lib: simplify installation of libbpf and libxdp submodule libraries

Instead of having the someone redundantly named 'lib/lib-install' folder,
let's rename it to just 'lib/install', and drop the 'usr/' prefix of the
files installed into that directory. Also, to simplify the configure
script, check in the directory to git so it's always present, and always
include it in the include and linker paths. On clean we just clear out the
contents.

Also, copy over libbpf.a to lib/install/lib alongside libxdp.a instead of
putting libbpf/src in the linker path.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>

Author: tohojo

configure

@@ -127,11 +127,8 @@ EOF
     echo submodule
     SUBMODULE_LIBBPF=1
     echo "SYSTEM_LIBBPF:=n" >> $CONFIG
-    echo 'CFLAGS += -I$(LIB_DIR)/lib-install/usr/include' >>$CONFIG
-    echo 'BPF_CFLAGS += -I$(LIB_DIR)/lib-install/usr/include' >>$CONFIG
-    echo 'LDFLAGS += -L$(LIB_DIR)/libbpf/src' >>$CONFIG
     echo 'LDLIBS += -l:libbpf.a' >>$CONFIG
-    echo 'OBJECT_LIBBPF = $(LIB_DIR)/libbpf/src/libbpf.a' >>$CONFIG
+    echo 'OBJECT_LIBBPF = $(LIB_DIR)/install/lib/libbpf.a' >>$CONFIG
     if ! [ -d "lib/libbpf/src" ] && [ -f ".gitmodules" ] && [ -e ".git" ]; then
         git submodule init && git submodule update
     fi
@@ -195,18 +192,15 @@ check_libxdp()
     echo "SYSTEM_LIBXDP:=n" >> $CONFIG
     if [ "$SUBMODULE_LIBBPF" -eq "1" ]; then
         echo "Configuring libxdp to use our libbpf submodule"
-        (export LIBBPF_DIR="$(readlink -m lib/libbpf)" LIBBPF_INCLUDE_DIR="$(readlink -m lib/lib-install/usr/include)";
+        (export LIBBPF_DIR="$(readlink -m lib/libbpf)" LIBBPF_INCLUDE_DIR="$(readlink -m lib/install/include)";
          cd lib/xdp-tools; ./configure)
     else
         echo "Configuring libxdp without our libbpf"
         (cd lib/xdp-tools; ./configure)
-        # these are already set if using libbpf as a submodule
-        echo 'CFLAGS += -I$(LIB_DIR)/lib-install/usr/include' >>$CONFIG
-        echo 'BPF_CFLAGS += -I$(LIB_DIR)/lib-install/usr/include' >>$CONFIG
     fi
-    echo 'LDFLAGS += -L$(LIB_DIR)/lib-install/usr/lib' >>$CONFIG
+    echo 'LDFLAGS += -L$(LIB_DIR)/install/lib' >>$CONFIG
     echo 'LDLIBS += -l:libxdp.a' >>$CONFIG
-    echo 'OBJECT_LIBXDP = $(LIB_DIR)/lib-install/usr/lib/libxdp.a' >>$CONFIG
+    echo 'OBJECT_LIBXDP = $(LIB_DIR)/install/lib/libxdp.a' >>$CONFIG
     if ! [ -d "lib/xdp-tools/lib" ] && [ -f ".gitmodules" ] && [ -e ".git" ]; then
         git submodule init && git submodule update
     fi

lib/.gitignore

@@ -2,7 +2,7 @@
 LIBBPF_CFLAGS:=$(if $(CFLAGS),$(CFLAGS),-g -O2 -Werror -Wall) -fPIC
 
 LIB_DIR = .
-LIB_INSTALL := lib-install
+LIB_INSTALL := $(LIB_DIR)/install
 include defines.mk
 
