Unify all common build system parts

Rather than duplicating the same thing over and over in every Makefile,
move it all to common.mk.

Other things fixed here:
 - doing subdirs in parallel
 - fix src!=build compiling in subdirs

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

1 files changed, 58 insertions, 0 deletions

diff --git a/common.mk b/common.mk
new file mode 100644
index 0000000..5dd21ab
--- /dev/null
+++ b/common.mk
@@ -0,0 +1,58 @@
+CC := $(CROSS)gcc
+AR := $(CROSS)ar
+RANLIB := $(CROSS)ranlib
+CFLAGS ?= -O2 -g
+CFLAGS += -Wall -Wwrite-strings -W
+
+DESTDIR ?= /usr/local
+PREFIX=/usr
+EXEC_PREFIX=$(PREFIX)
+SBINDIR=$(EXEC_PREFIX)/sbin
+MANDIR=$(PREFIX)/share/man
+INCLUDEDIR=$(PREFIX)/include
+
+ifndef BUILDDIR
+ifeq ($(origin CROSS),undefined)
+  BUILDDIR := $(PWD)
+else
+# Remove the trailing slash to make the directory name
+  BUILDDIR := $(PWD)/$(CROSS:-=)
+endif
+endif
+
+override TARGETS := $(addprefix $(BUILDDIR)/,$(TARGETS))
+
+SUBDIRS_ALL = $(patsubst %,subdirs_%_all,$(SUBDIRS))
+SUBDIRS_CLEAN = $(patsubst %,subdirs_%_clean,$(SUBDIRS))
+SUBDIRS_INSTALL = $(patsubst %,subdirs_%_install,$(SUBDIRS))
+
+all:: $(TARGETS) $(SUBDIRS_ALL)
+
+clean:: $(SUBDIRS_CLEAN)
+	rm -f $(BUILDDIR)/*.o $(TARGETS) $(BUILDDIR)/.*.c.dep
+
+install:: $(TARGETS) $(SUBDIRS_INSTALL)
+
+$(BUILDDIR)/%: $(BUILDDIR)/%.o
+	$(CC) $(CFLAGS) $(LDFLAGS) $(LDFLAGS_$(notdir $@)) -g -o $@ $^ $(LDLIBS) $(LDLIBS_$(notdir $@))
+
+$(BUILDDIR)/%.a:
+	$(AR) crv $@ $^
+	$(RANLIB) $@
+
+$(BUILDDIR)/%.o: %.c
+	mkdir -p $(dir $@)
+	$(CC) $(CPPFLAGS) $(CFLAGS) -c -o $@ $< -g -Wp,-MD,$(BUILDDIR)/.$(<F).dep
+
+subdirs_%:
+	d=$(patsubst subdirs_%,%,$@); \
+	t=`echo $$d | sed s:.*_::` d=`echo $$d | sed s:_.*::`; \
+	$(MAKE) BUILDDIR=$(BUILDDIR)/$$d -C $$d $$t
+
+.SUFFIXES:
+
+IGNORE=${wildcard $(BUILDDIR)/.*.c.dep}
+-include ${IGNORE}
+
+PHONY += all clean install
+.PHONY: $(PHONY)