Fix 'dvi' and 'pdf' texinfo doc generation.1.22.4.rc5

GNU make has a built-in variable 'TEXI2DVI' but it is not the case
of all 'make' implementations, which causes 'make doc' to fail with
an unclear message although 'texi2dvi' is available.  Also,
'texi2dvi' is invoked inconditionnally.

* m4/groff.m4 (GROFF_TEXI2DVI): new macro to detect properly the
presence of 'texi2dvi'.

* configure.ac: use 'GROFF_TEXI2DVI' and define automake conditional
'HAVE_TEXI2DVI'.

* doc/doc.am:
- Define TEXI2DVI to 'texi2dvi'.
- Print an error message if 'texi2dvi' is not available.

4 files changed, 47 insertions, 1 deletions

diff --git a/ChangeLog b/ChangeLog
index 5de9469aa..835d26c38 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,22 @@
+2018-12-18 Bertrand Garrigues <bertrand.garrigues@laposte.net>
+
+	Fix 'dvi' and 'pdf' texinfo doc generation.
+
+	GNU make has a built-in variable 'TEXI2DVI' but it is not the case
+	of all 'make' implementations, which causes 'make doc' to fail
+	with an unclear message although 'texi2dvi' is available.  Also,
+	'texi2dvi' is invoked inconditionnally.
+
+	* m4/groff.m4 (GROFF_TEXI2DVI): new macro to detect properly the
+	presence of 'texi2dvi'.
+
+	* configure.ac: use 'GROFF_TEXI2DVI' and define automake conditional
+	'HAVE_TEXI2DVI'.
+
+	* doc/doc.am:
+	- Define TEXI2DVI to 'texi2dvi'.
+	- Print an error message if 'texi2dvi' is not available.
+
 2018-12-08 Bertrand Garrigues <bertrand.garrigues@laposte.net>
 
 	Install texinfo doc on 'make install-pdf' and 'make install-html'
diff --git a/configure.ac b/configure.ac
index e0a049f65..28e75f175 100644
--- a/configure.ac
+++ b/configure.ac
@@ -70,6 +70,7 @@ AC_PROG_EGREP
 GROFF_PROG_YACC
 GROFF_DOC_CHECK
 GROFF_MAKEINFO
+GROFF_TEXI2DVI
 AC_PROG_RANLIB
 GROFF_INSTALL_SH
 GROFF_INSTALL_INFO
@@ -200,6 +201,7 @@ AM_CONDITIONAL([BUILD_OTHERDOC], [test -n "$make_otherdoc"])
 AM_CONDITIONAL([BUILD_EXAMPLES], [test -n "$make_examples"])
 AM_CONDITIONAL([INSTALL_SHIPPED_HTML], [test -n "$make_install_shipped_htmldoc"])
 AM_CONDITIONAL([HAVE_PDFTOOLS], [test "x$groff_have_pdftools" = "xyes" ])
+AM_CONDITIONAL([HAVE_TEXI2DVI], [test "x$groff_have_texi2dvi" = "xyes" ])
 
 AC_CONFIG_FILES([Makefile])
 AC_CONFIG_FILES([test-groff], [chmod +x test-groff])
diff --git a/doc/doc.am b/doc/doc.am
index 97332d74a..a3a2ff0bd 100644
--- a/doc/doc.am
+++ b/doc/doc.am
@@ -315,6 +315,12 @@ build_infodoc:
 endif
 EXTRA_DIST += doc/groff.texi doc/fdl.texi
 
+# GNU Make has a built-in variable TEXI2DVI but it is not the case of
+# all 'make' implementation.  As it default to 'texi2dvi' we simply
+# redefine it here.
+
+TEXI2DVI = texi2dvi
+texi2dvi_missing = no
 # Rules to generate various doc files from .texi files.
 .texi.txt:
 	@$(MKDIR_P) $(doc_builddir)
@@ -323,20 +329,30 @@ EXTRA_DIST += doc/groff.texi doc/fdl.texi
 	$(MAKEINFO) --enable-encoding -I$(doc_srcdir) --plaintext -o $@ $<
 
 .texi.dvi:
+if HAVE_TEXI2DVI
 	@$(MKDIR_P) $(doc_builddir)
 	LANG=C \
 	LC_ALL=C \
 	TEXINPUTS="$(top_srcdir)/build-aux:$(TEXINPUTS)" \
 	MAKEINFO='$(MAKEINFO) -I $(doc_srcdir)' \
 	$(TEXI2DVI) -e --batch --build-dir=doc/`basename $@`.t2d -o $@ $<
+else
+	@echo "Program texi2dvi is missing, cannot generate dvi doc"; \
+	exit 1
+endif
 
 .texi.pdf:
+if HAVE_TEXI2DVI
 	@$(MKDIR_P) $(doc_builddir)
 	LANG=C \
 	LC_ALL=C \
 	TEXINPUTS="$(top_srcdir)/build-aux:$(TEXINPUTS)" \
 	MAKEINFO='$(MAKEINFO) -I $(doc_srcdir)' \
 	$(TEXI2DVI) -e --batch --pdf --build-dir=doc/`basename $@`.t2p -o $@ $<
+else
+	@echo "Program texi2dvi is missing, cannot generate pdf doc"; \
+	exit 1
+endif
 
 # This will generate both html split into several files and html doc
 # in a single file. If texinfo version < 5.0, we process the resulting
diff --git a/m4/groff.m4 b/m4/groff.m4
index 75aa3e25b..5343f22f5 100644
--- a/m4/groff.m4
+++ b/m4/groff.m4
@@ -209,6 +209,15 @@ AC_DEFUN([GROFF_MAKEINFO],
    AC_SUBST([make_uninstall_infodoc])
    AC_SUBST([makeinfo_version_numeric])])
 
+AC_DEFUN([GROFF_TEXI2DVI],
+  [AC_CHECK_PROG([PROG_TEXI2DVI], [texi2dvi], [found], [missing])
+   if test "x$PROG_TEXI2DVI" = "xfound"; then
+      groff_have_texi2dvi=yes;
+   else
+      groff_have_texi2dvi=no;
+   fi
+   ])
+
 # The following programs are needed for grohtml.
 
 AC_DEFUN([GROFF_HTML_PROGRAMS],
@@ -1585,7 +1594,7 @@ AC_DEFUN([GROFF_REFERDIR_DEFAULT],
 AC_DEFUN([GROFF_PROG_XPMTOPPM],
   [AC_CHECK_PROG([XPMTOPPM], [xpmtoppm], [found], [missing])])
 
-# Check for make builtin variable RM
+# Check for make built-in variable RM
 AC_DEFUN([GROFF_MAKE_RM],
   [AC_MSG_CHECKING(whether make has builtin variable RM)
 cat <<EOF > test_make_rm.mk