Add default options loading and merging API

1 files changed, 186 insertions, 0 deletions

diff --git a/tests/default-options/driver.cxx b/tests/default-options/driver.cxx
new file mode 100644
index 0000000..a2ed43d
--- /dev/null
+++ b/tests/default-options/driver.cxx
@@ -0,0 +1,186 @@
+// file      : tests/default-options/driver.cxx -*- C++ -*-
+// copyright : Copyright (c) 2014-2019 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#include <cassert>
+
+#ifndef __cpp_lib_modules_ts
+#include <string>
+#include <vector>
+#include <iostream>
+#endif
+
+// Other includes.
+
+#ifdef __cpp_modules_ts
+#ifdef __cpp_lib_modules_ts
+import std.core;
+import std.io;
+#endif
+import butl.path;
+import butl.path_io;
+import butl.optional;
+import butl.fdstream;
+import butl.default_options;
+#else
+#include <libbutl/path.mxx>
+#include <libbutl/path-io.mxx>
+#include <libbutl/utility.mxx>         // eof()
+#include <libbutl/optional.mxx>
+#include <libbutl/fdstream.mxx>
+#include <libbutl/default-options.mxx>
+#endif
+
+using namespace std;
+using namespace butl;
+
+// Usage: argv[0] [-f <file>] [-d <start-dir>] [-s <sys-dir>] [-h <home-dir>]
+//                [-e] <cmd-options>
+//
+// Parse default options files, merge them with the command line options, and
+// print the resulting options to STDOUT one per line. Note that the options
+// instance is a vector of arbitrary strings.
+//
+// -f
+//    Default options file name. Can be specified multiple times.
+//
+// -d
+//    Directory to start the default options files search from.
+//
+// -s
+//    System directory.
+//
+// -h
+//    Home directory.
+//
+// -e
+//    Print the default options entries (rather than the merged options) to
+//    STDOUT one per line in the following format:
+//
+//    <file>,<space-separated-options>,<remote>
+//
+int
+main (int argc, const char* argv[])
+{
+  using butl::optional;
+
+  class scanner
+  {
+  public:
+    scanner (const string& f): ifs_ (f, fdopen_mode::in, ifdstream::badbit) {}
+
+    optional<string>
+    next ()
+    {
+      string s;
+      return !eof (getline (ifs_, s)) ? optional<string> (move (s)) : nullopt;
+    }
+
+  private:
+    ifdstream ifs_;
+  };
+
+  enum class unknow_mode
+  {
+    fail
+  };
+
+  class options: public vector<string>
+  {
+  public:
+    bool
+    parse (scanner& s, unknow_mode, unknow_mode)
+    {
+      bool r (false);
+      while (optional<string> o = s.next ())
+      {
+        push_back (move (*o));
+        r = true;
+      }
+      return r;
+    }
+
+    void
+    merge (const options& o)
+    {
+      insert (end (), o.begin (), o.end ());
+    }
+  };
+
+  // Parse and validate the arguments.
+  //
+  default_options_files fs;
+  optional<dir_path> sys_dir;
+  optional<dir_path> home_dir;
+  options cmd_ops;
+  bool print_entries (false);
+
+  for (int i (1); i != argc; ++i)
+  {
+    string op (argv[i]);
+
+    if (op == "-f")
+    {
+      assert (++i != argc);
+      fs.files.push_back (path (argv[i]));
+    }
+    else if (op == "-d")
+    {
+      assert (++i != argc);
+      fs.start_dir = dir_path (argv[i]);
+    }
+    else if (op == "-s")
+    {
+      assert (++i != argc);
+      sys_dir = dir_path (argv[i]);
+    }
+    else if (op == "-h")
+    {
+      assert (++i != argc);
+      home_dir = dir_path (argv[i]);
+    }
+    else if (op == "-e")
+    {
+      print_entries = true;
+    }
+    else
+      cmd_ops.push_back (argv[i]);
+  }
+
+  // Load and print the default options.
+  //
+  default_options<options> def_ops (
+    load_default_options<options, scanner, unknow_mode> (sys_dir,
+                                                         home_dir,
+                                                         fs));
+
+  if (print_entries)
+  {
+    for (const default_options_entry<options>& e: def_ops)
+    {
+      cout << e.file << ',';
+
+      for (const string& o: e.options)
+      {
+        if (&o != &e.options[0])
+          cout << ' ';
+
+        cout << o;
+      }
+
+      cout << (e.remote ? ",true" : ",false") << endl;
+    }
+  }
+
+  // Merge the options and print the result.
+  //
+  options ops (merge_default_options (def_ops, cmd_ops));
+
+  if (!print_entries)
+  {
+    for (const string& o: ops)
+      cout << o << endl;
+  }
+
+  return 0;
+}