IRInterpreter.cpp revision 3051ed73a487e92f12f8b6062f8415781453da21
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/DataEncoder.h"
11#include "lldb/Core/Log.h"
12#include "lldb/Core/ValueObjectConstResult.h"
13#include "lldb/Expression/ClangExpressionDeclMap.h"
14#include "lldb/Expression/ClangExpressionVariable.h"
15#include "lldb/Expression/IRForTarget.h"
16#include "lldb/Expression/IRInterpreter.h"
17
18#include "llvm/Constants.h"
19#include "llvm/Function.h"
20#include "llvm/Instructions.h"
21#include "llvm/Module.h"
22#include "llvm/Support/raw_ostream.h"
23#include "llvm/DataLayout.h"
24
25#include <map>
26
27using namespace llvm;
28
29IRInterpreter::IRInterpreter(lldb_private::ClangExpressionDeclMap &decl_map,
30                                           lldb_private::Stream *error_stream) :
31    m_decl_map(decl_map),
32    m_error_stream(error_stream)
33{
34
35}
36
37IRInterpreter::~IRInterpreter()
38{
39
40}
41
42static std::string
43PrintValue(const Value *value, bool truncate = false)
44{
45    std::string s;
46    raw_string_ostream rso(s);
47    value->print(rso);
48    rso.flush();
49    if (truncate)
50        s.resize(s.length() - 1);
51
52    size_t offset;
53    while ((offset = s.find('\n')) != s.npos)
54        s.erase(offset, 1);
55    while (s[0] == ' ' || s[0] == '\t')
56        s.erase(0, 1);
57
58    return s;
59}
60
61static std::string
62PrintType(const Type *type, bool truncate = false)
63{
64    std::string s;
65    raw_string_ostream rso(s);
66    type->print(rso);
67    rso.flush();
68    if (truncate)
69        s.resize(s.length() - 1);
70    return s;
71}
72
73typedef STD_SHARED_PTR(lldb_private::DataEncoder) DataEncoderSP;
74typedef STD_SHARED_PTR(lldb_private::DataExtractor) DataExtractorSP;
75
76class Memory
77{
78public:
79    typedef uint32_t                    index_t;
80
81    struct Allocation
82    {
83        // m_virtual_address is always the address of the variable in the virtual memory
84        // space provided by Memory.
85        //
86        // m_origin is always non-NULL and describes the source of the data (possibly
87        // m_data if this allocation is the authoritative source).
88        //
89        // Possible value configurations:
90        //
91        // Allocation type  getValueType()          getContextType()            m_origin->GetScalar()       m_data
92        // =========================================================================================================================
93        // FileAddress      eValueTypeFileAddress   eContextTypeInvalid         A location in a binary      NULL
94        //                                                                      image
95        //
96        // LoadAddress      eValueTypeLoadAddress   eContextTypeInvalid         A location in the target's  NULL
97        //                                                                      virtual memory
98        //
99        // Alloca           eValueTypeHostAddress   eContextTypeInvalid         == m_data->GetBytes()       Deleted at end of
100        //                                                                                                  execution
101        //
102        // PersistentVar    eValueTypeHostAddress   eContextTypeClangType       A persistent variable's     NULL
103        //                                                                      location in LLDB's memory
104        //
105        // Register         [ignored]               eContextTypeRegister        [ignored]                   Flushed to the register
106        //                                                                                                  at the end of execution
107
108        lldb::addr_t        m_virtual_address;
109        size_t              m_extent;
110        lldb_private::Value m_origin;
111        lldb::DataBufferSP  m_data;
112
113        Allocation (lldb::addr_t virtual_address,
114                    size_t extent,
115                    lldb::DataBufferSP data) :
116            m_virtual_address(virtual_address),
117            m_extent(extent),
118            m_data(data)
119        {
120        }
121
122        Allocation (const Allocation &allocation) :
123            m_virtual_address(allocation.m_virtual_address),
124            m_extent(allocation.m_extent),
125            m_origin(allocation.m_origin),
126            m_data(allocation.m_data)
127        {
128        }
129    };
130
131    typedef STD_SHARED_PTR(Allocation)  AllocationSP;
132
133    struct Region
134    {
135        AllocationSP m_allocation;
136        uint64_t m_base;
137        uint64_t m_extent;
138
139        Region () :
140            m_allocation(),
141            m_base(0),
142            m_extent(0)
143        {
144        }
145
146        Region (AllocationSP allocation, uint64_t base, uint64_t extent) :
147            m_allocation(allocation),
148            m_base(base),
149            m_extent(extent)
150        {
151        }
152
153        Region (const Region &region) :
154            m_allocation(region.m_allocation),
155            m_base(region.m_base),
156            m_extent(region.m_extent)
157        {
158        }
159
160        bool IsValid ()
161        {
162            return (bool) m_allocation;
163        }
164
165        bool IsInvalid ()
166        {
167            return !m_allocation;
168        }
169    };
170
171    typedef std::vector <AllocationSP>          MemoryMap;
172
173private:
174    lldb::addr_t        m_addr_base;
175    lldb::addr_t        m_addr_max;
176    MemoryMap           m_memory;
177    lldb::ByteOrder     m_byte_order;
178    lldb::addr_t        m_addr_byte_size;
179    DataLayout         &m_target_data;
180
181    lldb_private::ClangExpressionDeclMap   &m_decl_map;
182
183    MemoryMap::iterator LookupInternal (lldb::addr_t addr)
184    {
185        for (MemoryMap::iterator i = m_memory.begin(), e = m_memory.end();
186             i != e;
187             ++i)
188        {
189            if ((*i)->m_virtual_address <= addr &&
190                (*i)->m_virtual_address + (*i)->m_extent > addr)
191                return i;
192        }
193
194        return m_memory.end();
195    }
196
197public:
198    Memory (DataLayout &target_data,
199            lldb_private::ClangExpressionDeclMap &decl_map,
200            lldb::addr_t alloc_start,
201            lldb::addr_t alloc_max) :
202        m_addr_base(alloc_start),
203        m_addr_max(alloc_max),
204        m_target_data(target_data),
205        m_decl_map(decl_map)
206    {
207        m_byte_order = (target_data.isLittleEndian() ? lldb::eByteOrderLittle : lldb::eByteOrderBig);
208        m_addr_byte_size = (target_data.getPointerSize());
209    }
210
211    Region Malloc (size_t size, size_t align)
212    {
213        lldb::DataBufferSP data(new lldb_private::DataBufferHeap(size, 0));
214
215        if (data)
216        {
217            index_t index = m_memory.size();
218
219            const size_t mask = (align - 1);
220
221            m_addr_base += mask;
222            m_addr_base &= ~mask;
223
224            if (m_addr_base + size < m_addr_base ||
225                m_addr_base + size > m_addr_max)
