contrib/llvm/lib/DebugInfo/DWARF/DWARFExpression.cpp

   1 //===-- DWARFExpression.cpp -----------------------------------------------===//
   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/DebugInfo/DWARF/DWARFExpression.h"
  11 #include "llvm/BinaryFormat/Dwarf.h"
  12 #include "llvm/MC/MCRegisterInfo.h"
  13 #include "llvm/Support/Format.h"
  14 #include <cassert>
  15 #include <cstdint>
  16 #include <vector>
  17
  18 using namespace llvm;
  19 using namespace dwarf;
  20
  21 namespace llvm {
  22
  23 typedef std::vector<DWARFExpression::Operation::Description> DescVector;
  24
  25 static DescVector getDescriptions() {
  26   DescVector Descriptions;
  27   typedef DWARFExpression::Operation Op;
  28   typedef Op::Description Desc;
  29
  30   Descriptions.resize(0xff);
  31   Descriptions[DW_OP_addr] = Desc(Op::Dwarf2, Op::SizeAddr);
  32   Descriptions[DW_OP_deref] = Desc(Op::Dwarf2);
  33   Descriptions[DW_OP_const1u] = Desc(Op::Dwarf2, Op::Size1);
  34   Descriptions[DW_OP_const1s] = Desc(Op::Dwarf2, Op::SignedSize1);
  35   Descriptions[DW_OP_const2u] = Desc(Op::Dwarf2, Op::Size2);
  36   Descriptions[DW_OP_const2s] = Desc(Op::Dwarf2, Op::SignedSize2);
  37   Descriptions[DW_OP_const4u] = Desc(Op::Dwarf2, Op::Size4);
  38   Descriptions[DW_OP_const4s] = Desc(Op::Dwarf2, Op::SignedSize4);
  39   Descriptions[DW_OP_const8u] = Desc(Op::Dwarf2, Op::Size8);
  40   Descriptions[DW_OP_const8s] = Desc(Op::Dwarf2, Op::SignedSize8);
  41   Descriptions[DW_OP_constu] = Desc(Op::Dwarf2, Op::SizeLEB);
  42   Descriptions[DW_OP_consts] = Desc(Op::Dwarf2, Op::SignedSizeLEB);
  43   Descriptions[DW_OP_dup] = Desc(Op::Dwarf2);
  44   Descriptions[DW_OP_drop] = Desc(Op::Dwarf2);
  45   Descriptions[DW_OP_over] = Desc(Op::Dwarf2);
  46   Descriptions[DW_OP_pick] = Desc(Op::Dwarf2, Op::Size1);
  47   Descriptions[DW_OP_swap] = Desc(Op::Dwarf2);
  48   Descriptions[DW_OP_rot] = Desc(Op::Dwarf2);
  49   Descriptions[DW_OP_xderef] = Desc(Op::Dwarf2);
  50   Descriptions[DW_OP_abs] = Desc(Op::Dwarf2);
  51   Descriptions[DW_OP_and] = Desc(Op::Dwarf2);
  52   Descriptions[DW_OP_div] = Desc(Op::Dwarf2);
  53   Descriptions[DW_OP_minus] = Desc(Op::Dwarf2);
  54   Descriptions[DW_OP_mod] = Desc(Op::Dwarf2);
  55   Descriptions[DW_OP_mul] = Desc(Op::Dwarf2);
  56   Descriptions[DW_OP_neg] = Desc(Op::Dwarf2);
  57   Descriptions[DW_OP_not] = Desc(Op::Dwarf2);
  58   Descriptions[DW_OP_or] = Desc(Op::Dwarf2);
  59   Descriptions[DW_OP_plus] = Desc(Op::Dwarf2);
  60   Descriptions[DW_OP_plus_uconst] = Desc(Op::Dwarf2, Op::SizeLEB);
  61   Descriptions[DW_OP_shl] = Desc(Op::Dwarf2);
  62   Descriptions[DW_OP_shr] = Desc(Op::Dwarf2);
  63   Descriptions[DW_OP_shra] = Desc(Op::Dwarf2);
  64   Descriptions[DW_OP_xor] = Desc(Op::Dwarf2);
  65   Descriptions[DW_OP_skip] = Desc(Op::Dwarf2, Op::SignedSize2);
  66   Descriptions[DW_OP_bra] = Desc(Op::Dwarf2, Op::SignedSize2);
  67   Descriptions[DW_OP_eq] = Desc(Op::Dwarf2);
  68   Descriptions[DW_OP_ge] = Desc(Op::Dwarf2);
  69   Descriptions[DW_OP_gt] = Desc(Op::Dwarf2);
  70   Descriptions[DW_OP_le] = Desc(Op::Dwarf2);
  71   Descriptions[DW_OP_lt] = Desc(Op::Dwarf2);
  72   Descriptions[DW_OP_ne] = Desc(Op::Dwarf2);
  73   for (uint16_t LA = DW_OP_lit0; LA <= DW_OP_lit31; ++LA)
  74     Descriptions[LA] = Desc(Op::Dwarf2);
  75   for (uint16_t LA = DW_OP_reg0; LA <= DW_OP_reg31; ++LA)
  76     Descriptions[LA] = Desc(Op::Dwarf2);
  77   for (uint16_t LA = DW_OP_breg0; LA <= DW_OP_breg31; ++LA)
  78     Descriptions[LA] = Desc(Op::Dwarf2, Op::SignedSizeLEB);
  79   Descriptions[DW_OP_regx] = Desc(Op::Dwarf2, Op::SizeLEB);
  80   Descriptions[DW_OP_fbreg] = Desc(Op::Dwarf2, Op::SignedSizeLEB);
  81   Descriptions[DW_OP_bregx] = Desc(Op::Dwarf2, Op::SizeLEB, Op::SignedSizeLEB);
  82   Descriptions[DW_OP_piece] = Desc(Op::Dwarf2, Op::SizeLEB);
  83   Descriptions[DW_OP_deref_size] = Desc(Op::Dwarf2, Op::Size1);
