libbinder_rs: Add libbinder_rs_on_trusty_mock

Build a mock version of Trusty libbinder_rs
on Android for build testing purposes.

Bug: 242243245
Test: m libbinder_rs_on_trusty_mock
Change-Id: I1b61550af6fbbeac68903c41b5bd20729973b066

8 files changed, 79 insertions, 7 deletions

diff --git a/libs/binder/Android.bp b/libs/binder/Android.bp
index eec12e4cd5..401400d250 100644
--- a/libs/binder/Android.bp
+++ b/libs/binder/Android.bp
@@ -229,6 +229,7 @@ cc_defaults {
 cc_library_headers {
     name: "trusty_mock_headers",
     host_supported: true,
+    vendor_available: true,
 
     export_include_dirs: [
         "trusty/include",
@@ -243,12 +244,18 @@ cc_library_headers {
 cc_defaults {
     name: "trusty_mock_defaults",
     host_supported: true,
+    vendor_available: true,
 
     header_libs: [
         "libbinder_headers_base",
         "liblog_stub",
         "trusty_mock_headers",
     ],
+    export_header_lib_headers: [
+        "libbinder_headers_base",
+        "liblog_stub",
+        "trusty_mock_headers",
+    ],
 
     shared_libs: [
         "libutils_binder_sdk",
diff --git a/libs/binder/rust/Android.bp b/libs/binder/rust/Android.bp
index 57a38dc480..ef556d7f5f 100644
--- a/libs/binder/rust/Android.bp
+++ b/libs/binder/rust/Android.bp
@@ -35,6 +35,21 @@ rust_library {
 }
 
 rust_library {
+    name: "libbinder_rs_on_trusty_mock",
+    crate_name: "binder",
+    srcs: ["src/lib.rs"],
+    cfgs: [
+        "trusty",
+    ],
+    rustlibs: [
+        "libbinder_ndk_sys_on_trusty_mock",
+        "libdowncast_rs",
+        "liblibc",
+    ],
+    vendor: true,
+}
+
+rust_library {
     name: "libbinder_tokio_rs",
     crate_name: "binder_tokio",
     srcs: ["binder_tokio/lib.rs"],
@@ -89,6 +104,26 @@ rust_library {
     visibility: [":__subpackages__"],
 }
 
+rust_library {
+    name: "libbinder_ndk_sys_on_trusty_mock",
+    crate_name: "binder_ndk_sys",
+    srcs: [
+        "sys/lib.rs",
+        ":libbinder_ndk_bindgen_on_trusty_mock",
+    ],
+    cfgs: [
+        "trusty",
+    ],
+    shared_libs: [
+        "libbinder_ndk_on_trusty_mock",
+    ],
+    vendor: true,
+    // Lints are checked separately for libbinder_ndk_sys.
+    // The Trusty mock copy pulls in extra headers that
+    // don't pass the lints for the bindgen output.
+    lints: "none",
+}
+
 rust_bindgen {
     name: "libbinder_ndk_bindgen",
     crate_name: "binder_ndk_bindgen",
@@ -125,6 +160,28 @@ rust_bindgen {
     min_sdk_version: "Tiramisu",
 }
 
+rust_bindgen {
+    name: "libbinder_ndk_bindgen_on_trusty_mock",
+    crate_name: "binder_ndk_bindgen",
+    wrapper_src: "sys/BinderBindings.hpp",
+    source_stem: "bindings",
+    defaults: [
+        "trusty_mock_defaults",
+    ],
+
+    bindgen_flag_files: [
+        // Unfortunately the only way to specify the rust_non_exhaustive enum
+        // style for a type is to make it the default
+        // and then specify constified enums for the enums we don't want
+        // rustified
+        "libbinder_ndk_bindgen_flags.txt",
+    ],
+    shared_libs: [
+        "libbinder_ndk_on_trusty_mock",
+        "libc++",
+    ],
+}
+
 rust_test {
     name: "libbinder_rs-internal_test",
     crate_name: "binder",
diff --git a/libs/binder/rust/src/lib.rs b/libs/binder/rust/src/lib.rs
index 0540ed379b..0f9c58c0a2 100644
--- a/libs/binder/rust/src/lib.rs
+++ b/libs/binder/rust/src/lib.rs
@@ -100,9 +100,9 @@ mod error;
 mod native;
 mod parcel;
 mod proxy;
-#[cfg(not(target_os = "trusty"))]
+#[cfg(not(trusty))]
 mod service;
-#[cfg(not(target_os = "trusty"))]
+#[cfg(not(trusty))]
 mod state;
 
