1//===-- IRInterpreter.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/Core/DataExtractor.h"
11#include "lldb/Core/Error.h"
12#include "lldb/Core/Log.h"
13#include "lldb/Core/Scalar.h"
14#include "lldb/Core/StreamString.h"
15#include "lldb/Expression/IRMemoryMap.h"
16#include "lldb/Expression/IRInterpreter.h"
17
18#include "llvm/IR/Constants.h"
19#include "llvm/IR/DataLayout.h"
20#include "llvm/IR/Function.h"
21#include "llvm/IR/Instructions.h"
22#include "llvm/IR/Module.h"
23#include "llvm/Support/raw_ostream.h"
24
25#include <map>
26
27using namespace llvm;
28
29static std::string
30PrintValue(const Value *value, bool truncate = false)
31{
32    std::string s;
33    raw_string_ostream rso(s);
34    value->print(rso);
35    rso.flush();
36    if (truncate)
37        s.resize(s.length() - 1);
38
39    size_t offset;
40    while ((offset = s.find('\n')) != s.npos)
41        s.erase(offset, 1);
42    while (s[0] == ' ' || s[0] == '\t')
43        s.erase(0, 1);
44
45    return s;
46}
47
48static std::string
49PrintType(const Type *type, bool truncate = false)
50{
51    std::string s;
52    raw_string_ostream rso(s);
53    type->print(rso);
54    rso.flush();
55    if (truncate)
56        s.resize(s.length() - 1);
57    return s;
58}
59
60class InterpreterStackFrame
61{
62public:
63    typedef std::map <const Value*, lldb::addr_t> ValueMap;
64
65    ValueMap                                m_values;
66    DataLayout                             &m_target_data;
67    lldb_private::IRMemoryMap              &m_memory_map;
68    const BasicBlock                       *m_bb;
69    BasicBlock::const_iterator              m_ii;
70    BasicBlock::const_iterator              m_ie;
71
72    lldb::addr_t                            m_frame_process_address;
73    size_t                                  m_frame_size;
74    lldb::addr_t                            m_stack_pointer;
75
76    lldb::ByteOrder                         m_byte_order;
77    size_t                                  m_addr_byte_size;
78
79    InterpreterStackFrame (DataLayout &target_data,
80                           lldb_private::IRMemoryMap &memory_map,
81                           lldb::addr_t stack_frame_bottom,
82                           lldb::addr_t stack_frame_top) :
83        m_target_data (target_data),
84        m_memory_map (memory_map)
85    {
86        m_byte_order = (target_data.isLittleEndian() ? lldb::eByteOrderLittle : lldb::eByteOrderBig);
87        m_addr_byte_size = (target_data.getPointerSize(0));
88
89        m_frame_process_address = stack_frame_bottom;
90        m_frame_size = stack_frame_top - stack_frame_bottom;
91        m_stack_pointer = stack_frame_top;
92    }
93
94    ~InterpreterStackFrame ()
95    {
96    }
97
98    void Jump (const BasicBlock *bb)
99    {
100        m_bb = bb;
101        m_ii = m_bb->begin();
102        m_ie = m_bb->end();
103    }
104
105    std::string SummarizeValue (const Value *value)
106    {
107        lldb_private::StreamString ss;
108
109        ss.Printf("%s", PrintValue(value).c_str());
110
111        ValueMap::iterator i = m_values.find(value);
112
113        if (i != m_values.end())
114        {
115            lldb::addr_t addr = i->second;
116
117            ss.Printf(" 0x%llx", (unsigned long long)addr);
118        }
119
120        return ss.GetString();
121    }
122
123    bool AssignToMatchType (lldb_private::Scalar &scalar, uint64_t u64value, Type *type)
124    {
125        size_t type_size = m_target_data.getTypeStoreSize(type);
126
127        switch (type_size)
128        {
129        case 1:
130            scalar = (uint8_t)u64value;
131            break;
132        case 2:
133            scalar = (uint16_t)u64value;
134            break;
135        case 4:
136            scalar = (uint32_t)u64value;
137            break;
138        case 8:
139            scalar = (uint64_t)u64value;
140            break;
141        default:
142            return false;
143        }
144
145        return true;
146    }
147
148    bool EvaluateValue (lldb_private::Scalar &scalar, const Value *value, Module &module)
149    {
150        const Constant *constant = dyn_cast<Constant>(value);
151
152        if (constant)
153        {
154            APInt value_apint;
155
156            if (!ResolveConstantValue(value_apint, constant))
157                return false;
158
159            return AssignToMatchType(scalar, value_apint.getLimitedValue(), value->getType());
160        }
161        else
162        {
163            lldb::addr_t process_address = ResolveValue(value, module);
164            size_t value_size = m_target_data.getTypeStoreSize(value->getType());
165
166            lldb_private::DataExtractor value_extractor;
167            lldb_private::Error extract_error;
168
169            m_memory_map.GetMemoryData(value_extractor, process_address, value_size, extract_error);
170
171            if (!extract_error.Success())
172                return false;
173
174            lldb::offset_t offset = 0;
175            if (value_size == 1 || value_size == 2 || value_size == 4 || value_size == 8)
176            {
177                uint64_t u64value = value_extractor.GetMaxU64(&offset, value_size);
178                return AssignToMatchType(scalar, u64value, value->getType());
179            }
180        }
181
182        return false;
183    }
184
185    bool AssignValue (const Value *value, lldb_private::Scalar &scalar, Module &module)
186    {
187        lldb::addr_t process_address = ResolveValue (value, module);
188
189        if (process_address == LLDB_INVALID_ADDRESS)
190            return false;
191
192        lldb_private::Scalar cast_scalar;
193
194        if (!AssignToMatchType(cast_scalar, scalar.GetRawBits64(0), value->getType()))
195            return false;
196
197        size_t value_byte_size = m_target_data.getTypeStoreSize(value->getType());
198
199        lldb_private::DataBufferHeap buf(value_byte_size, 0);
200
201        lldb_private::Error get_data_error;
202
203        if (!cast_scalar.GetAsMemoryData(buf.GetBytes(), buf.GetByteSize(), m_byte_order, get_data_error))
204            return false;
205
206        lldb_private::Error write_error;
207
208        m_memory_map.WriteMemory(process_address, buf.GetBytes(), buf.GetByteSize(), write_error);
209
210        return write_error.Success();
211    }
212
213    bool ResolveConstantValue (APInt &value, const Constant *constant)
214    {
215        switch (constant->getValueID())
216        {
217        default:
218            break;
219        case Value::ConstantIntVal:
