lib/ExecutionEngine/JIT/JITDwarfEmitter.cpp

   1 //===----- JITDwarfEmitter.cpp - Write dwarf tables into memory -----------===//
   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 // This file defines a JITDwarfEmitter object that is used by the JIT to
  11 // write dwarf tables to memory.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "JIT.h"
  16 #include "JITDwarfEmitter.h"
  17 #include "llvm/Function.h"
  18 #include "llvm/ADT/DenseMap.h"
  19 #include "llvm/CodeGen/JITCodeEmitter.h"
  20 #include "llvm/CodeGen/MachineFunction.h"
  21 #include "llvm/CodeGen/MachineLocation.h"
  22 #include "llvm/CodeGen/MachineModuleInfo.h"
  23 #include "llvm/ExecutionEngine/JITMemoryManager.h"
  24 #include "llvm/Support/ErrorHandling.h"
  25 #include "llvm/Target/TargetAsmInfo.h"
  26 #include "llvm/Target/TargetData.h"
  27 #include "llvm/Target/TargetInstrInfo.h"
  28 #include "llvm/Target/TargetFrameInfo.h"
  29 #include "llvm/Target/TargetMachine.h"
  30 #include "llvm/Target/TargetRegisterInfo.h"
  31
  32 using namespace llvm;
  33
  34 JITDwarfEmitter::JITDwarfEmitter(JIT& theJit) : Jit(theJit) {}
  35
  36
  37 unsigned char* JITDwarfEmitter::EmitDwarfTable(MachineFunction& F,
  38                                                JITCodeEmitter& jce,
  39                                                unsigned char* StartFunction,
  40                                                unsigned char* EndFunction) {
  41   const TargetMachine& TM = F.getTarget();
  42   TD = TM.getTargetData();
  43   needsIndirectEncoding = TM.getTargetAsmInfo()->getNeedsIndirectEncoding();
  44   stackGrowthDirection = TM.getFrameInfo()->getStackGrowthDirection();
  45   RI = TM.getRegisterInfo();
  46   JCE = &jce;
  47
  48   unsigned char* ExceptionTable = EmitExceptionTable(&F, StartFunction,
  49                                                      EndFunction);
  50
  51   unsigned char* Result = 0;
  52   unsigned char* EHFramePtr = 0;
  53
  54   const std::vector<Function *> Personalities = MMI->getPersonalities();
  55   EHFramePtr = EmitCommonEHFrame(Personalities[MMI->getPersonalityIndex()]);
  56
  57   Result = EmitEHFrame(Personalities[MMI->getPersonalityIndex()], EHFramePtr,
  58                        StartFunction, EndFunction, ExceptionTable);
  59
  60   return Result;
  61 }
  62
  63
  64 void
  65 JITDwarfEmitter::EmitFrameMoves(intptr_t BaseLabelPtr,
  66                                 const std::vector<MachineMove> &Moves) const {
  67   unsigned PointerSize = TD->getPointerSize();
  68   int stackGrowth = stackGrowthDirection == TargetFrameInfo::StackGrowsUp ?
  69           PointerSize : -PointerSize;
  70   bool IsLocal = false;
  71   unsigned BaseLabelID = 0;
  72
  73   for (unsigned i = 0, N = Moves.size(); i < N; ++i) {
  74     const MachineMove &Move = Moves[i];
  75     unsigned LabelID = Move.getLabelID();
  76
  77     if (LabelID) {
  78       LabelID = MMI->MappedLabel(LabelID);
  79
  80       // Throw out move if the label is invalid.
  81       if (!LabelID) continue;
  82     }
  83
  84     intptr_t LabelPtr = 0;
  85     if (LabelID) LabelPtr = JCE->getLabelAddress(LabelID);
  86
  87     const MachineLocation &Dst = Move.getDestination();
  88     const MachineLocation &Src = Move.getSource();
  89
  90     // Advance row if new location.
  91     if (BaseLabelPtr && LabelID && (BaseLabelID != LabelID || !IsLocal)) {
  92       JCE->emitByte(dwarf::DW_CFA_advance_loc4);
  93       JCE->emitInt32(LabelPtr - BaseLabelPtr);
  94
  95       BaseLabelID = LabelID;
  96       BaseLabelPtr = LabelPtr;
  97       IsLocal = true;
  98     }
  99
 100     // If advancing cfa.
 101     if (Dst.isReg() && Dst.getReg() == MachineLocation::VirtualFP) {
 102       if (!Src.isReg()) {
 103         if (Src.getReg() == MachineLocation::VirtualFP) {
 104           JCE->emitByte(dwarf::DW_CFA_def_cfa_offset);
 105         } else {
 106           JCE->emitByte(dwarf::DW_CFA_def_cfa);
 107           JCE->emitULEB128Bytes(RI->getDwarfRegNum(Src.getReg(), true));
 108         }
 109
 110         int Offset = -Src.getOffset();
 111
 112         JCE->emitULEB128Bytes(Offset);
 113       } else {
 114         llvm_unreachable("Machine move no supported yet.");
 115       }
 116     } else if (Src.isReg() &&
 117       Src.getReg() == MachineLocation::VirtualFP) {
 118       if (Dst.isReg()) {
 119         JCE->emitByte(dwarf::DW_CFA_def_cfa_register);
 120         JCE->emitULEB128Bytes(RI->getDwarfRegNum(Dst.getReg(), true));
 121       } else {
 122         llvm_unreachable("Machine move no supported yet.");
 123       }
 124     } else {
 125       unsigned Reg = RI->getDwarfRegNum(Src.getReg(), true);
 126       int Offset = Dst.getOffset() / stackGrowth;
 127
 128       if (Offset < 0) {
 129         JCE->emitByte(dwarf::DW_CFA_offset_extended_sf);
 130         JCE->emitULEB128Bytes(Reg);
 131         JCE->emitSLEB128Bytes(Offset);
 132       } else if (Reg < 64) {
 133         JCE->emitByte(dwarf::DW_CFA_offset + Reg);
 134         JCE->emitULEB128Bytes(Offset);
 135       } else {
 136         JCE->emitByte(dwarf::DW_CFA_offset_extended);
 137         JCE->emitULEB128Bytes(Reg);
 138         JCE->emitULEB128Bytes(Offset);
 139       }
 140     }
 141   }
 142 }
 143
 144 /// SharedTypeIds - How many leading type ids two landing pads have in common.
