1 //===-- DWARFDebugLine.cpp --------------------------------------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 #include "DWARFDebugLine.h"
11
12 //#define ENABLE_DEBUG_PRINTF // DO NOT LEAVE THIS DEFINED: DEBUG ONLY!!!
13 #include <assert.h>
14
15 #include "lldb/Core/FileSpecList.h"
16 #include "lldb/Core/Log.h"
17 #include "lldb/Core/Module.h"
18 #include "lldb/Core/Timer.h"
19 #include "lldb/Host/Host.h"
20
21 #include "SymbolFileDWARF.h"
22 #include "LogChannelDWARF.h"
23
24 using namespace lldb;
25 using namespace lldb_private;
26 using namespace std;
27
28 //----------------------------------------------------------------------
29 // Parse
30 //
31 // Parse all information in the debug_line_data into an internal
32 // representation.
33 //----------------------------------------------------------------------
34 void
Parse(const DWARFDataExtractor & debug_line_data)35 DWARFDebugLine::Parse(const DWARFDataExtractor& debug_line_data)
36 {
37 m_lineTableMap.clear();
38 lldb::offset_t offset = 0;
39 LineTable::shared_ptr line_table_sp(new LineTable);
40 while (debug_line_data.ValidOffset(offset))
41 {
42 const lldb::offset_t debug_line_offset = offset;
43
44 if (line_table_sp.get() == NULL)
45 break;
46
47 if (ParseStatementTable(debug_line_data, &offset, line_table_sp.get()))
48 {
49 // Make sure we don't don't loop infinitely
50 if (offset <= debug_line_offset)
51 break;
52 //DEBUG_PRINTF("m_lineTableMap[0x%8.8x] = line_table_sp\n", debug_line_offset);
53 m_lineTableMap[debug_line_offset] = line_table_sp;
54 line_table_sp.reset(new LineTable);
55 }
56 else
57 ++offset; // Try next byte in line table
58 }
59 }
60
61 void
ParseIfNeeded(const DWARFDataExtractor & debug_line_data)62 DWARFDebugLine::ParseIfNeeded(const DWARFDataExtractor& debug_line_data)
63 {
64 if (m_lineTableMap.empty())
65 Parse(debug_line_data);
66 }
67
68
69 //----------------------------------------------------------------------
70 // DWARFDebugLine::GetLineTable
71 //----------------------------------------------------------------------
72 DWARFDebugLine::LineTable::shared_ptr
GetLineTable(const dw_offset_t offset) const73 DWARFDebugLine::GetLineTable(const dw_offset_t offset) const
74 {
75 DWARFDebugLine::LineTable::shared_ptr line_table_shared_ptr;
76 LineTableConstIter pos = m_lineTableMap.find(offset);
77 if (pos != m_lineTableMap.end())
78 line_table_shared_ptr = pos->second;
79 return line_table_shared_ptr;
80 }
81
82
83 //----------------------------------------------------------------------
84 // DumpStateToFile
85 //----------------------------------------------------------------------
86 static void
DumpStateToFile(dw_offset_t offset,const DWARFDebugLine::State & state,void * userData)87 DumpStateToFile (dw_offset_t offset, const DWARFDebugLine::State& state, void* userData)
88 {
89 Log *log = (Log *)userData;
90 if (state.row == DWARFDebugLine::State::StartParsingLineTable)
91 {
92 // If the row is zero we are being called with the prologue only
93 state.prologue->Dump (log);
94 log->PutCString ("Address Line Column File");
95 log->PutCString ("------------------ ------ ------ ------");
96 }
97 else if (state.row == DWARFDebugLine::State::DoneParsingLineTable)
98 {
99 // Done parsing line table
100 }
101 else
102 {
103 log->Printf( "0x%16.16" PRIx64 " %6u %6u %6u%s\n", state.address, state.line, state.column, state.file, state.end_sequence ? " END" : "");
104 }
105 }
106
107 //----------------------------------------------------------------------
108 // DWARFDebugLine::DumpLineTableRows
109 //----------------------------------------------------------------------
110 bool
DumpLineTableRows(Log * log,SymbolFileDWARF * dwarf2Data,dw_offset_t debug_line_offset)111 DWARFDebugLine::DumpLineTableRows(Log *log, SymbolFileDWARF* dwarf2Data, dw_offset_t debug_line_offset)
112 {
113 const DWARFDataExtractor& debug_line_data = dwarf2Data->get_debug_line_data();
114
115 if (debug_line_offset == DW_INVALID_OFFSET)
116 {
117 // Dump line table to a single file only
118 debug_line_offset = 0;
119 while (debug_line_data.ValidOffset(debug_line_offset))
120 debug_line_offset = DumpStatementTable (log, debug_line_data, debug_line_offset);
121 }
122 else
123 {
124 // Dump line table to a single file only
125 DumpStatementTable (log, debug_line_data, debug_line_offset);
126 }
127 return false;
128 }
129
130 //----------------------------------------------------------------------
131 // DWARFDebugLine::DumpStatementTable
132 //----------------------------------------------------------------------
133 dw_offset_t
DumpStatementTable(Log * log,const DWARFDataExtractor & debug_line_data,const dw_offset_t debug_line_offset)134 DWARFDebugLine::DumpStatementTable(Log *log, const DWARFDataExtractor& debug_line_data, const dw_offset_t debug_line_offset)
135 {
136 if (debug_line_data.ValidOffset(debug_line_offset))
137 {
138 lldb::offset_t offset = debug_line_offset;
139 log->Printf( "----------------------------------------------------------------------\n"
140 "debug_line[0x%8.8x]\n"
141 "----------------------------------------------------------------------\n", debug_line_offset);
142
143 if (ParseStatementTable(debug_line_data, &offset, DumpStateToFile, log))
144 return offset;
145 else
146 return debug_line_offset + 1; // Skip to next byte in .debug_line section
147 }
148
149 return DW_INVALID_OFFSET;
150 }
151
152
153 //----------------------------------------------------------------------
154 // DumpOpcodes
155 //----------------------------------------------------------------------
156 bool
DumpOpcodes(Log * log,SymbolFileDWARF * dwarf2Data,dw_offset_t debug_line_offset,uint32_t dump_flags)157 DWARFDebugLine::DumpOpcodes(Log *log, SymbolFileDWARF* dwarf2Data, dw_offset_t debug_line_offset, uint32_t dump_flags)
158 {
159 const DWARFDataExtractor& debug_line_data = dwarf2Data->get_debug_line_data();
160
161 if (debug_line_data.GetByteSize() == 0)
162 {
163 log->Printf( "< EMPTY >\n");
164 return false;
165 }
166
167 if (debug_line_offset == DW_INVALID_OFFSET)
168 {
169 // Dump line table to a single file only
170 debug_line_offset = 0;
171 while (debug_line_data.ValidOffset(debug_line_offset))
172 debug_line_offset = DumpStatementOpcodes (log, debug_line_data, debug_line_offset, dump_flags);
173 }
174 else
175 {
176 // Dump line table to a single file only
177 DumpStatementOpcodes (log, debug_line_data, debug_line_offset, dump_flags);
178 }
179 return false;
180 }
181
182 //----------------------------------------------------------------------
183 // DumpStatementOpcodes
184 //----------------------------------------------------------------------
185 dw_offset_t
