Move path and filesystem from build2 to libbutl

43 files changed, 93 insertions, 1627 deletions

diff --git a/build/algorithm b/build/algorithm
index c21457e..5138dfa 100644
--- a/build/algorithm
+++ b/build/algorithm
@@ -5,9 +5,9 @@
 #ifndef BUILD_ALGORITHM
 #define BUILD_ALGORITHM
 
+#include <build/types>
 #include <build/target>
 #include <build/operation>
-#include <build/timestamp>
 
 namespace build
 {
diff --git a/build/algorithm.cxx b/build/algorithm.cxx
index fe85c4e..2529e13 100644
--- a/build/algorithm.cxx
+++ b/build/algorithm.cxx
@@ -11,7 +11,6 @@
 
 #include <butl/utility> // reverse_iterate
 
-#include <build/path>
 #include <build/scope>
 #include <build/target>
 #include <build/prerequisite>
diff --git a/build/b.cxx b/build/b.cxx
index 24f4266..8e75c14 100644
--- a/build/b.cxx
+++ b/build/b.cxx
@@ -16,8 +16,9 @@
 #include <iostream>
 #include <system_error>
 
-#include <build/path>
-#include <build/name>
+#include <butl/filesystem>
+
+#include <build/types>
 #include <build/spec>
 #include <build/operation>
 #include <build/scope>
@@ -30,7 +31,6 @@
 #include <build/diagnostics>
 #include <build/context>
 #include <build/utility>
-#include <build/filesystem>
 
 #include <build/token>
 #include <build/lexer>
diff --git a/build/bin/module b/build/bin/module
index 749ce3f..e09e742 100644
--- a/build/bin/module
+++ b/build/bin/module
@@ -5,7 +5,7 @@
 #ifndef BUILD_BIN_MODULE
 #define BUILD_BIN_MODULE
 
-#include <build/path>
+#include <build/types>
 #include <build/module>
 
 namespace build
diff --git a/build/buildfile b/build/buildfile
index 8b4cb84..4cb9c59 100644
--- a/build/buildfile
+++ b/build/buildfile
@@ -5,9 +5,8 @@ bin = bin/{target rule module}
 cxx = cxx/{target rule module}
 
 exe{b}: cxx{b algorithm name operation spec scope variable target \
-  prerequisite rule file module context search diagnostics token \
-  lexer parser timestamp path path-io utility filesystem dump options \
-  $config $bin $cxx} $libs
+  prerequisite rule file module context search diagnostics token  \
+  lexer parser path-io utility dump options $config $bin $cxx} $libs
 
 #@@ TODO
 #
diff --git a/build/config/module b/build/config/module
index 317b25a..4ab3e7e 100644
--- a/build/config/module
+++ b/build/config/module
@@ -5,6 +5,7 @@
 #ifndef BUILD_CONFIG_MODULE
 #define BUILD_CONFIG_MODULE
 
+#include <build/types>
 #include <build/module>
 
 namespace build
diff --git a/build/config/module.cxx b/build/config/module.cxx
index ab7ed4e..7ac9071 100644
--- a/build/config/module.cxx
+++ b/build/config/module.cxx
@@ -4,15 +4,16 @@
 
 #include <build/config/module>
 
-#include <build/path>
+#include <butl/filesystem>
+
 #include <build/scope>
 #include <build/file>
-#include <build/filesystem>
 #include <build/diagnostics>
 
 #include <build/config/operation>
 
 using namespace std;
+using namespace butl;
 
 namespace build
 {
diff --git a/build/config/operation.cxx b/build/config/operation.cxx
index 567e636..89bef61 100644
--- a/build/config/operation.cxx
+++ b/build/config/operation.cxx
@@ -6,13 +6,15 @@
 
 #include <fstream>
 
+#include <butl/filesystem>
+
 #include <build/scope>
 #include <build/file>
 #include <build/context>
-#include <build/filesystem>
 #include <build/diagnostics>
 
 using namespace std;
+using namespace butl;
 
 namespace build
 {
diff --git a/build/context b/build/context
index 3a99014..dc865d2 100644
--- a/build/context
+++ b/build/context
@@ -8,10 +8,11 @@
 #include <string>
 #include <ostream>
 
-#include <build/path>
+#include <butl/filesystem>
+
+#include <build/types>
 #include <build/rule>
 #include <build/operation>
-#include <build/filesystem>
 
 namespace build
 {
@@ -37,7 +38,7 @@ namespace build
 
   // The dual interface wrapper for the {mk,rm}{file,dir}() functions
   // below that allows you to use it as a true/false return or a more
-  // detailed enum from <filesystem>
+  // detailed enum from <butl/filesystem>
   //
   template <typename T>
   struct fs_status
@@ -53,7 +54,7 @@ namespace build
   // directory will exist in the majority of case and performance is
   // important. See the fsdir{} rule for details.
   //
-  fs_status<mkdir_status>
+  fs_status<butl::mkdir_status>
   mkdir (const dir_path&);
 
   // Remove the file and print the standard diagnostics. The second
@@ -62,19 +63,19 @@ namespace build
   // being printed.
   //
   template <typename T>
-  fs_status<rmfile_status>
+  fs_status<butl::rmfile_status>
   rmfile (const path&, const T& target);
 
-  inline fs_status<rmfile_status>
+  inline fs_status<butl::rmfile_status>
   rmfile (const path& f) {return rmfile (f, f);}
 
   // Similar to rmfile() but for directories.
   //
   template <typename T>
-  fs_status<rmdir_status>
+  fs_status<butl::rmdir_status>
   rmdir (const dir_path&, const T& target);
 
-  inline fs_status<rmdir_status>
+  inline fs_status<butl::rmdir_status>
   rmdir (const dir_path& d) {return rmdir (d, d);}
 
   // Return the src/out directory corresponding to the given out/src. The
diff --git a/build/context.cxx b/build/context.cxx
index 7769c94..22b6f53 100644
--- a/build/context.cxx
+++ b/build/context.cxx
@@ -12,6 +12,7 @@
 #include <build/diagnostics>
 
 using namespace std;
+using namespace butl;
 
 namespace build
 {
diff --git a/build/context.txx b/build/context.txx
index 286d460..b9004e0 100644
--- a/build/context.txx
+++ b/build/context.txx
@@ -9,9 +9,11 @@
 namespace build
 {
   template <typename T>
-  fs_status<rmfile_status>
+  fs_status<butl::rmfile_status>
   rmfile (const path& f, const T& t)
   {
+    using namespace butl;
+
     // We don't want to print the command if we couldn't remove the
     // file because it does not exist (just like we don't print the
     // update command if the file is up to date). This makes the
@@ -45,9 +47,11 @@ namespace build
   }
 
   template <typename T>
-  fs_status<rmdir_status>
+  fs_status<butl::rmdir_status>
   rmdir (const dir_path& d, const T& t)
   {
+    using namespace butl;
+
     bool w (d == work); // Don't try to remove working directory.
     rmdir_status rs;
 
diff --git a/build/cxx/module b/build/cxx/module
index 11cd7bc..2d50f59 100644
--- a/build/cxx/module
+++ b/build/cxx/module
@@ -5,6 +5,7 @@
 #ifndef BUILD_CXX_MODULE
 #define BUILD_CXX_MODULE
 
+#include <build/types>
 #include <build/module>
 
 namespace build
diff --git a/build/cxx/module.cxx b/build/cxx/module.cxx
index 4193104..21f1b85 100644
--- a/build/cxx/module.cxx
+++ b/build/cxx/module.cxx
@@ -7,7 +7,6 @@
 #include <butl/process>
 #include <butl/fdstream>
 
