1 files changed, 109 insertions, 0 deletions
diff --git a/lld/lib/Driver/UniversalDriver.cpp b/lld/lib/Driver/UniversalDriver.cpp
new file mode 100644
index 00000000000..5164f9da69c
--- /dev/null
+++ b/lld/lib/Driver/UniversalDriver.cpp
@@ -0,0 +1,109 @@
+//===- lib/Driver/UniversalDriver.cpp -------------------------------------===//
+//
+//                             The LLVM Linker
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+///
+/// Concrete instance of the Driver for darwin's ld.
+///
+//===----------------------------------------------------------------------===//
+
+#include "lld/Driver/Driver.h"
+#include "lld/ReaderWriter/MachOTargetInfo.h"
+
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/Triple.h"
+#include "llvm/Option/Arg.h"
+#include "llvm/Option/Option.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/Host.h"
+#include "llvm/Support/ManagedStatic.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/Signals.h"
+
+#include <memory>
+
+namespace lld {
+
+
+bool UniversalDriver::link(int argc, const char *argv[]) {
+  // Convert argv[] C-array to vector.
+  std::vector<const char *> args;
+  args.assign(&argv[0], &argv[argc]);
+  
+  // Determine flavor of link based on command name or -flavor argument.
+  // Note: 'args' is modified to remove -flavor option.
+  Flavor flavor = selectFlavor(args);
+  
+  // Switch to appropriate driver.
+  switch (flavor) {
+  case Flavor::gnu_ld:
+    return GnuLdDriver::linkELF(args.size(), &args[0]);
+  case Flavor::darwin_ld:
+    return DarwinLdDriver::linkMachO(args.size(), &args[0]);
+  case Flavor::core:
+    return CoreDriver::link(args.size(), &args[0]);
+  case Flavor::win_link:
+    llvm_unreachable("Unsupported flavor");
+  case Flavor::invalid:
+    return true;
+  }
+}
+
+
+
+
+
+/// Pick the flavor of driver to use based on the command line and
+/// host environment.
+UniversalDriver::Flavor UniversalDriver::selectFlavor(
+                                              std::vector<const char*> &args) {
+  // -core as first arg is shorthand for -flavor core.
+  if (args.size() >= 1 && StringRef(args[1]) == "-core") {
+    args.erase(args.begin() + 1);
+    return Flavor::core;
+  }
+  // Handle -flavor as first arg.
+  if (args.size() >= 2 && StringRef(args[1]) == "-flavor") {
+    Flavor flavor = strToFlavor(args[2]);
+    args.erase(args.begin() + 1);
+    args.erase(args.begin() + 1);
+    if (flavor == Flavor::invalid)
+      llvm::errs() << "error: '" << args[2] << "' invalid value for -flavor.\n";
+    return flavor;
+  }
+
+  // Check if flavor is at end of program name (e.g. "lld-gnu");
+  SmallVector<StringRef, 3> components;
+  llvm::SplitString(args[0], components, "-");
+  Flavor flavor = strToFlavor(components.back());
+  
+  // If flavor still undetermined, then error out.
+  if (flavor == Flavor::invalid)
+    llvm::errs() << "error: failed to determine driver flavor from program name"
+                    " '" << args[0] << "'.\n";
+  return flavor;
+}
+
+/// Maps flavor strings to Flavor enum values.
+UniversalDriver::Flavor UniversalDriver::strToFlavor(StringRef str) {
+  return llvm::StringSwitch<Flavor>(str)
+           .Case("gnu",    Flavor::gnu_ld)
+           .Case("darwin", Flavor::darwin_ld)
+           .Case("link",   Flavor::win_link)
+           .Case("core",   Flavor::core)
+           .Case("ld",     Flavor::gnu_ld) // deprecated
+           .Default(Flavor::invalid);
+}
+
+
+} // namespace lld