226                return Region();
227
228            uint64_t base = m_addr_base;
229
230            m_memory.push_back(AllocationSP(new Allocation(base, size, data)));
231
232            m_addr_base += size;
233
234            AllocationSP alloc = m_memory[index];
235
236            alloc->m_origin.GetScalar() = (unsigned long long)data->GetBytes();
237            alloc->m_origin.SetContext(lldb_private::Value::eContextTypeInvalid, NULL);
238            alloc->m_origin.SetValueType(lldb_private::Value::eValueTypeHostAddress);
239
240            return Region(alloc, base, size);
241        }
242
243        return Region();
244    }
245
246    Region Malloc (Type *type)
247    {
248        return Malloc (m_target_data.getTypeAllocSize(type),
249                       m_target_data.getPrefTypeAlignment(type));
250    }
251
252    Region Place (Type *type, lldb::addr_t base, lldb_private::Value &value)
253    {
254        index_t index = m_memory.size();
255        size_t size = m_target_data.getTypeAllocSize(type);
256
257        m_memory.push_back(AllocationSP(new Allocation(base, size, lldb::DataBufferSP())));
258
259        AllocationSP alloc = m_memory[index];
260
261        alloc->m_origin = value;
262
263        return Region(alloc, base, size);
264    }
265
266    void Free (lldb::addr_t addr)
267    {
268        MemoryMap::iterator i = LookupInternal (addr);
269
270        if (i != m_memory.end())
271            m_memory.erase(i);
272    }
273
274    Region Lookup (lldb::addr_t addr, Type *type)
275    {
276        MemoryMap::iterator i = LookupInternal(addr);
277
278        if (i == m_memory.end() || !type->isSized())
279            return Region();
280
281        size_t size = m_target_data.getTypeStoreSize(type);
282
283        return Region(*i, addr, size);
284    }
285
286    DataEncoderSP GetEncoder (Region region)
287    {
288        if (region.m_allocation->m_origin.GetValueType() != lldb_private::Value::eValueTypeHostAddress)
289            return DataEncoderSP();
290
291        lldb::DataBufferSP buffer = region.m_allocation->m_data;
292
293        if (!buffer)
294            return DataEncoderSP();
295
296        size_t base_offset = (size_t)(region.m_base - region.m_allocation->m_virtual_address);
297
298        return DataEncoderSP(new lldb_private::DataEncoder(buffer->GetBytes() + base_offset, region.m_extent, m_byte_order, m_addr_byte_size));
299    }
300
301    DataExtractorSP GetExtractor (Region region)
302    {
303        if (region.m_allocation->m_origin.GetValueType() != lldb_private::Value::eValueTypeHostAddress)
304            return DataExtractorSP();
305
306        lldb::DataBufferSP buffer = region.m_allocation->m_data;
307        size_t base_offset = (size_t)(region.m_base - region.m_allocation->m_virtual_address);
308
309        if (buffer)
310            return DataExtractorSP(new lldb_private::DataExtractor(buffer->GetBytes() + base_offset, region.m_extent, m_byte_order, m_addr_byte_size));
311        else
312            return DataExtractorSP(new lldb_private::DataExtractor((uint8_t*)region.m_allocation->m_origin.GetScalar().ULongLong() + base_offset, region.m_extent, m_byte_order, m_addr_byte_size));
313    }
314
315    lldb_private::Value GetAccessTarget(lldb::addr_t addr)
316    {
317        MemoryMap::iterator i = LookupInternal(addr);
318
319        if (i == m_memory.end())
320            return lldb_private::Value();
321
322        lldb_private::Value target = (*i)->m_origin;
323
324        if (target.GetContextType() == lldb_private::Value::eContextTypeRegisterInfo)
325        {
326            target.SetContext(lldb_private::Value::eContextTypeInvalid, NULL);
327            target.SetValueType(lldb_private::Value::eValueTypeHostAddress);
328            target.GetScalar() = (unsigned long long)(*i)->m_data->GetBytes();
329        }
330
331        target.GetScalar() += (addr - (*i)->m_virtual_address);
332
333        return target;
334    }
335
336    bool Write (lldb::addr_t addr, const uint8_t *data, size_t length)
337    {
338        lldb_private::Value target = GetAccessTarget(addr);
339
340        return m_decl_map.WriteTarget(target, data, length);
341    }
342
343    bool Read (uint8_t *data, lldb::addr_t addr, size_t length)
344    {
345        lldb_private::Value source = GetAccessTarget(addr);
346
347        return m_decl_map.ReadTarget(data, source, length);
348    }
349
350    bool WriteToRawPtr (lldb::addr_t addr, const uint8_t *data, size_t length)
351    {
352        lldb_private::Value target = m_decl_map.WrapBareAddress(addr);
353
354        return m_decl_map.WriteTarget(target, data, length);
355    }
356
357    bool ReadFromRawPtr (uint8_t *data, lldb::addr_t addr, size_t length)
358    {
359        lldb_private::Value source = m_decl_map.WrapBareAddress(addr);
360
361        return m_decl_map.ReadTarget(data, source, length);
362    }
363
364    std::string PrintData (lldb::addr_t addr, size_t length)
365    {
366        lldb_private::Value target = GetAccessTarget(addr);
367
368        lldb_private::DataBufferHeap buf(length, 0);
369
370        if (!m_decl_map.ReadTarget(buf.GetBytes(), target, length))
371            return std::string("<couldn't read data>");
372
373        lldb_private::StreamString ss;
374
375        for (size_t i = 0; i < length; i++)
376        {
377            if ((!(i & 0xf)) && i)
378                ss.Printf("%02hhx - ", buf.GetBytes()[i]);
379            else
380                ss.Printf("%02hhx ", buf.GetBytes()[i]);
381        }
382
383        return ss.GetString();
384    }
385
386    std::string SummarizeRegion (Region &region)
387    {
388        lldb_private::StreamString ss;
389
390        lldb_private::Value base = GetAccessTarget(region.m_base);
391
392        ss.Printf("%llx [%s - %s %llx]",
393                  region.m_base,
394                  lldb_private::Value::GetValueTypeAsCString(base.GetValueType()),
395                  lldb_private::Value::GetContextTypeAsCString(base.GetContextType()),
396                  base.GetScalar().ULongLong());
397
398        ss.Printf(" %s", PrintData(region.m_base, region.m_extent).c_str());
399
400        return ss.GetString();
401    }
402};
403
404class InterpreterStackFrame
405{
406public:
407    typedef std::map <const Value*, Memory::Region> ValueMap;
408
409    ValueMap                                m_values;
410    Memory                                 &m_memory;
411    DataLayout                             &m_target_data;
412    lldb_private::ClangExpressionDeclMap   &m_decl_map;
413    const BasicBlock                       *m_bb;
414    BasicBlock::const_iterator              m_ii;
415    BasicBlock::const_iterator              m_ie;
416
417    lldb::ByteOrder                         m_byte_order;
418    size_t                                  m_addr_byte_size;
419
420    InterpreterStackFrame (DataLayout &target_data,
421                           Memory &memory,
422                           lldb_private::ClangExpressionDeclMap &decl_map) :
423        m_memory (memory),
424        m_target_data (target_data),
425        m_decl_map (decl_map)
426    {
427        m_byte_order = (target_data.isLittleEndian() ? lldb::eByteOrderLittle : lldb::eByteOrderBig);
