+++ /dev/null
-# Mage Build Tool by Matt McCutchen
-# http://www.kepreon.com/~matt/mage/
-
-
-# Remember the original default goal so we can restore it at the end of mage.mk.
-mg-orig-default-goal:=$(.DEFAULT_GOAL)
-
-# We use second-expansion heavily to dynamically compute prerequisites when they
-# are needed. Second-expansion lets us follow make's implicit rule search
-# instead of trying to anticipate which prerequisites it will need in advance.
-.SECONDEXPANSION:
-
-
-# TEXT UTILITIES
-empty:=
-bs:=\$(empty)
-hash:=\#
-pct:=%
-define nl
-
-
-endef
-# Shell-quote: a'b => 'a'\''b'
-sq='$(subst ','\'',$1)'
-# Make-quote: a$\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),$$(nl),$(subst $$,$$$$,$1)))
-# Return nonempty if the strings are equal, empty otherwise.
-# If the strings have only nice characters, you can do $(filter x$1,x$2).
-streq=$(findstring x$1,$(findstring x$2,x$1))
-
-# $(call fmt-make-assignment,foo,bar)
-# Output a make assignment that stores bar in variable foo.
-# The result is like `foo:=bar' but handles leading spaces, $, and
-# newlines appearing in bar safely.
-fmt-make-assignment=$1:=$$(empty)$(call mqas,$2)
-
-
-# TARGET OBFUSCATION
-
-# Mage uses two kinds of "obfuscated targets" (those that are not the simple
-# names of real files):
-# - An always-exists target like /.//. is used as a prerequisite of an implicit
-# rule. Since it exists, make doesn't second-expand its own prerequisites
-# until it is actually run. This way, a target's prerequisites can depend on
-# the results of previous command scripts.
-# - An alternative-name target like /.//./proc/self/cwd/bar is used to check the
-# mtime of a file without actually building it or introducing a circular
-# dependency.
-
-# $(newoid) allocates and returns a new obfuscation ID (oid). Example:
-# x:=$(newoid)
-# You can then refer to target $x or $x$(aname)bar (for any file bar).
-# Prerequisites and commands come from $($x@opr) and $($x@ocmd).
-# Target-specific variables $(oid) and $(otgt) (if alternate-name) are
-# available.
-
-opfx:=/./
-# TODO If the system doesn't support /proc/self/cwd, use something else.
-aname:=/proc/self/cwd/
-nextoid:=/./.
-newoid=$(nextoid)$(eval nextoid:=$(subst /.//////,//./,$(patsubst /.//////%,/././%,$(nextoid:.=/.))))
-
-# Target-specific variables for obfuscated targets.
-$(opfx)%: oid=$(word 1,$(subst $(aname), ,$@))
-$(opfx)%: otgt=$(word 2,$(subst $(aname), ,$@))
-
-# High-priority implicit rule for obfuscated targets. Works for both always-
-# exists and alternate-name targets.
-$(opfx)%: $$($$(oid)@opr)
- $($(oid)@ocmd)
-
-# Make won't use the same implicit rule more than once on its stack, so provide
-# a second copy of the rule to allow two obfuscated targets on the stack.
-# Needed for $(mg-genfile-oid)$(aname)bar.g <- $(mg-scout-oid)$(aname)bar .
-# The prerequisites must look different before second-expansion so the second
-# rule isn't discarded as a duplicate.
-$(opfx)%: $$(empty) $$($$(oid)@opr)
- $($(oid)@ocmd)
-
-# MAIN BUILD LOGIC
-
-# DESIGN:
-#
-# - To each generated file bar corresponds a "genfile" bar.g that contains some
-# information about how bar was generated, including the command (for rebuild on
-# command change) and the warnings (for replay).
-#
-# - bar.g's mtime is the last time Mage verified that bar was up to date. bar
-# needs to be regenerated iff a prerequisite is newer than *bar.g* (not bar).
-# If a prerequisite changes but the command gives the same contents for bar,
-# bar.g is touched but bar itself is not touched because files that depend on it
-# need not be regenerated.
-#
-# - If bar is newer than bar.g, the user has overridden it, and we should leave
-# the override in place but warn the user about it.
-#
-# - The user's Makefile defines Mage rules by calling mg-define-rule. Each Mage
-# rule becomes one underlying make rule with the same target and a little extra
-# magic. This is important so that all implicit rule competition takes place at
-# the same target. Additionally, the prerequisites are passed to an obfuscated
-# target for bar.g to see if any are newer than bar.g. This is done by the
-# single obfuscated implicit rule, keeping the number of implicit rules low.
-# Then the command script for bar checks for overrides, command change,
-# prerequisite change, etc. and acts accordingly.
-#
-# Target metadata variables for bar: (* means stored in bar.g)
-#
-# bar@cmd:=cat foo >bar.tmp
-# Generation command as given to the shell.*
-#
-# bar@warnings:=$(empty)yikes!
