[DWARFLinkerParallel] add AddressesMap interface.

[avl]

Summary

This patch is extracted from D96035. It adds AddressesMap map interface
to the DWARFLinkerParallel library. This interface mostly match with the
paired interface from the DWARFLinker library, except that it does
not depend on DIEInfo class.

Depends on D140787

[tschuett]

llvm/include/llvm/DWARFLinkerNext/AddressesMap.h

17 ↗

(On Diff #485724)

There is no next in the namespace? You can use nested namespaces.

38 ↗

(On Diff #485724)

Is this the same as returning std::optional<int64_t>?

[avl]

llvm/include/llvm/DWARFLinkerNext/AddressesMap.h

17 ↗

(On Diff #485724)

Current DWARFLinker does not use special namespace. Thus, name dwarflinker is free. I used it as it is shorter.

38 ↗

(On Diff #485724)

isLiveVariable can change passed value. Not just return new value:

AddrAdjust -= uint64_t(*Reloc.Mapping->getValue().ObjectAddress);

[avl]

llvm/include/llvm/DWARFLinkerNext/AddressesMap.h

38 ↗

(On Diff #485724)

please ignore above comment. yes, we can remove passing the value by reference. in this case it is probably better to rename the method:

std::optional<int64_t> getVariableAddress(const DWARFDie &DIE)

[tschuett]

llvm/include/llvm/DWARFLinkerNext/AddressesMap.h

43 ↗

(On Diff #485724)

It is an odd pattern to pass integers by reference for mutability.

[avl]

changed signature for isLiveVariable and isLiveSubprogram.

[avl]

rebased.

[avl]

ping.

[avl]

friendly ping.

[avl]

friendly ping.

[avl]

friendly ping.

[aprantl]

I'll defer to @JDevlieghere

[JDevlieghere]

LGMT with some wordsmithing

llvm/include/llvm/DWARFLinkerParallel/AddressesMap.h

32–33

36–41

45–50

61–62

[avl]

Thank you for the review!

llvm/include/llvm/DWARFLinkerParallel/AddressesMap.h

+//===- AddressesMap.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_DWARFLINKERPARALLEL_ADDRESSESMAP_H
+#define LLVM_DWARFLINKERPARALLEL_ADDRESSESMAP_H
+
+#include "llvm/ADT/AddressRanges.h"
+#include "llvm/DebugInfo/DWARF/DWARFDie.h"
+#include <cstdint>
+
+namespace llvm {
+namespace dwarflinker_parallel {
+
+/// Mapped value in the address map is the offset to apply to the
+/// linked address.
+using RangesTy = AddressRangesMap;
+
+/// AddressesMap represents information about valid addresses used
+/// by debug information. Valid addresses are those which points to
+/// live code sections. i.e. relocations for these addresses point
+/// into sections which would be/are placed into resulting binary.
+class AddressesMap {
+public:
+  virtual ~AddressesMap() = default;
+
+  /// Checks that there are valid relocations in the .debug_info
+  /// section.
+  virtual bool hasValidRelocs() = 0;
+
+  /// Checks that the specified variable \p DIE references the live code
+  /// section and returns the relocation adjustment value (to get the linked
+  /// address this value might be added to the source variable address).
+  /// Allowed kinds of input DIE: DW_TAG_variable, DW_TAG_constant.
+  /// \returns relocation adjustment value or std::nullopt if there is no
+  /// corresponding live address.
+  virtual std::optional<int64_t>
+  getVariableRelocAdjustment(const DWARFDie &DIE) = 0;
+
+  /// Checks that the specified subprogram \p DIE references the live code
+  /// section and returns the relocation adjustment value (to get the linked
+  /// address this value might be added to the source subprogram address).
+  /// Allowed kinds of input DIE: DW_TAG_subprogram, DW_TAG_label.
+  /// \returns relocation adjustment value or std::nullopt if there is no
+  /// corresponding live address.
+  virtual std::optional<int64_t>
+  getSubprogramRelocAdjustment(const DWARFDie &DIE) = 0;
+
+  /// Apply the valid relocations to the buffer \p Data, taking into
+  /// account that Data is at \p BaseOffset in the .debug_info section.
+  ///
+  /// \returns true whether any reloc has been applied.
+  virtual bool applyValidRelocs(MutableArrayRef<char> Data, uint64_t BaseOffset,
+                                bool IsLittleEndian) = 0;
+
+  /// Returns all valid functions address ranges (i.e., those ranges
+  /// which points to sections with code).
+  virtual RangesTy &getValidAddressRanges() = 0;
+
+  /// Erases all data.
+  virtual void clear() = 0;
+};
+
+} // end of namespace dwarflinker_parallel
+} // end namespace llvm
+
+#endif // LLVM_DWARFLINKERPARALLEL_ADDRESSESMAP_H

llvm/include/llvm/DWARFLinkerParallel/DWARFLinker.h

 //===- DWARFLinker.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_DWARFLINKERPARALLEL_DWARFLINKER_H
 #define LLVM_DWARFLINKERPARALLEL_DWARFLINKER_H
 
+#include "llvm/DWARFLinkerParallel/AddressesMap.h"
+
 namespace llvm {
 namespace dwarflinker_parallel {} // end namespace dwarflinker_parallel
 } // end namespace llvm
 
 #endif // LLVM_DWARFLINKERPARALLEL_DWARFLINKER_H