build/bd.cxx


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

#include <time.h> // tzset()

#include <vector>
#include <cstdlib>      // exit
#include <cassert>
#include <iostream>
#include <typeinfo>
#include <system_error>

#include <build/target>
#include <build/rule>
#include <build/process>

using namespace std;

namespace build
{
  bool
  match (target& t)
  {
    // Because we match the target first and then prerequisites,
    // any additional dependency information injected by the rule
    // will be covered as well.
    //
    if (!t.recipe ())
    {
      for (auto ti (&t.type_id ());
           ti != nullptr && !t.recipe ();
           ti = ti->base)
      {
        for (auto rs (rules.equal_range (ti->id));
             rs.first != rs.second;
             ++rs.first)
        {
          const rule& ru (rs.first->second);

          if (recipe re = ru.match (t))
          {
            t.recipe (re);
            break;
          }
        }
      }

      if (!t.recipe ())
      {
        cerr << "error: no rule to update target " << t << endl;
        return false;
      }
    }

    for (target& p: t.prerequisites ())
    {
      if (!match (p))
      {
        cerr << "info: required by " << t << endl;
        return false;
      }
    }

    return true;
  }

  target_state
  update (target& t)
  {
    assert (t.state () == target_state::unknown);

    target_state ts;

    for (target& p: t.prerequisites ())
    {
      if (p.state () == target_state::unknown)
      {
        p.state ((ts = update (p)));

        if (ts == target_state::failed)
          return ts;
      }
    }

    try
    {
      t.state ((ts = t.recipe () (t)));
      assert (ts != target_state::unknown);
      return ts;
    }
    catch (const process_error& e)
    {
      // Take care of failed children. In a multi-threaded program that
      // fork()'ed but did not exec(), it is unwise to try to do any kind
      // of cleanup (like unwinding the stack and running destructors).
      //
      assert (e.child ());
      exit (1);
    }
  }
}

#include <build/native>

#include <build/cxx/target>
#include <build/cxx/rule>


using namespace build;

int
main (int argc, char* argv[])
{
  // Initialize time conversion data that is used by localtime_r().
  //
  tzset ();

  cxx::link cxx_link;
  rules.emplace (typeid (exe), cxx_link);

  cxx::compile cxx_compile;
  rules.emplace (typeid (obj), cxx_compile);

  default_path_rule path_exists;
  rules.emplace (typeid (path_target), path_exists);

  //
  //
  using namespace build::cxx;

  exe bd ("bd");
  obj bd_o ("bd");
  bd.prerequisite (bd_o);

  cxx::cxx bd_cxx ("bd");
  bd_cxx.path (path ("bd.cxx"));

  bd_o.prerequisite (bd_cxx);

  //
  //
  if (!match (bd))
    return 1; // Diagnostics has already been issued.

  switch (update (bd))
  {
  case target_state::uptodate:
    {
      cerr << "info: target " << bd << " is up to date" << endl;
      break;
    }
  case target_state::updated:
    break;
  case target_state::failed:
    {
      cerr << "error: failed to update target " << bd << endl;
      return 1;
    }
  case target_state::unknown:
    assert (false);
  }
}