llvm/lib/DebugInfo/DWARF/DWARFDebugRangeList.cpp

   1 //===- DWARFDebugRangesList.cpp -------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
  10 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
  11 #include "llvm/Support/Errc.h"
  12 #include "llvm/Support/Format.h"
  13 #include "llvm/Support/raw_ostream.h"
  14 #include <cinttypes>
  15 #include <cstdint>
  16
  17 using namespace llvm;
  18
  19 bool DWARFDebugRangeList::RangeListEntry::isBaseAddressSelectionEntry(
  20     uint8_t AddressSize) const {
  21   assert(DWARFContext::isAddressSizeSupported(AddressSize));
  22   return StartAddress == dwarf::computeTombstoneAddress(AddressSize);
  23 }
  24
  25 void DWARFDebugRangeList::clear() {
  26   Offset = -1ULL;
  27   AddressSize = 0;
  28   Entries.clear();
  29 }
  30
  31 Error DWARFDebugRangeList::extract(const DWARFDataExtractor &data,
  32                                    uint64_t *offset_ptr) {
  33   clear();
  34   if (!data.isValidOffset(*offset_ptr))
  35     return createStringError(errc::invalid_argument,
  36                        "invalid range list offset 0x%" PRIx64, *offset_ptr);
  37
  38   AddressSize = data.getAddressSize();
  39   if (Error SizeErr = DWARFContext::checkAddressSizeSupported(
  40           AddressSize, errc::invalid_argument,
  41           "range list at offset 0x%" PRIx64, *offset_ptr))
  42     return SizeErr;
  43   Offset = *offset_ptr;
  44   while (true) {
  45     RangeListEntry Entry;
  46     Entry.SectionIndex = -1ULL;
  47
  48     uint64_t prev_offset = *offset_ptr;
  49     Entry.StartAddress = data.getRelocatedAddress(offset_ptr);
  50     Entry.EndAddress =
  51         data.getRelocatedAddress(offset_ptr, &Entry.SectionIndex);
  52
  53     // Check that both values were extracted correctly.
  54     if (*offset_ptr != prev_offset + 2 * AddressSize) {
  55       clear();
  56       return createStringError(errc::invalid_argument,
  57                          "invalid range list entry at offset 0x%" PRIx64,
  58                          prev_offset);
  59     }
  60     if (Entry.isEndOfListEntry())
  61       break;
  62     Entries.push_back(Entry);
  63   }
  64   return Error::success();
  65 }
  66
  67 void DWARFDebugRangeList::dump(raw_ostream &OS) const {
  68   const char *AddrFmt;
  69   switch (AddressSize) {
  70   case 2:
  71     AddrFmt = "%08" PRIx64 " %04" PRIx64 " %04" PRIx64 "\n";
  72     break;
  73   case 4:
  74     AddrFmt = "%08" PRIx64 " %08" PRIx64 " %08" PRIx64 "\n";
  75     break;
  76   case 8:
  77     AddrFmt = "%08" PRIx64 " %016" PRIx64 " %016" PRIx64 "\n";
  78     break;
  79   default:
  80     llvm_unreachable("unsupported address size");
  81   }
  82   for (const RangeListEntry &RLE : Entries)
  83     OS << format(AddrFmt, Offset, RLE.StartAddress, RLE.EndAddress);
  84   OS << format("%08" PRIx64 " <End of list>\n", Offset);
  85 }
  86
  87 DWARFAddressRangesVector DWARFDebugRangeList::getAbsoluteRanges(
  88     std::optional<object::SectionedAddress> BaseAddr) const {
  89   DWARFAddressRangesVector Res;
  90   // debug_addr can't use the max integer tombstone because that's used for the
  91   // base address specifier entry - so use max-1.
  92   uint64_t Tombstone = dwarf::computeTombstoneAddress(AddressSize) - 1;
  93   for (const RangeListEntry &RLE : Entries) {
  94     if (RLE.isBaseAddressSelectionEntry(AddressSize)) {
  95       BaseAddr = {RLE.EndAddress, RLE.SectionIndex};
  96       continue;
  97     }
  98
  99     DWARFAddressRange E;
 100     E.LowPC = RLE.StartAddress;
 101     if (E.LowPC == Tombstone)
 102       continue;
 103     E.HighPC = RLE.EndAddress;
 104     E.SectionIndex = RLE.SectionIndex;
 105     // Base address of a range list entry is determined by the closest preceding
 106     // base address selection entry in the same range list. It defaults to the
 107     // base address of the compilation unit if there is no such entry.
 108     if (BaseAddr) {
 109       if (BaseAddr->Address == Tombstone)
 110         continue;
 111       E.LowPC += BaseAddr->Address;
 112       E.HighPC += BaseAddr->Address;
 113       if (E.SectionIndex == -1ULL)
 114         E.SectionIndex = BaseAddr->SectionIndex;
 115     }
 116     Res.push_back(E);
 117   }
 118   return Res;
 119 }