 145 static unsigned SharedTypeIds(const LandingPadInfo *L,
 146                               const LandingPadInfo *R) {
 147   const std::vector<int> &LIds = L->TypeIds, &RIds = R->TypeIds;
 148   unsigned LSize = LIds.size(), RSize = RIds.size();
 149   unsigned MinSize = LSize < RSize ? LSize : RSize;
 150   unsigned Count = 0;
 151
 152   for (; Count != MinSize; ++Count)
 153     if (LIds[Count] != RIds[Count])
 154       return Count;
 155
 156   return Count;
 157 }
 158
 159
 160 /// PadLT - Order landing pads lexicographically by type id.
 161 static bool PadLT(const LandingPadInfo *L, const LandingPadInfo *R) {
 162   const std::vector<int> &LIds = L->TypeIds, &RIds = R->TypeIds;
 163   unsigned LSize = LIds.size(), RSize = RIds.size();
 164   unsigned MinSize = LSize < RSize ? LSize : RSize;
 165
 166   for (unsigned i = 0; i != MinSize; ++i)
 167     if (LIds[i] != RIds[i])
 168       return LIds[i] < RIds[i];
 169
 170   return LSize < RSize;
 171 }
 172
 173 namespace {
 174
 175 struct KeyInfo {
 176   static inline unsigned getEmptyKey() { return -1U; }
 177   static inline unsigned getTombstoneKey() { return -2U; }
 178   static unsigned getHashValue(const unsigned &Key) { return Key; }
 179   static bool isEqual(unsigned LHS, unsigned RHS) { return LHS == RHS; }
 180   static bool isPod() { return true; }
 181 };
 182
 183 /// ActionEntry - Structure describing an entry in the actions table.
 184 struct ActionEntry {
 185   int ValueForTypeID; // The value to write - may not be equal to the type id.
 186   int NextAction;
 187   struct ActionEntry *Previous;
 188 };
 189
 190 /// PadRange - Structure holding a try-range and the associated landing pad.
 191 struct PadRange {
 192   // The index of the landing pad.
 193   unsigned PadIndex;
 194   // The index of the begin and end labels in the landing pad's label lists.
 195   unsigned RangeIndex;
 196 };
 197
 198 typedef DenseMap<unsigned, PadRange, KeyInfo> RangeMapType;
 199
 200 /// CallSiteEntry - Structure describing an entry in the call-site table.
 201 struct CallSiteEntry {
 202   unsigned BeginLabel; // zero indicates the start of the function.
 203   unsigned EndLabel;   // zero indicates the end of the function.
 204   unsigned PadLabel;   // zero indicates that there is no landing pad.
 205   unsigned Action;
 206 };
 207
 208 }
 209
 210 unsigned char* JITDwarfEmitter::EmitExceptionTable(MachineFunction* MF,
 211                                          unsigned char* StartFunction,
 212                                          unsigned char* EndFunction) const {
 213   // Map all labels and get rid of any dead landing pads.
 214   MMI->TidyLandingPads();
 215
 216   const std::vector<GlobalVariable *> &TypeInfos = MMI->getTypeInfos();
 217   const std::vector<unsigned> &FilterIds = MMI->getFilterIds();
 218   const std::vector<LandingPadInfo> &PadInfos = MMI->getLandingPads();
 219   if (PadInfos.empty()) return 0;
 220
 221   // Sort the landing pads in order of their type ids.  This is used to fold
 222   // duplicate actions.
 223   SmallVector<const LandingPadInfo *, 64> LandingPads;
 224   LandingPads.reserve(PadInfos.size());
 225   for (unsigned i = 0, N = PadInfos.size(); i != N; ++i)
 226     LandingPads.push_back(&PadInfos[i]);
 227   std::sort(LandingPads.begin(), LandingPads.end(), PadLT);
 228
 229   // Negative type ids index into FilterIds, positive type ids index into
 230   // TypeInfos.  The value written for a positive type id is just the type
 231   // id itself.  For a negative type id, however, the value written is the
 232   // (negative) byte offset of the corresponding FilterIds entry.  The byte
 233   // offset is usually equal to the type id, because the FilterIds entries
 234   // are written using a variable width encoding which outputs one byte per
 235   // entry as long as the value written is not too large, but can differ.
 236   // This kind of complication does not occur for positive type ids because
 237   // type infos are output using a fixed width encoding.
 238   // FilterOffsets[i] holds the byte offset corresponding to FilterIds[i].
 239   SmallVector<int, 16> FilterOffsets;
 240   FilterOffsets.reserve(FilterIds.size());
 241   int Offset = -1;
 242   for(std::vector<unsigned>::const_iterator I = FilterIds.begin(),
 243     E = FilterIds.end(); I != E; ++I) {
 244     FilterOffsets.push_back(Offset);
 245     Offset -= TargetAsmInfo::getULEB128Size(*I);
 246   }
 247
 248   // Compute the actions table and gather the first action index for each
 249   // landing pad site.
