Exract most of DWARFCompileUnit into a new DWARFUnit to prepare for the coming DWARFTypeUnit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191233 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/DebugInfo/DWARFUnit.cpp b/lib/DebugInfo/DWARFUnit.cpp
new file mode 100644
index 0000000..c5ffb33
--- /dev/null
+++ b/lib/DebugInfo/DWARFUnit.cpp
@@ -0,0 +1,391 @@
+//===-- DWARFUnit.cpp -----------------------------------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "DWARFUnit.h"
+#include "DWARFContext.h"
+#include "llvm/DebugInfo/DWARFFormValue.h"
+#include "llvm/Support/Dwarf.h"
+#include "llvm/Support/Path.h"
+
+using namespace llvm;
+using namespace dwarf;
+
+DWARFUnit::DWARFUnit(const DWARFDebugAbbrev *DA, StringRef IS, StringRef AS,
+ StringRef RS, StringRef SS, StringRef SOS, StringRef AOS,
+ const RelocAddrMap *M, bool LE)
+ : Abbrev(DA), InfoSection(IS), AbbrevSection(AS), RangeSection(RS),
+ StringSection(SS), StringOffsetSection(SOS), AddrOffsetSection(AOS),
+ RelocMap(M), isLittleEndian(LE) {
+ clear();
+}
+
+DWARFUnit::~DWARFUnit() {
+}
+
+bool DWARFUnit::getAddrOffsetSectionItem(uint32_t Index,
+ uint64_t &Result) const {
+ uint32_t Offset = AddrOffsetSectionBase + Index * AddrSize;
+ if (AddrOffsetSection.size() < Offset + AddrSize)
+ return false;
+ DataExtractor DA(AddrOffsetSection, isLittleEndian, AddrSize);
+ Result = DA.getAddress(&Offset);
+ return true;
+}
+
+bool DWARFUnit::getStringOffsetSectionItem(uint32_t Index,
+ uint32_t &Result) const {
+ // FIXME: string offset section entries are 8-byte for DWARF64.
+ const uint32_t ItemSize = 4;
+ uint32_t Offset = Index * ItemSize;
+ if (StringOffsetSection.size() < Offset + ItemSize)
+ return false;
+ DataExtractor DA(StringOffsetSection, isLittleEndian, 0);
+ Result = DA.getU32(&Offset);
+ return true;
+}
+
+bool DWARFUnit::extractImpl(DataExtractor debug_info, uint32_t *offset_ptr) {
+ Length = debug_info.getU32(offset_ptr);
+ Version = debug_info.getU16(offset_ptr);
+ uint64_t abbrOffset = debug_info.getU32(offset_ptr);
+ AddrSize = debug_info.getU8(offset_ptr);
+
+ bool lengthOK = debug_info.isValidOffset(getNextUnitOffset() - 1);
+ bool versionOK = DWARFContext::isSupportedVersion(Version);
+ bool abbrOffsetOK = AbbrevSection.size() > abbrOffset;
+ bool addrSizeOK = AddrSize == 4 || AddrSize == 8;
+
+ if (!lengthOK || !versionOK || !addrSizeOK || !abbrOffsetOK)
+ return false;
+
+ Abbrevs = Abbrev->getAbbreviationDeclarationSet(abbrOffset);
+ return true;
+}
+
+bool DWARFUnit::extract(DataExtractor debug_info, uint32_t *offset_ptr) {
+ clear();
+
+ Offset = *offset_ptr;
+
+ if (debug_info.isValidOffset(*offset_ptr)) {
+ if (extractImpl(debug_info, offset_ptr))
+ return true;
+
+ // reset the offset to where we tried to parse from if anything went wrong
+ *offset_ptr = Offset;
+ }
+
+ return false;
+}
+
+uint32_t
+DWARFUnit::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 DWARFUnit::extractRangeList(uint32_t RangeListOffset,
+ DWARFDebugRangeList &RangeList) const {
+ // Require that compile unit is extracted.
+ assert(DieArray.size() > 0);
+ DataExtractor RangesData(RangeSection, isLittleEndian, AddrSize);
+ uint32_t ActualRangeListOffset = RangeSectionBase + RangeListOffset;
+ return RangeList.extract(RangesData, &ActualRangeListOffset);
+}
+
+void DWARFUnit::clear() {
+ Offset = 0;
+ Length = 0;
+ Version = 0;
+ Abbrevs = 0;
+ AddrSize = 0;
+ BaseAddr = 0;
+ RangeSectionBase = 0;
+ AddrOffsetSectionBase = 0;
+ clearDIEs(false);
+ DWO.reset();
+}
+
+const char *DWARFUnit::getCompilationDir() {
+ extractDIEsIfNeeded(true);
+ if (DieArray.empty())
+ return 0;
+ return DieArray[0].getAttributeValueAsString(this, DW_AT_comp_dir, 0);
+}
+
+uint64_t DWARFUnit::getDWOId() {
+ extractDIEsIfNeeded(true);
+ const uint64_t FailValue = -1ULL;
+ if (DieArray.empty())
+ return FailValue;
+ return DieArray[0]
+ .getAttributeValueAsUnsigned(this, DW_AT_GNU_dwo_id, FailValue);
+}
+
+void DWARFUnit::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 DWARFUnit::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 = getNextUnitOffset();
+ 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 DWARFUnit::extractDIEsIfNeeded(bool CUDieOnly) {
+ if ((CUDieOnly && DieArray.size() > 0) ||
+ DieArray.size() > 1)
+ return 0; // Already parsed.