DumpStatementOpcodes(Log * log,const DWARFDataExtractor & debug_line_data,const dw_offset_t debug_line_offset,uint32_t flags)186 DWARFDebugLine::DumpStatementOpcodes(Log *log, const DWARFDataExtractor& debug_line_data, const dw_offset_t debug_line_offset, uint32_t flags)
187 {
188 lldb::offset_t offset = debug_line_offset;
189 if (debug_line_data.ValidOffset(offset))
190 {
191 Prologue prologue;
192
193 if (ParsePrologue(debug_line_data, &offset, &prologue))
194 {
195 log->PutCString ("----------------------------------------------------------------------");
196 log->Printf ("debug_line[0x%8.8x]", debug_line_offset);
197 log->PutCString ("----------------------------------------------------------------------\n");
198 prologue.Dump (log);
199 }
200 else
201 {
202 offset = debug_line_offset;
203 log->Printf( "0x%8.8" PRIx64 ": skipping pad byte %2.2x", offset, debug_line_data.GetU8(&offset));
204 return offset;
205 }
206
207 Row row(prologue.default_is_stmt);
208 const dw_offset_t end_offset = debug_line_offset + prologue.total_length + sizeof(prologue.total_length);
209
210 assert(debug_line_data.ValidOffset(end_offset-1));
211
212 while (offset < end_offset)
213 {
214 const uint32_t op_offset = offset;
215 uint8_t opcode = debug_line_data.GetU8(&offset);
216 switch (opcode)
217 {
218 case 0: // Extended Opcodes always start with a zero opcode followed by
219 { // a uleb128 length so you can skip ones you don't know about
220
221 dw_offset_t ext_offset = offset;
222 dw_uleb128_t len = debug_line_data.GetULEB128(&offset);
223 dw_offset_t arg_size = len - (offset - ext_offset);
224 uint8_t sub_opcode = debug_line_data.GetU8(&offset);
225 // if (verbose)
226 // log->Printf( "Extended: <%u> %2.2x ", len, sub_opcode);
227
228 switch (sub_opcode)
229 {
230 case DW_LNE_end_sequence :
231 log->Printf( "0x%8.8x: DW_LNE_end_sequence", op_offset);
232 row.Dump(log);
233 row.Reset(prologue.default_is_stmt);
234 break;
235
236 case DW_LNE_set_address :
237 {
238 row.address = debug_line_data.GetMaxU64(&offset, arg_size);
239 log->Printf( "0x%8.8x: DW_LNE_set_address (0x%" PRIx64 ")", op_offset, row.address);
240 }
241 break;
242
243 case DW_LNE_define_file:
244 {
245 FileNameEntry fileEntry;
246 fileEntry.name = debug_line_data.GetCStr(&offset);
247 fileEntry.dir_idx = debug_line_data.GetULEB128(&offset);
248 fileEntry.mod_time = debug_line_data.GetULEB128(&offset);
249 fileEntry.length = debug_line_data.GetULEB128(&offset);
250 log->Printf( "0x%8.8x: DW_LNE_define_file('%s', dir=%i, mod_time=0x%8.8x, length=%i )",
251 op_offset,
252 fileEntry.name.c_str(),
253 fileEntry.dir_idx,
254 fileEntry.mod_time,
255 fileEntry.length);
256 prologue.file_names.push_back(fileEntry);
257 }
258 break;
259
260 default:
261 log->Printf( "0x%8.8x: DW_LNE_??? (%2.2x) - Skipping unknown upcode", op_offset, opcode);
262 // Length doesn't include the zero opcode byte or the length itself, but
263 // it does include the sub_opcode, so we have to adjust for that below
264 offset += arg_size;
265 break;
266 }
267 }
268 break;
269
270 // Standard Opcodes
271 case DW_LNS_copy:
272 log->Printf( "0x%8.8x: DW_LNS_copy", op_offset);
273 row.Dump (log);
274 break;
275
276 case DW_LNS_advance_pc:
277 {
278 dw_uleb128_t addr_offset_n = debug_line_data.GetULEB128(&offset);
279 dw_uleb128_t addr_offset = addr_offset_n * prologue.min_inst_length;
280 log->Printf( "0x%8.8x: DW_LNS_advance_pc (0x%x)", op_offset, addr_offset);
281 row.address += addr_offset;
282 }
283 break;
284
285 case DW_LNS_advance_line:
286 {
287 dw_sleb128_t line_offset = debug_line_data.GetSLEB128(&offset);
288 log->Printf( "0x%8.8x: DW_LNS_advance_line (%i)", op_offset, line_offset);
289 row.line += line_offset;
290 }
291 break;
292
293 case DW_LNS_set_file:
294 row.file = debug_line_data.GetULEB128(&offset);
295 log->Printf( "0x%8.8x: DW_LNS_set_file (%u)", op_offset, row.file);
296 break;
297
298 case DW_LNS_set_column:
299 row.column = debug_line_data.GetULEB128(&offset);
300 log->Printf( "0x%8.8x: DW_LNS_set_column (%u)", op_offset, row.column);
301 break;
302
303 case DW_LNS_negate_stmt:
304 row.is_stmt = !row.is_stmt;
305 log->Printf( "0x%8.8x: DW_LNS_negate_stmt", op_offset);
306 break;
307
308 case DW_LNS_set_basic_block:
309 row.basic_block = true;
310 log->Printf( "0x%8.8x: DW_LNS_set_basic_block", op_offset);
311 break;
312
313 case DW_LNS_const_add_pc:
314 {
315 uint8_t adjust_opcode = 255 - prologue.opcode_base;
316 dw_addr_t addr_offset = (adjust_opcode / prologue.line_range) * prologue.min_inst_length;
317 log->Printf( "0x%8.8x: DW_LNS_const_add_pc (0x%8.8" PRIx64 ")", op_offset, addr_offset);
318 row.address += addr_offset;
319 }
320 break;
321
322 case DW_LNS_fixed_advance_pc:
323 {
324 uint16_t pc_offset = debug_line_data.GetU16(&offset);
325 log->Printf( "0x%8.8x: DW_LNS_fixed_advance_pc (0x%4.4x)", op_offset, pc_offset);
326 row.address += pc_offset;
327 }
328 break;
329
330 case DW_LNS_set_prologue_end:
331 row.prologue_end = true;
332 log->Printf( "0x%8.8x: DW_LNS_set_prologue_end", op_offset);
333 break;
334
335 case DW_LNS_set_epilogue_begin:
336 row.epilogue_begin = true;
337 log->Printf( "0x%8.8x: DW_LNS_set_epilogue_begin", op_offset);
338 break;
339
340 case DW_LNS_set_isa:
341 row.isa = debug_line_data.GetULEB128(&offset);
342 log->Printf( "0x%8.8x: DW_LNS_set_isa (%u)", op_offset, row.isa);
343 break;
344
345 // Special Opcodes
346 default:
347 if (opcode < prologue.opcode_base)
348 {
349 // We have an opcode that this parser doesn't know about, skip
350 // the number of ULEB128 numbers that is says to skip in the
351 // prologue's standard_opcode_lengths array
352 uint8_t n = prologue.standard_opcode_lengths[opcode-1];
353 log->Printf( "0x%8.8x: Special : Unknown skipping %u ULEB128 values.", op_offset, n);
354 while (n > 0)
355 {
356 debug_line_data.GetULEB128(&offset);
357 --n;
358 }
359 }
360 else
361 {
362 uint8_t adjust_opcode = opcode - prologue.opcode_base;
363 dw_addr_t addr_offset = (adjust_opcode / prologue.line_range) * prologue.min_inst_length;
364 int32_t line_offset = prologue.line_base + (adjust_opcode % prologue.line_range);
365 log->Printf("0x%8.8x: address += 0x%" PRIx64 ", line += %i\n", op_offset, (uint64_t)addr_offset, line_offset);
366 row.address += addr_offset;
367 row.line += line_offset;
368 row.Dump (log);
369 }
370 break;
371 }
372 }
373 return end_offset;
374 }
375 return DW_INVALID_OFFSET;
376 }
377
378
379
380
381 //----------------------------------------------------------------------
382 // Parse
383 //
384 // Parse the entire line table contents calling callback each time a
385 // new prologue is parsed and every time a new row is to be added to
386 // the line table.
