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llvm-project/lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugLine.cpp

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//===-- DWARFDebugLine.cpp --------------------------------------*- C++ -*-===//
//
// 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 "DWARFDebugLine.h"
//#define ENABLE_DEBUG_PRINTF // DO NOT LEAVE THIS DEFINED: DEBUG ONLY!!!
#include <assert.h>
#include <memory>
#include "lldb/Core/FileSpecList.h"
#include "lldb/Core/Module.h"
#include "lldb/Host/Host.h"
#include "lldb/Utility/Log.h"
#include "lldb/Utility/Timer.h"
#include "DWARFUnit.h"
#include "LogChannelDWARF.h"
#include "SymbolFileDWARF.h"
using namespace lldb;
using namespace lldb_private;
using namespace std;
// Parse
//
// Parse all information in the debug_line_data into an internal
// representation.
void DWARFDebugLine::Parse(const DWARFDataExtractor &debug_line_data) {
m_lineTableMap.clear();
lldb::offset_t offset = 0;
LineTable::shared_ptr line_table_sp(new LineTable);
while (debug_line_data.ValidOffset(offset)) {
const lldb::offset_t debug_line_offset = offset;
if (line_table_sp.get() == nullptr)
break;
if (ParseStatementTable(debug_line_data, &offset, line_table_sp.get(), nullptr)) {
// Make sure we don't don't loop infinitely
if (offset <= debug_line_offset)
break;
// DEBUG_PRINTF("m_lineTableMap[0x%8.8x] = line_table_sp\n",
// debug_line_offset);
m_lineTableMap[debug_line_offset] = line_table_sp;
line_table_sp = std::make_shared<LineTable>();
} else
++offset; // Try next byte in line table
}
}
void DWARFDebugLine::ParseIfNeeded(const DWARFDataExtractor &debug_line_data) {
if (m_lineTableMap.empty())
Parse(debug_line_data);
}
// DWARFDebugLine::GetLineTable
DWARFDebugLine::LineTable::shared_ptr
DWARFDebugLine::GetLineTable(const dw_offset_t offset) const {
DWARFDebugLine::LineTable::shared_ptr line_table_shared_ptr;
LineTableConstIter pos = m_lineTableMap.find(offset);
if (pos != m_lineTableMap.end())
line_table_shared_ptr = pos->second;
return line_table_shared_ptr;
}
// Parse
//
// Parse the entire line table contents calling callback each time a new
// prologue is parsed and every time a new row is to be added to the line
// table.
void DWARFDebugLine::Parse(const DWARFDataExtractor &debug_line_data,
DWARFDebugLine::State::Callback callback,
void *userData) {
lldb::offset_t offset = 0;
if (debug_line_data.ValidOffset(offset)) {
if (!ParseStatementTable(debug_line_data, &offset, callback, userData, nullptr))
++offset; // Skip to next byte in .debug_line section
}
}
namespace {
struct EntryDescriptor {
dw_sleb128_t code;
dw_sleb128_t form;
};
static std::vector<EntryDescriptor>
ReadDescriptors(const DWARFDataExtractor &debug_line_data,
lldb::offset_t *offset_ptr) {
std::vector<EntryDescriptor> ret;
uint8_t n = debug_line_data.GetU8(offset_ptr);
for (uint8_t i = 0; i < n; ++i) {
EntryDescriptor ent;
ent.code = debug_line_data.GetULEB128(offset_ptr);
ent.form = debug_line_data.GetULEB128(offset_ptr);
ret.push_back(ent);
}
return ret;
}
} // namespace
// DWARFDebugLine::ParsePrologue
bool DWARFDebugLine::ParsePrologue(const DWARFDataExtractor &debug_line_data,
lldb::offset_t *offset_ptr,
Prologue *prologue, DWARFUnit *dwarf_cu) {
const lldb::offset_t prologue_offset = *offset_ptr;
// DEBUG_PRINTF("0x%8.8x: ParsePrologue()\n", *offset_ptr);
prologue->Clear();
uint32_t i;
const char *s;
prologue->total_length = debug_line_data.GetDWARFInitialLength(offset_ptr);
prologue->version = debug_line_data.GetU16(offset_ptr);
if (prologue->version < 2 || prologue->version > 5)
return false;
if (prologue->version >= 5) {
prologue->address_size = debug_line_data.GetU8(offset_ptr);
prologue->segment_selector_size = debug_line_data.GetU8(offset_ptr);
}
prologue->prologue_length = debug_line_data.GetDWARFOffset(offset_ptr);
const lldb::offset_t end_prologue_offset =
prologue->prologue_length + *offset_ptr;
prologue->min_inst_length = debug_line_data.GetU8(offset_ptr);
if (prologue->version >= 4)
prologue->maximum_operations_per_instruction =
