[PATCH v2 1/2] Allow generating a non-default set of documentation

[Junio C Hamano <gitster@pobox.com>]

By default, "make doc" generates the manpages and htmldocs in the
Documentation directory, but you may want to change this depending
on the target environment, e.g. to include 'pdf'.  Introduce a new
Makefile variable DEFAULT_DOC_TARGET to allow customizing this.

The primary motivation is to let us check documentation patches with

    $ DEFAULT_DOC_TARGET=git-push.1 make doc

but it is not so far-fetched to imagine that Windows users may want to
omit manpages with

    $ DEFAULT_DOC_TARGET=html make doc

or somesuch.  It won't be useful without additional support to tweak
the format installed by default via DEFAULT_DOC_INSTALL_TARGET, though.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Documentation/Makefile |  7 ++++++-
 Makefile               | 10 +++++++++-
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/Documentation/Makefile b/Documentation/Makefile
index 063fa69..0f8fdf8 100644
--- a/Documentation/Makefile
+++ b/Documentation/Makefile
@@ -1,3 +1,6 @@
+# The default target of this Makefile is...
+all::
+
 MAN1_TXT= \
 	$(filter-out $(addsuffix .txt, $(ARTICLES) $(SP_ARTICLES)), \
 		$(wildcard git-*.txt)) \
@@ -65,6 +68,8 @@ endif
 -include ../config.mak.autogen
 -include ../config.mak
 
+DEFAULT_DOC_TARGET ?= html man
+
 #
 # For docbook-xsl ...
 #	-1.68.1,	no extra settings are needed?
@@ -151,7 +156,7 @@ ifndef V
 endif
 endif
 
-all: html man
+all:: $(DEFAULT_DOC_TARGET)
 
 html: $(DOC_HTML)
 
diff --git a/Makefile b/Makefile
index 6b0c961..71655a7 100644
--- a/Makefile
+++ b/Makefile
@@ -281,6 +281,12 @@ all::
 #   DEFAULT_EDITOR='$GIT_FALLBACK_EDITOR',
 #   DEFAULT_EDITOR='"C:\Program Files\Vim\gvim.exe" --nofork'
 #
+# You can define DEFAULT_DOC_TARGET to change it from the built-in
+# default of generating manpages and htmldocs.  e.g.
+#
+#   DEFAULT_DOC_TARGET='man html info pdf'
+#   DEFAULT_DOC_TARGET='html'
+#
 # Define COMPUTE_HEADER_DEPENDENCIES to "yes" if you want dependencies on
 # header files to be automatically computed, to avoid rebuilding objects when
 # an unrelated header file changes.  Define it to "no" to use the hard-coded
@@ -1421,6 +1427,8 @@ ifneq (,$(SOCKLEN_T))
 	BASIC_CFLAGS += -Dsocklen_t=$(SOCKLEN_T)
 endif
 
+DEFAULT_DOC_TARGET ?= html man
+
 ifeq ($(uname_S),Darwin)
 	ifndef NO_FINK
 		ifeq ($(shell test -d /sw/lib && echo y),y)
@@ -2371,7 +2379,7 @@ $(XDIFF_LIB): $(XDIFF_OBJS)
 $(VCSSVN_LIB): $(VCSSVN_OBJS)
 	$(QUIET_AR)$(RM) $@ && $(AR) rcs $@ $(VCSSVN_OBJS)
 
-export DEFAULT_EDITOR DEFAULT_PAGER
+export DEFAULT_EDITOR DEFAULT_PAGER DEFAULT_DOC_TARGET
 
 doc:
 	$(MAKE) -C Documentation all
-- 
1.8.1.293.g4a210a9