-#include <build/path>
 #include <build/scope>
 #include <build/diagnostics>
 
diff --git a/build/cxx/rule b/build/cxx/rule
index 686d5ae..8c575fe 100644
--- a/build/cxx/rule
+++ b/build/cxx/rule
@@ -5,6 +5,7 @@
 #ifndef BUILD_CXX_RULE
 #define BUILD_CXX_RULE
 
+#include <build/types>
 #include <build/rule>
 
 namespace build
diff --git a/build/cxx/rule.cxx b/build/cxx/rule.cxx
index c0e6550..58d8e88 100644
--- a/build/cxx/rule.cxx
+++ b/build/cxx/rule.cxx
@@ -18,7 +18,6 @@
 #include <build/scope>
 #include <build/variable>
 #include <build/algorithm>
-#include <build/timestamp>
 #include <build/diagnostics>
 #include <build/context>
 
diff --git a/build/diagnostics b/build/diagnostics
index 05401b9..6c528f2 100644
--- a/build/diagnostics
+++ b/build/diagnostics
@@ -14,11 +14,15 @@
 #include <exception>
 #include <type_traits>
 
-#include <build/path>
+#include <butl/path>
+
 #include <build/path-io>
 
 namespace build
 {
+  using butl::path;
+  using butl::dir_path;
+
   // Throw this exception to terminate the build. The handler should
   // assume that the diagnostics has already been issued.
   //
diff --git a/build/file b/build/file
index 7f72282..7ac4d4d 100644
--- a/build/file
+++ b/build/file
@@ -5,8 +5,7 @@
 #ifndef BUILD_FILE
 #define BUILD_FILE
 
-#include <build/path>
-#include <build/name>
+#include <build/types>
 #include <build/variable> // list_value
 
 namespace build
diff --git a/build/file.cxx b/build/file.cxx
index 6f10391..5f899de 100644
--- a/build/file.cxx
+++ b/build/file.cxx
@@ -6,13 +6,15 @@
 
 #include <fstream>
 
+#include <butl/filesystem>
+
 #include <build/scope>
 #include <build/context>
 #include <build/parser>
-#include <build/filesystem>
 #include <build/diagnostics>
 
 using namespace std;
+using namespace butl;
 
 namespace build
 {
diff --git a/build/filesystem b/build/filesystem
deleted file mode 100644
index fbade4f..0000000
--- a/build/filesystem
+++ /dev/null
@@ -1,61 +0,0 @@
-// file      : build/filesystem -*- C++ -*-
-// copyright : Copyright (c) 2014-2015 Code Synthesis Ltd
-// license   : MIT; see accompanying LICENSE file
-
-#ifndef BUILD_FILESYSTEM
-#define BUILD_FILESYSTEM
-
-#include <sys/types.h> // mode_t
-
-#include <build/path>
-
-namespace build
-{
-  // Return true if the path is to an existing directory. Note that
-  // this function resolves symlinks.
-  //
-  bool
-  dir_exists (const path&);
-
-  // Return true if the path is to an existing regular file. Note that
-  // this function resolves symlinks.
-  //
-  bool
-  file_exists (const path&);
-
-  // Try to create a directory unless it already exists. If you expect
-  // the directory to exist and performance is important, then you
-  // should first call dir_exists() above since that's what this
-  // implementation will do to make sure the path is actually a
-  // directory.
-  //
-  // You should also probably use the default mode 0777 and let the
-  // umask mechanism adjust it to the user's preferences.
-  //
-  // Errors are reported by throwing std::system_error.
-  //
-  enum class mkdir_status {success, already_exists};
-
-  mkdir_status
-  try_mkdir (const path&, mode_t = 0777);
-
-  // Try to remove the directory returning not_exist if it does not
-  // exist and not_empty if it is not empty. All other errors are
-  // reported by throwing std::system_error.
-  //
-  enum class rmdir_status {success, not_exist, not_empty};
-
-  rmdir_status
-  try_rmdir (const path&);
-
-  // Try to remove the file (or symbolic link) returning not_exist if
-  // it does not exist. All other errors are reported by throwing
-  // std::system_error.
-  //
-  enum class rmfile_status {success, not_exist};
-
-  rmfile_status
-  try_rmfile (const path&);
-}
-
-#endif // BUILD_FILESYSTEM
diff --git a/build/filesystem.cxx b/build/filesystem.cxx
deleted file mode 100644
index 6485f34..0000000
--- a/build/filesystem.cxx
+++ /dev/null
@@ -1,101 +0,0 @@
-// file      : build/filesystem.cxx -*- C++ -*-
-// copyright : Copyright (c) 2014-2015 Code Synthesis Ltd
-// license   : MIT; see accompanying LICENSE file
-
-#include <build/filesystem>
-
-#include <unistd.h>    // rmdir(), unlink()
-#include <sys/types.h> // stat
-#include <sys/stat.h>  // stat, lstat(), S_IS*, mkdir()
-
-#include <system_error>
-
-using namespace std;
-
-namespace build
-{
-  bool
-  dir_exists (const path& p)
-  {
-    struct stat s;
-    if (::lstat (p.string ().c_str (), &s) != 0)
-    {
-      if (errno == ENOENT || errno == ENOTDIR)
-        return false;
-      else
-        throw system_error (errno, system_category ());
-    }
-
-    return S_ISDIR (s.st_mode);
-  }
-
-  bool
-  file_exists (const path& p)
-  {
-    struct stat s;
-    if (::lstat (p.string ().c_str (), &s) != 0)
-    {
-      if (errno == ENOENT || errno == ENOTDIR)
-        return false;
-      else
-        throw system_error (errno, system_category ());
-    }
-
-    return S_ISREG (s.st_mode);
-  }
-
-  mkdir_status
-  try_mkdir (const path& p, mode_t m)
-  {
-    mkdir_status r (mkdir_status::success);
-
-    if (::mkdir (p.string ().c_str (), m) != 0)
-    {
-      int e (errno);
-
-      // EEXIST means the path already exists but not necessarily as
-      // a directory.
-      //
-      if (e == EEXIST && dir_exists (p))
-        return mkdir_status::already_exists;
-      else
-        throw system_error (e, system_category ());
-    }
-
-    return r;
-  }
-
-  rmdir_status
-  try_rmdir (const path& p)
-  {
-    rmdir_status r (rmdir_status::success);
-
-    if (::rmdir (p.string ().c_str ()) != 0)
-    {
-      if (errno == ENOENT)
-        r = rmdir_status::not_exist;
-      else if (errno == ENOTEMPTY || errno == EEXIST)
-        r = rmdir_status::not_empty;
-      else
-        throw system_error (errno, system_category ());
-    }
-
-    return r;
-  }
-
-  rmfile_status
-  try_rmfile (const path& p)
-  {
-    rmfile_status r (rmfile_status::success);
-
-    if (::unlink (p.string ().c_str ()) != 0)
-    {
-      if (errno == ENOENT || errno == ENOTDIR)
-        r = rmfile_status::not_exist;
-      else
-        throw system_error (errno, system_category ());
-    }
-
-    return r;
-  }
-}
diff --git a/build/name b/build/name
index 412abad..924c123 100644
--- a/build/name
+++ b/build/name
@@ -10,10 +10,14 @@
 #include <iosfwd>
 #include <utility> // move()
 
-#include <build/path>
+#include <butl/path>
 
+// Note: include <build/types> instead of this file directly.
+//
 namespace build
 {
+  using butl::dir_path;
+
   // A name is what we operate on by default. Depending on the context,
   // it can be interpreted as a target or prerequisite name. A name
   // without a type and directory can be used to represent any text.
diff --git a/build/operation b/build/operation
index 7492050..51c9f88 100644
--- a/build/operation
+++ b/build/operation
@@ -11,7 +11,7 @@
 #include <cstdint>
 #include <functional> // reference_wrapper
 
