slirp: add a standalone Makefile

Add a simple Makefile to build libslirp.a, a static library version of
libslirp, to be used by QEMU during a transition period, until a
shared library is available.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20190212162524.31504-6-marcandre.lureau@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

slirp/Makefile

+ROOT_DIR := $(shell dirname $(realpath $(lastword $(MAKEFILE_LIST))))
+BUILD_DIR ?= .
+
+LIBSLIRP = $(BUILD_DIR)/libslirp.a
+
+all: $(LIBSLIRP)
+
+SRCS := $(wildcard src/*.c)
+OBJS := $(SRCS:%.c=$(BUILD_DIR)/%.o)
+DEPS := $(OBJS:%.o=%.d)
+
+INC_DIRS := $(BUILD_DIR)/src
+INC_FLAGS := $(addprefix -I,$(INC_DIRS))
+
+override CFLAGS +=					\
+	-DG_LOG_DOMAIN='"Slirp"'			\
+	$(shell $(PKG_CONFIG) --cflags glib-2.0)	\
+	$(INC_FLAGS)					\
+	-MMD -MP
+override LDFLAGS += $(shell $(PKG_CONFIG) --libs glib-2.0)
+
+$(LIBSLIRP): $(OBJS)
+
+.PHONY: clean
+
+clean:
+	rm -r $(OBJS) $(DEPS) $(LIBSLIRP)
+
+$(BUILD_DIR)/src/%.o: $(ROOT_DIR)/src/%.c
+	@$(MKDIR_P) $(dir $@)
+	$(call quiet-command,$(CC) $(CFLAGS) -c -o $@ $<,"CC","$@")
+
+%.a:
+	$(call quiet-command,rm -f $@ && $(AR) rcs $@ $^,"AR","$@")
+
+PKG_CONFIG ?= pkg-config
+MKDIR_P ?= mkdir -p
+quiet-command-run = $(if $(V),,$(if $2,printf "  %-7s %s\n" $2 $3 && ))$1
+quiet-@ = $(if $(V),,@)
+quiet-command = $(quiet-@)$(call quiet-command-run,$1,$2,$3)
+
+print-%:
+	@echo '$*=$($*)'
+
+.SUFFIXES:
+
+-include $(DEPS)