llvm/lib/DebugInfo/DWARFDebugArangeSet.cpp
2014-03-15 18:47:07 +00:00

105 lines
4.1 KiB
C++

//===-- DWARFDebugArangeSet.cpp -------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "DWARFDebugArangeSet.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cassert>
using namespace llvm;
void DWARFDebugArangeSet::clear() {
Offset = -1U;
std::memset(&HeaderData, 0, sizeof(Header));
ArangeDescriptors.clear();
}
bool
DWARFDebugArangeSet::extract(DataExtractor data, uint32_t *offset_ptr) {
if (data.isValidOffset(*offset_ptr)) {
ArangeDescriptors.clear();
Offset = *offset_ptr;
// 7.20 Address Range Table
//
// Each set of entries in the table of address ranges contained in
// the .debug_aranges section begins with a header consisting of: a
// 4-byte length containing the length of the set of entries for this
// compilation unit, not including the length field itself; a 2-byte
// version identifier containing the value 2 for DWARF Version 2; a
// 4-byte offset into the.debug_infosection; a 1-byte unsigned integer
// containing the size in bytes of an address (or the offset portion of
// an address for segmented addressing) on the target system; and a
// 1-byte unsigned integer containing the size in bytes of a segment
// descriptor on the target system. This header is followed by a series
// of tuples. Each tuple consists of an address and a length, each in
// the size appropriate for an address on the target architecture.
HeaderData.Length = data.getU32(offset_ptr);
HeaderData.Version = data.getU16(offset_ptr);
HeaderData.CuOffset = data.getU32(offset_ptr);
HeaderData.AddrSize = data.getU8(offset_ptr);
HeaderData.SegSize = data.getU8(offset_ptr);
// Perform basic validation of the header fields.
if (!data.isValidOffsetForDataOfSize(Offset, HeaderData.Length) ||
(HeaderData.AddrSize != 4 && HeaderData.AddrSize != 8)) {
clear();
return false;
}
// The first tuple following the header in each set begins at an offset
// that is a multiple of the size of a single tuple (that is, twice the
// size of an address). The header is padded, if necessary, to the
// appropriate boundary.
const uint32_t header_size = *offset_ptr - Offset;
const uint32_t tuple_size = HeaderData.AddrSize * 2;
uint32_t first_tuple_offset = 0;
while (first_tuple_offset < header_size)
first_tuple_offset += tuple_size;
*offset_ptr = Offset + first_tuple_offset;
Descriptor arangeDescriptor;
static_assert(sizeof(arangeDescriptor.Address) ==
sizeof(arangeDescriptor.Length),
"Different datatypes for addresses and sizes!");
assert(sizeof(arangeDescriptor.Address) >= HeaderData.AddrSize);
while (data.isValidOffset(*offset_ptr)) {
arangeDescriptor.Address = data.getUnsigned(offset_ptr, HeaderData.AddrSize);
arangeDescriptor.Length = data.getUnsigned(offset_ptr, HeaderData.AddrSize);
// Each set of tuples is terminated by a 0 for the address and 0
// for the length.
if (arangeDescriptor.Address || arangeDescriptor.Length)
ArangeDescriptors.push_back(arangeDescriptor);
else
break; // We are done if we get a zero address and length
}
return !ArangeDescriptors.empty();
}
return false;
}
void DWARFDebugArangeSet::dump(raw_ostream &OS) const {
OS << format("Address Range Header: length = 0x%8.8x, version = 0x%4.4x, ",
HeaderData.Length, HeaderData.Version)
<< format("cu_offset = 0x%8.8x, addr_size = 0x%2.2x, seg_size = 0x%2.2x\n",
HeaderData.CuOffset, HeaderData.AddrSize, HeaderData.SegSize);
const uint32_t hex_width = HeaderData.AddrSize * 2;
for (const auto &Desc : ArangeDescriptors) {
OS << format("[0x%*.*" PRIx64 " -", hex_width, hex_width, Desc.Address)
<< format(" 0x%*.*" PRIx64 ")\n",
hex_width, hex_width, Desc.getEndAddress());
}
}