Implement auto-synchronization via build system hook

15 files changed, 289 insertions, 95 deletions

diff --git a/bdep/bdep.cxx b/bdep/bdep.cxx
index 2541325..82a4259 100644
--- a/bdep/bdep.cxx
+++ b/bdep/bdep.cxx
@@ -121,7 +121,8 @@ try
 {
   using namespace cli;
 
-  exec_dir = path (argv[0]).directory ();
+  argv0 = argv[0];
+  exec_dir = path (argv0).directory ();
 
   // This is a little hack to make our baseutils for Windows work when called
   // with absolute path. In a nutshell, MSYS2's exec*p() doesn't search in the
diff --git a/bdep/config.cli b/bdep/config.cli
index c9b2ce8..2c9e19f 100644
--- a/bdep/config.cli
+++ b/bdep/config.cli
@@ -39,7 +39,8 @@ namespace bdep
         \b{bdep config rename} [<options>] [<prj-spec>] <cfg-spec> <cfg-name>\n
         \b{bdep config set} \ \ \ [<options>] [<prj-spec>] <cfg-spec>\n
         \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ [\b{--}[\b{no-}]\b{default}]\n
-        \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ [\b{--}[\b{no-}]\b{forward}]}
+        \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ [\b{--}[\b{no-}]\b{forward}]\n
+        \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ [\b{--}[\b{no-}]\b{auto-sync}]}
 
      \c{<cfg-spec> = \b{@}<cfg-name> | \b{--config}|\b{-c} <cfg-dir>\n
         <prj-spec> = \b{--directory}|\b{-d} <prj-dir>\n
@@ -89,7 +90,14 @@ namespace bdep
          initialized in a forwarded build configuration, its source directory
          is configured to forward to this configuration (see \l{b(1)} for
          details on forwarded configurations). To forward to a non-default
-         configuration use the \cb{--forward} option.|
+         configuration use the \cb{--forward} option.
+
+         Unless the \cb{--no-auto-sync} option is specified, an added or
+         created build configuration will be automatically synchronized on
+         every build system invocation. Note that this flag affects the entire
+         build configuration and if multiple projects share the same
+         configuration, then they must have a consistent auto-synchronization
+         setting.|
 
      \li|\cb{remove}
 
@@ -106,10 +114,12 @@ namespace bdep
      \li|\cb{set}
 
          The \cb{set} subcommand sets various properties of the specified
-         build configuration. These include the default
-         (\c{\b{--}[\b{no-}]\b{default}}) and forward
-         (\c{\b{--}[\b{no-}]\b{forward}}) flags. Note that changing the
-         forward flag requires an explicit \cb{sync} command to take effect.||"
+         build configuration. These include the
+         default (\c{\b{--}[\b{no-}]\b{default}}),
+         forward (\c{\b{--}[\b{no-}]\b{forward}}), and
+         auto-synchronization (\c{\b{--}[\b{no-}]\b{auto-sync}}) flags.
+         Note that changing any of these flags requires an explicit
+         \cb{sync} command to take effect.||"
 
     bool add;
     bool create;
diff --git a/bdep/config.cxx b/bdep/config.cxx
index 0dcea48..aeb1a5f 100644
--- a/bdep/config.cxx
+++ b/bdep/config.cxx
@@ -13,14 +13,13 @@ using namespace std;
 namespace bdep
 {
   shared_ptr<configuration>
-  cmd_config_add (const dir_path&    prj,
-                  database&          db,
-                  dir_path           path,
-                  optional<string>   name,
-                  optional<bool>     def,
-                  optional<bool>     fwd,
-                  optional<uint64_t> id,
-                  const char*        what)
+  cmd_config_add (const configuration_add_options& ao,
+                  const dir_path&                  prj,
+                  database&                        db,
+                  dir_path                         path,
+                  optional<string>                 name,
+                  optional<uint64_t>               id,
+                  const char*                      what)
   {
     if (!exists (path))
       fail << "configuration directory " << path << " does not exist";
@@ -29,11 +28,15 @@ namespace bdep
 
     using count = configuration_count;
 
