xref: /openbsd-src/gnu/llvm/lldb/source/Expression/IRInterpreter.cpp (revision f6aab3d83b51b91c24247ad2c2573574de475a82)
1 //===-- IRInterpreter.cpp -------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "lldb/Expression/IRInterpreter.h"
10 #include "lldb/Core/Module.h"
11 #include "lldb/Core/ModuleSpec.h"
12 #include "lldb/Core/ValueObject.h"
13 #include "lldb/Expression/DiagnosticManager.h"
14 #include "lldb/Expression/IRExecutionUnit.h"
15 #include "lldb/Expression/IRMemoryMap.h"
16 #include "lldb/Utility/ConstString.h"
17 #include "lldb/Utility/DataExtractor.h"
18 #include "lldb/Utility/Endian.h"
19 #include "lldb/Utility/LLDBLog.h"
20 #include "lldb/Utility/Log.h"
21 #include "lldb/Utility/Scalar.h"
22 #include "lldb/Utility/Status.h"
23 #include "lldb/Utility/StreamString.h"
24 
25 #include "lldb/Target/ABI.h"
26 #include "lldb/Target/ExecutionContext.h"
27 #include "lldb/Target/Target.h"
28 #include "lldb/Target/Thread.h"
29 #include "lldb/Target/ThreadPlan.h"
30 #include "lldb/Target/ThreadPlanCallFunctionUsingABI.h"
31 
32 #include "llvm/IR/Constants.h"
33 #include "llvm/IR/DataLayout.h"
34 #include "llvm/IR/Function.h"
35 #include "llvm/IR/Instructions.h"
36 #include "llvm/IR/Intrinsics.h"
37 #include "llvm/IR/LLVMContext.h"
38 #include "llvm/IR/Module.h"
39 #include "llvm/IR/Operator.h"
40 #include "llvm/Support/raw_ostream.h"
41 
42 #include <map>
43 
44 using namespace llvm;
45 using lldb_private::LLDBLog;
46 
PrintValue(const Value * value,bool truncate=false)47 static std::string PrintValue(const Value *value, bool truncate = false) {
48   std::string s;
49   raw_string_ostream rso(s);
50   value->print(rso);
51   rso.flush();
52   if (truncate)
53     s.resize(s.length() - 1);
54 
55   size_t offset;
56   while ((offset = s.find('\n')) != s.npos)
57     s.erase(offset, 1);
58   while (s[0] == ' ' || s[0] == '\t')
59     s.erase(0, 1);
60 
61   return s;
62 }
63 
PrintType(const Type * type,bool truncate=false)64 static std::string PrintType(const Type *type, bool truncate = false) {
65   std::string s;
66   raw_string_ostream rso(s);
67   type->print(rso);
68   rso.flush();
69   if (truncate)
70     s.resize(s.length() - 1);
71   return s;
72 }
73 
CanIgnoreCall(const CallInst * call)74 static bool CanIgnoreCall(const CallInst *call) {
75   const llvm::Function *called_function = call->getCalledFunction();
76 
77   if (!called_function)
78     return false;
79 
80   if (called_function->isIntrinsic()) {
81     switch (called_function->getIntrinsicID()) {
82     default:
83       break;
84     case llvm::Intrinsic::dbg_declare:
85     case llvm::Intrinsic::dbg_value:
86       return true;
87     }
88   }
89 
90   return false;
91 }
92 
93 class InterpreterStackFrame {
94 public:
95   typedef std::map<const Value *, lldb::addr_t> ValueMap;
96 
97   ValueMap m_values;
98   DataLayout &m_target_data;
99   lldb_private::IRExecutionUnit &m_execution_unit;
100   const BasicBlock *m_bb = nullptr;
101   const BasicBlock *m_prev_bb = nullptr;
102   BasicBlock::const_iterator m_ii;
103   BasicBlock::const_iterator m_ie;
104 
105   lldb::addr_t m_frame_process_address;
106   size_t m_frame_size;
107   lldb::addr_t m_stack_pointer;
108 
109   lldb::ByteOrder m_byte_order;
110   size_t m_addr_byte_size;
111 
InterpreterStackFrame(DataLayout & target_data,lldb_private::IRExecutionUnit & execution_unit,lldb::addr_t stack_frame_bottom,lldb::addr_t stack_frame_top)112   InterpreterStackFrame(DataLayout &target_data,
113                         lldb_private::IRExecutionUnit &execution_unit,
114                         lldb::addr_t stack_frame_bottom,
115                         lldb::addr_t stack_frame_top)
116       : m_target_data(target_data), m_execution_unit(execution_unit) {
117     m_byte_order = (target_data.isLittleEndian() ? lldb::eByteOrderLittle
118                                                  : lldb::eByteOrderBig);
119     m_addr_byte_size = (target_data.getPointerSize(0));
120 
121     m_frame_process_address = stack_frame_bottom;
122     m_frame_size = stack_frame_top - stack_frame_bottom;
123     m_stack_pointer = stack_frame_top;
124   }
125 
126   ~InterpreterStackFrame() = default;
127 
Jump(const BasicBlock * bb)128   void Jump(const BasicBlock *bb) {
129     m_prev_bb = m_bb;
130     m_bb = bb;
131     m_ii = m_bb->begin();
132     m_ie = m_bb->end();
133   }
134 
SummarizeValue(const Value * value)135   std::string SummarizeValue(const Value *value) {
136     lldb_private::StreamString ss;
137 
138     ss.Printf("%s", PrintValue(value).c_str());
139 
140     ValueMap::iterator i = m_values.find(value);
141 
142     if (i != m_values.end()) {
143       lldb::addr_t addr = i->second;
144 
145       ss.Printf(" 0x%llx", (unsigned long long)addr);
146     }
147 
148     return std::string(ss.GetString());
149   }
150 
AssignToMatchType(lldb_private::Scalar & scalar,llvm::APInt value,Type * type)151   bool AssignToMatchType(lldb_private::Scalar &scalar, llvm::APInt value,
152                          Type *type) {
153     size_t type_size = m_target_data.getTypeStoreSize(type);
154 
155     if (type_size > 8)
156       return false;
157 
158     if (type_size != 1)
159       type_size = PowerOf2Ceil(type_size);
160 
161     scalar = value.zextOrTrunc(type_size * 8);
162     return true;
163   }
164 
EvaluateValue(lldb_private::Scalar & scalar,const Value * value,Module & module)165   bool EvaluateValue(lldb_private::Scalar &scalar, const Value *value,
166                      Module &module) {
167     const Constant *constant = dyn_cast<Constant>(value);
168 
169     if (constant) {
170       if (constant->getValueID() == Value::ConstantFPVal) {
171         if (auto *cfp = dyn_cast<ConstantFP>(constant)) {
172           if (cfp->getType()->isDoubleTy())
173             scalar = cfp->getValueAPF().convertToDouble();
174           else if (cfp->getType()->isFloatTy())
175             scalar = cfp->getValueAPF().convertToFloat();
176           else
177             return false;
178           return true;
179         }
180         return false;
181       }
182       APInt value_apint;
183 
184       if (!ResolveConstantValue(value_apint, constant))
185         return false;
186 
187       return AssignToMatchType(scalar, value_apint, value->getType());
188     }
189 
190     lldb::addr_t process_address = ResolveValue(value, module);
191     size_t value_size = m_target_data.getTypeStoreSize(value->getType());
192 
193     lldb_private::DataExtractor value_extractor;
194     lldb_private::Status extract_error;
195 
196     m_execution_unit.GetMemoryData(value_extractor, process_address,
197                                    value_size, extract_error);
198 
199     if (!extract_error.Success())
200       return false;
201 
202     lldb::offset_t offset = 0;
203     if (value_size <= 8) {
204       Type *ty = value->getType();
205       if (ty->isDoubleTy()) {
206         scalar = value_extractor.GetDouble(&offset);
207         return true;
208       } else if (ty->isFloatTy()) {
209         scalar = value_extractor.GetFloat(&offset);
210         return true;
211       } else {
212         uint64_t u64value = value_extractor.GetMaxU64(&offset, value_size);
213         return AssignToMatchType(scalar, llvm::APInt(64, u64value),
214                                  value->getType());
215       }
216     }
217 
218     return false;
219   }
220 
AssignValue(const Value * value,lldb_private::Scalar scalar,Module & module)221   bool AssignValue(const Value *value, lldb_private::Scalar scalar,
222                    Module &module) {
223     lldb::addr_t process_address = ResolveValue(value, module);
224 
225     if (process_address == LLDB_INVALID_ADDRESS)
226       return false;
227 
228     lldb_private::Scalar cast_scalar;
229     Type *vty = value->getType();
230     if (vty->isFloatTy() || vty->isDoubleTy()) {
231       cast_scalar = scalar;
