1 //===- Interpreter.cpp - Top-Level LLVM Interpreter Implementation --------===//
2 //
3 // This file implements the top-level functionality for the LLVM interpreter.
4 // This interpreter is designed to be a very simple, portable, inefficient
5 // interpreter.
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "Interpreter.h"
10 #include "llvm/Target/TargetMachineImpls.h"
11 
12 /// createInterpreter - Create a new interpreter object.  This can never fail.
13 ///
14 ExecutionEngine *ExecutionEngine::createInterpreter(Module *M,
15 						    unsigned Config,
16 						    bool DebugMode,
17 						    bool TraceMode) {
18   return new Interpreter(M, Config, DebugMode, TraceMode);
19 }
20 
21 //===----------------------------------------------------------------------===//
22 // Interpreter ctor - Initialize stuff
23 //
24 Interpreter::Interpreter(Module *M, unsigned Config,
25 			 bool DebugMode, bool TraceMode)
26   : ExecutionEngine(M), ExitCode(0), Debug(DebugMode), Trace(TraceMode),
27     CurFrame(-1), TD("lli", (Config & TM::EndianMask) == TM::LittleEndian,
28 		     (Config & TM::PtrSizeMask) == TM::PtrSize64 ? 8 : 4,
29 		     (Config & TM::PtrSizeMask) == TM::PtrSize64 ? 8 : 4,
30 		     (Config & TM::PtrSizeMask) == TM::PtrSize64 ? 8 : 4) {
31 
32   setTargetData(TD);
33   // Initialize the "backend"
34   initializeExecutionEngine();
35   initializeExternalFunctions();
36   CW.setModule(M);  // Update Writer
37   emitGlobals();
38 }
39 
40 /// run - Start execution with the specified function and arguments.
41 ///
42 int Interpreter::run(const std::string &MainFunction,
43 		     const std::vector<std::string> &Args,
44                      const char ** envp) {
45   // Start interpreter into the main function...
46   //
47   if (!callMainFunction(MainFunction, Args) && !Debug) {
48     // If not in debug mode and if the call succeeded, run the code now...
49     run();
50   }
51 
52   do {
53     // If debug mode, allow the user to interact... also, if the user pressed
54     // ctrl-c or execution hit an error, enter the event loop...
55     if (Debug || isStopped())
56       handleUserInput();
57 
58     // If the program has exited, run atexit handlers...
59     if (ECStack.empty() && !AtExitHandlers.empty()) {
60       callFunction(AtExitHandlers.back(), std::vector<GenericValue>());
61       AtExitHandlers.pop_back();
62       run();
63     }
64   } while (!ECStack.empty());
65 
66   PerformExitStuff();
67   return ExitCode;
68 }
69 
70