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      1 //===-- DWARFExpression.cpp -------------------------------------*- C++ -*-===//
      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 "lldb/Expression/DWARFExpression.h"
     11 
     12 #include <vector>
     13 
     14 #include "lldb/Core/DataEncoder.h"
     15 #include "lldb/Core/dwarf.h"
     16 #include "lldb/Core/Log.h"
     17 #include "lldb/Core/RegisterValue.h"
     18 #include "lldb/Core/StreamString.h"
     19 #include "lldb/Core/Scalar.h"
     20 #include "lldb/Core/Value.h"
     21 #include "lldb/Core/VMRange.h"
     22 
     23 #include "lldb/Expression/ClangExpressionDeclMap.h"
     24 #include "lldb/Expression/ClangExpressionVariable.h"
     25 
     26 #include "lldb/Host/Endian.h"
     27 #include "lldb/Host/Host.h"
     28 
     29 #include "lldb/lldb-private-log.h"
     30 
     31 #include "lldb/Symbol/ClangASTType.h"
     32 #include "lldb/Symbol/ClangASTContext.h"
     33 #include "lldb/Symbol/Type.h"
     34 
     35 #include "lldb/Target/ABI.h"
     36 #include "lldb/Target/ExecutionContext.h"
     37 #include "lldb/Target/Process.h"
     38 #include "lldb/Target/RegisterContext.h"
     39 #include "lldb/Target/StackFrame.h"
     40 #include "lldb/Target/StackID.h"
     41 
     42 using namespace lldb;
     43 using namespace lldb_private;
     44 
     45 const char *
     46 DW_OP_value_to_name (uint32_t val)
     47 {
     48   static char invalid[100];
     49   switch (val) {
     50     case 0x03: return "DW_OP_addr";
     51     case 0x06: return "DW_OP_deref";
     52     case 0x08: return "DW_OP_const1u";
     53     case 0x09: return "DW_OP_const1s";
     54     case 0x0a: return "DW_OP_const2u";
     55     case 0x0b: return "DW_OP_const2s";
     56     case 0x0c: return "DW_OP_const4u";
     57     case 0x0d: return "DW_OP_const4s";
     58     case 0x0e: return "DW_OP_const8u";
     59     case 0x0f: return "DW_OP_const8s";
     60     case 0x10: return "DW_OP_constu";
     61     case 0x11: return "DW_OP_consts";
     62     case 0x12: return "DW_OP_dup";
     63     case 0x13: return "DW_OP_drop";
     64     case 0x14: return "DW_OP_over";
     65     case 0x15: return "DW_OP_pick";
     66     case 0x16: return "DW_OP_swap";
     67     case 0x17: return "DW_OP_rot";
     68     case 0x18: return "DW_OP_xderef";
     69     case 0x19: return "DW_OP_abs";
     70     case 0x1a: return "DW_OP_and";
     71     case 0x1b: return "DW_OP_div";
     72     case 0x1c: return "DW_OP_minus";
     73     case 0x1d: return "DW_OP_mod";
     74     case 0x1e: return "DW_OP_mul";
     75     case 0x1f: return "DW_OP_neg";
     76     case 0x20: return "DW_OP_not";
     77     case 0x21: return "DW_OP_or";
     78     case 0x22: return "DW_OP_plus";
     79     case 0x23: return "DW_OP_plus_uconst";
     80     case 0x24: return "DW_OP_shl";
     81     case 0x25: return "DW_OP_shr";
     82     case 0x26: return "DW_OP_shra";
     83     case 0x27: return "DW_OP_xor";
     84     case 0x2f: return "DW_OP_skip";
     85     case 0x28: return "DW_OP_bra";
     86     case 0x29: return "DW_OP_eq";
     87     case 0x2a: return "DW_OP_ge";
     88     case 0x2b: return "DW_OP_gt";
     89     case 0x2c: return "DW_OP_le";
     90     case 0x2d: return "DW_OP_lt";
     91     case 0x2e: return "DW_OP_ne";
     92     case 0x30: return "DW_OP_lit0";
     93     case 0x31: return "DW_OP_lit1";
     94     case 0x32: return "DW_OP_lit2";
     95     case 0x33: return "DW_OP_lit3";
     96     case 0x34: return "DW_OP_lit4";
     97     case 0x35: return "DW_OP_lit5";
     98     case 0x36: return "DW_OP_lit6";
     99     case 0x37: return "DW_OP_lit7";
    100     case 0x38: return "DW_OP_lit8";
    101     case 0x39: return "DW_OP_lit9";
    102     case 0x3a: return "DW_OP_lit10";
    103     case 0x3b: return "DW_OP_lit11";
    104     case 0x3c: return "DW_OP_lit12";
    105     case 0x3d: return "DW_OP_lit13";
    106     case 0x3e: return "DW_OP_lit14";
    107     case 0x3f: return "DW_OP_lit15";
    108     case 0x40: return "DW_OP_lit16";
    109     case 0x41: return "DW_OP_lit17";
    110     case 0x42: return "DW_OP_lit18";
    111     case 0x43: return "DW_OP_lit19";
    112     case 0x44: return "DW_OP_lit20";
    113     case 0x45: return "DW_OP_lit21";
    114     case 0x46: return "DW_OP_lit22";
    115     case 0x47: return "DW_OP_lit23";
    116     case 0x48: return "DW_OP_lit24";
    117     case 0x49: return "DW_OP_lit25";
    118     case 0x4a: return "DW_OP_lit26";
    119     case 0x4b: return "DW_OP_lit27";
    120     case 0x4c: return "DW_OP_lit28";
    121     case 0x4d: return "DW_OP_lit29";
    122     case 0x4e: return "DW_OP_lit30";
    123     case 0x4f: return "DW_OP_lit31";
    124     case 0x50: return "DW_OP_reg0";
    125     case 0x51: return "DW_OP_reg1";
    126     case 0x52: return "DW_OP_reg2";
    127     case 0x53: return "DW_OP_reg3";
    128     case 0x54: return "DW_OP_reg4";
    129     case 0x55: return "DW_OP_reg5";
    130     case 0x56: return "DW_OP_reg6";
    131     case 0x57: return "DW_OP_reg7";
    132     case 0x58: return "DW_OP_reg8";
    133     case 0x59: return "DW_OP_reg9";
    134     case 0x5a: return "DW_OP_reg10";
    135     case 0x5b: return "DW_OP_reg11";
    136     case 0x5c: return "DW_OP_reg12";
    137     case 0x5d: return "DW_OP_reg13";
    138     case 0x5e: return "DW_OP_reg14";
    139     case 0x5f: return "DW_OP_reg15";
    140     case 0x60: return "DW_OP_reg16";
    141     case 0x61: return "DW_OP_reg17";
    142     case 0x62: return "DW_OP_reg18";
    143     case 0x63: return "DW_OP_reg19";
    144     case 0x64: return "DW_OP_reg20";
    145     case 0x65: return "DW_OP_reg21";
    146     case 0x66: return "DW_OP_reg22";
    147     case 0x67: return "DW_OP_reg23";
    148     case 0x68: return "DW_OP_reg24";
    149     case 0x69: return "DW_OP_reg25";
    150     case 0x6a: return "DW_OP_reg26";
    151     case 0x6b: return "DW_OP_reg27";
    152     case 0x6c: return "DW_OP_reg28";
    153     case 0x6d: return "DW_OP_reg29";
    154     case 0x6e: return "DW_OP_reg30";
    155     case 0x6f: return "DW_OP_reg31";
    156     case 0x70: return "DW_OP_breg0";
    157     case 0x71: return "DW_OP_breg1";
    158     case 0x72: return "DW_OP_breg2";
    159     case 0x73: return "DW_OP_breg3";
    160     case 0x74: return "DW_OP_breg4";
    161     case 0x75: return "DW_OP_breg5";
    162     case 0x76: return "DW_OP_breg6";
    163     case 0x77: return "DW_OP_breg7";
    164     case 0x78: return "DW_OP_breg8";
    165     case 0x79: return "DW_OP_breg9";
    166     case 0x7a: return "DW_OP_breg10";
    167     case 0x7b: return "DW_OP_breg11";
    168     case 0x7c: return "DW_OP_breg12";
    169     case 0x7d: return "DW_OP_breg13";
    170     case 0x7e: return "DW_OP_breg14";
    171     case 0x7f: return "DW_OP_breg15";
    172     case 0x80: return "DW_OP_breg16";
    173     case 0x81: return "DW_OP_breg17";
    174     case 0x82: return "DW_OP_breg18";
    175     case 0x83: return "DW_OP_breg19";
    176     case 0x84: return "DW_OP_breg20";
    177     case 0x85: return "DW_OP_breg21";
    178     case 0x86: return "DW_OP_breg22";
    179     case 0x87: return "DW_OP_breg23";
    180     case 0x88: return "DW_OP_breg24";
    181     case 0x89: return "DW_OP_breg25";
    182     case 0x8a: return "DW_OP_breg26";
    183     case 0x8b: return "DW_OP_breg27";
    184     case 0x8c: return "DW_OP_breg28";
    185     case 0x8d: return "DW_OP_breg29";
    186     case 0x8e: return "DW_OP_breg30";
    187     case 0x8f: return "DW_OP_breg31";
    188     case 0x90: return "DW_OP_regx";
    189     case 0x91: return "DW_OP_fbreg";
    190     case 0x92: return "DW_OP_bregx";
    191     case 0x93: return "DW_OP_piece";
    192     case 0x94: return "DW_OP_deref_size";
    193     case 0x95: return "DW_OP_xderef_size";
    194     case 0x96: return "DW_OP_nop";
    195     case 0x97: return "DW_OP_push_object_address";
    196     case 0x98: return "DW_OP_call2";
    197     case 0x99: return "DW_OP_call4";
    198     case 0x9a: return "DW_OP_call_ref";
    199 //    case DW_OP_APPLE_array_ref: return "DW_OP_APPLE_array_ref";
    200 //    case DW_OP_APPLE_extern: return "DW_OP_APPLE_extern";
    201     case DW_OP_APPLE_uninit: return "DW_OP_APPLE_uninit";
    202 //    case DW_OP_APPLE_assign: return "DW_OP_APPLE_assign";
    203 //    case DW_OP_APPLE_address_of: return "DW_OP_APPLE_address_of";
    204 //    case DW_OP_APPLE_value_of: return "DW_OP_APPLE_value_of";
    205 //    case DW_OP_APPLE_deref_type: return "DW_OP_APPLE_deref_type";
    206 //    case DW_OP_APPLE_expr_local: return "DW_OP_APPLE_expr_local";
    207 //    case DW_OP_APPLE_constf: return "DW_OP_APPLE_constf";
    208 //    case DW_OP_APPLE_scalar_cast: return "DW_OP_APPLE_scalar_cast";
    209 //    case DW_OP_APPLE_clang_cast: return "DW_OP_APPLE_clang_cast";
    210 //    case DW_OP_APPLE_clear: return "DW_OP_APPLE_clear";
    211 //    case DW_OP_APPLE_error: return "DW_OP_APPLE_error";
    212     default:
    213        snprintf (invalid, sizeof(invalid), "Unknown DW_OP constant: 0x%x", val);
    214        return invalid;
    215   }
    216 }
    217 
    218 
    219 //----------------------------------------------------------------------
    220 // DWARFExpression constructor
    221 //----------------------------------------------------------------------
    222 DWARFExpression::DWARFExpression() :
    223     m_data(),
    224     m_reg_kind (eRegisterKindDWARF),
    225     m_loclist_slide (LLDB_INVALID_ADDRESS)
    226 {
    227 }
    228 
    229 DWARFExpression::DWARFExpression(const DWARFExpression& rhs) :
    230     m_data(rhs.m_data),
    231     m_reg_kind (rhs.m_reg_kind),
    232     m_loclist_slide(rhs.m_loclist_slide)
    233 {
    234 }
    235 
    236 
    237 DWARFExpression::DWARFExpression(const DataExtractor& data, lldb::offset_t data_offset, lldb::offset_t data_length) :
    238     m_data(data, data_offset, data_length),
    239     m_reg_kind (eRegisterKindDWARF),
    240     m_loclist_slide(LLDB_INVALID_ADDRESS)
    241 {
    242 }
    243 
    244 //----------------------------------------------------------------------
    245 // Destructor
    246 //----------------------------------------------------------------------
    247 DWARFExpression::~DWARFExpression()
    248 {
    249 }
    250 
    251 
    252 bool
    253 DWARFExpression::IsValid() const
    254 {
    255     return m_data.GetByteSize() > 0;
    256 }
    257 
    258 void
    259 DWARFExpression::SetOpcodeData (const DataExtractor& data)
    260 {
    261     m_data = data;
    262 }
    263 
    264 void
    265 DWARFExpression::CopyOpcodeData (const DataExtractor& data, lldb::offset_t data_offset, lldb::offset_t data_length)
    266 {
    267     const uint8_t *bytes = data.PeekData(data_offset, data_length);
    268     if (bytes)
    269     {
    270         m_data.SetData(DataBufferSP(new DataBufferHeap(bytes, data_length)));
    271         m_data.SetByteOrder(data.GetByteOrder());
    272         m_data.SetAddressByteSize(data.GetAddressByteSize());
    273     }
    274 }
    275 
    276 void
    277 DWARFExpression::SetOpcodeData (const DataExtractor& data, lldb::offset_t data_offset, lldb::offset_t data_length)
    278 {
    279     m_data.SetData(data, data_offset, data_length);
    280 }
    281 
    282 void
    283 DWARFExpression::DumpLocation (Stream *s, lldb::offset_t offset, lldb::offset_t length, lldb::DescriptionLevel level, ABI *abi) const
    284 {
    285     if (!m_data.ValidOffsetForDataOfSize(offset, length))
    286         return;
    287     const lldb::offset_t start_offset = offset;
    288     const lldb::offset_t end_offset = offset + length;
    289     while (m_data.ValidOffset(offset) && offset < end_offset)
    290     {
    291         const lldb::offset_t op_offset = offset;
    292         const uint8_t op = m_data.GetU8(&offset);
    293 
    294         switch (level)
    295         {
    296         default:
    297             break;
    298 
    299         case lldb::eDescriptionLevelBrief:
    300             if (offset > start_offset)
    301                 s->PutChar(' ');
    302             break;
    303 
    304         case lldb::eDescriptionLevelFull:
    305         case lldb::eDescriptionLevelVerbose:
    306             if (offset > start_offset)
    307                 s->EOL();
    308             s->Indent();
    309             if (level == lldb::eDescriptionLevelFull)
    310                 break;
    311             // Fall through for verbose and print offset and DW_OP prefix..