428        m_addr_byte_size = (target_data.getPointerSize());
429    }
430
431    void Jump (const BasicBlock *bb)
432    {
433        m_bb = bb;
434        m_ii = m_bb->begin();
435        m_ie = m_bb->end();
436    }
437
438    bool Cache (Memory::AllocationSP allocation, Type *type)
439    {
440        if (allocation->m_origin.GetContextType() != lldb_private::Value::eContextTypeRegisterInfo)
441            return false;
442
443        return m_decl_map.ReadTarget(allocation->m_data->GetBytes(), allocation->m_origin, allocation->m_data->GetByteSize());
444    }
445
446    std::string SummarizeValue (const Value *value)
447    {
448        lldb_private::StreamString ss;
449
450        ss.Printf("%s", PrintValue(value).c_str());
451
452        ValueMap::iterator i = m_values.find(value);
453
454        if (i != m_values.end())
455        {
456            Memory::Region region = i->second;
457
458            ss.Printf(" %s", m_memory.SummarizeRegion(region).c_str());
459        }
460
461        return ss.GetString();
462    }
463
464    bool AssignToMatchType (lldb_private::Scalar &scalar, uint64_t u64value, Type *type)
465    {
466        size_t type_size = m_target_data.getTypeStoreSize(type);
467
468        switch (type_size)
469        {
470        case 1:
471            scalar = (uint8_t)u64value;
472            break;
473        case 2:
474            scalar = (uint16_t)u64value;
475            break;
476        case 4:
477            scalar = (uint32_t)u64value;
478            break;
479        case 8:
480            scalar = (uint64_t)u64value;
481            break;
482        default:
483            return false;
484        }
485
486        return true;
487    }
488
489    bool EvaluateValue (lldb_private::Scalar &scalar, const Value *value, Module &module)
490    {
491        const Constant *constant = dyn_cast<Constant>(value);
492
493        if (constant)
494        {
495            if (const ConstantInt *constant_int = dyn_cast<ConstantInt>(constant))
496            {
497                return AssignToMatchType(scalar, constant_int->getLimitedValue(), value->getType());
498            }
499        }
500        else
501        {
502            Memory::Region region = ResolveValue(value, module);
503            DataExtractorSP value_extractor = m_memory.GetExtractor(region);
504
505            if (!value_extractor)
506                return false;
507
508            size_t value_size = m_target_data.getTypeStoreSize(value->getType());
509
510            uint32_t offset = 0;
511            uint64_t u64value = value_extractor->GetMaxU64(&offset, value_size);
512
513            return AssignToMatchType(scalar, u64value, value->getType());
514        }
515
516        return false;
517    }
518
519    bool AssignValue (const Value *value, lldb_private::Scalar &scalar, Module &module)
520    {
521        Memory::Region region = ResolveValue (value, module);
522
523        lldb_private::Scalar cast_scalar;
524
525        if (!AssignToMatchType(cast_scalar, scalar.GetRawBits64(0), value->getType()))
526            return false;
527
528        lldb_private::DataBufferHeap buf(cast_scalar.GetByteSize(), 0);
529
530        lldb_private::Error err;
531
532        if (!cast_scalar.GetAsMemoryData(buf.GetBytes(), buf.GetByteSize(), m_byte_order, err))
533            return false;
534
535        DataEncoderSP region_encoder = m_memory.GetEncoder(region);
536
537        memcpy(region_encoder->GetDataStart(), buf.GetBytes(), buf.GetByteSize());
538
539        return true;
540    }
541
542    bool ResolveConstantValue (APInt &value, const Constant *constant)
543    {
544        if (const ConstantInt *constant_int = dyn_cast<ConstantInt>(constant))
545        {
546            value = constant_int->getValue();
547            return true;
548        }
549        else if (const ConstantFP *constant_fp = dyn_cast<ConstantFP>(constant))
550        {
551            value = constant_fp->getValueAPF().bitcastToAPInt();
552            return true;
553        }
554        else if (const ConstantExpr *constant_expr = dyn_cast<ConstantExpr>(constant))
555        {
556            switch (constant_expr->getOpcode())
557            {
558                default:
559                    return false;
560                case Instruction::IntToPtr:
561                case Instruction::BitCast:
562                    return ResolveConstantValue(value, constant_expr->getOperand(0));
563                case Instruction::GetElementPtr:
564                {
565                    ConstantExpr::const_op_iterator op_cursor = constant_expr->op_begin();
566                    ConstantExpr::const_op_iterator op_end = constant_expr->op_end();
567
568                    Constant *base = dyn_cast<Constant>(*op_cursor);
569
570                    if (!base)
571                        return false;
572
573                    if (!ResolveConstantValue(value, base))
574                        return false;
575
576                    op_cursor++;
577
578                    if (op_cursor == op_end)
579                        return true; // no offset to apply!
580
581                    SmallVector <Value *, 8> indices (op_cursor, op_end);
582
583                    uint64_t offset = m_target_data.getIndexedOffset(base->getType(), indices);
584
585                    const bool is_signed = true;
586                    value += APInt(value.getBitWidth(), offset, is_signed);
587
588                    return true;
589                }
590            }
591        }
592
593        return false;
594    }
595
596    bool ResolveConstant (Memory::Region &region, const Constant *constant)
597    {
598        APInt resolved_value;
599
600        if (!ResolveConstantValue(resolved_value, constant))
601            return false;
602
603        const uint64_t *raw_data = resolved_value.getRawData();
604
605        size_t constant_size = m_target_data.getTypeStoreSize(constant->getType());
606        return m_memory.Write(region.m_base, (const uint8_t*)raw_data, constant_size);
607    }
608
609    Memory::Region ResolveValue (const Value *value, Module &module)
610    {
611        ValueMap::iterator i = m_values.find(value);
612
613        if (i != m_values.end())
614            return i->second;
615
616        const GlobalValue *global_value = dyn_cast<GlobalValue>(value);
617
618        // If the variable is indirected through the argument
619        // array then we need to build an extra level of indirection
620        // for it.  This is the default; only magic arguments like
621        // "this", "self", and "_cmd" are direct.
622        bool indirect_variable = true;
623
624        // Attempt to resolve the value using the program's data.
625        // If it is, the values to be created are:
626        //
627        // data_region - a region of memory in which the variable's data resides.
628        // ref_region - a region of memory in which its address (i.e., &var) resides.
629        //   In the JIT case, this region would be a member of the struct passed in.
630        // pointer_region - a region of memory in which the address of the pointer
631        //   resides.  This is an IR-level variable.
