3 files changed, 45 insertions, 5 deletions

diff --git a/source/compiler-core/slang-source-loc.h b/source/compiler-core/slang-source-loc.h
index 674ed2076..b52f2e50d 100644
--- a/source/compiler-core/slang-source-loc.h
+++ b/source/compiler-core/slang-source-loc.h
@@ -331,6 +331,12 @@ public:
         m_sourceMapKind = sourceMapKind;
     }
 
+    /// Set the source file as an included file
+    void setIncludedFile() { m_included = true; }
+
+    /// Check if the source file is an included file
+    bool isIncludedFile() { return m_included; }
+
     /// Ctor
     SourceFile(SourceManager* sourceManager, const PathInfo& pathInfo, size_t contentSize);
     /// Dtor
@@ -360,6 +366,9 @@ protected:
     ComPtr<IBoxValue<SourceMap>> m_sourceMap;
     // What kind of source map it is (if  there is one)
     SourceMapKind m_sourceMapKind = SourceMapKind::Normal;
+
+    // Indicate if the source file is an included file
+    bool m_included = false;
 };
 
 enum class SourceLocType
diff --git a/source/slang/slang-compiler.h b/source/slang/slang-compiler.h
index 8f7f7d49a..861719aac 100644
--- a/source/slang/slang-compiler.h
+++ b/source/slang/slang-compiler.h
@@ -1880,6 +1880,7 @@ public:
     {
         m_sourceArtifacts.clear();
         m_sourceFiles.clear();
+        m_includedFileSet.clear();
     }
 
     /// Add a source artifact
@@ -1888,6 +1889,8 @@ public:
     /// Add both the artifact and the sourceFile.
     void addSource(IArtifact* sourceArtifact, SourceFile* sourceFile);
 
+    void addIncludedSourceFileIfNotExist(SourceFile* sourceFile);
+
     // The entry points associated with this translation unit
     List<RefPtr<EntryPoint>> const& getEntryPoints() { return module->getEntryPoints(); }
 
@@ -1936,6 +1939,9 @@ protected:
     // NOTE! This member is generated lazily from m_sourceArtifacts
     // it is *necessary* to call requireSourceFiles to ensure it's in sync.
     List<SourceFile*> m_sourceFiles;
+
+    // Track all the included source files added in m_sourceFiles
+    HashSet<SourceFile*> m_includedFileSet;
 };
 
 enum class FloatingPointMode : SlangFloatingPointModeIntegral
diff --git a/source/slang/slang.cpp b/source/slang/slang.cpp
index 065b9de93..912cd2e10 100644
--- a/source/slang/slang.cpp
+++ b/source/slang/slang.cpp
@@ -2540,6 +2540,16 @@ void TranslationUnitRequest::addSource(IArtifact* sourceArtifact, SourceFile* so
     _addSourceFile(sourceFile);
 }
 
+void TranslationUnitRequest::addIncludedSourceFileIfNotExist(SourceFile* sourceFile)
+{
+    if (m_includedFileSet.contains(sourceFile))
+        return;
+
+    sourceFile->setIncludedFile();
+    m_sourceFiles.add(sourceFile);
+    m_includedFileSet.add(sourceFile);
+}
+
 PathInfo TranslationUnitRequest::_findSourcePathInfo(IArtifact* artifact)
 {
     auto pathRep = findRepresentation<IPathArtifactRepresentation>(artifact);
@@ -2652,7 +2662,6 @@ void TranslationUnitRequest::_addSourceFile(SourceFile* sourceFile)
 
 List<SourceFile*> const& TranslationUnitRequest::getSourceFiles()
 {
-    SLANG_ASSERT(m_sourceArtifacts.getCount() == m_sourceFiles.getCount());
     return m_sourceFiles;
 }
 
@@ -3072,8 +3081,15 @@ FrontEndCompileRequest::FrontEndCompileRequest(
 struct FrontEndPreprocessorHandler : PreprocessorHandler
 {
 public:
-    FrontEndPreprocessorHandler(Module* module, ASTBuilder* astBuilder, DiagnosticSink* sink)
-        : m_module(module), m_astBuilder(astBuilder), m_sink(sink)
+    FrontEndPreprocessorHandler(
+        Module* module,
+        ASTBuilder* astBuilder,
+        DiagnosticSink* sink,
+        TranslationUnitRequest* translationUnit)
+        : m_module(module)
+        , m_astBuilder(astBuilder)
+        , m_sink(sink)
+        , m_translationUnit(translationUnit)
     {
     }
 
@@ -3081,6 +3097,7 @@ protected:
     Module* m_module;
     ASTBuilder* m_astBuilder;
     DiagnosticSink* m_sink;
+    TranslationUnitRequest* m_translationUnit = nullptr;
 
     // The first task that this handler tries to deal with is
     // capturing all the files on which a module is dependent.
@@ -3092,6 +3109,7 @@ protected:
     void handleFileDependency(SourceFile* sourceFile) SLANG_OVERRIDE
     {
         m_module->addFileDependency(sourceFile);
+        m_translationUnit->addIncludedSourceFileIfNotExist(sourceFile);
     }
 
     // The second task that this handler deals with is detecting
@@ -3358,6 +3376,9 @@ static void _outputIncludes(
     // For all the source files
     for (SourceFile* sourceFile : sourceFiles)
     {
+        if (sourceFile->isIncludedFile())
+            continue;
+
         // Find an initial view (this is the view of this file, that doesn't have an initiating loc)
         SourceView* sourceView = _findInitialSourceView(sourceFile);
         if (!sourceView)
@@ -3429,7 +3450,7 @@ void FrontEndCompileRequest::parseTranslationUnit(TranslationUnitRequest* transl
     // preprocessoing can be communicated to later phases of
     // compilation.
     //
-    FrontEndPreprocessorHandler preprocessorHandler(module, astBuilder, getSink());
+    FrontEndPreprocessorHandler preprocessorHandler(module, astBuilder, getSink(), translationUnit);
 
     for (auto sourceFile : translationUnit->getSourceFiles())
     {
@@ -4950,7 +4971,11 @@ Linkage::IncludeResult Linkage::findAndIncludeFile(
     fileDecl->parentDecl = module->getModuleDecl();
     module->getIncludedSourceFileMap().add(sourceFile, fileDecl);
 
-    FrontEndPreprocessorHandler preprocessorHandler(module, module->getASTBuilder(), sink);
+    FrontEndPreprocessorHandler preprocessorHandler(
+        module,
+        module->getASTBuilder(),
+        sink,
+        translationUnit);
     auto combinedPreprocessorDefinitions = translationUnit->getCombinedPreprocessorDefinitions();
     SourceLanguage sourceLanguage = translationUnit->sourceLanguage;
     SlangLanguageVersion slangLanguageVersion = module->getModuleDecl()->languageVersion;