    312             s->Printf("0x%8.8" PRIx64 ": %s", op_offset, op >= DW_OP_APPLE_uninit ? "DW_OP_APPLE_" : "DW_OP_");
    313             break;
    314         }
    315 
    316         switch (op)
    317         {
    318         case DW_OP_addr:    *s << "DW_OP_addr(" << m_data.GetAddress(&offset) << ") "; break;         // 0x03 1 address
    319         case DW_OP_deref:   *s << "DW_OP_deref"; break;                                               // 0x06
    320         case DW_OP_const1u: s->Printf("DW_OP_const1u(0x%2.2x) ", m_data.GetU8(&offset)); break;       // 0x08 1 1-byte constant
    321         case DW_OP_const1s: s->Printf("DW_OP_const1s(0x%2.2x) ", m_data.GetU8(&offset)); break;       // 0x09 1 1-byte constant
    322         case DW_OP_const2u: s->Printf("DW_OP_const2u(0x%4.4x) ", m_data.GetU16(&offset)); break;      // 0x0a 1 2-byte constant
    323         case DW_OP_const2s: s->Printf("DW_OP_const2s(0x%4.4x) ", m_data.GetU16(&offset)); break;      // 0x0b 1 2-byte constant
    324         case DW_OP_const4u: s->Printf("DW_OP_const4u(0x%8.8x) ", m_data.GetU32(&offset)); break;      // 0x0c 1 4-byte constant
    325         case DW_OP_const4s: s->Printf("DW_OP_const4s(0x%8.8x) ", m_data.GetU32(&offset)); break;      // 0x0d 1 4-byte constant
    326         case DW_OP_const8u: s->Printf("DW_OP_const8u(0x%16.16" PRIx64 ") ", m_data.GetU64(&offset)); break;  // 0x0e 1 8-byte constant
    327         case DW_OP_const8s: s->Printf("DW_OP_const8s(0x%16.16" PRIx64 ") ", m_data.GetU64(&offset)); break;  // 0x0f 1 8-byte constant
    328         case DW_OP_constu:  s->Printf("DW_OP_constu(0x%" PRIx64 ") ", m_data.GetULEB128(&offset)); break;    // 0x10 1 ULEB128 constant
    329         case DW_OP_consts:  s->Printf("DW_OP_consts(0x%" PRId64 ") ", m_data.GetSLEB128(&offset)); break;    // 0x11 1 SLEB128 constant
    330         case DW_OP_dup:     s->PutCString("DW_OP_dup"); break;                                        // 0x12
    331         case DW_OP_drop:    s->PutCString("DW_OP_drop"); break;                                       // 0x13
    332         case DW_OP_over:    s->PutCString("DW_OP_over"); break;                                       // 0x14
    333         case DW_OP_pick:    s->Printf("DW_OP_pick(0x%2.2x) ", m_data.GetU8(&offset)); break;          // 0x15 1 1-byte stack index
    334         case DW_OP_swap:    s->PutCString("DW_OP_swap"); break;                                       // 0x16
    335         case DW_OP_rot:     s->PutCString("DW_OP_rot"); break;                                        // 0x17
    336         case DW_OP_xderef:  s->PutCString("DW_OP_xderef"); break;                                     // 0x18
    337         case DW_OP_abs:     s->PutCString("DW_OP_abs"); break;                                        // 0x19
    338         case DW_OP_and:     s->PutCString("DW_OP_and"); break;                                        // 0x1a
    339         case DW_OP_div:     s->PutCString("DW_OP_div"); break;                                        // 0x1b
    340         case DW_OP_minus:   s->PutCString("DW_OP_minus"); break;                                      // 0x1c
    341         case DW_OP_mod:     s->PutCString("DW_OP_mod"); break;                                        // 0x1d
    342         case DW_OP_mul:     s->PutCString("DW_OP_mul"); break;                                        // 0x1e
    343         case DW_OP_neg:     s->PutCString("DW_OP_neg"); break;                                        // 0x1f
    344         case DW_OP_not:     s->PutCString("DW_OP_not"); break;                                        // 0x20
    345         case DW_OP_or:      s->PutCString("DW_OP_or"); break;                                         // 0x21
    346         case DW_OP_plus:    s->PutCString("DW_OP_plus"); break;                                       // 0x22
    347         case DW_OP_plus_uconst:                                                                 // 0x23 1 ULEB128 addend
    348             s->Printf("DW_OP_plus_uconst(0x%" PRIx64 ") ", m_data.GetULEB128(&offset));
    349             break;
    350 
    351         case DW_OP_shl:     s->PutCString("DW_OP_shl"); break;                                        // 0x24
    352         case DW_OP_shr:     s->PutCString("DW_OP_shr"); break;                                        // 0x25
    353         case DW_OP_shra:    s->PutCString("DW_OP_shra"); break;                                       // 0x26
    354         case DW_OP_xor:     s->PutCString("DW_OP_xor"); break;                                        // 0x27
    355         case DW_OP_skip:    s->Printf("DW_OP_skip(0x%4.4x)", m_data.GetU16(&offset)); break;          // 0x2f 1 signed 2-byte constant
    356         case DW_OP_bra:     s->Printf("DW_OP_bra(0x%4.4x)", m_data.GetU16(&offset)); break;           // 0x28 1 signed 2-byte constant
    357         case DW_OP_eq:      s->PutCString("DW_OP_eq"); break;                                         // 0x29
    358         case DW_OP_ge:      s->PutCString("DW_OP_ge"); break;                                         // 0x2a
    359         case DW_OP_gt:      s->PutCString("DW_OP_gt"); break;                                         // 0x2b
    360         case DW_OP_le:      s->PutCString("DW_OP_le"); break;                                         // 0x2c
    361         case DW_OP_lt:      s->PutCString("DW_OP_lt"); break;                                         // 0x2d
    362         case DW_OP_ne:      s->PutCString("DW_OP_ne"); break;                                         // 0x2e
    363 
    364         case DW_OP_lit0:    // 0x30
    365         case DW_OP_lit1:    // 0x31
    366         case DW_OP_lit2:    // 0x32
    367         case DW_OP_lit3:    // 0x33
    368         case DW_OP_lit4:    // 0x34
    369         case DW_OP_lit5:    // 0x35
    370         case DW_OP_lit6:    // 0x36
    371         case DW_OP_lit7:    // 0x37
    372         case DW_OP_lit8:    // 0x38
    373         case DW_OP_lit9:    // 0x39
    374         case DW_OP_lit10:   // 0x3A
    375         case DW_OP_lit11:   // 0x3B
    376         case DW_OP_lit12:   // 0x3C
    377         case DW_OP_lit13:   // 0x3D
    378         case DW_OP_lit14:   // 0x3E
    379         case DW_OP_lit15:   // 0x3F
    380         case DW_OP_lit16:   // 0x40
    381         case DW_OP_lit17:   // 0x41
    382         case DW_OP_lit18:   // 0x42
    383         case DW_OP_lit19:   // 0x43
    384         case DW_OP_lit20:   // 0x44
    385         case DW_OP_lit21:   // 0x45
    386         case DW_OP_lit22:   // 0x46
    387         case DW_OP_lit23:   // 0x47
    388         case DW_OP_lit24:   // 0x48
    389         case DW_OP_lit25:   // 0x49
    390         case DW_OP_lit26:   // 0x4A
    391         case DW_OP_lit27:   // 0x4B
    392         case DW_OP_lit28:   // 0x4C
    393         case DW_OP_lit29:   // 0x4D
    394         case DW_OP_lit30:   // 0x4E
    395         case DW_OP_lit31:   s->Printf("DW_OP_lit%i", op - DW_OP_lit0); break; // 0x4f
    396 
    397         case DW_OP_reg0:    // 0x50
    398         case DW_OP_reg1:    // 0x51
    399         case DW_OP_reg2:    // 0x52
    400         case DW_OP_reg3:    // 0x53
    401         case DW_OP_reg4:    // 0x54
    402         case DW_OP_reg5:    // 0x55
    403         case DW_OP_reg6:    // 0x56
    404         case DW_OP_reg7:    // 0x57
    405         case DW_OP_reg8:    // 0x58
    406         case DW_OP_reg9:    // 0x59
    407         case DW_OP_reg10:   // 0x5A
    408         case DW_OP_reg11:   // 0x5B
    409         case DW_OP_reg12:   // 0x5C
    410         case DW_OP_reg13:   // 0x5D
    411         case DW_OP_reg14:   // 0x5E
    412         case DW_OP_reg15:   // 0x5F
    413         case DW_OP_reg16:   // 0x60
    414         case DW_OP_reg17:   // 0x61
    415         case DW_OP_reg18:   // 0x62
    416         case DW_OP_reg19:   // 0x63
    417         case DW_OP_reg20:   // 0x64
    418         case DW_OP_reg21:   // 0x65
    419         case DW_OP_reg22:   // 0x66
    420         case DW_OP_reg23:   // 0x67
    421         case DW_OP_reg24:   // 0x68
    422         case DW_OP_reg25:   // 0x69
    423         case DW_OP_reg26:   // 0x6A
    424         case DW_OP_reg27:   // 0x6B
    425         case DW_OP_reg28:   // 0x6C
    426         case DW_OP_reg29:   // 0x6D
    427         case DW_OP_reg30:   // 0x6E
    428         case DW_OP_reg31:   // 0x6F
    429             {
    430                 uint32_t reg_num = op - DW_OP_reg0;
    431                 if (abi)
    432                 {
    433                     RegisterInfo reg_info;
    434                     if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info))
    435                     {
    436                         if (reg_info.name)
    437                         {
    438                             s->PutCString (reg_info.name);
    439                             break;
    440                         }
    441                         else if (reg_info.alt_name)
    442                         {
    443                             s->PutCString (reg_info.alt_name);
    444                             break;
    445                         }
    446                     }
    447                 }
    448                 s->Printf("DW_OP_reg%u", reg_num); break;
    449             }
    450             break;
    451 
    452         case DW_OP_breg0:
    453         case DW_OP_breg1:
    454         case DW_OP_breg2:
    455         case DW_OP_breg3:
    456         case DW_OP_breg4:
    457         case DW_OP_breg5:
    458         case DW_OP_breg6:
    459         case DW_OP_breg7:
    460         case DW_OP_breg8:
    461         case DW_OP_breg9:
    462         case DW_OP_breg10:
    463         case DW_OP_breg11:
    464         case DW_OP_breg12:
    465         case DW_OP_breg13:
    466         case DW_OP_breg14:
    467         case DW_OP_breg15:
    468         case DW_OP_breg16:
    469         case DW_OP_breg17:
    470         case DW_OP_breg18:
    471         case DW_OP_breg19:
    472         case DW_OP_breg20:
    473         case DW_OP_breg21:
    474         case DW_OP_breg22:
    475         case DW_OP_breg23:
    476         case DW_OP_breg24:
    477         case DW_OP_breg25:
    478         case DW_OP_breg26:
    479         case DW_OP_breg27:
    480         case DW_OP_breg28:
    481         case DW_OP_breg29:
    482         case DW_OP_breg30:
    483         case DW_OP_breg31:
    484             {
    485                 uint32_t reg_num = op - DW_OP_breg0;
    486                 int64_t reg_offset = m_data.GetSLEB128(&offset);
    487                 if (abi)
    488                 {
    489                     RegisterInfo reg_info;
    490                     if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info))
    491                     {
    492                         if (reg_info.name)
    493                         {
    494                             s->Printf("[%s%+" PRIi64 "]", reg_info.name, reg_offset);
    495                             break;
    496                         }
    497                         else if (reg_info.alt_name)
    498                         {
    499                             s->Printf("[%s%+" PRIi64 "]", reg_info.alt_name, reg_offset);
    500                             break;
    501                         }
    502                     }
    503                 }
    504                 s->Printf("DW_OP_breg%i(0x%" PRIx64 ")", reg_num, reg_offset);
    505             }
    506             break;
    507 
    508         case DW_OP_regx:                                                    // 0x90 1 ULEB128 register
    509             {
    510                 uint32_t reg_num = m_data.GetULEB128(&offset);
    511                 if (abi)
    512                 {
    513                     RegisterInfo reg_info;
    514                     if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info))
    515                     {
    516                         if (reg_info.name)
    517                         {
    518                             s->PutCString (reg_info.name);
    519                             break;
    520                         }
    521                         else if (reg_info.alt_name)
    522                         {
    523                             s->PutCString (reg_info.alt_name);
    524                             break;
    525                         }
    526                     }
    527                 }
    528                 s->Printf("DW_OP_regx(%" PRIu32 ")", reg_num); break;
    529             }
    530             break;
    531         case DW_OP_fbreg:                                                   // 0x91 1 SLEB128 offset
    532             s->Printf("DW_OP_fbreg(%" PRIi64 ")",m_data.GetSLEB128(&offset));
    533             break;
    534         case DW_OP_bregx:                                                   // 0x92 2 ULEB128 register followed by SLEB128 offset
    535             {
    536                 uint32_t reg_num = m_data.GetULEB128(&offset);
    537                 int64_t reg_offset = m_data.GetSLEB128(&offset);
    538                 if (abi)
    539                 {
    540                     RegisterInfo reg_info;
    541                     if (abi->GetRegisterInfoByKind(m_reg_kind, reg_num, reg_info))
    542                     {
    543                         if (reg_info.name)
    544                         {
    545                             s->Printf("[%s%+" PRIi64 "]", reg_info.name, reg_offset);
    546                             break;
    547                         }
    548                         else if (reg_info.alt_name)
    549                         {
    550                             s->Printf("[%s%+" PRIi64 "]", reg_info.alt_name, reg_offset);
    551                             break;
    552                         }
    553                     }
    554                 }
    555                 s->Printf("DW_OP_bregx(reg=%" PRIu32 ",offset=%" PRIi64 ")", reg_num, reg_offset);
    556             }
    557             break;
    558         case DW_OP_piece:                                                   // 0x93 1 ULEB128 size of piece addressed
    559             s->Printf("DW_OP_piece(0x%" PRIx64 ")", m_data.GetULEB128(&offset));
    560             break;
    561         case DW_OP_deref_size:                                              // 0x94 1 1-byte size of data retrieved
    562             s->Printf("DW_OP_deref_size(0x%2.2x)", m_data.GetU8(&offset));
    563             break;
    564         case DW_OP_xderef_size:                                             // 0x95 1 1-byte size of data retrieved
    565             s->Printf("DW_OP_xderef_size(0x%2.2x)", m_data.GetU8(&offset));
    566             break;
    567         case DW_OP_nop: s->PutCString("DW_OP_nop"); break;                                    // 0x96
    568         case DW_OP_push_object_address: s->PutCString("DW_OP_push_object_address"); break;    // 0x97 DWARF3
    569         case DW_OP_call2:                                                   // 0x98 DWARF3 1 2-byte offset of DIE