632        do
633        {
634            lldb::LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
635
636            lldb_private::Value resolved_value;
637            lldb_private::ClangExpressionVariable::FlagType flags = 0;
638
639            if (global_value)
640            {
641                clang::NamedDecl *decl = IRForTarget::DeclForGlobal(global_value, &module);
642
643                if (!decl)
644                    break;
645
646                if (isa<clang::FunctionDecl>(decl))
647                {
648                    if (log)
649                        log->Printf("The interpreter does not handle function pointers at the moment");
650
651                    return Memory::Region();
652                }
653
654                resolved_value = m_decl_map.LookupDecl(decl, flags);
655            }
656            else
657            {
658                // Special-case "this", "self", and "_cmd"
659
660                std::string name_str = value->getName().str();
661
662                if (name_str == "this" ||
663                    name_str == "self" ||
664                    name_str == "_cmd")
665                    resolved_value = m_decl_map.GetSpecialValue(lldb_private::ConstString(name_str.c_str()));
666
667                indirect_variable = false;
668            }
669
670            if (resolved_value.GetScalar().GetType() != lldb_private::Scalar::e_void)
671            {
672                if (resolved_value.GetContextType() == lldb_private::Value::eContextTypeRegisterInfo)
673                {
674                    bool bare_register = (flags & lldb_private::ClangExpressionVariable::EVBareRegister);
675
676                    if (bare_register)
677                        indirect_variable = false;
678
679                    Memory::Region data_region = m_memory.Malloc(value->getType());
680                    data_region.m_allocation->m_origin = resolved_value;
681                    Memory::Region ref_region = m_memory.Malloc(value->getType());
682                    Memory::Region pointer_region;
683
684                    if (indirect_variable)
685                        pointer_region = m_memory.Malloc(value->getType());
686
687                    if (!Cache(data_region.m_allocation, value->getType()))
688                        return Memory::Region();
689
690                    if (ref_region.IsInvalid())
691                        return Memory::Region();
692
693                    if (pointer_region.IsInvalid() && indirect_variable)
694                        return Memory::Region();
695
696                    DataEncoderSP ref_encoder = m_memory.GetEncoder(ref_region);
697
698                    if (ref_encoder->PutAddress(0, data_region.m_base) == UINT32_MAX)
699                        return Memory::Region();
700
701                    if (log)
702                    {
703                        log->Printf("Made an allocation for register variable %s", PrintValue(value).c_str());
704                        log->Printf("  Data contents  : %s", m_memory.PrintData(data_region.m_base, data_region.m_extent).c_str());
705                        log->Printf("  Data region    : %llx", (unsigned long long)data_region.m_base);
706                        log->Printf("  Ref region     : %llx", (unsigned long long)ref_region.m_base);
707                        if (indirect_variable)
708                            log->Printf("  Pointer region : %llx", (unsigned long long)pointer_region.m_base);
709                    }
710
711                    if (indirect_variable)
712                    {
713                        DataEncoderSP pointer_encoder = m_memory.GetEncoder(pointer_region);
714
715                        if (pointer_encoder->PutAddress(0, ref_region.m_base) == UINT32_MAX)
716                            return Memory::Region();
717
718                        m_values[value] = pointer_region;
719                        return pointer_region;
720                    }
721                    else
722                    {
723                        m_values[value] = ref_region;
724                        return ref_region;
725                    }
726                }
727                else
728                {
729                    Memory::Region data_region = m_memory.Place(value->getType(), resolved_value.GetScalar().ULongLong(), resolved_value);
730                    Memory::Region ref_region = m_memory.Malloc(value->getType());
731                    Memory::Region pointer_region;
732
733                    if (indirect_variable)
734                        pointer_region = m_memory.Malloc(value->getType());
735
736                    if (ref_region.IsInvalid())
737                        return Memory::Region();
738
739                    if (pointer_region.IsInvalid() && indirect_variable)
740                        return Memory::Region();
741
742                    DataEncoderSP ref_encoder = m_memory.GetEncoder(ref_region);
743
744                    if (ref_encoder->PutAddress(0, data_region.m_base) == UINT32_MAX)
745                        return Memory::Region();
746
747                    if (indirect_variable)
748                    {
749                        DataEncoderSP pointer_encoder = m_memory.GetEncoder(pointer_region);
750
751                        if (pointer_encoder->PutAddress(0, ref_region.m_base) == UINT32_MAX)
752                            return Memory::Region();
753
754                        m_values[value] = pointer_region;
755                    }
756
757                    if (log)
758                    {
759                        log->Printf("Made an allocation for %s", PrintValue(value).c_str());
760                        log->Printf("  Data contents  : %s", m_memory.PrintData(data_region.m_base, data_region.m_extent).c_str());
761                        log->Printf("  Data region    : %llx", (unsigned long long)data_region.m_base);
762                        log->Printf("  Ref region     : %llx", (unsigned long long)ref_region.m_base);
763                        if (indirect_variable)
764                            log->Printf("  Pointer region : %llx", (unsigned long long)pointer_region.m_base);
765                    }
766
767                    if (indirect_variable)
768                        return pointer_region;
769                    else
770                        return ref_region;
771                }
772            }
773        }
774        while(0);
775
776        // Fall back and allocate space [allocation type Alloca]
777
778        Type *type = value->getType();
779
780        lldb::ValueSP backing_value(new lldb_private::Value);
781
782        Memory::Region data_region = m_memory.Malloc(type);
783        data_region.m_allocation->m_origin.GetScalar() = (unsigned long long)data_region.m_allocation->m_data->GetBytes();
784        data_region.m_allocation->m_origin.SetContext(lldb_private::Value::eContextTypeInvalid, NULL);
785        data_region.m_allocation->m_origin.SetValueType(lldb_private::Value::eValueTypeHostAddress);
786
787        const Constant *constant = dyn_cast<Constant>(value);
788
789        do
790        {
791            if (!constant)
792                break;
793
794            if (!ResolveConstant (data_region, constant))
795                return Memory::Region();
796        }
797        while(0);
798
799        m_values[value] = data_region;
800        return data_region;
801    }
802
803    bool ConstructResult (lldb::ClangExpressionVariableSP &result,
804                          const GlobalValue *result_value,
805                          const lldb_private::ConstString &result_name,
806                          lldb_private::TypeFromParser result_type,
807                          Module &module)
808    {
809        // The result_value resolves to P, a pointer to a region R containing the result data.
810        // If the result variable is a reference, the region R contains a pointer to the result R_final in the original process.
811
812        if (!result_value)
813            return true; // There was no slot for a result – the expression doesn't return one.
814
815        ValueMap::iterator i = m_values.find(result_value);
816
817        if (i == m_values.end())
818            return false; // There was a slot for the result, but we didn't write into it.
819
820        Memory::Region P = i->second;
821        DataExtractorSP P_extractor = m_memory.GetExtractor(P);
822
823        if (!P_extractor)
824            return false;
825
826        Type *pointer_ty = result_value->getType();
827        PointerType *pointer_ptr_ty = dyn_cast<PointerType>(pointer_ty);
828        if (!pointer_ptr_ty)
829            return false;
830        Type *R_ty = pointer_ptr_ty->getElementType();
831
832        uint32_t offset = 0;
833        lldb::addr_t pointer = P_extractor->GetAddress(&offset);
834
835        Memory::Region R = m_memory.Lookup(pointer, R_ty);
836
837        if (R.m_allocation->m_origin.GetValueType() != lldb_private::Value::eValueTypeHostAddress ||
838            !R.m_allocation->m_data)
839            return false;
840
841        lldb_private::Value base;
842
843        bool transient = false;
844        bool maybe_make_load = false;
845
846        if (m_decl_map.ResultIsReference(result_name))
847        {
848            PointerType *R_ptr_ty = dyn_cast<PointerType>(R_ty);
849            if (!R_ptr_ty)
850                return false;
851            Type *R_final_ty = R_ptr_ty->getElementType();
852
853            DataExtractorSP R_extractor = m_memory.GetExtractor(R);
854
855            if (!R_extractor)
856                return false;
857
858            offset = 0;
859            lldb::addr_t R_pointer = R_extractor->GetAddress(&offset);
860
861            Memory::Region R_final = m_memory.Lookup(R_pointer, R_final_ty);
862
863            if (R_final.m_allocation)
864            {
865                if (R_final.m_allocation->m_data)
866                    transient = true; // this is a stack allocation
867
868                base = R_final.m_allocation->m_origin;
869                base.GetScalar() += (R_final.m_base - R_final.m_allocation->m_virtual_address);
870            }
871            else
872            {
873                // We got a bare pointer.  We are going to treat it as a load address
874                // or a file address, letting decl_map make the choice based on whether
875                // or not a process exists.
