# ─ ¶ Non‐Recipe Variable Definitions ─────────────────────────────────
+# Non·empty if `help´ or `clean´, and no targets other than `help´ or `clean´, were specified as goals on the commandline.
+override notbuilding := $(and $(filter help clean,$(MAKECMDGOALS)),$(call not,$(filter-out help clean,$(MAKECMDGOALS))))
+
# (callable) Test to see if the prerequisites provided by the second argument matches the value in the file corresponding to the first argument in `$(BUILDDIR)/lastprereqs´.
# If not, save the new value and then add FORCE.
# Return them regardless.
#
# Calling this variable is useful when a given target should be updated whenever its list of prerequisites changes in addition to whenever there is a change to one of its prerequisites.
#
+# If `$(notbuilding)´ is non·empty, this variable produces no result to avoid unnecessary work.
+#
# ☡ This variable creates at least one subshell every time it is computed.
-override diffprereqs = $(if $(subst $(shell $(CAT) $(call quote,$(BUILDDIR)/lastprereqs/$1) 2>>/dev/null || :),,$2),$2 FORCE$(and $(shell $(call ensuredirectory,$(BUILDDIR)/lastprereqs) && $(PRINTF) '%s\n' $(call quote,$2) >|$(BUILDDIR)/lastprereqs/$1),),$2)
+override diffprereqs = $(if $(notbuilding),,$(if $(subst $(shell $(CAT) $(call quote,$(BUILDDIR)/lastprereqs/$1) 2>>/dev/null || :),,$2),$2 FORCE$(and $(shell $(call ensuredirectory,$(BUILDDIR)/lastprereqs) && $(PRINTF) '%s\n' $(call quote,$2) >|$(BUILDDIR)/lastprereqs/$1),),$2))
# (callable) Escape special characters for use in X·M·L.
override xmlesc = $(subst >,>,$(subst <,<,$(subst &,&,$1)))
# Phony rules; always consider these out·of·date.
.PHONY : FORCE all default clean gone info install list listout uninstall $(call built,$(recursivefiles)) ;
+ifeq ($(notbuilding),)
# Reload this make·file if the magic file, parser, dependencies, or destinations have changed.
#
# If the magic file or parser changed, then another restart will be required, as the dependencies and destinations will need to be regenerated.
$(THISDIR)/GNUmakefile : $(BUILDDIR)/magic.mgc $(BUILDDIR)/parser.xslt $(BUILDDIR)/dependencies $(BUILDDIR)/destinations
$(silent)$(TOUCH) $(THISDIR)/GNUmakefile
$(if $(filter $(BUILDDIR)/magic.mgc $(BUILDDIR)/parser.xslt,$?),$(call inform,$(PRINTF) '%b\n' '\0033[1mMagic file or parsers have updated. Restarting…\0033[22m' >&2)$(newline)$(silent)$(SLEEP) 1,$(if $(typeupdates),$(silent)$(RM) $(call quote,$(BUILDDIR)/.update-types)$(newline),)$(call inform,$(PRINTF) '%b\n' '\0033[1mDependency graph and output destinations updated. Restarting…\0033[22m' >&2))
+endif
# ─ ¶ Build Targets ───────────────────────────────────────────────────