[gnome-continuous-yocto/gnomeostree-3.28-rocko: 2334/8267] module.bbclass: use Module.symvers for dependants

[Emmanuele Bassi <ebassi src gnome org>]

commit fe90376acae1335c430ec400b8ada9ab3d536ee2
Author: André Draszik <git andred net>
Date:   Thu Aug 18 08:56:24 2016 +0100

    module.bbclass: use Module.symvers for dependants
    
    When compiling multiple external kernel modules, where one
    depends on the other, there are two problems at the
    moment:
    1) we get compile time warnings from the kernel build
       system due to missing symbols (from modpost).
    2) Any modules generated are missing dependency
       information (in the .modinfo elf section) for any
       dependencies outside the current source tree and
       outside the kernel itself.
    
    This is expected, but the kernel build system has a way to
    deal with this - the dependent module is expected to
    specify KBUILD_EXTRA_SYMBOLS (as a space-separated list)
    to point to any and all Module.symvers of kernel modules
    that are dependencies.
    
    While 1) by itself is not really a big issue, 2) prevents
    the packaging process from generating cross-source tree
    package dependencies.
    
    As a first step to solve the missing dependencies in
    packages created, we:
    1) install Module.symvers of all external kernel module
       builds (into a location that is automatically packaged
       into the -dev package)
    2) make use of KBUILD_EXTRA_SYMBOLS and pass the location
       of all Module.symvers of all kernel-module-* packages
       we depend on
    
    This solves both problems mentioned above.
    
    (From OE-Core rev: 88f1bc77c22091fccb00e80839adfdf34534187f)
    
    Signed-off-by: André Draszik <git andred net>
    Signed-off-by: Richard Purdie <richard purdie linuxfoundation org>

 meta/classes/module.bbclass |   15 +++++++++++++++
 1 files changed, 15 insertions(+), 0 deletions(-)
---
diff --git a/meta/classes/module.bbclass b/meta/classes/module.bbclass
index 01c9309..68e3d34 100644
--- a/meta/classes/module.bbclass
+++ b/meta/classes/module.bbclass
@@ -8,6 +8,15 @@ EXTRA_OEMAKE += "KERNEL_SRC=${STAGING_KERNEL_DIR}"
 
 MODULES_INSTALL_TARGET ?= "modules_install"
 
+python __anonymous () {
+    depends = d.getVar('DEPENDS', True)
+    extra_symbols = []
+    for dep in depends.split():
+        if dep.startswith("kernel-module-"):
+            extra_symbols.append("${STAGING_INCDIR}/" + dep + "/Module.symvers")
+    d.setVar('KBUILD_EXTRA_SYMBOLS', " ".join(extra_symbols))
+}
+
 module_do_compile() {
        unset CFLAGS CPPFLAGS CXXFLAGS LDFLAGS
        oe_runmake KERNEL_PATH=${STAGING_KERNEL_DIR}   \
@@ -15,6 +24,7 @@ module_do_compile() {
                   CC="${KERNEL_CC}" LD="${KERNEL_LD}" \
                   AR="${KERNEL_AR}" \
                   O=${STAGING_KERNEL_BUILDDIR} \
+                  KBUILD_EXTRA_SYMBOLS="${KBUILD_EXTRA_SYMBOLS}" \
                   ${MAKE_TARGETS}
 }
 
@@ -24,6 +34,11 @@ module_do_install() {
                   CC="${KERNEL_CC}" LD="${KERNEL_LD}" \
                   O=${STAGING_KERNEL_BUILDDIR} \
                   ${MODULES_INSTALL_TARGET}
+
+       install -d -m0755 ${D}${includedir}/${BPN}
+       cp -a --no-preserve=ownership ${B}/Module.symvers ${D}${includedir}/${BPN}
+       # it doesn't actually seem to matter which path is specified here
+       sed -e 's:${B}/::g' -i ${D}${includedir}/${BPN}/Module.symvers
 }
 
 EXPORT_FUNCTIONS do_compile do_install