1 //===- Interpreter.cpp - Top-Level LLVM Interpreter Implementation --------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the top-level functionality for the LLVM interpreter.
11 // This interpreter is designed to be a very simple, portable, inefficient
14 //===----------------------------------------------------------------------===//
16 #include "Interpreter.h"
17 #include "llvm/CodeGen/IntrinsicLowering.h"
18 #include "llvm/DerivedTypes.h"
19 #include "llvm/Module.h"
20 #include "llvm/ModuleProvider.h"
23 static struct RegisterInterp {
24 RegisterInterp() { Interpreter::Register(); }
28 void LinkInInterpreter() {
32 /// create - Create a new interpreter object. This can never fail.
34 ExecutionEngine *Interpreter::create(ModuleProvider *MP) {
37 M = MP->materializeModule();
39 return 0; // error materializing the module.
42 bool isLittleEndian = false;
43 switch (M->getEndianness()) {
44 case Module::LittleEndian: isLittleEndian = true; break;
45 case Module::BigEndian: isLittleEndian = false; break;
46 case Module::AnyPointerSize:
48 *(char*)&Test = 1; // Return true if the host is little endian
49 isLittleEndian = (Test == 1);
53 bool isLongPointer = false;
54 switch (M->getPointerSize()) {
55 case Module::Pointer32: isLongPointer = false; break;
56 case Module::Pointer64: isLongPointer = true; break;
57 case Module::AnyPointerSize:
58 isLongPointer = (sizeof(void*) == 8); // Follow host
62 return new Interpreter(M, isLittleEndian, isLongPointer);
65 //===----------------------------------------------------------------------===//
66 // Interpreter ctor - Initialize stuff
68 Interpreter::Interpreter(Module *M, bool isLittleEndian, bool isLongPointer)
70 TD("lli", isLittleEndian, isLongPointer ? 8 : 4, isLongPointer ? 8 : 4,
71 isLongPointer ? 8 : 4) {
73 memset(&ExitValue, 0, sizeof(ExitValue));
75 // Initialize the "backend"
76 initializeExecutionEngine();
77 initializeExternalFunctions();
80 IL = new DefaultIntrinsicLowering();
83 Interpreter::~Interpreter() {
87 void Interpreter::runAtExitHandlers () {
88 while (!AtExitHandlers.empty()) {
89 callFunction(AtExitHandlers.back(), std::vector<GenericValue>());
90 AtExitHandlers.pop_back();
95 /// run - Start execution with the specified function and arguments.
98 Interpreter::runFunction(Function *F,
99 const std::vector<GenericValue> &ArgValues) {
100 assert (F && "Function *F was null at entry to run()");
102 // Try extra hard not to pass extra args to a function that isn't
103 // expecting them. C programmers frequently bend the rules and
104 // declare main() with fewer parameters than it actually gets
105 // passed, and the interpreter barfs if you pass a function more
106 // parameters than it is declared to take. This does not attempt to
107 // take into account gratuitous differences in declared types,
109 std::vector<GenericValue> ActualArgs;
110 const unsigned ArgCount = F->getFunctionType()->getNumParams();
111 for (unsigned i = 0; i < ArgCount; ++i)
112 ActualArgs.push_back(ArgValues[i]);
114 // Set up the function call.
115 callFunction(F, ActualArgs);
117 // Start executing the function.