#
# clink.mk
# written by Kaz Kylheku 
# June 2005
#
# This a GNU Make include file that provides a system for creating a new CLISP
# linking set by adding modules to an existing one. These rules meet several
# objectives.  They:
#
# - replace the arcane old 'clisp-link add-module-set' script;
# - create a lisp image directly, without file copying, symbolic
#   links, generated shell scripts and other such things;
# - do not require the added module to be located in a particular
#   directory setup with a link.sh script; all the files and dependencies
#   are handled by these rules;
# - eliminate the use of clumsy symbolic links, since the new Lisp image
#   is linked directly out of the source directory, using relative paths.
#
# This makefile is intended to be included into another Makefile. It requires
# certain inputs in the form of certain variables being set prior to the
# inclusion. It produces outputs by assigning to variables.
#
# Input variables:
#
# CLK              A string serving as the namespace for all internal
#                  variables. This allows multiple independent instantiations 
#                  of the rules within a single GNU make process. If 
#                  you leave out this variable, it's set to CLINK_,
#                  and so all the $(CLK)X variables become just CLINK_X.
# $(CLK)SOURCE_LS  The name of the existing CLISP linking set, such as
#                  "base" or "full" (without the quotes). This makefile
#                  will find the linking set by itself, provided that the
#                  clisp executable is in the executable search path.
#                  If this variable is not set, it takes on the default
#                  value "base".
# $(CLK)TARGET_DIR The directory where to place the resulting lisp.run
#                  and lispinit.mem, with trailing slash!
# $(CLK)MODULES    Names of FFI modules with no .c or .lisp suffix.  
#                  It's assumed that for each of these, there is a .lisp
#                  file containing CLISP FFI definitions, and is compiled
#                  compiled to produce a .c file and a .fas file.
#                  It's possible, but pointless, to leave this variable unset.
# $(CLK)OBJECTS    Optional names of additional object files and libraries to 
#                  load into the new CLISP executable.
# $(CLK)PRELOAD    If this is not empty, then the boostrapping process
#                  will use an intermediate lispinit.mem, which will be
#                  stuffed with the specified Lisp modules. Probably the 
#                  biggest use for this is to set up packages. If you are 
#                  using DEF-CALL-OUT to make Lisp functions callable from C,
#                  and those functions are named by packaged symbols, then
#                  the package has to exist in the lispinit.mem, otherwise
#                  the lisp.run will fail to run at all. It will iterate
#                  over its global linked list of modules and bail when
#                  it sees references to nonexistent packages. But at this
#                  point we haven't had a chance to build our lispinit.mem.
#                  The way out of this chicken-egg problem is to build
#                  an intermediate lispinit.mem.
# $(CLK)LOAD       List of Lisp modules to load into the final memory image,
#                  not including those listed in $(CLK)MODULES.
#
# Output variables:
#
# $(CLK)CLEAN      List of intermediate files to be blown away by
#                  a "make clean".
#

# -- internals start here --

#
# Set up a default namespace
#

ifeq ($(CLK),)
CLK := CLINK_
endif

ifeq ($($(CLK)SOURCE_LS),)
$(CLK)SOURCE_LS := base
endif

#
# $(CLK)CLISP_DIR holds the CLISP library directory, underneath which
# one finds the linkkit and linking sets. E.g. /usr/local/lib/clisp
#

$(CLK)CLISP_DIR := $(shell clisp -q -norc -x \
                     '(progn (princ *lib-directory*) (values))')

#
# $(CLK)SOURCE_DIR is the source linking set, e.g. /usr/local/lib/clisp/full
#

$(CLK)SOURCE_DIR := $($(CLK)CLISP_DIR)$($(CLK)SOURCE_LS)/

#
# $(CLK)SOURCE_RUN is the Lisp executable in the source linking set.
# It could be lisp.run, or lisp.exe on Cygwin. So we just get it
# using wildcard expansion. (The GNU Make $(wildcard) function
# doesn't expand variables in the pattern, so we use shell echo).
#

$(CLK)SOURCE_RUN := $(filter-out %lisp.a,\
                                 $(shell echo $($(CLK)SOURCE_DIR)lisp.*))

$(CLK)LISPRUN := $(notdir $($(CLK)SOURCE_RUN))

#
# $(CLK)RUN_TGT is the target lisp.run that we want to build. 
# $(CLK)MEM_TGT is the target lispinit.mem that we want to build. 
# The rules in this makefile update that target, as well as the memory image.
# It's up to the parent makefile to hook these targets as dependencies in its
# own set of rules, so that these targets actually get updated.
#