232     } else {
233       scalar.MakeUnsigned();
234       if (!AssignToMatchType(cast_scalar, scalar.UInt128(llvm::APInt()),
235                              value->getType()))
236         return false;
237     }
238 
239     size_t value_byte_size = m_target_data.getTypeStoreSize(value->getType());
240 
241     lldb_private::DataBufferHeap buf(value_byte_size, 0);
242 
243     lldb_private::Status get_data_error;
244 
245     if (!cast_scalar.GetAsMemoryData(buf.GetBytes(), buf.GetByteSize(),
246                                      m_byte_order, get_data_error))
247       return false;
248 
249     lldb_private::Status write_error;
250 
251     m_execution_unit.WriteMemory(process_address, buf.GetBytes(),
252                                  buf.GetByteSize(), write_error);
253 
254     return write_error.Success();
255   }
256 
ResolveConstantValue(APInt & value,const Constant * constant)257   bool ResolveConstantValue(APInt &value, const Constant *constant) {
258     switch (constant->getValueID()) {
259     default:
260       break;
261     case Value::FunctionVal:
262       if (const Function *constant_func = dyn_cast<Function>(constant)) {
263         lldb_private::ConstString name(constant_func->getName());
264         bool missing_weak = false;
265         lldb::addr_t addr = m_execution_unit.FindSymbol(name, missing_weak);
266         if (addr == LLDB_INVALID_ADDRESS || missing_weak)
267           return false;
268         value = APInt(m_target_data.getPointerSizeInBits(), addr);
269         return true;
270       }
271       break;
272     case Value::ConstantIntVal:
273       if (const ConstantInt *constant_int = dyn_cast<ConstantInt>(constant)) {
274         value = constant_int->getValue();
275         return true;
276       }
277       break;
278     case Value::ConstantFPVal:
279       if (const ConstantFP *constant_fp = dyn_cast<ConstantFP>(constant)) {
280         value = constant_fp->getValueAPF().bitcastToAPInt();
281         return true;
282       }
283       break;
284     case Value::ConstantExprVal:
285       if (const ConstantExpr *constant_expr =
286               dyn_cast<ConstantExpr>(constant)) {
287         switch (constant_expr->getOpcode()) {
288         default:
289           return false;
290         case Instruction::IntToPtr:
291         case Instruction::PtrToInt:
292         case Instruction::BitCast:
293           return ResolveConstantValue(value, constant_expr->getOperand(0));
294         case Instruction::GetElementPtr: {
295           ConstantExpr::const_op_iterator op_cursor = constant_expr->op_begin();
296           ConstantExpr::const_op_iterator op_end = constant_expr->op_end();
297 
298           Constant *base = dyn_cast<Constant>(*op_cursor);
299 
300           if (!base)
301             return false;
302 
303           if (!ResolveConstantValue(value, base))
304             return false;
305 
306           op_cursor++;
307 
308           if (op_cursor == op_end)
309             return true; // no offset to apply!
310 
311           SmallVector<Value *, 8> indices(op_cursor, op_end);
312           Type *src_elem_ty =
313               cast<GEPOperator>(constant_expr)->getSourceElementType();
314 
315           // DataLayout::getIndexedOffsetInType assumes the indices are
316           // instances of ConstantInt.
317           uint64_t offset =
318               m_target_data.getIndexedOffsetInType(src_elem_ty, indices);
319 
320           const bool is_signed = true;
321           value += APInt(value.getBitWidth(), offset, is_signed);
322 
323           return true;
324         }
325         }
326       }
327       break;
328     case Value::ConstantPointerNullVal:
329       if (isa<ConstantPointerNull>(constant)) {
330         value = APInt(m_target_data.getPointerSizeInBits(), 0);
331         return true;
332       }
333       break;
334     }
335     return false;
336   }
337 
MakeArgument(const Argument * value,uint64_t address)338   bool MakeArgument(const Argument *value, uint64_t address) {
339     lldb::addr_t data_address = Malloc(value->getType());
340 
341     if (data_address == LLDB_INVALID_ADDRESS)
342       return false;
343 
344     lldb_private::Status write_error;
345 
346     m_execution_unit.WritePointerToMemory(data_address, address, write_error);
347 
348     if (!write_error.Success()) {
349       lldb_private::Status free_error;
350       m_execution_unit.Free(data_address, free_error);
351       return false;
352     }
353 
354     m_values[value] = data_address;
355 
356     lldb_private::Log *log(GetLog(LLDBLog::Expressions));
357 
358     if (log) {
359       LLDB_LOGF(log, "Made an allocation for argument %s",
360                 PrintValue(value).c_str());
361       LLDB_LOGF(log, "  Data region    : %llx", (unsigned long long)address);
362       LLDB_LOGF(log, "  Ref region     : %llx",
363                 (unsigned long long)data_address);
364     }
365 
366     return true;
367   }
368 
ResolveConstant(lldb::addr_t process_address,const Constant * constant)369   bool ResolveConstant(lldb::addr_t process_address, const Constant *constant) {
370     APInt resolved_value;
371 
372     if (!ResolveConstantValue(resolved_value, constant))
373       return false;
374 
375     size_t constant_size = m_target_data.getTypeStoreSize(constant->getType());
376     lldb_private::DataBufferHeap buf(constant_size, 0);
377 
378     lldb_private::Status get_data_error;
379 
380     lldb_private::Scalar resolved_scalar(
381         resolved_value.zextOrTrunc(llvm::NextPowerOf2(constant_size) * 8));
382     if (!resolved_scalar.GetAsMemoryData(buf.GetBytes(), buf.GetByteSize(),
383                                          m_byte_order, get_data_error))
384       return false;
385 
386     lldb_private::Status write_error;
387 
388     m_execution_unit.WriteMemory(process_address, buf.GetBytes(),
389                                  buf.GetByteSize(), write_error);
390 
391     return write_error.Success();
392   }
393 
Malloc(size_t size,uint8_t byte_alignment)394   lldb::addr_t Malloc(size_t size, uint8_t byte_alignment) {
395     lldb::addr_t ret = m_stack_pointer;
396 
397     ret -= size;
398     ret -= (ret % byte_alignment);
399 
400     if (ret < m_frame_process_address)
401       return LLDB_INVALID_ADDRESS;
402 
403     m_stack_pointer = ret;
404     return ret;
405   }
406 
Malloc(llvm::Type * type)407   lldb::addr_t Malloc(llvm::Type *type) {
408     lldb_private::Status alloc_error;
409 
410     return Malloc(m_target_data.getTypeAllocSize(type),
411                   m_target_data.getPrefTypeAlign(type).value());
412   }
413 
PrintData(lldb::addr_t addr,llvm::Type * type)414   std::string PrintData(lldb::addr_t addr, llvm::Type *type) {
415     size_t length = m_target_data.getTypeStoreSize(type);
416 
417     lldb_private::DataBufferHeap buf(length, 0);
418 
419     lldb_private::Status read_error;
420 
421     m_execution_unit.ReadMemory(buf.GetBytes(), addr, length, read_error);
422 
423     if (!read_error.Success())
424       return std::string("<couldn't read data>");
425 
426     lldb_private::StreamString ss;
427 
428     for (size_t i = 0; i < length; i++) {
429       if ((!(i & 0xf)) && i)
430         ss.Printf("%02hhx - ", buf.GetBytes()[i]);
431       else
432         ss.Printf("%02hhx ", buf.GetBytes()[i]);
433     }
434 
435     return std::string(ss.GetString());
436   }
437 
ResolveValue(const Value * value,Module & module)438   lldb::addr_t ResolveValue(const Value *value, Module &module) {
439     ValueMap::iterator i = m_values.find(value);
440 
441     if (i != m_values.end())
442       return i->second;
443 
444     // Fall back and allocate space [allocation type Alloca]
445 
446     lldb::addr_t data_address = Malloc(value->getType());
447 
448     if (const Constant *constant = dyn_cast<Constant>(value)) {
449       if (!ResolveConstant(data_address, constant)) {
