llvm-6502/lib/DebugInfo/DWARFCompileUnit.cpp

279 lines
9.4 KiB
C++

//===-- 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);
}