1 //===-- llc.cpp - Implement the LLVM Native Code Generator ----------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This is the llc code generator driver. It provides a convenient
11 // command-line interface for generating native assembly-language code
12 // or C code, given LLVM bitcode.
14 //===----------------------------------------------------------------------===//
16 #include "llvm/Bitcode/ReaderWriter.h"
17 #include "llvm/CodeGen/FileWriters.h"
18 #include "llvm/CodeGen/LinkAllCodegenComponents.h"
19 #include "llvm/CodeGen/LinkAllAsmWriterComponents.h"
20 #include "llvm/Target/SubtargetFeature.h"
21 #include "llvm/Target/TargetData.h"
22 #include "llvm/Target/TargetMachine.h"
23 #include "llvm/Target/TargetMachineRegistry.h"
24 #include "llvm/Transforms/Scalar.h"
25 #include "llvm/LLVMContext.h"
26 #include "llvm/Module.h"
27 #include "llvm/ModuleProvider.h"
28 #include "llvm/PassManager.h"
29 #include "llvm/Pass.h"
30 #include "llvm/Support/CommandLine.h"
31 #include "llvm/Support/FileUtilities.h"
32 #include "llvm/Support/ManagedStatic.h"
33 #include "llvm/Support/MemoryBuffer.h"
34 #include "llvm/Support/PluginLoader.h"
35 #include "llvm/Support/PrettyStackTrace.h"
36 #include "llvm/Support/RegistryParser.h"
37 #include "llvm/Support/raw_ostream.h"
38 #include "llvm/Analysis/Verifier.h"
39 #include "llvm/System/Signals.h"
40 #include "llvm/Config/config.h"
41 #include "llvm/LinkAllVMCore.h"
42 #include "llvm/Target/TargetSelect.h"
48 // General options for llc. Other pass-specific options are specified
49 // within the corresponding llc passes, and target-specific options
50 // and back-end code generation options are specified with the target machine.
52 static cl::opt<std::string>
53 InputFilename(cl::Positional, cl::desc("<input bitcode>"), cl::init("-"));
55 static cl::opt<std::string>
56 OutputFilename("o", cl::desc("Output filename"), cl::value_desc("filename"));
58 static cl::opt<bool> Force("f", cl::desc("Overwrite output files"));
60 // Determine optimization level.
63 cl::desc("Optimization level. [-O0, -O1, -O2, or -O3] "
69 static cl::opt<std::string>
70 TargetTriple("mtriple", cl::desc("Override target triple for module"));
72 static cl::opt<const TargetMachineRegistry::entry*, false,
73 RegistryParser<TargetMachine> >
74 MArch("march", cl::desc("Architecture to generate code for:"));
76 static cl::opt<std::string>
78 cl::desc("Target a specific cpu type (-mcpu=help for details)"),
79 cl::value_desc("cpu-name"),
82 static cl::list<std::string>
85 cl::desc("Target specific attributes (-mattr=help for details)"),
86 cl::value_desc("a1,+a2,-a3,..."));
88 cl::opt<TargetMachine::CodeGenFileType>
89 FileType("filetype", cl::init(TargetMachine::AssemblyFile),
90 cl::desc("Choose a file type (not all types are supported by all targets):"),
92 clEnumValN(TargetMachine::AssemblyFile, "asm",
93 "Emit an assembly ('.s') file"),
94 clEnumValN(TargetMachine::ObjectFile, "obj",
95 "Emit a native object ('.o') file [experimental]"),
96 clEnumValN(TargetMachine::DynamicLibrary, "dynlib",
97 "Emit a native dynamic library ('.so') file"
101 cl::opt<bool> NoVerify("disable-verify", cl::Hidden,
102 cl::desc("Do not verify input module"));
106 DisableRedZone("disable-red-zone",
107 cl::desc("Do not emit code that uses the red zone."),
111 NoImplicitFloats("no-implicit-float",
112 cl::desc("Don't generate implicit floating point instructions (x86-only)"),
115 // GetFileNameRoot - Helper function to get the basename of a filename.