387 //----------------------------------------------------------------------
388 void
Parse(const DWARFDataExtractor & debug_line_data,DWARFDebugLine::State::Callback callback,void * userData)389 DWARFDebugLine::Parse(const DWARFDataExtractor& debug_line_data, DWARFDebugLine::State::Callback callback, void* userData)
390 {
391 lldb::offset_t offset = 0;
392 if (debug_line_data.ValidOffset(offset))
393 {
394 if (!ParseStatementTable(debug_line_data, &offset, callback, userData))
395 ++offset; // Skip to next byte in .debug_line section
396 }
397 }
398
399
400 //----------------------------------------------------------------------
401 // DWARFDebugLine::ParsePrologue
402 //----------------------------------------------------------------------
403 bool
ParsePrologue(const DWARFDataExtractor & debug_line_data,lldb::offset_t * offset_ptr,Prologue * prologue)404 DWARFDebugLine::ParsePrologue(const DWARFDataExtractor& debug_line_data, lldb::offset_t* offset_ptr, Prologue* prologue)
405 {
406 const lldb::offset_t prologue_offset = *offset_ptr;
407
408 //DEBUG_PRINTF("0x%8.8x: ParsePrologue()\n", *offset_ptr);
409
410 prologue->Clear();
411 uint32_t i;
412 const char * s;
413 prologue->total_length = debug_line_data.GetDWARFInitialLength(offset_ptr);
414 prologue->version = debug_line_data.GetU16(offset_ptr);
415 if (prologue->version != 2)
416 return false;
417
418 prologue->prologue_length = debug_line_data.GetDWARFOffset(offset_ptr);
419 const lldb::offset_t end_prologue_offset = prologue->prologue_length + *offset_ptr;
420 prologue->min_inst_length = debug_line_data.GetU8(offset_ptr);
421 prologue->default_is_stmt = debug_line_data.GetU8(offset_ptr);
422 prologue->line_base = debug_line_data.GetU8(offset_ptr);
423 prologue->line_range = debug_line_data.GetU8(offset_ptr);
424 prologue->opcode_base = debug_line_data.GetU8(offset_ptr);
425
426 prologue->standard_opcode_lengths.reserve(prologue->opcode_base-1);
427
428 for (i=1; i<prologue->opcode_base; ++i)
429 {
430 uint8_t op_len = debug_line_data.GetU8(offset_ptr);
431 prologue->standard_opcode_lengths.push_back(op_len);
432 }
433
434 while (*offset_ptr < end_prologue_offset)
435 {
436 s = debug_line_data.GetCStr(offset_ptr);
437 if (s && s[0])
438 prologue->include_directories.push_back(s);
439 else
440 break;
441 }
442
443 while (*offset_ptr < end_prologue_offset)
444 {
445 const char* name = debug_line_data.GetCStr( offset_ptr );
446 if (name && name[0])
447 {
448 FileNameEntry fileEntry;
449 fileEntry.name = name;
450 fileEntry.dir_idx = debug_line_data.GetULEB128( offset_ptr );
451 fileEntry.mod_time = debug_line_data.GetULEB128( offset_ptr );
452 fileEntry.length = debug_line_data.GetULEB128( offset_ptr );
453 prologue->file_names.push_back(fileEntry);
454 }
455 else
456 break;
457 }
458
459 // XXX GNU as is broken for 64-Bit DWARF
460 if (*offset_ptr != end_prologue_offset)
461 {
462 Host::SystemLog (Host::eSystemLogWarning,
463 "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",
464 prologue_offset,
465 end_prologue_offset,
466 *offset_ptr);
467 }
468 return end_prologue_offset;
469 }
470
471 bool
ParseSupportFiles(const lldb::ModuleSP & module_sp,const DWARFDataExtractor & debug_line_data,const char * cu_comp_dir,dw_offset_t stmt_list,FileSpecList & support_files)472 DWARFDebugLine::ParseSupportFiles (const lldb::ModuleSP &module_sp,
473 const DWARFDataExtractor& debug_line_data,
474 const char *cu_comp_dir,
475 dw_offset_t stmt_list,
476 FileSpecList &support_files)
477 {
478 lldb::offset_t offset = stmt_list;
479 // Skip the total length
480 (void)debug_line_data.GetDWARFInitialLength(&offset);
481 const char * s;
482 uint32_t version = debug_line_data.GetU16(&offset);
483 if (version != 2)
484 return false;
485
486 const dw_offset_t end_prologue_offset = debug_line_data.GetDWARFOffset(&offset) + offset;
487 // Skip instruction length, default is stmt, line base, line range and
488 // opcode base, and all opcode lengths
489 offset += 4;
490 const uint8_t opcode_base = debug_line_data.GetU8(&offset);
491 offset += opcode_base - 1;
492 std::vector<std::string> include_directories;
493 include_directories.push_back(""); // Directory at index zero doesn't exist
494 while (offset < end_prologue_offset)
495 {
496 s = debug_line_data.GetCStr(&offset);
497 if (s && s[0])
498 include_directories.push_back(s);
499 else
500 break;
501 }
502 std::string fullpath;
503 std::string remapped_fullpath;
504 while (offset < end_prologue_offset)
505 {
506 const char* path = debug_line_data.GetCStr( &offset );
507 if (path && path[0])
508 {
509 uint32_t dir_idx = debug_line_data.GetULEB128( &offset );
510 debug_line_data.Skip_LEB128(&offset); // Skip mod_time
511 debug_line_data.Skip_LEB128(&offset); // Skip length
512
513 if (path[0] == '/')
514 {
515 // The path starts with a directory delimiter, so we are done.
