doc: fix doc generation

doc/Makefile.am

@@ -1,6 +1,6 @@
 # StarPU --- Runtime system for heterogeneous multicore architectures.
 #
-# Copyright (C) 2013, 2014  CNRS
+# Copyright (C) 2013, 2014, 2016  CNRS
 #
 # StarPU is free software; you can redistribute it and/or modify
 # it under the terms of the GNU Lesser General Public License as published by
@@ -13,12 +13,8 @@
 #
 # See the GNU Lesser General Public License in COPYING.LGPL for more details.
 
-if BUILD_DOC
 SUBDIRS = doxygen
 DIST_SUBDIRS = doxygen
-else
-DIST_SUBDIRS =
-endif
 
 EXTRA_DIST =    tutorial/hello_world.c \
 		tutorial/hello_world_plugin.c \

doc/doxygen/Makefile.am

@@ -19,12 +19,17 @@ DOXYGEN = doxygen
 PDFLATEX = pdflatex
 MAKEINDEX = makeindex
 
+if BUILD_DOC
 DOX_DIR = $(top_builddir)/doc/doxygen
+else
+DOX_DIR = $(top_srcdir)/doc/doxygen
+endif
+
 DOX_CONFIG = $(top_srcdir)/doc/doxygen/doxygen.cfg
 
 DOX_HTML_DIR = html
 DOX_LATEX_DIR = latex
-DOX_PDF = starpu.pdf
+DOX_PDF = $(DOX_DIR)/starpu.pdf
 DOX_TAG = starpu.tag
 
 chapters =	\
@@ -297,11 +302,13 @@ $(DOX_PDF): $(DOX_TAG) refman.tex
 	done
 	mv $(DOX_LATEX_DIR)/refman.pdf $(DOX_PDF)
 
+if BUILD_DOC
 CLEANFILES = $(DOX_TAG) starpu_config.h \
     -r \
     $(DOX_HTML_DIR) \
     $(DOX_LATEX_DIR) \
     $(DOX_PDF)
+endif
 
 # Rule to update documentation on web server. Should only be used locally.
 PUBLISHHOST	?= gforge