Add model mutex, make var_pool const by default

10 files changed, 106 insertions, 85 deletions

diff --git a/build2/cc/common b/build2/cc/common
index f0476f9..c11e733 100644
--- a/build2/cc/common
+++ b/build2/cc/common
@@ -210,8 +210,8 @@ namespace build2
 
     private:
       file&
-      resolve_library (name,
-                       scope&,
+      resolve_library (scope&,
+                       name,
                        lorder,
                        const dir_paths&,
                        optional<dir_paths>&) const;
diff --git a/build2/cc/common.cxx b/build2/cc/common.cxx
index 6429a38..b941e6e 100644
--- a/build2/cc/common.cxx
+++ b/build2/cc/common.cxx
@@ -4,7 +4,7 @@
 
 #include <build2/cc/common>
 
-#include <build2/file>   // import()
+#include <build2/file>        // import()
 #include <build2/scope>
 #include <build2/context>
 #include <build2/variable>
@@ -287,7 +287,7 @@ namespace build2
             if (sysd == nullptr) find_sysd ();
             if (!lo) find_lo ();
 
-            file& t (resolve_library (n, bs, *lo, *sysd, usrd));
+            file& t (resolve_library (bs, n, *lo, *sysd, usrd));
 
             if (proc_lib)
             {
@@ -386,8 +386,8 @@ namespace build2
     // that's the only way to guarantee it will be up-to-date.
     //
     file& common::
-    resolve_library (name n,
-                     scope& s,
+    resolve_library (scope& s,
+                     name n,
                      lorder lo,
                      const dir_paths& sysd,
                      optional<dir_paths>& usrd) const
@@ -768,7 +768,7 @@ namespace build2
       const char* bl (lt.a != nullptr
                       ? (lt.s != nullptr ? "both" : "static")
                       : "shared");
-      lt.assign ("bin.lib") = bl;
+      lt.assign (var_pool["bin.lib"]) = bl;
 
       target* r (l ? &lt : (p.is_a<liba> () ? static_cast<target*> (a) : s));
 
diff --git a/build2/cc/compile b/build2/cc/compile
index 67897f2..11b3919 100644
--- a/build2/cc/compile
+++ b/build2/cc/compile
@@ -27,10 +27,10 @@ namespace build2
       compile (data&&);
 
       virtual match_result
-      match (action, target&, const string& hint) const override;
+      match (slock&, action, target&, const string& hint) const override;
 
       virtual recipe
-      apply (action, target&) const override;
+      apply (slock&, action, target&) const override;
 
       target_state
       perform_update (action, target&) const;
@@ -40,10 +40,10 @@ namespace build2
 
     private:
       void
-      append_lib_options (cstrings&, target&, scope&, lorder) const;
+      append_lib_options (scope&, cstrings&, target&, lorder) const;
 
       void
-      hash_lib_options (sha256&, target&, scope&, lorder) const;
+      hash_lib_options (scope&, sha256&, target&, lorder) const;
 
       // Mapping of include prefixes (e.g., foo in <foo/bar>) for auto-
       // generated headers to directories where they will be generated.
@@ -61,10 +61,10 @@ namespace build2
       append_prefixes (prefix_map&, target&, const variable&) const;
 
       void
-      append_lib_prefixes (prefix_map&, target&, scope&, lorder) const;
+      append_lib_prefixes (scope&, prefix_map&, target&, lorder) const;
 
       prefix_map
-      build_prefix_map (target&, scope&, lorder) const;
+      build_prefix_map (scope&, target&, lorder) const;
 
       // Reverse-lookup target type from extension.
       //
@@ -74,7 +74,7 @@ namespace build2
       // Header dependency injection.
       //
       void
-      inject (action, target&, lorder, file&, depdb&) const;
+      inject (slock&, action, target&, lorder, file&, depdb&) const;
 
     private:
       const string rule_id;
diff --git a/build2/cc/compile.cxx b/build2/cc/compile.cxx
index f837765..bc35272 100644
--- a/build2/cc/compile.cxx
+++ b/build2/cc/compile.cxx
@@ -44,7 +44,7 @@ namespace build2
                    "insufficient space");
 
     match_result compile::
-    match (action a, target& t, const string&) const
+    match (slock& ml, action a, target& t, const string&) const
     {
       tracer trace (x, "compile::match");
 
