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/LLVMContext.h"
17 #include "llvm/Module.h"
18 #include "llvm/ModuleProvider.h"
19 #include "llvm/PassManager.h"
20 #include "llvm/Pass.h"
21 #include "llvm/ADT/Triple.h"
22 #include "llvm/Analysis/Verifier.h"
23 #include "llvm/Bitcode/ReaderWriter.h"
24 #include "llvm/CodeGen/FileWriters.h"
25 #include "llvm/CodeGen/LinkAllAsmWriterComponents.h"
26 #include "llvm/CodeGen/LinkAllCodegenComponents.h"
27 #include "llvm/CodeGen/ObjectCodeEmitter.h"
28 #include "llvm/Config/config.h"
29 #include "llvm/LinkAllVMCore.h"
30 #include "llvm/Support/CommandLine.h"
31 #include "llvm/Support/FileUtilities.h"
32 #include "llvm/Support/FormattedStream.h"
33 #include "llvm/Support/ManagedStatic.h"
34 #include "llvm/Support/MemoryBuffer.h"
35 #include "llvm/Support/PluginLoader.h"
36 #include "llvm/Support/PrettyStackTrace.h"
37 #include "llvm/System/Host.h"
38 #include "llvm/System/Signals.h"
39 #include "llvm/Target/SubtargetFeature.h"
40 #include "llvm/Target/TargetData.h"
41 #include "llvm/Target/TargetMachine.h"
42 #include "llvm/Target/TargetRegistry.h"
43 #include "llvm/Target/TargetSelect.h"
44 #include "llvm/Transforms/Scalar.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<std::string>
73 MArch("march", cl::desc("Architecture to generate code for (see --version)"));
75 static cl::opt<std::string>
77 cl::desc("Target a specific cpu type (-mcpu=help for details)"),
78 cl::value_desc("cpu-name"),
81 static cl::list<std::string>
84 cl::desc("Target specific attributes (-mattr=help for details)"),
85 cl::value_desc("a1,+a2,-a3,..."));
87 cl::opt<TargetMachine::CodeGenFileType>
88 FileType("filetype", cl::init(TargetMachine::AssemblyFile),
89 cl::desc("Choose a file type (not all types are supported by all targets):"),
91 clEnumValN(TargetMachine::AssemblyFile, "asm",
92 "Emit an assembly ('.s') file"),
93 clEnumValN(TargetMachine::ObjectFile, "obj",
94 "Emit a native object ('.o') file [experimental]"),
95 clEnumValN(TargetMachine::DynamicLibrary, "dynlib",
96 "Emit a native dynamic library ('.so') file"
100 cl::opt<bool> NoVerify("disable-verify", cl::Hidden,
101 cl::desc("Do not verify input module"));
105 DisableRedZone("disable-red-zone",
106 cl::desc("Do not emit code that uses the red zone."),
110 NoImplicitFloats("no-implicit-float",
111 cl::desc("Don't generate implicit floating point instructions (x86-only)"),
114 // GetFileNameRoot - Helper function to get the basename of a filename.
