aboutsummaryrefslogtreecommitdiffstats
path: root/lib/DebugInfo/DWARFDebugAranges.cpp
blob: f79862d606f5618baae107a71330d683e7e32773 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
//===-- DWARFDebugAranges.cpp -----------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "DWARFDebugAranges.h"
#include "DWARFCompileUnit.h"
#include "DWARFContext.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cassert>
using namespace llvm;

// Compare function DWARFDebugAranges::Range structures
static bool RangeLessThan(const DWARFDebugAranges::Range &range1,
                          const DWARFDebugAranges::Range &range2) {
  return range1.LoPC < range2.LoPC;
}

namespace {
  class CountArangeDescriptors {
  public:
    CountArangeDescriptors(uint32_t &count_ref) : Count(count_ref) {}
    void operator()(const DWARFDebugArangeSet &Set) {
      Count += Set.getNumDescriptors();
    }
    uint32_t &Count;
  };

  class AddArangeDescriptors {
  public:
    AddArangeDescriptors(DWARFDebugAranges::RangeColl &Ranges,
                         DWARFDebugAranges::ParsedCUOffsetColl &CUOffsets)
      : RangeCollection(Ranges),
        CUOffsetCollection(CUOffsets) {}
    void operator()(const DWARFDebugArangeSet &Set) {
      DWARFDebugAranges::Range Range;
      Range.Offset = Set.getCompileUnitDIEOffset();
      CUOffsetCollection.insert(Range.Offset);

      for (uint32_t i = 0, n = Set.getNumDescriptors(); i < n; ++i) {
        const DWARFDebugArangeSet::Descriptor *ArangeDescPtr =
            Set.getDescriptor(i);
        Range.LoPC = ArangeDescPtr->Address;
        Range.Length = ArangeDescPtr->Length;

        // Insert each item in increasing address order so binary searching
        // can later be done!
        DWARFDebugAranges::RangeColl::iterator InsertPos =
          std::lower_bound(RangeCollection.begin(), RangeCollection.end(),
                           Range, RangeLessThan);
        RangeCollection.insert(InsertPos, Range);
      }

    }
    DWARFDebugAranges::RangeColl &RangeCollection;
    DWARFDebugAranges::ParsedCUOffsetColl &CUOffsetCollection;
  };
}

bool DWARFDebugAranges::extract(DataExtractor debug_aranges_data) {
  if (debug_aranges_data.isValidOffset(0)) {
    uint32_t offset = 0;

    typedef std::vector<DWARFDebugArangeSet> SetCollection;
    SetCollection sets;

    DWARFDebugArangeSet set;
    Range range;
    while (set.extract(debug_aranges_data, &offset))
      sets.push_back(set);

    uint32_t count = 0;

    std::for_each(sets.begin(), sets.end(), CountArangeDescriptors(count));

    if (count > 0) {
      Aranges.reserve(count);
      AddArangeDescriptors range_adder(Aranges, ParsedCUOffsets);
      std::for_each(sets.begin(), sets.end(), range_adder);
    }
  }
  return false;
}

bool DWARFDebugAranges::generate(DWARFContext *ctx) {
  if (ctx) {
    const uint32_t num_compile_units = ctx->getNumCompileUnits();
    for (uint32_t cu_idx = 0; cu_idx < num_compile_units; ++cu_idx) {
      if (DWARFCompileUnit *cu = ctx->getCompileUnitAtIndex(cu_idx)) {
        uint32_t CUOffset = cu->getOffset();
        if (ParsedCUOffsets.insert(CUOffset).second)
          cu->buildAddressRangeTable(this, true);
      }
    }
  }
  sort(true, /* overlap size */ 0);
  return !isEmpty();
}

void DWARFDebugAranges::dump(raw_ostream &OS) const {
  const uint32_t num_ranges = getNumRanges();
  for (uint32_t i = 0; i < num_ranges; ++i) {
    const Range &range = Aranges[i];
    OS << format("0x%8.8x: [0x%8.8" PRIx64 " - 0x%8.8" PRIx64 ")\n",
                 range.Offset, (uint64_t)range.LoPC, (uint64_t)range.HiPC());
  }
}

