Index: ELF/Driver.h
===================================================================
--- ELF/Driver.h
+++ ELF/Driver.h
@@ -20,8 +20,12 @@
 
 extern class LinkerDriver *Driver;
 
-// Entry point of the ELF linker.
-void link(ArrayRef<const char *> Args);
+// An entry point of the ELF linker. It is not guranteed that the
+// function will return.
+void linkOrFail(ArrayRef<const char *> Args);
+
+// The other entry point of the ELF linker which is guaranteed to return.
+bool link(llvm::ArrayRef<const char *> Args, raw_ostream &Diag);
 
 class LinkerDriver {
 public:
Index: ELF/Driver.cpp
===================================================================
--- ELF/Driver.cpp
+++ ELF/Driver.cpp
@@ -29,7 +29,7 @@
 Configuration *elf2::Config;
 LinkerDriver *elf2::Driver;
 
-void elf2::link(ArrayRef<const char *> Args) {
+void elf2::linkOrFail(ArrayRef<const char *> Args) {
   Configuration C;
   LinkerDriver D;
   Config = &C;
Index: ELF/DriverUtils.cpp
===================================================================
--- ELF/DriverUtils.cpp
+++ ELF/DriverUtils.cpp
@@ -19,7 +19,9 @@
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Path.h"
+#include "llvm/Support/Program.h"
 #include "llvm/Support/StringSaver.h"
+#include "llvm/Support/raw_ostream.h"
 
 using namespace llvm;
 
@@ -118,3 +120,48 @@
     sys::path::append(Path, Dir, File);
   return Path.str();
 }
+
+// Returns LLD's path on the file system.
+static ErrorOr<std::string> getLldExecutable(StringRef Arg0) {
+  // First, look for "lld" from the current executable directory.
+  // (P just needs to be some symbol in the binary.)
+  void *P = (void *)(intptr_t)getLldExecutable;
+  SmallString<128> Dir;
+  Dir = sys::fs::getMainExecutable(Arg0.data(), &P);
+  sys::path::remove_filename(Dir);
+  if (ErrorOr<std::string> S = sys::findProgramByName("lld", {Dir}))
+    return S;
+
+  // If not found, look for "lld" from $PATH.
+  return sys::findProgramByName("lld");
+}
+
+// This is a wrapper for linkOrFail(). Unlike linkOrFail(),
+// this function always returns.
+bool elf2::link(ArrayRef<const char *> Args, raw_ostream &Diag) {
+  // "-lld-no-exec" is the marker that we are in a subprocess.
+  if (Args.size() > 1 && Args[1] == StringRef("-lld-no-exec")) {
+    std::vector<const char *> Argv(Args.begin(), Args.end());
+    Argv.erase(Argv.begin() + 1);
+    linkOrFail(Argv);
+    exit(0);
+  }
+
+  // We want to build arguments such that lld -flavor gnu Args[1]...
+  ErrorOr<std::string> ExeOrErr = getLldExecutable(Args[0]);
+  if (!ExeOrErr) {
+    Diag << "lld is not found\n";
+    return false;
+  }
+  const char *Exe = ExeOrErr->data();
+  std::vector<const char *> Argv = {Exe, "-flavor", "gnu", "-lld-no-exec"};
+  Argv.insert(Argv.end(), Args.begin() + 1, Args.end());
+  Argv.push_back(nullptr);
+
+  // Start a subprocess and return its result.
+  std::string ErrMsg;
+  int Status =
+      sys::ExecuteAndWait(Exe, Argv.data(), nullptr, nullptr, 0, 0, &ErrMsg);
+  Diag << ErrMsg;
+  return !Status;
+}
Index: include/lld/Driver/Driver.h
===================================================================
--- include/lld/Driver/Driver.h
+++ include/lld/Driver/Driver.h
@@ -125,7 +125,12 @@
 }
 
 namespace elf2 {
-void link(llvm::ArrayRef<const char *> args);
+// An entry point for the internal use. It is not guaranteed to return.
+void linkOrFail(llvm::ArrayRef<const char *> args);
+
+// If you want to call LLD ELF's main from your program, use this function.
+// It is guaranteed to return. Returns true on success.
+bool link(llvm::ArrayRef<const char *> args, raw_ostream &diag = llvm::errs());
 }
 
 /// Driver for lld unit tests
Index: lib/Driver/UniversalDriver.cpp
===================================================================
--- lib/Driver/UniversalDriver.cpp
+++ lib/Driver/UniversalDriver.cpp
@@ -205,7 +205,7 @@
   case Flavor::old_gnu_ld:
     return GnuLdDriver::linkELF(args, diagnostics);
   case Flavor::gnu_ld:
-    elf2::link(args);
+    elf2::linkOrFail(args);
     return true;
   case Flavor::darwin_ld:
     return DarwinLdDriver::linkMachO(args, diagnostics);