Documentation: add Docbook external references support

When writing technical documentation, it is often necessary to cross
reference to other information. When that other information is not in the
current document, additional support is needed, namely <olink>.

A new feature with version 1.7 of xorg-sgml-doctools adds references to
other documents within or outside this package.

This patch adds technical support for this feature but does not change
the content of the documentation as seen by the end user.

Each book or article must generate a database containing the href
of sections that can be referred to from another document. This database
is installed in DATAROOTDIR/sgml/X11/dbs. There is a requirement that
the value of DATAROOTDIR for xorg-sgml-doctools and for the package
documentation is the same. This forms a virtual document tree.

This database is consulted by other documents while they are being generated
in order to fulfill the missing information for linking.
Refer to the xorg-sgml-doctools for further technical information.

Co-authored-by: Matt Dew <marcoz@osource.org>

Signed-off-by: Gaetan Nadon <memsize@videotron.ca>

4 files changed, 110 insertions, 56 deletions

diff --git a/configure.ac b/configure.ac
index 880fc5a..a665dbc 100644
--- a/configure.ac
+++ b/configure.ac
@@ -13,15 +13,16 @@ AM_MAINTAINER_MODE
 # Initialize libtool
 AC_PROG_LIBTOOL
 
-# Require xorg-macros minimum of 1.10 for HAVE_STYLESHEETS in XORG_CHECK_SGML_DOCTOOLS
+# Require xorg-macros minimum of 1.12 for DocBook external references
 m4_ifndef([XORG_MACROS_VERSION],
-          [m4_fatal([must install xorg-macros 1.10 or later before running autoconf/autogen])])
-XORG_MACROS_VERSION(1.10)
+          [m4_fatal([must install xorg-macros 1.12 or later before running autoconf/autogen])])
+XORG_MACROS_VERSION(1.12)
 XORG_DEFAULT_OPTIONS
 XORG_ENABLE_DOCS
-XORG_WITH_XMLTO(0.0.20)
+XORG_WITH_XMLTO(0.0.22)
 XORG_WITH_FOP
-XORG_CHECK_SGML_DOCTOOLS(1.5)
+XORG_WITH_XSLTPROC
+XORG_CHECK_SGML_DOCTOOLS(1.7)
 
 # Obtain compiler/linker options for depedencies
 PKG_CHECK_MODULES(XMU, xt xext x11 xextproto)
diff --git a/doc/.gitignore b/doc/.gitignore
index 9e85e14..35b7958 100644
--- a/doc/.gitignore
+++ b/doc/.gitignore
@@ -2,3 +2,4 @@
 *.html
 *.pdf
 *.ps
+*.db
diff --git a/doc/Makefile.am b/doc/Makefile.am
index 83685dc..a8363ca 100644
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -1,61 +1,18 @@
-#
-# Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
-#
-# Permission is hereby granted, free of charge, to any person obtaining a
-# copy of this software and associated documentation files (the "Software"),
-# to deal in the Software without restriction, including without limitation
-# the rights to use, copy, modify, merge, publish, distribute, sublicense,
-# and/or sell copies of the Software, and to permit persons to whom the
-# Software is furnished to do so, subject to the following conditions:
-#
-# The above copyright notice and this permission notice (including the next
-# paragraph) shall be included in all copies or substantial portions of the
-# Software.
-#
-# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
-# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
-# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
-# DEALINGS IN THE SOFTWARE.
-#
 
 if ENABLE_DOCS
-dist_doc_DATA = Xmu.xml xlogo.svg
-
 if HAVE_XMLTO
-doc_DATA = Xmu.html
-
-if HAVE_FOP
-doc_DATA += Xmu.pdf Xmu.ps
-endif
-
-if HAVE_XMLTO_TEXT
-doc_DATA += Xmu.txt
-endif
-
-CLEANFILES = Xmu.txt Xmu.html Xmu.pdf Xmu.ps xorg.css
-
-if HAVE_STYLESHEETS
-XMLTO_FLAGS = 			\
-	-m $(XSL_STYLESHEET)	\
-	--stringparam img.src.path=$(abs_builddir)/	\
-	--stringparam html.stylesheet=$(STYLESHEET_SRCDIR)/xorg.css
-endif
 
-XML_SOURCEFILES =  $(srcdir)/Xmu.xml $(XSL_STYLESHEET)
+# Main DocBook/XML files (DOCTYPE book)
+docbook = Xmu.xml
 
-Xmu.txt: $(XML_SOURCEFILES)
-	$(AM_V_GEN)$(XMLTO) $(XMLTO_FLAGS) txt $(srcdir)/Xmu.xml
+# Included chapters, appendix, images
+chapters = xlogo.svg
 
-Xmu.html: $(XML_SOURCEFILES)
-	$(AM_V_GEN)$(XMLTO) $(XMLTO_FLAGS) xhtml-nochunks $(srcdir)/Xmu.xml
+# The location where the DocBook/XML files and their generated formats are installed
+shelfdir = $(docdir)
 
-Xmu.pdf: $(XML_SOURCEFILES)
-	$(AM_V_GEN)$(XMLTO) $(XMLTO_FLAGS) --with-fop pdf $(srcdir)/Xmu.xml
+# Generate DocBook/XML output formats with or without stylesheets
+include $(top_srcdir)/docbook.am
 
