# instead of trying to anticipate which prerequisites it will need in advance.
.SECONDEXPANSION:
+# Deletion of intermediate files messes everything up.
+# TODO: See if we can relax this requirement.
+.SECONDARY:
+
# TEXT UTILITIES
empty:=
bs:=\$(empty)
hash:=\#
+comma:=,
pct:=%
define nl
# Make-quote: a$\nb => a$$$(nl)b
# This is enough to assign the value, *but not to use it as an argument!*
mqas=$(subst $(hash),$$(hash),$(subst $(nl),$$(nl),$(subst $$,$$$$,$1)))
+# Make the value safe to use as an argument without doubling $.
+# *The implementation is incomplete*; I will improve it as needed.
+msarg=$(subst $(comma),$$(comma),$1)
# Return nonempty if the strings are equal, empty otherwise.
# If the strings have only nice characters, you can do $(filter x$1,x$2).
streq=$(findstring x$1,$(findstring x$2,x$1))
# prerequisite change, etc. and acts accordingly.
#
# Target metadata variables for bar: (* means stored in bar.g)
+# Now some variables are reused instead of remembered for every target.
+#
+# @name:=bar
+# Name of the target to which @cmd, @warnings, @deps refer.
#
-# bar@cmd:=cat foo >bar.tmp
+# @cmd:=cat foo >bar.tmp
# Generation command as given to the shell.*
#
-# bar@warnings:=$(empty)yikes!
+# @warnings:=$(empty)yikes!
# Data that the command printed to stdout or stderr, presumably warnings.*
#
-# bar@deps:=included@x oops@
+# @deps:=included@x oops@
# If dependency-logging, list of filename@revision used. Revision is x for
# exists and empty for doesn't exist. Later perhaps x will be the mtime.*
#
-# bar@gloaded:=1
-# Set if mgear has loaded bar.g and hasn't changed it since then.
-#
# bar@gdeps:=foo
# Static dependencies of bar, for checking by bar.g.
#
# - Vpath
# $(call gload,foo.o)
-# Make sure foo.o's genfile, if any, has been loaded.
+# Load foo.o's genfile, if any, into $(@cmd), etc.
define gload
-$(if $($1@gloaded),,$(eval
-$1@cmd:=
-$1@warnings:=
-$1@deps:=
+$(if $(filter $(@name),$1),,$(eval
+# TODO: Store and check the version of mgear that wrote the genfile.
+#@mgear-version:=
+@cmd:=
+@warnings:=
+@deps:=
-include $1.g
-$1@gloaded:=1
+@name:=$1
))
endef
+@name:=
# bar.g: scout bar and its dependencies and store $?. When implicit rules
# compete for bar, we depend on the rule make uses being the last one it
# second-expands so that $(bar@gdeps) is still correct.
mg-genfile-oid:=$(newoid)
mg-scout-oid:=$(newoid)
-$(mg-genfile-oid)@opr=$($(otgt:.g=)@gdeps) $(if $(wildcard $(otgt:.g=)),$(mg-scout-oid)$(aname)$(otgt:.g=),)
-$(mg-genfile-oid)@ocmd=$(eval $(otgt:.g=)@gq:=$?)
+$(mg-genfile-oid)@opr=$($(otgt:.g=)@gdeps) $(if $(wildcard $(otgt:.g=)),$(mg-scout-oid)$(aname)$(otgt:.g=),) MG-FORCE
+$(mg-genfile-oid)@ocmd=$(eval $(otgt:.g=)@gq:=$(filter-out MG-%,$?))
+$(mg-scout-oid)@opr:=
+$(mg-scout-oid)@ocmd:=
# Mgear-ized automatic variables.
-# $@: needs no translation
-# NOTE: $(mg@) is *eventual* target. Commands must write to temp file, $t .
+# For now, if you really want the eventual target, write $$(@).