@@ -58,7 +58,8 @@ namespace build2
       // file specified for an obj*{} member overrides the one specified for
       // the group. Also "see through" groups.
       //
-      for (prerequisite_member p: reverse_group_prerequisite_members (a, t))
+      for (prerequisite_member p:
+             reverse_group_prerequisite_members (ml, a, t))
       {
         if (p.is_a (x_src))
         {
@@ -75,7 +76,7 @@ namespace build2
     // (first one is cc.export.*) recursively, prerequisite libraries first.
     //
     void compile::
-    append_lib_options (cstrings& args, target& t, scope& bs, lorder lo) const
+    append_lib_options (scope& bs, cstrings& args, target& t, lorder lo) const
     {
       auto opt = [&args, this] (file& l, const string& t, bool com, bool exp)
       {
@@ -116,7 +117,7 @@ namespace build2
     }
 
     void compile::
-    hash_lib_options (sha256& cs, target& t, scope& bs, lorder lo) const
+    hash_lib_options (scope& bs, sha256& cs, target& t, lorder lo) const
     {
       auto opt = [&cs, this] (file& l, const string& t, bool com, bool exp)
       {
@@ -155,7 +156,7 @@ namespace build2
     // recursively, prerequisite libraries first.
     //
     void compile::
-    append_lib_prefixes (prefix_map& m, target& t, scope& bs, lorder lo) const
+    append_lib_prefixes (scope& bs, prefix_map& m, target& t, lorder lo) const
     {
       auto opt = [&m, this] (file& l, const string& t, bool com, bool exp)
       {
@@ -191,7 +192,7 @@ namespace build2
     }
 
     recipe compile::
-    apply (action a, target& xt) const
+    apply (slock& ml, action a, target& xt) const
     {
       tracer trace (x, "compile::apply");
 
@@ -250,7 +251,7 @@ namespace build2
 
       // Inject dependency on the output directory.
       //
-      fsdir* dir (inject_fsdir (a, t));
+      fsdir* dir (inject_fsdir (ml, a, t));
 
       // Search and match all the existing prerequisites. The injection code
       // takes care of the ones it is adding.
@@ -260,7 +261,7 @@ namespace build2
       //
       optional<dir_paths> usr_lib_dirs; // Extract lazily.
 
-      for (prerequisite_member p: group_prerequisite_members (a, t))
+      for (prerequisite_member p: group_prerequisite_members (ml, a, t))
       {
         // A dependency on a library is there so that we can get its
         // *.export.poptions. In particular, making sure it is executed before
@@ -281,7 +282,7 @@ namespace build2
                 search_library (
                   sys_lib_dirs, usr_lib_dirs, p.prerequisite) == nullptr)
             {
-              match_only (a, p.search ());
+              match_only (ml, a, p.search ());
             }
           }
 
@@ -293,7 +294,7 @@ namespace build2
         if (a.operation () == clean_id && !pt.dir.sub (rs.out_path ()))
           continue;
 
-        build2::match (a, pt);
+        build2::match (ml, a, pt);
         t.prerequisite_targets.push_back (&pt);
       }
 
@@ -351,7 +352,7 @@ namespace build2
 
         // Hash *.export.poptions from prerequisite libraries.
         //
-        hash_lib_options (cs, t, bs, lo);
+        hash_lib_options (bs, cs, t, lo);
 
         // Extra system header dirs (last).
         //
@@ -385,7 +386,7 @@ namespace build2
         if (dd.writing () || dd.mtime () > t.mtime ())
           t.mtime (timestamp_nonexistent);
 
-        inject (a, t, lo, src, dd);
+        inject (ml, a, t, lo, src, dd);
 
         dd.close ();
       }
@@ -525,7 +526,7 @@ namespace build2
     }
 
     auto compile::
-    build_prefix_map (target& t, scope& bs, lorder lo) const -> prefix_map
+    build_prefix_map (scope& bs, target& t, lorder lo) const -> prefix_map
     {
       prefix_map m;
 