    570             s->Printf("DW_OP_call2(0x%4.4x)", m_data.GetU16(&offset));
    571             break;
    572         case DW_OP_call4:                                                   // 0x99 DWARF3 1 4-byte offset of DIE
    573             s->Printf("DW_OP_call4(0x%8.8x)", m_data.GetU32(&offset));
    574             break;
    575         case DW_OP_call_ref:                                                // 0x9a DWARF3 1 4- or 8-byte offset of DIE
    576             s->Printf("DW_OP_call_ref(0x%8.8" PRIx64 ")", m_data.GetAddress(&offset));
    577             break;
    578 //      case DW_OP_form_tls_address: s << "form_tls_address"; break;        // 0x9b DWARF3
    579 //      case DW_OP_call_frame_cfa: s << "call_frame_cfa"; break;            // 0x9c DWARF3
    580 //      case DW_OP_bit_piece:                                               // 0x9d DWARF3 2
    581 //          s->Printf("DW_OP_bit_piece(0x%x, 0x%x)", m_data.GetULEB128(&offset), m_data.GetULEB128(&offset));
    582 //          break;
    583 //      case DW_OP_lo_user:     s->PutCString("DW_OP_lo_user"); break;                        // 0xe0
    584 //      case DW_OP_hi_user:     s->PutCString("DW_OP_hi_user"); break;                        // 0xff
    585 //        case DW_OP_APPLE_extern:
    586 //            s->Printf("DW_OP_APPLE_extern(%" PRIu64 ")", m_data.GetULEB128(&offset));
    587 //            break;
    588 //        case DW_OP_APPLE_array_ref:
    589 //            s->PutCString("DW_OP_APPLE_array_ref");
    590 //            break;
    591         case DW_OP_APPLE_uninit:
    592             s->PutCString("DW_OP_APPLE_uninit");  // 0xF0
    593             break;
    594 //        case DW_OP_APPLE_assign:        // 0xF1 - pops value off and assigns it to second item on stack (2nd item must have assignable context)
    595 //            s->PutCString("DW_OP_APPLE_assign");
    596 //            break;
    597 //        case DW_OP_APPLE_address_of:    // 0xF2 - gets the address of the top stack item (top item must be a variable, or have value_type that is an address already)
    598 //            s->PutCString("DW_OP_APPLE_address_of");
    599 //            break;
    600 //        case DW_OP_APPLE_value_of:      // 0xF3 - pops the value off the stack and pushes the value of that object (top item must be a variable, or expression local)
    601 //            s->PutCString("DW_OP_APPLE_value_of");
    602 //            break;
    603 //        case DW_OP_APPLE_deref_type:    // 0xF4 - gets the address of the top stack item (top item must be a variable, or a clang type)
    604 //            s->PutCString("DW_OP_APPLE_deref_type");
    605 //            break;
    606 //        case DW_OP_APPLE_expr_local:    // 0xF5 - ULEB128 expression local index
    607 //            s->Printf("DW_OP_APPLE_expr_local(%" PRIu64 ")", m_data.GetULEB128(&offset));
    608 //            break;
    609 //        case DW_OP_APPLE_constf:        // 0xF6 - 1 byte float size, followed by constant float data
    610 //            {
    611 //                uint8_t float_length = m_data.GetU8(&offset);
    612 //                s->Printf("DW_OP_APPLE_constf(<%u> ", float_length);
    613 //                m_data.Dump(s, offset, eFormatHex, float_length, 1, UINT32_MAX, DW_INVALID_ADDRESS, 0, 0);
    614 //                s->PutChar(')');
    615 //                // Consume the float data
    616 //                m_data.GetData(&offset, float_length);
    617 //            }
    618 //            break;
    619 //        case DW_OP_APPLE_scalar_cast:
    620 //            s->Printf("DW_OP_APPLE_scalar_cast(%s)", Scalar::GetValueTypeAsCString ((Scalar::Type)m_data.GetU8(&offset)));
    621 //            break;
    622 //        case DW_OP_APPLE_clang_cast:
    623 //            {
    624 //                clang::Type *clang_type = (clang::Type *)m_data.GetMaxU64(&offset, sizeof(void*));
    625 //                s->Printf("DW_OP_APPLE_clang_cast(%p)", clang_type);
    626 //            }
    627 //            break;
    628 //        case DW_OP_APPLE_clear:
    629 //            s->PutCString("DW_OP_APPLE_clear");
    630 //            break;
    631 //        case DW_OP_APPLE_error:         // 0xFF - Stops expression evaluation and returns an error (no args)
    632 //            s->PutCString("DW_OP_APPLE_error");
    633 //            break;
    634         }
    635     }
    636 }
    637 
    638 void
    639 DWARFExpression::SetLocationListSlide (addr_t slide)
    640 {
    641     m_loclist_slide = slide;
    642 }
    643 
    644 int
    645 DWARFExpression::GetRegisterKind ()
    646 {
    647     return m_reg_kind;
    648 }
    649 
    650 void
    651 DWARFExpression::SetRegisterKind (RegisterKind reg_kind)
    652 {
    653     m_reg_kind = reg_kind;
    654 }
    655 
    656 bool
    657 DWARFExpression::IsLocationList() const
    658 {
    659     return m_loclist_slide != LLDB_INVALID_ADDRESS;
    660 }
    661 
    662 void
    663 DWARFExpression::GetDescription (Stream *s, lldb::DescriptionLevel level, addr_t location_list_base_addr, ABI *abi) const
    664 {
    665     if (IsLocationList())
    666     {
    667         // We have a location list
    668         lldb::offset_t offset = 0;
    669         uint32_t count = 0;
    670         addr_t curr_base_addr = location_list_base_addr;
    671         while (m_data.ValidOffset(offset))
    672         {
    673             lldb::addr_t begin_addr_offset = m_data.GetAddress(&offset);
    674             lldb::addr_t end_addr_offset = m_data.GetAddress(&offset);
    675             if (begin_addr_offset < end_addr_offset)
    676             {
    677                 if (count > 0)
    678                     s->PutCString(", ");
    679                 VMRange addr_range(curr_base_addr + begin_addr_offset, curr_base_addr + end_addr_offset);
    680                 addr_range.Dump(s, 0, 8);
    681                 s->PutChar('{');
    682                 lldb::offset_t location_length = m_data.GetU16(&offset);
    683                 DumpLocation (s, offset, location_length, level, abi);
    684                 s->PutChar('}');
    685                 offset += location_length;
    686             }
    687             else if (begin_addr_offset == 0 && end_addr_offset == 0)
    688             {
    689                 // The end of the location list is marked by both the start and end offset being zero
    690                 break;
    691             }
    692             else
    693             {
    694                 if ((m_data.GetAddressByteSize() == 4 && (begin_addr_offset == UINT32_MAX)) ||
    695                     (m_data.GetAddressByteSize() == 8 && (begin_addr_offset == UINT64_MAX)))
    696                 {
    697                     curr_base_addr = end_addr_offset + location_list_base_addr;
    698                     // We have a new base address
    699                     if (count > 0)
    700                         s->PutCString(", ");
    701                     *s << "base_addr = " << end_addr_offset;
    702                 }
    703             }
    704 
    705             count++;
    706         }
    707     }
    708     else
    709     {
    710         // We have a normal location that contains DW_OP location opcodes
    711         DumpLocation (s, 0, m_data.GetByteSize(), level, abi);
    712     }
    713 }
    714 
    715 static bool
    716 ReadRegisterValueAsScalar
    717 (
    718     RegisterContext *reg_ctx,
    719     uint32_t reg_kind,
    720     uint32_t reg_num,
    721     Error *error_ptr,
    722     Value &value
    723 )
    724 {
    725     if (reg_ctx == NULL)
    726     {
    727         if (error_ptr)
    728             error_ptr->SetErrorStringWithFormat("No register context in frame.\n");
    729     }
    730     else
    731     {
    732         uint32_t native_reg = reg_ctx->ConvertRegisterKindToRegisterNumber(reg_kind, reg_num);
    733         if (native_reg == LLDB_INVALID_REGNUM)
    734         {
    735             if (error_ptr)
    736                 error_ptr->SetErrorStringWithFormat("Unable to convert register kind=%u reg_num=%u to a native register number.\n", reg_kind, reg_num);
    737         }
    738         else
    739         {
    740             const RegisterInfo *reg_info = reg_ctx->GetRegisterInfoAtIndex(native_reg);
    741             RegisterValue reg_value;
    742             if (reg_ctx->ReadRegister (reg_info, reg_value))
    743             {
    744                 if (reg_value.GetScalarValue(value.GetScalar()))
    745                 {
    746                     value.SetValueType (Value::eValueTypeScalar);
    747                     value.SetContext (Value::eContextTypeRegisterInfo,
    748                                       const_cast<RegisterInfo *>(reg_info));
    749                     if (error_ptr)
    750                         error_ptr->Clear();
    751                     return true;
    752                 }
    753                 else
    754                 {
    755                     // If we get this error, then we need to implement a value
    756                     // buffer in the dwarf expression evaluation function...
    757                     if (error_ptr)
    758                         error_ptr->SetErrorStringWithFormat ("register %s can't be converted to a scalar value",
    759                                                              reg_info->name);
    760                 }
    761             }
    762             else
    763             {
    764                 if (error_ptr)
    765                     error_ptr->SetErrorStringWithFormat("register %s is not available", reg_info->name);
    766             }
    767         }
    768     }
    769     return false;
    770 }
    771 
    772 //bool
    773 //DWARFExpression::LocationListContainsLoadAddress (Process* process, const Address &addr) const
    774 //{
    775 //    return LocationListContainsLoadAddress(process, addr.GetLoadAddress(process));
    776 //}
    777 //
    778 //bool
    779 //DWARFExpression::LocationListContainsLoadAddress (Process* process, addr_t load_addr) const
    780 //{
    781 //    if (load_addr == LLDB_INVALID_ADDRESS)
    782 //        return false;
    783 //
    784 //    if (IsLocationList())
    785 //    {
    786 //        lldb::offset_t offset = 0;
    787 //
    788 //        addr_t loc_list_base_addr = m_loclist_slide.GetLoadAddress(process);
    789 //
    790 //        if (loc_list_base_addr == LLDB_INVALID_ADDRESS)
    791 //            return false;
    792 //
    793 //        while (m_data.ValidOffset(offset))
    794 //        {
    795 //            // We need to figure out what the value is for the location.
    796 //            addr_t lo_pc = m_data.GetAddress(&offset);
    797 //            addr_t hi_pc = m_data.GetAddress(&offset);
    798 //            if (lo_pc == 0 && hi_pc == 0)
    799 //                break;
    800 //            else
    801 //            {
    802 //                lo_pc += loc_list_base_addr;
    803 //                hi_pc += loc_list_base_addr;
    804 //
    805 //                if (lo_pc <= load_addr && load_addr < hi_pc)
    806 //                    return true;
    807 //
    808 //                offset += m_data.GetU16(&offset);
    809 //            }
    810 //        }
    811 //    }
    812 //    return false;
    813 //}
    814 
    815 static offset_t
    816 GetOpcodeDataSize (const DataExtractor &data, const lldb::offset_t data_offset, const uint8_t op)
    817 {
    818     lldb::offset_t offset = data_offset;
    819     switch (op)
    820     {
    821         case DW_OP_addr:
    822         case DW_OP_call_ref:    // 0x9a 1 address sized offset of DIE (DWARF3)
    823             return data.GetAddressByteSize();
    824 
    825         // Opcodes with no arguments
    826         case DW_OP_deref:   // 0x06
    827         case DW_OP_dup:     // 0x12
    828         case DW_OP_drop:    // 0x13
    829         case DW_OP_over:    // 0x14
    830         case DW_OP_swap:    // 0x16
    831         case DW_OP_rot:     // 0x17
    832         case DW_OP_xderef:  // 0x18
    833         case DW_OP_abs:     // 0x19
    834         case DW_OP_and:     // 0x1a
    835         case DW_OP_div:     // 0x1b
    836         case DW_OP_minus:   // 0x1c
    837         case DW_OP_mod:     // 0x1d
    838         case DW_OP_mul:     // 0x1e
    839         case DW_OP_neg:     // 0x1f
    840         case DW_OP_not:     // 0x20
    841         case DW_OP_or:      // 0x21
    842         case DW_OP_plus:    // 0x22
    843         case DW_OP_shl:     // 0x24
    844         case DW_OP_shr:     // 0x25
    845         case DW_OP_shra:    // 0x26
    846         case DW_OP_xor:     // 0x27
    847         case DW_OP_eq:      // 0x29
    848         case DW_OP_ge:      // 0x2a
    849         case DW_OP_gt:      // 0x2b
    850         case DW_OP_le:      // 0x2c
    851         case DW_OP_lt:      // 0x2d
    852         case DW_OP_ne:      // 0x2e
    853         case DW_OP_lit0:    // 0x30
    854         case DW_OP_lit1:    // 0x31
    855         case DW_OP_lit2:    // 0x32
    856         case DW_OP_lit3:    // 0x33
    857         case DW_OP_lit4:    // 0x34
    858         case DW_OP_lit5:    // 0x35
    859         case DW_OP_lit6:    // 0x36
    860         case DW_OP_lit7:    // 0x37
    861         case DW_OP_lit8:    // 0x38
    862         case DW_OP_lit9:    // 0x39
    863         case DW_OP_lit10:   // 0x3A
    864         case DW_OP_lit11:   // 0x3B
    865         case DW_OP_lit12:   // 0x3C
    866         case DW_OP_lit13:   // 0x3D
    867         case DW_OP_lit14:   // 0x3E
    868         case DW_OP_lit15:   // 0x3F
    869         case DW_OP_lit16:   // 0x40
    870         case DW_OP_lit17:   // 0x41
    871         case DW_OP_lit18:   // 0x42
    872         case DW_OP_lit19:   // 0x43
    873         case DW_OP_lit20:   // 0x44
    874         case DW_OP_lit21:   // 0x45
    875         case DW_OP_lit22:   // 0x46
    876         case DW_OP_lit23:   // 0x47
    877         case DW_OP_lit24:   // 0x48
    878         case DW_OP_lit25:   // 0x49
    879         case DW_OP_lit26:   // 0x4A
    880         case DW_OP_lit27:   // 0x4B
    881         case DW_OP_lit28:   // 0x4C
    882         case DW_OP_lit29:   // 0x4D
    883         case DW_OP_lit30:   // 0x4E
    884         case DW_OP_lit31:   // 0x4f
    885         case DW_OP_reg0:    // 0x50
    886         case DW_OP_reg1:    // 0x51
    887         case DW_OP_reg2:    // 0x52
    888         case DW_OP_reg3:    // 0x53
    889         case DW_OP_reg4:    // 0x54
    890         case DW_OP_reg5:    // 0x55
    891         case DW_OP_reg6:    // 0x56
    892         case DW_OP_reg7:    // 0x57
    893         case DW_OP_reg8:    // 0x58
    894         case DW_OP_reg9:    // 0x59
    895         case DW_OP_reg10:   // 0x5A
    896         case DW_OP_reg11:   // 0x5B
    897         case DW_OP_reg12:   // 0x5C
    898         case DW_OP_reg13:   // 0x5D
    899         case DW_OP_reg14:   // 0x5E
    900         case DW_OP_reg15:   // 0x5F
