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223e47cc LB |
1 | //===- lib/MC/MCDwarf.cpp - MCDwarf implementation ------------------------===// |
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 "llvm/MC/MCDwarf.h" | |
970d7e83 | 11 | #include "llvm/ADT/Hashing.h" |
1a4d82fc | 12 | #include "llvm/ADT/STLExtras.h" |
970d7e83 LB |
13 | #include "llvm/ADT/SmallString.h" |
14 | #include "llvm/ADT/Twine.h" | |
15 | #include "llvm/Config/config.h" | |
223e47cc LB |
16 | #include "llvm/MC/MCAsmInfo.h" |
17 | #include "llvm/MC/MCContext.h" | |
970d7e83 | 18 | #include "llvm/MC/MCExpr.h" |
223e47cc | 19 | #include "llvm/MC/MCObjectFileInfo.h" |
1a4d82fc | 20 | #include "llvm/MC/MCObjectStreamer.h" |
223e47cc | 21 | #include "llvm/MC/MCRegisterInfo.h" |
1a4d82fc | 22 | #include "llvm/MC/MCSection.h" |
223e47cc | 23 | #include "llvm/MC/MCSymbol.h" |
223e47cc LB |
24 | #include "llvm/Support/Debug.h" |
25 | #include "llvm/Support/ErrorHandling.h" | |
223e47cc LB |
26 | #include "llvm/Support/LEB128.h" |
27 | #include "llvm/Support/Path.h" | |
28 | #include "llvm/Support/SourceMgr.h" | |
970d7e83 | 29 | #include "llvm/Support/raw_ostream.h" |
223e47cc LB |
30 | using namespace llvm; |
31 | ||
32 | // Given a special op, return the address skip amount (in units of | |
33 | // DWARF2_LINE_MIN_INSN_LENGTH. | |
34 | #define SPECIAL_ADDR(op) (((op) - DWARF2_LINE_OPCODE_BASE)/DWARF2_LINE_RANGE) | |
35 | ||
36 | // The maximum address skip amount that can be encoded with a special op. | |
37 | #define MAX_SPECIAL_ADDR_DELTA SPECIAL_ADDR(255) | |
38 | ||
39 | // First special line opcode - leave room for the standard opcodes. | |
40 | // Note: If you want to change this, you'll have to update the | |
41 | // "standard_opcode_lengths" table that is emitted in DwarfFileTable::Emit(). | |
42 | #define DWARF2_LINE_OPCODE_BASE 13 | |
43 | ||
44 | // Minimum line offset in a special line info. opcode. This value | |
45 | // was chosen to give a reasonable range of values. | |
46 | #define DWARF2_LINE_BASE -5 | |
47 | ||
48 | // Range of line offsets in a special line info. opcode. | |
49 | #define DWARF2_LINE_RANGE 14 | |
50 | ||
1a4d82fc JJ |
51 | static inline uint64_t ScaleAddrDelta(MCContext &Context, uint64_t AddrDelta) { |
52 | unsigned MinInsnLength = Context.getAsmInfo()->getMinInstAlignment(); | |
53 | if (MinInsnLength == 1) | |
223e47cc | 54 | return AddrDelta; |
1a4d82fc | 55 | if (AddrDelta % MinInsnLength != 0) { |
223e47cc LB |
56 | // TODO: report this error, but really only once. |
57 | ; | |
58 | } | |
1a4d82fc | 59 | return AddrDelta / MinInsnLength; |
223e47cc LB |
60 | } |
61 | ||
62 | // | |
63 | // This is called when an instruction is assembled into the specified section | |
64 | // and if there is information from the last .loc directive that has yet to have | |
65 | // a line entry made for it is made. | |
66 | // | |
1a4d82fc | 67 | void MCLineEntry::Make(MCObjectStreamer *MCOS, const MCSection *Section) { |
223e47cc LB |
68 | if (!MCOS->getContext().getDwarfLocSeen()) |
69 | return; | |
70 | ||
71 | // Create a symbol at in the current section for use in the line entry. | |
72 | MCSymbol *LineSym = MCOS->getContext().CreateTempSymbol(); | |
73 | // Set the value of the symbol to use for the MCLineEntry. | |
74 | MCOS->EmitLabel(LineSym); | |
75 | ||
76 | // Get the current .loc info saved in the context. | |
77 | const MCDwarfLoc &DwarfLoc = MCOS->getContext().getCurrentDwarfLoc(); | |
78 | ||
79 | // Create a (local) line entry with the symbol and the current .loc info. | |
80 | MCLineEntry LineEntry(LineSym, DwarfLoc); | |
81 | ||
82 | // clear DwarfLocSeen saying the current .loc info is now used. | |
83 | MCOS->getContext().ClearDwarfLocSeen(); | |
84 | ||
223e47cc | 85 | // Add the line entry to this section's entries. |
1a4d82fc JJ |
86 | MCOS->getContext() |
87 | .getMCDwarfLineTable(MCOS->getContext().getDwarfCompileUnitID()) | |
88 | .getMCLineSections() | |
89 | .addLineEntry(LineEntry, Section); | |
223e47cc LB |
90 | } |
91 | ||
92 | // | |
93 | // This helper routine returns an expression of End - Start + IntVal . | |
94 | // | |
95 | static inline const MCExpr *MakeStartMinusEndExpr(const MCStreamer &MCOS, | |
96 | const MCSymbol &Start, | |
97 | const MCSymbol &End, | |
98 | int IntVal) { | |
99 | MCSymbolRefExpr::VariantKind Variant = MCSymbolRefExpr::VK_None; | |
100 | const MCExpr *Res = | |
101 | MCSymbolRefExpr::Create(&End, Variant, MCOS.getContext()); | |
102 | const MCExpr *RHS = | |
103 | MCSymbolRefExpr::Create(&Start, Variant, MCOS.getContext()); | |
104 | const MCExpr *Res1 = | |
105 | MCBinaryExpr::Create(MCBinaryExpr::Sub, Res, RHS, MCOS.getContext()); | |
106 | const MCExpr *Res2 = | |
107 | MCConstantExpr::Create(IntVal, MCOS.getContext()); | |
108 | const MCExpr *Res3 = | |
109 | MCBinaryExpr::Create(MCBinaryExpr::Sub, Res1, Res2, MCOS.getContext()); | |
110 | return Res3; | |
111 | } | |
112 | ||
113 | // | |
114 | // This emits the Dwarf line table for the specified section from the entries | |
115 | // in the LineSection. | |
116 | // | |
1a4d82fc JJ |
117 | static inline void |
118 | EmitDwarfLineTable(MCObjectStreamer *MCOS, const MCSection *Section, | |
119 | const MCLineSection::MCLineEntryCollection &LineEntries) { | |
223e47cc LB |
120 | unsigned FileNum = 1; |
121 | unsigned LastLine = 1; | |
122 | unsigned Column = 0; | |
123 | unsigned Flags = DWARF2_LINE_DEFAULT_IS_STMT ? DWARF2_FLAG_IS_STMT : 0; | |
124 | unsigned Isa = 0; | |
1a4d82fc JJ |
125 | unsigned Discriminator = 0; |
126 | MCSymbol *LastLabel = nullptr; | |
223e47cc LB |
127 | |
128 | // Loop through each MCLineEntry and encode the dwarf line number table. | |
1a4d82fc JJ |
129 | for (auto it = LineEntries.begin(), |
130 | ie = LineEntries.end(); | |
131 | it != ie; ++it) { | |
223e47cc LB |
132 | |
133 | if (FileNum != it->getFileNum()) { | |
134 | FileNum = it->getFileNum(); | |
135 | MCOS->EmitIntValue(dwarf::DW_LNS_set_file, 1); | |
136 | MCOS->EmitULEB128IntValue(FileNum); | |
137 | } | |
138 | if (Column != it->getColumn()) { | |
139 | Column = it->getColumn(); | |
140 | MCOS->EmitIntValue(dwarf::DW_LNS_set_column, 1); | |
141 | MCOS->EmitULEB128IntValue(Column); | |
142 | } | |
1a4d82fc JJ |
143 | if (Discriminator != it->getDiscriminator()) { |
144 | Discriminator = it->getDiscriminator(); | |
145 | unsigned Size = getULEB128Size(Discriminator); | |
146 | MCOS->EmitIntValue(dwarf::DW_LNS_extended_op, 1); | |
147 | MCOS->EmitULEB128IntValue(Size + 1); | |
148 | MCOS->EmitIntValue(dwarf::DW_LNE_set_discriminator, 1); | |
149 | MCOS->EmitULEB128IntValue(Discriminator); | |
150 | } | |
223e47cc LB |
151 | if (Isa != it->getIsa()) { |
152 | Isa = it->getIsa(); | |
153 | MCOS->EmitIntValue(dwarf::DW_LNS_set_isa, 1); | |
154 | MCOS->EmitULEB128IntValue(Isa); | |
155 | } | |
156 | if ((it->getFlags() ^ Flags) & DWARF2_FLAG_IS_STMT) { | |
157 | Flags = it->getFlags(); | |
158 | MCOS->EmitIntValue(dwarf::DW_LNS_negate_stmt, 1); | |
159 | } | |
160 | if (it->getFlags() & DWARF2_FLAG_BASIC_BLOCK) | |
161 | MCOS->EmitIntValue(dwarf::DW_LNS_set_basic_block, 1); | |
162 | if (it->getFlags() & DWARF2_FLAG_PROLOGUE_END) | |
163 | MCOS->EmitIntValue(dwarf::DW_LNS_set_prologue_end, 1); | |
164 | if (it->getFlags() & DWARF2_FLAG_EPILOGUE_BEGIN) | |
165 | MCOS->EmitIntValue(dwarf::DW_LNS_set_epilogue_begin, 1); | |
166 | ||
167 | int64_t LineDelta = static_cast<int64_t>(it->getLine()) - LastLine; | |
168 | MCSymbol *Label = it->getLabel(); | |
169 | ||
170 | // At this point we want to emit/create the sequence to encode the delta in | |
171 | // line numbers and the increment of the address from the previous Label | |
172 | // and the current Label. | |
1a4d82fc | 173 | const MCAsmInfo *asmInfo = MCOS->getContext().getAsmInfo(); |
223e47cc | 174 | MCOS->EmitDwarfAdvanceLineAddr(LineDelta, LastLabel, Label, |
1a4d82fc | 175 | asmInfo->getPointerSize()); |
223e47cc LB |
176 | |
177 | LastLine = it->getLine(); | |
178 | LastLabel = Label; | |
179 | } | |
180 | ||
181 | // Emit a DW_LNE_end_sequence for the end of the section. | |
182 | // Using the pointer Section create a temporary label at the end of the | |
183 | // section and use that and the LastLabel to compute the address delta | |
184 | // and use INT64_MAX as the line delta which is the signal that this is | |
185 | // actually a DW_LNE_end_sequence. | |
186 | ||
187 | // Switch to the section to be able to create a symbol at its end. | |
1a4d82fc JJ |
188 | // TODO: keep track of the last subsection so that this symbol appears in the |
189 | // correct place. | |
223e47cc LB |
190 | MCOS->SwitchSection(Section); |
191 | ||
192 | MCContext &context = MCOS->getContext(); | |
193 | // Create a symbol at the end of the section. | |
194 | MCSymbol *SectionEnd = context.CreateTempSymbol(); | |
