Check for re-import at translation-unit level

Previously the code checked for a duplicate `#import` using a data structure attached to the compile request, but this would fail for nested imports.
It also wouldn't work for a combination of `#import` and `__import`.

This change makes it so that we instead track a set of already-imported modules in the semantic checking visitor, which is instantiated once per translation unit.
We also key this set on the actual module (AST) imported, rather than on path/name/whatever, so hopefully it will be robust to the same thing getting imported multiple ways.

1 files changed, 8 insertions, 2 deletions

diff --git a/source/slang/compiler.h b/source/slang/compiler.h
index 7c4a17607..a6f3eee0e 100644
--- a/source/slang/compiler.h
+++ b/source/slang/compiler.h
@@ -203,9 +203,16 @@ namespace Slang
         RefPtr<ProgramLayout> layout;
 
         // Modules that have been dynamically loaded via `import`
-        Dictionary<String, RefPtr<ProgramSyntaxNode>> loadedModulesMap;
+        //
+        // This is a list of unique modules loaded, in the order they were encountered.
         List<RefPtr<ProgramSyntaxNode> > loadedModulesList;
 
+        // Map from the logical name of a module to its definition
+        Dictionary<String, RefPtr<ProgramSyntaxNode>> mapPathToLoadedModule;
+
+        // Map from the path of a module file to its definition
+        Dictionary<String, RefPtr<ProgramSyntaxNode>> mapNameToLoadedModules;
+
 
         CompileRequest(Session* session)
             : mSession(session)
@@ -248,7 +255,6 @@ namespace Slang
             CodePosition const& loc);
 
         void handlePoundImport(
-            String const&       name,
             String const&       path,
             TokenList const&    tokens);