dpkg-gensymbols: add -a<arch> option.

Use this option to generate a symbol file or diff for any architecture provided
its binaries are already available.

debian/changelog

@@ -89,6 +89,7 @@ dpkg (1.15.6) UNRELEASED; urgency=low
     there is no way to detect symbol changes in the pattern match sets.
   * Add source version to the dpkg-gensymbols diff label, reformat it according
     to the rules of dpkg-name.
+  * Add -a<arch> option to dpkg-gensymbols.
 
   [ Jonathan Nieder ]
   * Fix a file handle leak in “dpkg-deb --info”. Thanks to Raphael Geissert

man/dpkg-gensymbols.1

@@ -415,6 +415,11 @@ libraries have been introduced.
 This value can be overridden by the environment variable
 DPKG_GENSYMBOLS_CHECK_LEVEL.
 .TP
+.BI \-a arch
+Assume \fIarch\fR as host architecture when processing symbol files. Use this
+option to generate a symbol file or diff for any architecture provided its
+binaries are already available.
+.TP
 .BI \-d
 Enable debug mode. Numerous messages are displayed to explain what 
 .B dpkg\-gensymbols

scripts/dpkg-gensymbols.pl

@@ -82,6 +82,8 @@ Options:
   -V                       verbose output. Write deprecated symbols and
                            pattern matching symbols as comments
                            (in template mode only).
+  -a<arch>                 assume <arch> as host architecture when processing
+                           symbol files.
   -d                       display debug information during work.
   -h, --help               show this help message.
       --version            show the version.
@@ -121,6 +123,8 @@ while (@ARGV) {
 	$template_mode = 1;
     } elsif (m/^-V$/) {
 	$verbose_output = 1;
+    } elsif (m/^-a(.+)$/) {
+	$host_arch = $1;
     } elsif (m/^-(h|-help)$/) {
 	usage();
 	exit(0);