debug_line_data.GetU8(offset_ptr);
else
prologue->maximum_operations_per_instruction = 1;
prologue->default_is_stmt = debug_line_data.GetU8(offset_ptr);
prologue->line_base = debug_line_data.GetU8(offset_ptr);
prologue->line_range = debug_line_data.GetU8(offset_ptr);
prologue->opcode_base = debug_line_data.GetU8(offset_ptr);
prologue->standard_opcode_lengths.reserve(prologue->opcode_base - 1);
for (i = 1; i < prologue->opcode_base; ++i) {
uint8_t op_len = debug_line_data.GetU8(offset_ptr);
prologue->standard_opcode_lengths.push_back(op_len);
}
if (prologue->version >= 5) {
std::vector<EntryDescriptor> dirEntryFormatV =
ReadDescriptors(debug_line_data, offset_ptr);
uint8_t dirCount = debug_line_data.GetULEB128(offset_ptr);
for (int i = 0; i < dirCount; ++i) {
for (EntryDescriptor &ent : dirEntryFormatV) {
DWARFFormValue value(dwarf_cu, ent.form);
if (ent.code != DW_LNCT_path) {
if (!value.SkipValue(debug_line_data, offset_ptr))
return false;
continue;
}
if (!value.ExtractValue(debug_line_data, offset_ptr))
return false;
prologue->include_directories.push_back(value.AsCString());
}
}
std::vector<EntryDescriptor> filesEntryFormatV =
ReadDescriptors(debug_line_data, offset_ptr);
llvm::DenseSet<std::pair<uint64_t, uint64_t>> seen;
uint8_t n = debug_line_data.GetULEB128(offset_ptr);
for (int i = 0; i < n; ++i) {
FileNameEntry entry;
for (EntryDescriptor &ent : filesEntryFormatV) {
DWARFFormValue value(dwarf_cu, ent.form);
if (!value.ExtractValue(debug_line_data, offset_ptr))
return false;
switch (ent.code) {
case DW_LNCT_path:
entry.name = value.AsCString();
break;
case DW_LNCT_directory_index:
entry.dir_idx = value.Unsigned();
break;
case DW_LNCT_timestamp:
entry.mod_time = value.Unsigned();
break;
case DW_LNCT_size:
entry.length = value.Unsigned();
break;
case DW_LNCT_MD5:
assert(value.Unsigned() == 16);
std::uninitialized_copy_n(value.BlockData(), 16,
entry.checksum.Bytes.begin());
break;
default:
break;
}
}
if (seen.insert(entry.checksum.words()).second)
prologue->file_names.push_back(entry);
}
} else {
while (*offset_ptr < end_prologue_offset) {
s = debug_line_data.GetCStr(offset_ptr);
if (s && s[0])
prologue->include_directories.push_back(s);
else
break;
}
while (*offset_ptr < end_prologue_offset) {
const char *name = debug_line_data.GetCStr(offset_ptr);
if (name && name[0]) {
FileNameEntry fileEntry;
fileEntry.name = name;
fileEntry.dir_idx = debug_line_data.GetULEB128(offset_ptr);
fileEntry.mod_time = debug_line_data.GetULEB128(offset_ptr);
fileEntry.length = debug_line_data.GetULEB128(offset_ptr);
prologue->file_names.push_back(fileEntry);
} else
break;
}
}
// XXX GNU as is broken for 64-Bit DWARF
if (*offset_ptr != end_prologue_offset) {
Host::SystemLog(Host::eSystemLogWarning,
"warning: parsing line table prologue at 0x%8.8" PRIx64
" should have ended at 0x%8.8" PRIx64
" but it ended at 0x%8.8" PRIx64 "\n",
prologue_offset, end_prologue_offset, *offset_ptr);
}
return end_prologue_offset;
}
bool DWARFDebugLine::ParseSupportFiles(
const lldb::ModuleSP &module_sp, const DWARFDataExtractor &debug_line_data,
dw_offset_t stmt_list, FileSpecList &support_files, DWARFUnit *dwarf_cu) {
lldb::offset_t offset = stmt_list;
Prologue prologue;
if (!ParsePrologue(debug_line_data, &offset, &prologue, dwarf_cu)) {
Host::SystemLog(Host::eSystemLogError, "error: parsing line table prologue "
"at 0x%8.8x (parsing ended around "
"0x%8.8" PRIx64 "\n",
stmt_list, offset);
return false;
}
FileSpec file_spec;
std::string remapped_file;
for (uint32_t file_idx = 1;
prologue.GetFile(file_idx, dwarf_cu->GetCompilationDirectory(),
dwarf_cu->GetPathStyle(), file_spec);
++file_idx) {
if (module_sp->RemapSourceFile(file_spec.GetPath(), remapped_file))
file_spec.SetFile(remapped_file, FileSpec::Style::native);
support_files.Append(file_spec);
}
return true;
}
// ParseStatementTable
//
// Parse a single line table (prologue and all rows) and call the callback
// function once for the prologue (row in state will be zero) and each time a
// row is to be added to the line table.