220            if (const ConstantInt *constant_int = dyn_cast<ConstantInt>(constant))
221            {
222                value = constant_int->getValue();
223                return true;
224            }
225            break;
226        case Value::ConstantFPVal:
227            if (const ConstantFP *constant_fp = dyn_cast<ConstantFP>(constant))
228            {
229                value = constant_fp->getValueAPF().bitcastToAPInt();
230                return true;
231            }
232            break;
233        case Value::ConstantExprVal:
234            if (const ConstantExpr *constant_expr = dyn_cast<ConstantExpr>(constant))
235            {
236                switch (constant_expr->getOpcode())
237                {
238                    default:
239                        return false;
240                    case Instruction::IntToPtr:
241                    case Instruction::PtrToInt:
242                    case Instruction::BitCast:
243                        return ResolveConstantValue(value, constant_expr->getOperand(0));
244                    case Instruction::GetElementPtr:
245                    {
246                        ConstantExpr::const_op_iterator op_cursor = constant_expr->op_begin();
247                        ConstantExpr::const_op_iterator op_end = constant_expr->op_end();
248
249                        Constant *base = dyn_cast<Constant>(*op_cursor);
250
251                        if (!base)
252                            return false;
253
254                        if (!ResolveConstantValue(value, base))
255                            return false;
256
257                        op_cursor++;
258
259                        if (op_cursor == op_end)
260                            return true; // no offset to apply!
261
262                        SmallVector <Value *, 8> indices (op_cursor, op_end);
263
264                        uint64_t offset = m_target_data.getIndexedOffset(base->getType(), indices);
265
266                        const bool is_signed = true;
267                        value += APInt(value.getBitWidth(), offset, is_signed);
268
269                        return true;
270                    }
271                }
272            }
273            break;
274        case Value::ConstantPointerNullVal:
275            if (isa<ConstantPointerNull>(constant))
276            {
277                value = APInt(m_target_data.getPointerSizeInBits(), 0);
278                return true;
279            }
280            break;
281        }
282        return false;
283    }
284
285    bool MakeArgument(const Argument *value, uint64_t address)
286    {
287        lldb::addr_t data_address = Malloc(value->getType());
288
289        if (data_address == LLDB_INVALID_ADDRESS)
290            return false;
291
292        lldb_private::Error write_error;
293
294        m_memory_map.WritePointerToMemory(data_address, address, write_error);
295
296        if (!write_error.Success())
297        {
298            lldb_private::Error free_error;
299            m_memory_map.Free(data_address, free_error);
300            return false;
301        }
302
303        m_values[value] = data_address;
304
305        lldb_private::Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
306
307        if (log)
308        {
309            log->Printf("Made an allocation for argument %s", PrintValue(value).c_str());
310            log->Printf("  Data region    : %llx", (unsigned long long)address);
311            log->Printf("  Ref region     : %llx", (unsigned long long)data_address);
312        }
313
314        return true;
315    }
316
317    bool ResolveConstant (lldb::addr_t process_address, const Constant *constant)
318    {
319        APInt resolved_value;
320
321        if (!ResolveConstantValue(resolved_value, constant))
322            return false;
323
324        const uint64_t *raw_data = resolved_value.getRawData();
325
326        size_t constant_size = m_target_data.getTypeStoreSize(constant->getType());
327
328        lldb_private::Error write_error;
329
330        m_memory_map.WriteMemory(process_address, (uint8_t*)raw_data, constant_size, write_error);
331
332        return write_error.Success();
333    }
334
335    lldb::addr_t Malloc (size_t size, uint8_t byte_alignment)
336    {
337        lldb::addr_t ret = m_stack_pointer;
338
339        ret -= size;
340        ret -= (ret % byte_alignment);
341
342        if (ret < m_frame_process_address)
343            return LLDB_INVALID_ADDRESS;
344
345        m_stack_pointer = ret;
346        return ret;
347    }
348
349    lldb::addr_t MallocPointer ()
350    {
351        return Malloc(m_target_data.getPointerSize(), m_target_data.getPointerPrefAlignment());
352    }
353
354    lldb::addr_t Malloc (llvm::Type *type)
355    {
356        lldb_private::Error alloc_error;
357
358        return Malloc(m_target_data.getTypeAllocSize(type), m_target_data.getPrefTypeAlignment(type));
359    }
360
361    std::string PrintData (lldb::addr_t addr, llvm::Type *type)
362    {
363        size_t length = m_target_data.getTypeStoreSize(type);
364
365        lldb_private::DataBufferHeap buf(length, 0);
366
367        lldb_private::Error read_error;
368
369        m_memory_map.ReadMemory(buf.GetBytes(), addr, length, read_error);
370
371        if (!read_error.Success())
372            return std::string("<couldn't read data>");
373
374        lldb_private::StreamString ss;
375
376        for (size_t i = 0; i < length; i++)
377        {
378            if ((!(i & 0xf)) && i)
379                ss.Printf("%02hhx - ", buf.GetBytes()[i]);
380            else
381                ss.Printf("%02hhx ", buf.GetBytes()[i]);
382        }
383
384        return ss.GetString();
385    }
386
387    lldb::addr_t ResolveValue (const Value *value, Module &module)
388    {
389        ValueMap::iterator i = m_values.find(value);
390
391        if (i != m_values.end())
392            return i->second;
393
394        // Fall back and allocate space [allocation type Alloca]
395
396        lldb::addr_t data_address = Malloc(value->getType());
397
398        if (const Constant *constant = dyn_cast<Constant>(value))
399        {
400            if (!ResolveConstant (data_address, constant))
401            {
402                lldb_private::Error free_error;
403                m_memory_map.Free(data_address, free_error);
404                return LLDB_INVALID_ADDRESS;
405            }
406        }
407
408        m_values[value] = data_address;
409        return data_address;
410    }
411};
412
413static const char *unsupported_opcode_error         = "Interpreter doesn't handle one of the expression's opcodes";
