1//===- Interpreter.cpp - Top-Level LLVM Interpreter Implementation --------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements the top-level functionality for the LLVM interpreter. 11// This interpreter is designed to be a very simple, portable, inefficient 12// interpreter. 13// 14//===----------------------------------------------------------------------===// 15 16#include "Interpreter.h" 17#include "llvm/CodeGen/IntrinsicLowering.h" 18#include "llvm/IR/DerivedTypes.h" 19#include "llvm/IR/Module.h" 20#include <cstring> 21using namespace llvm; 22 23namespace { 24 25static struct RegisterInterp { 26 RegisterInterp() { Interpreter::Register(); } 27} InterpRegistrator; 28 29} 30 31extern "C" void LLVMLinkInInterpreter() { } 32 33/// Create a new interpreter object. 34/// 35ExecutionEngine *Interpreter::create(std::unique_ptr<Module> M, 36 std::string *ErrStr) { 37 // Tell this Module to materialize everything and release the GVMaterializer. 38 if (std::error_code EC = M->materializeAll()) { 39 if (ErrStr) 40 *ErrStr = EC.message(); 41 // We got an error, just return 0 42 return nullptr; 43 } 44 45 return new Interpreter(std::move(M)); 46} 47 48//===----------------------------------------------------------------------===// 49// Interpreter ctor - Initialize stuff 50// 51Interpreter::Interpreter(std::unique_ptr<Module> M) 52 : ExecutionEngine(std::move(M)) { 53 54 memset(&ExitValue.Untyped, 0, sizeof(ExitValue.Untyped)); 55 // Initialize the "backend" 56 initializeExecutionEngine(); 57 initializeExternalFunctions(); 58 emitGlobals(); 59 60 IL = new IntrinsicLowering(getDataLayout()); 61} 62 63Interpreter::~Interpreter() { 64 delete IL; 65} 66 67void Interpreter::runAtExitHandlers () { 68 while (!AtExitHandlers.empty()) { 69 callFunction(AtExitHandlers.back(), None); 70 AtExitHandlers.pop_back(); 71 run(); 72 } 73} 74 75/// run - Start execution with the specified function and arguments. 76/// 77GenericValue Interpreter::runFunction(Function *F, 78 ArrayRef<GenericValue> ArgValues) { 79 assert (F && "Function *F was null at entry to run()"); 80 81 // Try extra hard not to pass extra args to a function that isn't 82 // expecting them. C programmers frequently bend the rules and 83 // declare main() with fewer parameters than it actually gets 84 // passed, and the interpreter barfs if you pass a function more 85 // parameters than it is declared to take. This does not attempt to 86 // take into account gratuitous differences in declared types, 87 // though. 88 const size_t ArgCount = F->getFunctionType()->getNumParams(); 89 ArrayRef<GenericValue> ActualArgs = 90 ArgValues.slice(0, std::min(ArgValues.size(), ArgCount)); 91 92 // Set up the function call. 93 callFunction(F, ActualArgs); 94 95 // Start executing the function. 96 run(); 97 98 return ExitValue; 99} 100