  84   Descriptions[DW_OP_xderef_size] = Desc(Op::Dwarf2, Op::Size1);
  85   Descriptions[DW_OP_nop] = Desc(Op::Dwarf2);
  86   Descriptions[DW_OP_push_object_address] = Desc(Op::Dwarf3);
  87   Descriptions[DW_OP_call2] = Desc(Op::Dwarf3, Op::Size2);
  88   Descriptions[DW_OP_call4] = Desc(Op::Dwarf3, Op::Size4);
  89   Descriptions[DW_OP_call_ref] = Desc(Op::Dwarf3, Op::SizeRefAddr);
  90   Descriptions[DW_OP_form_tls_address] = Desc(Op::Dwarf3);
  91   Descriptions[DW_OP_call_frame_cfa] = Desc(Op::Dwarf3);
  92   Descriptions[DW_OP_bit_piece] = Desc(Op::Dwarf3, Op::SizeLEB, Op::SizeLEB);
  93   Descriptions[DW_OP_implicit_value] =
  94       Desc(Op::Dwarf3, Op::SizeLEB, Op::SizeBlock);
  95   Descriptions[DW_OP_stack_value] = Desc(Op::Dwarf3);
  96   Descriptions[DW_OP_GNU_push_tls_address] = Desc(Op::Dwarf3);
  97   Descriptions[DW_OP_GNU_addr_index] = Desc(Op::Dwarf4, Op::SizeLEB);
  98   Descriptions[DW_OP_GNU_const_index] = Desc(Op::Dwarf4, Op::SizeLEB);
  99   return Descriptions;
 100 }
 101
 102 static DWARFExpression::Operation::Description getOpDesc(unsigned OpCode) {
 103   // FIXME: Make this constexpr once all compilers are smart enough to do it.
 104   static DescVector Descriptions = getDescriptions();
 105   // Handle possible corrupted or unsupported operation.
 106   if (OpCode >= Descriptions.size())
 107     return {};
 108   return Descriptions[OpCode];
 109 }
 110
 111 static uint8_t getRefAddrSize(uint8_t AddrSize, uint16_t Version) {
 112   return (Version == 2) ? AddrSize : 4;
 113 }
 114
 115 bool DWARFExpression::Operation::extract(DataExtractor Data, uint16_t Version,
 116                                          uint8_t AddressSize, uint32_t Offset) {
 117   Opcode = Data.getU8(&Offset);
 118
 119   Desc = getOpDesc(Opcode);
 120   if (Desc.Version == Operation::DwarfNA) {
 121     EndOffset = Offset;
 122     return false;
 123   }
 124
 125   for (unsigned Operand = 0; Operand < 2; ++Operand) {
 126     unsigned Size = Desc.Op[Operand];
 127     unsigned Signed = Size & Operation::SignBit;
 128
 129     if (Size == Operation::SizeNA)
 130       break;
 131
 132     switch (Size & ~Operation::SignBit) {
 133     case Operation::Size1:
 134       Operands[Operand] = Data.getU8(&Offset);
 135       if (Signed)
 136         Operands[Operand] = (int8_t)Operands[Operand];
 137       break;
 138     case Operation::Size2:
 139       Operands[Operand] = Data.getU16(&Offset);
 140       if (Signed)
 141         Operands[Operand] = (int16_t)Operands[Operand];
 142       break;
 143     case Operation::Size4:
 144       Operands[Operand] = Data.getU32(&Offset);
 145       if (Signed)
 146         Operands[Operand] = (int32_t)Operands[Operand];
 147       break;
 148     case Operation::Size8:
 149       Operands[Operand] = Data.getU64(&Offset);
 150       break;
 151     case Operation::SizeAddr:
 152       if (AddressSize == 8) {
 153         Operands[Operand] = Data.getU64(&Offset);
 154       } else {
 155         assert(AddressSize == 4);
 156         Operands[Operand] = Data.getU32(&Offset);
 157       }
 158       break;
 159     case Operation::SizeRefAddr:
 160       if (getRefAddrSize(AddressSize, Version) == 8) {
 161         Operands[Operand] = Data.getU64(&Offset);
 162       } else {
 163         assert(getRefAddrSize(AddressSize, Version) == 4);
 164         Operands[Operand] = Data.getU32(&Offset);
 165       }
 166       break;
 167     case Operation::SizeLEB:
 168       if (Signed)
 169         Operands[Operand] = Data.getSLEB128(&Offset);
 170       else
 171         Operands[Operand] = Data.getULEB128(&Offset);
 172       break;
 173     case Operation::SizeBlock:
 174       // We need a size, so this cannot be the first operand
 175       if (Operand == 0)
 176         return false;
 177       // Store the offset of the block as the value.
