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

---
 gcc/gcc/elna-diagnostic.cc    | 25 +++++++++++++++++++++----
 gcc/gcc/elna-module-loader.cc | 15 ++++++++++++---
 2 files changed, 33 insertions(+), 7 deletions(-)

(limited to 'gcc')

diff --git a/gcc/gcc/elna-diagnostic.cc b/gcc/gcc/elna-diagnostic.cc
index ea1f64c..1a65eed 100644
--- a/gcc/gcc/elna-diagnostic.cc
+++ b/gcc/gcc/elna-diagnostic.cc
@@ -63,9 +63,11 @@ namespace elna::gcc
         return make_location(caret, start, end);
     }
 
-    void report_errors(const std::deque<std::unique_ptr<boot::diagnostic>>& errors)
+    void report_errors(const boot::module_diagnostics& diagnostics)
     {
-        for (const auto& error : errors)
+        const linemap_guard guard(diagnostics.module);
+
+        for (const auto& error : diagnostics.errors())
         {
             if (error->position.start().available())
             {
@@ -79,8 +81,23 @@ namespace elna::gcc
             }
             if (auto note = error->note())
             {
-                const location_t note_loc = make_range(note->second);
-                inform(note_loc, "%s", note->first.c_str());
+                if (note->file.empty())
+                {
+                    const location_t note_loc = make_range(note->position);
+                    inform(note_loc, "%s", note->message.c_str());
+                }
+                else
+                {
+                    // Positions carry no file identity; render the note under
+                    // a map of the module the note points into. LC_RENAME
+                    // continues the current map under the new name without
+                    // recording an include edge, so no "In file included
+                    // from" chain is printed for the note.
+                    linemap_add(line_table, LC_RENAME, 0, ggc_strdup(note->file.native().c_str()), 1);
+                    const location_t note_loc = make_range(note->position);
+                    inform(note_loc, "%s", note->message.c_str());
+                    linemap_add(line_table, LC_RENAME, 0, ggc_strdup(diagnostics.module.native().c_str()), 1);
+                }
             }
         }
     }
diff --git a/gcc/gcc/elna-module-loader.cc b/gcc/gcc/elna-module-loader.cc
index 1dd7596..8827a1e 100644
--- a/gcc/gcc/elna-module-loader.cc
+++ b/gcc/gcc/elna-module-loader.cc
@@ -33,7 +33,7 @@ namespace elna::gcc
     }
 
     std::filesystem::path module_loader::resolve(const std::filesystem::path& relative,
-            const boot::source_position& position)
+            const boot::source_position& position, const std::filesystem::path& module)
     {
         std::vector<std::filesystem::path> found;
 
@@ -52,14 +52,20 @@ namespace elna::gcc
         }
         if (found.size() > 1)
         {
+            const linemap_guard guard(module);
             const location_t gcc_location = get_location(&position);
             error_at(gcc_location, "Module %s was found in more than one include path",
                     relative.native().c_str());
+
+            for (const auto& candidate : found)
+            {
+                inform(UNKNOWN_LOCATION, "  %s", candidate.native().c_str());
+            }
         }
         return std::filesystem::weakly_canonical(found.front());
     }
 
-    boot::dependency module_loader::read(const std::filesystem::path& key)
+    boot::read_result module_loader::read(const std::filesystem::path& key)
     {
         std::ifstream entry_point{ key, std::ios::in };
 
@@ -88,7 +94,10 @@ namespace elna::gcc
             const std::filesystem::path key = std::filesystem::weakly_canonical(filenames[i]);
             boot::dependency result = state.compile(key, loader, target);
 
-            report_errors(result.errors);
+            for (const auto& diagnostics : result.errors)
+            {
+                report_errors(diagnostics);
+            }
 
             if (result.value != nullptr)
             {
-- 
cgit v1.2.3