Redesign src/out scoping

We no longer enter paths from the src tree into scope map. Instead, targets
from the src tree now include their out tree directory (in essence their
"configuration"). This is then used to find a target's scope. See the
comment in class target for details.

The result of this change is that we can now again build multiple
configurations (out trees) for same project at once.

1 files changed, 12 insertions, 23 deletions

diff --git a/build2/dump.cxx b/build2/dump.cxx
index 648d8dd..442340f 100644
--- a/build2/dump.cxx
+++ b/build2/dump.cxx
@@ -18,7 +18,7 @@ namespace build2
   dump_variable (ostream& os,
                  const variable& var,
                  const lookup& org,
-                 scope& s,
+                 const scope& s,
                  bool target)
   {
     os << var.name << " = ";
@@ -63,7 +63,7 @@ namespace build2
   dump_variables (ostream& os,
                   string& ind,
                   const variable_map& vars,
-                  scope& s,
+                  const scope& s,
                   bool target)
   {
     for (const auto& e: vars)
@@ -79,7 +79,7 @@ namespace build2
   dump_variables (ostream& os,
                   string& ind,
                   const variable_type_map& vtm,
-                  scope& s)
+                  const scope& s)
   {
     for (const auto& vt: vtm)
     {
@@ -128,7 +128,11 @@ namespace build2
   }
 
   static void
-  dump_target (ostream& os, string& ind, action a, const target& t, scope& s)
+  dump_target (ostream& os,
+               string& ind,
+               action a,
+               const target& t,
+               const scope& s)
   {
     // Print the target and its prerequisites relative to the scope. To achieve
     // this we are going to temporarily lower the stream verbosity to level 1.
@@ -196,7 +200,7 @@ namespace build2
               action a,
               scope_map::const_iterator& i)
   {
-    scope& p (*i->second);
+    const scope& p (i->second);
     const dir_path& d (i->first);
     ++i;
 
@@ -235,23 +239,8 @@ namespace build2
 
     // Nested scopes of which we are an immediate parent.
     //
-    for (auto e (scopes.end ()); i != e && i->second->parent_scope () == &p;)
+    for (auto e (scopes.end ()); i != e && i->second.parent_scope () == &p;)
     {
-      // See what kind of scope entry this is. It can be:
-      //
-      // 1. Out-of-project scope.
-      // 2. In-project out entry.
-      // 3. In-project src entry.
-      //
-      // We want to print #2 and #3 as a single, unified scope.
-      //
-      scope& s (*i->second);
-      if (s.src_path_ != s.out_path_ && s.src_path_ == &i->first)
-      {
-        ++i;
-        continue;
-      }
-
       if (vb)
       {
         os << endl;
@@ -295,8 +284,8 @@ namespace build2
   void
   dump (action a)
   {
-    auto i (scopes.begin ());
-    assert (i->second == global_scope);
+    auto i (scopes.cbegin ());
+    assert (&i->second == global_scope);
 
     string ind;
     ostream& os (*diag_stream);