From 882583f64e517ab232edb6bbb7433631c655c9da Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Thu, 7 Nov 2019 11:12:43 +0200
Subject: Initial work on path_name use for `-` to stdin/stdout translation

---
 libbuild2/cc/link-rule.cxx                         |  2 +-
 libbuild2/cc/pkgconfig.cxx                         |  2 +-
 libbuild2/config/functions.cxx                     |  5 ++-
 libbuild2/config/init.cxx                          |  5 ++-
 libbuild2/config/operation.cxx                     | 33 +++++++++---------
 libbuild2/config/operation.hxx                     |  2 +-
 libbuild2/config/utility.cxx                       |  6 ++--
 libbuild2/context.cxx                              |  3 +-
 libbuild2/diagnostics.cxx                          |  2 +-
 libbuild2/diagnostics.hxx                          | 15 ++++++++
 libbuild2/dist/operation.cxx                       |  4 +--
 libbuild2/file.cxx                                 |  7 ++--
 libbuild2/lexer+comment.test.testscript            |  2 +-
 libbuild2/lexer+eval.test.testscript               |  4 +--
 libbuild2/lexer.hxx                                | 13 ++++---
 libbuild2/lexer.test.cxx                           |  3 +-
 libbuild2/parser.cxx                               |  4 +--
 .../script/lexer+description-line.test.testscript  |  2 +-
 .../test/script/lexer+variable.test.testscript     |  2 +-
 libbuild2/test/script/lexer.hxx                    | 10 +++---
 libbuild2/test/script/lexer.test.cxx               |  3 +-
 libbuild2/test/script/parser.cxx                   |  8 ++---
 libbuild2/test/script/runner.cxx                   |  8 ++---
 libbuild2/types.hxx                                | 22 ++++++++----
 libbuild2/utility.cxx                              | 40 +++++-----------------
 libbuild2/utility.hxx                              | 14 ++------
 26 files changed, 112 insertions(+), 109 deletions(-)

diff --git a/libbuild2/cc/link-rule.cxx b/libbuild2/cc/link-rule.cxx
index 8a3b493..62988c9 100644
--- a/libbuild2/cc/link-rule.cxx
+++ b/libbuild2/cc/link-rule.cxx
@@ -3014,7 +3014,7 @@ namespace build2
           }
           catch (const io_error& e)
           {
-            fail << "unable to write " << f << ": " << e;
+            fail << "unable to write to " << f << ": " << e;
           }
 
           // Replace input arguments with @file.
diff --git a/libbuild2/cc/pkgconfig.cxx b/libbuild2/cc/pkgconfig.cxx
index 31b0770..56acafc 100644
--- a/libbuild2/cc/pkgconfig.cxx
+++ b/libbuild2/cc/pkgconfig.cxx
@@ -1543,7 +1543,7 @@ namespace build2
       }
       catch (const io_error& e)
       {
-        fail << "unable to write " << p << ": " << e;
+        fail << "unable to write to " << p << ": " << e;
       }
     }
   }
diff --git a/libbuild2/config/functions.cxx b/libbuild2/config/functions.cxx
index 79447a4..b6ccb74 100644
--- a/libbuild2/config/functions.cxx
+++ b/libbuild2/config/functions.cxx
@@ -43,7 +43,10 @@ namespace build2
         // Empty project set should is ok as long as inherit is false.
         //
         project_set ps;
-        save_config (*s, os, "config.export()", false /* inherit */, ps);
+        save_config (*s,
+                     os, path_name ("config.export()"),
+                     false /* inherit */,
+                     ps);
 
         return os.str ();
       };
diff --git a/libbuild2/config/init.cxx b/libbuild2/config/init.cxx
index 2d4ed20..890efa3 100644
--- a/libbuild2/config/init.cxx
+++ b/libbuild2/config/init.cxx
@@ -169,8 +169,11 @@ namespace build2
 
       auto load_config_file = [&load_config] (const path& f, const location& l)
       {
+        // @@ PATH_NAME TODO
+        //
+        path_name fn (f);
         ifdstream ifs;
-        load_config (open_file_or_stdin (f, ifs), f, l);
+        load_config (open_file_or_stdin (fn, ifs), f /* fn */, l);
       };
 
