Index: lib/Basic/Targets.cpp
===================================================================
--- lib/Basic/Targets.cpp
+++ lib/Basic/Targets.cpp
@@ -823,6 +823,28 @@
   }
 };
 
+// Fuchsia Target
+template<typename Target>
+class FuchsiaTargetInfo : public OSTargetInfo<Target> {
+protected:
+  void getOSDefines(const LangOptions &Opts, const llvm::Triple &Triple,
+                    MacroBuilder &Builder) const override {
+    Builder.defineMacro("__Fuchsia__");
+    Builder.defineMacro("__ELF__");
+    if (Opts.POSIXThreads)
+      Builder.defineMacro("_REENTRANT");
+    // Required by the libc++ locale support.
+    if (Opts.CPlusPlus)
+      Builder.defineMacro("_GNU_SOURCE");
+  }
+public:
+  FuchsiaTargetInfo(const llvm::Triple &Triple,
+                    const TargetOptions &Opts)
+      : OSTargetInfo<Target>(Triple, Opts) {
+    this->MCountName = "__mcount";
+  }
+};
+
 // WebAssembly target
 template <typename Target>
 class WebAssemblyOSTargetInfo : public OSTargetInfo<Target> {
@@ -8263,6 +8285,8 @@
       return new LinuxTargetInfo<AArch64leTargetInfo>(Triple, Opts);
     case llvm::Triple::NetBSD:
       return new NetBSDTargetInfo<AArch64leTargetInfo>(Triple, Opts);
+    case llvm::Triple::Fuchsia:
+      return new FuchsiaTargetInfo<AArch64leTargetInfo>(Triple, Opts);
     default:
       return new AArch64leTargetInfo(Triple, Opts);
     }
@@ -8631,6 +8655,8 @@
       return new HaikuTargetInfo<X86_64TargetInfo>(Triple, Opts);
     case llvm::Triple::NaCl:
       return new NaClTargetInfo<X86_64TargetInfo>(Triple, Opts);
+    case llvm::Triple::Fuchsia:
+      return new FuchsiaTargetInfo<X86_64TargetInfo>(Triple, Opts);
     case llvm::Triple::PS4:
       return new PS4OSTargetInfo<X86_64TargetInfo>(Triple, Opts);
     default:
Index: lib/Driver/Driver.cpp
===================================================================
--- lib/Driver/Driver.cpp
+++ lib/Driver/Driver.cpp
@@ -3077,6 +3077,9 @@
     case llvm::Triple::NaCl:
       TC = new toolchains::NaClToolChain(*this, Target, Args);
       break;
+    case llvm::Triple::Fuchsia:
+      TC = new toolchains::Fuchsia(*this, Target, Args);
+      break;
     case llvm::Triple::Solaris:
       TC = new toolchains::Solaris(*this, Target, Args);
       break;
Index: lib/Driver/ToolChains.h
===================================================================
--- lib/Driver/ToolChains.h
+++ lib/Driver/ToolChains.h
@@ -1008,6 +1008,39 @@
   std::string NaClArmMacrosPath;
 };
 
+class LLVM_LIBRARY_VISIBILITY Fuchsia : public Generic_ELF {
+public:
+  Fuchsia(const Driver &D, const llvm::Triple &Triple,
+          const llvm::opt::ArgList &Args);
+
+  bool isPIEDefault() const override { return true; }
+  bool HasNativeLLVMSupport() const override { return true; }
+  bool IsIntegratedAssemblerDefault() const override { return true; }
+  llvm::DebuggerKind getDefaultDebuggerTuning() const override {
+    return llvm::DebuggerKind::GDB;
+  }
+
+  RuntimeLibType
+  GetRuntimeLibType(const llvm::opt::ArgList &Args) const override;
+  CXXStdlibType
+  GetCXXStdlibType(const llvm::opt::ArgList &Args) const override;
+
+  void addClangTargetOptions(const llvm::opt::ArgList &DriverArgs,
+                             llvm::opt::ArgStringList &CC1Args) const override;
+  void
+  AddClangSystemIncludeArgs(const llvm::opt::ArgList &DriverArgs,
+                            llvm::opt::ArgStringList &CC1Args) const override;
+  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;
+
+protected:
+  Tool *buildAssembler() const override;
+  Tool *buildLinker() const override;
+};
+
 /// TCEToolChain - A tool chain using the llvm bitcode tools to perform
 /// all subcommands. See http://tce.cs.tut.fi for our peculiar target.
