# make.configuration.deps file for thorn Formaline   -*-Makefile-*-



# Some configury magic

# Should we use gtar or tar?
TAR = $(shell gtar --help > /dev/null 2> /dev/null && echo gtar || echo tar)
# Is this gnu tar? If so, set this to 1, otherwise to 0. This is used
# to treat an exit code of 1 from gnu tar as non-fatal. This exit code
# indicates that files changed while reading, which can happen if the
# atime changed. (An atime change means that another program read the
# file, which is inconsequential.)
IS_GNUTAR = $(shell $(TAR) --version 2>/dev/null | grep -q 'GNU tar' && echo "1" || echo "0")

# Does tr support -C, or should we use -c instead?
TR_C = $(shell tr -C 'a' 'b' < /dev/null > /dev/null 2> /dev/null && echo 'tr -C' || echo 'tr -c')



################################################################################



# Create a tarball of the source code whenever this thorn is linked
# into an executable

TARBALL_DIR = $(SCRATCH_BUILD)/Formaline
FORMALINE_BIN_DIR = $(SCRATCH_BUILD)/Formaline/bin
CACTUS_CONFIG_DIR ?= $(CCTK_HOME)/configs

# The Formaline utilities (the perl scripts needed to create tarballs
# and execute git commands) are installed when Formaline's thorn
# library is built (see make.code.deps). To ensure that the utilities
# are available, we thus add a dependency on the thorn library.
#install-Formaline-utils: $(CCTK_LIBDIR)/$(LIBNAME_PREFIX)$(CCTK_LIBNAME_PREFIX)Formaline$(LIBNAME_SUFFIX)
#.PHONY: install-Formaline-utils
FORMALINE-UTILS = $(CCTK_LIBDIR)/$(LIBNAME_PREFIX)$(CCTK_LIBNAME_PREFIX)Formaline$(LIBNAME_SUFFIX)



#CACTUSLIBLINKLINE += $(CCTK_LIBDIR)/$(LIBNAME_PREFIX)$(CCTK_LIBNAME_PREFIX)Formaline-cactus-source$(LIBNAME_SUFFIX)
CACTUSLIBLINKLINE += -l$(CCTK_LIBNAME_PREFIX)Formaline-cactus-source

FRM-LIB = $(CCTK_LIBDIR)/$(LIBNAME_PREFIX)$(CCTK_LIBNAME_PREFIX)Formaline-cactus-source$(LIBNAME_SUFFIX)

$(EXEDIR)$(DIRSEP)$(EXE): $(FRM-LIB)

FRM-OBJS = $(TARBALL_DIR)/cactus-meta.o $(TARBALL_DIR)/build-id.o $(TARBALL_DIR)/config-Cactus.o $(TARBALL_DIR)/flesh-Cactus.o $(patsubst %,$(TARBALL_DIR)/thorn-%.o,$(notdir $(THORNS)))
FRM-OBJS-other = $(TARBALL_DIR)/config-Cactus-????.o $(TARBALL_DIR)/flesh-Cactus-????.o $(patsubst %,$(TARBALL_DIR)/thorn-%-????.o,$(notdir $(THORNS)))

$(FRM-LIB): $(FRM-OBJS)
#	$(AR) $(ARFLAGS) $@ $^
	$(MAKE) -f $(MAKE_DIR)/make.configuration $(FRM-LIB).objectlist.custom
	$(RM) $@ 2>/dev/null
	xargs -n $(FRM-OBJS-words-max) $(AR) $(ARFLAGS) $@ < $(FRM-LIB).objectlist
	$(RM) $(FRM-LIB).objectlist
	if test "x$(USE_RANLIB)" = "xyes"; then $(RANLIB) $(RANLIBFLAGS) $@; fi
	@echo $(DIVIDER)

.PRECIOUS: $(FRM-LIB)