void DWARFDebugAranges::Range::dump(raw_ostream &OS) const {
  OS << format("{0x%8.8x}: [0x%8.8" PRIx64 " - 0x%8.8" PRIx64 ")\n",
               Offset, LoPC, HiPC());
}

void DWARFDebugAranges::appendRange(uint32_t offset, uint64_t low_pc,
                                    uint64_t high_pc) {
  if (!Aranges.empty()) {
    if (Aranges.back().Offset == offset && Aranges.back().HiPC() == low_pc) {
      Aranges.back().setHiPC(high_pc);
      return;
    }
  }
  Aranges.push_back(Range(low_pc, high_pc, offset));
}

void DWARFDebugAranges::sort(bool minimize, uint32_t n) {
  const size_t orig_arange_size = Aranges.size();
  // Size of one? If so, no sorting is needed
  if (orig_arange_size <= 1)
    return;
  // Sort our address range entries
  std::stable_sort(Aranges.begin(), Aranges.end(), RangeLessThan);

  if (!minimize)
    return;

  // Most address ranges are contiguous from function to function
  // so our new ranges will likely be smaller. We calculate the size
  // of the new ranges since although std::vector objects can be resized,
  // the will never reduce their allocated block size and free any excesss
  // memory, so we might as well start a brand new collection so it is as
  // small as possible.

  // First calculate the size of the new minimal arange vector
  // so we don't have to do a bunch of re-allocations as we
  // copy the new minimal stuff over to the new collection.
  size_t minimal_size = 1;
  for (size_t i = 1; i < orig_arange_size; ++i) {
    if (!Range::SortedOverlapCheck(Aranges[i-1], Aranges[i], n))
      ++minimal_size;
  }

  // If the sizes are the same, then no consecutive aranges can be
  // combined, we are done.
  if (minimal_size == orig_arange_size)
    return;

  // Else, make a new RangeColl that _only_ contains what we need.
  RangeColl minimal_aranges;
  minimal_aranges.resize(minimal_size);
  uint32_t j = 0;
  minimal_aranges[j] = Aranges[0];
  for (size_t i = 1; i < orig_arange_size; ++i) {
    if(Range::SortedOverlapCheck (minimal_aranges[j], Aranges[i], n)) {
      minimal_aranges[j].setHiPC (Aranges[i].HiPC());
    } else {
      // Only increment j if we aren't merging
      minimal_aranges[++j] = Aranges[i];
    }
  }
  assert (j+1 == minimal_size);

  // Now swap our new minimal aranges into place. The local
  // minimal_aranges will then contian the old big collection
  // which will get freed.
  minimal_aranges.swap(Aranges);
}

uint32_t DWARFDebugAranges::findAddress(uint64_t address) const {
  if (!Aranges.empty()) {
    Range range(address);
    RangeCollIterator begin = Aranges.begin();
    RangeCollIterator end = Aranges.end();
    RangeCollIterator pos = std::lower_bound(begin, end, range, RangeLessThan);

    if (pos != end && pos->LoPC <= address && address < pos->HiPC()) {
      return pos->Offset;
    } else if (pos != begin) {
      --pos;
      if (pos->LoPC <= address && address < pos->HiPC())
        return (*pos).Offset;
    }
  }
  return -1U;
}

bool
DWARFDebugAranges::allRangesAreContiguous(uint64_t &LoPC, uint64_t &HiPC) const{
  if (Aranges.empty())
    return false;

  uint64_t next_addr = 0;
  RangeCollIterator begin = Aranges.begin();
  for (RangeCollIterator pos = begin, end = Aranges.end(); pos != end;
       ++pos) {
    if (pos != begin && pos->LoPC != next_addr)
      return false;
    next_addr = pos->HiPC();
  }
  // We checked for empty at the start of function so front() will be valid.
  LoPC = Aranges.front().LoPC;
  // We checked for empty at the start of function so back() will be valid.
  HiPC = Aranges.back().HiPC();
  return true;
}

bool DWARFDebugAranges::getMaxRange(uint64_t &LoPC, uint64_t &HiPC) const {
  if (Aranges.empty())
    return false;
  // We checked for empty at the start of function so front() will be valid.
  LoPC = Aranges.front().LoPC;
  // We checked for empty at the start of function so back() will be valid.
  HiPC = Aranges.back().HiPC();
  return true;
}