bool DWARFDebugLine::ParseStatementTable(
const DWARFDataExtractor &debug_line_data, lldb::offset_t *offset_ptr,
DWARFDebugLine::State::Callback callback, void *userData, DWARFUnit *dwarf_cu) {
Log *log(LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_LINE));
Prologue::shared_ptr prologue(new Prologue());
const dw_offset_t debug_line_offset = *offset_ptr;
static Timer::Category func_cat(LLVM_PRETTY_FUNCTION);
Timer scoped_timer(
func_cat, "DWARFDebugLine::ParseStatementTable (.debug_line[0x%8.8x])",
debug_line_offset);
if (!ParsePrologue(debug_line_data, offset_ptr, prologue.get(), dwarf_cu)) {
if (log)
log->Error("failed to parse DWARF line table prologue");
// Restore our offset and return false to indicate failure!
*offset_ptr = debug_line_offset;
return false;
}
if (log)
prologue->Dump(log);
const dw_offset_t end_offset =
debug_line_offset + prologue->total_length +
(debug_line_data.GetDWARFSizeofInitialLength());
State state(prologue, log, callback, userData);
while (*offset_ptr < end_offset) {
// DEBUG_PRINTF("0x%8.8x: ", *offset_ptr);
uint8_t opcode = debug_line_data.GetU8(offset_ptr);
if (opcode == 0) {
// Extended Opcodes always start with a zero opcode followed by a uleb128
// length so you can skip ones you don't know about
lldb::offset_t ext_offset = *offset_ptr;
dw_uleb128_t len = debug_line_data.GetULEB128(offset_ptr);
dw_offset_t arg_size = len - (*offset_ptr - ext_offset);
// DEBUG_PRINTF("Extended: <%2u> ", len);
uint8_t sub_opcode = debug_line_data.GetU8(offset_ptr);
switch (sub_opcode) {
case DW_LNE_end_sequence:
// Set the end_sequence register of the state machine to true and
// append a row to the matrix using the current values of the state-
// machine registers. Then reset the registers to the initial values
// specified above. Every statement program sequence must end with a
// DW_LNE_end_sequence instruction which creates a row whose address is
// that of the byte after the last target machine instruction of the
// sequence.
state.end_sequence = true;
state.AppendRowToMatrix(*offset_ptr);
state.Reset();
break;
case DW_LNE_set_address:
// Takes a single relocatable address as an operand. The size of the
// operand is the size appropriate to hold an address on the target
// machine. Set the address register to the value given by the
// relocatable address. All of the other statement program opcodes that
// affect the address register add a delta to it. This instruction
// stores a relocatable value into it instead.
if (arg_size == 4)
state.address = debug_line_data.GetU32(offset_ptr);
else // arg_size == 8
state.address = debug_line_data.GetU64(offset_ptr);
break;
case DW_LNE_define_file:
// Takes 4 arguments. The first is a null terminated string containing
// a source file name. The second is an unsigned LEB128 number
// representing the directory index of the directory in which the file
// was found. The third is an unsigned LEB128 number representing the
// time of last modification of the file. The fourth is an unsigned
// LEB128 number representing the length in bytes of the file. The time
// and length fields may contain LEB128(0) if the information is not
// available.
//
// The directory index represents an entry in the include_directories
// section of the statement program prologue. The index is LEB128(0) if
// the file was found in the current directory of the compilation,
// LEB128(1) if it was found in the first directory in the
// include_directories section, and so on. The directory index is
// ignored for file names that represent full path names.
//
// The files are numbered, starting at 1, in the order in which they
// appear; the names in the prologue come before names defined by the
// DW_LNE_define_file instruction. These numbers are used in the file
// register of the state machine.