# Unique ID for the build

# (force a new ID to be created every time)
# (do this after the thorn's library has been built, so that the
#  script gethostname.pl has been copied to the scratch directory)
# (generates also $(TOP)/CONFIG-ID)
.PRECIOUS: $(TOP)/BUILD-ID
.PHONY: $(TOP)/BUILD-ID
$(TOP)/BUILD-ID: $(CCTK_LIBDIR)/$(LIBNAME_PREFIX)$(CCTK_LIBNAME_PREFIX)Formaline$(LIBNAME_SUFFIX) $(FORMALINE-UTILS)
	config=`echo "$(EXE:cactus_%=%)" | $(TR_C) -d '[:alnum:]+-._]'` && \
	hostname=`$(FORMALINE_BIN_DIR)/gethostname.pl` && \
	user="$$USER" && \
	dirname=`echo "$(subst /,-,$(CCTK_HOME:/%=%))" | $(TR_C) -d '[:alnum:]+-._]'` && \
	timestamp=`date -u +%Y.%m.%d-%H.%M.%S` && \
	pid="$$$$" && \
	build_id="build-$$config-$$hostname-$$user-$$timestamp-$$pid" && \
	echo "$$build_id" > $@ && \
	config_id="config-$$config-$$hostname-$$dirname" && \
	echo "$$config_id" > $(TOP)/CONFIG-ID



.PRECIOUS: $(TARBALL_DIR)/build-id.o
$(TARBALL_DIR)/build-id.o: $(TARBALL_DIR)/build-id.c
	cd $(TARBALL_DIR) && $(CC) $(CFLAGS) -c -o $@ $^

.PRECIOUS: $(TARBALL_DIR)/build-id.c
$(TARBALL_DIR)/build-id.c: $(TOP)/BUILD-ID
	{ \
	echo '/* This is an auto-generated file -- do not edit */' && \
	build_id="$$(cat $(TOP)/BUILD-ID)" && \
	echo 'char const * const build_id = "'$$build_id'";' && \
	config_id="$$(cat $(TOP)/CONFIG-ID || echo 'NO-CONFIG-ID')" && \
	echo 'char const * const config_id = "'$$config_id'";'; \
	} > $@



# Meta information
$(TARBALL_DIR)/cactus-meta.o: $(TARBALL_DIR)/cactus-meta.c
	cd $(TARBALL_DIR) && $(CC) $(CFLAGS) -c -o $@ $^

$(TARBALL_DIR)/cactus-meta.c: $(TARBALL_DIR)/config-Cactus.c $(TARBALL_DIR)/flesh-Cactus.c $(patsubst %,$(TARBALL_DIR)/thorn-%.c,$(notdir $(THORNS))) $(FORMALINE-UTILS)
	$(FORMALINE_BIN_DIR)/makemetablob.pl CactusConfig Cactus $(notdir $(THORNS)) > $@

.PRECIOUS: $(TARBALL_DIR)/cactus-meta.c $(TARBALL_DIR)/cactus-meta.o



###############################################################################
# Configuration files
###############################################################################

# Note: Build first the source files %-????.c, then the source file
# $^, so that interruptions or build errors lead to a re-build
$(TARBALL_DIR)/config-Cactus.o: $(TARBALL_DIR)/config-Cactus.c
	@echo "Creating Formaline tarball for the configuration options"
	cd $(TARBALL_DIR) && \
	$(CC) $(CFLAGS) -c $(^:%.c=%-????.c) && \
	$(CC) $(CFLAGS) -c $^

$(TARBALL_DIR)/config-Cactus.c: $(TARBALL_DIR)/config-Cactus.tar.gz $(CCTK_HOME)/arrangements/CactusUtils/Formaline/src/util/VERSION $(FORMALINE-UTILS)
	$(RM) -f $(@:%.c=%-????.c)
	$(FORMALINE_BIN_DIR)/makeblob.pl $(@:%.c=%) '' CactusConfig < $<

$(TARBALL_DIR)/config-Cactus.tar.gz: $(TARBALL_DIR)/config-Cactus.files
	cd $(CCTK_HOME) && \
	$(TAR) czf $@ -T $< || [ $$(( $$? / ($(IS_GNUTAR)+1) )) -eq 0 ]

# This dependency means that the tarball for the configuration options
# is only updated if the flesh is actually recompiled. This does not
# catch changes to files that do not influence the executable.
$(TARBALL_DIR)/config-Cactus.files: $(CCTK_LIBDIR)/$(LIBNAME_PREFIX)$(CCTK_LIBNAME_PREFIX)$(FLESHLIB)$(LIBNAME_SUFFIX) $(TARBALL_DIR)/config-Cactus.ccldeps $(CONFIG)/make.thornlist
	mkdir -p $(TARBALL_DIR)/configs/$(notdir $(TOP))
	{ \
		cd $(CACTUS_CONFIG_DIR)/$(notdir $(TOP)) && \
		cp -r OptionList properties.ini RunScript ScriptFile SubmitScript Thornlist config-data config-info $(TARBALL_DIR)/configs/$(notdir $(TOP)); \
	} || true
	cd $(TARBALL_DIR) && \
	find configs/$(notdir $(TOP))/ \
		-name 'CVS' -prune -o \
		-name '_darcs' -prune -o \
		-name '.git' -prune -o \
		-name '.hg' -prune -o \
		-name '.svn' -prune -o \
		-name '*.log' -prune -o \
		-name '*.log.gz' -prune -o \
		-name '.?*' -prune -o \
		-name '*~' -prune -o \
		! -type d \
		-print > $@.tmp
	mv $@.tmp $@
	$(RM) -rf $(TARBALL_DIR)/configs