    901         case DW_OP_reg16:   // 0x60
    902         case DW_OP_reg17:   // 0x61
    903         case DW_OP_reg18:   // 0x62
    904         case DW_OP_reg19:   // 0x63
    905         case DW_OP_reg20:   // 0x64
    906         case DW_OP_reg21:   // 0x65
    907         case DW_OP_reg22:   // 0x66
    908         case DW_OP_reg23:   // 0x67
    909         case DW_OP_reg24:   // 0x68
    910         case DW_OP_reg25:   // 0x69
    911         case DW_OP_reg26:   // 0x6A
    912         case DW_OP_reg27:   // 0x6B
    913         case DW_OP_reg28:   // 0x6C
    914         case DW_OP_reg29:   // 0x6D
    915         case DW_OP_reg30:   // 0x6E
    916         case DW_OP_reg31:   // 0x6F
    917         case DW_OP_nop:     // 0x96
    918         case DW_OP_push_object_address: // 0x97 DWARF3
    919         case DW_OP_form_tls_address:    // 0x9b DWARF3
    920         case DW_OP_call_frame_cfa:      // 0x9c DWARF3
    921         case DW_OP_stack_value: // 0x9f DWARF4
    922             return 0;
    923 
    924         // Opcodes with a single 1 byte arguments
    925         case DW_OP_const1u:     // 0x08 1 1-byte constant
    926         case DW_OP_const1s:     // 0x09 1 1-byte constant
    927         case DW_OP_pick:        // 0x15 1 1-byte stack index
    928         case DW_OP_deref_size:  // 0x94 1 1-byte size of data retrieved
    929         case DW_OP_xderef_size: // 0x95 1 1-byte size of data retrieved
    930             return 1;
    931 
    932         // Opcodes with a single 2 byte arguments
    933         case DW_OP_const2u:     // 0x0a 1 2-byte constant
    934         case DW_OP_const2s:     // 0x0b 1 2-byte constant
    935         case DW_OP_skip:        // 0x2f 1 signed 2-byte constant
    936         case DW_OP_bra:         // 0x28 1 signed 2-byte constant
    937         case DW_OP_call2:       // 0x98 1 2-byte offset of DIE (DWARF3)
    938             return 2;
    939 
    940         // Opcodes with a single 4 byte arguments
    941         case DW_OP_const4u:     // 0x0c 1 4-byte constant
    942         case DW_OP_const4s:     // 0x0d 1 4-byte constant
    943         case DW_OP_call4:       // 0x99 1 4-byte offset of DIE (DWARF3)
    944             return 4;
    945 
    946         // Opcodes with a single 8 byte arguments
    947         case DW_OP_const8u:     // 0x0e 1 8-byte constant
    948         case DW_OP_const8s:     // 0x0f 1 8-byte constant
    949              return 8;
    950 
    951         // All opcodes that have a single ULEB (signed or unsigned) argument
    952         case DW_OP_constu:      // 0x10 1 ULEB128 constant
    953         case DW_OP_consts:      // 0x11 1 SLEB128 constant
    954         case DW_OP_plus_uconst: // 0x23 1 ULEB128 addend
    955         case DW_OP_breg0:       // 0x70 1 ULEB128 register
    956         case DW_OP_breg1:       // 0x71 1 ULEB128 register
    957         case DW_OP_breg2:       // 0x72 1 ULEB128 register
    958         case DW_OP_breg3:       // 0x73 1 ULEB128 register
    959         case DW_OP_breg4:       // 0x74 1 ULEB128 register
    960         case DW_OP_breg5:       // 0x75 1 ULEB128 register
    961         case DW_OP_breg6:       // 0x76 1 ULEB128 register
    962         case DW_OP_breg7:       // 0x77 1 ULEB128 register
    963         case DW_OP_breg8:       // 0x78 1 ULEB128 register
    964         case DW_OP_breg9:       // 0x79 1 ULEB128 register
    965         case DW_OP_breg10:      // 0x7a 1 ULEB128 register
    966         case DW_OP_breg11:      // 0x7b 1 ULEB128 register
    967         case DW_OP_breg12:      // 0x7c 1 ULEB128 register
    968         case DW_OP_breg13:      // 0x7d 1 ULEB128 register
    969         case DW_OP_breg14:      // 0x7e 1 ULEB128 register
    970         case DW_OP_breg15:      // 0x7f 1 ULEB128 register
    971         case DW_OP_breg16:      // 0x80 1 ULEB128 register
    972         case DW_OP_breg17:      // 0x81 1 ULEB128 register
    973         case DW_OP_breg18:      // 0x82 1 ULEB128 register
    974         case DW_OP_breg19:      // 0x83 1 ULEB128 register
    975         case DW_OP_breg20:      // 0x84 1 ULEB128 register
    976         case DW_OP_breg21:      // 0x85 1 ULEB128 register
    977         case DW_OP_breg22:      // 0x86 1 ULEB128 register
    978         case DW_OP_breg23:      // 0x87 1 ULEB128 register
    979         case DW_OP_breg24:      // 0x88 1 ULEB128 register
    980         case DW_OP_breg25:      // 0x89 1 ULEB128 register
    981         case DW_OP_breg26:      // 0x8a 1 ULEB128 register
    982         case DW_OP_breg27:      // 0x8b 1 ULEB128 register
    983         case DW_OP_breg28:      // 0x8c 1 ULEB128 register
    984         case DW_OP_breg29:      // 0x8d 1 ULEB128 register
    985         case DW_OP_breg30:      // 0x8e 1 ULEB128 register
    986         case DW_OP_breg31:      // 0x8f 1 ULEB128 register
    987         case DW_OP_regx:        // 0x90 1 ULEB128 register
    988         case DW_OP_fbreg:       // 0x91 1 SLEB128 offset
    989         case DW_OP_piece:       // 0x93 1 ULEB128 size of piece addressed
    990             data.Skip_LEB128(&offset);
    991             return offset - data_offset;
    992 
    993             // All opcodes that have a 2 ULEB (signed or unsigned) arguments
    994         case DW_OP_bregx:       // 0x92 2 ULEB128 register followed by SLEB128 offset
    995         case DW_OP_bit_piece:   // 0x9d ULEB128 bit size, ULEB128 bit offset (DWARF3);
    996             data.Skip_LEB128(&offset);
    997             data.Skip_LEB128(&offset);
    998             return offset - data_offset;
    999 
   1000         case DW_OP_implicit_value: // 0x9e ULEB128 size followed by block of that size (DWARF4)
   1001             {
   1002                 uint64_t block_len = data.Skip_LEB128(&offset);
   1003                 offset += block_len;
   1004                 return offset - data_offset;
   1005             }
   1006 
   1007         default:
   1008             break;
   1009     }
   1010     return LLDB_INVALID_OFFSET;
   1011 }
   1012 
   1013 lldb::addr_t
   1014 DWARFExpression::GetLocation_DW_OP_addr (uint32_t op_addr_idx, bool &error) const
   1015 {
   1016     error = false;
   1017     if (IsLocationList())
   1018         return LLDB_INVALID_ADDRESS;
   1019     lldb::offset_t offset = 0;
   1020     uint32_t curr_op_addr_idx = 0;
   1021     while (m_data.ValidOffset(offset))
   1022     {
   1023         const uint8_t op = m_data.GetU8(&offset);
   1024 
   1025         if (op == DW_OP_addr)
   1026         {
   1027             const lldb::addr_t op_file_addr = m_data.GetAddress(&offset);
   1028             if (curr_op_addr_idx == op_addr_idx)
   1029                 return op_file_addr;
   1030             else
   1031                 ++curr_op_addr_idx;
   1032         }
   1033         else
   1034         {
   1035             const offset_t op_arg_size = GetOpcodeDataSize (m_data, offset, op);
   1036             if (op_arg_size == LLDB_INVALID_OFFSET)
   1037             {
   1038                 error = true;
   1039                 break;
   1040             }
   1041             offset += op_arg_size;
   1042         }
   1043     }
   1044     return LLDB_INVALID_ADDRESS;
   1045 }
   1046 
   1047 bool
   1048 DWARFExpression::Update_DW_OP_addr (lldb::addr_t file_addr)
   1049 {
   1050     if (IsLocationList())
   1051         return false;
   1052     lldb::offset_t offset = 0;
   1053     while (m_data.ValidOffset(offset))
   1054     {
   1055         const uint8_t op = m_data.GetU8(&offset);
   1056 
   1057         if (op == DW_OP_addr)
   1058         {
   1059             const uint32_t addr_byte_size = m_data.GetAddressByteSize();
   1060             // We have to make a copy of the data as we don't know if this
   1061             // data is from a read only memory mapped buffer, so we duplicate
   1062             // all of the data first, then modify it, and if all goes well,
   1063             // we then replace the data for this expression
   1064 
   1065             // So first we copy the data into a heap buffer
   1066             std::unique_ptr<DataBufferHeap> head_data_ap (new DataBufferHeap (m_data.GetDataStart(),
   1067                                                                              m_data.GetByteSize()));
   1068 
   1069             // Make en encoder so we can write the address into the buffer using
   1070             // the correct byte order (endianness)
   1071             DataEncoder encoder (head_data_ap->GetBytes(),
   1072                                  head_data_ap->GetByteSize(),
   1073                                  m_data.GetByteOrder(),
   1074                                  addr_byte_size);
   1075 
   1076             // Replace the address in the new buffer
   1077             if (encoder.PutMaxU64 (offset, addr_byte_size, file_addr) == UINT32_MAX)
   1078                 return false;
   1079 
   1080             // All went well, so now we can reset the data using a shared
   1081             // pointer to the heap data so "m_data" will now correctly
   1082             // manage the heap data.
   1083             m_data.SetData (DataBufferSP (head_data_ap.release()));
   1084             return true;
   1085         }
   1086         else
   1087         {
   1088             const offset_t op_arg_size = GetOpcodeDataSize (m_data, offset, op);
   1089             if (op_arg_size == LLDB_INVALID_OFFSET)
   1090                 break;
   1091             offset += op_arg_size;
   1092         }
   1093     }
   1094     return false;
   1095 }
   1096 
   1097 bool
   1098 DWARFExpression::LocationListContainsAddress (lldb::addr_t loclist_base_addr, lldb::addr_t addr) const
   1099 {
   1100     if (addr == LLDB_INVALID_ADDRESS)
   1101         return false;
   1102 
   1103     if (IsLocationList())
   1104     {
   1105         lldb::offset_t offset = 0;
   1106 
   1107         if (loclist_base_addr == LLDB_INVALID_ADDRESS)
   1108             return false;
   1109 
   1110         while (m_data.ValidOffset(offset))
   1111         {
   1112             // We need to figure out what the value is for the location.
   1113             addr_t lo_pc = m_data.GetAddress(&offset);
   1114             addr_t hi_pc = m_data.GetAddress(&offset);
   1115             if (lo_pc == 0 && hi_pc == 0)
   1116                 break;
   1117             else
   1118             {
   1119                 lo_pc += loclist_base_addr - m_loclist_slide;
   1120                 hi_pc += loclist_base_addr - m_loclist_slide;
   1121 
   1122                 if (lo_pc <= addr && addr < hi_pc)
   1123                     return true;
   1124 
   1125                 offset += m_data.GetU16(&offset);
   1126             }
   1127         }
   1128     }
   1129     return false;
   1130 }
   1131 
   1132 bool
   1133 DWARFExpression::GetLocation (addr_t base_addr, addr_t pc, lldb::offset_t &offset, lldb::offset_t &length)
   1134 {
   1135     offset = 0;
   1136     if (!IsLocationList())
   1137     {
   1138         length = m_data.GetByteSize();
   1139         return true;
   1140     }
   1141 
   1142     if (base_addr != LLDB_INVALID_ADDRESS && pc != LLDB_INVALID_ADDRESS)
   1143     {
   1144         addr_t curr_base_addr = base_addr;
   1145 
   1146         while (m_data.ValidOffset(offset))
   1147         {
   1148             // We need to figure out what the value is for the location.
   1149             addr_t lo_pc = m_data.GetAddress(&offset);
   1150             addr_t hi_pc = m_data.GetAddress(&offset);
   1151             if (lo_pc == 0 && hi_pc == 0)
   1152             {
   1153                 break;
   1154             }
   1155             else
   1156             {
   1157                 lo_pc += curr_base_addr - m_loclist_slide;
   1158                 hi_pc += curr_base_addr - m_loclist_slide;
   1159 
   1160                 length = m_data.GetU16(&offset);
   1161 
   1162                 if (length > 0 && lo_pc <= pc && pc < hi_pc)
   1163                     return true;
   1164 
   1165                 offset += length;
   1166             }
   1167         }
   1168     }
   1169     offset = LLDB_INVALID_OFFSET;
   1170     length = 0;
   1171     return false;
   1172 }
   1173 
   1174 bool
   1175 DWARFExpression::DumpLocationForAddress (Stream *s,
   1176                                          lldb::DescriptionLevel level,
   1177                                          addr_t base_addr,
   1178                                          addr_t address,
   1179                                          ABI *abi)
   1180 {
   1181     lldb::offset_t offset = 0;
   1182     lldb::offset_t length = 0;
   1183 
   1184     if (GetLocation (base_addr, address, offset, length))
   1185     {
   1186         if (length > 0)
   1187         {
   1188             DumpLocation(s, offset, length, level, abi);
   1189             return true;
   1190         }
   1191     }
   1192     return false;
   1193 }
   1194 
   1195 bool
   1196 DWARFExpression::Evaluate
   1197 (
   1198     ExecutionContextScope *exe_scope,
   1199     ClangExpressionVariableList *expr_locals,
   1200     ClangExpressionDeclMap *decl_map,
   1201     lldb::addr_t loclist_base_load_addr,
   1202     const Value* initial_value_ptr,
   1203     Value& result,
   1204     Error *error_ptr
   1205 ) const
   1206 {
   1207     ExecutionContext exe_ctx (exe_scope);
   1208     return Evaluate(&exe_ctx, expr_locals, decl_map, NULL, loclist_base_load_addr, initial_value_ptr, result, error_ptr);
   1209 }
   1210 
   1211 bool
   1212 DWARFExpression::Evaluate
   1213 (
   1214     ExecutionContext *exe_ctx,
   1215     ClangExpressionVariableList *expr_locals,
   1216     ClangExpressionDeclMap *decl_map,
   1217     RegisterContext *reg_ctx,
   1218     lldb::addr_t loclist_base_load_addr,
   1219     const Value* initial_value_ptr,
   1220     Value& result,
   1221     Error *error_ptr
   1222 ) const
   1223 {
   1224     if (IsLocationList())
   1225     {
   1226         lldb::offset_t offset = 0;
   1227         addr_t pc;
   1228         StackFrame *frame = NULL;
   1229         if (reg_ctx)
   1230             pc = reg_ctx->GetPC();
   1231         else
   1232         {
   1233             frame = exe_ctx->GetFramePtr();
   1234             if (!frame)
   1235                 return false;
   1236             RegisterContextSP reg_ctx_sp = frame->GetRegisterContext();
   1237             if (!reg_ctx_sp)
   1238                 return false;
   1239             pc = reg_ctx_sp->GetPC();
   1240         }
   1241 
   1242         if (loclist_base_load_addr != LLDB_INVALID_ADDRESS)
   1243         {
   1244             if (pc == LLDB_INVALID_ADDRESS)
   1245             {
   1246                 if (error_ptr)
   1247                     error_ptr->SetErrorString("Invalid PC in frame.");
   1248                 return false;
   1249             }
   1250 
   1251             addr_t curr_loclist_base_load_addr = loclist_base_load_addr;
   1252 
   1253             while (m_data.ValidOffset(offset))
   1254             {
   1255                 // We need to figure out what the value is for the location.