       {
diff --git a/libbuild2/config/operation.cxx b/libbuild2/config/operation.cxx
index c9b5ef6..14576a0 100644
--- a/libbuild2/config/operation.cxx
+++ b/libbuild2/config/operation.cxx
@@ -50,7 +50,7 @@ namespace build2
       }
       catch (const io_error& e)
       {
-        fail << "unable to write " << f << ": " << e;
+        fail << "unable to write to " << f << ": " << e;
       }
     }
 
@@ -79,7 +79,7 @@ namespace build2
       }
       catch (const io_error& e)
       {
-        fail << "unable to write " << f << ": " << e;
+        fail << "unable to write to " << f << ": " << e;
       }
     }
 
@@ -90,8 +90,7 @@ namespace build2
     //
     void
     save_config (const scope& rs,
-                 ostream& os,
-                 const string& name,
+                 ostream& os, const path_name& on,
                  bool inherit,
                  const project_set& projects)
     {
@@ -100,8 +99,8 @@ namespace build2
       const module* mod (rs.lookup_module<const module> (module::name));
 
       if (mod == nullptr)
-        fail << "no configuration information available during this meta-"
-             << "operation";
+        fail (on) << "no configuration information available during this "
+                  << "meta-operation";
 
       try
       {
@@ -231,8 +230,8 @@ namespace build2
                 // then something is broken.
                 //
                 if (r == nullptr)
-                  fail << name << ": inherited variable " << var << " value "
-                       << "is not from a root scope";
+                  fail (on) << "inherited variable " << var << " value is not "
+                            << "from a root scope";
 
                 // If none of the outer project's configurations use this
                 // value, then we warn (unless we couldn't check) and save as
@@ -242,8 +241,8 @@ namespace build2
                 if (checked && org.first == ovr.first)
                 {
                   diag_record dr;
-                  dr << warn << name << ": saving previously inherited "
-                     << "variable " << var;
+                  dr << warn (on) << "saving previously inherited variable "
+                     << var;
 
                   dr << info << "because project " << *r << " no longer uses "
                      << "it in its configuration";
@@ -321,7 +320,7 @@ namespace build2
       }
       catch (const io_error& e)
       {
-        fail << "unable to write " << name << ": " << e;
+        fail << "unable to write to " << on << ": " << e;
       }
     }
 
@@ -331,21 +330,23 @@ namespace build2
                  bool inherit,
                  const project_set& projects)
     {
-      const string& fs (f.string () != "-" ? f.string () : "<stdout>");
+      path_name fn (f);
+
+      if (f.string () == "-")
+        fn.name = "<stdout>";
 
       if (verb)
-        text << (verb >= 2 ? "cat >" : "save ") << fs;
+        text << (verb >= 2 ? "cat >" : "save ") << fn;
 
       try
       {
         ofdstream ofs;
-        ostream& os ();
-        save_config (rs, open_file_or_stdout (f, ofs), fs, inherit, projects);
+        save_config (rs, open_file_or_stdout (fn, ofs), fn, inherit, projects);
         ofs.close ();
       }
       catch (const io_error& e)
       {
-        fail << "unable to write " << fs << ": " << e;
+        fail << "unable to write to " << fn << ": " << e;
       }
     }
 
diff --git a/libbuild2/config/operation.hxx b/libbuild2/config/operation.hxx
index 9ec854a..1b4a452 100644
--- a/libbuild2/config/operation.hxx
+++ b/libbuild2/config/operation.hxx
@@ -36,7 +36,7 @@ namespace build2
     //
     void
     save_config (const scope& rs,
-                 ostream&, const string& name,
+                 ostream&, const path_name&,
                  bool inherit,
                  const project_set&);
   }
diff --git a/libbuild2/config/utility.cxx b/libbuild2/config/utility.cxx
index 8a99a8b..56c1f79 100644
--- a/libbuild2/config/utility.cxx
+++ b/libbuild2/config/utility.cxx
@@ -215,7 +215,7 @@ namespace build2
         }
         catch (const io_error& e)
         {
-          fail << "unable to write " << f << ": " << e;
+          fail << "unable to write to " << f << ": " << e;
         }
       }
 