+mg@ = $@.tmp
# $%: haven't thought about it much, but probably needs no translation
mg< = $(firstword $(mg^))
mg? = $(filter-out $(opfx)%,$($@@gq))
# $|: needs no translation
# $*: needs no translation
-# $(call mg-translate-cmd,cat $$< >$$t)
+# $(call mg-translate-cmd,cat $$< >$$@)
# Replaces references to automatic variables with references to their mgear-ized
# counterparts. There might be false matches, e.g., $$@ => $$(mg@) ;
# to prevent that, write $$$(empty)@ instead. (c.f. autoconf empty quadrigraph)
-mg-translate-cmd=$(subst $$t,$$@.tmp,$(subst $$?,$$(mg?),$(subst $$<,$$(mg<),$(subst $$^,$$(mg^),$(subst $$+,$$(mg+),$1)))))
+mg-translate-cmd=$(subst $$@,$$(mg@),$(subst $$?,$$(mg?),$(subst $$<,$$(mg<),$(subst $$^,$$(mg^),$(subst $$+,$$(mg+),$1)))))
# $(call mg-prereq-predict,target,prerequisites)
# Expands to code that does the following at second-expansion time:
MG-FORCE:
.PHONY: MG-FORCE
-# $(call mg-define-rule,target,prerequisites,cmd)
-# Defines a rule. cmd is expanded again when it is run, at which time
-# Mgear-ized automatic variables are available.
+# $(call mg-define-rule,target,prerequisites,cmdvar)
+# Defines a rule. cmdvar is *the name of a variable* containing the command.
+# The variable is read immediately with $(value) and then expanded in the scope
+# of mgear-ized automatic variables each time the rule is run.
#
# I eradicated the target-specific variables because they fail when there are
# multiple implicit rules with the same target pattern.
# $(bar@gq).
define mg-define-rule
$(eval $1: $(call mg-prereq-predict,$1,$2) $2 MG-FORCE $(mg-genfile-oid)$(aname)$$$$@.g
- $$(call mg-rule-cmd,$(call mg-translate-cmd,$3)))
+ $$(call mg-rule-cmd,$(call msarg,$(call mg-translate-cmd,$(value $3)))))
endef
# TODO Provide a way to define static pattern rules.
$(mg-assign-cmd) >&3 &&\
$(mg-maybe-move-target) &&\
mv -f $@.g.tmp $@.g\
- ,$(if $($@@warnings),\
- $(info $($@@cmd) # mgear warning replay$(nl)$($@@warnings))\
+ ,$(if $(@warnings),\
+ $(info $1 # mgear warning replay$(nl)$(@warnings))\
)))
endef
# If the command changed, we must regenerate.
-mg-check-cmd=$(if $(call streq,$1,$($@@cmd)),,COMMAND-CHANGED)
+# HMMM What if the working directory changes? Most likely, the command will
+# also change and mgear will do the right thing.
+mg-check-cmd=$(if $(call streq,$1,$(@cmd)),,COMMAND-CHANGED)
# Pieces of mg-generate that I factored out to make mg-generate more readable.
-mg-assign-cmd=echo $(call sq,$(call fmt-make-assignment,$@@cmd,$1))
+mg-assign-cmd=echo $(call sq,$(call fmt-make-assignment,@cmd,$1))
mg-run-cmd={ ($1) 2>&1 && { [ -r $@.tmp ] || { echo 'mgear: error: Command for $@ succeeded without creating it!'; false; }; }; }
-mg-wrap-warnings=sed -re '1s/^/$@@warnings:=$$(empty)/; 1!s/^/$@@warnings+=$$(nl)/'
+mg-wrap-warnings=sed -re '1s/^/@warnings:=$$(empty)/; 1!s/^/@warnings+=$$(nl)/'
# Drat bash's lack of precedence between || and &&. Extra braces necessary.
mg-maybe-move-target={ cmp -s $@ $@.tmp || { echo >$@.g && mv -f $@.tmp $@; }; }
Matt McCutchen's Web Site / mgear / mgear.git / blobdiff