195 | // Set the value of the symbol, as we are at the end of the section. | |
196 | MCOS->EmitLabel(SectionEnd); | |
197 | ||
198 | // Switch back the dwarf line section. | |
199 | MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfLineSection()); | |
200 | ||
1a4d82fc | 201 | const MCAsmInfo *asmInfo = MCOS->getContext().getAsmInfo(); |
223e47cc | 202 | MCOS->EmitDwarfAdvanceLineAddr(INT64_MAX, LastLabel, SectionEnd, |
1a4d82fc | 203 | asmInfo->getPointerSize()); |
223e47cc LB |
204 | } |
205 | ||
206 | // | |
207 | // This emits the Dwarf file and the line tables. | |
208 | // | |
1a4d82fc | 209 | void MCDwarfLineTable::Emit(MCObjectStreamer *MCOS) { |
223e47cc | 210 | MCContext &context = MCOS->getContext(); |
1a4d82fc JJ |
211 | |
212 | auto &LineTables = context.getMCDwarfLineTables(); | |
213 | ||
214 | // Bail out early so we don't switch to the debug_line section needlessly and | |
215 | // in doing so create an unnecessary (if empty) section. | |
216 | if (LineTables.empty()) | |
217 | return; | |
218 | ||
223e47cc LB |
219 | // Switch to the section where the table will be emitted into. |
220 | MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfLineSection()); | |
221 | ||
970d7e83 | 222 | // Handle the rest of the Compile Units. |
1a4d82fc JJ |
223 | for (const auto &CUIDTablePair : LineTables) |
224 | CUIDTablePair.second.EmitCU(MCOS); | |
225 | } | |
226 | ||
227 | void MCDwarfDwoLineTable::Emit(MCStreamer &MCOS) const { | |
228 | MCOS.EmitLabel(Header.Emit(&MCOS, None).second); | |
229 | } | |
230 | ||
231 | std::pair<MCSymbol *, MCSymbol *> MCDwarfLineTableHeader::Emit(MCStreamer *MCOS) const { | |
232 | static const char StandardOpcodeLengths[] = { | |
233 | 0, // length of DW_LNS_copy | |
234 | 1, // length of DW_LNS_advance_pc | |
235 | 1, // length of DW_LNS_advance_line | |
236 | 1, // length of DW_LNS_set_file | |
237 | 1, // length of DW_LNS_set_column | |
238 | 0, // length of DW_LNS_negate_stmt | |
239 | 0, // length of DW_LNS_set_basic_block | |
240 | 0, // length of DW_LNS_const_add_pc | |
241 | 1, // length of DW_LNS_fixed_advance_pc | |
242 | 0, // length of DW_LNS_set_prologue_end | |
243 | 0, // length of DW_LNS_set_epilogue_begin | |
244 | 1 // DW_LNS_set_isa | |
245 | }; | |
246 | assert(array_lengthof(StandardOpcodeLengths) == (DWARF2_LINE_OPCODE_BASE - 1)); | |
247 | return Emit(MCOS, StandardOpcodeLengths); | |
248 | } | |
249 | ||
250 | static const MCExpr *forceExpAbs(MCStreamer &OS, const MCExpr* Expr) { | |
251 | MCContext &Context = OS.getContext(); | |
252 | assert(!isa<MCSymbolRefExpr>(Expr)); | |
253 | if (Context.getAsmInfo()->hasAggressiveSymbolFolding()) | |
254 | return Expr; | |
255 | ||
256 | MCSymbol *ABS = Context.CreateTempSymbol(); | |
257 | OS.EmitAssignment(ABS, Expr); | |
258 | return MCSymbolRefExpr::Create(ABS, Context); | |
970d7e83 LB |
259 | } |
260 | ||
1a4d82fc JJ |
261 | static void emitAbsValue(MCStreamer &OS, const MCExpr *Value, unsigned Size) { |
262 | const MCExpr *ABS = forceExpAbs(OS, Value); | |
263 | OS.EmitValue(ABS, Size); | |
264 | } | |
265 | ||
266 | std::pair<MCSymbol *, MCSymbol *> | |
267 | MCDwarfLineTableHeader::Emit(MCStreamer *MCOS, | |
268 | ArrayRef<char> StandardOpcodeLengths) const { | |
269 | ||
970d7e83 LB |
270 | MCContext &context = MCOS->getContext(); |
271 | ||
272 | // Create a symbol at the beginning of the line table. | |
1a4d82fc | 273 | MCSymbol *LineStartSym = Label; |
970d7e83 LB |
274 | if (!LineStartSym) |
275 | LineStartSym = context.CreateTempSymbol(); | |
276 | // Set the value of the symbol, as we are at the start of the line table. | |
223e47cc LB |
277 | MCOS->EmitLabel(LineStartSym); |
278 | ||
279 | // Create a symbol for the end of the section (to be set when we get there). | |
280 | MCSymbol *LineEndSym = context.CreateTempSymbol(); | |
281 | ||
282 | // The first 4 bytes is the total length of the information for this | |
283 | // compilation unit (not including these 4 bytes for the length). | |
1a4d82fc JJ |
284 | emitAbsValue(*MCOS, |
285 | MakeStartMinusEndExpr(*MCOS, *LineStartSym, *LineEndSym, 4), 4); | |
223e47cc LB |
286 | |
287 | // Next 2 bytes is the Version, which is Dwarf 2. | |
288 | MCOS->EmitIntValue(2, 2); | |
289 | ||
290 | // Create a symbol for the end of the prologue (to be set when we get there). | |
291 | MCSymbol *ProEndSym = context.CreateTempSymbol(); // Lprologue_end | |
292 | ||
293 | // Length of the prologue, is the next 4 bytes. Which is the start of the | |
294 | // section to the end of the prologue. Not including the 4 bytes for the | |
295 | // total length, the 2 bytes for the version, and these 4 bytes for the | |
296 | // length of the prologue. | |
1a4d82fc JJ |
297 | emitAbsValue( |
298 | *MCOS, | |
299 | MakeStartMinusEndExpr(*MCOS, *LineStartSym, *ProEndSym, (4 + 2 + 4)), 4); | |
223e47cc LB |
300 | |
301 | // Parameters of the state machine, are next. | |
1a4d82fc | 302 | MCOS->EmitIntValue(context.getAsmInfo()->getMinInstAlignment(), 1); |
223e47cc LB |
303 | MCOS->EmitIntValue(DWARF2_LINE_DEFAULT_IS_STMT, 1); |
304 | MCOS->EmitIntValue(DWARF2_LINE_BASE, 1); | |
305 | MCOS->EmitIntValue(DWARF2_LINE_RANGE, 1); | |
1a4d82fc | 306 | MCOS->EmitIntValue(StandardOpcodeLengths.size() + 1, 1); |
223e47cc LB |
307 | |
308 | // Standard opcode lengths | |
1a4d82fc JJ |
309 | for (char Length : StandardOpcodeLengths) |
310 | MCOS->EmitIntValue(Length, 1); | |
223e47cc LB |
311 | |
312 | // Put out the directory and file tables. | |
313 | ||
314 | // First the directory table. | |
223e47cc | 315 | for (unsigned i = 0; i < MCDwarfDirs.size(); i++) { |
970d7e83 LB |
316 | MCOS->EmitBytes(MCDwarfDirs[i]); // the DirectoryName |
317 | MCOS->EmitBytes(StringRef("\0", 1)); // the null term. of the string | |
223e47cc LB |
318 | } |
319 | MCOS->EmitIntValue(0, 1); // Terminate the directory list | |
320 | ||
321 | // Second the file table. | |
223e47cc | 322 | for (unsigned i = 1; i < MCDwarfFiles.size(); i++) { |
1a4d82fc JJ |
323 | assert(!MCDwarfFiles[i].Name.empty()); |
324 | MCOS->EmitBytes(MCDwarfFiles[i].Name); // FileName | |
970d7e83 | 325 | MCOS->EmitBytes(StringRef("\0", 1)); // the null term. of the string |
223e47cc | 326 | // the Directory num |
1a4d82fc | 327 | MCOS->EmitULEB128IntValue(MCDwarfFiles[i].DirIndex); |
223e47cc LB |
328 | MCOS->EmitIntValue(0, 1); // last modification timestamp (always 0) |
329 | MCOS->EmitIntValue(0, 1); // filesize (always 0) | |
330 | } | |
331 | MCOS->EmitIntValue(0, 1); // Terminate the file list | |
332 | ||
333 | // This is the end of the prologue, so set the value of the symbol at the | |
334 | // end of the prologue (that was used in a previous expression). | |
335 | MCOS->EmitLabel(ProEndSym); | |
336 | ||
1a4d82fc JJ |
337 | return std::make_pair(LineStartSym, LineEndSym); |
338 | } | |
339 | ||
340 | void MCDwarfLineTable::EmitCU(MCObjectStreamer *MCOS) const { | |
341 | MCSymbol *LineEndSym = Header.Emit(MCOS).second; | |
342 | ||
223e47cc | 343 | // Put out the line tables. |
1a4d82fc JJ |
344 | for (const auto &LineSec : MCLineSections.getMCLineEntries()) |
345 | EmitDwarfLineTable(MCOS, LineSec.first, LineSec.second); | |
223e47cc | 346 | |
223e47cc LB |
347 | // This is the end of the section, so set the value of the symbol at the end |
348 | // of this section (that was used in a previous expression). | |
349 | MCOS->EmitLabel(LineEndSym); | |
1a4d82fc | 350 | } |
223e47cc | 351 | |
1a4d82fc JJ |
352 | unsigned MCDwarfLineTable::getFile(StringRef &Directory, StringRef &FileName, |
353 | unsigned FileNumber) { | |
354 | return Header.getFile(Directory, FileName, FileNumber); | |
223e47cc LB |
355 | } |
356 | ||
1a4d82fc JJ |
357 | unsigned MCDwarfLineTableHeader::getFile(StringRef &Directory, |
358 | StringRef &FileName, | |
359 | unsigned FileNumber) { | |
360 | if (Directory == CompilationDir) | |
361 | Directory = ""; | |
362 | if (FileName.empty()) { | |
363 | FileName = "<stdin>"; | |
364 | Directory = ""; | |
365 | } | |
366 | assert(!FileName.empty()); | |
367 | if (FileNumber == 0) { | |
368 | FileNumber = SourceIdMap.size() + 1; | |
369 | assert((MCDwarfFiles.empty() || FileNumber == MCDwarfFiles.size()) && | |
370 | "Don't mix autonumbered and explicit numbered line table usage"); | |
85aaf69f SL |
371 | auto IterBool = SourceIdMap.insert( |
372 | std::make_pair((Directory + Twine('\0') + FileName).str(), FileNumber)); | |
373 | if (!IterBool.second) | |
374 | return IterBool.first->second; | |
1a4d82fc JJ |
375 | } |
376 | // Make space for this FileNumber in the MCDwarfFiles vector if needed. | |
377 | MCDwarfFiles.resize(FileNumber + 1); | |
378 | ||
379 | // Get the new MCDwarfFile slot for this FileNumber. | |
380 | MCDwarfFile &File = MCDwarfFiles[FileNumber]; | |
381 | ||
