text: //===- ObjCRuntime.cpp - Objective-C Runtime Handling -----------*- C++ -*-===//
  //
  //                     The LLVM Compiler Infrastructure
  //
  // This file is distributed under the University of Illinois Open Source
  // License. See LICENSE.TXT for details.
  //
  //===----------------------------------------------------------------------===//
  //
  // This file implements the ObjCRuntime class, which represents the
  // target Objective-C runtime.
  //
  //===----------------------------------------------------------------------===//
  
  #include "clang/Basic/ObjCRuntime.h"
  #include "llvm/Support/raw_ostream.h"
  //                                                                           //
  ///////////////////////////////////////////////////////////////////////////////
  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::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 == "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;
  }
  