 250   SmallVector<ActionEntry, 32> Actions;
 251   SmallVector<unsigned, 64> FirstActions;
 252   FirstActions.reserve(LandingPads.size());
 253
 254   int FirstAction = 0;
 255   unsigned SizeActions = 0;
 256   for (unsigned i = 0, N = LandingPads.size(); i != N; ++i) {
 257     const LandingPadInfo *LP = LandingPads[i];
 258     const std::vector<int> &TypeIds = LP->TypeIds;
 259     const unsigned NumShared = i ? SharedTypeIds(LP, LandingPads[i-1]) : 0;
 260     unsigned SizeSiteActions = 0;
 261
 262     if (NumShared < TypeIds.size()) {
 263       unsigned SizeAction = 0;
 264       ActionEntry *PrevAction = 0;
 265
 266       if (NumShared) {
 267         const unsigned SizePrevIds = LandingPads[i-1]->TypeIds.size();
 268         assert(Actions.size());
 269         PrevAction = &Actions.back();
 270         SizeAction = TargetAsmInfo::getSLEB128Size(PrevAction->NextAction) +
 271           TargetAsmInfo::getSLEB128Size(PrevAction->ValueForTypeID);
 272         for (unsigned j = NumShared; j != SizePrevIds; ++j) {
 273           SizeAction -= TargetAsmInfo::getSLEB128Size(PrevAction->ValueForTypeID);
 274           SizeAction += -PrevAction->NextAction;
 275           PrevAction = PrevAction->Previous;
 276         }
 277       }
 278
 279       // Compute the actions.
 280       for (unsigned I = NumShared, M = TypeIds.size(); I != M; ++I) {
 281         int TypeID = TypeIds[I];
 282         assert(-1-TypeID < (int)FilterOffsets.size() && "Unknown filter id!");
 283         int ValueForTypeID = TypeID < 0 ? FilterOffsets[-1 - TypeID] : TypeID;
 284         unsigned SizeTypeID = TargetAsmInfo::getSLEB128Size(ValueForTypeID);
 285
 286         int NextAction = SizeAction ? -(SizeAction + SizeTypeID) : 0;
 287         SizeAction = SizeTypeID + TargetAsmInfo::getSLEB128Size(NextAction);
 288         SizeSiteActions += SizeAction;
 289
 290         ActionEntry Action = {ValueForTypeID, NextAction, PrevAction};
 291         Actions.push_back(Action);
 292
 293         PrevAction = &Actions.back();
 294       }
 295
 296       // Record the first action of the landing pad site.
 297       FirstAction = SizeActions + SizeSiteActions - SizeAction + 1;
 298     } // else identical - re-use previous FirstAction
 299
 300     FirstActions.push_back(FirstAction);
 301
 302     // Compute this sites contribution to size.
 303     SizeActions += SizeSiteActions;
 304   }
 305
 306   // Compute the call-site table.  Entries must be ordered by address.
 307   SmallVector<CallSiteEntry, 64> CallSites;
 308
 309   RangeMapType PadMap;
 310   for (unsigned i = 0, N = LandingPads.size(); i != N; ++i) {
 311     const LandingPadInfo *LandingPad = LandingPads[i];
 312     for (unsigned j=0, E = LandingPad->BeginLabels.size(); j != E; ++j) {
 313       unsigned BeginLabel = LandingPad->BeginLabels[j];
 314       assert(!PadMap.count(BeginLabel) && "Duplicate landing pad labels!");
 315       PadRange P = { i, j };
 316       PadMap[BeginLabel] = P;
 317     }
 318   }
 319
 320   bool MayThrow = false;
 321   unsigned LastLabel = 0;
 322   for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
 323         I != E; ++I) {
 324     for (MachineBasicBlock::const_iterator MI = I->begin(), E = I->end();
 325           MI != E; ++MI) {
 326       if (!MI->isLabel()) {
 327         MayThrow |= MI->getDesc().isCall();
 328         continue;
 329       }
 330
 331       unsigned BeginLabel = MI->getOperand(0).getImm();
 332       assert(BeginLabel && "Invalid label!");
 333
 334       if (BeginLabel == LastLabel)
 335         MayThrow = false;
 336
 337       RangeMapType::iterator L = PadMap.find(BeginLabel);
 338
 339       if (L == PadMap.end())
 340         continue;
 341
 342       PadRange P = L->second;
 343       const LandingPadInfo *LandingPad = LandingPads[P.PadIndex];
 344
 345       assert(BeginLabel == LandingPad->BeginLabels[P.RangeIndex] &&
 346               "Inconsistent landing pad map!");
 347
 348       // If some instruction between the previous try-range and this one may
 349       // throw, create a call-site entry with no landing pad for the region
 350       // between the try-ranges.
 351       if (MayThrow) {
 352         CallSiteEntry Site = {LastLabel, BeginLabel, 0, 0};
 353         CallSites.push_back(Site);
 354       }
 355
 356       LastLabel = LandingPad->EndLabels[P.RangeIndex];
 357       CallSiteEntry Site = {BeginLabel, LastLabel,
 358         LandingPad->LandingPadLabel, FirstActions[P.PadIndex]};
 359
 360       assert(Site.BeginLabel && Site.EndLabel && Site.PadLabel &&
 361               "Invalid landing pad!");
 362
 363       // Try to merge with the previous call-site.
 364       if (CallSites.size()) {
 365         CallSiteEntry &Prev = CallSites.back();
 366         if (Site.PadLabel == Prev.PadLabel && Site.Action == Prev.Action) {
 367           // Extend the range of the previous entry.
 368           Prev.EndLabel = Site.EndLabel;
 369           continue;
 370         }
 371       }
 372
 373       // Otherwise, create a new call-site.
 374       CallSites.push_back(Site);
 375     }
 376   }
 377   // If some instruction between the previous try-range and the end of the
 378   // function may throw, create a call-site entry with no landing pad for the
 379   // region following the try-range.
 380   if (MayThrow) {
 381     CallSiteEntry Site = {LastLabel, 0, 0, 0};
 382     CallSites.push_back(Site);
 383   }
 384
 385   // Final tallies.
 386   unsigned SizeSites = CallSites.size() * (sizeof(int32_t) + // Site start.
 387                                             sizeof(int32_t) + // Site length.
 388                                             sizeof(int32_t)); // Landing pad.