450         lldb_private::Status free_error;
451         m_execution_unit.Free(data_address, free_error);
452         return LLDB_INVALID_ADDRESS;
453       }
454     }
455 
456     m_values[value] = data_address;
457     return data_address;
458   }
459 };
460 
461 static const char *unsupported_opcode_error =
462     "Interpreter doesn't handle one of the expression's opcodes";
463 static const char *unsupported_operand_error =
464     "Interpreter doesn't handle one of the expression's operands";
465 static const char *interpreter_internal_error =
466     "Interpreter encountered an internal error";
467 static const char *bad_value_error =
468     "Interpreter couldn't resolve a value during execution";
469 static const char *memory_allocation_error =
470     "Interpreter couldn't allocate memory";
471 static const char *memory_write_error = "Interpreter couldn't write to memory";
472 static const char *memory_read_error = "Interpreter couldn't read from memory";
473 static const char *infinite_loop_error = "Interpreter ran for too many cycles";
474 static const char *too_many_functions_error =
475     "Interpreter doesn't handle modules with multiple function bodies.";
476 
CanResolveConstant(llvm::Constant * constant)477 static bool CanResolveConstant(llvm::Constant *constant) {
478   switch (constant->getValueID()) {
479   default:
480     return false;
481   case Value::ConstantIntVal:
482   case Value::ConstantFPVal:
483   case Value::FunctionVal:
484     return true;
485   case Value::ConstantExprVal:
486     if (const ConstantExpr *constant_expr = dyn_cast<ConstantExpr>(constant)) {
487       switch (constant_expr->getOpcode()) {
488       default:
489         return false;
490       case Instruction::IntToPtr:
491       case Instruction::PtrToInt:
492       case Instruction::BitCast:
493         return CanResolveConstant(constant_expr->getOperand(0));
494       case Instruction::GetElementPtr: {
495         // Check that the base can be constant-resolved.
496         ConstantExpr::const_op_iterator op_cursor = constant_expr->op_begin();
497         Constant *base = dyn_cast<Constant>(*op_cursor);
498         if (!base || !CanResolveConstant(base))
499           return false;
500 
501         // Check that all other operands are just ConstantInt.
502         for (Value *op : make_range(constant_expr->op_begin() + 1,
503                                     constant_expr->op_end())) {
504           ConstantInt *constant_int = dyn_cast<ConstantInt>(op);
505           if (!constant_int)
506             return false;
507         }
508         return true;
509       }
510       }
511     } else {
512       return false;
513     }
514   case Value::ConstantPointerNullVal:
515     return true;
516   }
517 }
518 
CanInterpret(llvm::Module & module,llvm::Function & function,lldb_private::Status & error,const bool support_function_calls)519 bool IRInterpreter::CanInterpret(llvm::Module &module, llvm::Function &function,
520                                  lldb_private::Status &error,
521                                  const bool support_function_calls) {
522   lldb_private::Log *log(GetLog(LLDBLog::Expressions));
523 
524   bool saw_function_with_body = false;
525   for (Function &f : module) {
526     if (f.begin() != f.end()) {
527       if (saw_function_with_body) {
528         LLDB_LOGF(log, "More than one function in the module has a body");
529         error.SetErrorToGenericError();
530         error.SetErrorString(too_many_functions_error);
531         return false;
532       }
533       saw_function_with_body = true;
534       LLDB_LOGF(log, "Saw function with body: %s", f.getName().str().c_str());
535     }
536   }
537 
538   for (BasicBlock &bb : function) {
539     for (Instruction &ii : bb) {
540       switch (ii.getOpcode()) {
541       default: {
542         LLDB_LOGF(log, "Unsupported instruction: %s", PrintValue(&ii).c_str());
543         error.SetErrorToGenericError();
544         error.SetErrorString(unsupported_opcode_error);
545         return false;
546       }
547       case Instruction::Add:
548       case Instruction::Alloca:
549       case Instruction::BitCast:
550       case Instruction::Br:
551       case Instruction::PHI:
552         break;
553       case Instruction::Call: {
554         CallInst *call_inst = dyn_cast<CallInst>(&ii);
555 
556         if (!call_inst) {
557           error.SetErrorToGenericError();
558           error.SetErrorString(interpreter_internal_error);
559           return false;
560         }
561 
562         if (!CanIgnoreCall(call_inst) && !support_function_calls) {
563           LLDB_LOGF(log, "Unsupported instruction: %s",
564                     PrintValue(&ii).c_str());
565           error.SetErrorToGenericError();
566           error.SetErrorString(unsupported_opcode_error);
567           return false;
568         }
569       } break;
570       case Instruction::GetElementPtr:
571         break;
572       case Instruction::FCmp:
573       case Instruction::ICmp: {
574         CmpInst *cmp_inst = dyn_cast<CmpInst>(&ii);
575 
576         if (!cmp_inst) {
577           error.SetErrorToGenericError();
578           error.SetErrorString(interpreter_internal_error);
579           return false;
580         }
581 
582         switch (cmp_inst->getPredicate()) {
583         default: {
584           LLDB_LOGF(log, "Unsupported ICmp predicate: %s",
585                     PrintValue(&ii).c_str());
586 
587           error.SetErrorToGenericError();
588           error.SetErrorString(unsupported_opcode_error);
589           return false;
590         }
591         case CmpInst::FCMP_OEQ:
592         case CmpInst::ICMP_EQ:
593         case CmpInst::FCMP_UNE:
594         case CmpInst::ICMP_NE:
595         case CmpInst::FCMP_OGT:
596         case CmpInst::ICMP_UGT:
597         case CmpInst::FCMP_OGE:
598         case CmpInst::ICMP_UGE:
599         case CmpInst::FCMP_OLT:
600         case CmpInst::ICMP_ULT:
601         case CmpInst::FCMP_OLE:
602         case CmpInst::ICMP_ULE:
603         case CmpInst::ICMP_SGT:
604         case CmpInst::ICMP_SGE:
605         case CmpInst::ICMP_SLT:
606         case CmpInst::ICMP_SLE:
607           break;
608         }
609       } break;
610       case Instruction::And:
611       case Instruction::AShr:
612       case Instruction::IntToPtr:
613       case Instruction::PtrToInt:
614       case Instruction::Load:
615       case Instruction::LShr:
616       case Instruction::Mul:
617       case Instruction::Or:
618       case Instruction::Ret:
619       case Instruction::SDiv:
620       case Instruction::SExt:
621       case Instruction::Shl:
622       case Instruction::SRem:
623       case Instruction::Store:
624       case Instruction::Sub:
625       case Instruction::Trunc:
626       case Instruction::UDiv:
627       case Instruction::URem:
628       case Instruction::Xor:
629       case Instruction::ZExt:
630         break;
631       case Instruction::FAdd:
632       case Instruction::FSub:
633       case Instruction::FMul:
634       case Instruction::FDiv:
635         break;
636       }
637 
638       for (unsigned oi = 0, oe = ii.getNumOperands(); oi != oe; ++oi) {
639         Value *operand = ii.getOperand(oi);
640         Type *operand_type = operand->getType();
641 
642         switch (operand_type->getTypeID()) {
643         default:
644           break;
645         case Type::FixedVectorTyID:
646         case Type::ScalableVectorTyID: {
647           LLDB_LOGF(log, "Unsupported operand type: %s",
648                     PrintType(operand_type).c_str());
649           error.SetErrorString(unsupported_operand_error);
650           return false;
651         }
652         }
653 
654         // The IR interpreter currently doesn't know about
655         // 128-bit integers. As they're not that frequent,
656         // we can just fall back to the JIT rather than
657         // choking.
