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1 //===--- DWARFAcceleratorTable.cpp ----------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "llvm/DebugInfo/DWARF/DWARFAcceleratorTable.h"
11 #include "llvm/Support/Dwarf.h"
12 #include "llvm/Support/Format.h"
13 #include "llvm/Support/raw_ostream.h"
14 
15 namespace llvm {
16 
extract()17 bool DWARFAcceleratorTable::extract() {
18   uint32_t Offset = 0;
19 
20   // Check that we can at least read the header.
21   if (!AccelSection.isValidOffset(offsetof(Header, HeaderDataLength)+4))
22     return false;
23 
24   Hdr.Magic = AccelSection.getU32(&Offset);
25   Hdr.Version = AccelSection.getU16(&Offset);
26   Hdr.HashFunction = AccelSection.getU16(&Offset);
27   Hdr.NumBuckets = AccelSection.getU32(&Offset);
28   Hdr.NumHashes = AccelSection.getU32(&Offset);
29   Hdr.HeaderDataLength = AccelSection.getU32(&Offset);
30 
31   // Check that we can read all the hashes and offsets from the
32   // section (see SourceLevelDebugging.rst for the structure of the index).
33   if (!AccelSection.isValidOffset(sizeof(Hdr) + Hdr.HeaderDataLength +
34                                   Hdr.NumBuckets*4 + Hdr.NumHashes*8))
35     return false;
36 
37   HdrData.DIEOffsetBase = AccelSection.getU32(&Offset);
38   uint32_t NumAtoms = AccelSection.getU32(&Offset);
39 
40   for (unsigned i = 0; i < NumAtoms; ++i) {
41     uint16_t AtomType = AccelSection.getU16(&Offset);
42     uint16_t AtomForm = AccelSection.getU16(&Offset);
43     HdrData.Atoms.push_back(std::make_pair(AtomType, AtomForm));
44   }
45 
46   return true;
47 }
48 
dump(raw_ostream & OS) const49 void DWARFAcceleratorTable::dump(raw_ostream &OS) const {
50   // Dump the header.
51   OS << "Magic = " << format("0x%08x", Hdr.Magic) << '\n'
52      << "Version = " << format("0x%04x", Hdr.Version) << '\n'
53      << "Hash function = " << format("0x%08x", Hdr.HashFunction) << '\n'
54      << "Bucket count = " << Hdr.NumBuckets << '\n'
55      << "Hashes count = " << Hdr.NumHashes << '\n'
56      << "HeaderData length = " << Hdr.HeaderDataLength << '\n'
57      << "DIE offset base = " << HdrData.DIEOffsetBase << '\n'
58      << "Number of atoms = " << HdrData.Atoms.size() << '\n';
59 
60   unsigned i = 0;
61   SmallVector<DWARFFormValue, 3> AtomForms;
62   for (const auto &Atom: HdrData.Atoms) {
63     OS << format("Atom[%d] Type: ", i++);
64     if (const char *TypeString = dwarf::AtomTypeString(Atom.first))
65       OS << TypeString;
66     else
67       OS << format("DW_ATOM_Unknown_0x%x", Atom.first);
68     OS << " Form: ";
69     if (const char *FormString = dwarf::FormEncodingString(Atom.second))
70       OS << FormString;
71     else
72       OS << format("DW_FORM_Unknown_0x%x", Atom.second);
73     OS << '\n';
74     AtomForms.push_back(DWARFFormValue(Atom.second));
75   }
76 
77   // Now go through the actual tables and dump them.
78   uint32_t Offset = sizeof(Hdr) + Hdr.HeaderDataLength;
79   unsigned HashesBase = Offset + Hdr.NumBuckets * 4;
80   unsigned OffsetsBase = HashesBase + Hdr.NumHashes * 4;
81 
82   for (unsigned Bucket = 0; Bucket < Hdr.NumBuckets; ++Bucket) {
83     unsigned Index = AccelSection.getU32(&Offset);
84 
85     OS << format("Bucket[%d]\n", Bucket);
86     if (Index == UINT32_MAX) {
87       OS << "  EMPTY\n";
88       continue;
89     }
90 
91     for (unsigned HashIdx = Index; HashIdx < Hdr.NumHashes; ++HashIdx) {
92       unsigned HashOffset = HashesBase + HashIdx*4;
93       unsigned OffsetsOffset = OffsetsBase + HashIdx*4;
94       uint32_t Hash = AccelSection.getU32(&HashOffset);
95 
96       if (Hash % Hdr.NumBuckets != Bucket)
97         break;
98 
99       unsigned DataOffset = AccelSection.getU32(&OffsetsOffset);
100       OS << format("  Hash = 0x%08x Offset = 0x%08x\n", Hash, DataOffset);
101       if (!AccelSection.isValidOffset(DataOffset)) {
102         OS << "    Invalid section offset\n";
103         continue;
104       }
105       while (AccelSection.isValidOffsetForDataOfSize(DataOffset, 4)) {
106         unsigned StringOffset = AccelSection.getU32(&DataOffset);
107         RelocAddrMap::const_iterator Reloc = Relocs.find(DataOffset-4);
108         if (Reloc != Relocs.end())
109           StringOffset += Reloc->second.second;
110         if (!StringOffset)
111           break;
112         OS << format("    Name: %08x \"%s\"\n", StringOffset,
113                      StringSection.getCStr(&StringOffset));
114         unsigned NumData = AccelSection.getU32(&DataOffset);
115         for (unsigned Data = 0; Data < NumData; ++Data) {
116           OS << format("    Data[%d] => ", Data);
117           unsigned i = 0;
118           for (auto &Atom : AtomForms) {
119             OS << format("{Atom[%d]: ", i++);
120             if (Atom.extractValue(AccelSection, &DataOffset, nullptr))
121               Atom.dump(OS, nullptr);
122             else
123               OS << "Error extracting the value";
124             OS << "} ";
125           }
126           OS << '\n';
127         }
128       }
129     }
130   }
131 }
132 }
133