LLVM  12.0.0git
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1 //===-- Interpreter.h ------------------------------------------*- C++ -*--===//
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 // This header file defines the interpreter structure
10 //
11 //===----------------------------------------------------------------------===//
18 #include "llvm/IR/DataLayout.h"
19 #include "llvm/IR/Function.h"
20 #include "llvm/IR/InstVisitor.h"
21 #include "llvm/Support/DataTypes.h"
24 namespace llvm {
26 class IntrinsicLowering;
27 template<typename T> class generic_gep_type_iterator;
28 class ConstantExpr;
29 typedef generic_gep_type_iterator<User::const_op_iterator> gep_type_iterator;
32 // AllocaHolder - Object to track all of the blocks of memory allocated by
33 // alloca. When the function returns, this object is popped off the execution
34 // stack, which causes the dtor to be run, which frees all the alloca'd memory.
35 //
36 class AllocaHolder {
37  std::vector<void *> Allocations;
39 public:
42  // Make this type move-only.
43  AllocaHolder(AllocaHolder &&) = default;
44  AllocaHolder &operator=(AllocaHolder &&RHS) = default;
47  for (void *Allocation : Allocations)
48  free(Allocation);
49  }
51  void add(void *Mem) { Allocations.push_back(Mem); }
52 };
54 typedef std::vector<GenericValue> ValuePlaneTy;
56 // ExecutionContext struct - This struct represents one stack frame currently
57 // executing.
58 //
60  Function *CurFunction;// The currently executing function
61  BasicBlock *CurBB; // The currently executing BB
62  BasicBlock::iterator CurInst; // The next instruction to execute
63  CallBase *Caller; // Holds the call that called subframes.
64  // NULL if main func or debugger invoked fn
65  std::map<Value *, GenericValue> Values; // LLVM values used in this invocation
66  std::vector<GenericValue> VarArgs; // Values passed through an ellipsis
67  AllocaHolder Allocas; // Track memory allocated by alloca
69  ExecutionContext() : CurFunction(nullptr), CurBB(nullptr), CurInst(nullptr) {}
70 };
72 // Interpreter - This class represents the entirety of the interpreter.
73 //
74 class Interpreter : public ExecutionEngine, public InstVisitor<Interpreter> {
75  GenericValue ExitValue; // The return value of the called function
78  // The runtime stack of executing code. The top of the stack is the current
79  // function record.
80  std::vector<ExecutionContext> ECStack;
82  // AtExitHandlers - List of functions to call when the program exits,
83  // registered with the atexit() library function.
84  std::vector<Function*> AtExitHandlers;
86 public:
87  explicit Interpreter(std::unique_ptr<Module> M);
88  ~Interpreter() override;
90  /// runAtExitHandlers - Run any functions registered by the program's calls to
91  /// atexit(3), which we intercept and store in AtExitHandlers.
92  ///
93  void runAtExitHandlers();
95  static void Register() {
97  }
99  /// Create an interpreter ExecutionEngine.
100  ///
101  static ExecutionEngine *create(std::unique_ptr<Module> M,
102  std::string *ErrorStr = nullptr);
104  /// run - Start execution with the specified function and arguments.
105  ///
107  ArrayRef<GenericValue> ArgValues) override;
110  bool AbortOnFailure = true) override {
111  // FIXME: not implemented.
