//===--- TargetRegistry.cpp - Target registration -------------------------===//

//

//                     The LLVM Compiler Infrastructure

//

// This file is distributed under the University of Illinois Open Source

// License. See LICENSE.TXT for details.

//

//===----------------------------------------------------------------------===//

#include "llvm/Support/TargetRegistry.h"

#include "llvm/ADT/STLExtras.h"

#include "llvm/ADT/StringRef.h"

#include "llvm/Support/raw_ostream.h"

#include <cassert>

#include <vector>

using namespace llvm_ks;

// Clients are responsible for avoid race conditions in registration.

static Target *FirstTarget = nullptr;

iterator_range<TargetRegistry::iterator> TargetRegistry::targets() {

  return make_range(iterator(FirstTarget), iterator());

}

const Target *TargetRegistry::lookupTarget(const std::string &ArchName,

                                           Triple &TheTriple,

                                           std::string &Error) {

  // Allocate target machine.  First, check whether the user has explicitly

  // specified an architecture to compile for. If so we have to look it up by

  // name, because it might be a backend that has no mapping to a target triple.

  const Target *TheTarget = nullptr;

  if (!ArchName.empty()) {

    auto I =

        std::find_if(targets().begin(), targets().end(),

                     [&](const Target &T) { return ArchName == T.getName(); });

    if (I == targets().end()) {

      Error = "error: invalid target '" + ArchName + "'.\n";

      return nullptr;

    }

    TheTarget = &*I;

    // Adjust the triple to match (if known), otherwise stick with the

    // given triple.

    Triple::ArchType Type = Triple::getArchTypeForLLVMName(ArchName);

    if (Type != Triple::UnknownArch)

      TheTriple.setArch(Type);

  } else {

    // Get the target specific parser.

    std::string TempError;

    TheTarget = TargetRegistry::lookupTarget(TheTriple.getTriple(), TempError);

    if (!TheTarget) {

      Error = ": error: unable to get target for '"

            + TheTriple.getTriple()

            + "', see --version and --triple.\n";

      return nullptr;

    }

  }

  return TheTarget;

}

const Target *TargetRegistry::lookupTarget(const std::string &TT,

                                           std::string &Error) {

  // Provide special warning when no targets are initialized.

  if (targets().begin() == targets().end()) {

    Error = "Unable to find target for this triple (no targets are registered)";

    return nullptr;

  }

  Triple::ArchType Arch = Triple(TT).getArch();

  auto ArchMatch = [&](const Target &T) { return T.ArchMatchFn(Arch); };

  auto I = std::find_if(targets().begin(), targets().end(), ArchMatch);

  if (I == targets().end()) {

    Error = "No available targets are compatible with this triple.";

    return nullptr;

  }

  auto J = std::find_if(std::next(I), targets().end(), ArchMatch);

  if (J != targets().end()) {

    Error = std::string("Cannot choose between targets \"") + I->Name +

            "\" and \"" + J->Name + "\"";

    return nullptr;

  }

  return &*I;

}

void TargetRegistry::RegisterTarget(Target &T,

                                    const char *Name,

                                    const char *ShortDesc,

                                    Target::ArchMatchFnTy ArchMatchFn) {

  assert(Name && ShortDesc && ArchMatchFn &&

         "Missing required target information!");

  // Check if this target has already been initialized, we allow this as a

  // convenience to some clients.

  if (T.Name)

    return;

  // Add to the list of targets.

  T.Next = FirstTarget;

  FirstTarget = &T;

  T.Name = Name;

  T.ShortDesc = ShortDesc;

  T.ArchMatchFn = ArchMatchFn;

}

static int TargetArraySortFn(const std::pair<StringRef, const Target *> *LHS,

                             const std::pair<StringRef, const Target *> *RHS) {

  return LHS->first.compare(RHS->first);

}

void TargetRegistry::printRegisteredTargetsForVersion() {

  std::vector<std::pair<StringRef, const Target*> > Targets;

  size_t Width = 0;

  for (const auto &T : TargetRegistry::targets()) {

    Targets.push_back(std::make_pair(T.getName(), &T));

    Width = std::max(Width, Targets.back().first.size());

  }

  array_pod_sort(Targets.begin(), Targets.end(), TargetArraySortFn);

  raw_ostream &OS = outs();

  OS << "  Registered Targets:\n";

  for (unsigned i = 0, e = Targets.size(); i != e; ++i) {

    OS << "    " << Targets[i].first;

    OS.indent(Width - Targets[i].first.size()) << " - "

      << Targets[i].second->getShortDescription() << '\n';

  }

  if (Targets.empty())

    OS << "    (none)\n";

}