382 | // It is an error to use see the same number more than once. | |
383 | if (!File.Name.empty()) | |
384 | return 0; | |
385 | ||
386 | if (Directory.empty()) { | |
387 | // Separate the directory part from the basename of the FileName. | |
388 | StringRef tFileName = sys::path::filename(FileName); | |
389 | if (!tFileName.empty()) { | |
390 | Directory = sys::path::parent_path(FileName); | |
391 | if (!Directory.empty()) | |
392 | FileName = tFileName; | |
393 | } | |
394 | } | |
395 | ||
396 | // Find or make an entry in the MCDwarfDirs vector for this Directory. | |
397 | // Capture directory name. | |
398 | unsigned DirIndex; | |
399 | if (Directory.empty()) { | |
400 | // For FileNames with no directories a DirIndex of 0 is used. | |
401 | DirIndex = 0; | |
402 | } else { | |
403 | DirIndex = 0; | |
404 | for (unsigned End = MCDwarfDirs.size(); DirIndex < End; DirIndex++) { | |
405 | if (Directory == MCDwarfDirs[DirIndex]) | |
406 | break; | |
407 | } | |
408 | if (DirIndex >= MCDwarfDirs.size()) | |
409 | MCDwarfDirs.push_back(Directory); | |
410 | // The DirIndex is one based, as DirIndex of 0 is used for FileNames with | |
411 | // no directories. MCDwarfDirs[] is unlike MCDwarfFiles[] in that the | |
412 | // directory names are stored at MCDwarfDirs[DirIndex-1] where FileNames | |
413 | // are stored at MCDwarfFiles[FileNumber].Name . | |
414 | DirIndex++; | |
415 | } | |
416 | ||
417 | File.Name = FileName; | |
418 | File.DirIndex = DirIndex; | |
419 | ||
420 | // return the allocated FileNumber. | |
421 | return FileNumber; | |
223e47cc LB |
422 | } |
423 | ||
424 | /// Utility function to emit the encoding to a streamer. | |
425 | void MCDwarfLineAddr::Emit(MCStreamer *MCOS, int64_t LineDelta, | |
426 | uint64_t AddrDelta) { | |
1a4d82fc | 427 | MCContext &Context = MCOS->getContext(); |
223e47cc LB |
428 | SmallString<256> Tmp; |
429 | raw_svector_ostream OS(Tmp); | |
1a4d82fc | 430 | MCDwarfLineAddr::Encode(Context, LineDelta, AddrDelta, OS); |
970d7e83 | 431 | MCOS->EmitBytes(OS.str()); |
223e47cc LB |
432 | } |
433 | ||
434 | /// Utility function to encode a Dwarf pair of LineDelta and AddrDeltas. | |
1a4d82fc JJ |
435 | void MCDwarfLineAddr::Encode(MCContext &Context, int64_t LineDelta, |
436 | uint64_t AddrDelta, raw_ostream &OS) { | |
223e47cc LB |
437 | uint64_t Temp, Opcode; |
438 | bool NeedCopy = false; | |
439 | ||
440 | // Scale the address delta by the minimum instruction length. | |
1a4d82fc | 441 | AddrDelta = ScaleAddrDelta(Context, AddrDelta); |
223e47cc LB |
442 | |
443 | // A LineDelta of INT64_MAX is a signal that this is actually a | |
444 | // DW_LNE_end_sequence. We cannot use special opcodes here, since we want the | |
445 | // end_sequence to emit the matrix entry. | |
446 | if (LineDelta == INT64_MAX) { | |
447 | if (AddrDelta == MAX_SPECIAL_ADDR_DELTA) | |
448 | OS << char(dwarf::DW_LNS_const_add_pc); | |
449 | else { | |
450 | OS << char(dwarf::DW_LNS_advance_pc); | |
451 | encodeULEB128(AddrDelta, OS); | |
452 | } | |
453 | OS << char(dwarf::DW_LNS_extended_op); | |
454 | OS << char(1); | |
455 | OS << char(dwarf::DW_LNE_end_sequence); | |
456 | return; | |
457 | } | |
458 | ||
459 | // Bias the line delta by the base. | |
460 | Temp = LineDelta - DWARF2_LINE_BASE; | |
461 | ||
462 | // If the line increment is out of range of a special opcode, we must encode | |
463 | // it with DW_LNS_advance_line. | |
464 | if (Temp >= DWARF2_LINE_RANGE) { | |
465 | OS << char(dwarf::DW_LNS_advance_line); | |
466 | encodeSLEB128(LineDelta, OS); | |
467 | ||
468 | LineDelta = 0; | |
469 | Temp = 0 - DWARF2_LINE_BASE; | |
470 | NeedCopy = true; | |
471 | } | |
472 | ||
473 | // Use DW_LNS_copy instead of a "line +0, addr +0" special opcode. | |
474 | if (LineDelta == 0 && AddrDelta == 0) { | |
475 | OS << char(dwarf::DW_LNS_copy); | |
476 | return; | |
477 | } | |
478 | ||
479 | // Bias the opcode by the special opcode base. | |
480 | Temp += DWARF2_LINE_OPCODE_BASE; | |
481 | ||
482 | // Avoid overflow when addr_delta is large. | |
483 | if (AddrDelta < 256 + MAX_SPECIAL_ADDR_DELTA) { | |
484 | // Try using a special opcode. | |
485 | Opcode = Temp + AddrDelta * DWARF2_LINE_RANGE; | |
486 | if (Opcode <= 255) { | |
487 | OS << char(Opcode); | |
488 | return; | |
489 | } | |
490 | ||
491 | // Try using DW_LNS_const_add_pc followed by special op. | |
492 | Opcode = Temp + (AddrDelta - MAX_SPECIAL_ADDR_DELTA) * DWARF2_LINE_RANGE; | |
493 | if (Opcode <= 255) { | |
494 | OS << char(dwarf::DW_LNS_const_add_pc); | |
495 | OS << char(Opcode); | |
496 | return; | |
497 | } | |
498 | } | |
499 | ||
500 | // Otherwise use DW_LNS_advance_pc. | |
501 | OS << char(dwarf::DW_LNS_advance_pc); | |
502 | encodeULEB128(AddrDelta, OS); | |
503 | ||
504 | if (NeedCopy) | |
505 | OS << char(dwarf::DW_LNS_copy); | |
506 | else | |
507 | OS << char(Temp); | |
508 | } | |
509 | ||
223e47cc LB |
510 | // Utility function to write a tuple for .debug_abbrev. |
511 | static void EmitAbbrev(MCStreamer *MCOS, uint64_t Name, uint64_t Form) { | |
512 | MCOS->EmitULEB128IntValue(Name); | |
513 | MCOS->EmitULEB128IntValue(Form); | |
514 | } | |
515 | ||
516 | // When generating dwarf for assembly source files this emits | |
517 | // the data for .debug_abbrev section which contains three DIEs. | |
518 | static void EmitGenDwarfAbbrev(MCStreamer *MCOS) { | |
519 | MCContext &context = MCOS->getContext(); | |
520 | MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfAbbrevSection()); | |
521 | ||
522 | // DW_TAG_compile_unit DIE abbrev (1). | |
523 | MCOS->EmitULEB128IntValue(1); | |
524 | MCOS->EmitULEB128IntValue(dwarf::DW_TAG_compile_unit); | |
525 | MCOS->EmitIntValue(dwarf::DW_CHILDREN_yes, 1); | |
526 | EmitAbbrev(MCOS, dwarf::DW_AT_stmt_list, dwarf::DW_FORM_data4); | |
1a4d82fc JJ |
527 | if (MCOS->getContext().getGenDwarfSectionSyms().size() > 1 && |
528 | MCOS->getContext().getDwarfVersion() >= 3) { | |
529 | EmitAbbrev(MCOS, dwarf::DW_AT_ranges, dwarf::DW_FORM_data4); | |
530 | } else { | |
531 | EmitAbbrev(MCOS, dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr); | |
532 | EmitAbbrev(MCOS, dwarf::DW_AT_high_pc, dwarf::DW_FORM_addr); | |
533 | } | |
223e47cc | 534 | EmitAbbrev(MCOS, dwarf::DW_AT_name, dwarf::DW_FORM_string); |
1a4d82fc JJ |
535 | if (!context.getCompilationDir().empty()) |
536 | EmitAbbrev(MCOS, dwarf::DW_AT_comp_dir, dwarf::DW_FORM_string); | |
223e47cc LB |
537 | StringRef DwarfDebugFlags = context.getDwarfDebugFlags(); |
538 | if (!DwarfDebugFlags.empty()) | |
539 | EmitAbbrev(MCOS, dwarf::DW_AT_APPLE_flags, dwarf::DW_FORM_string); | |
540 | EmitAbbrev(MCOS, dwarf::DW_AT_producer, dwarf::DW_FORM_string); | |
541 | EmitAbbrev(MCOS, dwarf::DW_AT_language, dwarf::DW_FORM_data2); | |
542 | EmitAbbrev(MCOS, 0, 0); | |
543 | ||
544 | // DW_TAG_label DIE abbrev (2). | |
545 | MCOS->EmitULEB128IntValue(2); | |
546 | MCOS->EmitULEB128IntValue(dwarf::DW_TAG_label); | |
547 | MCOS->EmitIntValue(dwarf::DW_CHILDREN_yes, 1); | |
548 | EmitAbbrev(MCOS, dwarf::DW_AT_name, dwarf::DW_FORM_string); | |
549 | EmitAbbrev(MCOS, dwarf::DW_AT_decl_file, dwarf::DW_FORM_data4); | |
550 | EmitAbbrev(MCOS, dwarf::DW_AT_decl_line, dwarf::DW_FORM_data4); | |
551 | EmitAbbrev(MCOS, dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr); | |
552 | EmitAbbrev(MCOS, dwarf::DW_AT_prototyped, dwarf::DW_FORM_flag); | |
553 | EmitAbbrev(MCOS, 0, 0); | |
554 | ||
555 | // DW_TAG_unspecified_parameters DIE abbrev (3). | |
556 | MCOS->EmitULEB128IntValue(3); | |
557 | MCOS->EmitULEB128IntValue(dwarf::DW_TAG_unspecified_parameters); | |
558 | MCOS->EmitIntValue(dwarf::DW_CHILDREN_no, 1); | |
559 | EmitAbbrev(MCOS, 0, 0); | |
560 | ||
561 | // Terminate the abbreviations for this compilation unit. | |
562 | MCOS->EmitIntValue(0, 1); | |
563 | } | |
564 | ||
565 | // When generating dwarf for assembly source files this emits the data for | |
1a4d82fc JJ |
566 | // .debug_aranges section. This section contains a header and a table of pairs |
567 | // of PointerSize'ed values for the address and size of section(s) with line | |
568 | // table entries. | |
970d7e83 LB |
569 | static void EmitGenDwarfAranges(MCStreamer *MCOS, |
570 | const MCSymbol *InfoSectionSymbol) { | |
223e47cc LB |
571 | MCContext &context = MCOS->getContext(); |
572 | ||
1a4d82fc | 573 | auto &Sections = context.getGenDwarfSectionSyms(); |
223e47cc LB |
574 | |
575 | MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfARangesSection()); | |
576 | ||
577 | // This will be the length of the .debug_aranges section, first account for | |
578 | // the size of each item in the header (see below where we emit these items). | |
579 | int Length = 4 + 2 + 4 + 1 + 1; | |
580 | ||
581 | // Figure the padding after the header before the table of address and size | |
582 | // pairs who's values are PointerSize'ed. | |
