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-rw-r--r--lib/DebugInfo/DWARFDebugLine.cpp475
1 files changed, 475 insertions, 0 deletions
diff --git a/lib/DebugInfo/DWARFDebugLine.cpp b/lib/DebugInfo/DWARFDebugLine.cpp
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+++ b/lib/DebugInfo/DWARFDebugLine.cpp
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+//===-- DWARFDebugLine.cpp ------------------------------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "DWARFDebugLine.h"
+#include "llvm/Support/Dwarf.h"
+#include "llvm/Support/Format.h"
+#include "llvm/Support/raw_ostream.h"
+#include <algorithm>
+using namespace llvm;
+using namespace dwarf;
+
+void DWARFDebugLine::Prologue::dump(raw_ostream &OS) const {
+ OS << "Line table prologue:\n"
+ << format(" total_length: 0x%8.8x\n", TotalLength)
+ << format(" version: %u\n", Version)
+ << format("prologue_length: 0x%8.8x\n", PrologueLength)
+ << format("min_inst_length: %u\n", MinInstLength)
+ << format("default_is_stmt: %u\n", DefaultIsStmt)
+ << format(" line_base: %i\n", LineBase)
+ << format(" line_range: %u\n", LineRange)
+ << format(" opcode_base: %u\n", OpcodeBase);
+
+ for (uint32_t i = 0; i < StandardOpcodeLengths.size(); ++i)
+ OS << format("standard_opcode_lengths[%s] = %u\n", LNStandardString(i+1),
+ StandardOpcodeLengths[i]);
+
+ if (!IncludeDirectories.empty())
+ for (uint32_t i = 0; i < IncludeDirectories.size(); ++i)
+ OS << format("include_directories[%3u] = '", i+1)
+ << IncludeDirectories[i] << "'\n";
+
+ if (!FileNames.empty()) {
+ OS << " Dir Mod Time File Len File Name\n"
+ << " ---- ---------- ---------- -----------"
+ "----------------\n";
+ for (uint32_t i = 0; i < FileNames.size(); ++i) {
+ const FileNameEntry& fileEntry = FileNames[i];
+ OS << format("file_names[%3u] %4u ", i+1, fileEntry.DirIdx)
+ << format("0x%8.8x 0x%8.8x ", fileEntry.ModTime, fileEntry.Length)
+ << fileEntry.Name << '\n';
+ }
+ }
+}
+
+void DWARFDebugLine::Row::postAppend() {
+ BasicBlock = false;
+ PrologueEnd = false;
+ EpilogueBegin = false;
+}
+
+void DWARFDebugLine::Row::reset(bool default_is_stmt) {
+ Address = 0;
+ Line = 1;
+ Column = 0;
+ File = 1;
+ Isa = 0;
+ IsStmt = default_is_stmt;
+ BasicBlock = false;
+ EndSequence = false;
+ PrologueEnd = false;
+ EpilogueBegin = false;
+}
+
+void DWARFDebugLine::Row::dump(raw_ostream &OS) const {
+ OS << format("0x%16.16llx %6u %6u", Address, Line, Column)
+ << format(" %6u %3u ", File, Isa)
+ << (IsStmt ? " is_stmt" : "")
+ << (BasicBlock ? " basic_block" : "")
+ << (PrologueEnd ? " prologue_end" : "")
+ << (EpilogueBegin ? " epilogue_begin" : "")
+ << (EndSequence ? " end_sequence" : "")
+ << '\n';
+}
+
+void DWARFDebugLine::LineTable::dump(raw_ostream &OS) const {
+ Prologue.dump(OS);
+ OS << '\n';
+
+ if (!Rows.empty()) {
+ OS << "Address Line Column File ISA Flags\n"
+ << "------------------ ------ ------ ------ --- -------------\n";
+ for (std::vector<Row>::const_iterator pos = Rows.begin(),
+ end = Rows.end(); pos != end; ++pos)
+ pos->dump(OS);
+ }
+}
+
+DWARFDebugLine::State::~State() {}
+
+void DWARFDebugLine::State::appendRowToMatrix(uint32_t offset) {
+ ++row; // Increase the row number.
+ LineTable::appendRow(*this);
+ Row::postAppend();
+}
+
+DWARFDebugLine::DumpingState::~DumpingState() {}
+
+void DWARFDebugLine::DumpingState::finalize(uint32_t offset) {
+ LineTable::dump(OS);
+}
+
+const DWARFDebugLine::LineTable *
+DWARFDebugLine::getLineTable(uint32_t offset) const {
+ LineTableConstIter pos = LineTableMap.find(offset);
+ if (pos != LineTableMap.end())
+ return &pos->second;
+ return 0;
+}
+
+const DWARFDebugLine::LineTable *
+DWARFDebugLine::getOrParseLineTable(DataExtractor debug_line_data,
+ uint32_t offset) {
+ std::pair<LineTableIter, bool> pos =
+ LineTableMap.insert(LineTableMapTy::value_type(offset, LineTable()));
+ if (pos.second) {
+ // Parse and cache the line table for at this offset.