{
FileNameEntry fileEntry;
fileEntry.name = debug_line_data.GetCStr(offset_ptr);
fileEntry.dir_idx = debug_line_data.GetULEB128(offset_ptr);
fileEntry.mod_time = debug_line_data.GetULEB128(offset_ptr);
fileEntry.length = debug_line_data.GetULEB128(offset_ptr);
state.prologue->file_names.push_back(fileEntry);
}
break;
default:
// Length doesn't include the zero opcode byte or the length itself,
// but it does include the sub_opcode, so we have to adjust for that
// below
(*offset_ptr) += arg_size;
break;
}
} else if (opcode < prologue->opcode_base) {
switch (opcode) {
// Standard Opcodes
case DW_LNS_copy:
// Takes no arguments. Append a row to the matrix using the current
// values of the state-machine registers. Then set the basic_block
// register to false.
state.AppendRowToMatrix(*offset_ptr);
break;
case DW_LNS_advance_pc:
// Takes a single unsigned LEB128 operand, multiplies it by the
// min_inst_length field of the prologue, and adds the result to the
// address register of the state machine.
state.address +=
debug_line_data.GetULEB128(offset_ptr) * prologue->min_inst_length;
break;
case DW_LNS_advance_line:
// Takes a single signed LEB128 operand and adds that value to the line
// register of the state machine.
state.line += debug_line_data.GetSLEB128(offset_ptr);
break;
case DW_LNS_set_file:
// Takes a single unsigned LEB128 operand and stores it in the file
// register of the state machine.
state.file = debug_line_data.GetULEB128(offset_ptr);
break;
case DW_LNS_set_column:
// Takes a single unsigned LEB128 operand and stores it in the column
// register of the state machine.
state.column = debug_line_data.GetULEB128(offset_ptr);
break;
case DW_LNS_negate_stmt:
// Takes no arguments. Set the is_stmt register of the state machine to
// the logical negation of its current value.
state.is_stmt = !state.is_stmt;
break;
case DW_LNS_set_basic_block:
// Takes no arguments. Set the basic_block register of the state
// machine to true
state.basic_block = true;
break;
case DW_LNS_const_add_pc:
// Takes no arguments. Add to the address register of the state machine
// the address increment value corresponding to special opcode 255. The
// motivation for DW_LNS_const_add_pc is this: when the statement
// program needs to advance the address by a small amount, it can use a
// single special opcode, which occupies a single byte. When it needs
// to advance the address by up to twice the range of the last special
// opcode, it can use DW_LNS_const_add_pc followed by a special opcode,
// for a total of two bytes. Only if it needs to advance the address by
// more than twice that range will it need to use both
// DW_LNS_advance_pc and a special opcode, requiring three or more
// bytes.
{
uint8_t adjust_opcode = 255 - prologue->opcode_base;
dw_addr_t addr_offset = (adjust_opcode / prologue->line_range) *
prologue->min_inst_length;
state.address += addr_offset;
}
break;
case DW_LNS_fixed_advance_pc:
// Takes a single uhalf operand. Add to the address register of the
// state machine the value of the (unencoded) operand. This is the only
// extended opcode that takes an argument that is not a variable length
// number. The motivation for DW_LNS_fixed_advance_pc is this: existing
// assemblers cannot emit DW_LNS_advance_pc or special opcodes because
// they cannot encode LEB128 numbers or judge when the computation of a
// special opcode overflows and requires the use of DW_LNS_advance_pc.
// Such assemblers, however, can use DW_LNS_fixed_advance_pc instead,
// sacrificing compression.
state.address += debug_line_data.GetU16(offset_ptr);
break;
case DW_LNS_set_prologue_end:
// Takes no arguments. Set the prologue_end register of the state
// machine to true
state.prologue_end = true;
break;
case DW_LNS_set_epilogue_begin:
// Takes no arguments. Set the basic_block register of the state
// machine to true
state.epilogue_begin = true;
break;
case DW_LNS_set_isa:
// Takes a single unsigned LEB128 operand and stores it in the column
// register of the state machine.
state.isa = debug_line_data.GetULEB128(offset_ptr);
break;
default:
// Handle any unknown standard opcodes here. We know the lengths of
// such opcodes because they are specified in the prologue as a
// multiple of LEB128 operands for each opcode.
