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
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
|
//===-- DWARFCompileUnit.cpp ----------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "DWARFCompileUnit.h"
#include "DWARFContext.h"
#include "llvm/DebugInfo/DWARFFormValue.h"
#include "llvm/Support/Dwarf.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
using namespace dwarf;
DataExtractor DWARFCompileUnit::getDebugInfoExtractor() const {
return DataExtractor(InfoSection, isLittleEndian, AddrSize);
}
bool DWARFCompileUnit::extract(DataExtractor debug_info, uint32_t *offset_ptr) {
clear();
Offset = *offset_ptr;
if (debug_info.isValidOffset(*offset_ptr)) {
uint64_t abbrOffset;
Length = debug_info.getU32(offset_ptr);
Version = debug_info.getU16(offset_ptr);
abbrOffset = debug_info.getU32(offset_ptr);
AddrSize = debug_info.getU8(offset_ptr);
bool lengthOK = debug_info.isValidOffset(getNextCompileUnitOffset()-1);
bool versionOK = DWARFContext::isSupportedVersion(Version);
bool abbrOffsetOK = AbbrevSection.size() > abbrOffset;
bool addrSizeOK = AddrSize == 4 || AddrSize == 8;
if (lengthOK && versionOK && addrSizeOK && abbrOffsetOK && Abbrev != NULL) {
Abbrevs = Abbrev->getAbbreviationDeclarationSet(abbrOffset);
return true;
}
// reset the offset to where we tried to parse from if anything went wrong
*offset_ptr = Offset;
}
return false;
}
uint32_t
DWARFCompileUnit::extract(uint32_t offset, DataExtractor debug_info_data,
const DWARFAbbreviationDeclarationSet *abbrevs) {
clear();
Offset = offset;
if (debug_info_data.isValidOffset(offset)) {
Length = debug_info_data.getU32(&offset);
Version = debug_info_data.getU16(&offset);
bool abbrevsOK = debug_info_data.getU32(&offset) == abbrevs->getOffset();
Abbrevs = abbrevs;
AddrSize = debug_info_data.getU8(&offset);
bool versionOK = DWARFContext::isSupportedVersion(Version);
bool addrSizeOK = AddrSize == 4 || AddrSize == 8;
if (versionOK && addrSizeOK && abbrevsOK &&
debug_info_data.isValidOffset(offset))
return offset;
}
return 0;
}
bool DWARFCompileUnit::extractRangeList(uint32_t RangeListOffset,
DWARFDebugRangeList &RangeList) const {
// Require that compile unit is extracted.
assert(DieArray.size() > 0);
DataExtractor RangesData(RangeSection, isLittleEndian, AddrSize);
return RangeList.extract(RangesData, &RangeListOffset);
}
void DWARFCompileUnit::clear() {
Offset = 0;
Length = 0;
Version = 0;
Abbrevs = 0;
AddrSize = 0;
BaseAddr = 0;
clearDIEs(false);
}
void DWARFCompileUnit::dump(raw_ostream &OS) {
OS << format("0x%08x", Offset) << ": Compile Unit:"
<< " length = " << format("0x%08x", Length)
<< " version = " << format("0x%04x", Version)
<< " abbr_offset = " << format("0x%04x", Abbrevs->getOffset())
<< " addr_size = " << format("0x%02x", AddrSize)
<< " (next CU at " << format("0x%08x", getNextCompileUnitOffset())
<< ")\n";
const DWARFDebugInfoEntryMinimal *CU = getCompileUnitDIE(false);
assert(CU && "Null Compile Unit?");
CU->dump(OS, this, -1U);
}
const char *DWARFCompileUnit::getCompilationDir() {
extractDIEsIfNeeded(true);
if (DieArray.empty())
return 0;
return DieArray[0].getAttributeValueAsString(this, DW_AT_comp_dir, 0);
}
void DWARFCompileUnit::setDIERelations() {
if (DieArray.empty())
return;
DWARFDebugInfoEntryMinimal *die_array_begin = &DieArray.front();
DWARFDebugInfoEntryMinimal *die_array_end = &DieArray.back();
DWARFDebugInfoEntryMinimal *curr_die;
// We purposely are skipping the last element in the array in the loop below
// so that we can always have a valid next item
for (curr_die = die_array_begin; curr_die < die_array_end; ++curr_die) {
// Since our loop doesn't include the last element, we can always
// safely access the next die in the array.
