//===- ObjCRuntime.cpp - Objective-C Runtime Handling ---------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements the ObjCRuntime class, which represents the
// target Objective-C runtime.
//
//===----------------------------------------------------------------------===//

#include "clang/Basic/ObjCRuntime.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/VersionTuple.h"
#include "llvm/Support/raw_ostream.h"
#include <cstddef>
#include <string>

using namespace clang;

std::string ObjCRuntime::getAsString() const {
  std::string Result;
  {
    llvm::raw_string_ostream Out(Result);
    Out << *this;
  }
  return Result;
}

raw_ostream &clang::operator<<(raw_ostream &out, const ObjCRuntime &value) {
  switch (value.getKind()) {
  case ObjCRuntime::MacOSX: out << "macosx"; break;
  case ObjCRuntime::FragileMacOSX: out << "macosx-fragile"; break;
  case ObjCRuntime::iOS: out << "ios"; break;
  case ObjCRuntime::WatchOS: out << "watchos"; break;
  case ObjCRuntime::GNUstep: out << "gnustep"; break;
  case ObjCRuntime::GCC: out << "gcc"; break;
  case ObjCRuntime::ObjFW: out << "objfw"; break;
  }
  if (value.getVersion() > VersionTuple(0)) {
    out << '-' << value.getVersion();
  }
  return out;
}

bool ObjCRuntime::tryParse(StringRef input) {
  // Look for the last dash.
  std::size_t dash = input.rfind('-');

  // We permit dashes in the runtime name, and we also permit the
  // version to be omitted, so if we see a dash not followed by a
  // digit then we need to ignore it.
  if (dash != StringRef::npos && dash + 1 != input.size() &&
      (input[dash+1] < '0' || input[dash+1] > '9')) {
    dash = StringRef::npos;
  }

  // Everything prior to that must be a valid string name.
  Kind kind;
  StringRef runtimeName = input.substr(0, dash);
  Version = VersionTuple(0);
  if (runtimeName == "macosx") {
    kind = ObjCRuntime::MacOSX;
  } else if (runtimeName == "macosx-fragile") {
    kind = ObjCRuntime::FragileMacOSX;
  } else if (runtimeName == "ios") {
    kind = ObjCRuntime::iOS;
  } else if (runtimeName == "watchos") {
    kind = ObjCRuntime::WatchOS;
  } else if (runtimeName == "gnustep") {
    // If no version is specified then default to the most recent one that we
    // know about.
    Version = VersionTuple(1, 6);
    kind = ObjCRuntime::GNUstep;
  } else if (runtimeName == "gcc") {
    kind = ObjCRuntime::GCC;
  } else if (runtimeName == "objfw") {
    kind = ObjCRuntime::ObjFW;
    Version = VersionTuple(0, 8);
  } else {
    return true;
  }
  TheKind = kind;

  if (dash != StringRef::npos) {
    StringRef verString = input.substr(dash + 1);
    if (Version.tryParse(verString))
      return true;
  }

  if (kind == ObjCRuntime::ObjFW && Version > VersionTuple(0, 8))
    Version = VersionTuple(0, 8);

  return false;
}