1a4d82fc JJ |
583 | const MCAsmInfo *asmInfo = context.getAsmInfo(); |
584 | int AddrSize = asmInfo->getPointerSize(); | |
223e47cc LB |
585 | int Pad = 2 * AddrSize - (Length & (2 * AddrSize - 1)); |
586 | if (Pad == 2 * AddrSize) | |
587 | Pad = 0; | |
588 | Length += Pad; | |
589 | ||
590 | // Add the size of the pair of PointerSize'ed values for the address and size | |
1a4d82fc JJ |
591 | // of each section we have in the table. |
592 | Length += 2 * AddrSize * Sections.size(); | |
223e47cc LB |
593 | // And the pair of terminating zeros. |
594 | Length += 2 * AddrSize; | |
595 | ||
596 | ||
597 | // Emit the header for this section. | |
598 | // The 4 byte length not including the 4 byte value for the length. | |
599 | MCOS->EmitIntValue(Length - 4, 4); | |
600 | // The 2 byte version, which is 2. | |
601 | MCOS->EmitIntValue(2, 2); | |
602 | // The 4 byte offset to the compile unit in the .debug_info from the start | |
970d7e83 LB |
603 | // of the .debug_info. |
604 | if (InfoSectionSymbol) | |
1a4d82fc JJ |
605 | MCOS->EmitSymbolValue(InfoSectionSymbol, 4, |
606 | asmInfo->needsDwarfSectionOffsetDirective()); | |
970d7e83 LB |
607 | else |
608 | MCOS->EmitIntValue(0, 4); | |
223e47cc LB |
609 | // The 1 byte size of an address. |
610 | MCOS->EmitIntValue(AddrSize, 1); | |
611 | // The 1 byte size of a segment descriptor, we use a value of zero. | |
612 | MCOS->EmitIntValue(0, 1); | |
613 | // Align the header with the padding if needed, before we put out the table. | |
614 | for(int i = 0; i < Pad; i++) | |
615 | MCOS->EmitIntValue(0, 1); | |
616 | ||
1a4d82fc JJ |
617 | // Now emit the table of pairs of PointerSize'ed values for the section |
618 | // addresses and sizes. | |
619 | for (const auto &sec : Sections) { | |
620 | MCSymbol *StartSymbol = sec.second.first; | |
621 | MCSymbol *EndSymbol = sec.second.second; | |
622 | assert(StartSymbol && "StartSymbol must not be NULL"); | |
623 | assert(EndSymbol && "EndSymbol must not be NULL"); | |
624 | ||
625 | const MCExpr *Addr = MCSymbolRefExpr::Create( | |
626 | StartSymbol, MCSymbolRefExpr::VK_None, context); | |
627 | const MCExpr *Size = MakeStartMinusEndExpr(*MCOS, | |
628 | *StartSymbol, *EndSymbol, 0); | |
629 | MCOS->EmitValue(Addr, AddrSize); | |
630 | emitAbsValue(*MCOS, Size, AddrSize); | |
631 | } | |
223e47cc LB |
632 | |
633 | // And finally the pair of terminating zeros. | |
634 | MCOS->EmitIntValue(0, AddrSize); | |
635 | MCOS->EmitIntValue(0, AddrSize); | |
636 | } | |
637 | ||
638 | // When generating dwarf for assembly source files this emits the data for | |
639 | // .debug_info section which contains three parts. The header, the compile_unit | |
640 | // DIE and a list of label DIEs. | |
641 | static void EmitGenDwarfInfo(MCStreamer *MCOS, | |
642 | const MCSymbol *AbbrevSectionSymbol, | |
1a4d82fc JJ |
643 | const MCSymbol *LineSectionSymbol, |
644 | const MCSymbol *RangesSectionSymbol) { | |
223e47cc LB |
645 | MCContext &context = MCOS->getContext(); |
646 | ||
647 | MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfInfoSection()); | |
648 | ||
649 | // Create a symbol at the start and end of this section used in here for the | |
650 | // expression to calculate the length in the header. | |
651 | MCSymbol *InfoStart = context.CreateTempSymbol(); | |
652 | MCOS->EmitLabel(InfoStart); | |
653 | MCSymbol *InfoEnd = context.CreateTempSymbol(); | |
654 | ||
655 | // First part: the header. | |
656 | ||
657 | // The 4 byte total length of the information for this compilation unit, not | |
658 | // including these 4 bytes. | |
659 | const MCExpr *Length = MakeStartMinusEndExpr(*MCOS, *InfoStart, *InfoEnd, 4); | |
1a4d82fc | 660 | emitAbsValue(*MCOS, Length, 4); |
223e47cc | 661 | |
1a4d82fc JJ |
662 | // The 2 byte DWARF version. |
663 | MCOS->EmitIntValue(context.getDwarfVersion(), 2); | |
223e47cc | 664 | |
1a4d82fc | 665 | const MCAsmInfo &AsmInfo = *context.getAsmInfo(); |
223e47cc LB |
666 | // The 4 byte offset to the debug abbrevs from the start of the .debug_abbrev, |
667 | // it is at the start of that section so this is zero. | |
1a4d82fc | 668 | if (AbbrevSectionSymbol == nullptr) |
223e47cc | 669 | MCOS->EmitIntValue(0, 4); |
1a4d82fc JJ |
670 | else |
671 | MCOS->EmitSymbolValue(AbbrevSectionSymbol, 4, | |
672 | AsmInfo.needsDwarfSectionOffsetDirective()); | |
223e47cc | 673 | |
1a4d82fc JJ |
674 | const MCAsmInfo *asmInfo = context.getAsmInfo(); |
675 | int AddrSize = asmInfo->getPointerSize(); | |
223e47cc LB |
676 | // The 1 byte size of an address. |
677 | MCOS->EmitIntValue(AddrSize, 1); | |
678 | ||
679 | // Second part: the compile_unit DIE. | |
680 | ||
681 | // The DW_TAG_compile_unit DIE abbrev (1). | |
682 | MCOS->EmitULEB128IntValue(1); | |
683 | ||
684 | // DW_AT_stmt_list, a 4 byte offset from the start of the .debug_line section, | |
685 | // which is at the start of that section so this is zero. | |
1a4d82fc JJ |
686 | if (LineSectionSymbol) |
687 | MCOS->EmitSymbolValue(LineSectionSymbol, 4, | |
688 | AsmInfo.needsDwarfSectionOffsetDirective()); | |
689 | else | |
223e47cc | 690 | MCOS->EmitIntValue(0, 4); |
223e47cc | 691 | |
1a4d82fc JJ |
692 | if (RangesSectionSymbol) { |
693 | // There are multiple sections containing code, so we must use the | |
694 | // .debug_ranges sections. | |
223e47cc | 695 | |
1a4d82fc JJ |
696 | // AT_ranges, the 4 byte offset from the start of the .debug_ranges section |
697 | // to the address range list for this compilation unit. | |
698 | MCOS->EmitSymbolValue(RangesSectionSymbol, 4); | |
699 | } else { | |
700 | // If we only have one non-empty code section, we can use the simpler | |
701 | // AT_low_pc and AT_high_pc attributes. | |
702 | ||
703 | // Find the first (and only) non-empty text section | |
704 | auto &Sections = context.getGenDwarfSectionSyms(); | |
705 | const auto TextSection = Sections.begin(); | |
706 | assert(TextSection != Sections.end() && "No text section found"); | |
707 | ||
708 | MCSymbol *StartSymbol = TextSection->second.first; | |
709 | MCSymbol *EndSymbol = TextSection->second.second; | |
710 | assert(StartSymbol && "StartSymbol must not be NULL"); | |
711 | assert(EndSymbol && "EndSymbol must not be NULL"); | |
712 | ||
713 | // AT_low_pc, the first address of the default .text section. | |
714 | const MCExpr *Start = MCSymbolRefExpr::Create( | |
715 | StartSymbol, MCSymbolRefExpr::VK_None, context); | |
716 | MCOS->EmitValue(Start, AddrSize); | |
717 | ||
718 | // AT_high_pc, the last address of the default .text section. | |
719 | const MCExpr *End = MCSymbolRefExpr::Create( | |
720 | EndSymbol, MCSymbolRefExpr::VK_None, context); | |
721 | MCOS->EmitValue(End, AddrSize); | |
722 | } | |
223e47cc LB |
723 | |
724 | // AT_name, the name of the source file. Reconstruct from the first directory | |
725 | // and file table entries. | |
1a4d82fc | 726 | const SmallVectorImpl<std::string> &MCDwarfDirs = context.getMCDwarfDirs(); |
223e47cc | 727 | if (MCDwarfDirs.size() > 0) { |
970d7e83 | 728 | MCOS->EmitBytes(MCDwarfDirs[0]); |
1a4d82fc | 729 | MCOS->EmitBytes(sys::path::get_separator()); |
223e47cc | 730 | } |
1a4d82fc | 731 | const SmallVectorImpl<MCDwarfFile> &MCDwarfFiles = |
223e47cc | 732 | MCOS->getContext().getMCDwarfFiles(); |
1a4d82fc | 733 | MCOS->EmitBytes(MCDwarfFiles[1].Name); |
223e47cc LB |
734 | MCOS->EmitIntValue(0, 1); // NULL byte to terminate the string. |
735 | ||
736 | // AT_comp_dir, the working directory the assembly was done in. | |
1a4d82fc JJ |
737 | if (!context.getCompilationDir().empty()) { |
738 | MCOS->EmitBytes(context.getCompilationDir()); | |
739 | MCOS->EmitIntValue(0, 1); // NULL byte to terminate the string. | |
740 | } | |
223e47cc LB |
741 | |
742 | // AT_APPLE_flags, the command line arguments of the assembler tool. | |
743 | StringRef DwarfDebugFlags = context.getDwarfDebugFlags(); | |
744 | if (!DwarfDebugFlags.empty()){ | |
970d7e83 | 745 | MCOS->EmitBytes(DwarfDebugFlags); |
223e47cc LB |
746 | MCOS->EmitIntValue(0, 1); // NULL byte to terminate the string. |
747 | } | |
748 | ||
749 | // AT_producer, the version of the assembler tool. | |
970d7e83 | 750 | StringRef DwarfDebugProducer = context.getDwarfDebugProducer(); |
1a4d82fc | 751 | if (!DwarfDebugProducer.empty()) |
970d7e83 | 752 | MCOS->EmitBytes(DwarfDebugProducer); |
1a4d82fc JJ |
753 | else |
754 | MCOS->EmitBytes(StringRef("llvm-mc (based on LLVM " PACKAGE_VERSION ")")); | |
223e47cc LB |
755 | MCOS->EmitIntValue(0, 1); // NULL byte to terminate the string. |
756 | ||
757 | // AT_language, a 4 byte value. We use DW_LANG_Mips_Assembler as the dwarf2 | |
758 | // draft has no standard code for assembler. | |
759 | MCOS->EmitIntValue(dwarf::DW_LANG_Mips_Assembler, 2); | |
760 | ||
761 | // Third part: the list of label DIEs. | |
762 | ||
