diff mbox series

[bpf-next] tools/bpf: generate pkg-config file for libbpf

Message ID 20190319210639.6282-1-bluca@debian.org
State Changes Requested
Delegated to: BPF Maintainers
Headers show
Series [bpf-next] tools/bpf: generate pkg-config file for libbpf | expand

Commit Message

Luca Boccassi March 19, 2019, 9:06 p.m. UTC 
Generate a libbpf.pc file at build time so that users can rely
on pkg-config to find the library, its CFLAGS and LDFLAGS.

Signed-off-by: Luca Boccassi <bluca@debian.org>
---
 tools/lib/bpf/.gitignore         |  1 +
 tools/lib/bpf/Makefile           | 18 +++++++++++++++---
 tools/lib/bpf/libbpf.pc.template | 11 +++++++++++
 3 files changed, 27 insertions(+), 3 deletions(-)
 create mode 100644 tools/lib/bpf/libbpf.pc.template

Comments

Stanislav Fomichev March 19, 2019, 9:23 p.m. UTC | #1 
On 03/19, Luca Boccassi wrote:
> Generate a libbpf.pc file at build time so that users can rely
> on pkg-config to find the library, its CFLAGS and LDFLAGS.
> 
> Signed-off-by: Luca Boccassi <bluca@debian.org>
> ---
>  tools/lib/bpf/.gitignore         |  1 +
>  tools/lib/bpf/Makefile           | 18 +++++++++++++++---
>  tools/lib/bpf/libbpf.pc.template | 11 +++++++++++
>  3 files changed, 27 insertions(+), 3 deletions(-)
>  create mode 100644 tools/lib/bpf/libbpf.pc.template
> 
> diff --git a/tools/lib/bpf/.gitignore b/tools/lib/bpf/.gitignore
> index 4db74758c674..7d9e182a1f51 100644
> --- a/tools/lib/bpf/.gitignore
> +++ b/tools/lib/bpf/.gitignore
> @@ -1,3 +1,4 @@
>  libbpf_version.h
> +libbpf.pc
>  FEATURE-DUMP.libbpf
>  test_libbpf
> diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
> index a05c43468bd0..542c64e2a6d9 100644
> --- a/tools/lib/bpf/Makefile
> +++ b/tools/lib/bpf/Makefile
> @@ -80,6 +80,7 @@ libdir_SQ = $(subst ','\'',$(libdir))
>  libdir_relative_SQ = $(subst ','\'',$(libdir_relative))
>  
>  LIB_FILE = libbpf.a libbpf.so
> +PC_FILE = libbpf.pc
>  
>  VERSION		= $(BPF_VERSION)
>  PATCHLEVEL	= $(BPF_PATCHLEVEL)
> @@ -137,7 +138,7 @@ GLOBAL_SYM_COUNT = $(shell readelf -s --wide $(BPF_IN) | \
>  VERSIONED_SYM_COUNT = $(shell readelf -s --wide $(OUTPUT)libbpf.so | \
>  			      grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | sort -u | wc -l)
>  
> -CMD_TARGETS = $(LIB_FILE)
> +CMD_TARGETS = $(LIB_FILE) $(PC_FILE)
>  
>  CXX_TEST_TARGET = $(OUTPUT)test_libbpf
>  
> @@ -179,6 +180,12 @@ $(OUTPUT)libbpf.a: $(BPF_IN)
>  $(OUTPUT)test_libbpf: test_libbpf.cpp $(OUTPUT)libbpf.a
>  	$(QUIET_LINK)$(CXX) $(INCLUDES) $^ -lelf -o $@
>  
> +$(OUTPUT)libbpf.pc:
> +	$(QUIET_LINK)sed -e "s|@PREFIX@|$(prefix)|" \
Maybe QUIET_GEN instead? Or QUIET_INSTALL (tools/lib/traceevent/Makefile)?

> +		-e "s|@LIBDIR@|$(libdir_SQ)|" \
> +		-e "s|@VERSION@|$(shell make --no-print-directory -sC ../../.. kernelversion)|" \
Make it its own variable, like we do in bpftool?
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/bpf/bpftool/Makefile#n26

Also, I wonder what would happen in the case of out-of-tree libbpf:
https://github.com/libbpf/libbpf

Should there be some fallback?