-include $(TARBALL_DIR)/config-Cactus.ccldeps
# Make aborts if these dependencies vanish.  Therefore mention only files
# here that cannot go away.
$(TARBALL_DIR)/config-Cactus.ccldeps:
	mkdir -p $(TARBALL_DIR)
	{ \
	        echo "$(@:%.ccldeps=%.files) \\"; \
	        echo "$@: \\"; \
	        echo " $(CCTK_HOME)/src/interface.ccl \\"; \
	        echo " $(CCTK_HOME)/src/param.ccl \\"; \
	        echo " $(CCTK_HOME)/src/schedule.ccl"; \
	} > $@

.PRECIOUS: $(TARBALL_DIR)/config-Cactus.ccldeps $(TARBALL_DIR)/config-Cactus.files $(TARBALL_DIR)/config-Cactus.tar.gz $(TARBALL_DIR)/config-Cactus.c $(TARBALL_DIR)/config-Cactus.o



###############################################################################
# Flesh
###############################################################################

# Note: Build first the source files %-????.c, then the source file
# $^, so that interruptions or build errors lead to a re-build
$(TARBALL_DIR)/flesh-Cactus.o: $(TARBALL_DIR)/flesh-Cactus.c
	@echo "Creating Formaline tarball for the flesh"
	cd $(TARBALL_DIR) && \
	$(RM) -f $(^:%.c=%-????.o) && \
	$(CC) $(CFLAGS) -c $(^:%.c=%-????.c) && \
	$(CC) $(CFLAGS) -c $^

$(TARBALL_DIR)/flesh-Cactus.c: $(TARBALL_DIR)/flesh-Cactus.tar.gz $(CCTK_HOME)/arrangements/CactusUtils/Formaline/src/util/VERSION $(FORMALINE-UTILS)
	$(RM) -f $(@:%.c=%-????.c)
	$(FORMALINE_BIN_DIR)/makeblob.pl $(@:%.c=%) '' Cactus < $<

$(TARBALL_DIR)/flesh-Cactus.tar.gz: $(TARBALL_DIR)/flesh-Cactus.files
	cd $(CCTK_HOME) && \
	$(TAR) czf $@ -T $< || [ $$(( $$? / ($(IS_GNUTAR)+1) )) -eq 0 ]

# This dependency means that the tarball for the flesh is only updated
# if the flesh is actually recompiled.  This does not catch changes to
# files that do not influence the executable.
$(TARBALL_DIR)/flesh-Cactus.files: $(CCTK_LIBDIR)/$(LIBNAME_PREFIX)$(CCTK_LIBNAME_PREFIX)$(FLESHLIB)$(LIBNAME_SUFFIX) $(TARBALL_DIR)/flesh-Cactus.ccldeps $(CONFIG)/make.thornlist
	cd $(CCTK_HOME) && \
	find CONTRIBUTORS COPYRIGHT Makefile lib/ src/ \
		-name 'CVS' -prune -o \
		-name '_darcs' -prune -o \
		-name '.git' -prune -o \
		-name '.hg' -prune -o \
		-name '.svn' -prune -o \
		-name '*.log' -prune -o \
		-name '*.log.gz' -prune -o \
		-name '.?*' -prune -o \
		-name '*~' -prune -o \
		! -type d \
		-print > $@.tmp
	mv $@.tmp $@

-include $(TARBALL_DIR)/flesh-Cactus.ccldeps
# Make aborts if these dependencies vanish.  Therefore mention only files
# here that cannot go away.
$(TARBALL_DIR)/flesh-Cactus.ccldeps:
	mkdir -p $(TARBALL_DIR)
	{ \
	        echo "$(@:%.ccldeps=%.files) \\"; \
	        echo "$@: \\"; \
	        echo " $(CCTK_HOME)/src/interface.ccl \\"; \
	        echo " $(CCTK_HOME)/src/param.ccl \\"; \
	        echo " $(CCTK_HOME)/src/schedule.ccl"; \
	} > $@

