1 //===--- lib/CodeGen/DwarfPrinter.cpp - Dwarf Printer ---------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // Emit general DWARF directives.
12 //===----------------------------------------------------------------------===//
14 #include "DwarfPrinter.h"
15 #include "llvm/Module.h"
16 #include "llvm/CodeGen/AsmPrinter.h"
17 #include "llvm/CodeGen/MachineFrameInfo.h"
18 #include "llvm/CodeGen/MachineFunction.h"
19 #include "llvm/CodeGen/MachineModuleInfo.h"
20 #include "llvm/MC/MCAsmInfo.h"
21 #include "llvm/MC/MCContext.h"
22 #include "llvm/MC/MCExpr.h"
23 #include "llvm/MC/MCStreamer.h"
24 #include "llvm/MC/MCSymbol.h"
25 #include "llvm/Target/TargetData.h"
26 #include "llvm/Target/TargetFrameInfo.h"
27 #include "llvm/Target/TargetLoweringObjectFile.h"
28 #include "llvm/Target/TargetRegisterInfo.h"
29 #include "llvm/Support/Dwarf.h"
30 #include "llvm/Support/ErrorHandling.h"
31 #include "llvm/ADT/SmallString.h"
34 DwarfPrinter::DwarfPrinter(raw_ostream &OS, AsmPrinter *A, const MCAsmInfo *T,
36 : O(OS), Asm(A), MAI(T), TD(Asm->TM.getTargetData()),
37 RI(Asm->TM.getRegisterInfo()), M(NULL), MF(NULL), MMI(NULL),
38 SubprogramCount(0), Flavor(flavor), SetCounter(1) {}
40 /// SizeOfEncodedValue - Return the size of the encoding in bytes.
41 unsigned DwarfPrinter::SizeOfEncodedValue(unsigned Encoding) const {
42 if (Encoding == dwarf::DW_EH_PE_omit)
45 switch (Encoding & 0x07) {
46 case dwarf::DW_EH_PE_absptr:
47 return TD->getPointerSize();
48 case dwarf::DW_EH_PE_udata2:
50 case dwarf::DW_EH_PE_udata4:
52 case dwarf::DW_EH_PE_udata8:
56 assert(0 && "Invalid encoded value.");
60 void DwarfPrinter::PrintRelDirective(bool Force32Bit, bool isInSection) const {
61 if (isInSection && MAI->getDwarfSectionOffsetDirective())
62 O << MAI->getDwarfSectionOffsetDirective();
63 else if (Force32Bit || TD->getPointerSize() == sizeof(int32_t))
64 O << MAI->getData32bitsDirective();
66 O << MAI->getData64bitsDirective();
69 void DwarfPrinter::PrintRelDirective(unsigned Encoding) const {
70 unsigned Size = SizeOfEncodedValue(Encoding);
71 assert((Size == 4 || Size == 8) && "Do not support other types or rels!");
74 MAI->getData32bitsDirective() : MAI->getData64bitsDirective());
77 /// EOL - Print a newline character to asm stream. If a comment is present
78 /// then it will be printed first. Comments should not contain '\n'.
79 void DwarfPrinter::EOL(const Twine &Comment) const {
80 if (Asm->VerboseAsm && !Comment.isTriviallyEmpty()) {
81 Asm->O.PadToColumn(MAI->getCommentColumn());
82 Asm->O << Asm->MAI->getCommentString() << ' ' << Comment;
87 static const char *DecodeDWARFEncoding(unsigned Encoding) {
89 case dwarf::DW_EH_PE_absptr: return "absptr";
90 case dwarf::DW_EH_PE_omit: return "omit";
91 case dwarf::DW_EH_PE_pcrel: return "pcrel";
92 case dwarf::DW_EH_PE_udata4: return "udata4";
93 case dwarf::DW_EH_PE_udata8: return "udata8";
94 case dwarf::DW_EH_PE_sdata4: return "sdata4";
95 case dwarf::DW_EH_PE_sdata8: return "sdata8";
96 case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata4: return "pcrel udata4";
97 case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4: return "pcrel sdata4";
98 case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8: return "pcrel udata8";
99 case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8: return "pcrel sdata8";
100 case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |dwarf::DW_EH_PE_udata4:
101 return "indirect pcrel udata4";
102 case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |dwarf::DW_EH_PE_sdata4:
103 return "indirect pcrel sdata4";
104 case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |dwarf::DW_EH_PE_udata8:
105 return "indirect pcrel udata8";
106 case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |dwarf::DW_EH_PE_sdata8:
107 return "indirect pcrel sdata8";
110 return "<unknown encoding>";
113 /// EmitEncodingByte - Emit a .byte 42 directive that corresponds to an
114 /// encoding. If verbose assembly output is enabled, we output comments
115 /// describing the encoding. Desc is an optional string saying what the
116 /// encoding is specifying (e.g. "LSDA").