 389   for (unsigned i = 0, e = CallSites.size(); i < e; ++i)
 390     SizeSites += TargetAsmInfo::getULEB128Size(CallSites[i].Action);
 391
 392   unsigned SizeTypes = TypeInfos.size() * TD->getPointerSize();
 393
 394   unsigned TypeOffset = sizeof(int8_t) + // Call site format
 395                         // Call-site table length
 396                         TargetAsmInfo::getULEB128Size(SizeSites) +
 397                         SizeSites + SizeActions + SizeTypes;
 398
 399   unsigned TotalSize = sizeof(int8_t) + // LPStart format
 400                        sizeof(int8_t) + // TType format
 401                        TargetAsmInfo::getULEB128Size(TypeOffset) + // TType base offset
 402                        TypeOffset;
 403
 404   unsigned SizeAlign = (4 - TotalSize) & 3;
 405
 406   // Begin the exception table.
 407   JCE->emitAlignment(4);
 408   for (unsigned i = 0; i != SizeAlign; ++i) {
 409     JCE->emitByte(0);
 410     // Asm->EOL("Padding");
 411   }
 412
 413   unsigned char* DwarfExceptionTable = (unsigned char*)JCE->getCurrentPCValue();
 414
 415   // Emit the header.
 416   JCE->emitByte(dwarf::DW_EH_PE_omit);
 417   // Asm->EOL("LPStart format (DW_EH_PE_omit)");
 418   JCE->emitByte(dwarf::DW_EH_PE_absptr);
 419   // Asm->EOL("TType format (DW_EH_PE_absptr)");
 420   JCE->emitULEB128Bytes(TypeOffset);
 421   // Asm->EOL("TType base offset");
 422   JCE->emitByte(dwarf::DW_EH_PE_udata4);
 423   // Asm->EOL("Call site format (DW_EH_PE_udata4)");
 424   JCE->emitULEB128Bytes(SizeSites);
 425   // Asm->EOL("Call-site table length");
 426
 427   // Emit the landing pad site information.
 428   for (unsigned i = 0; i < CallSites.size(); ++i) {
 429     CallSiteEntry &S = CallSites[i];
 430     intptr_t BeginLabelPtr = 0;
 431     intptr_t EndLabelPtr = 0;
 432
 433     if (!S.BeginLabel) {
 434       BeginLabelPtr = (intptr_t)StartFunction;
 435       JCE->emitInt32(0);
 436     } else {
 437       BeginLabelPtr = JCE->getLabelAddress(S.BeginLabel);
 438       JCE->emitInt32(BeginLabelPtr - (intptr_t)StartFunction);
 439     }
 440
 441     // Asm->EOL("Region start");
 442
 443     if (!S.EndLabel) {
 444       EndLabelPtr = (intptr_t)EndFunction;
 445       JCE->emitInt32((intptr_t)EndFunction - BeginLabelPtr);
 446     } else {
 447       EndLabelPtr = JCE->getLabelAddress(S.EndLabel);
 448       JCE->emitInt32(EndLabelPtr - BeginLabelPtr);
 449     }
 450     //Asm->EOL("Region length");
 451
 452     if (!S.PadLabel) {
 453       JCE->emitInt32(0);
 454     } else {
 455       unsigned PadLabelPtr = JCE->getLabelAddress(S.PadLabel);
 456       JCE->emitInt32(PadLabelPtr - (intptr_t)StartFunction);
 457     }
 458     // Asm->EOL("Landing pad");
 459
 460     JCE->emitULEB128Bytes(S.Action);
 461     // Asm->EOL("Action");
 462   }
 463
 464   // Emit the actions.
 465   for (unsigned I = 0, N = Actions.size(); I != N; ++I) {
 466     ActionEntry &Action = Actions[I];
 467
 468     JCE->emitSLEB128Bytes(Action.ValueForTypeID);
 469     //Asm->EOL("TypeInfo index");
 470     JCE->emitSLEB128Bytes(Action.NextAction);
 471     //Asm->EOL("Next action");
 472   }
 473
 474   // Emit the type ids.
 475   for (unsigned M = TypeInfos.size(); M; --M) {
 476     GlobalVariable *GV = TypeInfos[M - 1];
 477
 478     if (GV) {
 479       if (TD->getPointerSize() == sizeof(int32_t)) {
 480         JCE->emitInt32((intptr_t)Jit.getOrEmitGlobalVariable(GV));
 481       } else {
 482         JCE->emitInt64((intptr_t)Jit.getOrEmitGlobalVariable(GV));
 483       }
 484     } else {
 485       if (TD->getPointerSize() == sizeof(int32_t))
 486         JCE->emitInt32(0);
 487       else
 488         JCE->emitInt64(0);
 489     }
 490     // Asm->EOL("TypeInfo");
 491   }
 492
 493   // Emit the filter typeids.
 494   for (unsigned j = 0, M = FilterIds.size(); j < M; ++j) {
 495     unsigned TypeID = FilterIds[j];
 496     JCE->emitULEB128Bytes(TypeID);
 497     //Asm->EOL("Filter TypeInfo index");
 498   }
 499
 500   JCE->emitAlignment(4);
 501
 502   return DwarfExceptionTable;
 503 }
 504
 505 unsigned char*
 506 JITDwarfEmitter::EmitCommonEHFrame(const Function* Personality) const {
 507   unsigned PointerSize = TD->getPointerSize();
 508   int stackGrowth = stackGrowthDirection == TargetFrameInfo::StackGrowsUp ?
 509           PointerSize : -PointerSize;
 510
 511   unsigned char* StartCommonPtr = (unsigned char*)JCE->getCurrentPCValue();
 512   // EH Common Frame header
 513   JCE->allocateSpace(4, 0);
 514   unsigned char* FrameCommonBeginPtr = (unsigned char*)JCE->getCurrentPCValue();
 515   JCE->emitInt32((int)0);
 516   JCE->emitByte(dwarf::DW_CIE_VERSION);
 517   JCE->emitString(Personality ? "zPLR" : "zR");
 518   JCE->emitULEB128Bytes(1);
 519   JCE->emitSLEB128Bytes(stackGrowth);
 520   JCE->emitByte(RI->getDwarfRegNum(RI->getRARegister(), true));
 521
 522   if (Personality) {
 523     // Augmentation Size: 3 small ULEBs of one byte each, and the personality
 524     // function which size is PointerSize.