.PRECIOUS: $(TARBALL_DIR)/flesh-Cactus.ccldeps $(TARBALL_DIR)/flesh-Cactus.files $(TARBALL_DIR)/flesh-Cactus.tar.gz $(TARBALL_DIR)/flesh-Cactus.c $(TARBALL_DIR)/flesh-Cactus.o



###############################################################################
# Thorns
###############################################################################

# Note: Build first the source files %-????.c, then the source file
# $^, so that interruptions or build errors lead to a re-build
$(TARBALL_DIR)/thorn-%.o: $(TARBALL_DIR)/thorn-%.c
	@echo "Creating Formaline tarball for thorn $*"
	cd $(TARBALL_DIR) && \
	$(RM) -f $(patsubst $(TARBALL_DIR)/%, %, $(^:%.c=%-????.o)) && \
	$(CC) $(CFLAGS) -c $(patsubst $(TARBALL_DIR)/%, %, $(^:%.c=%-????.c)) && \
	$(CC) $(CFLAGS) -c $(patsubst $(TARBALL_DIR)/%, %, $^)

$(TARBALL_DIR)/thorn-%.c: $(TARBALL_DIR)/thorn-%.tar.gz $(CCTK_HOME)/arrangements/CactusUtils/Formaline/src/util/VERSION $(FORMALINE-UTILS)
	cd $(TARBALL_DIR) && $(RM) -f $(@:$(TARBALL_DIR)/%.c=%-????.c)
	$(FORMALINE_BIN_DIR)/makeblob.pl $(@:%.c=%) $(patsubst %/,%,$(dir $(filter %/$(@:$(TARBALL_DIR)/thorn-%.c=%),$(THORNS)))) $(@:$(TARBALL_DIR)/thorn-%.c=%) < $<

$(TARBALL_DIR)/thorn-%.tar.gz: $(TARBALL_DIR)/thorn-%.files
	cd $(CCTK_HOME) && \
	$(TAR) czf $@ -T $< || [ $$(( $$? / ($(IS_GNUTAR)+1) )) -eq 0 ]

# This dependency means that the tarball for a thorn is only updated
# if the thorn is actually recompiled.  This does not catch changes to
# files that do not influence the executable.
$(TARBALL_DIR)/thorn-%.files: $(CCTK_LIBDIR)/$(LIBNAME_PREFIX)$(CCTK_LIBNAME_PREFIX)%$(LIBNAME_SUFFIX) $(TARBALL_DIR)/thorn-%.ccldeps
	cd $(CCTK_HOME) && \
	find arrangements/$(filter %/$*,$(THORNS))/. \
		-name 'data' -prune -o \
		-name 'doc' -prune -o \
		-name 'par' -prune -o \
		-name 'test' -prune -o \
		-name 'CVS' -prune -o \
		-name '*.log' -prune -o \
		-name '*.log.gz' -prune -o \
		-name '.?*' -prune -o \
		-name '*~' -prune -o \
		! -type d \
		-print | sed -e 's+/[.]/+/+g' > $@.tmp
	mv $@.tmp $@

-include $(patsubst %,$(TARBALL_DIR)/thorn-%.ccldeps,$(notdir $(THORNS)))
# Make aborts if these dependencies vanish.  Therefore mention only files
# here that cannot go away.
$(TARBALL_DIR)/thorn-%.ccldeps:
	mkdir -p $(TARBALL_DIR)
	{ \
	        echo "$(@:%.ccldeps=%.files) \\"; \
	        echo "$@: \\"; \
	        echo " $(CCTK_HOME)/arrangements/$(filter %/$*,$(THORNS))/interface.ccl \\"; \
	        echo " $(CCTK_HOME)/arrangements/$(filter %/$*,$(THORNS))/param.ccl \\"; \
	        echo " $(CCTK_HOME)/arrangements/$(filter %/$*,$(THORNS))/schedule.ccl"; \
	} > $@

.PRECIOUS: $(TARBALL_DIR)/thorn-%.ccldeps $(TARBALL_DIR)/thorn-%.files $(TARBALL_DIR)/thorn-%.tar.gz $(TARBALL_DIR)/thorn-%.c $(TARBALL_DIR)/thorn-%.o



###############################################################################
# Helpers
###############################################################################

# Create a file containing the names of all object files.

# Since the list may be too long to be passed to a shell, it is split
# into a set of rules which add lines to a file.  This file can later
# be used via xargs.