516 if (module_sp->RemapSourceFile (path, fullpath))
517 support_files.Append(FileSpec (fullpath.c_str(), false));
518 else
519 support_files.Append(FileSpec (path, false));
520 }
521 else
522 {
523 if (dir_idx > 0 && dir_idx < include_directories.size())
524 {
525 if (cu_comp_dir && include_directories[dir_idx][0] != '/')
526 {
527 fullpath = cu_comp_dir;
528
529 if (*fullpath.rbegin() != '/')
530 fullpath += '/';
531 fullpath += include_directories[dir_idx];
532
533 }
534 else
535 fullpath = include_directories[dir_idx];
536 }
537 else if (cu_comp_dir && cu_comp_dir[0])
538 {
539 fullpath = cu_comp_dir;
540 }
541
542 if (!fullpath.empty())
543 {
544 if (*fullpath.rbegin() != '/')
545 fullpath += '/';
546 }
547 fullpath += path;
548 if (module_sp->RemapSourceFile (fullpath.c_str(), remapped_fullpath))
549 support_files.Append(FileSpec (remapped_fullpath.c_str(), false));
550 else
551 support_files.Append(FileSpec (fullpath.c_str(), false));
552 }
553
554 }
555 }
556
557 if (offset != end_prologue_offset)
558 {
559 Host::SystemLog (Host::eSystemLogError,
560 "warning: parsing line table prologue at 0x%8.8x should have ended at 0x%8.8x but it ended at 0x%8.8" PRIx64 "\n",
561 stmt_list,
562 end_prologue_offset,
563 offset);
564 }
565 return end_prologue_offset;
566 }
567
568 //----------------------------------------------------------------------
569 // ParseStatementTable
570 //
571 // Parse a single line table (prologue and all rows) and call the
572 // callback function once for the prologue (row in state will be zero)
573 // and each time a row is to be added to the line table.
574 //----------------------------------------------------------------------
575 bool
ParseStatementTable(const DWARFDataExtractor & debug_line_data,lldb::offset_t * offset_ptr,DWARFDebugLine::State::Callback callback,void * userData)576 DWARFDebugLine::ParseStatementTable
577 (
578 const DWARFDataExtractor& debug_line_data,
579 lldb::offset_t* offset_ptr,
580 DWARFDebugLine::State::Callback callback,
581 void* userData
582 )
583 {
584 Log *log (LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_LINE));
585 Prologue::shared_ptr prologue(new Prologue());
586
587
588 const dw_offset_t debug_line_offset = *offset_ptr;
589
590 Timer scoped_timer (__PRETTY_FUNCTION__,
591 "DWARFDebugLine::ParseStatementTable (.debug_line[0x%8.8x])",
592 debug_line_offset);
593
594 if (!ParsePrologue(debug_line_data, offset_ptr, prologue.get()))
595 {
596 if (log)
597 log->Error ("failed to parse DWARF line table prologue");
598 // Restore our offset and return false to indicate failure!
599 *offset_ptr = debug_line_offset;
600 return false;
601 }
602
603 if (log)
604 prologue->Dump (log);
605
606 const dw_offset_t end_offset = debug_line_offset + prologue->total_length + (debug_line_data.GetDWARFSizeofInitialLength());
607
608 State state(prologue, log, callback, userData);
609
610 while (*offset_ptr < end_offset)
611 {
612 //DEBUG_PRINTF("0x%8.8x: ", *offset_ptr);
613 uint8_t opcode = debug_line_data.GetU8(offset_ptr);
614
615 if (opcode == 0)
616 {
617 // Extended Opcodes always start with a zero opcode followed by
618 // a uleb128 length so you can skip ones you don't know about
619 lldb::offset_t ext_offset = *offset_ptr;
620 dw_uleb128_t len = debug_line_data.GetULEB128(offset_ptr);
621 dw_offset_t arg_size = len - (*offset_ptr - ext_offset);
622
623 //DEBUG_PRINTF("Extended: <%2u> ", len);
624 uint8_t sub_opcode = debug_line_data.GetU8(offset_ptr);
625 switch (sub_opcode)
626 {
627 case DW_LNE_end_sequence:
628 // Set the end_sequence register of the state machine to true and
629 // append a row to the matrix using the current values of the
630 // state-machine registers. Then reset the registers to the initial
631 // values specified above. Every statement program sequence must end
632 // with a DW_LNE_end_sequence instruction which creates a row whose
633 // address is that of the byte after the last target machine instruction
634 // of the sequence.
635 state.end_sequence = true;
636 state.AppendRowToMatrix(*offset_ptr);
637 state.Reset();
638 break;
639
640 case DW_LNE_set_address:
641 // Takes a single relocatable address as an operand. The size of the
642 // operand is the size appropriate to hold an address on the target
643 // machine. Set the address register to the value given by the
644 // relocatable address. All of the other statement program opcodes
645 // that affect the address register add a delta to it. This instruction
646 // stores a relocatable value into it instead.
647 state.address = debug_line_data.GetAddress(offset_ptr);
648 break;
649
650 case DW_LNE_define_file:
651 // Takes 4 arguments. The first is a null terminated string containing
652 // a source file name. The second is an unsigned LEB128 number representing
653 // the directory index of the directory in which the file was found. The
654 // third is an unsigned LEB128 number representing the time of last
655 // modification of the file. The fourth is an unsigned LEB128 number
656 // representing the length in bytes of the file. The time and length
657 // fields may contain LEB128(0) if the information is not available.
658 //
659 // The directory index represents an entry in the include_directories
660 // section of the statement program prologue. The index is LEB128(0)
661 // if the file was found in the current directory of the compilation,
662 // LEB128(1) if it was found in the first directory in the
663 // include_directories section, and so on. The directory index is
664 // ignored for file names that represent full path names.
665 //
666 // The files are numbered, starting at 1, in the order in which they
667 // appear; the names in the prologue come before names defined by
668 // the DW_LNE_define_file instruction. These numbers are used in the
669 // the file register of the state machine.
670 {
671 FileNameEntry fileEntry;
672 fileEntry.name = debug_line_data.GetCStr(offset_ptr);
673 fileEntry.dir_idx = debug_line_data.GetULEB128(offset_ptr);
674 fileEntry.mod_time = debug_line_data.GetULEB128(offset_ptr);
675 fileEntry.length = debug_line_data.GetULEB128(offset_ptr);
676 state.prologue->file_names.push_back(fileEntry);
677 }
678 break;
679
680 default:
681 // Length doesn't include the zero opcode byte or the length itself, but
682 // it does include the sub_opcode, so we have to adjust for that below
683 (*offset_ptr) += arg_size;
684 break;
685 }
686 }
687 else if (opcode < prologue->opcode_base)
688 {
689 switch (opcode)
690 {
691 // Standard Opcodes
692 case DW_LNS_copy:
693 // Takes no arguments. Append a row to the matrix using the
694 // current values of the state-machine registers. Then set
695 // the basic_block register to false.
696 state.AppendRowToMatrix(*offset_ptr);
697 break;
698
699 case DW_LNS_advance_pc:
700 // Takes a single unsigned LEB128 operand, multiplies it by the
701 // min_inst_length field of the prologue, and adds the
702 // result to the address register of the state machine.
703 state.address += debug_line_data.GetULEB128(offset_ptr) * prologue->min_inst_length;
704 break;
705
706 case DW_LNS_advance_line:
707 // Takes a single signed LEB128 operand and adds that value to
708 // the line register of the state machine.
