diff options
Diffstat (limited to 'contrib/llvm/lib/DebugInfo/DWARFCompileUnit.cpp')
| -rw-r--r-- | contrib/llvm/lib/DebugInfo/DWARFCompileUnit.cpp | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/contrib/llvm/lib/DebugInfo/DWARFCompileUnit.cpp b/contrib/llvm/lib/DebugInfo/DWARFCompileUnit.cpp new file mode 100644 index 000000000000..24bf97ff608a --- /dev/null +++ b/contrib/llvm/lib/DebugInfo/DWARFCompileUnit.cpp @@ -0,0 +1,238 @@ +//===-- 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 "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(Context.getInfoSection(), + Context.isLittleEndian(), getAddressByteSize()); +} + +bool DWARFCompileUnit::extract(DataExtractor debug_info, uint32_t *offset_ptr) { + clear(); + + Offset = *offset_ptr; + + if (debug_info.isValidOffset(*offset_ptr)) { + uint64_t abbrOffset; + const DWARFDebugAbbrev *abbr = Context.getDebugAbbrev(); + 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 = Context.getAbbrevSection().size() > abbrOffset; + bool addrSizeOK = AddrSize == 4 || AddrSize == 8; + + if (lengthOK && versionOK && addrSizeOK && abbrOffsetOK && abbr != NULL) { + Abbrevs = abbr->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; +} + +void DWARFCompileUnit::clear() { + Offset = 0; + Length = 0; + Version = 0; + Abbrevs = 0; + AddrSize = 0; + BaseAddr = 0; + DieArray.clear(); +} + +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"; + + getCompileUnitDIE(false)->dump(OS, this, -1U); +} + +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); +} + +size_t DWARFCompileUnit::extractDIEsIfNeeded(bool cu_die_only) { + const size_t initial_die_array_size = DieArray.size(); + if ((cu_die_only && initial_die_array_size > 0) || + initial_die_array_size > 1) + return 0; // Already parsed + + // 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 next_cu_offset = getNextCompileUnitOffset(); + + DWARFDebugInfoEntryMinimal die; + // Keep a flat array of the DIE for binary lookup by DIE offset + uint32_t depth = 0; + // We are in our compile unit, parse starting at the offset + // we were told to parse + + const uint8_t *fixed_form_sizes = + DWARFFormValue::getFixedFormSizesForAddressSize(getAddressByteSize()); + + while (offset < next_cu_offset && + die.extractFast(this, fixed_form_sizes, &offset)) { + + if (depth == 0) { + uint64_t base_addr = + die.getAttributeValueAsUnsigned(this, DW_AT_low_pc, -1U); + if (base_addr == -1U) + base_addr = die.getAttributeValueAsUnsigned(this, DW_AT_entry_pc, 0); + setBaseAddress(base_addr); + } + + if (cu_die_only) { + addDIE(die); + return 1; + } + else if (depth == 0 && initial_die_array_size == 1) { + // Don't append the CU die as we already did that + } else { + addDIE (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 > next_cu_offset) { + fprintf (stderr, "warning: DWARF compile unit extends beyond its bounds cu 0x%8.8x at 0x%8.8x'\n", getOffset(), offset); + } + + setDIERelations(); + return DieArray.size(); +} + +void DWARFCompileUnit::clearDIEs(bool keep_compile_unit_die) { + if (DieArray.size() > 1) { + // 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 "tmp_array" goes out of scope, it will destroy the + // contents. + + // Save at least the compile unit DIE + std::vector<DWARFDebugInfoEntryMinimal> tmpArray; + DieArray.swap(tmpArray); + if (keep_compile_unit_die) + 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; + + 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); +} |