build system: use pkg-config to look up selinux libs

Newer versions of libselinux has started linking against more libs.
Rather than continuing hardcoding things, switch to using pkg-config
to query for its dependencies.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

diff --git a/Makefile b/Makefile
index fccde4a6a5d6be095752fb0c54eab1502d51acb8..3a0a5e1104cfc9436a99095379847f587820b35c 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -297,6 +297,7 @@ NM          = $(CROSS_COMPILE)nm
 STRIP          = $(CROSS_COMPILE)strip
 OBJCOPY                = $(CROSS_COMPILE)objcopy
 OBJDUMP                = $(CROSS_COMPILE)objdump
+PKG_CONFIG     ?= $(CROSS_COMPILE)pkg-config
 AWK            = awk
 GENKSYMS       = scripts/genksyms/genksyms
 DEPMOD         = /sbin/depmod

diff --git a/Makefile.flags b/Makefile.flags
index c43c8dca86f00a0ce2a22b9fdfa48b42359cf8f0..15dcc1f6ccbaba74e0107095034358881f78d641 100644 (file)
--- a/Makefile.flags
+++ b/Makefile.flags
@@ -74,6 +74,12 @@ ARCH_FPIC ?= -fpic
 ARCH_FPIE ?= -fpie
 ARCH_PIE ?= -pie
 
+# Usage: $(eval $(call pkg_check_modules,VARIABLE-PREFIX,MODULES))
+define pkg_check_modules
+$(1)_CFLAGS := $(shell $(PKG_CONFIG) $(PKG_CONFIG_FLAGS) --cflags $(2))
+$(1)_LIBS := $(shell $(PKG_CONFIG) $(PKG_CONFIG_FLAGS) --libs $(2))
+endef
+
 ifeq ($(CONFIG_BUILD_LIBBUSYBOX),y)
 # on i386: 14% smaller libbusybox.so
 # (code itself is 9% bigger, we save on relocs/PLT/GOT)
@@ -85,6 +91,7 @@ endif
 
 ifeq ($(CONFIG_STATIC),y)
 CFLAGS_busybox += -static
+PKG_CONFIG_FLAGS += --static
 endif
 
 ifeq ($(CONFIG_PIE),y)
@@ -127,7 +134,10 @@ LDLIBS += pam pam_misc pthread
 endif
 
 ifeq ($(CONFIG_SELINUX),y)
-LDLIBS += selinux sepol
+SELINUX_PC_MODULES = libselinux libsepol
+$(eval $(call pkg_check_modules,SELINUX,$(SELINUX_PC_MODULES)))
+CPPFLAGS += $(SELINUX_CFLAGS)
+LDLIBS += $(if $(SELINUX_LIBS),$(SELINUX_LIBS:-l%=%),$(SELINUX_PC_MODULES:lib%=%))
 endif
 
 ifeq ($(CONFIG_EFENCE),y)