112  return nullptr;
113  }
115  // Methods used to execute code:
116  // Place a call on the stack
118  void run(); // Execute instructions until nothing left to do
120  // Opcode Implementations
128  void visitICmpInst(ICmpInst &I);
129  void visitFCmpInst(FCmpInst &I);
131  void visitLoadInst(LoadInst &I);
132  void visitStoreInst(StoreInst &I);
134  void visitPHINode(PHINode &PN) {
135  llvm_unreachable("PHI nodes already handled!");
136  }
137  void visitTruncInst(TruncInst &I);
138  void visitZExtInst(ZExtInst &I);
139  void visitSExtInst(SExtInst &I);
141  void visitFPExtInst(FPExtInst &I);
152  void visitVAEndInst(VAEndInst &I);
155  void visitCallBase(CallBase &I);
158  void visitShl(BinaryOperator &I);
159  void visitLShr(BinaryOperator &I);
160  void visitAShr(BinaryOperator &I);
162  void visitVAArgInst(VAArgInst &I);
171  errs() << I << "\n";
172  llvm_unreachable("Instruction not interpretable yet!");
173  }
176  ArrayRef<GenericValue> ArgVals);
177  void exitCalled(GenericValue GV);
180  AtExitHandlers.push_back(F);
181  }
184  return &(ECStack.back ().VarArgs[0]);
185  }
187 private: // Helper functions
188  GenericValue executeGEPOperation(Value *Ptr, gep_type_iterator I,
191  // SwitchToNewBasicBlock - Start execution in a new basic block and run any
192  // PHI nodes in the top of the block. This is used for intraprocedural
193  // control flow.
194  //
195  void SwitchToNewBasicBlock(BasicBlock *Dest, ExecutionContext &SF);
197  void *getPointerToFunction(Function *F) override { return (void*)F; }
199  void initializeExecutionEngine() { }
200  void initializeExternalFunctions();
201  GenericValue getConstantExprValue(ConstantExpr *CE, ExecutionContext &SF);
202  GenericValue getOperandValue(Value *V, ExecutionContext &SF);
203  GenericValue executeTruncInst(Value *SrcVal, Type *DstTy,
204  ExecutionContext &SF);
205  GenericValue executeSExtInst(Value *SrcVal, Type *DstTy,
206  ExecutionContext &SF);
207  GenericValue executeZExtInst(Value *SrcVal, Type *DstTy,
208  ExecutionContext &SF);
209  GenericValue executeFPTruncInst(Value *SrcVal, Type *DstTy,
210  ExecutionContext &SF);
211  GenericValue executeFPExtInst(Value *SrcVal, Type *DstTy,
212  ExecutionContext &SF);
213  GenericValue executeFPToUIInst(Value *SrcVal, Type *DstTy,
214  ExecutionContext &SF);
215  GenericValue executeFPToSIInst(Value *SrcVal, Type *DstTy,
216  ExecutionContext &SF);
217  GenericValue executeUIToFPInst(Value *SrcVal, Type *DstTy,
218  ExecutionContext &SF);
219  GenericValue executeSIToFPInst(Value *SrcVal, Type *DstTy,
220  ExecutionContext &SF);
221  GenericValue executePtrToIntInst(Value *SrcVal, Type *DstTy,
222  ExecutionContext &SF);
223  GenericValue executeIntToPtrInst(Value *SrcVal, Type *DstTy,
224  ExecutionContext &SF);
225  GenericValue executeBitCastInst(Value *SrcVal, Type *DstTy,
226  ExecutionContext &SF);
227  GenericValue executeCastOperation(Instruction::CastOps opcode, Value *SrcVal,
228  Type *Ty, ExecutionContext &SF);
229  void popStackAndReturnValueToCaller(Type *RetTy, GenericValue Result);
231 };
233 } // End llvm namespace
235 #endif
static ExecutionEngine * create(std::unique_ptr< Module > M, std::string *ErrorStr=nullptr)
Create an interpreter ExecutionEngine.
Definition: Interpreter.cpp:34
Return a value (possibly void), from a function.
void visitVAArgInst(VAArgInst &I)
Definition: Execution.cpp:1765
generic_gep_type_iterator<> gep_type_iterator
std::vector< GenericValue > ValuePlaneTy
Definition: Interpreter.h:54
This instruction extracts a struct member or array element value from an aggregate value.
Base class for instruction visitors.
Definition: InstVisitor.h:79
Interpreter(std::unique_ptr< Module > M)
Definition: Interpreter.cpp:54
This class represents lattice values for constants.