116 static inline std::string
117 GetFileNameRoot(const std::string &InputFilename) {
118 std::string IFN = InputFilename;
119 std::string outputFilename;
120 int Len = IFN.length();
122 IFN[Len-3] == '.' && IFN[Len-2] == 'b' && IFN[Len-1] == 'c') {
123 outputFilename = std::string(IFN.begin(), IFN.end()-3); // s/.bc/.s/
125 outputFilename = IFN;
127 return outputFilename;
130 static raw_ostream *GetOutputStream(const char *ProgName) {
131 if (OutputFilename != "") {
132 if (OutputFilename == "-")
135 // Specified an output filename?
136 if (!Force && std::ifstream(OutputFilename.c_str())) {
137 // If force is not specified, make sure not to overwrite a file!
138 std::cerr << ProgName << ": error opening '" << OutputFilename
139 << "': file exists!\n"
140 << "Use -f command line argument to force output\n";
143 // Make sure that the Out file gets unlinked from the disk if we get a
145 sys::RemoveFileOnSignal(sys::Path(OutputFilename));
148 raw_ostream *Out = new raw_fd_ostream(OutputFilename.c_str(), true, error);
149 if (!error.empty()) {
150 std::cerr << error << '\n';
158 if (InputFilename == "-") {
159 OutputFilename = "-";
163 OutputFilename = GetFileNameRoot(InputFilename);
167 case TargetMachine::AssemblyFile:
168 if (MArch->Name[0] == 'c') {
169 if (MArch->Name[1] == 0)
170 OutputFilename += ".cbe.c";
171 else if (MArch->Name[1] == 'p' && MArch->Name[2] == 'p')
172 OutputFilename += ".cpp";
174 OutputFilename += ".s";
176 OutputFilename += ".s";
178 case TargetMachine::ObjectFile:
179 OutputFilename += ".o";
182 case TargetMachine::DynamicLibrary:
183 OutputFilename += LTDL_SHLIB_EXT;
188 if (!Force && std::ifstream(OutputFilename.c_str())) {
189 // If force is not specified, make sure not to overwrite a file!
190 std::cerr << ProgName << ": error opening '" << OutputFilename
191 << "': file exists!\n"
192 << "Use -f command line argument to force output\n";
196 // Make sure that the Out file gets unlinked from the disk if we get a
198 sys::RemoveFileOnSignal(sys::Path(OutputFilename));
201 raw_ostream *Out = new raw_fd_ostream(OutputFilename.c_str(), Binary, error);
202 if (!error.empty()) {
203 std::cerr << error << '\n';
211 // main - Entry point for the llc compiler.
213 int main(int argc, char **argv) {
214 sys::PrintStackTraceOnErrorSignal();
215 PrettyStackTraceProgram X(argc, argv);
217 llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
218 cl::ParseCommandLineOptions(argc, argv, "llvm system compiler\n");
220 InitializeAllTargets();
221 InitializeAllAsmPrinters();
223 // Load the module to be compiled...
224 std::string ErrorMessage;
225 std::auto_ptr<Module> M;
227 std::auto_ptr<MemoryBuffer> Buffer(
228 MemoryBuffer::getFileOrSTDIN(InputFilename, &ErrorMessage));
230 M.reset(ParseBitcodeFile(Buffer.get(), Context, &ErrorMessage));
232 std::cerr << argv[0] << ": bitcode didn't read correctly.\n";
233 std::cerr << "Reason: " << ErrorMessage << "\n";
236 Module &mod = *M.get();
238 // If we are supposed to override the target triple, do so now.
239 if (!TargetTriple.empty())
240 mod.setTargetTriple(TargetTriple);
242 // Allocate target machine. First, check whether the user has
243 // explicitly specified an architecture to compile for.
