crash_dump: fix warnings, turn on -Werror.

Test: mma
Change-Id: I0722fef7b513be976cbbe89f73e8bb7138a80442
diff --git a/debuggerd/Android.bp b/debuggerd/Android.bp
index af84be9..b385ea5 100644
--- a/debuggerd/Android.bp
+++ b/debuggerd/Android.bp
@@ -3,7 +3,7 @@
     cflags: [
         "-Wall",
         "-Wextra",
-        "-Wno-error",
+        "-Werror",
         "-Wno-nullability-completeness",
         "-Os",
     ],
diff --git a/debuggerd/crash_dump.cpp b/debuggerd/crash_dump.cpp
index 57a6c44..38b711f 100644
--- a/debuggerd/crash_dump.cpp
+++ b/debuggerd/crash_dump.cpp
@@ -199,10 +199,6 @@
   pid_t main_tid;
   pid_t pseudothread_tid;
 
-  if (target == 1) {
-    LOG(FATAL) << "target died before we could attach (received main tid = " << main_tid << ")";
-  }
-
   if (!android::base::ParseInt(argv[1], &main_tid, 1, std::numeric_limits<pid_t>::max())) {
     LOG(FATAL) << "invalid main tid: " << argv[1];
   }
@@ -211,6 +207,10 @@
     LOG(FATAL) << "invalid pseudothread tid: " << argv[2];
   }
 
+  if (target == 1) {
+    LOG(FATAL) << "target died before we could attach (received main tid = " << main_tid << ")";
+  }
+
   android::procinfo::ProcessInfo target_info;
   if (!android::procinfo::GetProcessInfo(main_tid, &target_info)) {
     LOG(FATAL) << "failed to fetch process info for target " << main_tid;
diff --git a/debuggerd/libdebuggerd/include/tombstone.h b/debuggerd/libdebuggerd/include/tombstone.h
index 8e60278..d2a4a4b 100644
--- a/debuggerd/libdebuggerd/include/tombstone.h
+++ b/debuggerd/libdebuggerd/include/tombstone.h
@@ -43,6 +43,7 @@
                                 ucontext_t* ucontext);
 
 // Compatibility shim.
+__attribute__((__unused__))
 static void engrave_tombstone_ucontext(int tombstone_fd, pid_t, pid_t, uintptr_t abort_msg_address,
                                        siginfo_t* siginfo, ucontext_t* ucontext) {
   engrave_tombstone_ucontext(tombstone_fd, abort_msg_address, siginfo, ucontext);