lib/MC/MCStreamer.cpp

   1 //===- lib/MC/MCStreamer.cpp - Streaming Machine Code Output --------------===//
   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/MCAsmInfo.h"
  11 #include "llvm/MC/MCContext.h"
  12 #include "llvm/MC/MCStreamer.h"
  13 #include "llvm/MC/MCExpr.h"
  14 #include "llvm/MC/MCObjectWriter.h"
  15 #include "llvm/Support/ErrorHandling.h"
  16 #include "llvm/Support/raw_ostream.h"
  17 #include "llvm/ADT/SmallString.h"
  18 #include "llvm/ADT/Twine.h"
  19 #include <cstdlib>
  20 using namespace llvm;
  21
  22 MCStreamer::MCStreamer(MCContext &Ctx) : Context(Ctx) {
  23   const MCSection *section = NULL;
  24   SectionStack.push_back(std::make_pair(section, section));
  25 }
  26
  27 MCStreamer::~MCStreamer() {
  28 }
  29
  30 raw_ostream &MCStreamer::GetCommentOS() {
  31   // By default, discard comments.
  32   return nulls();
  33 }
  34
  35 void MCStreamer::EmitDwarfSetLineAddr(int64_t LineDelta,
  36                                       const MCSymbol *Label, int PointerSize) {
  37   // emit the sequence to set the address
  38   EmitIntValue(dwarf::DW_LNS_extended_op, 1);
  39   EmitULEB128IntValue(PointerSize + 1);
  40   EmitIntValue(dwarf::DW_LNE_set_address, 1);
  41   EmitSymbolValue(Label, PointerSize);
  42
  43   // emit the sequence for the LineDelta (from 1) and a zero address delta.
  44   MCDwarfLineAddr::Emit(this, LineDelta, 0);
  45 }
  46
  47 /// EmitIntValue - Special case of EmitValue that avoids the client having to
  48 /// pass in a MCExpr for constant integers.
  49 void MCStreamer::EmitIntValue(uint64_t Value, unsigned Size,
  50                               unsigned AddrSpace) {
  51   assert(Size <= 8 && "Invalid size");
  52   assert((isUIntN(8 * Size, Value) || isIntN(8 * Size, Value)) &&
  53          "Invalid size");
  54   char buf[8];
  55   // FIXME: Endianness assumption.
  56   for (unsigned i = 0; i != Size; ++i)
  57     buf[i] = uint8_t(Value >> (i * 8));
  58   EmitBytes(StringRef(buf, Size), AddrSpace);
  59 }
  60
  61 /// EmitULEB128Value - Special case of EmitULEB128Value that avoids the
  62 /// client having to pass in a MCExpr for constant integers.
  63 void MCStreamer::EmitULEB128IntValue(uint64_t Value, unsigned AddrSpace) {
  64   SmallString<32> Tmp;
  65   raw_svector_ostream OSE(Tmp);
  66   MCObjectWriter::EncodeULEB128(Value, OSE);
  67   EmitBytes(OSE.str(), AddrSpace);
  68 }
  69
  70 /// EmitSLEB128Value - Special case of EmitSLEB128Value that avoids the
  71 /// client having to pass in a MCExpr for constant integers.
  72 void MCStreamer::EmitSLEB128IntValue(int64_t Value, unsigned AddrSpace) {
  73   SmallString<32> Tmp;
  74   raw_svector_ostream OSE(Tmp);
  75   MCObjectWriter::EncodeSLEB128(Value, OSE);
  76   EmitBytes(OSE.str(), AddrSpace);
  77 }
  78
  79 void MCStreamer::EmitAbsValue(const MCExpr *Value, unsigned Size,
  80                               unsigned AddrSpace) {
  81   if (getContext().getAsmInfo().hasAggressiveSymbolFolding()) {
  82     EmitValue(Value, Size, AddrSpace);
  83     return;
  84   }
  85   MCSymbol *ABS = getContext().CreateTempSymbol();
  86   EmitAssignment(ABS, Value);
  87   EmitSymbolValue(ABS, Size, AddrSpace);
  88 }
  89
  90
  91 void MCStreamer::EmitValue(const MCExpr *Value, unsigned Size,
  92                            unsigned AddrSpace) {
  93   EmitValueImpl(Value, Size, false, AddrSpace);
  94 }
  95
  96 void MCStreamer::EmitPCRelValue(const MCExpr *Value, unsigned Size,
  97                                 unsigned AddrSpace) {
  98   EmitValueImpl(Value, Size, true, AddrSpace);
  99 }
 100
 101 void MCStreamer::EmitSymbolValue(const MCSymbol *Sym, unsigned Size,
 102                                  bool isPCRel, unsigned AddrSpace) {
 103   EmitValueImpl(MCSymbolRefExpr::Create(Sym, getContext()), Size, isPCRel,
 104                 AddrSpace);
 105 }
 106
 107 void MCStreamer::EmitSymbolValue(const MCSymbol *Sym, unsigned Size,
 108                                  unsigned AddrSpace) {
 109   EmitSymbolValue(Sym, Size, false, AddrSpace);
 110 }
 111
 112 void MCStreamer::EmitPCRelSymbolValue(const MCSymbol *Sym, unsigned Size,
 113                                       unsigned AddrSpace) {
 114   EmitSymbolValue(Sym, Size, true, AddrSpace);
 115 }
 116
 117 void MCStreamer::EmitGPRel32Value(const MCExpr *Value) {
 118   report_fatal_error("unsupported directive in streamer");
 119 }
 120
 121 /// EmitFill - Emit NumBytes bytes worth of the value specified by
 122 /// FillValue.  This implements directives such as '.space'.
