardepsexclude] += "BB_NUMBER_THREADS SPDX_BUILD_HOST"
 do_create_spdx[vardeps] += "\
     SPDX_INCLUDE_BITBAKE_PARENT_BUILD \
     SPDX_PACKAGE_ADDITIONAL_PURPOSE \
@@ -170,7 +169,7 @@ python do_create_package_spdx() {
     import oe.spdx30_tasks
     oe.spdx30_tasks.create_package_spdx(d)
 }
-do_create_package_spdx[vardepsexclude] += "OVERRIDES SPDX_MULTILIB_SSTATE_ARCHS"
+oe.spdx30_tasks.create_package_spdx[vardepsexclude] = "OVERRIDES"
 
 addtask do_create_package_spdx after do_create_spdx before do_build do_rm_work
 SSTATETASKS += "do_create_package_spdx"

meta/lib/oe/__init__.py

@@ -11,4 +11,4 @@ __path__ = extend_path(__path__, __name__)
 # processed correctly (e.g. qa)
 BBIMPORTS = ["qa", "data", "path", "utils", "types", "package", "packagedata", \
              "packagegroup", "sstatesig", "lsb", "cachedpath", "license", \
-             "reproducible", "rust", "buildcfg", "go"]
+             "reproducible", "rust", "buildcfg", "go", "spdx30_tasks", "spdx_common"]

meta/lib/oe/spdx_common.py

@@ -12,7 +12,7 @@ import re
 import shutil
 
 from pathlib import Path
-
+from dataclasses import dataclass
 
 LIC_REGEX = re.compile(
     rb"^\W*SPDX-License-Identifier:\s*([ \w\d.()+-]+?)(?:\s+\W*)?$",
@@ -77,7 +77,11 @@ def process_sources(d):
     return True
 
 
-Dep = collections.namedtuple("Dep", ["pn", "hashfn", "in_taskhash"])
+@dataclass(frozen=True)
+class Dep(object):
+    pn: str
+    hashfn: str
+    in_taskhash: bool
 
 
 def collect_direct_deps(d, dep_task):