 use binder_ndk_sys as sys;
@@ -112,13 +112,13 @@ pub use binder::{BinderFeatures, FromIBinder, IBinder, Interface, Strong, Weak};
 pub use error::{ExceptionCode, IntoBinderResult, Status, StatusCode};
 pub use parcel::{ParcelFileDescriptor, Parcelable, ParcelableHolder};
 pub use proxy::{DeathRecipient, SpIBinder, WpIBinder};
-#[cfg(not(target_os = "trusty"))]
+#[cfg(not(trusty))]
 pub use service::{
     add_service, force_lazy_services_persist, get_declared_instances, get_interface, get_service,
     is_declared, is_handling_transaction, register_lazy_service, wait_for_interface,
     wait_for_service, LazyServiceGuard,
 };
-#[cfg(not(target_os = "trusty"))]
+#[cfg(not(trusty))]
 pub use state::{ProcessState, ThreadState};
 
 /// Binder result containing a [`Status`] on error.
diff --git a/libs/binder/rust/src/native.rs b/libs/binder/rust/src/native.rs
index da9d7dc948..c87cc94973 100644
--- a/libs/binder/rust/src/native.rs
+++ b/libs/binder/rust/src/native.rs
@@ -327,7 +327,7 @@ impl<T: Remotable> InterfaceClassMethods for Binder<T> {
     /// contains a `T` pointer in its user data. fd should be a non-owned file
     /// descriptor, and args must be an array of null-terminated string
     /// pointers with length num_args.
-    #[cfg(not(target_os = "trusty"))]
+    #[cfg(not(trusty))]
     unsafe extern "C" fn on_dump(
         binder: *mut sys::AIBinder,
         fd: i32,
@@ -374,7 +374,7 @@ impl<T: Remotable> InterfaceClassMethods for Binder<T> {
     }
 
     /// Called to handle the `dump` transaction.
-    #[cfg(target_os = "trusty")]
+    #[cfg(trusty)]
     unsafe extern "C" fn on_dump(
         _binder: *mut sys::AIBinder,
         _fd: i32,
diff --git a/libs/binder/rust/sys/lib.rs b/libs/binder/rust/sys/lib.rs
index c5c847b874..5352473272 100644
--- a/libs/binder/rust/sys/lib.rs
+++ b/libs/binder/rust/sys/lib.rs
@@ -25,7 +25,9 @@ mod bindings {
 }
 
 // Trusty puts the full path to the auto-generated file in BINDGEN_INC_FILE
-// and builds it with warnings-as-errors, so we need to use #[allow(bad_style)]
+// and builds it with warnings-as-errors, so we need to use #[allow(bad_style)].
+// We need to use cfg(target_os) instead of cfg(trusty) here because of
+// the difference between the two build systems, which we cannot mock.
 #[cfg(target_os = "trusty")]
 #[allow(bad_style)]
 mod bindings {
diff --git a/libs/binder/tests/Android.bp b/libs/binder/tests/Android.bp
index 424ff8448c..35002eb3c5 100644
--- a/libs/binder/tests/Android.bp
+++ b/libs/binder/tests/Android.bp
@@ -436,6 +436,7 @@ cc_test {
     required: [
         "libbinder_on_trusty_mock",
         "libbinder_ndk_on_trusty_mock",
+        "libbinder_rs_on_trusty_mock",
         "binderRpcTestService_on_trusty_mock",
         "binderRpcTest_on_trusty_mock",
     ],
diff --git a/libs/binder/trusty/rust/binder_ndk_sys/rules.mk b/libs/binder/trusty/rust/binder_ndk_sys/rules.mk
index 672d9b75ec..2aaa061ddf 100644
--- a/libs/binder/trusty/rust/binder_ndk_sys/rules.mk
+++ b/libs/binder/trusty/rust/binder_ndk_sys/rules.mk
@@ -29,6 +29,10 @@ MODULE_LIBRARY_DEPS += \
 	$(LIBBINDER_DIR)/trusty/ndk \
 	trusty/user/base/lib/trusty-sys \
 
+MODULE_RUSTFLAGS += \
+	--cfg 'android_vendor' \
+	--cfg 'trusty' \
+
 MODULE_BINDGEN_SRC_HEADER := $(LIBBINDER_DIR)/rust/sys/BinderBindings.hpp
 
 # Add the flags from the flag file
diff --git a/libs/binder/trusty/rust/rules.mk b/libs/binder/trusty/rust/rules.mk
index d343f14240..c5e671a4f5 100644
--- a/libs/binder/trusty/rust/rules.mk
+++ b/libs/binder/trusty/rust/rules.mk
@@ -32,6 +32,7 @@ MODULE_LIBRARY_DEPS += \
 
 MODULE_RUSTFLAGS += \
 	--cfg 'android_vendor' \
+	--cfg 'trusty' \
 
 # Trusty does not have `ProcessState`, so there are a few
 # doc links in `IBinder` that are still broken.