d34efeeef1
Currently libbpf version is specified in 2 places: libbpf.map and Makefile. They easily get out of sync and it's very easy to update one, but forget to update another one. In addition, Github projection of libbpf has to maintain its own version which has to be remembered to be kept in sync manually, which is very error-prone approach. This patch makes libbpf.map a source of truth for libbpf version and uses shell invocation to parse out correct full and major libbpf version to use during build. Now we need to make sure that once new release cycle starts, we need to add (initially) empty section to libbpf.map with correct latest version. This also will make it possible to keep Github projection consistent with kernel sources version of libbpf by adopting similar parsing of version from libbpf.map. v2->v3: - grep -o + sort -rV (Andrey); v1->v2: - eager version vars evaluation (Jakub); - simplified version regex (Andrey); Cc: Andrey Ignatov <rdna@fb.com> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This is a mirror of bpf-next linux tree's
tools/lib/bpf directory plus its supporting header files.
The following files will by sync'ed with bpf-next repo:
src/<->bpf-next/tools/lib/bpf/include/uapi/linux/bpf_common.h<->bpf-next/tools/include/uapi/linux/bpf_common.hinclude/uapi/linux/bpf.h<->bpf-next/tools/include/uapi/linux/bpf.hinclude/uapi/linux/btf.h<->bpf-next/tools/include/uapi/linux/btf.hinclude/uapi/linux/if_link.h<->bpf-next/tools/include/uapi/linux/if_link.hinclude/uapi/linux/if_xdp.h<->bpf-next/tools/include/uapi/linux/if_xdp.hinclude/uapi/linux/netlink.h<->bpf-next/tools/include/uapi/linux/netlink.hinclude/tools/libc_compat.h<->bpf-next/tools/include/tools/libc_compat.h
Other header files at this repo (include/linux/*.h) are reduced versions of
their counterpart files at bpf-next's tools/include/linux/*.h to make compilation
successful.
Build 
libelf is an internal dependency of libbpf and thus it is required to link
against and must be installed on the system for applications to work.
pkg-config is used by default to find libelf, and the program called can be
overridden with PKG_CONFIG.
If using pkg-config at build time is not desired, it can be disabled by setting
NO_PKG_CONFIG=1 when calling make.
To build both static libbpf.a and shared libbpf.so:
$ cd src
$ make
To build only static libbpf.a library in directory build/ and install them together with libbpf headers in a staging directory root/:
$ cd src
$ mkdir build root
$ BUILD_STATIC_ONLY=y OBJDIR=build DESTDIR=root make install
To build both static libbpf.a and shared libbpf.so against a custom libelf dependency installed in /build/root/ and install them together with libbpf headers in a build directory /build/root/:
$ cd src
$ PKG_CONFIG_PATH=/build/root/lib64/pkgconfig DESTDIR=/build/root make install
To integrate libbpf into a project which uses Meson building system define
[wrap-git] file in subprojects folder.
To add libbpf dependency to the parent parent project, e.g. for
libbpf_static_dep:
libbpf_obj = subproject('libbpf', required : true)
libbpf_static_dep = libbpf_proj.get_variable('libbpf_static_dep')
To validate changes to meson.build
$ python3 meson.py build
$ ninja -C build/
To install headers, libs and pkgconfig
$ cd build
$ ninja install