-#include <build/path>
+#include <build/types>
 #include <build/string-table>
 
 namespace build
diff --git a/build/parser b/build/parser
index 35b2f32..403fbaf 100644
--- a/build/parser
+++ b/build/parser
@@ -9,9 +9,8 @@
 #include <iosfwd>
 #include <utility> // move()
 
-#include <build/path>
+#include <build/types>
 #include <build/token>
-#include <build/name>
 #include <build/spec>
 #include <build/variable>    // list_value
 #include <build/diagnostics>
diff --git a/build/path b/build/path
deleted file mode 100644
index f107391..0000000
--- a/build/path
+++ /dev/null
@@ -1,553 +0,0 @@
-// file      : build/path -*- C++ -*-
-// copyright : Copyright (c) 2014-2015 Code Synthesis Ltd
-// license   : MIT; see accompanying LICENSE file
-
-#ifndef BUILD_PATH
-#define BUILD_PATH
-
-#include <string>
-#include <cstddef>    // ptrdiff_t
-#include <ostream>
-#include <utility>    // move
-#include <iterator>
-#include <exception>
-#include <functional> // hash
-
-namespace build
-{
-  template <typename C>
-  struct path_traits
-  {
-    typedef std::basic_string<C> string_type;
-    typedef typename string_type::size_type size_type;
-
-    // Canonical directory and path seperators.
-    //
-#ifdef _WIN32
-    static C const directory_separator = '\\';
-    static C const path_separator = ';';
-#else
-    static C const directory_separator = '/';
-    static C const path_separator = ':';
-#endif
-
-    // Directory separator tests. On some platforms there
-    // could be multiple seperators. For example, on Windows
-    // we check for both '/' and '\'.
-    //
-    static bool
-    is_separator (C c)
-    {
-#ifdef _WIN32
-      return c == '\\' || c == '/';
-#else
-      return c == '/';
-#endif
-    }
-
-    static size_type
-    find_separator (string_type const& s, size_type pos = 0)
-    {
-      for (size_type n (s.size ()); pos < n; ++pos)
-      {
-        if (is_separator (s[pos]))
-          return pos;
-      }
-
-      return string_type::npos;
-    }
-
-    static size_type
-    rfind_separator (string_type const& s, size_type pos = string_type::npos)
-    {
-      if (pos == string_type::npos)
-        pos = s.size ();
-      else
-        pos++;
-
-      for (; pos > 0; --pos)
-      {
-        if (is_separator (s[pos - 1]))
-          return pos - 1;
-      }
-
-      return string_type::npos;
-    }
-
-    // Return the position of '.' or npos if there is no extension.
-    //
-    static size_type
-    find_extension (string_type const& s)
-    {
-      size_type i (s.size ());
-
-      for (; i > 0; --i)
-      {
-        C c (s[i - 1]);
-
-        if (c == '.')
-          break;
-
-        if (is_separator (c))
-        {
-          i = 0;
-          break;
-        }
-      }
-
-      // Weed out paths like ".txt" (and "/.txt") and "txt.".
-      //
-      if (i > 1 && !is_separator (s[i - 2]) && i != s.size ())
-        return i - 1;
-      else
-        return string_type::npos;
-    }
-
-    static int
-    compare (string_type const& l, string_type const& r)
-    {
-      size_type ln (l.size ()), rn (r.size ()), n (ln < rn ? ln : rn);
-      for (size_type i (0); i != n; ++i)
-      {
-#ifdef _WIN32
-        C lc (tolower (l[i])), rc (tolower (r[i]));
-#else
-        C lc (l[i]), rc (r[i]);
-#endif
-        if (is_separator (lc) && is_separator (rc))
-          continue;
-
-        if (lc < rc) return -1;
-        if (lc > rc) return 1;
-      }
-
-      return ln < rn ? -1 : (ln > rn ? 1 : 0);
-    }
-
-    // Get/set current working directory. Throw std::system_error
-    // to report the underlying OS errors.
-    //
-    static string_type
-    current ();
-
-    static void
-    current (string_type const&);
-
-  private:
-#ifdef _WIN32
-    static C
-    tolower (C);
-#endif
-  };
-
-  template <typename C>
-  class invalid_basic_path;
-
-  template <typename C, typename K>
-  class basic_path;
-
-  template <typename C>
-  class path_data;
-
-  template <typename C>
-  struct dir_path_kind;
-
-  template <typename C>
-  struct any_path_kind
-  {
-    typedef path_data<C> base_type;
-    typedef basic_path<C, dir_path_kind<C>> dir_type;
-  };
-
-  template <typename C>
-  struct dir_path_kind
-  {
-    typedef basic_path<C, any_path_kind<C>> base_type;
-    typedef basic_path<C, dir_path_kind<C>> dir_type;
-  };
-
-  typedef basic_path<char, any_path_kind<char>> path;
-  typedef basic_path<char, dir_path_kind<char>> dir_path;
-  typedef invalid_basic_path<char> invalid_path;
-
-  typedef basic_path<wchar_t, any_path_kind<wchar_t>> wpath;
-  typedef basic_path<wchar_t, dir_path_kind<wchar_t>> dir_wpath;
-  typedef invalid_basic_path<wchar_t> invalid_wpath;
-
-  //
-  //
-  class invalid_path_base: std::exception
-  {
-  public:
-    virtual char const*
-    what () const throw ();
-  };
-
-  template <typename C>
-  class invalid_basic_path: public invalid_path_base
-  {
-  public:
-    typedef std::basic_string<C> string_type;
-
-    invalid_basic_path (C const* p): path_ (p) {}
-    invalid_basic_path (string_type const& p): path_ (p) {}
-    ~invalid_basic_path () throw () {}
-
-    string_type const&
-    path () const
-    {
-      return path_;
-    }
-
-  private:
-    string_type path_;
-  };
-
-  template <typename C>
-  class path_data
-  {
-  public:
-    typedef std::basic_string<C> string_type;
-
-    path_data () = default;
-
-    explicit
-    path_data (string_type s): path_ (std::move (s)) {}
-
-  protected:
-    string_type path_;
-  };
-
-  template <typename C, typename K>
-  class basic_path: public K::base_type
-  {
-  public:
-    typedef std::basic_string<C> string_type;
-    typedef typename string_type::size_type size_type;
-
-    typedef typename K::base_type base_type;
-    typedef typename K::dir_type dir_type;
-
-    typedef path_traits<C> traits;
-
-    // Construct special empty path. Note that we have to provide our
-    // own implementation rather than using '=default' to make clang
-    // allow default-initialized const instances of this type.
-    //
-    basic_path () {};
-
-    explicit
-    basic_path (C const* s): base_type (s) {init ();}
-
-    basic_path (C const* s, size_type n)
-        : base_type (string_type (s, n)) {init ();}
-
-    explicit
-    basic_path (string_type s): base_type (std::move (s)) {init ();}
-
-    basic_path (const string_type& s, size_type n)
-        : base_type (string_type (s, 0, n)) {init ();}
-
-    basic_path (const string_type& s, size_type p, size_type n)
-        : base_type (string_type (s, p, n)) {init ();}
-
-    void
-    swap (basic_path& p)
-    {
-      this->path_.swap (p.path_);
-    }
-
-    void
-    clear ()
-    {
-      this->path_.clear ();
-    }
-
-    // Get/set current working directory. Throw std::system_error
-    // to report the underlying OS errors.
-    //
-    static dir_type
-    current () {return dir_type (traits::current ());}
-
-    static void
-    current (basic_path const&);
