Reimplement module sidebuilding using an ad hoc subproject

3 files changed, 197 insertions, 148 deletions

diff --git a/build2/config/operation.cxx b/build2/config/operation.cxx
index c7cfefd..2fad6b0 100644
--- a/build2/config/operation.cxx
+++ b/build2/config/operation.cxx
@@ -415,7 +415,7 @@ namespace build2
     // disfigure
     //
     static void
-    load_project (scope& root)
+    bootstrap_project (scope& root)
     {
       if (auto l = root.vars[var_subprojects])
       {
@@ -432,7 +432,7 @@ namespace build2
 
           // The same logic for src_root as in create_bootstrap_inner().
           //
-          scope& nroot (create_root (root, out_nroot, dir_path ()));
+          scope& nroot (create_root (root, out_nroot, dir_path ())->second);
 
           if (!bootstrapped (nroot))
           {
@@ -447,7 +447,7 @@ namespace build2
             bootstrap_src (nroot);
           }
 
-          load_project (nroot);
+          bootstrap_project (nroot);
         }
       }
     }
@@ -476,7 +476,7 @@ namespace build2
       // disfigure all the subprojects (see disfigure_project() below), we
       // bootstrap all known subprojects.
       //
-      load_project (root);
+      bootstrap_project (root);
     }
 
     static void
@@ -644,151 +644,18 @@ namespace build2
     // create
     //
     static void
-    create_project (const dir_path& d,
-                    const strings& bmod,               // Bootstrap modules.
-                    const strings& rmod,               // Root modules.
-                    const variable_overrides& var_ovs)
+    save_config (const dir_path& d, const variable_overrides& var_ovs)
     {
-      // If the directory exists, verify it's empty. Otherwise, create it.
+      // Since there aren't any sub-projects yet, any config.import.* values
+      // that the user may want to specify won't be saved in config.build. So
+      // let's go ahead and mark them all to be saved. To do this, however, we
+      // need the config module (which is where this information is stored).
+      // And the module is created by init() during bootstrap. So what we are
+      // going to do is bootstrap the newly created project, similar to the
+      // way main() does it.
       //
-      if (exists (d))
-      {
-        if (!empty (d))
-          fail << "directory " << d << " exists and is not empty";
-      }
-      else
-        mkdir_p (d);
-
-      // Create the build/ subdirectory.
-      //
-      mkdir (d / build_dir);
-
-      // Write build/bootstrap.build.
-      //
-      {
-        path f (d / bootstrap_file);
-
-        if (verb)
-          text << (verb >= 2 ? "cat >" : "save ") << f;
-
-        try
-        {
-          ofdstream ofs (f);
-
-          // For now we disable amalgamating this project. Sooner or later
-          // someone will probably want to do this, though (i.e., nested
-          // configurations).
-          //
-          ofs << "# Generated by the create meta-operation. Edit if you " <<
-            "know what you are doing." << endl
-              << "#" << endl
-              << "project =" << endl
-              << "amalgamation =" << endl
-              << endl
-              << "using config" << endl;
-
-          for (const string& m: bmod)
-          {
-            if (m != "config")
-              ofs << "using " << m << endl;
-          }
-
-          ofs.close ();
-        }
-        catch (const io_error& e)
-        {
-          fail << "unable to write " << f << ": " << e;
-        }
-      }
-
-      // Write build/root.build.
-      //
-      {
-        path f (d / root_file);
-
-        if (verb)
-          text << (verb >= 2 ? "cat >" : "save ") << f;
-
-        try
-        {
-          ofdstream ofs (f);
-
-          ofs << "# Generated by the create meta-operation. Edit if you " <<
-            "know what you are doing." << endl
-              << "#" << endl;
-
-          for (const string& cm: rmod)
-          {
-            // If the module name start with '?', then use optional load.
-            //
-            bool opt (cm.front () == '?');
-            string m (cm, opt ? 1 : 0);
-
-            // Append .config unless the module name ends with '.', in which
-            // case strip it.
-            //
-            if (m.back () == '.')
-              m.pop_back ();
-            else
-              m += ".config";
-
-            ofs << "using" << (opt ? "?" : "") << " " << m << endl;
-          }
-
-          ofs.close ();
-        }
-        catch (const io_error& e)
-        {
-          fail << "unable to write " << f << ": " << e;
-        }
-      }
-
-      // Write root buildfile.
-      //
-      {
-        path f (d / "buildfile");
-
-        if (verb)
-          text << (verb >= 2 ? "cat >" : "save ") << f;
-
-        try
-        {
-          ofdstream ofs (f);
-
-          ofs << "# Generated by the create meta-operation. Edit if you " <<
-            "know what you are doing." << endl
-              << "#" << endl
-              << "./: {*/ -build/}" << endl;
-
-          ofs.close ();
-        }
-        catch (const io_error& e)
-        {
-          fail << "unable to write " << f << ": " << e;
-        }
-      }
-
-      // Well, this wasn't too bad. There is just one little snag: since there
-      // aren't any sub-projects yet, any config.import.* values that the user
-      // may want to specify won't be saved in config.build. So let's go ahead
-      // and mark them all to be saved. To do this, however, we need the
-      // config module (which is where this information is stored). And the
-      // module is created by init() during bootstrap. So what we are going to
-      // do is bootstrap the newly created project, similar to the way main()
-      // does it (except here we can omit all the guessing/sanity checks).
-      //
-      current_oname = &empty_string; // Make sure valid.
-
       scope& gs (*scope::global_);
-      scope& rs (create_root (gs, d, d));
-
-      if (!bootstrapped (rs))
-      {
-        bootstrap_out (rs);
-        setup_root (rs);
-        bootstrap_src (rs);
-      }
-
+      scope& rs (load_project (gs, d, d, false /* load */));
       module& m (*rs.modules.lookup<module> (module::name));
 