115 static inline std::string
116 GetFileNameRoot(const std::string &InputFilename) {
117 std::string IFN = InputFilename;
118 std::string outputFilename;
119 int Len = IFN.length();
121 IFN[Len-3] == '.' && IFN[Len-2] == 'b' && IFN[Len-1] == 'c') {
122 outputFilename = std::string(IFN.begin(), IFN.end()-3); // s/.bc/.s/
124 outputFilename = IFN;
126 return outputFilename;
129 static formatted_raw_ostream *GetOutputStream(const char *TargetName,
130 const char *ProgName) {
131 if (OutputFilename != "") {
132 if (OutputFilename == "-")
135 // Make sure that the Out file gets unlinked from the disk if we get a
137 sys::RemoveFileOnSignal(sys::Path(OutputFilename));
140 raw_fd_ostream *FDOut = new raw_fd_ostream(OutputFilename.c_str(),
141 /*Binary=*/true, Force, error);
142 if (!error.empty()) {
143 errs() << error << '\n';
145 errs() << "Use -f command line argument to force output\n";
149 formatted_raw_ostream *Out =
150 new formatted_raw_ostream(*FDOut, formatted_raw_ostream::DELETE_STREAM);
155 if (InputFilename == "-") {
156 OutputFilename = "-";
160 OutputFilename = GetFileNameRoot(InputFilename);
164 case TargetMachine::AssemblyFile:
165 if (TargetName[0] == 'c') {
166 if (TargetName[1] == 0)
167 OutputFilename += ".cbe.c";
168 else if (TargetName[1] == 'p' && TargetName[2] == 'p')
169 OutputFilename += ".cpp";
171 OutputFilename += ".s";
173 OutputFilename += ".s";
175 case TargetMachine::ObjectFile:
176 OutputFilename += ".o";
179 case TargetMachine::DynamicLibrary:
180 OutputFilename += LTDL_SHLIB_EXT;
185 // Make sure that the Out file gets unlinked from the disk if we get a
187 sys::RemoveFileOnSignal(sys::Path(OutputFilename));
190 raw_fd_ostream *FDOut = new raw_fd_ostream(OutputFilename.c_str(),
191 Binary, Force, error);
192 if (!error.empty()) {
193 errs() << error << '\n';
195 errs() << "Use -f command line argument to force output\n";
200 formatted_raw_ostream *Out =
201 new formatted_raw_ostream(*FDOut, formatted_raw_ostream::DELETE_STREAM);
206 // main - Entry point for the llc compiler.
208 int main(int argc, char **argv) {
209 sys::PrintStackTraceOnErrorSignal();
210 PrettyStackTraceProgram X(argc, argv);
211 LLVMContext &Context = getGlobalContext();
212 llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
214 // Initialize targets first.
215 InitializeAllTargets();
216 InitializeAllAsmPrinters();
218 cl::ParseCommandLineOptions(argc, argv, "llvm system compiler\n");
220 // Load the module to be compiled...
221 std::string ErrorMessage;
222 std::auto_ptr<Module> M;
224 std::auto_ptr<MemoryBuffer> Buffer(
225 MemoryBuffer::getFileOrSTDIN(InputFilename, &ErrorMessage));
227 M.reset(ParseBitcodeFile(Buffer.get(), Context, &ErrorMessage));
229 errs() << argv[0] << ": bitcode didn't read correctly.\n";
230 errs() << "Reason: " << ErrorMessage << "\n";
233 Module &mod = *M.get();
235 // If we are supposed to override the target triple, do so now.
236 if (!TargetTriple.empty())
237 mod.setTargetTriple(TargetTriple);
239 Triple TheTriple(mod.getTargetTriple());
240 if (TheTriple.getTriple().empty())
241 TheTriple.setTriple(sys::getHostTriple());
243 // Allocate target machine. First, check whether the user has explicitly
244 // specified an architecture to compile for. If so we have to look it up by
245 // name, because it might be a backend that has no mapping to a target triple.
246 const Target *TheTarget = 0;
247 if (!MArch.empty()) {
248 for (TargetRegistry::iterator it = TargetRegistry::begin(),
249 ie = TargetRegistry::end(); it != ie; ++it) {
250 if (MArch == it->getName()) {
257 errs() << argv[0] << ": error: invalid target '" << MArch << "'.\n";
261 // Adjust the triple to match (if known), otherwise stick with the
262 // module/host triple.
