Build bugfix: if a config.h header exists in $(top_srcdir),

then that header is used when building in a separate directory,
instead of the config.h generated in that directory.
To fix this, we move config.h into a config/ subdirectory.
The $(top_srcdir)/config is not in the include search path
when buiding in a separate build directory.
While we are at it, let's move all the configure materials
generated by the configure script into config/.

* Makefile: include config/config.make at the top. Removing the
rule which asserts the existence of configuration based on
the presence of config.make.
(CFLAGS): Add $(conf_dir) to include search path with -iquote.
(notconfigured): New conditionally-defined target for producing
the error message when the build system is not configured.
(NL, DEP): New variables.
($(OBJS)): Make dependent on config/config.make and config/config.h
with help of DEP macro.
(opt/lex.yy.o, dbg/lex.yy.o): Express dependency using DEP.
(y.tab.h): Split off as a dependent on y.tab.c rather than
a co-target in the rule.  The rule has a body to handle
the situation when y.tab.h is missing for some reason, but
y.tab.c already exists (and so won't be re-made, and so
y.tab.h won't be remade).

* configure: Require GNU Make 3.81 rather than 3.80.
(conf_dir): New variable.
(config_h, config_make, config_log): New variables.  These are used in
place of config.h, config.make and config.log.  Add conf_dir to
config.make variable.

1 files changed, 35 insertions, 12 deletions

diff --git a/Makefile b/Makefile
index 2e762ff3..b049eaaf 100644
--- a/Makefile
+++ b/Makefile
@@ -23,10 +23,11 @@
 # AND UNDER ANY THEORY OF LIABILITY, ARISING IN ANY WAY OUT OF THE USE OF THIS
 # SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-include config.make
+-include config/config.make
 
 VERBOSE :=
-CFLAGS := -iquote $(top_srcdir) $(LANG_FLAGS) $(DIAG_FLAGS) \
+CFLAGS := -iquote $(conf_dir) -iquote $(top_srcdir) \
+          $(LANG_FLAGS) $(DIAG_FLAGS) \
           $(DBG_FLAGS) $(PLATFORM_FLAGS) $(EXTRA_FLAGS)
 CFLAGS += -iquote mpi-$(mpi_version)
 CFLAGS := $(filter-out $(REMOVE_FLAGS),$(CFLAGS))
@@ -100,6 +101,13 @@ opt/%.o: %.c
 	$(call ABBREV,CC,$<)
 	$(V)$(CC) $(OPT_FLAGS) $(CFLAGS) -c -o $@ $<
 
+ifeq ($(PROG),)
+.PHONY: notconfigured
+notconfigured:
+	$(V)echo "configuration missing: you didn't run the configure script!"
+	$(V)exit 1
+endif
+
 .PHONY: all
 all: $(BUILD_TARGETS)
 
@@ -113,13 +121,25 @@ $(PROG)-dbg: $(DBG_OBJS)
 
 VPATH := $(top_srcdir)
 
+# Newline constant
+define NL
+
+
+endef
+
+define DEP
+$(1): $(2)
+
+$(eval $(foreach item,$(1),DEP_$(item) += $(2)$(NL)))
+endef
+
 # Pull in dependencies
 -include $(OBJS:.o=.d) $(OBJS:.o=.v)
 
-opt/lex.yy.o: y.tab.h
-dbg/lex.yy.o: y.tab.h
-DEP_opt/lex.yy.o += y.tab.h
-DEP_dbg/lex.yy.o += y.tab.h
+# Add dependencies
+$(call DEP,$(OBJS),$(conf_dir)/config.make $(conf_dir)/config.h)
+$(call DEP,opt/lex.yy.o dbg/lex.yy.o,y.tab.h)
+
 
 $(eval $(foreach dep,$(OPT_OBJS:.o=.d) $(DBG_OBJS:.o=.d),\
           $(call DEP_INSTANTIATE,$(dep))))
@@ -130,7 +150,14 @@ lex.yy.c: parser.l
 	$(V)$(LEX) $(LEX_DBG_FLAGS) $<
 	$(V)chmod a-w $@
 
-y.tab.c y.tab.h: parser.y config.make
+y.tab.h: y.tab.c
+	$(V)if ! [ -e y.tab.h ] ; then                            \
+	  echo "Someone removed y.tab.h but left y.tab.c" ;       \
+	  echo "Remove y.tab.c and re-run make" ;                 \
+	  exit 1;                                                 \
+	fi
+
+y.tab.c: parser.y
 	$(call ABBREV,YACC)
 	$(V)rm -f y.tab.c
 	$(V)if $(YACC) -v -d $< ; then chmod a-w y.tab.c ; true ; else rm y.tab.c ; false ; fi
@@ -165,7 +192,7 @@ repatch:
 
 .PHONY: distclean
 distclean: clean
-	rm -f config.h config.make config.log
+	rm -rf $(conf_dir)
 	rm -rf mpi-$(mpi_version)
 
 TESTS_TMP := txr.test.out
@@ -313,10 +340,6 @@ txr-manpage.html: txr.1 genman.txr
 txr-manpage.pdf: txr.1
 	tbl $< | pdfroff -man --no-toc - > $@
 
-config.make config.h:
-	$(V)echo "$@ missing: you didn't run ./configure"
-	$(V)exit 1
-
 #
 # Special targets used by ./configure
 #