@@ -536,7 +537,7 @@ namespace build2
 
       // Then process the include directories from prerequisite libraries.
       //
-      append_lib_prefixes (m, t, bs, lo);
+      append_lib_prefixes (bs, m, t, lo);
 
       return m;
     }
@@ -715,7 +716,12 @@ namespace build2
     }
 
     void compile::
-    inject (action a, target& t, lorder lo, file& src, depdb& dd) const
+    inject (slock& ml,
+            action a,
+            target& t,
+            lorder lo,
+            file& src,
+            depdb& dd) const
     {
       tracer trace (x, "compile::inject");
 
@@ -739,14 +745,14 @@ namespace build2
       const process_path* xc (nullptr);
       cstrings args;
 
-      auto init_args = [&t, lo, &src, &rs, &bs, &xc, &args, this] ()
+      auto init_args = [&ml, &t, lo, &src, &rs, &bs, &xc, &args, this] ()
       {
         xc = &cast<process_path> (rs[x_path]);
         args.push_back (xc->recall_string ());
 
         // Add *.export.poptions from prerequisite libraries.
         //
-        append_lib_options (args, t, bs, lo);
+        append_lib_options (bs, args, t, lo);
 
         append_options (args, t, c_poptions);
         append_options (args, t, x_poptions);
@@ -895,7 +901,7 @@ namespace build2
       // from the depdb cache or from the compiler run. Return whether the
       // extraction process should be restarted.
       //
-      auto add = [&trace, &update, &pm, a, &t, lo, &dd, &bs, this]
+      auto add = [&trace, &ml, &update, &pm, a, &t, lo, &dd, &bs, this]
         (path f, bool cache) -> bool
       {
         // Find or maybe insert the target.
@@ -991,7 +997,7 @@ namespace build2
           // then we would have failed below.
           //
           if (pm.empty ())
-            pm = build_prefix_map (t, bs, lo);
+            pm = build_prefix_map (bs, t, lo);
 
           // First try the whole file. Then just the directory.
           //
@@ -1068,7 +1074,7 @@ namespace build2
 
         // Match to a rule.
         //
-        build2::match (a, *pt);
+        build2::match (ml, a, *pt);
 
         // Update.
         //
@@ -1417,7 +1423,7 @@ namespace build2
 
       // Add *.export.poptions from prerequisite libraries.
       //
-      append_lib_options (args, t, bs, lo);
+      append_lib_options (bs, args, t, lo);
 
       // Extra system header dirs (last).
       //
diff --git a/build2/cc/init.cxx b/build2/cc/init.cxx
index a162daa..ebe7653 100644
--- a/build2/cc/init.cxx
+++ b/build2/cc/init.cxx
@@ -35,7 +35,7 @@ namespace build2
 
       // Enter variables. Note: some overridable, some not.
       //
-      auto& v (var_pool);
+      auto& v (var_pool.rw (r));
 
       v.insert<strings> ("config.cc.poptions", true);
       v.insert<strings> ("config.cc.coptions", true);
@@ -90,10 +90,12 @@ namespace build2
 
       assert (first);
 
+      auto& vp (var_pool.rw (rs));
+
       // Load cc.core.vars.
       //
       if (!cast_false<bool> (rs["cc.core.vars.loaded"]))
-        load_module ("cc.core.vars", rs, rs, loc);
+        load_module (rs, rs, "cc.core.vars", loc);
 
       // Configure.
       //
@@ -169,14 +171,20 @@ namespace build2
         variable_map h;
         if (first)
         {
-          h.assign ("config.bin.target") =
-            cast<target_triplet> (rs["cc.target"]).string ();
+          // Note that these variables have not yet been registered (we don't
+          // yet have the "bin.vars" module).
+          //
+          const variable& t (vp.insert ("config.bin.target"));
+          h.assign (t) = cast<target_triplet> (rs["cc.target"]).string ();
 
           if (auto l = hints["config.bin.pattern"])
-            h.assign ("config.bin.pattern") = cast<string> (l);
+          {
+            const variable& p (vp.insert ("config.bin.pattern"));
+            h.assign (p) = cast<string> (l);
+          }
         }
 
-        load_module ("bin.config", rs, rs, loc, false, h);
+        load_module (rs, rs, "bin.config", loc, false, h);
       }
 
