Reject declarations shadowing imports

1 files changed, 14 insertions, 6 deletions

diff --git a/boot/symbol.cc b/boot/symbol.cc
index 8855d52..7ef09c9 100644
--- a/boot/symbol.cc
+++ b/boot/symbol.cc
@@ -17,6 +17,7 @@ along with GCC; see the file COPYING3.  If not see
 
 #include "elna/boot/symbol.h"
 
+#include <ranges>
 #include <cassert>
 #include <utility>
 
@@ -356,21 +357,28 @@ namespace elna::boot
         this->symbols = std::make_shared<symbol_table>(global_table);
     }
 
+    std::shared_ptr<info> symbol_bag::lookup_import(const std::string& name) const
+    {
+        const auto found = std::ranges::find_if(this->imports,
+            [&name](const std::shared_ptr<symbol_table>& import_bag) {
+                return import_bag->lookup(name) != nullptr;
+            }
+        );
+        return found == this->imports.cend() ? nullptr : (*found)->lookup(name);
+    }
+
     std::shared_ptr<info> symbol_bag::lookup(const std::string& name)
     {
-        for (const auto& import_bag : this->imports)
+        if (auto result = this->lookup_import(name))
         {
-            if (auto result = import_bag->lookup(name))
-            {
-                return result;
-            }
+            return result;
         }
         return this->symbols->lookup(name);
     }
 
     bool symbol_bag::enter(const std::string& name, const std::shared_ptr<info>& entry)
     {
-        return this->symbols->enter(name, entry);
+        return this->lookup_import(name) == nullptr && this->symbols->enter(name, entry);
     }
 
     std::shared_ptr<symbol_table> symbol_bag::enter()