 525     JCE->emitULEB128Bytes(3 + PointerSize);
 526
 527     // We set the encoding of the personality as direct encoding because we use
 528     // the function pointer. The encoding is not relative because the current
 529     // PC value may be bigger than the personality function pointer.
 530     if (PointerSize == 4) {
 531       JCE->emitByte(dwarf::DW_EH_PE_sdata4);
 532       JCE->emitInt32(((intptr_t)Jit.getPointerToGlobal(Personality)));
 533     } else {
 534       JCE->emitByte(dwarf::DW_EH_PE_sdata8);
 535       JCE->emitInt64(((intptr_t)Jit.getPointerToGlobal(Personality)));
 536     }
 537
 538     JCE->emitULEB128Bytes(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4);
 539     JCE->emitULEB128Bytes(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4);
 540
 541   } else {
 542     JCE->emitULEB128Bytes(1);
 543     JCE->emitULEB128Bytes(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4);
 544   }
 545
 546   std::vector<MachineMove> Moves;
 547   RI->getInitialFrameState(Moves);
 548   EmitFrameMoves(0, Moves);
 549   JCE->emitAlignment(PointerSize);
 550
 551   JCE->emitInt32At((uintptr_t*)StartCommonPtr,
 552               (uintptr_t)((unsigned char*)JCE->getCurrentPCValue() -
 553                           FrameCommonBeginPtr));
 554
 555   return StartCommonPtr;
 556 }
 557
 558
 559 unsigned char*
 560 JITDwarfEmitter::EmitEHFrame(const Function* Personality,
 561                              unsigned char* StartCommonPtr,
 562                              unsigned char* StartFunction,
 563                              unsigned char* EndFunction,
 564                              unsigned char* ExceptionTable) const {
 565   unsigned PointerSize = TD->getPointerSize();
 566
 567   // EH frame header.
 568   unsigned char* StartEHPtr = (unsigned char*)JCE->getCurrentPCValue();
 569   JCE->allocateSpace(4, 0);
 570   unsigned char* FrameBeginPtr = (unsigned char*)JCE->getCurrentPCValue();
 571   // FDE CIE Offset
 572   JCE->emitInt32(FrameBeginPtr - StartCommonPtr);
 573   JCE->emitInt32(StartFunction - (unsigned char*)JCE->getCurrentPCValue());
 574   JCE->emitInt32(EndFunction - StartFunction);
 575
 576   // If there is a personality and landing pads then point to the language
 577   // specific data area in the exception table.
 578   if (MMI->getPersonalityIndex()) {
 579     JCE->emitULEB128Bytes(4);
 580
 581     if (!MMI->getLandingPads().empty()) {
 582       JCE->emitInt32(ExceptionTable - (unsigned char*)JCE->getCurrentPCValue());
 583     } else {
 584       JCE->emitInt32((int)0);
 585     }
 586   } else {
 587     JCE->emitULEB128Bytes(0);
 588   }
 589
 590   // Indicate locations of function specific  callee saved registers in
 591   // frame.
 592   EmitFrameMoves((intptr_t)StartFunction, MMI->getFrameMoves());
 593
 594   JCE->emitAlignment(PointerSize);
 595
 596   // Indicate the size of the table
 597   JCE->emitInt32At((uintptr_t*)StartEHPtr,
 598               (uintptr_t)((unsigned char*)JCE->getCurrentPCValue() -
 599                           StartEHPtr));
 600
 601   // Double zeroes for the unwind runtime
 602   if (PointerSize == 8) {
 603     JCE->emitInt64(0);
 604     JCE->emitInt64(0);
 605   } else {
 606     JCE->emitInt32(0);
 607     JCE->emitInt32(0);
 608   }
 609
 610
 611   return StartEHPtr;
 612 }
 613
 614 unsigned JITDwarfEmitter::GetDwarfTableSizeInBytes(MachineFunction& F,
 615                                          JITCodeEmitter& jce,
 616                                          unsigned char* StartFunction,
 617                                          unsigned char* EndFunction) {
 618   const TargetMachine& TM = F.getTarget();
 619   TD = TM.getTargetData();
 620   needsIndirectEncoding = TM.getTargetAsmInfo()->getNeedsIndirectEncoding();
 621   stackGrowthDirection = TM.getFrameInfo()->getStackGrowthDirection();
 622   RI = TM.getRegisterInfo();
 623   JCE = &jce;
 624   unsigned FinalSize = 0;
 625
 626   FinalSize += GetExceptionTableSizeInBytes(&F);
 627
 628   const std::vector<Function *> Personalities = MMI->getPersonalities();
 629   FinalSize +=
 630     GetCommonEHFrameSizeInBytes(Personalities[MMI->getPersonalityIndex()]);
 631
 632   FinalSize += GetEHFrameSizeInBytes(Personalities[MMI->getPersonalityIndex()],
 633                                      StartFunction);
 634
 635   return FinalSize;
 636 }
 637
 638 /// RoundUpToAlign - Add the specified alignment to FinalSize and returns
 639 /// the new value.
 640 static unsigned RoundUpToAlign(unsigned FinalSize, unsigned Alignment) {
 641   if (Alignment == 0) Alignment = 1;
 642   // Since we do not know where the buffer will be allocated, be pessimistic.
 643   return FinalSize + Alignment;
 644 }
 645
 646 unsigned
 647 JITDwarfEmitter::GetEHFrameSizeInBytes(const Function* Personality,
 648                                        unsigned char* StartFunction) const {
 649   unsigned PointerSize = TD->getPointerSize();
 650   unsigned FinalSize = 0;
 651   // EH frame header.
 652   FinalSize += PointerSize;
 653   // FDE CIE Offset
 654   FinalSize += 3 * PointerSize;
 655   // If there is a personality and landing pads then point to the language
 656   // specific data area in the exception table.