414static const char *unsupported_operand_error        = "Interpreter doesn't handle one of the expression's operands";
415//static const char *interpreter_initialization_error = "Interpreter couldn't be initialized";
416static const char *interpreter_internal_error       = "Interpreter encountered an internal error";
417static const char *bad_value_error                  = "Interpreter couldn't resolve a value during execution";
418static const char *memory_allocation_error          = "Interpreter couldn't allocate memory";
419static const char *memory_write_error               = "Interpreter couldn't write to memory";
420static const char *memory_read_error                = "Interpreter couldn't read from memory";
421static const char *infinite_loop_error              = "Interpreter ran for too many cycles";
422//static const char *bad_result_error                 = "Result of expression is in bad memory";
423
424bool
425IRInterpreter::CanInterpret (llvm::Module &module,
426                             llvm::Function &function,
427                             lldb_private::Error &error)
428{
429    lldb_private::Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
430
431    bool saw_function_with_body = false;
432
433    for (Module::iterator fi = module.begin(), fe = module.end();
434         fi != fe;
435         ++fi)
436    {
437        if (fi->begin() != fi->end())
438        {
439            if (saw_function_with_body)
440                return false;
441            saw_function_with_body = true;
442        }
443    }
444
445    for (Function::iterator bbi = function.begin(), bbe = function.end();
446         bbi != bbe;
447         ++bbi)
448    {
449        for (BasicBlock::iterator ii = bbi->begin(), ie = bbi->end();
450             ii != ie;
451             ++ii)
452        {
453            switch (ii->getOpcode())
454            {
455            default:
456                {
457                    if (log)
458                        log->Printf("Unsupported instruction: %s", PrintValue(ii).c_str());
459                    error.SetErrorToGenericError();
460                    error.SetErrorString(unsupported_opcode_error);
461                    return false;
462                }
463            case Instruction::Add:
464            case Instruction::Alloca:
465            case Instruction::BitCast:
466            case Instruction::Br:
467            case Instruction::GetElementPtr:
468                break;
469            case Instruction::ICmp:
470                {
471                    ICmpInst *icmp_inst = dyn_cast<ICmpInst>(ii);
472
473                    if (!icmp_inst)
474                    {
475                        error.SetErrorToGenericError();
476                        error.SetErrorString(interpreter_internal_error);
477                        return false;
478                    }
479
480                    switch (icmp_inst->getPredicate())
481                    {
482                    default:
483                    {
484                        if (log)
485                            log->Printf("Unsupported ICmp predicate: %s", PrintValue(ii).c_str());
486
487                        error.SetErrorToGenericError();
488                        error.SetErrorString(unsupported_opcode_error);
489                        return false;
490                    }
491                    case CmpInst::ICMP_EQ:
492                    case CmpInst::ICMP_NE:
493                    case CmpInst::ICMP_UGT:
494                    case CmpInst::ICMP_UGE:
495                    case CmpInst::ICMP_ULT:
496                    case CmpInst::ICMP_ULE:
497                    case CmpInst::ICMP_SGT:
498                    case CmpInst::ICMP_SGE:
499                    case CmpInst::ICMP_SLT:
500                    case CmpInst::ICMP_SLE:
501                        break;
502                    }
503                }
504                break;
505            case Instruction::And:
506            case Instruction::AShr:
507            case Instruction::IntToPtr:
508            case Instruction::PtrToInt:
509            case Instruction::Load:
510            case Instruction::LShr:
511            case Instruction::Mul:
512            case Instruction::Or:
513            case Instruction::Ret:
514            case Instruction::SDiv:
515            case Instruction::SExt:
516            case Instruction::Shl:
517            case Instruction::SRem:
518            case Instruction::Store:
519            case Instruction::Sub:
520            case Instruction::UDiv:
521            case Instruction::URem:
522            case Instruction::Xor:
523            case Instruction::ZExt:
524                break;
525            }
526
527            for (int oi = 0, oe = ii->getNumOperands();
528                 oi != oe;
529                 ++oi)
530            {
531                Value *operand = ii->getOperand(oi);
532                Type *operand_type = operand->getType();
533
534                switch (operand_type->getTypeID())
535                {
536                default:
537                    break;
538                case Type::VectorTyID:
539                    {
540                        if (log)
541                            log->Printf("Unsupported operand type: %s", PrintType(operand_type).c_str());
542                        error.SetErrorString(unsupported_operand_error);
543                        return false;
544                    }
545                }
546            }
547        }
548
549    }
550
551    return true;}
552
553bool
554IRInterpreter::Interpret (llvm::Module &module,
555                          llvm::Function &function,
556                          llvm::ArrayRef<lldb::addr_t> args,
557                          lldb_private::IRMemoryMap &memory_map,
558                          lldb_private::Error &error,
559                          lldb::addr_t stack_frame_bottom,
560                          lldb::addr_t stack_frame_top)
561{
562    lldb_private::Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
563
564    if (log)
565    {
566        std::string s;
567        raw_string_ostream oss(s);
568
569        module.print(oss, NULL);
570
571        oss.flush();
572
573        log->Printf("Module as passed in to IRInterpreter::Interpret: \n\"%s\"", s.c_str());
574    }
575
576    DataLayout data_layout(&module);
577
578    InterpreterStackFrame frame(data_layout, memory_map, stack_frame_bottom, stack_frame_top);
579
580    if (frame.m_frame_process_address == LLDB_INVALID_ADDRESS)
581    {
582        error.SetErrorString("Couldn't allocate stack frame");
583    }
584