 class LLVM_LIBRARY_VISIBILITY TCEToolChain : public ToolChain {
Index: lib/Driver/ToolChains.cpp
===================================================================
--- lib/Driver/ToolChains.cpp
+++ lib/Driver/ToolChains.cpp
@@ -4761,6 +4761,108 @@
   ToolChain::addProfileRTLibs(Args, CmdArgs);
 }
 
+/// Fuchsia - Fuchsia tool chain which can call as(1) and ld(1) directly.
+
+Fuchsia::Fuchsia(const Driver &D, const llvm::Triple &Triple,
+                 const ArgList &Args)
+    : Generic_ELF(D, Triple, Args) {
+
+  getFilePaths().push_back(D.SysRoot + "/lib");
+  getFilePaths().push_back(D.ResourceDir + "/lib/fuchsia");
+
+  // Use LLD by default.
+  DefaultLinker = "lld";
+}
+
+Tool *Fuchsia::buildAssembler() const {
+  return new tools::gnutools::Assembler(*this);
+}
+
+Tool *Fuchsia::buildLinker() const {
+  return new tools::fuchsia::Linker(*this);
+}
+
+ToolChain::RuntimeLibType Fuchsia::GetRuntimeLibType(
+    const ArgList &Args) const {
+  if (Arg *A = Args.getLastArg(options::OPT_rtlib_EQ)) {
+    StringRef Value = A->getValue();
+    if (Value != "compiler-rt")
+      getDriver().Diag(diag::err_drv_invalid_rtlib_name)
+        << A->getAsString(Args);
+  }
+
+  return ToolChain::RLT_CompilerRT;
+}
+
+ToolChain::CXXStdlibType
+Fuchsia::GetCXXStdlibType(const ArgList &Args) const {
+  if (Arg *A = Args.getLastArg(options::OPT_stdlib_EQ)) {
+    StringRef Value = A->getValue();
+    if (Value != "libc++")
+      getDriver().Diag(diag::err_drv_invalid_stdlib_name)
+        << A->getAsString(Args);
+  }
+
+  return ToolChain::CST_Libcxx;
+}
+
+void Fuchsia::addClangTargetOptions(const ArgList &DriverArgs,
+                                    ArgStringList &CC1Args) const {
+  if (DriverArgs.hasFlag(options::OPT_fuse_init_array,
+                         options::OPT_fno_use_init_array, true))
+    CC1Args.push_back("-fuse-init-array");
+}
+
+void Fuchsia::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
+                                        ArgStringList &CC1Args) const {
+  const Driver &D = getDriver();
+
+  if (DriverArgs.hasArg(options::OPT_nostdinc))
+    return;
+
+  if (!DriverArgs.hasArg(options::OPT_nobuiltininc)) {
+    SmallString<128> P(D.ResourceDir);
+    llvm::sys::path::append(P, "include");
+    addSystemInclude(DriverArgs, CC1Args, P);
+  }
+
+  if (DriverArgs.hasArg(options::OPT_nostdlibinc))
+    return;
+
+  // Check for configure-time C include directories.
