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

[via llvm-commits]

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+//===- 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;
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avl-llvm wrote:

At present moment no linkers have use cases when tables can be added. But from the general point of view we can want to generate different sets of accel tables and then it is good if interface allows this.

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