709 state.line += debug_line_data.GetSLEB128(offset_ptr);
710 break;
711
712 case DW_LNS_set_file:
713 // Takes a single unsigned LEB128 operand and stores it in the file
714 // register of the state machine.
715 state.file = debug_line_data.GetULEB128(offset_ptr);
716 break;
717
718 case DW_LNS_set_column:
719 // Takes a single unsigned LEB128 operand and stores it in the
720 // column register of the state machine.
721 state.column = debug_line_data.GetULEB128(offset_ptr);
722 break;
723
724 case DW_LNS_negate_stmt:
725 // Takes no arguments. Set the is_stmt register of the state
726 // machine to the logical negation of its current value.
727 state.is_stmt = !state.is_stmt;
728 break;
729
730 case DW_LNS_set_basic_block:
731 // Takes no arguments. Set the basic_block register of the
732 // state machine to true
733 state.basic_block = true;
734 break;
735
736 case DW_LNS_const_add_pc:
737 // Takes no arguments. Add to the address register of the state
738 // machine the address increment value corresponding to special
739 // opcode 255. The motivation for DW_LNS_const_add_pc is this:
740 // when the statement program needs to advance the address by a
741 // small amount, it can use a single special opcode, which occupies
742 // a single byte. When it needs to advance the address by up to
743 // twice the range of the last special opcode, it can use
744 // DW_LNS_const_add_pc followed by a special opcode, for a total
745 // of two bytes. Only if it needs to advance the address by more
746 // than twice that range will it need to use both DW_LNS_advance_pc
747 // and a special opcode, requiring three or more bytes.
748 {
749 uint8_t adjust_opcode = 255 - prologue->opcode_base;
750 dw_addr_t addr_offset = (adjust_opcode / prologue->line_range) * prologue->min_inst_length;
751 state.address += addr_offset;
752 }
753 break;
754
755 case DW_LNS_fixed_advance_pc:
756 // Takes a single uhalf operand. Add to the address register of
757 // the state machine the value of the (unencoded) operand. This
758 // is the only extended opcode that takes an argument that is not
759 // a variable length number. The motivation for DW_LNS_fixed_advance_pc
760 // is this: existing assemblers cannot emit DW_LNS_advance_pc or
761 // special opcodes because they cannot encode LEB128 numbers or
762 // judge when the computation of a special opcode overflows and
763 // requires the use of DW_LNS_advance_pc. Such assemblers, however,
764 // can use DW_LNS_fixed_advance_pc instead, sacrificing compression.
765 state.address += debug_line_data.GetU16(offset_ptr);
766 break;
767
768 case DW_LNS_set_prologue_end:
769 // Takes no arguments. Set the prologue_end register of the
770 // state machine to true
771 state.prologue_end = true;
772 break;
773
774 case DW_LNS_set_epilogue_begin:
775 // Takes no arguments. Set the basic_block register of the
776 // state machine to true
777 state.epilogue_begin = true;
778 break;
779
780 case DW_LNS_set_isa:
781 // Takes a single unsigned LEB128 operand and stores it in the
782 // column register of the state machine.
783 state.isa = debug_line_data.GetULEB128(offset_ptr);
784 break;
785
786 default:
787 // Handle any unknown standard opcodes here. We know the lengths
788 // of such opcodes because they are specified in the prologue
789 // as a multiple of LEB128 operands for each opcode.
790 {
791 uint8_t i;
792 assert (opcode - 1 < prologue->standard_opcode_lengths.size());
793 const uint8_t opcode_length = prologue->standard_opcode_lengths[opcode - 1];
794 for (i=0; i<opcode_length; ++i)
795 debug_line_data.Skip_LEB128(offset_ptr);
796 }
797 break;
798 }
799 }
800 else
801 {
802 // Special Opcodes
803
804 // A special opcode value is chosen based on the amount that needs
805 // to be added to the line and address registers. The maximum line
806 // increment for a special opcode is the value of the line_base
807 // field in the header, plus the value of the line_range field,
808 // minus 1 (line base + line range - 1). If the desired line
809 // increment is greater than the maximum line increment, a standard
810 // opcode must be used instead of a special opcode. The "address
811 // advance" is calculated by dividing the desired address increment
812 // by the minimum_instruction_length field from the header. The
813 // special opcode is then calculated using the following formula:
814 //
815 // opcode = (desired line increment - line_base) + (line_range * address advance) + opcode_base
816 //
817 // If the resulting opcode is greater than 255, a standard opcode
818 // must be used instead.
819 //
820 // To decode a special opcode, subtract the opcode_base from the
821 // opcode itself to give the adjusted opcode. The amount to
822 // increment the address register is the result of the adjusted
823 // opcode divided by the line_range multiplied by the
824 // minimum_instruction_length field from the header. That is:
825 //
826 // address increment = (adjusted opcode / line_range) * minimum_instruction_length
827 //
828 // The amount to increment the line register is the line_base plus
829 // the result of the adjusted opcode modulo the line_range. That is:
830 //
831 // line increment = line_base + (adjusted opcode % line_range)
832
833 uint8_t adjust_opcode = opcode - prologue->opcode_base;
834 dw_addr_t addr_offset = (adjust_opcode / prologue->line_range) * prologue->min_inst_length;
835 int32_t line_offset = prologue->line_base + (adjust_opcode % prologue->line_range);
836 state.line += line_offset;
837 state.address += addr_offset;
838 state.AppendRowToMatrix(*offset_ptr);
839 }
840 }
841
842 state.Finalize( *offset_ptr );
843
844 return end_offset;
845 }
846
847
848 //----------------------------------------------------------------------
849 // ParseStatementTableCallback
850 //----------------------------------------------------------------------
851 static void
ParseStatementTableCallback(dw_offset_t offset,const DWARFDebugLine::State & state,void * userData)852 ParseStatementTableCallback(dw_offset_t offset, const DWARFDebugLine::State& state, void* userData)
853 {
854 DWARFDebugLine::LineTable* line_table = (DWARFDebugLine::LineTable*)userData;
855 if (state.row == DWARFDebugLine::State::StartParsingLineTable)
856 {
857 // Just started parsing the line table, so lets keep a reference to
858 // the prologue using the supplied shared pointer
859 line_table->prologue = state.prologue;
860 }
861 else if (state.row == DWARFDebugLine::State::DoneParsingLineTable)
862 {
863 // Done parsing line table, nothing to do for the cleanup
864 }
865 else
866 {
867 // We have a new row, lets append it
868 line_table->AppendRow(state);
869 }
870 }
871
872 //----------------------------------------------------------------------
873 // ParseStatementTable
874 //
875 // Parse a line table at offset and populate the LineTable class with
876 // the prologue and all rows.