763 | // Loop on saved info for dwarf labels and create the DIEs for them. | |
1a4d82fc JJ |
764 | const std::vector<MCGenDwarfLabelEntry> &Entries = |
765 | MCOS->getContext().getMCGenDwarfLabelEntries(); | |
766 | for (const auto &Entry : Entries) { | |
223e47cc LB |
767 | // The DW_TAG_label DIE abbrev (2). |
768 | MCOS->EmitULEB128IntValue(2); | |
769 | ||
770 | // AT_name, of the label without any leading underbar. | |
1a4d82fc | 771 | MCOS->EmitBytes(Entry.getName()); |
223e47cc LB |
772 | MCOS->EmitIntValue(0, 1); // NULL byte to terminate the string. |
773 | ||
774 | // AT_decl_file, index into the file table. | |
1a4d82fc | 775 | MCOS->EmitIntValue(Entry.getFileNumber(), 4); |
223e47cc LB |
776 | |
777 | // AT_decl_line, source line number. | |
1a4d82fc | 778 | MCOS->EmitIntValue(Entry.getLineNumber(), 4); |
223e47cc LB |
779 | |
780 | // AT_low_pc, start address of the label. | |
1a4d82fc | 781 | const MCExpr *AT_low_pc = MCSymbolRefExpr::Create(Entry.getLabel(), |
223e47cc | 782 | MCSymbolRefExpr::VK_None, context); |
1a4d82fc | 783 | MCOS->EmitValue(AT_low_pc, AddrSize); |
223e47cc LB |
784 | |
785 | // DW_AT_prototyped, a one byte flag value of 0 saying we have no prototype. | |
786 | MCOS->EmitIntValue(0, 1); | |
787 | ||
788 | // The DW_TAG_unspecified_parameters DIE abbrev (3). | |
789 | MCOS->EmitULEB128IntValue(3); | |
790 | ||
791 | // Add the NULL DIE terminating the DW_TAG_unspecified_parameters DIE's. | |
792 | MCOS->EmitIntValue(0, 1); | |
793 | } | |
223e47cc LB |
794 | |
795 | // Add the NULL DIE terminating the Compile Unit DIE's. | |
796 | MCOS->EmitIntValue(0, 1); | |
797 | ||
798 | // Now set the value of the symbol at the end of the info section. | |
799 | MCOS->EmitLabel(InfoEnd); | |
800 | } | |
801 | ||
1a4d82fc JJ |
802 | // When generating dwarf for assembly source files this emits the data for |
803 | // .debug_ranges section. We only emit one range list, which spans all of the | |
804 | // executable sections of this file. | |
805 | static void EmitGenDwarfRanges(MCStreamer *MCOS) { | |
806 | MCContext &context = MCOS->getContext(); | |
807 | auto &Sections = context.getGenDwarfSectionSyms(); | |
808 | ||
809 | const MCAsmInfo *AsmInfo = context.getAsmInfo(); | |
810 | int AddrSize = AsmInfo->getPointerSize(); | |
811 | ||
812 | MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfRangesSection()); | |
813 | ||
814 | for (const auto sec : Sections) { | |
815 | ||
816 | MCSymbol *StartSymbol = sec.second.first; | |
817 | MCSymbol *EndSymbol = sec.second.second; | |
818 | assert(StartSymbol && "StartSymbol must not be NULL"); | |
819 | assert(EndSymbol && "EndSymbol must not be NULL"); | |
820 | ||
821 | // Emit a base address selection entry for the start of this section | |
822 | const MCExpr *SectionStartAddr = MCSymbolRefExpr::Create( | |
823 | StartSymbol, MCSymbolRefExpr::VK_None, context); | |
824 | MCOS->EmitFill(AddrSize, 0xFF); | |
825 | MCOS->EmitValue(SectionStartAddr, AddrSize); | |
826 | ||
827 | // Emit a range list entry spanning this section | |
828 | const MCExpr *SectionSize = MakeStartMinusEndExpr(*MCOS, | |
829 | *StartSymbol, *EndSymbol, 0); | |
830 | MCOS->EmitIntValue(0, AddrSize); | |
831 | emitAbsValue(*MCOS, SectionSize, AddrSize); | |
832 | } | |
833 | ||
834 | // Emit end of list entry | |
835 | MCOS->EmitIntValue(0, AddrSize); | |
836 | MCOS->EmitIntValue(0, AddrSize); | |
837 | } | |
838 | ||
223e47cc LB |
839 | // |
840 | // When generating dwarf for assembly source files this emits the Dwarf | |
841 | // sections. | |
842 | // | |
1a4d82fc | 843 | void MCGenDwarfInfo::Emit(MCStreamer *MCOS) { |
223e47cc | 844 | MCContext &context = MCOS->getContext(); |
1a4d82fc JJ |
845 | |
846 | // Create the dwarf sections in this order (.debug_line already created). | |
847 | const MCAsmInfo *AsmInfo = context.getAsmInfo(); | |
970d7e83 | 848 | bool CreateDwarfSectionSymbols = |
1a4d82fc JJ |
849 | AsmInfo->doesDwarfUseRelocationsAcrossSections(); |
850 | MCSymbol *LineSectionSymbol = nullptr; | |
851 | if (CreateDwarfSectionSymbols) | |
852 | LineSectionSymbol = MCOS->getDwarfLineTableSymbol(0); | |
853 | MCSymbol *AbbrevSectionSymbol = nullptr; | |
854 | MCSymbol *InfoSectionSymbol = nullptr; | |
855 | MCSymbol *RangesSectionSymbol = NULL; | |
856 | ||
857 | // Create end symbols for each section, and remove empty sections | |
858 | MCOS->getContext().finalizeDwarfSections(*MCOS); | |
859 | ||
860 | // If there are no sections to generate debug info for, we don't need | |
861 | // to do anything | |
862 | if (MCOS->getContext().getGenDwarfSectionSyms().empty()) | |
863 | return; | |
864 | ||
865 | // We only use the .debug_ranges section if we have multiple code sections, | |
866 | // and we are emitting a DWARF version which supports it. | |
867 | const bool UseRangesSection = | |
868 | MCOS->getContext().getGenDwarfSectionSyms().size() > 1 && | |
869 | MCOS->getContext().getDwarfVersion() >= 3; | |
870 | CreateDwarfSectionSymbols |= UseRangesSection; | |
871 | ||
223e47cc | 872 | MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfInfoSection()); |
970d7e83 LB |
873 | if (CreateDwarfSectionSymbols) { |
874 | InfoSectionSymbol = context.CreateTempSymbol(); | |
875 | MCOS->EmitLabel(InfoSectionSymbol); | |
876 | } | |
223e47cc | 877 | MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfAbbrevSection()); |
970d7e83 | 878 | if (CreateDwarfSectionSymbols) { |
223e47cc LB |
879 | AbbrevSectionSymbol = context.CreateTempSymbol(); |
880 | MCOS->EmitLabel(AbbrevSectionSymbol); | |
223e47cc | 881 | } |
1a4d82fc JJ |
882 | if (UseRangesSection) { |
883 | MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfRangesSection()); | |
884 | if (CreateDwarfSectionSymbols) { | |
885 | RangesSectionSymbol = context.CreateTempSymbol(); | |
886 | MCOS->EmitLabel(RangesSectionSymbol); | |
887 | } | |
888 | } | |
223e47cc | 889 | |
1a4d82fc JJ |
890 | assert((RangesSectionSymbol != NULL) || !UseRangesSection); |
891 | ||
892 | MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfARangesSection()); | |
223e47cc LB |
893 | |
894 | // Output the data for .debug_aranges section. | |
970d7e83 | 895 | EmitGenDwarfAranges(MCOS, InfoSectionSymbol); |
223e47cc | 896 | |
1a4d82fc JJ |
897 | if (UseRangesSection) |
898 | EmitGenDwarfRanges(MCOS); | |
899 | ||
223e47cc LB |
900 | // Output the data for .debug_abbrev section. |
901 | EmitGenDwarfAbbrev(MCOS); | |
902 | ||
903 | // Output the data for .debug_info section. | |
1a4d82fc JJ |
904 | EmitGenDwarfInfo(MCOS, AbbrevSectionSymbol, LineSectionSymbol, |
905 | RangesSectionSymbol); | |
223e47cc LB |
906 | } |
907 | ||
908 | // | |
909 | // When generating dwarf for assembly source files this is called when symbol | |
910 | // for a label is created. If this symbol is not a temporary and is in the | |
911 | // section that dwarf is being generated for, save the needed info to create | |
912 | // a dwarf label. | |
913 | // | |
914 | void MCGenDwarfLabelEntry::Make(MCSymbol *Symbol, MCStreamer *MCOS, | |
915 | SourceMgr &SrcMgr, SMLoc &Loc) { | |
1a4d82fc | 916 | // We won't create dwarf labels for temporary symbols. |
223e47cc LB |
917 | if (Symbol->isTemporary()) |
918 | return; | |
919 | MCContext &context = MCOS->getContext(); | |
1a4d82fc JJ |
920 | // We won't create dwarf labels for symbols in sections that we are not |
921 | // generating debug info for. | |
922 | if (!context.getGenDwarfSectionSyms().count(MCOS->getCurrentSection().first)) | |
223e47cc LB |
923 | return; |
924 | ||
925 | // The dwarf label's name does not have the symbol name's leading | |
926 | // underbar if any. | |
927 | StringRef Name = Symbol->getName(); | |
928 | if (Name.startswith("_")) | |
929 | Name = Name.substr(1, Name.size()-1); | |
930 | ||
931 | // Get the dwarf file number to be used for the dwarf label. | |
932 | unsigned FileNumber = context.getGenDwarfFileNumber(); | |
933 | ||
934 | // Finding the line number is the expensive part which is why we just don't | |
935 | // pass it in as for some symbols we won't create a dwarf label. | |
1a4d82fc | 936 | unsigned CurBuffer = SrcMgr.FindBufferContainingLoc(Loc); |
223e47cc LB |
937 | unsigned LineNumber = SrcMgr.FindLineNumber(Loc, CurBuffer); |
938 | ||
939 | // We create a temporary symbol for use for the AT_high_pc and AT_low_pc | |
940 | // values so that they don't have things like an ARM thumb bit from the | |
941 | // original symbol. So when used they won't get a low bit set after | |
942 | // relocation. | |
943 | MCSymbol *Label = context.CreateTempSymbol(); | |
944 | MCOS->EmitLabel(Label); | |
945 | ||
946 | // Create and entry for the info and add it to the other entries. | |
1a4d82fc JJ |
947 | MCOS->getContext().addMCGenDwarfLabelEntry( |
948 | MCGenDwarfLabelEntry(Name, FileNumber, LineNumber, Label)); | |
223e47cc LB |