FRM-OBJS-words = $(words $(FRM-OBJS))

ifeq ($(shell uname),AIX)
# Be conservative about the maximum number of objects that can be
# handled at once.  AIX has a command line length limit of about
# 32000.  Each object's path name may be about 200 characters long.
FRM-OBJS-words-max = 100
else
# Assume that the system has no limit to speak of.
FRM-OBJS-words-max = 10000
endif

ifeq ($(shell test $(FRM-OBJS-words) -le $(FRM-OBJS-words-max) && echo 1), 1)

# The list is short.  Create the file directly, which is faster.

.PHONY: $(FRM-LIB).objectlist.custom
$(FRM-LIB).objectlist.custom:
	echo $(FRM-OBJS) $(FRM-OBJS-other) > $(FRM-LIB).objectlist

else

# The list is long.  Create the file via a set of rules, one rule per
# object file.

FRM-OBJS-added = $(FRM-OBJS:%=%.added) $(FRM-OBJS-other:%=%.added)

.PHONY: $(FRM-LIB).objectlist.custom
$(FRM-LIB).objectlist.custom: $(FRM-OBJS-added)

# Truncate the file
.PHONY: $(FRM-LIB).objectlist.create
$(FRM-LIB).objectlist.create:
	: > $(FRM-LIB).objectlist

# Add a line to the file
.PHONY: $(FRM-OBJS-added)
$(FRM-OBJS-added): $(FRM-LIB).objectlist.create
	echo $(@:%.added=%) >> $(FRM-LIB).objectlist

endif



###############################################################################
# Git repository of source code
###############################################################################



# Does git exist, or should we do nothing instead?
GIT-CMD := $(shell env PATH="$(SCRATCH_BUILD)/external/git/bin:$(SCRATCH_BUILD)/git-1.6.6.1/bin:$(SCRATCH_BUILD)/git-1.6.0.6/bin:$$HOME/git/bin:$$PATH" which git)
HAVE-GIT := $(shell '$(GIT-CMD)' --version > /dev/null 2>&1 && echo 'true' || echo 'false')
GIT := $(shell $(HAVE-GIT) && echo '$(FORMALINE_BIN_DIR)/git-lock.pl $(GIT-CMD)' || { echo 'Formaline: WARNING: git command not found' >&2 && echo 'true'; })



ifeq ($(HAVE-GIT),true)

main: git-store-source

.PHONY: git-store-source
git-store-source: git-commit-everything git-push-everything
	echo "Formaline: Done."
	echo "Formaline: (Formaline has finished updating the git repositories."
	echo "Formaline:  If the build process seems to hang, some other command"
	echo "Formaline:  is still running, e.g. the final link stage.)"

GIT-TAG-DIR     = $(SCRATCH_BUILD)/Formaline
GIT-BIN         = $(FORMALINE_BIN_DIR)
GIT-ROOT        = $(CCTK_HOME)
GIT-REPO        = $(TOP)/configjar.git
GIT-MASTER-REPO = $(CCTK_HOME)/cactusjar.git

GIT-THORNS      = $(notdir $(THORNS))

BUILD-ID-FILE   = $(TOP)/BUILD-ID
CONFIG-ID-FILE  = $(TOP)/CONFIG-ID

.PHONY: git-push-everything
git-push-everything: git-commit-everything $(BUILD-ID-FILE) $(FORMALINE-UTILS)
	{ \
	'$(GIT-BIN)/git-init-master-repo.pl' '$(GIT)' '$(GIT-MASTER-REPO)' && \
	eval "$$('$(GIT-BIN)/git-get-localdir.pl' '$(GIT)')" && \
	if [ -e "$(CCTK_HOME)/cactus.config" ]; then \
		. "$(CCTK_HOME)/cactus.config"; \
	fi && \
	export CACTUS_LOCAL_GIT_REPO CACTUS_CENTRAL_GIT_REPO && \
	'$(GIT-BIN)/git-push-everything.pl' '$(GIT)' '$(GIT-REPO)' '$(GIT-MASTER-REPO)'; \
	} || echo "Formaline: WARNING: Error while pushing to master repository"

.PHONY: git-commit-everything
git-commit-everything: $(GIT-TAG-DIR)/flesh-Cactus.git-tag $(GIT-THORNS:%=$(GIT-TAG-DIR)/thorn-%.git-tag) $(BUILD-ID-FILE) git-rm-unused-thorns $(FORMALINE-UTILS)
	{ \
	'$(GIT-BIN)/git-commit-everything.pl' '$(GIT)' '$(GIT-REPO)' '$(GIT-ROOT)' "$$(cat $(BUILD-ID-FILE))" "$$(cat $(CONFIG-ID-FILE))"; \
	} || echo "Formaline: WARNING: Error while committing to repository"