+    optional<bool> def, fwd;
     {
       using query = bdep::query<configuration>;
 
       // By default the first added configuration is the default.
       //
+      if (ao.default_ () || ao.no_default ())
+        def = ao.default_ () && !ao.no_default ();
+
       if (!def)
         def = (db.query_value<count> () == 0);
       else if (*def)
@@ -46,6 +49,9 @@ namespace bdep
       // By default the default configuration is forwarded unless another
       // is already forwarded.
       //
+      if (ao.forward () || ao.no_forward ())
+        fwd = ao.forward ()  && !ao.no_forward ();
+
       if (!fwd)
         fwd = *def && db.query_one<configuration> (query::forward) == nullptr;
       else if (*fwd)
@@ -73,6 +79,7 @@ namespace bdep
         move (rel_path),
         *def,
         *fwd,
+        !ao.no_auto_sync (),
         {} /* packages */});
 
     try
@@ -107,12 +114,13 @@ namespace bdep
     if (verb)
     {
       diag_record dr (text);
-      /*            */ dr << what << " configuration ";
-      if (r->name)     dr << '@' << *r->name << ' ';
-      /*            */ dr << r->path << " (" << *r->id;
-      if (r->default_) dr << ", default";
-      if (r->forward)  dr << ", forwarded";
-      /*            */ dr << ')';
+      /*              */ dr << what << " configuration ";
+      if (r->name)       dr << '@' << *r->name << ' ';
+      /*              */ dr << r->path << " (" << *r->id;
+      if (r->default_)   dr << ", default";
+      if (r->forward)    dr << ", forwarded";
+      if (r->auto_sync)  dr << ", auto-synchronized";
+      /*              */ dr << ')';
     }
 
     return r;
@@ -125,15 +133,14 @@ namespace bdep
   }
 
   shared_ptr<configuration>
-  cmd_config_create (const common_options& co,
-                     const dir_path&       prj,
-                     database&             db,
-                     dir_path              path,
-                     cli::scanner&         cfg_args,
-                     optional<string>      name,
-                     optional<bool>        def,
-                     optional<bool>        fwd,
-                     optional<uint64_t>    id)
+  cmd_config_create (const common_options&            co,
+                     const configuration_add_options& ao,
+                     const dir_path&                  prj,
+                     database&                        db,
+                     dir_path                         path,
+                     cli::scanner&                    cfg_args,
+                     optional<string>                 name,
+                     optional<uint64_t>               id)
   {
     // Call bpkg to create the configuration.
     //
@@ -145,12 +152,11 @@ namespace bdep
       run_bpkg (co, "create", "-d", path, args);
     }
 
-    return cmd_config_add (prj,
+    return cmd_config_add (ao,
+                           prj,
                            db,
                            move (path),
                            move (name),
-                           def,
-                           fwd,
                            id,
                            "created");
   }
@@ -192,10 +198,17 @@ namespace bdep
     if (o.forward () && o.no_forward ())
       fail << "both --forward and --no-forward specified";
 
-    return (o.default_ ()   ? "--default"    :
-            o.forward ()    ? "--forward"    :
-            o.no_default () ? "--no-default" :
-            o.no_forward () ? "--no-forward" : nullptr);
+    // --[no-]auto-sync
+    //
+    if (o.auto_sync () && o.no_auto_sync ())
+      fail << "both --auto-sync and --no-auto-sync specified";
+
+    return (o.default_ ()     ? "--default"      :
+            o.no_default ()   ? "--no-default"   :
+            o.forward ()      ? "--forward"      :
+            o.no_forward ()   ? "--no-forward"   :
+            o.auto_sync ()    ? "--auto-sync"    :
+            o.no_auto_sync () ? "--no-auto-sync" : nullptr);
   }
 
