UBUNTU: [Packaging] buildinfo -- add compiler information to the flavour ABI

In getabis we extract the compiler information from an arbitrary .ko.
As we will not have those when only using buildinfo ABI information we
need to collect the compiler information during the build.

BugLink: http://bugs.launchpad.net/bugs/1806380Signed-off-by: Andy Whitcroft <apw@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

debian/rules.d/2-binary-arch.mk

@@ -412,6 +412,17 @@ endif
 		/sbin/modinfo $$ko | grep ^firmware || true; \
 	done | sort -u >$(abidir)/$*.fwinfo
 
+	# Build the final ABI compiler information.
+	ko=$$(find $(pkgdir_bin) $(pkgdir) $(pkgdir_ex) -name \*.ko | head -1); \
+	readelf -p .comment "$$ko" | gawk ' \
+		($$1 == "[") { \
+			printf("%s", $$3); \
+			for (n=4; n<=NF; n++) { \
+				printf(" %s", $$n); \
+			} \
+			print "" \
+		}' | sort -u >$(abidir)/$*.compiler
+
 	# Build the final ABI retpoline information.
 	if grep -q CONFIG_RETPOLINE=y $(builddir)/build-$*/.config; then \
 		echo "# retpoline v1.0" >$(abidir)/$*.retpoline; \
@@ -433,6 +444,8 @@ endif
 		$(pkgdir_bldinfo)/usr/lib/linux/$(abi_release)-$*/fwinfo
 	install -m644 $(abidir)/$*.retpoline \
 		$(pkgdir_bldinfo)/usr/lib/linux/$(abi_release)-$*/retpoline
+	install -m644 $(abidir)/$*.compiler \
+		$(pkgdir_bldinfo)/usr/lib/linux/$(abi_release)-$*/compiler
 
 headers_tmp := $(CURDIR)/debian/tmp-headers
 headers_dir := $(CURDIR)/debian/linux-libc-dev