[PATCH] lib: compile memcat_p only when needed

[Enrico Weigelt, metux IT consult]

The library function memcat_p() is currently used only once.
(drivers/hwtracing/stm). So, often completely unused.

Reducing the kernel size by about 4k by compiling it
conditionally, only when needed.

Signed-off-by: Enrico Weigelt, metux IT consult <info@xxxxxxxxx>
---
 drivers/hwtracing/stm/Kconfig | 1 +
 lib/Kconfig                   | 3 +++
 lib/Kconfig.debug             | 1 +
 lib/Makefile                  | 4 +++-
 4 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/hwtracing/stm/Kconfig b/drivers/hwtracing/stm/Kconfig
index aad594fe79cc..8ce5cfd759d1 100644
--- a/drivers/hwtracing/stm/Kconfig
+++ b/drivers/hwtracing/stm/Kconfig
@@ -3,6 +3,7 @@ config STM
 	tristate "System Trace Module devices"
 	select CONFIGFS_FS
 	select SRCU
+	select GENERIC_LIB_MEMCAT_P
 	help
 	  A System Trace Module (STM) is a device exporting data in System
 	  Trace Protocol (STP) format as defined by MIPI STP standards.
diff --git a/lib/Kconfig b/lib/Kconfig
index b46a9fd122c8..b42ed8d68937 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -686,6 +686,9 @@ config GENERIC_LIB_CMPDI2
 config GENERIC_LIB_UCMPDI2
 	bool
 
+config GENERIC_LIB_MEMCAT_P
+	tristate
+
 config PLDMFW
 	bool
 	default n
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index c789b39ed527..beb5adb2f0b7 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2334,6 +2334,7 @@ config TEST_DEBUG_VIRTUAL
 
 config TEST_MEMCAT_P
 	tristate "Test memcat_p() helper function"
+	select GENERIC_LIB_MEMCAT_P
 	help
 	  Test the memcat_p() helper for correctly merging two
 	  pointer arrays together.
diff --git a/lib/Makefile b/lib/Makefile
index ce45af50983a..18fd6630be0b 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -36,7 +36,9 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \
 	 flex_proportions.o ratelimit.o show_mem.o \
 	 is_single_threaded.o plist.o decompress.o kobject_uevent.o \
 	 earlycpio.o seq_buf.o siphash.o dec_and_lock.o \
-	 nmi_backtrace.o nodemask.o win_minmax.o memcat_p.o
+	 nmi_backtrace.o nodemask.o win_minmax.o
+
+obj-$(CONFIG_GENERIC_LIB_MEMCAT_P) += memcat_p.o
 
 lib-$(CONFIG_PRINTK) += dump_stack.o
 lib-$(CONFIG_SMP) += cpumask.o
-- 
2.11.0