585    int arg_index = 0;
586
587    for (llvm::Function::arg_iterator ai = function.arg_begin(), ae = function.arg_end();
588         ai != ae;
589         ++ai, ++arg_index)
590    {
591        if (args.size() < arg_index)
592        {
593            error.SetErrorString ("Not enough arguments passed in to function");
594            return false;
595        }
596
597        lldb::addr_t ptr = args[arg_index];
598
599        frame.MakeArgument(ai, ptr);
600    }
601
602    uint32_t num_insts = 0;
603
604    frame.Jump(function.begin());
605
606    while (frame.m_ii != frame.m_ie && (++num_insts < 4096))
607    {
608        const Instruction *inst = frame.m_ii;
609
610        if (log)
611            log->Printf("Interpreting %s", PrintValue(inst).c_str());
612
613        switch (inst->getOpcode())
614        {
615            default:
616                break;
617            case Instruction::Add:
618            case Instruction::Sub:
619            case Instruction::Mul:
620            case Instruction::SDiv:
621            case Instruction::UDiv:
622            case Instruction::SRem:
623            case Instruction::URem:
624            case Instruction::Shl:
625            case Instruction::LShr:
626            case Instruction::AShr:
627            case Instruction::And:
628            case Instruction::Or:
629            case Instruction::Xor:
630            {
631                const BinaryOperator *bin_op = dyn_cast<BinaryOperator>(inst);
632
633                if (!bin_op)
634                {
635                    if (log)
636                        log->Printf("getOpcode() returns %s, but instruction is not a BinaryOperator", inst->getOpcodeName());
637                    error.SetErrorToGenericError();
638                    error.SetErrorString(interpreter_internal_error);
639                    return false;
640                }
641
642                Value *lhs = inst->getOperand(0);
643                Value *rhs = inst->getOperand(1);
644
645                lldb_private::Scalar L;
646                lldb_private::Scalar R;
647
648                if (!frame.EvaluateValue(L, lhs, module))
649                {
650                    if (log)
651                        log->Printf("Couldn't evaluate %s", PrintValue(lhs).c_str());
652                    error.SetErrorToGenericError();
653                    error.SetErrorString(bad_value_error);
654                    return false;
655                }
656
657                if (!frame.EvaluateValue(R, rhs, module))
658                {
659                    if (log)
660                        log->Printf("Couldn't evaluate %s", PrintValue(rhs).c_str());
661                    error.SetErrorToGenericError();
662                    error.SetErrorString(bad_value_error);
663                    return false;
664                }
665
666                lldb_private::Scalar result;
667
668                switch (inst->getOpcode())
669                {
670                    default:
671                        break;
672                    case Instruction::Add:
673                        result = L + R;
674                        break;
675                    case Instruction::Mul:
676                        result = L * R;
677                        break;
678                    case Instruction::Sub:
679                        result = L - R;
680                        break;
681                    case Instruction::SDiv:
682                        L.MakeSigned();
683                        R.MakeSigned();
684                        result = L / R;
685                        break;
686                    case Instruction::UDiv:
687                        result = L.GetRawBits64(0) / R.GetRawBits64(1);
688                        break;
689                    case Instruction::SRem:
690                        L.MakeSigned();
691                        R.MakeSigned();
692                        result = L % R;
693                        break;
694                    case Instruction::URem:
695                        result = L.GetRawBits64(0) % R.GetRawBits64(1);
696                        break;
697                    case Instruction::Shl:
698                        result = L << R;
699                        break;
700                    case Instruction::AShr:
701                        result = L >> R;
702                        break;
703                    case Instruction::LShr:
704                        result = L;
705                        result.ShiftRightLogical(R);
706                        break;
707                    case Instruction::And:
708                        result = L & R;
709                        break;
710                    case Instruction::Or:
711                        result = L | R;
712                        break;
713                    case Instruction::Xor:
714                        result = L ^ R;
715                        break;
716                }
717
718                frame.AssignValue(inst, result, module);
719
720                if (log)
721                {
722                    log->Printf("Interpreted a %s", inst->getOpcodeName());
723                    log->Printf("  L : %s", frame.SummarizeValue(lhs).c_str());
724                    log->Printf("  R : %s", frame.SummarizeValue(rhs).c_str());
725                    log->Printf("  = : %s", frame.SummarizeValue(inst).c_str());
726                }
727            }
728                break;
729            case Instruction::Alloca:
730            {
731                const AllocaInst *alloca_inst = dyn_cast<AllocaInst>(inst);
732
733                if (!alloca_inst)
734                {
735                    if (log)
736                        log->Printf("getOpcode() returns Alloca, but instruction is not an AllocaInst");
737                    error.SetErrorToGenericError();
738                    error.SetErrorString(interpreter_internal_error);
739                    return false;
740                }
741
742                if (alloca_inst->isArrayAllocation())
743                {
744                    if (log)
745                        log->Printf("AllocaInsts are not handled if isArrayAllocation() is true");
746                    error.SetErrorToGenericError();
747                    error.SetErrorString(unsupported_opcode_error);
748                    return false;
749                }
750
751                // The semantics of Alloca are:
752                //   Create a region R of virtual memory of type T, backed by a data buffer
753                //   Create a region P of virtual memory of type T*, backed by a data buffer