949 | } |
950 | ||
951 | static int getDataAlignmentFactor(MCStreamer &streamer) { | |
952 | MCContext &context = streamer.getContext(); | |
1a4d82fc JJ |
953 | const MCAsmInfo *asmInfo = context.getAsmInfo(); |
954 | int size = asmInfo->getCalleeSaveStackSlotSize(); | |
955 | if (asmInfo->isStackGrowthDirectionUp()) | |
223e47cc LB |
956 | return size; |
957 | else | |
958 | return -size; | |
959 | } | |
960 | ||
961 | static unsigned getSizeForEncoding(MCStreamer &streamer, | |
962 | unsigned symbolEncoding) { | |
963 | MCContext &context = streamer.getContext(); | |
964 | unsigned format = symbolEncoding & 0x0f; | |
965 | switch (format) { | |
966 | default: llvm_unreachable("Unknown Encoding"); | |
967 | case dwarf::DW_EH_PE_absptr: | |
968 | case dwarf::DW_EH_PE_signed: | |
1a4d82fc | 969 | return context.getAsmInfo()->getPointerSize(); |
223e47cc LB |
970 | case dwarf::DW_EH_PE_udata2: |
971 | case dwarf::DW_EH_PE_sdata2: | |
972 | return 2; | |
973 | case dwarf::DW_EH_PE_udata4: | |
974 | case dwarf::DW_EH_PE_sdata4: | |
975 | return 4; | |
976 | case dwarf::DW_EH_PE_udata8: | |
977 | case dwarf::DW_EH_PE_sdata8: | |
978 | return 8; | |
979 | } | |
980 | } | |
981 | ||
1a4d82fc JJ |
982 | static void emitFDESymbol(MCObjectStreamer &streamer, const MCSymbol &symbol, |
983 | unsigned symbolEncoding, bool isEH) { | |
223e47cc | 984 | MCContext &context = streamer.getContext(); |
1a4d82fc JJ |
985 | const MCAsmInfo *asmInfo = context.getAsmInfo(); |
986 | const MCExpr *v = asmInfo->getExprForFDESymbol(&symbol, | |
987 | symbolEncoding, | |
988 | streamer); | |
223e47cc | 989 | unsigned size = getSizeForEncoding(streamer, symbolEncoding); |
1a4d82fc JJ |
990 | if (asmInfo->doDwarfFDESymbolsUseAbsDiff() && isEH) |
991 | emitAbsValue(streamer, v, size); | |
992 | else | |
993 | streamer.EmitValue(v, size); | |
223e47cc LB |
994 | } |
995 | ||
996 | static void EmitPersonality(MCStreamer &streamer, const MCSymbol &symbol, | |
997 | unsigned symbolEncoding) { | |
998 | MCContext &context = streamer.getContext(); | |
1a4d82fc JJ |
999 | const MCAsmInfo *asmInfo = context.getAsmInfo(); |
1000 | const MCExpr *v = asmInfo->getExprForPersonalitySymbol(&symbol, | |
1001 | symbolEncoding, | |
1002 | streamer); | |
223e47cc LB |
1003 | unsigned size = getSizeForEncoding(streamer, symbolEncoding); |
1004 | streamer.EmitValue(v, size); | |
1005 | } | |
1006 | ||
223e47cc LB |
1007 | namespace { |
1008 | class FrameEmitterImpl { | |
1009 | int CFAOffset; | |
223e47cc LB |
1010 | bool IsEH; |
1011 | const MCSymbol *SectionStart; | |
1012 | public: | |
1a4d82fc JJ |
1013 | FrameEmitterImpl(bool isEH) |
1014 | : CFAOffset(0), IsEH(isEH), SectionStart(nullptr) {} | |
223e47cc LB |
1015 | |
1016 | void setSectionStart(const MCSymbol *Label) { SectionStart = Label; } | |
1017 | ||
1a4d82fc JJ |
1018 | /// Emit the unwind information in a compact way. |
1019 | void EmitCompactUnwind(MCObjectStreamer &streamer, | |
223e47cc LB |
1020 | const MCDwarfFrameInfo &frame); |
1021 | ||
1a4d82fc | 1022 | const MCSymbol &EmitCIE(MCObjectStreamer &streamer, |
223e47cc LB |
1023 | const MCSymbol *personality, |
1024 | unsigned personalityEncoding, | |
1025 | const MCSymbol *lsda, | |
1026 | bool IsSignalFrame, | |
1a4d82fc JJ |
1027 | unsigned lsdaEncoding, |
1028 | bool IsSimple); | |
1029 | MCSymbol *EmitFDE(MCObjectStreamer &streamer, | |
223e47cc LB |
1030 | const MCSymbol &cieStart, |
1031 | const MCDwarfFrameInfo &frame); | |
1a4d82fc JJ |
1032 | void EmitCFIInstructions(MCObjectStreamer &streamer, |
1033 | ArrayRef<MCCFIInstruction> Instrs, | |
223e47cc | 1034 | MCSymbol *BaseLabel); |
1a4d82fc | 1035 | void EmitCFIInstruction(MCObjectStreamer &Streamer, |
223e47cc LB |
1036 | const MCCFIInstruction &Instr); |
1037 | }; | |
1038 | ||
1039 | } // end anonymous namespace | |
1040 | ||
1a4d82fc | 1041 | static void emitEncodingByte(MCObjectStreamer &Streamer, unsigned Encoding) { |
223e47cc LB |
1042 | Streamer.EmitIntValue(Encoding, 1); |
1043 | } | |
1044 | ||
1a4d82fc | 1045 | void FrameEmitterImpl::EmitCFIInstruction(MCObjectStreamer &Streamer, |
223e47cc LB |
1046 | const MCCFIInstruction &Instr) { |
1047 | int dataAlignmentFactor = getDataAlignmentFactor(Streamer); | |
223e47cc LB |
1048 | |
1049 | switch (Instr.getOperation()) { | |
970d7e83 LB |
1050 | case MCCFIInstruction::OpRegister: { |
1051 | unsigned Reg1 = Instr.getRegister(); | |
1052 | unsigned Reg2 = Instr.getRegister2(); | |
970d7e83 LB |
1053 | Streamer.EmitIntValue(dwarf::DW_CFA_register, 1); |
1054 | Streamer.EmitULEB128IntValue(Reg1); | |
1055 | Streamer.EmitULEB128IntValue(Reg2); | |
1056 | return; | |
1057 | } | |
1a4d82fc JJ |
1058 | case MCCFIInstruction::OpWindowSave: { |
1059 | Streamer.EmitIntValue(dwarf::DW_CFA_GNU_window_save, 1); | |
1060 | return; | |
1061 | } | |
970d7e83 LB |
1062 | case MCCFIInstruction::OpUndefined: { |
1063 | unsigned Reg = Instr.getRegister(); | |
970d7e83 LB |
1064 | Streamer.EmitIntValue(dwarf::DW_CFA_undefined, 1); |
1065 | Streamer.EmitULEB128IntValue(Reg); | |
1066 | return; | |
1067 | } | |
1068 | case MCCFIInstruction::OpAdjustCfaOffset: | |
1069 | case MCCFIInstruction::OpDefCfaOffset: { | |
1070 | const bool IsRelative = | |
1071 | Instr.getOperation() == MCCFIInstruction::OpAdjustCfaOffset; | |
223e47cc | 1072 | |
970d7e83 | 1073 | Streamer.EmitIntValue(dwarf::DW_CFA_def_cfa_offset, 1); |
223e47cc | 1074 | |
970d7e83 LB |
1075 | if (IsRelative) |
1076 | CFAOffset += Instr.getOffset(); | |
1077 | else | |
1078 | CFAOffset = -Instr.getOffset(); | |
223e47cc | 1079 | |
970d7e83 | 1080 | Streamer.EmitULEB128IntValue(CFAOffset); |
223e47cc | 1081 | |
970d7e83 LB |
1082 | return; |
1083 | } | |
1084 | case MCCFIInstruction::OpDefCfa: { | |
970d7e83 | 1085 | Streamer.EmitIntValue(dwarf::DW_CFA_def_cfa, 1); |
970d7e83 | 1086 | Streamer.EmitULEB128IntValue(Instr.getRegister()); |
970d7e83 | 1087 | CFAOffset = -Instr.getOffset(); |
970d7e83 LB |
1088 | Streamer.EmitULEB128IntValue(CFAOffset); |
1089 | ||
1090 | return; | |
1091 | } | |
1092 | ||
1093 | case MCCFIInstruction::OpDefCfaRegister: { | |
970d7e83 | 1094 | Streamer.EmitIntValue(dwarf::DW_CFA_def_cfa_register, 1); |
970d7e83 LB |
1095 | Streamer.EmitULEB128IntValue(Instr.getRegister()); |
1096 | ||
1097 | return; | |
1098 | } | |
1099 | ||
1100 | case MCCFIInstruction::OpOffset: | |
1101 | case MCCFIInstruction::OpRelOffset: { | |
1102 | const bool IsRelative = | |
1103 | Instr.getOperation() == MCCFIInstruction::OpRelOffset; | |
1104 | ||
1105 | unsigned Reg = Instr.getRegister(); | |
1106 | int Offset = Instr.getOffset(); | |
223e47cc LB |
1107 | if (IsRelative) |
1108 | Offset -= CFAOffset; | |
1109 | Offset = Offset / dataAlignmentFactor; | |
1110 | ||
1111 | if (Offset < 0) { | |
223e47cc | 1112 | Streamer.EmitIntValue(dwarf::DW_CFA_offset_extended_sf, 1); |
223e47cc | 1113 | Streamer.EmitULEB128IntValue(Reg); |
223e47cc LB |
1114 | Streamer.EmitSLEB128IntValue(Offset); |
1115 | } else if (Reg < 64) { | |
223e47cc | 1116 | Streamer.EmitIntValue(dwarf::DW_CFA_offset + Reg, 1); |
223e47cc LB |
1117 | Streamer.EmitULEB128IntValue(Offset); |
1118 | } else { | |
223e47cc | 1119 | Streamer.EmitIntValue(dwarf::DW_CFA_offset_extended, 1); |
223e47cc | 1120 | Streamer.EmitULEB128IntValue(Reg); |
223e47cc LB |
1121 | Streamer.EmitULEB128IntValue(Offset); |
1122 | } | |
1123 | return; | |
1124 | } | |
970d7e83 | 1125 | case MCCFIInstruction::OpRememberState: |
223e47cc LB |
1126 | Streamer.EmitIntValue(dwarf::DW_CFA_remember_state, 1); |
1127 | return; | |
970d7e83 | 1128 | case MCCFIInstruction::OpRestoreState: |
223e47cc LB |
1129 | Streamer.EmitIntValue(dwarf::DW_CFA_restore_state, 1); |
1130 | return; | |
970d7e83 LB |
1131 | case MCCFIInstruction::OpSameValue: { |
1132 | unsigned Reg = Instr.getRegister(); | |
223e47cc | 1133 | Streamer.EmitIntValue(dwarf::DW_CFA_same_value, 1); |
223e47cc LB |
1134 | Streamer.EmitULEB128IntValue(Reg); |
1135 | return; | |
1136 | } | |
970d7e83 LB |
1137 | case MCCFIInstruction::OpRestore: { |
1138 | unsigned Reg = Instr.getRegister(); | |
223e47cc LB |
1139 | Streamer.EmitIntValue(dwarf::DW_CFA_restore | Reg, 1); |
1140 | return; | |
1141 | } | |
970d7e83 | 1142 | case MCCFIInstruction::OpEscape: |
970d7e83 | 1143 | Streamer.EmitBytes(Instr.getValues()); |
223e47cc LB |
1144 | return; |
1145 | } | |
1146 | llvm_unreachable("Unhandled case in switch"); | |
1147 | } | |
1148 | ||
1a4d82fc JJ |
1149 | /// Emit frame instructions to describe the layout of the frame. |
1150 | void FrameEmitterImpl::EmitCFIInstructions(MCObjectStreamer &streamer, | |
1151 | ArrayRef<MCCFIInstruction> Instrs, | |
223e47cc LB |
1152 | MCSymbol *BaseLabel) { |
1153 | for (unsigned i = 0, N = Instrs.size(); i < N; ++i) { | |
1154 | const MCCFIInstruction &Instr = Instrs[i]; | |