       // Verify bin's target matches ours (we do it even if we loaded it
@@ -205,20 +213,20 @@ namespace build2
         if (cast<string> (l) != "shared")
         {
           if (!cast_false<bool> (rs["bin.ar.config.loaded"]))
-            load_module ("bin.ar.config", rs, rs, loc);
+            load_module (rs, rs, "bin.ar.config", loc);
         }
       }
 
       if (cid == "msvc")
       {
         if (!cast_false<bool> (rs["bin.ld.config.loaded"]))
-          load_module ("bin.ld.config", rs, rs, loc);
+          load_module (rs, rs, "bin.ld.config", loc);
       }
 
       if (tsys == "mingw32")
       {
         if (!cast_false<bool> (rs["bin.rc.config.loaded"]))
-          load_module ("bin.rc.config", rs, rs, loc);
+          load_module (rs, rs, "bin.rc.config", loc);
       }
 
       // Load (optionally) the pkgconfig.config module.
@@ -233,10 +241,13 @@ namespace build2
         // Prepare configuration hints.
         //
         variable_map h;
-        h.assign ("config.pkgconfig.target") =
-          cast<target_triplet> (rs["cc.target"]);
 
-        load_module ("pkgconfig.config", rs, rs, loc, true, h);
+        // Note that this variable has not yet been registered.
+        //
+        const variable& t (vp.insert ("config.pkgconfig.target"));
+        h.assign (t) = cast<target_triplet> (rs["cc.target"]);
+
+        load_module (rs, rs, "pkgconfig.config", loc, true, h);
       }
 
       return true;
@@ -259,12 +270,12 @@ namespace build2
       // Load cc.core.config.
       //
       if (!cast_false<bool> (rs["cc.core.config.loaded"]))
-        load_module ("cc.core.config", rs, rs, loc, false, hints);
+        load_module (rs, rs, "cc.core.config", loc, false, hints);
 
       // Load the bin module.
       //
       if (!cast_false<bool> (rs["bin.loaded"]))
-        load_module ("bin", rs, rs, loc);
+        load_module (rs, rs, "bin", loc);
 
       const string& cid (cast<string> (rs["cc.id"]));
       const string& tsys (cast<string> (rs["cc.target.system"]));
@@ -277,7 +288,7 @@ namespace build2
         if (cast<string> (l) != "shared")
         {
           if (!cast_false<bool> (rs["bin.ar.loaded"]))
-            load_module ("bin.ar", rs, rs, loc);
+            load_module (rs, rs, "bin.ar", loc);
         }
       }
 
@@ -287,7 +298,7 @@ namespace build2
       if (cid == "msvc")
       {
         if (!cast_false<bool> (rs["bin.ld.loaded"]))
-          load_module ("bin.ld", rs, rs, loc);
+          load_module (rs, rs, "bin.ld", loc);
       }
 
       // If our target is MinGW, then we will need the resource compiler
@@ -296,7 +307,7 @@ namespace build2
       if (tsys == "mingw32")
       {
         if (!cast_false<bool> (rs["bin.rc.loaded"]))
-          load_module ("bin.rc", rs, rs, loc);
+          load_module (rs, rs, "bin.rc", loc);
       }
 
       return true;
@@ -308,13 +319,13 @@ namespace build2
     //
     static inline bool
     init_alias (tracer& trace,
+                scope& rs,
+                scope& bs,
                 const char* m,
                 const char* c,
                 const char* c_loaded,
                 const char* cxx,
                 const char* cxx_loaded,
-                scope& rs,
-                scope& bs,
                 const location& loc,
                 const variable_map& hints)
     {
@@ -338,13 +349,13 @@ namespace build2
       //
       if (lc && lp && rs["config.c"])
       {
-        load_module (c, rs, rs, loc, false, hints);
-        load_module (cxx, rs, rs, loc, false, hints);
+        load_module (rs, rs, c, loc, false, hints);
+        load_module (rs, rs, cxx, loc, false, hints);
       }
       else
       {
-        if (lp) load_module (cxx, rs, rs, loc, false, hints);
-        if (lc) load_module (c, rs, rs, loc, false, hints);
+        if (lp) load_module (rs, rs, cxx, loc, false, hints);
+        if (lc) load_module (rs, rs, c, loc, false, hints);
       }
 