876
877                base.SetContext(lldb_private::Value::eContextTypeInvalid, NULL);
878                base.SetValueType(lldb_private::Value::eValueTypeFileAddress);
879                base.GetScalar() = (unsigned long long)R_pointer;
880                maybe_make_load = true;
881            }
882        }
883        else
884        {
885            base.SetContext(lldb_private::Value::eContextTypeInvalid, NULL);
886            base.SetValueType(lldb_private::Value::eValueTypeHostAddress);
887            base.GetScalar() = (unsigned long long)R.m_allocation->m_data->GetBytes() + (R.m_base - R.m_allocation->m_virtual_address);
888        }
889
890        return m_decl_map.CompleteResultVariable (result, base, result_name, result_type, transient, maybe_make_load);
891    }
892};
893
894bool
895IRInterpreter::maybeRunOnFunction (lldb::ClangExpressionVariableSP &result,
896                                   const lldb_private::ConstString &result_name,
897                                   lldb_private::TypeFromParser result_type,
898                                   Function &llvm_function,
899                                   Module &llvm_module,
900                                   lldb_private::Error &err)
901{
902    if (supportsFunction (llvm_function, err))
903        return runOnFunction(result,
904                             result_name,
905                             result_type,
906                             llvm_function,
907                             llvm_module,
908                             err);
909    else
910        return false;
911}
912
913static const char *unsupported_opcode_error         = "Interpreter doesn't handle one of the expression's opcodes";
914static const char *interpreter_initialization_error = "Interpreter couldn't be initialized";
915static const char *interpreter_internal_error       = "Interpreter encountered an internal error";
916static const char *bad_value_error                  = "Interpreter couldn't resolve a value during execution";
917static const char *memory_allocation_error          = "Interpreter couldn't allocate memory";
918static const char *memory_write_error               = "Interpreter couldn't write to memory";
919static const char *memory_read_error                = "Interpreter couldn't read from memory";
920static const char *infinite_loop_error              = "Interpreter ran for too many cycles";
921static const char *bad_result_error                 = "Result of expression is in bad memory";
922
923bool
924IRInterpreter::supportsFunction (Function &llvm_function,
925                                 lldb_private::Error &err)
926{
927    lldb::LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
928
929    for (Function::iterator bbi = llvm_function.begin(), bbe = llvm_function.end();
930         bbi != bbe;
931         ++bbi)
932    {
933        for (BasicBlock::iterator ii = bbi->begin(), ie = bbi->end();
934             ii != ie;
935             ++ii)
936        {
937            switch (ii->getOpcode())
938            {
939            default:
940                {
941                    if (log)
942                        log->Printf("Unsupported instruction: %s", PrintValue(ii).c_str());
943                    err.SetErrorToGenericError();
944                    err.SetErrorString(unsupported_opcode_error);
945                    return false;
946                }
947            case Instruction::Add:
948            case Instruction::Alloca:
949            case Instruction::BitCast:
950            case Instruction::Br:
951            case Instruction::GetElementPtr:
952                break;
953            case Instruction::ICmp:
954                {
955                    ICmpInst *icmp_inst = dyn_cast<ICmpInst>(ii);
956
957                    if (!icmp_inst)
958                    {
959                        err.SetErrorToGenericError();
960                        err.SetErrorString(interpreter_internal_error);
961                        return false;
962                    }
963
964                    switch (icmp_inst->getPredicate())
965                    {
966                    default:
967                        {
968                            if (log)
969                                log->Printf("Unsupported ICmp predicate: %s", PrintValue(ii).c_str());
970
971                            err.SetErrorToGenericError();
972                            err.SetErrorString(unsupported_opcode_error);
973                            return false;
974                        }
975                    case CmpInst::ICMP_EQ:
976                    case CmpInst::ICMP_NE:
977                    case CmpInst::ICMP_UGT:
978                    case CmpInst::ICMP_UGE:
979                    case CmpInst::ICMP_ULT:
980                    case CmpInst::ICMP_ULE:
981                    case CmpInst::ICMP_SGT:
982                    case CmpInst::ICMP_SGE:
983                    case CmpInst::ICMP_SLT:
984                    case CmpInst::ICMP_SLE:
985                        break;
986                    }
987                }
988                break;
989            case Instruction::IntToPtr:
990            case Instruction::Load:
991            case Instruction::Mul:
992            case Instruction::Ret:
993            case Instruction::SDiv:
994            case Instruction::Store:
995            case Instruction::Sub:
996            case Instruction::UDiv:
997            case Instruction::ZExt:
998                break;
999            }
1000        }
1001    }
1002
1003    return true;
1004}
1005
1006bool
1007IRInterpreter::runOnFunction (lldb::ClangExpressionVariableSP &result,
1008                              const lldb_private::ConstString &result_name,
1009                              lldb_private::TypeFromParser result_type,
1010                              Function &llvm_function,
1011                              Module &llvm_module,
1012                              lldb_private::Error &err)
1013{
1014    lldb::LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
1015
1016    lldb_private::ClangExpressionDeclMap::TargetInfo target_info = m_decl_map.GetTargetInfo();
1017
1018    if (!target_info.IsValid())
1019    {
1020        err.SetErrorToGenericError();
1021        err.SetErrorString(interpreter_initialization_error);
1022        return false;
1023    }
1024
1025    lldb::addr_t alloc_min;
1026    lldb::addr_t alloc_max;
1027
1028    switch (target_info.address_byte_size)
1029    {
1030    default:
1031        err.SetErrorToGenericError();
1032        err.SetErrorString(interpreter_initialization_error);
1033        return false;
1034    case 4:
1035        alloc_min = 0x00001000llu;
1036        alloc_max = 0x0000ffffllu;
1037        break;
1038    case 8:
1039        alloc_min = 0x0000000000001000llu;
1040        alloc_max = 0x000000000000ffffllu;
1041        break;
1042    }
1043
1044    DataLayout target_data(&llvm_module);
1045    if (target_data.getPointerSize() != target_info.address_byte_size)
1046    {
1047        err.SetErrorToGenericError();
1048        err.SetErrorString(interpreter_initialization_error);
1049        return false;
1050    }
1051    if (target_data.isLittleEndian() != (target_info.byte_order == lldb::eByteOrderLittle))
1052    {
1053        err.SetErrorToGenericError();
1054        err.SetErrorString(interpreter_initialization_error);
1055        return false;
1056    }
1057
1058    Memory memory(target_data, m_decl_map, alloc_min, alloc_max);
1059    InterpreterStackFrame frame(target_data, memory, m_decl_map);
1060
1061    uint32_t num_insts = 0;
1062
1063    frame.Jump(llvm_function.begin());
1064
1065    while (frame.m_ii != frame.m_ie && (++num_insts < 4096))
1066    {
1067        const Instruction *inst = frame.m_ii;
1068
1069        if (log)
1070            log->Printf("Interpreting %s", PrintValue(inst).c_str());
1071
1072        switch (inst->getOpcode())
1073        {
1074        default:
1075            break;
1076        case Instruction::Add:
1077        case Instruction::Sub:
1078        case Instruction::Mul:
1079        case Instruction::SDiv:
1080        case Instruction::UDiv:
1081            {
1082                const BinaryOperator *bin_op = dyn_cast<BinaryOperator>(inst);
1083
1084                if (!bin_op)
1085                {
1086                    if (log)
1087                        log->Printf("getOpcode() returns %s, but instruction is not a BinaryOperator", inst->getOpcodeName());
1088                    err.SetErrorToGenericError();
1089                    err.SetErrorString(interpreter_internal_error);
1090                    return false;
1091                }
1092
1093                Value *lhs = inst->getOperand(0);
1094                Value *rhs = inst->getOperand(1);
1095
1096                lldb_private::Scalar L;
1097                lldb_private::Scalar R;
1098
1099                if (!frame.EvaluateValue(L, lhs, llvm_module))