{
uint8_t i;
assert(static_cast<size_t>(opcode - 1) <
prologue->standard_opcode_lengths.size());
const uint8_t opcode_length =
prologue->standard_opcode_lengths[opcode - 1];
for (i = 0; i < opcode_length; ++i)
debug_line_data.Skip_LEB128(offset_ptr);
}
break;
}
} else {
// Special Opcodes
// A special opcode value is chosen based on the amount that needs
// to be added to the line and address registers. The maximum line
// increment for a special opcode is the value of the line_base field in
// the header, plus the value of the line_range field, minus 1 (line base
// + line range - 1). If the desired line increment is greater than the
// maximum line increment, a standard opcode must be used instead of a
// special opcode. The "address advance" is calculated by dividing the
// desired address increment by the minimum_instruction_length field from
// the header. The special opcode is then calculated using the following
// formula:
//
// opcode = (desired line increment - line_base) + (line_range * address
// advance) + opcode_base
//
// If the resulting opcode is greater than 255, a standard opcode must be
// used instead.
//
// To decode a special opcode, subtract the opcode_base from the opcode
// itself to give the adjusted opcode. The amount to increment the
// address register is the result of the adjusted opcode divided by the
// line_range multiplied by the minimum_instruction_length field from the
// header. That is:
//
// address increment = (adjusted opcode / line_range) *
// minimum_instruction_length
//
// The amount to increment the line register is the line_base plus the
// result of the adjusted opcode modulo the line_range. That is:
//
// line increment = line_base + (adjusted opcode % line_range)
uint8_t adjust_opcode = opcode - prologue->opcode_base;
dw_addr_t addr_offset =
(adjust_opcode / prologue->line_range) * prologue->min_inst_length;
int32_t line_offset =
prologue->line_base + (adjust_opcode % prologue->line_range);
state.line += line_offset;
state.address += addr_offset;
state.AppendRowToMatrix(*offset_ptr);
}
}
state.Finalize(*offset_ptr);
return end_offset;
}
// ParseStatementTableCallback
static void ParseStatementTableCallback(dw_offset_t offset,
const DWARFDebugLine::State &state,
void *userData) {
DWARFDebugLine::LineTable *line_table = (DWARFDebugLine::LineTable *)userData;
if (state.row == DWARFDebugLine::State::StartParsingLineTable) {
// Just started parsing the line table, so lets keep a reference to the
// prologue using the supplied shared pointer
line_table->prologue = state.prologue;
} else if (state.row == DWARFDebugLine::State::DoneParsingLineTable) {
// Done parsing line table, nothing to do for the cleanup
} else {
// We have a new row, lets append it
line_table->AppendRow(state);
}
}
// ParseStatementTable
//
// Parse a line table at offset and populate the LineTable class with the
// prologue and all rows.
bool DWARFDebugLine::ParseStatementTable(
const DWARFDataExtractor &debug_line_data, lldb::offset_t *offset_ptr,
LineTable *line_table, DWARFUnit *dwarf_cu) {
return ParseStatementTable(debug_line_data, offset_ptr,
ParseStatementTableCallback, line_table, dwarf_cu);
}
inline bool DWARFDebugLine::Prologue::IsValid() const {
return SymbolFileDWARF::SupportedVersion(version);
}
// DWARFDebugLine::Prologue::Dump
void DWARFDebugLine::Prologue::Dump(Log *log) {
uint32_t i;
log->Printf("Line table prologue:");
log->Printf(" total_length: 0x%8.8x", total_length);
log->Printf(" version: %u", version);
log->Printf("prologue_length: 0x%8.8x", prologue_length);
log->Printf("min_inst_length: %u", min_inst_length);
log->Printf("default_is_stmt: %u", default_is_stmt);
log->Printf(" line_base: %i", line_base);
log->Printf(" line_range: %u", line_range);
log->Printf(" opcode_base: %u", opcode_base);
for (i = 0; i < standard_opcode_lengths.size(); ++i) {
log->Printf("standard_opcode_lengths[%s] = %u", DW_LNS_value_to_name(i + 1),
standard_opcode_lengths[i]);
}
if (!include_directories.empty()) {
for (i = 0; i < include_directories.size(); ++i) {
log->Printf("include_directories[%3u] = '%s'", i + 1,
include_directories[i]);
}
}
if (!file_names.empty()) {
log->PutCString(" Dir Mod Time File Len File Name");
log->PutCString(" ---- ---------- ---------- "
"---------------------------");
for (i = 0; i < file_names.size(); ++i) {
const FileNameEntry &fileEntry = file_names[i];
log->Printf("file_names[%3u] %4u 0x%8.8x 0x%8.8x %s", i + 1,
fileEntry.dir_idx, fileEntry.mod_time, fileEntry.length,
fileEntry.name);
}
}
}
// DWARFDebugLine::ParsePrologue::Append
//
// Append the contents of the prologue to the binary stream buffer
// void
// DWARFDebugLine::Prologue::Append(BinaryStreamBuf& buff) const
//{
// uint32_t i;
//
// buff.Append32(total_length);
// buff.Append16(version);
// buff.Append32(prologue_length);
// buff.Append8(min_inst_length);
// buff.Append8(default_is_stmt);
// buff.Append8(line_base);
// buff.Append8(line_range);
// buff.Append8(opcode_base);
//
// for (i=0; i<standard_opcode_lengths.size(); ++i)
// buff.Append8(standard_opcode_lengths[i]);
//
// for (i=0; i<include_directories.size(); ++i)
// buff.AppendCStr(include_directories[i].c_str());
// buff.Append8(0); // Terminate the include directory section with empty
// string
//
// for (i=0; i<file_names.size(); ++i)
// {
// buff.AppendCStr(file_names[i].name.c_str());
// buff.Append32_as_ULEB128(file_names[i].dir_idx);
// buff.Append32_as_ULEB128(file_names[i].mod_time);
// buff.Append32_as_ULEB128(file_names[i].length);
// }
// buff.Append8(0); // Terminate the file names section with empty string
//}
bool DWARFDebugLine::Prologue::GetFile(uint32_t file_idx,
const FileSpec &comp_dir,
FileSpec::Style style,
FileSpec &file) const {
uint32_t idx = file_idx - 1; // File indexes are 1 based...