658         if (operand_type->getPrimitiveSizeInBits() > 64) {
659           LLDB_LOGF(log, "Unsupported operand type: %s",
660                     PrintType(operand_type).c_str());
661           error.SetErrorString(unsupported_operand_error);
662           return false;
663         }
664 
665         if (Constant *constant = llvm::dyn_cast<Constant>(operand)) {
666           if (!CanResolveConstant(constant)) {
667             LLDB_LOGF(log, "Unsupported constant: %s",
668                       PrintValue(constant).c_str());
669             error.SetErrorString(unsupported_operand_error);
670             return false;
671           }
672         }
673       }
674     }
675   }
676 
677   return true;
678 }
679 
Interpret(llvm::Module & module,llvm::Function & function,llvm::ArrayRef<lldb::addr_t> args,lldb_private::IRExecutionUnit & execution_unit,lldb_private::Status & error,lldb::addr_t stack_frame_bottom,lldb::addr_t stack_frame_top,lldb_private::ExecutionContext & exe_ctx)680 bool IRInterpreter::Interpret(llvm::Module &module, llvm::Function &function,
681                               llvm::ArrayRef<lldb::addr_t> args,
682                               lldb_private::IRExecutionUnit &execution_unit,
683                               lldb_private::Status &error,
684                               lldb::addr_t stack_frame_bottom,
685                               lldb::addr_t stack_frame_top,
686                               lldb_private::ExecutionContext &exe_ctx) {
687   lldb_private::Log *log(GetLog(LLDBLog::Expressions));
688 
689   if (log) {
690     std::string s;
691     raw_string_ostream oss(s);
692 
693     module.print(oss, nullptr);
694 
695     oss.flush();
696 
697     LLDB_LOGF(log, "Module as passed in to IRInterpreter::Interpret: \n\"%s\"",
698               s.c_str());
699   }
700 
701   DataLayout data_layout(&module);
702 
703   InterpreterStackFrame frame(data_layout, execution_unit, stack_frame_bottom,
704                               stack_frame_top);
705 
706   if (frame.m_frame_process_address == LLDB_INVALID_ADDRESS) {
707     error.SetErrorString("Couldn't allocate stack frame");
708   }
709 
710   int arg_index = 0;
711 
712   for (llvm::Function::arg_iterator ai = function.arg_begin(),
713                                     ae = function.arg_end();
714        ai != ae; ++ai, ++arg_index) {
715     if (args.size() <= static_cast<size_t>(arg_index)) {
716       error.SetErrorString("Not enough arguments passed in to function");
717       return false;
718     }
719 
720     lldb::addr_t ptr = args[arg_index];
721 
722     frame.MakeArgument(&*ai, ptr);
723   }
724 
725   uint32_t num_insts = 0;
726 
727   frame.Jump(&function.front());
728 
729   while (frame.m_ii != frame.m_ie && (++num_insts < 4096)) {
730     const Instruction *inst = &*frame.m_ii;
731 
732     LLDB_LOGF(log, "Interpreting %s", PrintValue(inst).c_str());
733 
734     switch (inst->getOpcode()) {
735     default:
736       break;
737 
738     case Instruction::Add:
739     case Instruction::Sub:
740     case Instruction::Mul:
741     case Instruction::SDiv:
742     case Instruction::UDiv:
743     case Instruction::SRem:
744     case Instruction::URem:
745     case Instruction::Shl:
746     case Instruction::LShr:
747     case Instruction::AShr:
748     case Instruction::And:
749     case Instruction::Or:
750     case Instruction::Xor:
751     case Instruction::FAdd:
752     case Instruction::FSub:
753     case Instruction::FMul:
754     case Instruction::FDiv: {
755       const BinaryOperator *bin_op = dyn_cast<BinaryOperator>(inst);
756 
757       if (!bin_op) {
758         LLDB_LOGF(
759             log,
760             "getOpcode() returns %s, but instruction is not a BinaryOperator",
761             inst->getOpcodeName());
762         error.SetErrorToGenericError();
763         error.SetErrorString(interpreter_internal_error);
764         return false;
765       }
766 
767       Value *lhs = inst->getOperand(0);
768       Value *rhs = inst->getOperand(1);
769 
770       lldb_private::Scalar L;
771       lldb_private::Scalar R;
772 
773       if (!frame.EvaluateValue(L, lhs, module)) {
774         LLDB_LOGF(log, "Couldn't evaluate %s", PrintValue(lhs).c_str());
775         error.SetErrorToGenericError();
776         error.SetErrorString(bad_value_error);
777         return false;
778       }
779 
780       if (!frame.EvaluateValue(R, rhs, module)) {
781         LLDB_LOGF(log, "Couldn't evaluate %s", PrintValue(rhs).c_str());
782         error.SetErrorToGenericError();
783         error.SetErrorString(bad_value_error);
784         return false;
785       }
786 
787       lldb_private::Scalar result;
788 
789       switch (inst->getOpcode()) {
790       default:
791         break;
792       case Instruction::Add:
793       case Instruction::FAdd:
794         result = L + R;
795         break;
796       case Instruction::Mul:
797       case Instruction::FMul:
798         result = L * R;
799         break;
800       case Instruction::Sub:
801       case Instruction::FSub:
802         result = L - R;
803         break;
804       case Instruction::SDiv:
805         L.MakeSigned();
806         R.MakeSigned();
807         result = L / R;
808         break;
809       case Instruction::UDiv:
810         L.MakeUnsigned();
811         R.MakeUnsigned();
812         result = L / R;
813         break;
814       case Instruction::FDiv:
815         result = L / R;
816         break;
817       case Instruction::SRem:
818         L.MakeSigned();
819         R.MakeSigned();
820         result = L % R;
821         break;
822       case Instruction::URem:
823         L.MakeUnsigned();
824         R.MakeUnsigned();
825         result = L % R;
826         break;
827       case Instruction::Shl:
828         result = L << R;
829         break;
830       case Instruction::AShr:
831         result = L >> R;
832         break;
833       case Instruction::LShr:
834         result = L;
835         result.ShiftRightLogical(R);
836         break;
837       case Instruction::And:
838         result = L & R;
839         break;
840       case Instruction::Or:
841         result = L | R;
842         break;
843       case Instruction::Xor:
844         result = L ^ R;
845         break;
846       }
847 
848       frame.AssignValue(inst, result, module);
849 
850       if (log) {
851         LLDB_LOGF(log, "Interpreted a %s", inst->getOpcodeName());
852         LLDB_LOGF(log, "  L : %s", frame.SummarizeValue(lhs).c_str());
853         LLDB_LOGF(log, "  R : %s", frame.SummarizeValue(rhs).c_str());
854         LLDB_LOGF(log, "  = : %s", frame.SummarizeValue(inst).c_str());
855       }
856     } break;
857     case Instruction::Alloca: {
858       const AllocaInst *alloca_inst = cast<AllocaInst>(inst);
859 
860       if (alloca_inst->isArrayAllocation()) {
861         LLDB_LOGF(log,
