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/CodeGen/ObjectCodeEmitter.h"
21 #include "llvm/Target/SubtargetFeature.h"
22 #include "llvm/Target/TargetData.h"
23 #include "llvm/Target/TargetMachine.h"
24 #include "llvm/Target/TargetMachineRegistry.h"
25 #include "llvm/Transforms/Scalar.h"
26 #include "llvm/LLVMContext.h"
27 #include "llvm/Module.h"
28 #include "llvm/ModuleProvider.h"
29 #include "llvm/PassManager.h"
30 #include "llvm/Pass.h"
31 #include "llvm/Support/CommandLine.h"
32 #include "llvm/Support/FileUtilities.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/Support/RegistryParser.h"
38 #include "llvm/Support/raw_ostream.h"
39 #include "llvm/Analysis/Verifier.h"
40 #include "llvm/System/Signals.h"
41 #include "llvm/Config/config.h"
42 #include "llvm/LinkAllVMCore.h"
43 #include "llvm/Target/TargetSelect.h"
49 // General options for llc. Other pass-specific options are specified
50 // within the corresponding llc passes, and target-specific options
51 // and back-end code generation options are specified with the target machine.
53 static cl::opt<std::string>
54 InputFilename(cl::Positional, cl::desc("<input bitcode>"), cl::init("-"));
56 static cl::opt<std::string>
57 OutputFilename("o", cl::desc("Output filename"), cl::value_desc("filename"));
59 static cl::opt<bool> Force("f", cl::desc("Overwrite output files"));
61 // Determine optimization level.
64 cl::desc("Optimization level. [-O0, -O1, -O2, or -O3] "
70 static cl::opt<std::string>
71 TargetTriple("mtriple", cl::desc("Override target triple for module"));
73 static cl::opt<const TargetMachineRegistry::entry*, false,
74 RegistryParser<TargetMachine> >
75 MArch("march", cl::desc("Architecture to generate code for:"));
77 static cl::opt<std::string>
79 cl::desc("Target a specific cpu type (-mcpu=help for details)"),
80 cl::value_desc("cpu-name"),
83 static cl::list<std::string>
86 cl::desc("Target specific attributes (-mattr=help for details)"),
87 cl::value_desc("a1,+a2,-a3,..."));
89 cl::opt<TargetMachine::CodeGenFileType>
90 FileType("filetype", cl::init(TargetMachine::AssemblyFile),
91 cl::desc("Choose a file type (not all types are supported by all targets):"),
93 clEnumValN(TargetMachine::AssemblyFile, "asm",
94 "Emit an assembly ('.s') file"),
95 clEnumValN(TargetMachine::ObjectFile, "obj",
96 "Emit a native object ('.o') file [experimental]"),
97 clEnumValN(TargetMachine::DynamicLibrary, "dynlib",
98 "Emit a native dynamic library ('.so') file"
102 cl::opt<bool> NoVerify("disable-verify", cl::Hidden,
103 cl::desc("Do not verify input module"));
107 DisableRedZone("disable-red-zone",
108 cl::desc("Do not emit code that uses the red zone."),
112 NoImplicitFloats("no-implicit-float",
113 cl::desc("Don't generate implicit floating point instructions (x86-only)"),
116 // GetFileNameRoot - Helper function to get the basename of a filename.
117 static inline std::string
118 GetFileNameRoot(const std::string &InputFilename) {
119 std::string IFN = InputFilename;
120 std::string outputFilename;
121 int Len = IFN.length();
123 IFN[Len-3] == '.' && IFN[Len-2] == 'b' && IFN[Len-1] == 'c') {
124 outputFilename = std::string(IFN.begin(), IFN.end()-3); // s/.bc/.s/
126 outputFilename = IFN;
128 return outputFilename;
131 static raw_ostream *GetOutputStream(const char *ProgName) {
132 if (OutputFilename != "") {
133 if (OutputFilename == "-")
136 // Specified an output filename?
137 if (!Force && std::ifstream(OutputFilename.c_str())) {
138 // If force is not specified, make sure not to overwrite a file!
139 std::cerr << ProgName << ": error opening '" << OutputFilename
140 << "': file exists!\n"
141 << "Use -f command line argument to force output\n";
144 // Make sure that the Out file gets unlinked from the disk if we get a
146 sys::RemoveFileOnSignal(sys::Path(OutputFilename));
149 raw_ostream *Out = new raw_fd_ostream(OutputFilename.c_str(), true, error);
150 if (!error.empty()) {
151 std::cerr << error << '\n';
159 if (InputFilename == "-") {
160 OutputFilename = "-";
164 OutputFilename = GetFileNameRoot(InputFilename);
168 case TargetMachine::AssemblyFile:
169 if (MArch->Name[0] == 'c') {
170 if (MArch->Name[1] == 0)
171 OutputFilename += ".cbe.c";
172 else if (MArch->Name[1] == 'p' && MArch->Name[2] == 'p')
173 OutputFilename += ".cpp";
175 OutputFilename += ".s";
177 OutputFilename += ".s";
179 case TargetMachine::ObjectFile:
180 OutputFilename += ".o";
183 case TargetMachine::DynamicLibrary:
184 OutputFilename += LTDL_SHLIB_EXT;
189 if (!Force && std::ifstream(OutputFilename.c_str())) {
190 // If force is not specified, make sure not to overwrite a file!
