Index: cfe/trunk/lib/Driver/Driver.cpp
===================================================================
--- cfe/trunk/lib/Driver/Driver.cpp
+++ cfe/trunk/lib/Driver/Driver.cpp
@@ -2030,6 +2030,9 @@
   ToolChain *&TC = ToolChains[Target.str()];
   if (!TC) {
     switch (Target.getOS()) {
+    case llvm::Triple::CloudABI:
+      TC = new toolchains::CloudABI(*this, Target, Args);
+      break;
     case llvm::Triple::Darwin:
     case llvm::Triple::MacOSX:
     case llvm::Triple::IOS:
Index: cfe/trunk/lib/Driver/ToolChains.h
===================================================================
--- cfe/trunk/lib/Driver/ToolChains.h
+++ cfe/trunk/lib/Driver/ToolChains.h
@@ -512,6 +512,31 @@
                              llvm::opt::ArgStringList &CC1Args) const override;
 };
 
+class LLVM_LIBRARY_VISIBILITY CloudABI : public Generic_ELF {
+public:
+  CloudABI(const Driver &D, const llvm::Triple &Triple,
+           const llvm::opt::ArgList &Args);
+  bool HasNativeLLVMSupport() const override { return true; }
+
+  bool IsMathErrnoDefault() const override { return false; }
+  bool IsObjCNonFragileABIDefault() const override { return true; }
+
+  CXXStdlibType GetCXXStdlibType(const llvm::opt::ArgList &Args)
+      const override {
+    return ToolChain::CST_Libcxx;
+  }
+  void AddClangCXXStdlibIncludeArgs(
+      const llvm::opt::ArgList &DriverArgs,
+      llvm::opt::ArgStringList &CC1Args) const override;
+  void AddCXXStdlibLibArgs(const llvm::opt::ArgList &Args,
+                           llvm::opt::ArgStringList &CmdArgs) const override;
+
+  bool isPIEDefault() const override { return false; }
+
+protected:
+  Tool *buildLinker() const override;
+};
+
 class LLVM_LIBRARY_VISIBILITY Solaris : public Generic_GCC {
 public:
   Solaris(const Driver &D, const llvm::Triple &Triple,
Index: cfe/trunk/lib/Driver/ToolChains.cpp
===================================================================
--- cfe/trunk/lib/Driver/ToolChains.cpp
+++ cfe/trunk/lib/Driver/ToolChains.cpp
@@ -2340,6 +2340,36 @@
   return false;
 }
 
+// CloudABI - CloudABI tool chain which can call ld(1) directly.
+
+CloudABI::CloudABI(const Driver &D, const llvm::Triple &Triple,
+                   const ArgList &Args)
+    : Generic_ELF(D, Triple, Args) {
+  SmallString<128> P(getDriver().Dir);
+  llvm::sys::path::append(P, "..", getTriple().str(), "lib");
+  getFilePaths().push_back(P.str());
+}
+
+void CloudABI::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
+                                            ArgStringList &CC1Args) const {
+  if (DriverArgs.hasArg(options::OPT_nostdlibinc) &&
+      DriverArgs.hasArg(options::OPT_nostdincxx))
+    return;
+
+  SmallString<128> P(getDriver().Dir);
+  llvm::sys::path::append(P, "..", getTriple().str(), "include/c++/v1");
+  addSystemInclude(DriverArgs, CC1Args, P.str());
+}
+
+void CloudABI::AddCXXStdlibLibArgs(const ArgList &Args,
+                                   ArgStringList &CmdArgs) const {
+  CmdArgs.push_back("-lc++");
+  CmdArgs.push_back("-lc++abi");
+  CmdArgs.push_back("-lunwind");
+}
+
+Tool *CloudABI::buildLinker() const { return new tools::cloudabi::Link(*this); }
+
 /// OpenBSD - OpenBSD tool chain which can call as(1) and ld(1) directly.
 
 OpenBSD::OpenBSD(const Driver &D, const llvm::Triple& Triple, const ArgList &Args)
Index: cfe/trunk/lib/Driver/Tools.h
===================================================================
--- cfe/trunk/lib/Driver/Tools.h
+++ cfe/trunk/lib/Driver/Tools.h
@@ -248,6 +248,22 @@
   bool hasPPCAbiArg(const llvm::opt::ArgList &Args, const char *Value);
 }
 
+  /// cloudabi -- Directly call GNU Binutils linker
+namespace cloudabi {
+class LLVM_LIBRARY_VISIBILITY Link : public GnuTool {
+public:
+  Link(const ToolChain &TC) : GnuTool("cloudabi::Link", "linker", TC) {}
+
+  bool hasIntegratedCPP() const override { return false; }
+  bool isLinkJob() const override { return true; }
+
+  void ConstructJob(Compilation &C, const JobAction &JA,
+                    const InputInfo &Output, const InputInfoList &Inputs,
+                    const llvm::opt::ArgList &TCArgs,
+                    const char *LinkingOutput) const override;
+};
+} // end namespace cloudabi
+
 namespace darwin {
   llvm::Triple::ArchType getArchTypeForMachOArchName(StringRef Str);
   void setTripleTypeForMachOArchName(llvm::Triple &T, StringRef Str);
Index: cfe/trunk/lib/Driver/Tools.cpp
===================================================================
--- cfe/trunk/lib/Driver/Tools.cpp
+++ cfe/trunk/lib/Driver/Tools.cpp
@@ -5725,6 +5725,76 @@
   return Args.MakeArgString(Res + ".d");
 }
 