862                   "AllocaInsts are not handled if isArrayAllocation() is true");
863         error.SetErrorToGenericError();
864         error.SetErrorString(unsupported_opcode_error);
865         return false;
866       }
867 
868       // The semantics of Alloca are:
869       //   Create a region R of virtual memory of type T, backed by a data
870       //   buffer
871       //   Create a region P of virtual memory of type T*, backed by a data
872       //   buffer
873       //   Write the virtual address of R into P
874 
875       Type *T = alloca_inst->getAllocatedType();
876       Type *Tptr = alloca_inst->getType();
877 
878       lldb::addr_t R = frame.Malloc(T);
879 
880       if (R == LLDB_INVALID_ADDRESS) {
881         LLDB_LOGF(log, "Couldn't allocate memory for an AllocaInst");
882         error.SetErrorToGenericError();
883         error.SetErrorString(memory_allocation_error);
884         return false;
885       }
886 
887       lldb::addr_t P = frame.Malloc(Tptr);
888 
889       if (P == LLDB_INVALID_ADDRESS) {
890         LLDB_LOGF(log,
891                   "Couldn't allocate the result pointer for an AllocaInst");
892         error.SetErrorToGenericError();
893         error.SetErrorString(memory_allocation_error);
894         return false;
895       }
896 
897       lldb_private::Status write_error;
898 
899       execution_unit.WritePointerToMemory(P, R, write_error);
900 
901       if (!write_error.Success()) {
902         LLDB_LOGF(log, "Couldn't write the result pointer for an AllocaInst");
903         error.SetErrorToGenericError();
904         error.SetErrorString(memory_write_error);
905         lldb_private::Status free_error;
906         execution_unit.Free(P, free_error);
907         execution_unit.Free(R, free_error);
908         return false;
909       }
910 
911       frame.m_values[alloca_inst] = P;
912 
913       if (log) {
914         LLDB_LOGF(log, "Interpreted an AllocaInst");
915         LLDB_LOGF(log, "  R : 0x%" PRIx64, R);
916         LLDB_LOGF(log, "  P : 0x%" PRIx64, P);
917       }
918     } break;
919     case Instruction::BitCast:
920     case Instruction::ZExt: {
921       const CastInst *cast_inst = cast<CastInst>(inst);
922 
923       Value *source = cast_inst->getOperand(0);
924 
925       lldb_private::Scalar S;
926 
927       if (!frame.EvaluateValue(S, source, module)) {
928         LLDB_LOGF(log, "Couldn't evaluate %s", PrintValue(source).c_str());
929         error.SetErrorToGenericError();
930         error.SetErrorString(bad_value_error);
931         return false;
932       }
933 
934       frame.AssignValue(inst, S, module);
935     } break;
936     case Instruction::SExt: {
937       const CastInst *cast_inst = cast<CastInst>(inst);
938 
939       Value *source = cast_inst->getOperand(0);
940 
941       lldb_private::Scalar S;
942 
943       if (!frame.EvaluateValue(S, source, module)) {
944         LLDB_LOGF(log, "Couldn't evaluate %s", PrintValue(source).c_str());
945         error.SetErrorToGenericError();
946         error.SetErrorString(bad_value_error);
947         return false;
948       }
949 
950       S.MakeSigned();
951 
952       lldb_private::Scalar S_signextend(S.SLongLong());
953 
954       frame.AssignValue(inst, S_signextend, module);
955     } break;
956     case Instruction::Br: {
957       const BranchInst *br_inst = cast<BranchInst>(inst);
958 
959       if (br_inst->isConditional()) {
960         Value *condition = br_inst->getCondition();
961 
962         lldb_private::Scalar C;
963 
964         if (!frame.EvaluateValue(C, condition, module)) {
965           LLDB_LOGF(log, "Couldn't evaluate %s", PrintValue(condition).c_str());
966           error.SetErrorToGenericError();
967           error.SetErrorString(bad_value_error);
968           return false;
969         }
970 
971         if (!C.IsZero())
972           frame.Jump(br_inst->getSuccessor(0));
973         else
974           frame.Jump(br_inst->getSuccessor(1));
975 
976         if (log) {
977           LLDB_LOGF(log, "Interpreted a BrInst with a condition");
978           LLDB_LOGF(log, "  cond : %s",
979                     frame.SummarizeValue(condition).c_str());
980         }
981       } else {
982         frame.Jump(br_inst->getSuccessor(0));
983 
984         if (log) {
985           LLDB_LOGF(log, "Interpreted a BrInst with no condition");
986         }
987       }
988     }
989       continue;
990     case Instruction::PHI: {
991       const PHINode *phi_inst = cast<PHINode>(inst);
992       if (!frame.m_prev_bb) {
993         LLDB_LOGF(log,
994                   "Encountered PHI node without having jumped from another "
995                   "basic block");
996         error.SetErrorToGenericError();
997         error.SetErrorString(interpreter_internal_error);
998         return false;
999       }
1000 
1001       Value *value = phi_inst->getIncomingValueForBlock(frame.m_prev_bb);
1002       lldb_private::Scalar result;
1003       if (!frame.EvaluateValue(result, value, module)) {
1004         LLDB_LOGF(log, "Couldn't evaluate %s", PrintValue(value).c_str());
1005         error.SetErrorToGenericError();
1006         error.SetErrorString(bad_value_error);
1007         return false;
1008       }
1009       frame.AssignValue(inst, result, module);
1010 
1011       if (log) {
1012         LLDB_LOGF(log, "Interpreted a %s", inst->getOpcodeName());
1013         LLDB_LOGF(log, "  Incoming value : %s",
1014                   frame.SummarizeValue(value).c_str());
1015       }
1016     } break;
1017     case Instruction::GetElementPtr: {
1018       const GetElementPtrInst *gep_inst = cast<GetElementPtrInst>(inst);
1019 
1020       const Value *pointer_operand = gep_inst->getPointerOperand();
1021       Type *src_elem_ty = gep_inst->getSourceElementType();
1022 
1023       lldb_private::Scalar P;
1024 
1025       if (!frame.EvaluateValue(P, pointer_operand, module)) {
1026         LLDB_LOGF(log, "Couldn't evaluate %s",
1027                   PrintValue(pointer_operand).c_str());
1028         error.SetErrorToGenericError();
1029         error.SetErrorString(bad_value_error);
1030         return false;
1031       }
1032 
1033       typedef SmallVector<Value *, 8> IndexVector;
1034       typedef IndexVector::iterator IndexIterator;
1035 
1036       SmallVector<Value *, 8> indices(gep_inst->idx_begin(),
1037                                       gep_inst->idx_end());
1038 
1039       SmallVector<Value *, 8> const_indices;
1040 
1041       for (IndexIterator ii = indices.begin(), ie = indices.end(); ii != ie;
1042            ++ii) {
1043         ConstantInt *constant_index = dyn_cast<ConstantInt>(*ii);
1044 
1045         if (!constant_index) {
1046           lldb_private::Scalar I;
1047 
1048           if (!frame.EvaluateValue(I, *ii, module)) {
1049             LLDB_LOGF(log, "Couldn't evaluate %s", PrintValue(*ii).c_str());