Definition: AllocatorList.h:23
void visitAllocaInst(AllocaInst &I)
Definition: Execution.cpp:1017
void visitStoreInst(StoreInst &I)
Definition: Execution.cpp:1104
void visitUnaryOperator(UnaryOperator &I)
Definition: Execution.cpp:62
This represents the llvm.va_end intrinsic.
void visitVACopyInst(VACopyInst &I)
Definition: Execution.cpp:1130
void visitTruncInst(TruncInst &I)
Definition: Execution.cpp:1702
void visitFPToUIInst(FPToUIInst &I)
Definition: Execution.cpp:1737
This class represents zero extension of integer types.
void visitCallBase(CallBase &I)
Definition: Execution.cpp:1158
void visitGetElementPtrInst(GetElementPtrInst &I)
Definition: Execution.cpp:1087
AllocaHolder Allocas
Definition: Interpreter.h:67
BasicBlock::iterator CurInst
Definition: Interpreter.h:62
std::map< Value *, GenericValue > Values
Definition: Interpreter.h:65
This instruction constructs a fixed permutation of two input vectors.
void visitExtractElementInst(ExtractElementInst &I)
Definition: Execution.cpp:1794
void visitShl(BinaryOperator &I)
Definition: Execution.cpp:1186
Base class for all callable instructions (InvokeInst and CallInst) Holds everything related to callin...
Definition: InstrTypes.h:1164
This class represents a sign extension of integer types.
An instruction for reading from memory.
Definition: Instructions.h:174
void visitFCmpInst(FCmpInst &I)
Definition: Execution.cpp:665
This class represents the LLVM 'select' instruction.
void visitSelectInst(SelectInst &I)
Definition: Execution.cpp:861
void * getPointerToNamedFunction(StringRef Name, bool AbortOnFailure=true) override
getPointerToNamedFunction - This method returns the address of the specified function by using the dl...
Definition: Interpreter.h:109
This class represents a cast from a pointer to an integer.
void visitInsertElementInst(InsertElementInst &I)
Definition: Execution.cpp:1827
void visitFPTruncInst(FPTruncInst &I)
Definition: Execution.cpp:1717
This represents the llvm.va_start intrinsic.
void visitPHINode(PHINode &PN)
Definition: Interpreter.h:134
This instruction compares its operands according to the predicate given to the constructor.
This class represents a no-op cast from one type to another.
void callFunction(Function *F, ArrayRef< GenericValue > ArgVals)
Definition: Execution.cpp:2119
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory),...
Definition: APInt.h:32
void visitInsertValueInst(InsertValueInst &I)
Definition: Execution.cpp:1969
An instruction for storing to memory.
Definition: Instructions.h:303
This class represents a cast from floating point to signed integer.
void visitBitCastInst(BitCastInst &I)
Definition: Execution.cpp:1757
This class represents a truncation of integer types.
static void Register()
Definition: Interpreter.h:95
an instruction for type-safe pointer arithmetic to access elements of arrays and structs
Definition: Instructions.h:905
void visitLShr(BinaryOperator &I)
Definition: Execution.cpp:1213
void visitICmpInst(ICmpInst &I)
Definition: Execution.cpp:332
This instruction inserts a single (scalar) element into a VectorType value.
void visitVAStartInst(VAStartInst &I)
Definition: Execution.cpp:1118
LLVM Basic Block Representation.
Definition: BasicBlock.h:58
Conditional or Unconditional Branch instruction.
This function has undefined behavior.
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
AllocaHolder & operator=(AllocaHolder &&RHS)=default
Indirect Branch Instruction.
void visitIndirectBrInst(IndirectBrInst &I)
Definition: Execution.cpp:968
void visitZExtInst(ZExtInst &I)
Definition: Execution.cpp:1712
void exitCalled(GenericValue GV)
Definition: Execution.cpp:875
This instruction compares its operands according to the predicate given to the constructor.
raw_fd_ostream & errs()
This returns a reference to a raw_ostream for standard error.