+  StringRef CIncludeDirs(C_INCLUDE_DIRS);
+  if (CIncludeDirs != "") {
+    SmallVector<StringRef, 5> dirs;
+    CIncludeDirs.split(dirs, ":");
+    for (StringRef dir : dirs) {
+      StringRef Prefix =
+          llvm::sys::path::is_absolute(dir) ? StringRef(D.SysRoot) : "";
+      addExternCSystemInclude(DriverArgs, CC1Args, Prefix + dir);
+    }
+    return;
+  }
+
+  addExternCSystemInclude(DriverArgs, CC1Args, D.SysRoot + "/include");
+}
+
+void Fuchsia::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
+                                           ArgStringList &CC1Args) const {
+  if (DriverArgs.hasArg(options::OPT_nostdlibinc) ||
+      DriverArgs.hasArg(options::OPT_nostdincxx))
+    return;
+
+  addSystemInclude(DriverArgs, CC1Args,
+                   getDriver().SysRoot + "/include/c++/v1");
+}
+
+void Fuchsia::AddCXXStdlibLibArgs(const ArgList &Args,
+                                  ArgStringList &CmdArgs) const {
+  (void) GetCXXStdlibType(Args);
+  CmdArgs.push_back("-lc++");
+  CmdArgs.push_back("-lc++abi");
+  CmdArgs.push_back("-lunwind");
+}
+
 /// DragonFly - DragonFly tool chain which can call as(1) and ld(1) directly.
 
 DragonFly::DragonFly(const Driver &D, const llvm::Triple &Triple,
Index: lib/Driver/Tools.h
===================================================================
--- lib/Driver/Tools.h
+++ lib/Driver/Tools.h
@@ -596,6 +596,21 @@
 };
 } // end namespace nacltools
 
+namespace fuchsia {
+class LLVM_LIBRARY_VISIBILITY Linker : public GnuTool {
+public:
+  Linker(const ToolChain &TC) : GnuTool("fuchsia::Linker", "ld.lld", 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 fuchsia
+
 /// minix -- Directly call GNU Binutils assembler and linker
 namespace minix {
 class LLVM_LIBRARY_VISIBILITY Assembler : public GnuTool {
Index: lib/Driver/Tools.cpp
===================================================================
--- lib/Driver/Tools.cpp
+++ lib/Driver/Tools.cpp
@@ -9493,6 +9493,7 @@
       llvm_unreachable("unsupported OS");
     case llvm::Triple::Win32:
     case llvm::Triple::Linux:
+    case llvm::Triple::Fuchsia:
       addClangRT(TC, Args, CmdArgs);
       break;
     }
@@ -9979,6 +9980,112 @@
   C.addCommand(llvm::make_unique<Command>(JA, *this, Exec, CmdArgs, Inputs));
 }
 
+void fuchsia::Linker::ConstructJob(Compilation &C, const JobAction &JA,
+                                   const InputInfo &Output,
+                                   const InputInfoList &Inputs,
+                                   const ArgList &Args,
+                                   const char *LinkingOutput) const {
+  const toolchains::Fuchsia &ToolChain =
+      static_cast<const toolchains::Fuchsia &>(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);
+
+  const char *Exec = Args.MakeArgString(ToolChain.GetLinkerPath());
+  if (llvm::sys::path::filename(Exec).equals_lower("lld")) {
+    CmdArgs.push_back("-flavor");
+    CmdArgs.push_back("gnu");