+void cloudabi::Link::ConstructJob(Compilation &C, const JobAction &JA,
+                                  const InputInfo &Output,
+                                  const InputInfoList &Inputs,
+                                  const ArgList &Args,
+                                  const char *LinkingOutput) const {
+  const ToolChain &ToolChain = getToolChain();
+  const Driver &D = ToolChain.getDriver();
+  ArgStringList CmdArgs;
+
+  // Silence warning for "clang -g foo.o -o foo"
+  Args.ClaimAllArgs(options::OPT_g_Group);
+  // and "clang -emit-llvm foo.o -o foo"
+  Args.ClaimAllArgs(options::OPT_emit_llvm);
+  // and for "clang -w foo.o -o foo". Other warning options are already
+  // handled somewhere else.
+  Args.ClaimAllArgs(options::OPT_w);
+
+  if (!D.SysRoot.empty())
+    CmdArgs.push_back(Args.MakeArgString("--sysroot=" + D.SysRoot));
+
+  // CloudABI only supports static linkage.
+  CmdArgs.push_back("-Bstatic");
+  CmdArgs.push_back("--eh-frame-hdr");
+  CmdArgs.push_back("--gc-sections");
+
+  if (Output.isFilename()) {
+    CmdArgs.push_back("-o");
+    CmdArgs.push_back(Output.getFilename());
+  } else {
+    assert(Output.isNothing() && "Invalid output.");
+  }
+
+  if (!Args.hasArg(options::OPT_nostdlib) &&
+      !Args.hasArg(options::OPT_nostartfiles)) {
+    CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crt0.o")));
+    CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crtbegin.o")));
+  }
+
+  Args.AddAllArgs(CmdArgs, options::OPT_L);
+  const ToolChain::path_list &Paths = ToolChain.getFilePaths();
+  for (const auto &Path : Paths)
+    CmdArgs.push_back(Args.MakeArgString(StringRef("-L") + Path));
+  Args.AddAllArgs(CmdArgs, options::OPT_T_Group);
+  Args.AddAllArgs(CmdArgs, options::OPT_e);
+  Args.AddAllArgs(CmdArgs, options::OPT_s);
+  Args.AddAllArgs(CmdArgs, options::OPT_t);
+  Args.AddAllArgs(CmdArgs, options::OPT_Z_Flag);
+  Args.AddAllArgs(CmdArgs, options::OPT_r);
+
+  if (D.IsUsingLTO(ToolChain, Args))
+    AddGoldPlugin(ToolChain, Args, CmdArgs);
+
+  AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs);
+
+  if (!Args.hasArg(options::OPT_nostdlib) &&
+      !Args.hasArg(options::OPT_nodefaultlibs)) {
+    if (D.CCCIsCXX())
+      ToolChain.AddCXXStdlibLibArgs(Args, CmdArgs);
+    CmdArgs.push_back("-lc");
+    CmdArgs.push_back("-lcompiler_rt");
+  }
+
+  if (!Args.hasArg(options::OPT_nostdlib) &&
+      !Args.hasArg(options::OPT_nostartfiles))
+    CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crtend.o")));
+
+  const char *Exec = Args.MakeArgString(ToolChain.GetLinkerPath());
+  C.addCommand(llvm::make_unique<Command>(JA, *this, Exec, CmdArgs));
+}
+
 void darwin::Assemble::ConstructJob(Compilation &C, const JobAction &JA,
                                     const InputInfo &Output,
                                     const InputInfoList &Inputs,
Index: cfe/trunk/test/Driver/cloudabi.c
===================================================================
--- cfe/trunk/test/Driver/cloudabi.c
+++ cfe/trunk/test/Driver/cloudabi.c
@@ -0,0 +1,3 @@
+// RUN: %clang %s -### -target x86_64-unknown-cloudabi 2>&1 | FileCheck %s
+// CHECK: "-cc1" "-triple" "x86_64-unknown-cloudabi"
+// CHECK: "-Bstatic" "--eh-frame-hdr" "--gc-sections" "-o" "a.out" "crt0.o" "crtbegin.o" "{{.*}}" "{{.*}}" "-lc" "-lcompiler_rt" "crtend.o"
Index: cfe/trunk/test/Driver/cloudabi.cpp
===================================================================
--- cfe/trunk/test/Driver/cloudabi.cpp
+++ cfe/trunk/test/Driver/cloudabi.cpp
@@ -0,0 +1,3 @@
+// RUN: %clangxx %s -### -target x86_64-unknown-cloudabi 2>&1 | FileCheck %s
+// CHECK: "-cc1" "-triple" "x86_64-unknown-cloudabi"
+// CHECK: "-Bstatic" "--eh-frame-hdr" "--gc-sections" "-o" "a.out" "crt0.o" "crtbegin.o" "{{.*}}" "{{.*}}" "-lc++" "-lc++abi" "-lunwind" "-lc" "-lcompiler_rt" "crtend.o"