llvm-mirror/lib/DebugInfo/DWARF/DWARFDebugInfoEntry.cpp
Chandler Carruth ae65e281f3 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00

70 lines
2.6 KiB
C++

//===- DWARFDebugInfoEntry.cpp --------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "llvm/DebugInfo/DWARF/DWARFDebugInfoEntry.h"
#include "llvm/ADT/Optional.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugAbbrev.h"
#include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
#include "llvm/DebugInfo/DWARF/DWARFUnit.h"
#include "llvm/Support/DataExtractor.h"
#include <cstddef>
#include <cstdint>
using namespace llvm;
using namespace dwarf;
bool DWARFDebugInfoEntry::extractFast(const DWARFUnit &U,
uint32_t *OffsetPtr) {
DWARFDataExtractor DebugInfoData = U.getDebugInfoExtractor();
const uint32_t UEndOffset = U.getNextUnitOffset();
return extractFast(U, OffsetPtr, DebugInfoData, UEndOffset, 0);
}
bool DWARFDebugInfoEntry::extractFast(const DWARFUnit &U, uint32_t *OffsetPtr,
const DWARFDataExtractor &DebugInfoData,
uint32_t UEndOffset, uint32_t D) {
Offset = *OffsetPtr;
Depth = D;
if (Offset >= UEndOffset || !DebugInfoData.isValidOffset(Offset))
return false;
uint64_t AbbrCode = DebugInfoData.getULEB128(OffsetPtr);
if (0 == AbbrCode) {
// NULL debug tag entry.
AbbrevDecl = nullptr;
return true;
}
AbbrevDecl = U.getAbbreviations()->getAbbreviationDeclaration(AbbrCode);
if (nullptr == AbbrevDecl) {
// Restore the original offset.
*OffsetPtr = Offset;
return false;
}
// See if all attributes in this DIE have fixed byte sizes. If so, we can
// just add this size to the offset to skip to the next DIE.
if (Optional<size_t> FixedSize = AbbrevDecl->getFixedAttributesByteSize(U)) {
*OffsetPtr += *FixedSize;
return true;
}
// Skip all data in the .debug_info for the attributes
for (const auto &AttrSpec : AbbrevDecl->attributes()) {
// Check if this attribute has a fixed byte size.
if (auto FixedSize = AttrSpec.getByteSize(U)) {
// Attribute byte size if fixed, just add the size to the offset.
*OffsetPtr += *FixedSize;
} else if (!DWARFFormValue::skipValue(AttrSpec.Form, DebugInfoData,
OffsetPtr, U.getFormParams())) {
// We failed to skip this attribute's value, restore the original offset
// and return the failure status.
*OffsetPtr = Offset;
return false;
}
}
return true;
}