 123 void MCStreamer::EmitFill(uint64_t NumBytes, uint8_t FillValue,
 124                           unsigned AddrSpace) {
 125   const MCExpr *E = MCConstantExpr::Create(FillValue, getContext());
 126   for (uint64_t i = 0, e = NumBytes; i != e; ++i)
 127     EmitValue(E, 1, AddrSpace);
 128 }
 129
 130 bool MCStreamer::EmitDwarfFileDirective(unsigned FileNo,
 131                                         StringRef Filename) {
 132   return getContext().GetDwarfFile(Filename, FileNo) == 0;
 133 }
 134
 135 void MCStreamer::EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
 136                                        unsigned Column, unsigned Flags,
 137                                        unsigned Isa,
 138                                        unsigned Discriminator) {
 139   getContext().setCurrentDwarfLoc(FileNo, Line, Column, Flags, Isa,
 140                                   Discriminator);
 141 }
 142
 143 MCDwarfFrameInfo *MCStreamer::getCurrentFrameInfo() {
 144   if (FrameInfos.empty())
 145     return NULL;
 146   return &FrameInfos.back();
 147 }
 148
 149 void MCStreamer::EnsureValidFrame() {
 150   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
 151   if (!CurFrame || CurFrame->End)
 152     report_fatal_error("No open frame");
 153 }
 154
 155 void MCStreamer::EmitCFIStartProc() {
 156   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
 157   if (CurFrame && !CurFrame->End)
 158     report_fatal_error("Starting a frame before finishing the previous one!");
 159   MCDwarfFrameInfo Frame;
 160   Frame.Begin = getContext().CreateTempSymbol();
 161   EmitLabel(Frame.Begin);
 162   FrameInfos.push_back(Frame);
 163 }
 164
 165 void MCStreamer::EmitCFIEndProc() {
 166   EnsureValidFrame();
 167   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
 168   CurFrame->End = getContext().CreateTempSymbol();
 169   EmitLabel(CurFrame->End);
 170 }
 171
 172 void MCStreamer::EmitCFIDefCfa(int64_t Register, int64_t Offset) {
 173   EnsureValidFrame();
 174   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
 175   MCSymbol *Label = getContext().CreateTempSymbol();
 176   EmitLabel(Label);
 177   MachineLocation Dest(MachineLocation::VirtualFP);
 178   MachineLocation Source(Register, -Offset);
 179   MCCFIInstruction Instruction(Label, Dest, Source);
 180   CurFrame->Instructions.push_back(Instruction);
 181 }
 182
 183 void MCStreamer::EmitCFIDefCfaOffset(int64_t Offset) {
 184   EnsureValidFrame();
 185   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
 186   MCSymbol *Label = getContext().CreateTempSymbol();
 187   EmitLabel(Label);
 188   MachineLocation Dest(MachineLocation::VirtualFP);
 189   MachineLocation Source(MachineLocation::VirtualFP, -Offset);
 190   MCCFIInstruction Instruction(Label, Dest, Source);
 191   CurFrame->Instructions.push_back(Instruction);
 192 }
 193
 194 void MCStreamer::EmitCFIAdjustCfaOffset(int64_t Adjustment) {
 195   EnsureValidFrame();
 196   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
 197   MCSymbol *Label = getContext().CreateTempSymbol();
 198   EmitLabel(Label);
 199   MachineLocation Dest(MachineLocation::VirtualFP);
 200   MachineLocation Source(MachineLocation::VirtualFP, Adjustment);
 201   MCCFIInstruction Instruction(MCCFIInstruction::RelMove, Label, Dest, Source);
 202   CurFrame->Instructions.push_back(Instruction);
 203 }
 204
 205 void MCStreamer::EmitCFIDefCfaRegister(int64_t Register) {
 206   EnsureValidFrame();
 207   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
 208   MCSymbol *Label = getContext().CreateTempSymbol();
 209   EmitLabel(Label);
 210   MachineLocation Dest(Register);
 211   MachineLocation Source(MachineLocation::VirtualFP);
 212   MCCFIInstruction Instruction(Label, Dest, Source);
 213   CurFrame->Instructions.push_back(Instruction);
 214 }
 215
 216 void MCStreamer::EmitCFIOffset(int64_t Register, int64_t Offset) {
 217   EnsureValidFrame();
 218   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
 219   MCSymbol *Label = getContext().CreateTempSymbol();