117 void DwarfPrinter::EmitEncodingByte(unsigned Val, const char *Desc) {
118 if (Asm->VerboseAsm) {
120 Asm->OutStreamer.AddComment(Twine(Desc)+" Encoding = " +
121 Twine(DecodeDWARFEncoding(Val)));
123 Asm->OutStreamer.AddComment(Twine("Encoding = ") +
124 DecodeDWARFEncoding(Val));
127 Asm->OutStreamer.EmitIntValue(Val, 1, 0/*addrspace*/);
130 /// EmitCFAByte - Emit a .byte 42 directive for a DW_CFA_xxx value.
131 void DwarfPrinter::EmitCFAByte(unsigned Val) {
132 if (Asm->VerboseAsm) {
133 if (Val >= dwarf::DW_CFA_offset && Val < dwarf::DW_CFA_offset+64)
134 Asm->OutStreamer.AddComment("DW_CFA_offset + Reg (" +
135 Twine(Val-dwarf::DW_CFA_offset) + ")");
137 Asm->OutStreamer.AddComment(dwarf::CallFrameString(Val));
139 Asm->OutStreamer.EmitIntValue(Val, 1, 0/*addrspace*/);
142 /// EmitSLEB128 - emit the specified signed leb128 value.
143 void DwarfPrinter::EmitSLEB128(int Value, const char *Desc) const {
144 if (Asm->VerboseAsm && Desc)
145 Asm->OutStreamer.AddComment(Desc);
147 if (MAI->hasLEB128()) {
148 O << "\t.sleb128\t" << Value;
149 Asm->OutStreamer.AddBlankLine();
153 // If we don't have .sleb128, emit as .bytes.
154 int Sign = Value >> (8 * sizeof(Value) - 1);
158 unsigned char Byte = static_cast<unsigned char>(Value & 0x7f);
160 IsMore = Value != Sign || ((Byte ^ Sign) & 0x40) != 0;
161 if (IsMore) Byte |= 0x80;
162 Asm->OutStreamer.EmitIntValue(Byte, 1, /*addrspace*/0);
166 /// EmitULEB128 - emit the specified signed leb128 value.
167 void DwarfPrinter::EmitULEB128(unsigned Value, const char *Desc,
168 unsigned PadTo) const {
169 if (Asm->VerboseAsm && Desc)
170 Asm->OutStreamer.AddComment(Desc);
172 if (MAI->hasLEB128() && PadTo == 0) {
173 O << "\t.uleb128\t" << Value;
174 Asm->OutStreamer.AddBlankLine();
178 // If we don't have .uleb128 or we want to emit padding, emit as .bytes.
180 unsigned char Byte = static_cast<unsigned char>(Value & 0x7f);
182 if (Value || PadTo != 0) Byte |= 0x80;
183 Asm->OutStreamer.EmitIntValue(Byte, 1, /*addrspace*/0);
188 Asm->OutStreamer.EmitFill(PadTo - 1, 0x80/*fillval*/, 0/*addrspace*/);
189 Asm->OutStreamer.EmitFill(1, 0/*fillval*/, 0/*addrspace*/);
194 /// PrintLabelName - Print label name in form used by Dwarf writer.
196 void DwarfPrinter::PrintLabelName(const char *Tag, unsigned Number) const {
197 O << MAI->getPrivateGlobalPrefix() << Tag;
198 if (Number) O << Number;
200 void DwarfPrinter::PrintLabelName(const char *Tag, unsigned Number,
201 const char *Suffix) const {
202 O << MAI->getPrivateGlobalPrefix() << Tag;
203 if (Number) O << Number;
207 /// EmitLabel - Emit location label for internal use by Dwarf.
209 void DwarfPrinter::EmitLabel(const char *Tag, unsigned Number) const {
210 PrintLabelName(Tag, Number);
214 /// EmitReference - Emit a reference to a label.
216 void DwarfPrinter::EmitReference(const char *Tag, unsigned Number,
217 bool IsPCRelative, bool Force32Bit) const {
218 PrintRelDirective(Force32Bit);
219 PrintLabelName(Tag, Number);
220 if (IsPCRelative) O << "-" << MAI->getPCSymbol();
222 void DwarfPrinter::EmitReference(const std::string &Name, bool IsPCRelative,
223 bool Force32Bit) const {
224 PrintRelDirective(Force32Bit);
226 if (IsPCRelative) O << "-" << MAI->getPCSymbol();
229 void DwarfPrinter::EmitReference(const MCSymbol *Sym, bool IsPCRelative,
230 bool Force32Bit) const {
231 PrintRelDirective(Force32Bit);
233 if (IsPCRelative) O << "-" << MAI->getPCSymbol();
236 void DwarfPrinter::EmitReference(const char *Tag, unsigned Number,
237 unsigned Encoding) const {
238 SmallString<64> Name;
239 raw_svector_ostream(Name) << MAI->getPrivateGlobalPrefix()
242 MCSymbol *Sym = Asm->OutContext.GetOrCreateSymbol(Name.str());
243 EmitReference(Sym, Encoding);
246 void DwarfPrinter::EmitReference(const MCSymbol *Sym, unsigned Encoding) const {
247 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
249 PrintRelDirective(Encoding);
250 O << *TLOF.getSymbolForDwarfReference(Sym, Asm->MMI, Encoding);;
253 void DwarfPrinter::EmitReference(const GlobalValue *GV, unsigned Encoding)const {
254 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
256 PrintRelDirective(Encoding);
257 O << *TLOF.getSymbolForDwarfGlobalReference(GV, Asm->Mang,
258 Asm->MMI, Encoding);;
261 /// EmitDifference - Emit the difference between two labels. If this assembler
262 /// supports .set, we emit a .set of a temporary and then use it in the .word.
