autotools: docbook build improvements

Let the make recipe fail if a dependency is missing. That is more user-friendly
(a2x: command not found) than an empty target and having to re-run configure.

Test for both w3m and lynx when generating text files. If neither is available
skip it.

Add an explicit target to build pdf documentation.

Change-Id: I760475acd7278f5ab5a782c1828a134c58cf7b42
Reviewed-on: https://code.wireshark.org/review/15229
Petri-Dish: João Valverde <j@v6e.pt>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: João Valverde <j@v6e.pt>

2 files changed, 25 insertions, 64 deletions

diff --git a/configure.ac b/configure.ac
index 2b16f059d0..d142736925 100644
--- a/configure.ac
+++ b/configure.ac
@@ -726,34 +726,19 @@ AX_LIBSMI
 #
 # Check for programs used when building DocBook documentation.
 #
-
-# Check for a2x (convert asciidoc to another format)
-AC_PATH_PROG(A2X, a2x)
-AC_CHECK_PROG(HAVE_A2X, a2x, "yes", "no")
-AM_CONDITIONAL(HAVE_A2X, test x$HAVE_A2X = xyes)
-
-# Check for fop (translate .fo to e.g. pdf)
-AC_PATH_PROG(FOP, fop)
-AC_CHECK_PROG(HAVE_FOP, fop, "yes", "no")
-AM_CONDITIONAL(HAVE_FOP, test x$HAVE_FOP = xyes)
-
-# TODO: HAVE_LYNX and HAVE_W3M are unused. Maybe require one of them
-# to be found when a2x is enabled? Otherwise it will fail later...
-# Check for lynx (asciidoc text format from html)
-AC_PATH_PROG(LYNX, lynx)
-AC_CHECK_PROG(HAVE_LYNX, lynx, "yes", "no")
-AM_CONDITIONAL(HAVE_LYNX, test x$HAVE_LYNX = xyes)
-
-# Check for w3m (asciidoc text format from html)
-AC_PATH_PROG(W3M, w3m)
-AC_CHECK_PROG(HAVE_W3M, w3m, "yes", "no")
-AM_CONDITIONAL(HAVE_W3M, test x$HAVE_W3M = xyes)
-
-# Check for xsltproc
-AC_PATH_PROG(XSLTPROC, xsltproc)
-AC_CHECK_PROG(HAVE_XSLTPROC, xsltproc, "yes", "no")
-AM_CONDITIONAL(HAVE_XSLTPROC, test x$HAVE_XSLTPROC = xyes)
-
+AC_CHECK_PROGS(XSLTPROC, xsltproc, xsltproc)
+AC_CHECK_PROGS(A2X, a2x, a2x)
+AC_CHECK_PROGS(FOP, fop, fop)
+
+# HTML to text processor
+AC_MSG_CHECKING([for an HTML to text processor])
+AS_IF([w3m -version >&AS_MESSAGE_LOG_FD 2>&1], [have_a2x_text=w3m],
+	[lynx -version >&AS_MESSAGE_LOG_FD 2>&1], [have_a2x_text=lynx],
+	[have_a2x_text=no])
+AC_MSG_RESULT([$have_a2x_text])
+AM_CONDITIONAL(HAVE_A2X_TEXT, [test "x$have_a2x_text" != xno])
+AS_IF([test $have_a2x_text = lynx], [A2X_LYNX="--lynx"])
+AC_SUBST(A2X_LYNX)
 
 # Check for packaging utilities
 # For now, we check to see if the various packaging utilites are in our
diff --git a/docbook/Makefile.am b/docbook/Makefile.am
index c31eb8d353..d67543b2e7 100644
--- a/docbook/Makefile.am
+++ b/docbook/Makefile.am
@@ -14,10 +14,6 @@ FOP_OPTS=-Xmx256m
 A2X_HTML_OPTS="--stylesheet=ws.css"
 A2X_TEXT_OPTS=
 