1100                {
1101                    if (log)
1102                        log->Printf("Couldn't evaluate %s", PrintValue(lhs).c_str());
1103                    err.SetErrorToGenericError();
1104                    err.SetErrorString(bad_value_error);
1105                    return false;
1106                }
1107
1108                if (!frame.EvaluateValue(R, rhs, llvm_module))
1109                {
1110                    if (log)
1111                        log->Printf("Couldn't evaluate %s", PrintValue(rhs).c_str());
1112                    err.SetErrorToGenericError();
1113                    err.SetErrorString(bad_value_error);
1114                    return false;
1115                }
1116
1117                lldb_private::Scalar result;
1118
1119                switch (inst->getOpcode())
1120                {
1121                default:
1122                    break;
1123                case Instruction::Add:
1124                    result = L + R;
1125                    break;
1126                case Instruction::Mul:
1127                    result = L * R;
1128                    break;
1129                case Instruction::Sub:
1130                    result = L - R;
1131                    break;
1132                case Instruction::SDiv:
1133                    result = L / R;
1134                    break;
1135                case Instruction::UDiv:
1136                    result = L.GetRawBits64(0) / R.GetRawBits64(1);
1137                    break;
1138                }
1139
1140                frame.AssignValue(inst, result, llvm_module);
1141
1142                if (log)
1143                {
1144                    log->Printf("Interpreted a %s", inst->getOpcodeName());
1145                    log->Printf("  L : %s", frame.SummarizeValue(lhs).c_str());
1146                    log->Printf("  R : %s", frame.SummarizeValue(rhs).c_str());
1147                    log->Printf("  = : %s", frame.SummarizeValue(inst).c_str());
1148                }
1149            }
1150            break;
1151        case Instruction::Alloca:
1152            {
1153                const AllocaInst *alloca_inst = dyn_cast<AllocaInst>(inst);
1154
1155                if (!alloca_inst)
1156                {
1157                    if (log)
1158                        log->Printf("getOpcode() returns Alloca, but instruction is not an AllocaInst");
1159                    err.SetErrorToGenericError();
1160                    err.SetErrorString(interpreter_internal_error);
1161                    return false;
1162                }
1163
1164                if (alloca_inst->isArrayAllocation())
1165                {
1166                    if (log)
1167                        log->Printf("AllocaInsts are not handled if isArrayAllocation() is true");
1168                    err.SetErrorToGenericError();
1169                    err.SetErrorString(unsupported_opcode_error);
1170                    return false;
1171                }
1172
1173                // The semantics of Alloca are:
1174                //   Create a region R of virtual memory of type T, backed by a data buffer
1175                //   Create a region P of virtual memory of type T*, backed by a data buffer
1176                //   Write the virtual address of R into P
1177
1178                Type *T = alloca_inst->getAllocatedType();
1179                Type *Tptr = alloca_inst->getType();
1180
1181                Memory::Region R = memory.Malloc(T);
1182
1183                if (R.IsInvalid())
1184                {
1185                    if (log)
1186                        log->Printf("Couldn't allocate memory for an AllocaInst");
1187                    err.SetErrorToGenericError();
1188                    err.SetErrorString(memory_allocation_error);
1189                    return false;
1190                }
1191
1192                Memory::Region P = memory.Malloc(Tptr);
1193
1194                if (P.IsInvalid())
1195                {
1196                    if (log)
1197                        log->Printf("Couldn't allocate the result pointer for an AllocaInst");
1198                    err.SetErrorToGenericError();
1199                    err.SetErrorString(memory_allocation_error);
1200                    return false;
1201                }
1202
1203                DataEncoderSP P_encoder = memory.GetEncoder(P);
1204
1205                if (P_encoder->PutAddress(0, R.m_base) == UINT32_MAX)
1206                {
1207                    if (log)
1208                        log->Printf("Couldn't write the result pointer for an AllocaInst");
1209                    err.SetErrorToGenericError();
1210                    err.SetErrorString(memory_write_error);
1211                    return false;
1212                }
1213
1214                frame.m_values[alloca_inst] = P;
1215
1216                if (log)
1217                {
1218                    log->Printf("Interpreted an AllocaInst");
1219                    log->Printf("  R : %s", memory.SummarizeRegion(R).c_str());
1220                    log->Printf("  P : %s", frame.SummarizeValue(alloca_inst).c_str());
1221                }
1222            }
1223            break;
1224        case Instruction::BitCast:
1225        case Instruction::ZExt:
1226            {
1227                const CastInst *cast_inst = dyn_cast<CastInst>(inst);
1228
1229                if (!cast_inst)
1230                {
1231                    if (log)
1232                        log->Printf("getOpcode() returns %s, but instruction is not a BitCastInst", cast_inst->getOpcodeName());
1233                    err.SetErrorToGenericError();
1234                    err.SetErrorString(interpreter_internal_error);
1235                    return false;
1236                }
1237
1238                Value *source = cast_inst->getOperand(0);
1239
1240                lldb_private::Scalar S;
1241
1242                if (!frame.EvaluateValue(S, source, llvm_module))
1243                {
1244                    if (log)
1245                        log->Printf("Couldn't evaluate %s", PrintValue(source).c_str());
1246                    err.SetErrorToGenericError();
1247                    err.SetErrorString(bad_value_error);
1248                    return false;
1249                }
1250
1251                frame.AssignValue(inst, S, llvm_module);
1252            }
1253            break;
1254        case Instruction::Br:
1255            {
1256                const BranchInst *br_inst = dyn_cast<BranchInst>(inst);
1257
1258                if (!br_inst)
1259                {
1260                    if (log)
1261                        log->Printf("getOpcode() returns Br, but instruction is not a BranchInst");
1262                    err.SetErrorToGenericError();
1263                    err.SetErrorString(interpreter_internal_error);
1264                    return false;
1265                }
1266
1267                if (br_inst->isConditional())
1268                {
1269                    Value *condition = br_inst->getCondition();
1270
1271                    lldb_private::Scalar C;
1272
1273                    if (!frame.EvaluateValue(C, condition, llvm_module))
1274                    {
1275                        if (log)
1276                            log->Printf("Couldn't evaluate %s", PrintValue(condition).c_str());
1277                        err.SetErrorToGenericError();
1278                        err.SetErrorString(bad_value_error);
1279                        return false;
1280                    }
1281
1282                    if (C.GetRawBits64(0))
1283                        frame.Jump(br_inst->getSuccessor(0));
1284                    else
1285                        frame.Jump(br_inst->getSuccessor(1));
1286
1287                    if (log)
1288                    {
1289                        log->Printf("Interpreted a BrInst with a condition");
1290                        log->Printf("  cond : %s", frame.SummarizeValue(condition).c_str());
1291                    }
1292                }
1293                else
1294                {
1295                    frame.Jump(br_inst->getSuccessor(0));
1296
1297                    if (log)
1298                    {
1299                        log->Printf("Interpreted a BrInst with no condition");
1300                    }
1301                }
1302            }
1303            continue;
1304        case Instruction::GetElementPtr:
1305            {
1306                const GetElementPtrInst *gep_inst = dyn_cast<GetElementPtrInst>(inst);
1307
1308                if (!gep_inst)
1309                {
1310                    if (log)
1311                        log->Printf("getOpcode() returns GetElementPtr, but instruction is not a GetElementPtrInst");
1312                    err.SetErrorToGenericError();
1313                    err.SetErrorString(interpreter_internal_error);
1314                    return false;