754                //   Write the virtual address of R into P
755
756                Type *T = alloca_inst->getAllocatedType();
757                Type *Tptr = alloca_inst->getType();
758
759                lldb::addr_t R = frame.Malloc(T);
760
761                if (R == LLDB_INVALID_ADDRESS)
762                {
763                    if (log)
764                        log->Printf("Couldn't allocate memory for an AllocaInst");
765                    error.SetErrorToGenericError();
766                    error.SetErrorString(memory_allocation_error);
767                    return false;
768                }
769
770                lldb::addr_t P = frame.Malloc(Tptr);
771
772                if (P == LLDB_INVALID_ADDRESS)
773                {
774                    if (log)
775                        log->Printf("Couldn't allocate the result pointer for an AllocaInst");
776                    error.SetErrorToGenericError();
777                    error.SetErrorString(memory_allocation_error);
778                    return false;
779                }
780
781                lldb_private::Error write_error;
782
783                memory_map.WritePointerToMemory(P, R, write_error);
784
785                if (!write_error.Success())
786                {
787                    if (log)
788                        log->Printf("Couldn't write the result pointer for an AllocaInst");
789                    error.SetErrorToGenericError();
790                    error.SetErrorString(memory_write_error);
791                    lldb_private::Error free_error;
792                    memory_map.Free(P, free_error);
793                    memory_map.Free(R, free_error);
794                    return false;
795                }
796
797                frame.m_values[alloca_inst] = P;
798
799                if (log)
800                {
801                    log->Printf("Interpreted an AllocaInst");
802                    log->Printf("  R : 0x%" PRIx64, R);
803                    log->Printf("  P : 0x%" PRIx64, P);
804                }
805            }
806                break;
807            case Instruction::BitCast:
808            case Instruction::ZExt:
809            {
810                const CastInst *cast_inst = dyn_cast<CastInst>(inst);
811
812                if (!cast_inst)
813                {
814                    if (log)
815                        log->Printf("getOpcode() returns %s, but instruction is not a BitCastInst", cast_inst->getOpcodeName());
816                    error.SetErrorToGenericError();
817                    error.SetErrorString(interpreter_internal_error);
818                    return false;
819                }
820
821                Value *source = cast_inst->getOperand(0);
822
823                lldb_private::Scalar S;
824
825                if (!frame.EvaluateValue(S, source, module))
826                {
827                    if (log)
828                        log->Printf("Couldn't evaluate %s", PrintValue(source).c_str());
829                    error.SetErrorToGenericError();
830                    error.SetErrorString(bad_value_error);
831                    return false;
832                }
833
834                frame.AssignValue(inst, S, module);
835            }
836                break;
837            case Instruction::SExt:
838            {
839                const CastInst *cast_inst = dyn_cast<CastInst>(inst);
840
841                if (!cast_inst)
842                {
843                    if (log)
844                        log->Printf("getOpcode() returns %s, but instruction is not a BitCastInst", cast_inst->getOpcodeName());
845                    error.SetErrorToGenericError();
846                    error.SetErrorString(interpreter_internal_error);
847                    return false;
848                }
849
850                Value *source = cast_inst->getOperand(0);
851
852                lldb_private::Scalar S;
853
854                if (!frame.EvaluateValue(S, source, module))
855                {
856                    if (log)
857                        log->Printf("Couldn't evaluate %s", PrintValue(source).c_str());
858                    error.SetErrorToGenericError();
859                    error.SetErrorString(bad_value_error);
860                    return false;
861                }
862
863                S.MakeSigned();
864
865                lldb_private::Scalar S_signextend(S.SLongLong());
866
867                frame.AssignValue(inst, S_signextend, module);
868            }
869                break;
870            case Instruction::Br:
871            {
872                const BranchInst *br_inst = dyn_cast<BranchInst>(inst);
873
874                if (!br_inst)
875                {
876                    if (log)
877                        log->Printf("getOpcode() returns Br, but instruction is not a BranchInst");
878                    error.SetErrorToGenericError();
879                    error.SetErrorString(interpreter_internal_error);
880                    return false;
881                }
882
883                if (br_inst->isConditional())
884                {
885                    Value *condition = br_inst->getCondition();
886
887                    lldb_private::Scalar C;
888
889                    if (!frame.EvaluateValue(C, condition, module))
890                    {
891                        if (log)
892                            log->Printf("Couldn't evaluate %s", PrintValue(condition).c_str());
893                        error.SetErrorToGenericError();
894                        error.SetErrorString(bad_value_error);
895                        return false;
896                    }
897
898                    if (C.GetRawBits64(0))
899                        frame.Jump(br_inst->getSuccessor(0));
900                    else
901                        frame.Jump(br_inst->getSuccessor(1));
902
903                    if (log)
904                    {
905                        log->Printf("Interpreted a BrInst with a condition");
906                        log->Printf("  cond : %s", frame.SummarizeValue(condition).c_str());
907                    }
908                }
909                else
910                {
911                    frame.Jump(br_inst->getSuccessor(0));
912
913                    if (log)
914                    {
915                        log->Printf("Interpreted a BrInst with no condition");
916                    }
917                }
918            }
919                continue;
920            case Instruction::GetElementPtr:
921            {
922                const GetElementPtrInst *gep_inst = dyn_cast<GetElementPtrInst>(inst);