@@ -263,7 +263,7 @@ namespace build2
         }
         catch (const io_error& e)
         {
-          fail << "unable to write " << f << ": " << e;
+          fail << "unable to write to " << f << ": " << e;
         }
       }
 
@@ -287,7 +287,7 @@ namespace build2
         }
         catch (const io_error& e)
         {
-          fail << "unable to write " << f << ": " << e;
+          fail << "unable to write to " << f << ": " << e;
         }
       }
     }
diff --git a/libbuild2/context.cxx b/libbuild2/context.cxx
index b4a3e93..9ed69a5 100644
--- a/libbuild2/context.cxx
+++ b/libbuild2/context.cxx
@@ -284,7 +284,8 @@ namespace build2
       // (basically what's necessary inside a double-quoted literal plus the
       // single quote).
       //
-      lexer l (is, path ("<cmdline>"), 1 /* line */, "\'\"\\$(");
+      path in ("<cmdline>"); // @@ PATH_NAME: make name
+      lexer l (is, in, 1 /* line */, "\'\"\\$(");
 
       // At the buildfile level the scope-specific variable should be
       // separated from the directory with a whitespace, for example:
diff --git a/libbuild2/diagnostics.cxx b/libbuild2/diagnostics.cxx
index f1b8f74..8c1805c 100644
--- a/libbuild2/diagnostics.cxx
+++ b/libbuild2/diagnostics.cxx
@@ -109,7 +109,7 @@ namespace build2
 
     if (!loc_.empty ())
     {
-      r << *loc_.file << ':';
+      r << loc_.file << ':';
 
       if (!diag_no_line)
       {
diff --git a/libbuild2/diagnostics.hxx b/libbuild2/diagnostics.hxx
index 6d06dec..9008fc3 100644
--- a/libbuild2/diagnostics.hxx
+++ b/libbuild2/diagnostics.hxx
@@ -300,6 +300,15 @@ namespace build2
     location_prologue_base (const char* type,
                             const char* mod,
                             const char* name,
+                            const path_name& f,
+                            stream_verbosity sverb)
+        : type_ (type), mod_ (mod), name_ (name),
+          loc_ (f),
+          sverb_ (sverb) {}
+
+    location_prologue_base (const char* type,
+                            const char* mod,
+                            const char* name,
                             path&& f,
                             stream_verbosity sverb)
         : type_ (type), mod_ (mod), name_ (name),
@@ -346,6 +355,12 @@ namespace build2
       return location_prologue (epilogue_, type_, mod_, name_, l, sverb_ ());
     }
 
+    location_prologue
+    operator() (const path_name& f) const
+    {
+      return location_prologue (epilogue_, type_, mod_, name_, f, sverb_ ());
+    }
+
     // fail (relative (src)) << ...
     //
     location_prologue
diff --git a/libbuild2/dist/operation.cxx b/libbuild2/dist/operation.cxx
index ad829df..e3dadff 100644
--- a/libbuild2/dist/operation.cxx
+++ b/libbuild2/dist/operation.cxx
@@ -144,7 +144,7 @@ namespace build2
       // since the meta operation is dist and we know what we are doing.
       //
       values params;
-      const path locf ("<dist>");
+      const path locf ("<dist>"); // @@ PATH_NAME TODO
       const location loc (&locf); // Dummy location.
 