 657   if (MMI->getPersonalityIndex()) {
 658     FinalSize += TargetAsmInfo::getULEB128Size(4);
 659     FinalSize += PointerSize;
 660   } else {
 661     FinalSize += TargetAsmInfo::getULEB128Size(0);
 662   }
 663
 664   // Indicate locations of function specific  callee saved registers in
 665   // frame.
 666   FinalSize += GetFrameMovesSizeInBytes((intptr_t)StartFunction,
 667                                         MMI->getFrameMoves());
 668
 669   FinalSize = RoundUpToAlign(FinalSize, 4);
 670
 671   // Double zeroes for the unwind runtime
 672   FinalSize += 2 * PointerSize;
 673
 674   return FinalSize;
 675 }
 676
 677 unsigned JITDwarfEmitter::GetCommonEHFrameSizeInBytes(const Function* Personality)
 678   const {
 679
 680   unsigned PointerSize = TD->getPointerSize();
 681   int stackGrowth = stackGrowthDirection == TargetFrameInfo::StackGrowsUp ?
 682           PointerSize : -PointerSize;
 683   unsigned FinalSize = 0;
 684   // EH Common Frame header
 685   FinalSize += PointerSize;
 686   FinalSize += 4;
 687   FinalSize += 1;
 688   FinalSize += Personality ? 5 : 3; // "zPLR" or "zR"
 689   FinalSize += TargetAsmInfo::getULEB128Size(1);
 690   FinalSize += TargetAsmInfo::getSLEB128Size(stackGrowth);
 691   FinalSize += 1;
 692
 693   if (Personality) {
 694     FinalSize += TargetAsmInfo::getULEB128Size(7);
 695
 696     // Encoding
 697     FinalSize+= 1;
 698     //Personality
 699     FinalSize += PointerSize;
 700
 701     FinalSize += TargetAsmInfo::getULEB128Size(dwarf::DW_EH_PE_pcrel);
 702     FinalSize += TargetAsmInfo::getULEB128Size(dwarf::DW_EH_PE_pcrel);
 703
 704   } else {
 705     FinalSize += TargetAsmInfo::getULEB128Size(1);
 706     FinalSize += TargetAsmInfo::getULEB128Size(dwarf::DW_EH_PE_pcrel);
 707   }
 708
 709   std::vector<MachineMove> Moves;
 710   RI->getInitialFrameState(Moves);
 711   FinalSize += GetFrameMovesSizeInBytes(0, Moves);
 712   FinalSize = RoundUpToAlign(FinalSize, 4);
 713   return FinalSize;
 714 }
 715
 716 unsigned
 717 JITDwarfEmitter::GetFrameMovesSizeInBytes(intptr_t BaseLabelPtr,
 718                                   const std::vector<MachineMove> &Moves) const {
 719   unsigned PointerSize = TD->getPointerSize();
 720   int stackGrowth = stackGrowthDirection == TargetFrameInfo::StackGrowsUp ?
 721           PointerSize : -PointerSize;
 722   bool IsLocal = BaseLabelPtr;
 723   unsigned FinalSize = 0;
 724
 725   for (unsigned i = 0, N = Moves.size(); i < N; ++i) {
 726     const MachineMove &Move = Moves[i];
 727     unsigned LabelID = Move.getLabelID();
 728
 729     if (LabelID) {
 730       LabelID = MMI->MappedLabel(LabelID);
 731
 732       // Throw out move if the label is invalid.
 733       if (!LabelID) continue;
 734     }
 735
 736     intptr_t LabelPtr = 0;
 737     if (LabelID) LabelPtr = JCE->getLabelAddress(LabelID);
 738
 739     const MachineLocation &Dst = Move.getDestination();
 740     const MachineLocation &Src = Move.getSource();
 741
 742     // Advance row if new location.
 743     if (BaseLabelPtr && LabelID && (BaseLabelPtr != LabelPtr || !IsLocal)) {
 744       FinalSize++;
 745       FinalSize += PointerSize;
 746       BaseLabelPtr = LabelPtr;
 747       IsLocal = true;
 748     }
 749
 750     // If advancing cfa.
 751     if (Dst.isReg() && Dst.getReg() == MachineLocation::VirtualFP) {
 752       if (!Src.isReg()) {
 753         if (Src.getReg() == MachineLocation::VirtualFP) {
 754           ++FinalSize;
 755         } else {
 756           ++FinalSize;
 757           unsigned RegNum = RI->getDwarfRegNum(Src.getReg(), true);
 758           FinalSize += TargetAsmInfo::getULEB128Size(RegNum);
 759         }
 760
 761         int Offset = -Src.getOffset();
 762
 763         FinalSize += TargetAsmInfo::getULEB128Size(Offset);
 764       } else {
 765         llvm_unreachable("Machine move no supported yet.");
 766       }
 767     } else if (Src.isReg() &&
 768       Src.getReg() == MachineLocation::VirtualFP) {
 769       if (Dst.isReg()) {
 770         ++FinalSize;
 771         unsigned RegNum = RI->getDwarfRegNum(Dst.getReg(), true);
 772         FinalSize += TargetAsmInfo::getULEB128Size(RegNum);
 773       } else {
 774         llvm_unreachable("Machine move no supported yet.");
 775       }
 776     } else {
 777       unsigned Reg = RI->getDwarfRegNum(Src.getReg(), true);
 778       int Offset = Dst.getOffset() / stackGrowth;
 779
 780       if (Offset < 0) {
 781         ++FinalSize;
 782         FinalSize += TargetAsmInfo::getULEB128Size(Reg);
 783         FinalSize += TargetAsmInfo::getSLEB128Size(Offset);
 784       } else if (Reg < 64) {
 785         ++FinalSize;
 786         FinalSize += TargetAsmInfo::getULEB128Size(Offset);
 787       } else {
 788         ++FinalSize;
 789         FinalSize += TargetAsmInfo::getULEB128Size(Reg);
 790         FinalSize += TargetAsmInfo::getULEB128Size(Offset);
 791       }
 792     }
 793   }
 794   return FinalSize;
 795 }
 796
 797 unsigned
 798 JITDwarfEmitter::GetExceptionTableSizeInBytes(MachineFunction* MF) const {
 799   unsigned FinalSize = 0;
 800
 801   // Map all labels and get rid of any dead landing pads.