   1256                 addr_t lo_pc = m_data.GetAddress(&offset);
   1257                 addr_t hi_pc = m_data.GetAddress(&offset);
   1258                 if (lo_pc == 0 && hi_pc == 0)
   1259                 {
   1260                     break;
   1261                 }
   1262                 else
   1263                 {
   1264                     lo_pc += curr_loclist_base_load_addr - m_loclist_slide;
   1265                     hi_pc += curr_loclist_base_load_addr - m_loclist_slide;
   1266 
   1267                     uint16_t length = m_data.GetU16(&offset);
   1268 
   1269                     if (length > 0 && lo_pc <= pc && pc < hi_pc)
   1270                     {
   1271                         return DWARFExpression::Evaluate (exe_ctx, expr_locals, decl_map, reg_ctx, m_data, offset, length, m_reg_kind, initial_value_ptr, result, error_ptr);
   1272                     }
   1273                     offset += length;
   1274                 }
   1275             }
   1276         }
   1277         if (error_ptr)
   1278             error_ptr->SetErrorString ("variable not available");
   1279         return false;
   1280     }
   1281 
   1282     // Not a location list, just a single expression.
   1283     return DWARFExpression::Evaluate (exe_ctx, expr_locals, decl_map, reg_ctx, m_data, 0, m_data.GetByteSize(), m_reg_kind, initial_value_ptr, result, error_ptr);
   1284 }
   1285 
   1286 
   1287 
   1288 bool
   1289 DWARFExpression::Evaluate
   1290 (
   1291     ExecutionContext *exe_ctx,
   1292     ClangExpressionVariableList *expr_locals,
   1293     ClangExpressionDeclMap *decl_map,
   1294     RegisterContext *reg_ctx,
   1295     const DataExtractor& opcodes,
   1296     const lldb::offset_t opcodes_offset,
   1297     const lldb::offset_t opcodes_length,
   1298     const uint32_t reg_kind,
   1299     const Value* initial_value_ptr,
   1300     Value& result,
   1301     Error *error_ptr
   1302 )
   1303 {
   1304 
   1305     if (opcodes_length == 0)
   1306     {
   1307         if (error_ptr)
   1308             error_ptr->SetErrorString ("no location, value may have been optimized out");
   1309         return false;
   1310     }
   1311     std::vector<Value> stack;
   1312 
   1313     Process *process = NULL;
   1314     StackFrame *frame = NULL;
   1315 
   1316     if (exe_ctx)
   1317     {
   1318         process = exe_ctx->GetProcessPtr();
   1319         frame = exe_ctx->GetFramePtr();
   1320     }
   1321     if (reg_ctx == NULL && frame)
   1322         reg_ctx = frame->GetRegisterContext().get();
   1323 
   1324     if (initial_value_ptr)
   1325         stack.push_back(*initial_value_ptr);
   1326 
   1327     lldb::offset_t offset = opcodes_offset;
   1328     const lldb::offset_t end_offset = opcodes_offset + opcodes_length;
   1329     Value tmp;
   1330     uint32_t reg_num;
   1331 
   1332     // Make sure all of the data is available in opcodes.
   1333     if (!opcodes.ValidOffsetForDataOfSize(opcodes_offset, opcodes_length))
   1334     {
   1335         if (error_ptr)
   1336             error_ptr->SetErrorString ("invalid offset and/or length for opcodes buffer.");
   1337         return false;
   1338     }
   1339     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
   1340 
   1341 
   1342     while (opcodes.ValidOffset(offset) && offset < end_offset)
   1343     {
   1344         const lldb::offset_t op_offset = offset;
   1345         const uint8_t op = opcodes.GetU8(&offset);
   1346 
   1347         if (log && log->GetVerbose())
   1348         {
   1349             size_t count = stack.size();
   1350             log->Printf("Stack before operation has %lu values:", count);
   1351             for (size_t i=0; i<count; ++i)
   1352             {
   1353                 StreamString new_value;
   1354                 new_value.Printf("[%" PRIu64 "]", (uint64_t)i);
   1355                 stack[i].Dump(&new_value);
   1356                 log->Printf("  %s", new_value.GetData());
   1357             }
   1358             log->Printf("0x%8.8" PRIx64 ": %s", op_offset, DW_OP_value_to_name(op));
   1359         }
   1360         switch (op)
   1361         {
   1362         //----------------------------------------------------------------------
   1363         // The DW_OP_addr operation has a single operand that encodes a machine
   1364         // address and whose size is the size of an address on the target machine.
   1365         //----------------------------------------------------------------------
   1366         case DW_OP_addr:
   1367             stack.push_back(Scalar(opcodes.GetAddress(&offset)));
   1368             stack.back().SetValueType (Value::eValueTypeFileAddress);
   1369             break;
   1370 
   1371         //----------------------------------------------------------------------
   1372         // The DW_OP_addr_sect_offset4 is used for any location expressions in
   1373         // shared libraries that have a location like:
   1374         //  DW_OP_addr(0x1000)
   1375         // If this address resides in a shared library, then this virtual
   1376         // address won't make sense when it is evaluated in the context of a
   1377         // running process where shared libraries have been slid. To account for
   1378         // this, this new address type where we can store the section pointer
   1379         // and a 4 byte offset.
   1380         //----------------------------------------------------------------------
   1381 //      case DW_OP_addr_sect_offset4:
   1382 //          {
   1383 //              result_type = eResultTypeFileAddress;
   1384 //              lldb::Section *sect = (lldb::Section *)opcodes.GetMaxU64(&offset, sizeof(void *));
   1385 //              lldb::addr_t sect_offset = opcodes.GetU32(&offset);
   1386 //
   1387 //              Address so_addr (sect, sect_offset);
   1388 //              lldb::addr_t load_addr = so_addr.GetLoadAddress();
   1389 //              if (load_addr != LLDB_INVALID_ADDRESS)
   1390 //              {
   1391 //                  // We successfully resolve a file address to a load
   1392 //                  // address.
   1393 //                  stack.push_back(load_addr);
   1394 //                  break;
   1395 //              }
   1396 //              else
   1397 //              {
   1398 //                  // We were able
   1399 //                  if (error_ptr)
   1400 //                      error_ptr->SetErrorStringWithFormat ("Section %s in %s is not currently loaded.\n", sect->GetName().AsCString(), sect->GetModule()->GetFileSpec().GetFilename().AsCString());
   1401 //                  return false;
   1402 //              }
   1403 //          }
   1404 //          break;
   1405 
   1406         //----------------------------------------------------------------------
   1407         // OPCODE: DW_OP_deref
   1408         // OPERANDS: none
   1409         // DESCRIPTION: Pops the top stack entry and treats it as an address.
   1410         // The value retrieved from that address is pushed. The size of the
   1411         // data retrieved from the dereferenced address is the size of an
   1412         // address on the target machine.
   1413         //----------------------------------------------------------------------
   1414         case DW_OP_deref:
   1415             {
   1416                 Value::ValueType value_type = stack.back().GetValueType();
   1417                 switch (value_type)
   1418                 {
   1419                 case Value::eValueTypeHostAddress:
   1420                     {
   1421                         void *src = (void *)stack.back().GetScalar().ULongLong();
   1422                         intptr_t ptr;
   1423                         ::memcpy (&ptr, src, sizeof(void *));
   1424                         stack.back().GetScalar() = ptr;
   1425                         stack.back().ClearContext();
   1426                     }
   1427                     break;
   1428                 case Value::eValueTypeLoadAddress:
   1429                     if (exe_ctx)
   1430                     {
   1431                         if (process)
   1432                         {
   1433                             lldb::addr_t pointer_addr = stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
   1434                             uint8_t addr_bytes[sizeof(lldb::addr_t)];
   1435                             uint32_t addr_size = process->GetAddressByteSize();
   1436                             Error error;
   1437                             if (process->ReadMemory(pointer_addr, &addr_bytes, addr_size, error) == addr_size)
   1438                             {
   1439                                 DataExtractor addr_data(addr_bytes, sizeof(addr_bytes), process->GetByteOrder(), addr_size);
   1440                                 lldb::offset_t addr_data_offset = 0;
   1441                                 stack.back().GetScalar() = addr_data.GetPointer(&addr_data_offset);
   1442                                 stack.back().ClearContext();
   1443                             }
   1444                             else
   1445                             {
   1446                                 if (error_ptr)
   1447                                     error_ptr->SetErrorStringWithFormat ("Failed to dereference pointer from 0x%" PRIx64 " for DW_OP_deref: %s\n",
   1448                                                                          pointer_addr,
   1449                                                                          error.AsCString());
   1450                                 return false;
   1451                             }
   1452                         }
   1453                         else
   1454                         {
   1455                             if (error_ptr)
   1456                                 error_ptr->SetErrorStringWithFormat ("NULL process for DW_OP_deref.\n");
   1457                             return false;
   1458                         }
   1459                     }
   1460                     else
   1461                     {
   1462                         if (error_ptr)
   1463                             error_ptr->SetErrorStringWithFormat ("NULL execution context for DW_OP_deref.\n");
   1464                         return false;
   1465                     }
   1466                     break;
   1467 
   1468                 default:
   1469                     break;
   1470                 }
   1471 
   1472             }
   1473             break;
   1474 
   1475         //----------------------------------------------------------------------
   1476         // OPCODE: DW_OP_deref_size
   1477         // OPERANDS: 1
   1478         //  1 - uint8_t that specifies the size of the data to dereference.
   1479         // DESCRIPTION: Behaves like the DW_OP_deref operation: it pops the top
   1480         // stack entry and treats it as an address. The value retrieved from that
   1481         // address is pushed. In the DW_OP_deref_size operation, however, the
   1482         // size in bytes of the data retrieved from the dereferenced address is
   1483         // specified by the single operand. This operand is a 1-byte unsigned
   1484         // integral constant whose value may not be larger than the size of an
   1485         // address on the target machine. The data retrieved is zero extended
   1486         // to the size of an address on the target machine before being pushed
   1487         // on the expression stack.
   1488         //----------------------------------------------------------------------
   1489         case DW_OP_deref_size:
   1490             {
   1491                 uint8_t size = opcodes.GetU8(&offset);
   1492                 Value::ValueType value_type = stack.back().GetValueType();
   1493                 switch (value_type)
   1494                 {
   1495                 case Value::eValueTypeHostAddress:
   1496                     {
   1497                         void *src = (void *)stack.back().GetScalar().ULongLong();
   1498                         intptr_t ptr;
   1499                         ::memcpy (&ptr, src, sizeof(void *));
   1500                         // I can't decide whether the size operand should apply to the bytes in their
   1501                         // lldb-host endianness or the target endianness.. I doubt this'll ever come up
   1502                         // but I'll opt for assuming big endian regardless.
   1503                         switch (size)
   1504                         {
   1505                             case 1: ptr = ptr & 0xff; break;
   1506                             case 2: ptr = ptr & 0xffff; break;
   1507                             case 3: ptr = ptr & 0xffffff; break;
   1508                             case 4: ptr = ptr & 0xffffffff; break;
   1509                             // the casts are added to work around the case where intptr_t is a 32 bit quantity;
   1510                             // presumably we won't hit the 5..7 cases if (void*) is 32-bits in this program.
   1511                             case 5: ptr = (intptr_t) ptr & 0xffffffffffULL; break;
   1512                             case 6: ptr = (intptr_t) ptr & 0xffffffffffffULL; break;
   1513                             case 7: ptr = (intptr_t) ptr & 0xffffffffffffffULL; break;
   1514                             default: break;
   1515                         }
   1516                         stack.back().GetScalar() = ptr;
   1517                         stack.back().ClearContext();
   1518                     }
   1519                     break;
   1520                 case Value::eValueTypeLoadAddress:
   1521                     if (exe_ctx)
   1522                     {
   1523                         if (process)
   1524                         {
   1525                             lldb::addr_t pointer_addr = stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
   1526                             uint8_t addr_bytes[sizeof(lldb::addr_t)];
   1527                             Error error;
   1528                             if (process->ReadMemory(pointer_addr, &addr_bytes, size, error) == size)
   1529                             {
   1530                                 DataExtractor addr_data(addr_bytes, sizeof(addr_bytes), process->GetByteOrder(), size);
   1531                                 lldb::offset_t addr_data_offset = 0;
   1532                                 switch (size)
   1533                                 {
   1534                                     case 1: stack.back().GetScalar() = addr_data.GetU8(&addr_data_offset); break;
   1535                                     case 2: stack.back().GetScalar() = addr_data.GetU16(&addr_data_offset); break;
   1536                                     case 4: stack.back().GetScalar() = addr_data.GetU32(&addr_data_offset); break;
   1537                                     case 8: stack.back().GetScalar() = addr_data.GetU64(&addr_data_offset); break;
   1538                                     default: stack.back().GetScalar() = addr_data.GetPointer(&addr_data_offset);
   1539                                 }
   1540                                 stack.back().ClearContext();
   1541                             }
   1542                             else
   1543                             {
   1544                                 if (error_ptr)
   1545                                     error_ptr->SetErrorStringWithFormat ("Failed to dereference pointer from 0x%" PRIx64 " for DW_OP_deref: %s\n",
   1546                                                                          pointer_addr,
   1547                                                                          error.AsCString());
   1548                                 return false;
   1549                             }
   1550                         }
   1551                         else
   1552                         {
   1553                             if (error_ptr)
   1554                                 error_ptr->SetErrorStringWithFormat ("NULL process for DW_OP_deref.\n");
   1555                             return false;
   1556                         }
   1557                     }
   1558                     else
   1559                     {
   1560                         if (error_ptr)
   1561                             error_ptr->SetErrorStringWithFormat ("NULL execution context for DW_OP_deref.\n");
   1562                         return false;
   1563                     }
   1564                     break;
   1565 
   1566                 default:
   1567                     break;
   1568                 }
   1569 
   1570             }
   1571             break;
   1572 
   1573         //----------------------------------------------------------------------
   1574         // OPCODE: DW_OP_xderef_size
   1575         // OPERANDS: 1
   1576         //  1 - uint8_t that specifies the size of the data to dereference.
