Makefile: consolidate .FORCE-* targets

Providing multiple targets to force a rebuild is unnecessary
complication.

Avoid using a name that could conflict with future special
targets in GNU make (a leading period followed by uppercase
letters).

The corresponding change to the git-gui Makefile is left for
another patch.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/Makefile

@@ -204,7 +204,7 @@ install-pdf: pdf
 install-html: html
 	'$(SHELL_PATH_SQ)' ./install-webdoc.sh $(DESTDIR)$(htmldir)
 
-../GIT-VERSION-FILE: .FORCE-GIT-VERSION-FILE
+../GIT-VERSION-FILE: FORCE
 	$(QUIET_SUBDIR0)../ $(QUIET_SUBDIR1) GIT-VERSION-FILE
 
 -include ../GIT-VERSION-FILE
@@ -337,4 +337,4 @@ quick-install-man:
 quick-install-html:
 	'$(SHELL_PATH_SQ)' ./install-doc-quick.sh $(HTML_REF) $(DESTDIR)$(htmldir)
 
-.PHONY: .FORCE-GIT-VERSION-FILE
+.PHONY: FORCE

Makefile

@@ -222,7 +222,7 @@ all::
 #   DEFAULT_EDITOR='$GIT_FALLBACK_EDITOR',
 #   DEFAULT_EDITOR='"C:\Program Files\Vim\gvim.exe" --nofork'
 
-GIT-VERSION-FILE: .FORCE-GIT-VERSION-FILE
+GIT-VERSION-FILE: FORCE
 	@$(SHELL_PATH) ./GIT-VERSION-GEN
 -include GIT-VERSION-FILE
 
@@ -1632,7 +1632,7 @@ git.o git.spec \
 
 %.o: %.c GIT-CFLAGS
 	$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) $<
-%.s: %.c GIT-CFLAGS .FORCE-LISTING
+%.s: %.c GIT-CFLAGS FORCE
 	$(QUIET_CC)$(CC) -S $(ALL_CFLAGS) $<
 %.o: %.S GIT-CFLAGS
 	$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) $<
@@ -1723,7 +1723,7 @@ cscope:
 TRACK_CFLAGS = $(subst ','\'',$(ALL_CFLAGS)):\
              $(bindir_SQ):$(gitexecdir_SQ):$(template_dir_SQ):$(prefix_SQ)
 
-GIT-CFLAGS: .FORCE-GIT-CFLAGS
+GIT-CFLAGS: FORCE
 	@FLAGS='$(TRACK_CFLAGS)'; \
 	    if test x"$$FLAGS" != x"`cat GIT-CFLAGS 2>/dev/null`" ; then \
 		echo 1>&2 "    * new build flags or prefix"; \
@@ -1733,7 +1733,7 @@ GIT-CFLAGS: .FORCE-GIT-CFLAGS
 # We need to apply sq twice, once to protect from the shell
 # that runs GIT-BUILD-OPTIONS, and then again to protect it
 # and the first level quoting from the shell that runs "echo".
-GIT-BUILD-OPTIONS: .FORCE-GIT-BUILD-OPTIONS
+GIT-BUILD-OPTIONS: FORCE
 	@echo SHELL_PATH=\''$(subst ','\'',$(SHELL_PATH_SQ))'\' >$@
 	@echo PERL_PATH=\''$(subst ','\'',$(PERL_PATH_SQ))'\' >>$@
 	@echo TAR=\''$(subst ','\'',$(subst ','\'',$(TAR)))'\' >>$@
@@ -1745,14 +1745,12 @@ GIT-BUILD-OPTIONS: .FORCE-GIT-BUILD-OPTIONS
 ifndef NO_TCLTK
 TRACK_VARS = $(subst ','\'',-DTCLTK_PATH='$(TCLTK_PATH_SQ)')
 
-GIT-GUI-VARS: .FORCE-GIT-GUI-VARS
+GIT-GUI-VARS: FORCE
 	@VARS='$(TRACK_VARS)'; \
 	    if test x"$$VARS" != x"`cat $@ 2>/dev/null`" ; then \
 		echo 1>&2 "    * new Tcl/Tk interpreter location"; \
 		echo "$$VARS" >$@; \
             fi
-
-.PHONY: .FORCE-GIT-GUI-VARS
 endif
 
 ### Testing rules
@@ -1972,8 +1970,7 @@ endif
 
 .PHONY: all install clean strip
 .PHONY: shell_compatibility_test please_set_SHELL_PATH_to_a_more_modern_shell
-.PHONY: .FORCE-GIT-VERSION-FILE TAGS tags cscope .FORCE-GIT-CFLAGS
-.PHONY: .FORCE-GIT-BUILD-OPTIONS .FORCE-LISTING
+.PHONY: FORCE TAGS tags cscope
 
 ### Check documentation
 #