923
924                if (!gep_inst)
925                {
926                    if (log)
927                        log->Printf("getOpcode() returns GetElementPtr, but instruction is not a GetElementPtrInst");
928                    error.SetErrorToGenericError();
929                    error.SetErrorString(interpreter_internal_error);
930                    return false;
931                }
932
933                const Value *pointer_operand = gep_inst->getPointerOperand();
934                Type *pointer_type = pointer_operand->getType();
935
936                lldb_private::Scalar P;
937
938                if (!frame.EvaluateValue(P, pointer_operand, module))
939                {
940                    if (log)
941                        log->Printf("Couldn't evaluate %s", PrintValue(pointer_operand).c_str());
942                    error.SetErrorToGenericError();
943                    error.SetErrorString(bad_value_error);
944                    return false;
945                }
946
947                typedef SmallVector <Value *, 8> IndexVector;
948                typedef IndexVector::iterator IndexIterator;
949
950                SmallVector <Value *, 8> indices (gep_inst->idx_begin(),
951                                                  gep_inst->idx_end());
952
953                SmallVector <Value *, 8> const_indices;
954
955                for (IndexIterator ii = indices.begin(), ie = indices.end();
956                     ii != ie;
957                     ++ii)
958                {
959                    ConstantInt *constant_index = dyn_cast<ConstantInt>(*ii);
960
961                    if (!constant_index)
962                    {
963                        lldb_private::Scalar I;
964
965                        if (!frame.EvaluateValue(I, *ii, module))
966                        {
967                            if (log)
968                                log->Printf("Couldn't evaluate %s", PrintValue(*ii).c_str());
969                            error.SetErrorToGenericError();
970                            error.SetErrorString(bad_value_error);
971                            return false;
972                        }
973
974                        if (log)
975                            log->Printf("Evaluated constant index %s as %llu", PrintValue(*ii).c_str(), I.ULongLong(LLDB_INVALID_ADDRESS));
976
977                        constant_index = cast<ConstantInt>(ConstantInt::get((*ii)->getType(), I.ULongLong(LLDB_INVALID_ADDRESS)));
978                    }
979
980                    const_indices.push_back(constant_index);
981                }
982
983                uint64_t offset = data_layout.getIndexedOffset(pointer_type, const_indices);
984
985                lldb_private::Scalar Poffset = P + offset;
986
987                frame.AssignValue(inst, Poffset, module);
988
989                if (log)
990                {
991                    log->Printf("Interpreted a GetElementPtrInst");
992                    log->Printf("  P       : %s", frame.SummarizeValue(pointer_operand).c_str());
993                    log->Printf("  Poffset : %s", frame.SummarizeValue(inst).c_str());
994                }
995            }
996                break;
997            case Instruction::ICmp:
998            {
999                const ICmpInst *icmp_inst = dyn_cast<ICmpInst>(inst);
1000
1001                if (!icmp_inst)
1002                {
1003                    if (log)
1004                        log->Printf("getOpcode() returns ICmp, but instruction is not an ICmpInst");
1005                    error.SetErrorToGenericError();
1006                    error.SetErrorString(interpreter_internal_error);
1007                    return false;
1008                }
1009
1010                CmpInst::Predicate predicate = icmp_inst->getPredicate();
1011
1012                Value *lhs = inst->getOperand(0);
1013                Value *rhs = inst->getOperand(1);
1014
1015                lldb_private::Scalar L;
1016                lldb_private::Scalar R;
1017
1018                if (!frame.EvaluateValue(L, lhs, module))
1019                {
1020                    if (log)
1021                        log->Printf("Couldn't evaluate %s", PrintValue(lhs).c_str());
1022                    error.SetErrorToGenericError();
1023                    error.SetErrorString(bad_value_error);
1024                    return false;
1025                }
1026
1027                if (!frame.EvaluateValue(R, rhs, module))
1028                {
1029                    if (log)
1030                        log->Printf("Couldn't evaluate %s", PrintValue(rhs).c_str());
1031                    error.SetErrorToGenericError();
1032                    error.SetErrorString(bad_value_error);
1033                    return false;
1034                }
1035
1036                lldb_private::Scalar result;
1037
1038                switch (predicate)
1039                {
1040                    default:
1041                        return false;
1042                    case CmpInst::ICMP_EQ:
1043                        result = (L == R);
1044                        break;
1045                    case CmpInst::ICMP_NE:
1046                        result = (L != R);
1047                        break;
1048                    case CmpInst::ICMP_UGT:
1049                        result = (L.GetRawBits64(0) > R.GetRawBits64(0));
1050                        break;
1051                    case CmpInst::ICMP_UGE:
1052                        result = (L.GetRawBits64(0) >= R.GetRawBits64(0));
1053                        break;
1054                    case CmpInst::ICMP_ULT:
1055                        result = (L.GetRawBits64(0) < R.GetRawBits64(0));
1056                        break;
1057                    case CmpInst::ICMP_ULE:
1058                        result = (L.GetRawBits64(0) <= R.GetRawBits64(0));
1059                        break;
1060                    case CmpInst::ICMP_SGT:
1061                        L.MakeSigned();
1062                        R.MakeSigned();
1063                        result = (L > R);
1064                        break;
1065                    case CmpInst::ICMP_SGE:
1066                        L.MakeSigned();
1067                        R.MakeSigned();
1068                        result = (L >= R);
1069                        break;
1070                    case CmpInst::ICMP_SLT:
1071                        L.MakeSigned();
1072                        R.MakeSigned();
1073                        result = (L < R);
1074                        break;