   1577         // DESCRIPTION: Behaves like the DW_OP_xderef operation: the entry at
   1578         // the top of the stack is treated as an address. The second stack
   1579         // entry is treated as an "address space identifier" for those
   1580         // architectures that support multiple address spaces. The top two
   1581         // stack elements are popped, a data item is retrieved through an
   1582         // implementation-defined address calculation and pushed as the new
   1583         // stack top. In the DW_OP_xderef_size operation, however, the size in
   1584         // bytes of the data retrieved from the dereferenced address is
   1585         // specified by the single operand. This operand is a 1-byte unsigned
   1586         // integral constant whose value may not be larger than the size of an
   1587         // address on the target machine. The data retrieved is zero extended
   1588         // to the size of an address on the target machine before being pushed
   1589         // on the expression stack.
   1590         //----------------------------------------------------------------------
   1591         case DW_OP_xderef_size:
   1592             if (error_ptr)
   1593                 error_ptr->SetErrorString("Unimplemented opcode: DW_OP_xderef_size.");
   1594             return false;
   1595         //----------------------------------------------------------------------
   1596         // OPCODE: DW_OP_xderef
   1597         // OPERANDS: none
   1598         // DESCRIPTION: Provides an extended dereference mechanism. The entry at
   1599         // the top of the stack is treated as an address. The second stack entry
   1600         // is treated as an "address space identifier" for those architectures
   1601         // that support multiple address spaces. The top two stack elements are
   1602         // popped, a data item is retrieved through an implementation-defined
   1603         // address calculation and pushed as the new stack top. The size of the
   1604         // data retrieved from the dereferenced address is the size of an address
   1605         // on the target machine.
   1606         //----------------------------------------------------------------------
   1607         case DW_OP_xderef:
   1608             if (error_ptr)
   1609                 error_ptr->SetErrorString("Unimplemented opcode: DW_OP_xderef.");
   1610             return false;
   1611 
   1612         //----------------------------------------------------------------------
   1613         // All DW_OP_constXXX opcodes have a single operand as noted below:
   1614         //
   1615         // Opcode           Operand 1
   1616         // ---------------  ----------------------------------------------------
   1617         // DW_OP_const1u    1-byte unsigned integer constant
   1618         // DW_OP_const1s    1-byte signed integer constant
   1619         // DW_OP_const2u    2-byte unsigned integer constant
   1620         // DW_OP_const2s    2-byte signed integer constant
   1621         // DW_OP_const4u    4-byte unsigned integer constant
   1622         // DW_OP_const4s    4-byte signed integer constant
   1623         // DW_OP_const8u    8-byte unsigned integer constant
   1624         // DW_OP_const8s    8-byte signed integer constant
   1625         // DW_OP_constu     unsigned LEB128 integer constant
   1626         // DW_OP_consts     signed LEB128 integer constant
   1627         //----------------------------------------------------------------------
   1628         case DW_OP_const1u             :    stack.push_back(Scalar(( uint8_t)opcodes.GetU8 (&offset))); break;
   1629         case DW_OP_const1s             :    stack.push_back(Scalar((  int8_t)opcodes.GetU8 (&offset))); break;
   1630         case DW_OP_const2u             :    stack.push_back(Scalar((uint16_t)opcodes.GetU16 (&offset))); break;
   1631         case DW_OP_const2s             :    stack.push_back(Scalar(( int16_t)opcodes.GetU16 (&offset))); break;
   1632         case DW_OP_const4u             :    stack.push_back(Scalar((uint32_t)opcodes.GetU32 (&offset))); break;
   1633         case DW_OP_const4s             :    stack.push_back(Scalar(( int32_t)opcodes.GetU32 (&offset))); break;
   1634         case DW_OP_const8u             :    stack.push_back(Scalar((uint64_t)opcodes.GetU64 (&offset))); break;
   1635         case DW_OP_const8s             :    stack.push_back(Scalar(( int64_t)opcodes.GetU64 (&offset))); break;
   1636         case DW_OP_constu              :    stack.push_back(Scalar(opcodes.GetULEB128 (&offset))); break;
   1637         case DW_OP_consts              :    stack.push_back(Scalar(opcodes.GetSLEB128 (&offset))); break;
   1638 
   1639         //----------------------------------------------------------------------
   1640         // OPCODE: DW_OP_dup
   1641         // OPERANDS: none
   1642         // DESCRIPTION: duplicates the value at the top of the stack
   1643         //----------------------------------------------------------------------
   1644         case DW_OP_dup:
   1645             if (stack.empty())
   1646             {
   1647                 if (error_ptr)
   1648                     error_ptr->SetErrorString("Expression stack empty for DW_OP_dup.");
   1649                 return false;
   1650             }
   1651             else
   1652                 stack.push_back(stack.back());
   1653             break;
   1654 
   1655         //----------------------------------------------------------------------
   1656         // OPCODE: DW_OP_drop
   1657         // OPERANDS: none
   1658         // DESCRIPTION: pops the value at the top of the stack
   1659         //----------------------------------------------------------------------
   1660         case DW_OP_drop:
   1661             if (stack.empty())
   1662             {
   1663                 if (error_ptr)
   1664                     error_ptr->SetErrorString("Expression stack empty for DW_OP_drop.");
   1665                 return false;
   1666             }
   1667             else
   1668                 stack.pop_back();
   1669             break;
   1670 
   1671         //----------------------------------------------------------------------
   1672         // OPCODE: DW_OP_over
   1673         // OPERANDS: none
   1674         // DESCRIPTION: Duplicates the entry currently second in the stack at
   1675         // the top of the stack.
   1676         //----------------------------------------------------------------------
   1677         case DW_OP_over:
   1678             if (stack.size() < 2)
   1679             {
   1680                 if (error_ptr)
   1681                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_over.");
   1682                 return false;
   1683             }
   1684             else
   1685                 stack.push_back(stack[stack.size() - 2]);
   1686             break;
   1687 
   1688 
   1689         //----------------------------------------------------------------------
   1690         // OPCODE: DW_OP_pick
   1691         // OPERANDS: uint8_t index into the current stack
   1692         // DESCRIPTION: The stack entry with the specified index (0 through 255,
   1693         // inclusive) is pushed on the stack
   1694         //----------------------------------------------------------------------
   1695         case DW_OP_pick:
   1696             {
   1697                 uint8_t pick_idx = opcodes.GetU8(&offset);
   1698                 if (pick_idx < stack.size())
   1699                     stack.push_back(stack[pick_idx]);
   1700                 else
   1701                 {
   1702                     if (error_ptr)
   1703                         error_ptr->SetErrorStringWithFormat("Index %u out of range for DW_OP_pick.\n", pick_idx);
   1704                     return false;
   1705                 }
   1706             }
   1707             break;
   1708 
   1709         //----------------------------------------------------------------------
   1710         // OPCODE: DW_OP_swap
   1711         // OPERANDS: none
   1712         // DESCRIPTION: swaps the top two stack entries. The entry at the top
   1713         // of the stack becomes the second stack entry, and the second entry
   1714         // becomes the top of the stack
   1715         //----------------------------------------------------------------------
   1716         case DW_OP_swap:
   1717             if (stack.size() < 2)
   1718             {
   1719                 if (error_ptr)
   1720                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_swap.");
   1721                 return false;
   1722             }
   1723             else
   1724             {
   1725                 tmp = stack.back();
   1726                 stack.back() = stack[stack.size() - 2];
   1727                 stack[stack.size() - 2] = tmp;
   1728             }
   1729             break;
   1730 
   1731         //----------------------------------------------------------------------
   1732         // OPCODE: DW_OP_rot
   1733         // OPERANDS: none
   1734         // DESCRIPTION: Rotates the first three stack entries. The entry at
   1735         // the top of the stack becomes the third stack entry, the second
   1736         // entry becomes the top of the stack, and the third entry becomes
   1737         // the second entry.
   1738         //----------------------------------------------------------------------
   1739         case DW_OP_rot:
   1740             if (stack.size() < 3)
   1741             {
   1742                 if (error_ptr)
   1743                     error_ptr->SetErrorString("Expression stack needs at least 3 items for DW_OP_rot.");
   1744                 return false;
   1745             }
   1746             else
   1747             {
   1748                 size_t last_idx = stack.size() - 1;
   1749                 Value old_top = stack[last_idx];
   1750                 stack[last_idx] = stack[last_idx - 1];
   1751                 stack[last_idx - 1] = stack[last_idx - 2];
   1752                 stack[last_idx - 2] = old_top;
   1753             }
   1754             break;
   1755 
   1756         //----------------------------------------------------------------------
   1757         // OPCODE: DW_OP_abs
   1758         // OPERANDS: none
   1759         // DESCRIPTION: pops the top stack entry, interprets it as a signed
   1760         // value and pushes its absolute value. If the absolute value can not be
   1761         // represented, the result is undefined.
   1762         //----------------------------------------------------------------------
   1763         case DW_OP_abs:
   1764             if (stack.empty())
   1765             {
   1766                 if (error_ptr)
   1767                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_abs.");
   1768                 return false;
   1769             }
   1770             else if (stack.back().ResolveValue(exe_ctx).AbsoluteValue() == false)
   1771             {
   1772                 if (error_ptr)
   1773                     error_ptr->SetErrorString("Failed to take the absolute value of the first stack item.");
   1774                 return false;
   1775             }
   1776             break;
   1777 
   1778         //----------------------------------------------------------------------
   1779         // OPCODE: DW_OP_and
   1780         // OPERANDS: none
   1781         // DESCRIPTION: pops the top two stack values, performs a bitwise and
   1782         // operation on the two, and pushes the result.
   1783         //----------------------------------------------------------------------
   1784         case DW_OP_and:
   1785             if (stack.size() < 2)
   1786             {
   1787                 if (error_ptr)
   1788                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_and.");
   1789                 return false;
   1790             }
   1791             else
   1792             {
   1793                 tmp = stack.back();
   1794                 stack.pop_back();
   1795                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) & tmp.ResolveValue(exe_ctx);
   1796             }
   1797             break;
   1798 
   1799         //----------------------------------------------------------------------
   1800         // OPCODE: DW_OP_div
   1801         // OPERANDS: none
   1802         // DESCRIPTION: pops the top two stack values, divides the former second
   1803         // entry by the former top of the stack using signed division, and
   1804         // pushes the result.
   1805         //----------------------------------------------------------------------
   1806         case DW_OP_div:
   1807             if (stack.size() < 2)
   1808             {
   1809                 if (error_ptr)
   1810                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_div.");
   1811                 return false;
   1812             }
   1813             else
   1814             {
   1815                 tmp = stack.back();
   1816                 if (tmp.ResolveValue(exe_ctx).IsZero())
   1817                 {
   1818                     if (error_ptr)
   1819                         error_ptr->SetErrorString("Divide by zero.");
   1820                     return false;
   1821                 }
   1822                 else
   1823                 {
   1824                     stack.pop_back();
   1825                     stack.back() = stack.back().ResolveValue(exe_ctx) / tmp.ResolveValue(exe_ctx);
   1826                     if (!stack.back().ResolveValue(exe_ctx).IsValid())
   1827                     {
   1828                         if (error_ptr)
   1829                             error_ptr->SetErrorString("Divide failed.");
   1830                         return false;
   1831                     }
   1832                 }
   1833             }
   1834             break;
   1835 
   1836         //----------------------------------------------------------------------
   1837         // OPCODE: DW_OP_minus
   1838         // OPERANDS: none
   1839         // DESCRIPTION: pops the top two stack values, subtracts the former top
   1840         // of the stack from the former second entry, and pushes the result.
   1841         //----------------------------------------------------------------------
   1842         case DW_OP_minus:
   1843             if (stack.size() < 2)
   1844             {
   1845                 if (error_ptr)
   1846                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_minus.");
   1847                 return false;
   1848             }
   1849             else
   1850             {
   1851                 tmp = stack.back();
   1852                 stack.pop_back();
   1853                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) - tmp.ResolveValue(exe_ctx);
   1854             }
   1855             break;
   1856 
   1857         //----------------------------------------------------------------------
   1858         // OPCODE: DW_OP_mod
   1859         // OPERANDS: none
   1860         // DESCRIPTION: pops the top two stack values and pushes the result of
   1861         // the calculation: former second stack entry modulo the former top of
   1862         // the stack.
   1863         //----------------------------------------------------------------------
   1864         case DW_OP_mod:
   1865             if (stack.size() < 2)
   1866             {
   1867                 if (error_ptr)
   1868                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_mod.");
   1869                 return false;
   1870             }
   1871             else
   1872             {
   1873                 tmp = stack.back();
   1874                 stack.pop_back();
   1875                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) % tmp.ResolveValue(exe_ctx);
   1876             }
   1877             break;
   1878 
   1879 
   1880         //----------------------------------------------------------------------
   1881         // OPCODE: DW_OP_mul
   1882         // OPERANDS: none
   1883         // DESCRIPTION: pops the top two stack entries, multiplies them
   1884         // together, and pushes the result.
   1885         //----------------------------------------------------------------------
   1886         case DW_OP_mul:
   1887             if (stack.size() < 2)
   1888             {
   1889                 if (error_ptr)
   1890                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_mul.");
   1891                 return false;
   1892             }
   1893             else
   1894             {
   1895                 tmp = stack.back();
   1896                 stack.pop_back();
   1897                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) * tmp.ResolveValue(exe_ctx);
   1898             }
   1899             break;
   1900 
   1901         //----------------------------------------------------------------------
   1902         // OPCODE: DW_OP_neg
   1903         // OPERANDS: none
   1904         // DESCRIPTION: pops the top stack entry, and pushes its negation.
   1905         //----------------------------------------------------------------------
   1906         case DW_OP_neg:
   1907             if (stack.empty())
   1908             {
   1909                 if (error_ptr)
   1910                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_neg.");
   1911                 return false;
   1912             }
   1913             else
   1914             {
   1915                 if (stack.back().ResolveValue(exe_ctx).UnaryNegate() == false)
   1916                 {
   1917                     if (error_ptr)
   1918                         error_ptr->SetErrorString("Unary negate failed.");
   1919                     return false;
   1920                 }
   1921             }
   1922             break;
   1923 
   1924         //----------------------------------------------------------------------
   1925         // OPCODE: DW_OP_not
   1926         // OPERANDS: none
   1927         // DESCRIPTION: pops the top stack entry, and pushes its bitwise
   1928         // complement
   1929         //----------------------------------------------------------------------
   1930         case DW_OP_not:
   1931             if (stack.empty())
   1932             {
   1933                 if (error_ptr)
   1934                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_not.");
   1935                 return false;
   1936             }
   1937             else
   1938             {
   1939                 if (stack.back().ResolveValue(exe_ctx).OnesComplement() == false)
   1940                 {
   1941                     if (error_ptr)
   1942                         error_ptr->SetErrorString("Logical NOT failed.");
   1943                     return false;
   1944                 }
   1945             }
   1946             break;
   1947 
   1948         //----------------------------------------------------------------------
   1949         // OPCODE: DW_OP_or
   1950         // OPERANDS: none
   1951         // DESCRIPTION: pops the top two stack entries, performs a bitwise or
   1952         // operation on the two, and pushes the result.