 220   EmitLabel(Label);
 221   MachineLocation Dest(Register, Offset);
 222   MachineLocation Source(Register, Offset);
 223   MCCFIInstruction Instruction(Label, Dest, Source);
 224   CurFrame->Instructions.push_back(Instruction);
 225 }
 226
 227 void MCStreamer::EmitCFIRelOffset(int64_t Register, int64_t Offset) {
 228   EnsureValidFrame();
 229   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
 230   MCSymbol *Label = getContext().CreateTempSymbol();
 231   EmitLabel(Label);
 232   MachineLocation Dest(Register, Offset);
 233   MachineLocation Source(Register, Offset);
 234   MCCFIInstruction Instruction(MCCFIInstruction::RelMove, Label, Dest, Source);
 235   CurFrame->Instructions.push_back(Instruction);
 236 }
 237
 238 void MCStreamer::EmitCFIPersonality(const MCSymbol *Sym,
 239                                     unsigned Encoding) {
 240   EnsureValidFrame();
 241   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
 242   CurFrame->Personality = Sym;
 243   CurFrame->PersonalityEncoding = Encoding;
 244 }
 245
 246 void MCStreamer::EmitCFILsda(const MCSymbol *Sym, unsigned Encoding) {
 247   EnsureValidFrame();
 248   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
 249   CurFrame->Lsda = Sym;
 250   CurFrame->LsdaEncoding = Encoding;
 251 }
 252
 253 void MCStreamer::EmitCFIRememberState() {
 254   EnsureValidFrame();
 255   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
 256   MCSymbol *Label = getContext().CreateTempSymbol();
 257   EmitLabel(Label);
 258   MCCFIInstruction Instruction(MCCFIInstruction::Remember, Label);
 259   CurFrame->Instructions.push_back(Instruction);
 260 }
 261
 262 void MCStreamer::EmitCFIRestoreState() {
 263   // FIXME: Error if there is no matching cfi_remember_state.
 264   EnsureValidFrame();
 265   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
 266   MCSymbol *Label = getContext().CreateTempSymbol();
 267   EmitLabel(Label);
 268   MCCFIInstruction Instruction(MCCFIInstruction::Restore, Label);
 269   CurFrame->Instructions.push_back(Instruction);
 270 }
 271
 272 void MCStreamer::EmitCFISameValue(int64_t Register) {
 273   EnsureValidFrame();
 274   MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
 275   MCSymbol *Label = getContext().CreateTempSymbol();
 276   EmitLabel(Label);
 277   MCCFIInstruction Instruction(MCCFIInstruction::SameValue, Label, Register);
 278   CurFrame->Instructions.push_back(Instruction);
 279 }
 280
 281 void MCStreamer::EmitFnStart() {
 282   errs() << "Not implemented yet\n";
 283   abort();
 284 }
 285
 286 void MCStreamer::EmitFnEnd() {
 287   errs() << "Not implemented yet\n";
 288   abort();
 289 }
 290
 291 void MCStreamer::EmitCantUnwind() {
 292   errs() << "Not implemented yet\n";
 293   abort();
 294 }
 295
 296 void MCStreamer::EmitHandlerData() {
 297   errs() << "Not implemented yet\n";
 298   abort();
 299 }
 300
 301 void MCStreamer::EmitPersonality(const MCSymbol *Personality) {
 302   errs() << "Not implemented yet\n";
 303   abort();
 304 }
 305
 306 void MCStreamer::EmitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset) {
 307   errs() << "Not implemented yet\n";
 308   abort();
 309 }
 310
 311 void MCStreamer::EmitPad(int64_t Offset) {
 312   errs() << "Not implemented yet\n";
 313   abort();
 314 }
 315
 316 void MCStreamer::EmitRegSave(const SmallVectorImpl<unsigned> &RegList, bool) {
 317   errs() << "Not implemented yet\n";
 318   abort();
 319 }
 320
 321 /// EmitRawText - If this file is backed by an assembly streamer, this dumps
 322 /// the specified string in the output .s file.  This capability is
 323 /// indicated by the hasRawTextSupport() predicate.
 324 void MCStreamer::EmitRawText(StringRef String) {
 325   errs() << "EmitRawText called on an MCStreamer that doesn't support it, "
 326   " something must not be fully mc'ized\n";
 327   abort();
 328 }
 329
 330 void MCStreamer::EmitRawText(const Twine &T) {
 331   SmallString<128> Str;
 332   T.toVector(Str);
 333   EmitRawText(Str.str());
 334 }