1075                    case CmpInst::ICMP_SLE:
1076                        L.MakeSigned();
1077                        R.MakeSigned();
1078                        result = (L <= R);
1079                        break;
1080                }
1081
1082                frame.AssignValue(inst, result, module);
1083
1084                if (log)
1085                {
1086                    log->Printf("Interpreted an ICmpInst");
1087                    log->Printf("  L : %s", frame.SummarizeValue(lhs).c_str());
1088                    log->Printf("  R : %s", frame.SummarizeValue(rhs).c_str());
1089                    log->Printf("  = : %s", frame.SummarizeValue(inst).c_str());
1090                }
1091            }
1092                break;
1093            case Instruction::IntToPtr:
1094            {
1095                const IntToPtrInst *int_to_ptr_inst = dyn_cast<IntToPtrInst>(inst);
1096
1097                if (!int_to_ptr_inst)
1098                {
1099                    if (log)
1100                        log->Printf("getOpcode() returns IntToPtr, but instruction is not an IntToPtrInst");
1101                    error.SetErrorToGenericError();
1102                    error.SetErrorString(interpreter_internal_error);
1103                    return false;
1104                }
1105
1106                Value *src_operand = int_to_ptr_inst->getOperand(0);
1107
1108                lldb_private::Scalar I;
1109
1110                if (!frame.EvaluateValue(I, src_operand, module))
1111                {
1112                    if (log)
1113                        log->Printf("Couldn't evaluate %s", PrintValue(src_operand).c_str());
1114                    error.SetErrorToGenericError();
1115                    error.SetErrorString(bad_value_error);
1116                    return false;
1117                }
1118
1119                frame.AssignValue(inst, I, module);
1120
1121                if (log)
1122                {
1123                    log->Printf("Interpreted an IntToPtr");
1124                    log->Printf("  Src : %s", frame.SummarizeValue(src_operand).c_str());
1125                    log->Printf("  =   : %s", frame.SummarizeValue(inst).c_str());
1126                }
1127            }
1128                break;
1129            case Instruction::PtrToInt:
1130            {
1131                const PtrToIntInst *ptr_to_int_inst = dyn_cast<PtrToIntInst>(inst);
1132
1133                if (!ptr_to_int_inst)
1134                {
1135                    if (log)
1136                        log->Printf("getOpcode() returns PtrToInt, but instruction is not an PtrToIntInst");
1137                    error.SetErrorToGenericError();
1138                    error.SetErrorString(interpreter_internal_error);
1139                    return false;
1140                }
1141
1142                Value *src_operand = ptr_to_int_inst->getOperand(0);
1143
1144                lldb_private::Scalar I;
1145
1146                if (!frame.EvaluateValue(I, src_operand, module))
1147                {
1148                    if (log)
1149                        log->Printf("Couldn't evaluate %s", PrintValue(src_operand).c_str());
1150                    error.SetErrorToGenericError();
1151                    error.SetErrorString(bad_value_error);
1152                    return false;
1153                }
1154
1155                frame.AssignValue(inst, I, module);
1156
1157                if (log)
1158                {
1159                    log->Printf("Interpreted a PtrToInt");
1160                    log->Printf("  Src : %s", frame.SummarizeValue(src_operand).c_str());
1161                    log->Printf("  =   : %s", frame.SummarizeValue(inst).c_str());
1162                }
1163            }
1164                break;
1165            case Instruction::Load:
1166            {
1167                const LoadInst *load_inst = dyn_cast<LoadInst>(inst);
1168
1169                if (!load_inst)
1170                {
1171                    if (log)
1172                        log->Printf("getOpcode() returns Load, but instruction is not a LoadInst");
1173                    error.SetErrorToGenericError();
1174                    error.SetErrorString(interpreter_internal_error);
1175                    return false;
1176                }
1177
1178                // The semantics of Load are:
1179                //   Create a region D that will contain the loaded data
1180                //   Resolve the region P containing a pointer
1181                //   Dereference P to get the region R that the data should be loaded from
1182                //   Transfer a unit of type type(D) from R to D
1183
1184                const Value *pointer_operand = load_inst->getPointerOperand();
1185
1186                Type *pointer_ty = pointer_operand->getType();
1187                PointerType *pointer_ptr_ty = dyn_cast<PointerType>(pointer_ty);
1188                if (!pointer_ptr_ty)
1189                {
1190                    if (log)
1191                        log->Printf("getPointerOperand()->getType() is not a PointerType");
1192                    error.SetErrorToGenericError();
1193                    error.SetErrorString(interpreter_internal_error);
1194                    return false;
1195                }
1196                Type *target_ty = pointer_ptr_ty->getElementType();
1197
1198                lldb::addr_t D = frame.ResolveValue(load_inst, module);
1199                lldb::addr_t P = frame.ResolveValue(pointer_operand, module);
1200
1201                if (D == LLDB_INVALID_ADDRESS)
1202                {
1203                    if (log)
1204                        log->Printf("LoadInst's value doesn't resolve to anything");
1205                    error.SetErrorToGenericError();
1206                    error.SetErrorString(bad_value_error);
1207                    return false;
1208                }
1209
1210                if (P == LLDB_INVALID_ADDRESS)
1211                {
1212                    if (log)
1213                        log->Printf("LoadInst's pointer doesn't resolve to anything");
1214                    error.SetErrorToGenericError();
1215                    error.SetErrorString(bad_value_error);
1216                    return false;
1217                }
1218
1219                lldb::addr_t R;
1220                lldb_private::Error read_error;
1221                memory_map.ReadPointerFromMemory(&R, P, read_error);
1222
1223                if (!read_error.Success())
1224                {
1225                    if (log)
1226                        log->Printf("Couldn't read the address to be loaded for a LoadInst");