> +		< $@.template > $@
> +
>  check: check_abi
>  
>  check_abi: $(OUTPUT)libbpf.so
> @@ -208,7 +215,12 @@ install_headers:
>  		$(call do_install,libbpf.h,$(prefix)/include/bpf,644);
>  		$(call do_install,btf.h,$(prefix)/include/bpf,644);
>  
> -install: install_lib
> +install_pkgconfig: $(PC_FILE)
> +	$(call QUIET_INSTALL, $(PC_FILE)) \
> +		$(call do_install,$(PC_FILE),$(libdir_SQ)/pkgconfig,644)
> +
> +
> +install: install_lib install_pkgconfig
>  
>  ### Cleaning rules
>  
> @@ -218,7 +230,7 @@ config-clean:
>  
>  clean:
>  	$(call QUIET_CLEAN, libbpf) $(RM) $(TARGETS) $(CXX_TEST_TARGET) \
> -		*.o *~ *.a *.so .*.d .*.cmd LIBBPF-CFLAGS
> +		*.o *~ *.a *.so .*.d .*.cmd *.pc LIBBPF-CFLAGS
>  	$(call QUIET_CLEAN, core-gen) $(RM) $(OUTPUT)FEATURE-DUMP.libbpf
>  
>  
> diff --git a/tools/lib/bpf/libbpf.pc.template b/tools/lib/bpf/libbpf.pc.template
> new file mode 100644
> index 000000000000..0cac2f5f54a6
> --- /dev/null
> +++ b/tools/lib/bpf/libbpf.pc.template
> @@ -0,0 +1,11 @@
> +prefix=@PREFIX@
> +libdir=@LIBDIR@
> +includedir=${prefix}/include/bpf
> +
> +Name: libbpf
> +URL: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> +Description: Linux kernel BPF library
> +Version: @VERSION@
> +Libs: -L${libdir} -lbpf
> +Requires.private: libelf
> +Cflags: -I${includedir}
> -- 
> 2.20.1
>
Luca Boccassi March 19, 2019, 11:02 p.m. UTC | #2 
On Tue, 2019-03-19 at 14:23 -0700, Stanislav Fomichev wrote:
> On 03/19, Luca Boccassi wrote:
> > Generate a libbpf.pc file at build time so that users can rely
> > on pkg-config to find the library, its CFLAGS and LDFLAGS.
> > 
> > Signed-off-by: Luca Boccassi <bluca@debian.org>
> > ---
> >  tools/lib/bpf/.gitignore         |  1 +
> >  tools/lib/bpf/Makefile           | 18 +++++++++++++++---
> >  tools/lib/bpf/libbpf.pc.template | 11 +++++++++++
> >  3 files changed, 27 insertions(+), 3 deletions(-)
> >  create mode 100644 tools/lib/bpf/libbpf.pc.template
> > 
> > diff --git a/tools/lib/bpf/.gitignore b/tools/lib/bpf/.gitignore
> > index 4db74758c674..7d9e182a1f51 100644
> > --- a/tools/lib/bpf/.gitignore
> > +++ b/tools/lib/bpf/.gitignore
> > @@ -1,3 +1,4 @@
> >  libbpf_version.h
> > +libbpf.pc
> >  FEATURE-DUMP.libbpf
> >  test_libbpf
> > diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
> > index a05c43468bd0..542c64e2a6d9 100644
> > --- a/tools/lib/bpf/Makefile
> > +++ b/tools/lib/bpf/Makefile
> > @@ -80,6 +80,7 @@ libdir_SQ = $(subst ','\'',$(libdir))
> >  libdir_relative_SQ = $(subst ','\'',$(libdir_relative))
> >  
> >  LIB_FILE = libbpf.a libbpf.so
> > +PC_FILE = libbpf.pc
> >  
> >  VERSION		= $(BPF_VERSION)
> >  PATCHLEVEL	= $(BPF_PATCHLEVEL)
> > @@ -137,7 +138,7 @@ GLOBAL_SYM_COUNT = $(shell readelf -s --wide
> > $(BPF_IN) | \
> >  VERSIONED_SYM_COUNT = $(shell readelf -s --wide $(OUTPUT)libbpf.so
> > | \
> >  			      grep -Eo '[^ ]+@LIBBPF_' | cut -d@
> > -f1 | sort -u | wc -l)
> >  
> > -CMD_TARGETS = $(LIB_FILE)
> > +CMD_TARGETS = $(LIB_FILE) $(PC_FILE)
> >  
> >  CXX_TEST_TARGET = $(OUTPUT)test_libbpf
> >  
> > @@ -179,6 +180,12 @@ $(OUTPUT)libbpf.a: $(BPF_IN)
> >  $(OUTPUT)test_libbpf: test_libbpf.cpp $(OUTPUT)libbpf.a
> >  	$(QUIET_LINK)$(CXX) $(INCLUDES) $^ -lelf -o $@
> >  
> > +$(OUTPUT)libbpf.pc:
> > +	$(QUIET_LINK)sed -e "s|@PREFIX@|$(prefix)|" \
> 
> Maybe QUIET_GEN instead? Or QUIET_INSTALL
> (tools/lib/traceevent/Makefile)?