 178       Operands[Operand] = Offset;
 179       Offset += Operands[Operand - 1];
 180       break;
 181     default:
 182       llvm_unreachable("Unknown DWARFExpression Op size");
 183     }
 184   }
 185
 186   EndOffset = Offset;
 187   return true;
 188 }
 189
 190 static bool prettyPrintRegisterOp(raw_ostream &OS, uint8_t Opcode,
 191                                   uint64_t Operands[2],
 192                                   const MCRegisterInfo *MRI, bool isEH) {
 193   if (!MRI)
 194     return false;
 195
 196   uint64_t DwarfRegNum;
 197   unsigned OpNum = 0;
 198
 199   if (Opcode == DW_OP_bregx || Opcode == DW_OP_regx)
 200     DwarfRegNum = Operands[OpNum++];
 201   else if (Opcode >= DW_OP_breg0 && Opcode < DW_OP_bregx)
 202     DwarfRegNum = Opcode - DW_OP_breg0;
 203   else
 204     DwarfRegNum = Opcode - DW_OP_reg0;
 205
 206   int LLVMRegNum = MRI->getLLVMRegNum(DwarfRegNum, isEH);
 207   if (LLVMRegNum >= 0) {
 208     if (const char *RegName = MRI->getName(LLVMRegNum)) {
 209       if ((Opcode >= DW_OP_breg0 && Opcode <= DW_OP_breg31) ||
 210           Opcode == DW_OP_bregx)
 211         OS << format(" %s%+" PRId64, RegName, Operands[OpNum]);
 212       else
 213         OS << ' ' << RegName;
 214       return true;
 215     }
 216   }
 217
 218   return false;
 219 }
 220
 221 bool DWARFExpression::Operation::print(raw_ostream &OS,
 222                                        const DWARFExpression *Expr,
 223                                        const MCRegisterInfo *RegInfo,
 224                                        bool isEH) {
 225   if (Error) {
 226     OS << "<decoding error>";
 227     return false;
 228   }
 229
 230   StringRef Name = OperationEncodingString(Opcode);
 231   assert(!Name.empty() && "DW_OP has no name!");
 232   OS << Name;
 233
 234   if ((Opcode >= DW_OP_breg0 && Opcode <= DW_OP_breg31) ||
 235       (Opcode >= DW_OP_reg0 && Opcode <= DW_OP_reg31) ||
 236       Opcode == DW_OP_bregx || Opcode == DW_OP_regx)
 237     if (prettyPrintRegisterOp(OS, Opcode, Operands, RegInfo, isEH))
 238       return true;
 239
 240   for (unsigned Operand = 0; Operand < 2; ++Operand) {
 241     unsigned Size = Desc.Op[Operand];
 242     unsigned Signed = Size & Operation::SignBit;
 243
 244     if (Size == Operation::SizeNA)
 245       break;
 246
 247     if (Size == Operation::SizeBlock) {
 248       uint32_t Offset = Operands[Operand];
 249       for (unsigned i = 0; i < Operands[Operand - 1]; ++i)
 250         OS << format(" 0x%02x", Expr->Data.getU8(&Offset));
 251     } else {
 252       if (Signed)
 253         OS << format(" %+" PRId64, (int64_t)Operands[Operand]);
 254       else
 255         OS << format(" 0x%" PRIx64, Operands[Operand]);
 256     }
 257   }
 258   return true;
 259 }
 260
 261 void DWARFExpression::print(raw_ostream &OS, const MCRegisterInfo *RegInfo,
 262                             bool IsEH) const {
 263   for (auto &Op : *this) {
 264     if (!Op.print(OS, this, RegInfo, IsEH)) {
 265       uint32_t FailOffset = Op.getEndOffset();
 266       while (FailOffset < Data.getData().size())
 267         OS << format(" %02x", Data.getU8(&FailOffset));
 268       return;
 269     }
 270     if (Op.getEndOffset() < Data.getData().size())
 271       OS << ", ";
 272   }
 273 }
 274
 275 } // namespace llvm