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> 21 using namespace llvm; 22 23 namespace { 24 25 static struct RegisterInterp { 26 RegisterInterp() { Interpreter::Register(); } 27 } InterpRegistrator; 28 29 } 30 31 extern "C" void LLVMLinkInInterpreter() { } 32 33 /// Create a new interpreter object. 34 /// 35 ExecutionEngine *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 // 51 Interpreter::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 63 Interpreter::~Interpreter() { 64 delete IL; 65 } 66 67 void 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 /// 77 GenericValue 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
