snapuesrd: Build snapuserd_test on host.

Bug: 288273605
Test: snapuserd_test
Change-Id: I10e099feff30f09b8c9f0b9dcca64336cb0861b9

fs_mgr/libsnapshot/snapuserd/Android.bp

@@ -90,6 +90,7 @@ cc_library_static {
     ramdisk_available: true,
     vendor_ramdisk_available: true,
     recovery_available: true,
+    host_supported: true,
 }
 
 cc_defaults {
@@ -256,4 +257,5 @@ cc_test {
     },
     auto_gen_config: true,
     require_root: false,
+    host_supported: true,
 }

fs_mgr/libsnapshot/snapuserd/include/snapuserd/snapuserd_kernel.h

@@ -14,6 +14,8 @@
 
 #pragma once
 
+#include <linux/types.h>
+
 namespace android {
 namespace snapshot {
 
@@ -70,7 +72,7 @@ struct disk_header {
 
     /* In sectors */
     uint32_t chunk_size;
-} __packed;
+} __attribute__((packed));
 
 // A disk exception is a mapping of old_chunk to new_chunk
 // old_chunk is the chunk ID of a dm-snapshot device.
@@ -78,7 +80,7 @@ struct disk_header {
 struct disk_exception {
     uint64_t old_chunk;
     uint64_t new_chunk;
-} __packed;
+} __attribute__((packed));
 
 // Control structures to communicate with dm-user
 // It comprises of header and a payload

fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_test.cpp

@@ -41,6 +41,7 @@
 #include "handler_manager.h"
 #include "snapuserd_core.h"
 #include "testing/dm_user_harness.h"
+#include "testing/host_harness.h"
 #include "testing/temp_device.h"
 #include "utility.h"
 
@@ -80,7 +81,11 @@ class SnapuserdTestBase : public ::testing::Test {
 };
 
 void SnapuserdTestBase::SetUp() {
+#if __ANDROID__
     harness_ = std::make_unique<DmUserTestHarness>();
+#else
+    harness_ = std::make_unique<HostTestHarness>();
+#endif
 }
 
 void SnapuserdTestBase::TearDown() {}
@@ -269,7 +274,9 @@ void SnapuserdTest::TearDown() {
 }
 
 void SnapuserdTest::Shutdown() {
-    ASSERT_TRUE(dmuser_dev_->Destroy());
+    if (dmuser_dev_) {
+        ASSERT_TRUE(dmuser_dev_->Destroy());
+    }
 
     auto misc_device = "/dev/dm-user/" + system_device_ctrl_name_;
     ASSERT_TRUE(handlers_->DeleteHandler(system_device_ctrl_name_));