1 //===- lli.cpp - LLVM Interpreter / Dynamic compiler ----------------------===//
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 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 interpreter if no JIT is available for this platform.
13 //
14 //===----------------------------------------------------------------------===//
15
16 #include "llvm/LLVMContext.h"
17 #include "llvm/Module.h"
18 #include "llvm/Type.h"
19 #include "llvm/ADT/Triple.h"
20 #include "llvm/Bitcode/ReaderWriter.h"
21 #include "llvm/CodeGen/LinkAllCodegenComponents.h"
22 #include "llvm/ExecutionEngine/GenericValue.h"
23 #include "llvm/ExecutionEngine/Interpreter.h"
24 #include "llvm/ExecutionEngine/JIT.h"
25 #include "llvm/ExecutionEngine/JITEventListener.h"
26 #include "llvm/ExecutionEngine/MCJIT.h"
27 #include "llvm/Support/CommandLine.h"
28 #include "llvm/Support/IRReader.h"
29 #include "llvm/Support/ManagedStatic.h"
30 #include "llvm/Support/MemoryBuffer.h"
31 #include "llvm/Support/PluginLoader.h"
32 #include "llvm/Support/PrettyStackTrace.h"
33 #include "llvm/Support/raw_ostream.h"
34 #include "llvm/Support/Process.h"
35 #include "llvm/Support/Signals.h"
36 #include "llvm/Target/TargetSelect.h"
37 #include <cerrno>
38
39 #ifdef __CYGWIN__
40 #include <cygwin/version.h>
41 #if defined(CYGWIN_VERSION_DLL_MAJOR) && CYGWIN_VERSION_DLL_MAJOR<1007
42 #define DO_NOTHING_ATEXIT 1
43 #endif
44 #endif
45
46 using namespace llvm;
47
48 namespace {
49 cl::opt<std::string>
50 InputFile(cl::desc("<input bitcode>"), cl::Positional, cl::init("-"));
51
52 cl::list<std::string>
53 InputArgv(cl::ConsumeAfter, cl::desc("<program arguments>..."));
54
55 cl::opt<bool> ForceInterpreter("force-interpreter",
56 cl::desc("Force interpretation: disable JIT"),
57 cl::init(false));
58
59 cl::opt<bool> UseMCJIT(
60 "use-mcjit", cl::desc("Enable use of the MC-based JIT (if available)"),
61 cl::init(false));
62
63 // Determine optimization level.
64 cl::opt<char>
65 OptLevel("O",
66 cl::desc("Optimization level. [-O0, -O1, -O2, or -O3] "
67 "(default = '-O2')"),
68 cl::Prefix,
69 cl::ZeroOrMore,
70 cl::init(' '));
71
72 cl::opt<std::string>
73 TargetTriple("mtriple", cl::desc("Override target triple for module"));
74
75 cl::opt<std::string>
76 MArch("march",
77 cl::desc("Architecture to generate assembly for (see --version)"));
78
79 cl::opt<std::string>
80 MCPU("mcpu",
81 cl::desc("Target a specific cpu type (-mcpu=help for details)"),
82 cl::value_desc("cpu-name"),
83 cl::init(""));
84
85 cl::list<std::string>
86 MAttrs("mattr",
87 cl::CommaSeparated,
88 cl::desc("Target specific attributes (-mattr=help for details)"),
89 cl::value_desc("a1,+a2,-a3,..."));
90
91 cl::opt<std::string>
92 EntryFunc("entry-function",
93 cl::desc("Specify the entry function (default = 'main') "
94 "of the executable"),
95 cl::value_desc("function"),
96 cl::init("main"));
97
98 cl::opt<std::string>
99 FakeArgv0("fake-argv0",
100 cl::desc("Override the 'argv[0]' value passed into the executing"
101 " program"), cl::value_desc("executable"));
102
103 cl::opt<bool>
104 DisableCoreFiles("disable-core-files", cl::Hidden,
105 cl::desc("Disable emission of core files if possible"));
106
107 cl::opt<bool>
108 NoLazyCompilation("disable-lazy-compilation",
109 cl::desc("Disable JIT lazy compilation"),
110 cl::init(false));
111
112 cl::opt<Reloc::Model>
113 RelocModel("relocation-model",
114 cl::desc("Choose relocation model"),
115 cl::init(Reloc::Default),
116 cl::values(
117 clEnumValN(Reloc::Default, "default",
118 "Target default relocation model"),
119 clEnumValN(Reloc::Static, "static",
120 "Non-relocatable code"),
121 clEnumValN(Reloc::PIC_, "pic",
122 "Fully relocatable, position independent code"),
123 clEnumValN(Reloc::DynamicNoPIC, "dynamic-no-pic",
124 "Relocatable external references, non-relocatable code"),
125 clEnumValEnd));
126 }
127
128 static ExecutionEngine *EE = 0;
129
do_shutdown()130 static void do_shutdown() {
131 // Cygwin-1.5 invokes DLL's dtors before atexit handler.
132 #ifndef DO_NOTHING_ATEXIT
133 delete EE;
134 llvm_shutdown();
135 #endif
136 }
137
138 //===----------------------------------------------------------------------===//
139 // main Driver function
140 //
main(int argc,char ** argv,char * const * envp)141 int main(int argc, char **argv, char * const *envp) {
142 sys::PrintStackTraceOnErrorSignal();
143 PrettyStackTraceProgram X(argc, argv);
144
145 LLVMContext &Context = getGlobalContext();
146 atexit(do_shutdown); // Call llvm_shutdown() on exit.