if (idx < file_names.size()) {
file.SetFile(file_names[idx].name, style);
if (file.IsRelative()) {
if (file_names[idx].dir_idx > 0) {
const uint32_t dir_idx = file_names[idx].dir_idx - 1;
if (dir_idx < include_directories.size()) {
file.PrependPathComponent(include_directories[dir_idx]);
if (!file.IsRelative())
return true;
}
}
if (comp_dir)
file.PrependPathComponent(comp_dir);
}
return true;
}
return false;
}
void DWARFDebugLine::LineTable::AppendRow(const DWARFDebugLine::Row &state) {
rows.push_back(state);
}
// Compare function for the binary search in
// DWARFDebugLine::LineTable::LookupAddress()
static bool FindMatchingAddress(const DWARFDebugLine::Row &row1,
const DWARFDebugLine::Row &row2) {
return row1.address < row2.address;
}
// DWARFDebugLine::LineTable::LookupAddress
uint32_t DWARFDebugLine::LineTable::LookupAddress(dw_addr_t address,
dw_addr_t cu_high_pc) const {
uint32_t index = UINT32_MAX;
if (!rows.empty()) {
// Use the lower_bound algorithm to perform a binary search since we know
// that our line table data is ordered by address.
DWARFDebugLine::Row row;
row.address = address;
Row::const_iterator begin_pos = rows.begin();
Row::const_iterator end_pos = rows.end();
Row::const_iterator pos =
lower_bound(begin_pos, end_pos, row, FindMatchingAddress);
if (pos == end_pos) {
if (address < cu_high_pc)
return rows.size() - 1;
} else {
// Rely on fact that we are using a std::vector and we can do pointer
// arithmetic to find the row index (which will be one less that what we
// found since it will find the first position after the current address)
// since std::vector iterators are just pointers to the container type.
index = pos - begin_pos;
if (pos->address > address) {
if (index > 0)
--index;
else
index = UINT32_MAX;
}
}
}
return index; // Failed to find address
}
// DWARFDebugLine::Row::Row
DWARFDebugLine::Row::Row(bool default_is_stmt)
: address(0), line(1), column(0), file(1), is_stmt(default_is_stmt),
basic_block(false), end_sequence(false), prologue_end(false),
epilogue_begin(false), isa(0) {}
// Called after a row is appended to the matrix
void DWARFDebugLine::Row::PostAppend() {
basic_block = false;
prologue_end = false;
epilogue_begin = false;
}
// DWARFDebugLine::Row::Reset
void DWARFDebugLine::Row::Reset(bool default_is_stmt) {
address = 0;
line = 1;
column = 0;
file = 1;
is_stmt = default_is_stmt;
basic_block = false;
end_sequence = false;
prologue_end = false;
epilogue_begin = false;
isa = 0;
}
// DWARFDebugLine::Row::Dump
void DWARFDebugLine::Row::Dump(Log *log) const {
log->Printf("0x%16.16" PRIx64 " %6u %6u %6u %3u %s%s%s%s%s", address, line,
column, file, isa, is_stmt ? " is_stmt" : "",
basic_block ? " basic_block" : "",
prologue_end ? " prologue_end" : "",
epilogue_begin ? " epilogue_begin" : "",
end_sequence ? " end_sequence" : "");
}
// Compare function LineTable structures
static bool AddressLessThan(const DWARFDebugLine::Row &a,
const DWARFDebugLine::Row &b) {
return a.address < b.address;
}
// Insert a row at the correct address if the addresses can be out of order
// which can only happen when we are linking a line table that may have had
// it's contents rearranged.