-#if HAVE_LYNX
-A2X_TEXT_OPTS+="--lynx"
-#endif
-
 ############### YOU SHOULDN'T HAVE TO EDIT ANYTHING BELOW THIS LINE! ################
 
 include Makefile.common
@@ -25,28 +21,16 @@ include Makefile.common
 # Automatically generate .pdf files from .fo files
 # Suse needs FOP_OPTS, Debian needs JAVA_OPTS
 .fo.pdf:
-if HAVE_FOP
 	FOP_OPTS=$(FOP_OPTS) JAVA_OPTS=$(FOP_OPTS) $(FOP) $< $@
-else
-	@echo
-	@echo "Error: FOP is needed to create PDFs!"
-	@false
-endif
 
-if HAVE_XSLTPROC
-ALL_TARGETS=wsug wsdg release_notes
-endif
+all: wsug wsdg release-notes
 
-all: $(ALL_TARGETS)
+all-pdf: wsug-pdf wsdg-pdf release-notes-pdf
 
 # Wireshark User Guide
-if HAVE_FOP
-WSUG_TARGETS=wsug_html_chunked wsug_html user-guide-a4.pdf user-guide-us.pdf
-else
-WSUG_TARGETS=wsug_html_chunked wsug_html
-endif
+wsug: wsug_html_chunked wsug_html
 
-wsug: $(WSUG_TARGETS)
+wsug-pdf: wsug user-guide-a4.pdf user-guide-us.pdf
 
 user-guide.xml: user-guide.asciidoc $(WSUG_FILES)
 	$(A2X) --verbose \
@@ -106,17 +90,9 @@ wsluarm: make-wsluarm.pl $(WSLUA_MODULES)
 
 
 # Wireshark Developer Guide
-if HAVE_A2X
-if HAVE_FOP
-WSDG_TARGETS=wsdg_html_chunked wsdg_html developer-guide-a4.pdf developer-guide-us.pdf
-else
-WSDG_TARGETS=wsdg_html_chunked wsdg_html
-endif
-else
-WSDG_TARGETS=
-endif
+wsdg: wsdg_html_chunked wsdg_html
 
-wsdg: $(WSDG_TARGETS)
+wsdg-pdf: wsdg developer-guide-a4.pdf developer-guide-us.pdf
 
 developer-guide.xml: developer-guide.asciidoc $(WSDG_FILES)
 	$(A2X) --verbose \
@@ -173,14 +149,14 @@ developer-guide-a4.fo: $(WSDG_SOURCE) custom_layer_pdf.xsl
 		    --path .:wsluarm_src:$(srcdir) \
 		    --nonet $(srcdir)/custom_layer_pdf.xsl $< > $@
 
-
-if HAVE_FOP
-RELEASE_NOTES_TARGETS=release-notes.html release-notes.txt release-notes-a4.pdf release-notes-us.pdf
+# Release notes
+if HAVE_A2X_TEXT
+release-notes: release-notes.html release-notes.txt
 else
-RELEASE_NOTES_TARGETS=release-notes.html release-notes.txt
+release-notes: release-notes.html
 endif
 
-release_notes: $(RELEASE_NOTES_TARGETS)
+release-notes-pdf: release-notes release-notes-a4.pdf release-notes-us.pdf
 
 # create html single page file
 release-notes.html: $(RELEASE_NOTES_SOURCE)
@@ -192,7 +168,7 @@ release-notes.html: $(RELEASE_NOTES_SOURCE)
 # create txt single page file (through HTML)
 release-notes.txt: $(RELEASE_NOTES_SOURCE)
 	@ echo --- RELEASE NOTES - TXT ---
-	TZ=UTC $(A2X) --format=text $(A2X_TEXT_OPTS) \
+	TZ=UTC $(A2X) --format=text @A2X_LYNX@ $(A2X_TEXT_OPTS) \
 		--xsltproc-opts "--stringparam generate.toc \"article nop\"" \
 		--destination-dir=$(builddir) \
 		$(srcdir)/release-notes.asciidoc && \