Index: cfe/trunk/lib/Driver/Tools.cpp
===================================================================
--- cfe/trunk/lib/Driver/Tools.cpp
+++ cfe/trunk/lib/Driver/Tools.cpp
@@ -11002,6 +11002,11 @@
     } 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")));
     }
   }