perf: enable man pages for 'help' functionality

When using 'perf help <subcommand>', it can't find 'man' command and pages for
perf.
The perf man pages depends on the xmlto-native and asciidoc-native, so we just
need to add the two packages to the DEPENDS variable and add 'man'to
RDEPENDS_perf-doc.

(From OE-Core rev: bbff6b07256d63d318066eb1357763467532dd70)

Signed-off-by: Dengke Du <dengke.du@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-kernel/perf/perf.bb

@@ -30,6 +30,8 @@ DEPENDS = " \
     ${SCRIPTING_DEPENDS} \
     ${LIBUNWIND_DEPENDS} \
     bison flex xz \
+    xmlto-native \
+    asciidoc-native \
 "
 
 do_configure[depends] += "virtual/kernel:do_shared_workdir"
@@ -90,7 +92,6 @@ EXTRA_OEMAKE += "\
     'sharedir=${datadir}' \
     'sysconfdir=${sysconfdir}' \
     'perfexecdir=${libexecdir}/perf-core' \
-    \
     'ETC_PERFCONFIG=${@os.path.relpath(sysconfdir, prefix)}' \
     'sharedir=${@os.path.relpath(datadir, prefix)}' \
     'mandir=${@os.path.relpath(mandir, prefix)}' \
@@ -138,6 +139,13 @@ do_configure_prepend () {
                -e 's,\ .config-detected, $(OUTPUT)/config-detected,g' \
             ${S}/tools/perf/config/Makefile
     fi
+    # The man pages installation is "$(INSTALL) -d -m 755 $(DESTDIR)$(man1dir)"
+    # in ${S}/tools/perf/Documentation/Makefile, if the mandir set to '?=', it
+    # will use the relative path 'share/man', in the way it will resulting in
+    # incorrect installation for man pages.
+    if [ -e "${S}/tools/perf/Documentation/Makefile" ]; then
+	sed -i 's,^mandir?=,mandir:=,' ${S}/tools/perf/Documentation/Makefile
+    fi
     if [ -e "${S}/tools/perf/Makefile.perf" ]; then
         sed -i -e 's,\ .config-detected, $(OUTPUT)/config-detected,g' \
             ${S}/tools/perf/Makefile.perf
@@ -197,6 +205,7 @@ PACKAGE_ARCH = "${MACHINE_ARCH}"
 PACKAGES =+ "${PN}-archive ${PN}-tests ${PN}-perl ${PN}-python"
 
 RDEPENDS_${PN} += "elfutils bash"
+RDEPENDS_${PN}-doc += "man"
 RDEPENDS_${PN}-archive =+ "bash"
 RDEPENDS_${PN}-python =+ "bash python python-modules"
 RDEPENDS_${PN}-perl =+ "bash perl perl-modules"