263 Triple::ArchType Type = Triple::getArchTypeForLLVMName(MArch);
264 if (Type != Triple::UnknownArch)
265 TheTriple.setArch(Type);
268 TheTarget = TargetRegistry::lookupTarget(TheTriple.getTriple(), Err);
269 if (TheTarget == 0) {
270 errs() << argv[0] << ": error auto-selecting target for module '"
271 << Err << "'. Please use the -march option to explicitly "
272 << "pick a target.\n";
277 // Package up features to be passed to target/subtarget
278 std::string FeaturesStr;
279 if (MCPU.size() || MAttrs.size()) {
280 SubtargetFeatures Features;
281 Features.setCPU(MCPU);
282 for (unsigned i = 0; i != MAttrs.size(); ++i)
283 Features.AddFeature(MAttrs[i]);
284 FeaturesStr = Features.getString();
287 std::auto_ptr<TargetMachine>
288 target(TheTarget->createTargetMachine(TheTriple.getTriple(), FeaturesStr));
289 assert(target.get() && "Could not allocate target machine!");
290 TargetMachine &Target = *target.get();
292 // Figure out where we are going to send the output...
293 formatted_raw_ostream *Out = GetOutputStream(TheTarget->getName(), argv[0]);
294 if (Out == 0) return 1;
296 CodeGenOpt::Level OLvl = CodeGenOpt::Default;
299 errs() << argv[0] << ": invalid optimization level.\n";
302 case '0': OLvl = CodeGenOpt::None; break;
304 case '2': OLvl = CodeGenOpt::Default; break;
305 case '3': OLvl = CodeGenOpt::Aggressive; break;
308 // If this target requires addPassesToEmitWholeFile, do it now. This is
309 // used by strange things like the C backend.
310 if (Target.WantsWholeFile()) {
313 // Add the target data from the target machine, if it exists, or the module.
314 if (const TargetData *TD = Target.getTargetData())
315 PM.add(new TargetData(*TD));
317 PM.add(new TargetData(&mod));
320 PM.add(createVerifierPass());
322 // Ask the target to add backend passes as necessary.
323 if (Target.addPassesToEmitWholeFile(PM, *Out, FileType, OLvl)) {
324 errs() << argv[0] << ": target does not support generation of this"
326 if (Out != &fouts()) delete Out;
327 // And the Out file is empty and useless, so remove it now.
328 sys::Path(OutputFilename).eraseFromDisk();
333 // Build up all of the passes that we want to do to the module.
334 ExistingModuleProvider Provider(M.release());
335 FunctionPassManager Passes(&Provider);
337 // Add the target data from the target machine, if it exists, or the module.
338 if (const TargetData *TD = Target.getTargetData())
339 Passes.add(new TargetData(*TD));
341 Passes.add(new TargetData(&mod));
345 Passes.add(createVerifierPass());
348 // Ask the target to add backend passes as necessary.
349 ObjectCodeEmitter *OCE = 0;
351 // Override default to generate verbose assembly.
352 Target.setAsmVerbosityDefault(true);
354 switch (Target.addPassesToEmitFile(Passes, *Out, FileType, OLvl)) {
356 assert(0 && "Invalid file model!");
358 case FileModel::Error:
359 errs() << argv[0] << ": target does not support generation of this"
361 if (Out != &fouts()) delete Out;
362 // And the Out file is empty and useless, so remove it now.
363 sys::Path(OutputFilename).eraseFromDisk();
365 case FileModel::AsmFile:
367 case FileModel::MachOFile:
368 OCE = AddMachOWriter(Passes, *Out, Target);
370 case FileModel::ElfFile:
371 OCE = AddELFWriter(Passes, *Out, Target);
375 if (Target.addPassesToEmitFileFinish(Passes, OCE, OLvl)) {
376 errs() << argv[0] << ": target does not support generation of this"
378 if (Out != &fouts()) delete Out;
379 // And the Out file is empty and useless, so remove it now.
380 sys::Path(OutputFilename).eraseFromDisk();
384 Passes.doInitialization();
386 // Run our queue of passes all at once now, efficiently.
387 // TODO: this could lazily stream functions out of the module.
388 for (Module::iterator I = mod.begin(), E = mod.end(); I != E; ++I)
389 if (!I->isDeclaration()) {
391 I->addFnAttr(Attribute::NoRedZone);
392 if (NoImplicitFloats)
393 I->addFnAttr(Attribute::NoImplicitFloat);
397 Passes.doFinalization();
402 // Delete the ostream if it's not a stdout stream
403 if (Out != &fouts()) delete Out;