+ State state;
+ if (!parseStatementTable(debug_line_data, &offset, state))
+ return 0;
+ pos.first->second = state;
+ }
+ return &pos.first->second;
+}
+
+bool
+DWARFDebugLine::parsePrologue(DataExtractor debug_line_data,
+ uint32_t *offset_ptr, Prologue *prologue) {
+ const uint32_t prologue_offset = *offset_ptr;
+
+ prologue->clear();
+ prologue->TotalLength = debug_line_data.getU32(offset_ptr);
+ prologue->Version = debug_line_data.getU16(offset_ptr);
+ if (prologue->Version != 2)
+ return false;
+
+ prologue->PrologueLength = debug_line_data.getU32(offset_ptr);
+ const uint32_t end_prologue_offset = prologue->PrologueLength + *offset_ptr;
+ prologue->MinInstLength = debug_line_data.getU8(offset_ptr);
+ prologue->DefaultIsStmt = debug_line_data.getU8(offset_ptr);
+ prologue->LineBase = debug_line_data.getU8(offset_ptr);
+ prologue->LineRange = debug_line_data.getU8(offset_ptr);
+ prologue->OpcodeBase = debug_line_data.getU8(offset_ptr);
+
+ prologue->StandardOpcodeLengths.reserve(prologue->OpcodeBase-1);
+ for (uint32_t i = 1; i < prologue->OpcodeBase; ++i) {
+ uint8_t op_len = debug_line_data.getU8(offset_ptr);
+ prologue->StandardOpcodeLengths.push_back(op_len);
+ }
+
+ while (*offset_ptr < end_prologue_offset) {
+ const char *s = debug_line_data.getCStr(offset_ptr);
+ if (s && s[0])
+ prologue->IncludeDirectories.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.DirIdx = debug_line_data.getULEB128(offset_ptr);
+ fileEntry.ModTime = debug_line_data.getULEB128(offset_ptr);
+ fileEntry.Length = debug_line_data.getULEB128(offset_ptr);
+ prologue->FileNames.push_back(fileEntry);
+ } else {
+ break;
+ }
+ }
+
+ if (*offset_ptr != end_prologue_offset) {
+ fprintf(stderr, "warning: parsing line table prologue at 0x%8.8x should"
+ " have ended at 0x%8.8x but it ended ad 0x%8.8x\n",
+ prologue_offset, end_prologue_offset, *offset_ptr);
+ }
+ return end_prologue_offset;
+}
+
+bool
+DWARFDebugLine::parseStatementTable(DataExtractor debug_line_data,
+ uint32_t *offset_ptr, State &state) {
+ const uint32_t debug_line_offset = *offset_ptr;
+
+ Prologue *prologue = &state.Prologue;
+
+ if (!parsePrologue(debug_line_data, offset_ptr, prologue)) {
+ // Restore our offset and return false to indicate failure!
+ *offset_ptr = debug_line_offset;
+ return false;
+ }
+
+ const uint32_t end_offset = debug_line_offset + prologue->TotalLength +
+ sizeof(prologue->TotalLength);
+
+ state.reset();
+
+ while (*offset_ptr < end_offset) {
+ 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
+ uint32_t ext_offset = *offset_ptr;
+ uint64_t len = debug_line_data.getULEB128(offset_ptr);
+ uint32_t arg_size = len - (*offset_ptr - ext_offset);
+
+ 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.EndSequence = 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.
+ state.Address = debug_line_data.getAddress(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
+ // the file register of the state machine.
+ {
+ FileNameEntry fileEntry;
+ fileEntry.Name = debug_line_data.getCStr(offset_ptr);
+ fileEntry.DirIdx = debug_line_data.getULEB128(offset_ptr);
+ fileEntry.ModTime = debug_line_data.getULEB128(offset_ptr);
+ fileEntry.Length = debug_line_data.getULEB128(offset_ptr);
+ prologue->FileNames.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->OpcodeBase) {
+ 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->MinInstLength;
+ 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.IsStmt = !state.IsStmt;
+ break;
+
+ case DW_LNS_set_basic_block:
+ // Takes no arguments. Set the basic_block register of the
+ // state machine to true
+ state.BasicBlock = 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->OpcodeBase;
+ uint64_t addr_offset = (adjust_opcode / prologue->LineRange) *
+ prologue->MinInstLength;
+ 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.PrologueEnd = true;
+ break;
+
+ case DW_LNS_set_epilogue_begin:
+ // Takes no arguments. Set the basic_block register of the
+ // state machine to true
+ state.EpilogueBegin = 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.
+ {
+ assert(opcode - 1U < prologue->StandardOpcodeLengths.size());
+ uint8_t opcode_length = prologue->StandardOpcodeLengths[opcode - 1];
+ for (uint8_t i=0; i<opcode_length; ++i)
+ debug_line_data.getULEB128(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->OpcodeBase;
+ uint64_t addr_offset = (adjust_opcode / prologue->LineRange) *
+ prologue->MinInstLength;
+ int32_t line_offset = prologue->LineBase +
+ (adjust_opcode % prologue->LineRange);
+ state.Line += line_offset;
+ state.Address += addr_offset;
+ state.appendRowToMatrix(*offset_ptr);
+ }
+ }
+
+ state.finalize(*offset_ptr);
+
+ return end_offset;
+}
+
+static bool findMatchingAddress(const DWARFDebugLine::Row& row1,
+ const DWARFDebugLine::Row& row2) {
+ return row1.Address < row2.Address;
+}
+
+uint32_t
+DWARFDebugLine::LineTable::lookupAddress(uint64_t address,
+ uint64_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;
+ typedef std::vector<Row>::const_iterator iterator;
+ iterator begin_pos = Rows.begin();
+ iterator end_pos = Rows.end();
+ iterator pos = std::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.
+}
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