// file      : build2/cc/module.cxx -*- C++ -*-
// copyright : Copyright (c) 2014-2016 Code Synthesis Ltd
// license   : MIT; see accompanying LICENSE file

#include <build2/cc/module>

#include <iomanip> // left, setw()

#include <butl/triplet>

#include <build2/scope>
#include <build2/context>
#include <build2/diagnostics>

#include <build2/bin/target>

#include <build2/config/utility>
#include <build2/install/utility>

#include <build2/cc/guess>

using namespace std;
using namespace butl;

namespace build2
{
  namespace cc
  {
    void config_module::
    init (scope& r,
          scope& b,
          const location& loc,
          bool first,
          const variable_map&)
    {
      tracer trace (x, "config_init");

      bool cc_loaded (cast_false<bool> (b["cc.core.config.loaded"]));

      // Configure.
      //
      compiler_info ci; // For program patterns.

      if (first)
      {
        // Adjust module priority (compiler). Also order cc module before us
        // (we don't want to use priorities for that in case someone manages
        // to slot in-between).
        //
        if (!cc_loaded)
          config::save_module (r, "cc", 250);

        config::save_module (r, x, 250);

        const variable& config_c_coptions (var_pool["config.cc.coptions"]);

        // config.x
        //

        // Normally we will have a persistent configuration and computing the
        // default value every time will be a waste. So try without a default
        // first.
        //
        auto p (config::omitted (r, config_x));

        if (p.first == nullptr)
        {
          // If someone already loaded cc.core.config then use its toolchain
          // id and (optional) pattern to guess an appropriate default (e.g.,
          // for {gcc, *-4.9} we will get g++-4.9).
          //
          path d (cc_loaded
                  ? guess_default (x_lang,
                                   cast<string> (r["cc.id"]),
                                   cast_null<string> (r["cc.pattern"]))
                  : path (x_default));

          // If this value was hinted, save it as commented out so that if the
          // user changes the source of the pattern, this one will get updated
          // as well.
          //
          auto p1 (config::required (r,
                                     config_x,
                                     d,
                                     false,
                                     cc_loaded ? config::save_commented : 0));
          p.first = &p1.first.get ();
          p.second = p1.second;
        }

        // Figure out which compiler we are dealing with, its target, etc.
        //
        const path& xc (cast<path> (*p.first));
        ci = guess (x_lang,
                    xc,
                    cast_null<strings> (r[config_c_coptions]),
                    cast_null<strings> (r[config_x_coptions]));

        // If this is a new value (e.g., we are configuring), then print the
        // report at verbosity level 2 and up (-v).
        //
        if (verb >= (p.second ? 2 : 3))
        {
          diag_record dr (text);

          {
            dr << x << ' ' << project (r) << '@' << r.out_path () << '\n'
               << "  " << left << setw (11) << x << ci.path << '\n'
               << "  id         " << ci.id << '\n'
               << "  version    " << ci.version.string << '\n'
               << "  major      " << ci.version.major << '\n'
               << "  minor      " << ci.version.minor << '\n'
               << "  patch      " << ci.version.patch << '\n';
          }

          if (!ci.version.build.empty ())
            dr << "  build      " << ci.version.build << '\n';

          {
            dr << "  signature  " << ci.signature << '\n'
               << "  target     " << ci.target << '\n';
          }

          if (!ci.cc_pattern.empty ()) // bin_pattern printed by bin
            dr << "  pattern    " << ci.cc_pattern << '\n';

          {
            dr << "  checksum   " << ci.checksum;
          }
        }

        r.assign (x_path) = move (ci.path);
        r.assign (x_id) = ci.id.string ();
        r.assign (x_id_type) = move (ci.id.type);
        r.assign (x_id_variant) = move (ci.id.variant);

        r.assign (x_version) = move (ci.version.string);
        r.assign (x_version_major) = ci.version.major;
        r.assign (x_version_minor) = ci.version.minor;
        r.assign (x_version_patch) = ci.version.patch;
        r.assign (x_version_build) = move (ci.version.build);

        r.assign (x_signature) = move (ci.signature);
        r.assign (x_checksum) = move (ci.checksum);

        // Split/canonicalize the target. First see if the user asked us to
        // use config.sub.
        //
        if (ops.config_sub_specified ())
        {
          ci.target = run<string> (ops.config_sub (),
                                   ci.target.c_str (),
                                   [] (string& l) {return move (l);});
          l5 ([&]{trace << "config.sub target: '" << ci.target << "'";});
        }

        try
        {
          string canon;
          triplet t (ci.target, canon);

          l5 ([&]{trace << "canonical target: '" << canon << "'; "
                        << "class: " << t.class_;});

          // Enter as x.target.{cpu,vendor,system,version,class}.
          //
          r.assign (x_target) = move (canon);
          r.assign (x_target_cpu) = move (t.cpu);
          r.assign (x_target_vendor) = move (t.vendor);
          r.assign (x_target_system) = move (t.system);
          r.assign (x_target_version) = move (t.version);
          r.assign (x_target_class) = move (t.class_);
        }
        catch (const invalid_argument& e)
        {
          // This is where we suggest that the user specifies --config-sub to
          // help us out.
          //
          fail << "unable to parse " << x_lang << "compiler target '"
               << ci.target << "': " << e.what () <<
            info << "consider using the --config-sub option";
        }
      }