877 //----------------------------------------------------------------------
878 bool
ParseStatementTable(const DWARFDataExtractor & debug_line_data,lldb::offset_t * offset_ptr,LineTable * line_table)879 DWARFDebugLine::ParseStatementTable(const DWARFDataExtractor& debug_line_data, lldb::offset_t *offset_ptr, LineTable* line_table)
880 {
881 return ParseStatementTable(debug_line_data, offset_ptr, ParseStatementTableCallback, line_table);
882 }
883
884
885 inline bool
IsValid() const886 DWARFDebugLine::Prologue::IsValid() const
887 {
888 return SymbolFileDWARF::SupportedVersion(version);
889 }
890
891 //----------------------------------------------------------------------
892 // DWARFDebugLine::Prologue::Dump
893 //----------------------------------------------------------------------
894 void
Dump(Log * log)895 DWARFDebugLine::Prologue::Dump(Log *log)
896 {
897 uint32_t i;
898
899 log->Printf( "Line table prologue:");
900 log->Printf( " total_length: 0x%8.8x", total_length);
901 log->Printf( " version: %u", version);
902 log->Printf( "prologue_length: 0x%8.8x", prologue_length);
903 log->Printf( "min_inst_length: %u", min_inst_length);
904 log->Printf( "default_is_stmt: %u", default_is_stmt);
905 log->Printf( " line_base: %i", line_base);
906 log->Printf( " line_range: %u", line_range);
907 log->Printf( " opcode_base: %u", opcode_base);
908
909 for (i=0; i<standard_opcode_lengths.size(); ++i)
910 {
911 log->Printf( "standard_opcode_lengths[%s] = %u", DW_LNS_value_to_name(i+1), standard_opcode_lengths[i]);
912 }
913
914 if (!include_directories.empty())
915 {
916 for (i=0; i<include_directories.size(); ++i)
917 {
918 log->Printf( "include_directories[%3u] = '%s'", i+1, include_directories[i].c_str());
919 }
920 }
921
922 if (!file_names.empty())
923 {
924 log->PutCString (" Dir Mod Time File Len File Name");
925 log->PutCString (" ---- ---------- ---------- ---------------------------");
926 for (i=0; i<file_names.size(); ++i)
927 {
928 const FileNameEntry& fileEntry = file_names[i];
929 log->Printf ("file_names[%3u] %4u 0x%8.8x 0x%8.8x %s",
930 i+1,
931 fileEntry.dir_idx,
932 fileEntry.mod_time,
933 fileEntry.length,
934 fileEntry.name.c_str());
935 }
936 }
937 }
938
939
940 //----------------------------------------------------------------------
941 // DWARFDebugLine::ParsePrologue::Append
942 //
943 // Append the contents of the prologue to the binary stream buffer
944 //----------------------------------------------------------------------
945 //void
946 //DWARFDebugLine::Prologue::Append(BinaryStreamBuf& buff) const
947 //{
948 // uint32_t i;
949 //
950 // buff.Append32(total_length);
951 // buff.Append16(version);
952 // buff.Append32(prologue_length);
953 // buff.Append8(min_inst_length);
954 // buff.Append8(default_is_stmt);
955 // buff.Append8(line_base);
956 // buff.Append8(line_range);
957 // buff.Append8(opcode_base);
958 //
959 // for (i=0; i<standard_opcode_lengths.size(); ++i)
960 // buff.Append8(standard_opcode_lengths[i]);
961 //
962 // for (i=0; i<include_directories.size(); ++i)
963 // buff.AppendCStr(include_directories[i].c_str());
964 // buff.Append8(0); // Terminate the include directory section with empty string
965 //
966 // for (i=0; i<file_names.size(); ++i)
967 // {
968 // buff.AppendCStr(file_names[i].name.c_str());
969 // buff.Append32_as_ULEB128(file_names[i].dir_idx);
970 // buff.Append32_as_ULEB128(file_names[i].mod_time);
971 // buff.Append32_as_ULEB128(file_names[i].length);
972 // }
973 // buff.Append8(0); // Terminate the file names section with empty string
974 //}
975
976
GetFile(uint32_t file_idx,std::string & path,std::string & directory) const977 bool DWARFDebugLine::Prologue::GetFile(uint32_t file_idx, std::string& path, std::string& directory) const
978 {
979 uint32_t idx = file_idx - 1; // File indexes are 1 based...
980 if (idx < file_names.size())
981 {
982 path = file_names[idx].name;
983 uint32_t dir_idx = file_names[idx].dir_idx - 1;
984 if (dir_idx < include_directories.size())
985 directory = include_directories[dir_idx];
986 else
987 directory.clear();
988 return true;
989 }
990 return false;
991 }
992
993 //----------------------------------------------------------------------
994 // DWARFDebugLine::LineTable::Dump
995 //----------------------------------------------------------------------
996 void
Dump(Log * log) const997 DWARFDebugLine::LineTable::Dump(Log *log) const
998 {
999 if (prologue.get())
1000 prologue->Dump (log);
1001
1002 if (!rows.empty())
1003 {
1004 log->PutCString ("Address Line Column File ISA Flags");
1005 log->PutCString ("------------------ ------ ------ ------ --- -------------");
1006 Row::const_iterator pos = rows.begin();
1007 Row::const_iterator end = rows.end();
1008 while (pos != end)
1009 {
1010 (*pos).Dump (log);
1011 ++pos;
1012 }
1013 }
1014 }
1015
1016
1017 void
AppendRow(const DWARFDebugLine::Row & state)1018 DWARFDebugLine::LineTable::AppendRow(const DWARFDebugLine::Row& state)
1019 {
1020 rows.push_back(state);
1021 }
1022
1023
1024
1025 //----------------------------------------------------------------------
1026 // Compare function for the binary search in DWARFDebugLine::LineTable::LookupAddress()
1027 //----------------------------------------------------------------------
FindMatchingAddress(const DWARFDebugLine::Row & row1,const DWARFDebugLine::Row & row2)1028 static bool FindMatchingAddress (const DWARFDebugLine::Row& row1, const DWARFDebugLine::Row& row2)
1029 {
1030 return row1.address < row2.address;
1031 }
1032
1033
1034 //----------------------------------------------------------------------
1035 // DWARFDebugLine::LineTable::LookupAddress
1036 //----------------------------------------------------------------------
1037 uint32_t
LookupAddress(dw_addr_t address,dw_addr_t cu_high_pc) const1038 DWARFDebugLine::LineTable::LookupAddress(dw_addr_t address, dw_addr_t cu_high_pc) const
1039 {
1040 uint32_t index = UINT32_MAX;
1041 if (!rows.empty())
1042 {
1043 // Use the lower_bound algorithm to perform a binary search since we know
1044 // that our line table data is ordered by address.
1045 DWARFDebugLine::Row row;
1046 row.address = address;
1047 Row::const_iterator begin_pos = rows.begin();
1048 Row::const_iterator end_pos = rows.end();
1049 Row::const_iterator pos = lower_bound(begin_pos, end_pos, row, FindMatchingAddress);
1050 if (pos == end_pos)
1051 {
1052 if (address < cu_high_pc)
1053 return rows.size()-1;
1054 }
1055 else
1056 {
1057 // Rely on fact that we are using a std::vector and we can do
1058 // pointer arithmetic to find the row index (which will be one less
1059 // that what we found since it will find the first position after
1060 // the current address) since std::vector iterators are just
1061 // pointers to the container type.