       const operations& ops (rs->root_extra->operations);
@@ -822,7 +822,7 @@ namespace build2
         }
         catch (const io_error& e)
         {
-          fail << "unable to write " << cp << ": " << e;
+          fail << "unable to write to " << cp << ": " << e;
         }
       }
 
diff --git a/libbuild2/file.cxx b/libbuild2/file.cxx
index 974dc2b..2bc9af6 100644
--- a/libbuild2/file.cxx
+++ b/libbuild2/file.cxx
@@ -188,14 +188,17 @@ namespace build2
   static void
   source (scope& root, scope& base, const path& bf, bool boot)
   {
+    path_name fn (bf);
     try
     {
+      // @@ PATH_NAME TODO
+      //
       ifdstream ifs;
-      return source (root, base, open_file_or_stdin (bf, ifs), bf, boot);
+      return source (root, base, open_file_or_stdin (fn, ifs), bf /* fn */, boot);
     }
     catch (const io_error& e)
     {
-      fail << "unable to read buildfile " << bf << ": " << e;
+      fail << "unable to read buildfile " << fn << ": " << e;
     }
   }
 
diff --git a/libbuild2/lexer+comment.test.testscript b/libbuild2/lexer+comment.test.testscript
index 6ad1202..5cc9b47 100644
--- a/libbuild2/lexer+comment.test.testscript
+++ b/libbuild2/lexer+comment.test.testscript
@@ -134,6 +134,6 @@
   #\
   comment
   EOI
-  stdin:3:1: error: unterminated multi-line comment
+  <stdin>:3:1: error: unterminated multi-line comment
   EOE
 }
diff --git a/libbuild2/lexer+eval.test.testscript b/libbuild2/lexer+eval.test.testscript
index 86f804a..963f3d0 100644
--- a/libbuild2/lexer+eval.test.testscript
+++ b/libbuild2/lexer+eval.test.testscript
@@ -66,11 +66,11 @@ EOO
 : newline
 :
 $* <'x' >- 2>>EOE != 0
-stdin:1:2: error: newline in evaluation context
+<stdin>:1:2: error: newline in evaluation context
 EOE
 
 : eof
 :
 $* <:'' 2>>EOE != 0
-stdin:1:1: error: unterminated evaluation context
+<stdin>:1:1: error: unterminated evaluation context
 EOE
diff --git a/libbuild2/lexer.hxx b/libbuild2/lexer.hxx
index a2c7431..bd2ac74 100644
--- a/libbuild2/lexer.hxx
+++ b/libbuild2/lexer.hxx
@@ -84,13 +84,14 @@ namespace build2
   public:
     // If escape is not NULL then only escape sequences with characters from
     // this string are considered "effective escapes" with all others passed
-    // through as is. Note that the escape string is not copied.
+    // through as is. Note that neither the name nor escape arguments are
+    // copied.
     //
     lexer (istream& is,
            const path& name,
            uint64_t line = 1, // Start line in the stream.
            const char* escapes = nullptr)
-        : lexer (is, name, line, escapes, true /* set_mode */) {}
+      : lexer (is, name, line, escapes, true /* set_mode */) {}
 
     const path&
     name () const {return name_;}
@@ -180,13 +181,11 @@ namespace build2
     // Lexer state.
     //
   protected:
-    lexer (istream& is,
-           const path& name,
-           uint64_t line,
+    lexer (istream& is, const path& name, uint64_t line,
            const char* escapes,
            bool set_mode)
         : char_scanner (is, true /* crlf */, line),
-          fail ("error", &name_),
+          fail ("error", &name),
           name_ (name),
           sep_ (false)
     {
@@ -194,7 +193,7 @@ namespace build2
         mode (lexer_mode::normal, '@', escapes);
     }
 
-    const path name_; // @@ TODO: why not shallow (like istream)?
+    const path& name_;
     std::stack<state> state_;
 
     bool sep_; // True if we skipped spaces in peek().
diff --git a/libbuild2/lexer.test.cxx b/libbuild2/lexer.test.cxx
index 84520d1..2e2f152 100644
--- a/libbuild2/lexer.test.cxx
+++ b/libbuild2/lexer.test.cxx
@@ -48,7 +48,8 @@ namespace build2
 
