Rework scoping logic

Now the src directory is entered into the scope map and points to
the same scope as out. This means that targets that are in src,
not out (e.g., source files) will "see" rules, variables, etc.
This becomes important when we try, for example, to install a
source file (say, a header) from src: we need the rule as well
as the install.* variables.

1 files changed, 81 insertions, 12 deletions

diff --git a/build/file.cxx b/build/file.cxx
index b303740..dd9b294 100644
--- a/build/file.cxx
+++ b/build/file.cxx
@@ -115,7 +115,16 @@ namespace build
   scope&
   create_root (const dir_path& out_root, const dir_path& src_root)
   {
-    scope& rs (scopes.insert (out_root, true).first);
+    auto i (scopes.insert (out_root, nullptr, true, true));
+    scope& rs (*i->second);
+
+    // Set out_path. src_path is set in setup_root() below.
+    //
+    if (rs.out_path_ != &i->first)
+    {
+      assert (rs.out_path_ == nullptr);
+      rs.out_path_ = &i->first;
+    }
 
     // Enter built-in meta-operation and operation names. Loading of
     // modules (via the src bootstrap; see below) can result in
@@ -168,9 +177,70 @@ namespace build
   }
 
   void
+  setup_root (scope& s)
+  {
+    value& v (s.assign ("src_root"));
+    assert (v);
+
+    // Register and set src_path.
+    //
+    if (s.src_path_ == nullptr)
+      s.src_path_ = &scopes.insert (as<dir_path> (v), &s, false, true)->first;
+  }
+
+  scope&
+  setup_base (scope_map::iterator i,
+              const dir_path& out_base,
+              const dir_path& src_base)
+  {
+    scope& s (*i->second);
+
+    // Set src/out_path. The key (i->first) can be either out_base
+    // or src_base.
+    //
+    if (s.out_path_ == nullptr)
+    {
+      s.out_path_ =
+        i->first == out_base
+        ? &i->first
+        : &scopes.insert (out_base, &s, true, false)->first;
+    }
+
+    if (s.src_path_ == nullptr)
+    {
+      s.src_path_ =
+        i->first == src_base
+        ? &i->first
+        : &scopes.insert (src_base, &s, false, false)->first;
+    }
+
+    // Set src/out_base variables.
+    //
+    {
+      value& v (s.assign ("out_base"));
+
+      if (!v)
+        v = out_base;
+      else
+        assert (as<dir_path> (v) == out_base);
+    }
+
+    {
+      value& v (s.assign ("src_base"));
+
+      if (!v)
+        v = src_base;
+      else
+        assert (as<dir_path> (v) == src_base);
+    }
+
+    return s;
+  }
+
+  void
   bootstrap_out (scope& root)
   {
-    path bf (root.path () / path ("build/bootstrap/src-root.build"));
+    path bf (root.out_path () / path ("build/bootstrap/src-root.build"));
 
     if (!file_exists (bf))
       return;
@@ -334,7 +404,7 @@ namespace build
 
     bool r (false);
 
-    const dir_path& out_root (root.path ());
+    const dir_path& out_root (root.out_path ());
     const dir_path& src_root (root.src_path ());
 
     path bf (src_root / path ("build/bootstrap.build"));
@@ -370,7 +440,7 @@ namespace build
 
       if (scope* aroot = root.parent_scope ()->root_scope ())
       {
-        const dir_path& ad (aroot->path ());
+        const dir_path& ad (aroot->out_path ());
         dir_path rd (ad.relative (out_root));
 
         // If we already have the amalgamation variable set, verify
@@ -526,7 +596,7 @@ namespace build
       return;
 
     const dir_path& d (as<dir_path> (*l));
-    dir_path out_root (root.path () / d);
+    dir_path out_root (root.out_path () / d);
     out_root.normalize ();
 
     // src_root is a bit more complicated. Here we have three cases:
@@ -557,7 +627,7 @@ namespace build
       }
     }
 
-    rs.src_path_ = &as<dir_path> (v);
+    setup_root (rs);
 
     bootstrap_src (rs);
     create_bootstrap_outer (rs);
@@ -578,7 +648,7 @@ namespace build
         if (n.pair != '\0')
           continue; // Skip project names.
 
-        dir_path out_root (root.path () / n.dir);
+        dir_path out_root (root.out_path () / n.dir);
 
         if (!out_base.sub (out_root))
           continue;
@@ -595,7 +665,7 @@ namespace build
             ? out_root
             : (root.src_path () / n.dir);
 
-        rs.src_path_ = &as<dir_path> (v);
+        setup_root (rs);
 
         bootstrap_src (rs);
 
@@ -671,7 +741,7 @@ namespace build
         if (i != m.end ())
         {
           const dir_path& d ((*i).second);
-          out_root = r->path () / d;
+          out_root = r->out_path () / d;
           fallback_src_root = r->src_path () / d;
           break;
         }
@@ -745,8 +815,6 @@ namespace build
       if (!src_root.empty () && p != src_root)
         fail (loc) << "bootstrapped src_root " << p << " does not match "
                    << "discovered " << src_root;
-
-      root.src_path_ = &p;
     }
     // Otherwise, use fallback if available.
     //
@@ -754,12 +822,13 @@ namespace build
     {
       value& v (root.assign ("src_root"));
       v = move (fallback_src_root);
-      root.src_path_ = &as<dir_path> (v);
     }
     else
       fail (loc) << "unable to determine src_root for imported " << project <<
         info << "consider configuring " << out_root;
 
+    setup_root (root);
+
     bootstrap_src (root);
 
     // Bootstrap outer roots if any. Loading will be done by