1050             error.SetErrorToGenericError();
1051             error.SetErrorString(bad_value_error);
1052             return false;
1053           }
1054 
1055           LLDB_LOGF(log, "Evaluated constant index %s as %llu",
1056                     PrintValue(*ii).c_str(), I.ULongLong(LLDB_INVALID_ADDRESS));
1057 
1058           constant_index = cast<ConstantInt>(ConstantInt::get(
1059               (*ii)->getType(), I.ULongLong(LLDB_INVALID_ADDRESS)));
1060         }
1061 
1062         const_indices.push_back(constant_index);
1063       }
1064 
1065       uint64_t offset =
1066           data_layout.getIndexedOffsetInType(src_elem_ty, const_indices);
1067 
1068       lldb_private::Scalar Poffset = P + offset;
1069 
1070       frame.AssignValue(inst, Poffset, module);
1071 
1072       if (log) {
1073         LLDB_LOGF(log, "Interpreted a GetElementPtrInst");
1074         LLDB_LOGF(log, "  P       : %s",
1075                   frame.SummarizeValue(pointer_operand).c_str());
1076         LLDB_LOGF(log, "  Poffset : %s", frame.SummarizeValue(inst).c_str());
1077       }
1078     } break;
1079     case Instruction::FCmp:
1080     case Instruction::ICmp: {
1081       const CmpInst *icmp_inst = cast<CmpInst>(inst);
1082 
1083       CmpInst::Predicate predicate = icmp_inst->getPredicate();
1084 
1085       Value *lhs = inst->getOperand(0);
1086       Value *rhs = inst->getOperand(1);
1087 
1088       lldb_private::Scalar L;
1089       lldb_private::Scalar R;
1090 
1091       if (!frame.EvaluateValue(L, lhs, module)) {
1092         LLDB_LOGF(log, "Couldn't evaluate %s", PrintValue(lhs).c_str());
1093         error.SetErrorToGenericError();
1094         error.SetErrorString(bad_value_error);
1095         return false;
1096       }
1097 
1098       if (!frame.EvaluateValue(R, rhs, module)) {
1099         LLDB_LOGF(log, "Couldn't evaluate %s", PrintValue(rhs).c_str());
1100         error.SetErrorToGenericError();
1101         error.SetErrorString(bad_value_error);
1102         return false;
1103       }
1104 
1105       lldb_private::Scalar result;
1106 
1107       switch (predicate) {
1108       default:
1109         return false;
1110       case CmpInst::ICMP_EQ:
1111       case CmpInst::FCMP_OEQ:
1112         result = (L == R);
1113         break;
1114       case CmpInst::ICMP_NE:
1115       case CmpInst::FCMP_UNE:
1116         result = (L != R);
1117         break;
1118       case CmpInst::ICMP_UGT:
1119         L.MakeUnsigned();
1120         R.MakeUnsigned();
1121         result = (L > R);
1122         break;
1123       case CmpInst::ICMP_UGE:
1124         L.MakeUnsigned();
1125         R.MakeUnsigned();
1126         result = (L >= R);
1127         break;
1128       case CmpInst::FCMP_OGE:
1129         result = (L >= R);
1130         break;
1131       case CmpInst::FCMP_OGT:
1132         result = (L > R);
1133         break;
1134       case CmpInst::ICMP_ULT:
1135         L.MakeUnsigned();
1136         R.MakeUnsigned();
1137         result = (L < R);
1138         break;
1139       case CmpInst::FCMP_OLT:
1140         result = (L < R);
1141         break;
1142       case CmpInst::ICMP_ULE:
1143         L.MakeUnsigned();
1144         R.MakeUnsigned();
1145         result = (L <= R);
1146         break;
1147       case CmpInst::FCMP_OLE:
1148         result = (L <= R);
1149         break;
1150       case CmpInst::ICMP_SGT:
1151         L.MakeSigned();
1152         R.MakeSigned();
1153         result = (L > R);
1154         break;
1155       case CmpInst::ICMP_SGE:
1156         L.MakeSigned();
1157         R.MakeSigned();
1158         result = (L >= R);
1159         break;
1160       case CmpInst::ICMP_SLT:
1161         L.MakeSigned();
1162         R.MakeSigned();
1163         result = (L < R);
1164         break;
1165       case CmpInst::ICMP_SLE:
1166         L.MakeSigned();
1167         R.MakeSigned();
1168         result = (L <= R);
1169         break;
1170       }
1171 
1172       frame.AssignValue(inst, result, module);
1173 
1174       if (log) {
1175         LLDB_LOGF(log, "Interpreted an ICmpInst");
1176         LLDB_LOGF(log, "  L : %s", frame.SummarizeValue(lhs).c_str());
1177         LLDB_LOGF(log, "  R : %s", frame.SummarizeValue(rhs).c_str());
1178         LLDB_LOGF(log, "  = : %s", frame.SummarizeValue(inst).c_str());
1179       }
1180     } break;
1181     case Instruction::IntToPtr: {
1182       const IntToPtrInst *int_to_ptr_inst = cast<IntToPtrInst>(inst);
1183 
1184       Value *src_operand = int_to_ptr_inst->getOperand(0);
1185 
1186       lldb_private::Scalar I;
1187 
1188       if (!frame.EvaluateValue(I, src_operand, module)) {
1189         LLDB_LOGF(log, "Couldn't evaluate %s", PrintValue(src_operand).c_str());
1190         error.SetErrorToGenericError();
1191         error.SetErrorString(bad_value_error);
1192         return false;
1193       }
1194 
1195       frame.AssignValue(inst, I, module);
1196 
1197       if (log) {
1198         LLDB_LOGF(log, "Interpreted an IntToPtr");
1199         LLDB_LOGF(log, "  Src : %s", frame.SummarizeValue(src_operand).c_str());
1200         LLDB_LOGF(log, "  =   : %s", frame.SummarizeValue(inst).c_str());
1201       }
1202     } break;
1203     case Instruction::PtrToInt: {
1204       const PtrToIntInst *ptr_to_int_inst = cast<PtrToIntInst>(inst);
1205 
1206       Value *src_operand = ptr_to_int_inst->getOperand(0);
1207 
1208       lldb_private::Scalar I;
1209 
1210       if (!frame.EvaluateValue(I, src_operand, module)) {
1211         LLDB_LOGF(log, "Couldn't evaluate %s", PrintValue(src_operand).c_str());
1212         error.SetErrorToGenericError();
1213         error.SetErrorString(bad_value_error);
1214         return false;
1215       }
1216 
1217       frame.AssignValue(inst, I, module);
1218 
1219       if (log) {
1220         LLDB_LOGF(log, "Interpreted a PtrToInt");
1221         LLDB_LOGF(log, "  Src : %s", frame.SummarizeValue(src_operand).c_str());
1222         LLDB_LOGF(log, "  =   : %s", frame.SummarizeValue(inst).c_str());
1223       }
1224     } break;
1225     case Instruction::Trunc: {
1226       const TruncInst *trunc_inst = cast<TruncInst>(inst);
1227 
1228       Value *src_operand = trunc_inst->getOperand(0);
1229 
1230       lldb_private::Scalar I;
1231 
1232       if (!frame.EvaluateValue(I, src_operand, module)) {
1233         LLDB_LOGF(log, "Couldn't evaluate %s", PrintValue(src_operand).c_str());
1234         error.SetErrorToGenericError();
1235         error.SetErrorString(bad_value_error);
1236         return false;
1237       }
1238 
1239       frame.AssignValue(inst, I, module);
1240 
1241       if (log) {
1242         LLDB_LOGF(log, "Interpreted a Trunc");
1243         LLDB_LOGF(log, "  Src : %s", frame.SummarizeValue(src_operand).c_str());
1244         LLDB_LOGF(log, "  =   : %s", frame.SummarizeValue(inst).c_str());
1245       }
1246     } break;