       // Most alternative modes auto-expire so we need something underneath.
       //
-      lexer l (cin, path ("stdin"));
+      path in ("<stdin>"); // @@ PATH_NAME TODO
+      lexer l (cin, in);
 
       if (m != lexer_mode::normal)
         l.mode (m);
diff --git a/libbuild2/parser.cxx b/libbuild2/parser.cxx
index 533853c..7289338 100644
--- a/libbuild2/parser.cxx
+++ b/libbuild2/parser.cxx
@@ -1622,7 +1622,7 @@ namespace build2
           });
 
         source (is,
-                path ("<stdout>"),
+                path ("<stdout>"), // @@ PATH_NAME TODO
                 l,
                 false /* enter */,
                 false /* default_target */);
@@ -5382,7 +5382,7 @@ namespace build2
   // normally: perform(update($identity(foo/ bar/))).
   //
   buildspec parser::
-  parse_buildspec (istream& is, const path& name)
+  parse_buildspec (istream& is, const path& name) // @@ PATH_NAME TODO
   {
     path_ = &name;
 
diff --git a/libbuild2/test/script/lexer+description-line.test.testscript b/libbuild2/test/script/lexer+description-line.test.testscript
index bb5948a..3fa51bd 100644
--- a/libbuild2/test/script/lexer+description-line.test.testscript
+++ b/libbuild2/test/script/lexer+description-line.test.testscript
@@ -29,5 +29,5 @@ EOO
 $* <:"foo" >>EOO 2>>EOE != 0
 'foo'
 EOO
-stdin:1:4: error: expected newline at the end of description line
+<stdin>:1:4: error: expected newline at the end of description line
 EOE
diff --git a/libbuild2/test/script/lexer+variable.test.testscript b/libbuild2/test/script/lexer+variable.test.testscript
index 64b2bee..7c0807a 100644
--- a/libbuild2/test/script/lexer+variable.test.testscript
+++ b/libbuild2/test/script/lexer+variable.test.testscript
@@ -65,6 +65,6 @@ test.arguments = variable
   : multi-digit
   :
   $* <"10" 2>>EOE != 0
-  stdin:1:1: error: multi-digit special variable name
+  <stdin>:1:1: error: multi-digit special variable name
   EOE
 }
diff --git a/libbuild2/test/script/lexer.hxx b/libbuild2/test/script/lexer.hxx
index d96e91b..4083161 100644
--- a/libbuild2/test/script/lexer.hxx
+++ b/libbuild2/test/script/lexer.hxx
@@ -45,15 +45,15 @@ namespace build2
         using base_lexer = build2::lexer;
         using base_mode = build2::lexer_mode;
 
+        // Note that neither the name nor escape arguments are copied.
+        //
         lexer (istream& is,
                const path& name,
                lexer_mode m,
                const char* escapes = nullptr)
-            : base_lexer (is,
-                          name,
-                          1       /* line */,
-                          nullptr /* escapes */,
-                          false   /* set_mode */)
+            : base_lexer (is, name, 1 /* line */,
+                          nullptr     /* escapes */,
+                          false       /* set_mode */)
         {
           mode (m, '\0', escapes);
         }
diff --git a/libbuild2/test/script/lexer.test.cxx b/libbuild2/test/script/lexer.test.cxx
index 5a421b8..fc26acc 100644
--- a/libbuild2/test/script/lexer.test.cxx
+++ b/libbuild2/test/script/lexer.test.cxx
@@ -53,7 +53,8 @@ namespace build2
                   m == lexer_mode::description_line ||
                   m == lexer_mode::variable);
 
