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 if (M->getEndianness() == Module::AnyEndianness) {
44 *(char*)&Test = 1; // Return true if the host is little endian
45 bool isLittleEndian = (Test == 1);
46 M->setEndianness(isLittleEndian ? Module::LittleEndian : Module::BigEndian);
49 if (M->getPointerSize() == Module::AnyPointerSize) {
51 bool Ptr64 = sizeof(void*) == 8;
52 M->setPointerSize(Ptr64 ? Module::Pointer64 : Module::Pointer32);
55 return new Interpreter(M);
58 //===----------------------------------------------------------------------===//
59 // Interpreter ctor - Initialize stuff
61 Interpreter::Interpreter(Module *M) : ExecutionEngine(M), TD("lli", M) {
63 memset(&ExitValue, 0, sizeof(ExitValue));
65 // Initialize the "backend"
66 initializeExecutionEngine();
67 initializeExternalFunctions();
70 IL = new DefaultIntrinsicLowering();
73 Interpreter::~Interpreter() {
77 void Interpreter::runAtExitHandlers () {
78 while (!AtExitHandlers.empty()) {
79 callFunction(AtExitHandlers.back(), std::vector<GenericValue>());
80 AtExitHandlers.pop_back();
85 /// run - Start execution with the specified function and arguments.
88 Interpreter::runFunction(Function *F,
89 const std::vector<GenericValue> &ArgValues) {
90 assert (F && "Function *F was null at entry to run()");
92 // Try extra hard not to pass extra args to a function that isn't
93 // expecting them. C programmers frequently bend the rules and
94 // declare main() with fewer parameters than it actually gets
95 // passed, and the interpreter barfs if you pass a function more
96 // parameters than it is declared to take. This does not attempt to
97 // take into account gratuitous differences in declared types,
99 std::vector<GenericValue> ActualArgs;
100 const unsigned ArgCount = F->getFunctionType()->getNumParams();
101 for (unsigned i = 0; i < ArgCount; ++i)
102 ActualArgs.push_back(ArgValues[i]);
104 // Set up the function call.
105 callFunction(F, ActualArgs);
107 // Start executing the function.