1247     case Instruction::Load: {
1248       const LoadInst *load_inst = cast<LoadInst>(inst);
1249 
1250       // The semantics of Load are:
1251       //   Create a region D that will contain the loaded data
1252       //   Resolve the region P containing a pointer
1253       //   Dereference P to get the region R that the data should be loaded from
1254       //   Transfer a unit of type type(D) from R to D
1255 
1256       const Value *pointer_operand = load_inst->getPointerOperand();
1257 
1258       lldb::addr_t D = frame.ResolveValue(load_inst, module);
1259       lldb::addr_t P = frame.ResolveValue(pointer_operand, module);
1260 
1261       if (D == LLDB_INVALID_ADDRESS) {
1262         LLDB_LOGF(log, "LoadInst's value doesn't resolve to anything");
1263         error.SetErrorToGenericError();
1264         error.SetErrorString(bad_value_error);
1265         return false;
1266       }
1267 
1268       if (P == LLDB_INVALID_ADDRESS) {
1269         LLDB_LOGF(log, "LoadInst's pointer doesn't resolve to anything");
1270         error.SetErrorToGenericError();
1271         error.SetErrorString(bad_value_error);
1272         return false;
1273       }
1274 
1275       lldb::addr_t R;
1276       lldb_private::Status read_error;
1277       execution_unit.ReadPointerFromMemory(&R, P, read_error);
1278 
1279       if (!read_error.Success()) {
1280         LLDB_LOGF(log, "Couldn't read the address to be loaded for a LoadInst");
1281         error.SetErrorToGenericError();
1282         error.SetErrorString(memory_read_error);
1283         return false;
1284       }
1285 
1286       Type *target_ty = load_inst->getType();
1287       size_t target_size = data_layout.getTypeStoreSize(target_ty);
1288       lldb_private::DataBufferHeap buffer(target_size, 0);
1289 
1290       read_error.Clear();
1291       execution_unit.ReadMemory(buffer.GetBytes(), R, buffer.GetByteSize(),
1292                                 read_error);
1293       if (!read_error.Success()) {
1294         LLDB_LOGF(log, "Couldn't read from a region on behalf of a LoadInst");
1295         error.SetErrorToGenericError();
1296         error.SetErrorString(memory_read_error);
1297         return false;
1298       }
1299 
1300       lldb_private::Status write_error;
1301       execution_unit.WriteMemory(D, buffer.GetBytes(), buffer.GetByteSize(),
1302                                  write_error);
1303       if (!write_error.Success()) {
1304         LLDB_LOGF(log, "Couldn't write to a region on behalf of a LoadInst");
1305         error.SetErrorToGenericError();
1306         error.SetErrorString(memory_write_error);
1307         return false;
1308       }
1309 
1310       if (log) {
1311         LLDB_LOGF(log, "Interpreted a LoadInst");
1312         LLDB_LOGF(log, "  P : 0x%" PRIx64, P);
1313         LLDB_LOGF(log, "  R : 0x%" PRIx64, R);
1314         LLDB_LOGF(log, "  D : 0x%" PRIx64, D);
1315       }
1316     } break;
1317     case Instruction::Ret: {
1318       return true;
1319     }
1320     case Instruction::Store: {
1321       const StoreInst *store_inst = cast<StoreInst>(inst);
1322 
1323       // The semantics of Store are:
1324       //   Resolve the region D containing the data to be stored
1325       //   Resolve the region P containing a pointer
1326       //   Dereference P to get the region R that the data should be stored in
1327       //   Transfer a unit of type type(D) from D to R
1328 
1329       const Value *value_operand = store_inst->getValueOperand();
1330       const Value *pointer_operand = store_inst->getPointerOperand();
1331 
1332       lldb::addr_t D = frame.ResolveValue(value_operand, module);
1333       lldb::addr_t P = frame.ResolveValue(pointer_operand, module);
1334 
1335       if (D == LLDB_INVALID_ADDRESS) {
1336         LLDB_LOGF(log, "StoreInst's value doesn't resolve to anything");
1337         error.SetErrorToGenericError();
1338         error.SetErrorString(bad_value_error);
1339         return false;
1340       }
1341 
1342       if (P == LLDB_INVALID_ADDRESS) {
1343         LLDB_LOGF(log, "StoreInst's pointer doesn't resolve to anything");
1344         error.SetErrorToGenericError();
1345         error.SetErrorString(bad_value_error);
1346         return false;
1347       }
1348 
1349       lldb::addr_t R;
1350       lldb_private::Status read_error;
1351       execution_unit.ReadPointerFromMemory(&R, P, read_error);
1352 
1353       if (!read_error.Success()) {
1354         LLDB_LOGF(log, "Couldn't read the address to be loaded for a LoadInst");
1355         error.SetErrorToGenericError();
1356         error.SetErrorString(memory_read_error);
1357         return false;
1358       }
1359 
1360       Type *target_ty = value_operand->getType();
1361       size_t target_size = data_layout.getTypeStoreSize(target_ty);
1362       lldb_private::DataBufferHeap buffer(target_size, 0);
1363 
1364       read_error.Clear();
1365       execution_unit.ReadMemory(buffer.GetBytes(), D, buffer.GetByteSize(),
1366                                 read_error);
1367       if (!read_error.Success()) {
1368         LLDB_LOGF(log, "Couldn't read from a region on behalf of a StoreInst");
1369         error.SetErrorToGenericError();
1370         error.SetErrorString(memory_read_error);
1371         return false;
1372       }
1373 
1374       lldb_private::Status write_error;
1375       execution_unit.WriteMemory(R, buffer.GetBytes(), buffer.GetByteSize(),
1376                                  write_error);
1377       if (!write_error.Success()) {
1378         LLDB_LOGF(log, "Couldn't write to a region on behalf of a StoreInst");
1379         error.SetErrorToGenericError();
1380         error.SetErrorString(memory_write_error);
1381         return false;
1382       }
1383 
1384       if (log) {
1385         LLDB_LOGF(log, "Interpreted a StoreInst");
1386         LLDB_LOGF(log, "  D : 0x%" PRIx64, D);
1387         LLDB_LOGF(log, "  P : 0x%" PRIx64, P);
1388         LLDB_LOGF(log, "  R : 0x%" PRIx64, R);
1389       }
1390     } break;
1391     case Instruction::Call: {
1392       const CallInst *call_inst = cast<CallInst>(inst);
1393 
1394       if (CanIgnoreCall(call_inst))
1395         break;
1396 
1397       // Get the return type
1398       llvm::Type *returnType = call_inst->getType();
1399       if (returnType == nullptr) {
1400         error.SetErrorToGenericError();
1401         error.SetErrorString("unable to access return type");
1402         return false;
1403       }
1404 
1405       // Work with void, integer and pointer return types
1406       if (!returnType->isVoidTy() && !returnType->isIntegerTy() &&
1407           !returnType->isPointerTy()) {
1408         error.SetErrorToGenericError();
1409         error.SetErrorString("return type is not supported");
1410         return false;
1411       }
1412 
1413       // Check we can actually get a thread
