1 files changed, 115 insertions, 0 deletions
diff --git a/libbuild2/utility.txx b/libbuild2/utility.txx
new file mode 100644
index 0000000..a91cb15
--- /dev/null
+++ b/libbuild2/utility.txx
@@ -0,0 +1,115 @@
+// file      : libbuild2/utility.txx -*- C++ -*-
+// copyright : Copyright (c) 2014-2019 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+namespace build2
+{
+  template <typename I, typename F>
+  void
+  append_option_values (cstrings& args, const char* o, I b, I e, F&& get)
+  {
+    if (b != e)
+    {
+      args.reserve (args.size () + (e - b));
+
+      for (; b != e; ++b)
+      {
+        args.push_back (o);
+        args.push_back (get (*b));
+      }
+    }
+  }
+
+  template <typename I, typename F>
+  void
+  hash_option_values (sha256& cs, const char* o, I b, I e, F&& get)
+  {
+    for (; b != e; ++b)
+    {
+      cs.append (o);
+      cs.append (get (*b));
+    }
+  }
+
+  template <typename K>
+  basic_path<char, K>
+  relative (const basic_path<char, K>& p)
+  {
+    typedef basic_path<char, K> path;
+
+    const dir_path& b (*relative_base);
+
+    if (p.simple () || b.empty ())
+      return p;
+
+    if (p.sub (b))
+      return p.leaf (b);
+
+    if (p.root_directory () == b.root_directory ())
+    {
+      path r (p.relative (b));
+
+      if (r.string ().size () < p.string ().size ())
+        return r;
+    }
+
+    return p;
+  }
+
+  template <typename T, typename F>
+  T
+  run (uint16_t verbosity,
+       const process_env& pe,
+       const char* args[],
+       F&& f,
+       bool err,
+       bool ignore_exit,
+       sha256* checksum)
+  {
+    process pr (run_start (verbosity,
+                           pe,
+                           args,
+                           0  /* stdin */,
+                           -1 /* stdout */,
+                           err));
+    T r;
+    string l; // Last line of output.
+
+    try
+    {
+      ifdstream is (move (pr.in_ofd), butl::fdstream_mode::skip);
+
+      // Make sure we keep the last line.
+      //
+      for (bool last (is.peek () == ifdstream::traits_type::eof ());
+           !last && getline (is, l); )
+      {
+        last = (is.peek () == ifdstream::traits_type::eof ());
+
+        trim (l);
+
+        if (checksum != nullptr)
+          checksum->append (l);
+
+        if (r.empty ())
+        {
+          r = f (l, last);
+
+          if (!r.empty () && checksum == nullptr)
+            break;
+        }
+      }
+
+      is.close ();
+    }
+    catch (const io_error&)
+    {
+      // Presumably the child process failed. Let run_finish() deal with that.
+    }
+
+    if (!(run_finish (args, pr, err, l) || ignore_exit))
+      r = T ();
+
+    return r;
+  }
+}