       return true;
@@ -360,10 +371,11 @@ namespace build2
                  const variable_map& hints)
     {
       tracer trace ("cc::config_init");
-      return init_alias (trace, "cc.config",
+      return init_alias (trace, rs, bs,
+                         "cc.config",
                          "c.config",   "c.config.loaded",
                          "cxx.config", "cxx.config.loaded",
-                         rs, bs, loc, hints);
+                         loc, hints);
     }
 
     bool
@@ -376,10 +388,11 @@ namespace build2
           const variable_map& hints)
     {
       tracer trace ("cc::init");
-      return init_alias (trace, "cc",
+      return init_alias (trace, rs, bs,
+                         "cc",
                          "c",   "c.loaded",
                          "cxx", "cxx.loaded",
-                         rs, bs, loc, hints);
+                         loc, hints);
     }
   }
 }
diff --git a/build2/cc/install b/build2/cc/install
index 561ed87..ff7af4d 100644
--- a/build2/cc/install
+++ b/build2/cc/install
@@ -25,10 +25,10 @@ namespace build2
       install (data&&, const link&);
 
       virtual target*
-      filter (action, target&, prerequisite_member) const override;
+      filter (slock&, action, target&, prerequisite_member) const override;
 
       virtual match_result
-      match (action, target&, const string&) const override;
+      match (slock&, action, target&, const string&) const override;
 
       virtual void
       install_extra (file&, const install_dir&) const override;
diff --git a/build2/cc/install.cxx b/build2/cc/install.cxx
index 28d7db2..074654b 100644
--- a/build2/cc/install.cxx
+++ b/build2/cc/install.cxx
@@ -23,7 +23,7 @@ namespace build2
     install (data&& d, const link& l): common (move (d)), link_ (l) {}
 
     target* install::
-    filter (action a, target& t, prerequisite_member p) const
+    filter (slock& ml, action a, target& t, prerequisite_member p) const
     {
       if (t.is_a<exe> ())
       {
@@ -53,11 +53,11 @@ namespace build2
           return pt->in (t.weak_scope ()) ? pt : nullptr;
       }
 
-      return file_rule::filter (a, t, p);
+      return file_rule::filter (ml, a, t, p);
     }
 
     match_result install::
-    match (action a, target& t, const string& hint) const
+    match (slock& ml, action a, target& t, const string& hint) const
     {
       // @@ How do we split the hint between the two?
       //
@@ -65,8 +65,8 @@ namespace build2
       // We only want to handle installation if we are also the
       // ones building this target. So first run link's match().
       //
-      match_result r (link_.match (a, t, hint));
-      return r ? install::file_rule::match (a, t, "") : r;
+      match_result r (link_.match (ml, a, t, hint));
+      return r ? install::file_rule::match (ml, a, t, "") : r;
     }
 
     void install::
diff --git a/build2/cc/link b/build2/cc/link
index c7d3c93..5f28204 100644
--- a/build2/cc/link
+++ b/build2/cc/link
@@ -25,10 +25,10 @@ namespace build2
       link (data&&);
 
       virtual match_result
-      match (action, target&, const string& hint) const override;
+      match (slock&, action, target&, const string& hint) const override;
 
       virtual recipe
-      apply (action, target&) const override;
+      apply (slock&, action, target&) const override;
 
       target_state
       perform_update (action, target&) const;
diff --git a/build2/cc/link.cxx b/build2/cc/link.cxx
index c94eb26..6de294a 100644
--- a/build2/cc/link.cxx
+++ b/build2/cc/link.cxx
@@ -41,7 +41,7 @@ namespace build2
     }
 
     match_result link::
-    match (action a, target& t, const string& hint) const
+    match (slock& ml, action a, target& t, const string& hint) const
     {
       tracer trace (x, "link::match");
 
@@ -64,7 +64,7 @@ namespace build2
       //
       bool seen_x (false), seen_c (false), seen_obj (false), seen_lib (false);
 
-      for (prerequisite_member p: group_prerequisite_members (a, t))
+      for (prerequisite_member p: group_prerequisite_members (ml, a, t))
       {
         if (p.is_a (x_src))
         {
@@ -145,7 +145,7 @@ namespace build2
 
         optional<dir_paths> usr_lib_dirs; // Extract lazily.
 
