diff --git a/trick_source/codegen/Interface_Code_Gen/PrintAttributes.cpp b/trick_source/codegen/Interface_Code_Gen/PrintAttributes.cpp
index 758a84cd..5d443163 100644
--- a/trick_source/codegen/Interface_Code_Gen/PrintAttributes.cpp
+++ b/trick_source/codegen/Interface_Code_Gen/PrintAttributes.cpp
@@ -395,8 +395,11 @@ std::set<std::string> PrintAttributes::getEmptyFiles() {
         const clang::FileEntry * fe = (*fi).first ;
 #if (LIBCLANG_MAJOR < 4) // TODO delete when RHEL 7 no longer supported
         std::string header_file_name = fe->getName() ;
-#else
+#elif (LIBCLANG_MAJOR >= 4 && LIBCLANG_MAJOR < 18) 
         std::string header_file_name = fe->getName().str() ;
+#else
+        const clang::FileEntryRef fer = fi->first ;
+        std::string header_file_name = fer.getName().str();
 #endif
 
         if ( visited_files.find(header_file_name) != visited_files.end() ) {
diff --git a/trick_source/codegen/Interface_Code_Gen/Utilities.cpp b/trick_source/codegen/Interface_Code_Gen/Utilities.cpp
index 39bec7d5..11080f27 100644
--- a/trick_source/codegen/Interface_Code_Gen/Utilities.cpp
+++ b/trick_source/codegen/Interface_Code_Gen/Utilities.cpp
@@ -66,68 +66,69 @@ std::string trim(const std::string& str, const std::string& whitespace ) {
 }
 
 bool isInUserCode( clang::CompilerInstance & ci , clang::SourceLocation sl , HeaderSearchDirs & hsd ) {
-    clang::FileID fid = ci.getSourceManager().getFileID(sl) ;
     bool ret = false ;
-    if ( ! fid.isInvalid() ) {
-        const clang::FileEntry * fe = ci.getSourceManager().getFileEntryForID(fid) ;
-        if ( fe != NULL ) {
-#if (LIBCLANG_MAJOR < 4) // TODO delete when RHEL 7 no longer supported
-            char * resolved_path = almostRealPath( fe->getName() ) ;
-#else
-            char * resolved_path = almostRealPath( fe->getName().str() ) ;
-#endif
-            if ( resolved_path != NULL ) {
-                if ( hsd.isPathInUserDir(resolved_path)) {
-                    ret = true ;
-                }
-                free(resolved_path) ;
-            }
+    char* resolved_path = getResolvedPath(ci, sl);
+
+    if ( resolved_path != NULL ) {
+        if ( hsd.isPathInUserDir(resolved_path)) {
+            ret = true ;
         }
+        free(resolved_path) ;
     }
+
     return ret ;
 }
 
 bool isInUserOrTrickCode( clang::CompilerInstance & ci , clang::SourceLocation sl , HeaderSearchDirs & hsd ) {
-    clang::FileID fid = ci.getSourceManager().getFileID(sl) ;
     bool ret = false ;
-    if ( ! fid.isInvalid() ) {
-        const clang::FileEntry * fe = ci.getSourceManager().getFileEntryForID(fid) ;
-        if ( fe != NULL ) {
-#if (LIBCLANG_MAJOR < 4) // TODO delete when RHEL 7 no longer supported
-            char * resolved_path = almostRealPath( fe->getName() ) ;
-#else
-            char * resolved_path = almostRealPath( fe->getName().str() ) ;
-#endif
-            if ( resolved_path != NULL ) {
-                if ( hsd.isPathInUserOrTrickDir(resolved_path)) {
-                    ret = true ;
-                }
-                free(resolved_path) ;
-            }
+    char* resolved_path = getResolvedPath(ci, sl);
+    
+    if ( resolved_path != NULL ) {
+        if ( hsd.isPathInUserOrTrickDir(resolved_path)) {
+            ret = true ;
         }
+        free(resolved_path) ;
     }
+    
     return ret ;
 }
 
