1 //===- lli.cpp - LLVM Interpreter / Dynamic compiler ----------------------===//
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 utility provides a simple wrapper around the LLVM Execution Engines,
11 // which allow the direct execution of LLVM programs through a Just-In-Time
12 // compiler, or through an intepreter if no JIT is available for this platform.
14 //===----------------------------------------------------------------------===//
16 #include "llvm/Module.h"
17 #include "llvm/ModuleProvider.h"
18 #include "llvm/Type.h"
19 #include "llvm/Bytecode/Reader.h"
20 #include "llvm/ExecutionEngine/ExecutionEngine.h"
21 #include "llvm/ExecutionEngine/GenericValue.h"
22 #include "Support/CommandLine.h"
23 #include "llvm/System/Signals.h"
30 InputFile(cl::desc("<input bytecode>"), cl::Positional, cl::init("-"));
33 InputArgv(cl::ConsumeAfter, cl::desc("<program arguments>..."));
35 cl::opt<bool> ForceInterpreter("force-interpreter",
36 cl::desc("Force interpretation: disable JIT"),
40 FakeArgv0("fake-argv0",
41 cl::desc("Override the 'argv[0]' value passed into the executing"
42 " program"), cl::value_desc("executable"));
45 //===----------------------------------------------------------------------===//
46 // main Driver function
48 int main(int argc, char **argv, char * const *envp) {
49 cl::ParseCommandLineOptions(argc, argv,
50 " llvm interpreter & dynamic compiler\n");
51 PrintStackTraceOnErrorSignal();
53 // Load the bytecode...
55 ModuleProvider *MP = 0;
57 MP = getBytecodeModuleProvider(InputFile);
58 } catch (std::string &err) {
59 std::cerr << "Error loading program '" << InputFile << "': " << err << "\n";
63 ExecutionEngine *EE = ExecutionEngine::create(MP, ForceInterpreter);
64 assert(EE && "Couldn't create an ExecutionEngine, not even an interpreter?");
66 // If the user specifically requested an argv[0] to pass into the program, do
68 if (!FakeArgv0.empty()) {
69 InputFile = FakeArgv0;
71 // Otherwise, if there is a .bc suffix on the executable strip it off, it
72 // might confuse the program.
73 if (InputFile.rfind(".bc") == InputFile.length() - 3)
74 InputFile.erase(InputFile.length() - 3);
77 // Add the module's name to the start of the vector of arguments to main().
78 InputArgv.insert(InputArgv.begin(), InputFile);
80 // Call the main function from M as if its signature were:
81 // int main (int argc, char **argv, const char **envp)
82 // using the contents of Args to determine argc & argv, and the contents of
83 // EnvVars to determine envp.
85 Function *Fn = MP->getModule()->getMainFunction();
87 std::cerr << "'main' function not found in module.\n";
92 int Result = EE->runFunctionAsMain(Fn, InputArgv, envp);
94 // If the program didn't explicitly call exit, call exit now, for the program.
95 // This ensures that any atexit handlers get called correctly.
96 Function *Exit = MP->getModule()->getOrInsertFunction("exit", Type::VoidTy,
99 std::vector<GenericValue> Args;
100 GenericValue ResultGV;
101 ResultGV.IntVal = Result;
102 Args.push_back(ResultGV);
103 EE->runFunction(Exit, Args);
105 std::cerr << "ERROR: exit(" << Result << ") returned!\n";