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"
24 static struct RegisterInterp {
25 RegisterInterp() { Interpreter::Register(); }
29 void LinkInInterpreter() {
33 /// create - Create a new interpreter object. This can never fail.
35 ExecutionEngine *Interpreter::create(ModuleProvider *MP, std::string* ErrStr) {
36 // Tell this ModuleProvide to materialize and release the module
37 Module *M = MP->releaseModule(ErrStr);
39 // We got an error, just return 0
42 // This is a bit nasty, but the ExecutionEngine won't be able to delete the
43 // module due to use/def issues if we don't delete this MP here. Below we
44 // construct a new Interpreter with the Module we just got. This creates a
45 // new ExistingModuleProvider in the EE instance. Consequently, MP is left
46 // dangling and it contains references into the module which cause problems
47 // when the module is deleted via the ExistingModuleProvide via EE.
50 // FIXME: This should probably compute the entire data layout
51 std::string DataLayout;
53 *(char*)&Test = 1; // Return true if the host is little endian
54 bool isLittleEndian = (Test == 1);
55 DataLayout.append(isLittleEndian ? "e" : "E");
57 bool Ptr64 = sizeof(void*) == 8;
58 DataLayout.append(Ptr64 ? "-p:64:64" : "-p:32:32");
60 M->setDataLayout(DataLayout);
62 return new Interpreter(M);
65 //===----------------------------------------------------------------------===//
66 // Interpreter ctor - Initialize stuff
68 Interpreter::Interpreter(Module *M) : ExecutionEngine(M), TD(M) {
70 memset(&ExitValue, 0, sizeof(ExitValue));
72 // Initialize the "backend"
73 initializeExecutionEngine();
74 initializeExternalFunctions();
77 IL = new IntrinsicLowering(TD);
80 Interpreter::~Interpreter() {
84 void Interpreter::runAtExitHandlers () {
85 while (!AtExitHandlers.empty()) {
86 callFunction(AtExitHandlers.back(), std::vector<GenericValue>());
87 AtExitHandlers.pop_back();
92 /// run - Start execution with the specified function and arguments.
95 Interpreter::runFunction(Function *F,
96 const std::vector<GenericValue> &ArgValues) {
97 assert (F && "Function *F was null at entry to run()");
99 // Try extra hard not to pass extra args to a function that isn't
100 // expecting them. C programmers frequently bend the rules and
101 // declare main() with fewer parameters than it actually gets
102 // passed, and the interpreter barfs if you pass a function more
103 // parameters than it is declared to take. This does not attempt to
104 // take into account gratuitous differences in declared types,
106 std::vector<GenericValue> ActualArgs;
107 const unsigned ArgCount = F->getFunctionType()->getNumParams();
108 for (unsigned i = 0; i < ArgCount; ++i)
109 ActualArgs.push_back(ArgValues[i]);
111 // Set up the function call.
112 callFunction(F, ActualArgs);
114 // Start executing the function.