[PATCH v2] btrfs-progs: btrfsutil: add pkg-config files for btrfsutil

[Sheng Mao <shngmao@gmail.com>]

Add pc file for btrfsutil libraries. Users can use
pkg-config to set up compilation and linking flags.

The paths in pc file depend on prefix variable but
ignore DESTDIR. DESTDIR is used for packaging and
it should not affect the paths in pc file.

Signed-off-by: Sheng Mao <shngmao@gmail.com>
---
 .gitignore                      |  1 +
 Makefile                        |  9 +++++++-
 Makefile.inc.in                 |  1 +
 configure.ac                    | 12 ++++++++++
 libbtrfsutil/libbtrfsutil.pc.in | 11 +++++++++
 tests/pkg-config-tests.sh       | 41 +++++++++++++++++++++++++++++++++
 6 files changed, 74 insertions(+), 1 deletion(-)
 create mode 100644 libbtrfsutil/libbtrfsutil.pc.in
 create mode 100644 tests/pkg-config-tests.sh

diff --git a/.gitignore b/.gitignore
index 1c70ec94..67404361 100644
--- a/.gitignore
+++ b/.gitignore
@@ -97,3 +97,4 @@
 /Documentation/mkfs.btrfs.8
 
 *.patch
+*.pc
diff --git a/Makefile b/Makefile
index c788b91b..42ba9d7f 100644
--- a/Makefile
+++ b/Makefile
@@ -436,13 +436,18 @@ test-clean:
 	@echo "Cleaning tests"
 	$(Q)bash tests/clean-tests.sh
 
+test-pkg-config:
+	@echo "Test pkg-config settings"
+	export libdir incdir
+	$(Q)bash tests/pkg-config-tests.sh
+
 test-inst: all
 	@tmpdest=`mktemp --tmpdir -d btrfs-inst.XXXXXX` && \
 		echo "Test installation to $$tmpdest" && \
 		$(MAKE) $(MAKEOPTS) DESTDIR=$$tmpdest install && \
 		$(RM) -rf -- $$tmpdest
 
-test: test-check test-check-lowmem test-mkfs test-misc test-cli test-convert test-fuzz
+test: test-check test-check-lowmem test-mkfs test-misc test-cli test-convert test-fuzz test-pkg-config
 
 testsuite: btrfs-corrupt-block btrfs-find-root btrfs-select-super fssum
 	@echo "Export tests as a package"
@@ -779,6 +784,8 @@ endif
 	$(INSTALL) -m755 -d $(DESTDIR)$(incdir)/btrfs
 	$(INSTALL) -m644 $(libbtrfs_headers) $(DESTDIR)$(incdir)/btrfs
 	$(INSTALL) -m644 libbtrfsutil/btrfsutil.h $(DESTDIR)$(incdir)
+	$(INSTALL) -m755 -d $(DESTDIR)$(pkgconfigdir)
+	$(INSTALL) -m644 libbtrfsutil/libbtrfsutil.pc $(DESTDIR)$(pkgconfigdir)
 endif
 
 ifeq ($(PYTHON_BINDINGS),1)
diff --git a/Makefile.inc.in b/Makefile.inc.in
index f3cd2733..9f493371 100644
--- a/Makefile.inc.in
+++ b/Makefile.inc.in
@@ -41,6 +41,7 @@ libdir ?= @libdir@
 incdir = @includedir@
 udevdir = @UDEVDIR@
 udevruledir = ${udevdir}/rules.d
+pkgconfigdir = @pkgconfigdir@
 
 # external libs required by various binaries; for btrfs-foo,
 # specify btrfs_foo_libs = <list of libs>; see $($(subst...)) rules in Makefile
diff --git a/configure.ac b/configure.ac
index 7c2c9b8d..a693ad4e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -12,6 +12,10 @@ LIBBTRFS_MAJOR=0
 LIBBTRFS_MINOR=1
 LIBBTRFS_PATCHLEVEL=2
 
+BTRFS_UTIL_VERSION_MAJOR=1
+BTRFS_UTIL_VERSION_MINOR=2
+BTRFS_UTIL_VERSION_PATCH=0
+
 CFLAGS=${CFLAGS:-"-g -O1 -Wall -D_FORTIFY_SOURCE=2"}
 AC_SUBST([CFLAGS])
 