1062 index = pos - begin_pos;
1063 if (pos->address > address)
1064 {
1065 if (index > 0)
1066 --index;
1067 else
1068 index = UINT32_MAX;
1069 }
1070 }
1071 }
1072 return index; // Failed to find address
1073 }
1074
1075
1076 //----------------------------------------------------------------------
1077 // DWARFDebugLine::Row::Row
1078 //----------------------------------------------------------------------
Row(bool default_is_stmt)1079 DWARFDebugLine::Row::Row(bool default_is_stmt) :
1080 address(0),
1081 line(1),
1082 column(0),
1083 file(1),
1084 is_stmt(default_is_stmt),
1085 basic_block(false),
1086 end_sequence(false),
1087 prologue_end(false),
1088 epilogue_begin(false),
1089 isa(0)
1090 {
1091 }
1092
1093 //----------------------------------------------------------------------
1094 // Called after a row is appended to the matrix
1095 //----------------------------------------------------------------------
1096 void
PostAppend()1097 DWARFDebugLine::Row::PostAppend()
1098 {
1099 basic_block = false;
1100 prologue_end = false;
1101 epilogue_begin = false;
1102 }
1103
1104
1105 //----------------------------------------------------------------------
1106 // DWARFDebugLine::Row::Reset
1107 //----------------------------------------------------------------------
1108 void
Reset(bool default_is_stmt)1109 DWARFDebugLine::Row::Reset(bool default_is_stmt)
1110 {
1111 address = 0;
1112 line = 1;
1113 column = 0;
1114 file = 1;
1115 is_stmt = default_is_stmt;
1116 basic_block = false;
1117 end_sequence = false;
1118 prologue_end = false;
1119 epilogue_begin = false;
1120 isa = 0;
1121 }
1122 //----------------------------------------------------------------------
1123 // DWARFDebugLine::Row::Dump
1124 //----------------------------------------------------------------------
1125 void
Dump(Log * log) const1126 DWARFDebugLine::Row::Dump(Log *log) const
1127 {
1128 log->Printf( "0x%16.16" PRIx64 " %6u %6u %6u %3u %s%s%s%s%s",
1129 address,
1130 line,
1131 column,
1132 file,
1133 isa,
1134 is_stmt ? " is_stmt" : "",
1135 basic_block ? " basic_block" : "",
1136 prologue_end ? " prologue_end" : "",
1137 epilogue_begin ? " epilogue_begin" : "",
1138 end_sequence ? " end_sequence" : "");
1139 }
1140
1141 //----------------------------------------------------------------------
1142 // Compare function LineTable structures
1143 //----------------------------------------------------------------------
AddressLessThan(const DWARFDebugLine::Row & a,const DWARFDebugLine::Row & b)1144 static bool AddressLessThan (const DWARFDebugLine::Row& a, const DWARFDebugLine::Row& b)
1145 {
1146 return a.address < b.address;
1147 }
1148
1149
1150
1151 // Insert a row at the correct address if the addresses can be out of
1152 // order which can only happen when we are linking a line table that
1153 // may have had it's contents rearranged.
1154 void
Insert(Row::collection & state_coll,const Row & state)1155 DWARFDebugLine::Row::Insert(Row::collection& state_coll, const Row& state)
1156 {
1157 // If we don't have anything yet, or if the address of the last state in our
1158 // line table is less than the current one, just append the current state
1159 if (state_coll.empty() || AddressLessThan(state_coll.back(), state))
1160 {
1161 state_coll.push_back(state);
1162 }
1163 else
1164 {
1165 // Do a binary search for the correct entry
1166 pair<Row::iterator, Row::iterator> range(equal_range(state_coll.begin(), state_coll.end(), state, AddressLessThan));
1167
1168 // If the addresses are equal, we can safely replace the previous entry
1169 // with the current one if the one it is replacing is an end_sequence entry.
1170 // We currently always place an extra end sequence when ever we exit a valid
1171 // address range for a function in case the functions get rearranged by
1172 // optimizations or by order specifications. These extra end sequences will
1173 // disappear by getting replaced with valid consecutive entries within a
1174 // compile unit if there are no gaps.
1175 if (range.first == range.second)
1176 {
1177 state_coll.insert(range.first, state);
1178 }
1179 else
1180 {
1181 if ((distance(range.first, range.second) == 1) && range.first->end_sequence == true)
1182 {
1183 *range.first = state;
1184 }
1185 else
1186 {
1187 state_coll.insert(range.second, state);
1188 }
1189 }
1190 }
1191 }
1192
1193 void
Dump(Log * log,const Row::collection & state_coll)1194 DWARFDebugLine::Row::Dump(Log *log, const Row::collection& state_coll)
1195 {
1196 std::for_each (state_coll.begin(), state_coll.end(), bind2nd(std::mem_fun_ref(&Row::Dump),log));
1197 }
1198
1199
1200 //----------------------------------------------------------------------
1201 // DWARFDebugLine::State::State
1202 //----------------------------------------------------------------------
State(Prologue::shared_ptr & p,Log * l,DWARFDebugLine::State::Callback cb,void * userData)1203 DWARFDebugLine::State::State(Prologue::shared_ptr& p, Log *l, DWARFDebugLine::State::Callback cb, void* userData) :
1204 Row (p->default_is_stmt),
1205 prologue (p),
1206 log (l),
1207 callback (cb),
1208 callbackUserData (userData),
1209 row (StartParsingLineTable)
1210 {
1211 // Call the callback with the initial row state of zero for the prologue
1212 if (callback)
1213 callback(0, *this, callbackUserData);
1214 }
1215
1216 //----------------------------------------------------------------------
1217 // DWARFDebugLine::State::Reset
1218 //----------------------------------------------------------------------
1219 void
Reset()1220 DWARFDebugLine::State::Reset()
1221 {
1222 Row::Reset(prologue->default_is_stmt);
1223 }
1224
1225 //----------------------------------------------------------------------
1226 // DWARFDebugLine::State::AppendRowToMatrix
1227 //----------------------------------------------------------------------
1228 void
AppendRowToMatrix(dw_offset_t offset)1229 DWARFDebugLine::State::AppendRowToMatrix(dw_offset_t offset)
1230 {
1231 // Each time we are to add an entry into the line table matrix
1232 // call the callback function so that someone can do something with
1233 // the current state of the state machine (like build a line table
1234 // or dump the line table!)
