Index: lib/sanitizer_common/sanitizer_unwind_posix_libcdep.cc
===================================================================
--- lib/sanitizer_common/sanitizer_unwind_posix_libcdep.cc
+++ lib/sanitizer_common/sanitizer_unwind_posix_libcdep.cc
@@ -108,6 +108,8 @@
   return UNWIND_CONTINUE;
 }
 
+#if !SANITIZER_IOS
+
 void BufferedStackTrace::SlowUnwindStack(uptr pc, u32 max_depth) {
   CHECK_GE(max_depth, 2);
   size = 0;
@@ -153,6 +155,8 @@
     trace_buffer[size++] = frames[i].absolute_pc + 2;
 }
 
+#endif
+
 }  // namespace __sanitizer
 
 #endif  // SANITIZER_POSIX