-        for (prerequisite_member p: group_prerequisite_members (a, t))
+        for (prerequisite_member p: group_prerequisite_members (ml, a, t))
         {
           if (p.is_a<lib> () || p.is_a<liba> () || p.is_a<libs> ())
           {
@@ -159,7 +159,7 @@ namespace build2
             if (pt == nullptr)
             {
               pt = &p.search ();
-              match_only (a, *pt);
+              match_only (ml, a, *pt);
             }
 
             // If the prerequisite came from the lib{} group, then also
@@ -316,7 +316,7 @@ namespace build2
     }
 
     recipe link::
-    apply (action a, target& xt) const
+    apply (slock& ml, action a, target& xt) const
     {
       tracer trace (x, "link::apply");
 
@@ -415,7 +415,7 @@ namespace build2
 
       // Inject dependency on the output directory.
       //
-      inject_fsdir (a, t);
+      inject_fsdir (ml, a, t);
 
       optional<dir_paths> usr_lib_dirs; // Extract lazily.
 
@@ -429,7 +429,7 @@ namespace build2
                               lt == otype::a ? obja::static_type :
                               objs::static_type);
 
-      for (prerequisite_member p: group_prerequisite_members (a, t))
+      for (prerequisite_member p: group_prerequisite_members (ml, a, t))
       {
         target* pt (nullptr);
 
@@ -471,7 +471,7 @@ namespace build2
             pt = &link_member (*l, lo);
           }
 
-          build2::match (a, *pt);
+          build2::match (ml, a, *pt);
           t.prerequisite_targets.push_back (pt);
           continue;
         }
@@ -567,7 +567,7 @@ namespace build2
         //
         bool found (false);
         for (prerequisite_member p1:
-               reverse_group_prerequisite_members (a, *pt))
+               reverse_group_prerequisite_members (ml, a, *pt))
         {
           // Most of the time we will have just a single source so fast-path
           // that case.
@@ -576,7 +576,7 @@ namespace build2
           {
             if (!found)
             {
-              build2::match (a, *pt); // Now p1 should be resolved.
+              build2::match (ml, a, *pt); // Now p1 should be resolved.
 
               // Searching our own prerequisite is ok.
               //
@@ -637,7 +637,7 @@ namespace build2
               ot.prerequisites.emplace_back (p);
           }
 
-          build2::match (a, *pt);
+          build2::match (ml, a, *pt);
         }
 
         t.prerequisite_targets.push_back (pt);
diff --git a/build2/cc/module.cxx b/build2/cc/module.cxx
index 3e20694..c7c7c3c 100644
--- a/build2/cc/module.cxx
+++ b/build2/cc/module.cxx
@@ -279,6 +279,8 @@ namespace build2
         //
         variable_map h;
 
+        // Note that all these variables have already been registered.
+        //
         h.assign ("config.cc.id") = cast<string> (rs[x_id]);
         h.assign ("config.cc.target") = cast<target_triplet> (rs[x_target]);
 
@@ -288,7 +290,7 @@ namespace build2
         if (!ci.bin_pattern.empty ())
           h.assign ("config.bin.pattern") = move (ci.bin_pattern);
 
-        load_module ("cc.core.config", rs, rs, loc, false, h);
+        load_module (rs, rs, "cc.core.config", loc, false, h);
       }
       else
       {
@@ -331,7 +333,7 @@ namespace build2
       // extra bin.* modules we may need.
       //
       if (!cast_false<bool> (rs["cc.core.loaded"]))
-        load_module ("cc.core", rs, rs, loc);
+        load_module (rs, rs, "cc.core", loc);
 
       // Register target types and configure their "installability".
       //
@@ -347,7 +349,7 @@ namespace build2
         for (const target_type* const* ht (x_hdr); *ht != nullptr; ++ht)
         {
           t.insert (**ht);
-          install_path (**ht, rs, dir_path ("include"));
+          install_path (rs, **ht, dir_path ("include"));
         }
       }