spdxcheck: enforce SPDX license tags on build system files

Sponsored-by: https://despairlabs.com/sponsor/
Signed-off-by: Rob Norris <robn@despairlabs.com>

Author: robn

scripts/spdxcheck.pl

@@ -82,6 +82,11 @@
 	man/man?/*.?
 	man/man?/*.?.in
 
+	# Build system
+	*.ac
+	*.am
+	*.m4
+
 	# Unsuffixed programs (or generated of same)
 	cmd/zarcstat.in
 	cmd/zarcsummary
@@ -98,8 +103,6 @@
 
 	# Misc items that have clear licensing info but aren't easily matched,
 	# or are the first of a class that we aren't ready to match yet.
-	config/ax_code_coverage.m4
-	configure.ac
 	module/lua/README.zfs
 	scripts/kmodtool
 	tests/zfs-tests/tests/functional/inheritance/README.config
@@ -141,7 +144,6 @@
 	tests/zfs-tests/tests/functional/tmpfile/tmpfile_003_pos.c
 	tests/zfs-tests/tests/functional/tmpfile/tmpfile_test.c
 
-	autogen.sh
 	contrib/bpftrace/zfs-trace.sh
 	contrib/pyzfs/docs/source/conf.py
 	contrib/pyzfs/libzfs_core/test/__init__.py
@@ -190,8 +192,18 @@
 	'module/icp' => ['Apache-2.0', 'CDDL-1.0'],
 	'contrib/icp' => ['Apache-2.0', 'CDDL-1.0'],
 
-	# Python bindings are always Apache-2.0
-	'contrib/pyzfs' => ['Apache-2.0'],
+	# Python bindings are always Apache-2.0; CDDL is available for build
+	# files in that dir.
+	'contrib/pyzfs' => ['Apache-2.0', 'CDDL-1.0'],
+
+	# Common licenses for autoconf macros; some of these are complex
+	# with exceptions, so we don't have a "generic" list as such, just
+	# a list of all the ones currently in use.
+	'config' => [
+	    'CDDL-1.0', 'LGPL-2.1-or-later', 'FSFAP', 'FSFULLR',
+	    'GPL-2.0-or-later WITH Autoconf-exception-generic',
+	    'GPL-3.0-or-later WITH Autoconf-exception-macro',
+	],
 );
 
 # This is a list of "special case" license tags that are in use in the tree,
@@ -237,9 +249,6 @@
 	'OpenSSL-standalone' => [qw(
 		module/icp/asm-x86_64/aes/aes_aesni.S
 	)],
-	'LGPL-2.1-or-later' => [qw(
-		config/ax_code_coverage.m4
-	)],
 
 	# Legacy inclusions of BSD-2-Clause files in Linux SPL.
 	'BSD-2-Clause' => [qw(