-# Data that the command printed to stdout or stderr, presumably warnings.*
-#
-# bar@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 Mage has loaded bar.g and hasn't changed it since then.
-#
-# bar@gdeps:=foo
-# Static dependencies of bar, for checking by bar.g.
-#
-# bar@gq:=foo $(mg-scout-oid)$(aname)bar
-# $? from the rule for bar.g; used by the rule for bar.
-#
-# bar@checked:=1
-# Set when Mage determines that a file is up to date or depends on it being
-# so determined. Used to decide which prerequisite to check next for a
-# dependency-logging command.
-#
-# bar@dlc-ran:=1
-# Indicates that Mage is in the middle of building bar using a dependency-
-# logging command. Means that bar.g.tmp, not bar.g, is the most current
-# genfile.
-#
-## If the rule for bar is overridden, we clear the information from bar.g so
-## that it is as if bar.g didn't exist. -- Not currently needed
-#
-# Some make features with which Mage's compatibility has not been investigated:
-# - Command-line options (especially --dry-run, --question, --touch,
-# --always-make, --keep-going, --jobs, --assume-old, and --assume-new)
-# - Static pattern rules
-# - Vpath
-
-# $(call gload,foo.o)
-# Make sure foo.o's genfile, if any, has been loaded.
-define gload
-$(if $($1@gloaded),,$(eval
-$1@cmd:=
-$1@warnings:=
-$1@deps:=
--include $1.g
-$1@gloaded:=1
-))
-endef
-
-# 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:=$?)
-
-# Mage-ized automatic variables.
-# $@: needs no translation
-# NOTE: $(mg@) is *eventual* target. Commands must write to temp file, $t .
-# $%: haven't thought about it much, but probably needs no translation
-mg< = $(firstword $(mg^))
-mg? = $(filter-out $(opfx)%,$($@@gq))
-mg^ = $(filter-out MG-% $(opfx)%,$^)
-mg+ = $(filter-out MG-% $(opfx)%,$+)
-# $|: needs no translation
-# $*: needs no translation
-
-# $(call mg-translate-cmd,cat $$< >$$t)
-# Replaces references to automatic variables with references to their Mage-ized
-# counterparts. There might be false matches, e.g., $$@ => $$(mg@) ;
-# to prevent that, write $$$(empty)@ instead. (c.f. autoconf empty quadrigraph)
-mg-translate-cmd=$(subst $$t,$$@.tmp,$(subst $$?,$$(mg?),$(subst $$<,$$(mg<),$(subst $$^,$$(mg^),$(subst $$+,$$(mg+),$1)))))
-
-# $(call mg-prereq-predict,target,prerequisites)
-# Expands to code that does the following at second-expansion time:
-# 1. Computes the actual prerequisites from the given prerequisite patterns by
-# translating % to $* and prepending a directory if appropriate.
-# 2. Saves both existing ($+) and newly computed prerequisites to $(bar@gdeps)
-# where the rule for bar.g can get them.
-# Factor out set-gdeps because make gets confused if the macro for the
-# prerequisites has a colon. Make replaces the first % with the stem *before
-# expansion*, so use $(pct) to protect some %s.
-mg-set-gdeps=$(eval $@@gdeps:=$1)
-mg-prereq-predict=$$$$(call mg-set-gdeps,$$$$+ $(if $(findstring /,$1),$$$$(subst $$$$(pct),$$$*,$2),$$$$(addprefix $$$$(dir $$$$@),$$$$(subst $$$$(pct),$$$$*,$2))))
-
-# Used to make the rule for bar always run so we can act based on $(bar@gdeps)
-# and check for command change.
-MG-FORCE:
-.PHONY: MG-FORCE
-
-# $(call mg-define-rule,target,prerequisites,cmd)
-# Defines a rule. cmd is expanded again when it is run, at which time
-# Mage-ized automatic variables are available.
-#
-# I eradicated the target-specific variables because they fail when there are
-# multiple implicit rules with the same target pattern.
-#
-# Rule for the target. Set $(bar@gdeps) to all prerequisites. Apply the new
-# prerequisites. The command script always runs. Depend on bar.g to get
-# $(bar@gq).
-define mg-define-rule
-$(eval $1: $(call mg-prereq-predict,$1,$2) $2 MG-FORCE $(mg-genfile-oid)$(aname)$$$$@.g
- $$(call mg-rule-cmd,$(call mg-translate-cmd,$3)))
-endef
-
-# TODO Provide a way to define static pattern rules.
-
-# Procedure to generate bar. Now $@ is bar, so we say $@.g for bar.g.
-# If an override:
-# 1. Complain. (Should we stop "`bar' is up to date" using @:; ?)
-# 2. This would be the place to clear bar's metadata if we wanted to.
-# Otherwise, check prereqs, command, and nonexistence to decide whether bar
-# needs to be regenerated. If so:
-# 1. Note that the genfile is about to change.
