doc: Add doxygen support

The code should start getting switched to document using JavaDoc
style comments, at least for public declarations.

Makefile.am

@@ -59,6 +59,14 @@ EXTRA_DIST = \
 	debian/shlibs.default \
 	debian/shlibs.override
 
+.PHONY: doc
+
+doc:
+	$(DOXYGEN) doc/Doxyfile
+
+clean-local:
+	rm -rf doc/html/
+
 .PHONY: ChangeLog
 DISTCLEANFILES = ChangeLog
 

configure.ac

@@ -57,6 +57,8 @@ AC_PROG_CC
 AC_PROG_CXX
 AC_PROG_LEX
 AC_PROG_RANLIB
+AC_CHECK_PROGS([DOXYGEN], [doxygen])
+AC_CHECK_PROG([HAVE_DOT], [dot], [YES], [NO])
 DPKG_PROG_PERL
 
 # Checks for operating system services and capabilities.
@@ -118,6 +120,7 @@ AC_CONFIG_FILES([ Makefile
 		  lib/compat/Makefile
 		  lib/dpkg/Makefile
 		  lib/dpkg/test/Makefile
+		  doc/Doxyfile
 		  man/Makefile
 		  po/Makefile.in
 		  scripts/Makefile

debian/changelog

@@ -31,6 +31,7 @@ dpkg (1.15.5) UNRELEASED; urgency=low
   * Fix build macros to allow start-stop-deaemon to use TIOCNOTTY.
   * Generate the autoconf version from git to make it easier to see when a
     snapshot version is being used.
+  * Add infrastructure for doxygen, for now not installed anywhere.
 
   [ Raphaël Hertzog ]
   * Add versioned dependency on base-files (>= 5.0.0) to dpkg-dev to ensure

doc/.gitignore

@@ -0,0 +1,2 @@
+Doxyfile
+html

doc/coding-style.txt

@@ -41,6 +41,11 @@ other changes to be done on them, oterwise we get unneeded fuzzies.
 
   <http://www.cl.cam.ac.uk/~mgk25/ucs/quotes.html>
 
+Code documentation
+~~~~~~~~~~~~~~~~~~
+
+Public declarations should be documented using JavaDoc style comments.
+
 Indentation, alignment and spacing
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~