1227                    error.SetErrorToGenericError();
1228                    error.SetErrorString(memory_read_error);
1229                    return false;
1230                }
1231
1232                size_t target_size = data_layout.getTypeStoreSize(target_ty);
1233                lldb_private::DataBufferHeap buffer(target_size, 0);
1234
1235                read_error.Clear();
1236                memory_map.ReadMemory(buffer.GetBytes(), R, buffer.GetByteSize(), read_error);
1237                if (!read_error.Success())
1238                {
1239                    if (log)
1240                        log->Printf("Couldn't read from a region on behalf of a LoadInst");
1241                    error.SetErrorToGenericError();
1242                    error.SetErrorString(memory_read_error);
1243                    return false;
1244                }
1245
1246                lldb_private::Error write_error;
1247                memory_map.WriteMemory(D, buffer.GetBytes(), buffer.GetByteSize(), write_error);
1248                if (!write_error.Success())
1249                {
1250                    if (log)
1251                        log->Printf("Couldn't write to a region on behalf of a LoadInst");
1252                    error.SetErrorToGenericError();
1253                    error.SetErrorString(memory_read_error);
1254                    return false;
1255                }
1256
1257                if (log)
1258                {
1259                    log->Printf("Interpreted a LoadInst");
1260                    log->Printf("  P : 0x%" PRIx64, P);
1261                    log->Printf("  R : 0x%" PRIx64, R);
1262                    log->Printf("  D : 0x%" PRIx64, D);
1263                }
1264            }
1265                break;
1266            case Instruction::Ret:
1267            {
1268                return true;
1269            }
1270            case Instruction::Store:
1271            {
1272                const StoreInst *store_inst = dyn_cast<StoreInst>(inst);
1273
1274                if (!store_inst)
1275                {
1276                    if (log)
1277                        log->Printf("getOpcode() returns Store, but instruction is not a StoreInst");
1278                    error.SetErrorToGenericError();
1279                    error.SetErrorString(interpreter_internal_error);
1280                    return false;
1281                }
1282
1283                // The semantics of Store are:
1284                //   Resolve the region D containing the data to be stored
1285                //   Resolve the region P containing a pointer
1286                //   Dereference P to get the region R that the data should be stored in
1287                //   Transfer a unit of type type(D) from D to R
1288
1289                const Value *value_operand = store_inst->getValueOperand();
1290                const Value *pointer_operand = store_inst->getPointerOperand();
1291
1292                Type *pointer_ty = pointer_operand->getType();
1293                PointerType *pointer_ptr_ty = dyn_cast<PointerType>(pointer_ty);
1294                if (!pointer_ptr_ty)
1295                    return false;
1296                Type *target_ty = pointer_ptr_ty->getElementType();
1297
1298                lldb::addr_t D = frame.ResolveValue(value_operand, module);
1299                lldb::addr_t P = frame.ResolveValue(pointer_operand, module);
1300
1301                if (D == LLDB_INVALID_ADDRESS)
1302                {
1303                    if (log)
1304                        log->Printf("StoreInst's value doesn't resolve to anything");
1305                    error.SetErrorToGenericError();
1306                    error.SetErrorString(bad_value_error);
1307                    return false;
1308                }
1309
1310                if (P == LLDB_INVALID_ADDRESS)
1311                {
1312                    if (log)
1313                        log->Printf("StoreInst's pointer doesn't resolve to anything");
1314                    error.SetErrorToGenericError();
1315                    error.SetErrorString(bad_value_error);
1316                    return false;
1317                }
1318
1319                lldb::addr_t R;
1320                lldb_private::Error read_error;
1321                memory_map.ReadPointerFromMemory(&R, P, read_error);
1322
1323                if (!read_error.Success())
1324                {
1325                    if (log)
1326                        log->Printf("Couldn't read the address to be loaded for a LoadInst");
1327                    error.SetErrorToGenericError();
1328                    error.SetErrorString(memory_read_error);
1329                    return false;
1330                }
1331
1332                size_t target_size = data_layout.getTypeStoreSize(target_ty);
1333                lldb_private::DataBufferHeap buffer(target_size, 0);
1334
1335                read_error.Clear();
1336                memory_map.ReadMemory(buffer.GetBytes(), D, buffer.GetByteSize(), read_error);
1337                if (!read_error.Success())
1338                {
1339                    if (log)
1340                        log->Printf("Couldn't read from a region on behalf of a StoreInst");
1341                    error.SetErrorToGenericError();
1342                    error.SetErrorString(memory_read_error);
1343                    return false;
1344                }
1345
1346                lldb_private::Error write_error;
1347                memory_map.WriteMemory(R, buffer.GetBytes(), buffer.GetByteSize(), write_error);
1348                if (!write_error.Success())
1349                {
1350                    if (log)
1351                        log->Printf("Couldn't write to a region on behalf of a StoreInst");
1352                    error.SetErrorToGenericError();
1353                    error.SetErrorString(memory_write_error);
1354                    return false;
1355                }
1356
1357                if (log)
1358                {
1359                    log->Printf("Interpreted a StoreInst");
1360                    log->Printf("  D : 0x%" PRIx64, D);
1361                    log->Printf("  P : 0x%" PRIx64, P);
1362                    log->Printf("  R : 0x%" PRIx64, R);
1363                }
1364            }
1365                break;
1366        }
1367
1368        ++frame.m_ii;
1369    }
1370
1371    if (num_insts >= 4096)
1372    {
1373        error.SetErrorToGenericError();
1374        error.SetErrorString(infinite_loop_error);
1375        return false;
1376    }
1377
1378    return false;
1379}
1380