Interpreter.h revision 0b12b5f50ec77a8bd01b92d287c52d748619bb4b 
1//===-- Interpreter.h ------------------------------------------*- C++ -*--===//
2//
3// This header file defines the interpreter structure
4//
5//===----------------------------------------------------------------------===//
6
7#ifndef LLI_INTERPRETER_H
8#define LLI_INTERPRETER_H
9
10// Uncomment this line to enable profiling of structure field accesses.
11#define PROFILE_STRUCTURE_FIELDS 1
12
13
14#include "llvm/Module.h"
15#include "llvm/Function.h"
16#include "llvm/BasicBlock.h"
17#include "Support/DataTypes.h"
18#include "llvm/Assembly/CachedWriter.h"
19
20extern CachedWriter CW;     // Object to accellerate printing of LLVM
21
22struct MethodInfo;          // Defined in ExecutionAnnotations.h
23class CallInst;
24class ReturnInst;
25class BranchInst;
26class AllocationInst;
27
28typedef uint64_t PointerTy;
29
30union GenericValue {
31  bool            BoolVal;
32  unsigned char   UByteVal;
33  signed   char   SByteVal;
34  unsigned short  UShortVal;
35  signed   short  ShortVal;
36  unsigned int    UIntVal;
37  signed   int    IntVal;
38  uint64_t        ULongVal;
39  int64_t         LongVal;
40  double          DoubleVal;
41  float           FloatVal;
42  PointerTy       PointerVal;
43};
44
45// AllocaHolder - Object to track all of the blocks of memory allocated by
46// alloca.  When the function returns, this object is poped off the execution
47// stack, which causes the dtor to be run, which frees all the alloca'd memory.
48//
49class AllocaHolder {
50  friend class AllocaHolderHandle;
51  std::vector<void*> Allocations;
52  unsigned RefCnt;
53public:
54  AllocaHolder() : RefCnt(0) {}
55  void add(void *mem) { Allocations.push_back(mem); }
56  ~AllocaHolder() {
57    for (unsigned i = 0; i < Allocations.size(); ++i)
58      free(Allocations[i]);
59  }
60};
61
62// AllocaHolderHandle gives AllocaHolder value semantics so we can stick it into
63// a vector...
64//
65class AllocaHolderHandle {
66  AllocaHolder *H;
67public:
68  AllocaHolderHandle() : H(new AllocaHolder()) { H->RefCnt++; }
69  AllocaHolderHandle(const AllocaHolderHandle &AH) : H(AH.H) { H->RefCnt++; }
70  ~AllocaHolderHandle() { if (--H->RefCnt == 0) delete H; }
71
72  void add(void *mem) { H->add(mem); }
73};
74
75typedef std::vector<GenericValue> ValuePlaneTy;
76
77// ExecutionContext struct - This struct represents one stack frame currently
78// executing.
79//
80struct ExecutionContext {
81  Function             *CurMethod;  // The currently executing function
82  BasicBlock           *CurBB;      // The currently executing BB
83  BasicBlock::iterator  CurInst;    // The next instruction to execute
84  MethodInfo           *MethInfo;   // The MethInfo annotation for the function
85  std::vector<ValuePlaneTy>  Values;// ValuePlanes for each type
86
87  BasicBlock           *PrevBB;     // The previous BB or null if in first BB
88  CallInst             *Caller;     // Holds the call that called subframes.
89                                    // NULL if main func or debugger invoked fn
90  AllocaHolderHandle    Allocas;    // Track memory allocated by alloca
91};
92
93// Interpreter - This class represents the entirety of the interpreter.
94//
95class Interpreter {
96  Module *CurMod;              // The current Module being executed (0 if none)
97  int ExitCode;                // The exit code to be returned by the lli util
98  bool Profile;                // Profiling enabled?
99  bool Trace;                  // Tracing enabled?
100  int CurFrame;                // The current stack frame being inspected
101
102  // The runtime stack of executing code.  The top of the stack is the current
103  // function record.
104  std::vector<ExecutionContext> ECStack;
105
106public:
107  Interpreter();
108  inline ~Interpreter() { CW.setModule(0); delete CurMod; }
109
110  // getExitCode - return the code that should be the exit code for the lli
111  // utility.
112  inline int getExitCode() const { return ExitCode; }
113
114  // enableProfiling() - Turn profiling on, clear stats?
115  void enableProfiling() { Profile = true; }
116  void enableTracing() { Trace = true; }
117
118  void handleUserInput();
119
120  // User Interation Methods...
121  void loadModule(const std::string &Filename);
122  bool flushModule();
123  bool callMethod(const std::string &Name);      // return true on failure
124  void setBreakpoint(const std::string &Name);
125  void infoValue(const std::string &Name);
126  void print(const std::string &Name);
127  static void print(const Type *Ty, GenericValue V);
128  static void printValue(const Type *Ty, GenericValue V);
129
130  // Hack until we can parse command line args...
131  bool callMainMethod(const std::string &MainName,
132                      const std::vector<std::string> &InputFilename);
133
134  void list();             // Do the 'list' command
135  void printStackTrace();  // Do the 'backtrace' command
136
137  // Code execution methods...
138  void callMethod(Function *F, const std::vector<GenericValue> &ArgVals);
139  bool executeInstruction(); // Execute one instruction...
140
141  void stepInstruction();  // Do the 'step' command
142  void nextInstruction();  // Do the 'next' command
143  void run();              // Do the 'run' command
144  void finish();           // Do the 'finish' command
145
146  // Opcode Implementations
147  void executeCallInst(CallInst &I, ExecutionContext &SF);
148  void executeRetInst(ReturnInst &I, ExecutionContext &SF);
149  void executeBrInst(BranchInst &I, ExecutionContext &SF);
150  void executeAllocInst(AllocationInst &I, ExecutionContext &SF);
151  GenericValue callExternalMethod(Function *F,
152                                  const std::vector<GenericValue> &ArgVals);
153  void exitCalled(GenericValue GV);
154
155  // getCurrentMethod - Return the currently executing method
156  inline Function *getCurrentMethod() const {
157    return CurFrame < 0 ? 0 : ECStack[CurFrame].CurMethod;
158  }
159
160  // isStopped - Return true if a program is stopped.  Return false if no
161  // program is running.
162  //
163  inline bool isStopped() const { return !ECStack.empty(); }
164
165private:  // Helper functions
166  // getCurrentExecutablePath() - Return the directory that the lli executable
167  // lives in.
168  //
169  std::string getCurrentExecutablePath() const;
170
171  // printCurrentInstruction - Print out the instruction that the virtual PC is
172  // at, or fail silently if no program is running.
173  //
174  void printCurrentInstruction();
175
176  // printStackFrame - Print information about the specified stack frame, or -1
177  // for the default one.
178  //
179  void printStackFrame(int FrameNo = -1);
180
181  // LookupMatchingNames - Search the current function namespace, then the
182  // global namespace looking for values that match the specified name.  Return
183  // ALL matches to that name.  This is obviously slow, and should only be used
184  // for user interaction.
185  //
186  std::vector<Value*> LookupMatchingNames(const std::string &Name);
187
188  // ChooseOneOption - Prompt the user to choose among the specified options to
189  // pick one value.  If no options are provided, emit an error.  If a single
190  // option is provided, just return that option.
191  //
192  Value *ChooseOneOption(const std::string &Name,
193                         const std::vector<Value*> &Opts);
194
195
196  void initializeExecutionEngine();
197  void initializeExternalMethods();
198};
199
200#endif
201