Add scope::lookup_original_info() that provides additional info about lookup

1 files changed, 23 insertions, 2 deletions

diff --git a/libbuild2/scope.hxx b/libbuild2/scope.hxx
index 09d61e9..f821411 100644
--- a/libbuild2/scope.hxx
+++ b/libbuild2/scope.hxx
@@ -190,12 +190,33 @@ namespace build2
     // can be used to skip a number of initial lookups.
     //
     pair<lookup_type, size_t>
-    lookup_original (const variable&,
+    lookup_original (const variable& var,
                      const target_key* tk = nullptr,
                      const target_key* g1k = nullptr,
                      const target_key* g2k = nullptr,
-                     size_t start_depth = 1) const;
+                     size_t start_depth = 1) const
+    {
+      return lookup_original_info (var, tk, g1k, g2k, start_depth).lookup;
+    }
+
+    // As above but also return an indication of whether the resulting value
+    // was modified by a target type/pattern-specific append/prepend.
+    //
+    struct original_info
+    {
+      pair<lookup_type, size_t> lookup;
+      bool modified;
+    };
 
+    original_info
+    lookup_original_info (const variable&,
+                          const target_key* tk,
+                          const target_key* g1k = nullptr,
+                          const target_key* g2k = nullptr,
+                          size_t start_depth = 1) const;
+
+    // Implementation details (used by scope target lookup).
+    //
     pair<lookup_type, size_t>
     lookup_override (const variable& var,
                      pair<lookup_type, size_t> original,