Index: cfe/trunk/lib/Driver/ToolChain.cpp
===================================================================
--- cfe/trunk/lib/Driver/ToolChain.cpp
+++ cfe/trunk/lib/Driver/ToolChain.cpp
@@ -367,8 +367,10 @@
       TT.isWindowsMSVCEnvironment() || TT.isWindowsItaniumEnvironment();
 
   const char *Prefix = IsITANMSVCWindows ? "" : "lib";
-  const char *Suffix = Shared ? (Triple.isOSWindows() ? ".dll" : ".so")
+  const char *Suffix = Shared ? (Triple.isOSWindows() ? ".lib" : ".so")
                               : (IsITANMSVCWindows ? ".lib" : ".a");
+  if (Shared && Triple.isWindowsGNUEnvironment())
+    Suffix = ".dll.a";
 
   for (const auto &LibPath : getLibraryPaths()) {
     SmallString<128> P(LibPath);
Index: cfe/trunk/lib/Driver/ToolChains/MinGW.h
===================================================================
--- cfe/trunk/lib/Driver/ToolChains/MinGW.h
+++ cfe/trunk/lib/Driver/ToolChains/MinGW.h
@@ -65,6 +65,8 @@
   bool isPIEDefault() const override;
   bool isPICDefaultForced() const override;
 
+  SanitizerMask getSupportedSanitizers() const override;
+
   llvm::ExceptionHandling GetExceptionModel(
       const llvm::opt::ArgList &Args) const override;
 
Index: cfe/trunk/lib/Driver/ToolChains/MinGW.cpp
===================================================================
--- cfe/trunk/lib/Driver/ToolChains/MinGW.cpp
+++ cfe/trunk/lib/Driver/ToolChains/MinGW.cpp
@@ -14,6 +14,7 @@
 #include "clang/Driver/Driver.h"
 #include "clang/Driver/DriverDiagnostic.h"
 #include "clang/Driver/Options.h"
+#include "clang/Driver/SanitizerArgs.h"
 #include "llvm/Option/ArgList.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Path.h"
@@ -95,7 +96,7 @@
                                         const char *LinkingOutput) const {
   const ToolChain &TC = getToolChain();
   const Driver &D = TC.getDriver();
-  // const SanitizerArgs &Sanitize = TC.getSanitizerArgs();
+  const SanitizerArgs &Sanitize = TC.getSanitizerArgs();
 
   ArgStringList CmdArgs;
 
@@ -187,8 +188,6 @@
   TC.AddFilePathLibArgs(Args, CmdArgs);
   AddLinkerInputs(TC, Inputs, Args, CmdArgs, JA);
 
-  // TODO: Add ASan stuff here
-
   // TODO: Add profile stuff here
 
   if (TC.ShouldLinkCXXStdlib(Args)) {
@@ -231,6 +230,24 @@
       if (Args.hasArg(options::OPT_pthread))
         CmdArgs.push_back("-lpthread");
 
+      if (Sanitize.needsAsanRt()) {
+        // MinGW always links against a shared MSVCRT.
+        CmdArgs.push_back(
+            TC.getCompilerRTArgString(Args, "asan_dynamic", true));
+        CmdArgs.push_back(
+            TC.getCompilerRTArgString(Args, "asan_dynamic_runtime_thunk"));
+        CmdArgs.push_back(Args.MakeArgString("--require-defined"));
+        CmdArgs.push_back(Args.MakeArgString(TC.getArch() == llvm::Triple::x86
+                                                 ? "___asan_seh_interceptor"
+                                                 : "__asan_seh_interceptor"));
+        // Make sure the linker consider all object files from the dynamic
+        // runtime thunk.
+        CmdArgs.push_back(Args.MakeArgString("--whole-archive"));
+        CmdArgs.push_back(Args.MakeArgString(
+            TC.getCompilerRT(Args, "asan_dynamic_runtime_thunk")));
+        CmdArgs.push_back(Args.MakeArgString("--no-whole-archive"));
+      }
+
       if (!HasWindowsApp) {
         // Add system libraries. If linking to libwindowsapp.a, that import
         // library replaces all these and we shouldn't accidentally try to
@@ -407,6 +424,12 @@
   return llvm::ExceptionHandling::DwarfCFI;
 }
 
+SanitizerMask toolchains::MinGW::getSupportedSanitizers() const {
+  SanitizerMask Res = ToolChain::getSupportedSanitizers();
+  Res |= SanitizerKind::Address;
+  return Res;
+}
+
 void toolchains::MinGW::AddCudaIncludeArgs(const ArgList &DriverArgs,
                                            ArgStringList &CC1Args) const {
   CudaInstallation.AddCudaIncludeArgs(DriverArgs, CC1Args);
Index: cfe/trunk/test/Driver/mingw-sanitizers.c
===================================================================
--- cfe/trunk/test/Driver/mingw-sanitizers.c
+++ cfe/trunk/test/Driver/mingw-sanitizers.c
@@ -0,0 +1,11 @@
+// RUN: %clang -target i686-windows-gnu %s -### -fsanitize=address 2>&1 | FileCheck --check-prefix=ASAN-I686 %s
+// ASAN-I686: "{{.*}}libclang_rt.asan_dynamic-i386.dll.a"
+// ASAN-I686: "{{[^"]*}}libclang_rt.asan_dynamic_runtime_thunk-i386.a"
+// ASAN-I686: "--require-defined" "___asan_seh_interceptor"
+// ASAN-I686: "--whole-archive" "{{.*}}libclang_rt.asan_dynamic_runtime_thunk-i386.a" "--no-whole-archive"
+
+// RUN: %clang -target x86_64-windows-gnu %s -### -fsanitize=address 2>&1 | FileCheck --check-prefix=ASAN-X86_64 %s
+// ASAN-X86_64: "{{.*}}libclang_rt.asan_dynamic-x86_64.dll.a"
+// ASAN-X86_64: "{{[^"]*}}libclang_rt.asan_dynamic_runtime_thunk-x86_64.a"
+// ASAN-X86_64: "--require-defined" "__asan_seh_interceptor"
+// ASAN-X86_64: "--whole-archive" "{{.*}}libclang_rt.asan_dynamic_runtime_thunk-x86_64.a" "--no-whole-archive"