Add support for multiple variable overrides

Now we can do:

$ b config.cxx.coptions=-O3 config.cxx.coptions=-O0

Or even:

$ b config.cxx.coptions=-O3 config.cxx.coptions+=-g

3 files changed, 7 insertions, 15 deletions

diff --git a/build2/config/operation.cxx b/build2/config/operation.cxx
index 724b92d..7d6fc74 100644
--- a/build2/config/operation.cxx
+++ b/build2/config/operation.cxx
@@ -131,7 +131,7 @@ namespace build2
             const variable& var (sv.var);
 
             pair<lookup, size_t> org (root.find_original (var));
-            pair<lookup, size_t> ovr (var.override == nullptr
+            pair<lookup, size_t> ovr (var.overrides == nullptr
                                       ? org
                                       : root.find_override (var, org));
             const lookup& l (ovr.first);
@@ -859,19 +859,11 @@ namespace build2
       {
         const variable& var (p.first->first);
 
-        // Annoyingly, this is one of the __override/__prefix/__suffix
-        // values. So we strip the last component.
+        // Annoyingly, this can be (always is?) one of the overrides
+        // (__override, __prefix, etc).
         //
-        size_t n (var.name.size ());
-
-        if (var.name.compare (n - 11, 11, ".__override") == 0)
-          n -= 11;
-        else if (var.name.compare (n - 9, 9, ".__prefix") == 0)
-          n -= 9;
-        else if (var.name.compare (n - 9, 9, ".__suffix") == 0)
-          n -= 9;
-
-        m.save_variable (*vp.find (string (var.name, 0, n)));
+        size_t n (var.override ());
+        m.save_variable (n != 0 ? *vp.find (string (var.name, 0, n)) : var);
       }
 
       // Now project-specific. For now we just save all of them and let
diff --git a/build2/config/utility.cxx b/build2/config/utility.cxx
index cc89d2f..e15c689 100644
--- a/build2/config/utility.cxx
+++ b/build2/config/utility.cxx
@@ -33,7 +33,7 @@ namespace build2
       if (l.defined () && l->extra)
         n = true;
 
-      if (var.override != nullptr)
+      if (var.overrides != nullptr)
       {
         pair<lookup, size_t> ovr (r.find_override (var, move (org)));
 
diff --git a/build2/config/utility.txx b/build2/config/utility.txx
index 4f3429f..b8e0acc 100644
--- a/build2/config/utility.txx
+++ b/build2/config/utility.txx
@@ -47,7 +47,7 @@ namespace build2
       else if (l->extra)
         n = (save_flags & save_commented) == 0; // Absence means default.
 
-      if (var.override != nullptr)
+      if (var.overrides != nullptr)
       {
         pair<lookup, size_t> ovr (root.find_override (var, move (org)));