build/config/utility.cxx


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83

// file      : build/config/utility.cxx -*- C++ -*-
// copyright : Copyright (c) 2014-2015 Code Synthesis Ltd
// license   : MIT; see accompanying LICENSE file

#include <build/config/utility>

#include <build/context>

using namespace std;

namespace build
{
  namespace config
  {
    const value&
    optional (scope& root, const variable& var)
    {
      auto l (root[var]);

      return l.defined ()
        ? l.belongs (*global_scope) ? (root.assign (var) = *l) : *l
        : root.assign (var); // NULL
    }

    const value&
    optional_absolute (scope& root, const variable& var)
    {
      auto l (root[var]);

      if (!l.defined ())
        return root.assign (var); // NULL

      if (!l.belongs (*global_scope)) // Value from (some) root scope.
        return *l;

      // Make the command-line value absolute. This is necessary to avoid
      // a warning issued by the config module about global/root scope
      // value mismatch.
      //
      value& v (const_cast<value&> (*l));

      if (v && !v.empty ())
      {
        dir_path& d (as<dir_path> (v));

        if (d.relative ())
        {
          d = work / d;
          d.normalize ();
        }
      }

      return root.assign (var) = v;
    }

    bool
    specified (scope& r, const string& ns)
    {
      // Search all outer scopes for any value in this namespace.
      //
      for (scope* s (&r); s != nullptr; s = s->parent_scope ())
      {
        auto p (s->vars.find_namespace (ns));
        if (p.first != p.second)
          return true;
      }

      return false;
    }

    void
    append_options (cstrings& args, const const_strings_value& sv)
    {
      if (!sv.empty ())
      {
        args.reserve (args.size () + sv.size ());

        for (const string& s: sv)
          args.push_back (s.c_str ());
      }
    }
  }
}