   int
diff --git a/bdep/config.hxx b/bdep/config.hxx
index b521bac..6bc732e 100644
--- a/bdep/config.hxx
+++ b/bdep/config.hxx
@@ -14,25 +14,23 @@
 namespace bdep
 {
   shared_ptr<configuration>
-  cmd_config_add (const dir_path&    prj,
+  cmd_config_add (const configuration_add_options&,
+                  const dir_path&    prj,
                   database&,
                   dir_path           path,
                   optional<string>   name,
-                  optional<bool>     default_ = nullopt,
-                  optional<bool>     forward  = nullopt,
                   optional<uint64_t> id = nullopt,
                   const char*        what = "added");
 
   shared_ptr<configuration>
   cmd_config_create (const common_options&,
-                     const dir_path&        prj,
+                     const configuration_add_options&,
+                     const dir_path&    prj,
                      database&,
-                     dir_path               path,
-                     cli::scanner&          args,
-                     optional<string>       name,
-                     optional<bool>         default_ = nullopt,
-                     optional<bool>         forward  = nullopt,
-                     optional<uint64_t>     id = nullopt);
+                     dir_path           path,
+                     cli::scanner&      args,
+                     optional<string>   name,
+                     optional<uint64_t> id = nullopt);
 
   int
   cmd_config (const cmd_config_options&, cli::scanner& args);
diff --git a/bdep/init.cxx b/bdep/init.cxx
index 1875c42..303c475 100644
--- a/bdep/init.cxx
+++ b/bdep/init.cxx
@@ -18,14 +18,13 @@ namespace bdep
 {
   shared_ptr<configuration>
   cmd_init_config (const configuration_name_options& o,
+                   const configuration_add_options& ao,
                    const dir_path& prj,
                    database& db,
                    const dir_path& cfg,
                    cli::scanner& args,
                    bool ca,
-                   bool cc,
-                   optional<bool> cd,
-                   optional<bool> cf)
+                   bool cc)
   {
     const char* m (!ca ? "--config-create" :
                    !cc ? "--config-add"    : nullptr);
@@ -52,8 +51,8 @@ namespace bdep
     }
 
     return ca
-      ? cmd_config_add    (   prj, db, cfg,       move (nm), cd, cf, move (id))
-      : cmd_config_create (o, prj, db, cfg, args, move (nm), cd, cf, move (id));
+      ? cmd_config_add    (   ao, prj, db, cfg,       move (nm), move (id))
+      : cmd_config_create (o, ao, prj, db, cfg, args, move (nm), move (id));
   }
 
   void
@@ -117,7 +116,7 @@ namespace bdep
       db.update (c);
       t.commit ();
 
-      cmd_sync (o, prj, c);
+      cmd_sync (o, prj, c, false /* implicit */);
     }
   }
 
@@ -181,25 +180,16 @@ namespace bdep
     configurations cfgs;
     if (ca || cc)
     {
-      optional<bool> cd;
-      if (o.default_ () || o.no_default ())
-        cd = o.default_ () && !o.no_default ();
-
-      optional<bool> cf;
-      if (o.forward () || o.no_forward ())
-        cf = o.forward ()  && !o.no_forward ();
-
       cfgs.push_back (
         cmd_init_config (
           o,
+          o,
           prj,
           db,
           ca ? o.config_add () : o.config_create (),
           args,
           ca,
-          cc,
-          cd,
-          cf));
+          cc));
 
       // Fall through.
     }
diff --git a/bdep/init.hxx b/bdep/init.hxx
index 6e52737..1ac46c1 100644
--- a/bdep/init.hxx
+++ b/bdep/init.hxx
@@ -17,14 +17,13 @@ namespace bdep
   //
   shared_ptr<configuration>
   cmd_init_config (const configuration_name_options&,
+                   const configuration_add_options&,
                    const dir_path& prj,
                    database&,
                    const dir_path& cfg,
                    cli::scanner& cfg_args,
                    bool config_add_specified,
-                   bool config_create_specified,
-                   optional<bool> config_default,
-                   optional<bool> config_forward);
+                   bool config_create_specified);
 