+  }
+
+  if (!D.SysRoot.empty())
+    CmdArgs.push_back(Args.MakeArgString("--sysroot=" + D.SysRoot));
+
+  if (!Args.hasArg(options::OPT_shared) && !Args.hasArg(options::OPT_r))
+    CmdArgs.push_back("-pie");
+
+  if (Args.hasArg(options::OPT_rdynamic))
+    CmdArgs.push_back("-export-dynamic");
+
+  if (Args.hasArg(options::OPT_s))
+    CmdArgs.push_back("-s");
+
+  if (Args.hasArg(options::OPT_r))
+    CmdArgs.push_back("-r");
+  else
+    CmdArgs.push_back("--build-id");
+
+  if (!Args.hasArg(options::OPT_static))
+    CmdArgs.push_back("--eh-frame-hdr");
+
+  if (Args.hasArg(options::OPT_static))
+    CmdArgs.push_back("-Bstatic");
+  else if (Args.hasArg(options::OPT_shared))
+    CmdArgs.push_back("-shared");
+
+  if (!Args.hasArg(options::OPT_static)) {
+    if (Args.hasArg(options::OPT_rdynamic))
+      CmdArgs.push_back("-export-dynamic");
+
+    if (!Args.hasArg(options::OPT_shared)) {
+      CmdArgs.push_back("-dynamic-linker");
+      CmdArgs.push_back(Args.MakeArgString(D.DyldPrefix + "ld.so.1"));
+    }
+  }
+
+  CmdArgs.push_back("-o");
+  CmdArgs.push_back(Output.getFilename());
+
+  if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles)) {
+    if (!Args.hasArg(options::OPT_shared)) {
+      CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("Scrt1.o")));
+    }
+  }
+
+  Args.AddAllArgs(CmdArgs, options::OPT_L);
+  Args.AddAllArgs(CmdArgs, options::OPT_u);
+
+  ToolChain.AddFilePathLibArgs(Args, CmdArgs);
+
+  AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs);
+
+  if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) {
+    if (Args.hasArg(options::OPT_static))
+      CmdArgs.push_back("-Bdynamic");
+
+    if (D.CCCIsCXX()) {
+      bool OnlyLibstdcxxStatic = Args.hasArg(options::OPT_static_libstdcxx) &&
+                                 !Args.hasArg(options::OPT_static);
+      if (OnlyLibstdcxxStatic)
+        CmdArgs.push_back("-Bstatic");
+      ToolChain.AddCXXStdlibLibArgs(Args, CmdArgs);
+      if (OnlyLibstdcxxStatic)
+        CmdArgs.push_back("-Bdynamic");
+      CmdArgs.push_back("-lm");
+    }
+
+    AddRunTimeLibs(ToolChain, D, CmdArgs, Args);
+
+    if (Args.hasArg(options::OPT_pthread) ||
+        Args.hasArg(options::OPT_pthreads))
+      CmdArgs.push_back("-lpthread");
+
+    if (Args.hasArg(options::OPT_fsplit_stack))
+      CmdArgs.push_back("--wrap=pthread_create");
+
+    CmdArgs.push_back("-lc");
+  }
+
+  C.addCommand(llvm::make_unique<Command>(JA, *this, Exec, CmdArgs, Inputs));
+}
+
 void minix::Assembler::ConstructJob(Compilation &C, const JobAction &JA,
                                     const InputInfo &Output,
                                     const InputInfoList &Inputs,
Index: test/Driver/fuchsia.c
===================================================================
--- /dev/null
+++ test/Driver/fuchsia.c
@@ -0,0 +1,40 @@
+// RUN: %clang %s -### --target=x86_64-unknown-fuchsia \
