[clang] [WIP] Implement `-dump-deserialized-declaration-ranges` flag. (PR #133910)

[Ilya Biryukov via cfe-commits]

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@@ -121,6 +267,26 @@ FrontendAction::CreateWrappedASTConsumer(CompilerInstance &CI,
   if (!Consumer)
     return nullptr;
 
+  std::vector<std::unique_ptr<ASTConsumer>> Consumers;
+  llvm::StringRef DumpDeserializedDeclarationRangesPath =
+      CI.getFrontendOpts().DumpDeserializedDeclarationRangesPath;
+  if (!DumpDeserializedDeclarationRangesPath.empty()) {
+    std::error_code ErrorCode;
+    auto FileStream = std::make_unique<llvm::raw_fd_ostream>(
+        DumpDeserializedDeclarationRangesPath, ErrorCode,
+        llvm::sys::fs::OF_None);
+    if (!ErrorCode) {
+      auto Printer = std::make_unique<DeserializedDeclsLineRangePrinter>(
+          CI.getSourceManager(), std::move(FileStream));
+      Consumers.push_back(std::move(Printer));
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ilya-biryukov wrote:

NIT: inline Printer, `Consumers.push_back(std::make_unique...)`

https://github.com/llvm/llvm-project/pull/133910