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, std::string* ErrStr) {
35 // Tell this ModuleProvide to materialize and release the module
36 Module *M = MP->releaseModule(ErrStr);
38 // We got an error, just return 0
41 // This is a bit nasty, but the ExecutionEngine won't be able to delete the
42 // module due to use/def issues if we don't delete this MP here. Below we
43 // construct a new Interpreter with the Module we just got. This creates a
44 // new ExistingModuleProvider in the EE instance. Consequently, MP is left
45 // dangling and it contains references into the module which cause problems
46 // when the module is deleted via the ExistingModuleProvide via EE.
49 // FIXME: This should probably compute the entire data layout
50 std::string DataLayout;
52 *(char*)&Test = 1; // Return true if the host is little endian
53 bool isLittleEndian = (Test == 1);
54 DataLayout.append(isLittleEndian ? "e" : "E");
56 bool Ptr64 = sizeof(void*) == 8;
57 DataLayout.append(Ptr64 ? "-p:64:64" : "-p:32:32");
59 M->setDataLayout(DataLayout);
61 return new Interpreter(M);
64 //===----------------------------------------------------------------------===//
65 // Interpreter ctor - Initialize stuff
67 Interpreter::Interpreter(Module *M) : ExecutionEngine(M), TD(M) {
69 memset(&ExitValue, 0, sizeof(ExitValue));
71 // Initialize the "backend"
72 initializeExecutionEngine();
73 initializeExternalFunctions();
76 IL = new IntrinsicLowering(TD);
79 Interpreter::~Interpreter() {
83 void Interpreter::runAtExitHandlers () {
84 while (!AtExitHandlers.empty()) {
85 callFunction(AtExitHandlers.back(), std::vector<GenericValue>());
86 AtExitHandlers.pop_back();
91 /// run - Start execution with the specified function and arguments.
94 Interpreter::runFunction(Function *F,
95 const std::vector<GenericValue> &ArgValues) {
96 assert (F && "Function *F was null at entry to run()");
98 // Try extra hard not to pass extra args to a function that isn't
99 // expecting them. C programmers frequently bend the rules and
100 // declare main() with fewer parameters than it actually gets
101 // passed, and the interpreter barfs if you pass a function more
102 // parameters than it is declared to take. This does not attempt to
103 // take into account gratuitous differences in declared types,
105 std::vector<GenericValue> ActualArgs;
106 const unsigned ArgCount = F->getFunctionType()->getNumParams();
107 for (unsigned i = 0; i < ArgCount; ++i)
108 ActualArgs.push_back(ArgValues[i]);
110 // Set up the function call.
111 callFunction(F, ActualArgs);
113 // Start executing the function.