Index: llvm/trunk/include/llvm/ADT/Triple.h
===================================================================
--- llvm/trunk/include/llvm/ADT/Triple.h
+++ llvm/trunk/include/llvm/ADT/Triple.h
@@ -144,6 +144,7 @@
     Darwin,
     DragonFly,
     FreeBSD,
+    Fuchsia,
     IOS,
     KFreeBSD,
     Linux,
@@ -462,6 +463,10 @@
     return getOS() == Triple::FreeBSD;
   }
 
+  bool isOSFuchsia() const {
+    return getOS() == Triple::Fuchsia;
+  }
+
   bool isOSDragonFly() const { return getOS() == Triple::DragonFly; }
 
   bool isOSSolaris() const {
Index: llvm/trunk/lib/Support/Triple.cpp
===================================================================
--- llvm/trunk/lib/Support/Triple.cpp
+++ llvm/trunk/lib/Support/Triple.cpp
@@ -168,6 +168,7 @@
   case Darwin: return "darwin";
   case DragonFly: return "dragonfly";
   case FreeBSD: return "freebsd";
+  case Fuchsia: return "fuchsia";
   case IOS: return "ios";
   case KFreeBSD: return "kfreebsd";
   case Linux: return "linux";
@@ -438,6 +439,7 @@
     .StartsWith("darwin", Triple::Darwin)
     .StartsWith("dragonfly", Triple::DragonFly)
     .StartsWith("freebsd", Triple::FreeBSD)
+    .StartsWith("fuchsia", Triple::Fuchsia)
     .StartsWith("ios", Triple::IOS)
     .StartsWith("kfreebsd", Triple::KFreeBSD)
     .StartsWith("linux", Triple::Linux)
Index: llvm/trunk/lib/Target/X86/X86TargetMachine.cpp
===================================================================
--- llvm/trunk/lib/Target/X86/X86TargetMachine.cpp
+++ llvm/trunk/lib/Target/X86/X86TargetMachine.cpp
@@ -54,6 +54,8 @@
     return make_unique<X86FreeBSDTargetObjectFile>();
   if (TT.isOSLinux() || TT.isOSNaCl())
     return make_unique<X86LinuxNaClTargetObjectFile>();
+  if (TT.isOSFuchsia())
+    return make_unique<X86FuchsiaTargetObjectFile>();
   if (TT.isOSBinFormatELF())
     return make_unique<X86ELFTargetObjectFile>();
   if (TT.isKnownWindowsMSVCEnvironment() || TT.isWindowsCoreCLREnvironment())
Index: llvm/trunk/lib/Target/X86/X86TargetObjectFile.h
===================================================================
--- llvm/trunk/lib/Target/X86/X86TargetObjectFile.h
+++ llvm/trunk/lib/Target/X86/X86TargetObjectFile.h
@@ -55,6 +55,11 @@
     void Initialize(MCContext &Ctx, const TargetMachine &TM) override;
   };
 
+  /// \brief This implementation is used for Fuchsia on x86-64.
+  class X86FuchsiaTargetObjectFile : public X86ELFTargetObjectFile {
+    void Initialize(MCContext &Ctx, const TargetMachine &TM) override;
+  };
+
   /// X86LinuxNaClTargetObjectFile - This implementation is used for linux and
   /// Native Client on x86 and x86-64.
   class X86LinuxNaClTargetObjectFile : public X86ELFTargetObjectFile {
Index: llvm/trunk/lib/Target/X86/X86TargetObjectFile.cpp
===================================================================
--- llvm/trunk/lib/Target/X86/X86TargetObjectFile.cpp
+++ llvm/trunk/lib/Target/X86/X86TargetObjectFile.cpp
@@ -73,6 +73,13 @@
 }
 
 void
+X86FuchsiaTargetObjectFile::Initialize(MCContext &Ctx,
+                                       const TargetMachine &TM) {
+  TargetLoweringObjectFileELF::Initialize(Ctx, TM);
+  InitializeELF(TM.Options.UseInitArray);
+}
+
+void
 X86LinuxNaClTargetObjectFile::Initialize(MCContext &Ctx,
                                          const TargetMachine &TM) {
   TargetLoweringObjectFileELF::Initialize(Ctx, TM);
Index: llvm/trunk/unittests/ADT/TripleTest.cpp
===================================================================
--- llvm/trunk/unittests/ADT/TripleTest.cpp
+++ llvm/trunk/unittests/ADT/TripleTest.cpp
@@ -200,6 +200,12 @@
   EXPECT_EQ(Triple::CloudABI, T.getOS());
   EXPECT_EQ(Triple::UnknownEnvironment, T.getEnvironment());
 
+  T = Triple("x86_64-unknown-fuchsia");
+  EXPECT_EQ(Triple::x86_64, T.getArch());
+  EXPECT_EQ(Triple::UnknownVendor, T.getVendor());
+  EXPECT_EQ(Triple::Fuchsia, T.getOS());
+  EXPECT_EQ(Triple::UnknownEnvironment, T.getEnvironment());
+
   T = Triple("wasm32-unknown-unknown");
   EXPECT_EQ(Triple::wasm32, T.getArch());
   EXPECT_EQ(Triple::UnknownVendor, T.getVendor());