$(CLK)RUN_TGT := $($(CLK)TARGET_DIR)$($(CLK)LISPRUN)
$(CLK)MEM_TGT := $($(CLK)TARGET_DIR)lispinit.mem
$(CLK)MOD_TABLE_TGT := $($(CLK)TARGET_DIR)modules.o
$(CLK)MOD_HEADER_TGT := $($(CLK)TARGET_DIR)modules.h
$(CLK)PRELOAD_FAS_TGTS := $(addsuffix .fas,$($(CLK)PRELOAD))
$(CLK)PRELOAD_LIB_TGTS := $(addsuffix .lib,$($(CLK)PRELOAD))
$(CLK)LOAD_FAS_TGTS := $(addsuffix .fas,$($(CLK)LOAD))
$(CLK)LOAD_LIB_TGTS := $(addsuffix .lib,$($(CLK)LOAD))
$(CLK)FAS_TGTS := $(addsuffix .fas,$($(CLK)MODULES))
$(CLK)C_TGTS := $(addsuffix .c,$($(CLK)MODULES))
$(CLK)OBJ_TGTS := $(addsuffix .o,$($(CLK)MODULES))
$(CLK)LIB_TGTS := $(addsuffix .lib,$($(CLK)MODULES))
$(CLK)VARS_MKF := $($(CLK)TARGET_DIR)vars.mk
$(CLK)CLEAN := $($(CLK)RUN_TGT) $($(CLK)MEM_TGT) $($(CLK)MOD_TABLE_TGT) \
               $($(CLK)VARS_MKF) $($(CLK)FAS_TGTS) $($(CLK)C_TGTS) \
               $($(CLK)OBJ_TGTS) $($(CLK)LIB_TGTS) $($(CLK)MOD_HEADER_TGT) \
               $($(CLK)PRELOAD_FAS_TGTS) $($(CLK)PRELOAD_LIB_TGTS) \
               $($(CLK)LOAD_FAS_TGTS) $($(CLK)LOAD_LIB_TGTS)
$(CLK)ALL_OBJ_TGTS := $($(CLK)OBJ_TGTS) $($(CLK)MOD_TABLE_TGT)

#
# Rule to create the vars.mk file in the target directory.
# This rule also creates the target directory, if it does
# not exist. Since vars.mk is a dependency of this makefile
# itself by way of include, this rule is processed first,
# and so ensures that the target directory exist.
#


$($(CLK)VARS_MKF):
	mkdir -p $(CLINK_TARGET_DIR)
	. $(CLINK_SOURCE_DIR)makevars ; \
	  echo "\$$(\$$(CLK)RUN_TGT): CFLAGS += $$CFLAGS" > $@ ; \
	  echo "\$$(\$$(CLK)ALL_OBJ_TGTS): CPPFLAGS += $$CPPFLAGS" >> $@ ; \
	  echo "\$$(\$$(CLK)RUN_TGT): CLFLAGS += $$CLFLAGS" >> $@ ; \
	  echo "\$$(CLK)LIBS := $$LIBS" >> $@

$($(CLK)MOD_TABLE_TGT): CFLAGS += -I$(CLINK_TARGET_DIR)

$($(CLK)MOD_TABLE_TGT): $($(CLK)CLISP_DIR)linkkit/modules.c \
                               $($(CLK)MOD_HEADER_TGT)
	$(CC) $(CFLAGS) -c -o $@ $<

$($(CLK)MOD_HEADER_TGT):
	$(RM) $@
	for mod in $(CLINK_MODULES) ; do echo "MODULE($$mod)" >> $@ ; done

ifneq ($(MAKECMDGOALS),clean)
include $($(CLK)VARS_MKF)
endif

#
# $(CLK)SOURCE_ARS is the list of archive files in the source linking
# set. We get this by way of the $(CLK)LIBS variable in the makevars file
# in that directory, rather than by wildcard globbing. The reason for
# that is that we don't want to mistakenly include libnoreadline.a.
#

$(CLK)SOURCE_ARS := $(foreach LIB,$($(CLK)LIBS),\
                              $(if $(filter -%,$(LIB)),,$($(CLK)SOURCE_DIR)$(LIB)))

#
# $(CLK)SOURCE_LIBS is a list of additional libraries that need
# to be linked. Like $(CLK)SOURCE_ARS, this comes from the $(CLK)LIBS variable
# in the makevars file of the source linking set. 
#

$(CLK)SOURCE_LIBS := $(foreach LIB,$($(CLK)LIBS),\
                               $(if $(filter -%,$(LIB)),\
				  $(LIB),))