1155 | MCSymbol *Label = Instr.getLabel(); | |
1156 | // Throw out move if the label is invalid. | |
1157 | if (Label && !Label->isDefined()) continue; // Not emitted, in dead code. | |
1158 | ||
1159 | // Advance row if new location. | |
1160 | if (BaseLabel && Label) { | |
1161 | MCSymbol *ThisSym = Label; | |
1162 | if (ThisSym != BaseLabel) { | |
223e47cc LB |
1163 | streamer.EmitDwarfAdvanceFrameAddr(BaseLabel, ThisSym); |
1164 | BaseLabel = ThisSym; | |
1165 | } | |
1166 | } | |
1167 | ||
1168 | EmitCFIInstruction(streamer, Instr); | |
1169 | } | |
1170 | } | |
1171 | ||
1a4d82fc JJ |
1172 | /// Emit the unwind information in a compact way. |
1173 | void FrameEmitterImpl::EmitCompactUnwind(MCObjectStreamer &Streamer, | |
223e47cc LB |
1174 | const MCDwarfFrameInfo &Frame) { |
1175 | MCContext &Context = Streamer.getContext(); | |
1176 | const MCObjectFileInfo *MOFI = Context.getObjectFileInfo(); | |
223e47cc LB |
1177 | |
1178 | // range-start range-length compact-unwind-enc personality-func lsda | |
1179 | // _foo LfooEnd-_foo 0x00000023 0 0 | |
1180 | // _bar LbarEnd-_bar 0x00000025 __gxx_personality except_tab1 | |
1181 | // | |
1182 | // .section __LD,__compact_unwind,regular,debug | |
1183 | // | |
1184 | // # compact unwind for _foo | |
1185 | // .quad _foo | |
1186 | // .set L1,LfooEnd-_foo | |
1187 | // .long L1 | |
1188 | // .long 0x01010001 | |
1189 | // .quad 0 | |
1190 | // .quad 0 | |
1191 | // | |
1192 | // # compact unwind for _bar | |
1193 | // .quad _bar | |
1194 | // .set L2,LbarEnd-_bar | |
1195 | // .long L2 | |
1196 | // .long 0x01020011 | |
1197 | // .quad __gxx_personality | |
1198 | // .quad except_tab1 | |
1199 | ||
1200 | uint32_t Encoding = Frame.CompactUnwindEncoding; | |
1a4d82fc JJ |
1201 | if (!Encoding) return; |
1202 | bool DwarfEHFrameOnly = (Encoding == MOFI->getCompactUnwindDwarfEHFrameOnly()); | |
223e47cc LB |
1203 | |
1204 | // The encoding needs to know we have an LSDA. | |
1a4d82fc | 1205 | if (!DwarfEHFrameOnly && Frame.Lsda) |
223e47cc LB |
1206 | Encoding |= 0x40000000; |
1207 | ||
223e47cc | 1208 | // Range Start |
1a4d82fc | 1209 | unsigned FDEEncoding = MOFI->getFDEEncoding(); |
223e47cc | 1210 | unsigned Size = getSizeForEncoding(Streamer, FDEEncoding); |
1a4d82fc | 1211 | Streamer.EmitSymbolValue(Frame.Begin, Size); |
223e47cc LB |
1212 | |
1213 | // Range Length | |
1214 | const MCExpr *Range = MakeStartMinusEndExpr(Streamer, *Frame.Begin, | |
1215 | *Frame.End, 0); | |
1a4d82fc | 1216 | emitAbsValue(Streamer, Range, 4); |
223e47cc LB |
1217 | |
1218 | // Compact Encoding | |
1219 | Size = getSizeForEncoding(Streamer, dwarf::DW_EH_PE_udata4); | |
223e47cc LB |
1220 | Streamer.EmitIntValue(Encoding, Size); |
1221 | ||
223e47cc LB |
1222 | // Personality Function |
1223 | Size = getSizeForEncoding(Streamer, dwarf::DW_EH_PE_absptr); | |
1a4d82fc | 1224 | if (!DwarfEHFrameOnly && Frame.Personality) |
223e47cc LB |
1225 | Streamer.EmitSymbolValue(Frame.Personality, Size); |
1226 | else | |
1227 | Streamer.EmitIntValue(0, Size); // No personality fn | |
1228 | ||
1229 | // LSDA | |
1230 | Size = getSizeForEncoding(Streamer, Frame.LsdaEncoding); | |
1a4d82fc | 1231 | if (!DwarfEHFrameOnly && Frame.Lsda) |
223e47cc LB |
1232 | Streamer.EmitSymbolValue(Frame.Lsda, Size); |
1233 | else | |
1234 | Streamer.EmitIntValue(0, Size); // No LSDA | |
223e47cc LB |
1235 | } |
1236 | ||
1a4d82fc | 1237 | const MCSymbol &FrameEmitterImpl::EmitCIE(MCObjectStreamer &streamer, |
223e47cc LB |
1238 | const MCSymbol *personality, |
1239 | unsigned personalityEncoding, | |
1240 | const MCSymbol *lsda, | |
1241 | bool IsSignalFrame, | |
1a4d82fc JJ |
1242 | unsigned lsdaEncoding, |
1243 | bool IsSimple) { | |
223e47cc | 1244 | MCContext &context = streamer.getContext(); |
1a4d82fc | 1245 | const MCRegisterInfo *MRI = context.getRegisterInfo(); |
223e47cc | 1246 | const MCObjectFileInfo *MOFI = context.getObjectFileInfo(); |
223e47cc | 1247 | |
1a4d82fc | 1248 | MCSymbol *sectionStart = context.CreateTempSymbol(); |
223e47cc | 1249 | streamer.EmitLabel(sectionStart); |
223e47cc LB |
1250 | |
1251 | MCSymbol *sectionEnd = context.CreateTempSymbol(); | |
1252 | ||
1253 | // Length | |
1254 | const MCExpr *Length = MakeStartMinusEndExpr(streamer, *sectionStart, | |
1255 | *sectionEnd, 4); | |
1a4d82fc | 1256 | emitAbsValue(streamer, Length, 4); |
223e47cc LB |
1257 | |
1258 | // CIE ID | |
1259 | unsigned CIE_ID = IsEH ? 0 : -1; | |
223e47cc LB |
1260 | streamer.EmitIntValue(CIE_ID, 4); |
1261 | ||
1262 | // Version | |
1a4d82fc JJ |
1263 | // For DWARF2, we use CIE version 1 |
1264 | // For DWARF3+, we use CIE version 3 | |
1265 | uint8_t CIEVersion = context.getDwarfVersion() <= 2 ? 1 : 3; | |
1266 | streamer.EmitIntValue(CIEVersion, 1); | |
223e47cc LB |
1267 | |
1268 | // Augmentation String | |
1269 | SmallString<8> Augmentation; | |
1270 | if (IsEH) { | |
223e47cc LB |
1271 | Augmentation += "z"; |
1272 | if (personality) | |
1273 | Augmentation += "P"; | |
1274 | if (lsda) | |
1275 | Augmentation += "L"; | |
1276 | Augmentation += "R"; | |
1277 | if (IsSignalFrame) | |
1278 | Augmentation += "S"; | |
970d7e83 | 1279 | streamer.EmitBytes(Augmentation.str()); |
223e47cc LB |
1280 | } |
1281 | streamer.EmitIntValue(0, 1); | |
1282 | ||
1283 | // Code Alignment Factor | |
1a4d82fc | 1284 | streamer.EmitULEB128IntValue(context.getAsmInfo()->getMinInstAlignment()); |
223e47cc LB |
1285 | |
1286 | // Data Alignment Factor | |
223e47cc LB |
1287 | streamer.EmitSLEB128IntValue(getDataAlignmentFactor(streamer)); |
1288 | ||
1289 | // Return Address Register | |
1a4d82fc JJ |
1290 | if (CIEVersion == 1) { |
1291 | assert(MRI->getRARegister() <= 255 && | |
1292 | "DWARF 2 encodes return_address_register in one byte"); | |
1293 | streamer.EmitIntValue(MRI->getDwarfRegNum(MRI->getRARegister(), true), 1); | |
1294 | } else { | |
1295 | streamer.EmitULEB128IntValue( | |
1296 | MRI->getDwarfRegNum(MRI->getRARegister(), true)); | |
1297 | } | |
223e47cc LB |
1298 | |
1299 | // Augmentation Data Length (optional) | |
1300 | ||
1301 | unsigned augmentationLength = 0; | |
1302 | if (IsEH) { | |
1303 | if (personality) { | |
1304 | // Personality Encoding | |
1305 | augmentationLength += 1; | |
1306 | // Personality | |
1307 | augmentationLength += getSizeForEncoding(streamer, personalityEncoding); | |
1308 | } | |
1309 | if (lsda) | |
1310 | augmentationLength += 1; | |
1311 | // Encoding of the FDE pointers | |
1312 | augmentationLength += 1; | |
1313 | ||
223e47cc LB |
1314 | streamer.EmitULEB128IntValue(augmentationLength); |
1315 | ||
1316 | // Augmentation Data (optional) | |
1317 | if (personality) { | |
1318 | // Personality Encoding | |
1a4d82fc | 1319 | emitEncodingByte(streamer, personalityEncoding); |
223e47cc | 1320 | // Personality |
223e47cc LB |
1321 | EmitPersonality(streamer, *personality, personalityEncoding); |
1322 | } | |
1323 | ||
1324 | if (lsda) | |
1a4d82fc | 1325 | emitEncodingByte(streamer, lsdaEncoding); |
223e47cc LB |
1326 | |
1327 | // Encoding of the FDE pointers | |
1a4d82fc | 1328 | emitEncodingByte(streamer, MOFI->getFDEEncoding()); |
223e47cc LB |
1329 | } |
1330 | ||
1331 | // Initial Instructions | |
1332 | ||
1a4d82fc JJ |
1333 | const MCAsmInfo *MAI = context.getAsmInfo(); |
1334 | if (!IsSimple) { | |
1335 | const std::vector<MCCFIInstruction> &Instructions = | |
1336 | MAI->getInitialFrameState(); | |
1337 | EmitCFIInstructions(streamer, Instructions, nullptr); | |
223e47cc LB |
1338 | } |
1339 | ||
223e47cc | 1340 | // Padding |
1a4d82fc | 1341 | streamer.EmitValueToAlignment(IsEH ? 4 : MAI->getPointerSize()); |
223e47cc LB |
1342 | |
1343 | streamer.EmitLabel(sectionEnd); | |
1344 | return *sectionStart; | |
1345 | } | |
1346 | ||
1a4d82fc | 1347 | MCSymbol *FrameEmitterImpl::EmitFDE(MCObjectStreamer &streamer, |
223e47cc LB |
1348 | const MCSymbol &cieStart, |
1349 | const MCDwarfFrameInfo &frame) { | |
1350 | MCContext &context = streamer.getContext(); | |
1351 | MCSymbol *fdeStart = context.CreateTempSymbol(); | |
1352 | MCSymbol *fdeEnd = context.CreateTempSymbol(); | |
1353 | const MCObjectFileInfo *MOFI = context.getObjectFileInfo(); | |
223e47cc LB |
1354 | |
1355 | // Length | |
1356 | const MCExpr *Length = MakeStartMinusEndExpr(streamer, *fdeStart, *fdeEnd, 0); | |
1a4d82fc | 1357 | emitAbsValue(streamer, Length, 4); |
223e47cc LB |
1358 | |
1359 | streamer.EmitLabel(fdeStart); | |
1360 | ||
1361 | // CIE Pointer | |
1a4d82fc | 1362 | const MCAsmInfo *asmInfo = context.getAsmInfo(); |
223e47cc LB |
1363 | if (IsEH) { |
1364 | const MCExpr *offset = MakeStartMinusEndExpr(streamer, cieStart, *fdeStart, | |
1365 | 0); | |
1a4d82fc JJ |
1366 | emitAbsValue(streamer, offset, 4); |
1367 | } else if (!asmInfo->doesDwarfUseRelocationsAcrossSections()) { | |
223e47cc LB |