-
-  public:
-    bool
-    empty () const
-    {
-      return this->path_.empty ();
-    }
-
-    bool
-    absolute () const;
-
-    bool
-    relative () const
-    {
-      return !absolute ();
-    }
-
-    bool
-    root () const;
-
-    // Return true if *this is a sub-path of the specified path (i.e.,
-    // the specified path is a prefix). Expects both paths to be
-    // normalized. Note that this function returns true if the paths
-    // are equal. Empty path is considered a prefix of any path.
-    //
-    bool
-    sub (const basic_path&) const;
-
-    // Return true if *this is a super-path of the specified path (i.e.,
-    // the specified path is a suffix). Expects both paths to be
-    // normalized. Note that this function returns true if the paths
-    // are equal. Empty path is considered a suffix of any path.
-    //
-    bool
-    sup (const basic_path&) const;
-
-  public:
-    // Return the path without the directory part.
-    //
-    basic_path
-    leaf () const;
-
-    // Return the path without the specified directory part. Throws
-    // invalid_path if the directory is not a prefix of *this. Expects
-    // both paths to be normalized.
-    //
-    basic_path
-    leaf (basic_path const&) const;
-
-    // Return the directory part of the path or empty path if
-    // there is no directory.
-    //
-    dir_type
-    directory () const;
-
-    // Return the directory part of the path without the specified
-    // leaf part. Throws invalid_path if the leaf is not a suffix of
-    // *this. Expects both paths to be normalized.
-    //
-    dir_type
-    directory (basic_path const&) const;
-
-    // Return the root directory of the path or empty path if
-    // the directory is not absolute.
-    //
-    dir_type
-    root_directory () const;
-
-    // Return the path without the extension, if any.
-    //
-    basic_path
-    base () const;
-
-    // Return the extension or NULL if not present.
-    //
-    const C*
-    extension () const;
-
-    // Return a path relative to the specified path that is equivalent
-    // to *this. Throws invalid_path if a relative path cannot be derived
-    // (e.g., paths are on different drives on Windows).
-    //
-    basic_path
-    relative (basic_path) const;
-
-    // Iteration over path components.
-    //
-  public:
-    struct iterator
-    {
-      typedef string_type value_type;
-      typedef string_type* pointer;
-      typedef string_type& reference;
-      typedef std::ptrdiff_t difference_type;
-      typedef std::forward_iterator_tag iterator_category;
-
-      typedef typename string_type::size_type size_type;
-
-      iterator (): p_ (nullptr) {}
-      iterator (const string_type& p, size_type b, size_type e)
-          : p_ (&p), b_ (b), e_ (e) {}
-
-      iterator&
-      operator++ ()
-      {
-        b_ = e_;
-
-        if (b_ != string_type::npos)
-          e_ = traits::find_separator (*p_, ++b_);
-
-        return *this;
-      }
-
-      iterator
-      operator++ (int) {iterator r (*this); return ++r;}
-
-      string_type operator* () const
-      {
-        return string_type (*p_, b_, (e_ != string_type::npos ? e_ - b_ : e_));
-      }
-
-      friend bool
-      operator== (const iterator& x, const iterator& y)
-      {
-        return x.p_ == y.p_ && x.b_ == y.b_ && x.e_ == y.e_;
-      }
-
-      friend bool
-      operator!= (const iterator& x, const iterator& y) {return !(x == y);}
-
-    private:
-      // b != npos && e == npos - last component
-      // b == npos && e == npos - one past last component (end)
-      //
-      const string_type* p_;
-      size_type b_;
-      size_type e_;
-    };
-
-    iterator begin () const;
-    iterator end () const;
-
-  public:
-    // Normalize the path. This includes collapsing the '.' and '..'
-    // directories if possible, collapsing multiple directory
-    // separators, and converting all directory separators to the
-    // canonical form. Returns *this.
-    //
-    basic_path&
-    normalize ();
-
-    // Make the path absolute using the current directory unless
-    // it is already absolute.
-    //
-    basic_path&
-    complete ();
-
-  public:
-    basic_path&
-    operator/= (basic_path const&);
-
-    basic_path
-    operator+ (string_type const& s) const
-    {
-      return basic_path (this->path_ + s);
-    }
-
-    basic_path
-    operator+ (C c) const
-    {
-      return basic_path (this->path_ + c);
-    }
-
-    basic_path&
-    operator+= (string_type const& s)
-    {
-      this->path_ += s;
-      return *this;
-    }
-
-    basic_path&
-    operator+= (C c)
-    {
-      this->path_ += c;
-      return *this;
-    }
-
-    // Note that comparison is case-insensitive if the filesystem is
-    // not case-sensitive (e.g., Windows).
-    //
-    bool
-    operator== (basic_path const& x) const
-    {
-      return traits::compare (this->path_, x.path_) == 0;
-    }
-
-    bool
-    operator!= (basic_path const& x) const
-    {
-      return !(*this == x);
-    }
-
-    bool
-    operator< (basic_path const& x) const
-    {
-      return traits::compare (this->path_, x.path_) < 0;
-    }
-
-  public:
-    const string_type&
-    string () const
-    {
-      return this->path_;
-    }
-
-    // If possible, return a POSIX representation of the path. For example,
-    // for a Windows path in the form foo\bar this function will return
-    // foo/bar. If it is not possible to create a POSIX representation for
-    // this path (e.g., c:\foo), this function will throw the invalid_path
-    // exception.
-    //
-    string_type
-    posix_string () const;
-
-  private:
-    void
-    init ();
-  };
-
-  template <typename C, typename K>
-  inline basic_path<C, K>
-  operator/ (basic_path<C, K> const& x, basic_path<C, K> const& y)
-  {
-    basic_path<C, K> r (x);
-    r /= y;
-    return r;
-  }
-
-  // Additional operators for certain path kind combinations.
-  //
-  template <typename C>
-  inline basic_path<C, any_path_kind<C>>
-  operator/ (basic_path<C, dir_path_kind<C>> const& x,
-             basic_path<C, any_path_kind<C>> const& y)
-  {
-    basic_path<C, any_path_kind<C>> r (x);
-    r /= y;
-    return r;
-  }
-
-  // IO
-  //
-
-  /*
-  template <typename C, typename K>
-  inline std::basic_ostream<C>&
-  operator<< (std::basic_ostream<C>& os, basic_path<C, K> const& p)
-  {
-    return os << p.string ();
-  }
-  */
-}
-
-namespace std
-{
-  template <typename C, typename K>
-  struct hash<build::basic_path<C, K>>: hash<basic_string<C>>
-  {
-    size_t
-    operator() (const build::basic_path<C, K>& p) const noexcept
-    {
-      return hash<basic_string<C>>::operator() (p.string ());
-    }
-  };
-}
-
-#include <build/path.ixx>
-#include <build/path.txx>
-
-#endif // BUILD_PATH
diff --git a/build/path-io b/build/path-io
index c2130da..888a8b4 100644
--- a/build/path-io
+++ b/build/path-io
@@ -7,10 +7,15 @@
 
