[DWARF] Make DWARFDataExtractor possible to be used with both 32- and 64-bit offsets.

[ikudrin]

Summary

This is a temporary patch to make the transition to 64-bit offsets in DebugInfo/DWARF more smooth.

[aprantl]

include/llvm/DebugInfo/DWARF/DWARFDataExtractor.h

39

I'm surprised that Size is still 32 bits?

[probinson]

include/llvm/DebugInfo/DWARF/DWARFDataExtractor.h

39

This is the size of the relocated value, and can be no larger than 8; is there some reason to make the type wider?

include/llvm/DebugInfo/DWARF/DWARFDataExtractor.h

DWARFDataExtractor(const DWARFObject &Obj, const DWARFSection &Section,
         Section(&Section) {}
 
   /// Constructor for cases when there are no relocations.
   DWARFDataExtractor(StringRef Data, bool IsLittleEndian, uint8_t AddressSize)
     : DataExtractor(Data, IsLittleEndian, AddressSize) {}
 
   /// Extracts a value and applies a relocation to the result if
   /// one exists for the given offset.
-  uint64_t getRelocatedValue(uint32_t Size, uint32_t *Off,
+  template <typename TOff>
+  uint64_t getRelocatedValue(uint32_t Size, TOff *Off,
                              uint64_t *SectionIndex = nullptr) const;
 
   /// Extracts an address-sized value and applies a relocation to the result if
   /// one exists for the given offset.
-  uint64_t getRelocatedAddress(uint32_t *Off, uint64_t *SecIx = nullptr) const {
+  template <typename TOff>
+  uint64_t getRelocatedAddress(TOff *Off, uint64_t *SecIx = nullptr) const {
     return getRelocatedValue(getAddressSize(), Off, SecIx);
   }
 
   /// Extracts a DWARF-encoded pointer in \p Offset using \p Encoding.
   /// There is a DWARF encoding that uses a PC-relative adjustment.
   /// For these values, \p AbsPosOffset is used to fix them, which should
   /// reflect the absolute address of this pointer.
-  Optional<uint64_t> getEncodedPointer(uint32_t *Offset, uint8_t Encoding,
+  template <typename TOff>
+  Optional<uint64_t> getEncodedPointer(TOff *Offset, uint8_t Encoding,
                                        uint64_t AbsPosOffset = 0) const;
 
   size_t size() const { return Section == nullptr ? 0 : Section->Data.size(); }
 };
 
 } // end namespace llvm
 
 #endif // LLVM_DEBUGINFO_DWARFDATAEXTRACTOR_H

lib/DebugInfo/DWARF/DWARFDataExtractor.cpp

 //===- DWARFDataExtractor.cpp ---------------------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
 #include "llvm/BinaryFormat/Dwarf.h"
 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
 
 using namespace llvm;
 
-uint64_t DWARFDataExtractor::getRelocatedValue(uint32_t Size, uint32_t *Off,
+template <typename TOff>
+uint64_t DWARFDataExtractor::getRelocatedValue(uint32_t Size, TOff *Off,
                                                uint64_t *SecNdx) const {
   if (SecNdx)
     *SecNdx = object::SectionedAddress::UndefSection;
   if (!Section)
     return getUnsigned(Off, Size);
   Optional<RelocAddrEntry> E = Obj->find(*Section, *Off);
   uint64_t A = getUnsigned(Off, Size);
   if (!E)
     return A;
   if (SecNdx)
     *SecNdx = E->SectionIndex;
   return E->Resolver(E->Reloc, E->SymbolValue, A);
 }
 
+template <typename TOff>
 Optional<uint64_t>
-DWARFDataExtractor::getEncodedPointer(uint32_t *Offset, uint8_t Encoding,
+DWARFDataExtractor::getEncodedPointer(TOff *Offset, uint8_t Encoding,
                                       uint64_t PCRelOffset) const {
   if (Encoding == dwarf::DW_EH_PE_omit)
     return None;
 
   uint64_t Result = 0;
-  uint32_t OldOffset = *Offset;
+  TOff OldOffset = *Offset;
   // First get value
   switch (Encoding & 0x0F) {
   case dwarf::DW_EH_PE_absptr:
     switch (getAddressSize()) {
     case 2:
     case 4:
     case 8:
       Result = getUnsigned(Offset, getAddressSize());
DWARFDataExtractor::getEncodedPointer(TOff *Offset, uint8_t Encoding,
   case dwarf::DW_EH_PE_aligned:
   default:
     *Offset = OldOffset;
     return None;
   }
 
   return Result;
 }
+
+template uint64_t
+DWARFDataExtractor::getRelocatedValue<uint32_t>(uint32_t Size, uint32_t *Off,
+                                                uint64_t *SecNdx) const;
+template uint64_t
+DWARFDataExtractor::getRelocatedValue<uint64_t>(uint32_t Size, uint64_t *Off,
+                                                uint64_t *SecNdx) const;
+template Optional<uint64_t> DWARFDataExtractor::getEncodedPointer<uint32_t>(
+    uint32_t *Offset, uint8_t Encoding, uint64_t PCRelOffset) const;
+template Optional<uint64_t> DWARFDataExtractor::getEncodedPointer<uint64_t>(
+    uint64_t *Offset, uint8_t Encoding, uint64_t PCRelOffset) const;