+// RUN:     --sysroot=%S/platform 2>&1 | FileCheck %s
+// CHECK: {{.*}}clang{{.*}}" "-cc1"
+// CHECK: "-fuse-init-array"
+// CHECK: "-isysroot" "[[SYSROOT:[^"]+]]"
+// CHECK: "-internal-externc-isystem" "[[SYSROOT]]{{/|\\\\}}include"
+// CHECK: {{.*}}lld{{.*}}" "-flavor" "gnu"
+// CHECK: "--sysroot=[[SYSROOT]]"
+// CHECK: "-pie"
+// CHECK: "--build-id"
+// CHECK: "-dynamic-linker" "ld.so.1"
+// CHECK: Scrt1.o
+// CHECK-NOT: crti.o
+// CHECK-NOT: crtbegin.o
+// CHECK: "-L[[SYSROOT]]/lib"
+// CHECK: "{{.*[/\\]}}libclang_rt.builtins-x86_64.a"
+// CHECK: "-lc"
+// CHECK-NOT: crtend.o
+// CHECK-NOT: crtn.o
+
+// RUN: %clang %s -### --target=x86_64-unknown-fuchsia -rtlib=libgcc 2>&1 \
+// RUN:     | FileCheck %s -check-prefix=CHECK-RTLIB
+// CHECK-RTLIB: error: invalid runtime library name in argument '-rtlib=libgcc'
+
+// RUN: %clang %s -### --target=x86_64-unknown-fuchsia -static 2>&1 \
+// RUN:     | FileCheck %s -check-prefix=CHECK-STATIC
+// CHECK-STATIC: "-Bstatic"
+// CHECK-STATIC: "-Bdynamic"
+// CHECK-STATIC: "-lc"
+
+// RUN: %clang %s -### --target=x86_64-unknown-fuchsia -shared 2>&1 \
+// RUN:     | FileCheck %s -check-prefix=CHECK-SHARED
+// CHECK-SHARED-NOT: "-pie"
+// CHECK-SHARED: "-shared"
+
+// RUN: %clang %s -### --target=x86_64-unknown-fuchsia -r 2>&1 \
+// RUN:     | FileCheck %s -check-prefix=CHECK-RELOCATABLE
+// CHECK-RELOCATABLE-NOT: "-pie"
+// CHECK-RELOCATABLE-NOT: "--build-id"
+// CHECK-RELOCATABLE: "-r"
Index: test/Driver/fuchsia.cpp
===================================================================
--- /dev/null
+++ test/Driver/fuchsia.cpp
@@ -0,0 +1,33 @@
+// RUN: %clangxx %s -### --target=x86_64-unknown-fuchsia \
+// RUN:     --sysroot=%S/platform 2>&1 | FileCheck %s
+// CHECK: {{.*}}clang{{.*}}" "-cc1"
+// CHECK: "-fuse-init-array"
+// CHECK: "-isysroot" "[[SYSROOT:[^"]+]]"
+// CHECK: "-internal-isystem" "[[SYSROOT]]{{/|\\\\}}include{{/|\\\\}}c++{{/|\\\\}}v1"
+// CHECK: "-internal-externc-isystem" "[[SYSROOT]]{{/|\\\\}}include"
+// CHECK: {{.*}}lld{{.*}}" "-flavor" "gnu"
+// CHECK: "--sysroot=[[SYSROOT]]"
+// CHECK: "-pie"
+// CHECK: "--build-id"
+// CHECK: "-dynamic-linker" "ld.so.1"
+// CHECK: Scrt1.o
+// CHECK-NOT: crti.o
+// CHECK-NOT: crtbegin.o
+// CHECK: "-L[[SYSROOT]]/lib"
+// CHECK: "-lc++" "-lc++abi" "-lunwind" "-lm"
+// CHECK: "{{.*[/\\]}}libclang_rt.builtins-x86_64.a"
+// CHECK: "-lc"
+// CHECK-NOT: crtend.o
+// CHECK-NOT: crtn.o
+
+// RUN: %clangxx %s -### --target=x86_64-unknown-fuchsia -stdlib=libstdc++ 2>&1 \
+// RUN:     | FileCheck %s -check-prefix=CHECK-STDLIB
+// CHECK-STDLIB: error: invalid library name in argument '-stdlib=libstdc++'
+
+// RUN: %clangxx %s -### --target=x86_64-unknown-fuchsia -static-libstdc++ 2>&1 \
+// RUN:     | FileCheck %s -check-prefix=CHECK-STATIC
+// CHECK-STATIC: "-Bstatic"
+// CHECK-STATIC: "-lc++" "-lc++abi" "-lunwind"
+// CHECK-STATIC: "-Bdynamic"
+// CHECK-STATIC: "-lm"
+// CHECK-STATIC: "-lc"