Changed to QUIET_GEN in v2.

> > +		-e "s|@LIBDIR@|$(libdir_SQ)|" \
> > +		-e "s|@VERSION@|$(shell make --no-print-directory
> > -sC ../../.. kernelversion)|" \
> 
> Make it its own variable, like we do in bpftool?
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tr
> ee/tools/bpf/bpftool/Makefile#n26

Done in v2.

> Also, I wonder what would happen in the case of out-of-tree libbpf:
> https://github.com/libbpf/libbpf
> 
> Should there be some fallback?

That tree looks like it's autosynced from the kernel tree, isn't it?
Then it will just pick up the change and start generating the pc file
as well, won't it?
Stanislav Fomichev March 19, 2019, 11:12 p.m. UTC | #3 
On 03/19, Luca Boccassi wrote:
> On Tue, 2019-03-19 at 14:23 -0700, Stanislav Fomichev wrote:
> > On 03/19, Luca Boccassi wrote:
> > > Generate a libbpf.pc file at build time so that users can rely
> > > on pkg-config to find the library, its CFLAGS and LDFLAGS.
> > > 
> > > Signed-off-by: Luca Boccassi <bluca@debian.org>
> > > ---
> > >  tools/lib/bpf/.gitignore         |  1 +
> > >  tools/lib/bpf/Makefile           | 18 +++++++++++++++---
> > >  tools/lib/bpf/libbpf.pc.template | 11 +++++++++++
> > >  3 files changed, 27 insertions(+), 3 deletions(-)
> > >  create mode 100644 tools/lib/bpf/libbpf.pc.template
> > > 
> > > diff --git a/tools/lib/bpf/.gitignore b/tools/lib/bpf/.gitignore
> > > index 4db74758c674..7d9e182a1f51 100644
> > > --- a/tools/lib/bpf/.gitignore
> > > +++ b/tools/lib/bpf/.gitignore
> > > @@ -1,3 +1,4 @@
> > >  libbpf_version.h
> > > +libbpf.pc
> > >  FEATURE-DUMP.libbpf
> > >  test_libbpf
> > > diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
> > > index a05c43468bd0..542c64e2a6d9 100644
> > > --- a/tools/lib/bpf/Makefile
> > > +++ b/tools/lib/bpf/Makefile
> > > @@ -80,6 +80,7 @@ libdir_SQ = $(subst ','\'',$(libdir))
> > >  libdir_relative_SQ = $(subst ','\'',$(libdir_relative))
> > >  
> > >  LIB_FILE = libbpf.a libbpf.so
> > > +PC_FILE = libbpf.pc
> > >  
> > >  VERSION		= $(BPF_VERSION)
> > >  PATCHLEVEL	= $(BPF_PATCHLEVEL)
> > > @@ -137,7 +138,7 @@ GLOBAL_SYM_COUNT = $(shell readelf -s --wide
> > > $(BPF_IN) | \
> > >  VERSIONED_SYM_COUNT = $(shell readelf -s --wide $(OUTPUT)libbpf.so
> > > | \
> > >  			      grep -Eo '[^ ]+@LIBBPF_' | cut -d@
> > > -f1 | sort -u | wc -l)
> > >  
> > > -CMD_TARGETS = $(LIB_FILE)
> > > +CMD_TARGETS = $(LIB_FILE) $(PC_FILE)
> > >  
> > >  CXX_TEST_TARGET = $(OUTPUT)test_libbpf
> > >  
> > > @@ -179,6 +180,12 @@ $(OUTPUT)libbpf.a: $(BPF_IN)
> > >  $(OUTPUT)test_libbpf: test_libbpf.cpp $(OUTPUT)libbpf.a
> > >  	$(QUIET_LINK)$(CXX) $(INCLUDES) $^ -lelf -o $@
> > >  
> > > +$(OUTPUT)libbpf.pc:
> > > +	$(QUIET_LINK)sed -e "s|@PREFIX@|$(prefix)|" \
> > 
> > Maybe QUIET_GEN instead? Or QUIET_INSTALL
> > (tools/lib/traceevent/Makefile)?
> 
> Changed to QUIET_GEN in v2.
> 
> > > +		-e "s|@LIBDIR@|$(libdir_SQ)|" \
> > > +		-e "s|@VERSION@|$(shell make --no-print-directory
> > > -sC ../../.. kernelversion)|" \
> > 
> > Make it its own variable, like we do in bpftool?
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tr
> > ee/tools/bpf/bpftool/Makefile#n26
> 
> Done in v2.
> 
> > Also, I wonder what would happen in the case of out-of-tree libbpf:
> > https://github.com/libbpf/libbpf
> > 
> > Should there be some fallback?
> 
> That tree looks like it's autosynced from the kernel tree, isn't it?
> Then it will just pick up the change and start generating the pc file
> as well, won't it?
Yes, it's autosynched, but it autosyncs only tools/lib/bpf directory
and it lacks top-level makefile with kernelversion target. I guess in
this case make will spill out an error to stderr and version will be empty.

