1 //===-- DWARFCompileUnit.cpp ----------------------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #include "DWARFCompileUnit.h"
11 #include "DWARFContext.h"
12 #include "DWARFFormValue.h"
13 #include "llvm/Support/Dwarf.h"
14 #include "llvm/Support/Format.h"
15 #include "llvm/Support/raw_ostream.h"
17 using namespace dwarf;
19 DataExtractor DWARFCompileUnit::getDebugInfoExtractor() const {
20 return DataExtractor(Context.getInfoSection(),
21 Context.isLittleEndian(), getAddressByteSize());
24 bool DWARFCompileUnit::extract(DataExtractor debug_info, uint32_t *offset_ptr) {
29 if (debug_info.isValidOffset(*offset_ptr)) {
31 const DWARFDebugAbbrev *abbr = Context.getDebugAbbrev();
32 Length = debug_info.getU32(offset_ptr);
33 Version = debug_info.getU16(offset_ptr);
34 abbrOffset = debug_info.getU32(offset_ptr);
35 AddrSize = debug_info.getU8(offset_ptr);
37 bool lengthOK = debug_info.isValidOffset(getNextCompileUnitOffset()-1);
38 bool versionOK = DWARFContext::isSupportedVersion(Version);
39 bool abbrOffsetOK = Context.getAbbrevSection().size() > abbrOffset;
40 bool addrSizeOK = AddrSize == 4 || AddrSize == 8;
42 if (lengthOK && versionOK && addrSizeOK && abbrOffsetOK && abbr != NULL) {
43 Abbrevs = abbr->getAbbreviationDeclarationSet(abbrOffset);
47 // reset the offset to where we tried to parse from if anything went wrong
55 DWARFCompileUnit::extract(uint32_t offset, DataExtractor debug_info_data,
56 const DWARFAbbreviationDeclarationSet *abbrevs) {
61 if (debug_info_data.isValidOffset(offset)) {
62 Length = debug_info_data.getU32(&offset);
63 Version = debug_info_data.getU16(&offset);
64 bool abbrevsOK = debug_info_data.getU32(&offset) == abbrevs->getOffset();
66 AddrSize = debug_info_data.getU8 (&offset);
68 bool versionOK = DWARFContext::isSupportedVersion(Version);
69 bool addrSizeOK = AddrSize == 4 || AddrSize == 8;
71 if (versionOK && addrSizeOK && abbrevsOK &&
72 debug_info_data.isValidOffset(offset))
78 void DWARFCompileUnit::clear() {
88 void DWARFCompileUnit::dump(raw_ostream &OS) {
89 OS << format("0x%08x", Offset) << ": Compile Unit:"
90 << " length = " << format("0x%08x", Length)
91 << " version = " << format("0x%04x", Version)
92 << " abbr_offset = " << format("0x%04x", Abbrevs->getOffset())
93 << " addr_size = " << format("0x%02x", AddrSize)
94 << " (next CU at " << format("0x%08x", getNextCompileUnitOffset())
97 getCompileUnitDIE(false)->dump(OS, this, -1U);
100 const char *DWARFCompileUnit::getCompilationDir() {
101 extractDIEsIfNeeded(true);
102 if (DieArray.empty())
104 return DieArray[0].getAttributeValueAsString(this, DW_AT_comp_dir, 0);
107 void DWARFCompileUnit::setDIERelations() {
108 if (DieArray.empty())
110 DWARFDebugInfoEntryMinimal *die_array_begin = &DieArray.front();
111 DWARFDebugInfoEntryMinimal *die_array_end = &DieArray.back();
112 DWARFDebugInfoEntryMinimal *curr_die;
113 // We purposely are skipping the last element in the array in the loop below
114 // so that we can always have a valid next item
115 for (curr_die = die_array_begin; curr_die < die_array_end; ++curr_die) {
116 // Since our loop doesn't include the last element, we can always
117 // safely access the next die in the array.
118 DWARFDebugInfoEntryMinimal *next_die = curr_die + 1;
120 const DWARFAbbreviationDeclaration *curr_die_abbrev =
121 curr_die->getAbbreviationDeclarationPtr();
123 if (curr_die_abbrev) {
125 if (curr_die_abbrev->hasChildren())
126 next_die->setParent(curr_die);
128 curr_die->setSibling(next_die);
130 // NULL DIE that terminates a sibling chain
131 DWARFDebugInfoEntryMinimal *parent = curr_die->getParent();
133 parent->setSibling(next_die);
137 // Since we skipped the last element, we need to fix it up!