1368 | const MCExpr *offset = MakeStartMinusEndExpr(streamer, *SectionStart, |
1369 | cieStart, 0); | |
1a4d82fc | 1370 | emitAbsValue(streamer, offset, 4); |
223e47cc LB |
1371 | } else { |
1372 | streamer.EmitSymbolValue(&cieStart, 4); | |
1373 | } | |
1374 | ||
1375 | // PC Begin | |
1a4d82fc JJ |
1376 | unsigned PCEncoding = |
1377 | IsEH ? MOFI->getFDEEncoding() : (unsigned)dwarf::DW_EH_PE_absptr; | |
223e47cc | 1378 | unsigned PCSize = getSizeForEncoding(streamer, PCEncoding); |
1a4d82fc | 1379 | emitFDESymbol(streamer, *frame.Begin, PCEncoding, IsEH); |
223e47cc LB |
1380 | |
1381 | // PC Range | |
1382 | const MCExpr *Range = MakeStartMinusEndExpr(streamer, *frame.Begin, | |
1383 | *frame.End, 0); | |
1a4d82fc | 1384 | emitAbsValue(streamer, Range, PCSize); |
223e47cc LB |
1385 | |
1386 | if (IsEH) { | |
1387 | // Augmentation Data Length | |
1388 | unsigned augmentationLength = 0; | |
1389 | ||
1390 | if (frame.Lsda) | |
1391 | augmentationLength += getSizeForEncoding(streamer, frame.LsdaEncoding); | |
1392 | ||
223e47cc LB |
1393 | streamer.EmitULEB128IntValue(augmentationLength); |
1394 | ||
1395 | // Augmentation Data | |
1396 | if (frame.Lsda) | |
1a4d82fc | 1397 | emitFDESymbol(streamer, *frame.Lsda, frame.LsdaEncoding, true); |
223e47cc LB |
1398 | } |
1399 | ||
1400 | // Call Frame Instructions | |
223e47cc LB |
1401 | EmitCFIInstructions(streamer, frame.Instructions, frame.Begin); |
1402 | ||
1403 | // Padding | |
1404 | streamer.EmitValueToAlignment(PCSize); | |
1405 | ||
1406 | return fdeEnd; | |
1407 | } | |
1408 | ||
1409 | namespace { | |
1410 | struct CIEKey { | |
1a4d82fc JJ |
1411 | static const CIEKey getEmptyKey() { |
1412 | return CIEKey(nullptr, 0, -1, false, false); | |
1413 | } | |
1414 | static const CIEKey getTombstoneKey() { | |
1415 | return CIEKey(nullptr, -1, 0, false, false); | |
223e47cc | 1416 | } |
1a4d82fc JJ |
1417 | |
1418 | CIEKey(const MCSymbol *Personality_, unsigned PersonalityEncoding_, | |
1419 | unsigned LsdaEncoding_, bool IsSignalFrame_, bool IsSimple_) | |
1420 | : Personality(Personality_), PersonalityEncoding(PersonalityEncoding_), | |
1421 | LsdaEncoding(LsdaEncoding_), IsSignalFrame(IsSignalFrame_), | |
1422 | IsSimple(IsSimple_) {} | |
1423 | const MCSymbol *Personality; | |
223e47cc LB |
1424 | unsigned PersonalityEncoding; |
1425 | unsigned LsdaEncoding; | |
1426 | bool IsSignalFrame; | |
1a4d82fc | 1427 | bool IsSimple; |
223e47cc LB |
1428 | }; |
1429 | } | |
1430 | ||
1431 | namespace llvm { | |
1432 | template <> | |
1433 | struct DenseMapInfo<CIEKey> { | |
1434 | static CIEKey getEmptyKey() { | |
1435 | return CIEKey::getEmptyKey(); | |
1436 | } | |
1437 | static CIEKey getTombstoneKey() { | |
1438 | return CIEKey::getTombstoneKey(); | |
1439 | } | |
1440 | static unsigned getHashValue(const CIEKey &Key) { | |
1441 | return static_cast<unsigned>(hash_combine(Key.Personality, | |
1442 | Key.PersonalityEncoding, | |
1443 | Key.LsdaEncoding, | |
1a4d82fc JJ |
1444 | Key.IsSignalFrame, |
1445 | Key.IsSimple)); | |
223e47cc LB |
1446 | } |
1447 | static bool isEqual(const CIEKey &LHS, | |
1448 | const CIEKey &RHS) { | |
1449 | return LHS.Personality == RHS.Personality && | |
1450 | LHS.PersonalityEncoding == RHS.PersonalityEncoding && | |
1451 | LHS.LsdaEncoding == RHS.LsdaEncoding && | |
1a4d82fc JJ |
1452 | LHS.IsSignalFrame == RHS.IsSignalFrame && |
1453 | LHS.IsSimple == RHS.IsSimple; | |
223e47cc LB |
1454 | } |
1455 | }; | |
1456 | } | |
1457 | ||
1a4d82fc | 1458 | void MCDwarfFrameEmitter::Emit(MCObjectStreamer &Streamer, MCAsmBackend *MAB, |
223e47cc | 1459 | bool IsEH) { |
1a4d82fc JJ |
1460 | Streamer.generateCompactUnwindEncodings(MAB); |
1461 | ||
223e47cc | 1462 | MCContext &Context = Streamer.getContext(); |
1a4d82fc JJ |
1463 | const MCObjectFileInfo *MOFI = Context.getObjectFileInfo(); |
1464 | FrameEmitterImpl Emitter(IsEH); | |
1465 | ArrayRef<MCDwarfFrameInfo> FrameArray = Streamer.getDwarfFrameInfos(); | |
223e47cc LB |
1466 | |
1467 | // Emit the compact unwind info if available. | |
1a4d82fc JJ |
1468 | bool NeedsEHFrameSection = !MOFI->getSupportsCompactUnwindWithoutEHFrame(); |
1469 | if (IsEH && MOFI->getCompactUnwindSection()) { | |
1470 | bool SectionEmitted = false; | |
1471 | for (unsigned i = 0, n = FrameArray.size(); i < n; ++i) { | |
1472 | const MCDwarfFrameInfo &Frame = FrameArray[i]; | |
1473 | if (Frame.CompactUnwindEncoding == 0) continue; | |
1474 | if (!SectionEmitted) { | |
1475 | Streamer.SwitchSection(MOFI->getCompactUnwindSection()); | |
1476 | Streamer.EmitValueToAlignment(Context.getAsmInfo()->getPointerSize()); | |
1477 | SectionEmitted = true; | |
1478 | } | |
1479 | NeedsEHFrameSection |= | |
1480 | Frame.CompactUnwindEncoding == | |
1481 | MOFI->getCompactUnwindDwarfEHFrameOnly(); | |
1482 | Emitter.EmitCompactUnwind(Streamer, Frame); | |
223e47cc | 1483 | } |
1a4d82fc JJ |
1484 | } |
1485 | ||
1486 | if (!NeedsEHFrameSection) return; | |
1487 | ||
1488 | const MCSection &Section = | |
1489 | IsEH ? *const_cast<MCObjectFileInfo*>(MOFI)->getEHFrameSection() : | |
1490 | *MOFI->getDwarfFrameSection(); | |
223e47cc | 1491 | |
223e47cc LB |
1492 | Streamer.SwitchSection(&Section); |
1493 | MCSymbol *SectionStart = Context.CreateTempSymbol(); | |
1494 | Streamer.EmitLabel(SectionStart); | |
1495 | Emitter.setSectionStart(SectionStart); | |
1496 | ||
1a4d82fc JJ |
1497 | MCSymbol *FDEEnd = nullptr; |
1498 | DenseMap<CIEKey, const MCSymbol *> CIEStarts; | |
223e47cc | 1499 | |
1a4d82fc JJ |
1500 | const MCSymbol *DummyDebugKey = nullptr; |
1501 | NeedsEHFrameSection = !MOFI->getSupportsCompactUnwindWithoutEHFrame(); | |
223e47cc LB |
1502 | for (unsigned i = 0, n = FrameArray.size(); i < n; ++i) { |
1503 | const MCDwarfFrameInfo &Frame = FrameArray[i]; | |
1a4d82fc JJ |
1504 | |
1505 | // Emit the label from the previous iteration | |
1506 | if (FDEEnd) { | |
1507 | Streamer.EmitLabel(FDEEnd); | |
1508 | FDEEnd = nullptr; | |
1509 | } | |
1510 | ||
1511 | if (!NeedsEHFrameSection && Frame.CompactUnwindEncoding != | |
1512 | MOFI->getCompactUnwindDwarfEHFrameOnly()) | |
1513 | // Don't generate an EH frame if we don't need one. I.e., it's taken care | |
1514 | // of by the compact unwind encoding. | |
1515 | continue; | |
1516 | ||
223e47cc | 1517 | CIEKey Key(Frame.Personality, Frame.PersonalityEncoding, |
1a4d82fc | 1518 | Frame.LsdaEncoding, Frame.IsSignalFrame, Frame.IsSimple); |
223e47cc LB |
1519 | const MCSymbol *&CIEStart = IsEH ? CIEStarts[Key] : DummyDebugKey; |
1520 | if (!CIEStart) | |
1521 | CIEStart = &Emitter.EmitCIE(Streamer, Frame.Personality, | |
1522 | Frame.PersonalityEncoding, Frame.Lsda, | |
1523 | Frame.IsSignalFrame, | |
1a4d82fc JJ |
1524 | Frame.LsdaEncoding, |
1525 | Frame.IsSimple); | |
223e47cc LB |
1526 | |
1527 | FDEEnd = Emitter.EmitFDE(Streamer, *CIEStart, Frame); | |
223e47cc LB |
1528 | } |
1529 | ||
1a4d82fc | 1530 | Streamer.EmitValueToAlignment(Context.getAsmInfo()->getPointerSize()); |
223e47cc LB |
1531 | if (FDEEnd) |
1532 | Streamer.EmitLabel(FDEEnd); | |
1533 | } | |
1534 | ||
1a4d82fc | 1535 | void MCDwarfFrameEmitter::EmitAdvanceLoc(MCObjectStreamer &Streamer, |
223e47cc | 1536 | uint64_t AddrDelta) { |
1a4d82fc | 1537 | MCContext &Context = Streamer.getContext(); |
223e47cc LB |
1538 | SmallString<256> Tmp; |
1539 | raw_svector_ostream OS(Tmp); | |
1a4d82fc | 1540 | MCDwarfFrameEmitter::EncodeAdvanceLoc(Context, AddrDelta, OS); |
970d7e83 | 1541 | Streamer.EmitBytes(OS.str()); |
223e47cc LB |
1542 | } |
1543 | ||
1a4d82fc JJ |
1544 | void MCDwarfFrameEmitter::EncodeAdvanceLoc(MCContext &Context, |
1545 | uint64_t AddrDelta, | |
223e47cc | 1546 | raw_ostream &OS) { |
1a4d82fc JJ |
1547 | // Scale the address delta by the minimum instruction length. |
1548 | AddrDelta = ScaleAddrDelta(Context, AddrDelta); | |
1549 | ||
223e47cc LB |
1550 | if (AddrDelta == 0) { |
1551 | } else if (isUIntN(6, AddrDelta)) { | |
1552 | uint8_t Opcode = dwarf::DW_CFA_advance_loc | AddrDelta; | |
1553 | OS << Opcode; | |
1554 | } else if (isUInt<8>(AddrDelta)) { | |
1555 | OS << uint8_t(dwarf::DW_CFA_advance_loc1); | |
1556 | OS << uint8_t(AddrDelta); | |
1557 | } else if (isUInt<16>(AddrDelta)) { | |
1558 | // FIXME: check what is the correct behavior on a big endian machine. | |
1559 | OS << uint8_t(dwarf::DW_CFA_advance_loc2); | |
1560 | OS << uint8_t( AddrDelta & 0xff); | |
1561 | OS << uint8_t((AddrDelta >> 8) & 0xff); | |
1562 | } else { | |
1563 | // FIXME: check what is the correct behavior on a big endian machine. | |
1564 | assert(isUInt<32>(AddrDelta)); | |
1565 | OS << uint8_t(dwarf::DW_CFA_advance_loc4); | |
1566 | OS << uint8_t( AddrDelta & 0xff); | |
1567 | OS << uint8_t((AddrDelta >> 8) & 0xff); | |
1568 | OS << uint8_t((AddrDelta >> 16) & 0xff); | |
1569 | OS << uint8_t((AddrDelta >> 24) & 0xff); | |
1570 | ||
1571 | } | |
1572 | } |