       // Save all the global config.import.* variables.
@@ -834,7 +701,7 @@ namespace build2
                        bool lifted,
                        const location& l)
     {
-      tracer trace ("create_project");
+      tracer trace ("preprocess_create");
 
       // The overall plan is to create the project(s), update the buildspec,
       // clear the parameters, and then continue as if we were the configure
@@ -865,6 +732,8 @@ namespace build2
         fail (l) << "invalid module name: " << e.what ();
       }
 
+      current_oname = &empty_string; // Make sure valid.
+
       // Now handle each target in each operation spec.
       //
       for (const opspec& os: spec)
@@ -919,7 +788,21 @@ namespace build2
 
           l5 ([&]{trace << "creating project in " << d;});
 
-          create_project (d, bmod, rmod, var_ovs);
+          // For now we disable amalgamating this project. Sooner or later
+          // someone will probably want to do this, though (i.e., nested
+          // configurations).
+          //
+          create_project (d,
+                          dir_path (), /* amalgamation */
+                          bmod,
+                          "",          /* root_pre */
+                          rmod,
+                          "",          /* root_post */
+                          true,        /* config */
+                          true,        /* buildfile */
+                          "the create meta-operation");
+
+          save_config (d, var_ovs);
         }
       }
 
diff --git a/build2/config/utility.cxx b/build2/config/utility.cxx
index c195e0b..1c80d13 100644
--- a/build2/config/utility.cxx
+++ b/build2/config/utility.cxx
@@ -4,7 +4,10 @@
 
 #include <build2/config/utility.hxx>
 
+#include <build2/file.hxx>
 #include <build2/context.hxx>
+#include <build2/filesystem.hxx>
+#include <build2/diagnostics.hxx>
 
