[clang][analyzer] Load config through the proper VFS

Author: jansvoboda11

clang/lib/StaticAnalyzer/Checkers/Yaml.h

@@ -14,6 +14,7 @@
 #ifndef LLVM_CLANG_LIB_STATICANALYZER_CHECKER_YAML_H
 #define LLVM_CLANG_LIB_STATICANALYZER_CHECKER_YAML_H
 
+#include "clang/Basic/SourceManager.h"
 #include "clang/StaticAnalyzer/Core/CheckerManager.h"
 #include "llvm/Support/VirtualFileSystem.h"
 #include "llvm/Support/YAMLTraits.h"
@@ -31,9 +32,12 @@ std::optional<T> getConfiguration(CheckerManager &Mgr, Checker *Chk,
   if (ConfigFile.trim().empty())
     return std::nullopt;
 
-  llvm::vfs::FileSystem *FS = llvm::vfs::getRealFileSystem().get();
+  auto &VFS = Mgr.getASTContext()
+                  .getSourceManager()
+                  .getFileManager()
+                  .getVirtualFileSystem();
   llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> Buffer =
-      FS->getBufferForFile(ConfigFile.str());
+      VFS.getBufferForFile(ConfigFile.str());
 
   if (Buffer.getError()) {
     Mgr.reportInvalidCheckerOptionValue(Chk, Option,