263 void DwarfPrinter::EmitDifference(const char *TagHi, unsigned NumberHi,
264 const char *TagLo, unsigned NumberLo,
266 if (MAI->hasSetDirective()) {
267 // FIXME: switch to OutStreamer.EmitAssignment.
269 PrintLabelName("set", SetCounter, Flavor);
271 PrintLabelName(TagHi, NumberHi);
273 PrintLabelName(TagLo, NumberLo);
276 PrintRelDirective(IsSmall);
277 PrintLabelName("set", SetCounter, Flavor);
280 PrintRelDirective(IsSmall);
281 PrintLabelName(TagHi, NumberHi);
283 PrintLabelName(TagLo, NumberLo);
287 void DwarfPrinter::EmitSectionOffset(const char* Label, const char* Section,
288 unsigned LabelNumber,
289 unsigned SectionNumber,
290 bool IsSmall, bool isEH,
292 bool printAbsolute = false;
294 printAbsolute = MAI->isAbsoluteEHSectionOffsets();
296 printAbsolute = MAI->isAbsoluteDebugSectionOffsets();
298 if (MAI->hasSetDirective() && useSet) {
299 // FIXME: switch to OutStreamer.EmitAssignment.
301 PrintLabelName("set", SetCounter, Flavor);
303 PrintLabelName(Label, LabelNumber);
305 if (!printAbsolute) {
307 PrintLabelName(Section, SectionNumber);
311 PrintRelDirective(IsSmall);
312 PrintLabelName("set", SetCounter, Flavor);
315 PrintRelDirective(IsSmall, true);
316 PrintLabelName(Label, LabelNumber);
318 if (!printAbsolute) {
320 PrintLabelName(Section, SectionNumber);
325 /// EmitFrameMoves - Emit frame instructions to describe the layout of the
327 void DwarfPrinter::EmitFrameMoves(const char *BaseLabel, unsigned BaseLabelID,
328 const std::vector<MachineMove> &Moves,
331 Asm->TM.getFrameInfo()->getStackGrowthDirection() ==
332 TargetFrameInfo::StackGrowsUp ?
333 TD->getPointerSize() : -TD->getPointerSize();
334 bool IsLocal = BaseLabel && strcmp(BaseLabel, "label") == 0;
336 for (unsigned i = 0, N = Moves.size(); i < N; ++i) {
337 const MachineMove &Move = Moves[i];
338 unsigned LabelID = Move.getLabelID();
341 LabelID = MMI->MappedLabel(LabelID);
343 // Throw out move if the label is invalid.
344 if (!LabelID) continue;
347 const MachineLocation &Dst = Move.getDestination();
348 const MachineLocation &Src = Move.getSource();
350 // Advance row if new location.
351 if (BaseLabel && LabelID && (BaseLabelID != LabelID || !IsLocal)) {
352 EmitCFAByte(dwarf::DW_CFA_advance_loc4);
353 EmitDifference("label", LabelID, BaseLabel, BaseLabelID, true);
356 BaseLabelID = LabelID;
362 if (Dst.isReg() && Dst.getReg() == MachineLocation::VirtualFP) {
364 if (Src.getReg() == MachineLocation::VirtualFP) {
365 EmitCFAByte(dwarf::DW_CFA_def_cfa_offset);
367 EmitCFAByte(dwarf::DW_CFA_def_cfa);
368 EmitULEB128(RI->getDwarfRegNum(Src.getReg(), isEH), "Register");
371 int Offset = -Src.getOffset();
372 EmitULEB128(Offset, "Offset");
374 llvm_unreachable("Machine move not supported yet.");
376 } else if (Src.isReg() &&
377 Src.getReg() == MachineLocation::VirtualFP) {
379 EmitCFAByte(dwarf::DW_CFA_def_cfa_register);
380 EmitULEB128(RI->getDwarfRegNum(Dst.getReg(), isEH), "Register");
382 llvm_unreachable("Machine move not supported yet.");
385 unsigned Reg = RI->getDwarfRegNum(Src.getReg(), isEH);
386 int Offset = Dst.getOffset() / stackGrowth;
389 EmitCFAByte(dwarf::DW_CFA_offset_extended_sf);
390 EmitULEB128(Reg, "Reg");
391 EmitSLEB128(Offset, "Offset");
392 } else if (Reg < 64) {
393 EmitCFAByte(dwarf::DW_CFA_offset + Reg);
394 EmitULEB128(Offset, "Offset");
396 EmitCFAByte(dwarf::DW_CFA_offset_extended);
397 EmitULEB128(Reg, "Reg");
398 EmitULEB128(Offset, "Offset");