@@ -300,18 +304,25 @@ AC_SUBST([LZO2_LIBS])
 AC_SUBST([LZO2_LIBS_STATIC])
 AC_SUBST([LZO2_CFLAGS])
 
+dnl call PKG_INSTALLDIR from pkg.m4 to set pkgconfigdir
+m4_ifdef([PKG_INSTALLDIR], [PKG_INSTALLDIR], [AC_MSG_ERROR([please install pkgconf])])
 
 dnl library stuff
 AC_SUBST([LIBBTRFS_MAJOR])
 AC_SUBST([LIBBTRFS_MINOR])
 AC_SUBST([LIBBTRFS_PATCHLEVEL])
 
+AC_SUBST([BTRFS_UTIL_VERSION_MAJOR])
+AC_SUBST([BTRFS_UTIL_VERSION_MINOR])
+AC_SUBST([BTRFS_UTIL_VERSION_PATCH])
+
 AC_CONFIG_HEADERS([config.h])
 
 AC_CONFIG_FILES([
 Makefile.inc
 Documentation/Makefile
 version.h
+libbtrfsutil/libbtrfsutil.pc
 ])
 
 AC_OUTPUT
@@ -325,6 +336,7 @@ AC_MSG_RESULT([
 	bindir:             ${bindir}
 	libdir:             ${libdir}
 	includedir:         ${includedir}
+	pkgconfigdir:       ${pkgconfigdir}
 
 	compiler:           ${CC}
 	cflags:             ${CFLAGS}
diff --git a/libbtrfsutil/libbtrfsutil.pc.in b/libbtrfsutil/libbtrfsutil.pc.in
new file mode 100644
index 00000000..81e66622
--- /dev/null
+++ b/libbtrfsutil/libbtrfsutil.pc.in
@@ -0,0 +1,11 @@
+prefix=@prefix@
+exec_prefix=@exec_prefix@
+libdir=@libdir@
+includedir=@includedir@
+
+Name: libbtrfsutil
+Description: libbtrfsutil library
+Version: @BTRFS_UTIL_VERSION_MAJOR@.@BTRFS_UTIL_VERSION_MINOR@.@BTRFS_UTIL_VERSION_PATCH@
+URL: http://btrfs.wiki.kernel.org
+Cflags: -I${includedir}
+Libs: -L${libdir} -lbtrfsutil
diff --git a/tests/pkg-config-tests.sh b/tests/pkg-config-tests.sh
new file mode 100644
index 00000000..faf15956
--- /dev/null
+++ b/tests/pkg-config-tests.sh
@@ -0,0 +1,41 @@
+#!/bin/sh
+#
+# test pkg-config can find libbtrfsutil
+
+SCRIPT_DIR=$(dirname $(readlink -f "$0"))
+TOP=$(readlink -f "$SCRIPT_DIR/../")
+if [ ! -f "$TOP/configure.ac" ]; then
+    exit 0
+fi
+
+export PKG_CONFIG_PATH="$TOP/libbtrfsutil"
+PKG_CONFIG=pkg-config
+LIBNAME=libbtrfsutil
+
+die() {
+	echo "ERROR: $@"
+	exit 1
+}
+
+test-exists() {
+    ${PKG_CONFIG} --exists $1 || die "$1 doesn't exist"
+}
+
+test-pkg-config() {
+    if [ "$#" != "3" ]; then
+        echo "$0 needs 3 arguments"
+        exit 1
+    fi
+    libname="$1"
+    flags="$2"
+    actual="$(${PKG_CONFIG} $flags $libname | awk '{gsub(/^\s+|\s+$/,"")}1')"
+    expected="$3"
+
+    if [ "$actual" != "$expected" ]; then
+        die "pkg-config $flags failed on $libname: '$actual' != '$expected'"
+    fi
+}
+
+test-exists "$LIBNAME"
+test-pkg-config "$LIBNAME" "--cflags" "-I${incdir}"
+test-pkg-config "$LIBNAME" "--libs"  "-L${libdir} -lbtrfsutil"
-- 
2.25.1