void DWARFDebugLine::Row::Insert(Row::collection &state_coll,
const Row &state) {
// If we don't have anything yet, or if the address of the last state in our
// line table is less than the current one, just append the current state
if (state_coll.empty() || AddressLessThan(state_coll.back(), state)) {
state_coll.push_back(state);
} else {
// Do a binary search for the correct entry
pair<Row::iterator, Row::iterator> range(equal_range(
state_coll.begin(), state_coll.end(), state, AddressLessThan));
// If the addresses are equal, we can safely replace the previous entry
// with the current one if the one it is replacing is an end_sequence
// entry. We currently always place an extra end sequence when ever we exit
// a valid address range for a function in case the functions get
// rearranged by optimizations or by order specifications. These extra end
// sequences will disappear by getting replaced with valid consecutive
// entries within a compile unit if there are no gaps.
if (range.first == range.second) {
state_coll.insert(range.first, state);
} else {
if ((distance(range.first, range.second) == 1) &&
range.first->end_sequence == true) {
*range.first = state;
} else {
state_coll.insert(range.second, state);
}
}
}
}
// DWARFDebugLine::State::State
DWARFDebugLine::State::State(Prologue::shared_ptr &p, Log *l,
DWARFDebugLine::State::Callback cb, void *userData)
: Row(p->default_is_stmt), prologue(p), log(l), callback(cb),
callbackUserData(userData), row(StartParsingLineTable) {
// Call the callback with the initial row state of zero for the prologue
if (callback)
callback(0, *this, callbackUserData);
}
// DWARFDebugLine::State::Reset
void DWARFDebugLine::State::Reset() { Row::Reset(prologue->default_is_stmt); }
// DWARFDebugLine::State::AppendRowToMatrix
void DWARFDebugLine::State::AppendRowToMatrix(dw_offset_t offset) {
// Each time we are to add an entry into the line table matrix call the
// callback function so that someone can do something with the current state
// of the state machine (like build a line table or dump the line table!)
if (log) {
if (row == 0) {
log->PutCString("Address Line Column File ISA Flags");
log->PutCString(
"------------------ ------ ------ ------ --- -------------");
}
Dump(log);
}
++row; // Increase the row number before we call our callback for a real row
if (callback)
callback(offset, *this, callbackUserData);
PostAppend();
}
// DWARFDebugLine::State::Finalize
void DWARFDebugLine::State::Finalize(dw_offset_t offset) {
// Call the callback with a special row state when we are done parsing a line
// table
row = DoneParsingLineTable;
if (callback)
callback(offset, *this, callbackUserData);
}
// void
// DWARFDebugLine::AppendLineTableData
//(
// const DWARFDebugLine::Prologue* prologue,
// const DWARFDebugLine::Row::collection& state_coll,
// const uint32_t addr_size,
// BinaryStreamBuf &debug_line_data
//)
//{
// if (state_coll.empty())
// {
// // We have no entries, just make an empty line table
// debug_line_data.Append8(0);
// debug_line_data.Append8(1);
// debug_line_data.Append8(DW_LNE_end_sequence);
// }
// else
// {
// DWARFDebugLine::Row::const_iterator pos;
// Row::const_iterator end = state_coll.end();
// bool default_is_stmt = prologue->default_is_stmt;
// const DWARFDebugLine::Row reset_state(default_is_stmt);
// const DWARFDebugLine::Row* prev_state = &reset_state;
// const int32_t max_line_increment_for_special_opcode =
// prologue->MaxLineIncrementForSpecialOpcode();
// for (pos = state_coll.begin(); pos != end; ++pos)
// {
// const DWARFDebugLine::Row& curr_state = *pos;
// int32_t line_increment = 0;
// dw_addr_t addr_offset = curr_state.address - prev_state->address;
// dw_addr_t addr_advance = (addr_offset) / prologue->min_inst_length;
// line_increment = (int32_t)(curr_state.line - prev_state->line);
//
// // If our previous state was the reset state, then let's emit the
// // address to keep GDB's DWARF parser happy. If we don't start each
// // sequence with a DW_LNE_set_address opcode, the line table won't
// // get slid properly in GDB.