246 MArch = TargetMachineRegistry::getClosestStaticTargetForModule(mod, Err);
248 std::cerr << argv[0] << ": error auto-selecting target for module '"
249 << Err << "'. Please use the -march option to explicitly "
250 << "pick a target.\n";
255 // Package up features to be passed to target/subtarget
256 std::string FeaturesStr;
257 if (MCPU.size() || MAttrs.size()) {
258 SubtargetFeatures Features;
259 Features.setCPU(MCPU);
260 for (unsigned i = 0; i != MAttrs.size(); ++i)
261 Features.AddFeature(MAttrs[i]);
262 FeaturesStr = Features.getString();
265 std::auto_ptr<TargetMachine> target(MArch->CtorFn(mod, FeaturesStr));
266 assert(target.get() && "Could not allocate target machine!");
267 TargetMachine &Target = *target.get();
269 // Figure out where we are going to send the output...
270 raw_ostream *Out = GetOutputStream(argv[0]);
271 if (Out == 0) return 1;
273 CodeGenOpt::Level OLvl = CodeGenOpt::Default;
276 std::cerr << argv[0] << ": invalid optimization level.\n";
279 case '0': OLvl = CodeGenOpt::None; break;
281 case '2': OLvl = CodeGenOpt::Default; break;
282 case '3': OLvl = CodeGenOpt::Aggressive; break;
285 // If this target requires addPassesToEmitWholeFile, do it now. This is
286 // used by strange things like the C backend.
287 if (Target.WantsWholeFile()) {
289 PM.add(new TargetData(*Target.getTargetData()));
291 PM.add(createVerifierPass());
293 // Ask the target to add backend passes as necessary.
294 if (Target.addPassesToEmitWholeFile(PM, *Out, FileType, OLvl)) {
295 std::cerr << argv[0] << ": target does not support generation of this"
297 if (Out != &outs()) delete Out;
298 // And the Out file is empty and useless, so remove it now.
299 sys::Path(OutputFilename).eraseFromDisk();
304 // Build up all of the passes that we want to do to the module.
305 ExistingModuleProvider Provider(M.release());
306 FunctionPassManager Passes(&Provider);
307 Passes.add(new TargetData(*Target.getTargetData()));
311 Passes.add(createVerifierPass());
314 // Ask the target to add backend passes as necessary.
315 MachineCodeEmitter *MCE = 0;
317 // Override default to generate verbose assembly.
318 Target.setAsmVerbosityDefault(true);
320 switch (Target.addPassesToEmitFile(Passes, *Out, FileType, OLvl)) {
322 assert(0 && "Invalid file model!");
324 case FileModel::Error:
325 std::cerr << argv[0] << ": target does not support generation of this"
327 if (Out != &outs()) delete Out;
328 // And the Out file is empty and useless, so remove it now.
329 sys::Path(OutputFilename).eraseFromDisk();
331 case FileModel::AsmFile:
333 case FileModel::MachOFile:
334 MCE = AddMachOWriter(Passes, *Out, Target);
336 case FileModel::ElfFile:
337 MCE = AddELFWriter(Passes, *Out, Target);
341 if (Target.addPassesToEmitFileFinish(Passes, MCE, OLvl)) {
342 std::cerr << argv[0] << ": target does not support generation of this"
344 if (Out != &outs()) delete Out;
345 // And the Out file is empty and useless, so remove it now.
346 sys::Path(OutputFilename).eraseFromDisk();
350 Passes.doInitialization();
352 // Run our queue of passes all at once now, efficiently.
353 // TODO: this could lazily stream functions out of the module.
354 for (Module::iterator I = mod.begin(), E = mod.end(); I != E; ++I)
355 if (!I->isDeclaration()) {
357 I->addFnAttr(Attribute::NoRedZone);
358 if (NoImplicitFloats)
359 I->addFnAttr(Attribute::NoImplicitFloat);
363 Passes.doFinalization();
366 // Delete the ostream if it's not a stdout stream
367 if (Out != &outs()) delete Out;