 802   MMI->TidyLandingPads();
 803
 804   const std::vector<GlobalVariable *> &TypeInfos = MMI->getTypeInfos();
 805   const std::vector<unsigned> &FilterIds = MMI->getFilterIds();
 806   const std::vector<LandingPadInfo> &PadInfos = MMI->getLandingPads();
 807   if (PadInfos.empty()) return 0;
 808
 809   // Sort the landing pads in order of their type ids.  This is used to fold
 810   // duplicate actions.
 811   SmallVector<const LandingPadInfo *, 64> LandingPads;
 812   LandingPads.reserve(PadInfos.size());
 813   for (unsigned i = 0, N = PadInfos.size(); i != N; ++i)
 814     LandingPads.push_back(&PadInfos[i]);
 815   std::sort(LandingPads.begin(), LandingPads.end(), PadLT);
 816
 817   // Negative type ids index into FilterIds, positive type ids index into
 818   // TypeInfos.  The value written for a positive type id is just the type
 819   // id itself.  For a negative type id, however, the value written is the
 820   // (negative) byte offset of the corresponding FilterIds entry.  The byte
 821   // offset is usually equal to the type id, because the FilterIds entries
 822   // are written using a variable width encoding which outputs one byte per
 823   // entry as long as the value written is not too large, but can differ.
 824   // This kind of complication does not occur for positive type ids because
 825   // type infos are output using a fixed width encoding.
 826   // FilterOffsets[i] holds the byte offset corresponding to FilterIds[i].
 827   SmallVector<int, 16> FilterOffsets;
 828   FilterOffsets.reserve(FilterIds.size());
 829   int Offset = -1;
 830   for(std::vector<unsigned>::const_iterator I = FilterIds.begin(),
 831     E = FilterIds.end(); I != E; ++I) {
 832     FilterOffsets.push_back(Offset);
 833     Offset -= TargetAsmInfo::getULEB128Size(*I);
 834   }
 835
 836   // Compute the actions table and gather the first action index for each
 837   // landing pad site.
 838   SmallVector<ActionEntry, 32> Actions;
 839   SmallVector<unsigned, 64> FirstActions;
 840   FirstActions.reserve(LandingPads.size());
 841
 842   int FirstAction = 0;
 843   unsigned SizeActions = 0;
 844   for (unsigned i = 0, N = LandingPads.size(); i != N; ++i) {
 845     const LandingPadInfo *LP = LandingPads[i];
 846     const std::vector<int> &TypeIds = LP->TypeIds;
 847     const unsigned NumShared = i ? SharedTypeIds(LP, LandingPads[i-1]) : 0;
 848     unsigned SizeSiteActions = 0;
 849
 850     if (NumShared < TypeIds.size()) {
 851       unsigned SizeAction = 0;
 852       ActionEntry *PrevAction = 0;
 853
 854       if (NumShared) {
 855         const unsigned SizePrevIds = LandingPads[i-1]->TypeIds.size();
 856         assert(Actions.size());
 857         PrevAction = &Actions.back();
 858         SizeAction = TargetAsmInfo::getSLEB128Size(PrevAction->NextAction) +
 859           TargetAsmInfo::getSLEB128Size(PrevAction->ValueForTypeID);
 860         for (unsigned j = NumShared; j != SizePrevIds; ++j) {
 861           SizeAction -= TargetAsmInfo::getSLEB128Size(PrevAction->ValueForTypeID);
 862           SizeAction += -PrevAction->NextAction;
 863           PrevAction = PrevAction->Previous;
 864         }
 865       }
 866
 867       // Compute the actions.
 868       for (unsigned I = NumShared, M = TypeIds.size(); I != M; ++I) {
 869         int TypeID = TypeIds[I];
 870         assert(-1-TypeID < (int)FilterOffsets.size() && "Unknown filter id!");
 871         int ValueForTypeID = TypeID < 0 ? FilterOffsets[-1 - TypeID] : TypeID;
 872         unsigned SizeTypeID = TargetAsmInfo::getSLEB128Size(ValueForTypeID);
 873
 874         int NextAction = SizeAction ? -(SizeAction + SizeTypeID) : 0;
 875         SizeAction = SizeTypeID + TargetAsmInfo::getSLEB128Size(NextAction);
 876         SizeSiteActions += SizeAction;
 877
 878         ActionEntry Action = {ValueForTypeID, NextAction, PrevAction};
 879         Actions.push_back(Action);
 880
 881         PrevAction = &Actions.back();
 882       }
 883
 884       // Record the first action of the landing pad site.
 885       FirstAction = SizeActions + SizeSiteActions - SizeAction + 1;
 886     } // else identical - re-use previous FirstAction
 887
 888     FirstActions.push_back(FirstAction);
 889
 890     // Compute this sites contribution to size.
 891     SizeActions += SizeSiteActions;
 892   }
 893
 894   // Compute the call-site table.  Entries must be ordered by address.
