uninative: Add allow-shlib-undefined to BUILD_LDFLAGS and drop other workarounds

We have a problem when for example, a glibc 2.27 based system builds some
library like libpopt-native and puts it into sstate then it is reused
on a pre glibc-2.27 system to build something which depends on popt like
rpm-native. This results in an error like:

recipe-sysroot-native/usr/lib/libpopt.so: undefined reference to `glob@GLIBC_2.27'

In the past we've had this problem with new symbols like getrandom and
getentropy, here its with a more complex symbol where there is an old
version and a newer version.

We've looked into various options, basically we cannot link against our
uninative libc/ld.so since we don't have the right headers or compiler
link libraries. The compiler doesn't allow you to switch in a new set
either, even if we did want to ship them. Shipping a complete compiler,
dev headers and libs also isn't an option.

On the other hand if we follow the ld man page, it does say:

"""
The reasons for allowing undefined symbol references in shared libraries
specified at link time are that:

- A shared library specified at link time may not be the same as the one
  that is available at load time, so the symbol might actually be
  resolvable at load time.
"""

which is exactly this case. By the time the binary runs, it will use
our uninative loader and libc and the symbol will be available.

Therefore we basically have a choice, we get weird intermittent bugs,
we drop uninative entirely, or we pass this option.

If we pass the option, we can drop the other workarounds too.

(From OE-Core rev: 75a62ede393bf6b4972390ef5290d50add19341a)

(From OE-Core rev: d18bf7fa8e80d6cfaf3fdbe1ab06eec84b954432)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/uninative.bbclass

@@ -9,7 +9,7 @@ UNINATIVE_TARBALL ?= "${BUILD_ARCH}-nativesdk-libc.tar.bz2"
 UNINATIVE_DLDIR ?= "${DL_DIR}/uninative/"
 
 # Enabling uninative will change the following variables so they need to go the parsing white list to prevent multiple recipe parsing
-BB_HASHCONFIG_WHITELIST += "NATIVELSBSTRING SSTATEPOSTUNPACKFUNCS"
+BB_HASHCONFIG_WHITELIST += "NATIVELSBSTRING SSTATEPOSTUNPACKFUNCS BUILD_LDFLAGS"
 
 addhandler uninative_event_fetchloader
 uninative_event_fetchloader[eventmask] = "bb.event.BuildStarted"
@@ -129,6 +129,8 @@ def enable_uninative(d):
         d.setVar("NATIVELSBSTRING", "universal%s" % oe.utils.host_gcc_version(d))
         d.appendVar("SSTATEPOSTUNPACKFUNCS", " uninative_changeinterp")
         d.appendVarFlag("SSTATEPOSTUNPACKFUNCS", "vardepvalueexclude", "| uninative_changeinterp")
+        d.appendVar("BUILD_LDFLAGS", " -Wl,--allow-shlib-undefined")
+        d.appendVarFlag("BUILD_LDFLAGS", "vardepvalueexclude", "| -Wl,--allow-shlib-undefined")
         d.prependVar("PATH", "${STAGING_DIR}-uninative/${BUILD_ARCH}-linux${bindir_native}:")
 
 python uninative_changeinterp () {

meta/recipes-core/expat/expat/no_getrandom.patch

@@ -1,23 +0,0 @@
-The native version of expat may be used on older systems which dont have glibc 2.25
-and hence don't have getrandom() thanks to uninative. Disable the libc call and
-use the syscall instead to avoid a compatibility issue until we have 2.25 everywhere
-we support with uninative.
-
-RP
-2017/8/14
-
-Upstream-Status: Inappropriate
-
-Index: expat-2.2.3/configure.ac
-===================================================================
---- expat-2.2.3.orig/configure.ac
-+++ expat-2.2.3/configure.ac
-@@ -151,7 +151,7 @@ AC_LINK_IFELSE([AC_LANG_SOURCE([
-   #include <stdlib.h>  /* for NULL */
-   #include <sys/random.h>
-   int main() {
--    return getrandom(NULL, 0U, 0U);
-+    return getrandomBREAKME(NULL, 0U, 0U);
-   }
- ])], [
-     AC_DEFINE([HAVE_GETRANDOM], [1],

meta/recipes-core/expat/expat_2.2.5.bb

@@ -11,8 +11,6 @@ SRC_URI = "${SOURCEFORGE_MIRROR}/expat/expat-${PV}.tar.bz2 \
            file://libtool-tag.patch \
 	  "
 
-SRC_URI_append_class-native = " file://no_getrandom.patch"
-
 SRC_URI[md5sum] = "789e297f547980fc9ecc036f9a070d49"
 SRC_URI[sha256sum] = "d9dc32efba7e74f788fcc4f212a43216fc37cf5f23f4c2339664d473353aedf6"
 

meta/recipes-core/util-linux/util-linux/no_getrandom.patch

@@ -1,21 +0,0 @@
-getrandom() is only available in glibc 2.25+ and uninative may relocate 
-binaries onto systems that don't have this function. For now, force the 
-code to the older codepath until we can come up with a better solution 
-for this kind of issue.
-
-Upstream-Status: Inappropriate
-RP
-2016/8/15
-
-Index: util-linux-2.30/configure.ac
-===================================================================
---- util-linux-2.30.orig/configure.ac
-+++ util-linux-2.30/configure.ac
-@@ -399,7 +399,6 @@ AC_CHECK_FUNCS([ \
- 	getdtablesize \
- 	getexecname \
- 	getmntinfo \
--	getrandom \
- 	getrlimit \
- 	getsgnam \
- 	inotify_init \

meta/recipes-core/util-linux/util-linux_2.31.bb

@@ -15,7 +15,6 @@ SRC_URI += "file://configure-sbindir.patch \
             file://display_testname_for_subtest.patch \
             file://avoid_parallel_tests.patch \
 "
-SRC_URI_append_class-native = " file://no_getrandom.patch"
 SRC_URI[md5sum] = "5b6821c403c3cc6e7775f74df1882a20"
 SRC_URI[sha256sum] = "f9be7cdcf4fc5c5064a226599acdda6bdf3d86c640152ba01ea642d91108dc8a"
 

meta/recipes-devtools/python/python3-native_3.5.5.bb

@@ -42,8 +42,7 @@ DEPENDS = "openssl-native bzip2-replacement-native zlib-native readline-native s
 
 inherit native
 
-# uninative may be used on pre glibc 2.25 systems which don't have getentropy
-EXTRA_OECONF_append = " --bindir=${bindir}/${PN} --without-ensurepip ac_cv_func_getentropy=no"
+EXTRA_OECONF_append = " --bindir=${bindir}/${PN} --without-ensurepip"
 
 EXTRA_OEMAKE = '\
   LIBC="" \