Pattern-type config.** variables with global visibility by default

3 files changed, 62 insertions, 56 deletions

diff --git a/libbuild2/config/init.cxx b/libbuild2/config/init.cxx
index ca34d52..f15bfc5 100644
--- a/libbuild2/config/init.cxx
+++ b/libbuild2/config/init.cxx
@@ -37,15 +37,21 @@ namespace build2
 
       l5 ([&]{trace << "for " << rs;});
 
-      // Note that the config.<name>* variables belong to the module <name>.
-      // So the only "special" variables we can allocate in config.* are
-      // config.config.*, names that have been "gifted" to us by other modules
-      // (like config.version below) as well as names that we have reserved to
-      // not be valid module names (`build`). We also currently treat `import`
-      // as special.
+      // Note that the config.<name>* variables belong to the module/project
+      // <name>. So the only "special" variables we can allocate in config.**
+      // are config.config.**, names that have been "gifted" to us by other
+      // modules (like config.version below) as well as names that we have
+      // reserved to not be valid module names (`build`). We also currently
+      // treat `import` as special.
+      //
+      // NOTE: all config.** variables are by default made (via a pattern) to
+      // be overridable with global visibility. So we must override this if a
+      // different semantics is required.
       //
       auto& vp (rs.var_pool ());
 
+      const auto v_p (variable_visibility::project);
+
       // While config.config.load (see below) could theoretically be specified
       // in a buildfile, config.config.save is expected to always be specified
       // as a command line override.
@@ -88,9 +94,7 @@ namespace build2
       // Use the NULL value to clear.
       //
       auto& c_p (vp.insert<vector<pair<string, string>>> (
-                   "config.config.persist",
-                   true /* ovr */,
-                   variable_visibility::project));
+                   "config.config.persist", true /* ovr */, v_p));
 
       // Only create the module if we are configuring or creating or if it was
       // requested with config.config.module (useful if we need to call
@@ -99,7 +103,7 @@ namespace build2
       // Detecting the former (configuring/creating) is a bit tricky since the
       // build2 core may not yet know if this is the case. But we know.
       //
-      auto& c_m (vp.insert<bool> ("config.config.module", false /*ovr*/));
+      auto& c_m (vp.insert<bool> ("config.config.module", false /*ovr*/, v_p));
 
       const string& mname (ctx.current_mname);
       const string& oname (ctx.current_oname);
@@ -161,8 +165,11 @@ namespace build2
       l5 ([&]{trace << "for " << rs;});
 
       auto& vp (rs.var_pool ());
+
+      const auto v_p (variable_visibility::project);
+
       auto& c_l (vp.insert<paths> ("config.config.load", true /* ovr */));
-      auto& c_v (vp.insert<uint64_t> ("config.version", false /*ovr*/));
+      auto& c_v (vp.insert<uint64_t> ("config.version", false /*ovr*/, v_p));
 
       // Load config.build if one exists followed by extra files specified in
       // config.config.load (we don't need to worry about disfigure since we
diff --git a/libbuild2/config/utility.cxx b/libbuild2/config/utility.cxx
index 7415085..cf0f73b 100644
--- a/libbuild2/config/utility.cxx
+++ b/libbuild2/config/utility.cxx
@@ -84,7 +84,7 @@ namespace build2
     bool
     unconfigured (scope& rs, const string& n)
     {
-      // Pattern-typed in boot() as bool.
+      // Pattern-typed as bool.
       //
       const variable& var (
         rs.var_pool ().insert ("config." + n + ".configured"));
@@ -98,7 +98,7 @@ namespace build2
     bool
     unconfigured (scope& rs, const string& n, bool v)
     {
-      // Pattern-typed in boot() as bool.
+      // Pattern-typed as bool.
       //
       const variable& var (
         rs.var_pool ().insert ("config." + n + ".configured"));
diff --git a/libbuild2/context.cxx b/libbuild2/context.cxx
index 827894b..724a16e 100644
--- a/libbuild2/context.cxx
+++ b/libbuild2/context.cxx
@@ -476,65 +476,64 @@ namespace build2
 
     // Enter builtin variables and patterns.
     //
+    const auto v_g (variable_visibility::normal); // Global.
+    const auto v_p (variable_visibility::project);
+    const auto v_t (variable_visibility::target);
+    const auto v_q (variable_visibility::prereq);
 
-    // All config.* variables are by default overridable.
+    // All config.** variables are by default overridable with global
+    // visibility.
     //
-    vp.insert_pattern ("config.**", nullopt, true, nullopt, true, false);
+    // For the config.**.configured semantics, see config::unconfigured().
+    //
+    vp.insert_pattern ("config.**", nullopt, true, v_g, true, false);
+    vp.insert_pattern<bool> ("config.**.configured", false, v_p);
 