 #include <iosfwd>
 
-#include <build/path>
+#include <butl/path>
 
+// Custom path IO.
+//
 namespace build
 {
+  using butl::path;
+  using butl::dir_path;
+
   std::ostream&
   operator<< (std::ostream&, const path&);
 
diff --git a/build/path-map b/build/path-map
deleted file mode 100644
index 8355ccc..0000000
--- a/build/path-map
+++ /dev/null
@@ -1,88 +0,0 @@
-// file      : build/path-map -*- C++ -*-
-// copyright : Copyright (c) 2014-2015 Code Synthesis Ltd
-// license   : MIT; see accompanying LICENSE file
-
-#ifndef BUILD_PATH_MAP
-#define BUILD_PATH_MAP
-
-#include <butl/prefix-map>
-
-#include <build/path>
-
-namespace butl
-{
-
-  // @@ Remove butl:: when move to libbutl.
-
-  // prefix_map for paths
-  //
-  // The paths should be normalized.
-  //
-  // Note that the path's representation of POSIX root ('/') is
-  // inconsistent in that we have a trailing delimiter at the end of
-  // the path (its "proper" representation would have been an empty
-  // string but that would have clashed with empty paths). To work
-  // around this snag, this implementation, during key comparison,
-  // detects '/' and treats it as empty. Note that the map will
-  // still store the key as you have first inserted it. So if you
-  // want a particular representation, pre-populate the map with
-  // it.
-  //
-  template <typename C, typename K>
-  struct compare_prefix<build::basic_path<C, K>>: compare_prefix<std::basic_string<C>>
-  {
-    typedef build::basic_path<C, K> key_type;
-
-    typedef C delimiter_type;
-    typedef std::basic_string<C> string_type;
-    typedef compare_prefix<std::basic_string<C>> base;
-
-    explicit
-    compare_prefix (delimiter_type d): base (d) {}
-
-    bool
-    operator() (const key_type& x, const key_type& y) const
-    {
-      const auto& xs (x.string ());
-      const auto& ys (y.string ());
-
-#ifdef _WIN32
-      return base::compare (xs.c_str (),
-                            xs.size (),
-                            ys.c_str (),
-                            ys.size ()) < 0;
-#else
-      return base::compare (xs.c_str (),
-                            x.root () ? 0 : xs.size (),
-                            ys.c_str (),
-                            y.root () ? 0 : ys.size ()) < 0;
-#endif
-    }
-
-    bool
-    prefix (const key_type& p, const key_type& k) const
-    {
-      const auto& ps (p.string ());
-      const auto& ks (k.string ());
-
-#ifdef _WIN32
-      return base::prefix (ps, ks);
-#else
-      return base::prefix (p.root () ? string_type () : ps,
-                           k.root () ? string_type () : ks);
-#endif
-    }
-  };
-}
-
-namespace build
-{
-  template <typename T>
-  using path_map = butl::prefix_map<path, T, path::traits::directory_separator>;
-
-  template <typename T>
-  using dir_path_map =
-    butl::prefix_map<dir_path, T, dir_path::traits::directory_separator>;
-}
-
-#endif // BUILD_PATH_MAP
diff --git a/build/path.cxx b/build/path.cxx
deleted file mode 100644
index 3a3ea3d..0000000
--- a/build/path.cxx
+++ /dev/null
@@ -1,109 +0,0 @@
-// file      : build/path.cxx -*- C++ -*-
-// copyright : Copyright (c) 2014-2015 Code Synthesis Ltd
-// license   : MIT; see accompanying LICENSE file
-
-#include <build/path>
-
-#ifdef _WIN32
-#  include <stdlib.h> // _MAX_PATH
-#  include <direct.h> // _[w]getcwd, _[w]chdir
-#else
-#  include <errno.h>  // EINVAL
-#  include <stdlib.h> // mbstowcs, wcstombs
-#  include <limits.h> // PATH_MAX
-#  include <unistd.h> // getcwd, chdir
-#endif
-
-#include <system_error>
-
-using namespace std;
-
-namespace build
-{
-  char const* invalid_path_base::
-  what () const throw ()
-  {
-    return "invalid filesystem path";
-  }
-
-  //
-  // char
-  //
-
-  template <>
-  path_traits<char>::string_type path_traits<char>::
-  current ()
-  {
-    // @@ throw system_error (and in the other current() versions).
-
-#ifdef _WIN32
-    char cwd[_MAX_PATH];
-    if(_getcwd(cwd, _MAX_PATH) == 0)
-      throw system_error (errno, system_category ());
-#else
-    char cwd[PATH_MAX];
-    if (getcwd (cwd, PATH_MAX) == 0)
-      throw system_error (errno, system_category ());
-#endif
-
-    return string_type (cwd);
-  }
-
-  template <>
-  void path_traits<char>::
-  current (string_type const& s)
-  {
-#ifdef _WIN32
-    if(_chdir(s.c_str ()) != 0)
-      throw system_error (errno, system_category ());
-#else
-    if (chdir (s.c_str ()) != 0)
-      throw system_error (errno, system_category ());
-#endif
-  }
-
-  //
-  // wchar_t
-  //
-
-  template <>
-  path_traits<wchar_t>::string_type path_traits<wchar_t>::
-  current ()
-  {
-#ifdef _WIN32
-    wchar_t wcwd[_MAX_PATH];
-    if(_wgetcwd(wcwd, _MAX_PATH) == 0)
-      throw system_error (errno, system_category ());
-#else
-    char cwd[PATH_MAX];
-    if (getcwd (cwd, PATH_MAX) == 0)
-      throw system_error (errno, system_category ());
-
-    wchar_t wcwd[PATH_MAX];
-    if (mbstowcs (wcwd, cwd, PATH_MAX) == size_type (-1))
-      throw system_error (EINVAL, system_category ());
-#endif
-
-    return string_type (wcwd);
-  }
-
-  template <>
-  void path_traits<wchar_t>::
-  current (string_type const& s)
-  {
-#ifdef _WIN32
-    if(_wchdir(s.c_str ()) != 0)
-      throw system_error (errno, system_category ());
-#else
-    char ns[PATH_MAX + 1];
-
-    if (wcstombs (ns, s.c_str (), PATH_MAX) == size_type (-1))
-      throw system_error (EINVAL, system_category ());
-
-    ns[PATH_MAX] = '\0';
-
-    if (chdir (ns) != 0)
-      throw system_error (errno, system_category ());
-#endif
-  }
-}
diff --git a/build/path.ixx b/build/path.ixx
deleted file mode 100644
index 9193fba..0000000
--- a/build/path.ixx
+++ /dev/null
@@ -1,171 +0,0 @@
-// file      : build/path.ixx -*- C++ -*-
-// copyright : Copyright (c) 2014-2015 Code Synthesis Ltd
-// license   : MIT; see accompanying LICENSE file
-
-#ifdef _WIN32
-#  include <cctype>  // std::tolower
-#  include <cwctype> // std::towlower
-#endif
-
-namespace build
-{
-#ifdef _WIN32
-  template <>
-  inline char path_traits<char>::
-  tolower (char c)
-  {
-    return std::tolower (c);
-  }
-
-  template <>
-  inline wchar_t path_traits<wchar_t>::
-  tolower (wchar_t c)
-  {
-    return std::towlower (c);
-  }
-#endif
-
-  template <typename C, typename K>
-  inline bool basic_path<C, K>::
-  absolute () const
-  {
-#ifdef _WIN32
-    return this->path_.size () > 1 && this->path_[1] == ':';
-#else
-    return !this->path_.empty () && traits::is_separator (this->path_[0]);
-#endif
-  }
-
-  template <typename C, typename K>
-  inline bool basic_path<C, K>::
-  root () const
-  {
-#ifdef _WIN32
-    return this->path_.size () == 2 && this->path_[1] == ':';
-#else
-    return this->path_.size () == 1 && traits::is_separator (this->path_[0]);
-#endif
-  }
-
-  template <typename C, typename K>
-  inline bool basic_path<C, K>::
-  sub (const basic_path& p) const
-  {
-    size_type n (p.path_.size ());
-
-    if (n == 0)
-      return true;
-
-    size_type m (this->path_.size ());
-
-    // The second condition guards against the /foo-bar vs /foo case.
-    //
-    return m >= n && this->path_.compare (0, n, p.path_) == 0 &&
-      (traits::is_separator (p.path_.back ()) || // p ends with a separator
-       m == n                                 || // *this == p
-       traits::is_separator (this->path_[n]));   // next char is a separator
-  }
-
-  template <typename C, typename K>
-  inline bool basic_path<C, K>::
-  sup (const basic_path& p) const
-  {
-    size_type n (p.path_.size ());
-
-    if (n == 0)
-      return true;
-
-    size_type m (this->path_.size ());
-
-    // The second condition guards against the /foo-bar vs bar case.
-    //
-    return m >= n && this->path_.compare (m - n, n, p.path_) == 0 &&
-      (m == n                                   ||     // *this == p
-       traits::is_separator (this->path_[m - n - 1])); // prev char separator
-  }
-
-  template <typename C, typename K>
-  inline auto basic_path<C, K>::
-  begin () const -> iterator
-  {
-    size_type b, e;
-
-    if (this->path_.empty ())