 SUBDIRS=
@@ -16,6 +16,8 @@ all: $(OBJECT_LIBBPF) $(OBJECT_LIBXDP)
 clean: libbpf_clean libxdp_clean
 	@for i in $(SUBDIRS); \
 	do $(MAKE) -C $$i clean; done
+	$(Q)find $(LIB_INSTALL) -type f -not -name .gitignore -delete
+	$(Q)find $(LIB_INSTALL) -type d -empty -delete
 
 install:
 	install -m 0755 -d $(DESTDIR)$(HDRDIR)
@@ -35,15 +37,15 @@ endif
 # Detect submodule libbpf source file changes
 LIBBPF_SOURCES := $(wildcard libbpf/src/*.[ch])
 
-libbpf/src/libbpf.a: $(LIBBPF_SOURCES)
+$(LIB_INSTALL)/lib/libbpf.a: $(LIBBPF_SOURCES)
 	@echo ; echo "  libbpf"
 	$(QUIET_CC)$(MAKE) -C libbpf/src CFLAGS="$(LIBBPF_CFLAGS)" $P
-	$(QUIET_INSTALL)$(MAKE) -C libbpf/src DESTDIR=../../$(LIB_INSTALL) install_headers $P
+	$(QUIET_INSTALL)$(MAKE) -C libbpf/src DESTDIR=../../$(LIB_INSTALL) PREFIX= install_headers $P
+	$(Q)cp -fp libbpf/src/libbpf.a install/lib/
 
 .PHONY: libbpf_clean
 libbpf_clean:
 	$(Q)$(MAKE) -C libbpf/src clean $P
-	$(Q)$(RM) -r $(LIB_INSTALL)
 
 else
 
@@ -61,15 +63,14 @@ endif
 LIBXDP_SOURCES := $(wildcard xdp-tools/lib/libxdp/*.[ch])
 
 
-$(LIB_INSTALL)/usr/lib/libxdp.a: $(LIBXDP_SOURCES)
+$(LIB_INSTALL)/lib/libxdp.a: $(LIBXDP_SOURCES)
 	@echo ; echo "  libxdp"
 	$(QUIET_CC)$(MAKE) -C xdp-tools BUILD_STATIC_ONLY=1 libxdp  $P
-	$(QUIET_INSTALL)$(MAKE) -C xdp-tools DESTDIR=../../../$(LIB_INSTALL) PREFIX=/usr BUILD_STATIC_ONLY=1 libxdp_install $P
+	$(QUIET_INSTALL)$(MAKE) -C xdp-tools DESTDIR=../../../$(LIB_INSTALL) PREFIX= BUILD_STATIC_ONLY=1 libxdp_install $P
 
 .PHONY: libxdp_clean
 libxdp_clean:
 	$(Q)$(MAKE) -C xdp-tools clean $P
-	$(Q)$(RM) -r $(LIB_INSTALL)
 
 else
 

lib/Makefile

@@ -47,8 +47,9 @@ BPF_CFLAGS += -D__TARGET_ARCH_$(ARCH)
 # BPF-prog kern and userspace shares struct via header file:
 KERN_USER_H ?= $(wildcard common_kern_user.h)
 
-CFLAGS += -I$(INCLUDE_DIR) -I$(HEADER_DIR) -I$(LIB_DIR)/util $(EXTRA_CFLAGS)
-BPF_CFLAGS += -I$(INCLUDE_DIR) -I$(HEADER_DIR) $(EXTRA_CFLAGS)
+CFLAGS += -I$(INCLUDE_DIR) -I$(HEADER_DIR) -I$(LIB_DIR)/util -I$(LIB_DIR)/install/include $(EXTRA_CFLAGS)
+BPF_CFLAGS += -I$(INCLUDE_DIR) -I$(HEADER_DIR) -I$(LIB_DIR)/install/include $(EXTRA_CFLAGS)
+LDFLAGS += -L$(LIB_DIR)/install/lib
 
 BPF_HEADERS := $(wildcard $(HEADER_DIR)/*/*.h) $(wildcard $(INCLUDE_DIR)/*/*.h)
 

lib/common.mk

@@ -0,0 +1,4 @@
+*
+!.gitignore
+!include
+!lib

lib/install/.gitignore

@@ -0,0 +1,2 @@
+*
+!.gitignore

lib/install/include/.gitignore

@@ -0,0 +1,2 @@
+*
+!.gitignore