   // Initialize each package in each configuration skipping those that are
   // already initialized. Then synchronize each configuration.
diff --git a/bdep/new.cxx b/bdep/new.cxx
index a6074b8..85acad4 100644
--- a/bdep/new.cxx
+++ b/bdep/new.cxx
@@ -617,25 +617,16 @@ namespace bdep
 
     if (ca || cc)
     {
-      optional<bool> cd;
-      if (o.default_ () || o.no_default ())
-        cd = o.default_ () && !o.no_default ();
-
-      optional<bool> cf;
-      if (o.forward () || o.no_forward ())
-        cf = o.forward ()  && !o.no_forward ();
-
       configurations cfgs {
         cmd_init_config (
           o,
+          o,
           prj,
           db,
           ca ? o.config_add () : o.config_create (),
           args,
           ca,
-          cc,
-          cd,
-          cf)};
+          cc)};
 
       package_locations pkgs {{n, dir_path ()}}; // project == package
 
diff --git a/bdep/project.cli b/bdep/project.cli
index 137c77d..2fe37e4 100644
--- a/bdep/project.cli
+++ b/bdep/project.cli
@@ -31,6 +31,17 @@ namespace bdep
     {
       "Don't make the added or created configuration forwarded."
     }
+
+    bool --auto-sync
+    {
+      "Make the added or created configuration automatically synchronized."
+    }
+
+    bool --no-auto-sync
+    {
+      "Don't make the added or created configuration automatically
+       synchronized."
+    }
   };
 
   // Common options for commands that accept --config-id and @<cfg-name>.
diff --git a/bdep/project.hxx b/bdep/project.hxx
index 2e8d366..bbfd41d 100644
--- a/bdep/project.hxx
+++ b/bdep/project.hxx
@@ -79,6 +79,7 @@ namespace bdep
 
     bool default_;
     bool forward;
+    bool auto_sync;
 
     // We made it a vector instead of set/map since we are unlikely to have
     // more than a handful of packages. We may, however, want to use a change-
diff --git a/bdep/project.xml b/bdep/project.xml
index 8d1bf26..b9da262 100644
--- a/bdep/project.xml
+++ b/bdep/project.xml
@@ -7,6 +7,7 @@
       <column name="relative_path" type="TEXT" null="true"/>
       <column name="default" type="INTEGER" null="true"/>
       <column name="forward" type="INTEGER" null="true"/>
+      <column name="auto_sync" type="INTEGER" null="true"/>
       <primary-key auto="true">
         <column name="id"/>
       </primary-key>
diff --git a/bdep/sync.cli b/bdep/sync.cli
index 4fd5cb8..61d15cb 100644
--- a/bdep/sync.cli
+++ b/bdep/sync.cli
@@ -198,5 +198,28 @@ namespace bdep
     {
       "Don't prompt for confirmation when up/down-grading dependencies."
     }
+
+    bool --implicit
+    {
+      "Perform implicit synchronization. This mode is normally used by other
+       tools (for example, a build system hook) to ensure packages and
+       configurations are synchronized. To improve performance, especially for
+       the \"everything is already synchronized\" case, \cb{sync} executed in
+       this mode assumes that no configuration flags (see \l{bdep-config(1)})
+       have changed since the last explicit synchronization.
+
+       To avoid recursive re-synchronization, the \cb{sync} command maintains
+       the \cb{BDEP_SYNCED_CONFIGS} environment variable. It contains a
+       space-separated, \cb{\"}-quoted list of configuration paths that have
+       been or are being synchronized by the current \cb{bdep} invocation
+       chain. The \cb{sync} command in the implicit mode also examines this
+       variable and silently ignores synchronization requests that have been
+       or are already being performed."
+    }
+
+    // The build system hook protocol version. Internal, undocumented, and
+    // implies --implicit.
+    //
+    uint16_t --hook = 0;
   };
 }
diff --git a/bdep/sync.cxx b/bdep/sync.cxx
index 6c29a50..b95aa54 100644
--- a/bdep/sync.cxx
+++ b/bdep/sync.cxx
@@ -4,6 +4,8 @@
 
