How to get static library in sdk? - sdk

Question

Everyone who searched how to include a static library in SDK, surely read this thread from 2014. I tried what they suggested, but that didn't work.
Reading the yocto mega manual version 2.1 (yocto morty), I found in chapter 5.9.12. (Poky Reference Distribution Changes), that they added DISABLE_STATIC variable, to disable generation of static libraries. I tried adding this to my recipe, and it didn't enable adding static library to SDK:
DISABLE_STATIC = ""
I can see the library in the sysroot when building the image. But it is not getting in the SDK.
So, what exactly do I need to do to get a static library and the headers in SDK?
What worked is adding the staticdev package to ´IMAGE_INSTALL´ in local.conf, but I don't want to have to do that.
I created an example recipe, which demonstrates my problem. The directory structure is like this:
example-staticlib/
example-staticlib/example-staticlib_0.1.bb
example-staticlib/files/
example-staticlib/files/lib.c
example-staticlib/files/lib.h
example-staticlib/files/Makefile
example-staticlib_0.1.bb :
DESCRIPTION = "example stared library"
LICENSE = "LGPLv2"
LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/LGPL-2.0;md5=9427b8ccf5cf3df47c29110424c9641a"
SRC_URI = "file://lib.c \
file://lib.h \
file://Makefile"
PR = "r0"
S = "${WORKDIR}"
ALLOW_EMPTY_${PN} = "1"
do_install () {
oe_runmake install DEST=${D}
}
TOOLCHAIN_TARGET_TASK += "example-staticlib-dev"
TOOLCHAIN_TARGET_TASK += "example-staticlib-staticdev"
lib.c:
int foo()
{
return 42;
}
lib.h:
int foo();
Makefile:
TARGET=libexample.a
all:$(TARGET)
install :
#install -d $(DEST)/usr/lib/
#install -m 0644 $(TARGET) $(DEST)/usr/lib/
#install -d $(DEST)/usr/include/
#install -m 0644 lib.h $(DEST)/usr/include/
$(TARGET) : lib.c
$(CC) -c lib.c -o lib.o
$(AR) rcs $# lib.o
clean:
rm -rf lib.o $(TARGET)
How exactly to modify the recipe, in order to get the static library in the SDK?

Answer 1

Following your added example.
Adding the following line to your image recipe (or to an .bbappend, eg core-image-minimal.bbappend)
TOOLCHAIN_TARGET_TASK += "example-staticlib-staticdev"
should work for you. That will give you the .a file in the SDK, after running bitbake core-image-minimal -c populate_sdk. (Again assuming that the image used is core-image-minimal).
That your experiment to add the .a file to ${PN}-dev didn't work, is duet to the order of how files are put into packages. The order is ${PN}-dbg ${PN}-staticdev ${PN}-dev ${PN}-doc ${PN}-locale ${PACKAGE_BEFORE_PN} ${PN}. Thus, the .a file will, regardless, be put into ${PN}-staticdev, as that packages is handled prior to {PN}-dev.
Note, you add this line, TOOLCHAIN_TARGET_TASK += "example-staticlib-staticdev" to your image recipe, thus, you need to write the package name instead of PN.

Answer 2

I tried a way which doesn't require editing the image recipe.
example-staticlib_0.1.bb :
After do_install. I didn't use TOOLCHAIN_TARGET_TASK
FILES_${PN}-staticdev += "${libdir}/libexample.a"
RDEPENDS_${PN}-dev += "${PN}-staticdev"
BBCLASSEXTEND = "native nativesdk"