libcutils: vendor_available
By setting vendor_available, the following may become true:
* a prebuilt library from this release may be used at runtime by
in a later releasse (by vendor code compiled against this release).
so this library shouldn't depend on runtime state that may change
in the future.
* this library may be loaded twice into a single process (potentially
an old version and a newer version). The symbols will be isolated
using linker namespaces, but this may break assumptions about 1
library in 1 process (your singletons will run twice).
Background:
This means that these modules may be built and installed twice --
once for the system partition and once for the vendor partition. The
system version will build just like today, and will be used by the
framework components on /system. The vendor version will build
against a reduced set of exports and libraries -- similar to, but
separate from, the NDK. This means that all your dependencies must
also mark vendor_available.
At runtime, /system binaries will load libraries from /system/lib*,
while /vendor binaries will load libraries from /vendor/lib*. There
are some exceptions in both directions -- bionic(libc,etc) and liblog
are always loaded from /system. And SP-HALs (OpenGL, etc) may load
/vendor code into /system processes, but the dependencies of those
libraries will load from /vendor until it reaches a library that's
always on /system. In the SP-HAL case, if both framework and vendor
libraries depend on a library of the same name, both versions will be
loaded, but they will be isolated from each other.
It's possible to compile differently -- reducing your source files,
exporting different include directories, etc. For details see:
https://android-review.googlesource.com/368372
None of this is enabled unless the device opts into the system/vendor
split with BOARD_VNDK_VERSION := current.
Bug: 36426473
Bug: 36079834
Test: m -j libcutils
Test: attempt to compile with BOARD_VNDK_VERSION := current
Test: (sanity) boot internal marlin
Change-Id: I76f9b28ef08a26d84d1365881e00696cc1dcfe5d
diff --git a/libcutils/Android.bp b/libcutils/Android.bp
index f668f18..8b382de 100644
--- a/libcutils/Android.bp
+++ b/libcutils/Android.bp
@@ -31,16 +31,14 @@
]
cc_library_headers {
- name: "libcutils_vndk_headers",
- host_supported: true,
- export_include_dirs: ["include_vndk"],
-}
-
-cc_library_headers {
name: "libcutils_headers",
+ vendor_available: true,
host_supported: true,
export_include_dirs: ["include"],
target: {
+ vendor: {
+ export_include_dirs: ["include_vndk"],
+ },
linux_bionic: {
enabled: true,
},
@@ -52,6 +50,7 @@
cc_library {
name: "libcutils",
+ vendor_available: true,
host_supported: true,
srcs: [
"config_utils.c",