Index: lib/Driver/Tools.cpp
===================================================================
--- lib/Driver/Tools.cpp
+++ lib/Driver/Tools.cpp
@@ -10999,6 +10999,11 @@
     } else {
       for (const auto &Lib : {"asan", "asan_cxx"})
         CmdArgs.push_back(TC.getCompilerRTArgString(Args, Lib));
+      // Make sure the linker consider all object files from the static library.
+      // This is necessary because instrumented dlls need access to all the
+      // interface exported by the static lib in the main executable.
+      CmdArgs.push_back(Args.MakeArgString(std::string("-wholearchive:") +
+          TC.getCompilerRT(Args, "asan")));
     }
   }