//
// if (prev_state == &reset_state)
// {
// debug_line_data.Append8(0); // Extended opcode
// debug_line_data.Append32_as_ULEB128(addr_size + 1); // Length of
// opcode bytes
// debug_line_data.Append8(DW_LNE_set_address);
// debug_line_data.AppendMax64(curr_state.address, addr_size);
// addr_advance = 0;
// }
//
// if (prev_state->file != curr_state.file)
// {
// debug_line_data.Append8(DW_LNS_set_file);
// debug_line_data.Append32_as_ULEB128(curr_state.file);
// }
//
// if (prev_state->column != curr_state.column)
// {
// debug_line_data.Append8(DW_LNS_set_column);
// debug_line_data.Append32_as_ULEB128(curr_state.column);
// }
//
// // Don't do anything fancy if we are at the end of a sequence
// // as we don't want to push any extra rows since the
// DW_LNE_end_sequence
// // will push a row itself!
// if (curr_state.end_sequence)
// {
// if (line_increment != 0)
// {
// debug_line_data.Append8(DW_LNS_advance_line);
// debug_line_data.Append32_as_SLEB128(line_increment);
// }
//
// if (addr_advance > 0)
// {
// debug_line_data.Append8(DW_LNS_advance_pc);
// debug_line_data.Append32_as_ULEB128(addr_advance);
// }
//
// // Now push the end sequence on!
// debug_line_data.Append8(0);
// debug_line_data.Append8(1);
// debug_line_data.Append8(DW_LNE_end_sequence);
//
// prev_state = &reset_state;
// }
// else
// {
// if (line_increment || addr_advance)
// {
// if (line_increment > max_line_increment_for_special_opcode)
// {
// debug_line_data.Append8(DW_LNS_advance_line);
// debug_line_data.Append32_as_SLEB128(line_increment);
// line_increment = 0;
// }
//
// uint32_t special_opcode = (line_increment >=
// prologue->line_base) ? ((line_increment -
// prologue->line_base) + (prologue->line_range * addr_advance)
// + prologue->opcode_base) : 256;
// if (special_opcode > 255)
// {
// // Both the address and line won't fit in one special
// opcode
// // check to see if just the line advance will?
// uint32_t special_opcode_line = ((line_increment >=
// prologue->line_base) && (line_increment != 0)) ?
// ((line_increment - prologue->line_base) +
// prologue->opcode_base) : 256;
//
//
// if (special_opcode_line > 255)
// {
// // Nope, the line advance won't fit by itself, check
// the address increment by itself
// uint32_t special_opcode_addr = addr_advance ?
// ((0 - prologue->line_base) +
// (prologue->line_range * addr_advance) +
// prologue->opcode_base) : 256;
//
// if (special_opcode_addr > 255)
// {
// // Neither the address nor the line will fit in
// a
// // special opcode, we must manually enter both
// then
// // do a DW_LNS_copy to push a row (special
// opcode
// // automatically imply a new row is pushed)
// if (line_increment != 0)
// {
// debug_line_data.Append8(DW_LNS_advance_line);
// debug_line_data.Append32_as_SLEB128(line_increment);
// }
//
// if (addr_advance > 0)
// {
// debug_line_data.Append8(DW_LNS_advance_pc);
// debug_line_data.Append32_as_ULEB128(addr_advance);
// }
//
// // Now push a row onto the line table manually
// debug_line_data.Append8(DW_LNS_copy);
//
// }
// else
// {
// // The address increment alone will fit into a
// special opcode
// // so modify our line change, then issue a
// special opcode
// // for the address increment and it will push a
// row into the
// // line table
// if (line_increment != 0)
// {
// debug_line_data.Append8(DW_LNS_advance_line);
// debug_line_data.Append32_as_SLEB128(line_increment);
// }
//
// // Advance of line and address will fit into a
// single byte special opcode
// // and this will also push a row onto the line
// table
// debug_line_data.Append8(special_opcode_addr);
// }
// }
// else
// {
// // The line change alone will fit into a special
// opcode
// // so modify our address increment first, then issue
// a
// // special opcode for the line change and it will
// push
// // a row into the line table
// if (addr_advance > 0)
// {
// debug_line_data.Append8(DW_LNS_advance_pc);
// debug_line_data.Append32_as_ULEB128(addr_advance);
// }
//
// // Advance of line and address will fit into a
// single byte special opcode
// // and this will also push a row onto the line table
// debug_line_data.Append8(special_opcode_line);
// }
// }
// else
// {
// // Advance of line and address will fit into a single
// byte special opcode
// // and this will also push a row onto the line table
// debug_line_data.Append8(special_opcode);
// }
// }
// prev_state = &curr_state;
// }
// }
// }
//}
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