1315                }
1316
1317                const Value *pointer_operand = gep_inst->getPointerOperand();
1318                Type *pointer_type = pointer_operand->getType();
1319
1320                lldb_private::Scalar P;
1321
1322                if (!frame.EvaluateValue(P, pointer_operand, llvm_module))
1323                {
1324                    if (log)
1325                        log->Printf("Couldn't evaluate %s", PrintValue(pointer_operand).c_str());
1326                    err.SetErrorToGenericError();
1327                    err.SetErrorString(bad_value_error);
1328                    return false;
1329                }
1330
1331                typedef SmallVector <Value *, 8> IndexVector;
1332                typedef IndexVector::iterator IndexIterator;
1333
1334                SmallVector <Value *, 8> indices (gep_inst->idx_begin(),
1335                                                  gep_inst->idx_end());
1336
1337                SmallVector <Value *, 8> const_indices;
1338
1339                for (IndexIterator ii = indices.begin(), ie = indices.end();
1340                     ii != ie;
1341                     ++ii)
1342                {
1343                    ConstantInt *constant_index = dyn_cast<ConstantInt>(*ii);
1344
1345                    if (!constant_index)
1346                    {
1347                        lldb_private::Scalar I;
1348
1349                        if (!frame.EvaluateValue(I, *ii, llvm_module))
1350                        {
1351                            if (log)
1352                                log->Printf("Couldn't evaluate %s", PrintValue(*ii).c_str());
1353                            err.SetErrorToGenericError();
1354                            err.SetErrorString(bad_value_error);
1355                            return false;
1356                        }
1357
1358                        if (log)
1359                            log->Printf("Evaluated constant index %s as %llu", PrintValue(*ii).c_str(), I.ULongLong(LLDB_INVALID_ADDRESS));
1360
1361                        constant_index = cast<ConstantInt>(ConstantInt::get((*ii)->getType(), I.ULongLong(LLDB_INVALID_ADDRESS)));
1362                    }
1363
1364                    const_indices.push_back(constant_index);
1365                }
1366
1367                uint64_t offset = target_data.getIndexedOffset(pointer_type, const_indices);
1368
1369                lldb_private::Scalar Poffset = P + offset;
1370
1371                frame.AssignValue(inst, Poffset, llvm_module);
1372
1373                if (log)
1374                {
1375                    log->Printf("Interpreted a GetElementPtrInst");
1376                    log->Printf("  P       : %s", frame.SummarizeValue(pointer_operand).c_str());
1377                    log->Printf("  Poffset : %s", frame.SummarizeValue(inst).c_str());
1378                }
1379            }
1380            break;
1381        case Instruction::ICmp:
1382            {
1383                const ICmpInst *icmp_inst = dyn_cast<ICmpInst>(inst);
1384
1385                if (!icmp_inst)
1386                {
1387                    if (log)
1388                        log->Printf("getOpcode() returns ICmp, but instruction is not an ICmpInst");
1389                    err.SetErrorToGenericError();
1390                    err.SetErrorString(interpreter_internal_error);
1391                    return false;
1392                }
1393
1394                CmpInst::Predicate predicate = icmp_inst->getPredicate();
1395
1396                Value *lhs = inst->getOperand(0);
1397                Value *rhs = inst->getOperand(1);
1398
1399                lldb_private::Scalar L;
1400                lldb_private::Scalar R;
1401
1402                if (!frame.EvaluateValue(L, lhs, llvm_module))
1403                {
1404                    if (log)
1405                        log->Printf("Couldn't evaluate %s", PrintValue(lhs).c_str());
1406                    err.SetErrorToGenericError();
1407                    err.SetErrorString(bad_value_error);
1408                    return false;
1409                }
1410
1411                if (!frame.EvaluateValue(R, rhs, llvm_module))
1412                {
1413                    if (log)
1414                        log->Printf("Couldn't evaluate %s", PrintValue(rhs).c_str());
1415                    err.SetErrorToGenericError();
1416                    err.SetErrorString(bad_value_error);
1417                    return false;
1418                }
1419
1420                lldb_private::Scalar result;
1421
1422                switch (predicate)
1423                {
1424                default:
1425                    return false;
1426                case CmpInst::ICMP_EQ:
1427                    result = (L == R);
1428                    break;
1429                case CmpInst::ICMP_NE:
1430                    result = (L != R);
1431                    break;
1432                case CmpInst::ICMP_UGT:
1433                    result = (L.GetRawBits64(0) > R.GetRawBits64(0));
1434                    break;
1435                case CmpInst::ICMP_UGE:
1436                    result = (L.GetRawBits64(0) >= R.GetRawBits64(0));
1437                    break;
1438                case CmpInst::ICMP_ULT:
1439                    result = (L.GetRawBits64(0) < R.GetRawBits64(0));
1440                    break;
1441                case CmpInst::ICMP_ULE:
1442                    result = (L.GetRawBits64(0) <= R.GetRawBits64(0));
1443                    break;
1444                case CmpInst::ICMP_SGT:
1445                    result = (L > R);
1446                    break;
1447                case CmpInst::ICMP_SGE:
1448                    result = (L >= R);
1449                    break;
1450                case CmpInst::ICMP_SLT:
1451                    result = (L < R);
1452                    break;
1453                case CmpInst::ICMP_SLE:
1454                    result = (L <= R);
1455                    break;
1456                }
1457
1458                frame.AssignValue(inst, result, llvm_module);
1459
1460                if (log)
1461                {
1462                    log->Printf("Interpreted an ICmpInst");
1463                    log->Printf("  L : %s", frame.SummarizeValue(lhs).c_str());
1464                    log->Printf("  R : %s", frame.SummarizeValue(rhs).c_str());
1465                    log->Printf("  = : %s", frame.SummarizeValue(inst).c_str());
1466                }
1467            }
1468            break;
1469        case Instruction::IntToPtr:
1470            {
1471                const IntToPtrInst *int_to_ptr_inst = dyn_cast<IntToPtrInst>(inst);
1472
1473                if (!int_to_ptr_inst)
1474                {
1475                    if (log)
1476                        log->Printf("getOpcode() returns IntToPtr, but instruction is not an IntToPtrInst");
1477                    err.SetErrorToGenericError();
1478                    err.SetErrorString(interpreter_internal_error);
1479                    return false;
1480                }
1481
1482                Value *src_operand = int_to_ptr_inst->getOperand(0);
1483
1484                lldb_private::Scalar I;
1485
1486                if (!frame.EvaluateValue(I, src_operand, llvm_module))
1487                {
1488                    if (log)
1489                        log->Printf("Couldn't evaluate %s", PrintValue(src_operand).c_str());
1490                    err.SetErrorToGenericError();
1491                    err.SetErrorString(bad_value_error);
1492                    return false;
1493                }
1494
1495                frame.AssignValue(inst, I, llvm_module);
1496
1497                if (log)
1498                {
1499                    log->Printf("Interpreted an IntToPtr");
1500                    log->Printf("  Src : %s", frame.SummarizeValue(src_operand).c_str());
1501                    log->Printf("  =   : %s", frame.SummarizeValue(inst).c_str());
1502                }
1503            }
1504            break;
1505        case Instruction::Load:
1506            {
1507                const LoadInst *load_inst = dyn_cast<LoadInst>(inst);
1508
1509                if (!load_inst)
1510                {
1511                    if (log)
1512                        log->Printf("getOpcode() returns Load, but instruction is not a LoadInst");
1513                    err.SetErrorToGenericError();
1514                    err.SetErrorString(interpreter_internal_error);
1515                    return false;
1516                }
1517
1518                // The semantics of Load are:
1519                //   Create a region D that will contain the loaded data
1520                //   Resolve the region P containing a pointer
1521                //   Dereference P to get the region R that the data should be loaded from
1522                //   Transfer a unit of type type(D) from R to D
1523
1524                const Value *pointer_operand = load_inst->getPointerOperand();