   1953         //----------------------------------------------------------------------
   1954         case DW_OP_or:
   1955             if (stack.size() < 2)
   1956             {
   1957                 if (error_ptr)
   1958                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_or.");
   1959                 return false;
   1960             }
   1961             else
   1962             {
   1963                 tmp = stack.back();
   1964                 stack.pop_back();
   1965                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) | tmp.ResolveValue(exe_ctx);
   1966             }
   1967             break;
   1968 
   1969         //----------------------------------------------------------------------
   1970         // OPCODE: DW_OP_plus
   1971         // OPERANDS: none
   1972         // DESCRIPTION: pops the top two stack entries, adds them together, and
   1973         // pushes the result.
   1974         //----------------------------------------------------------------------
   1975         case DW_OP_plus:
   1976             if (stack.size() < 2)
   1977             {
   1978                 if (error_ptr)
   1979                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_plus.");
   1980                 return false;
   1981             }
   1982             else
   1983             {
   1984                 tmp = stack.back();
   1985                 stack.pop_back();
   1986                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) + tmp.ResolveValue(exe_ctx);
   1987             }
   1988             break;
   1989 
   1990         //----------------------------------------------------------------------
   1991         // OPCODE: DW_OP_plus_uconst
   1992         // OPERANDS: none
   1993         // DESCRIPTION: pops the top stack entry, adds it to the unsigned LEB128
   1994         // constant operand and pushes the result.
   1995         //----------------------------------------------------------------------
   1996         case DW_OP_plus_uconst:
   1997             if (stack.empty())
   1998             {
   1999                 if (error_ptr)
   2000                     error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_plus_uconst.");
   2001                 return false;
   2002             }
   2003             else
   2004             {
   2005                 const uint64_t uconst_value = opcodes.GetULEB128(&offset);
   2006                 // Implicit conversion from a UINT to a Scalar...
   2007                 stack.back().ResolveValue(exe_ctx) += uconst_value;
   2008                 if (!stack.back().ResolveValue(exe_ctx).IsValid())
   2009                 {
   2010                     if (error_ptr)
   2011                         error_ptr->SetErrorString("DW_OP_plus_uconst failed.");
   2012                     return false;
   2013                 }
   2014             }
   2015             break;
   2016 
   2017         //----------------------------------------------------------------------
   2018         // OPCODE: DW_OP_shl
   2019         // OPERANDS: none
   2020         // DESCRIPTION:  pops the top two stack entries, shifts the former
   2021         // second entry left by the number of bits specified by the former top
   2022         // of the stack, and pushes the result.
   2023         //----------------------------------------------------------------------
   2024         case DW_OP_shl:
   2025             if (stack.size() < 2)
   2026             {
   2027                 if (error_ptr)
   2028                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_shl.");
   2029                 return false;
   2030             }
   2031             else
   2032             {
   2033                 tmp = stack.back();
   2034                 stack.pop_back();
   2035                 stack.back().ResolveValue(exe_ctx) <<= tmp.ResolveValue(exe_ctx);
   2036             }
   2037             break;
   2038 
   2039         //----------------------------------------------------------------------
   2040         // OPCODE: DW_OP_shr
   2041         // OPERANDS: none
   2042         // DESCRIPTION: pops the top two stack entries, shifts the former second
   2043         // entry right logically (filling with zero bits) by the number of bits
   2044         // specified by the former top of the stack, and pushes the result.
   2045         //----------------------------------------------------------------------
   2046         case DW_OP_shr:
   2047             if (stack.size() < 2)
   2048             {
   2049                 if (error_ptr)
   2050                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_shr.");
   2051                 return false;
   2052             }
   2053             else
   2054             {
   2055                 tmp = stack.back();
   2056                 stack.pop_back();
   2057                 if (stack.back().ResolveValue(exe_ctx).ShiftRightLogical(tmp.ResolveValue(exe_ctx)) == false)
   2058                 {
   2059                     if (error_ptr)
   2060                         error_ptr->SetErrorString("DW_OP_shr failed.");
   2061                     return false;
   2062                 }
   2063             }
   2064             break;
   2065 
   2066         //----------------------------------------------------------------------
   2067         // OPCODE: DW_OP_shra
   2068         // OPERANDS: none
   2069         // DESCRIPTION: pops the top two stack entries, shifts the former second
   2070         // entry right arithmetically (divide the magnitude by 2, keep the same
   2071         // sign for the result) by the number of bits specified by the former
   2072         // top of the stack, and pushes the result.
   2073         //----------------------------------------------------------------------
   2074         case DW_OP_shra:
   2075             if (stack.size() < 2)
   2076             {
   2077                 if (error_ptr)
   2078                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_shra.");
   2079                 return false;
   2080             }
   2081             else
   2082             {
   2083                 tmp = stack.back();
   2084                 stack.pop_back();
   2085                 stack.back().ResolveValue(exe_ctx) >>= tmp.ResolveValue(exe_ctx);
   2086             }
   2087             break;
   2088 
   2089         //----------------------------------------------------------------------
   2090         // OPCODE: DW_OP_xor
   2091         // OPERANDS: none
   2092         // DESCRIPTION: pops the top two stack entries, performs the bitwise
   2093         // exclusive-or operation on the two, and pushes the result.
   2094         //----------------------------------------------------------------------
   2095         case DW_OP_xor:
   2096             if (stack.size() < 2)
   2097             {
   2098                 if (error_ptr)
   2099                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_xor.");
   2100                 return false;
   2101             }
   2102             else
   2103             {
   2104                 tmp = stack.back();
   2105                 stack.pop_back();
   2106                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) ^ tmp.ResolveValue(exe_ctx);
   2107             }
   2108             break;
   2109 
   2110 
   2111         //----------------------------------------------------------------------
   2112         // OPCODE: DW_OP_skip
   2113         // OPERANDS: int16_t
   2114         // DESCRIPTION:  An unconditional branch. Its single operand is a 2-byte
   2115         // signed integer constant. The 2-byte constant is the number of bytes
   2116         // of the DWARF expression to skip forward or backward from the current
   2117         // operation, beginning after the 2-byte constant.
   2118         //----------------------------------------------------------------------
   2119         case DW_OP_skip:
   2120             {
   2121                 int16_t skip_offset = (int16_t)opcodes.GetU16(&offset);
   2122                 lldb::offset_t new_offset = offset + skip_offset;
   2123                 if (new_offset >= opcodes_offset && new_offset < end_offset)
   2124                     offset = new_offset;
   2125                 else
   2126                 {
   2127                     if (error_ptr)
   2128                         error_ptr->SetErrorString("Invalid opcode offset in DW_OP_skip.");
   2129                     return false;
   2130                 }
   2131             }
   2132             break;
   2133 
   2134         //----------------------------------------------------------------------
   2135         // OPCODE: DW_OP_bra
   2136         // OPERANDS: int16_t
   2137         // DESCRIPTION: A conditional branch. Its single operand is a 2-byte
   2138         // signed integer constant. This operation pops the top of stack. If
   2139         // the value popped is not the constant 0, the 2-byte constant operand
   2140         // is the number of bytes of the DWARF expression to skip forward or
   2141         // backward from the current operation, beginning after the 2-byte
   2142         // constant.
   2143         //----------------------------------------------------------------------
   2144         case DW_OP_bra:
   2145             {
   2146                 tmp = stack.back();
   2147                 stack.pop_back();
   2148                 int16_t bra_offset = (int16_t)opcodes.GetU16(&offset);
   2149                 Scalar zero(0);
   2150                 if (tmp.ResolveValue(exe_ctx) != zero)
   2151                 {
   2152                     lldb::offset_t new_offset = offset + bra_offset;
   2153                     if (new_offset >= opcodes_offset && new_offset < end_offset)
   2154                         offset = new_offset;
   2155                     else
   2156                     {
   2157                         if (error_ptr)
   2158                             error_ptr->SetErrorString("Invalid opcode offset in DW_OP_bra.");
   2159                         return false;
   2160                     }
   2161                 }
   2162             }
   2163             break;
   2164 
   2165         //----------------------------------------------------------------------
   2166         // OPCODE: DW_OP_eq
   2167         // OPERANDS: none
   2168         // DESCRIPTION: pops the top two stack values, compares using the
   2169         // equals (==) operator.
   2170         // STACK RESULT: push the constant value 1 onto the stack if the result
   2171         // of the operation is true or the constant value 0 if the result of the
   2172         // operation is false.
   2173         //----------------------------------------------------------------------
   2174         case DW_OP_eq:
   2175             if (stack.size() < 2)
   2176             {
   2177                 if (error_ptr)
   2178                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_eq.");
   2179                 return false;
   2180             }
   2181             else
   2182             {
   2183                 tmp = stack.back();
   2184                 stack.pop_back();
   2185                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) == tmp.ResolveValue(exe_ctx);
   2186             }
   2187             break;
   2188 
   2189         //----------------------------------------------------------------------
   2190         // OPCODE: DW_OP_ge
   2191         // OPERANDS: none
   2192         // DESCRIPTION: pops the top two stack values, compares using the
   2193         // greater than or equal to (>=) operator.
   2194         // STACK RESULT: push the constant value 1 onto the stack if the result
   2195         // of the operation is true or the constant value 0 if the result of the
   2196         // operation is false.
   2197         //----------------------------------------------------------------------
   2198         case DW_OP_ge:
   2199             if (stack.size() < 2)
   2200             {
   2201                 if (error_ptr)
   2202                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_ge.");
   2203                 return false;
   2204             }
   2205             else
   2206             {
   2207                 tmp = stack.back();
   2208                 stack.pop_back();
   2209                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) >= tmp.ResolveValue(exe_ctx);
   2210             }
   2211             break;
   2212 
   2213         //----------------------------------------------------------------------
   2214         // OPCODE: DW_OP_gt
   2215         // OPERANDS: none
   2216         // DESCRIPTION: pops the top two stack values, compares using the
   2217         // greater than (>) operator.
   2218         // STACK RESULT: push the constant value 1 onto the stack if the result
   2219         // of the operation is true or the constant value 0 if the result of the
   2220         // operation is false.
   2221         //----------------------------------------------------------------------
   2222         case DW_OP_gt:
   2223             if (stack.size() < 2)
   2224             {
   2225                 if (error_ptr)
   2226                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_gt.");
   2227                 return false;
   2228             }
   2229             else
   2230             {
   2231                 tmp = stack.back();
   2232                 stack.pop_back();
   2233                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) > tmp.ResolveValue(exe_ctx);
   2234             }
   2235             break;
   2236 
   2237         //----------------------------------------------------------------------
   2238         // OPCODE: DW_OP_le
   2239         // OPERANDS: none
   2240         // DESCRIPTION: pops the top two stack values, compares using the
   2241         // less than or equal to (<=) operator.
   2242         // STACK RESULT: push the constant value 1 onto the stack if the result
   2243         // of the operation is true or the constant value 0 if the result of the
   2244         // operation is false.
   2245         //----------------------------------------------------------------------
   2246         case DW_OP_le:
   2247             if (stack.size() < 2)
   2248             {
   2249                 if (error_ptr)
   2250                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_le.");
   2251                 return false;
   2252             }
   2253             else
   2254             {
   2255                 tmp = stack.back();
   2256                 stack.pop_back();
   2257                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) <= tmp.ResolveValue(exe_ctx);
   2258             }
   2259             break;
   2260 
   2261         //----------------------------------------------------------------------
   2262         // OPCODE: DW_OP_lt
   2263         // OPERANDS: none
   2264         // DESCRIPTION: pops the top two stack values, compares using the
   2265         // less than (<) operator.
   2266         // STACK RESULT: push the constant value 1 onto the stack if the result
   2267         // of the operation is true or the constant value 0 if the result of the
   2268         // operation is false.
   2269         //----------------------------------------------------------------------
   2270         case DW_OP_lt:
   2271             if (stack.size() < 2)
   2272             {
   2273                 if (error_ptr)
   2274                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_lt.");
   2275                 return false;
   2276             }
   2277             else
   2278             {
   2279                 tmp = stack.back();
   2280                 stack.pop_back();
   2281                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) < tmp.ResolveValue(exe_ctx);
   2282             }
   2283             break;
   2284 
   2285         //----------------------------------------------------------------------
   2286         // OPCODE: DW_OP_ne
   2287         // OPERANDS: none
   2288         // DESCRIPTION: pops the top two stack values, compares using the
   2289         // not equal (!=) operator.
   2290         // STACK RESULT: push the constant value 1 onto the stack if the result
   2291         // of the operation is true or the constant value 0 if the result of the
   2292         // operation is false.
   2293         //----------------------------------------------------------------------
   2294         case DW_OP_ne:
   2295             if (stack.size() < 2)
   2296             {
   2297                 if (error_ptr)
   2298                     error_ptr->SetErrorString("Expression stack needs at least 2 items for DW_OP_ne.");
   2299                 return false;
   2300             }
   2301             else
   2302             {
   2303                 tmp = stack.back();
   2304                 stack.pop_back();
   2305                 stack.back().ResolveValue(exe_ctx) = stack.back().ResolveValue(exe_ctx) != tmp.ResolveValue(exe_ctx);
   2306             }
   2307             break;
   2308 
   2309         //----------------------------------------------------------------------
   2310         // OPCODE: DW_OP_litn
   2311         // OPERANDS: none
   2312         // DESCRIPTION: encode the unsigned literal values from 0 through 31.
   2313         // STACK RESULT: push the unsigned literal constant value onto the top
   2314         // of the stack.
   2315         //----------------------------------------------------------------------
   2316         case DW_OP_lit0:
   2317         case DW_OP_lit1:
   2318         case DW_OP_lit2:
   2319         case DW_OP_lit3:
   2320         case DW_OP_lit4:
   2321         case DW_OP_lit5:
   2322         case DW_OP_lit6:
   2323         case DW_OP_lit7:
   2324         case DW_OP_lit8:
   2325         case DW_OP_lit9:
   2326         case DW_OP_lit10:
   2327         case DW_OP_lit11:
   2328         case DW_OP_lit12:
   2329         case DW_OP_lit13:
   2330         case DW_OP_lit14:
   2331         case DW_OP_lit15:
   2332         case DW_OP_lit16:
   2333         case DW_OP_lit17:
   2334         case DW_OP_lit18:
   2335         case DW_OP_lit19:
   2336         case DW_OP_lit20:
   2337         case DW_OP_lit21:
   2338         case DW_OP_lit22:
   2339         case DW_OP_lit23:
   2340         case DW_OP_lit24:
   2341         case DW_OP_lit25:
   2342         case DW_OP_lit26:
   2343         case DW_OP_lit27:
   2344         case DW_OP_lit28:
   2345         case DW_OP_lit29:
   2346         case DW_OP_lit30:
   2347         case DW_OP_lit31:
   2348             stack.push_back(Scalar(op - DW_OP_lit0));
   2349             break;
   2350 
   2351         //----------------------------------------------------------------------
   2352         // OPCODE: DW_OP_regN
   2353         // OPERANDS: none
   2354         // DESCRIPTION: Push the value in register n on the top of the stack.
