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// file : build/config/utility -*- C++ -*-
// copyright : Copyright (c) 2014-2015 Code Synthesis Ltd
// license : MIT; see accompanying LICENSE file
#ifndef BUILD_CONFIG_UTILITY
#define BUILD_CONFIG_UTILITY
#include <string>
#include <utility> // pair
#include <build/types>
#include <build/diagnostics>
namespace build
{
class scope;
class list_value;
namespace config
{
// Set, if necessary, a required config.* variable.
//
// Return the reference to the value as well as the indication of
// whether the variable has actually been set.
//
template <typename T>
std::pair<const T&, bool>
required (scope& root, const char* name, const T& default_value);
std::pair<const std::string&, bool>
required (scope& root, const char* name, const char* default_value);
// Set, if necessary, an optional config.* variable. In particular,
// an unspecified variable is set to NULL which is used to distinguish
// between the "configured as unspecified" and "not yet configured"
// cases.
//
// Return the pointer to the value, which can be NULL.
//
template <typename T>
const T*
optional (scope& root, const char* name);
// Add all the values from a variable to the C-string list. T is
// either target or scope.
//
template <typename T>
void
append_options (cstrings& args, T& s, const char* var)
{
if (auto val = s[var])
{
for (const name& n: val.template as<const list_value&> ())
{
if (n.simple ())
args.push_back (n.value.c_str ());
else if (n.directory ())
args.push_back (n.dir.string ().c_str ());
else
fail << "expected option instead of " << n <<
info << "in variable " << var;
}
}
}
// Check if a specified option is present. T is either target or scope.
//
template <typename T>
bool
find_option (const char* option, T& s, const char* var)
{
if (auto val = s[var])
{
for (const name& n: val.template as<const list_value&> ())
{
if (n.simple () && n.value == option)
return true;
}
}
return false;
}
}
}
#include <build/config/utility.txx>
#endif // BUILD_CONFIG_UTILITY
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