[llvm] [DWARFLinker][DWARFLinkerParallel][NFC] Refactor DWARFLinker&DWARFLinkerParallel to have a common library. Part 1. (PR #75925)

[Felipe de Azevedo Piovezan via llvm-commits]

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@@ -0,0 +1,98 @@
+//===- DWARFLinkerBase.h ----------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_DWARFLINKER_DWARFLINKERBASE_H
+#define LLVM_DWARFLINKER_DWARFLINKERBASE_H
+#include "AddressesMap.h"
+#include "DWARFFile.h"
+#include "llvm/ADT/AddressRanges.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/DebugInfo/DWARF/DWARFContext.h"
+#include "llvm/DebugInfo/DWARF/DWARFDebugLine.h"
+#include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
+#include "llvm/DebugInfo/DWARF/DWARFDie.h"
+#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
+#include <map>
+namespace llvm {
+class DWARFUnit;
+
+namespace dwarflinker {
+
+/// The base interface for DWARFLinker implementations.
+class DWARFLinkerBase {
+public:
+  virtual ~DWARFLinkerBase() = default;
+  using MessageHandlerTy = std::function<void(
+      const Twine &Warning, StringRef Context, const DWARFDie *DIE)>;
+  using ObjFileLoaderTy = std::function<ErrorOr<DWARFFile &>(
+      StringRef ContainerName, StringRef Path)>;
+  using InputVerificationHandlerTy =
+      std::function<void(const DWARFFile &File, llvm::StringRef Output)>;
+  using ObjectPrefixMapTy = std::map<std::string, std::string>;
+  using CompileUnitHandlerTy = function_ref<void(const DWARFUnit &Unit)>;
+  using TranslatorFuncTy = std::function<StringRef(StringRef)>;
+  using SwiftInterfacesMapTy = std::map<std::string, std::string>;
+  /// Type of output file.
+  enum class OutputFileType : uint8_t {
+    Object,
+    Assembly,
+  };
+  /// The kind of accelerator tables we should emit.
+  enum class AccelTableKind : uint8_t {
+    Apple,     ///< .apple_names, .apple_namespaces, .apple_types, .apple_objc.
+    Pub,       ///< .debug_pubnames, .debug_pubtypes
+    DebugNames ///< .debug_names.
+  };
+  /// Add object file to be linked. Pre-load compile unit die. Call
+  /// \p OnCUDieLoaded for each compile unit die. If specified \p File
+  /// has reference to the Clang module then such module would be
+  /// pre-loaded by \p Loader for !Update case.
+  ///
+  /// \pre NoODR, Update options should be set before call to addObjectFile.
+  virtual void addObjectFile(
+      DWARFFile &File, ObjFileLoaderTy Loader = nullptr,
+      CompileUnitHandlerTy OnCUDieLoaded = [](const DWARFUnit &) {}) = 0;
+  /// Link debug info for added objFiles. Object files are linked all together.
+  virtual Error link() = 0;
+  /// A number of methods setting various linking options:
+  /// Allows to generate log of linking process to the standard output.
+  virtual void setVerbosity(bool Verbose) = 0;
+  /// Print statistics to standard output.
+  virtual void setStatistics(bool Statistics) = 0;
+  /// Verify the input DWARF.
+  virtual void setVerifyInputDWARF(bool Verify) = 0;
+  /// Do not unique types according to ODR.
+  virtual void setNoODR(bool NoODR) = 0;
+  /// Update index tables only(do not modify rest of DWARF).
+  virtual void setUpdateIndexTablesOnly(bool Update) = 0;
+  /// Allow generating valid, but non-deterministic output.
+  virtual void setAllowNonDeterministicOutput(bool) = 0;
+  /// Set whether to keep the enclosing function for a static variable.
+  virtual void setKeepFunctionForStatic(bool KeepFunctionForStatic) = 0;
+  /// Use specified number of threads for parallel files linking.
+  virtual void setNumThreads(unsigned NumThreads) = 0;
+  /// Add kind of accelerator tables to be generated.
+  virtual void addAccelTableKind(AccelTableKind Kind) = 0;
+  /// Set prepend path for clang modules.
+  virtual void setPrependPath(const std::string &Ppath) = 0;
----------------
felipepiovezan wrote:

I noticed you change this, which is good, but you also changed the _member variable_ from `std::string` to `StringRef`. This may be fine, but you need to make sure the variable lifetimes are ok. My original comment was just about the interface, as I am not familiar with the lifetime of the variables here to be certain it is safe to _store_ a StringRef

https://github.com/llvm/llvm-project/pull/75925