+
+ bool HasCUDie = DieArray.size() > 0;
+ extractDIEsToVector(!HasCUDie, !CUDieOnly, DieArray);
+
+ if (DieArray.empty())
+ return 0;
+
+ // If CU DIE was just parsed, copy several attribute values from it.
+ if (!HasCUDie) {
+ 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);
+ AddrOffsetSectionBase =
+ DieArray[0].getAttributeValueAsReference(this, DW_AT_GNU_addr_base, 0);
+ RangeSectionBase =
+ DieArray[0].getAttributeValueAsReference(this, DW_AT_GNU_ranges_base, 0);
+ }
+
+ setDIERelations();
+ return DieArray.size();
+}
+
+DWARFUnit::DWOHolder::DWOHolder(object::ObjectFile *DWOFile)
+ : DWOFile(DWOFile),
+ DWOContext(cast<DWARFContext>(DIContext::getDWARFContext(DWOFile))),
+ DWOU(0) {
+ if (DWOContext->getNumDWOCompileUnits() > 0)
+ DWOU = DWOContext->getDWOCompileUnitAtIndex(0);
+}
+
+bool DWARFUnit::parseDWO() {
+ if (DWO.get() != 0)
+ return false;
+ extractDIEsIfNeeded(true);
+ if (DieArray.empty())
+ return false;
+ const char *DWOFileName =
+ DieArray[0].getAttributeValueAsString(this, DW_AT_GNU_dwo_name, 0);
+ if (DWOFileName == 0)
+ return false;
+ const char *CompilationDir =
+ DieArray[0].getAttributeValueAsString(this, DW_AT_comp_dir, 0);
+ SmallString<16> AbsolutePath;
+ if (sys::path::is_relative(DWOFileName) && CompilationDir != 0) {
+ sys::path::append(AbsolutePath, CompilationDir);
+ }
+ sys::path::append(AbsolutePath, DWOFileName);
+ object::ObjectFile *DWOFile =
+ object::ObjectFile::createObjectFile(AbsolutePath);
+ if (!DWOFile)
+ return false;
+ // Reset DWOHolder.
+ DWO.reset(new DWOHolder(DWOFile));
+ DWARFUnit *DWOCU = DWO->getUnit();
+ // Verify that compile unit in .dwo file is valid.
+ if (DWOCU == 0 || DWOCU->getDWOId() != getDWOId()) {
+ DWO.reset();
+ return false;
+ }
+ // Share .debug_addr and .debug_ranges section with compile unit in .dwo
+ DWOCU->setAddrOffsetSection(AddrOffsetSection, AddrOffsetSectionBase);
+ DWOCU->setRangesSection(RangeSection, RangeSectionBase);
+ return true;
+}
+
+void DWARFUnit::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
+DWARFUnit::buildAddressRangeTable(DWARFDebugAranges *debug_aranges,
+ bool clear_dies_if_already_not_parsed,
+ uint32_t CUOffsetInAranges) {
+ // 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, CUOffsetInAranges);
+ bool DWOCreated = parseDWO();
+ if (DWO.get()) {
+ // If there is a .dwo file for this compile unit, then skeleton CU DIE
+ // doesn't have children, and we should instead build address range table
+ // from DIEs in the .debug_info.dwo section of .dwo file.
+ DWO->getUnit()->buildAddressRangeTable(
+ debug_aranges, clear_dies_if_already_not_parsed, CUOffsetInAranges);
+ }
+ if (DWOCreated && clear_dies_if_already_not_parsed)
+ DWO.reset();
+
+ // Keep memory down by clearing DIEs if this generate function
+ // caused them to be parsed.
+ if (clear_dies)
+ clearDIEs(true);
+}
+
+const DWARFDebugInfoEntryMinimal *
+DWARFUnit::getSubprogramForAddress(uint64_t Address) {
+ extractDIEsIfNeeded(false);
+ for (size_t i = 0, n = DieArray.size(); i != n; i++)
+ if (DieArray[i].isSubprogramDIE() &&
+ DieArray[i].addressRangeContainsAddress(this, Address)) {
+ return &DieArray[i];
+ }
+ return 0;
+}
+
+DWARFDebugInfoEntryInlinedChain
+DWARFUnit::getInlinedChainForAddress(uint64_t Address) {
+ // First, find a subprogram that contains the given address (the root
+ // of inlined chain).
+ const DWARFUnit *ChainCU = 0;
+ const DWARFDebugInfoEntryMinimal *SubprogramDIE =
+ getSubprogramForAddress(Address);
+ if (SubprogramDIE) {
+ ChainCU = this;
+ } else {
+ // Try to look for subprogram DIEs in the DWO file.
+ parseDWO();
+ if (DWO.get()) {
+ SubprogramDIE = DWO->getUnit()->getSubprogramForAddress(Address);
+ if (SubprogramDIE)
+ ChainCU = DWO->getUnit();
+ }
+ }
+
+ // Get inlined chain rooted at this subprogram DIE.
+ if (!SubprogramDIE)
+ return DWARFDebugInfoEntryInlinedChain();
+ return SubprogramDIE->getInlinedChainForAddress(ChainCU, Address);
+}