-      b = e = string_type::npos;
-
-#ifndef _WIN32
-    else if (root ())
-    {
-      // We want to return a single empty component. Here we return
-      // the begin position one past the end. Not sure if this legal.
-      //
-      b = 1;
-      e = string_type::npos;
-    }
-#endif
-    else
-    {
-      b = 0;
-      e = traits::find_separator (this->path_);
-    }
-
-    return iterator (this->path_, b, e);
-  }
-
-  template <typename C, typename K>
-  inline auto basic_path<C, K>::
-  end () const -> iterator
-  {
-    return iterator (this->path_, string_type::npos, string_type::npos);
-  }
-
-  template <typename C, typename K>
-  inline basic_path<C, K>& basic_path<C, K>::
-  complete ()
-  {
-    if (relative ())
-      *this = current () / *this;
-
-    return *this;
-  }
-
-  template <typename C, typename K>
-  inline typename basic_path<C, K>::dir_type basic_path<C, K>::
-  root_directory () const
-  {
-    return absolute ()
-#ifdef _WIN32
-      ? dir_type (this->path_, 2)
-#else
-      ? dir_type ("/")
-#endif
-      : dir_type ();
-  }
-
-  template <typename C, typename K>
-  inline basic_path<C, K> basic_path<C, K>::
-  base () const
-  {
-    size_type p (traits::find_extension (this->path_));
-    return p != string_type::npos
-      ? basic_path (this->path_.c_str (), p)
-      : *this;
-  }
-
-  template <typename C, typename K>
-  inline const C* basic_path<C, K>::
-  extension () const
-  {
-    size_type p (traits::find_extension (this->path_));
-    return p != string_type::npos ? this->path_.c_str () + p + 1 : nullptr;
-  }
-
-#ifndef _WIN32
-  template <typename C, typename K>
-  inline typename basic_path<C, K>::string_type basic_path<C, K>::
-  posix_string () const
-  {
-    return string ();
-  }
-#endif
-}
diff --git a/build/path.txx b/build/path.txx
deleted file mode 100644
index c664eaf..0000000
--- a/build/path.txx
+++ /dev/null
@@ -1,256 +0,0 @@
-// file      : build/path.txx -*- C++ -*-
-// copyright : Copyright (c) 2014-2015 Code Synthesis Ltd
-// license   : MIT; see accompanying LICENSE file
-
-#include <vector>
-
-namespace build
-{
-  template <typename C, typename K>
-  basic_path<C, K> basic_path<C, K>::
-  leaf () const
-  {
-    size_type p (traits::rfind_separator (this->path_));
-
-    return p != string_type::npos
-      ? basic_path (this->path_.c_str () + p + 1, this->path_.size () - p - 1)
-      : *this;
-  }
-
-  template <typename C, typename K>
-  typename basic_path<C, K>::dir_type basic_path<C, K>::
-  directory () const
-  {
-    if (root ())
-      return dir_type ();
-
-    size_type p (traits::rfind_separator (this->path_));
-
-    // Include the trailing slash so that we get correct behavior
-    // if directory is root.
-    //
-    return p != string_type::npos
-      ? dir_type (this->path_.c_str (), p + 1)
-      : dir_type ();
-  }
-
-#ifdef _WIN32
-  template <typename C, typename K>
-  typename basic_path<C, K>::string_type basic_path<C, K>::
-  posix_string () const
-  {
-    if (absolute ())
-      throw invalid_basic_path<C> (this->path_);
-
-    string_type r (this->path_);
-
-    // Translate Windows-style separators to the POSIX ones.
-    //
-    for (size_type i (0), n (r.size ()); i != n; ++i)
-      if (r[i] == '\\')
-        r[i] = '/';
-
-    return r;
-  }
-#endif
-
-  template <typename C, typename K>
-  basic_path<C, K>& basic_path<C, K>::
-  operator/= (basic_path<C, K> const& r)
-  {
-    if (r.absolute () && !this->path_.empty ()) // Allow ('' / '/foo').
-      throw invalid_basic_path<C> (r.path_);
-
-    if (this->path_.empty () || r.path_.empty ())
-    {
-      this->path_ += r.path_;
-      return *this;
-    }
-
-    if (!traits::is_separator (this->path_[this->path_.size () - 1]))
-      this->path_ += traits::directory_separator;
-
-    this->path_ += r.path_;
-    return *this;
-  }
-
-  template <typename C, typename K>
-  basic_path<C, K> basic_path<C, K>::
-  leaf (basic_path<C, K> const& d) const
-  {
-    size_type n (d.path_.size ());
-
-    if (n == 0)
-      return *this;
-
-    if (!sub (d))
-      throw invalid_basic_path<C> (this->path_);
-
-    size_type m (this->path_.size ());
-
-    if (n != m
-#ifndef _WIN32
-        && !d.root ()
-#endif
-    )
-      n++; // Skip the directory separator (unless it is POSIX root).
-
-    return basic_path (this->path_.c_str () + n, m - n);
-  }
-
-  template <typename C, typename K>
-  typename basic_path<C, K>::dir_type basic_path<C, K>::
-  directory (basic_path<C, K> const& l) const
-  {
-    size_type n (l.path_.size ());
-
-    if (n == 0)
-      return dir_type (this->path_);
-
-    if (!sup (l))
-      throw invalid_basic_path<C> (this->path_);
-
-    size_type m (this->path_.size ());
-
-    if (n != m)
-      n++; // Skip the directory separator.
-
-    return dir_type (this->path_.c_str (), m - n);
-  }
-
-  template <typename C, typename K>
-  basic_path<C, K> basic_path<C, K>::
-  relative (basic_path<C, K> d) const
-  {
-    basic_path r;
-
-    for (;; d = d.directory ())
-    {
-      if (sub (d))
-        break;
-
-      r /= basic_path ("..");
-
-      // Roots of the paths do not match.
-      //
-      if (d.root ())
-        throw invalid_basic_path<C> (this->path_);
-    }
-
-    return r / leaf (d);
-  }
-
-  template <typename C, typename K>
-  basic_path<C, K>& basic_path<C, K>::
-  normalize ()
-  {
-    if (empty ())
-      return *this;
-
-    bool abs (absolute ());
-
-    typedef std::vector<string_type> paths;
-    paths ps;
-
-    for (size_type b (0), e (traits::find_separator (this->path_)),
-           n (this->path_.size ());;
-         e = traits::find_separator (this->path_, b))
-    {
-      string_type s (this->path_, b, e == string_type::npos ? e : e - b);
-      ps.push_back (s);
-
-      if (e == string_type::npos)
-        break;
-
-      ++e;
-
-      while (e < n && traits::is_separator (this->path_[e]))
-        ++e;
-
-      if (e == n)
-        break;
-
-      b = e;
-    }
-
-    // First collapse '.' and '..'.
-    //
-    paths r;
-
-    for (typename paths::const_iterator i (ps.begin ()), e (ps.end ());
-         i != e; ++i)
-    {
-      string_type const& s (*i);
-      size_type n (s.size ());
-
-      if (n == 1 && s[0] == '.')
-        continue;
-
-      if (n == 2 && s[0] == '.' && s[1] == '.')
-      {
-        // Pop the last directory from r unless it is '..'.
-        //
-        if (!r.empty ())
-        {
-          string_type const& s1 (r.back ());
-
-          if (!(s1.size () == 2 && s1[0] == '.' && s1[1] == '.'))
-          {
-            // Cannot go past the root directory.
-            //
-            if (abs && r.size () == 1)
-              throw invalid_basic_path<C> (this->path_);
-
-            r.pop_back ();
-            continue;
-          }
-        }
-      }
-
-      r.push_back (s);
-    }
-
-    // Reassemble the path.
-    //
-    string_type p;
-
-    for (typename paths::const_iterator i (r.begin ()), e (r.end ());
-         i != e;)
-    {
-      p += *i;
-
-      if (++i != e)
-        p += traits::directory_separator;
-    }
-
-    if (p.empty () && !r.empty ())
-      p += traits::directory_separator; // Root directory.
-
-    this->path_.swap (p);
-    return *this;
-  }
-
-  template <typename C, typename K>
-  void basic_path<C, K>::
-  current (basic_path const& p)
-  {
-    const string_type& s (p.string ());
-
-    if (s.empty ())
-      throw invalid_basic_path<char> (s);
-
-    traits::current (s);
-  }
-
-  template <typename C, typename K>
-  void basic_path<C, K>::
-  init ()
-  {
-    // Strip trailing slashes except for the case where the single
-    // slash represents the root directory.
-    //
-    size_type n (this->path_.size ());
-    for (; n > 1 && traits::is_separator (this->path_[n - 1]); --n) ;
-    this->path_.resize (n);
-  }
-}
diff --git a/build/prerequisite b/build/prerequisite
index ba850ec..0d3428f 100644
--- a/build/prerequisite
+++ b/build/prerequisite
@@ -13,7 +13,7 @@
 #include <typeindex>
 #include <functional> // reference_wrapper
 
