Index: lib/Driver/MSVCToolChain.cpp
===================================================================
--- lib/Driver/MSVCToolChain.cpp
+++ lib/Driver/MSVCToolChain.cpp
@@ -94,6 +94,18 @@
   return getArch() == llvm::Triple::x86_64;
 }
 
+bool MSVCToolChain::GetDefaultStandaloneDebug() const {
+  // Microsoft debuggers can't lookup type names across type stream boundaries.
+  // This means that types implemented in b.dll used by a.dll sometimes can't be
+  // found when debugging a.dll. Clang will emit types marked with dllimport to
+  // try to cope with this case, but is not a complete heuristic. Non-standalone
+  // type info is also incompatble with /DEBUG:FASTLINK, which leaves all debug
+  // info, including types, in object files. In this case, the type stream is
+  // limited to the TU, and every TU needs to have all the types required to be
+  // complete by that TU for debugging.
+  return true;
+}
+
 #ifdef USE_WIN32
 static bool readFullStringValue(HKEY hkey, const char *valueName,
                                 std::string &value) {
Index: lib/Driver/ToolChains.h
===================================================================
--- lib/Driver/ToolChains.h
+++ lib/Driver/ToolChains.h
@@ -1139,6 +1139,7 @@
   bool isPICDefault() const override;
   bool isPIEDefault() const override;
   bool isPICDefaultForced() const override;
+  bool GetDefaultStandaloneDebug() const override;
 
   void
   AddClangSystemIncludeArgs(const llvm::opt::ArgList &DriverArgs,
Index: test/Driver/cl-options.c
===================================================================
--- test/Driver/cl-options.c
+++ test/Driver/cl-options.c
@@ -452,11 +452,11 @@
 
 // RUN: %clang_cl /Zi /c -### -- %s 2>&1 | FileCheck -check-prefix=Zi %s
 // Zi: "-gcodeview"
-// Zi: "-debug-info-kind=limited"
+// Zi: "-debug-info-kind=standalone"
 
 // RUN: %clang_cl /Z7 /c -### -- %s 2>&1 | FileCheck -check-prefix=Z7 %s
 // Z7: "-gcodeview"
-// Z7: "-debug-info-kind=limited"
+// Z7: "-debug-info-kind=standalone"
 
 // RUN: %clang_cl /Zd /c -### -- %s 2>&1 | FileCheck -check-prefix=Z7GMLT %s
 // Z7GMLT: "-gcodeview"
@@ -466,6 +466,10 @@
 // ZGMLT: "-gcodeview"
 // ZGMLT: "-debug-info-kind=line-tables-only"
 
+// RUN: %clang_cl /Z7 -flimit-debug-info /c -### -- %s 2>&1 | FileCheck -check-prefix=Z7LIMITED %s
+// Z7LIMITED: "-gcodeview"
+// Z7LIMITED: "-debug-info-kind=limited"
+
 // RUN: %clang_cl /c -### -- %s 2>&1 | FileCheck -check-prefix=BreproDefault %s
 // BreproDefault: "-mincremental-linker-compatible"
 
@@ -485,7 +489,7 @@
 // which made it "win". This test could not detect that bug.
 // RUN: %clang_cl /Z7 -gdwarf /c -### -- %s 2>&1 | FileCheck -check-prefix=Z7_gdwarf %s
 // Z7_gdwarf: "-gcodeview"
-// Z7_gdwarf: "-debug-info-kind=limited"
+// Z7_gdwarf: "-debug-info-kind=standalone"
 // Z7_gdwarf: "-dwarf-version=4"
 
 // RUN: %clang_cl -fmsc-version=1800 -TP -### -- %s 2>&1 | FileCheck -check-prefix=CXX11 %s