 895   SmallVector<CallSiteEntry, 64> CallSites;
 896
 897   RangeMapType PadMap;
 898   for (unsigned i = 0, N = LandingPads.size(); i != N; ++i) {
 899     const LandingPadInfo *LandingPad = LandingPads[i];
 900     for (unsigned j=0, E = LandingPad->BeginLabels.size(); j != E; ++j) {
 901       unsigned BeginLabel = LandingPad->BeginLabels[j];
 902       assert(!PadMap.count(BeginLabel) && "Duplicate landing pad labels!");
 903       PadRange P = { i, j };
 904       PadMap[BeginLabel] = P;
 905     }
 906   }
 907
 908   bool MayThrow = false;
 909   unsigned LastLabel = 0;
 910   for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
 911         I != E; ++I) {
 912     for (MachineBasicBlock::const_iterator MI = I->begin(), E = I->end();
 913           MI != E; ++MI) {
 914       if (!MI->isLabel()) {
 915         MayThrow |= MI->getDesc().isCall();
 916         continue;
 917       }
 918
 919       unsigned BeginLabel = MI->getOperand(0).getImm();
 920       assert(BeginLabel && "Invalid label!");
 921
 922       if (BeginLabel == LastLabel)
 923         MayThrow = false;
 924
 925       RangeMapType::iterator L = PadMap.find(BeginLabel);
 926
 927       if (L == PadMap.end())
 928         continue;
 929
 930       PadRange P = L->second;
 931       const LandingPadInfo *LandingPad = LandingPads[P.PadIndex];
 932
 933       assert(BeginLabel == LandingPad->BeginLabels[P.RangeIndex] &&
 934               "Inconsistent landing pad map!");
 935
 936       // If some instruction between the previous try-range and this one may
 937       // throw, create a call-site entry with no landing pad for the region
 938       // between the try-ranges.
 939       if (MayThrow) {
 940         CallSiteEntry Site = {LastLabel, BeginLabel, 0, 0};
 941         CallSites.push_back(Site);
 942       }
 943
 944       LastLabel = LandingPad->EndLabels[P.RangeIndex];
 945       CallSiteEntry Site = {BeginLabel, LastLabel,
 946         LandingPad->LandingPadLabel, FirstActions[P.PadIndex]};
 947
 948       assert(Site.BeginLabel && Site.EndLabel && Site.PadLabel &&
 949               "Invalid landing pad!");
 950
 951       // Try to merge with the previous call-site.
 952       if (CallSites.size()) {
 953         CallSiteEntry &Prev = CallSites.back();
 954         if (Site.PadLabel == Prev.PadLabel && Site.Action == Prev.Action) {
 955           // Extend the range of the previous entry.
 956           Prev.EndLabel = Site.EndLabel;
 957           continue;
 958         }
 959       }
 960
 961       // Otherwise, create a new call-site.
 962       CallSites.push_back(Site);
 963     }
 964   }
 965   // If some instruction between the previous try-range and the end of the
 966   // function may throw, create a call-site entry with no landing pad for the
 967   // region following the try-range.
 968   if (MayThrow) {
 969     CallSiteEntry Site = {LastLabel, 0, 0, 0};
 970     CallSites.push_back(Site);
 971   }
 972
 973   // Final tallies.
 974   unsigned SizeSites = CallSites.size() * (sizeof(int32_t) + // Site start.
 975                                             sizeof(int32_t) + // Site length.
 976                                             sizeof(int32_t)); // Landing pad.
 977   for (unsigned i = 0, e = CallSites.size(); i < e; ++i)
 978     SizeSites += TargetAsmInfo::getULEB128Size(CallSites[i].Action);
 979
 980   unsigned SizeTypes = TypeInfos.size() * TD->getPointerSize();
 981
 982   unsigned TypeOffset = sizeof(int8_t) + // Call site format
 983                         // Call-site table length
 984                         TargetAsmInfo::getULEB128Size(SizeSites) +
 985                         SizeSites + SizeActions + SizeTypes;
 986
 987   unsigned TotalSize = sizeof(int8_t) + // LPStart format
 988                        sizeof(int8_t) + // TType format
 989                        TargetAsmInfo::getULEB128Size(TypeOffset) + // TType base offset
 990                        TypeOffset;
 991
 992   unsigned SizeAlign = (4 - TotalSize) & 3;
 993
 994   // Begin the exception table.
 995   FinalSize = RoundUpToAlign(FinalSize, 4);
 996   for (unsigned i = 0; i != SizeAlign; ++i) {
 997     ++FinalSize;
 998   }
 999
1000   unsigned PointerSize = TD->getPointerSize();
1001
1002   // Emit the header.
1003   ++FinalSize;
1004   // Asm->EOL("LPStart format (DW_EH_PE_omit)");
1005   ++FinalSize;
1006   // Asm->EOL("TType format (DW_EH_PE_absptr)");
1007   ++FinalSize;
1008   // Asm->EOL("TType base offset");
1009   ++FinalSize;
1010   // Asm->EOL("Call site format (DW_EH_PE_udata4)");
1011   ++FinalSize;
1012   // Asm->EOL("Call-site table length");
1013
1014   // Emit the landing pad site information.
1015   for (unsigned i = 0; i < CallSites.size(); ++i) {
1016     CallSiteEntry &S = CallSites[i];
1017
1018     // Asm->EOL("Region start");
1019     FinalSize += PointerSize;
1020
1021     //Asm->EOL("Region length");
1022     FinalSize += PointerSize;
1023
1024     // Asm->EOL("Landing pad");
1025     FinalSize += PointerSize;
1026
1027     FinalSize += TargetAsmInfo::getULEB128Size(S.Action);
1028     // Asm->EOL("Action");
1029   }
1030
1031   // Emit the actions.
1032   for (unsigned I = 0, N = Actions.size(); I != N; ++I) {
1033     ActionEntry &Action = Actions[I];
1034
1035     //Asm->EOL("TypeInfo index");
1036     FinalSize += TargetAsmInfo::getSLEB128Size(Action.ValueForTypeID);
1037     //Asm->EOL("Next action");
1038     FinalSize += TargetAsmInfo::getSLEB128Size(Action.NextAction);
1039   }
1040
1041   // Emit the type ids.
1042   for (unsigned M = TypeInfos.size(); M; --M) {
1043     // Asm->EOL("TypeInfo");
1044     FinalSize += PointerSize;
1045   }
1046
1047   // Emit the filter typeids.
1048   for (unsigned j = 0, M = FilterIds.size(); j < M; ++j) {
1049     unsigned TypeID = FilterIds[j];
1050     FinalSize += TargetAsmInfo::getULEB128Size(TypeID);
1051     //Asm->EOL("Filter TypeInfo index");
1052   }
1053
1054   FinalSize = RoundUpToAlign(FinalSize, 4);
1055
1056   return FinalSize;
1057 }