-#include <build/path>
+#include <build/types>
 #include <build/target-key>
 #include <build/utility> // extension_pool
 #include <build/diagnostics>
diff --git a/build/rule b/build/rule
index 04d3650..c7134e1 100644
--- a/build/rule
+++ b/build/rule
@@ -12,6 +12,7 @@
 
 #include <butl/prefix-map>
 
+#include <build/types>
 #include <build/target>
 #include <build/operation>
 
diff --git a/build/rule.cxx b/build/rule.cxx
index a99611b..b3dfaeb 100644
--- a/build/rule.cxx
+++ b/build/rule.cxx
@@ -7,14 +7,15 @@
 #include <utility>      // move()
 #include <system_error>
 
+#include <butl/filesystem>
+
 #include <build/scope>
 #include <build/algorithm>
 #include <build/diagnostics>
-#include <build/timestamp>
-#include <build/filesystem>
 #include <build/context>
 
 using namespace std;
+using namespace butl;
 
 namespace build
 {
diff --git a/build/scope b/build/scope
index 7dec7a2..5266370 100644
--- a/build/scope
+++ b/build/scope
@@ -9,8 +9,9 @@
 #include <unordered_set>
 #include <unordered_map>
 
-#include <build/path>
-#include <build/path-map>
+#include <butl/path-map>
+
+#include <build/types>
 #include <build/variable>
 #include <build/prerequisite>
 #include <build/operation>
@@ -133,7 +134,8 @@ namespace build
     temp_scope (scope& p) {path_ = p.path_; parent_ = &p; root_ = p.root_;}
   };
 
-  class scope_map: public dir_path_map<scope>
+  using scope_map_base = butl::dir_path_map<scope>;
+  class scope_map: public scope_map_base
   {
   public:
     // Note that we assume the first insertion into the map is that
@@ -160,9 +162,6 @@ namespace build
       //
       return find (dir_path (p.string ()));
     }
-
-  private:
-    typedef dir_path_map<scope> base;
   };
 
   extern scope_map scopes;
diff --git a/build/scope.cxx b/build/scope.cxx
index 2b24702..5bd2b62 100644
--- a/build/scope.cxx
+++ b/build/scope.cxx
@@ -119,14 +119,14 @@ namespace build
     // Normally we would have a scope for the full path so try
     // that before making any copies.
     //
-    auto i (base::find (k));
+    auto i (scope_map_base::find (k));
 
     if (i != end ())
       return i->second;
 
     for (dir_path d (k.directory ());; d = d.directory ())
     {
-      auto i (base::find (d));
+      auto i (scope_map_base::find (d));
 
       if (i != end ())
         return i->second;
diff --git a/build/search.cxx b/build/search.cxx
index dc59a9b..ee6e20f 100644
--- a/build/search.cxx
+++ b/build/search.cxx
@@ -4,17 +4,16 @@
 
 #include <build/search>
 
-#include <utility>  // move
+#include <utility>  // move()
 #include <cassert>
 
-#include <build/path>
 #include <build/scope>
 #include <build/target>
 #include <build/prerequisite>
-#include <build/timestamp>
 #include <build/diagnostics>
 
 using namespace std;
+using namespace butl;
 
 namespace build
 {
diff --git a/build/spec b/build/spec
index bdfda4c..f50110b 100644
--- a/build/spec
+++ b/build/spec
@@ -10,8 +10,7 @@
 #include <iosfwd>
 #include <utility> // move()
 
-#include <build/path>
-#include <build/name>
+#include <build/types>
 
 namespace build
 {
diff --git a/build/target b/build/target
index d12a8e5..9388065 100644
--- a/build/target
+++ b/build/target
@@ -19,9 +19,7 @@
 #include <butl/utility>     // compare_c_string
 #include <butl/multi-index> // map_iterator_adapter
 
-#include <build/path>
-#include <build/timestamp>
-#include <build/name>
+#include <build/types>
 #include <build/variable>
 #include <build/operation>
 #include <build/target-key>
diff --git a/build/target-key b/build/target-key
index 2fa2186..9e74c27 100644
--- a/build/target-key
+++ b/build/target-key
@@ -9,7 +9,7 @@
 #include <typeindex>
 #include <ostream>
 
