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//===-- 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";
extractDIEsIfNeeded(false);
DieArray[0].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();
}
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