1235 if (log)
1236 {
1237 if (row == 0)
1238 {
1239 log->PutCString ("Address Line Column File ISA Flags");
1240 log->PutCString ("------------------ ------ ------ ------ --- -------------");
1241 }
1242 Dump (log);
1243 }
1244
1245 ++row; // Increase the row number before we call our callback for a real row
1246 if (callback)
1247 callback(offset, *this, callbackUserData);
1248 PostAppend();
1249 }
1250
1251 //----------------------------------------------------------------------
1252 // DWARFDebugLine::State::Finalize
1253 //----------------------------------------------------------------------
1254 void
Finalize(dw_offset_t offset)1255 DWARFDebugLine::State::Finalize(dw_offset_t offset)
1256 {
1257 // Call the callback with a special row state when we are done parsing a
1258 // line table
1259 row = DoneParsingLineTable;
1260 if (callback)
1261 callback(offset, *this, callbackUserData);
1262 }
1263
1264 //void
1265 //DWARFDebugLine::AppendLineTableData
1266 //(
1267 // const DWARFDebugLine::Prologue* prologue,
1268 // const DWARFDebugLine::Row::collection& state_coll,
1269 // const uint32_t addr_size,
1270 // BinaryStreamBuf &debug_line_data
1271 //)
1272 //{
1273 // if (state_coll.empty())
1274 // {
1275 // // We have no entries, just make an empty line table
1276 // debug_line_data.Append8(0);
1277 // debug_line_data.Append8(1);
1278 // debug_line_data.Append8(DW_LNE_end_sequence);
1279 // }
1280 // else
1281 // {
1282 // DWARFDebugLine::Row::const_iterator pos;
1283 // Row::const_iterator end = state_coll.end();
1284 // bool default_is_stmt = prologue->default_is_stmt;
1285 // const DWARFDebugLine::Row reset_state(default_is_stmt);
1286 // const DWARFDebugLine::Row* prev_state = &reset_state;
1287 // const int32_t max_line_increment_for_special_opcode = prologue->MaxLineIncrementForSpecialOpcode();
1288 // for (pos = state_coll.begin(); pos != end; ++pos)
1289 // {
1290 // const DWARFDebugLine::Row& curr_state = *pos;
1291 // int32_t line_increment = 0;
1292 // dw_addr_t addr_offset = curr_state.address - prev_state->address;
1293 // dw_addr_t addr_advance = (addr_offset) / prologue->min_inst_length;
1294 // line_increment = (int32_t)(curr_state.line - prev_state->line);
1295 //
1296 // // If our previous state was the reset state, then let's emit the
1297 // // address to keep GDB's DWARF parser happy. If we don't start each
1298 // // sequence with a DW_LNE_set_address opcode, the line table won't
1299 // // get slid properly in GDB.
1300 //
1301 // if (prev_state == &reset_state)
1302 // {
1303 // debug_line_data.Append8(0); // Extended opcode
1304 // debug_line_data.Append32_as_ULEB128(addr_size + 1); // Length of opcode bytes
1305 // debug_line_data.Append8(DW_LNE_set_address);
1306 // debug_line_data.AppendMax64(curr_state.address, addr_size);
1307 // addr_advance = 0;
1308 // }
1309 //
1310 // if (prev_state->file != curr_state.file)
1311 // {
1312 // debug_line_data.Append8(DW_LNS_set_file);
1313 // debug_line_data.Append32_as_ULEB128(curr_state.file);
1314 // }
1315 //
1316 // if (prev_state->column != curr_state.column)
1317 // {
1318 // debug_line_data.Append8(DW_LNS_set_column);
1319 // debug_line_data.Append32_as_ULEB128(curr_state.column);
1320 // }
1321 //
1322 // // Don't do anything fancy if we are at the end of a sequence
1323 // // as we don't want to push any extra rows since the DW_LNE_end_sequence
1324 // // will push a row itself!
1325 // if (curr_state.end_sequence)
1326 // {
1327 // if (line_increment != 0)
1328 // {
1329 // debug_line_data.Append8(DW_LNS_advance_line);
1330 // debug_line_data.Append32_as_SLEB128(line_increment);
1331 // }
1332 //
1333 // if (addr_advance > 0)
1334 // {
1335 // debug_line_data.Append8(DW_LNS_advance_pc);
1336 // debug_line_data.Append32_as_ULEB128(addr_advance);
1337 // }
1338 //
1339 // // Now push the end sequence on!
1340 // debug_line_data.Append8(0);
1341 // debug_line_data.Append8(1);
1342 // debug_line_data.Append8(DW_LNE_end_sequence);
1343 //
1344 // prev_state = &reset_state;
1345 // }
1346 // else
1347 // {
1348 // if (line_increment || addr_advance)
1349 // {
1350 // if (line_increment > max_line_increment_for_special_opcode)
1351 // {
1352 // debug_line_data.Append8(DW_LNS_advance_line);
1353 // debug_line_data.Append32_as_SLEB128(line_increment);
1354 // line_increment = 0;
1355 // }
1356 //
1357 // uint32_t special_opcode = (line_increment >= prologue->line_base) ? ((line_increment - prologue->line_base) + (prologue->line_range * addr_advance) + prologue->opcode_base) : 256;
1358 // if (special_opcode > 255)
1359 // {
1360 // // Both the address and line won't fit in one special opcode
1361 // // check to see if just the line advance will?
1362 // uint32_t special_opcode_line = ((line_increment >= prologue->line_base) && (line_increment != 0)) ?
1363 // ((line_increment - prologue->line_base) + prologue->opcode_base) : 256;
1364 //
1365 //
1366 // if (special_opcode_line > 255)
1367 // {
1368 // // Nope, the line advance won't fit by itself, check the address increment by itself
1369 // uint32_t special_opcode_addr = addr_advance ?
1370 // ((0 - prologue->line_base) + (prologue->line_range * addr_advance) + prologue->opcode_base) : 256;
1371 //
1372 // if (special_opcode_addr > 255)
1373 // {
1374 // // Neither the address nor the line will fit in a
1375 // // special opcode, we must manually enter both then
1376 // // do a DW_LNS_copy to push a row (special opcode
1377 // // automatically imply a new row is pushed)
1378 // if (line_increment != 0)
1379 // {
1380 // debug_line_data.Append8(DW_LNS_advance_line);
1381 // debug_line_data.Append32_as_SLEB128(line_increment);
1382 // }
1383 //
1384 // if (addr_advance > 0)
1385 // {
1386 // debug_line_data.Append8(DW_LNS_advance_pc);
1387 // debug_line_data.Append32_as_ULEB128(addr_advance);
1388 // }
1389 //
1390 // // Now push a row onto the line table manually
1391 // debug_line_data.Append8(DW_LNS_copy);
1392 //
1393 // }
1394 // else
1395 // {
1396 // // The address increment alone will fit into a special opcode
1397 // // so modify our line change, then issue a special opcode
1398 // // for the address increment and it will push a row into the
1399 // // line table
1400 // if (line_increment != 0)
1401 // {
1402 // debug_line_data.Append8(DW_LNS_advance_line);
1403 // debug_line_data.Append32_as_SLEB128(line_increment);
1404 // }
1405 //
1406 // // Advance of line and address will fit into a single byte special opcode
1407 // // and this will also push a row onto the line table
1408 // debug_line_data.Append8(special_opcode_addr);
1409 // }
1410 // }
1411 // else
1412 // {
1413 // // The line change alone will fit into a special opcode
1414 // // so modify our address increment first, then issue a
1415 // // special opcode for the line change and it will push
1416 // // a row into the line table
1417 // if (addr_advance > 0)
1418 // {
1419 // debug_line_data.Append8(DW_LNS_advance_pc);
1420 // debug_line_data.Append32_as_ULEB128(addr_advance);
1421 // }
1422 //
1423 // // Advance of line and address will fit into a single byte special opcode
1424 // // and this will also push a row onto the line table
1425 // debug_line_data.Append8(special_opcode_line);
1426 // }
1427 // }
1428 // else
1429 // {
1430 // // Advance of line and address will fit into a single byte special opcode
1431 // // and this will also push a row onto the line table
1432 // debug_line_data.Append8(special_opcode);
1433 // }
1434 // }
1435 // prev_state = &curr_state;
1436 // }
1437 // }
1438 // }
1439 //}
1440