# Wait until after thorn Formaline has been built, so that its
# utilities are available
.PHONY: git-rm-unused-thorns
git-rm-unused-thorns: $(CCTK_LIBDIR)/$(LIBNAME_PREFIX)$(CCTK_LIBNAME_PREFIX)Formaline$(LIBNAME_SUFFIX) $(FORMALINE-UTILS)
	{ \
	'$(GIT-BIN)/git-rm-unused-thorns.pl' '$(GIT)' '$(GIT-REPO)' '$(GIT-ROOT)' $(THORNS); \
	} || echo "Formaline: WARNING: Error while removing unused thorns"

.PRECIOUS: $(GIT-TAG-DIR)/flesh-Cactus.git-tag
$(GIT-TAG-DIR)/flesh-Cactus.git-tag: $(TARBALL_DIR)/flesh-Cactus.files $(FORMALINE-UTILS)
	mkdir -p $(GIT-TAG-DIR)
	{ \
	'$(GIT-BIN)/git-init-repo.pl' '$(GIT)' '$(GIT-REPO)' && \
	echo "Formaline: Adding flesh to git repository..." && \
	'$(GIT-BIN)/git-rm-thorn.pl' '$(GIT)' '$(GIT-REPO)' '$(GIT-ROOT)' 'Cactus' CONTRIBUTORS COPYRIGHT Makefile lib src configs && \
	xargs '$(GIT-BIN)/git-add-thorn.pl' '$(GIT)' '$(GIT-REPO)' '$(GIT-ROOT)' 'Cactus' < $(TARBALL_DIR)/flesh-Cactus.files && \
	: > $@; \
	} || echo "Formaline: WARNING: Error while adding flesh to git repository"

.PRECIOUS: $(GIT-TAG-DIR)/thorn-%.git-tag
$(GIT-TAG-DIR)/thorn-%.git-tag: $(TARBALL_DIR)/thorn-%.files $(FORMALINE-UTILS)
	mkdir -p $(GIT-TAG-DIR)
	{ \
	'$(GIT-BIN)/git-init-repo.pl' '$(GIT)' '$(GIT-REPO)' && \
	echo "Formaline: Adding thorn $* to git repository..." && \
	'$(GIT-BIN)/git-rm-thorn.pl' '$(GIT)' '$(GIT-REPO)' '$(GIT-ROOT)' '$*' "'"'arrangements/*/$*'"'" && \
	xargs '$(GIT-BIN)/git-add-thorn.pl' '$(GIT)' '$(GIT-REPO)' '$(GIT-ROOT)' '$*' < $(TARBALL_DIR)/thorn-$*.files && \
	: > $@; \
	} || echo "Formaline: WARNING: Error while adding thorn $* to git repository"

endif



# NOTE:

# Define environment variable CACTUS_CENTRAL_GIT_REPO where the source trees
# are automatically pushed

# git-archive --prefix=Cactus/ wavetoy | gzip > wavetoy.tar.gz
# git-archive --prefix=Cactus/ wavetoy | { cd /somewhere && tar xf -; }

# git init
# git pull <repo> <branch>

# git clone <repo>
# git checkout <tag>



# TODO:
# 8. Create a separate git repository for every thorn, which would
#    make git operations more parallel
# 9. Do not copy all branches/tags to the central repo all the time
# 10. Add a "git reset --mixed" in the beginning to ensure the
#     repository is in a consistent state.  Add "git rm -r --cached ."
#     as well?
# 11. Execute a "rm scratch/*.git-tag" if there are problems, and try
#     again
# 12. Use subdirectories in scratch directory
# 13. Calculate and output md5sum for source files and the source tree
#     to see more easily whether and which files changed
# 14. cd into thorn directory, and use lstat/readlink to follow
#     symbolic links, to make thing work with recent versions of git



# DONE:
# 1. Remember git-archive to get a tarball
# 3. Push the commits automatically to a central (write-only?) repository
# 4. What if the Cactus directory is alread the root of a git repository?
# 5. Place the .git repository into the config subdirectory
# 6. Push it automatically into a subdirectory of the main Cactus directory
# 7. Figure out how to handle conflicting branch names

# WONT:
# 2. Don't create a version history; instead, leave all commits independent