 #include <build2/config/module.hxx>
 
@@ -151,5 +154,152 @@ namespace build2
       if (module* m = r.modules.lookup<module> (module::name))
         m->save_module (name, prio);
     }
+
+    void
+    create_project (const dir_path& d,
+                    const build2::optional<dir_path>& amal,
+                    const strings& bmod,
+                    const string&  rpre,
+                    const strings& rmod,
+                    const string&  rpos,
+                    bool config,
+                    bool buildfile,
+                    const char* who,
+                    uint16_t verbosity)
+    {
+      string hdr ("# Generated by " + string (who) + ". Edit if you know"
+                  " what you are doing.\n"
+                  "#");
+
+      // If the directory exists, verify it's empty. Otherwise, create it.
+      //
+      if (exists (d))
+      {
+        if (!empty (d))
+          fail << "directory " << d << " exists and is not empty";
+      }
+      else
+        mkdir_p (d, verbosity);
+
+      // Create the build/ subdirectory.
+      //
+      mkdir (d / build_dir, verbosity);
+
+      // Write build/bootstrap.build.
+      //
+      {
+        path f (d / bootstrap_file);
+
+        if (verb >= verbosity)
+          text << (verb >= 2 ? "cat >" : "save ") << f;
+
+        try
+        {
+          ofdstream ofs (f);
+
+          ofs << hdr << endl
+              << "project =" << endl;
+
+          if (amal)
+          {
+            ofs << "amalgamation =";
+
+            if (!amal->empty ())
+              ofs << ' ' << amal->representation ();
+
+            ofs << endl;
+          }
+
+          ofs << endl;
+
+          if (config)
+            ofs << "using config" << endl;
+
+          for (const string& m: bmod)
+          {
+            if (!config || m != "config")
+              ofs << "using " << m << endl;
+          }
+
+          ofs.close ();
+        }
+        catch (const io_error& e)
+        {
+          fail << "unable to write " << f << ": " << e;
+        }
+      }
+
+      // Write build/root.build.
+      //
+      {
+        path f (d / root_file);
+
+        if (verb >= verbosity)
+          text << (verb >= 2 ? "cat >" : "save ") << f;
+
+        try
+        {
+          ofdstream ofs (f);
+
+          ofs << hdr << endl;
+
+          if (!rpre.empty ())
+            ofs << rpre << endl
+                << endl;
+
+          for (const string& cm: rmod)
+          {
+            // If the module name start with '?', then use optional load.
+            //
+            bool opt (cm.front () == '?');
+            string m (cm, opt ? 1 : 0);
+
+            // Append .config unless the module name ends with '.', in which
+            // case strip it.
+            //
+            if (m.back () == '.')
+              m.pop_back ();
+            else
+              m += ".config";
+
+            ofs << "using" << (opt ? "?" : "") << " " << m << endl;
+          }
+
+          if (!rpos.empty ())
+            ofs << endl
+                << rpre << endl;
+
+          ofs.close ();
+        }
+        catch (const io_error& e)
+        {
+          fail << "unable to write " << f << ": " << e;
+        }
+      }
+
+      // Write root buildfile.
+      //
+      if (buildfile)
+      {
+        path f (d / "buildfile");
+
+        if (verb >= verbosity)
+          text << (verb >= 2 ? "cat >" : "save ") << f;
+
+        try
+        {
+          ofdstream ofs (f);
+
+          ofs << hdr << endl
+              << "./: {*/ -build/}" << endl;
+
+          ofs.close ();
+        }
+        catch (const io_error& e)
+        {
+          fail << "unable to write " << f << ": " << e;
+        }
+      }
+    }
   }
 }
diff --git a/build2/config/utility.hxx b/build2/config/utility.hxx
index 33a3985..c09dc07 100644
--- a/build2/config/utility.hxx
+++ b/build2/config/utility.hxx
@@ -92,6 +92,8 @@ namespace build2
     //
     // Return the value (as always defined lookup), which can be NULL.
     //
+    // @@ Rename since clashes with the optional class template.
+    //
     lookup
     optional (scope& root, const variable&);
 
@@ -144,6 +146,20 @@ namespace build2
     //
     void
     save_module (scope& root, const char* name, int prio = 0);
+
+    // Create a project in the specified directory.
+    //
+    void
+    create_project (const dir_path& d,
+                    const build2::optional<dir_path>& amalgamation,
+                    const strings& boot_modules,    // Bootstrap modules.
+                    const string&  root_pre,        // Extra root.build text.
+                    const strings& root_modules,    // Root modules.
+                    const string&  root_post,       // Extra root.build text.
+                    bool config,                    // Load config module.
+                    bool buildfile,                 // Create root buildfile.
+                    const char* who,                // Who is creating it.
+                    uint16_t verbosity = 1);        // Diagnostic verbosity.
   }
 }