# Copyright (c) 2018 Simon Hudon. All rights reserved.
# Released under Apache 2.0 license as described in the file LICENSE.
# Authors: Simon Hudon, Sebastian Ullrich, Leonardo de Moura

# We compile all source files in $PKG/ as well as $PKG.lean. $PKG is also used for naming binary files.
ifndef PKG
  PKG = $(strip $(subst .lean,, $(wildcard *.lean)))
  ifneq ($(words $(PKG)), 1)
    $(error no unique .lean file found in current directory, please specify PKG)
  endif
endif

LEAN = lean
LEANC = leanc
LEAN_AR = ar
OUT = build
OLEAN_OUT = $(OUT)
TEMP_OUT = $(OUT)/temp
C_OUT = $(TEMP_OUT)
BIN_OUT = $(OUT)/bin
LIB_OUT = $(OUT)/lib
BIN_NAME = $(PKG)
STATIC_LIB_NAME = lib$(PKG).a
LEAN_OPTS = @LEAN_EXTRA_MAKE_OPTS@
LEANC_OPTS = -O3 -DNDEBUG
LINK_OPTS =

SRCS = $(shell find $(PKG) -name '*.lean' 2> /dev/null || true; find $(PKG).lean 2> /dev/null)
DEPS = $(addprefix $(TEMP_OUT)/,$(SRCS:.lean=.depend))
export LEAN_PATH += @LEAN_PATH_SEPARATOR@$(OLEAN_OUT)
OBJS = $(addprefix $(OLEAN_OUT)/, $(SRCS:.lean=.olean))

SHELL = /usr/bin/env bash -euo pipefail

.PHONY: all bin lib depends clean

all: $(OBJS)

bin: $(BIN_OUT)/$(BIN_NAME)

lib: $(LIB_OUT)/$(STATIC_LIB_NAME)

depends: $(DEPS)

$(OLEAN_OUT)/$(PKG) $(LIB_OUT) $(BIN_OUT):
	@mkdir -p "$@"

# Make sure the .olean output directory exists so that `lean --deps` knows where this package's
# .olean files will be located even before any of them are actually built.
$(TEMP_OUT)/%.depend: %.lean | $(OLEAN_OUT)/$(PKG)
	@mkdir -p "$(TEMP_OUT)/$(*D)"
# use separate assignment to ensure failure propagation
# convert path separators and newlines on Windows
	@deps=`$(LEAN) --deps $< | tr '\\\\' / | tr -d '\\r'`; echo $(OLEAN_OUT)/$(<:.lean=.olean): $$deps > $@

$(OLEAN_OUT)/%.olean: %.lean $(TEMP_OUT)/%.depend $(MORE_DEPS)
ifdef CMAKE_LIKE_OUTPUT
	@echo "[    ] Building $<"
endif
	@mkdir -p $(OLEAN_OUT)/$(*D)
	$(LEAN) $(LEAN_OPTS) -o "$@" --c="$(TEMP_OUT)/$*.c.tmp" $<
# create the .c file atomically
	mv "$(TEMP_OUT)/$*.c.tmp" "$(TEMP_OUT)/$*.c"

ifndef C_ONLY
$(TEMP_OUT)/%.c: $(OLEAN_OUT)/%.olean
	@
endif

$(TEMP_OUT)/%.o: $(C_OUT)/%.c
ifdef CMAKE_LIKE_OUTPUT
	@echo "[    ] Building $<"
endif
	@mkdir -p "$(@D)"
ifdef PROFILE
	\time -f "%U %S" $(LEANC) -c -o $@ $< $(LEANC_OPTS) 2>&1 > /dev/null | awk '{ printf "C compilation %fs\n", $$1 + $$2 }' > /dev/stderr
else
	$(LEANC) -c -o $@ $< $(LEANC_OPTS)
endif

$(BIN_OUT)/$(BIN_NAME): $(addprefix $(TEMP_OUT)/,$(SRCS:.lean=.o)) | $(BIN_OUT)
ifdef CMAKE_LIKE_OUTPUT
	@echo "[    ] Linking $@"
endif
ifdef PROFILE
	\time -f "%U %S" $(LEANC) -o "$@" $^ $(LINK_OPTS) 2>&1 > /dev/null | awk '{ printf "C linking %fs\n", $$1 + $$2 }' > /dev/stderr
else
	$(LEANC) -o "$@" $^ $(LINK_OPTS)
endif

$(LIB_OUT)/$(STATIC_LIB_NAME): $(addprefix $(TEMP_OUT)/,$(SRCS:.lean=.o)) | $(LIB_OUT)
	@rm -f $@
	@$(LEAN_AR) rcs $@ $^

clean:
	rm -rf $(OUT)

.PRECIOUS: $(TEMP_OUT)/%.c

ifndef C_ONLY
include $(DEPS)
endif