Function * CurFunction
Definition: Interpreter.h:60
GenericValue * getFirstVarArg()
Definition: Interpreter.h:183
BasicBlock * CurBB
Definition: Interpreter.h:61
void visitExtractValueInst(ExtractValueInst &I)
Definition: Execution.cpp:1926
This class represents a cast from an integer to a pointer.
void visitFPToSIInst(FPToSIInst &I)
Definition: Execution.cpp:1742
void visitIntToPtrInst(IntToPtrInst &I)
Definition: Execution.cpp:1752
void visitFPExtInst(FPExtInst &I)
Definition: Execution.cpp:1722
void visitInstruction(Instruction &I)
Definition: Interpreter.h:170
This class represents the va_arg llvm instruction, which returns an argument of the specified type gi...
~Interpreter() override
Definition: Interpreter.cpp:66
void visitUnreachableInst(UnreachableInst &I)
Definition: Execution.cpp:932
static ExecutionEngine *(* InterpCtor)(std::unique_ptr< Module > M, std::string *ErrorStr)
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
Abstract interface for implementation execution of LLVM modules, designed to support both interpreter...
void visitShuffleVectorInst(ShuffleVectorInst &I)
Definition: Execution.cpp:1859
std::vector< GenericValue > VarArgs
Definition: Interpreter.h:66
void visitReturnInst(ReturnInst &I)
Definition: Execution.cpp:918
void visitSExtInst(SExtInst &I)
Definition: Execution.cpp:1707
This class represents a cast from floating point to unsigned integer.
GenericValue runFunction(Function *F, ArrayRef< GenericValue > ArgValues) override
run - Start execution with the specified function and arguments.
Definition: Interpreter.cpp:80
void visitPtrToIntInst(PtrToIntInst &I)
Definition: Execution.cpp:1747
InstListType::iterator iterator
Instruction iterators...
Definition: BasicBlock.h:90
void runAtExitHandlers()
runAtExitHandlers - Run any functions registered by the program's calls to atexit(3),...
Definition: Interpreter.cpp:70
void visitBranchInst(BranchInst &I)
Definition: Execution.cpp:936
void visitAShr(BinaryOperator &I)
Definition: Execution.cpp:1240
void add(void *Mem)
Definition: Interpreter.h:51
#define I(x, y, z)
Definition: MD5.cpp:59
void visitSIToFPInst(SIToFPInst &I)
Definition: Execution.cpp:1732
This class represents a cast unsigned integer to floating point.
This instruction extracts a single (scalar) element from a VectorType value.
void visitBinaryOperator(BinaryOperator &I)
Definition: Execution.cpp:736
void visitLoadInst(LoadInst &I)
Definition: Execution.cpp:1093
void visitVAEndInst(VAEndInst &I)
Definition: Execution.cpp:1126
Multiway switch.
This class represents a cast from signed integer to floating point.
This represents the llvm.va_copy intrinsic.
This class represents a truncation of floating point types.
LLVM Value Representation.
Definition: Value.h:75
void visitUIToFPInst(UIToFPInst &I)
Definition: Execution.cpp:1727
void visitIntrinsicInst(IntrinsicInst &I)
Definition: Execution.cpp:1135
void addAtExitHandler(Function *F)
Definition: Interpreter.h:179
GenericValue callExternalFunction(Function *F, ArrayRef< GenericValue > ArgVals)
void visitSwitchInst(SwitchInst &I)
Definition: Execution.cpp:949
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:57
This class represents an extension of floating point types.
A wrapper class for inspecting calls to intrinsic functions.
Definition: IntrinsicInst.h:44
an instruction to allocate memory on the stack
Definition: Instructions.h:61
This instruction inserts a struct field of array element value into an aggregate value.