-          lexer l (cin, path ("stdin"), u ? lexer_mode::command_line : m);
+          path in ("<stdin>"); // @@ PATH_NAME TODO
+          lexer l (cin, in, u ? lexer_mode::command_line : m);
           if (u)
             l.mode (m);
 
diff --git a/libbuild2/test/script/parser.cxx b/libbuild2/test/script/parser.cxx
index bc06ce8..d5e437b 100644
--- a/libbuild2/test/script/parser.cxx
+++ b/libbuild2/test/script/parser.cxx
@@ -2302,9 +2302,9 @@ namespace build2
                   // cmd $args               # cmd x="foo bar"
                   //
 
-                  path name ("<string>");
                   istringstream is (s);
-                  lexer lex (is, name,
+                  path in ("<string>"); // @@ PATH_NAME TODO
+                  lexer lex (is, in,
                              lexer_mode::command_expansion,
                              "\'\"\\");
 
@@ -2315,7 +2315,7 @@ namespace build2
                   // fail(t). Rather we should do fail(l).
                   //
                   token t (lex.next ());
-                  location l (build2::get_location (t, name));
+                  location l (build2::get_location (t, in));
                   t.separated = true;
 
                   string w;
@@ -2324,7 +2324,7 @@ namespace build2
                   for (; t.type != type::eos; t = lex.next ())
                   {
                     type tt (t.type);
-                    l = build2::get_location (t, name);
+                    l = build2::get_location (t, in);
 
                     // Re-lexing double-quotes will recognize $, ( inside as
                     // tokens so we have to reverse them back. Since we don't
diff --git a/libbuild2/test/script/runner.cxx b/libbuild2/test/script/runner.cxx
index 520be43..e56dc41 100644
--- a/libbuild2/test/script/runner.cxx
+++ b/libbuild2/test/script/runner.cxx
@@ -167,7 +167,7 @@ namespace build2
         }
         catch (const io_error& e)
         {
-          fail (ll) << "unable to write " << p << ": " << e;
+          fail (ll) << "unable to write to " << p << ": " << e;
         }
       }
 
@@ -339,7 +339,7 @@ namespace build2
             }
             catch (const io_error& e)
             {
-              fail (ll) << "unable to write " << ep << ": " << e;
+              fail (ll) << "unable to write to " << ep << ": " << e;
             }
 
             // Diff utility prints the differences to stdout. But for the
@@ -1134,7 +1134,7 @@ namespace build2
                                       value (move (ns)),
                                       *ats,
                                       token_type::assign,
-                                      path ("<attributes>"));
+                                      path ("<attributes>")); // @@ PATH_NAME TODO
           }
         }
         catch (const io_error& e)
@@ -1536,7 +1536,7 @@ namespace build2
           }
           catch (const io_error& e)
           {
-            fail (ll) << "unable to write " << p << ": " << e;
+            fail (ll) << "unable to write to " << p << ": " << e;
           }
 
           return fd;
diff --git a/libbuild2/types.hxx b/libbuild2/types.hxx
index b14a365..192b01f 100644
--- a/libbuild2/types.hxx
+++ b/libbuild2/types.hxx
@@ -227,6 +227,7 @@ namespace build2
   // <libbutl/path-map.mxx>
   //
   using butl::path;
+  using butl::path_name;
   using butl::dir_path;
   using butl::path_cast;
   using butl::basic_path;
@@ -274,13 +275,13 @@ namespace build2
   using butl::sha256;
 
   // <libbutl/process.mxx>
-  // <libbutl/fdstream.mxx>
-  //
   using butl::process;
   using butl::process_env;
   using butl::process_path;
   using butl::process_error;
 
+  // <libbutl/fdstream.mxx>
+  //
   using butl::auto_fd;
   using butl::ifdstream;
   using butl::ofdstream;
@@ -319,12 +320,16 @@ namespace build2
     location (const path* f = nullptr, uint64_t l = 0, uint64_t c = 0)
         : file (f), line (l), column (c) {}
 