 #include <bdep/sync.hxx>
 
+#include <stdlib.h> // getenv() setenv()/_putenv()
+
 #include <bdep/database.hxx>
 #include <bdep/diagnostics.hxx>
 
@@ -22,6 +24,7 @@ namespace bdep
   cmd_sync (const common_options& co,
             const dir_path& prj,
             const shared_ptr<configuration>& c,
+            bool implicit,
             bool fetch,
             bool yes,
             optional<bool> upgrade,   // true - upgrade,   false - patch
@@ -44,6 +47,10 @@ namespace bdep
     // We also use the repository name rather than the location as a sanity
     // check (the repository must have been added as part of init).
     //
+    // @@ For implicit fetch this will print diagnostics/progress before
+    //    "synchronizing <cfg-dir>:". Maybe rep-fetch also needs something
+    //    like --plan but for progress? Plus there might be no sync at all.
+    //
     if (fetch)
       run_bpkg (co,
                 "fetch",
@@ -110,36 +117,42 @@ namespace bdep
       }
     }
 
+    // For implicit sync (normally performed on one configuration at a time)
+    // add the configuration directory to the plan header.
+    //
+    // We use the configuration directory rather than the name because this
+    // could be a multi-project configuration and in the implicit mode there
+    // will normally be no "originating project" (unlike with explicit sync).
+    //
+    string plan (implicit
+                 ? "synchronizing " + c->path.representation () + ':'
+                 : "synchronizing:");
+
     run_bpkg (co,
               "build",
               "-d", c->path,
               "--no-fetch",
               "--configure-only",
               "--keep-out",
-              "--plan", "synchronizing:",
+              "--plan", plan,
               (yes ? "--yes" : nullptr),
               args);
 
-
     // Handle configuration forwarding.
     //
     // We do it here (instead of, say init) because a change in a package may
     // introduce new subprojects. Though it would be nice to only do this if
-    // the package was upgraded (probably by comparing before/after versions
-    // @@ TODO: changed flag below).
+    // the package was upgraded.
+    //
+    // @@ TODO: changed flag below: Probably by comparing before/after
+    //          versions. Or, even simpler, if pkg-build signalled that
+    //          nothing has changed (the --exit-result idea) -- then we
+    //          can skip the whole thing.
     //
     // Also, the current thinking is that config set --[no-]forward is best
     // implemented by just changing the flag on the configuration and then
     // requiring an explicit sync to configure/disfigure forwards.
     //
-    // @@ TODO: could optimize out version query/comparison if pkg-build
-    //    signalled that nothing has changed (the --exit-result idea). Would
-    //    be nice to optimize the whole thing. Maybe --force flag (for things
-    //    like config set --no-forward)? Or maybe we should require explicit
-    //    sync for certain changes (and pass --implicit or some such in hook
-    //    -- after all, configuring forward of a project being bootstrapped
-    //    might get tricky).
-    //
     package_locations pls (load_packages (prj));
 