     // file.cxx:import() (note that order is important; see insert_pattern()).
     //
-    vp.insert_pattern<abs_dir_path> (
-      "config.import.*", true, variable_visibility::normal, true);
-    vp.insert_pattern<path> (
-      "config.import.**", true, variable_visibility::normal, true);
+    vp.insert_pattern<abs_dir_path> ("config.import.*",  true, v_g, true);
+    vp.insert_pattern<path>         ("config.import.**", true, v_g, true);
 
     // module.cxx:boot/init_module().
     //
-    {
-      auto v_p (variable_visibility::project);
-
-      vp.insert_pattern<bool> ("**.booted", false, v_p);
-      vp.insert_pattern<bool> ("**.loaded", false, v_p);
-      vp.insert_pattern<bool> ("**.configured", false, v_p);
-    }
-
-    {
-      auto v_p (variable_visibility::project);
-      auto v_t (variable_visibility::target);
-      auto v_q (variable_visibility::prereq);
+    // Note that we also have the config.<module>.configured variable (see
+    // above).
+    //
+    vp.insert_pattern<bool> ("**.booted",     false /* overridable */, v_p);
+    vp.insert_pattern<bool> ("**.loaded",     false,                   v_p);
+    vp.insert_pattern<bool> ("**.configured", false,                   v_p);
 
-      var_src_root = &vp.insert<dir_path> ("src_root");
-      var_out_root = &vp.insert<dir_path> ("out_root");
-      var_src_base = &vp.insert<dir_path> ("src_base");
-      var_out_base = &vp.insert<dir_path> ("out_base");
+    var_src_root = &vp.insert<dir_path> ("src_root");
+    var_out_root = &vp.insert<dir_path> ("out_root");
+    var_src_base = &vp.insert<dir_path> ("src_base");
+    var_out_base = &vp.insert<dir_path> ("out_base");
 
-      var_forwarded = &vp.insert<bool> ("forwarded", v_p);
+    var_forwarded = &vp.insert<bool> ("forwarded", v_p);
 
-      // Note that subprojects is not typed since the value requires
-      // pre-processing (see file.cxx).
-      //
-      var_project      = &vp.insert<project_name> ("project",      v_p);
-      var_amalgamation = &vp.insert<dir_path>     ("amalgamation", v_p);
-      var_subprojects  = &vp.insert               ("subprojects",  v_p);
-      var_version      = &vp.insert<string>       ("version",      v_p);
+    // Note that subprojects is not typed since the value requires
+    // pre-processing (see file.cxx).
+    //
+    var_project      = &vp.insert<project_name> ("project",      v_p);
+    var_amalgamation = &vp.insert<dir_path>     ("amalgamation", v_p);
+    var_subprojects  = &vp.insert               ("subprojects",  v_p);
+    var_version      = &vp.insert<string>       ("version",      v_p);
 
-      var_project_url     = &vp.insert<string> ("project.url",     v_p);
-      var_project_summary = &vp.insert<string> ("project.summary", v_p);
+    var_project_url     = &vp.insert<string> ("project.url",     v_p);
+    var_project_summary = &vp.insert<string> ("project.summary", v_p);
 
-      var_import_target = &vp.insert<name> ("import.target");
+    var_import_target = &vp.insert<name> ("import.target");
 
-      var_extension = &vp.insert<string> ("extension", v_t);
-      var_clean     = &vp.insert<bool>   ("clean",    v_t);
-      var_backlink  = &vp.insert<string> ("backlink", v_t);
-      var_include   = &vp.insert<string> ("include",  v_q);
+    var_extension = &vp.insert<string> ("extension", v_t);
+    var_clean     = &vp.insert<bool>   ("clean",    v_t);
+    var_backlink  = &vp.insert<string> ("backlink", v_t);
+    var_include   = &vp.insert<string> ("include",  v_q);
 
-      // Backlink executables and (generated) documentation by default.
-      //
-      gs.target_vars[exe::static_type]["*"].assign (var_backlink) = "true";
-      gs.target_vars[doc::static_type]["*"].assign (var_backlink) = "true";
+    // Backlink executables and (generated) documentation by default.
+    //
+    gs.target_vars[exe::static_type]["*"].assign (var_backlink) = "true";
+    gs.target_vars[doc::static_type]["*"].assign (var_backlink) = "true";
 
-      var_build_meta_operation = &vp.insert<string> ("build.meta_operation");
-    }
+    var_build_meta_operation = &vp.insert<string> ("build.meta_operation");
 
     // Register builtin rules.
     //