-# 2. Echo the command being run.
-# On error, skip to 8:
-# 3. Open the new genfile bar.g.tmp for writing.
-# 4. Run the command to bar.tmp, storing warnings in bar.g.tmp.
-# 5. Store the command in bar.g.tmp. Do it here to ensure that bar.g.tmp
-# is at least as new as bar.tmp.
-# 6. If bar.tmp differs from bar:
-# a. Clear and touch bar.g (so bar doesn't become an override if we're
-# killed between steps 6b and 7).
-# b. Move in the new bar.
-# 7. Now that bar is known to be up to date, move in the new bar.g.
-# 8. Defensively remove both temporary files and exit with the exit code
-# from before the removal. (trap EXIT)
-# If not:
-# 1. If there were warnings, replay them. (HMMM To stderr?)
-# HMMM .tmp in displayed command looks ugly
-define mg-rule-cmd
- $(if $(filter $(mg-scout-oid)$(aname)$@,$($@@gq)),\
- $(info Mage: warning: Manually created/modified file at $@ overrides rule.)\
- ,$(call gload,$@)$(if $($@@gq)$(if $(wildcard $@),,TARGET-DNE)$(mg-check-cmd),\
- $(eval $@@gloaded:=)$(info $1)\
- @trap 'rm -f $@.tmp $@.g.tmp' EXIT &&\
- exec 3>$@.g.tmp &&\
- set -o pipefail && { $(mg-run-cmd) | tee /dev/fd/4 | $(mg-wrap-warnings) >&3; } 4>&1 &&\
- $(mg-assign-cmd) >&3 &&\
- $(mg-maybe-move-target) &&\
- mv -f $@.g.tmp $@.g\
- ,$(if $($@@warnings),\
- $(info $($@@cmd) # Mage warning replay$(nl)$($@@warnings))\
- )))
-endef
-
-# If the command changed, we must regenerate.
-mg-check-cmd=$(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-run-cmd={ ($1) 2>&1 && { [ -r $@.tmp ] || { echo 'Mage: error: Command for $@ succeeded without creating it!'; false; }; }; }
-mg-wrap-warnings=sed -re '1s/^/$@@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 $@; }; }
-
-# Just add additional prerequisites. This cannot add prerequisite patterns to
-# an implicit rule, but it can add specific prerequisites to an individual use
-# of an implicit rule. Currently, Mage picks up the target's prerequisites from
-# make, so this just attaches the given prerequisites to the target, but the
-# implementation might change in the future.
-mg-define-prereq=$(eval $1: $2)
-
-
-# DEPENDENCY-LOGGING COMMANDS
-
-mg-dlc-static-run-oid:=$(mg-genfile-oid)
-
-# $(call mg-define-rule-dlc,target,static-prerequisites,cmd,dep-converter)
-# Analogue of mg-define-rule for a dependency-logging command.
-# I haven't decided on the format for the dep-converter yet.
-define mg-define-rule-dlc
-$(eval
-
-# FINISH
-
-# Rule for the target. Set $(bar@gdeps) to all prerequisites. Apply the new
-# prerequisites. The command script always runs. Finally, do the static run
-# and then the first dynamic check.
-$1: $(call mg-prereq-predict,$1,$2) $2 MG-FORCE $(mg-dlc-static-run-oid)$(aname)$$$$@.g $$$$(call dlc-next-dchk,$$$$(target))
-# TODO: Move the finished file into place or something
-# $$(call mg-rule-cmd,$3)
-)
-endef
-
-#mg-dlc-next-dchk=$(call mg-dlc-next-dchk-1,$1,$(newoid))
-#mg-dlc-next-dchk-1=$(eval $2@opr=$$(call mg-dlc-dchk-pr,$1,$2))$2
-#
-## $(call mg-dlc-dchk-pr,target,oid)
-#mg-dlc-dchk-pr=$(call mg-dlc-dchk-pr-1,$1,$2,$(call next-unchecked-prereq,$($1@deps)))
-## $(call mg-next-unchecked-prereq,foo.c bar.h baz.h)
-#mg-next-unchecked-prereq=$(firstword $(foreach p,$1,$(if $($p@checked),,$p)))
-#define mg-dlc-dchk-pr-1
-#$(if $3,$(call mg-dlc-drun,$1,$2,$3) $(call mg-dlc-next-dchk,$1),)
-#endef
-#
-## $(call mg-dlc-drun,target,oid,prereq). FINISH
-#define mg-dlc-drun
-#$(eval
-#$2$(aname)$3@opr:=$3
-#$2$(aname)$3@ocmd:=
-#)$2$(aname)$3
-#endef
-#
-#
-## END
-
-# We don't want anything we defined to become the default goal.
-.DEFAULT_GOAL := $(mg-orig-default-goal)
Matt McCutchen's Web Site / mgear / mgear.git / blobdiff