     for (const package_state& p: c->packages)
@@ -177,7 +190,7 @@ namespace bdep
         if (changed || !e)
           o = "configure:";
       }
-      else
+      else if (!implicit) // Requires explicit sync.
       {
         //@@ This is broken: we will disfigure forwards to other configs.
         //   Looks like we will need to test that the forward is to this
@@ -195,18 +208,71 @@ namespace bdep
         run_b (co, o, arg);
       }
     }
+
+    // Add/remove auto-synchronization build system hook.
+    //
+    if (!implicit)
+    {
+      path f (c->path / "build" / "bootstrap" / "pre-bdep-sync.build");
+      bool e (exists (f));
+
+      if (c->auto_sync)
+      {
+        if (!e)
+        {
+          mk (f.directory ());
+
+          try
+          {
+            ofdstream os (f);
+
+            // Should we analyze BDEP_SYNCED_CONFIGS ourselves or should we
+            // let bdep-sync to it for us? Doing it here instead of spawning a
+            // process (which will loading the database, etc) will be faster.
+            // But, on the other hand, this is only an issue for commands like
+            // update and test that do their own implicit sync.
+            //
+            // cfgs = $getenv(BDEP_SYNCED_CONFIGS)
+            // if! $null($cfgs)
+            //   cfgs = [dir_paths] $regex.split($cfgs, ' *"([^"]*)" *', '\1')
+            //
+            os << "# Created automatically by bdep."                   << endl
+               << "#"                                                  << endl
+               << "if ($build.meta_operation != 'info'      && \\"     << endl
+               << "    $build.meta_operation != 'configure' && \\"     << endl
+               << "    $build.meta_operation != 'disfigure')"          << endl
+               << "  run " << argv0 << " sync --hook=1 "               <<
+              "--config \"$out_root\" "                                <<
+              "-d '" << prj.string () << "'"                           << endl;
+
+            os.close ();
+          }
+          catch (const io_error& e)
+          {
+            fail << "unable to write " << f << ": " << e;
+          }
+        }
+      }
+      else
+      {
+        if (e)
+          rm (f);
+      }
+    }
   }
 
   void
   cmd_sync (const common_options& co,
             const dir_path& prj,
             const shared_ptr<configuration>& c,
+            bool implicit,
             bool fetch,
             bool yes)
   {
     cmd_sync (co,
               prj,
               c,
+              implicit,
               fetch,
               yes,
               nullopt              /* upgrade   */,
@@ -216,7 +282,7 @@ namespace bdep
   }
 
   int
-  cmd_sync (const cmd_sync_options& o, cli::scanner& args)
+  cmd_sync (cmd_sync_options&& o, cli::scanner& args)
   {
     tracer trace ("sync");
 
@@ -242,6 +308,29 @@ namespace bdep
     strings dep_pkgs;
     for (; args.more (); dep_pkgs.push_back (args.next ())) ;
 
