text: //===--- HeaderSearchOptions.h ----------------------------------*- C++ -*-===//
  //
  //                     The LLVM Compiler Infrastructure
  //
  // This file is distributed under the University of Illinois Open Source
  // License. See LICENSE.TXT for details.
  //
  //===----------------------------------------------------------------------===//
  
  #ifndef LLVM_CLANG_LEX_HEADERSEARCHOPTIONS_H
  #define LLVM_CLANG_LEX_HEADERSEARCHOPTIONS_H
  
  #include "clang/Basic/LLVM.h"
  #include "llvm/ADT/IntrusiveRefCntPtr.h"
  #include "llvm/ADT/SetVector.h"
  #include "llvm/ADT/StringRef.h"
  #include <string>
  #include <vector>
  
  namespace clang {
  
  namespace frontend {
    /// IncludeDirGroup - Identifiers the group a include entry belongs to, which
    /// represents its relative positive in the search list.  A \#include of a ""
    /// path starts at the -iquote group, then searches the Angled group, then
    /// searches the system group, etc.
    enum IncludeDirGroup {
      Quoted = 0,     ///< '\#include ""' paths, added by 'gcc -iquote'.
      Angled,         ///< Paths for '\#include <>' added by '-I'.
      IndexHeaderMap, ///< Like Angled, but marks header maps used when
                         ///  building frameworks.
      System,         ///< Like Angled, but marks system directories.
      ExternCSystem,  ///< Like System, but headers are implicitly wrapped in
                      ///  extern "C".
      CSystem,        ///< Like System, but only used for C.
      CXXSystem,      ///< Like System, but only used for C++.
      ObjCSystem,     ///< Like System, but only used for ObjC.
      ObjCXXSystem,   ///< Like System, but only used for ObjC++.
      After           ///< Like System, but searched after the system directories.
    };
  }
  
  /// HeaderSearchOptions - Helper class for storing options related to the
  /// initialization of the HeaderSearch object.
  class HeaderSearchOptions : public RefCountedBase<HeaderSearchOptions> {
  public:
    struct Entry {
      std::string Path;
      frontend::IncludeDirGroup Group;
      unsigned IsFramework : 1;
      
      /// IgnoreSysRoot - This is false if an absolute path should be treated
      /// relative to the sysroot, or true if it should always be the absolute
      /// path.
      unsigned IgnoreSysRoot : 1;
  
      Entry(StringRef path, frontend::IncludeDirGroup group, bool isFramework,
            bool ignoreSysRoot)
        : Path(path), Group(group), IsFramework(isFramework),
          IgnoreSysRoot(ignoreSysRoot) {}
    };
  
    struct SystemHeaderPrefix {
      /// A prefix to be matched against paths in \#include directives.
      std::string Prefix;
  
      /// True if paths beginning with this prefix should be treated as system
      /// headers.
      bool IsSystemHeader;
  
      SystemHeaderPrefix(StringRef Prefix, bool IsSystemHeader)
        : Prefix(Prefix), IsSystemHeader(IsSystemHeader) {}
    };
  
    /// If non-empty, the directory to use as a "virtual system root" for include
    /// paths.
    std::string Sysroot;
  
    /// User specified include entries.
    std::vector<Entry> UserEntries;
  
    /// User-specified system header prefixes.
    std::vector<SystemHeaderPrefix> SystemHeaderPrefixes;
  
    /// The directory which holds the compiler resource files (builtin includes,
    /// etc.).
    std::string ResourceDir;
  
    /// \brief The directory used for the module cache.
    std::string ModuleCachePath;
  
    /// \brief The directory used for a user build.
    std::string ModuleUserBuildPath;
  
    /// \brief Whether we should disable the use of the hash string within the
    /// module cache.
    ///
    /// Note: Only used for testing!
    unsigned DisableModuleHash : 1;
  
    /// \brief Interpret module maps.  This option is implied by full modules.
    unsigned ModuleMaps : 1;
  
    /// \brief The interval (in seconds) between pruning operations.
    ///
    /// This operation is expensive, because it requires Clang to walk through
    /// the directory structure of the module cache, stat()'ing and removing
    /// files.
    ///
    /// The default value is large, e.g., the operation runs once a week.
    unsigned ModuleCachePruneInterval;
  
    /// \brief The time (in seconds) after which an unused module file will be
    /// considered unused and will, therefore, be pruned.
    ///
    /// When the module cache is pruned, any module file that has not been
    /// accessed in this many seconds will be removed. The default value is
    /// large, e.g., a month, to avoid forcing infrequently-used modules to be
    /// regenerated often.
    unsigned ModuleCachePruneAfter;
  
    /// \brief The time in seconds when the build session started.
    ///
    /// This time is used by other optimizations in header search and module
    /// loading.
    uint64_t BuildSessionTimestamp;
  
    /// \brief The set of macro names that should be ignored for the purposes
    /// of computing the module hash.
    llvm::SetVector<std::string> ModulesIgnoreMacros;
  
    /// \brief The set of user-provided module-map-files.
    llvm::SetVector<std::string> ModuleMapFiles;
  
    /// \brief The set of user-provided virtual filesystem overlay files.
    std::vector<std::string> VFSOverlayFiles;
  
    /// Include the compiler builtin includes.
    unsigned UseBuiltinIncludes : 1;
  
    /// Include the system standard include search directories.
    unsigned UseStandardSystemIncludes : 1;
  
    /// Include the system standard C++ library include search directories.
    unsigned UseStandardCXXIncludes : 1;
  
    /// Use libc++ instead of the default libstdc++.
    unsigned UseLibcxx : 1;
  
    /// Whether header search information should be output as for -v.
    unsigned Verbose : 1;
  
    /// \brief If true, skip verifying input files used by modules if the
    /// module was already verified during this build session (see
    /// \c BuildSessionTimestamp).
    unsigned ModulesValidateOncePerBuildSession : 1;
  
    /// \brief Whether to validate system input files when a module is loaded.
    unsigned ModulesValidateSystemHeaders : 1;
  
  public:
    HeaderSearchOptions(StringRef _Sysroot = "/")
      : Sysroot(_Sysroot), DisableModuleHash(0), ModuleMaps(0),
        ModuleCachePruneInterval(7*24*60*60),
        ModuleCachePruneAfter(31*24*60*60),
        BuildSessionTimestamp(0),
        UseBuiltinIncludes(true),
        UseStandardSystemIncludes(true), UseStandardCXXIncludes(true),
        UseLibcxx(false), Verbose(false),
        ModulesValidateOncePerBuildSession(false),
        ModulesValidateSystemHeaders(false) {}
  
    /// AddPath - Add the \p Path path to the specified \p Group list.
    void AddPath(StringRef Path, frontend::IncludeDirGroup Group,
                 bool IsFramework, bool IgnoreSysRoot) {
      UserEntries.push_back(Entry(Path, Group, IsFramework, IgnoreSysRoot));
    }
  
    /// AddSystemHeaderPrefix - Override whether \#include directives naming a
    /// path starting with \p Prefix should be considered as naming a system
    /// header.
    void AddSystemHeaderPrefix(StringRef Prefix, bool IsSystemHeader) {
      SystemHeaderPrefixes.push_back(SystemHeaderPrefix(Prefix, IsSystemHeader));
    }
  
    void AddVFSOverlayFile(StringRef Name) {
      VFSOverlayFiles.push_back(Name);
    }
  };
  
  } // end namespace clang
  
  #endif
  