+    explicit
+    location (const path_name& f, uint64_t l = 0, uint64_t c = 0)
+        : file (f), line (l), column (c) {}
+
     bool
-    empty () const {return file == nullptr;}
+    empty () const {return file.path == nullptr;}
 
-    const path* file;
-    uint64_t    line;
-    uint64_t    column;
+    path_name file;
+    uint64_t  line;
+    uint64_t  column;
   };
 
   // See context.
@@ -342,11 +347,14 @@ namespace build2
 //
 namespace std
 {
-  // Path printing with trailing slash for directories.
+  // Path printing potentially relative with trailing slash for directories.
   //
   LIBBUILD2_SYMEXPORT ostream&
   operator<< (ostream&, const ::butl::path&);
 
+  LIBBUILD2_SYMEXPORT ostream&
+  operator<< (ostream&, const ::butl::path_name&);
+
   // Print as recall[@effect].
   //
   LIBBUILD2_SYMEXPORT ostream&
diff --git a/libbuild2/utility.cxx b/libbuild2/utility.cxx
index 7f40688..b7637f5 100644
--- a/libbuild2/utility.cxx
+++ b/libbuild2/utility.cxx
@@ -8,7 +8,7 @@
 
 #include <cerrno>   // ENOENT
 #include <cstring>  // strlen(), str[n]cmp()
-#include <iostream> // cin cout cerr
+#include <iostream> // cerr
 
 #include <libbuild2/target.hxx>
 #include <libbuild2/context.hxx>
@@ -45,6 +45,12 @@ namespace std
   }
 
   ostream&
+  operator<< (ostream& os, const ::butl::path_name& pn)
+  {
+    return pn.name ? (os << *pn.name) : (os << *pn.path);
+  }
+
+  ostream&
   operator<< (ostream& os, const ::butl::process_path& p)
   {
     using namespace build2;
@@ -100,36 +106,6 @@ namespace build2
   dir_path home;
   const dir_path* relative_base = &work;
 
-  istream&
-  open_file_or_stdin (const path& f, ifdstream& ifs)
-  {
-    if (f.string () != "-")
-    {
-      ifs.open (f);
-      return ifs;
-    }
-    else
-    {
-      cin.exceptions (ifdstream::failbit | ifdstream::badbit);
-      return cin;
-    }
-  }
-
-  ostream&
-  open_file_or_stdout (const path& f, ofdstream& ofs)
-  {
-    if (f.string () != "-")
-    {
-      ofs.open (f);
-      return ofs;
-    }
-    else
-    {
-      cout.exceptions (ofdstream::failbit | ofdstream::badbit);
-      return cout;
-    }
-  }
-
   path
   relative (const path_target& t)
   {
@@ -141,7 +117,7 @@ namespace build2
   string
   diag_relative (const path& p, bool cur)
   {
-    if (p.string () == "-")
+    if (p.string () == "-") // @@ PATH_NAME: remove
       return "<stdin>";
 
     const path& b (*relative_base);
diff --git a/libbuild2/utility.hxx b/libbuild2/utility.hxx
index 8cd33cf..23ad19b 100644
--- a/libbuild2/utility.hxx
+++ b/libbuild2/utility.hxx
@@ -88,18 +88,10 @@ namespace build2
 
   using butl::eof;
 
-  // Open a file or, if the file name is `-`, stdin/stdout.
+  // <libbutl/fdstream.mxx>
   //
-  // Note that ofdstream::close() should be called explicitly if not stdout
-  // (but harmless to call even if it is). Also note that our overload of
-  // operator<<(path) always translats `-` to `<stdin>` so care must be taken
-  // when issuing diagnostics.
-  //
-  istream&
-  open_file_or_stdin (const path&, ifdstream&);
-
-  ostream&
-  open_file_or_stdout (const path&, ofdstream&);
+  using butl::open_file_or_stdin;
+  using butl::open_file_or_stdout;
 
   // Diagnostics state (verbosity level, etc; see <libbuild2/diagnostics.hxx>).
   //
-- 
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