-#include <build/path>
+#include <build/types>
 
 namespace build
 {
diff --git a/build/timestamp b/build/timestamp
deleted file mode 100644
index 3479a77..0000000
--- a/build/timestamp
+++ /dev/null
@@ -1,54 +0,0 @@
-// file      : build/timestamp -*- C++ -*-
-// copyright : Copyright (c) 2014-2015 Code Synthesis Ltd
-// license   : MIT; see accompanying LICENSE file
-
-#ifndef BUILD_TIMESTAMP
-#define BUILD_TIMESTAMP
-
-#include <chrono>
-#include <string>
-#include <iosfwd>
-
-#include <build/path>
-
-namespace build
-{
-  // On all three main platforms that we target (GNU/Linux, Windows (both
-  // VC++ and GCC/MinGW64), and MacOS X) with recent C++ runtimes,
-  // system_clock has nanoseconds resolution and counts from the UNIX
-  // epoch. The latter is important since struct stat also returns times
-  // based on UNIX epoch.
-  //
-  // The underlying type for nanoseconds duration is signed integer type
-  // of at least 64 bits (currently int64_t). Because it is signed, we
-  // will overflow in year 2262 but by then the underlying type will
-  // most likely have changed to something larger than 64-bit.
-  //
-  // So to support other platforms that could possibly use a different
-  // system_clock resolutions (e.g., microseconds), we actually not going
-  // to assume anywhere (except perhaps timestamp.cxx) that we are dealing
-  // with nanoseconds or the 64-bit underlying type.
-  //
-  using std::chrono::system_clock;
-
-  using timestamp = system_clock::time_point;
-  using duration = system_clock::duration;
-
-  const timestamp timestamp_unknown {duration {-1}};
-  const timestamp timestamp_nonexistent {duration {0}};
-
-  std::ostream&
-  operator<< (std::ostream&, const timestamp&);
-
-  std::ostream&
-  operator<< (std::ostream&, const duration&);
-
-  // Returns timestamp_nonexistent if the entry at the specified path
-  // does not exist. All other errors are reported by throwing
-  // std::system_error.
-  //
-  timestamp
-  path_mtime (const path&);
-};
-
-#endif // BUILD_TIMESTAMP
diff --git a/build/timestamp.cxx b/build/timestamp.cxx
deleted file mode 100644
index 9d6e70c..0000000
--- a/build/timestamp.cxx
+++ /dev/null
@@ -1,177 +0,0 @@
-// file      : build/timestamp.cxx -*- C++ -*-
-// copyright : Copyright (c) 2014-2015 Code Synthesis Ltd
-// license   : MIT; see accompanying LICENSE file
-
-#include <build/timestamp>
-
-#include <unistd.h>    // stat
-#include <sys/types.h> // stat
-#include <sys/stat.h>  // stat
-
-#include <time.h> // localtime, gmtime, strftime
-
-#include <ostream>
-#include <system_error>
-
-using namespace std;
-
-namespace build
-{
-  // Figuring out whether we have the nanoseconds in some form.
-  //
-  template <typename S>
-  constexpr auto nsec (const S* s) -> decltype(s->st_mtim.tv_nsec)
-  {
-    return s->st_mtim.tv_nsec; // POSIX (GNU/Linux, Solaris).
-  }
-
-  template <typename S>
-  constexpr auto nsec (const S* s) -> decltype(s->st_mtimespec.tv_nsec)
-  {
-    return s->st_mtimespec.tv_nsec; // MacOS X.
-  }
-
-  template <typename S>
-  constexpr auto nsec (const S* s) -> decltype(s->st_mtime_n)
-  {
-    return s->st_mtime_n; // AIX 5.2 and later.
-  }
-
-  template <typename S>
-  constexpr int nsec (...) {return 0;}
-
-  timestamp
-  path_mtime (const path& p)
-  {
-    struct stat s;
-    if (stat (p.string ().c_str (), &s) != 0)
-    {
-      if (errno == ENOENT || errno == ENOTDIR)
-        return timestamp_nonexistent;
-      else
-        throw system_error (errno, system_category ());
-    }
-
-    return system_clock::from_time_t (s.st_mtime) +
-      chrono::duration_cast<duration> (
-        chrono::nanoseconds (nsec<struct stat> (&s)));
-  }
-
-  ostream&
-  operator<< (ostream& os, const timestamp& ts)
-  {
-    // @@ replace with put_time()
-    //
-
-    time_t t (system_clock::to_time_t (ts));
-
-    if (t == 0)
-      return os << "<nonexistent>";
-
-    std::tm tm;
-    if (localtime_r (&t, &tm) == nullptr)
-      throw system_error (errno, system_category ());
-
-    // If year is greater than 9999, we will overflow.
-    //
-    char buf[20]; // YYYY-MM-DD HH:MM:SS\0
-    if (strftime (buf, sizeof (buf), "%Y-%m-%d %H:%M:%S", &tm) == 0)
-      return os << "<beyond year 9999>";
-
-    os << buf;
-
-    using namespace chrono;
-
-    timestamp sec (system_clock::from_time_t (t));
-    nanoseconds ns (duration_cast<nanoseconds> (ts - sec));
-
-    if (ns != nanoseconds::zero ())
-    {
-      os << '.';
-      os.width (9);
-      os.fill ('0');
-      os << ns.count ();
-    }
-
-    return os;
-  }
-
-  ostream&
-  operator<< (ostream& os, const duration& d)
-  {
-    // @@ replace with put_time()
-    //
-
-    timestamp ts; // Epoch.
-    ts += d;
-
-    time_t t (system_clock::to_time_t (ts));
-
-    const char* fmt (nullptr);
-    const char* unt ("nanoseconds");
-    if (t >= 365 * 12 * 24 * 60 * 60)
-    {
-      fmt = "%Y-%m-%d %H:%M:%S";
-      unt = "years";
-    }
-    else if (t >= 12 * 24 * 60* 60)
-    {
-      fmt = "%m-%d %H:%M:%S";
-      unt = "months";
-    }
-    else if (t >= 24 * 60* 60)
-    {
-      fmt = "%d %H:%M:%S";
-      unt = "days";
-    }
-    else if (t >= 60 * 60)
-    {
-      fmt = "%H:%M:%S";
-      unt = "hours";
-    }
-    else if (t >= 60)
-    {
-      fmt = "%M:%S";
-      unt = "minutes";
-    }
-    else if (t >= 1)
-    {
-      fmt = "%S";
-      unt = "seconds";
-    }
-
-    if (fmt != nullptr)
-    {
-      std::tm tm;
-      if (gmtime_r (&t, &tm) == nullptr)
-        throw system_error (errno, system_category ());
-
-      char buf[20]; // YYYY-MM-DD HH:MM:SS\0
-      if (strftime (buf, sizeof (buf), fmt, &tm) == 0)
-        return os << "<beyond 9999>";
-
-      os << buf;
-    }
-
-    using namespace chrono;
-
-    timestamp sec (system_clock::from_time_t (t));
-    nanoseconds ns (duration_cast<nanoseconds> (ts - sec));
-
-    if (ns != nanoseconds::zero ())
-    {
-      if (fmt != nullptr)
-      {
-        os << '.';
-        os.width (9);
-        os.fill ('0');
-      }
-
-      os << ns.count () << ' ' << unt;
-    }
-    else if (fmt == 0)
-      os << '0';
-
-    return os;
-  }
-}
diff --git a/build/types b/build/types
index c29890a..5f6b3de 100644
--- a/build/types
+++ b/build/types
@@ -7,13 +7,32 @@
 
 #include <vector>
 
-#include <build/path>
+#include <butl/path>
+#include <butl/timestamp>
+
+#include <build/name>
 
 namespace build
 {
   // Commonly-used types.
   //
 
+  // <butl/path>
+  //
+  using butl::path;
+  using butl::dir_path;
+  using butl::basic_path;
+  using butl::invalid_path;
+
+  // <butl/timestamp>
+  //
+  using butl::system_clock;
+  using butl::timestamp;
+  using butl::duration;
+  using butl::timestamp_unknown;
+  using butl::timestamp_nonexistent;
+  using butl::operator<<;
+
   typedef std::vector<path> paths;
   typedef std::vector<dir_path> dir_paths;
 }
diff --git a/build/utility b/build/utility
index 717a9ed..4135b37 100644
--- a/build/utility
+++ b/build/utility
@@ -11,7 +11,7 @@
 #include <exception>
 #include <unordered_set>
 
-#include <build/path>
+#include <build/types>
 
 namespace build
 {
diff --git a/build/variable b/build/variable
index 42f0787..2164f92 100644
--- a/build/variable
+++ b/build/variable
@@ -16,8 +16,7 @@
 
 #include <butl/prefix-map>
 
-#include <build/path>
-#include <build/name>
+#include <build/types>
 
 namespace build
 {