lli.cpp revision f74edf28b6a23d156aeb93750adfe301cdd851cc 
1//===- lli.cpp - LLVM Interpreter / Dynamic compiler ----------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
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.
7//
8//===----------------------------------------------------------------------===//
9//
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.
13//
14//===----------------------------------------------------------------------===//
15
16#include "llvm/Module.h"
17#include "llvm/ModuleProvider.h"
18#include "llvm/Type.h"
19#include "llvm/Bytecode/Reader.h"
20#include "llvm/CodeGen/LinkAllCodegenComponents.h"
21#include "llvm/ExecutionEngine/JIT.h"
22#include "llvm/ExecutionEngine/Interpreter.h"
23#include "llvm/ExecutionEngine/GenericValue.h"
24#include "llvm/Support/CommandLine.h"
25#include "llvm/Support/ManagedStatic.h"
26#include "llvm/Support/PluginLoader.h"
27#include "llvm/System/Process.h"
28#include "llvm/System/Signals.h"
29#include <iostream>
30
31using namespace llvm;
32
33namespace {
34  cl::opt<std::string>
35  InputFile(cl::desc("<input bytecode>"), cl::Positional, cl::init("-"));
36
37  cl::list<std::string>
38  InputArgv(cl::ConsumeAfter, cl::desc("<program arguments>..."));
39
40  cl::opt<bool> ForceInterpreter("force-interpreter",
41                                 cl::desc("Force interpretation: disable JIT"),
42                                 cl::init(false));
43  cl::opt<std::string>
44  TargetTriple("mtriple", cl::desc("Override target triple for module"));
45
46  cl::opt<std::string>
47  FakeArgv0("fake-argv0",
48            cl::desc("Override the 'argv[0]' value passed into the executing"
49                     " program"), cl::value_desc("executable"));
50
51  cl::opt<bool>
52  DisableCoreFiles("disable-core-files", cl::Hidden,
53                   cl::desc("Disable emission of core files if possible"));
54}
55
56//===----------------------------------------------------------------------===//
57// main Driver function
58//
59int main(int argc, char **argv, char * const *envp) {
60  atexit(llvm_shutdown);  // Call llvm_shutdown() on exit.
61  try {
62    cl::ParseCommandLineOptions(argc, argv,
63                                " llvm interpreter & dynamic compiler\n");
64    sys::PrintStackTraceOnErrorSignal();
65
66    // If the user doesn't want core files, disable them.
67    if (DisableCoreFiles)
68      sys::Process::PreventCoreFiles();
69
70    // Load the bytecode...
71    std::string ErrorMsg;
72    ModuleProvider *MP = 0;
73    MP = getBytecodeModuleProvider(InputFile, &ErrorMsg);
74    if (!MP) {
75      std::cerr << "Error loading program '" << InputFile << "': "
76                << ErrorMsg << "\n";
77      exit(1);
78    }
79
80    // If we are supposed to override the target triple, do so now.
81    if (!TargetTriple.empty())
82      MP->getModule()->setTargetTriple(TargetTriple);
83
84    ExecutionEngine *EE = ExecutionEngine::create(MP, ForceInterpreter);
85    assert(EE &&"Couldn't create an ExecutionEngine, not even an interpreter?");
86
87    // If the user specifically requested an argv[0] to pass into the program,
88    // do it now.
89    if (!FakeArgv0.empty()) {
90      InputFile = FakeArgv0;
91    } else {
92      // Otherwise, if there is a .bc suffix on the executable strip it off, it
93      // might confuse the program.
94      if (InputFile.rfind(".bc") == InputFile.length() - 3)
95        InputFile.erase(InputFile.length() - 3);
96    }
97
98    // Add the module's name to the start of the vector of arguments to main().
99    InputArgv.insert(InputArgv.begin(), InputFile);
100
101    // Call the main function from M as if its signature were:
102    //   int main (int argc, char **argv, const char **envp)
103    // using the contents of Args to determine argc & argv, and the contents of
104    // EnvVars to determine envp.
105    //
106    Function *Fn = MP->getModule()->getMainFunction();
107    if (!Fn) {
108      std::cerr << "'main' function not found in module.\n";
109      return -1;
110    }
111
112    // Run static constructors.
113    EE->runStaticConstructorsDestructors(false);
114
115    // Run main.
116    int Result = EE->runFunctionAsMain(Fn, InputArgv, envp);
117
118    // Run static destructors.
119    EE->runStaticConstructorsDestructors(true);
120
121    exit(Result);
122    std::cerr << "ERROR: exit(" << Result << ") returned!\n";
123    abort();
124  } catch (const std::string& msg) {
125    std::cerr << argv[0] << ": " << msg << "\n";
126  } catch (...) {
127    std::cerr << argv[0] << ": Unexpected unknown exception occurred.\n";
128  }
129  abort();
130}
131