138 if (die_array_begin < die_array_end)
139 curr_die->setParent(die_array_begin);
142 size_t DWARFCompileUnit::extractDIEsIfNeeded(bool cu_die_only) {
143 const size_t initial_die_array_size = DieArray.size();
144 if ((cu_die_only && initial_die_array_size > 0) ||
145 initial_die_array_size > 1)
146 return 0; // Already parsed
148 // Set the offset to that of the first DIE and calculate the start of the
149 // next compilation unit header.
150 uint32_t offset = getFirstDIEOffset();
151 uint32_t next_cu_offset = getNextCompileUnitOffset();
153 DWARFDebugInfoEntryMinimal die;
154 // Keep a flat array of the DIE for binary lookup by DIE offset
156 // We are in our compile unit, parse starting at the offset
157 // we were told to parse
159 const uint8_t *fixed_form_sizes =
160 DWARFFormValue::getFixedFormSizesForAddressSize(getAddressByteSize());
162 while (offset < next_cu_offset &&
163 die.extractFast(this, fixed_form_sizes, &offset)) {
167 die.getAttributeValueAsUnsigned(this, DW_AT_low_pc, -1U);
168 if (base_addr == -1U)
169 base_addr = die.getAttributeValueAsUnsigned(this, DW_AT_entry_pc, 0);
170 setBaseAddress(base_addr);
177 else if (depth == 0 && initial_die_array_size == 1) {
178 // Don't append the CU die as we already did that
183 const DWARFAbbreviationDeclaration *abbrDecl =
184 die.getAbbreviationDeclarationPtr();
187 if (abbrDecl->hasChildren())
194 break; // We are done with this compile unit!
199 // Give a little bit of info if we encounter corrupt DWARF (our offset
200 // should always terminate at or before the start of the next compilation
202 if (offset > next_cu_offset) {
203 fprintf (stderr, "warning: DWARF compile unit extends beyond its bounds cu 0x%8.8x at 0x%8.8x'\n", getOffset(), offset);
207 return DieArray.size();
210 void DWARFCompileUnit::clearDIEs(bool keep_compile_unit_die) {
211 if (DieArray.size() > (unsigned)keep_compile_unit_die) {
212 // std::vectors never get any smaller when resized to a smaller size,
213 // or when clear() or erase() are called, the size will report that it
214 // is smaller, but the memory allocated remains intact (call capacity()
215 // to see this). So we need to create a temporary vector and swap the
216 // contents which will cause just the internal pointers to be swapped
217 // so that when "tmp_array" goes out of scope, it will destroy the
220 // Save at least the compile unit DIE
221 std::vector<DWARFDebugInfoEntryMinimal> tmpArray;
222 DieArray.swap(tmpArray);
223 if (keep_compile_unit_die)
224 DieArray.push_back(tmpArray.front());
229 DWARFCompileUnit::buildAddressRangeTable(DWARFDebugAranges *debug_aranges,
230 bool clear_dies_if_already_not_parsed){
231 // This function is usually called if there in no .debug_aranges section
232 // in order to produce a compile unit level set of address ranges that
233 // is accurate. If the DIEs weren't parsed, then we don't want all dies for
234 // all compile units to stay loaded when they weren't needed. So we can end
235 // up parsing the DWARF and then throwing them all away to keep memory usage
237 const bool clear_dies = extractDIEsIfNeeded(false) > 1 &&
238 clear_dies_if_already_not_parsed;
239 DieArray[0].buildAddressRangeTable(this, debug_aranges);
241 // Keep memory down by clearing DIEs if this generate function
242 // caused them to be parsed.
247 const DWARFDebugInfoEntryMinimal*
248 DWARFCompileUnit::getFunctionDIEForAddress(int64_t address) {
249 extractDIEsIfNeeded(false);
250 for (size_t i = 0, n = DieArray.size(); i != n; i++) {
251 if (DieArray[i].addressRangeContainsAddress(this, address))