1414       if (exe_ctx.GetThreadPtr() == nullptr) {
1415         error.SetErrorToGenericError();
1416         error.SetErrorString("unable to acquire thread");
1417         return false;
1418       }
1419 
1420       // Make sure we have a valid process
1421       if (!exe_ctx.GetProcessPtr()) {
1422         error.SetErrorToGenericError();
1423         error.SetErrorString("unable to get the process");
1424         return false;
1425       }
1426 
1427       // Find the address of the callee function
1428       lldb_private::Scalar I;
1429       const llvm::Value *val = call_inst->getCalledOperand();
1430 
1431       if (!frame.EvaluateValue(I, val, module)) {
1432         error.SetErrorToGenericError();
1433         error.SetErrorString("unable to get address of function");
1434         return false;
1435       }
1436       lldb_private::Address funcAddr(I.ULongLong(LLDB_INVALID_ADDRESS));
1437 
1438       lldb_private::DiagnosticManager diagnostics;
1439       lldb_private::EvaluateExpressionOptions options;
1440 
1441       llvm::FunctionType *prototype = call_inst->getFunctionType();
1442 
1443       // Find number of arguments
1444       const int numArgs = call_inst->arg_size();
1445 
1446       // We work with a fixed array of 16 arguments which is our upper limit
1447       static lldb_private::ABI::CallArgument rawArgs[16];
1448       if (numArgs >= 16) {
1449         error.SetErrorToGenericError();
1450         error.SetErrorString("function takes too many arguments");
1451         return false;
1452       }
1453 
1454       // Push all function arguments to the argument list that will be passed
1455       // to the call function thread plan
1456       for (int i = 0; i < numArgs; i++) {
1457         // Get details of this argument
1458         llvm::Value *arg_op = call_inst->getArgOperand(i);
1459         llvm::Type *arg_ty = arg_op->getType();
1460 
1461         // Ensure that this argument is an supported type
1462         if (!arg_ty->isIntegerTy() && !arg_ty->isPointerTy()) {
1463           error.SetErrorToGenericError();
1464           error.SetErrorStringWithFormat("argument %d must be integer type", i);
1465           return false;
1466         }
1467 
1468         // Extract the arguments value
1469         lldb_private::Scalar tmp_op = 0;
1470         if (!frame.EvaluateValue(tmp_op, arg_op, module)) {
1471           error.SetErrorToGenericError();
1472           error.SetErrorStringWithFormat("unable to evaluate argument %d", i);
1473           return false;
1474         }
1475 
1476         // Check if this is a string literal or constant string pointer
1477         if (arg_ty->isPointerTy()) {
1478           lldb::addr_t addr = tmp_op.ULongLong();
1479           size_t dataSize = 0;
1480 
1481           bool Success = execution_unit.GetAllocSize(addr, dataSize);
1482           (void)Success;
1483           assert(Success &&
1484                  "unable to locate host data for transfer to device");
1485           // Create the required buffer
1486           rawArgs[i].size = dataSize;
1487           rawArgs[i].data_up.reset(new uint8_t[dataSize + 1]);
1488 
1489           // Read string from host memory
1490           execution_unit.ReadMemory(rawArgs[i].data_up.get(), addr, dataSize,
1491                                     error);
1492           assert(!error.Fail() &&
1493                  "we have failed to read the string from memory");
1494 
1495           // Add null terminator
1496           rawArgs[i].data_up[dataSize] = '\0';
1497           rawArgs[i].type = lldb_private::ABI::CallArgument::HostPointer;
1498         } else /* if ( arg_ty->isPointerTy() ) */
1499         {
1500           rawArgs[i].type = lldb_private::ABI::CallArgument::TargetValue;
1501           // Get argument size in bytes
1502           rawArgs[i].size = arg_ty->getIntegerBitWidth() / 8;
1503           // Push value into argument list for thread plan
1504           rawArgs[i].value = tmp_op.ULongLong();
1505         }
1506       }
1507 
1508       // Pack the arguments into an llvm::array
1509       llvm::ArrayRef<lldb_private::ABI::CallArgument> args(rawArgs, numArgs);
1510 
1511       // Setup a thread plan to call the target function
1512       lldb::ThreadPlanSP call_plan_sp(
1513           new lldb_private::ThreadPlanCallFunctionUsingABI(
1514               exe_ctx.GetThreadRef(), funcAddr, *prototype, *returnType, args,
1515               options));
1516 
1517       // Check if the plan is valid
1518       lldb_private::StreamString ss;
1519       if (!call_plan_sp || !call_plan_sp->ValidatePlan(&ss)) {
1520         error.SetErrorToGenericError();
1521         error.SetErrorStringWithFormat(
1522             "unable to make ThreadPlanCallFunctionUsingABI for 0x%llx",
1523             I.ULongLong());
1524         return false;
1525       }
1526 
1527       exe_ctx.GetProcessPtr()->SetRunningUserExpression(true);
1528 
1529       // Execute the actual function call thread plan
1530       lldb::ExpressionResults res = exe_ctx.GetProcessRef().RunThreadPlan(
1531           exe_ctx, call_plan_sp, options, diagnostics);
1532 
1533       // Check that the thread plan completed successfully
1534       if (res != lldb::ExpressionResults::eExpressionCompleted) {
1535         error.SetErrorToGenericError();
1536         error.SetErrorString("ThreadPlanCallFunctionUsingABI failed");
1537         return false;
1538       }
1539 
1540       exe_ctx.GetProcessPtr()->SetRunningUserExpression(false);
1541 
1542       // Void return type
1543       if (returnType->isVoidTy()) {
1544         // Cant assign to void types, so we leave the frame untouched
1545       } else
1546           // Integer or pointer return type
1547           if (returnType->isIntegerTy() || returnType->isPointerTy()) {
1548         // Get the encapsulated return value
1549         lldb::ValueObjectSP retVal = call_plan_sp.get()->GetReturnValueObject();
1550 
1551         lldb_private::Scalar returnVal = -1;
1552         lldb_private::ValueObject *vobj = retVal.get();
1553 
1554         // Check if the return value is valid
1555         if (vobj == nullptr || !retVal) {
1556           error.SetErrorToGenericError();
1557           error.SetErrorString("unable to get the return value");
1558           return false;
1559         }
1560 
1561         // Extract the return value as a integer
1562         lldb_private::Value &value = vobj->GetValue();
1563         returnVal = value.GetScalar();
1564 
1565         // Push the return value as the result
1566         frame.AssignValue(inst, returnVal, module);
1567       }
1568     } break;
1569     }
1570 
1571     ++frame.m_ii;
1572   }
1573 
1574   if (num_insts >= 4096) {
1575     error.SetErrorToGenericError();
1576     error.SetErrorString(infinite_loop_error);
1577     return false;
1578   }
1579 
1580   return false;
1581 }
1582