> 
> -- 
> Kind regards,
> Luca Boccassi
diff mbox series

Patch

diff --git a/tools/lib/bpf/.gitignore b/tools/lib/bpf/.gitignore
index 4db74758c674..7d9e182a1f51 100644
--- a/tools/lib/bpf/.gitignore
+++ b/tools/lib/bpf/.gitignore
@@ -1,3 +1,4 @@ 
 libbpf_version.h
+libbpf.pc
 FEATURE-DUMP.libbpf
 test_libbpf
diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
index a05c43468bd0..542c64e2a6d9 100644
--- a/tools/lib/bpf/Makefile
+++ b/tools/lib/bpf/Makefile
@@ -80,6 +80,7 @@  libdir_SQ = $(subst ','\'',$(libdir))
 libdir_relative_SQ = $(subst ','\'',$(libdir_relative))
 
 LIB_FILE = libbpf.a libbpf.so
+PC_FILE = libbpf.pc
 
 VERSION		= $(BPF_VERSION)
 PATCHLEVEL	= $(BPF_PATCHLEVEL)
@@ -137,7 +138,7 @@  GLOBAL_SYM_COUNT = $(shell readelf -s --wide $(BPF_IN) | \
 VERSIONED_SYM_COUNT = $(shell readelf -s --wide $(OUTPUT)libbpf.so | \
 			      grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | sort -u | wc -l)
 
-CMD_TARGETS = $(LIB_FILE)
+CMD_TARGETS = $(LIB_FILE) $(PC_FILE)
 
 CXX_TEST_TARGET = $(OUTPUT)test_libbpf
 
@@ -179,6 +180,12 @@  $(OUTPUT)libbpf.a: $(BPF_IN)
 $(OUTPUT)test_libbpf: test_libbpf.cpp $(OUTPUT)libbpf.a
 	$(QUIET_LINK)$(CXX) $(INCLUDES) $^ -lelf -o $@
 
+$(OUTPUT)libbpf.pc:
+	$(QUIET_LINK)sed -e "s|@PREFIX@|$(prefix)|" \
+		-e "s|@LIBDIR@|$(libdir_SQ)|" \
+		-e "s|@VERSION@|$(shell make --no-print-directory -sC ../../.. kernelversion)|" \
+		< $@.template > $@
+
 check: check_abi
 
 check_abi: $(OUTPUT)libbpf.so
@@ -208,7 +215,12 @@  install_headers:
 		$(call do_install,libbpf.h,$(prefix)/include/bpf,644);
 		$(call do_install,btf.h,$(prefix)/include/bpf,644);
 
-install: install_lib
+install_pkgconfig: $(PC_FILE)
+	$(call QUIET_INSTALL, $(PC_FILE)) \
+		$(call do_install,$(PC_FILE),$(libdir_SQ)/pkgconfig,644)
+
+
+install: install_lib install_pkgconfig
 
 ### Cleaning rules
 
@@ -218,7 +230,7 @@  config-clean:
 
 clean:
 	$(call QUIET_CLEAN, libbpf) $(RM) $(TARGETS) $(CXX_TEST_TARGET) \
-		*.o *~ *.a *.so .*.d .*.cmd LIBBPF-CFLAGS
+		*.o *~ *.a *.so .*.d .*.cmd *.pc LIBBPF-CFLAGS
 	$(call QUIET_CLEAN, core-gen) $(RM) $(OUTPUT)FEATURE-DUMP.libbpf
 
 
diff --git a/tools/lib/bpf/libbpf.pc.template b/tools/lib/bpf/libbpf.pc.template
new file mode 100644
index 000000000000..0cac2f5f54a6
--- /dev/null
+++ b/tools/lib/bpf/libbpf.pc.template
@@ -0,0 +1,11 @@ 
+prefix=@PREFIX@
+libdir=@LIBDIR@
+includedir=${prefix}/include/bpf
+
+Name: libbpf
+URL: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
+Description: Linux kernel BPF library
+Version: @VERSION@
+Libs: -L${libdir} -lbpf
+Requires.private: libelf
+Cflags: -I${includedir}