1525
1526                Type *pointer_ty = pointer_operand->getType();
1527                PointerType *pointer_ptr_ty = dyn_cast<PointerType>(pointer_ty);
1528                if (!pointer_ptr_ty)
1529                {
1530                    if (log)
1531                        log->Printf("getPointerOperand()->getType() is not a PointerType");
1532                    err.SetErrorToGenericError();
1533                    err.SetErrorString(interpreter_internal_error);
1534                    return false;
1535                }
1536                Type *target_ty = pointer_ptr_ty->getElementType();
1537
1538                Memory::Region D = frame.ResolveValue(load_inst, llvm_module);
1539                Memory::Region P = frame.ResolveValue(pointer_operand, llvm_module);
1540
1541                if (D.IsInvalid())
1542                {
1543                    if (log)
1544                        log->Printf("LoadInst's value doesn't resolve to anything");
1545                    err.SetErrorToGenericError();
1546                    err.SetErrorString(bad_value_error);
1547                    return false;
1548                }
1549
1550                if (P.IsInvalid())
1551                {
1552                    if (log)
1553                        log->Printf("LoadInst's pointer doesn't resolve to anything");
1554                    err.SetErrorToGenericError();
1555                    err.SetErrorString(bad_value_error);
1556                    return false;
1557                }
1558
1559                DataExtractorSP P_extractor(memory.GetExtractor(P));
1560                DataEncoderSP D_encoder(memory.GetEncoder(D));
1561
1562                uint32_t offset = 0;
1563                lldb::addr_t pointer = P_extractor->GetAddress(&offset);
1564
1565                Memory::Region R = memory.Lookup(pointer, target_ty);
1566
1567                if (R.IsValid())
1568                {
1569                    if (!memory.Read(D_encoder->GetDataStart(), R.m_base, target_data.getTypeStoreSize(target_ty)))
1570                    {
1571                        if (log)
1572                            log->Printf("Couldn't read from a region on behalf of a LoadInst");
1573                        err.SetErrorToGenericError();
1574                        err.SetErrorString(memory_read_error);
1575                        return false;
1576                    }
1577                }
1578                else
1579                {
1580                    if (!memory.ReadFromRawPtr(D_encoder->GetDataStart(), pointer, target_data.getTypeStoreSize(target_ty)))
1581                    {
1582                        if (log)
1583                            log->Printf("Couldn't read from a raw pointer on behalf of a LoadInst");
1584                        err.SetErrorToGenericError();
1585                        err.SetErrorString(memory_read_error);
1586                        return false;
1587                    }
1588                }
1589
1590                if (log)
1591                {
1592                    log->Printf("Interpreted a LoadInst");
1593                    log->Printf("  P : %s", frame.SummarizeValue(pointer_operand).c_str());
1594                    if (R.IsValid())
1595                        log->Printf("  R : %s", memory.SummarizeRegion(R).c_str());
1596                    else
1597                        log->Printf("  R : raw pointer 0x%llx", (unsigned long long)pointer);
1598                    log->Printf("  D : %s", frame.SummarizeValue(load_inst).c_str());
1599                }
1600            }
1601            break;
1602        case Instruction::Ret:
1603            {
1604                if (result_name.IsEmpty())
1605                    return true;
1606
1607                GlobalValue *result_value = llvm_module.getNamedValue(result_name.GetCString());
1608
1609                if (!frame.ConstructResult(result, result_value, result_name, result_type, llvm_module))
1610                {
1611                    if (log)
1612                        log->Printf("Couldn't construct the expression's result");
1613                    err.SetErrorToGenericError();
1614                    err.SetErrorString(bad_result_error);
1615                    return false;
1616                }
1617
1618                return true;
1619            }
1620        case Instruction::Store:
1621            {
1622                const StoreInst *store_inst = dyn_cast<StoreInst>(inst);
1623
1624                if (!store_inst)
1625                {
1626                    if (log)
1627                        log->Printf("getOpcode() returns Store, but instruction is not a StoreInst");
1628                    err.SetErrorToGenericError();
1629                    err.SetErrorString(interpreter_internal_error);
1630                    return false;
1631                }
1632
1633                // The semantics of Store are:
1634                //   Resolve the region D containing the data to be stored
1635                //   Resolve the region P containing a pointer
1636                //   Dereference P to get the region R that the data should be stored in
1637                //   Transfer a unit of type type(D) from D to R
1638
1639                const Value *value_operand = store_inst->getValueOperand();
1640                const Value *pointer_operand = store_inst->getPointerOperand();
1641
1642                Type *pointer_ty = pointer_operand->getType();
1643                PointerType *pointer_ptr_ty = dyn_cast<PointerType>(pointer_ty);
1644                if (!pointer_ptr_ty)
1645                    return false;
1646                Type *target_ty = pointer_ptr_ty->getElementType();
1647
1648                Memory::Region D = frame.ResolveValue(value_operand, llvm_module);
1649                Memory::Region P = frame.ResolveValue(pointer_operand, llvm_module);
1650
1651                if (D.IsInvalid())
1652                {
1653                    if (log)
1654                        log->Printf("StoreInst's value doesn't resolve to anything");
1655                    err.SetErrorToGenericError();
1656                    err.SetErrorString(bad_value_error);
1657                    return false;
1658                }
1659
1660                if (P.IsInvalid())
1661                {
1662                    if (log)
1663                        log->Printf("StoreInst's pointer doesn't resolve to anything");
1664                    err.SetErrorToGenericError();
1665                    err.SetErrorString(bad_value_error);
1666                    return false;
1667                }
1668
1669                DataExtractorSP P_extractor(memory.GetExtractor(P));
1670                DataExtractorSP D_extractor(memory.GetExtractor(D));
1671
1672                if (!P_extractor || !D_extractor)
1673                    return false;
1674
1675                uint32_t offset = 0;
1676                lldb::addr_t pointer = P_extractor->GetAddress(&offset);
1677
1678                Memory::Region R = memory.Lookup(pointer, target_ty);
1679
1680                if (R.IsValid())
1681                {
1682                    if (!memory.Write(R.m_base, D_extractor->GetDataStart(), target_data.getTypeStoreSize(target_ty)))
1683                    {
1684                        if (log)
1685                            log->Printf("Couldn't write to a region on behalf of a LoadInst");
1686                        err.SetErrorToGenericError();
1687                        err.SetErrorString(memory_write_error);
1688                        return false;
1689                    }
1690                }
1691                else
1692                {
1693                    if (!memory.WriteToRawPtr(pointer, D_extractor->GetDataStart(), target_data.getTypeStoreSize(target_ty)))
1694                    {
1695                        if (log)
1696                            log->Printf("Couldn't write to a raw pointer on behalf of a LoadInst");
1697                        err.SetErrorToGenericError();
1698                        err.SetErrorString(memory_write_error);
1699                        return false;
1700                    }
1701                }
1702
1703
1704                if (log)
1705                {
1706                    log->Printf("Interpreted a StoreInst");
1707                    log->Printf("  D : %s", frame.SummarizeValue(value_operand).c_str());
1708                    log->Printf("  P : %s", frame.SummarizeValue(pointer_operand).c_str());
1709                    log->Printf("  R : %s", memory.SummarizeRegion(R).c_str());
1710                }
1711            }
1712            break;
1713        }
1714
1715        ++frame.m_ii;
1716    }
1717
1718    if (num_insts >= 4096)
1719    {
1720        err.SetErrorToGenericError();
1721        err.SetErrorString(infinite_loop_error);
1722        return false;
1723    }
1724
1725    return false;
1726}
1727