+    // --hook
+    //
+    if (o.hook_specified ())
+    {
+      if (o.hook () != 1)
+        fail << "unsupported build system hook protocol" <<
+          info << "project requires re-initialization";
+
+      o.implicit (true); // Implies --implicit.
+    }
+
+    // --implicit
+    //
+    if (o.implicit ())
+    {
+      if (const char* n = (o.upgrade () ? "--upgrade|-u" :
+                           o.patch ()   ? "--patch|-p"   : nullptr))
+        fail << "--implicit specified with " << n;
+
+      if (!dep_pkgs.empty ())
+        fail << "--implicit specified with dependency package";
+    }
+
     // We could be running from a package directory (or the user specified one
     // with -d) that has not been init'ed in this configuration. Unless we are
     // upgrading specific dependencies, we want to diagnose that since such a
@@ -306,6 +395,7 @@ namespace bdep
         cmd_sync (o,
                   prj,
                   c,
+                  false /* implicit */,
                   !fetch,
                   o.recursive () || o.immediate () ? o.yes () : true,
                   !o.patch (), // Upgrade by default unless patch requested.
@@ -322,6 +412,7 @@ namespace bdep
         cmd_sync (o,
                   prj,
                   c,
+                  false /* implicit */,
                   !fetch,
                   o.yes (),
                   o.upgrade (),
@@ -331,9 +422,64 @@ namespace bdep
       }
       else
       {
-        // The first form: sync of project packages.
+        // The first form: sync of project packages (potentially implicit).
+        //
+
+        // Update the BDEP_SYNCED_CONFIGS environment variable.
         //
-        cmd_sync (o, prj, c, !fetch, true /* yes */);
+        // Note that it covers both depth and breadth (i.e., we don't restore
+        // the previous value before returning). The idea here is for commands
+        // like update or test would perform an implicit sync which will then
+        // be "noticed" by the build system hook. This should be both faster
+        // (no need to spawn multiple bdep processes) and simpler (no need to
+        // worry about who has the database open, etc).
+        //
+        {
+          const char n[] = "BDEP_SYNCED_CONFIGS";
+
+          string v;
+          const string& p (c->path.string ());
+
+          if (const char* e = getenv (n))
+          {
+            v = e;
+
+            // Check if this configuration is already (being) synchronized.
+            //
+            for (size_t b (0), e (0);
+                 (e = v.find ('"', e)) != string::npos; // Skip leading ' '.
+                 ++e)                                   // Skip trailing '"'.
+            {
+              size_t n (next_word (v, b, e, '"'));
+
+              // Both paths are normilized so we can just compare them as
+              // strings.
+              //
+              if (path::traits::compare (v.c_str () + b, n,
+                                         p.c_str (),     p.size ()) == 0)
+              {
+                if (o.implicit ())
+                  return 0; // Ignore.
+                else
+                  fail << "explicit re-synchronization of " << c->path;
+              }
+            }
+
+            v += ' ';
+          }
+
+          v += '"';
+          v += p;
+          v += '"';
+
+#ifndef _WIN32
+          setenv (n, v.c_str (), 1 /* overwrite */);
+#else
+          _putenv ((string (n) + '=' + v).c_str ());
+#endif
+        }
+
+        cmd_sync (o, prj, c, o.implicit (), !fetch, true /* yes */);
       }
     }
 
diff --git a/bdep/sync.hxx b/bdep/sync.hxx
index b397c10..8edd4b4 100644
--- a/bdep/sync.hxx
+++ b/bdep/sync.hxx
@@ -20,11 +20,12 @@ namespace bdep
   cmd_sync (const common_options&,
             const dir_path& prj,
             const shared_ptr<configuration>&,
+            bool implicit,
             bool fetch = true,
             bool yes = true);
 
   int
-  cmd_sync (const cmd_sync_options&, cli::scanner& args);
+  cmd_sync (cmd_sync_options&&, cli::scanner& args);
 }
 
 #endif // BDEP_SYNC_HXX
diff --git a/bdep/utility.cxx b/bdep/utility.cxx
index a902273..e048a5a 100644
--- a/bdep/utility.cxx
+++ b/bdep/utility.cxx
@@ -26,6 +26,7 @@ namespace bdep
   const path repositories_file   ("repositories.manifest");
   const path configurations_file ("configurations.manifest");
 
+  const char* argv0;
   dir_path exec_dir;
 
   bool
diff --git a/bdep/utility.hxx b/bdep/utility.hxx
index 31cd0cb..09e0e45 100644
--- a/bdep/utility.hxx
+++ b/bdep/utility.hxx
@@ -40,6 +40,10 @@ namespace bdep
   using butl::ucase;
   using butl::lcase;
   using butl::casecmp;
+
+  using butl::trim;
+  using butl::next_word;
+
   using butl::reverse_iterate;
 
   using butl::exception_guard;
@@ -66,6 +70,10 @@ namespace bdep
   extern const path repositories_file;   // repositories.manifest
   extern const path configurations_file; // configurations.manifest
 
+  // Process path (argv[0]).
+  //
+  extern const char* argv0;
+
   // Directory extracted from argv[0] (i.e., this process' recall directory)
   // or empty if there is none. Can be used as a search fallback.
   //