Depending on how ld.config.txt is configured, there can be multiple
built-in namespaces created by the linker from the beginning of a
process. android_get_exported_namespace is a platform only API for
getting a handle (android_namespace_t*) to one of the built-in namespaces
with given name. The returned namespace can then be given to
android_dlopen_ext in order to explicitly specify the target namespace
where the library is searched and loaded from.
Note that this function only returns 'exported' namespaces created via
ld.config.txt file. In order to export a namespace, the visible property
should be set to true:
namespace.<name>.visible = true
Namespaces are hidden by default. Hidden namespaces and namespaces
that are created programmatically, notably 'classloader-namespace',
aren't returned by this function.
Bug: 36851137
Test: confirmed that namespaces created with ld.config.txt is retrieved.
Test: linker-unit-tests passes
Merged-in: I714b510fa24f77e42c3dfc4c827b3befa8bb2951
Change-Id: I0d05fa7e0e116009edf8ea362ab46774bc617cbf
(cherry picked from commit d7c4832e6a)
This change allows customization of default namespace
configuration for different executables. It also enables
target_sdk_version setup for binaries (note that this
option should explicitly be enabled in ld.config.txt).
Bug: http://b/30706810
Bug: http://b/30435785
Test: run linker-unit-tests/bionic-unit-tests, boot angler
Change-Id: Ibbe87209acf1538fc9cec04944f3d22a190c38f1