147
148 // If we have a native target, initialize it to ensure it is linked in and
149 // usable by the JIT.
150 InitializeNativeTarget();
151 InitializeNativeTargetAsmPrinter();
152
153 cl::ParseCommandLineOptions(argc, argv,
154 "llvm interpreter & dynamic compiler\n");
155
156 // If the user doesn't want core files, disable them.
157 if (DisableCoreFiles)
158 sys::Process::PreventCoreFiles();
159
160 // Load the bitcode...
161 SMDiagnostic Err;
162 Module *Mod = ParseIRFile(InputFile, Err, Context);
163 if (!Mod) {
164 Err.Print(argv[0], errs());
165 return 1;
166 }
167
168 // If not jitting lazily, load the whole bitcode file eagerly too.
169 std::string ErrorMsg;
170 if (NoLazyCompilation) {
171 if (Mod->MaterializeAllPermanently(&ErrorMsg)) {
172 errs() << argv[0] << ": bitcode didn't read correctly.\n";
173 errs() << "Reason: " << ErrorMsg << "\n";
174 exit(1);
175 }
176 }
177
178 EngineBuilder builder(Mod);
179 builder.setMArch(MArch);
180 builder.setMCPU(MCPU);
181 builder.setMAttrs(MAttrs);
182 builder.setRelocationModel(RelocModel);
183 builder.setErrorStr(&ErrorMsg);
184 builder.setEngineKind(ForceInterpreter
185 ? EngineKind::Interpreter
186 : EngineKind::JIT);
187
188 // If we are supposed to override the target triple, do so now.
189 if (!TargetTriple.empty())
190 Mod->setTargetTriple(Triple::normalize(TargetTriple));
191
192 // Enable MCJIT, if desired.
193 if (UseMCJIT)
194 builder.setUseMCJIT(true);
195
196 CodeGenOpt::Level OLvl = CodeGenOpt::Default;
197 switch (OptLevel) {
198 default:
199 errs() << argv[0] << ": invalid optimization level.\n";
200 return 1;
201 case ' ': break;
202 case '0': OLvl = CodeGenOpt::None; break;
203 case '1': OLvl = CodeGenOpt::Less; break;
204 case '2': OLvl = CodeGenOpt::Default; break;
205 case '3': OLvl = CodeGenOpt::Aggressive; break;
206 }
207 builder.setOptLevel(OLvl);
208
209 EE = builder.create();
210 if (!EE) {
211 if (!ErrorMsg.empty())
212 errs() << argv[0] << ": error creating EE: " << ErrorMsg << "\n";
213 else
214 errs() << argv[0] << ": unknown error creating EE!\n";
215 exit(1);
216 }
217
218 EE->RegisterJITEventListener(createOProfileJITEventListener());
219
220 EE->DisableLazyCompilation(NoLazyCompilation);
221
222 // If the user specifically requested an argv[0] to pass into the program,
223 // do it now.
224 if (!FakeArgv0.empty()) {
225 InputFile = FakeArgv0;
226 } else {
227 // Otherwise, if there is a .bc suffix on the executable strip it off, it
228 // might confuse the program.
229 if (StringRef(InputFile).endswith(".bc"))
230 InputFile.erase(InputFile.length() - 3);
231 }
232
233 // Add the module's name to the start of the vector of arguments to main().
234 InputArgv.insert(InputArgv.begin(), InputFile);
235
236 // Call the main function from M as if its signature were:
237 // int main (int argc, char **argv, const char **envp)
238 // using the contents of Args to determine argc & argv, and the contents of
239 // EnvVars to determine envp.
240 //
241 Function *EntryFn = Mod->getFunction(EntryFunc);
242 if (!EntryFn) {
243 errs() << '\'' << EntryFunc << "\' function not found in module.\n";
244 return -1;
245 }
246
247 // If the program doesn't explicitly call exit, we will need the Exit
248 // function later on to make an explicit call, so get the function now.
249 Constant *Exit = Mod->getOrInsertFunction("exit", Type::getVoidTy(Context),
250 Type::getInt32Ty(Context),
251 NULL);
252
253 // Reset errno to zero on entry to main.
254 errno = 0;
255
256 // Run static constructors.
257 EE->runStaticConstructorsDestructors(false);
258
259 if (NoLazyCompilation) {
260 for (Module::iterator I = Mod->begin(), E = Mod->end(); I != E; ++I) {
261 Function *Fn = &*I;
262 if (Fn != EntryFn && !Fn->isDeclaration())
263 EE->getPointerToFunction(Fn);
264 }
265 }
266
267 // Run main.
268 int Result = EE->runFunctionAsMain(EntryFn, InputArgv, envp);
269
270 // Run static destructors.
271 EE->runStaticConstructorsDestructors(true);
272
273 // If the program didn't call exit explicitly, we should call it now.
274 // This ensures that any atexit handlers get called correctly.
275 if (Function *ExitF = dyn_cast<Function>(Exit)) {
276 std::vector<GenericValue> Args;
277 GenericValue ResultGV;
278 ResultGV.IntVal = APInt(32, Result);
279 Args.push_back(ResultGV);
280 EE->runFunction(ExitF, Args);
281 errs() << "ERROR: exit(" << Result << ") returned!\n";
282 abort();
283 } else {
284 errs() << "ERROR: exit defined with wrong prototype!\n";
285 abort();
286 }
287 }
288