191 std::cerr << ProgName << ": error opening '" << OutputFilename
192 << "': file exists!\n"
193 << "Use -f command line argument to force output\n";
197 // Make sure that the Out file gets unlinked from the disk if we get a
199 sys::RemoveFileOnSignal(sys::Path(OutputFilename));
202 raw_ostream *Out = new raw_fd_ostream(OutputFilename.c_str(), Binary, error);
203 if (!error.empty()) {
204 std::cerr << error << '\n';
212 // main - Entry point for the llc compiler.
214 int main(int argc, char **argv) {
215 sys::PrintStackTraceOnErrorSignal();
216 PrettyStackTraceProgram X(argc, argv);
218 llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
219 cl::ParseCommandLineOptions(argc, argv, "llvm system compiler\n");
221 InitializeAllTargets();
222 InitializeAllAsmPrinters();
224 // Load the module to be compiled...
225 std::string ErrorMessage;
226 std::auto_ptr<Module> M;
228 std::auto_ptr<MemoryBuffer> Buffer(
229 MemoryBuffer::getFileOrSTDIN(InputFilename, &ErrorMessage));
231 M.reset(ParseBitcodeFile(Buffer.get(), Context, &ErrorMessage));
233 std::cerr << argv[0] << ": bitcode didn't read correctly.\n";
234 std::cerr << "Reason: " << ErrorMessage << "\n";
237 Module &mod = *M.get();
239 // If we are supposed to override the target triple, do so now.
240 if (!TargetTriple.empty())
241 mod.setTargetTriple(TargetTriple);
243 // Allocate target machine. First, check whether the user has
244 // explicitly specified an architecture to compile for.
247 MArch = TargetMachineRegistry::getClosestStaticTargetForModule(mod, Err);
249 std::cerr << argv[0] << ": error auto-selecting target for module '"
250 << Err << "'. Please use the -march option to explicitly "
251 << "pick a target.\n";
256 // Package up features to be passed to target/subtarget
257 std::string FeaturesStr;
258 if (MCPU.size() || MAttrs.size()) {
259 SubtargetFeatures Features;
260 Features.setCPU(MCPU);
261 for (unsigned i = 0; i != MAttrs.size(); ++i)
262 Features.AddFeature(MAttrs[i]);
263 FeaturesStr = Features.getString();
266 std::auto_ptr<TargetMachine> target(MArch->CtorFn(mod, FeaturesStr));
267 assert(target.get() && "Could not allocate target machine!");
268 TargetMachine &Target = *target.get();
270 // Figure out where we are going to send the output...
271 raw_ostream *Out = GetOutputStream(argv[0]);
272 if (Out == 0) return 1;
274 CodeGenOpt::Level OLvl = CodeGenOpt::Default;
277 std::cerr << argv[0] << ": invalid optimization level.\n";
280 case '0': OLvl = CodeGenOpt::None; break;
282 case '2': OLvl = CodeGenOpt::Default; break;
283 case '3': OLvl = CodeGenOpt::Aggressive; break;
286 // If this target requires addPassesToEmitWholeFile, do it now. This is
287 // used by strange things like the C backend.
288 if (Target.WantsWholeFile()) {
290 PM.add(new TargetData(*Target.getTargetData()));
292 PM.add(createVerifierPass());
294 // Ask the target to add backend passes as necessary.
295 if (Target.addPassesToEmitWholeFile(PM, *Out, FileType, OLvl)) {
296 std::cerr << argv[0] << ": target does not support generation of this"
298 if (Out != &outs()) delete Out;
299 // And the Out file is empty and useless, so remove it now.
300 sys::Path(OutputFilename).eraseFromDisk();
305 // Build up all of the passes that we want to do to the module.
306 ExistingModuleProvider Provider(M.release());
307 FunctionPassManager Passes(&Provider);
308 Passes.add(new TargetData(*Target.getTargetData()));
312 Passes.add(createVerifierPass());
315 // Ask the target to add backend passes as necessary.
316 ObjectCodeEmitter *OCE = 0;
318 // Override default to generate verbose assembly.
319 Target.setAsmVerbosityDefault(true);
321 switch (Target.addPassesToEmitFile(Passes, *Out, FileType, OLvl)) {
323 assert(0 && "Invalid file model!");
325 case FileModel::Error:
326 std::cerr << argv[0] << ": target does not support generation of this"
328 if (Out != &outs()) delete Out;
329 // And the Out file is empty and useless, so remove it now.
330 sys::Path(OutputFilename).eraseFromDisk();
332 case FileModel::AsmFile:
334 case FileModel::MachOFile:
335 OCE = AddMachOWriter(Passes, *Out, Target);
337 case FileModel::ElfFile:
338 OCE = AddELFWriter(Passes, *Out, Target);
342 if (Target.addPassesToEmitFileFinish(Passes, OCE, OLvl)) {
343 std::cerr << argv[0] << ": target does not support generation of this"
345 if (Out != &outs()) delete Out;
346 // And the Out file is empty and useless, so remove it now.
347 sys::Path(OutputFilename).eraseFromDisk();
351 Passes.doInitialization();
353 // Run our queue of passes all at once now, efficiently.
354 // TODO: this could lazily stream functions out of the module.
355 for (Module::iterator I = mod.begin(), E = mod.end(); I != E; ++I)
356 if (!I->isDeclaration()) {
358 I->addFnAttr(Attribute::NoRedZone);
359 if (NoImplicitFloats)
360 I->addFnAttr(Attribute::NoImplicitFloat);
364 Passes.doFinalization();
367 // Delete the ostream if it's not a stdout stream
368 if (Out != &outs()) delete Out;