From 8e655a0786aec5e0215e09f2a9629c6f32e34793 Mon Sep 17 00:00:00 2001
From: Eugen Wissner <belka@caraus.de>
Date: Fri, 28 Aug 2026 02:39:42 +0200
Subject: Reject declarations shadowing imports

---
 boot/name_analysis.cc | 55 +++++++++++++++++++++++++++++++++++++++------------
 1 file changed, 42 insertions(+), 13 deletions(-)

(limited to 'boot/name_analysis.cc')

diff --git a/boot/name_analysis.cc b/boot/name_analysis.cc
index 30d3cda..10b8a8d 100644
--- a/boot/name_analysis.cc
+++ b/boot/name_analysis.cc
@@ -24,7 +24,7 @@ along with GCC; see the file COPYING3.  If not see
 namespace elna::boot
 {
     declaration_error::declaration_error(const source_position position, const std::string& name, payload_type payload)
-        : diagnostic(position), name(name), payload(payload)
+        : diagnostic(position), name(name), payload(std::move(payload))
     {
     }
 
@@ -57,11 +57,12 @@ namespace elna::boot
         }, this->payload);
     }
 
-    std::optional<std::pair<std::string, source_position>> declaration_error::note() const
+    std::optional<diagnostic_note> declaration_error::note() const
     {
         if (std::holds_alternative<redefinition>(this->payload))
         {
-            return previous_declaration_note(std::get<redefinition>(this->payload).original);
+            return previous_declaration_note(std::get<redefinition>(this->payload).original,
+                    "previously declared here", std::get<redefinition>(this->payload).file);
         }
         else
         {
@@ -99,7 +100,7 @@ namespace elna::boot
         }, this->payload);
     }
 
-    std::optional<std::pair<std::string, source_position>> const_qualifier_error::note() const
+    std::optional<diagnostic_note> const_qualifier_error::note() const
     {
         if (std::holds_alternative<not_initialized>(this->payload))
         {
@@ -175,7 +176,7 @@ namespace elna::boot
         }, payload);
     }
 
-    std::optional<std::pair<std::string, source_position>> member_error::note() const
+    std::optional<diagnostic_note> member_error::note() const
     {
         if (std::holds_alternative<duplicate>(this->payload))
         {
@@ -201,8 +202,9 @@ namespace elna::boot
         }
     }
 
-    name_analysis_visitor::name_analysis_visitor(symbol_bag bag, const target_info& target)
-        :  bag(std::move(bag)), constant_evaluator(this->bag, target)
+    name_analysis_visitor::name_analysis_visitor(symbol_bag bag, const target_info& target,
+            std::filesystem::path module_file)
+        :  bag(std::move(bag)), constant_evaluator(this->bag, target), module_file(std::move(module_file))
     {
     }
 
@@ -295,7 +297,15 @@ namespace elna::boot
 
         info->exported = declaration->identifier.exported();
         info->position.emplace(declaration->position());
-        this->bag.enter(declaration->identifier.name(), info);
+        info->file = this->module_file;
+
+        if (!this->bag.enter(declaration->identifier.name(), info))
+        {
+            auto original = this->bag.lookup(declaration->identifier.name());
+            add_error<declaration_error>(declaration->identifier.id().position(), declaration->identifier.name(),
+                    declaration_error::redefinition{ .original = original->position,
+                            .file = this->redefinition_file(original) });
+        }
     }
 
     void name_analysis_visitor::visit(pointer_type_expression *expression)
@@ -542,17 +552,25 @@ namespace elna::boot
         this->current_type = type(result_type);
     }
 
+    std::filesystem::path name_analysis_visitor::redefinition_file(
+            const std::shared_ptr<info>& original) const
+    {
+        return original->file != this->module_file ? original->file : std::filesystem::path{};
+    }
+
     std::shared_ptr<variable_info> name_analysis_visitor::register_variable(const std::string& name,
             const bool is_extern, const source_position position)
     {
         auto variable_symbol = std::make_shared<variable_info>(this->current_type, is_extern);
         variable_symbol->position.emplace(position);
+        variable_symbol->file = this->module_file;
 
         if (!this->bag.enter(name, variable_symbol))
         {
             auto original = this->bag.lookup(name);
             add_error<declaration_error>(position, name,
-                    declaration_error::redefinition{ .original = original->position });
+                    declaration_error::redefinition{ .original = original->position,
+                            .file = this->redefinition_file(original) });
         }
         return variable_symbol;
     }
@@ -631,7 +649,14 @@ namespace elna::boot
         }
         info->exported = declaration->identifier.exported();
         info->position.emplace(declaration->position());
-        this->bag.enter(declaration->identifier.name(), info);
+        info->file = this->module_file;
+        if (!this->bag.enter(declaration->identifier.name(), info))
+        {
+            auto original = this->bag.lookup(declaration->identifier.name());
+            add_error<declaration_error>(declaration->identifier.id().position(), declaration->identifier.name(),
+                    declaration_error::redefinition{ .original = original->position,
+                            .file = this->redefinition_file(original) });
+        }
     }
 
     void name_analysis_visitor::visit(procedure_call *call)
@@ -666,12 +691,16 @@ namespace elna::boot
         {
             this->bag.enter();
             auto variable_type = lookup_primitive_type("Int");
-            this->bag.enter("count", std::make_shared<variable_info>(variable_type, false));
+            auto count_symbol = std::make_shared<variable_info>(variable_type, false);
+            count_symbol->file = this->module_file;
+            this->bag.enter("count", count_symbol);
 
             variable_type = lookup_primitive_type("Word8");
             variable_type = type(std::make_shared<pointer_type>(variable_type));
             variable_type = type(std::make_shared<pointer_type>(variable_type));
-            this->bag.enter("parameters", std::make_shared<variable_info>(variable_type, false));
+            auto parameters_symbol = std::make_shared<variable_info>(variable_type, false);
+            parameters_symbol->file = this->module_file;
+            this->bag.enter("parameters", parameters_symbol);
 
             for (statement *const statement : unit->entry_point)
             {
@@ -971,7 +1000,7 @@ namespace elna::boot
         {
             add_error<declaration_error>(declaration->identifier.id().position(),
                     declaration->identifier.id().name(),
-                    declaration_error::redefinition{ .original = declaration->position() });
+                    declaration_error::redefinition{ .original = declaration->position(), .file = {} });
         }
     }
 
-- 
cgit v1.2.3