DWARFDebugInfoEntryMinimal *next_die = curr_die + 1;
const DWARFAbbreviationDeclaration *curr_die_abbrev =
curr_die->getAbbreviationDeclarationPtr();
if (curr_die_abbrev) {
// Normal DIE
if (curr_die_abbrev->hasChildren())
next_die->setParent(curr_die);
else
curr_die->setSibling(next_die);
} else {
// NULL DIE that terminates a sibling chain
DWARFDebugInfoEntryMinimal *parent = curr_die->getParent();
if (parent)
parent->setSibling(next_die);
}
}
// Since we skipped the last element, we need to fix it up!
if (die_array_begin < die_array_end)
curr_die->setParent(die_array_begin);
}
void DWARFCompileUnit::extractDIEsToVector(
bool AppendCUDie, bool AppendNonCUDies,
std::vector<DWARFDebugInfoEntryMinimal> &Dies) const {
if (!AppendCUDie && !AppendNonCUDies)
return;
// Set the offset to that of the first DIE and calculate the start of the
// next compilation unit header.
uint32_t Offset = getFirstDIEOffset();
uint32_t NextCUOffset = getNextCompileUnitOffset();
DWARFDebugInfoEntryMinimal DIE;
uint32_t Depth = 0;
const uint8_t *FixedFormSizes =
DWARFFormValue::getFixedFormSizes(getAddressByteSize(), getVersion());
bool IsCUDie = true;
while (Offset < NextCUOffset &&
DIE.extractFast(this, FixedFormSizes, &Offset)) {
if (IsCUDie) {
if (AppendCUDie)
Dies.push_back(DIE);
if (!AppendNonCUDies)
break;
// The average bytes per DIE entry has been seen to be
// around 14-20 so let's pre-reserve the needed memory for
// our DIE entries accordingly.
Dies.reserve(Dies.size() + getDebugInfoSize() / 14);
IsCUDie = false;
} else {
Dies.push_back(DIE);
}
const DWARFAbbreviationDeclaration *AbbrDecl =
DIE.getAbbreviationDeclarationPtr();
if (AbbrDecl) {
// Normal DIE
if (AbbrDecl->hasChildren())
++Depth;
} else {
// NULL DIE.
if (Depth > 0)
--Depth;
if (Depth == 0)
break; // We are done with this compile unit!
}
}
// Give a little bit of info if we encounter corrupt DWARF (our offset
// should always terminate at or before the start of the next compilation
// unit header).
if (Offset > NextCUOffset)
fprintf(stderr, "warning: DWARF compile unit extends beyond its "
"bounds cu 0x%8.8x at 0x%8.8x'\n", getOffset(), Offset);
}
size_t DWARFCompileUnit::extractDIEsIfNeeded(bool CUDieOnly) {
if ((CUDieOnly && DieArray.size() > 0) ||
DieArray.size() > 1)
return 0; // Already parsed.
extractDIEsToVector(DieArray.empty(), !CUDieOnly, DieArray);
// Set the base address of current compile unit.
if (!DieArray.empty()) {
uint64_t BaseAddr =
DieArray[0].getAttributeValueAsUnsigned(this, DW_AT_low_pc, -1U);
if (BaseAddr == -1U)
BaseAddr = DieArray[0].getAttributeValueAsUnsigned(this, DW_AT_entry_pc, 0);
setBaseAddress(BaseAddr);
}
setDIERelations();
return DieArray.size();
}
void DWARFCompileUnit::clearDIEs(bool KeepCUDie) {
if (DieArray.size() > (unsigned)KeepCUDie) {
// std::vectors never get any smaller when resized to a smaller size,
// or when clear() or erase() are called, the size will report that it
// is smaller, but the memory allocated remains intact (call capacity()
// to see this). So we need to create a temporary vector and swap the
// contents which will cause just the internal pointers to be swapped
// so that when temporary vector goes out of scope, it will destroy the
// contents.
std::vector<DWARFDebugInfoEntryMinimal> TmpArray;
DieArray.swap(TmpArray);
// Save at least the compile unit DIE
if (KeepCUDie)
DieArray.push_back(TmpArray.front());
}
}
void
DWARFCompileUnit::buildAddressRangeTable(DWARFDebugAranges *debug_aranges,
bool clear_dies_if_already_not_parsed){
// This function is usually called if there in no .debug_aranges section
// in order to produce a compile unit level set of address ranges that
// is accurate. If the DIEs weren't parsed, then we don't want all dies for
// all compile units to stay loaded when they weren't needed. So we can end
// up parsing the DWARF and then throwing them all away to keep memory usage
// down.
const bool clear_dies = extractDIEsIfNeeded(false) > 1 &&
clear_dies_if_already_not_parsed;
DieArray[0].buildAddressRangeTable(this, debug_aranges);
// Keep memory down by clearing DIEs if this generate function
// caused them to be parsed.
if (clear_dies)
clearDIEs(true);
}
DWARFDebugInfoEntryInlinedChain
DWARFCompileUnit::getInlinedChainForAddress(uint64_t Address) {
// First, find a subprogram that contains the given address (the root
// of inlined chain).
extractDIEsIfNeeded(false);
const DWARFDebugInfoEntryMinimal *SubprogramDIE = 0;
for (size_t i = 0, n = DieArray.size(); i != n; i++) {
if (DieArray[i].isSubprogramDIE() &&
DieArray[i].addressRangeContainsAddress(this, Address)) {
SubprogramDIE = &DieArray[i];
break;
}
}
// Get inlined chain rooted at this subprogram DIE.
if (!SubprogramDIE)
return DWARFDebugInfoEntryInlinedChain();
return SubprogramDIE->getInlinedChainForAddress(this, Address);
}
|