   2355         //----------------------------------------------------------------------
   2356         case DW_OP_reg0:
   2357         case DW_OP_reg1:
   2358         case DW_OP_reg2:
   2359         case DW_OP_reg3:
   2360         case DW_OP_reg4:
   2361         case DW_OP_reg5:
   2362         case DW_OP_reg6:
   2363         case DW_OP_reg7:
   2364         case DW_OP_reg8:
   2365         case DW_OP_reg9:
   2366         case DW_OP_reg10:
   2367         case DW_OP_reg11:
   2368         case DW_OP_reg12:
   2369         case DW_OP_reg13:
   2370         case DW_OP_reg14:
   2371         case DW_OP_reg15:
   2372         case DW_OP_reg16:
   2373         case DW_OP_reg17:
   2374         case DW_OP_reg18:
   2375         case DW_OP_reg19:
   2376         case DW_OP_reg20:
   2377         case DW_OP_reg21:
   2378         case DW_OP_reg22:
   2379         case DW_OP_reg23:
   2380         case DW_OP_reg24:
   2381         case DW_OP_reg25:
   2382         case DW_OP_reg26:
   2383         case DW_OP_reg27:
   2384         case DW_OP_reg28:
   2385         case DW_OP_reg29:
   2386         case DW_OP_reg30:
   2387         case DW_OP_reg31:
   2388             {
   2389                 reg_num = op - DW_OP_reg0;
   2390 
   2391                 if (ReadRegisterValueAsScalar (reg_ctx, reg_kind, reg_num, error_ptr, tmp))
   2392                     stack.push_back(tmp);
   2393                 else
   2394                     return false;
   2395             }
   2396             break;
   2397         //----------------------------------------------------------------------
   2398         // OPCODE: DW_OP_regx
   2399         // OPERANDS:
   2400         //      ULEB128 literal operand that encodes the register.
   2401         // DESCRIPTION: Push the value in register on the top of the stack.
   2402         //----------------------------------------------------------------------
   2403         case DW_OP_regx:
   2404             {
   2405                 reg_num = opcodes.GetULEB128(&offset);
   2406                 if (ReadRegisterValueAsScalar (reg_ctx, reg_kind, reg_num, error_ptr, tmp))
   2407                     stack.push_back(tmp);
   2408                 else
   2409                     return false;
   2410             }
   2411             break;
   2412 
   2413         //----------------------------------------------------------------------
   2414         // OPCODE: DW_OP_bregN
   2415         // OPERANDS:
   2416         //      SLEB128 offset from register N
   2417         // DESCRIPTION: Value is in memory at the address specified by register
   2418         // N plus an offset.
   2419         //----------------------------------------------------------------------
   2420         case DW_OP_breg0:
   2421         case DW_OP_breg1:
   2422         case DW_OP_breg2:
   2423         case DW_OP_breg3:
   2424         case DW_OP_breg4:
   2425         case DW_OP_breg5:
   2426         case DW_OP_breg6:
   2427         case DW_OP_breg7:
   2428         case DW_OP_breg8:
   2429         case DW_OP_breg9:
   2430         case DW_OP_breg10:
   2431         case DW_OP_breg11:
   2432         case DW_OP_breg12:
   2433         case DW_OP_breg13:
   2434         case DW_OP_breg14:
   2435         case DW_OP_breg15:
   2436         case DW_OP_breg16:
   2437         case DW_OP_breg17:
   2438         case DW_OP_breg18:
   2439         case DW_OP_breg19:
   2440         case DW_OP_breg20:
   2441         case DW_OP_breg21:
   2442         case DW_OP_breg22:
   2443         case DW_OP_breg23:
   2444         case DW_OP_breg24:
   2445         case DW_OP_breg25:
   2446         case DW_OP_breg26:
   2447         case DW_OP_breg27:
   2448         case DW_OP_breg28:
   2449         case DW_OP_breg29:
   2450         case DW_OP_breg30:
   2451         case DW_OP_breg31:
   2452             {
   2453                 reg_num = op - DW_OP_breg0;
   2454 
   2455                 if (ReadRegisterValueAsScalar (reg_ctx, reg_kind, reg_num, error_ptr, tmp))
   2456                 {
   2457                     int64_t breg_offset = opcodes.GetSLEB128(&offset);
   2458                     tmp.ResolveValue(exe_ctx) += (uint64_t)breg_offset;
   2459                     tmp.ClearContext();
   2460                     stack.push_back(tmp);
   2461                     stack.back().SetValueType (Value::eValueTypeLoadAddress);
   2462                 }
   2463                 else
   2464                     return false;
   2465             }
   2466             break;
   2467         //----------------------------------------------------------------------
   2468         // OPCODE: DW_OP_bregx
   2469         // OPERANDS: 2
   2470         //      ULEB128 literal operand that encodes the register.
   2471         //      SLEB128 offset from register N
   2472         // DESCRIPTION: Value is in memory at the address specified by register
   2473         // N plus an offset.
   2474         //----------------------------------------------------------------------
   2475         case DW_OP_bregx:
   2476             {
   2477                 reg_num = opcodes.GetULEB128(&offset);
   2478 
   2479                 if (ReadRegisterValueAsScalar (reg_ctx, reg_kind, reg_num, error_ptr, tmp))
   2480                 {
   2481                     int64_t breg_offset = opcodes.GetSLEB128(&offset);
   2482                     tmp.ResolveValue(exe_ctx) += (uint64_t)breg_offset;
   2483                     tmp.ClearContext();
   2484                     stack.push_back(tmp);
   2485                     stack.back().SetValueType (Value::eValueTypeLoadAddress);
   2486                 }
   2487                 else
   2488                     return false;
   2489             }
   2490             break;
   2491 
   2492         case DW_OP_fbreg:
   2493             if (exe_ctx)
   2494             {
   2495                 if (frame)
   2496                 {
   2497                     Scalar value;
   2498                     if (frame->GetFrameBaseValue(value, error_ptr))
   2499                     {
   2500                         int64_t fbreg_offset = opcodes.GetSLEB128(&offset);
   2501                         value += fbreg_offset;
   2502                         stack.push_back(value);
   2503                         stack.back().SetValueType (Value::eValueTypeLoadAddress);
   2504                     }
   2505                     else
   2506                         return false;
   2507                 }
   2508                 else
   2509                 {
   2510                     if (error_ptr)
   2511                         error_ptr->SetErrorString ("Invalid stack frame in context for DW_OP_fbreg opcode.");
   2512                     return false;
   2513                 }
   2514             }
   2515             else
   2516             {
   2517                 if (error_ptr)
   2518                     error_ptr->SetErrorStringWithFormat ("NULL execution context for DW_OP_fbreg.\n");
   2519                 return false;
   2520             }
   2521 
   2522             break;
   2523 
   2524         //----------------------------------------------------------------------
   2525         // OPCODE: DW_OP_nop
   2526         // OPERANDS: none
   2527         // DESCRIPTION: A place holder. It has no effect on the location stack
   2528         // or any of its values.
   2529         //----------------------------------------------------------------------
   2530         case DW_OP_nop:
   2531             break;
   2532 
   2533         //----------------------------------------------------------------------
   2534         // OPCODE: DW_OP_piece
   2535         // OPERANDS: 1
   2536         //      ULEB128: byte size of the piece
   2537         // DESCRIPTION: The operand describes the size in bytes of the piece of
   2538         // the object referenced by the DWARF expression whose result is at the
   2539         // top of the stack. If the piece is located in a register, but does not
   2540         // occupy the entire register, the placement of the piece within that
   2541         // register is defined by the ABI.
   2542         //
   2543         // Many compilers store a single variable in sets of registers, or store
   2544         // a variable partially in memory and partially in registers.
   2545         // DW_OP_piece provides a way of describing how large a part of a
   2546         // variable a particular DWARF expression refers to.
   2547         //----------------------------------------------------------------------
   2548         case DW_OP_piece:
   2549             if (error_ptr)
   2550                 error_ptr->SetErrorString ("Unimplemented opcode DW_OP_piece.");
   2551             return false;
   2552 
   2553         //----------------------------------------------------------------------
   2554         // OPCODE: DW_OP_push_object_address
   2555         // OPERANDS: none
   2556         // DESCRIPTION: Pushes the address of the object currently being
   2557         // evaluated as part of evaluation of a user presented expression.
   2558         // This object may correspond to an independent variable described by
   2559         // its own DIE or it may be a component of an array, structure, or class
   2560         // whose address has been dynamically determined by an earlier step
   2561         // during user expression evaluation.
   2562         //----------------------------------------------------------------------
   2563         case DW_OP_push_object_address:
   2564             if (error_ptr)
   2565                 error_ptr->SetErrorString ("Unimplemented opcode DW_OP_push_object_address.");
   2566             return false;
   2567 
   2568         //----------------------------------------------------------------------
   2569         // OPCODE: DW_OP_call2
   2570         // OPERANDS:
   2571         //      uint16_t compile unit relative offset of a DIE
   2572         // DESCRIPTION: Performs subroutine calls during evaluation
   2573         // of a DWARF expression. The operand is the 2-byte unsigned offset
   2574         // of a debugging information entry in the current compilation unit.
   2575         //
   2576         // Operand interpretation is exactly like that for DW_FORM_ref2.
   2577         //
   2578         // This operation transfers control of DWARF expression evaluation
   2579         // to the DW_AT_location attribute of the referenced DIE. If there is
   2580         // no such attribute, then there is no effect. Execution of the DWARF
   2581         // expression of a DW_AT_location attribute may add to and/or remove from
   2582         // values on the stack. Execution returns to the point following the call
   2583         // when the end of the attribute is reached. Values on the stack at the
   2584         // time of the call may be used as parameters by the called expression
   2585         // and values left on the stack by the called expression may be used as
   2586         // return values by prior agreement between the calling and called
   2587         // expressions.
   2588         //----------------------------------------------------------------------
   2589         case DW_OP_call2:
   2590             if (error_ptr)
   2591                 error_ptr->SetErrorString ("Unimplemented opcode DW_OP_call2.");
   2592             return false;
   2593         //----------------------------------------------------------------------
   2594         // OPCODE: DW_OP_call4
   2595         // OPERANDS: 1
   2596         //      uint32_t compile unit relative offset of a DIE
   2597         // DESCRIPTION: Performs a subroutine call during evaluation of a DWARF
   2598         // expression. For DW_OP_call4, the operand is a 4-byte unsigned offset
   2599         // of a debugging information entry in  the current compilation unit.
   2600         //
   2601         // Operand interpretation DW_OP_call4 is exactly like that for
   2602         // DW_FORM_ref4.
   2603         //
   2604         // This operation transfers control of DWARF expression evaluation
   2605         // to the DW_AT_location attribute of the referenced DIE. If there is
   2606         // no such attribute, then there is no effect. Execution of the DWARF
   2607         // expression of a DW_AT_location attribute may add to and/or remove from
   2608         // values on the stack. Execution returns to the point following the call
   2609         // when the end of the attribute is reached. Values on the stack at the
   2610         // time of the call may be used as parameters by the called expression
   2611         // and values left on the stack by the called expression may be used as
   2612         // return values by prior agreement between the calling and called
   2613         // expressions.
   2614         //----------------------------------------------------------------------
   2615         case DW_OP_call4:
   2616             if (error_ptr)
   2617                 error_ptr->SetErrorString ("Unimplemented opcode DW_OP_call4.");
   2618             return false;
   2619 
   2620         //----------------------------------------------------------------------
   2621         // OPCODE: DW_OP_stack_value
   2622         // OPERANDS: None
   2623         // DESCRIPTION: Specifies that the object does not exist in memory but
   2624         // rather is a constant value.  The value from the top of the stack is
   2625         // the value to be used.  This is the actual object value and not the
   2626         // location.
   2627         //----------------------------------------------------------------------
   2628         case DW_OP_stack_value:
   2629             stack.back().SetValueType(Value::eValueTypeScalar);
   2630             break;
   2631 
   2632         //----------------------------------------------------------------------
   2633         // OPCODE: DW_OP_call_frame_cfa
   2634         // OPERANDS: None
   2635         // DESCRIPTION: Specifies a DWARF expression that pushes the value of
   2636         // the canonical frame address consistent with the call frame information
   2637         // located in .debug_frame (or in the FDEs of the eh_frame section).
   2638         //----------------------------------------------------------------------
   2639         case DW_OP_call_frame_cfa:
   2640             if (frame)
   2641             {
   2642                 // Note that we don't have to parse FDEs because this DWARF expression
   2643                 // is commonly evaluated with a valid stack frame.
   2644                 StackID id = frame->GetStackID();
   2645                 addr_t cfa = id.GetCallFrameAddress();
   2646                 if (cfa != LLDB_INVALID_ADDRESS)
   2647                 {
   2648                     stack.push_back(Scalar(cfa));
   2649                     stack.back().SetValueType (Value::eValueTypeHostAddress);
   2650                 }
   2651                 else
   2652                     if (error_ptr)
   2653                         error_ptr->SetErrorString ("Stack frame does not include a canonical frame address for DW_OP_call_frame_cfa opcode.");
   2654             }
   2655             else
   2656             {
   2657                 if (error_ptr)
   2658                     error_ptr->SetErrorString ("Invalid stack frame in context for DW_OP_call_frame_cfa opcode.");
   2659                 return false;
   2660             }
   2661             break;
   2662         default:
   2663             if (log)
   2664                 log->Printf("Unhandled opcode %s in DWARFExpression.", DW_OP_value_to_name(op));
   2665             break;
   2666         }
   2667     }
   2668 
   2669     if (stack.empty())
   2670     {
   2671         if (error_ptr)
   2672             error_ptr->SetErrorString ("Stack empty after evaluation.");
   2673         return false;
   2674     }
   2675     else if (log && log->GetVerbose())
   2676     {
   2677         size_t count = stack.size();
   2678         log->Printf("Stack after operation has %lu values:", count);
   2679         for (size_t i=0; i<count; ++i)
   2680         {
   2681             StreamString new_value;
   2682             new_value.Printf("[%" PRIu64 "]", (uint64_t)i);
   2683             stack[i].Dump(&new_value);
   2684             log->Printf("  %s", new_value.GetData());
   2685         }
   2686     }
   2687 
   2688     result = stack.back();
   2689     return true;    // Return true on success
   2690 }
   2691 
   2692