$($(CLK)RUN_TGT): $($(CLK)SOURCE_ARS) $($(CLK)MOD_TABLE_TGT) \
                  $($(CLK)OBJ_TGTS) $($(CLK)OBJECTS)
	$(CC) $(CFLAGS) $(CLFLAGS) -o $@ $^ $(CLINK_SOURCE_LIBS)

$($(CLK)OBJ_TGTS): $($(CLK)C_TGTS)
	$(CC) $(CFLAGS) -I$(CLINK_CLISP_DIR)linkkit -o $@ $^ -c

$($(CLK)C_TGTS): %.c: %.lisp
	"$(CLINK_SOURCE_RUN)" -B "$(CLINK_CLISP_DIR)" \
	  -M "$(CLINK_SOURCE_DIR)lispinit.mem" -q -c $<

$($(CLK)PRELOAD_FAS_TGTS): %.fas: %.lisp
	"$(CLINK_SOURCE_RUN)" -B "$(CLINK_CLISP_DIR)" \
	  -M "$(CLINK_SOURCE_DIR)lispinit.mem" -q -c $<

$($(CLK)LOAD_FAS_TGTS): %.fas: %.lisp
	"$(CLINK_RUN_TGT)" -B "$(CLINK_CLISP_DIR)" \
	  -M "$(CLINK_INTERMEDIATE_MEM)" -q -c $<

#
# If $(CLK)PRELOAD contains something, then we need to set up rules that
# make an intermediate memory image by loading these files using the original
# linking set. The new CLISP binary is then used in conjunction with this
# intermediate image to load more Lisp code and dump the final image.
#

ifeq ($($(CLK)PRELOAD),)
$(CLK)INTERMEDIATE_MEM := $($(CLK)SOURCE_DIR)lispinit.mem
else
$(CLK)INTERMEDIATE_MEM := $($(CLK)TARGET_DIR)intermediate.mem

$(CLK)CLEAN += $($(CLK)INTERMEDIATE_MEM)

$($(CLK)INTERMEDIATE_MEM): $($(CLK)PRELOAD_FAS_TGTS)
	"$(CLINK_SOURCE_RUN)" -B "$(CLINK_CLISP_DIR)" \
	  -M "$(CLINK_SOURCE_DIR)lispinit.mem" -norc -q -i \
	  $(CLINK_PRELOAD) -x "(saveinitmem \"$@\")"
endif

$($(CLK)MEM_TGT): $($(CLK)RUN_TGT) $($(CLK)INTERMEDIATE_MEM) \
                  $($(CLK)FAS_TGTS) $($(CLK)LOAD_FAS_TGTS)
	"$(CLINK_RUN_TGT)" -B "$(CLINK_CLISP_DIR)" \
	  -M "$(CLINK_INTERMEDIATE_MEM)" -norc -q -i \
	  $(CLINK_MODULES) $(CLINK_LOAD) -x "(saveinitmem \"$@\")"

#
# Hack: GNU Make has a problem. Variables that occur in
# rule action bodies are expanded when those rules are run, not when
# they are defined, and there doesn't appear to be a way to change
# the behavior. So the namespace trick $($(CLK)VAR) won't work
# within rule bodies; the value of the global variable CLK will be taken at the
# time the rule is run to update its target, not at the time the makefile is
# read out.  The target-specific-assignment mechanism, however, gives us a kind
# of dynamic scoping namespace surrounding a target, so here we exploit that to
# create target-local ``bindings'' of all our global namespaced variables. We
# use those bindings in rule bodies.
#

$($(CLK)CLEAN): CLINK_TARGET_DIR := $($(CLK)TARGET_DIR)
$($(CLK)CLEAN): CLINK_CLISP_DIR := $($(CLK)CLISP_DIR)
$($(CLK)CLEAN): CLINK_SOURCE_DIR := $($(CLK)SOURCE_DIR)
$($(CLK)CLEAN): CLINK_SOURCE_RUN := $($(CLK)SOURCE_RUN)
$($(CLK)CLEAN): CLINK_MODULES := $($(CLK)MODULES)
$($(CLK)CLEAN): CLINK_SOURCE_LIBS := $($(CLK)SOURCE_LIBS)
$($(CLK)CLEAN): CLINK_PRELOAD := $($(CLK)PRELOAD)
$($(CLK)CLEAN): CLINK_LOAD := $($(CLK)LOAD)
$($(CLK)CLEAN): CLINK_INTERMEDIATE_MEM := $($(CLK)INTERMEDIATE_MEM)
$($(CLK)CLEAN): CLINK_RUN_TGT := $($(CLK)RUN_TGT)