 std::string getFileName( clang::CompilerInstance & ci , clang::SourceLocation sl , HeaderSearchDirs & hsd ) {
-    clang::FileID fid = ci.getSourceManager().getFileID(sl) ;
     std::string file_name;
-    char* resolved_path;
+    char* resolved_path = getResolvedPath(ci, sl);
+
+    if (resolved_path != NULL ) {
+        if (hsd.isPathInUserDir(resolved_path)) {
+            file_name.append(resolved_path);
+        }
+        free(resolved_path);
+    }
+    
+    return file_name;
+}
+
+char * getResolvedPath(clang::CompilerInstance & ci , clang::SourceLocation sl) {
+    clang::FileID fid = ci.getSourceManager().getFileID(sl) ;
+    char* resolved_path = NULL;
+
     if ( ! fid.isInvalid() ) {
         const clang::FileEntry * fe = ci.getSourceManager().getFileEntryForID(fid) ;
         if ( fe != NULL ) {
 #if (LIBCLANG_MAJOR < 4) // TODO delete when RHEL 7 no longer supported
-            char * resolved_path = almostRealPath( fe->getName() ) ;
+        resolved_path = almostRealPath( fe->getName() ) ;
+#elif (LIBCLANG_MAJOR >= 4 && LIBCLANG_MAJOR < 18) 
+        resolved_path = almostRealPath( fe->getName().str() ) ;
 #else
-            char * resolved_path = almostRealPath( fe->getName().str() ) ;
+        const clang::CustomizableOptional<clang::FileEntryRef> cfer = ci.getSourceManager().getFileEntryRefForID(fid) ;
+        if (cfer.has_value()) {
+            resolved_path = almostRealPath( cfer->getName().str() ) ;
+        }
+        
 #endif
-            if ( resolved_path != NULL  and hsd.isPathInUserDir(resolved_path)) {
-                file_name.append(resolved_path);
-            }
-            free(resolved_path);
         }
     }
-    return file_name;
+
+    return resolved_path;
 }
 
 #include <iostream>
diff --git a/trick_source/codegen/Interface_Code_Gen/Utilities.hh b/trick_source/codegen/Interface_Code_Gen/Utilities.hh
index 6fcfe13d..90491c0c 100644
--- a/trick_source/codegen/Interface_Code_Gen/Utilities.hh
+++ b/trick_source/codegen/Interface_Code_Gen/Utilities.hh
@@ -21,7 +21,7 @@ bool isInUserOrTrickCode( clang::CompilerInstance & ci , clang::SourceLocation s
 std::string getFileName( clang::CompilerInstance & ci , clang::SourceLocation sl , HeaderSearchDirs & hsd ) ;
 char * almostRealPath( const std::string& in_path ) ;
 char * almostRealPath( const char * in_path ) ;
-
+char * getResolvedPath(clang::CompilerInstance & ci , clang::SourceLocation sl);
 std::string color(const Color& color, const std::string& text);
 std::string bold(const std::string& text);
 std::string underline(const std::string& text);
diff --git a/trick_source/codegen/Interface_Code_Gen/main.cpp b/trick_source/codegen/Interface_Code_Gen/main.cpp
index 84380329..41d26c4a 100644
--- a/trick_source/codegen/Interface_Code_Gen/main.cpp
+++ b/trick_source/codegen/Interface_Code_Gen/main.cpp
@@ -312,7 +312,7 @@ int main(int argc, char * argv[]) {
 #if (LIBCLANG_MAJOR >= 10 && LIBCLANG_MAJOR < 18)
     const clang::FileEntry* fileEntry = ci.getFileManager().getFile(inputFilePath).get();
 #elif (LIBCLANG_MAJOR >= 18)
-    clang::FileEntryRef fileEntryRef = llvm::cantFail(ci.getFileManager().getFileRef(inputFilePath));
+    const clang::FileEntryRef fileEntryRef = llvm::cantFail(ci.getFileManager().getFileRef(inputFilePath));
 #else
     const clang::FileEntry* fileEntry = ci.getFileManager().getFile(inputFilePath);
 #endif