adbd: compile for host.

Preparatory step for testing adb on GCE on non-linux hosts: instead of
pointing them at a device (emulated or otherwise), point them at adbd
running on a linux host instead.

Test: adbd & adb connect localhost:5555; adb -e wait-for-device shell
Change-Id: Ib22d51a4fc9e6e68f71bf1b3b9b2e1b0bd844760
diff --git a/adb/daemon/main.cpp b/adb/daemon/main.cpp
index f6f1acc..fce3a4f 100644
--- a/adb/daemon/main.cpp
+++ b/adb/daemon/main.cpp
@@ -18,7 +18,10 @@
 
 #include "sysdeps.h"
 
+#if defined(__BIONIC__)
 #include <android/fdsan.h>
+#endif
+
 #include <errno.h>
 #include <getopt.h>
 #include <malloc.h>
@@ -34,12 +37,15 @@
 #include <android-base/macros.h>
 #include <android-base/properties.h>
 #include <android-base/stringprintf.h>
+
+#if defined(__ANDROID__)
 #include <libminijail.h>
 #include <log/log_properties.h>
 #include <scoped_minijail.h>
 
 #include <private/android_filesystem_config.h>
 #include "selinux/android.h"
+#endif
 
 #include "adb.h"
 #include "adb_auth.h"
@@ -49,6 +55,7 @@
 
 #include "mdns.h"
 
+#if defined(__ANDROID__)
 static const char* root_seclabel = nullptr;
 
 static bool should_drop_capabilities_bounding_set() {
@@ -167,10 +174,14 @@
         }
     }
 }
+#endif
 
 static void setup_port(int port) {
+    LOG(INFO) << "adbd listening on port " << port;
     local_init(port);
+#if defined(__ANDROID__)
     setup_mdns(port);
+#endif
 }
 
 int adbd_main(int server_port) {
@@ -178,10 +189,12 @@
 
     signal(SIGPIPE, SIG_IGN);
 
+#if defined(__BIONIC__)
     auto fdsan_level = android_fdsan_get_error_level();
     if (fdsan_level == ANDROID_FDSAN_ERROR_LEVEL_DISABLED) {
         android_fdsan_set_error_level(ANDROID_FDSAN_ERROR_LEVEL_WARN_ONCE);
     }
+#endif
 
     init_transport_registration();
 
@@ -206,14 +219,19 @@
           " unchanged.\n");
     }
 
+#if defined(__ANDROID__)
     drop_privileges(server_port);
+#endif
 
     bool is_usb = false;
+
+#if defined(__ANDROID__)
     if (access(USB_FFS_ADB_EP0, F_OK) == 0) {
         // Listen on USB.
         usb_init();
         is_usb = true;
     }
+#endif
 
     // If one of these properties is set, also listen on that port.
     // If one of the properties isn't set and we couldn't listen on usb, listen
@@ -244,8 +262,10 @@
 }
 
 int main(int argc, char** argv) {
+#if defined(__BIONIC__)
     // Set M_DECAY_TIME so that our allocations aren't immediately purged on free.
     mallopt(M_DECAY_TIME, 1);
+#endif
 
     while (true) {
         static struct option opts[] = {
@@ -261,19 +281,21 @@
         }
 
         switch (c) {
-        case 's':
-            root_seclabel = optarg;
-            break;
-        case 'b':
-            adb_device_banner = optarg;
-            break;
-        case 'v':
-            printf("Android Debug Bridge Daemon version %d.%d.%d\n", ADB_VERSION_MAJOR,
-                   ADB_VERSION_MINOR, ADB_SERVER_VERSION);
-            return 0;
-        default:
-            // getopt already prints "adbd: invalid option -- %c" for us.
-            return 1;
+#if defined(__ANDROID__)
+            case 's':
+                root_seclabel = optarg;
+                break;
+#endif
+            case 'b':
+                adb_device_banner = optarg;
+                break;
+            case 'v':
+                printf("Android Debug Bridge Daemon version %d.%d.%d\n", ADB_VERSION_MAJOR,
+                       ADB_VERSION_MINOR, ADB_SERVER_VERSION);
+                return 0;
+            default:
+                // getopt already prints "adbd: invalid option -- %c" for us.
+                return 1;
         }
     }