      // config.x.{p,c,l}options
      // config.x.libs
      //
      // These are optional. We also merge them into the corresponding
      // x.* variables.
      //
      // The merging part gets a bit tricky if this module has already
      // been loaded in one of the outer scopes. By doing the straight
      // append we would just be repeating the same options over and
      // over. So what we are going to do is only append to a value if
      // it came from this scope. Then the usage for merging becomes:
      //
      // x.coptions = <overridable options> # Note: '='.
      // using x
      // x.coptions += <overriding options> # Note: '+='.
      //
      b.assign (x_poptions) += cast_null<strings> (
        config::optional (r, config_x_poptions));

      b.assign (x_coptions) += cast_null<strings> (
        config::optional (r, config_x_coptions));

      b.assign (x_loptions) += cast_null<strings> (
        config::optional (r, config_x_loptions));

      b.assign (x_libs) += cast_null<strings> (
        config::optional (r, config_x_libs));

      // Load cc.core.config.
      //
      if (!cc_loaded)
      {
        // Prepare configuration hints. They are only used on the first load
        // of cc.core.config so we only populate them on our first load.
        //
        variable_map h;
        if (first)
        {
          h.assign ("config.cc.id") = cast<string> (r[x_id]);
          h.assign ("config.cc.target") = cast<string> (r[x_target]);

          if (!ci.cc_pattern.empty ())
            h.assign ("config.cc.pattern") = move (ci.cc_pattern);

          if (!ci.bin_pattern.empty ())
            h.assign ("config.bin.pattern") = move (ci.bin_pattern);
        }

        load_module ("cc.core.config", r, b, loc, false, h);
      }
      else if (first)
      {
        // If cc.core.config is already loaded, verify its configuration
        // matched ours since it could have been loaded by another c-family
        // module.
        //
        auto check = [&r, &loc, this](const char* cvar,
                                      const variable& xvar,
                                      const char* w)
        {
          const string& cv (cast<string> (r[cvar]));
          const string& xv (cast<string> (r[xvar]));

          if (cv != xv)
            fail (loc) << "cc and " << x << " module " << w << " mismatch" <<
              info << cvar << " is " << cv <<
              info << xvar.name << " is " << xv;
        };

        // Note that we don't require that patterns match. Presumably, if the
        // toolchain id and target are the same, then where exactly the tools
        // come from doesn't really matter.
        //
        check ("cc.id",     x_id,     "toolchain");
        check ("cc.target", x_target, "target");
      }
    }

    void module::
    init (scope& r,
          scope& b,
          const location& loc,
          bool,
          const variable_map&)
    {
      tracer trace (x, "init");

      // Load cc.core. Besides other things, this will load bin (core) plus
      // extra bin.* modules we may need.
      //
      if (!cast_false<bool> (b["cc.core.loaded"]))
        load_module ("cc.core", r, b, loc);

      // Register target types and configure their "installability".
      //
      {
        using namespace install;

        auto& t (b.target_types);

        t.insert (x_src);

        // Install headers into install.include.
        //
        for (const target_type* const* ht (x_hdr); *ht != nullptr; ++ht)
        {
          t.insert (**ht);
          install_path (**ht, b, dir_path ("include"));
        }
      }

      // Register rules.
      //
      {
        using namespace bin;

        auto& r (b.rules);

        // We register for configure so that we detect unresolved imports
        // during configuration rather that later, e.g., during update.
        //
        // @@ Should we check if install module was loaded (see bin)?
        //
        compile& cr (*this);
        link&    lr (*this);
        install& ir (*this);

        r.insert<obje> (perform_update_id,    x_compile, cr);
        r.insert<obje> (perform_clean_id,     x_compile, cr);
        r.insert<obje> (configure_update_id,  x_compile, cr);

        r.insert<exe>  (perform_update_id,    x_link, lr);
        r.insert<exe>  (perform_clean_id,     x_link, lr);
        r.insert<exe>  (configure_update_id,  x_link, lr);

        r.insert<exe>  (perform_install_id,   x_install, ir);
        r.insert<exe>  (perform_uninstall_id, x_uninstall, ir);

        // Only register static object/library rules if the bin.ar module is
        // loaded (by us or by the user).
        //
        if (cast_false<bool> (b["bin.ar.loaded"]))
        {
          r.insert<obja> (perform_update_id,    x_compile, cr);
          r.insert<obja> (perform_clean_id,     x_compile, cr);
          r.insert<obja> (configure_update_id,  x_compile, cr);

          r.insert<liba> (perform_update_id,    x_link, lr);
          r.insert<liba> (perform_clean_id,     x_link, lr);
          r.insert<liba> (configure_update_id,  x_link, lr);

          r.insert<liba> (perform_install_id,   x_install, ir);
          r.insert<liba> (perform_uninstall_id, x_uninstall, ir);
        }

        r.insert<objs> (perform_update_id,   x_compile, cr);
        r.insert<objs> (perform_clean_id,    x_compile, cr);
        r.insert<objs> (configure_update_id, x_compile, cr);

        r.insert<libs> (perform_update_id,   x_link, lr);
        r.insert<libs> (perform_clean_id,    x_link, lr);
        r.insert<libs> (configure_update_id, x_link, lr);

        r.insert<libs> (perform_install_id,   x_install, ir);
        r.insert<libs> (perform_uninstall_id, x_uninstall, ir);
      }
    }
  }
}