-Xmu.ps: $(XML_SOURCEFILES)
-	$(AM_V_GEN)$(XMLTO) $(XMLTO_FLAGS) --with-fop ps $(srcdir)/Xmu.xml
 endif HAVE_XMLTO
 endif ENABLE_DOCS
diff --git a/docbook.am b/docbook.am
new file mode 100644
index 0000000..3cf21e8
--- /dev/null
+++ b/docbook.am
@@ -0,0 +1,95 @@
+#
+# Generate output formats for a single DocBook/XML with/without chapters
+#
+# Variables set by the calling Makefile:
+# shelfdir: the location where the docs/specs are installed. Typically $(docdir)
+# docbook:  the main DocBook/XML file, no chapters, appendix or image files
+# chapters: all files pulled in by an XInclude statement and images.
+#
+
+#
+# This makefile is intended for Users Documentation and Functional Specifications.
+# Do not use for Developer Documentation which is not installed and does not require olink.
+# Refer to http://www.x.org/releases/X11R7.6/doc/xorg-docs/ReleaseNotes.html#id2584393
+# for an explanation on documents classification.
+#
+
+# DocBook/XML generated output formats to be installed
+shelf_DATA =
+
+# DocBook/XML file with chapters, appendix and images it includes
+dist_shelf_DATA = $(docbook) $(chapters)
+
+#
+# Generate DocBook/XML output formats with or without stylesheets
+#
+
+# Stylesheets are available if the package xorg-sgml-doctools is installed
+if HAVE_STYLESHEETS
+
+# The location where all cross reference databases are installed
+sgmldbsdir = $(XORG_SGML_PATH)/X11/dbs
+masterdb = "$(sgmldbsdir)/masterdb$(suffix $@).xml"
+XMLTO_FLAGS =							\
+	--searchpath "$(XORG_SGML_PATH)/X11"			\
+	--stringparam target.database.document=$(masterdb)	\
+	--stringparam current.docid="$(<:.xml=)"		\
+	--stringparam collect.xref.targets="no"
+
+XMLTO_XHTML_FLAGS = \
+	-x $(STYLESHEET_SRCDIR)/xorg-xhtml.xsl \
+	--stringparam html.stylesheet=$(STYLESHEET_SRCDIR)/xorg.css
+
+XMLTO_FO_FLAGS = \
+	-x $(STYLESHEET_SRCDIR)/xorg-fo.xsl
+endif HAVE_STYLESHEETS
+
+shelf_DATA += $(docbook:.xml=.html)
+%.html: %.xml  $(chapters)
+	$(AM_V_GEN)$(XMLTO) $(XMLTO_FLAGS) $(XMLTO_XHTML_FLAGS) xhtml-nochunks $<
+
+if HAVE_FOP
+shelf_DATA += $(docbook:.xml=.pdf) $(docbook:.xml=.ps)
+%.pdf: %.xml $(chapters)
+	$(AM_V_GEN)$(XMLTO) $(XMLTO_FLAGS) $(XMLTO_FO_FLAGS) --with-fop pdf $<
+%.ps: %.xml $(chapters)
+	$(AM_V_GEN)$(XMLTO) $(XMLTO_FLAGS) $(XMLTO_FO_FLAGS) --with-fop ps $<
+endif HAVE_FOP
+
+if HAVE_XMLTO_TEXT
+shelf_DATA += $(docbook:.xml=.txt)
+%.txt: %.xml $(chapters)
+	$(AM_V_GEN)$(XMLTO) $(XMLTO_FLAGS) $(XMLTO_XHTML_FLAGS) txt $<
+endif HAVE_XMLTO_TEXT
+
+#
+# Generate documents cross-reference target databases
+#
+
+# This is only possible if the xorg-sgml-doctools package is installed
+if HAVE_STYLESHEETS
+if HAVE_XSLTPROC
+
+# DocBook/XML generated document cross-reference database
+sgmldbs_DATA = $(docbook:.xml=.html.db) $(docbook:.xml=.fo.db)
+
+# Generate DocBook/XML document cross-reference database
+# Flags for the XSL Transformation processor generating xref target databases
+XSLTPROC_FLAGS =					\
+	--path "$(XORG_SGML_PATH)/X11"			\
+	--stringparam targets.filename "$@"		\
+	--stringparam collect.xref.targets "only"	\
+	--nonet --xinclude
+
+%.html.db: %.xml  $(chapters)
+	$(AM_V_GEN)$(XSLTPROC) $(XSLTPROC_FLAGS) \
+	http://docbook.sourceforge.net/release/xsl/current/xhtml/docbook.xsl $<
+
+%.fo.db: %.xml $(chapters)
+	$(AM_V_GEN)$(XSLTPROC) $(XSLTPROC_FLAGS) \
+	http://docbook.sourceforge.net/release/xsl/current/fo/docbook.xsl $<
+
+endif HAVE_XSLTPROC
+endif HAVE_STYLESHEETS
+
+CLEANFILES = $(shelf_DATA) $(sgmldbs_DATA)